JP4503429B2 - Manufacturing method of semiconductor device - Google Patents

Description

  The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device capable of forming an appropriate amount of an adhesive layer on a bonding surface of an individual chip.

  Semiconductor wafers such as silicon and gallium arsenide are manufactured in a large diameter state, and the wafer is cut and separated (diced) into element small pieces (IC chips) and then transferred to a mounting process which is the next process. At this time, the semiconductor wafer is subjected to dicing, cleaning, drying, expanding, and pick-up processes in a state of being adhered to the adhesive tape in advance, and then transferred to the next bonding process.

  In such a process, the picked-up chip is usually transferred to a die bonding step, which is the next step, after an adhesive layer is formed on the back surface. However, with the miniaturization of the chip, it is difficult to apply an appropriate amount of adhesive to the back surface of the chip.

  For this reason, in order to simplify the processes of the pick-up process and the bonding process, a so-called direct die bonding process using a dicing / die bonding adhesive sheet having both a wafer fixing function and a die bonding function has been proposed. (For example, Patent Documents 1 to 3).

  This adhesive sheet for dicing / die bonding is composed of an adhesive layer made of a specific composition and a base material. In the dicing process, the adhesive layer has a function of fixing the wafer. At the time of dicing, the adhesive layer is cut together with the wafer, and an adhesive layer having the same shape as the cut chip is formed. When the chip is picked up after the dicing is completed, the adhesive layer is peeled off together with the chip. When the IC chip with the adhesive layer is placed on the substrate and heated, the thermosetting resin in the adhesive layer exhibits an adhesive force, and the adhesion between the IC chip and the substrate is completed. According to such a direct die bonding process, not only the above-described adhesive application process to the chip back surface can be omitted, but also an appropriate amount of adhesive layer can be easily applied to the chip back surface even for a small chip. It becomes possible to form.

  On the other hand, as a method for achieving thinning of a chip, Patent Document 4 discloses a method for manufacturing a semiconductor chip in which a groove having a predetermined depth is formed from the front side of a wafer and then ground from the back side. Further, Patent Document 4 discloses a method in which, after the back surface grinding step, the pellets attached to the mounting tape are separated from the mounting tape and fixed to the lead frame. This method is also called a “first dicing method” and is an effective means for obtaining an ultrathin chip.

  However, in such a tip dicing method, wafer singulation (chip formation) is completed when grinding of the back surface of the wafer is completed. If the above-mentioned dicing / die-bonding adhesive sheet is applied to the tip dicing method, it is applied directly to the wafer-shaped chip group, and only the adhesive layer of the dicing / die-bonding adhesive sheet is separated. It was necessary to cut into chip sizes in this process.

In order to solve such a problem, in Patent Document 5, “a groove having a depth of cut shallower than the wafer thickness is formed from the wafer surface on which the semiconductor circuit is formed, and a surface protection sheet is attached to the circuit surface. In addition to reducing the thickness of the wafer by grinding the back surface of the semiconductor wafer, the wafer is finally divided into individual chips, and the ground surface is divided into a base material and an adhesive layer formed thereon. The dicing die bond sheet is attached, the surface protection sheet is peeled off, the adhesive layer of the dicing die bond sheet exposed between the chips is cut, and the adhesive layer together with the chips is combined with the dicing die bond sheet. A method for manufacturing a semiconductor device, which is peeled from a base material and a chip is fixed on a predetermined base via the adhesive layer ”is disclosed.

However, such a method requires a cutting device that can perform extremely precise processing for cutting the adhesive layer, and is not an excellent method in terms of workability, yield, and cost.
JP-A-2-32181 JP-A-8-239636 Japanese Patent Laid-Open No. 10-8001 JP-A-5-335411 Japanese Patent Laid-Open No. 2001-156027

  The present invention has been made in view of the prior art as described above, and provides a method for manufacturing a semiconductor device in which an appropriate amount of adhesive can be easily applied to a bonding surface of a microchip and contamination on a circuit surface can be reduced. It is intended to provide.

