JP2009132830A - Adhesive composition and dicing die attach film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive composition causing no migration to a viscous layer and excellently following a minute pattern on a substrate to produce a cured product having no void. <P>SOLUTION: The adhesive composition is used for constructing an adhesive layer of the dicing die attach film comprising a base material, the viscous layer on the base material, and the adhesive layer on the viscous layer. The adhesive composition comprises (A) an epoxy resin showing a solid state at 25°C and having viscosity of 10-500 mPa s at 50°C, (B) at least one thermoplastic resin, which has functional groups reactive with the epoxy resin (A) and selected from polyimide silicone resins and phenoxy resins, (C) a catalytic amount of an epoxy resin curing catalyst, and (D) an organic filler in amount of 5-90 mass% of the adhesive composition. The content of the component (B) is decided so that a molar ratio of the amount of the epoxy groups of the component (A) to the amount of the functional groups of the component (B) becomes 3-50. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an adhesive composition suitably used for adhering a semiconductor chip to a substrate, and in particular, there is no transition to an adhesive layer in a dicing die attach film, and excellent storage stability at room temperature. The present invention relates to an adhesive composition and a dicing die attach film provided with an adhesive layer made of the composition.

  A semiconductor device fixes a large-diameter silicon wafer on an adhesive film (dicing film), dices (cuts and separates), peels off the cut chip from the dicing film, and picks up the picked-up chip. Is manufactured by thermocompression bonding and fixing with a curable liquid adhesive (die bond agent) or the like on a semiconductor device substrate. Recently, a dicing die attach adhesive film (or a dicing die bond film) that serves both as a dicing film and a die bonding agent has been used. This film is fixed so that the chip does not fly during dicing, and after dicing, it is taken out with the adhesive attached to the chip (pickup), and in the die bonding process, the adhesive is cured and bonded to the semiconductor device substrate. .

  As a dicing die attach film, a film in which a thermoplastic polyimide resin is formed on a plastic film base material has been proposed (Patent Document 1). The film is fixed by thermocompression bonding of the wafer onto the polyimide resin layer, followed by dicing, taking out the diced chip with the polyimide resin layer attached (pickup), thermocompression fixing to the semiconductor device substrate, and heat bonding To do. However, since the polyimide resin layer and the wafer are firmly adhered to each other by thermocompression bonding, the chip pick-up (pickup) property cannot be easily controlled.

  In order to facilitate pick-up, a film base material on which a photopolymerizable adhesive layer is formed comprises (A) a polyimide resin, (B) an epoxy resin, (C) a phenol resin, and (D) a curing accelerator. A dicing die-bonding film in which a resin layer is formed has been proposed (Patent Document 2).

On the other hand, a circuit on a substrate on which a semiconductor chip is mounted becomes finer year by year, and a filling property of a minute recess in the circuit (hereinafter referred to as “gap fill performance”) is required for an adhesive. That is, if the filling property is insufficient, a fine gap may be generated at the time of die attachment, and the adhesive film may be peeled off starting from the gap.
JP 2003-347321 A JP 2002-256236 A

  The present inventors, as an adhesive having excellent gap fill properties, include an adhesive containing a phenoxy resin and an epoxy resin (Japanese Patent Application No. 2007-91934), and a combination of a phenoxy resin and an epoxy resin with a specific phenolic curing agent. Invented an adhesive (Japanese Patent Application No. 2007-229217). These give a cured product having excellent gap fill properties and excellent heat stress resistance.

  However, it has been found that when these adhesives are applied on the pressure-sensitive adhesive layer, there may be a problem that a substance considered to be a low molecular weight substance from the adhesive layer to the pressure-sensitive adhesive layer migrates. The present invention aims to solve this problem.

As a result of intensive studies to achieve the above object, the present inventor has found that the above object can be achieved by using a predetermined epoxy resin and combining it with a curing agent having a predetermined functional group amount.
That is, the present invention is as follows.
An adhesive composition for constituting an adhesive layer of a dicing die attach film comprising a substrate, an adhesive layer on the substrate, and an adhesive layer on the adhesive layer,
(A) an epoxy resin that is in a solid state at 25 ° C. and has a viscosity at 50 ° C. of 10 mPa · s to 500 mPa · s,
(B) At least one thermoplastic resin selected from polyimide silicone resin or phenoxy resin having a functional group reactive with the epoxy resin (A), the amount of the epoxy group of the component (A) with respect to the amount of the functional group In an amount such that the molar ratio of
(C) a catalyst amount of an epoxy resin curing catalyst, and (D) an inorganic filler at 5 to 90% by mass of the adhesive composition,
An adhesive composition comprising.

  The adhesive composition of the present invention has a high storage stability at normal temperature (25 ° C., hereinafter the same) and is semi-solid or solid without fluidity and does not migrate to the adhesive layer. When heated, the composition becomes flexible and becomes a shape along the unevenness of the substrate, and when heated, gives a cured product having low elasticity and excellent heat resistance.

