JP6417711B2 - Method for producing ground substrate, and film-like pressure-sensitive adhesive and laminate used therefor - Google Patents

Description

  The present invention relates to a method for producing a ground substrate, and a film-like pressure-sensitive adhesive and a laminate used for the method. More specifically, the present invention relates to, for example, a film shape that allows a substrate to be ground such as a silicon wafer fixed on a support to be easily ground to a desired thickness and easily peeled from the support. It is related with the manufacturing method of the base material thinned using the adhesive, the laminated body joined through the said film-like adhesive, and a laminated body.

  With the increasing functionality of electronic devices such as smartphones and tablet PCs, stacked MCPs (Multi Chip Packages), in which semiconductor elements are stacked in multiple stages and increased in capacity, have become widespread. Advantageous film adhesives are widely used as adhesives for die bonding. However, in spite of such a trend toward multi-functionality, the current connection method of semiconductor elements using wire bonds tends to slow down the operation of electronic devices due to the limited data processing speed. It is in. In addition, since there is a growing need to keep power consumption low and to use the battery for a longer time without charging, power saving is also being demanded. From such a viewpoint, in recent years, a semiconductor device having a new structure in which semiconductor elements are connected to each other by a through electrode instead of a wire bond has been developed for the purpose of further speeding up and power saving.

  Although a semiconductor device having a new structure has been developed as described above, there is still a demand for higher capacity, and development of a technology capable of stacking semiconductor elements in more stages is progressing regardless of the package structure. However, in order to stack a large number of semiconductor elements in a limited space, it is indispensable to stably reduce the thickness of the semiconductor elements.

  At present, in a grinding process for thinning a semiconductor element, it is a mainstream to apply a support tape called a so-called BG tape to the semiconductor element and perform grinding in a supported state. However, the thinned semiconductor element is likely to warp due to the influence of the circuit applied to the surface, and the BG tape which is a deformable tape material cannot sufficiently support the thinned semiconductor element.

  From such a background, a thinning process of a semiconductor element using a silicon wafer or glass, which is a material harder than BG tape, as a support has been proposed, and the semiconductor element and the silicon wafer or glass as a support are adhered to each other. Materials have been proposed. In such an adhesive, it is required as an important characteristic that it can be peeled off from the support without damaging the semiconductor element after grinding. However, in order to satisfy such a characteristic, intensive studies have been made on the peeling method. Yes. For example, those using dissolution of the adhesive with a solvent, those having improved peelability by reducing the adhesiveness by heating, and those using modifying or eliminating the adhesive by laser irradiation can be mentioned. However, since it takes time to dissolve the pressure-sensitive adhesive in the solvent, the productivity tends to decrease. In addition, the method of reducing the adhesiveness by heating is concerned about the influence on the semiconductor element due to heating and is inferior in heat resistance, and therefore cannot be used in a process application for forming a through electrode or the like. On the other hand, in the method of modifying or eliminating the adhesive by laser irradiation, introduction of expensive laser equipment is indispensable, and considerable investment is indispensable for application of such a process. In addition, a technique for enhancing the releasability by performing a release treatment on the surface of the semiconductor element or the support in advance is generally adopted, but such a release component is finally washed away, This is one of the causes of an increase in manufacturing cost as well as an increase in work processes such as application of a release component and cleaning and removal.

  The ground semiconductor element may be peeled off from the support, but may be peeled off after a circuit is formed on the ground semiconductor element surface. In such a case, since the pressure-sensitive adhesive is exposed to a high temperature such as 200 ° C. in the circuit forming step, it is required to be lightly peeled even after heating at 200 ° C.

Japanese Patent No. 4565804 Patent No. 4936667

  In recent years, thinning of semiconductor elements has been promoted for the purpose of increasing the capacity of semiconductor devices, and adhesives for fixing semiconductor elements to a support such as a silicon wafer or glass during grinding have been developed. There is room for further improvement from the viewpoint of high cost and high capital investment. In particular, most of such pressure-sensitive adhesives are liquid, and are used by being applied to a semiconductor element or support by spin coating or the like and forming a film by heating or UV irradiation. However, in such a case, variation in pressure-sensitive adhesive is likely to cause variations in the thickness after grinding in each semiconductor element, and in spin coating, it is necessary to discard the material scattered by rotation during application, etc. There are challenges. On the other hand, with a film-like pressure-sensitive adhesive, the film thickness can be controlled more easily, and thickness variations between individual semiconductor elements can be reduced. Moreover, since it can form into a film on a semiconductor element or a support body by simple methods, such as a lamination, it can be anticipated that workability | operativity will also become favorable.

