JP2010258086A - Adhesive sheet for semiconductor, and dicing tape integrated type adhesive sheet for semiconductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin-film adhesive sheet for a semiconductor that has adhesivity equivalent to or more than conventional one and is superior in filling property of unevenness during molding. <P>SOLUTION: The adhesive sheet is made of adhesive resin composition containing at least high molecular weight element, wherein the adhesive strength between an adhesive sheet before curing at 70°C and a silicon wafer is ≥100 N/m, the elastic modulus is 1 to 3,000 MPa at 35°C, the storage elasticity after curing is less than 5 MPa at 170°C by dynamic viscoelasticity, and a ratio of adhesive strength after curing and moisture adsorption to die shear strength before moisture adsorption is ≥0.7 or. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a semiconductor adhesive sheet and a dicing integrated semiconductor adhesive sheet.

  Conventionally, the thickness of the adhesive sheet used for the semiconductor element has been 10 μm to 60 μm. However, with recent miniaturization and high performance of the semiconductor element, the support member used is also miniaturized and finer. Has come to be required. In response to these requirements, the adhesive sheet is required to be further thinned. However, when the conventional adhesive sheet is thinned, sufficient characteristics cannot be obtained. Therefore, an adhesive sheet that can be thinned is required to cope with the above requirement.

  This adhesive sheet is used in the individual piece attaching method or the silicon wafer back surface attaching method. When manufacturing the semiconductor device using the former individual piece attaching method adhesive sheet, the reel-like adhesive sheet is cut or punched. If the adhesiveness to the silicon wafer is low, cutting waste such as a silicon wafer enters between the adhesive sheet and damages the semiconductor element in the subsequent process, resulting in a decrease in yield. There's a problem. When trying to solve this problem with conventional technology, increasing the low molecular weight component, increasing the low temperature softening component, etc. have been studied. In this case, in order to improve the adhesiveness of the adhesive sheet itself, combined with dicing tape When using it, there arises a problem that the pickup property is lowered.

  On the other hand, reliability is one of the most important characteristics as a mounting board on which various electronic components such as semiconductor elements are mounted. Among them, the connection reliability against thermal fatigue is a very important item because it is directly related to the reliability of the equipment using the mounting substrate. As a cause of lowering the connection reliability, there is a thermal stress generated by using various materials having different thermal expansion coefficients. This is because the thermal expansion coefficient of the semiconductor element is as small as about 4 ppm / ° C., whereas the thermal expansion coefficient of the wiring board on which the electronic component is mounted is as large as 15 ppm / ° C. Since thermal stress is generated by the thermal strain, this stress relaxation is a problem. Further, such a wiring board generally has unevenness due to wiring, and it is necessary to bury the unevenness of the wiring board. From the viewpoints of stress relaxation and embedding on the substrate, it is desirable that the adhesive sheet for semiconductors has a somewhat low elastic modulus after curing, but it is common to add an inorganic filler to improve the cutting property of the adhesive sheet. In addition, it is known that the adhesive sheet becomes highly elastic and the adhesiveness with the silicon wafer decreases, and it is necessary to satisfy both the adhesiveness with the silicon wafer and the reliability of the semiconductor package when thinning the adhesive sheet for semiconductors. It has become.

JP 2006-093213 A

When the conventional adhesive sheet is made thin, the adhesive force with the silicon wafer is insufficient, so cutting waste enters between the silicon wafer in the singulation process, and foreign matter is found between the mounting board and the adhesive sheet during molding. A problem of intrusion occurred. In addition, as semiconductor devices have higher performance, smaller size, and thinner thickness, there is a demand for thinner adhesive sheets for semiconductors. Conventional semiconductor sheets are used in a thickness of 10 μm to 60 μm. However, when the thickness is reduced, the adhesive strength with a silicon wafer and the embedding property of the semiconductor element in the state before curing are lowered.
An object of the present invention is to provide an adhesive sheet for a semiconductor which is an adhesive sheet of a thin film and has an adhesive property equal to or higher than that of a conventional one and is excellent in uneven embedding property at the time of molding. And it aims at providing the adhesive sheet for semiconductors which improved the embedding property of the unevenness | corrugation of a semiconductor element, the adhesive force with a silicon wafer, and the wettability to an organic substrate.