Hereinafter, it demonstrates for every component of a composition.
[(A) component]
The epoxy resin (A) used in the present invention is in a solid state at 25 ° C., and has a viscosity of 10 mPa · s to 500 mPa · s, preferably 20 to 300 mPa · s at 50 ° C. As a result of various studies by the inventors, it was found that it is mainly an epoxy resin that migrates to the adhesive layer, and the migration can be effectively prevented by limiting the fluidity of the epoxy resin at 25 ° C. In the present invention, the solid state need only have no fluidity, and may be a semi-solid state having flexibility when touched lightly with a hand or the like. Moreover, what is necessary is just to satisfy | fill the said requirements as (A) component whole, and a liquid epoxy resin may be included in 25 degreeC. Although depending on the molecular weight of the solid resin used in combination, the liquid resin is preferably 10% by weight or less, more preferably 5% by weight or less of the component (A). The viscosity at 50 ° C. can be measured with a cone and plate rotational viscometer. If the viscosity at 50 ° C. is less than the lower limit, the adhesive flows too much at the time of die attachment, and the resin tends to protrude over a wide range. On the other hand, if the upper limit is exceeded, a high temperature is required for die attachment, and the substrate warps. Cause.

  Preferably, component (A) comprises a solid epoxy resin at 25 ° C. having a weight average molecular weight of 600 or less, more preferably 500-200. The weight average molecular weight is a value in terms of polystyrene resin determined by GPC measurement. When the molecular weight is larger than 600, it is generally in a solid state at 25 ° C., but the thermocompression bonding property tends to deteriorate. On the other hand, even if the molecular weight is 600 or less, those that are not solid at 25 ° C. tend to migrate to the adhesive layer.

Examples of the epoxy resin include bis (4-hydroxyphenyl) methane or a diglycidyl ether of this halide and a polycondensation product thereof (so-called bisphenol F type epoxy resin), a diglycidyl ether of resorcin, a polyphenol or a polyphenol. Epoxy novolaks obtained by condensing epichlorohydrin with epoxy novolak type phenol resins (or halogenated novolac type phenol resins) such as epoxy glycidyl ether or polyglycidyl ester, phenol novolak, cresol novolak obtained by condensing monohydric alcohol and epichlorohydrin That is, novolac type epoxy resin), biphenyl type epoxy resin, phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, cyclopentadiene And epoxy resins. These may be a mixture of two or more thereof. Further, as described above, the component (A) as a whole can be used by mixing a liquid epoxy resin at room temperature as long as it satisfies the solid state at 25 ° C. and the viscosity at 50 ° C. is within a predetermined range. . Preferably, a bisphenol F type epoxy resin is used.

[Component (B)]
(B) A component is at least 1 type of thermoplastic resin chosen from the polyimide silicone resin and phenoxy resin which have a functional group reactive with the said epoxy resin (A). There are various functional groups reactive with the epoxy resin (A), such as a hydroxyl group, an acid anhydride group, and an amino group, and among them, a phenolic hydroxyl group, an amino group, and an epoxy group are preferable.

The thermoplastic resin (B) has a polystyrene-equivalent weight average molecular weight of 10,000 to 200,000, preferably 20,000 to 100,000, more preferably 30,000 to 80,000. When the weight average molecular weight is less than the lower limit value, it is difficult to form a coating film. On the other hand, when the weight average molecular weight is larger than the upper limit value, it is sufficient to fill the unevenness of the substrate surface having a fine circuit pattern. It is difficult to get softness.

（式中、Ｘは芳香族環又は脂肪族環を含む四価の有機基、Ｙは二価の有機基、ｑは１〜３００の整数である。）
上記ポリイミドシリコーン樹脂は、下記繰り返し単位を有するポリアミック酸樹脂を、常法により脱水、閉環することで得ることができる。

（式中、Ｘ、Ｙ、ｑは上で定義したとおりである。） From the viewpoint of adhesiveness, a polyimide silicone resin having a phenolic hydroxyl group having the following repeating unit is preferable.

(In the formula, X is a tetravalent organic group containing an aromatic ring or an aliphatic ring, Y is a divalent organic group, and q is an integer of 1 to 300.)
The polyimide silicone resin can be obtained by dehydrating and ring-closing a polyamic acid resin having the following repeating units by a conventional method.

(Wherein X, Y and q are as defined above.)

（但し、Ｘは上記と同様の意味を示す。）
で表されるテトラカルボン酸二無水物と、下記構造式（６）
Ｈ₂Ｎ−Ｙ−ＮＨ₂ （６）
（但し、Ｙは上記と同様の意味を示す。）
で表されるジアミンを、常法に従って、ほぼ等モルで、有機溶剤中で反応させることによって得ることができる。 The polyamic acid resin represented by the formula (3) has the following structural formula (5)

(However, X has the same meaning as described above.)
A tetracarboxylic dianhydride represented by the following structural formula (6)
H ₂ N—Y—NH ₂ (6)
(However, Y has the same meaning as described above.)
Can be obtained by reacting in a substantially equimolar amount in an organic solvent according to a conventional method.