  In general, a release component is applied in advance to the surface of the semiconductor element or the support in order to improve the peelability, but it is difficult to say that it is an efficient process because it is finally removed by washing. Here, if the application of the mold release component can be eliminated, the work process can be shortened and the material cost can be reduced, and the semiconductor element can be manufactured at a lower cost.

  The present invention has been made in view of the above circumstances, and can easily grind a substrate to be ground such as a silicon wafer fixed on a support to a desired thickness. Even after heat treatment at 200 ° C., a semiconductor element is provided. Alternatively, a film-like pressure-sensitive adhesive that makes it possible to easily separate the ground substrate from the support without any prior application of a release component on the surface of the support, and the substrate to be ground via the film-like pressure-sensitive adhesive It is an object of the present invention to provide a laminate in which a substrate and a support are joined, and a method for producing a thinned substrate using such a laminate.

  In one aspect, the present invention is a film-like pressure-sensitive adhesive having a thickness of 5 μm to 130 μm made of a thermosetting resin composition, and the film-like pressure-sensitive adhesive is directly laminated on a substrate to be ground at 130 ° C. A film-like pressure-sensitive adhesive having a 30 ° peel strength between the film-like pressure-sensitive adhesive and the substrate to be ground of 300 N / m or less after heating for 15 minutes at 170 ° C. for 15 minutes and at 200 ° C. for 10 minutes. provide. According to such a film-like pressure-sensitive adhesive, a substrate to be ground such as a silicon wafer fixed on a support can be easily ground to a desired thickness, and even after heat treatment at 200 ° C., the surface of the semiconductor element or the support Even if there is no prior application of a release component, it is possible to easily separate the ground substrate from the support.

  In another aspect, the present invention comprises (a) the above film-like pressure-sensitive adhesive, (b) a support, and (c) a substrate to be ground, wherein (a) the film-like pressure-sensitive adhesive is (c) Provided is a laminate in which the substrate is laminated on a grinding substrate, and (c) the substrate to be ground is fixed to (b) a support through (a) a film-like adhesive.

  In still another aspect, the present invention provides (c) a step of grinding a substrate to be ground provided in the laminate, and (a) a film-like adhesive is (c) on the substrate to be ground or (b) (C) the step of separating the ground substrate to be ground (b) from the support so as to remain on either side of the support, and (c) the substrate to be ground or (b) from the support (a And a step of peeling the film-like pressure-sensitive adhesive.

  According to the present invention, a substrate to be ground such as a silicon wafer fixed on a support can be easily ground to a desired thickness, and even after heat treatment at 200 ° C., a release component is not formed on the surface of the semiconductor element or the support. It is possible to provide a film-like pressure-sensitive adhesive that makes it possible to easily separate a ground substrate from a support without prior application.

  In addition, according to the present invention, a laminate in which the substrate to be ground and the support are joined via the film adhesive and a method for producing a thinned substrate using such a laminate are provided. can do.

  Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

  In order to solve the above-mentioned problems, the present inventors have conducted intensive research on the selection of the resin of the film-like pressure-sensitive adhesive to be used and the adjustment of the physical properties. Then, the present inventors control the shear viscosity to form a laminate without generating voids, and control the peel strength between the film-like adhesive after the predetermined heat treatment and the silicon mirror wafer. Thus, while holding sufficiently the substrate to be ground such as semiconductor elements at the time of grinding, without special pretreatment such as laser irradiation, and without prior application of the mold release component to the surface of the support for semiconductor elements or transport, It has been found that a film-like pressure-sensitive adhesive that can be easily peeled can be obtained without substantially generating a residue on the surface of the peeled semiconductor element and support. Specifically, the film-like pressure-sensitive adhesive according to this embodiment is directly laminated on a silicon mirror wafer and heated in the order of 15 minutes at 130 ° C., 15 minutes at 170 ° C. and 10 minutes at 200 ° C. The 30 ° peel strength between the adhesive and the silicon mirror wafer is preferably 300 N / m or less. In order to obtain such peel strength, for example, a film-like pressure-sensitive adhesive can be obtained by adding a silicone compound as a release component to a film mainly composed of a thermosetting component and a high molecular weight component.

  In this embodiment, it is important to form a laminate without generating voids, and to maintain wafer retention during grinding and heat resistance at 200 ° C., which appropriately contains a thermosetting component. It can be achieved by controlling the fluidity before curing and the elastic modulus after curing.

  In addition, it is important to make it possible to peel the release component without prior application and to suppress the generation of residues after peeling, but it has been found that this can be achieved by appropriately selecting and blending a silicone compound.

  The silicone compound is a silicone compound having a crosslinkable functional group or a silicone compound having a functional group capable of interacting with a hydroxy group formed by the reaction of an epoxy resin that is a thermosetting component. This is preferable from the viewpoint of preventing elution and suppressing the generation of residues after peeling.