The gist of the present invention aimed at solving such problems is as follows.
(1) Adhesive for an adhesive sheet in which a wafer-shaped chip group obtained by dividing a semiconductor wafer is composed of a stretchable base material and an adhesive layer of a brittle body laminated so as to be peelable from the base material A step of bonding the bonding surface of the chip group on the layer;
A step of breaking the adhesive layer of the adhesive sheet while separating the interval between the chips by expanding the adhesive sheet;
A method for manufacturing a semiconductor device, comprising a step of picking up a chip with an adhesive layer and bonding through an adhesive layer formed on a bonding surface.
(2) The adhesive sheet has a Young's modulus of the substrate at room temperature (23 ° C.) of 500 MPa or less,
The method for producing a semiconductor device according to (1), wherein the adhesive layer has a breaking elongation of 1 to 350% and a breaking stress of 1000 N / cm ² or less.
(3) The method for manufacturing a semiconductor device according to (1), wherein the adhesive layer of the brittle body is obtained by subjecting the adhesive layer to a brittleness treatment.
(4) The method for manufacturing a semiconductor device according to (3), wherein the embrittlement treatment is that the adhesive layer is thermosetting or energy ray curable and is subjected to the hardening treatment. . (5) The method for manufacturing a semiconductor device according to (3), wherein the embrittlement treatment is a cooling treatment.
(6) The method for manufacturing a semiconductor device according to (1), wherein the adhesive layer is broken by applying a mechanical impact to the adhesive sheet before the chip interval is expanded by the expand.
(7) The method of manufacturing a semiconductor device according to (6), wherein the mechanical impact is ultrasonic vibration.
(8) Adhering to the bonding surface of a semiconductor wafer an adhesive surface of an adhesive sheet comprising an extendable base material and an adhesive layer of a brittle body laminated so as to be peelable from the base material; By cutting the wafer and separating the semiconductor wafer so that the adhesive layer of the adhesive sheet is not cut,
A wafer-shaped chip group in which semiconductor wafers are singulated is formed on an adhesive layer of an adhesive sheet including an extendable base material and an adhesive layer of a brittle body that is laminated so as to be peelable from the base material. The method for manufacturing a semiconductor device according to (1), wherein the bonding surface of the chip group is adhered.
(9) After forming a wafer-shaped chip group by dividing the semiconductor wafer into individual pieces, an adhesive sheet comprising an extendable base material and an adhesive layer of a brittle body laminated so as to be peelable from the base material By sticking the adhesive surface of the chip to the bonding surface of the chip group,
A wafer-shaped chip group in which semiconductor wafers are singulated is formed on an adhesive layer of an adhesive sheet including an extendable base material and an adhesive layer of a brittle body that is laminated so as to be peelable from the base material. The method for manufacturing a semiconductor device according to (1), wherein the bonding surface of the chip group is adhered.
(10) A semiconductor wafer in which chips are connected via a fragile portion formed inside a semiconductor wafer is composed of an extendable base material and an adhesive layer of a brittle body laminated so as to be peelable from the base material. A step of bonding the bonding surface of the chip group on the adhesive layer of the adhesive sheet,
By expanding the adhesive sheet, the semiconductor wafer is broken and separated into pieces starting from the fragile portion, and at the same time, the gap between the chips is separated and the adhesive layer of the adhesive sheet is broken.
A method for manufacturing a semiconductor device, comprising a step of picking up a chip with an adhesive layer and bonding through an adhesive layer formed on a bonding surface.
(11) By irradiating a laser beam focused on the inside of the semiconductor wafer along a planned cutting line that divides each circuit of the semiconductor wafer, and locally modifying the inside of the semiconductor wafer to form a fragile portion, The method for manufacturing a semiconductor wafer according to (10), further comprising a step of obtaining a semiconductor wafer in which chip groups are connected via a fragile portion formed inside the semiconductor wafer.

  According to the method for manufacturing a semiconductor device according to the present invention, since the adhesive layer of the adhesive sheet is in a brittle state, the adhesive layer has the same shape as the chip at the time of expansion or when a mechanical impact is applied. Break into pieces. Therefore, it becomes easy to form an appropriate amount of adhesive layer on the bonding surface of individual chips, and a newly required manufacturing apparatus is unnecessary or can be handled by adding a simple apparatus. It is inexpensive and has excellent workability.

Hereinafter, the present invention will be described more specifically with reference to the drawings.
The method for manufacturing a semiconductor device according to the present invention includes the following steps 1 to 3 as essential steps.
Step 1: An adhesive for an adhesive sheet in which a wafer-shaped chip group obtained by dividing a semiconductor wafer is composed of a stretchable base material and an adhesive layer of a brittle body laminated so as to be peelable from the base material. The process which makes the bonding surface of this chip group affixed on the layer (refer FIG. 1A and B)
As shown in FIG. 1A, in the chip group 1, a large number of chips 3 are stuck to the adhesive sheet 10 while maintaining the wafer shape, and the solid lines on the surface of the chip group 1 are cutting lines dividing each circuit. 2. Therefore, the adhesive layer 12 is exposed in the cutting line 2. 1B is a cross-sectional view taken along the line aa in FIG. 1A.

  The chip 3 is obtained by forming a circuit on a conventionally used silicon semiconductor wafer, gallium arsenide semiconductor wafer or the like and then separating the circuit into pieces. However, the semiconductor wafer is not limited to these, and various semiconductor wafers can be obtained. Can be used. Formation of a circuit 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 semiconductor wafer circuit forming step, a predetermined circuit is formed. The thickness of the chip 3 is not particularly limited. However, since the manufacturing method of the present invention is particularly effective for an ultrathin chip, the thickness of the chip 3 is preferably 200 μm or less, and more preferably about 30 to 150 μm.

In the present invention, the bonding surface of the chip usually indicates the back surface of the chip, but when the circuit surface side is bonded to the substrate as in flip chip bonding, it indicates the circuit forming surface.

  The means for realizing the state in which the bonding surface side of the wafer-shaped chip group 1 is attached to the adhesive sheet 10 as shown in FIG. 1 is not particularly limited. As a result, any route may be used as long as the state shown in FIG. 1 is realized.

  For example, the semiconductor wafer may be diced using a normal dicing sheet and transferred to the adhesive sheet 10 to achieve a state where the chip group maintains the wafer shape on the adhesive sheet 10. Moreover, the same shape can be made by using the adhesive sheet 10 as a dicing sheet and dicing (semi-full cut) only the semiconductor wafer into chips so as not to cut the adhesive layer 12 of the adhesive sheet 10.

  Further, instead of a dicing apparatus using a dicing blade, a dicing apparatus using a laser beam (laser dicer) may be used. Since the laser dicer controls the focal point of the laser beam to divide the wafer, it is easy to control so that the adhesive layer is not cut together. If the adhesive layer is cut with a laser beam together with the wafer, the volatile decomposition component of the adhesive may adhere to the circuit surface and become contaminated, so the method of the present invention is effective.

  Further, dicing may be performed by a method known as stealth dicing. The stealth dicing method is a dicing method in which only the inside of the wafer is focused and irradiated with a laser to modify the focal part, and then the locus is broken by stress, so the adhesive layer is cut simultaneously. Can not do it. For this reason, the method of the present invention is particularly effective.