  Here, examples of the tetracarboxylic dianhydride represented by the formula (5) include, but are not limited to, the following.

  These tetracarboxylic dianhydrides represented by the above formula (5) may be used singly or in combination of two or more as desired.

  Of the diamines represented by the above formula (6), it is preferable that 1 to 80 mol%, more preferably 1 to 60 mol% is a diaminosiloxane compound represented by the following structural formula (1). It is desirable from the viewpoint of solubility in a solvent, adhesion to a substrate, low elasticity, and flexibility.

（式中、Ｒ¹は同種または異種の炭素原子数３〜９の二価の有機基であり、Ｒ²およびＲ³は、夫々、同一または異種の非置換もしくは置換の炭素原子数１〜８の一価炭化水素基であり、ｍは１〜２００の整数である。）

Wherein R ¹ is the same or different divalent organic group having 3 to 9 carbon atoms, and R ² and R ³ are the same or different unsubstituted or substituted carbon atoms of 1 to 8, respectively. And m is an integer of 1 to 200.)

In the siloxane diamine (or α, ω-diaminopolysiloxane) represented by the general formula (1), examples of the divalent organic group having 3 to 9 carbon atoms represented by R ¹ include — (CH _{2 ) 3 -, - (CH 2} ) 4 -, - CH 2 CH (CH 3) -, - (CH 2) 6 -, - (CH 2) 8 - alkylene group and the like; formula

のいずれかで表されるアリーレン基；これらを組み合わせたアルキレン・アリーレン基；−（ＣＨ₂）₃−Ｏ−，−（ＣＨ₂）₄−Ｏ−等のオキシアルキレン基；下記式

Any represented by an arylene group; these combinations alkylene-arylene group _{;-( CH 2) 3 -O -,} - (CH 2) 4 oxyalkylene group -O- and the like; formula

のいずれかで表されるオキシアリーレン基；下記式

An oxyarylene group represented by any of the following:

で表されるオキシアルキレン・アリーレン基等の、エーテル結合を含んでもよい二価炭化水素基が挙げられる。

And a divalent hydrocarbon group which may contain an ether bond, such as an oxyalkylene / arylene group represented by the formula:

Examples of R ² or R ³ include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a hexyl group, a cyclohexyl group, a 2-ethylhexyl group, and an octyl group. Allyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, alkenyl group such as hexenyl group, aryl group such as phenyl group, tolyl group, xylyl group, aralkyl group such as benzyl group, phenylethyl group, etc. Groups in which part or all of the hydrogen atoms bonded to the carbon atoms of the hydrocarbon group are substituted with halogen atoms such as fluorine, bromine, chlorine, etc., for example, chloromethyl group, bromoethyl group, 3,3,3-trifluoro Examples include halogen-substituted alkyl groups such as propyl group, and among them, methyl group and phenyl group are preferable.

  These diaminosiloxane compounds represented by the above formula (1) can be used alone or in combination of two or more as desired.

  Examples of the diamine represented by the above formula (6) other than the diaminosiloxane compound represented by the above formula (1) include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, and 4,4. '-Diaminodiphenyl ether, 2,2'-bis (4-aminophenyl) propane, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (p-aminophenylsulfonyl) benzene, 1,4-bis (m-aminophenylsulfonyl) benzene, 1,4-bis (p-amino) Phenylthioether) benzene, 1,4-bis (m-aminophenylthioether) benzene, 2,2- [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [3-methyl-4- (4-aminophenoxy) phenyl] propane, 2,2-bis [3-chloro-4- (4) -Aminophenoxy) phenyl] propane, 1,1-bis [4- (4-aminophenoxy) phenyl] ethane, 1,1-bis [3-methyl-4- (4-aminophenoxy) phenyl] ethane, 1, 1-bis [3-chloro-4- (4-aminophenoxy) phenyl] ethane, 1,1-bis [3,5-dimethyl-4- (4-aminophenoxy) phenyl] ethane, bis [4- (4 -Aminophenoxy) phenyl] methane, bis [3-methyl-4- (4-aminophenoxy) phenyl] methane, bis [3-chloro-4- (4-aminophenoxy) phenyl] methane, bi [3,5-dimethyl-4- (4-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] per Examples thereof include aromatic ring-containing diamines such as fluoropropane, and preferably p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 1,4-bis (3- Aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [3-methyl-4- (4) -Aminophenoxy) phenyl] propane and the like.

（式中、Ｒ⁴は独立に水素原子又はフッ素、臭素、よう素などのハロゲン原子、あるいはアルキル基、アルケニル基、アルキニル基、トリフルオロメチル基、フェニル基などの非置換又は置換の炭素原子数１〜８の一価炭化水素基であり、各芳香環に付いている置換基は異なっていてもよく、ｎは０〜５の整数である。Ａ、Ｂはおのおの１種単独でも、２種以上の組み合わせでもよい。Ｒは水素原子、ハロゲン原子又は非置換もしくは置換の一価炭化水素基である。） The phenolic hydroxyl group can be obtained by using a diamine compound having a phenolic hydroxyl group. Examples of such a diamine include those having the following structure.