The present invention is as follows.
(1) An adhesive sheet comprising an adhesive resin composition containing at least a high molecular weight component, wherein the adhesive strength between the adhesive sheet before curing at 70 ° C. and the silicon wafer is 100 N / m or more, and elasticity at 35 ° C. The rate of elasticity is 1 to 3000 MPa, the storage elastic modulus by dynamic viscoelasticity measurement after curing is less than 5 MPa at 170 ° C., and the ratio of adhesive force after moisture absorption after curing / die shear strength ratio before moisture absorption is 0. An adhesive sheet for semiconductors, wherein the adhesive sheet is 7 or more.
(2) The adhesive sheet for semiconductor, wherein the adhesive resin composition does not contain a filler.
(3) The adhesive sheet for a semiconductor described above, wherein the adhesive resin composition further contains a silane coupling agent having an isocyanate group.
(4) The said adhesive sheet for semiconductors whose thickness is 1 micrometer-5 micrometers.
(5) The above-mentioned adhesive sheet for semiconductor, characterized in that, in the high molecular weight component, Tg is −10 to 60 ° C. and the weight average molecular weight is 20,000 to 1,000,000.
(6) A dicing integrated semiconductor adhesive sheet obtained by laminating the semiconductor adhesive sheet and a dicing tape.

  The present inventors have found that conventional problems can be solved by improving the adhesion between a thin film (5 μm or less) adhesive sheet and a silicon wafer and controlling the elastic modulus after curing. Moreover, since the adhesive sheet does not contain a filler, a good appearance can be obtained even with a thin film (thickness of 5 μm or less). Since the adhesive sheet of the present invention does not have a filler, it can improve the adhesive force with the silicon wafer and improve the embedding property of the semiconductor elements. Furthermore, the adhesive force with a silicon wafer is improved by adding a silane coupling agent having an isocyanate group.

  The present invention is an adhesive sheet comprising an adhesive resin composition containing at least a high molecular weight component, wherein the adhesive strength between the adhesive sheet before curing at 70 ° C. and the silicon wafer is 100 N / m or more, and 35 ° C. The elastic modulus is 1-3000 MPa, the storage elastic modulus by dynamic viscoelasticity measurement after curing is less than 5 MPa at 170 ° C., and the ratio of the adhesive strength after moisture absorption after curing / die shear strength ratio before moisture absorption is 0. .7 or more.

  The adhesive force between the adhesive sheet before curing of the adhesive sheet for semiconductor of the present invention at 70 ° C. and the silicon wafer is 100 N / m or more. If the adhesive force with the silicon wafer is less than 100 N / m, cutting waste may enter between the adhesive sheet and the like in a dicing process for dividing the silicon wafer into pieces. The adhesive strength with the silicon wafer of the present invention was determined by using a 90 ° peel tester (manufactured by Tester Sangyo Co., Ltd.), attaching a reinforcing tape to the adhesive sheet, and then peeling off a part of the adhesive sheet from the silicon wafer. The peel strength when pulled at a test speed of 50 mm / sec at an angle of 90 ° at 0 ° C. was measured as the adhesive strength.

The storage elastic modulus at 170 ° C. after 3 hours at 170 ° C. is preferably less than 5 MPa, and more preferably 2 to 4 MPa. If the storage elastic modulus at 170 ° C. after curing is less than 1 MPa, the adhesive sheet may protrude, and if it is 5 MPa or more, the embeddability in the substrate irregularities may be lowered. The elastic modulus is measured by using a dynamic viscoelasticity measuring device (DVE-V4 manufactured by Rheology), applying a tensile load to the cured adhesive, and having a frequency of 10 Hz and a temperature increase rate of 3 to 10 ° C./min to −50 ° C. To 300 ° C. in a temperature dependence measurement mode.
Bonding using a hot roll laminator under conditions of temperature 70 ° C., pressure 0.3 MPa, speed 0.3 m / min, and then organic substrate (containing epoxy resin in glass cloth under conditions of 0.1 MPa, 5 s, 120 ° C. The adhesive strength between the adhesive sheet and the substrate after the moisture absorption treatment (temperature 85 ° C., humidity 85% atmosphere, 48 hours) Was measured by die shear strength measurement (manufactured by Dage, measurement temperature 180 ° C.) under the condition of 265 ° C.