  In the stealth dicing method, a fragile portion is formed in a semiconductor wafer along a planned cutting line that divides each circuit of the semiconductor wafer. In this state, each chip group is connected via the fragile portion, and the wafer shape is maintained as a whole. The formation of the fragile portion is performed by irradiating the semiconductor wafer with a laser beam along the planned cutting line. The inside of the wafer is locally heated by the laser light irradiation and modified by a change in crystal structure or the like. The modified part is overstressed and potentially fragile compared to surrounding sites. Therefore, when a stress is applied to the semiconductor wafer, cracks grow in the vertical direction of the wafer starting from the fragile portion, and the wafer can be divided into chips.

Details of the stealth dicing method are described in, for example, “Electronic Materials, September 2002, pp. 17-21”, JP-A-2003-88982.
Moreover, you may apply what is called the previous dicing mentioned above. That is, a groove having a depth of cut shallower than the wafer thickness is formed from the surface of the wafer on which the semiconductor circuit is formed, a surface protection sheet is adhered to the circuit surface, and the back surface of the semiconductor wafer is ground. In addition to reducing the thickness and finally dividing into individual chips 3, the adhesive sheet 10 is attached to the ground surface, and the surface protective sheet is peeled off, whereby the chip group is formed on the adhesive sheet 10. May be aligned in a wafer shape.

The adhesive sheet 10 includes a base material 11 and an adhesive layer 12 formed thereon. The adhesive sheet 10 can take any shape such as a tape shape or a label shape.
Hereinafter, the substrate 11 and the adhesive layer 12 will be described.

A stretchable film is used as the base material 11 of the adhesive sheet 10. For example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, and a polyurethane are used. A single layer or laminated film such as a film, an ethylene vinyl acetate film, an ionomer resin film, an ethylene / (meth) acrylic acid copolymer film, an ethylene / (meth) acrylic acid ester copolymer film, or a fluororesin film is used. Moreover, these crosslinked films may be sufficient. Furthermore, when the adhesive layer 12 described later is ultraviolet curable, a transparent (ultraviolet transmissive) film is used as the substrate 11, but the adhesive layer 12 is non-curable or electron beam curable. In some cases, opaque films can also be used.

  Among these films, a film having a Young's modulus (23 ° C.) of 500 MPa or less, more preferably about 50 to 300 MPa is preferably used. In addition, when performing the embrittlement process of an adhesive bond layer by cooling so that it may mention later, it is preferable that the Young's modulus in the said cooling temperature is 500 Mpa or less. By using such a base material, the later-described expanding process can be performed smoothly.

In the method for manufacturing a semiconductor device according to the present invention, as will be described later, the adhesive layer 12 is fixedly left on the bonding surface of the chip 3 and picked up from the base material 11. For this reason, the surface tension of the surface of the substrate 11 in contact with the adhesive layer 12 is preferably 40 mN / m or less, more preferably 37 mN / m or less, and particularly preferably 35 mN / m or less. Such a base material having a low surface tension can be obtained by appropriately selecting the material, and a mold release agent such as silicone resin or alkyd resin is applied to the surface of the base material to perform a release treatment. It can also be obtained by applying

The film thickness of such a base material 11 is 10-500 micrometers normally, Preferably it is 15-300 micrometers, Most preferably, it is about 20-250 micrometers.
In the method for manufacturing a semiconductor device of the present invention, the adhesive layer 12 is disposed on the bonding surface of the picked-up chip, has a function as an adhesive for fixing to the chip mounting substrate during die bonding, and has an adhesive sheet 10. When the wafer is diced above, it is used for holding and fixing the wafer.

  As such an adhesive, a conventionally known adhesive is used without particular limitation. However, in order to facilitate peeling from the surface of the substrate 11, the adhesive layer 12 preferably has an energy ray curable component. By curing the energy ray curable component, the adhesive force is reduced, so that the substrate 11 can be easily peeled off. Moreover, it is preferable to have a thermosetting component in order to firmly fix the chip mounting substrate during bonding. After mounting on the chip mounting substrate, the thermosetting component is activated by heating and can be firmly bonded to the chip mounting substrate.

  As an adhesive agent, the mixture of binder resin and thermosetting resin which have pressure-sensitive adhesiveness at normal temperature, for example is mentioned. Examples of the binder resin having pressure-sensitive adhesive properties at room temperature include acrylic resins, polyester resins, polyvinyl ethers, urethane resins, and polyamides. The thermosetting resin is generally epoxy, phenoxy, phenol, resorcinol, urea, melamine, furan, unsaturated polyester, silicone or the like, and is used in combination with an appropriate curing accelerator. As these thermosetting resins, those having a relatively low molecular weight can be preferably used as compared with the binder resin. Moreover, in order to control peelability from the base material 11, it is preferable to mix | blend ultraviolet curable resins, such as a urethane type acrylate oligomer, with an adhesive agent. When an ultraviolet curable resin is blended, it adheres well to the substrate 11 before irradiation with ultraviolet rays, and is easily peeled off from the substrate 11 after irradiation with ultraviolet rays.

The adhesive composed of each component as described above has energy ray curability and heat curability, adheres to the base material 11 and contributes to fixing of the wafer (chip group). It can be used as an adhesive for bonding the chip mounting substrate. Finally, a cured product with high impact resistance can be obtained through thermal curing, and it has an excellent balance between shear strength and peel strength, and can maintain sufficient adhesive properties even under severe heat and humidity conditions. .

