JP5522773B2 - Semiconductor wafer holding method, chip body manufacturing method, and spacer - Google Patents

Description

  The present invention relates to a method for holding a semiconductor wafer having a circuit formed on the front surface and an annular convex portion on the outer periphery of the back surface, a chip body manufacturing method using the holding method, and a spacer used in the holding method.

  After a circuit is formed on the surface of the semiconductor wafer, grinding is performed on the back side of the wafer, and a back grinding process for adjusting the thickness of the wafer and a dicing process for dividing the wafer into a predetermined chip size are performed. With the spread of IC cards in recent years, the semiconductor chip that is a constituent member thereof is being made thinner. For this reason, it has been required to reduce the thickness of a conventional wafer having a thickness of about 350 μm to 50 to 100 μm or less. However, as the semiconductor wafer becomes thinner, the risk of breakage increases during processing and transportation.

  For this reason, as shown in FIGS. 4 to 6, when grinding the back surface of the wafer, it is proposed to grind only the back inner peripheral portion 16 and leave the annular convex portion 17 on the back outer peripheral portion to give the wafer rigidity. (Patent Documents 1, 2, 3, etc.). As shown in FIG. 4, the surface of the wafer 11 has a surplus portion 15 in which a circuit 13 is not formed within a range of several mm from the outer peripheral end, and the circuit 13 is formed on the inner peripheral portion 14 of the wafer excluding the surplus portion. ing. In the wafer having the annular convex portion, the rear inner peripheral portion 16 corresponding to the circuit forming portion (wafer inner peripheral portion 14) on the front surface is ground to a predetermined thickness, and corresponds to the surplus portion 15 where no circuit is formed. The back outer peripheral portion remains without being ground and becomes an annular convex portion 17. Since the annular protrusion 17 has a relatively high rigidity, the wafer 11 ground in the above-described form can be stably transported and stored, and damage during processing is reduced. 5 is a perspective view from the back surface side where the annular convex portion 17 is formed, and FIG. 6 is a cross-sectional view of FIG.

When the back surface of the semiconductor wafer as described above is held on the table, a space is formed between the back surface inner peripheral portion 16 and the table. For this reason, it has been proposed to attach a die-bonding adhesive film to the inner surface 16 of the back surface of the semiconductor wafer, and then apply a dicing tape to the back surface of the semiconductor wafer for dicing (Patent Document 4).
Japanese Unexamined Patent Publication No. 2007-19379 JP 2007-266352 A JP 2007-287796 JP 2007-73767

  When dicing a semiconductor wafer, the entire back surface of the wafer is fixed with an adhesive sheet called a dicing sheet, and the outer periphery of the dicing sheet is fixed with a ring frame. Thereafter, dicing is performed along the streets between the circuits while recognizing the circuit pattern from the wafer surface side. During dicing, the wafer is fully cut to create a chip, and the dicing depth is set so as not to cut the dicing sheet. As a result, the generated chip is held on the dicing sheet, and then the chip is picked up by a predetermined means.

  However, when only the inner peripheral portion of the back surface of the wafer is ground as described above and the annular convex portion is left on the outer peripheral portion, there is a space between the inner peripheral portion 16 of the back surface and the dicing sheet. At the portion, the inner periphery of the wafer hangs down, making it difficult to perform dicing. Further, even when a die-bonding adhesive film is attached to the space between the back inner peripheral part 16 and the dicing sheet, the die-bonding adhesive film is not thick enough to fill the space. Hangs down, making dicing difficult, and may cause wafer cracking.

  Therefore, in the present invention, only the back inner peripheral portion of the wafer is ground, the outer peripheral portion has an annular convex portion, and the wafer rear surface in which a step is formed between the inner peripheral plane and the annular convex portion, A semiconductor wafer holding method in which a spacer capable of suppressing wafer vibration during dicing is attached to the inner surface of the back surface, and a dicing sheet is attached to the back surface of the wafer via the spacer, a chip body manufacturing method using the holding method, and the It aims at providing the spacer used for the holding | maintenance method.

