JP2006225566A - Film-like adhesive, adhesive sheet and semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film-like adhesive sufficiently satisfying both processability such as low temperature laminatability and reliability of a semiconductor device such as reflow resistance and the like. <P>SOLUTION: The film-like adhesive is used for bonding a semiconductor element to an adherend and has an adhesive layer containing a polyurethane-amide-imide resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a film adhesive, an adhesive sheet, and a semiconductor device using the same.

  Conventionally, a silver paste has been mainly used for joining a semiconductor element and a semiconductor element mounting support member. However, with the recent increase in the size of semiconductor elements and the reduction in size and performance of semiconductor packages, the support members used are also required to be reduced in size and density. In response to these requirements, with silver paste, wetting spreadability, occurrence of defects during wire bonding due to protrusion and inclination of semiconductor elements, difficulty in controlling the thickness of silver paste, and generation of voids in silver paste, It has become impossible to cope with the request. For this reason, in order to cope with the above demand, in recent years, a film-like adhesive has been used (see, for example, Patent Document 1 and Patent Document 2).

  This film-like adhesive is used in an individual piece attaching method or a wafer back surface attaching method. In the case of manufacturing a semiconductor device using the film adhesive of the former individual piece pasting method, first the reel-like film adhesive is cut into individual pieces by cutting or punching, and then adhered to a support member, the film The semiconductor element separated by the dicing process is joined to the support member with a shaped adhesive to produce a support member with a semiconductor element. Thereafter, a semiconductor device is obtained through a wire bonding process, a sealing process, and the like (see, for example, Patent Document 3). However, in order to use the film adhesive of the piece pasting method, a dedicated assembly device that cuts out the film adhesive and adheres it to the support member is necessary, so compared with the method using silver paste There was a problem that the manufacturing cost was high.

  On the other hand, when manufacturing a semiconductor device using a film adhesive on the back side of the wafer, one surface of the film adhesive is first attached to the back surface of the semiconductor wafer, and a dicing sheet is attached to the other side of the film adhesive. to paste together. Thereafter, the semiconductor element is separated into pieces from the wafer by dicing, and the separated semiconductor element with a film adhesive is picked up, joined to a support member, and then subjected to subsequent steps such as wire bonding and sealing. Thus, a semiconductor device is obtained. This film adhesive on the backside of the wafer is used to join a semiconductor element with a film adhesive to a support member, so that an apparatus for separating the film adhesive into pieces is not required, and a conventional assembly apparatus for silver paste. Can be used by modifying a part of the apparatus as it is or by adding a hot platen. Therefore, it attracts attention as a method in which the manufacturing cost can be kept relatively low among the assembling methods using the film adhesive (for example, see Patent Document 4).

  However, in recent years, in addition to the above-described reduction in size, thickness, and performance of semiconductor elements, multifunctional functions have progressed, and accordingly, 3D packages in which a plurality of semiconductor elements are stacked are rapidly increasing. On the other hand, since the package thickness proceeds in the direction of thinning, the semiconductor wafer is further thinned. Along with this, wafer cracking during transportation and wafer cracking when a film adhesive is applied to the backside of the wafer have become apparent. In order to prevent this, a method of bonding a protective tape made of polyolefin (commonly called back grind tape) to the wafer surface is being adopted. However, the softening temperature of the back grind tape is 100 ° C. or lower, and further, a film-like adhesive that can be attached to the back surface of the wafer at a temperature lower than 100 ° C. in order to suppress wafer warpage due to thermal stress. The demand is getting stronger. Furthermore, good process characteristics at the time of assembling a semiconductor device, such as pick-up property after dicing, that is, easy peeling between the film adhesive and the dicing sheet are required.

  Further, as a semiconductor device using a film adhesive, reliability, that is, reflow resistance such as heat resistance and moisture heat resistance is also required. Accordingly, there is an increasing demand for a film-like adhesive that can achieve a high degree of compatibility between process characteristics including low-temperature laminating properties and reliability of semiconductor devices including reflow resistance.

  Until now, in order to achieve both low-temperature workability and heat resistance, a film-like adhesive combining a thermoplastic resin having a relatively low Tg and a thermosetting resin has been proposed (for example, see Patent Document 5). However, in the conventional material system, as the Tg of the thermoplastic resin to be used is lowered, the adhesive strength during heating proceeds in a decreasing direction, and there is a limit to improving the characteristics even when a thermosetting resin is combined. In order to achieve a high degree of compatibility between low-temperature processability and heat resistance, further detailed or precise material design is required.

Japanese Patent Laid-Open No. 3-192178 JP-A-4-234472 Japanese Patent Laid-Open No. 9-17810 Japanese Patent Laid-Open No. 4-196246 Patent No. 3014578 specification

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a film-like adhesive that can achieve high compatibility between process characteristics such as low-temperature laminating properties and semiconductor device reliability such as reflow resistance. Moreover, an object of this invention is to provide the adhesive sheet excellent in process characteristics, such as easy peelability. Furthermore, an object of the present invention is to provide a semiconductor device which is excellent in productivity and excellent in high adhesive strength and moisture resistance when heated.

（式中、Ｒ_１は芳香族環及び／又は直鎖、分岐若しくは環状脂肪族炭化水素を含む２価の有機基、Ｒ_２は分子量１００〜１００００の２価の有機基、Ｒ_３は４個以上の炭素原子を含む３価の有機基、ｎは１〜１００の整数である）で表される繰り返し単位を有するポリウレタンアミドイミド樹脂である上記フィルム状接着剤に関する。
また、本発明は、前記ポリウレタンアミドイミド樹脂が、ジイソシアネートとジオールとを反応させて得られるウレタンオリゴマーを、トリカルボン酸無水物で鎖延長して得たブロック共重合体である上記フィルム状接着剤に関する。
また、本発明は、前記ジイソシアネートが、下記一般式（II）

で表されるジイソシアネートである上記フィルム状接着剤に関する。
また、本発明は、前記ジオールが、下記一般式（III）

（式中、ｎは１〜１００の整数である）で表されるジオールである上記フィルム状接着剤に関する。
また、本発明は、前記トリカルボン酸無水物が、下記一般式（IV）

で表される無水トリメリット酸である上記フィルム状接着剤に関する。
また、本発明は、前記ポリウレタンアミドイミド樹脂の重量平均分子量が１万〜３０万である上記フィルム状接着剤に関する。
また、本発明は、前記接着剤層が、さらに熱硬化性樹脂を含有してなる上記フィルム状接着剤に関する。
また、本発明は、前記熱硬化性樹脂がエポキシ樹脂である上記フィルム状接着剤に関する。
また、本発明は、前記接着剤層が、さらにフィラーを含有してなる上記フィルム状接着剤に関する。
また、本発明は、前記接着剤層の主分散ピーク温度が−１００〜５０℃である上記フィルム状接着剤に関する。
また、本発明は、前記接着剤層の２０℃における貯蔵弾性率が１０００ＭＰａ以下である上記フィルム状接着剤に関する。
また、本発明は、前記接着剤層を１８０℃の熱盤上で加熱圧着したときのフロー量が５０〜２０００μｍである上記フィルム状接着剤に関する。
また、本発明は、被着体が、配線付き有機基板である上記フィルム状接着剤に関する。
また、本発明は、上記フィルム状接着剤と、ダイシングシートとを積層した構造を有してなる接着シートに関する。
また、本発明は、前記ダイシングシートが、基材フィルム、及び基材フィルム上に設けた放射線硬化型粘着剤層を有してなる上記接着シートに関する。
さらに、本発明は、上記フィルム状接着剤により、半導体素子と半導体搭載用支持部材、及び／又は、半導体素子と半導体素子が接着された構造を有してなる半導体装置に関する。 The inventors of the present invention have intensively studied to solve the above problems, and as a result, have come to provide the following solutions.
That is, the present invention is a film adhesive used for adhering a semiconductor element to an adherend, and has an adhesive layer containing a polyurethane amide imide resin. It relates to adhesives.
In the present invention, the polyurethane amide imide resin is represented by the following general formula (I):