  From the above viewpoint, the film-like pressure-sensitive adhesive (thermosetting resin composition) according to this embodiment includes, for example, (a1) a thermosetting component, (a2) a high molecular weight component, and (a3) a silicone compound. contains. The high molecular weight component may have a weight average molecular weight of 150,000 to 1,000,000 and / or a glass transition temperature of −50 ° C. to 50 ° C. From the viewpoint of obtaining an appropriate peel strength after heat treatment, the content of (a2) high molecular weight component is 25 to 1200 parts by mass with respect to 100 parts by mass of (a1) thermosetting component, and (a3) silicone compound The content of is preferably 8 to 430 parts by mass.

  The weight average molecular weight is a polystyrene conversion value using a standard polystyrene calibration curve by gel permeation chromatography (GPC).

  The glass transition temperature is measured using a DSC (thermal differential scanning calorimeter) (for example, “Thermo Plus 2” manufactured by Rigaku Corporation).

  It is necessary to produce a laminate without damaging the substrate to be ground typified by semiconductor elements and without generating voids, but this can be achieved by controlling the film adhesive before curing I found. More specifically, 80-150 ° C./0.01-0.2 MPa / 1-5 min by controlling the shear viscosity to be 20000 Pa · s or less at any temperature of 40 ° C. to 150 ° C. A laminate is produced without damaging and generating voids by vacuum-bonding the substrate to be ground and the support to which the film-like adhesive is attached under a mild condition of 1-15 mbar. can do.

  The above-mentioned shear viscosity is measured when ARES (manufactured by Rheometric Scientific Co., Ltd.) is used and measured while increasing the temperature at a heating rate of 10 ° C./min while giving 5% strain to the film adhesive. Means.

  In addition, it is preferable to securely fix and maintain the substrate to be ground on the support even during the heat treatment at 200 ° C., and the elastic modulus at 200 ° C. after curing of the film-like pressure-sensitive adhesive is preferably 0.1 MPa or more. If the elastic modulus at high temperature is 0.1 MPa or more, the warpage of the substrate to be ground thinned and the occurrence of warpage at a high temperature due to the difference in linear expansion coefficient between the substrate to be ground and the support are suppressed. There is a tendency to.

Hereinafter, each component will be described.
<(A1) Thermosetting component>
A thermosetting component is comprised from the compound which can form a crosslinked structure by heating. The thermosetting component includes, for example, an epoxy resin and / or a phenol resin. From the viewpoint of obtaining a film-like pressure-sensitive adhesive having a shear viscosity of 20000 Pa · s or less at any temperature of 40 to 150 ° C. as described above, the (a1) thermosetting component according to this embodiment is thermosetting. It is preferable to contain 40 parts by mass or more of at least one of a phenol resin and an epoxy resin having a softening point of 110 ° C. or lower or room temperature (for example, 23 ° C.) with respect to 100 parts by mass of the component. The phenol resin preferably has a softening point of 110 ° C. or lower or is liquid at room temperature. By containing such a (a1) thermosetting component, the residual viscosity after press-bonding can be suppressed without excessively increasing the shear viscosity of the film-like pressure-sensitive adhesive.

  There are no particular limitations on the epoxy resin and phenol resin that can satisfy such characteristics. Examples of the epoxy resin include bifunctional epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin (for example, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) And novolak type epoxy resins such as YDCN-700-10). Examples of the phenol resin include Milex XLC series and XL series (for example, Milex XLC-LL) manufactured by Mitsui Chemicals, Inc., and HE series (for example, HE-200C-10) manufactured by Air Water Corporation.

  Other epoxy resins and phenol resins are not particularly limited as long as smooth curability can be obtained at a temperature of 200 ° C. or lower, but YDF2001 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., GPH103 manufactured by Nippon Kayaku Co., Ltd. Etc.

<(A2) High molecular weight component>
The (a2) high molecular weight component according to this embodiment preferably has a weight average molecular weight of 150,000 to 1,000,000 and a glass transition temperature (Tg) of −50 ° C. to 50 ° C. Moreover, the high molecular weight component may have a monomer unit having a crosslinkable functional group in a mass ratio of 1 to 10%. It is preferable that the thermosetting resin composition of this embodiment contains a 25-1200 mass part high molecular weight component with respect to 100 mass parts of above-mentioned (a1) thermosetting components. (A2) By setting the weight average molecular weight, Tg, monomer ratio having a crosslinkable functional group, and the content of the high molecular weight component as described above, the elastic modulus at 200 ° C. after the curing of the film-like pressure-sensitive adhesive is 0.00. It can be 1 MPa or more.