  In the present invention, when the content of the high molecular weight component (thermoplastic resin) is less than 40% by mass, the elastic modulus after curing may be high and the embedding property to the substrate unevenness may be lowered, and storage after curing is also possible. It becomes difficult to control the elastic modulus. On the other hand, if it exceeds 95% by mass, the elastic modulus after curing is low and the reliability may be lowered, and it becomes difficult to control the storage elastic modulus after curing. Therefore, the content of the high molecular weight component (thermoplastic resin) is preferably 40 to 95% by mass, and more preferably 45 to 70% by mass. The weight average molecular weight of the high molecular weight component is preferably 20,000 to 1,000,000, more preferably 100,000 to 900,000, and most preferably 200,000 to 800,000. If the weight average molecular weight is less than 20,000, there is a possibility that the strength and flexibility in sheet form and film form will be lowered and tackiness will be increased. Sexuality gets worse.

  In the adhesive sheet of the present invention, since the storage elastic modulus after curing is 6 MPa or more at 150 ° C. and less than 5 MPa at 170 ° C., the filler content is 5% by mass or less with respect to the adhesive resin composition. It is more preferable that the filler is not contained.

  Examples of the high molecular weight component include a polyamide resin, a polyimide resin, and a polyamideimide resin. The weight average molecular weight including 0.5 to 6% by mass of glycidyl acrylate or glycidyl methacrylate which is incompatible with the epoxy resin is 500,000 or more. A certain epoxy group-containing acrylic copolymer is preferred.

  The epoxy group-containing acrylic copolymer having a weight average molecular weight of 0.5 to 6% by mass including glycidyl acrylate or glycidyl methacrylate is not particularly limited, and HTR-860P-3DR manufactured by Nagase Chemtech Co., Ltd. Can be used. When the functional group monomer is carboxylic acid type acrylic acid or hydroxyl group type hydroxymethyl (meth) acrylate, the crosslinking reaction is likely to proceed, gelling in the varnish state, and increasing the degree of curing in the pre-curing state This is not preferable because there is a problem such as a decrease in adhesive strength due to. Moreover, the quantity of the glycidyl (meth) acrylate used as a functional group monomer shall be 2-6 mass% copolymer ratio. If it is 2% by mass or less, the adhesive force may be reduced, and if it is 6% by mass or more, gelation may occur. The balance can be ethyl (meth) acrylate or butyl (meth) acrylate or a mixture of both, but the mixing ratio is determined in consideration of the glass transition temperature of the copolymer (hereinafter abbreviated as Tg), and Tg is It is preferable that it is -10 degreeC or more and 60 degrees C or less. If Tg is less than −10 ° C., the tackiness of the adhesive sheet in the pre-curing state increases, and the handleability may deteriorate. The polymerization method is not particularly limited, and pearl polymerization, solution polymerization and the like can be used.

  The adhesive resin composition used in the present invention preferably contains a thermosetting resin in order to obtain a good adhesive force after curing. Examples of such compounds include epoxy resins, cyanate resins, bismaleimide resins, phenol resins, urea resins, melamine resins, alkyd resins, acrylic resins, unsaturated polyester resins, diaryl phthalate resins, silicone resins, resorcinol formaldehyde resins, From xylene resin, furan resin, polyurethane resin, ketone resin, triaryl cyanurate resin, polyisocyanate resin, resin containing tris (2-hydroxyethyl) isocyanurate, resin containing triaryl trimellitate, cyclopentadiene Examples include synthesized resins and thermosetting resins by trimerization of aromatic dicyanamide. Among these, an epoxy resin, a cyanate resin, and a bismaleimide resin are preferable, and an epoxy resin is more preferable in that an excellent adhesive force can be given at a high temperature. In addition, these thermosetting resins can be used individually or in combination of 2 or more types.