(In the formula, R ₁ is a divalent organic group containing an aromatic ring and / or a linear, branched or cyclic aliphatic hydrocarbon, R ₂ is a divalent organic group having a molecular weight of 100 to 10,000, and R ₃ is 4 It is related with the said film adhesive which is a polyurethane amideimide resin which has a repeating unit represented by the trivalent organic group containing the above carbon atom, and n is an integer of 1-100.
The present invention also relates to the film adhesive, wherein the polyurethane amide imide resin is a block copolymer obtained by chain-extending a urethane oligomer obtained by reacting a diisocyanate and a diol with a tricarboxylic acid anhydride. .
In the present invention, the diisocyanate is represented by the following general formula (II):

It is related with the said film adhesive which is diisocyanate represented by these.
In the present invention, the diol may be represented by the following general formula (III):

(Wherein, n is an integer of 1 to 100).
In the present invention, the tricarboxylic acid anhydride is represented by the following general formula (IV):

It is related with the said film adhesive which is the trimellitic anhydride represented by these.
Moreover, this invention relates to the said film adhesive whose weight average molecular weights of the said polyurethane amide imide resin are 10,000-300,000.
Moreover, this invention relates to the said film adhesive with which the said adhesive bond layer contains a thermosetting resin further.
Moreover, this invention relates to the said film adhesive whose said thermosetting resin is an epoxy resin.
Moreover, this invention relates to the said film adhesive in which the said adhesive bond layer contains a filler further.
Moreover, this invention relates to the said film adhesive whose main dispersion peak temperature of the said adhesive bond layer is -100-50 degreeC.
Moreover, this invention relates to the said film adhesive whose storage elastic modulus in 20 degreeC of the said adhesive bond layer is 1000 Mpa or less.
Moreover, this invention relates to the said film adhesive whose flow amount when the said adhesive bond layer is thermocompression-bonded on a 180 degreeC hot platen is 50-2000 micrometers.
Moreover, this invention relates to the said film adhesive whose adherend is an organic substrate with a wiring.
Moreover, this invention relates to the adhesive sheet which has the structure which laminated | stacked the said film adhesive and the dicing sheet.
Moreover, this invention relates to the said adhesive sheet in which the said dicing sheet has a base film and the radiation-curable adhesive layer provided on the base film.
Furthermore, the present invention relates to a semiconductor device having a structure in which a semiconductor element and a semiconductor mounting support member and / or a semiconductor element and a semiconductor element are bonded by the film adhesive.

ADVANTAGE OF THE INVENTION According to this invention, the film adhesive of the wafer back surface attachment system which can respond | correspond to 3D package which laminated | stacked the ultra-thin wafer and the several semiconductor element can be provided. When a film adhesive is attached to the back surface of the wafer (hereinafter referred to as “laminate”), it is usually heated to a temperature at which the film adhesive melts. If the film adhesive of the present invention is used, Lamination can be performed on the back surface of the wafer at a temperature lower than the softening temperature of the protective tape or the dicing tape to be bonded. As a result, thermal stress is also reduced, and problems such as warpage of a wafer that becomes thicker and thinner can be solved. Moreover, the design which can control the fluidity | liquidity of an adhesive bond layer precisely is attained. In addition, since high adhesive strength at high temperatures can be ensured, heat resistance and moisture resistance reliability can be improved, and the manufacturing process of the semiconductor device can be simplified. Furthermore, by optimizing the adhesive layer (adding other components, optimizing film composition, etc.), thermal stress such as wafer warpage can be further reduced, chip skipping during dicing is suppressed, pick-up properties, and semiconductor devices The workability at the time of manufacturing and the low outgassing property can be further improved.
Moreover, according to this invention, the adhesive sheet which bonded the said film adhesive and the dicing sheet can be provided. According to the adhesive sheet of the present invention, it is possible to provide a material that can simplify the pasting process up to the dicing process.
Furthermore, according to the present invention, a semiconductor device using the film adhesive can be provided. The semiconductor device of the present invention is a highly reliable semiconductor device with a simplified manufacturing process. The semiconductor device of the present invention has heat resistance and moisture resistance required when a semiconductor element having a large difference in thermal expansion coefficient is mounted on a semiconductor element mounting support member.

  The film adhesive of the present invention comprises an adhesive layer containing a polyurethane amide imide resin (also referred to as poly (amide-imide-urethane), poly (urethane-amide imide), poly (urethane-amide-imide)). Have. In the present invention, the thickness of the adhesive layer is preferably 5 to 100 μm. As a form of the film adhesive, as shown in FIG. 1, a single-layer film adhesive 1 consisting only of the adhesive layer 2 can be mentioned. In the case of this form, it is preferable to carry in the form of a tape having a width of about 1 to 20 mm or a sheet of about 10 to 50 cm and wound around a winding core. Moreover, the structure which provides the adhesive bond layer 2 in the single side | surface (not shown) or both surfaces (refer FIG. 2) of the base film 3 may be sufficient. In addition, in order to prevent damage and contamination of the adhesive layer, a cover film can be provided on the adhesive layer as appropriate. For example, as shown in FIG. 3, a film-like adhesive having a structure in which the adhesive layer 2 is provided on the base film 3 and the cover film 4 is further provided may be used.

（式中、Ｒ_１は芳香族環及び／又は直鎖、分岐若しくは環状脂肪族炭化水素を含む２価の有機基、Ｒ_２は分子量１００〜１００００の２価の有機基、Ｒ_３は４個以上の炭素原子を含む３価の有機基、ｎは１〜１００の整数である）で表される樹脂が挙げられる。 (Polyurethane amide imide resin)
Hereinafter, the adhesive layer used for the film adhesive of the present invention will be described. The adhesive layer is characterized by containing at least a polyurethane amide imide resin, and the polyurethane amide imide resin has the following general formula (I):

(In the formula, R ₁ is a divalent organic group containing an aromatic ring and / or a linear, branched or cyclic aliphatic hydrocarbon, R ₂ is a divalent organic group having a molecular weight of 100 to 10,000, and R ₃ is 4 A trivalent organic group containing the above carbon atoms, and n is an integer of 1 to 100).

R ₁ is an aromatic ring or a divalent organic group containing a linear, branched or cyclic aliphatic hydrocarbon, preferably a benzene residue, toluene residue, xylene residue, naphthalene residue, linear, branched, Or a cyclic alkyl group, or these mixed groups are mentioned, More preferably, a xylene residue and a diphenylmethane residue are mentioned.
R ₂ is a divalent organic group having a molecular weight of 100 to 10,000, preferably a polyether residue, a polyester residue, a polycarbonate residue, a polycarbonate residue, a polycaprolactone residue, or a polysiloxane residue, and more preferably Includes a polyether residue.
R ₃ is a trivalent organic group containing 4 or more carbon atoms, preferably an aromatic ring residue, a straight chain, branched or cyclic aliphatic hydrocarbon residue, an ether residue, a thioether residue, a carbonyl residue. A group, a sulfonyl residue, a silane residue, and an ester residue, and more preferably a benzene residue.

  More specifically, the polyurethane amide imide resin includes a block copolymer obtained by extending a urethane oligomer obtained from diisocyanate and diol with a tricarboxylic acid anhydride. Hereinafter, a method for obtaining the polyurethane amide imide resin in this way will be described.

Examples of the diisocyanate that is a component of the urethane oligomer include diphenylmethane-4, 4′-diisocyanate, diphenylmethane-2, 4′-diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, and 1,6-hexa Methylene diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 1,1′-methylene-bis (4-isocyanatocyclohexane), 1,3-bis (isocyanatomethyl) benzene, 1,3 -Bis (isocyanatomethyl) cyclohexane etc. are mentioned, These can be used individually or in combination. Of these, diisocyanates represented by the following general formula (II) are preferred because they have good polymerization reactivity and can effectively control the molecular weight of the resulting polyurethane amideimide resin.

  As the diol component, a diol having an average molecular weight of 100 to 10,000 is used. As the main chain structure, polypropylene glycol, polyethylene glycol, polypropylene glycol / polyethylene glycol copolymer, polytetramethylene glycol, poly (ethylene adipate) is used. ), Poly (diethylene adipate), poly (propylene adipate), poly (tetramethylene adipate), poly (hexamethylene adipate), poly (neopentylene adipate), poly (hexamethylene sebacate), poly-ε-caprolactone, Examples thereof include poly (hexamethylene carbonate) and poly (siloxane), and these can be used alone or in combination.