Wherein R ⁴ is independently a hydrogen atom or a halogen atom such as fluorine, bromine or iodine, or an unsubstituted or substituted carbon atom such as an alkyl group, alkenyl group, alkynyl group, trifluoromethyl group or phenyl group. 1 to 8 monovalent hydrocarbon groups, the substituents attached to each aromatic ring may be different, and n is an integer of 0 to 5. A and B are each a single type or two types. A combination of the above may be used, and R is a hydrogen atom, a halogen atom, or an unsubstituted or substituted monovalent hydrocarbon group.)

Here, as the unsubstituted or substituted monovalent hydrocarbon group having 1 to 8 carbon atoms of R ⁴ , for example, the same as those exemplified for R ² and R ³ above, and an ethynyl group, a propynyl group, Alkynyl groups such as a butenyl group and a hexynyl group can be exemplified. When R is an unsubstituted or substituted monovalent hydrocarbon group, examples of R include the same as those exemplified for R ⁴ above.

（上式中、Ｒは水素原子、フッ素、臭素、よう素などのハロゲン原子、又は炭素数１〜８の、アルキル基、アルケニル基、アルキニル基、トリフルオロメチル基、フェニル基などの非置換又はハロゲン置換の１価炭化水素基であり、各芳香族環に付いている置換基は異なっていてもよく、Ｘは単結合、メチレン基、又はプロピレン基である。） Moreover, the following are mentioned as another diamine which has a phenolic hydroxyl group.

(In the above formula, R is a hydrogen atom, a halogen atom such as fluorine, bromine or iodine, or an unsubstituted alkyl group, alkenyl group, alkynyl group, trifluoromethyl group, phenyl group or the like having 1 to 8 carbon atoms, or (This is a halogen-substituted monovalent hydrocarbon group, and the substituent attached to each aromatic ring may be different, and X is a single bond, a methylene group, or a propylene group.)

  Among the diamine compounds having a phenolic hydroxyl group, a diamine compound represented by the following formula (2) is particularly preferable.

（式中、Ｒ⁴は上で定義したとおりである。）

(Wherein R ⁴ is as defined above.)

  As a compounding quantity of the said diamine compound which has a phenolic hydroxyl group, it is preferable that it is 5-60 mol% with respect to the whole diamine compound, and especially 10-40 mol%. When a polyimide silicone resin having a blending amount in this range is used, a composition having a high adhesive force and forming a flexible adhesive layer can be obtained.

  In addition, the monoamine which has a phenolic hydroxyl group can also be used for introduction | transduction of a phenolic hydroxyl group, The monoamine which has the following structure is mentioned as the example.

（式中、Ｒ⁴は上記と同じであり、各芳香環に付いている置換基は異なっていても構わない。Ｄは１種単独で用いても２種以上を併用してもよい。また、ｐは１〜３の整数である。）

(In the formula, R ⁴ is the same as above, and the substituents attached to each aromatic ring may be different. D may be used alone or in combination of two or more. , P is an integer from 1 to 3.)

  When a monoamine having a phenolic hydroxyl group is used, the blending amount is 1 to 10 mol% with respect to the entire diamine compound.

  The polyamic acid resin can be synthesized by dissolving the above starting materials in a solvent in an inert atmosphere and reacting them usually at 80 ° C. or lower, preferably 0 to 40 ° C. The obtained polyamic acid resin is usually heated to 100 to 200 ° C., preferably 150 to 200 ° C., thereby dehydrating and ring-closing the acid amide portion of the polyamic acid resin to synthesize the target polyimide resin. it can.

  The organic solvent used for the reaction may not be one that can completely dissolve the starting material as long as it is inert to the resulting polyamic acid. Examples include tetrahydrofuran, 1,4-dioxane, cyclopentanone, cyclohexanone, γ-butyrolactone, N-methylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide and dimethyl sulfoxide, preferably aprotic Polar solvents, particularly preferably N-methylpyrrolidone, cyclohexanone and γ-butyrolactone. These solvents can be used singly or in combination of two or more.

  In order to facilitate the dehydration ring closure, it is desirable to use an azeotropic dehydrating agent such as toluene or xylene. Further, dehydration ring closure can be performed at a low temperature using an acetic anhydride / pyridine mixed solution.

  In order to adjust the molecular weight of polyamic acid and polyimide resin, maleic anhydride, dicarboxylic acid anhydride such as phthalic anhydride and / or aniline, n-butylamine, monoamine having phenolic hydroxyl group mentioned above are added. You can also However, the addition amount of dicarboxylic anhydride is usually 0 to 2 parts by mass per 100 parts by mass of tetracarboxylic dianhydride, and the addition amount of monoamine is usually 0 to 2 parts by mass per 100 parts by mass of diamine. Part.