  The thermosetting resin is not particularly limited as long as the softening point measured by a ring and ball method is 50 ° C. or higher. For example, Epicoat 1001, 1002, 1003, 1055, 1004, 1004AF, 1007, manufactured by Yuka Shell Epoxy Co., Ltd. 1009, 1003F, 1004F, manufactured by Dow Chemical Japan Co., Ltd. E. R. Bisphenol A type epoxy resins such as 661, 662, 663U, 664, 664U, 667, 642U, 672U, 673MF, 668, 669, etc., bisphenol F type epoxy resins such as YDF-2004 manufactured by Tohto Kasei Co., Ltd., Nippon Kayaku Co., Ltd. Phenol novolac type epoxy resin such as EPPN-201 manufactured by Epikap 180S65 manufactured by Yuka Shell Epoxy Co., Ltd., Araldite ECN1273, 1280, 1299 manufactured by Ciba Specialty Chemicals, YDCN-701, 702, 703, 704 manufactured by Tohto Kasei Co., Ltd. Nippon Kayaku Co., Ltd. EOCN-1020, 102S, 103S, 104S, Sumitomo Chemical Co., Ltd. ESCN-195X, 200L, 220, etc. Cresol novolac epoxy resin, oily shell epoxy Epon 1031S, Epicoat 1032H60, 157S70, Nippon Kayaku Co., Ltd., EPPN 501H, 502H, etc., polyfunctional epoxy resins, Ciba Specialty Chemicals Co., Ltd., Araldite PT810, etc. It is not limited to.

  The silane coupling agent used in the present invention is effective for further improving the adhesive force with a silicon wafer, and a silane coupling agent having an isocyanate group is particularly preferable. Examples of the silane coupling agent having an isocyanate group include compounds having an isocyanate group and an alkoxysilyl group at both ends of an alkyl group, for example, γ-isocyanatepropyltrimethoxysilane, γ-isocyanatepropyltriethoxysilane, Examples include γ-isocyanatopropylmethyldimethoxysilane, γ-isocyanatopropylmethyldiethoxysilane, and the like can be used alone or in combination of two or more. It can also be used in combination with other silane coupling agents, and the type is not limited. For example, vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, etc. Methacryloylsilanes such as vinylsilanes, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, methyltri (methacryloyloxyethoxy) silane, β- (3,4 -Epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, methyltri Epoxy group-containing silanes such as (zyloxy) silane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N -Phenyl-γ-aminopropyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, N-methyl-3-aminopropyltrimethoxysilane, triaminopropyl-trimethoxysilane, 3- Aminosilanes such as 4,5-dihydroimidazol-1-yl-propyltrimethoxysilane, amyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, 3-mercaptopropyl-methyldimethoxysilane Mercaptosilanes such as ethylene, urea bond-containing silanes such as 3-ureidopropyltriethoxysilane and 3-ureidopropyltrimethoxysilane, trimethylsilyl isocyanate, dimethylsilyl isocyanate, methylsilyl triisocyanate, vinylsilyl triisocyanate, phenylsilyltri Isocyanate group-containing silanes such as isocyanate, tetraisocyanate silane, ethoxysilane isocyanate, 3-chloropropyl-methyldimethoxysilane, 3-chloropropyl-dimethoxysilane, 3-cyanopropyl-triethoxysilane, hexamethyldisilazane, N, o-bis (trimethylsilyl) acetamide, methyltrimethoxysilane, methyltriethoxysilane, ethyltrichlorosilane, n-propyltrimethyl Toxisilane, isobutyltrimethoxysilane, octyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, N-β (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane, octadecyldimethyl [3- (trimethoxy Silyl) propyl] ammonium chloride, γ-chloropropylmethyldichlorosilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, and the like can be used.

  0.005-5 mass% is preferable with respect to 100 mass% of total amounts of an adhesive resin composition, and, as for the addition amount of a silane coupling agent, 0.01-3 mass% is more preferable. If the addition amount is less than 0.005% by mass, the effect of improving the adhesive force tends to be not obtained, and if it exceeds 5% by mass, the cost performance tends to decrease.

  The adhesive resin composition may include a curing agent that cures the thermosetting resin. An example of such a curing agent is a phenol resin. The phenolic resin is not particularly limited, and has a water absorption of 2% by mass or less after being put into a constant temperature and humidity chamber of 85 ° C. and 85% RH for 48%, and heated at 350 ° C. measured with a thermogravimetric analyzer (TGA). A material having a mass reduction rate (temperature increase rate: 5 ° C./min, atmosphere: nitrogen) of less than 5% by mass can be used. Such a phenol resin is usually obtained by reacting a phenol compound and a xylylene compound which is a divalent linking group in the presence of no catalyst or an acid catalyst. Representative examples of the phenol resin produced in this way include the Mirex XLC-series and XL series manufactured by Mitsui Chemicals.

