CN100428418C - Wafer Separation Method - Google Patents

Abstract

The invention provides a method for dividing a wafer, comprising: a bonding process of a protective component, bonding a protective component on the surface of the wafer; a grinding process, grinding the back of the wafer with the protective component bonded on the surface; The side is irradiated with the pulsed laser light which is transmissive to the wafer along the planned dividing line, forming a metamorphic region along the planned dividing line inside the wafer; the adhesive sheet bonding process is to bond the adhesive sheet on the back side of the wafer; the frame holding process is to place the The adhesive sheet side of the wafer is bonded to the dicing tape mounted on the ring frame; the dividing process is to apply external force along the dividing line where the metamorphic region is formed on the wafer, and divide it into individual chips; the expanding process is to bond the wafer The dicing tape is expanded to widen the interval between the chips, thereby breaking the bonding sheet; and the pick-up process picks up each chip with the bonding sheet bonded on the back side from the expanded dicing tape.

Description

Wafer Separation Method

technical field

The present invention relates to a method for dividing a wafer, wherein a wafer having functional elements arranged in a region divided by planned dividing lines formed in a grid pattern on the surface is divided along the planned dividing lines, and a chip for bonding is mounted on the back surface of individual chips. An adhesive sheet (film) picks up the divided individual chips.

Background technique

In the semiconductor device manufacturing process, a plurality of regions are divided by predetermined division lines called streets arranged in a grid on the surface of a substantially wafer-shaped semiconductor wafer, and in the divided regions, formed IC, LSI and other circuits (functional components). Then, by cutting the semiconductor wafer along planned dividing lines, the regions where the circuits are formed are divided to manufacture individual semiconductor chips. It is also possible to separate the optical device wafer into individual photodiodes, Optical devices such as laser diodes are widely used in electrical equipment.

Cutting of the above-mentioned semiconductor wafer, optical device wafer, etc. along the planned dividing line is generally performed by a cutting device called a "dicer". This cutting device includes: a fixed table (chucktable: clamp table) for holding a workpiece such as a semiconductor wafer or an optical device wafer, a cutting member for cutting the workpiece held on the fixed table, and The cutting feed member moves the fixed table and the cutting member relatively. The cutting member includes a spindle unit having a drive mechanism that rotationally drives a rotary spindle and a cutting tool and the rotary spindle mounted on the spindle. The cutting blade is composed of a disc-shaped base and an annular cutting blade attached to the outer peripheral portion of the side surface of the base. For example, diamond with a particle diameter of about 3 μm is fixed on the base by electroforming to form a thickness of about 20 μm.

However, since the cutting blade has a thickness of about 20 μm, the width of the planned dividing line for dividing chips needs to be about 50 μm, and the area ratio of the planned dividing line to the wafer area is large, so there is a problem of poor productivity. In addition, sapphire substrates, silicon carbide substrates, etc. have high Mohs hardness, so cutting by the above-mentioned cutting blade is not necessarily easy.

On the other hand, in recent years, as a method of dividing a plate-shaped workpiece such as a semiconductor wafer, a laser processing method has been tried that uses a pulsed laser beam that is transparent to the workpiece and irradiates it at a converging point inside the region to be divided. Pulsed laser light. The division method using this laser processing method is a method as follows: from one surface side of the workpiece to the inside, the pulsed laser light in the infrared region that is transparent to the workpiece is irradiated at the focal point, Deteriorated regions are continuously formed inside the workpiece along the intended division line, and an external force is applied along the planned division line whose strength has decreased due to the formation of the altered region, thereby dividing the workpiece.

Patent Document 1: Japanese Patent No. 3408805

Moreover, the semiconductor chip is divided into individual semiconductor chips, and an adhesive sheet for diebonding called a die bonding film with a thickness of 20 to 40 μm, which is formed of epoxy resin or the like, is mounted on the back surface of the semiconductor chip. The adhesive sheet is bonded to the adhesive sheet frame supporting the semiconductor chip by heating. The method of mounting an adhesive sheet for die bonding on the back surface of a semiconductor chip is as follows: After adhering an adhesive sheet on the back surface of a semiconductor chip, and bonding a semiconductor wafer to a dicing tape with the adhesive sheet interposed therebetween, The semiconductor chip with the adhesive sheet mounted on the back surface is formed by cutting along the row pitch formed on the surface of the semiconductor wafer with a cutter blade together with the adhesive sheet (for example, refer to Patent Document 2: Japanese Patent Application Laid-Open No. 2000-1829995).

However, if the method disclosed in Japanese Patent Application Laid-Open No. 2000-182995 is adopted, there is a problem that when the adhesive sheet is cut together with the semiconductor wafer by a cutting blade to be divided into individual semiconductor chips, defects are generated on the back surface of the semiconductor chip, and the A whisker-like burr occurs on the adhesive sheet, which causes wire breakage during wire bonding.

In order to solve such problems, the following techniques have been proposed: inserting an adhesive sheet for bonding the protective sheet in the middle of the back surface of the wafer, irradiating pulsed laser light from the surface side of the wafer, forming a metamorphic region inside the wafer, and then expanding the The protective sheet divides the wafer into individual chips together with the adhesive sheet (for example, refer to Patent Document 3: Japanese Patent Laid-Open No. 2003-228467).

However, in the technology disclosed in Japanese Patent Application Laid-Open No. 2003-228467, since the protective sheet is bonded by inserting an adhesive sheet for bonding the chip in the middle of the back surface of the wafer, and the pulsed laser light is irradiated from the surface side of the wafer, it cannot be A metamorphic region is uniformly formed inside the wafer. That is, various films are laminated on the surface of the wafer, and the surface is not necessarily smooth. Therefore, if the pulsed laser beam is irradiated from the surface side of the wafer, the laser beam is diffusely reflected, and it is difficult to uniformly locate the laser beam at a predetermined position inside the wafer, and as a result, the metamorphic region cannot be uniformly formed inside the wafer. .

Contents of the invention

The present invention is proposed in view of the above facts, and its main technical task is to provide a method for dividing a wafer, which can ensure the following process: using pulsed laser light to uniformly form a metamorphic region along a predetermined dividing line inside the wafer, along the The degenerated area is divided into individual chips, and an adhesive sheet for bonding is mounted on the back surface of the individual chips, and the divided individual chips are picked up.

In order to solve the above-mentioned main technical problems, according to the method of dividing a wafer according to the invention of claim 1, the wafer in which the functional elements are provided in the area divided by the planned dividing line formed in a grid pattern on the surface is divided along the planned dividing line, It is characterized in that it includes the following steps:

A protective part bonding process, bonding a protective part on the surface of the wafer;

A lapping process, lapping the backside of the wafer with the protective member attached to the surface;

The metamorphic region forming step is to irradiate pulsed laser light which is transparent to the wafer from the back side of the polished wafer along the planned dividing line, and form the metamorphic region inside the wafer along the planned dividing line;

An adhesive sheet bonding process, bonding an adhesive sheet for bonding the wafer on the back side of the wafer in which the metamorphic region is formed along the planned dividing line;

Frame holding process, bonding the adhesive sheet side of the wafer bonded with the adhesive sheet to the dicing tape mounted on the ring frame;

The dividing step is to apply an external force along the planned dividing line forming the metamorphic region of the wafer held on the frame, and divide the wafer into individual chips along the planned dividing line;

an expanding process of expanding the dicing tape to which the wafers divided into individual chips are bonded to widen the intervals between the individual chips, thereby breaking the bonding sheet; and

In the pick-up process, each chip with the adhesive sheet bonded on the back side is picked up from the expanded dicing tape.

In addition, in order to solve the above-mentioned main technical problems, according to the method of dividing a wafer according to the invention of claim 2, a wafer in which functional elements are provided in a region partitioned by planned dividing lines formed in a grid pattern on the surface is divided along the planned dividing lines. Segmentation is characterized in that comprising the following steps:

A protective part bonding process, bonding a protective part on the surface of the wafer;

A lapping process, lapping the backside of the wafer with the protective member attached to the surface;

The metamorphic region forming step is to irradiate pulsed laser light which is transparent to the wafer from the back side of the polished wafer along the planned dividing line, and form the metamorphic region inside the wafer along the planned dividing line;

The dividing step is to apply an external force along the planned dividing line of the wafer, and divide the wafer into individual chips along the planned dividing line, and the above-mentioned wafer forms a metamorphic region along the planned dividing line;

Adhesive sheet bonding process, bonding an adhesive sheet for bonding the wafer on the back of the wafer that is divided into individual chips;

Frame holding process, bonding the adhesive sheet side of the wafer bonded with the adhesive sheet to the dicing tape mounted on the ring frame;

an expanding process of expanding the dicing tape to which the wafers divided into individual chips are bonded to widen the intervals between the individual chips, thereby breaking the bonding sheet; and

In the pick-up process, each chip with the adhesive sheet bonded on the back side is picked up from the expanded dicing tape.