In addition, before using the adhesive sheet 10, in order to protect the adhesive layer 12, a release film may be laminated on the adhesive surface.
Step 2: a step of separating the gap between the chips and expanding the adhesive layer of the adhesive sheet by expanding the adhesive sheet (see FIG. 2).

In the present invention, in step 2, it is important to set the adhesive layer 12 so as to exhibit the following specific fracture characteristics.
That is, the elongation at break of the adhesive layer 12 in step 2 is 1 to 350%, preferably 20 to 350%, particularly preferably 50 to 150%, and the breaking stress is 1000 N / cm ² or less.
Preferably from 100~800N / cm ^2.

  The adhesive layer 12 exhibiting the above breaking characteristics is easily broken when subjected to a predetermined stress. However, since the deformation (elongation) of the adhesive fixed to the bonding surface of the chip 3 is constrained, this portion does not break. On the other hand, deformation of the adhesive between the chips (that is, the cutting line 2) is not restricted. For this reason, stress concentrates more in the position between chips than the position which faces a chip | tip, and the adhesive bond layer 12 fractures | ruptures. As a result, as shown in FIG. 2, a state in which the chips 3 having the adhesive on the bonding surface are aligned with each other at a predetermined interval is achieved.

  The adhesive layer 12 may itself have the above breaking properties under expanded conditions, otherwise it may be bonded to the adhesive by some physical or chemical treatment prior to the expanding step. The layer 12 may satisfy the above breaking characteristics.

  For example, the above breaking characteristics can be achieved by cooling the adhesive layer 12. In general, since the polymer that is the main component of the adhesive has a low elongation at break at a low temperature, the adhesive layer 12 also tends to show brittleness at a low temperature. Therefore, even if the breaking property at normal temperature of the adhesive layer 12 is not the aforementioned value, the desired breaking property can be obtained by appropriately cooling the temperature in step 2.

  Further, when the adhesive layer 12 is curable, the fracture characteristics can be controlled by curing the adhesive layer 12 in step 2. In general, an adhesive having curability has a low elongation at break due to curing and tends to be brittle. Usually, when the amount of the curable component (thermosetting component and / or energy beam curable component) in the curable adhesive increases, the elongation at break after curing decreases. By selecting, desired fracture characteristics can be obtained.

  In the case of using a curable adhesive layer, since it may be impossible to perform die bonding when the entire surface of the adhesive sheet 10 is cured, it is desirable that the adhesive layer 12 is partially cured only between the chips. In the case where the adhesive layer 12 is energy ray curable, the semiconductor chip 3 serves as a mask. Therefore, the gap between the chips can be partially cured by irradiating energy rays from the chip side. When the adhesive layer 12 is thermosetting, partial curing can be performed by bringing a heating iron or heating wire having a specific shape into contact with the adhesive sheet 10. Alternatively, the adhesive layer may be partially cured by condensing the light beam between the chips using a laser beam or an infrared lamp.

The breaking of the adhesive layer can be performed by the expanding process as described above, but may be performed by applying another mechanical impact such as ultrasonic vibration to the adhesive layer 12 prior to the expanding process. When the ultrasonic vibration is applied to the adhesive sheet 10, the ultrasonic vibrator is directly brought into contact with the table to which the adhesive sheet 10 is fixed or the semiconductor chip 3. If the frequency is such that the chip 3 resonates, the adhesive layer 12 can be sufficiently broken even if the applied vibration is small.

  Further, when the adhesive layer 12 is ruptured by the expand, the expansion ratio varies depending on the rupture characteristics of the adhesive layer 12 and the chip size, but is preferably 10% or more, more preferably 15% or more. The expand is a state in which the outer periphery of the adhesive sheet 10 to which the individual wafer-shaped chip groups are fixed is fixed to the ring frame, and the expand is pressed against a cylindrical jig arranged along the inner ring of the ring frame. Can be done. The expansion rate (%) is defined by the following formula.

  When the wafer is singulated by the above-described stealth dicing method, the thermal shock (rapid heating, rapid cooling), mechanical shock (ultrasonic wave) is applied to the wafer in a state where the wafer is fixed to the adhesive sheet prior to step 2. (Vibration) may be applied, cracks may be grown in the vertical direction of the wafer starting from the fragile portion, and the wafer may be divided into chips. By such a method, the wafer-shaped chip group in which the semiconductor wafer is separated into pieces can be put on the adhesive sheet. In this case, although the chips are divided, they are in close contact with each other, and the distance between them is substantially zero. Therefore, in this case, only the adhesive layer between the chips cannot be partially cured using energy rays. For this reason, when only the adhesive layer between chips is partially cured, a method other than energy beam irradiation is employed.

  Further, when the wafer is singulated by the above stealth dicing method, the wafer may be singulated simultaneously with the expansion. The tension when the adhesive sheet is stretched during expansion is propagated to the wafer fixed on the adhesive sheet. At this time, if a fragile portion is formed inside the wafer, the fragile portion cannot resist tension, and breakage occurs at the fragile portion. As a result, cracks grow in the vertical direction of the wafer starting from the fragile portion, and the wafer can be divided into chips.

Process 3: The process of picking up with the adhesive layer accompanying the chip and bonding through the adhesive layer formed on the bonding surface.
The pickup of the chip 3 can be performed by a known method using a suction collet or the like. Moreover, you may push up a chip | tip from the adhesive sheet 10 side with a push-up pin as needed.