The gist of the present invention aimed at solving such problems is as follows.
(1) A spacer having an adhesive layer is attached to a region surrounded by the annular convex portion of the semiconductor wafer having a circuit formed on the front surface and an annular convex portion on the outer peripheral portion of the back surface,
A method for holding a semiconductor wafer, comprising attaching a dicing sheet to the back surface of the semiconductor wafer via the spacer.
(2) The semiconductor wafer is held by the method for holding a semiconductor wafer of (1) above, and the semiconductor wafer is separated into pieces to produce chips.
A method of manufacturing a chip body for picking up the chip.
(3) A spacer formed by laminating or laminating an adhesive film comprising a base material and an adhesive layer formed thereon.

  According to the present invention, a spacer is affixed to a region surrounded by an annular convex portion of a semiconductor wafer 11 having a circuit 13 formed on the front surface and an annular convex portion 17 on the outer peripheral portion of the rear surface, and dicing is performed on the rear surface of the wafer via the spacer. By sticking the sheet, vibration of the wafer can be suppressed during dicing, and a chip body can be manufactured without causing damage or chipping of the wafer.

  Hereinafter, preferred embodiments of the present invention will be described more specifically with reference to the drawings, including the best mode.

  In the semiconductor wafer holding method of the present invention, as shown in FIG. 1, a circuit 13 is formed on the front surface, and the region surrounded by the annular convex portion 17 of the semiconductor wafer 11 having the annular convex portion 17 on the back surface outer peripheral portion, A spacer 40 having an outer diameter slightly smaller than the inner diameter of the annular convex portion 17 is attached, and the dicing sheet 10 is attached via the spacer 40. 2 and 3 are the spacers of the present invention, FIG. 4 is a plan view of the circuit surface side of the semiconductor wafer 11 having the circuit 13 formed on the front surface and the annular protrusion 17 on the back outer peripheral portion, and FIG. The perspective view from the back surface side in which the part 17 was formed, FIG. 6 shows sectional drawing of FIG.

  The semiconductor wafer 11 may be a silicon wafer or a compound semiconductor wafer such as gallium / arsenic. The formation of the circuit 13 on the wafer surface can be performed by various methods including conventionally used methods such as an etching method and a lift-off method. In the circuit forming process of the semiconductor wafer, a predetermined circuit 13 is formed. The circuit 13 is formed in a lattice pattern on the surface of the inner peripheral portion 14 of the wafer 11, and a surplus portion 15 that does not have a circuit remains in a range of several mm from the outer peripheral end. The thickness of the wafer 11 before grinding is not particularly limited, but is usually about 500 to 1000 μm.

  At the time of back grinding, an adhesive sheet called a surface protective sheet is attached to the circuit surface in order to protect the circuit 13 on the surface. In the back surface grinding, the circuit surface side (that is, the surface protection sheet side) of the wafer 11 is fixed by a chuck table or the like, and the back surface side where the circuit 13 is not formed is ground by a grinder. At the time of back surface grinding, first, the entire back surface is ground to a predetermined thickness, and then only the back surface inner peripheral portion 16 corresponding to the circuit forming portion (inner peripheral portion 14) on the front surface is ground, and the surplus portion 15 where the circuit 13 is not formed. The back surface area corresponding to is left without being ground. As a result, in the semiconductor wafer 11 after grinding, only the inner peripheral portion 16 on the back surface is further thinly ground, and the annular convex portion 17 remains on the outer peripheral portion. Such back surface grinding can be performed by, for example, a known method described in Patent Documents 1 to 3 described above.

  The total thickness T1 (see FIG. 6) of the annular convex portion 17 is not particularly limited as long as it provides the wafer with the necessary rigidity and does not impair the handling properties, and is generally about 400 to 725 μm. . The width of the annular convex portion is about the width of the surplus portion 15, and is generally about 2 to 5 mm. The thickness T2 of the inner peripheral portion 16 depends on the device design, and is usually about 25 to 200 μm. Therefore, the step (T1-T2) between the plane of the inner peripheral portion 16 and the annular convex portion 17 is about 200 to 700 μm.