（式中、ｎは１〜１００の整数である） Among these, a diol represented by the following general formula (III) is preferable in that good moisture reliability can be obtained.

(In the formula, n is an integer of 1 to 100)

  The composition ratio of diisocyanate and diol constituting the urethane oligomer is preferably 0.1 to 1.0 mol of the diol component with respect to 1.0 mol of diisocyanate.

The tricarboxylic acid anhydride for chain extending the urethane oligomer is preferably 1,2,4-benzenetricarboxylic acid-1,2-anhydride represented by the following general formula (IV).

  The composition ratio of the polyurethane oligomer and the tricarboxylic acid anhydride constituting the polyurethane amideimide resin is preferably 0.1 to 2.0 mol of the tricarboxylic acid anhydride with respect to 1.0 mol of the polyurethane oligomer.

  Further, when this tricarboxylic acid anhydride is used as a raw material for polyurethane amide imide resin, the difference between the endothermic onset temperature and the endothermic peak temperature by differential scanning calorimetry (DSC) is within 10 ° C. as an indicator of purity. preferable. The endothermic start temperature and the endothermic peak temperature are measured using DSC (DSC-7 model, manufactured by Perkin Elmer) under the conditions of a sample amount of 5 mg, a heating rate of 5 ° C./min, and a measurement atmosphere: nitrogen. Use the value when

The polyurethane amide imide resin can be synthesized by a usual method such as a solution polymerization method. For example, in the case of a solution polymerization method, a diisocyanate and a diol are dissolved in a solvent in which the generated polyurethaneamidoimide resin is dissolved, for example, N-methyl-2-pyrrolidone, and reacted at 50 ° C. to 200 ° C. for 30 minutes to 5 hours, A urethane oligomer is synthesized, and a tricarboxylic acid anhydride is further added and reacted at 70 ° C. to 250 ° C. for 1 hour to 10 hours to synthesize a target polyurethane amideimide resin. In the synthesis, a tertiary amine or the like can be used as a catalyst. However, in the case of using a film-like adhesive in which a polyurethane amideimide resin and a thermosetting resin are combined, the presence / absence and addition amount of the catalyst are adjusted for the purpose of controlling fluidity during heating. In addition, said polyurethane amide imide resin may mix (blend) individually or in mixture of 2 or more types as needed.
(Reference: Tzong-Liu Wang, Fang-Jung Huang, Polymer International, 46 280 (1998))

  Moreover, it is preferable that the weight average molecular weight of the polyurethane amide imide resin is controlled within a range of 10,000 to 300,000 from the viewpoint of ensuring film formability and desirable fluidity during heat, and further ensuring the toughness of the film. Therefore, 30,000 to 200,000 are more preferable, and 70,000 to 150,000 are even more preferable. In addition, said weight average molecular weight is a weight average molecular weight when measured in polystyrene conversion using gel permeation chromatography (C-R4A by Shimadzu Corporation).

  The laminable temperature of the film adhesive of the present invention is preferably not higher than the heat resistance or softening temperature of the protective tape of the wafer, that is, the back grind tape, or not higher than the heat resistance or softening temperature of the dicing sheet. 10-100 degreeC is preferable also from a viewpoint of suppressing curvature, More preferably, it is 20-80 degreeC. In order to enable lamination at these temperatures, the Tg of the polyurethane amide imide resin is preferably adjusted to -100 to 50 ° C, more preferably -80 to 30 ° C. When the Tg exceeds 50 ° C., the possibility of laminating the film adhesive exceeds 100 ° C., and when the Tg is less than −100 ° C., the handleability of the film adhesive is deteriorated. Tend. In addition, said Tg is Tg when using DSC (DSC-7 type | mold by Perkin-Elmer Co., Ltd.) and measuring on the conditions of sample amount 10mg, temperature increase rate 5 degree-C / min, and measurement atmosphere: nitrogen. .

(Other ingredients)
The film adhesive of the present invention can further use a thermosetting resin. The thermosetting resin is a reactive compound that causes a crosslinking reaction by heat. Examples of such a compound include epoxy resins, cyanate ester resins, bismaleimide resins, phenol resins, urea resins, melamine resins, alkyd resins, Acrylic resin, unsaturated polyester resin, diallyl phthalate resin, silicone resin, resorcinol formaldehyde resin, xylene resin, furan resin, polyurethane resin, ketone resin, triallyl cyanurate resin, polyisocyanate resin, tris (2-hydroxyethyl) isocyanur Examples thereof include a resin containing a lactate, a resin containing triallyl trimellitate, a thermosetting resin synthesized from cyclopentadiene, and a thermosetting resin by trimerization of aromatic dicyanamide. Among these, an epoxy resin is preferable in that it can have an excellent adhesive force at a high temperature. In addition, these thermosetting resins can be used individually or in combination of 2 or more types.

  When the above thermosetting resin is used, its content can be compatible with both low outgassing property and film forming property (toughness), and heat resistance by thermosetting can be effectively imparted to 100 parts by weight of the polyurethane amideimide resin. 0.01 to 200 parts by weight is preferable, and 0.1 to 100 parts by weight is more preferable.

  In order to cure the thermosetting resin, a curing agent or a catalyst can be used, and a curing agent and a curing accelerator, or a catalyst and a promoter can be used in combination as necessary. About the addition amount of the said hardening | curing agent and a hardening accelerator, and the presence or absence of addition, it judges and adjusts in the range which can ensure the fluidity | liquidity at the time of the desirable heat mentioned later and the heat resistance after hardening.

  As an epoxy resin which is one of the preferred thermosetting resins, those containing at least two epoxy groups in the molecule are more preferable, and phenol glycidyl ether type epoxy resins are extremely preferable in terms of curability and cured product characteristics. preferable. Examples of such resins include bisphenol A type (or AD type, S type, and F type) glycidyl ether, water-added bisphenol A type glycidyl ether, ethylene oxide adduct bisphenol A type glycidyl ether, and propylene oxide adduct. Bisphenol A glycidyl ether, phenol novolac resin glycidyl ether, cresol novolac resin glycidyl ether, bisphenol A novolak resin glycidyl ether, naphthalene resin glycidyl ether, trifunctional (or tetrafunctional) glycidyl ether, dicyclo Examples include glycidyl ether of pentadienephenol resin, glycidyl ester of dimer acid, trifunctional (or tetrafunctional) glycidylamine, glycidylamine of naphthalene resin, etc. It is. These can be used alone or in combination of two or more. In addition, it is preferable to use a high-purity product in which the impurity ions, alkali metal ions, alkaline earth metal ions, halogen ions, particularly chlorine ions and hydrolyzable chlorine are reduced to 300 ppm or less for these epoxy resins. This is preferable for prevention of corrosion and corrosion of metal conductor circuits.

  Examples of the curing agent include phenolic compounds, aliphatic amines, alicyclic amines, aromatic polyamines, polyamides, aliphatic acid anhydrides, alicyclic acid anhydrides, aromatic acid anhydrides, dicyandiamide, organic acids. Examples include dihydrazide, boron trifluoride amine complex, imidazoles, and tertiary amines. Curing agents when using epoxy resins as thermosetting resins include, for example, phenolic compounds, aliphatic amines, alicyclic amines, aromatic polyamines, polyamides, aliphatic acid anhydrides, alicyclic acid anhydrides. , Aromatic acid anhydride, dicyandiamide, organic acid dihydrazide, boron trifluoride amine complex, imidazoles, tertiary amines, etc. Among them, phenolic compounds are preferred, and at least two phenolic hydroxyl groups are present in the molecule. A phenolic compound is more preferable. Examples of such compounds include phenol novolak resins, cresol novolak resins, t-butylphenol novolak resins, dicyclopentagen cresol novolak resins, dicyclopentagen phenol novolak resins, xylylene-modified phenol novolak resins, naphthol compounds, trisphenols. Examples thereof include tetrakisphenol novolac resin, bisphenol A novolac resin, poly-p-vinylphenol resin, and phenol aralkyl resin. Among these, those having a number average molecular weight in the range of 400 to 1500 are preferable. Thereby, at the time of assembling and heating the semiconductor device, it is possible to effectively reduce outgas which causes contamination of the semiconductor element or the device.