  (A2) If the monomer unit having a crosslinkable functional group in the high molecular weight component is 1% or more in terms of mass ratio, the film-like pressure-sensitive adhesive can form a sufficient crosslink after curing, and a semiconductor element or the like can be formed in the grinding process. The substrate to be ground can be sufficiently held. Furthermore, foaming of the film-like pressure-sensitive adhesive can be suppressed during heating at 200 ° C. when a circuit is formed on the ground element surface. On the other hand, if the mass ratio is 10% or less, the shear viscosity of the film-like pressure-sensitive adhesive is not easily increased by the crosslinking reaction, and an excessive increase in shear viscosity due to heating in the production process of the film-like pressure-sensitive adhesive is controlled. It tends to be easy to do. In addition, deterioration of the film-like pressure-sensitive adhesive over time can be suppressed.

  (A2) If the Tg of the high molecular weight component is −50 ° C. or higher, or the weight average molecular weight is 150,000 or higher, excessive protrusion of the film-like pressure-sensitive adhesive can be suppressed without causing excessive decrease in shear viscosity. , Less likely to contaminate the device. On the other hand, if Tg is 50 ° C. or lower or the weight average molecular weight is 1,000,000 or lower, excessive increase in shear viscosity is unlikely to occur, and shear viscosity becomes 20000 Pa · s or less when heated at 150 ° C. There is little risk of voids remaining later.

  Further, if the content of the (a2) high molecular weight component is 25 parts by mass or more with respect to 100 parts by mass of the (a1) thermosetting component, the film-like pressure-sensitive adhesive is not excessively reduced without causing an excessive decrease in shear viscosity. The protrusion can be suppressed and there is little possibility of contaminating the apparatus. On the other hand, if the content of (a2) high molecular weight component is 1200 parts by mass or less with respect to 100 parts by mass of (a1) thermosetting component, excessive increase in shear viscosity hardly occurs, and when heated at 150 ° C. Since the shear viscosity is 20000 Pa · s or less, there is little possibility that voids remain as a result. Further, the film-like pressure-sensitive adhesive can form a sufficient crosslink after being cured, and a substrate to be ground such as a semiconductor element can be sufficiently held in the grinding process. Furthermore, foaming of the film-like pressure-sensitive adhesive can be suppressed during heating at 200 ° C. when a circuit is formed on the ground element surface.

  Examples of the (a2) high molecular weight component include polyimide resin, (meth) acrylic resin, and urethane resin, and (meth) acrylic resin is preferable. (A2) The high molecular weight component preferably has a crosslinkable functional group. Examples of the crosslinkable functional group include an epoxy group, an alcoholic group, and a phenolic hydroxyl group. From such a viewpoint, a (meth) acrylic resin such as a (meth) acrylic copolymer obtained by polymerizing a functional monomer having an epoxy group such as glycidyl (meth) acrylate as a crosslinkable functional group is more preferable. In addition, “(meth) acryl” in the present specification means “acryl” or “methacryl” corresponding thereto.

  Examples of the (meth) acrylic resin include an epoxy group-containing (meth) acrylic ester copolymer, an epoxy group-containing (meth) acrylic rubber, and the like, and an epoxy group-containing (meth) acrylic rubber is preferable. Epoxy group-containing (meth) acrylic rubber is mainly composed of (meth) acrylic acid ester, and is mainly a copolymer of butyl (meth) acrylate and acrylonitrile, ethyl (meth) acrylate and acrylonitrile, A rubber having an epoxy group made of such a copolymer is preferable.

<(A3) Silicone compound>
The (a3) silicone compound according to the present embodiment preferably has a 5% weight loss temperature of 200 ° C. or higher from the viewpoint of realizing heat resistance at 200 ° C.

  In addition, (a3) the silicone compound can be easily ground even after heating at 200 ° C., with a 30 ° peel strength between the film-like pressure-sensitive adhesive and the substrate to be ground being 300 N / m or less, and without prior application of a release component. From the viewpoint of making the substrate peelable from the support and suppressing the generation of residues after peeling, it is preferable to contain 8 to 430 parts by mass with respect to 100 parts by mass of the (a1) thermosetting component. If it is 8 parts by mass or more, sufficient peelability is obtained, and the peel strength tends to be suppressed, and if it is 430 parts by mass or less, it is a phase for (a1) thermosetting component and (a2) high molecular weight component. The solubility tends to increase and the film tends to be easily molded.

  Further, from the viewpoint of suppressing the generation of residues after peeling, (a3) the silicone compound interacts with a hydroxy group formed by the reaction of a silicone compound having a crosslinkable functional group or an epoxy resin which is a thermosetting component. It is preferable that it is a silicone compound which has a functional group which can do. Examples of such silicone compounds include SH3773M and L-7001 manufactured by Toray Dow Corning Co., Ltd., KF105 and X-22-4741 manufactured by Shin-Etsu Chemical Co., Ltd., and the like.