  A curing accelerator can also be added to the adhesive resin composition. There is no restriction | limiting in particular in a hardening accelerator, Various imidazoles can be used. Examples of imidazoles include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, and the like. Two or more kinds can be used in combination.

  0.003-5 mass parts is preferable with respect to 100 mass parts of total amounts with an epoxy resin and a phenol resin, and, as for the addition amount of a hardening accelerator, 0.005-3 mass parts is more preferable. When the addition amount is less than 0.003 parts by mass, the curability tends to be inferior, and when it exceeds 5 parts by mass, the storage stability tends to decrease.

  Furthermore, an ion scavenger can be added to the adhesive resin composition in order to adsorb ionic impurities and improve insulation reliability during moisture absorption. As the ion scavenger, there is no particular limitation, and a compound known as a copper damage preventive agent to prevent copper from ionizing and dissolving, for example, a triazine thiol compound, a bisphenol-based reducing agent, etc. can be used. Inorganic ion adsorbents such as zirconium-based and antimony bismuth-based magnesium aluminum compounds can also be used. The addition amount of the ion scavenger is preferably 1 to 10% by mass from the effect of addition, heat resistance and cost.

  The weight average molecular weight of the thermosetting resin is not particularly limited, but if it is less than 10,000, it is often a low-viscosity liquid and may reduce the breakability of the adhesive sheet. Moreover, when it exceeds 100,000, there is a possibility that the breakability of the adhesive sheet is lowered due to the entanglement of molecules between the resins as the molecular weight increases. Therefore, the weight average molecular weight of the thermosetting resin is preferably from 10,000 to 100,000, more preferably from 20,000 to 10,000, and from 30,000 to 5,000. Is most preferred.

The adhesive sheet for semiconductors of the present invention can be obtained by dissolving or dispersing the adhesive resin composition in a solvent to form a varnish, applying the solution on a support film and heating to remove the solvent.
As the support film, a plastic film such as a polytetrafluoroethylene film, a polyethylene terephthalate film, a polyethylene film, a polypropylene film, a polymethylpentene film, or a polyimide film can be used. It can also be processed and used. The support film can be peeled off at the time of use, and only the adhesive sheet can be used, or it can be used together with the support film and removed later.

The varnishing solvent is not particularly limited, but in consideration of volatility during coating and heating, methyl ethyl ketone, acetone, methyl isobutyl ketone, 2-ethoxyethanol, toluene, xylene, butyl cellosolve, methanol, ethanol It is preferable to use a solvent having a relatively low boiling point such as 2-methoxyethanol. For the purpose of improving the coating properties, a solvent having a relatively high boiling point such as dimethylacetamide, dimethylformamide, N-methylpyrrolidone, cyclohexanone can be added.
As a method for applying the varnish to the support film, a known method can be used, and examples thereof include a knife coating method, a roll coating method, a spray coating method, a gravure coating method, a bar coating method, and a curtain coating method. .

  The thickness of the adhesive sheet is preferably 1 to 5 μm. If it is thinner than 1 μm, film forming properties are difficult, and if it is thicker than 5 μm, it does not meet the recent customer requirements. On the other hand, two or more adhesive sheets in the adhesive member of the present invention can be bonded together in order to obtain a desired thickness. In this case, it is necessary to have a bonding condition in which peeling between the adhesive sheets does not occur.

  Moreover, said adhesive sheet is used also as a dicing tape integrated adhesive sheet previously bonded with the dicing tape. In this case, the efficiency of the operation can be improved in that the laminating process on the wafer is performed only once. Examples of the dicing tape used in the present invention include plastic films such as a polytetrafluoroethylene film, a polyethylene terephthalate film, a polyethylene film, a polypropylene film, a polymethylpentene film, and a polyimide film. These can be used in a multilayer structure with other materials. Further, surface treatment such as primer coating, UV treatment, corona discharge treatment, polishing treatment and etching treatment may be performed as necessary. The dicing tape preferably has adhesiveness, and an adhesive layer may be provided on one side of the dicing tape. This can be formed by applying and drying a resin composition having an appropriate tack strength obtained by adjusting the ratio of the liquid component and the Tg of the high molecular weight component in the resin composition of the pressure-sensitive adhesive layer.