  The curing accelerator is not particularly limited as long as it cures a thermosetting resin. For example, imidazoles, dicyandiamide derivatives, dicarboxylic acid dihydrazide, triphenylphosphine, tetraphenylphosphonium tetraphenylborate, 2-ethyl- Examples include 4-methylimidazole-tetraphenylborate and 1,8-diazabicyclo [5.4.0] undecene-7-tetraphenylborate.

  In the adhesive layer, a filler can be further used, for example, metal filler such as silver powder, gold powder, copper powder, nickel powder, alumina, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate. , Magnesium silicate, Calcium oxide, Magnesium oxide, Aluminum oxide, Aluminum nitride, Crystalline silica, Amorphous silica, Boron nitride, Titania, Glass, Iron oxide, Ceramic and other inorganic fillers, Carbon, Rubber fillers and other organic A filler etc. are mentioned, It can use without a restriction | limiting especially regardless of a kind, a shape, etc.

  The filler can be used properly according to the desired function. For example, the metal filler is added for the purpose of imparting conductivity, thermal conductivity, thixotropy, etc. to the adhesive composition, and the nonmetallic inorganic filler is thermally conductive, low thermal expansion, low hygroscopicity to the adhesive layer. The organic filler is added for the purpose of imparting toughness to the adhesive layer. These metal fillers, inorganic fillers or organic fillers can be used alone or in combination of two or more. Among them, a metal filler, an inorganic filler, or an insulating filler is preferable, and an inorganic filler or an insulating filler is preferable in that it can provide conductivity, thermal conductivity, low moisture absorption characteristics, insulating properties, and the like required for an adhesive material for a semiconductor device. Among the fillers, boron nitride is more preferable because it has good dispersibility with respect to the resin varnish and can impart a high adhesive force during heating.

  The filler preferably has an average particle size of 10 μm or less, a maximum particle size of 25 μm or less, an average particle size of 5 μm or less, and a maximum particle size of 20 μm or less. When the average particle diameter exceeds 10 μm and the maximum particle diameter exceeds 25 μm, the effect of improving fracture toughness tends to be not obtained. Although there is no restriction | limiting in particular in a lower limit, Usually, both are 0.01 micrometer.

  The filler preferably satisfies both an average particle size of 10 μm or less and a maximum particle size of 25 μm or less. When a filler having a maximum particle size of 25 μm or less but an average particle size exceeding 10 μm is used, there is a tendency that high adhesive strength cannot be obtained. Further, when a filler having an average particle size of 10 μm or less but having a maximum particle size exceeding 25 μm is used, the particle size distribution is widened and the adhesive strength tends to vary. Moreover, in this invention, when processing an adhesive composition into a thin film form and using it, the surface becomes rough and there exists a tendency for adhesive force to fall.

  Examples of the method for measuring the average particle size and the maximum particle size of the filler include a method of measuring the particle size of about 200 fillers using a scanning electron microscope (SEM). As a measuring method using SEM, for example, a sample obtained by adhering a semiconductor element and a semiconductor mounting support member using an adhesive layer and then heat-curing (preferably at 150 to 200 ° C. for 1 to 10 hours) is used. The method of producing, cutting the center part of this sample, and observing the cross section by SEM etc. is mentioned. At this time, it is preferable that the existence probability of the filler is 80% or more of the total filler.

  Although the usage-amount of the said filler is decided according to the characteristic or function to provide, it is 1-50 volume% with respect to the sum total of a resin component and a filler, Preferably it is 2-40 volume%, More preferably, it is 5-30 volume. %. By increasing the amount of filler, a high elastic modulus can be achieved, and dicing performance (cutability by a dicer blade), wire bonding performance (ultrasonic efficiency), and adhesive strength during heating can be effectively improved. If the filler is increased more than necessary, the low-temperature sticking property and the interfacial adhesion with the adherend, which are the characteristics of the present invention, are impaired, and the reliability including reflow resistance is reduced. It is preferable to be within the range. The optimal filler content is determined to balance the required properties. Mixing and kneading in the case of using a filler can be carried out by appropriately combining dispersers such as ordinary stirrers, crackers, three rolls, and ball mills.

  Various coupling agents can also be added to the film adhesive of the present invention in order to improve the interfacial bonding between different materials. Examples of the coupling agent include silane-based, titanium-based, and aluminum-based, and among them, a silane-based coupling agent is preferable because it is highly effective. The amount of the coupling agent used is preferably 0.01 to 20 parts by weight with respect to 100 parts by weight of the polyurethane amide imide resin from the viewpoint of the effect, heat resistance and cost.

  An ion scavenger can be further added to the film adhesive of the present invention in order to adsorb ionic impurities and improve insulation reliability during moisture absorption. Such an ion scavenger is not particularly limited, for example, triazine thiol compound, a compound known as a copper damage inhibitor to prevent copper from being ionized and dissolved, such as a bisphenol-based reducing agent, zirconium-based, Examples include inorganic ion adsorbents such as antimony bismuth-based magnesium aluminum compounds. The amount of the ion scavenger used is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the polyurethane amide imide resin from the viewpoint of the effect of addition, heat resistance, cost, and the like.

  In the present invention, a softener, an anti-aging agent, a colorant, a flame retardant, a tackifier such as a terpene resin, and a thermoplastic polymer component may be appropriately added to the adhesive layer. Thermoplastic polymer components used to improve adhesion and provide stress relaxation during curing include polyvinyl butyral resin, polyvinyl formal resin, polyester resin, polyamide resin, polyimide resin, xylene resin, phenoxy resin, polyurethane resin , Urea resin, acrylic rubber and the like. These polymer components preferably have a molecular weight of 5,000 to 500,000.

(Method for producing film adhesive having an adhesive layer)
In the film-like adhesive of the present invention, the adhesive layer is composed of a polyurethane amideimide resin, and if necessary, a thermosetting resin, a filler, and other components mixed and kneaded in an organic solvent to form a varnish (adhesive layer). After preparing a coating varnish), the varnish layer is formed on a substrate film, dried by heating and then removed from the substrate. The above mixing and kneading can be carried out by appropriately combining dispersers such as ordinary stirrers, crackers, three rolls, and ball mills. The heating and drying conditions are not particularly limited as long as the solvent used is sufficiently volatilized, but the heating is usually performed at 50 to 200 ° C. for 0.1 to 90 minutes.

  The organic solvent used in the production of the adhesive layer, that is, the varnish solvent is not limited as long as the material can be uniformly dissolved, kneaded, or dispersed. For example, dimethylformamide, dimethylacetamide, N-methyl-2- Examples include pyrrolidone, dimethyl sulfoxide, diethylene glycol dimethyl ether, toluene, benzene, xylene, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, dioxane, cyclohexanone, and ethyl acetate. However, in the case of an adhesive layer in which a thermosetting resin such as an epoxy resin is added to a polyurethane amide imide resin, if an amide solvent such as dimethylformamide, dimethylacetamide or N-methyl-2-pyrrolidone is selected, the thermosetting reaction Therefore, when adjusting the flow amount of the adhesive layer described later, a solvent is appropriately selected in consideration of these effects.

  The base film used in the production of the film adhesive of the present invention is not particularly limited as long as it can withstand the above heating and drying conditions. For example, polyester film, polypropylene film, polyethylene terephthalate film, polyimide film , Polyetherimide film, polyether naphthalate film, methylpentene film and the like. Two or more kinds of these base films may be combined to form a multilayer film, or the surface may be treated with a release agent such as silicone or silica. At this time, an adhesive layer with a base film using the base film as a support without removing the base film may be used as a film adhesive.

  Next, the present invention will be described with some preferred embodiments. As for the film adhesive as 1 aspect of this invention, it is preferable that the main dispersion peak temperature of the adhesive bond layer before use (before adhering a semiconductor element to a to-be-adhered body) is -100-50 degreeC. More preferably, it is -80 degreeC-30 degreeC. The main dispersion peak temperature refers to the adhesive layer before use, using a rheometric viscoelasticity analyzer RSA-2, and the adhesive layer size is 35 mm × 10 mm, the heating rate is 5 ° C./min, the frequency is 1 Hz, and the measurement temperature. It is a tan δ peak temperature in the vicinity of Tg when measured in the tensile mode under the condition of −150 to 300 ° C. When the tan δ peak temperature is less than −100 ° C., the tack force on the surface of the adhesive layer becomes too strong, and the handleability of the film adhesive is deteriorated. When the tan δ peak temperature exceeds 50 ° C., the laminating temperature is There is a tendency that the possibility of exceeding 100 ° C increases. In addition, the main dispersion peak temperature of the said adhesive bond layer can be adjusted to -100-50 degreeC by using the polyurethane amideimide resin whose Tg is -100-50 degreeC. When adding a thermosetting resin and a filler, the addition amount is adjusted so that the main dispersion peak temperature of the adhesive layer is in the range of −100 to 50 ° C.