<(A4) Curing accelerator>
The film-like pressure-sensitive adhesive according to this embodiment may contain (a4) a curing accelerator. (A4) As the curing accelerator, an imidazole compound is preferable. When the curing accelerator has too high reactivity, excessive curing proceeds in the heat-drying step for producing the film-like pressure-sensitive adhesive, causing an increase in shear viscosity before curing, which may cause voids during production of the laminate. Also, there is a tendency to cause significant deterioration over time. On the other hand, a curing accelerator that is too low in reactivity not only delays the heat curing of the film-like pressure-sensitive adhesive and increases the curing time, but also causes insufficient crosslinking even when heat-cured. May not be securely fixed to the support.

  As content of (a4) hardening accelerator, it is preferable that it is 0.05-3.0 mass parts with respect to 100 mass parts of said (a1) thermosetting components. If content of a hardening accelerator is 0.05 mass part or more, hardening by heating will fully advance and there exists a tendency which can fix a to-be-ground base material to a support body reliably. Furthermore, if it is 0.05 mass part or more, since long-time heat processing is not required for hardening and the heat curing of a film adhesive can be implemented in a short time, it is preferable. On the other hand, if content of a hardening accelerator is 3.0 mass parts or less, there is little possibility that shear viscosity will rise by the heating in the manufacturing process of a film adhesive, and it can suppress degradation with time.

<(A5) Inorganic filler>
In the film-like pressure-sensitive adhesive according to this embodiment, (a5) inorganic filler may be appropriately added as necessary. By adding an inorganic filler, the elastic modulus can be easily controlled. The amount of the inorganic filler added is preferably 70 parts by mass or less with respect to 100 parts by mass of the (a1) thermosetting component. By making the addition amount of the inorganic filler 70 parts by mass or less, an excessive increase in the shear viscosity of the film-like pressure-sensitive adhesive can be suppressed.

  (A5) Examples of the inorganic filler include various particles such as titanium oxide, alumina, and silica. Examples of the shape of the inorganic filler include a true spherical shape and an indeterminate shape, but are not particularly limited thereto. The particle diameter is not particularly limited as long as it is smaller than the film thickness of the film-like pressure-sensitive adhesive, but is preferably 5 μm or less in consideration of the film-forming property of the film-like pressure-sensitive adhesive. Alumina or silica is preferable from the viewpoint of a wide selection range of particle diameter and shape, but silica is more preferable from a viewpoint of being cheaper. Examples of such (a5) inorganic filler include SC2050-HLG, SC1030-HLG and YA050C-HHG manufactured by Admatechs Co., Ltd., R972 manufactured by Nippon Aerosil Co., Ltd., and the like.

<Method for producing film adhesive>
The film-like pressure-sensitive adhesive is formed by a method in which the above-mentioned pressure-sensitive adhesive composition containing each component is mixed and kneaded in an organic solvent to prepare a varnish, and the produced varnish is applied onto a substrate film and dried. Can do.

  The above mixing and kneading can be carried out by using a normal stirrer, a raking machine, a three-roller, a ball mill or other dispersing machine, and appropriately combining these. The above-mentioned heat drying is not particularly limited as long as the solvent used is sufficiently volatilized, but it can be usually performed by heating at 60 ° C. to 200 ° C. for 0.1 to 90 minutes.

  The organic solvent for producing the varnish is not particularly limited as long as it can uniformly dissolve, knead or disperse the above components, and a conventionally known one can be used. Examples of such a solvent include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, toluene, xylene, and the like. It is preferable to use methyl ethyl ketone, cyclohexanone, etc. in terms of fast drying speed and low price.

  There is no restriction | limiting in particular as said base film, For example, a polyester film, a polypropylene film (OPP film etc.), a polyethylene terephthalate film, a polyimide film, a polyetherimide film, a polyether naphthalate film, a methylpentene film etc. are mentioned. .

  The thickness of the film-like pressure-sensitive adhesive is preferably equal to or less than the unevenness on the surface of the semiconductor element, preferably 5 to 130 μm, from the viewpoint of sufficiently embedding the unevenness on the surface of the semiconductor element.

<Manufacturing method of thinned substrate to be ground>
An example of a method for manufacturing a substrate to be ground such as a thinned silicon wafer according to this embodiment will be described below. (B) A film-like pressure-sensitive adhesive is affixed on a support at 60 to 120 ° C. by roll lamination. For example, a glass plate or a silicon wafer is used as the support. Next, (c) the substrate to be ground is (80) 150-150 ° C./0.01-0.2 MPa / 1-5 min, 1-15 mbar using a vacuum bonding apparatus on the film-like adhesive. Vacuum bonding is performed to obtain a laminate. (C) The non-circuit surface of the substrate to be ground in the obtained laminate is ground to a desired thickness, and then (a) the film-like pressure-sensitive adhesive and (b) the support are removed to support (b) Collect body. Next, after grinding (c) the film-like pressure-sensitive adhesive remaining on the substrate to be ground was peeled and removed under room temperature to 80 ° C. heating conditions (c) the substrate to be ground Can be obtained.