  The phenoxy resin is a resin derived from epichlorohydrin and bisphenol A or F, for example, trade names PKHC, PKHH, PKHJ (all manufactured by Sakai Chemical Co., Ltd.), bisphenol A, bisphenol F mixed type trade names Epicoat 4250, Epicoat 4275, Epicoat 1255HX30, Epicoat 5580BPX40 using brominated epoxy (all manufactured by Nippon Kayaku Co., Ltd.), Bisphenol A type trade names YP-50, YP-50S, YP-55, YP-70 (all Toto Kasei) JER E1256, E4250, E4275, YX6954BH30, YL7290BH30 (all manufactured by Japan Epoxy Resin Co., Ltd.) and the like. JER E1256 is preferably used in that it has the above-described weight average molecular weight.

Since the phenoxy resin has an epoxy group at the terminal and reacts with the component (A), it is not necessary to separately add a reactive group.

  Preferably, the functional group equivalent of the component (B) is 200 g / eq to 20,000 g / eq, more preferably 300 to 10,000 g / eq. Resins having a functional group equivalent less than the lower limit are highly reactive and may not sufficiently fill the unevenness of the substrate surface having a fine circuit pattern. On the other hand, a resin having a functional group equivalent exceeding the above upper limit may have insufficient heat resistance and adhesive strength due to a lack of crosslinking points with the epoxy resin.

  In the above (A) epoxy resin and (B) thermoplastic resin, the molar ratio of the total amount of the epoxy group of the component (A) to the total amount of the functional group of the component (B) is 3 to 50, preferably 3 to 40, Is blended in an amount of A composition having a molar ratio of less than the lower limit exhibits gap fill performance, but requires a high die bonding temperature, and tends to reduce the moisture resistance reliability of the resulting cured product. On the other hand, when the upper limit is exceeded, the gap fill property at the time of thermal history is lowered.

[Component (C)]
(C) There is no restriction | limiting in particular in an epoxy resin curing catalyst, You may use a well-known thing. Examples include phosphorus catalysts and amine catalysts.

  Here, examples of the phosphorus catalyst include triphenylphosphine, triphenylphosphonium triphenylborate, tetraphenylphosphonium tetraphenylborate, and tetraphenylphosphine-tetraphenylborate shown below.

（式中、Ｒ⁵〜Ｒ¹²は、それぞれ独立に、水素原子又はフッ素、臭素、よう素などのハロゲン原子、あるいはアルキル基、アルケニル基、アルキニル基、又は炭素原子数１〜８のアルコキシ基、トリフルオロメチル基、フェニル基などの非置換もしくは置換の炭素原子数１〜８の一価炭化水素基であり、総てまたは一部の置換基が同一でも、おのおの異なっていても構わない。）

(Wherein R ^{5 to} R ¹² are each independently a hydrogen atom or a halogen atom such as fluorine, bromine or iodine, or an alkyl group, an alkenyl group, an alkynyl group, or an alkoxy group having 1 to 8 carbon atoms, (It is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 8 carbon atoms such as a trifluoromethyl group and a phenyl group, and all or some of the substituents may be the same or different.)

Here, examples of the monovalent hydrocarbon group of R ^{5 to} R ¹² include those similar to those exemplified for R ⁴ above, and alkoxy such as methoxy group, ethoxy group, propoxy group, isopropoxy group, and butoxy group. Examples include groups.

  Examples of the amine catalyst include imidazole derivatives such as dicyandiamide, 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and the like. Is mentioned. Preferably, dicyandiamide is used.

  The epoxy resin curing catalyst in the present invention can be used singly or in combination of two or more. The blending amount of the epoxy resin curing catalyst (C) can be an effective amount as a catalyst.

[(D) component]
Examples of the inorganic filler (D) used in the present invention include conductive particles such as silica fine powder, alumina, titanium oxide, carbon black, and silver particles. As a compounding quantity of this filler, 5-90 mass% of an adhesive composition, Preferably it is 10-70 mass%, More preferably, it is 40-70 mass%. When the blending amount is less than the lower limit, it is difficult to achieve electrical conductivity, thermal conductivity, low water absorption, low linear expansion, and the like, which are blending purposes of the inorganic filler. On the other hand, when the upper limit value is exceeded, the viscosity of the composition is increased, and the fluidity when applied to the film substrate is deteriorated.

The average particle size of the inorganic filler is preferably from 0.1 to 10 μm, more preferably from 0.5 to 7 μm. When the average particle diameter of the inorganic filler is within this range, good smoothness of the surface of the applied adhesive layer can be obtained. Further, in recent years, the thickness of the adhesive layer is often required to be 15 to 50 μm, but if the average particle size of the inorganic filler is within the above range, even if there are secondary aggregated particles, It is easy to satisfy this requirement.

In addition to the components (A) to (D), various additives may be blended in the composition of the present invention in amounts that do not impair the object of the present invention. Examples of the additive include a wetting improver, an antioxidant, and a heat stabilizer. Since the amount of the additive used is small, a concentration gradient hardly occurs in the adhesive layer, the pressure-sensitive adhesive of the dicing film, and the base film layer, but those in a solid state at room temperature are preferable.

[Method for producing composition]
The adhesive composition of the present invention can be prepared by mixing the above (A) to (D) and other components with a mixer or the like according to a conventional method.