In order to solve the above-mentioned main technical problems, according to the method of dividing a wafer according to the third aspect of the invention, the wafer in which the functional elements are provided in the area divided by the planned dividing line formed in a grid pattern on the surface is divided along the planned dividing line, It is characterized in that it includes the following steps:

In the frame holding process, the surface of the wafer is bonded to the dicing tape mounted on the ring frame;

Grinding process, grinding the backside of the wafer whose surface is bonded to the dicing tape mounted on the frame;

The metamorphic region forming step is to irradiate pulsed laser light which is transparent to the wafer from the back side of the polished wafer along the planned dividing line, and form the metamorphic region inside the wafer along the planned dividing line;

An adhesive sheet bonding process, bonding an adhesive sheet for bonding the wafer on the back side of the wafer in which the metamorphic region is formed along the planned dividing line;

The dividing step is to apply an external force along the planned dividing line forming the metamorphic region of the wafer held on the frame, and divide the wafer into individual chips along the planned dividing line;

an expanding process of expanding the dicing tape to which the wafers divided into individual chips are bonded to widen the intervals between the individual chips, thereby breaking the bonding sheet; and

In the pick-up process, each chip with the adhesive sheet bonded on the back side is picked up from the expanded dicing tape.

In order to solve the above-mentioned main technical problems, according to the method of dividing a wafer according to the invention of claim 4, the wafer in which the functional elements are provided in the area divided by the planned dividing line formed in a grid pattern on the surface is divided along the planned dividing line, It is characterized in that it includes the following steps:

In the frame holding process, the surface of the wafer is bonded to the dicing tape mounted on the ring frame;

Grinding process, grinding the backside of the wafer whose surface is bonded to the dicing tape mounted on the frame;

The metamorphic region forming step is to irradiate pulsed laser light which is transparent to the wafer from the back side of the polished wafer along the planned dividing line, and form the metamorphic region inside the wafer along the planned dividing line;

The dividing step is to apply an external force along the planned dividing line forming the metamorphic region of the wafer held on the frame, and divide the wafer into individual chips along the planned dividing line;

Adhesive sheet bonding process, bonding an adhesive sheet for bonding the wafer on the back of the wafer that is divided into individual chips;

an expanding process of expanding the dicing tape to which the wafers divided into individual chips are bonded to widen the intervals between the individual chips, thereby breaking the bonding sheet; and

In the pick-up process, each chip with the adhesive sheet bonded on the back side is picked up from the expanded dicing tape.

Preferably, in the above-mentioned modified region forming step, the modified region formed inside the wafer is formed exposed at least on the surface of the wafer.

Preferably, the dividing step is performed by expanding the dicing tape in the expanding step.

The effect of the invention is as follows:

Since the dividing method of the wafer of the present invention is composed of the above steps, the following process can be ensured: the wafer is provided with functional elements in the area divided by the planned division line formed in a grid on the surface, and the wafer is divided along the division from the back side of the wafer. A predetermined line is irradiated with a pulsed laser light that is transparent to the wafer, whereby a metamorphic region is uniformly formed inside the wafer along the divisional predetermined line, along which the metamorphic region is divided into individual chips, and the back surface of the single chip is mounted for The adhesive sheet of the adhesive sheet picks up the divided chips.

Description of drawings

FIG. 1 is a perspective view of a semiconductor wafer divided by a dividing method according to the present invention.

2 is a perspective view showing a state in which a protective member is bonded to the surface of a semiconductor wafer in a step of bonding a protective member according to the invention of the first aspect of the wafer dividing method.

3 is an explanatory diagram of a polishing step of the invention of the first aspect of the wafer dividing method.

4 is a perspective view of main parts of a laser processing apparatus for performing a modified region forming step in a wafer dividing method.

FIG. 5 is a block diagram schematically showing the configuration of laser beam irradiation means included in the laser processing apparatus shown in FIG. 4 .

Fig. 6 is a schematic diagram for explaining the diameter of the focused spot of the pulsed laser beam.

7 is an explanatory diagram of a modified region forming step of the invention according to the first aspect of the wafer dividing method.

FIG. 8 is an explanatory diagram showing a state in which altered regions are formed by stacking altered regions inside the wafer in the altered region forming step shown in FIG. 7 .

9 is an explanatory view showing an adhesive sheet bonding step of bonding an adhesive sheet for bonding to the back surface of the wafer subjected to the modified region forming step of the first aspect of the wafer dividing method.

10 is an explanatory view showing a frame holding step of the invention according to the first aspect of the wafer dividing method.

FIG. 11 is an explanatory diagram showing a first embodiment of a dividing step of the wafer dividing method according to the present invention.

FIG. 12 is an explanatory view showing a second embodiment of the dividing step of the wafer dividing method according to the present invention.

FIG. 13 is an explanatory view showing a third embodiment of the dividing step of the wafer dividing method according to the present invention.

FIG. 14 is an explanatory view showing a fourth embodiment of the dividing step of the wafer dividing method according to the present invention.

15 is a perspective view of a pick-up device for performing the expanding step and the picking-up step of the wafer dividing method according to the present invention.

Fig. 16 is an explanatory view showing an expanding step of the invention of the first aspect of the wafer dividing method.

Fig. 17 is an explanatory diagram of performing a dividing step and an expanding step using the pick-up device shown in Fig. 15 .

FIG. 18 is an explanatory view showing an embodiment of a dividing step of the second aspect of the invention of the wafer dividing method.

Fig. 19 is an explanatory view showing an adhesive sheet bonding step of the invention according to the second aspect of the wafer dividing method.

FIG. 20 is an explanatory diagram showing a frame holding step of the second aspect of the wafer dividing method.

21 is a perspective view showing a state in which the surface of the wafer is bonded to the dicing tape attached to the ring frame in the frame holding step of the third aspect of the wafer dividing method.

Fig. 22 is an explanatory diagram of a polishing step of the third aspect of the wafer dividing method.

Fig. 23 is an explanatory diagram of a modified region forming step in the invention of the third aspect of the wafer dividing method.

Fig. 24 is an explanatory diagram showing an adhesive sheet bonding step of the third aspect of the wafer dividing method.

FIG. 25 is an explanatory view showing an embodiment of a dividing step of the third aspect of the wafer dividing method.

Fig. 26 is an explanatory view showing an expanding step of the third aspect of the wafer dividing method.

Fig. 27 is an explanatory diagram of a dividing step and an expanding step in carrying out the invention of claim 3 using the pick-up device shown in Fig. 15 .

Fig. 28 is an explanatory view showing an adhesive sheet bonding step of the fourth aspect of the wafer dividing method.

Detailed ways

Hereinafter, preferred embodiments of the method for dividing a wafer according to the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, there is shown a perspective view of a semiconductor wafer as a wafer processed according to the present invention. The semiconductor wafer 2 shown in FIG. 1 is made of a silicon wafer. On the surface 2a, a plurality of planned dividing lines 21 are formed in a grid pattern, and in a plurality of regions divided (divided) by the plurality of planned dividing lines 21, a A circuit 22 as a functional element.

The invention of the first aspect of the dividing method of dividing the semiconductor wafer 2 thus constituted along the plurality of planned dividing lines 21 will be described.

In the invention of Claim 1, first, the protective member 3 is bonded to the surface 2a of the semiconductor wafer 2 as shown in FIG. 2 (protective member bonding step).