  Further, when used in manufacturing a semiconductor device, it has an adhesive force that prevents the semiconductor element from scattering during dicing, and after that, it must be peeled off from the dicing tape during pick-up. For example, separation may be difficult when the adhesive strength of the adhesive sheet or dicing tape is too high and the peel strength when they are laminated is 150 N / m or more. Therefore, it is preferable to appropriately adjust the tack strength of the adhesive sheet, and as a method thereof, the adhesive strength and tack strength tend to increase by increasing the fluidity of the adhesive sheet at room temperature (25 ° C.). What is necessary is just to utilize that there exists a tendency for adhesive strength and tack strength to fall, if fluidity | liquidity is reduced. For example, in order to increase fluidity, there are methods such as increasing the plasticizer content and increasing the tackifier content. Conversely, when the fluidity is lowered, the content of the compound may be reduced. Examples of the plasticizer include monofunctional acrylic monomers, monofunctional epoxy resins, liquid epoxy resins, acrylic resins, and epoxy-based so-called diluents.

  The adhesive sheet of the present invention may be used by itself, but can also be used as a dicing tape-integrated adhesive sheet in which the adhesive sheet of the present invention is laminated on a conventionally known dicing tape. The peel strength of the dicing tape integrated adhesive sheet obtained by laminating the adhesive sheet and the dicing tape is preferably 150 N / m or less, and more preferably 50 N / m or less. As a method of laminating the adhesive sheet on the dicing tape, in addition to printing, a pre-made adhesive sheet can be pressed on the dicing tape and a hot roll laminating method. However, it can be continuously manufactured and is hot in terms of efficiency. A roll laminating method is preferred. In addition, the film thickness of the dicing tape is not particularly limited, and is appropriately determined based on the knowledge of a person skilled in the art depending on the film thickness of the adhesive sheet and the application of the dicing tape-integrated adhesive sheet. The film has a handleability of 60 to 200 μm, preferably 70 to 170 μm in terms of good handleability.

  The adhesive sheet of the present invention is suitably used when manufacturing a semiconductor device. When a semiconductor device is manufactured, the semiconductor mounting support member can be used without being limited to a substrate material such as a lead frame having a die pad, a ceramic substrate, or an organic substrate. As the ceramic substrate, an alumina substrate, an aluminum nitride substrate, or the like can be used. As an organic substrate, an FR-4 substrate in which an epoxy resin is impregnated in a glass cloth, a BT substrate in which a bismaleimide-triazine resin is impregnated, a polyimide film substrate using a polyimide film as a base material, or the like is used. Can do. Further, as the semiconductor mounting support member, a wiring may be formed.

  The shape of the wiring may be any of single-sided wiring, double-sided wiring, and multilayer wiring, and may be provided with through-holes and non-through-holes that are electrically connected as necessary. Further, when the wiring appears on the outer surface of the semiconductor device, it is preferable to provide a protective resin layer. As a method of attaching the adhesive member to the support member, a method of cutting the adhesive member into a predetermined shape and thermocompression bonding the cut adhesive member to a desired position of the support member is generally limited. Not what you want.

  As the structure of the semiconductor device, the electrode of the semiconductor element and the support member are connected by wire bonding, and the electrode of the semiconductor element and the support member are connected by inner lead bonding of tape automated bonding (TAB). Although there are structures, etc., the present invention is not limited to these and is effective in any case. As the semiconductor element, a general semiconductor element such as an IC, LSI, VLSI can be used.

  The thermal stress generated between the semiconductor element and the supporting member is significant when the area difference between the semiconductor element and the supporting member is small. However, the semiconductor device uses a low elastic modulus adhesive member to relieve the thermal stress and increase reliability. Ensure sex. These effects appear very effectively when the area of the semiconductor element is 70% or more of the area of the support member. In such a semiconductor device having a small area difference between the semiconductor element and the support member, the external connection terminals are often provided in an area. Further, as a characteristic of the adhesive member, volatile matter from the adhesive sheet can be suppressed in a heated process such as a process of thermocompression bonding the adhesive member to a desired position of the support member or a process of connecting by wire bonding.