By such a pickup operation, the chip 3 is picked up with the adhesive layer 12 having the same shape as the chip 3 fixed to the bonding surface of the chip 3.
Thereafter, the chip 3 is placed on a predetermined chip mounting substrate such as a lead frame through the adhesive layer 12, and die bonding is completed by performing heating and pressurization as necessary.

  After die bonding, a semiconductor device is obtained through normal processes such as wire bonding and resin sealing.

According to the method for manufacturing a semiconductor device according to the present invention, since the adhesive layer of the adhesive sheet is in a brittle state, the adhesive layer is broken and separated into the same shape as the chip at the time of expansion or when a mechanical impact is applied. To do. Therefore, it becomes easy to form an appropriate amount of adhesive layer on the bonding surface of individual chips, and a newly required manufacturing apparatus is unnecessary or can be handled by adding a simple apparatus. It is inexpensive and has excellent workability.
(Example)
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.

In the following examples, “breaking elongation”, “breaking stress”, and “Young's modulus” were evaluated as follows.
"Elongation at break""Stress at break"
The adhesives used for the adhesive sheets of the examples and comparative examples were formed and laminated so as to have a thickness of 200 μm, and this adhesive film was stretched at room temperature (23 ° C.) according to JIS K7127 at a pulling rate of 200 mm / min.
Measured with Here, the ultraviolet irradiation device (manufactured by LINTEC Corporation, Adwill RAD2000) for Example 2 after ultraviolet irradiation using the (light quantity 200 mJ / cm ^2), thermoset for Example 4 (
Measurement was carried out after 1 minute at 200 ° C. Only Example 3 was measured at a temperature of 0 ° C.

"Young's modulus"
The base material used for the adhesive sheet of an Example and a comparative example was measured according to JISK7127 at the tensile speed of 200 mm / min. In addition, about Example 3, it measured in the environment of 0 degreeC.
Example 1
The polyethylene terephthalate film (Lintec Corp., SP-PET3801, thickness 38 μm) obtained by peeling the adhesive composition consisting of the following Formulation 1 with a silicone-based release agent has a dry film thickness of 20 μm. Then, it was bonded to a polyethylene film having a surface tension of 30 mN / m and a thickness of 80 μm to prepare a thermosetting adhesive sheet.

Half-cut dicing was performed on the mirror surface of an unpolished silicon wafer (150 mm diameter) with a dicing machine to a size of 10 mm × 10 mm and a depth of 120 μm. Next, a surface protection tape (Adwill E-3100D, manufactured by Lintec Corporation) is applied to the dicing surface, and 100% is applied from the back side using a wafer polisher.
Polishing was performed to a thickness of μm to separate the wafer into pieces (first dicing step).

While sticking said adhesive sheet to the grinding | polishing surface of a chip | tip, the edge part was fixed to the ring frame (The product made by DISCO, MODTF2-6-1, internal diameter 200mm). Then peel off the surface protection tape,
A group of chips aligned in a wafer shape was fixed on the adhesive layer of the adhesive sheet. This was expanded using a die bond apparatus (manufactured by Nidec Machine Co., Ltd., CPS-100) with 18 mm being pulled down (expand rate of adhesive sheet 18%).

The adhesive layer of the adhesive sheet was completely broken at the position between the chips. When the fracture surface of the adhesive layer was confirmed, a portion greatly deformed on the fracture surface was not seen.
(Formulation 1)
(1) Acrylate ester copolymer BA / VAc / MA / GMA / 2HEA = 20/35/10/20/15 (weight average molecular weight 400,000): 10 parts by weight However, BA is butyl acrylate, and VAc is vinyl acetate , GMA represents glycidyl methacrylate, and 2HEA represents 2-hydroxyethyl acrylate.
(2) Epoxy resin Japan Epoxy Resin, Epicoat 828 (liquid bisphenol A type, average epoxy equivalent 190): 30 parts by weight Dainippon Ink & Chemicals, Epiklon AM-020-P (solid bisphenol A type, average epoxy) Equivalent 640): 40 parts by weight Nippon Kayaku Co., Ltd., EOCN-104S (orthocresol novolak type, average epoxy equivalent 220)
): 40 parts by weight
(3) Phenolic resin Dainippon Ink & Chemicals, Phenolite TD-2131 (phenol novolac type, average hydroxyl group equivalent 103): 45 parts by weight
(4) Curing accelerator Shikoku Kasei Co., Ltd. Curesol 2PHZPW (imidazole compound): 0.5 parts by weight
(5) Others Toshiba Fine Ceramics, glass fine CUS-10 (high purity fused silica filler, average particle size 8.0 μm): 110 parts by weight Admatechs, Admafine SO-C2 (high purity synthetic silica filler, average Particle size 0
. 5 μm): 12.5 parts by weight MKC silicate MSEP2 (silane coupling agent) manufactured by Mitsui Chemicals: 2 parts by weight (Example 2)
The adhesive layer formulation of Example 1 was changed from Formulation 1 to Formulation 2 below to prepare an adhesive sheet having thermosetting properties and energy beam curability. Subsequently, wafer singulation, adhesion sheet sticking, and expansion (breaking of the adhesive layer) were performed in the same manner as in Example 1. However, before expanding, the adhesive layer was irradiated with ultraviolet rays (light quantity 200 mJ / cm ² ) from the chip surface to partially embrittle the adhesive layer in a lattice shape.