When the protective member 3 is bonded to the front surface 2a of the semiconductor wafer 2 by carrying out the protective member bonding step, a polishing step of polishing the back surface 2b of the semiconductor wafer 2 to have a mirror surface is carried out. This polishing step is performed to prevent diffuse reflection of the infrared laser light irradiated from the back surface 2 b side of the semiconductor wafer 2 . That is, in a wafer formed of silicon or the like, if the interior is irradiated with infrared laser light at the converging point, if the surface roughness of the surface on which the infrared laser light is irradiated is thick, it will be diffusely reflected on the surface, and the laser light will not reach a predetermined target. It is difficult to form a predetermined metamorphic region inside the converging point. This grinding step is carried out using a grinding device in the embodiment shown in FIG. 3 . That is, in the grinding process, first, as shown in FIG. 3 , the protective member 3 side of the semiconductor wafer 2 is placed on the fixed table 41 of the grinding device 4 (therefore, the back surface 2 b of the semiconductor wafer 2 becomes the upper side), and a suction member (not shown) is used. The semiconductor wafer 2 is sucked and held on the fixing table 41 . Then, while the fixed table 41 is rotated at, for example, 300 rpm, the grinding tool 43 provided with the grinding stone 42 is rotated at 6000 rpm to contact the back surface 2 b of the semiconductor wafer 2, thereby mirror-finishing and grinding the back surface 2 b of the semiconductor wafer 2. The grindstone 42 is a grinding grindstone in which abrasive grains such as zirconia are dispersed on a soft member such as felt and fixed with an appropriate adhesive. In this mirror-finishing step, the back surface 2b of the semiconductor wafer 2 as the processed surface is mirror-finished to a surface roughness (Ra) specified by JIS B0601 of 0.05 μm or less (Ra≤0.05 μm), preferably 0.02 μm. Below (Ra≤0.02μm).

Next, a modified region forming step is performed in which the polished semiconductor wafer 2 is irradiated with pulsed laser light along the planned dividing line from the back surface 2b side to form a modified region inside the wafer along the planned dividing line. This altered region forming step is carried out using the laser processing apparatus 5 shown in FIGS. 4 to 6 . The laser processing device 5 shown in FIGS. 4 to 6 is provided with: a fixed table 51 holding a workpiece; a laser beam irradiation member 52 for irradiating a laser beam on the workpiece held on the fixed table 51; The imaging means 53 for imaging the workpiece on the fixed table 51 . The fixed table 51 is configured to suck and hold the workpiece, and moves in the machining feed direction indicated by arrow X and the index feed direction indicated by arrow Y in FIG. 4 by a movement mechanism not shown.

The above-mentioned laser irradiation member 52 includes a cylindrical casing 521 arranged substantially horizontally. As shown in FIG. 5 , a pulsed laser light oscillating member 522 and a transmission optical system 523 are provided inside a housing 521 . The pulsed laser beam oscillation unit 522 includes a pulsed laser beam oscillator 522a composed of a YAG laser oscillator or a YVO4 laser oscillator, and a repetition frequency setting unit 522b attached to the pulsed laser beam oscillator 522a. The transfer optical system 523 includes appropriate optical elements such as beam splitters. A condenser 524 is mounted on the front end of the bracket 521. The condenser 524 itself may be of a known form and accommodates a condenser lens (not shown) composed of a group of lenses. The laser beam oscillated by the pulsed laser light oscillating member 522 passes through the transmission optical system 523 to the condenser 524, and is irradiated from the condenser 524 to the workpiece held on the fixed table 51 with a predetermined spot diameter D. superior. This condensing spot diameter D shows the pulsed laser light of Gaussian distribution shown in Fig. 6 under the situation that the condensing objective lens 524a of condensing device 524 is irradiated, D (μm)=4*λ*f/(π*W ), where λ is defined as the wavelength (μm) of the pulsed laser light, W is defined as the diameter (mm) of the pulsed laser light incident on the objective lens 524a, and f is defined as the focal length (mm) of the objective lens 524a.

The imaging member 53 mounted on the front end portion of the housing 521 constituting the above-mentioned laser beam irradiation member 52 includes, in addition to the imaging device (CCD) for imaging with visible light in the illustrated embodiment, it also includes The infrared illumination member on the workpiece, the optical system that captures the infrared rays irradiated by the infrared illumination member, and the imaging element (infrared CCD) that outputs the electrical signal corresponding to the infrared rays captured by the optical system, etc. The image signal is sent to the control unit described later.

Referring to FIG. 4 , FIG. 7 and FIG. 8 , a modified region forming step performed using the laser processing apparatus 6 described above will be described.

In this metamorphic region forming step, at first the protective member 3 side of the semiconductor wafer 2 whose back surface 2b has been ground is placed on the fixed table 51 of the laser processing device 6 shown in FIG. The back surface 2b is the upper side), and the semiconductor wafer 2 is sucked and held on the fixing table 51 by a suction member not shown in the figure. The fixing table 51 on which the semiconductor wafer 2 is sucked and held is placed directly below the imaging member 53 by a movement mechanism not shown in the figure.

When the fixed table 61 is placed directly under the imaging member 53 , a calibration operation of detecting a processing region to be laser processed of the semiconductor wafer 2 is performed by the imaging member 53 and a control member not shown in the figure. That is, the imaging unit 53 and the control unit not shown in the figure perform image processing such as pattern matching for aligning the planned dividing line 21 formed in the predetermined direction of the semiconductor wafer 2 and the alignment of the irradiation position of the laser light. The position of the condenser 524 of the laser beam irradiation member 52 that irradiates the laser beam along the planned division line 21 is aligned. Also, alignment of the irradiation position of the laser beam is similarly performed for the above-mentioned predetermined direction formed on the semiconductor wafer 2 and for the planned dividing line 21 extending vertically. At this time, although the surface 2a of the semiconductor wafer 2 on which the planned dividing line 21 is formed is located on the lower side, since the imaging member 53 includes an infrared illuminating member, an optical system for capturing infrared rays, and an imaging element for outputting an electrical signal corresponding to the infrared rays as described above, (Infrared CCD) and other imaging means, so the dividing line 21 can be imaged through the back surface 2b.

If the planned dividing line 21 formed on the semiconductor wafer 2 held on the fixed table 51 is detected as described above, and the laser beam irradiation position is calibrated, the fixed table 51 is moved as shown in FIG. 7( a) To the laser beam irradiation area where the light collector 524 of the laser beam irradiation member 52 for irradiating the laser beam is located, one end (left end in FIG. directly below the device 524. Then, while irradiating the transmissive pulsed laser beam from the concentrator 524, the fixed table 51, that is, the semiconductor wafer 2 is moved at a predetermined feed speed in the direction indicated by the arrow X in FIG. 7(a). Then, as shown in FIG. 7( b), if the irradiation position of the focused light 524 of the laser beam irradiation member 52 reaches the position of the other end of the dividing line 21, the irradiation of the pulsed laser beam is stopped, and the fixing table 51, that is, the semiconductor, is stopped. Wafer 2 movement. In this modified region forming step, by aligning the converging point P of the pulsed laser beam near the surface 2a (lower surface) of the semiconductor wafer 2, the modified region 210 is exposed on the surface 2a (lower surface) and formed inwardly from the surface 2a. . The metamorphic region 210 is formed as a molten resolidified layer. By forming the altered region 210 exposed on the surface 2 a of the semiconductor wafer 2 as described above, division by applying an external force along the altered region 210 becomes easy.

Furthermore, the processing conditions of the above-mentioned modified region forming step are set as follows, for example:

Light source: LD excitation Q-switched Nd:YVO4 laser

Wavelength: 1064nm pulsed laser

Pulse output: 10μJ

Spot diameter: φ1μm

Pulse width: 40ns

Peak power density at the spot: 3.2×10 ¹⁰ W/cm ²

Repeat frequency: 100kHz

Processing feed speed: 100mm/sec

Furthermore, when the thickness of the semiconductor wafer 2 is thick, the above-described modified region forming process is performed multiple times by changing the light-converging point P in stages as shown in FIG. 8 , thereby forming a plurality of modified regions 210 . Furthermore, since the thickness of the altered region formed at one time is about 50 μm under the above processing conditions, six layers of altered regions are formed on the wafer 2 having a thickness of 300 μm in the illustrated embodiment. As a result, the altered region 210 formed inside the semiconductor wafer 2 is formed along the planned dividing line 21 from the front surface 2 a to the back surface 2 b.

In the above-mentioned modified region forming process, if the modified region 210 is formed along the planned division line 21 inside the semiconductor wafer 2, then an adhesive sheet bonding step is performed, as shown in FIG. Adhesive sheet 6 for adhesive sheet. Moreover, the adhesive sheet 6 uses the adhesive sheet of thickness 25 micrometers in embodiment. Moreover, the adhesive sheet 6 can use the acrylic adhesive sheet (FH-800) manufactured and sold by Hitachi Chemical Co., Ltd., a polyimide adhesive sheet (DF-400), etc., for example.