  The wiring substrate used for the semiconductor mounting substrate wiring substrate can be used without being limited to the substrate material such as a ceramic substrate or an organic substrate. As the ceramic substrate, an alumina substrate, an aluminum nitride substrate, or the like can be used. As an organic substrate, an FR-4 substrate in which an epoxy resin is impregnated in a glass cloth, a BT substrate in which a bismaleimide-triazine resin is impregnated, a polyimide film substrate using a polyimide film as a base material, or the like is used. Can do.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
<Methods for producing adhesive sheets of Examples and Comparative Examples>
YDCN-703 (trade name, manufactured by Toto Kasei Co., Ltd., cresol novolac type epoxy resin, epoxy equivalent 210) as an epoxy resin, and Millex XLC-LL (trade name, phenol resin, hydroxyl group manufactured by Mitsui Chemicals) as a phenol resin (curing agent) Equivalent 175, water absorption rate 1.8%, heating mass reduction rate at 350 ° C. 4%), KBE9007 (manufactured by Shin-Etsu Chemical Co., Ltd.) and A− as a silane coupling agent with respect to 200 parts by mass of these thermosetting resins 189 (manufactured by Nihon Unicar Co., Ltd.), as an inorganic filler, cyclohexanone is added to a composition comprising Aerosil R972 (trade name, silica, average particle size 0.016 μm, manufactured by Nippon Aerosil Co., Ltd.), and stirred and mixed. And kneaded for 90 minutes. Acrylic rubber HTR-860P-3 (trade name, manufactured by Nagase Chemtech Co., Ltd., weight average molecular weight 1 million) containing glycidyl acrylate or glycidyl methacrylate 2 to 6% by mass as a high molecular weight component, and Curazole 2PZ-CN as a curing accelerator (Product name, 1-cyanoethyl-2-phenylimidazole, manufactured by Shikoku Kasei Kogyo Co., Ltd.) was mixed and stirred and vacuum degassed. The prepared adhesive resin composition varnish was applied to a 38 μm thick release-treated polyethylene terephthalate film, dried by heating at 140 ° C. for 5 minutes, and a B-stage state (before curing) with a film thickness of 5 μm. And an adhesive sheet provided with a carrier film was produced. Similarly, each adhesive sheet shown in Table 1 was prepared. Table 1 shows the parts by mass of Examples 1 to 4 and Comparative Examples 1 to 5.

(Wafer adhesion)
For adhesion to the silicon wafer, use a hot laminator to attach the adhesive sheet and the silicon wafer at a temperature of 70 ° C., a pressure of 0.3 MPa, and a speed of 0.3 m / min. The measurement was performed at a speed of 50 mm / sec in a 25 ° C. atmosphere using a 90 ° peel tester manufactured by Tester Sangyo Co., Ltd.

(Including cutting waste)
The entering of the cutting waste when the silicon wafer was separated into pieces was performed by observing a sample after dicing by a DISCO dicer from the back side. The case where the cutting waste did not enter was indicated as ◯, and the case where the cutting waste entered was indicated as ×.

(Storage modulus)
Using a dynamic viscoelasticity measuring device (DVE-V4 manufactured by Rheology), the adhesive sheet was thermally cured at 170 ° C. for 3 hours, a tensile load was applied, a frequency of 10 Hz, and a temperature increase rate of 3 to 10 ° C. / The measurement was performed in a temperature dependence measurement mode in which measurement was performed from 25 ° C. to 300 ° C. in min. As a result of the measurement of the storage elastic modulus at 170 ° C., a value of less than 5 MPa was evaluated as ◯, and a value of 5 MPa or more was evaluated as x. Moreover, as a result of the measurement of the elastic modulus at 35 ° C., the case of 1 to 3000 MPa was rated as ◯, and the others were marked as x.

(Wettability with substrate)
Regarding the wettability with the substrate, a test piece that was separated into 10 × 10 mm □ after bonding a silicon wafer and an adhesive sheet was placed on an organic substrate (epoxy resin on glass cloth) under the conditions of 0.1 MPa, 5 s, and 120 ° C. Was bonded to a substrate coated with AUS308 on FR-4 impregnated with FR-4, and then the area ratio (%) at which the substrate and the adhesive sheet were in contact with each other was evaluated.