  The film-like adhesive as one aspect of the present invention preferably has a storage elastic modulus at 20 ° C. of 1000 MPa or less of the adhesive layer before use (before the semiconductor element is bonded to the adherend). More preferably, it is 500 MPa or less. The storage elastic modulus refers to the adhesive layer before use, using a rheometric viscoelasticity analyzer RSA-2, and the adhesive layer size is 35 mm × 10 mm, the heating rate is 5 ° C./min, the frequency is 1 Hz, and the measurement temperature is − It is a storage elastic modulus at 20 ° C. when measured in a tensile mode under conditions of 150 to 300 ° C. When the storage elastic modulus exceeds 1000 MPa, the possibility that the laminating temperature of the film adhesive exceeds 100 ° C. tends to increase. The lower limit value of the storage elastic modulus is not particularly limited, but is 0.01 MPa or more. In addition, the storage elastic modulus in 20 degreeC of the said adhesive bond layer can be adjusted to 1000 Mpa or less by using the polyurethane amideimide resin whose Tg is -100-50 degreeC and a weight average molecular weight is 10,000-300,000. When adding a thermosetting resin and a filler, the addition amount is adjusted so that the storage elastic modulus at 20 ° C. of the adhesive layer is 1000 MPa or less.

The film-like adhesive as one embodiment of the present invention has a flow amount of 50 to 2000 μm when the adhesive layer before use (before the semiconductor element is bonded to the adherend) is heat-pressed on a 180 ° C. hot platen. It is preferable that More preferably, it is 100-1000 micrometers. The flow amount is 10 mm × 10 mm × 40 μm thickness (note that the adhesive layer thickness was adjusted with an error of ± 5 μm. Hereinafter, the description of the error of the adhesive layer thickness is the same as described above, and will be omitted. ) Adhesive layer coated substrate (50 μm thick PET film) with an adhesive layer sandwiched between two slide glasses (Matsunami, 76 mm × 26 mm × 1.0 to 1.2 mm thick) Is the maximum value when the amount of protrusion from the PET base film after applying a load of 100 kgf / cm ² on a hot plate at 180 ° C. and thermocompression bonding for 90 seconds is observed with an optical microscope.

  If the flow amount at this time is less than 50 μm, there is a tendency that the adhesive layer cannot sufficiently bury the irregularities on the substrate with wiring due to heat and pressure during transfer molding. On the other hand, if it exceeds 2000 μm, it flows due to the thermal history during die bonding or wire bonding, and it becomes easy for the adhesive layer to entrain the remaining bubbles between the irregularities on the substrate, and the heat in the transfer molding process. Even when a pressure is applied, the bubbles cannot be completely removed and remain as voids in the adhesive layer, and the voids tend to be the starting point and easily foam during moisture absorption reflow.

  In addition, even if Tg of the said polyurethane amide imide resin is -100-50 degreeC by using the polyurethane amide imide resin whose weight average molecular weight is 10,000-300,000, said flow amount is controlled to 50-2000 micrometers. it can. In general, when a thermoplastic resin-based adhesive layer is heated and pressure-bonded at a temperature of Tg or higher, the adhesive layer largely flows due to the micro-brown motion of the thermoplastic resin. However, like the polyurethane amide imide resin of the present invention, In the case where the main chain has a relatively polar skeleton and the polymerization form is preferably a block copolymer resin, an interaction between molecules due to the interaction between the highly polar skeletons occurs, and the polymerization Due to the intermolecular aggregation caused by the morphology, flow at temperatures exceeding Tg is suppressed. In the case of the polyurethane amide imide resin of the present invention, intermolecular aggregation is likely to occur due to hydrogen bonds generated between urethane bonds, between amide bonds, or between urethane bonds and amide bonds, and as a result, flow at a temperature of Tg or higher. Proceeds in the direction that is suppressed. On the other hand, a polyimide resin that does not contain such a highly polar skeleton and whose polymerization form is a random copolymer hardly exhibits the intermolecular interaction as described above. And about the adhesive bond layer which uses the polyimide resin whose Tg is -100-50 degreeC, it is difficult to control said flow amount within 2000 micrometers.

  When adding a thermosetting resin and a filler, the addition amount is adjusted so that the flow amount is in the range of 50 to 2000 μm. In particular, when adding a thermosetting resin, it is preferable to optimize not only the amount of thermosetting resin added, but also the structure and the number of functional groups, because the flow rate of the adhesive layer decreases due to heat curing. . By reducing the addition amount of the thermosetting resin or reducing the number of functional groups, it is possible to suppress a decrease in the flow amount. In addition, when an epoxy resin is selected and added as the thermosetting resin, a urethane bond, an amide bond, or a reactive end group such as an isocyanate group, an acid anhydride group, or a carboxyl group, and an epoxy group of a polyurethane amide imide resin are used. There is also a possibility of a crosslinking reaction, and this reaction also contributes to a decrease in fluidity. Therefore, the flow amount can be adjusted by controlling the weight average molecular weight of the polyurethane amide imide resin. When the average molecular weight of the polyurethane amide imide resin is increased, the number of the reactive terminal groups is decreased, so that the reaction with the epoxy group is suppressed, and the decrease in the flow amount is suppressed. The above phenomenon is not limited to the polyurethane amide imide resin, but the same can be said for a normal polyimide resin. Thus, the flow amount can be adjusted by adjusting the average molecular weight of the polyurethane amide imide resin.

Moreover, the adhesive sheet which has the structure which laminated | stacked the film adhesive which has an adhesive layer demonstrated so far, and the dicing sheet as 1 aspect of this invention is mentioned. Examples of the dicing sheet include a dicing sheet having a structure in which an adhesive layer is laminated on a base film. In the case of this aspect, it is preferable that the film adhesive is formed in advance in a shape close to the wafer (pre-cut).
More specifically, as an adhesive sheet, as shown in FIG. 4, an adhesive sheet 5 in which a base film 8, a pressure-sensitive adhesive layer 7, and the film adhesive 1 of the present invention are formed in this order is exemplified. This adhesive sheet is an integrated adhesive sheet including at least the film adhesive 1 and the dicing sheet 6 for the purpose of simplifying the semiconductor device manufacturing process. That is, it is an adhesive sheet having characteristics required for both a dicing sheet and a die bonding film.

  In this way, a pressure-sensitive adhesive layer that functions as a dicing sheet was provided on the base film, and the film-like adhesive of the present invention that functions as a die bonding film was further laminated on the pressure-sensitive adhesive layer. Therefore, it functions as a dicing sheet during dicing and as a die bonding film during die bonding. Therefore, the integrated adhesive sheet is laminated on the back surface of the wafer while heating the film adhesive of the integrated adhesive sheet on the back surface of the semiconductor wafer, diced, and then picked up as a semiconductor element with a film adhesive. Can be used.

  The pressure-sensitive adhesive layer may be either a pressure-sensitive type or a radiation-curing type, but the radiation-curing type has a high adhesive force during dicing, and is irradiated with ultraviolet rays (UV) before picking up. It is preferable in terms of low adhesive strength and easy control of adhesive strength. The radiation-curing pressure-sensitive adhesive layer should have sufficient adhesive strength so that the semiconductor element does not scatter during dicing, and has a low adhesive strength that does not damage the semiconductor element in the subsequent pick-up process of the semiconductor element. Conventionally known ones can be used without particular limitation.