  As mentioned above, although (a) film-like adhesive which concerns on this invention, its manufacturing method, and (c) the manufacturing method of the to-be-ground base material reduced in thickness was demonstrated, this invention is not necessarily the embodiment mentioned above. However, the present invention is not limited to this, and changes may be made as appropriate without departing from the spirit of the invention.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

(Examples 1-10 and Comparative Examples 1-2)
(A1) epoxy resin and phenol resin as thermosetting resin, product name and composition ratio (unit: part by mass) shown in Table 1 or Table 2, (a3) silicone compound, and (a5) inorganic filler as required Cyclohexanone was added to the composition and mixed with stirring. To this, (a2) acrylic rubber as a high molecular weight component shown in Table 1 or Table 2 is added and stirred, and (a4) a curing accelerator shown in Table 1 or Table 2 is added to make each component uniform. To obtain a varnish of a thermosetting resin composition for forming a film-like pressure-sensitive adhesive.

The symbol of each component in Table 1 and Table 2 means the following.
(Epoxy resin)
EXA830-CRP (trade name, manufactured by DIC Corporation, bisphenol F type epoxy resin, epoxy equivalent: 155-163, liquid at room temperature).
YDCN-700-10 (trade name, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., cresol novolac type epoxy resin, epoxy equivalent: 210, softening point: 75-85 ° C).

(Phenolic resin)
Millex XLC-LL (trade name, manufactured by Mitsui Chemicals, phenol resin, hydroxyl equivalent: 175, softening point: 77 ° C.).
GPH103 (trade name, manufactured by Nippon Kayaku Co., Ltd., phenol resin, hydroxyl group equivalent: 230, softening point: 99 to 106 ° C.).

(Acrylic rubber)
Acrylic rubber HTR-860P-3CSP (sample name, manufactured by Teikoku Chemical Industry Co., Ltd., weight average molecular weight: 800,000, glycidyl functional group monomer ratio: 3 mass%, Tg: −7 ° C.).
Acrylic rubber HTR-860P-30B-CHN (sample name, manufactured by Teikoku Chemical Industry Co., Ltd., weight average molecular weight: 230,000, glycidyl functional group monomer ratio: 8% by mass, Tg: −7 ° C.).

(Silicone compound)
TA31-209E (trade name, manufactured by Hitachi Chemical Co., Ltd., thermosetting resin, 5% weight reduction temperature: 233 ° C.).
KF-105 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., epoxy-modified silicone oil, 5% weight reduction temperature: 223 ° C.).
X-22-4741 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., epoxy / polyether-modified silicone oil, 5% weight reduction temperature: 201 ° C.).
SH3773M (trade name, manufactured by Toray Dow Corning Co., Ltd., polyether-modified silicone oil, 5% weight reduction temperature: 215 ° C.).

(Curing accelerator)
Cureazole 2PZ-CN (trade name, manufactured by Shikoku Kasei Kogyo Co., Ltd., 1-cyanoethyl-2-phenylimidazole).

(Inorganic filler)
R972 (trade name, manufactured by Nippon Aerosil Co., Ltd., surface treatment: dimethylsilane treatment, average particle size: 0.016 μm).
SC2050-HLG (trade name, manufactured by Admatechs Co., Ltd., surface treatment: epoxysilane treatment, average particle size: 0.5 μm).
SC2050 phenylsilane treated product (prototype, manufactured by Admatechs, surface treatment: phenylsilane treatment, average particle size: 0.5 μm).

  Next, each varnish obtained was filtered through a 100 mesh filter and vacuum degassed. The varnish after vacuum defoaming was applied onto a polyethylene terephthalate (PET) film having a thickness of 38 μm as a base film. The applied varnish was heat-dried in two stages of 90 ° C. for 5 minutes, followed by 140 ° C. for 5 minutes. Thus, a film-like pressure-sensitive adhesive having a thickness of 40 μm formed on a PET film as a base film was obtained.

<Evaluation of various physical properties>
About the obtained film-like pressure-sensitive adhesive, shear viscosity, 200 ° C. elastic modulus after curing, 30 ° peel strength from the silicon mirror wafer, confirmation of the presence or absence of voids in the laminate, peelability with a debonding apparatus, and heat resistance at 200 ° C. Sexuality was evaluated.