After the above-mentioned adhesive sheet bonding step is carried out, a frame holding step is carried out to bond the adhesive sheet 6 side of the semiconductor wafer 2 to the dicing tape attached to the ring frame. In the frame holding process, as shown in FIG. 10 , the adhesive sheet 6 side of the semiconductor wafer 2 is bonded to the surface of the stretchable dicing tape 70 attached to the ring frame 7 . Then, the protective member 3 bonded on the surface 2a of the semiconductor wafer 2 is peeled off. Furthermore, in the above-mentioned dicing tape 70 , in the illustrated embodiment, an acrylic resin-based paste with a thickness of about 5 μm is applied to the surface of a sheet base material made of polyvinyl chloride (PVC) with a thickness of 100 μm. As the paste, a paste having a property that the adhesive force is lowered by external stimuli such as ultraviolet rays is used.

In addition, in the frame holding step, an adhesive sheet may be attached to the back surface 2b of the semiconductor wafer 2 . In this case, the composite tape in which the adhesive sheet is integrally formed on the dicing tape can be used, for example, a composite tape (LE-5000) manufactured and sold by Lintec (Lintec Co., Ltd.). That is, the back surface 2b of the semiconductor wafer 2 is bonded to the adhesive sheet formed on the surface of the dicing tape. Therefore, by using a composite tape in which an adhesive sheet is integrally formed on a dicing tape, the adhesive sheet adhering step and the frame holding step can be performed simultaneously.

After the above-mentioned frame holding step is performed, a dividing step is performed to divide the semiconductor wafer 2 along the planned dividing line 21 .

A first embodiment of the dividing step will be described with reference to FIG. 11 . The first embodiment of the dividing step shown in FIG. 11 uses an ultrasonic dividing device 8 . The ultrasonic dividing device 8 includes a cylindrical base 81 , a first ultrasonic oscillator 82 , and a second ultrasonic oscillator 83 . The cylindrical base 81 constituting the ultrasonic dividing device 8 has a placement surface 81 a on which the above-mentioned frame 7 is placed on the upper surface, and the frame 7 is placed on the placement surface 81 a and fixed by a jig 84 . The base 81 is configured to be movable in the left-right direction and in the direction perpendicular to the paper surface in FIG. 11 by a moving member not shown in the figure, and is also configured to be rotatable. The first ultrasonic oscillator 82 and the second ultrasonic oscillator 83 constituting the ultrasonic dividing device 8 are disposed opposite to each other on the upper side and the lower side of the semiconductor wafer 2 (the adhesive sheet 6 is bonded on the back surface 2b), and generate longitudinal waves of a predetermined frequency. (Dense-Dense Wave), the above-mentioned semiconductor wafer 2 is supported by the frame 7 placed on the placement surface 81 a of the cylindrical base 81 with the dicing tape 70 interposed therebetween. In order to implement the above-mentioned dividing process using the ultrasonic dividing device 8 thus constituted, the side on which the dicing tape 70 is attached is placed on the placement surface 81a of the cylindrical base 81 (therefore, the surface 2a of the semiconductor wafer 2 becomes the upper side), and Reference numeral 84 fixes the frame 7 supporting the semiconductor wafer 2 (deterioration region 210 is formed along the planned dividing line 21 ) with the dicing tape 70 interposed therebetween. Then, the base 81 is moved by a moving member not shown in the figure, so that one end (the left end in FIG. 12 ) of the planned dividing line 21 formed on the semiconductor wafer 2 is positioned at the position from the first ultrasonic oscillator 82 and the second ultrasonic oscillator 83. The position where the ultrasonic wave takes place. Then, the first ultrasonic oscillator 82 and the second ultrasonic oscillator 83 are operated to generate longitudinal waves (dense and dense waves) with a frequency of, for example, 28 kHz, respectively, and the base 81 is moved, for example, at a distance of 50 to 100 mm in the direction shown by the arrow. /sec speed feed. As a result, the ultrasonic waves generated by the first ultrasonic oscillator 82 and the second ultrasonic oscillator 83 act on the surface and the back surface along the planned dividing line 21 of the semiconductor wafer 2, so the semiconductor wafer 2 forms a degenerated region 210 along which the intensity decreases. The planned dividing line 21 is divided. When the dividing step is performed along the predetermined dividing line as described above, the base 81 is index-feeded in a direction perpendicular to the paper surface by an amount corresponding to the interval of the dividing line 21 to perform the dividing step. When the dividing process is performed on all the planned dividing lines 21 extending along the predetermined direction, the base 81 is rotated by 90 degrees, and the above-mentioned dividing process is performed on the planned dividing lines 21 formed on the semiconductor wafer 2 along the direction perpendicular to the predetermined direction. , whereby the semiconductor wafer 2 is divided into individual chips. Also, the adhesive sheet 6 bonded to the back surface of the semiconductor wafer 2 is broken.

Next, a second embodiment of the dividing step will be described with reference to FIG. 12 . The second embodiment of the dividing step shown in FIG. 12 is implemented using the same laser processing device 9 as the laser processing device shown in FIGS. 4 to 6 described above. That is, the dicing tape 60 side is placed on the fixed table 91 of the laser processing device 9 (therefore the surface 2a of the semiconductor wafer 2 becomes the upper side), and the suction member not shown in the figure is sucked and held with the dicing tape 70 being supported on the frame. 7 on the semiconductor wafer 2 (altered region 210 is formed along the planned dividing line 21), and the frame 7 is fixed by the clamp mechanism 92. Then, the fixing table 91 is moved to the laser beam irradiation area where the condenser 93 of the laser beam irradiation member is located, and one end (the left end in FIG. 12 ) of the predetermined dividing line 21 is located directly below the condenser 93 . Then, while the semiconductor wafer 2 is irradiated with absorptive continuous-wave laser light from the concentrator 93, the fixed table 91, that is, the semiconductor wafer 2 is moved at a predetermined processing feed rate in the direction shown by the arrow X1 in FIG. If the other end (the right end in FIG. 12 ) of the predetermined dividing line 21 reaches the irradiation position of the light collector 93, the irradiation of the laser beam is stopped, and the movement of the fixed table 91, that is, the semiconductor wafer 2, is stopped. In this dividing step, the converging point P of the continuous wave laser beam is aligned with the surface 2a (upper surface) of the semiconductor wafer 2, and thermal stress is applied to the dividing line 21 where the altered region 210 is formed by heating, thereby imparting a thermal shock. As a result, the semiconductor wafer 2 is divided along the dividing line 21 in which the altered region 210 is formed. In addition, in the dividing process, the laser beam irradiated along the planned dividing line 21 where the modified region 210 is formed is sufficient to heat the semiconductor wafer 2 and provide an output of an appropriate temperature gradient (100 to 400° C.), and the silicon will not be damaged. molten.

And, the processing conditions of the above-mentioned division process are set as follows, for example:

Light source: LD excited Nd:YAG second harmonic laser (CW)

Wavelength: 532nm

Output: 10W

Concentrating spot diameter: φ0.5mm (heating includes the larger area of metamorphic area 110)

Processing feed speed: 100mm/sec

If the division process as described above is carried out, the fixing table 91, that is, the semiconductor wafer 2 is index-feeded along the direction perpendicular to the paper surface in FIG. Machining feed is performed while irradiating the continuous wave laser beam. Then, if the above-mentioned processing feed and index feed are performed along all the planned division lines 21 formed in the predetermined direction, the fixed table 91, that is, the semiconductor wafer 2 is rotated by 90 degrees, and formed along the vertical direction relative to the predetermined direction. The planned dividing line 21 of the semiconductor wafer 2 is cut and divided along the planned dividing line 21 formed on the semiconductor wafer 2 by performing the above-mentioned processing feed and index feeding. Furthermore, the adhesive sheet 6 adhered to the back surface of the semiconductor wafer 2 is not broken.