(Adhesiveness: Adhesive strength between adhesive sheet and substrate)
For adhesion, a 5 × 5 mm size adhesive sheet is bonded to a semiconductor chip (5 × 5 mm size) using a hot roll laminator at a temperature of 70 ° C., a pressure of 0.3 MPa, and a speed of 0.3 m / min. Then, pressure-bonded to an organic substrate (a substrate coated with AUS308 on FR-4 in which an epoxy resin is impregnated in a glass cloth) under conditions of 0.1 MPa, 5 s, and 120 ° C., cured at 170 ° C. for 3 hours, and then subjected to moisture absorption treatment. The adhesive strength between the adhesive sheet and the substrate after (temperature 85 ° C., humidity 85% atmosphere for 48 hours) was measured by die shear strength measurement (manufactured by Dage) under the condition of 265 ° C. The adhesion strength after moisture absorption treatment / adhesion strength before moisture absorption treatment was 0.7 or more, and less than 0.7 was x.

(Fillability)
As for the filling property, an adhesive sheet having a size of 10 × 10 mm was bonded to a silicon wafer using a hot roll laminator at a temperature of 70 ° C., a pressure of 0.3 MPa, and a speed of 0.3 m / min, and then 0.2 MPa. After being attached to a substrate having unevenness of 2 μm at 120 ° C. for 2 s, it was cured at 170 ° C. for 30 minutes. Thereafter, resin sealing was performed to produce an evaluation package. Initial fillability was observed. If the embedding was sufficient, it was marked as ◯, and if embedding was insufficient, it was marked as x.

(1 μm sheet production)
The possibility of producing an adhesive sheet having a thickness of 1 μm was indicated as “◯” and the impossibility as “impossible”.
Table 2 below shows the property evaluation results of the adhesive sheets of Examples 1 to 4 and Comparative Examples 1 to 5.

  Examples 1-4 satisfy the target characteristics in all items such as adhesion to silicon wafer (adhesive force), penetration of cutting waste, storage elastic modulus after curing, and embedding property (fillability). An adhesive sheet having a thickness of 1 μm can also be produced. In addition, in Examples 2 to 4 to which a silane coupling agent having an isocyanate group was added, adhesion with a silicon wafer was improved and wettability with an organic substrate was improved. An excellent effect was confirmed by the embedding property.

  Since the comparative examples 1-5 contain the filler, the adhesive force with a silicon wafer was low, and it resulted in a cutting waste entering between adhesive sheets. Further, it was difficult to produce a 1 μm adhesive sheet. Since Comparative Example 3 has a large amount of rubber, the elastic modulus and filling property satisfy the target characteristics, but the adhesive force is low. Moreover, since it contains a filler, it is difficult to produce an adhesive sheet having a thickness of 1 μm.

  Since the comparative example 4 had few rubber components with respect to a hardening | curing agent, the storage elastic modulus of 170 degreeC after hardening was higher than a target value, and resulted in inferior filling property. In Comparative Example 5, since the amount of rubber was small, the storage elastic modulus at 170 ° C. after curing was high, and the filling property was poor.

  As mentioned above, although this invention has been demonstrated using the Example, it turned out that there exist the following effects. Since the adhesive resin composition of the present invention does not have a filler, it can improve the adhesive force with the silicon wafer and improve the embedding property of the unevenness of the semiconductor element. Furthermore, the addition of a silane coupling agent having an isocyanate group improves the adhesion with the silicon wafer.

Claims (6)

  An adhesive sheet comprising an adhesive resin composition containing at least a high molecular weight component, wherein the adhesive strength between the adhesive sheet before curing at 70 ° C. and the silicon wafer is 100 N / m or more, and the elastic modulus at 35 ° C. is 1 ˜3000 MPa, storage elastic modulus after curing by dynamic viscoelasticity measurement is less than 5 MPa at 170 ° C., and adhesive strength after moisture absorption treatment after curing / die shear strength ratio before moisture absorption treatment is 0.7 or more An adhesive sheet for semiconductors, characterized in that it exists.   The adhesive resin composition for semiconductor according to claim 1, wherein the adhesive resin composition does not contain a filler.   The adhesive resin composition for semiconductor according to claim 1 or 2, wherein the adhesive resin composition further contains a silane coupling agent having an isocyanate group.   The adhesive sheet for a semiconductor according to any one of claims 1 to 3, wherein the thickness is 1 µm to 5 µm.   5. The adhesive sheet for semiconductor according to claim 1, wherein the high molecular weight component has a Tg of −10 to 60 ° C. and a weight average molecular weight of 20,000 to 1,000,000.   6. A dicing integrated semiconductor adhesive sheet obtained by laminating the semiconductor adhesive sheet according to claim 1 and a dicing tape.