At this time, at the stage of laminating at 80 ° C. on the semiconductor wafer, the radiation after the 90 ° peel peeling force at 25 ° C. of the film adhesive on the semiconductor wafer was UV-irradiated under the conditions of A and exposure amount 500 mJ / cm ^2. When the 90 ° peel peel strength at 25 ° C. with respect to the film adhesive of the curable pressure-sensitive adhesive layer is B, the AB value is preferably 1 N / m or more, more preferably 5 N / m or more, 10 N / m or more is even more preferable.

  If the above value (A-B) is less than 1 N / m, each element tends to be damaged at the time of pick-up, or at the time of pick-up, it is peeled off first at the silicon chip and film-like adhesive interface and cannot be picked up effectively. Tend.

  The 90 ° C. peel peel force A at 25 ° C. of the film adhesive on the semiconductor wafer is the method shown in FIG. 7 after laminating the film adhesive on the back surface of the semiconductor wafer (back grind treated surface) at 80 ° C. It refers to the peel strength when the film adhesive 1 (1 cm width) (9: semiconductor wafer, 12: support) is peeled off in the 90 ° C. direction at 100 mm / min.

The 90 ° peel release force B at 25 ° C. against the film adhesive of the radiation curable pressure-sensitive adhesive layer after UV irradiation under the above-mentioned exposure amount of 500 mJ / cm ² is applied to the back surface of the semiconductor wafer (back grind processing surface). After laminating at 80 ° C., the dicing sheet is laminated at room temperature, and the dicing sheet 6 (1 cm width) (1: film adhesive, 9: semiconductor wafer, 12: support) is 90 ° direction by the method shown in FIG. The peel peeling force when peeled off at 100 mm / min.
Lamination can be performed by the method shown in FIG. 5 or FIG.

The radiation curable pressure-sensitive adhesive layer preferably has the above-described properties, and specifically, a layer containing a pressure-sensitive adhesive and a radiation polymerizable oligomer can be used.
In this case, the pressure-sensitive adhesive constituting the radiation curable pressure-sensitive adhesive layer is preferably an acrylic pressure-sensitive adhesive. More specifically, for example, a (meth) acrylic acid ester copolymer having (meth) acrylic acid ester or a derivative thereof as a main constituent monomer unit, or a mixture of these copolymers may be mentioned. In addition, in this specification, when describing like (meth) acrylic acid ester, both methacrylic acid ester and acrylic acid ester are shown.

  Examples of the (meth) acrylic acid ester copolymer include at least one (meth) acrylic acid alkyl ester monomer selected from (meth) acrylic acid alkyl esters having an alkyl group having 1 to 15 carbon atoms. From the group consisting of (a), glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, vinyl acetate, styrene and vinyl chloride Copolymerization of selected polar monomer (b) having no acid group and comonomer (c) having at least one acid group selected from the group consisting of acrylic acid, methacrylic acid and maleic acid Examples include coalescence.

  As a copolymerization ratio of the (meth) acrylic acid alkyl ester monomer (a), the polar monomer (b) having no acid group, and the comonomer (c) having an acid group, the weight ratio is a / b / c. = It is preferable to mix | blend in the range of 35-99 / 1-60 / 0-5. Moreover, it is not necessary to use the comonomer (c) which has an acid group, and it is preferable to mix | blend in the range of a / b = 70-95 / 5-30 in that case.

  When the polar monomer (b) having no acid group is copolymerized in excess of 60% by weight as a comonomer, the radiation curable pressure-sensitive adhesive layer becomes a completely compatible system, and the elastic modulus after radiation curing exceeds 10 MPa. Therefore, there is a tendency that sufficient expandability and pickup properties cannot be obtained. On the other hand, when the polar monomer (b) having no acid group is copolymerized at less than 1% by weight, the radiation-curable pressure-sensitive adhesive layer tends to be a non-uniform dispersion system, and good pressure-sensitive adhesive properties tend not to be obtained.

  In addition, when using (meth) acrylic acid as a comonomer which has an acid group, it is preferable that the copolymerization amount of (meth) acrylic acid is 5 weight% or less. When (meth) acrylic acid is copolymerized in an amount exceeding 5% by weight as a comonomer having an acid group, the radiation-curable pressure-sensitive adhesive layer tends to be completely compatible, and sufficient expandability and pickup properties tend not to be obtained. .

  Moreover, as a weight average molecular weight of the (meth) acrylic acid ester copolymer which can be obtained by copolymerizing these monomers, 200,000-1 million are preferable and 400,000-800,000 are more preferable.

  Although there is no restriction | limiting in particular as a molecular weight of the radiation-polymerizable oligomer which comprises a radiation curing type adhesive layer, Usually, about 3000-30000 are preferable, and about 5000-10000 are preferable.

  The radiation-polymerizable oligomer is preferably uniformly dispersed in the radiation-curable pressure-sensitive adhesive layer. The dispersed particle size is preferably 1 to 30 μm, and more preferably 1 to 10 μm. The dispersed particle diameter is a value determined by observing the radiation curable pressure-sensitive adhesive layer with a 600 × microscope and actually measuring the particle diameter of the oligomer dispersed on the scale in the microscope. Further, the uniformly dispersed state (uniform dispersion) refers to a state in which the distance between adjacent particles is 0.1 to 10 μm.

  Examples of the radiation-polymerizable oligomer include compounds having at least one carbon-carbon double bond in the molecule such as urethane acrylate oligomer, epoxy-modified urethane acrylate oligomer, epoxy acrylate oligomer, and the like. A urethane acrylate oligomer is preferable in that various compounds can be selected according to the purpose.

  The urethane acrylate oligomer is, for example, a polyol compound such as polyester type or polyether, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diene. For example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate are added to terminal isocyanate urethane prepolymers obtained by reacting with isocyanate compounds such as isocyanate, diphenylmethane, and 4,4-diisocyanate. Acrylate or methacrylate having a hydroxyl group such as 2-hydroxypropyl methacrylate, polyethylene glycol acrylate, polyethylene glycol methacrylate, etc. It can be obtained by reacting and.

  Although there is no restriction | limiting in particular as molecular weight of the said urethane acrylate-type oligomer, 3000-30000 are preferable, 3000-10000 are more preferable, 4000-8000 are very preferable.

  In the dicing sheet used in the present invention, the blending ratio of the pressure-sensitive adhesive and the radiation-polymerizable oligomer in the radiation-curable pressure-sensitive adhesive layer is 20 to 200 parts by weight of the radiation-polymerizable oligomer with respect to 100 parts by weight of the pressure-sensitive adhesive. It is preferable that 50 to 150 parts by weight is used.

  By setting the blending ratio as described above, a large initial adhesive force can be obtained between the radiation curable pressure-sensitive adhesive layer and the film adhesive, and the adhesive force is greatly reduced after radiation irradiation. The attached semiconductor element can be picked up from the dicing sheet. In addition, since a certain degree of elastic modulus is maintained, it becomes easy to obtain a desired chip interval in the expanding process, and the chip body is not displaced and the pickup can be stably performed. If necessary, other components may be added in addition to the above components.

The film adhesive of the present invention includes a semiconductor element such as IC and LSI, a lead frame such as a 42 alloy lead frame and a copper lead frame; a plastic film such as a polyimide resin and an epoxy resin; a polyimide resin on a substrate such as a glass nonwoven fabric; What is impregnated and cured with a plastic such as an epoxy resin; can be used as an adhesive material for die bonding for bonding to an adherend such as a semiconductor mounting support member such as ceramics such as alumina. Among them, it is suitably used as an adhesive material for die bonding for bonding an organic substrate having an uneven surface on a surface such as an organic substrate having an organic resist layer on the surface and an organic substrate having wiring on the surface, and a semiconductor element.
Further, in the Stacked-PKG having a structure in which a plurality of semiconductor elements are stacked, it is also suitably used as an adhesive material for bonding the semiconductor elements to the semiconductor elements.

  About the use of the film adhesive of this invention, a semiconductor device provided with the film adhesive of this invention is demonstrated concretely using drawing. In recent years, semiconductor devices having various structures have been proposed, and the use of the film adhesive of the present invention is not limited to the semiconductor devices having the structure described below.

  FIG. 9 shows a semiconductor device having a general structure. In FIG. 9, a semiconductor element 21 is bonded to a semiconductor mounting support member 22 via the film adhesive 1 of the present invention, and a connection terminal (not shown) of the semiconductor element 21 is connected to an external connection terminal (not shown) via a wire 23. (Not shown) and electrically sealed with a sealing material 24.