Next, a third embodiment of the dividing step will be described with reference to FIG. 13 . The third embodiment of the dividing step shown in FIG. 13 is carried out using a bending dividing device 11 composed of a cylindrical base 111 and a bending load imparting member 113 . That is, the frame 8 supporting the semiconductor wafer 2 (with the modified region 210 formed along the planned dividing line 21 ) with the dicing tape 70 interposed therebetween is placed on the placement surface 111 a of the cylindrical base 111 with the dicing tape 70 side as the upper side. (Therefore, the surface 2 a of the semiconductor wafer 2 becomes the lower side), and it is fixed by the jig 112 . Then, the surface 2 a (lower surface) of the semiconductor wafer 2 is placed on a plurality of cylindrical support members 114 arranged in parallel to each other constituting the bending load imparting member 113 . At this time, the dividing line 21 formed in the predetermined direction of the semiconductor wafer 2 is placed between the supporting members 114 and 114 . Then, the dicing tape 70 bonded to the back surface 2 b of the semiconductor wafer 2 is pressed by the pressing member 115 along the planned dividing line 21 . As a result, a bending load acts on the semiconductor wafer 2 along the planned dividing line 21, a tensile stress occurs on the surface 2a, and the semiconductor wafer 2 is cut and divided along the planned dividing line 21 where the altered region 210 is formed and the strength is lowered. . Then, if it has been divided along the planned dividing line 21, which is the modified region 210 formed in the predetermined direction, the cylindrical base 111, that is, the semiconductor wafer 2, is rotated 90 degrees, and is formed along the planned dividing line formed at right angles to the predetermined direction. The lines 21 carry out the above-mentioned dividing operation, whereby the semiconductor wafer 2 can be divided into individual chips. Furthermore, the adhesive sheet 6 adhered to the back surface of the semiconductor wafer 2 is not completely broken although there are some broken parts.

Next, a fourth embodiment of the dividing step will be described with reference to FIG. 14 . The fourth embodiment of the dividing step shown in FIG. 14 is carried out using a bending dividing device 12 composed of a cylindrical base 121 and a pressing member 123 as a bending load imparting member. The base 121 is configured to be movable in the left-right direction and the direction perpendicular to the paper surface in FIG. 14 by a moving member not shown in the figure, and is also configured to be rotatable. The frame 7 supporting the semiconductor wafer 2 (the modified region 210 is formed along the planned dividing line 21 ) with the dicing tape 70 interposed therebetween is placed on the dicing tape 70 side (therefore the surface 2 a of the semiconductor wafer 2 becomes the upper side), and is fixed by a jig 122 On the placement surface 121a of the cylindrical base 121 configured as above. Next, the base 121 is moved by a moving member not shown in the figure, so that one end (the left end in FIG. 14 ) of the predetermined dividing line 21 formed on the semiconductor wafer 2 is located at a position facing the pressing member 123, and the The pressing member 123 moves upward in FIG. 14 and is positioned to press the dicing tape 70 on which the semiconductor wafer 2 is bonded. Then, the base 121 is moved in the direction indicated by the arrow. As a result, on the semiconductor wafer 2, a bending load acts along the planned dividing line 21 pressed by the pressing member 123, a tensile stress is generated on the surface 2a, and the semiconductor wafer 2 is formed along the planned dividing line 21 where the degenerated region 210 is formed and the strength is reduced. Line 21 is broken and divided. When the dividing step is carried out along the predetermined dividing line 21 as described above, the base 121 is index-feeded by an amount corresponding to the interval of the dividing line 21 in a direction perpendicular to the paper surface, and the dividing step is carried out. If the dividing process is carried out along all the planned dividing lines 21 extending in the predetermined direction as described above, the base 121 is rotated by 90 degrees, and the dividing process is performed on the semiconductor wafer 2 on the planned dividing lines 21 formed in the direction perpendicular to the predetermined direction. The above-mentioned dividing process whereby the semiconductor wafer 2 is divided into individual chips. Furthermore, the adhesive sheet 7 adhered to the back surface of the semiconductor wafer 2 is not completely broken although there are some broken parts.

In addition, in the dividing process of dividing the semiconductor wafer 2 along the planned dividing line 21, in addition to the above-mentioned dividing method, the following method can be used: for example, the semiconductor wafer 2 bonded on the dicing tape The tab 7) is placed on a soft rubber sheet, and the upper surface thereof is pressed with a roller, whereby the semiconductor wafer 2 is cut along the planned dividing line 21 where the degenerated region 210 is formed and the strength is lowered.

After the above-mentioned dividing step is performed, an expanding step is performed to expand the dicing tape on which the wafers divided into individual chips are bonded to expand the interval between the individual chips, thereby breaking the adhesive sheet 7 . This expanding step is carried out using the pick-up device 13 shown in FIGS. 15 and 16 . Here, the pick-up device 13 will be explained. The illustrated pick-up device 13 is equipped with a cylindrical base 131 and an expansion member 132. The cylindrical base 131 forms a placement surface 131a on which the frame 7 is placed. The expansion member 132 is concentrically arranged in the base 131 and is used The dicing tape 70 installed on the frame 7 is expanded by pressing. The expansion member 132 includes a cylindrical expansion member 133 that supports the region 701 of the dicing tape 70 where the semiconductor wafer 2 exists. The expansion part 133 is configured to be able to move up and down between the reference position shown in FIG. 16(a) and the expansion position shown in FIG. direction (the axial direction of the cylindrical base 131). Furthermore, in the illustrated embodiment, an ultraviolet irradiation lamp 134 is provided in the expansion member 133 .

The expanding process performed using the pick-up device 13 as described above will be described with reference to FIGS. 15 and 16 .

The frame 7, to which the dicing tape 70 of the back surface 2b of the semiconductor wafer 2 divided into individual chips 20 as described above, is mounted, is placed on the cylindrical base 131 shown in FIGS. 15 and 16(a). The surface 131a is fixed on the base 131 by a clamp 135 . Next, as shown in FIG. 16(b), the expansion member 133 of the expansion member 132 supporting the area 701 where the semiconductor wafer 2 of the above-mentioned dicing tape 70 exists is moved from FIG. ) to the expanded position shown in Figure 16(b) above. As a result, since the stretchable dicing tape 70 is expanded, a deviation occurs between the dicing tape 70 and the chip 20, and the adhesion is lowered, so that the chip 20 can be easily detached from the dicing tape 70. Gaps are formed between the semiconductor chips 20 . Furthermore, when a gap is formed between the semiconductor chips 20 , the adhesive sheet 6 adhered to the back surface of the semiconductor wafer 2 is broken along each side of each semiconductor chip 20 .

Next, as shown in FIG. 15 , the pick-up suction head (collet) 136 arranged above the pick-up device 13 is moved to detach the single chip 20 with the adhesive sheet 6 bonded on the back from the upper surface of the dicing tape 70, Transfer to a tray or a bonding process not shown in the figure. At this time, the ultraviolet irradiation lamp 134 provided in the expansion member 133 is turned on to irradiate ultraviolet rays on the dicing tape 70 to reduce the adhesive force of the dicing tape 70 and thereby facilitate detachment.

The above-mentioned dividing process can also be carried out by using the pick-up device 13 as described above. That is, the frame 7 supporting the semiconductor wafer 2 shown in FIG. On the placing surface 131a of the pedestal, it is fixed on the base 131 with a clamp 135 . Next, as shown in FIG. 17( b), the expansion member 133 of the expansion member 132 supporting the area 701 where the semiconductor wafer 2 of the above-mentioned dicing tape 70 exists is moved from FIG. ) to the expanded position shown in Figure 17(b) above. As a result, since the stretchable dicing tape 70 is expanded, the tensile force acts radially on the semiconductor wafer 2 bonded with the dicing tape 70 . If the pulling force acts radially on the semiconductor wafer 2 as described above, the intensity of the metamorphic region 210 formed along the planned dividing line decreases, so the semiconductor wafer 2 is broken along the metamorphic region 210 and is divided into individual semiconductor chips. 20, and the adhesive sheet 6 bonded to the back surface of the semiconductor wafer 2 is also broken along each side of each semiconductor chip 20. Moreover, the expansion amount of the dicing tape 70 in the above-mentioned division process, that is, the stretching amount, can be adjusted by the upward movement of the expansion member 133. According to experiments by the inventors, when the dicing tape 70 is stretched by about 20 mm, the semiconductor wafer 2 can be stretched. Disconnected along the metamorphic zone 210 . By carrying out the dividing process as described above, a deviation occurs between the dicing tape 70 and the chip 20, and the adhesion is reduced, so the chip 20 becomes a state where it is easy to be detached from the dicing tape 70, and a gap is formed between the individual chips 20. gap. Thereafter, as shown in FIG. 15 , the pick-up suction head 136 arranged above the pick-up device 13 is moved, and the single chip 20 with the adhesive sheet 6 bonded on the back is detached from the upper surface of the dicing tape 70 and transported to the top surface of the dicing tape 70 . Tray or die bonding process not shown.