  After the back grinding process, a process of removing the crushed layer generated by grinding may be performed. Further, following the back surface grinding step, if necessary, the back surface may be subjected to processing involving heat generation such as etching processing, metal film deposition on the back surface, or processing performed at a high temperature such as organic film baking. . According to the wafer 11 in which only the inner peripheral portion 16 on the back surface is ground to a predetermined thickness and the annular convex portion 17 is provided on the outer peripheral portion, the annular convex portion 17 has high rigidity, so that the wafer is not damaged. , Storage, processing, etc. can be performed.

  After the back surface grinding step, as shown in FIG. 1, a spacer 40 having an outer diameter slightly smaller than the inner diameter of the annular convex portion 17 is attached to a region surrounded by the annular convex portion 17 on the grinding surface side of the wafer 11. The wafer 11 is diced by attaching the dicing sheet 10 to the back surface of the wafer via 40. Dicing is performed along dicing street DS (see FIG. 4) formed on the wafer surface so as to separate the circuits 13 into individual pieces. In addition, the surface protection sheet stuck on the wafer surface may be peeled off before the dicing sheet 10 is stuck, or may be peeled off after the dicing sheet 10 is stuck. Moreover, you may peel the surface protection sheet which protected the circuit from the chip | tip surface separated into pieces after completion | finish of a dicing process.

  In the method for holding a semiconductor wafer according to the present invention, the spacer 40 is attached to the inner surface 16 of the wafer back surface by attaching only the spacer 40 to the inner surface 16 of the wafer back surface using a device called a mounter (bonding device). A method of sticking the dicing sheet 10 to the back surface of the wafer through the spacer 40, or sticking the spacer 40 to the dicing sheet 10 and sticking the spacer 40 with a device called a mounter so as to fit the inner peripheral portion 16 of the back surface of the wafer. By the method. In particular, the pasting is preferably performed under vacuum (reduced pressure atmosphere).

  The spacer 40 has an adhesive layer 42. The pressure-sensitive adhesive layer 42 is formed on one side of the base material 41, and the base material 41 is formed by laminating a single layer of resin film or a resin film described later. The number of laminated resin films is not particularly limited. In FIG. 3, the spacer 40 is formed by forming the adhesive layer 42 on the four-layered resin film laminate in which the resin films 41e, 41f, 41g, and 41h are laminated. Become. The material of the resin film to be laminated may be the same or different.

  Moreover, you may form the spacer 40 by laminating | stacking the adhesive film which formed the adhesive layer on the resin film. The number of the adhesive films laminated is not particularly limited. In FIG. 2, the spacer 40 has four layers in which the adhesive layers 42a (42), 42b, 42c, and 42d are formed on the resin films 41a, 41b, 41c, and 41d. It consists of an adhesive film. That is, the spacer 40 only needs to form the pressure-sensitive adhesive layer 42 on the sticking surface to the back inner peripheral portion 16 of the wafer 11. The material of the resin film and the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive film to be laminated may be the same or different.

  The thickness of the spacer 40 is appropriately selected according to a step (T1-T2) between the plane of the inner peripheral surface 16 of the back surface of the semiconductor wafer 11 and the annular convex portion 17, preferably 95 to 105% of the step, particularly preferably. Is 97 to 100% of the step.

  The outer diameter of the spacer 40 is appropriately selected depending on the inner diameter of the annular convex portion 17 of the semiconductor wafer 11, and is preferably 95 to 100% of the inner diameter.

  The Young's modulus of the spacer 40 is preferably 1000 MPa or more, more preferably 1000 to 10000 MPa, and particularly preferably 2000 to 6500 MPa. When the Young's modulus of the spacer 40 is in the above range, vibrations when dicing the wafer can be suppressed, and wafer cracking and chipping can be prevented. When the Young's modulus is greater than 10,000 MPa, the wafer dicing is not affected, but the spacer may be difficult to peel off after dicing.