The adhesive layer of the adhesive sheet was completely broken at the position between the chips. When the fracture surface of the adhesive layer was confirmed, a portion greatly deformed on the fracture surface was not seen.
(Formulation 2)
(1) Acrylate ester copolymer BA / VAc / MA / GMA / 2HEA = 20/35/10/20/15 (weight average molecular weight 400,000): 10 parts by weight
(2) Epoxy resin Japan Epoxy Resin, Epicoat 828 (liquid bisphenol A type, average epoxy equivalent 190): 30 parts by weight Dainippon Ink & Chemicals, Epiklon AM-020-P (solid bisphenol A type, average epoxy) Equivalent 640): 40 parts by weight Nippon Kayaku Co., Ltd., XD-10000L (dicyclopentadiene skeleton, average epoxy equivalent 245):
40 parts by weight
(3) Phenol resin, Mitsui Chemicals, Millex XLC-4L (phenol aralkyl type, average hydroxyl equivalent 170)
): 45 parts by weight
(4) Curing accelerator Shikoku Kasei Co., Ltd. Curesol 2PHZPW (imidazole compound): 0.5 parts by weight
(5) Energy ray curable resin Nippon Kayaku Co., Ltd., Karayad DPHA (dipentaerythritol hexaacrylate): 1
0 parts by weight
(6) Photoinitiator Ciba Specialty Chemicals, Irgacure 184: 0.3 parts by weight
(7) Others Toto Kasei phenototo YP-50-EK35 (phenoxy resin): 15 parts by weight Mitsubishi Chemical MKC silicate MSEP2 (silane coupling agent): 2 parts by weight (Example 3)
The adhesive layer formulation of Example 1 was changed from Formulation 1 to Formulation 3 to create an adhesive sheet having thermosetting properties. Subsequently, wafer singulation, adhesion sheet sticking, and expansion (breaking of the adhesive layer) were performed in the same manner as in Example 1. However, before expanding, the adhesive sheet to which the chip group was bonded and fixed was cooled to 0 ° C. for 2 hours with a constant temperature bath, and expanded immediately after taking out.

The adhesive layer of the adhesive sheet was completely broken at the position between the chips. When the fracture surface of the adhesive layer was confirmed, a portion greatly deformed on the fracture surface was not seen.
(Formulation 3)
(1) Acrylate ester copolymer BA / MA / GMA / 2HEA = 55/10/20/15 (weight average molecular weight 800,000): 20 parts by weight
(2) Epoxy resin, manufactured by Japan Epoxy Resin, Epicoat 828 (liquid bisphenol A type, average epoxy equivalent 190): 60 parts by weight Japan Epoxy Resin, Epicoat 1055 (solid bisphenol A type, average epoxy equivalent 925): 10 weights Parts Nippon Kayaku Co., Ltd., XD-1000L (dicyclopentadiene skeleton, average epoxy equivalent 245): 30 parts by weight
(3) Phenol resin, Mitsui Chemicals, Millex XLC-4L (phenol aralkyl type, average hydroxyl equivalent 170)
): 66 parts by weight
(4) Curing accelerator Shikoku Kasei Co., Ltd. Curesol 2PHZ: 0.5 parts by weight
(5) Others MKC silicate MSEP2 manufactured by Mitsubishi Chemical Corporation: 0.5 parts by weight (Example 4)
The adhesive layer formulation of Example 1 was changed from Formulation 1 to Formulation 3 to create an adhesive sheet having thermosetting properties. Subsequently, wafer singulation, adhesion sheet sticking, and expansion (breaking of the adhesive layer) were performed in the same manner as in Example 1. However, before expanding, a heating wire (nichrome wire, approximately 200 to 250 ° C.) was applied to each line between the chips of the adhesive sheet to partially embrittle the adhesive layer in a lattice shape.

The adhesive layer of the adhesive sheet was completely broken at the position between the chips. When the fracture surface of the adhesive layer was confirmed, a portion greatly deformed on the fracture surface was not seen.
(Example 5)
Using the same adhesive sheet as in Example 1, the wafer was separated into pieces and the adhesive sheet was attached. Thereafter, an adhesive sheet for bonding and fixing the chip group is placed on a smooth metal table, two ultrasonic horns are brought into contact with adjacent chips from the upper surface of the chip, and an adhesive layer positioned between the chips is formed. This was repeated, and this was repeated to break the adhesive layer between all the chips.

The adhesive layer of the adhesive sheet was completely broken at the position between the chips. When the fracture surface of the adhesive layer was confirmed, a portion greatly deformed on the fracture surface was not seen.
(Example 6)
The dry film thickness is 20 μm on the release surface of a polyethylene terephthalate film (SP-PET3811 (S), thickness 38 μm) manufactured by Lintec Co. Then, it was bonded to an ethylene-methyl methacrylate copolymer film having a surface tension of 35 mN / m and a thickness of 80 μm, and an adhesive sheet having thermosetting property and energy ray curable property was prepared.

Chemical mechanical polish (CMP) treated silicon wafer (150mm diameter, thickness 1
The above-mentioned adhesive sheet was affixed to the (00 μm) CMP-treated surface and fixed to a wafer dicing ring frame (manufactured by DISCO, MODTF2-6-1). Thereafter, the adhesive layer was irradiated with ultraviolet rays from the substrate surface using an ultraviolet irradiation device (manufactured by Lintec, Adwill RAD2000m / 8), and the adhesive layer was semi-cured.