Next, the invention of the second aspect of the wafer dividing method will be described.

The invention of claim 2 is an invention in which the order of the adhesive sheet bonding step, the frame holding step, and the dividing step of the invention of the first claim is changed.

That is, in the invention of claim 2, first, the step of adhering the protective member of the invention of claim 1 as described above is carried out. Protection Member Bonding Process As shown in FIG. 2 , the protection member 3 is bonded to the surface 2 a of the semiconductor wafer 2 .

Once the protective member bonding step is carried out, the polishing step of the invention of the first aspect as described above is carried out. That is, in the polishing step, as shown in FIG. 3, the back surface 2b of the semiconductor wafer 2 is polished to be processed into a mirror surface.

Then, a modified region forming step is carried out, in which the polished semiconductor wafer 2 is irradiated with pulsed laser light along the planned dividing line from the back surface 2b side to form a modified region inside the wafer along the planned dividing line. That is, the modified region forming process uses the laser processing apparatus shown in FIGS. As shown in Fig. 7 (a) (b), along the predetermined dividing line 21, irradiate the semiconductor wafer with the pulsed laser light of transmissibility from light collector 524, make fixed table 51 along Fig. 7 (a) at the same time The process feed is performed in the direction indicated by the arrow X1 , whereby the altered region 210 is formed along the dividing line 21 inside the semiconductor wafer 2 .

As described above, if the altered region 210 is formed inside the semiconductor wafer 2 along the planned dividing line 21 by performing the protective member bonding step, the grinding step, and the altered region forming step, the semiconductor wafer is divided along the planned dividing line 21. 2 of the division process. This dividing step is carried out using the laser processing apparatus 9 shown in FIG. 12 described above. That is, in the dividing process of the present embodiment, as shown in FIG. 18 , on the fixed table 91 of the laser processing apparatus 9, the protective member 3 side of the semiconductor wafer 2 formed with the modified region 210 along the planned dividing line 21 is placed (so the semiconductor wafer 2, the back surface 2b becomes the upper side), and is sucked and held by a suction member not shown in the figure. Next, the fixing table 91 is moved to the laser beam irradiation area where the condenser 93 of the laser beam irradiation member is located, so that one end (the left end in FIG. 18 ) of the predetermined dividing line 21 is located directly below the condenser 93 . Then, while the semiconductor wafer 2 is irradiated with absorptive continuous-wave laser light from the concentrator 93, the fixed table 91, that is, the semiconductor wafer 2 is moved at a predetermined processing feed rate in the direction shown by the arrow X1 in FIG. If the other end (the right end in FIG. 18 ) of the predetermined dividing line 21 reaches the irradiation position of the light collector 93, the irradiation of the laser beam is stopped, and the movement of the fixed table 91, that is, the semiconductor wafer 2, is stopped. In this dividing step, the converging point P of the continuous wave laser beam is aligned with the back surface 2b (upper surface) of the semiconductor wafer 2, and the planned dividing line 21 where the modified region 210 is formed is heated, thereby generating thermal stress and imparting a thermal shock. . As a result, a breaking portion is formed along the planned dividing line 21 where the modified region 210 is formed, and the semiconductor wafer 2 is divided. In addition, in the splitting step, the output of the laser light irradiated along the planned splitting line 21 where the altered region 210 is formed is sufficient to heat the semiconductor wafer 2 and give an appropriate temperature gradient (100 to 400° C.) without melting the silicon. . In addition, the processing conditions in the above-mentioned dividing step may be the same as those in the above-mentioned embodiment shown in FIG. 19 .

If the above-mentioned dividing process is carried out, then the fixing table 91, that is, the semiconductor wafer 2 is indexed and fed along the direction perpendicular to the paper surface in FIG. Processing feed while irradiating continuous wave laser beam. Then, if the above-mentioned processing feed and index feed are performed along all the planned dividing lines 21 formed in the predetermined direction, the fixed table 91, that is, the semiconductor wafer 2 is rotated by 90 degrees, and the fixed table 91 is rotated by 90 degrees, along the division lines formed perpendicular to the predetermined direction. The planned line 21 is cut and divided along the planned line 21 formed on the semiconductor wafer 2 by performing the above-mentioned processing feed and index feed. Furthermore, the semiconductor wafer 2 is divided into individual chips by being cut along the planned dividing line 21, but since the protective member 3 is adhered to the back surface 2b of the semiconductor wafer 2, it is not scattered and the form of the wafer is maintained.

Moreover, in the dividing process of dividing the semiconductor wafer 2 along the planned dividing line 21, in addition to the above-mentioned dividing method, the following method can also be used: for example, placing the semiconductor wafer 2 bonded on the protective member on a soft rubber sheet , the semiconductor wafer 2 is cut along the planned dividing line 21 where the altered region 210 is formed and the strength is lowered by pressing the upper surface thereof with a roller.

If the semiconductor wafer 2 is divided into individual semiconductor chips by implementing the above-mentioned division process, an adhesive sheet bonding process is implemented. As shown in FIG. on the back surface 2b of the semiconductor wafer 2. In addition, as the adhesive sheet 6, the same adhesive sheet as that in the invention of the first aspect may be used.

After the above-mentioned adhesive sheet bonding step is carried out, a frame holding step is carried out to bond the adhesive sheet 6 side of the semiconductor wafer 2 to the dicing tape attached to the ring frame. In the frame holding process, as shown in FIG. 20 , the adhesive sheet 6 side of the semiconductor wafer 2 divided into individual chips 20 is bonded to the surface of the stretchable dicing tape 70 mounted on the ring frame 7 . Then, the protective member 3 bonded on the surface 2a of the semiconductor wafer 2 is peeled off. Moreover, the said dicing tape 70 should just be the same tape as the dicing tape used in the said 1st invention.

Furthermore, in the frame holding process, an adhesive sheet can be attached to the back surface 2b of the semiconductor wafer 2 . At this time, as the composite tape in which the adhesive sheet is integrally formed on the dicing tape, for example, a composite tape (LE-5000) manufactured and sold by Lintec (Lintec Co., Ltd.) can be used. That is, the back surface 2b of the semiconductor wafer 2 is bonded to the adhesive sheet formed on the surface of the dicing tape. Therefore, by using a composite tape in which an adhesive sheet is integrally formed on a dicing tape, the adhesive sheet adhering step and the frame holding step can be performed simultaneously.

After the above-mentioned frame holding step is performed, an expanding step is performed to expand the dicing tape to which the wafers divided into individual chips are bonded, thereby expanding the intervals between the individual chips. This expanding step is carried out using the pick-up device 13 shown in FIG. 15 as in the invention of the first aspect described above. That is, the frame 7 mounted with the dicing tape 70 bonded with the back surface 2b of the semiconductor wafer 2 divided into individual chips 20 by the above-mentioned dividing process is placed on the cylindrical frame shown in FIGS. 15 and 16(a). The placement surface 131 a of the base 131 is fixed on the base 131 by a clamp 135 . Next, as shown in FIG. 16( b), the expansion member 133 of the expansion member 132 supporting the area 701 where the semiconductor wafer 2 of the above-mentioned dicing tape 70 exists is moved from FIG. ) to the expanded position shown in Figure 16(b) above. As a result, since the stretchable dicing tape 70 is expanded, misalignment occurs between the dicing tape 70 and the chip 20, and the adhesiveness decreases, so that the chip 20 can be easily detached from the dicing tape 70, and, Gaps are formed between individual semiconductor chips 20 . Furthermore, when a gap is formed between the semiconductor chips 20 , the adhesive sheet 6 adhered to the back surface of the semiconductor wafer 2 is broken along each side of each semiconductor chip 20 .

Next, as in the invention of the above-mentioned first aspect, the pick-up suction head 136 arranged above the pick-up device 13 shown in FIG. The upper surface is detached, and it is transported to a tray or a bonding process not shown in the figure.

Next, the invention of claim 3 of the wafer dividing method will be described.