  The material of the resin film used for the spacer 40 is not particularly limited as long as the physical properties are satisfied. For example, polyethylene terephthalate film, polyethylene naphthalate film, polyimide film, polypropylene film, polyvinyl chloride film, vinyl chloride copolymer A film, a polyurethane film, a polystyrene film, a polycarbonate film, a fluororesin film, a film made of a water additive or a modified product thereof, and the like are used. These crosslinked films are also used. The above-mentioned substrate may be a single type, or may be a composite film in which two or more types are combined.

  Further, as will be described later, when the pressure-sensitive adhesive layer 42 is formed of an ultraviolet curable pressure-sensitive adhesive and ultraviolet rays are used as energy rays to be irradiated to cure the pressure-sensitive adhesive, a resin film that is transparent to the ultraviolet rays is used. preferable. In addition, since it does not need to be transparent when using an electron beam as an energy beam, the transparent film which colored these other than said film, an opaque film, etc. can be used.

  Moreover, in order to improve adhesiveness with an adhesive, the upper surface of a resin film, ie, the resin film surface on the side where the adhesive layer 42 is provided, may be subjected to corona treatment or a primer layer. Various coating films may be applied to the surface opposite to the pressure-sensitive adhesive layer 42. The spacer 40 is manufactured by using the resin film as described above and providing an adhesive layer 42 thereon.

  The pressure-sensitive adhesive layer 42 is preferably formed of a weakly viscous pressure-sensitive adhesive having removability or an ultraviolet curable pressure-sensitive adhesive.

  Moreover, the thickness of the adhesive layer 42 is preferably 3 to 20 μm, more preferably 5 to 10 μm. If the thickness of the pressure-sensitive adhesive layer 42 is too thin, sufficient adhesive strength may not be obtained. On the other hand, if the pressure-sensitive adhesive layer 42 is too thick, the wafer may vibrate when the wafer 11 is diced, and chipping may occur.

  The pressure-sensitive adhesive layer 42 can be formed of various conventionally known pressure-sensitive adhesives. Such an adhesive is not limited at all, but an adhesive such as rubber-based, acrylic-based, silicone-based, or polyvinyl ether is used. In addition, an energy ray curable adhesive, a heat-foaming adhesive, or a water swelling adhesive can be used. As the energy ray curable (UV curable, electron beam curable, etc.) type adhesive, it is particularly preferable to use an ultraviolet curable adhesive. Note that a release sheet may be laminated on the pressure-sensitive adhesive layer 42 in order to protect the pressure-sensitive adhesive layer before use.

  The release sheet is not particularly limited. For example, a film made of a resin such as polyethylene terephthalate, polypropylene, or polyethylene or a foamed film thereof, paper such as glassine paper, coated paper, laminated paper, silicone-based, fluorine A system and a release agent such as a long chain alkyl group-containing carbamate can be used.

  The method of providing the pressure-sensitive adhesive layer 42 on the surface of the resin film may be a method in which the pressure-sensitive adhesive layer formed by applying a predetermined thickness on the release sheet may be transferred to the surface of the resin film, or directly applied to the surface of the resin film. Then, the pressure-sensitive adhesive layer 42 may be formed.

  In order to satisfy the specific physical properties as described above, the spacer 40 securely holds the wafer 11 and the chip 12 when dicing the wafer, prevents sagging of the inner peripheral portion of the wafer, suppresses vibration, and breaks the wafer. And chipping can be prevented.

  The dicing sheet 10 includes a base material 1 and an adhesive layer 2 formed on one surface thereof. The dicing sheet 10 is not particularly limited as long as it can be attached to the back surface of the wafer via the spacer 40 and can hold the wafer 11.