Next, a stealth dicing method using a stealth dicing apparatus (manufactured by Hamamatsu Photonics) was performed to make the dicing line brittle so that the semiconductor wafer had a chip size of 10 mm × 10 mm. Subsequently, 18 mm was pulled down using a die bonding apparatus (manufactured by Nidec Machine Co., Ltd., CPS-100) and expanded to completely separate the chip, and the adhesive layer was also broken to the same size as the chip. Further, the chip was picked up with a needle pushed up from the base material side of the adhesive sheet on the die bonding apparatus and an adhesive layer having the same shape as the chip laminated on the back surface of the chip. The adhesive layer of the adhesive sheet was completely broken at the position between the chips. When the fracture surface of the adhesive layer was confirmed, no greatly deformed portion was found on the fracture surface.
(Formulation 4)
(1) Acrylate ester copolymer BA / MA / GMA / 2HEA = 55/10/20/15 (weight average molecular weight 800,000): 20 parts by weight
(2) Epoxy resin, manufactured by Japan Epoxy Resin, Epicoat 828 (liquid bisphenol A type, average epoxy equivalent 190): 30 parts by weight Japan Epoxy Resin, Epicoat 1055 (solid bisphenol A type, average epoxy equivalent 925): 40 wt. Department made by Nippon Kayaku Co., Ltd., EOCN-104S (orthocresol novolak type, average epoxy equivalent 220)
): 10 parts by weight
(3) Curing accelerator Shikoku Kasei Co., Ltd. Curesol 2PHZ: 1 part by weight
(4) Curing agent manufactured by Asahi Denka Co., Ltd., Adeka Hardener 3636AS: 1 part by weight
(5) Energy ray curable resin Kayrad DPHA (dipentaerythritol hexaacrylate) manufactured by Nippon Kayaku Co., Ltd .: 12 parts by weight
(6) Photoinitiator Ciba Specialty Chemicals, Irgacure 184: 0.4 parts by weight
(7) Others MKC silicate MSEP2 manufactured by Mitsubishi Chemical Corporation: 0.5 part by weight (Example 7)
The adhesive composition in Example 6 was changed from Formulation 4 to Formula 5 below to prepare an adhesive sheet having thermosetting properties and energy beam curability. Subsequently, CMP processing of the silicon wafer, adhesion of the adhesive sheet, ultraviolet irradiation, stealth dicing, expansion (breakage of the wafer and the adhesive layer), and chip pickup were performed in the same manner as in Example 6. The adhesive layer of the adhesive sheet was completely broken at the position between the chips. When the fracture surface of the adhesive layer was confirmed, no greatly deformed portion was found on the fracture surface.
(Formulation 5)
(1) Acrylate ester copolymer BA / MA / GMA / 2HEA = 55/10/20/15 (weight average molecular weight 320,000): 20 parts by weight
(2) Epoxy resin, manufactured by Japan Epoxy Resin, Epicoat 828 (liquid bisphenol A type, average epoxy equivalent 190): 30 parts by weight Japan Epoxy Resin, Epicoat 1055 (solid bisphenol A type, average epoxy equivalent 925): 40 wt. Department made by Nippon Kayaku Co., Ltd., EOCN-104S (orthocresol novolak type, average epoxy equivalent 220)
): 10 parts by weight
(3) Curing accelerator Shikoku Kasei Co., Ltd. Curesol 2PHZ: 1 part by weight
(4) Curing agent manufactured by Asahi Denka Co., Ltd., Adeka Hardener 3636AS: 1 part by weight
(5) Energy ray curable resin Kayrad DPHA (dipentaerythritol hexaacrylate) manufactured by Nippon Kayaku Co., Ltd .: 24 parts by weight
(6) Photoinitiator Ciba Specialty Chemicals, Irgacure 184: 0.8 parts by weight
(7) Others MKC silicate MSEP2 manufactured by Mitsubishi Chemical Corporation: 0.5 parts by weight (comparative example)
An experiment was conducted in the same manner as in Example 3 except that the adhesive sheet of Example 3 was used and the expansion was performed at room temperature.

  The adhesive layer of the adhesive sheet was broken at the position between the chips, but when the fracture surface of the adhesive layer was confirmed, the fracture surface was greatly torn and deformed.

FIG. 1A is a perspective view showing one step of a method of manufacturing a semiconductor device according to the present invention, and FIG. 1B is a cross-sectional view taken along the line aa in FIG. 1A. 1 shows one step of a method of manufacturing a semiconductor device according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Chip group 2 ... Cutting line 3 ... Chip 10 ... Adhesive sheet 11 ... Expandable base material 12 ... Adhesive layer

Claims (10)