  The obtained composition preferably has a melt viscosity at 40 to 80 ° C. (that is, a melt viscosity over the entire temperature range of 40 to 80 ° C.) of 10,000 mPa · s (= 10 Pa · s) or less. Is 8,000 mPa · s (= 8 Pa · s) or less. Usually, the pressure bonding of the semiconductor wafer to the adhesive film is performed at 40 to 80 ° C. and the pressure of 0.01 to 10 MPa, particularly 0.1 to 2 MPa. When the melt viscosity is greater than 10,000 mPa · s, It is difficult to attach the adhesive layer to the back surface of the semiconductor wafer, and in some cases, wafer strips may fly in the dicing process, or the adhesive layer may not adhere to the wafer and remain on the dicing mount in the wafer pick-up process. Here, in order to lower the melt viscosity, it is possible to perform the pasting at a pasting temperature of 80 ° C. or higher, but when the wafer and the adhesive are pasted at a high temperature, the adhesive and the wafer Due to the difference in coefficient of linear expansion, when it is allowed to cool to room temperature, the bonded adhesive and the wafer may be warped, or in the worst case, the wafer may be destroyed during the process.

[Dicing die attach film]
The adhesive composition obtained above is dissolved in an aprotic polar solvent such as toluene, cyclohexanone, or NMP at an appropriate concentration, applied onto a supporting substrate by coating, etc., and then dried to bond. Layer. As this film-forming support substrate, polyethylene, polypropylene, polyester, polyamide, polyimide, polyamideimide, polyetherimide, polytetrafluoroethylene, paper, metal foil, etc., or those whose surfaces have been subjected to mold release treatment should be used. Can do. Separately, an adhesive layer is formed on the support substrate. The pressure-sensitive adhesive layer may be a known one, and can be obtained, for example, by applying and drying a composition containing a (meth) acrylic resin mixture and a photopolymerization initiator. A dicing / diattach film or tape can be obtained by laminating the adhesive layer on the obtained adhesive layer. The supporting substrate on the adhesive layer is peeled off and the wafer is attached. After dicing, the pressure-sensitive adhesive layer is photocured and then the chip is picked up, and the adhesive layer is peeled off from the pressure-sensitive adhesive layer in a state where the adhesive layer is bonded to the chip piece. Next, the individual pieces are dyached to the substrate via the adhesive layer, and then the adhesive layer is cured.

  Drying when forming the adhesive layer is preferably performed at room temperature to 200 ° C., particularly 80 to 150 ° C. for 1 minute to 1 hour, particularly 3 to 10 minutes. There is no restriction | limiting in particular in the film thickness of an adhesive bond layer, It can select according to the objective, It is preferable that it is 10-100 micrometers, and it is especially preferable that it is 15-50 micrometers. Moreover, when hardening this adhesive bond layer, it is preferable to make it harden | cure at the temperature of 100-200 degreeC, especially 120-180 degreeC for 30 minutes-5 hours, especially 1-2 hours.

  In addition, the adhesive composition of this invention can also be used in the various processes with adhesion | attachment as a normal adhesive agent.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention, this invention is not restrict | limited to the following Example.

Resins and the like used in Examples and Comparative Examples are as follows.
(A) Component epoxy resin 1: RE602S (bisphenol F type epoxy resin, manufactured by Nippon Kayaku Co., Ltd.), state at 25 ° C .: solid state; viscosity at 50 ° C .: 150 mPa.s s; Mw: 340
Epoxy resin 2: RE310S (manufactured by Nippon Kayaku Co., Ltd.), state at 25 ° C .: liquid state; 15 Pa. s; Mw370
(B) component Phenoxy resin: Mw about 60,000, JER E1256 (made by Japan epoxy resin company)
Polyimide silicone resin 1: The synthesis method will be described later.
Polyimide silicone resin 2: The synthesis method will be described later.
(C) Component dicyandiamide (DICY-7): manufactured by Japan Epoxy Resin Co., Ltd. (D) Component silica: SE2050, manufactured by Admatechs
Resin epoxy resin 3 used in Comparative Example 3: Epicoat 4004P (manufactured by JER), 25 ° C. state: solid state; softening point 85 ° C., Mw 1800