In the invention according to claim 3, first, a frame holding step is performed to bond the surface 2a of the semiconductor wafer 2 to the dicing tape attached to the ring frame. In the frame holding process, as shown in FIG. 21 , the surface 2 a of the semiconductor wafer 2 is bonded to the surface of the stretchable dicing tape 70 attached to the ring frame 7 . Moreover, the said dicing tape 70 should just be the same tape as the dicing tape used in the said 1st invention.

After the surface of the semiconductor wafer 2 is adhered to the dicing tape 70 attached to the ring frame 7 by performing the frame holding process, a polishing process is performed to polish the back surface 2b of the semiconductor wafer 2 to be processed into a mirror surface. This polishing step is carried out using the above-mentioned polishing device 4 shown in FIG. 3 . That is, in the polishing process, as shown in FIG. 22, the dicing tape 70 side of the semiconductor wafer 2 is placed on the fixed table 41 of the polishing device 4 (therefore the back surface 2b of the semiconductor wafer 2 becomes the upper side), and a suction member not shown in the figure is used. The semiconductor wafer 2 is sucked and held on the fixing table 41 . In addition, in FIG. 22 , although illustration of the ring frame 7 to which the dicing tape 70 is attached is omitted, the ring frame 7 is held by an appropriate clamp mechanism provided on the fixing table 41 . In this way, if the semiconductor wafer 2 is held on the fixed table 41, the fixed table 41 is rotated at, for example, 300 rpm, and the grinding tool 53 having the grinding stone 52 is, for example, Rotate at 6000rpm to come into contact with the back surface 2b of the semiconductor wafer 2, thereby mirror-finishing the back surface 2b of the semiconductor wafer 2. The agent is fixed.

Next, a modified region forming step is carried out in which the mirror-finished semiconductor wafer 2 is irradiated with pulsed laser light along the planned dividing line from the rear surface 2b side of the semiconductor wafer 2 to form a modified region inside the wafer along the planned dividing line. This altered region forming step is carried out using the laser processing apparatus shown in FIGS. 4 to 6 as in the invention of the first aspect described above. This metamorphic region forming process is first shown in Figure 23, the dicing tape 30 side of the semiconductor wafer 2 that the back side 2b has been ground is placed on the fixed table 51 of the laser processing device 5 (so the ground side of the semiconductor wafer 2 is ground). 2b becomes the upper side), and the semiconductor wafer 2 is sucked and held on the fixing table 51 by a suction member not shown in the figure. In addition, in FIG. 23 , although the illustration of the ring frame 7 on which the dicing tape 70 is attached is omitted, the ring frame 7 is held by an appropriate clamp mechanism provided on the fixing table 51 . In this way, if the semiconductor wafer 2 is held on the fixed table 51, after performing the above-mentioned calibration operation in the same manner as the modified region forming process of the invention of the first aspect, the light is transferred from the light collector 524 along the predetermined division line 21 The modified region 210 is formed inside the semiconductor wafer 2 along the planned dividing line 21 by processing and feeding the fixed table 51 while irradiating the pulsed laser beam which is transparent to the semiconductor wafer.

If the altered region 210 is formed along the planned dividing line 21 inside the semiconductor wafer 2 by the above-mentioned altered region forming process, then as shown in FIG. on the back side 2 b of the semiconductor wafer 2 . In addition, the adhesive sheet 6 may be the same film as the adhesive sheet of the invention of the first aspect described above.

After the above-mentioned adhesive sheet bonding step is carried out, a splitting step is performed, and an external force is applied along the planned splitting line 21 of the semiconductor wafer 2 held on the frame 7 on which the altered region 210 is formed, and the wafer 2 is moved along the planned splitting line. 21 is divided into individual chips. This dividing step can be carried out using, for example, the ultrasonic dividing device 8 shown in FIG. 11 described above. That is, as shown in FIG. 25, the side on which the dicing tape 80 is attached is placed on the placement surface 81a of the cylindrical base 81 (therefore, the side of the semiconductor wafer 2 on which the adhesive sheet 6 is bonded on the back surface 2b becomes the upper side), The frame 7 holding the semiconductor wafer 2 (deteriorated region 210 formed along the planned dividing line 21 ) is fixed by the jig 84 with the dicing tape 70 interposed therebetween. Next, the base 81 is moved by a moving member not shown in the figure so that one end (the left end in FIG. 25 ) of the predetermined dividing line 21 formed on the semiconductor wafer 2 is positioned at the end (left end in FIG. 25 ) from the first ultrasonic oscillator 82 and the second ultrasonic wave. The position where the ultrasonic waves of the oscillator 83 act. Then, the first ultrasonic oscillator 82 and the second ultrasonic oscillator 83 are operated to generate longitudinal waves (dense and dense waves) with a frequency of, for example, 28 kHz, respectively, and the base 81 is moved along the direction indicated by the arrow at a rate of, for example, 50 to 100 mm/sec. speed feed. As a result, the ultrasonic waves generated by the first ultrasonic oscillator 82 and the second ultrasonic oscillator 83 act on the surface and the back surface along the planned dividing line 21 of the semiconductor wafer 2, so the semiconductor wafer 2 is formed along the modified region 210 and its strength is reduced. The planned dividing line 21 is divided. By performing this dividing process along all the planned dividing lines 21 formed on the semiconductor wafer 2, the semiconductor wafer 2 is divided into individual chips. Also, the adhesive sheet 6 bonded to the back surface 2b of the semiconductor wafer 2 is not broken.

After the above-mentioned dividing step is performed, an expanding step is performed to expand the dicing tape on which the wafers divided into individual chips are bonded to expand the interval between the individual chips, thereby breaking the adhesive sheet 7 . This expanding step is carried out using a pick-up device 13 shown in FIG. 15 .

The frame 7 with the dicing tape 70 installed is placed on the placement surface 131a of the cylindrical base 131 as shown in Figure 26 (a), and is fixed on the base 131 by the clamp 155. Back side 2 b of semiconductor wafer 2 which is divided into individual chips 20 . Next, as shown in FIG. 26( b ), the expansion member 133 of the expansion member 132 supporting the area where the semiconductor wafer 2 of the above-mentioned dicing tape 70 exists is moved from the position in FIG. The reference position moves to the expanded position shown in Fig. 26(b) above. As a result, since the stretchable dicing tape 70 is expanded, a deviation occurs between the dicing tape 70 and the chip 20, and the adhesion is lowered, so that the chip 20 can be easily detached from the dicing tape 70. Gaps are formed between the individual semiconductor chips 20 . Furthermore, when a gap is formed between the semiconductor chips 20 , the adhesive sheet 6 bonded to the back surface of the semiconductor wafer 2 is broken along each side of each semiconductor chip 20 .

Next, the pick-up suction head 136 arranged above the pick-up device 13 as shown in FIG. and the back side are transported to a tray or a bonding process not shown in the figure. At this time, by turning on the ultraviolet irradiation lamp 134 arranged in the expansion member 133 to irradiate ultraviolet rays on the dicing tape 30, the adhesive force of the dicing tape 30 is reduced, thereby enabling easier detachment.

The above-mentioned dividing step can also be implemented by using the above-mentioned pick-up device 13 . That is, as shown in FIG. 27( a), the frame 7 supporting the semiconductor wafer 2 (with the modified region 210 formed along the planned dividing line 21 ) before the above-mentioned dividing process is placed on the cylinder with the dicing tape 70 interposed therebetween. On the placing surface 131a of the base 131 of the shape, it is fixed on the base 131 by the clamp 135 . Next, as shown in FIG. 27(b), the expansion member 133 of the expansion member 132 supporting the region 701 where the semiconductor wafer 2 of the above-mentioned dicing tape 70 exists is moved from FIG. ) to the expanded position shown in Fig. 27(b) above. As a result, since the stretchable dicing tape 70 is expanded, the tensile force acts radially on the semiconductor wafer 2 to which the dicing tape 70 is bonded. If the tensile force acts radially on the semiconductor wafer 2 as described above, the strength of the degenerated region 210 formed along the planned division line decreases, so the semiconductor wafer 2 is broken along the degenerated region 210 and is divided into individual semiconductor chips. 20, and the adhesive sheet 6 bonded to the back surface of the semiconductor wafer 2 is also broken along each side of each semiconductor chip 20. By carrying out the dividing step in this way, a deviation occurs between the dicing tape 70 and the chip 20, and the adhesion is lowered, so the chip 20 can be easily detached from the dicing tape 70, and a gap is formed between the individual chips 20. . Afterwards, as shown in FIG. 15 , the pick-up suction head 136 arranged above the pick-up device 13 is operated, and the single chip 20 with the adhesive sheet 6 bonded on the back is detached from the upper surface of the dicing tape 70 and transported to The tray or the bonding process not shown in the figure. Furthermore, since the side of the adhesive sheet 6 bonded to the back surface of the chip 20 is held by the pick-up head 136, it is preferably conveyed to a tray not shown in the figure by a front-to-back reversing member.