  Although the material of the base material 1 used for the dicing sheet 10 is not particularly limited, for example, a low density polyethylene (LDPE) film, a linear low density polyethylene (LLDPE) film, a high density polyethylene (HDPE) film, a polypropylene film, Polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate copolymer film, ionomer resin film, ethylene (Meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, fluororesin Irumu, and the film is used consisting of the hydrogenated product or modified product or the like. These crosslinked films are also used. The above-mentioned base material may be one kind alone, or may be a composite film in which two or more kinds are combined.

  As will be described later, when the pressure-sensitive adhesive layer 2 is formed of an ultraviolet curable pressure-sensitive adhesive and ultraviolet rays are used as energy rays to be irradiated to cure the pressure-sensitive adhesive, a substrate that is transparent to the ultraviolet rays is used. preferable. In addition, since it does not need to be transparent when using an electron beam as an energy beam, the transparent film which colored these other than said film, an opaque film, etc. can be used.

  Moreover, in order to improve adhesiveness with an adhesive, the upper surface of the base material 1, ie, the base material surface on the side where the adhesive layer 2 is provided, may be subjected to corona treatment or a primer layer. Various coatings may be applied to the surface opposite to the pressure-sensitive adhesive layer 2. The dicing sheet 10 is manufactured by providing a pressure-sensitive adhesive layer on the substrate as described above.

  The pressure-sensitive adhesive layer 2 can be formed of various conventionally known pressure-sensitive adhesives. Such an adhesive is not limited at all, but an adhesive such as rubber-based, acrylic-based, silicone-based, or polyvinyl ether is used. In addition, an energy ray curable adhesive, a heat-foaming adhesive, or a water swelling adhesive can be used. As the energy ray curable (UV curable, electron beam curable, etc.) type adhesive, it is particularly preferable to use an ultraviolet curable adhesive. The pressure-sensitive adhesive layer 2 may be laminated with a release sheet to protect the pressure-sensitive adhesive layer before use.

  The release sheet is not particularly limited. For example, a film made of a resin such as polyethylene terephthalate, polypropylene, or polyethylene or a foamed film thereof, paper such as glassine paper, coated paper, laminated paper, silicone-based, fluorine A system and a release agent such as a long chain alkyl group-containing carbamate can be used.

  The method of providing the pressure-sensitive adhesive layer 2 on the surface of the substrate 1 may be such that the pressure-sensitive adhesive layer 2 applied and formed on the release sheet so as to have a predetermined film thickness may be transferred to the surface of the substrate 1. The pressure-sensitive adhesive layer 2 may be formed by coating directly on the surface.

  The chip body manufacturing method uses the semiconductor wafer holding method of the present invention to divide the semiconductor wafer 11 into pieces (dicing) to produce chips and pick up the chips. As an example, when the wafer 11 is diced, the peripheral portion of the dicing sheet 10 is fixed by the ring frame 5, and then the wafer 11 is formed into chips by a known technique such as using a rotating round blade such as the dicing blade 3 to pick up the chips. The method etc. are mentioned. According to the method for manufacturing a chip body according to the present invention, the vibration of the wafer during dicing can be suppressed and the wafer and the chip can be securely held, thereby improving the yield of the chip and preventing the dicing apparatus from being damaged by the scattering of the chip. it can. If the adhesive layer 42 of the spacer 40 is formed of an ultraviolet curable adhesive, the pickup of the chip 12 is performed by irradiating the adhesive layer 42 with ultraviolet rays to reduce the adhesive force prior to the pickup of the chip 12. Can be easily performed.

  In addition, after the dicing is completed, the chips may be picked up after transferring the chips arranged on the dicing sheet 10 to another adhesive sheet for picking up.

  Thereafter, the picked-up chip 12 is die-bonded and resin-sealed by a conventional method to manufacture a semiconductor device.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. In the following examples and comparative examples, a silicon wafer having the following shape and the following pressure-sensitive adhesive composition were used. In addition, the Young's modulus and dicing suitability of the spacers in Examples and Comparative Examples were evaluated as follows.