  FIG. 10 shows an example of a semiconductor device having a structure in which semiconductor elements are bonded to each other. In FIG. 10, the first stage semiconductor element 21a is bonded to the semiconductor mounting support member 22 via the film adhesive 1 of the present invention, and the film adhesive 1 of the present invention is further formed on the first stage semiconductor element 21a. The second-stage semiconductor element 21b is bonded via The connection terminals (not shown) of the first-stage semiconductor element 21a and the second-stage semiconductor element 21b are electrically connected to external connection terminals via wires 23 and sealed with a sealing material. Thus, the film adhesive of the present invention can be suitably used for a semiconductor device having a structure in which a plurality of semiconductor elements are stacked.

  In addition, a semiconductor device (semiconductor package) having the above-described structure has the film adhesive of the present invention sandwiched between a semiconductor element and a semiconductor mounting support member, and is bonded by thermocompression bonding, and then a wire bonding step. It is obtained by passing through processes, such as a sealing process with a sealing material, as needed. The heating temperature in the thermocompression bonding step is usually 20 to 250 ° C., and the heating time is usually 0.1 to 300 seconds.

  Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

  Using the following PUAI-1 and PI-A to C, film coating varnishes were prepared as shown in the formulation tables of Tables 1 and 2.

(Synthesis example)
<PUAI-1>
In a 300 ml flask equipped with a thermometer, a stirrer, a cooling tube, and a nitrogen inflow tube, diphenylmethane-4,4′-diisocyanate 18.68 g (manufactured by Wako Pure Chemical Industries, Ltd.), polytetramethylene glycol 59. 74 g (manufactured by Wako Pure Chemical Industries, Ltd.) (0.4 mol of diol with respect to 1 mol of diisocyanate) and 130 g of N-methyl-2-pyrrolidone (dehydrated grade) were charged and reacted at 100 ° C. for 1 hour in a nitrogen atmosphere. A urethane oligomer solution was obtained. Next, trimellitic anhydride (1,2,4-benzenetricarboxylic acid 1,2-anhydride) previously heat-treated in an oven at 140 ° C. for 12 hours (difference between endothermic onset temperature and endothermic peak temperature by DSC: 3 ° C.) 7.16 g (1 mol of tricarboxylic acid anhydride per 1 mol of urethane oligomer) was added, and the mixture was further reacted at 160 ° C. for 3 hours to obtain a polyurethane amideimide solution (PUAI-1). As a result of measuring GPC of the obtained polyurethane amideimide, it was Mw = 92400 and Mn = 45200 in terms of polystyrene.

<PI-A>
In a 300 ml flask equipped with a thermometer, a stirrer, a condenser tube and a nitrogen inlet tube, 2.73 g (0.02 mol) of 2,2-bis (4-aminophenoxyphenyl) propane and 24.00 g of polysiloxane diamine (Shin-Etsu Silicone) KF-8010 (molecular weight: 900)) (0.08 mol) and 176.5 g of N-methyl-2-pyrrolidone (dehydrated grade) were charged and stirred. After dissolution of the diamine, 17.40 g of decamethylene bistrimellitic dianhydride (crystallized by DSC: difference between endothermic onset temperature and endothermic peak: 5 ° C.) recrystallized and purified in advance with acetic anhydride while cooling the flask in an ice bath. 0.1 mol) was added in small portions. After reacting at room temperature for 8 hours, 117.7 g of xylene was added, and heated at 180 ° C. while blowing nitrogen gas, and xylene was removed azeotropically with water to obtain a polyimide solution (PI-A). As a result of measuring GPC of the obtained polyimide, it was Mw = 12300 and Mn = 28700 in terms of polystyrene.

<PI-B>
4. In a 300 ml flask equipped with a thermometer, a stirrer, a condenser tube, and a nitrogen inflow tube, 2,71 g (0.045 mol) of 1,12-diaminododecane, polyether diamine (manufactured by BASF, ED2000 (molecular weight: 1923)) 77 g (0.01 mol), 1,3-bis (3-aminopropyl) tetramethyldisiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., LP-7100) 3.35 g (0.045 mol), previously recrystallized and purified with acetic anhydride 4, 4 ′-(4,4′-isopropylidenediphenoxy) bis (phthalic dianhydride) (difference between endothermic onset temperature and endothermic peak by DSC: 2.5 ° C.) 15.62 g (0.1 mol), and N -113 g of methyl-2-pyrrolidone was charged and stirred and reacted while heating at 180 ° C while blowing nitrogen gas. The generated water was removed to obtain a polyimide solution (PI-C). As a result of measuring GPC of the obtained polyimide, it was Mw = 22600 and Mn = 121400 in terms of polystyrene.

<PI-C>
In a 300 ml flask equipped with a thermometer, stirrer, condenser, and nitrogen inlet tube was added 13.67 g (0.1 mol) of 2,2-bis (4-aminophenoxyphenyl) propane and 124 g of N-methyl-2-pyrrolidone. Were stirred. After dissolution of the diamine, 17.40 g of decamethylene bistrimellitic dianhydride (crystallized by DSC: difference between endothermic onset temperature and endothermic peak: 5 ° C.) recrystallized and purified in advance with acetic anhydride while cooling the flask in an ice bath. 0.1 mol) was added in small portions. After reacting at room temperature for 8 hours, 83 g of xylene was added and heated at 180 ° C. while blowing nitrogen gas to azeotropically remove xylene together with water to obtain a polyimide solution (PI-C). As a result of measuring GPC of the obtained polyimide, it was Mw = 22800 and Mn = 12,000 in terms of polystyrene.

In Tables 1 and 2, various symbols mean the following.
ESCN-195: Sumitomo Chemical, cresol novolac-type solid epoxy resin (epoxy equivalent 200, molecular weight: 778),
TrisP-PA: Honshu Chemical, trisphenol novolak (OH equivalent: 141, molecular weight: 424),
TPPK: Tokyo Kasei, tetraphenylphosphonium tetraphenylborate,
NMP: Kanto Chemical, N-methyl-2-pyrrolidone,
HP-P1: Mizushima alloy iron, boron nitride (average particle size: 1.0 μm, maximum particle size: 5.1 μm)

Each of these varnishes was applied to a substrate (peeling agent-treated PET) to a thickness of 40 μm, heated in an oven at 80 ° C. for 30 minutes, then 150 ° C. for 30 minutes, and then peeled off from the substrate at room temperature. A film adhesive consisting of a single adhesive layer was obtained.
Tables 3 and 4 show the property evaluation results of the film adhesives of Examples 1-2 and Comparative Examples 1-3.

<20 ° C storage elastic modulus>
About the adhesive layer before use, adhesive layer size 35 mm × 10 mm × 40 μm thickness, temperature rising rate 5 ° C./min, frequency 1 Hz, measurement temperature −150 to 300 ° C. using Rheometrics Viscoelasticity Analyzer RSA-2 The storage elastic modulus at 20 ° C. when measured under the conditions was measured. “Before use” means “before the semiconductor element and the adherend are bonded using the adhesive layer”. The same applies hereinafter.

<Main dispersion peak temperature>
About the adhesive layer before use, adhesive layer size 35 mm × 10 mm × 40 μm thickness, temperature rising rate 5 ° C./min, frequency 1 Hz, measurement temperature −150 to 300 ° C. using Rheometrics Viscoelasticity Analyzer RSA-2 The tan δ peak temperature in the vicinity of Tg was measured, and this was used as the main dispersion temperature of the adhesive layer.

<Chip fly during dicing>
The film adhesive 1 was laminated on the back surface of the silicon wafer 9 using an apparatus having a roll 11 and a support 12 shown in FIG. At that time, the film adhesive 1 was laminated on the back surface of the silicon wafer 9 having a thickness of 5 inches and 300 μm under the conditions of roll temperature of the apparatus: 80 ° C., linear pressure: 4 kgf / cm, and feed rate: 0.5 m / min. . Thereafter, a dicing sheet (UC-334EP manufactured by Furukawa Electric) having a radiation curable pressure-sensitive adhesive layer on the base film was further laminated on the other surface of the film-like adhesive with a wafer facing the wafer. Thereafter, using a dicer, the silicon wafer was observed for dicing to a size of 5 mm × 5 mm under the conditions of a dicing speed of 10 mm / sec and a rotation speed of 30000 rpm, and the above chip jump was 10% of the total chip quantity. When the following occurs, the chip skipping is “no”, and when it exceeds 10%, the chip skipping is “present”. Note that the skip of the remaining chip cutout at the wafer edge was excluded from the evaluation.