[Shear viscosity]
The shear viscosity of the film adhesive was evaluated by the following method.
The base film was peeled and removed from the film-like pressure-sensitive adhesive obtained above (thickness: 40 μm), and then roll-laminated at 80 ° C. and four layers were stacked to obtain a laminate having a thickness of 160 μm. This was punched into a 10 mm square in the thickness direction to obtain a quadrangular laminate having a 10 mm square and a thickness of 160 μm. A circular aluminum plate jig having a diameter of 8 mm was set in a dynamic viscoelastic device ARES (manufactured by Rheometric Scientific), and a laminate of a film-like adhesive punched out was set here. Thereafter, measurement was performed while increasing the temperature to 150 ° C. at a temperature increase rate of 20 ° C./min while giving a strain of 5% at 35 ° C., and the temperature at which the shear viscosity value was 20000 Pa · s was recorded.

[200 ° C elastic modulus after curing]
The 200 ° C. elastic modulus after curing of the film adhesive was evaluated by the following method.
The substrate film was peeled and removed from the film-like pressure-sensitive adhesive (thickness 40 μm) obtained above, then cut into 4 mm width and 30 mm length, and heated in a 130 ° C. oven for 15 minutes and 170 ° C. for 15 minutes. The obtained sample was set in a dynamic viscoelastic device (product name: manufactured by Rheogel-E4000 Co., Ltd. UMB), applied with a tensile load, measured at a frequency of 10 Hz and a temperature rising rate of 3 ° C./min, and at 200 ° C. The measured value was recorded.

[30 ° peel strength from silicon mirror wafer]
The 30 ° peel strength from the silicon mirror wafer was evaluated by the following method.
The film-like adhesive (thickness 40 μm) obtained above was roll-laminated at 80 ° C. on the surface of a 625 μm-thick silicon mirror wafer (6 inches). After peeling the base film from the obtained sample, the film-like pressure-sensitive adhesive was cured by heating in an oven at 130 ° C. for 15 minutes and at 170 ° C. for 15 minutes. Then, after heating at 200 degreeC for 10 minute (s) and sticking an adhesive tape (the Oji Tac Co., Ltd. product, PP tape # 400, product number 204H) as a support tape, it cut out to 10 mm width. Using the cut sample, a peel test was performed at a speed of 300 mm / s with a peel tester set so that the peel angle was 30 °, and the peel strength at that time was recorded. In the peel test, no adhesive residue remained on the silicon mirror wafer after the film-like pressure sensitive adhesive of each Example was peeled off.

[Confirmation of presence or absence of voids in the laminate]
The presence or absence of voids in the laminate was confirmed by the following method.
A silicon mirror wafer was used as the support, and the film-like pressure-sensitive adhesive (thickness 40 μm) obtained above was attached thereto by roll lamination at 80 ° C. to obtain a support equipped with the film-like pressure-sensitive adhesive. Next, the base film on the film-like adhesive is peeled off, and a base material to be ground (silicon mirror wafer, thickness 770 μm) is placed here at 120 ° C./0.1 MPa / 5 min with a vacuum bonding apparatus (manufactured by SUSS MicroTech, LF12). Vacuum bonding was performed at 5 mbar to obtain a laminate. The laminated body thus obtained was inspected with an ultrasonic imaging apparatus SAT (manufactured by Hitachi Construction Machinery, FS200II), and the presence or absence of voids was confirmed. The evaluation criteria for the presence or absence of voids are as follows.
○: Void ratio is less than 5%.
X: Void ratio is 5% or more.

[Peelability with debonding equipment]
The peelability of the film adhesive with a debonding apparatus was evaluated by the following method.
A silicon mirror wafer was used as the support, and the film-like pressure-sensitive adhesive (thickness 40 μm) obtained above was attached thereto by roll lamination at 80 ° C. to obtain a support equipped with the film-like pressure-sensitive adhesive. Next, the base film on the film-like adhesive is peeled off, and a base material to be ground (silicon mirror wafer, thickness 770 μm) is placed here at 120 ° C./0.1 MPa / 5 min with a vacuum bonding apparatus (manufactured by SUSS MicroTech, LF12). Vacuum bonding was performed at 5 mbar to obtain a laminate. The laminate thus obtained is heated at 130 ° C. for 15 minutes and 170 ° C. for 1 minute to cure the film-like pressure-sensitive adhesive, and then grinds the substrate to be ground to 50 μm with a grinder (manufactured by Disco, DGP8761HC). Grinded. Next, after heating at 200 ° C. for 10 minutes, a dicing tape (manufactured by Furukawa Electric Co., Ltd., UC-353EP-110) is pasted on the substrate to be ground, and a debonding apparatus (manufactured by SUSS MicroTech, DB12T). Debond evaluation was performed. A sample in which both of the support and the substrate to be ground could be separated without damage was marked with ◯, and a sample that could not be separated or damaged was marked with ×.