(Wafer shape)
Outer diameter: 150mm
Inner diameter of annular projection: 145mm
Inner peripheral thickness: 100 μm
Annular projection thickness: 400 μm

(Adhesive composition A)
Polyisocyanate compound (Coronate L (manufactured by Nippon Polyurethane Co., Ltd.)) 1 with respect to a 30% by weight toluene solution of an acrylic copolymer (weight average molecular weight 600,000) consisting of 90 parts by weight of butyl acrylate and 10 parts by weight of acrylic acid The weight part was mixed and the adhesive composition A was obtained.

(Adhesive composition B)
A polyisocyanate compound (coronate) was added to a 30% by weight toluene solution of an acrylic copolymer (weight average molecular weight 600,000) consisting of 80 parts by weight of butyl acrylate, 15 parts by weight of methyl methacrylate, and 5 parts by weight of 2-hydroxyethyl acrylate. L (manufactured by Nippon Polyurethane Co., Ltd.)) 3 parts by weight was mixed to obtain an adhesive composition B.

(Adhesive composition C)
A polyvalent isocyanate compound (coronate) was added to a 30% by weight toluene solution of an acrylic copolymer (weight average molecular weight 580,000) comprising 75 parts by weight of butyl acrylate, 17 parts by weight of methyl methacrylate, and 8 parts by weight of 2-hydroxyethyl acrylate. 5 parts by weight of L (manufactured by Nippon Polyurethane Co., Ltd.) was mixed to obtain an adhesive composition C.

(Young's modulus of spacer)
The Young's modulus of the spacer was measured at a tensile speed of 200 mm / min using an autograph manufactured by Shimadzu Corporation in accordance with JIS K7161: 1994 (sample size: 15 mm × 100 mm).

(Dicing conditions)
The dicing of the wafer was performed using a dicing machine (model number: DFD651) manufactured by DISCO Corporation with a cutting speed of 80 mm / second, a chip size of 2 mm square, and a cutting depth of 30 μm into the dicing sheet.

(Dicing aptitude)
The presence or absence of chip scattering, wafer cracking, chip end chipping (chipping) during dicing was inspected, and when chips were scattered, the wafer was cracked, or chipping occurred, it was determined as “bad”.

<Example 1>
(Spacer production)
As the resin film, a polyethylene terephthalate (PET) film having a thickness of 50 μm was used. After the adhesive composition A was applied on the resin film so that the thickness after drying was 25 μm, it was dried (100 ° C., 1 minute). The adhesive film A which has an adhesive layer was obtained.

  Subsequently, the adhesive layer of the adhesive film A was bonded to the resin film of the adhesive film A prepared separately. This process was repeated twice in total to obtain a laminated adhesive film A having a total thickness of 225 μm.

  In addition to the adhesive film A, a PET film having a thickness of 50 μm was used as the resin film, and the adhesive composition B was applied on the resin film so that the thickness after drying was 25 μm, and then dried (100 And adhesive film B having an adhesive layer was produced.

  The pressure-sensitive adhesive layer of the laminated pressure-sensitive adhesive film A was bonded to the resin film of the pressure-sensitive adhesive film B and cut into a circle having a diameter of 143 mm to obtain a spacer having a total thickness of 300 μm.

(Production of dicing sheet)
The pressure-sensitive adhesive composition C was applied on a 38 μm-thick PET film (SP-PET3811 (S) (manufactured by Lintec Corporation) having been subjected to a silicone-based release treatment so that the thickness after drying was 10 μm and dried (100 ° C. 1 minute) to form an adhesive layer. A polyvinyl chloride film having a thickness of 80 μm was used as a substrate for the dicing sheet, and the pressure-sensitive adhesive layer was bonded to the substrate and transferred, and the peeled PET film was peeled off to obtain a dicing sheet having a total thickness of 90 μm.

  Using the spacer, a pressure-sensitive adhesive layer of the spacer was attached to the inner periphery of the back surface of the wafer by a vacuum bonding apparatus (RAD3800m / 12 (manufactured by Lintec Corporation)). Next, the dicing sheet was attached to the back surface of the wafer via a spacer, the dicing sheet surface was held on a flat chuck table, and the wafer was diced to pick up chips. Table 1 shows the Young's modulus and dicing suitability of the spacer.