A wafer-shaped chip group in which semiconductor wafers are singulated is formed on an adhesive layer of an adhesive sheet including an extendable base material and an adhesive layer of a brittle body that is laminated so as to be peelable from the base material. , A step of bonding the bonding surface of the chip group,
A step of breaking the adhesive layer by applying ultrasonic vibration to the adhesive sheet before separating the chip interval by the expand;
A step of spacing the chips apart by expanding the adhesive sheet;
A method for manufacturing a semiconductor device, comprising a step of picking up a chip with an adhesive layer and bonding through an adhesive layer formed on a bonding surface. A wafer-shaped chip group in which semiconductor wafers are singulated is formed on an adhesive layer of an adhesive sheet including an extendable base material and an adhesive layer of a brittle body that is laminated so as to be peelable from the base material. , A step of bonding the bonding surface of the chip group (however, the adhesive sheet has a base material Young's modulus of 500 MPa or less at room temperature (23 ° C.), and the adhesive layer has a breaking elongation. 1 to 350%, and the breaking stress is 1000 N / cm ² or less),
A step of separating the gap between the chips and breaking the adhesive layer of the adhesive sheet by expanding the adhesive sheet;
A method for manufacturing a semiconductor device, comprising a step of picking up a chip with an adhesive layer and bonding through an adhesive layer formed on a bonding surface. A wafer-shaped chip group in which semiconductor wafers are separated into pieces is formed on an adhesive layer of an adhesive sheet composed of an extendable base material and an adhesive layer laminated so as to be peelable from the base material. A process of bonding the bonding surface;
A step of subjecting the adhesive layer to a cooling treatment, and making the adhesive layer an adhesive layer of a brittle body having the following fracture characteristics (however, the adhesive sheet is formed from the Young of the substrate at the cooling temperature) The rate is 500 MPa or less, the breaking property of the adhesive layer is that the breaking elongation is 1 to 350%, and the breaking stress is 10
00 N / cm ² or less),
A step of separating the space between the chips and breaking the adhesive layer of the brittle body of the adhesive sheet by expanding the adhesive sheet during or immediately after the cooling process;
A method for manufacturing a semiconductor device, comprising a step of picking up a chip with an adhesive layer and bonding through an adhesive layer formed on a bonding surface. A wafer-shaped chip group in which semiconductor wafers are singulated is formed on an adhesive layer of an adhesive sheet including an extendable base material and a thermosetting adhesive layer laminated so as to be peelable from the base material. A step of attaching the bonding surface of the chip group,
A process of subjecting the adhesive layer only partially to the adhesive layer between the chips, and making the adhesive layer an adhesive layer of a brittle body having the following fracture characteristics (however, the adhesive sheet has a room temperature ( The Young's modulus of the substrate at 23 ° C. is 500 MPa or less, and the breaking properties of the adhesive layer of the brittle body after the thermosetting treatment are breaking elongation of 1 to 350% and breaking stress of 1000 N. / cm ² or less),
A step of breaking the adhesive layer of the brittle body of the adhesive sheet while separating the spaces between the chips by expanding the adhesive sheet;
A method for manufacturing a semiconductor device, comprising a step of picking up a chip with an adhesive layer and bonding through an adhesive layer formed on a bonding surface. A wafer-shaped chip group in which semiconductor wafers are singulated is formed on an adhesive layer of an adhesive sheet including an extendable base material and an energy ray-curable adhesive layer laminated so as to be peelable from the base material. , A step of bonding the bonding surface of the chip group,
An energy ray curing treatment is applied to the adhesive layer by partially curing between the chips by irradiating energy rays from the tip side, and the adhesive layer is made of a brittle material having the following fracture characteristics. step of the adhesive layer (provided that the adhesive sheet is not more than the Young's modulus is 500MPa of the substrate at room temperature (23 ° C.), breaking properties of the adhesive layer of the brittle-like member after said energy beam curing process Has a breaking elongation of 1 to 350% and a breaking stress of 1000 N / cm ² or less),
A step of breaking the adhesive layer of the brittle body of the adhesive sheet while separating the spaces between the chips by expanding the adhesive sheet;
A method for manufacturing a semiconductor device, comprising a step of picking up a chip with an adhesive layer and bonding through an adhesive layer formed on a bonding surface.   The adhesive layer is selected from at least a binder resin selected from acrylic resin, polyester resin, polyvinyl ether, urethane resin and polyamide, and epoxy, phenoxy, phenol, resorcinol, urea, melamine, furan, unsaturated polyester and silicone. The method for manufacturing a semiconductor device according to claim 1, comprising a mixture with a thermosetting resin. Adhering to the bonding surface of the semiconductor wafer an adhesive surface of an adhesive sheet composed of an extendable base material and the adhesive layer laminated so as to be peelable from the base material, cutting the semiconductor wafer, By separating the semiconductor wafer so that the adhesive layer of the adhesive sheet is not cut,
A group of wafer-shaped chips in which a semiconductor wafer is divided into pieces, the chip group on an adhesive layer of an adhesive sheet comprising an extendable base material and the adhesive layer laminated so as to be peelable from the base material. The method for manufacturing a semiconductor device according to claim 1, wherein the bonding surface is attached. After the semiconductor wafer is singulated to form a wafer-shaped chip group, the adhesive surface of the adhesive sheet comprising the stretchable base material and the adhesive layer laminated so as to be peelable from the base material is the chip. By sticking to the bonding surface of the group,
A group of wafer-shaped chips in which a semiconductor wafer is divided into pieces, the chip group on an adhesive layer of an adhesive sheet comprising an extendable base material and the adhesive layer laminated so as to be peelable from the base material. The method for manufacturing a semiconductor device according to claim 1, wherein the bonding surface is attached. An adhesive sheet comprising a stretchable base material and a brittle adhesive layer laminated so that the semiconductor wafer, in which chip groups are connected via a fragile portion formed inside the semiconductor wafer, is peelable from the base material A step in which the bonding surface of the chip group is stuck on the adhesive layer (where the adhesive sheet has a base material Young's modulus of 500 MPa or less at room temperature (23 ° C.), The breaking elongation of the layer is 1 to 350%, and the breaking stress is 1000 N / cm ² or less),
By expanding the adhesive sheet, the semiconductor wafer is broken and separated into pieces starting from the fragile portion, and at the same time, the gap between the chips is separated and the adhesive layer of the adhesive sheet is broken.
A method for manufacturing a semiconductor device, comprising a step of picking up a chip with an adhesive layer and bonding through an adhesive layer formed on a bonding surface. The semiconductor wafer interior is formed by focusing the inside of the semiconductor wafer along the planned cutting line that divides each circuit of the semiconductor wafer and irradiating the laser beam to locally modify the inside of the semiconductor wafer to form a weakened portion. The method for manufacturing a semiconductor device according to claim 9, further comprising a step of obtaining a semiconductor wafer in which chip groups are connected via a fragile portion formed on the substrate.

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