[Heat resistance at 200 ° C]
The heat resistance at 200 ° C. of the film adhesive was evaluated by the following method.
A 625 μm thick silicon mirror wafer (6 inches) was cut into 30 mm square pieces by blade dicing. The film-like adhesive obtained above was roll-laminated at 80 ° C. on the surface of the silicon mirror wafer that had been cut into pieces. Next, after peeling and removing the base film on the film-like adhesive, a slide glass having a thickness of 0.1 to 0.2 mm and a size of about 18 mm square is roll-laminated at 80 ° C. on the film-like adhesive. A laminated product sandwiched between a silicon wafer and a slide glass was produced. The obtained sample was heated at 130 ° C. for 15 minutes and 170 ° C. for 15 minutes to cure the film adhesive, and then heated at 200 ° C. for 10 minutes.

The sample thus obtained was observed from the slide glass surface, and the image was analyzed with software such as Photoshop (registered trademark), and the heat resistance at 200 ° C. was determined from the ratio of voids in the total area of the film adhesive. evaluated. The evaluation criteria are as follows.
○: Void ratio is less than 5%.
X: Void ratio is 5% or more.

  As is clear from the results shown in Tables 3 and 4, the film-like pressure-sensitive adhesives of Examples 1 to 10 were compared with the film-like pressure-sensitive adhesives of Comparative Examples 1 and 2 at 30 ° peel strength from the silicon mirror wafer. As a result, it was confirmed that the debonding evaluation was good.

Claims (6)

A film-like pressure-sensitive adhesive having a thickness of 5 μm to 130 μm made of a thermosetting resin composition,
(A1) A thermosetting component containing at least one of an epoxy resin and a phenol resin, wherein the epoxy resin has a softening point of 110 ° C. or lower or is liquid at room temperature, and the epoxy resin and the phenol resin A thermosetting component having a total amount of 40 parts by mass or more with respect to 100 parts by mass of the thermosetting component;
(A2) a high molecular weight component having a weight average molecular weight of 150,000 to 1,000,000 and a glass transition temperature of −50 ° C. to 50 ° C. and containing 1 to 10% by mass of monomer units having a crosslinkable functional group;
(A3) a silicone compound having a crosslinkable functional group and having a 5% mass reduction temperature of 200 ° C. or higher;
(A4) a curing accelerator and, if necessary,
(A5) inorganic filler;
Containing
For 100 parts by mass of the (a1) thermosetting component,
The content of the (a2) high molecular weight component is 25 to 1200 parts by mass,
The content of the (a3) silicone compound is 8 to 430 parts by mass,
The content of the (a4) curing accelerator is 0.05 to 3.0 parts by mass, and
The content of the (a5) inorganic filler is 70 parts by mass or less,
The film-like adhesive and the silicon mirror wafer were directly laminated on the silicon mirror wafer and heated in order of 15 minutes at 130 ° C., 15 minutes at 170 ° C. and 10 minutes at 200 ° C. Ri der 30 ° peel strength is 300N / m or less between,
The elastic modulus at 200 ° C. after curing is 0.1 MPa or more,
The shear viscosity before curing as measured while raising the temperature from 35 ° C., the temperature at which the shear viscosity decreases below 20000 Pa · s is Ru 40 ° C. to 150 DEG ° C. der, film-like adhesive.   The film adhesive is directly laminated on the silicon mirror wafer and heated in order of 130 ° C. for 15 minutes, 170 ° C. for 15 minutes, and 200 ° C. for 10 minutes, and then the residue is substantially left on the silicon mirror wafer. The film-like pressure-sensitive adhesive according to claim 1, wherein the film-like pressure-sensitive adhesive can be peeled off from the silicon mirror wafer. (A) The film-like pressure-sensitive adhesive according to claim 1 or 2 , (b) a support, and (c) a substrate to be ground.
The (a) film-like adhesive is laminated on the (c) substrate to be ground, and the (c) substrate to be ground is attached to the (b) support via the (a) film-like adhesive. A laminate that is fixed. The laminate according to claim 3 , wherein the (b) support is a glass plate or a silicon mirror wafer. The laminate according to claim 3 or 4 , wherein the substrate to be ground (c) is a silicon mirror wafer. A step of grinding the substrate to be ground (c) provided in the laminate according to any one of claims 3 to 5,
The ground substrate (c) to be ground (b) so that the (a) film-like pressure-sensitive adhesive remains on either the (c) ground substrate or the (b) support. ) Separating from the support;
(C) peeling the (a) film-like pressure-sensitive adhesive from the (c) substrate to be ground or the (b) support;
A method for producing a ground substrate.