Next, the invention of claim 4 of the wafer dividing method will be described.

The invention of claim 4 is an invention in which the order of the adhesive sheet bonding step and the dividing step of the invention of claim 3 is reversed.

That is, in the invention of claim 4, the above-mentioned steps are carried out sequentially in the order of the frame holding step, the polishing step, and the modified region forming step of the invention of claim 3 above.

When modified region 210 is formed inside semiconductor wafer 2 along planned dividing line 21 by performing the above-mentioned frame holding step, grinding step and modified region forming step, a dividing step is performed to divide semiconductor wafer 2 along planned dividing line 21 . This dividing step can be carried out as described above using, for example, each of the dividing devices shown in FIGS. 11 , 12 , 13 , and 14 .

After the above-mentioned dividing step is carried out, an adhesive sheet bonding step is carried out in which an adhesive sheet for bonding is bonded to the back surface of the wafer divided into individual chips. That is, as shown in FIG. 28, the above-mentioned dividing process is carried out in a state of being adhered to the dicing tape 70 mounted on the ring frame 7, and the back surface 2b of the semiconductor wafer 2 divided into individual chips 20 is bonded. Adhesive sheet 6 for adhesive sheet. In addition, the adhesive sheet 6 may be the same film as the adhesive sheet used in the invention of the first aspect described above.

After the above-mentioned adhesive sheet bonding step is performed, an expanding step is performed to expand the dicing tape on which the wafers divided into individual chips are bonded to expand the interval between the chips, thereby breaking the adhesive sheet 7 . This expanding step is carried out as shown in Fig. 25(a)(b) using the pick-up device 13 shown in Fig. 15 .

Claims (10)

1, a kind of dividing method of wafer will be cut apart along cutting apart preset lines at the wafer that is provided with function element by the zone of cutting apart the preset lines differentiation that becomes clathrate ground to form on the surface, it is characterized in that comprising following operation:

The guard block bonding process is at the surperficial bonding guard block of wafer;

Grinding step grinds the back side of the wafer of bonding guard block on the surface;

Rotten district forms operation, from by attrition process the rear side of wafer along cutting apart the preset lines irradiation wafer is had radioparent pulse laser light, form rotten district in the inside of wafer along cutting apart preset lines;

The adhesive sheet bonding process is along cutting apart the back side that preset lines has formed the wafer in rotten district, the bonding adhesive sheet that is used for bonding die;

Framework keeps operation, and this adhesive sheet side with the wafer of bonding adhesive sheet is bonded on the section adhesive tape that is installed on ring-shaped frame;

Segmentation process, along the formation that is maintained at the wafer on the framework preset lines of cutting apart in rotten district give external force, wafer is divided into single chip along cutting apart preset lines;

Expansion process with the bonding section adhesive tape expansion that is divided into the wafer of single chip, is widened the interval of each chip chamber, disconnects this adhesive sheet thus; And

Pick up operation, from by the section adhesive tape expanded, each chip of bonding overleaf this adhesive sheet is picked up.

2, the dividing method of the wafer of putting down in writing as claim 1 is characterized in that, forms in operation in this rotten district, exposes formation on the surface of wafer at least in the rotten district that the inside of wafer forms.

As the dividing method of claim 1 or 2 wafers of being put down in writing, it is characterized in that 3, this segmentation process is undertaken by expansion section adhesive tape in this expansion process.

4, a kind of dividing method of wafer will be cut apart along cutting apart preset lines at the wafer that is provided with function element by the zone of cutting apart the preset lines differentiation that becomes clathrate ground to form on the surface, it is characterized in that comprising following operation:

The guard block bonding process is at the surperficial bonding guard block of wafer;

Grinding step grinds the back side of the wafer of bonding guard block on the surface;

Rotten district forms operation, from by attrition process the rear side of wafer along cutting apart the preset lines irradiation wafer is had radioparent pulse laser light, form rotten district in the inside of wafer along cutting apart preset lines;

Segmentation process is given external force along the preset lines of cutting apart of wafer, and wafer is divided into single chip along cutting apart preset lines, and above-mentioned wafer has formed rotten district along cutting apart preset lines;

The adhesive sheet bonding process, at the back side of the wafer that is divided into single chip, the bonding adhesive sheet that is used for bonding die;

Framework keeps operation, and this adhesive sheet side with the wafer of bonding adhesive sheet is bonded on the section adhesive tape that is installed on ring-shaped frame;

Expansion process with the bonding section adhesive tape expansion that is divided into the wafer of single chip, is widened the interval of each chip chamber, disconnects this adhesive sheet thus; And

Pick up operation, from by the section adhesive tape expanded, each chip of bonding overleaf this adhesive sheet is picked up.

5, the dividing method of the wafer of putting down in writing as claim 4 is characterized in that, forms in operation in this rotten district, exposes formation on the surface of wafer at least in the rotten district that the inside of wafer forms.

6, a kind of dividing method of wafer will be cut apart along cutting apart preset lines at the wafer that is provided with function element by the zone of cutting apart the preset lines differentiation that becomes clathrate ground to form on the surface, it is characterized in that comprising following operation:

Framework keeps operation, with the surface of wafer, is bonded on the section adhesive tape that is installed on ring-shaped frame;

Grinding step, grind at the back side that the surface is bonded to the wafer on the section adhesive tape that is installed in framework;

Rotten district forms operation, from by attrition process the rear side of wafer along cutting apart the preset lines irradiation wafer is had radioparent pulse laser light, form rotten district in the inside of wafer along cutting apart preset lines;

The adhesive sheet bonding process is along cutting apart the back side that preset lines has formed the wafer in rotten district, the bonding adhesive sheet that is used for bonding die;

Segmentation process, along the formation that is maintained at the wafer on the framework preset lines of cutting apart in rotten district give external force, wafer is divided into single chip along cutting apart preset lines;

Expansion process with the bonding section adhesive tape expansion that is divided into the wafer of single chip, is widened the interval of each chip chamber, disconnects this adhesive sheet thus; And

Pick up operation, from by the section adhesive tape expanded, each chip of bonding overleaf this adhesive sheet is picked up.

7, the dividing method of the wafer of putting down in writing as claim 6 is characterized in that, forms in operation in this rotten district, exposes formation on the surface of wafer at least in the rotten district that the inside of wafer forms.

As the dividing method of claim 6 or 7 wafers of being put down in writing, it is characterized in that 8, this segmentation process is undertaken by expansion section adhesive tape in this expansion process.

9, a kind of dividing method of wafer will be cut apart along cutting apart preset lines at the wafer that is provided with function element by the zone of cutting apart the preset lines differentiation that becomes clathrate ground to form on the surface, it is characterized in that comprising following operation:

Framework keeps operation, with the surface of wafer, is bonded on the section adhesive tape that is installed on ring-shaped frame;

Grinding step, grind at the back side that the surface is bonded to the wafer on the section adhesive tape that is installed in framework;

Rotten district forms operation, from by attrition process the rear side of wafer along cutting apart the preset lines irradiation wafer is had radioparent pulse laser light, form rotten district in the inside of wafer along cutting apart preset lines;

Segmentation process, along the formation that is maintained at the wafer on the framework preset lines of cutting apart in rotten district give external force, wafer is divided into single chip along cutting apart preset lines;

The adhesive sheet bonding process, at the back side of the wafer that is divided into single chip, the bonding adhesive sheet that is used for bonding die;

Expansion process with the bonding section adhesive tape expansion that is divided into the wafer of single chip, is widened the interval of each chip chamber, disconnects this adhesive sheet thus; And

Pick up operation, from by the section adhesive tape expanded, each chip of bonding overleaf this adhesive sheet is picked up.

10, the dividing method of the wafer of putting down in writing as claim 9 is characterized in that, forms in operation in this rotten district, exposes formation on the surface of wafer at least in the rotten district that the inside of wafer forms.

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