次に、下記式：

で示されるフェノール性水酸基を有する芳香族ジアミン（ジアミン−１）１７．２５質量部と１００質量部の２−メチルピロリドンを、還流冷却器が連結されたコック付きの２５ｍｌ水分定量受器、温度計、攪拌器を備えた１リットルのセパラブルフラスコに仕込み、分散させ、前出の酸無水物リッチのアミック酸オリゴマーを滴下した後、室温で１６時間攪拌し、ポリアミック酸溶液を合成した。その後、キシレン２５ｍｌを投入してから温度を上げ、約１８０℃で２時間還流させた。水分定量受器に所定量の水がたまっていること、水の流出が見られなくなっていることを確認し、水分定量受器にたまっている流出液を除去しながら、１８０℃でキシレンを除去した。反応終了後、大過剰のメタノール中に得られた反応液を滴下し、ポリマーを析出させ、減圧乾燥して、骨格中にフェノール性の水酸基を有するポリイミド樹脂を得た。
得られたポリイミド樹脂の赤外吸光スペクトルを測定したところ、未反応の官能基があることを示すポリアミック酸に基づく吸収は現れず、１７８０ｃｍ^-1及び１７２０ｃｍ^-1にイミド基に基づく吸収を確認し、３５００ｃｍ^-1にフェノール性水酸基に基づく吸収を確認した。得られた樹脂のポリスチレン換算の重量平均分子量は５０，０００であり、官能基当量は１４４０ｇ／ｅｑであった。 Synthetic reflux condenser of polyimide silicone resin 1 Connected to a 25 ml water quantitative receiver with a cock, thermometer, and 1-liter separable flask equipped with a stirrer, diaminosiloxane represented by the following structural formula (KF-8010, (Shin-Etsu Chemical Co., Ltd.) 44.03 parts by mass and 100 parts by mass of 2-methylpyrrolidone as a reaction solvent were added and stirred at 80 ° C. to disperse the diamine. A solution of 38.72 parts by mass of 6FDA (2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane) and 100 parts by mass of 2-methylpyrrolidone as an acid anhydride was added dropwise thereto at room temperature for 2 hours. By carrying out a stirring reaction, an acid anhydride-rich amic acid oligomer was synthesized.

Next, the following formula:

25 ml moisture determination receiver with a cock connected to a reflux condenser, 17.25 parts by mass and 100 parts by mass of 2-methylpyrrolidone having a phenolic hydroxyl group represented by formula (diamine-1) and a thermometer The mixture was charged and dispersed in a 1 liter separable flask equipped with a stirrer, and the above-mentioned acid anhydride-rich amic acid oligomer was added dropwise, followed by stirring at room temperature for 16 hours to synthesize a polyamic acid solution. Thereafter, 25 ml of xylene was added, the temperature was raised, and the mixture was refluxed at about 180 ° C. for 2 hours. Confirm that the specified amount of water has accumulated in the moisture meter and that no water has flowed out, and remove xylene at 180 ° C while removing the effluent collected in the meter. did. After completion of the reaction, the reaction solution obtained in a large excess of methanol was added dropwise to precipitate a polymer and dried under reduced pressure to obtain a polyimide resin having a phenolic hydroxyl group in the skeleton.
When the infrared absorption spectrum of the obtained polyimide resin was measured, absorption based on polyamic acid indicating that there was an unreacted functional group did not appear, and absorption based on an imide group was confirmed at 1780 cm ⁻¹ and 1720 cm ^−1. Absorption based on a phenolic hydroxyl group was confirmed at 3500 cm ⁻¹ . The weight average molecular weight of polystyrene conversion of the obtained resin was 50,000, and the functional group equivalent was 1440 g / eq.

で示されるフェノール性水酸基を有するジアミン（ＨＡＢ、和歌山精化製）８.３１質量部を使用したことを除き、ポリイミドシリコーン樹脂１と同様にして、ポリイミドシリコーン樹脂２を得た。ポリイミドシリコーン樹脂２のポリスチレン換算の重量平均分子量は５５，０００であり、官能基当量は７６０ｇ／ｅｑであった。 Synthetic diaminosiloxane (KF-8010) of polyimide silicone resin 2 49.01 parts by mass, 6FDA 42.68 parts by mass, and instead of diamine-1, the following formula:

A polyimide silicone resin 2 was obtained in the same manner as the polyimide silicone resin 1 except that 8.31 parts by mass of a diamine having a phenolic hydroxyl group represented by (HAB, manufactured by Wakayama Seika) was used. The weight average molecular weight in terms of polystyrene of the polyimide silicone resin 2 was 55,000, and the functional group equivalent was 760 g / eq.

[Examples 1 to 5, Reference Examples 1 to 3]
In about 50 parts by mass of cyclohexanenon, polyimide silicone resins 1 and 2 or phenoxy resin in an amount (parts by mass) shown in Table 1 were dissolved. Next, the solution and other components in the amounts shown in Table 1 were mixed to obtain a composition having a solid content of about 70% by weight. In Table 1, the functional group ratio is (A) total epoxy group amount of epoxy resin / (B) total functional group component.

Preparation of Adhesive Film Release of a 38 μm thick PET film (hereinafter referred to as a base film) obtained by coating the compositions obtained in Examples 1 to 5 and Reference Examples 1 to 3 with a fluorine-containing silicone release agent. It apply | coated so that the thickness after drying might be set to about 25 micrometers on a mold surface. On the applied composition, another base film was placed so that the release surface of the film was in contact with the composition, and dried by heating at 110 ° C. for 10 minutes.