<Example 2>
A spacer and a dicing sheet were obtained and evaluated in the same manner as in Example 1 except that the resin film used for the spacer was a polyimide film. Table 1 shows the Young's modulus and dicing suitability of the spacer.

<Example 3>
A spacer and a dicing sheet were obtained and evaluated in the same manner as in Example 1 except that the resin film used for the spacer was a polyethylene naphthalate film. Table 1 shows the Young's modulus and dicing suitability of the spacer.

<Comparative Example 1>
A wafer was held on a flat chuck table via a dicing sheet without using a spacer, and dicing was performed in the same manner as in Example 1. Table 1 shows the dicing suitability.

<Comparative example 2>
The wafer was held via a dicing sheet on a chuck table on which a stainless steel plate having a shape that fits with the inner periphery of the back surface of the wafer was used without using a spacer, and dicing was performed in the same manner as in Example 1. Table 1 shows the dicing suitability.

  When the spacers of Examples 1 to 3 were used, they could be used without any problem even in the dicing process.

  When dicing is performed by holding the wafer on a flat chuck table without using a spacer (Comparative Example 1), there is a space between the inner peripheral portion of the back surface of the wafer and the chuck table, so that the inner peripheral portion of the wafer is During the dicing, it hangs down to the chuck table side, the dicing blade could not cut the wafer, and the chips could not be separated. In addition, wafer cracking occurred.

  When the wafer is held and diced (Comparative Example 2) on a chuck table in which a stainless steel plate having a shape that fits with the inner peripheral portion of the back surface of the wafer is disposed without using the spacer, the inner peripheral portion of the wafer is Since the wafer was not fixed to the chuck table, the wafer vibrated during dicing and chipping occurred.

1 shows a chip holding method and a dicing method using the holding method according to the present invention. 1 shows a spacer according to the present invention. 1 shows a spacer according to the present invention. The top view of the circuit formation surface of a semiconductor wafer is shown. The perspective view of the semiconductor wafer in which the annular convex part was formed in the back peripheral part is shown. FIG. 6 shows a cross-sectional view of FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base material of dicing sheet 2 ... Adhesive layer 3 of dicing sheet ... Dicing blade 5 ... Ring frame 10 ... Dicing sheet 11 ... Semiconductor wafer (wafer)
12 ... Semiconductor chip (chip)
DESCRIPTION OF SYMBOLS 13 ... Circuit 14 ... Circuit surface inner peripheral part 15 ... Excess part 16 ... Back surface inner peripheral part 17 ... Ring-shaped convex part 40 ... Spacer 41 ... Base material 41a-41h ... Resin film 42 ... Adhesive layer 42a-42d ... Adhesive layer

Claims (4)

Circuits are formed on the front surface, and a spacer having an adhesive layer is attached to a region surrounded by the annular protrusions of the semiconductor wafer having an annular protrusion on the outer periphery of the back surface,
A semiconductor wafer holding method for attaching a dicing sheet to the back surface of a semiconductor wafer via the spacer,
The pressure-sensitive adhesive layer have a removability,
The spacer is a pressure-sensitive adhesive film composed of a base material and a pressure-sensitive adhesive layer formed thereon or a laminate thereof, and the thickness of the spacer is a region surrounded by the annular convex portion and the annular convex portion. A method for holding a semiconductor wafer, which is 95 to 105% of the level difference therebetween .   The method for holding a semiconductor wafer according to claim 1, wherein the spacer has a Young's modulus of 1000 MPa or more. A semiconductor wafer is held by the method for holding a semiconductor wafer according to claim 1 or 2, the semiconductor wafer is singulated to produce a chip,
A method of manufacturing a chip body for picking up the chip.   A spacer formed by a single layer or a laminate of an adhesive film comprising a base material and an adhesive layer formed thereon, which is used in the method for holding a semiconductor wafer according to claim 1.

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