<Flow amount>
10 mm × 10 mm × 40 μm-thick film adhesive (pre-use film; with 50 μm-thick PET base film) was used as a sample, and two slide glasses (Matsunami manufactured, 76 mm × 26 mm × 1.0-1.2 mm thick) ), A load of 100 kgf / cm ² is applied on a 180 ° C. hot platen, and the maximum value when the amount of protrusion from the PET base material after thermocompression bonding for 90 seconds is observed with an optical microscope with a scale is the maximum value. The amount of flow.

<Peel strength>
Using a silicon chip (5 mm x 5 mm x 0.4 mm thickness) and a film adhesive (5 mm x 5 mm x 40 µm thickness) on an organic substrate (thickness 0.1 mm) with a solder resist layer (thickness 15 µm) on the surface Temperature: Tg (dispersion peak temperature) of adhesive layer + 100 ° C., pressure: 500 gf / chip, time: 3 sec. After die bonding, temperature: 180 ° C., pressure: 5 kgf / chip, time: 90 sec. And thermocompression bonded. Further, the film adhesive was heated and cured at 180 ° C. for 5 hours, heated on a heating plate at 260 ° C. for 20 seconds, and then measured using an adhesive force evaluation apparatus shown in FIG. The peel strength was measured under the condition of sec.

<State of film adhesive after transfer molding>
A silicon chip (6.5 mm × 6.5 mm × 280 μm thickness) is placed on an organic substrate (thickness 0.1 mm) with a copper wiring (wiring height 12 μm) with a solder resist layer (thickness 15 μm) on the surface. Using a film adhesive (6.5 mm × 6.5 mm × 40 μm thickness), die bonding was performed under the conditions of temperature: Tg (dispersion peak temperature) of the adhesive layer + 100 ° C., pressure: 300 gf / chip, and time: 3 sec. Thereafter, transfer molding was performed (mold temperature: 180 ° C., cure time: 2 min), and the sealing material was heated and cured in an oven at 180 ° C. for 5 hours to obtain a semiconductor device (CSP 96 pin, sealing area: 10 mm). × 10 mm, thickness: 0.8 mm). Then, the state of the adhesive layer was observed using an ultrasonic probe video device HYE-FOUCUS manufactured by Hitachi, Ltd., and the presence or absence of foaming and the presence or absence of filling with respect to the irregularities on the substrate surface were examined. (○: No foaming or unfilled, ×: Foamed or unfilled)

<Reflow resistance>
Silicon chip (6.5mm × 6.5mm × 280μm thickness) is filmed on organic substrate (thickness 0.1mm) with copper wiring (wiring height 12μm) with 15μm thick solder resist layer on the surface After die bonding under the conditions of Tg (dispersion peak temperature) of the adhesive layer + 100 ° C. × 300 gf / chip × 3 sec with a shaped adhesive (6.5 mm × 6.5 mm × 40 μm thickness), transfer molding is performed (mold) (Temperature: 180 ° C., cure time: 2 min) and the sealing material was heated and cured in an oven at 180 ° C. for 5 hours to obtain a semiconductor device (CSP 96 pin, sealing area: 10 mm × 10 mm, thickness: 0.8 mm) . This semiconductor device was subjected to moisture absorption treatment at 30 ° C. and 60% RH 192h in a constant temperature and humidity chamber, and then an IR reflow device manufactured by TAMURA (semiconductor device surface peak temperature: 265 ° C., temperature profile: semiconductor device surface temperature as a reference, in accordance with JEDEC standards. 3), and the presence or absence of peeling and breakage of the adhesive layer was examined using an ultrasonic exploration imaging apparatus HYE-FOUCUS manufactured by Hitachi, Ltd. Thereafter, the central portion of the semiconductor device was cut and the cut surface was polished, and then a cross section of the semiconductor device was observed using an Olympus metal microscope to examine whether the adhesive layer was peeled off or broken. The evaluation standard for reflow resistance was that no peeling or breakage was observed. (○: No peeling and destruction, peeling or destruction)

It is sectional drawing which shows an example of the single-layer film adhesive which consists only of an adhesive bond layer. It is sectional drawing which shows an example of the film adhesive which provides an adhesive layer on both surfaces of a base film. It is sectional drawing which shows an example of a film adhesive provided with a base film, an adhesive bond layer, and a cover film. It is sectional drawing which shows an example of an adhesive sheet. It is a conceptual diagram which shows an example of the laminating method used in this invention. It is a conceptual diagram which shows an example of the laminating method used in this invention. It is a conceptual diagram which shows the measuring method of the 90 degree peel force with respect to the silicon wafer of the film adhesive of this invention. It is a figure which shows the measuring method of 90 degree peel force with respect to the film adhesive of this invention of a dicing sheet. It is a conceptual diagram which shows an example of the semiconductor device using the film adhesive of this invention. It is a conceptual diagram which shows an example of the semiconductor device using the film adhesive of this invention. It is the schematic which shows a peel strength measuring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Film adhesive 2 Adhesive layer 3 Base film 4 Cover film 5 Adhesive sheet 6 Dicing sheet 7 Adhesive layer 8 Base film 9 Silicon wafer 11 Roll 12 Support body 21, 21a, 21b Semiconductor element 22 Support for semiconductor mounting Member 23 Wire 24 Sealing material 31 Lead frame 32 Push-pull gauge 33 Hot platen

Claims (17)

  A film adhesive used for adhering a semiconductor element to an adherend, comprising an adhesive layer containing a polyurethane amideimide resin. The polyurethane amide imide resin is represented by the following general formula (I)

(In the formula, R ₁ is a divalent organic group containing an aromatic ring and / or a linear, branched or cyclic aliphatic hydrocarbon, R ₂ is a divalent organic group having a molecular weight of 100 to 10,000, and R ₃ is 4 (The trivalent organic group containing the above carbon atoms, n is an integer of 1 to 100)
The film adhesive according to claim 1, which is a polyurethane amide imide resin having a repeating unit represented by:   2. The film adhesive according to claim 1, wherein the polyurethane amide imide resin is a block copolymer obtained by extending a urethane oligomer obtained by reacting a diisocyanate and a diol with a tricarboxylic acid anhydride. The diisocyanate is represented by the following general formula (II)

The film adhesive according to claim 3, which is a diisocyanate represented by the formula: The diol is represented by the following general formula (III)

(Where n is an integer from 1 to 100)
The film adhesive according to claim 3, which is a diol represented by the formula: The tricarboxylic acid anhydride is represented by the following general formula (IV)

The film adhesive of Claim 3 which is trimellitic anhydride represented by these.   The film adhesive according to claim 1, wherein the polyurethane amideimide resin has a weight average molecular weight of 10,000 to 300,000.   The film adhesive according to claim 1, wherein the adhesive layer further contains a thermosetting resin.   The film adhesive according to claim 8, wherein the thermosetting resin is an epoxy resin.   The film adhesive according to claim 1, wherein the adhesive layer further contains a filler.   The film adhesive according to claim 1, wherein a main dispersion peak temperature of the adhesive layer is -100 to 50 ° C.   The film adhesive of Claim 1 whose storage elastic modulus in 20 degreeC of the said adhesive bond layer is 1000 Mpa or less.   The film adhesive according to claim 1, wherein a flow amount when the adhesive layer is hot-pressed on a hot plate at 180 ° C is 50 to 2000 µm.   The film adhesive according to any one of claims 1 to 13, wherein the adherend is an organic substrate with wiring.   An adhesive sheet having a structure in which the film adhesive according to claim 1 and a dicing sheet are laminated.   The adhesive sheet according to claim 15, wherein the dicing sheet has a base film and a radiation curable pressure-sensitive adhesive layer provided on the base film. A semiconductor device having a structure in which a semiconductor element and a semiconductor mounting support member and / or a semiconductor element and a semiconductor element are bonded by the film adhesive according to claim 1.

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