Separately, an adhesive layer for bonding the adhesive layer was prepared by the following method. A copolymer having a weight average molecular weight of 500,000 obtained by copolymerizing 50 parts by weight of 2-ethylhexyl acrylate, 10 parts by weight of butyl acrylate, 37 parts by weight of vinyl acetate, and 3 parts by weight of 2-hydroxyethyl methacrylate. 69 parts by weight of a polyfunctional urethane acrylate oligomer having a molecular weight of 25,000 with respect to 100 parts by weight of a polymer (acrylic polymer), and 2,2-dimethoxy-2-phenylacetophenone as a photopolymerization initiator An aliphatic aromatic copolymer petroleum resin comprising 8 parts by weight with respect to 100 parts by weight of the oligomer, a softening point of 100 ° C., and an aliphatic: aromatic molar ratio of 6: 4 is 14 parts by weight with respect to 100 parts by weight of the acrylic polymer. A pressure-sensitive adhesive comprising 7 parts by weight of polyisocyanate-based crosslinking agent and 100 parts by weight of an acrylic polymer. Liquid a polyethylene film having a thickness of 100 [mu] m (Nippa Co., PE 100) was applied so that the thickness after drying becomes 10 [mu] m, and dried for 5 minutes at 80 ° C..

Thereafter, the adhesive films of Examples 1 to 5 and Reference Examples 1 to 3 were laminated on the adhesive layer on the adhesive layer side to prepare a dicing film / die attach film. The obtained film was aged at room temperature for 30 days and then subjected to each test shown below. The results are shown in Table 1.

Measurement of epoxy content in adhesive layer by GPC The amount of resin content transferred to the adhesive layer during storage for 30 days was measured by GPC. Immediately after preparation (initial stage) and after standing for 30 days, each dicing die attach film was irradiated with 300 mJ of ultraviolet light using a high-pressure mercury lamp through the polyethylene film to cure the adhesive layer. After cooling to room temperature, the adhesive layer was peeled from the adhesive layer, dissolved in THF to 1 wt%, and subjected to GPC measurement. The measurement was performed using a TSK Gel G2000H, GMH-L (manufactured by Tosoh Corporation) column using THF with a TOSOH HLC-8220 GPC apparatus equipped with a refractive index detector. FIG. 1 shows an example of a GPC chromatogram. In the chromatogram, the peak of 33 to 35 minutes is that of the epoxy resin. Compared to the peak of the epoxy resin on the initial chromatogram, it can be seen that the peak is smaller after 30 days of standing. Among the peaks, the decrease (%) in area intensity after standing for 30 days from the area intensity (initial) immediately after preparation of the effluent from 33.5 minutes to 34 minutes was determined. In Table 1, A shows that the amount of reduction was less than 15%, and B was the amount of reduction of 15% or more.

The adhesive layer peeled off after aging at room temperature for 30 days was pasted on one surface of a transparent glass chip having a 25 μm gap fill performance of 5 mm × 5 mm × 500 μm. The obtained transparent glass chip with an adhesive layer was pressure-bonded onto a PCB having irregularities with an average height of 5 μm through the adhesive layer under the conditions of 130 ° C., 0.1 MPa, and 1 second. Next, after adding a heat history of 150 ° C. and 30 minutes corresponding to the heat history of wire bonding, pressing was performed from above the glass chip under the conditions of 175 ° C. and 7 MPa for 90 seconds corresponding to EMC sealing. The obtained pseudo device was observed with a microscope, and a gap was filled in and there was no void, and A was a void even in one place. The results are shown in Table 1.

A 3 mm x 3 mm x 25 µm adhesive layer peeled after room temperature aging for 30 days was pasted between the polished surfaces of a 10 mm x 10 mm silicon wafer and a 3 mm x 3 mm silicon wafer and fixed with the adhesive layer sandwiched between them. Specimens were made. This was thermocompression bonded for 1 second under conditions of 130 ° C. and 0.1 MPa. The obtained laminate was heat-treated at 175 ° C. for 4 hours to cure the adhesive layer, and an adhesive test piece was produced. Thereafter, using a Dage 4000 manufactured by Dage, the shear adhesive strength (MPa) was measured at a speed of 200 μm / second and a height of 50 μm.

Shear adhesive strength after wet heat A test piece similar to the above-mentioned test piece for measuring shearing adhesive strength was prepared and left for 168 hours under 85 ° C./60% RH condition, and then an IR reflow furnace with a maximum temperature of 260 ° C. The shear adhesive strength when passed three times was measured.

As shown in Table 1, the adhesive layer obtained from the composition of the present invention is excellent in storage stability at room temperature, and gives a cured product having no voids and firmly adhering to the substrate on which the wiring pattern is formed. be able to. In the compositions of Reference Examples 1 and 2, the epoxy resin component was in a liquid state, the transition to the adhesive layer was large, and the gap fill performance was inferior. In Reference Example 3, the migration of the epoxy resin was small, but the viscosity at 50 ° C. was high and the gap fill performance was inferior.

  The composition of the present invention is suitable as an adhesive for a dicing die attach film including an adhesive layer and an adhesive layer on the adhesive layer.

It is a GPC chromatogram of the adhesive composition after standing at room temperature for 30 days.

Claims (8)

An adhesive composition for constituting an adhesive layer of a dicing die attach film comprising a substrate, an adhesive layer on the substrate, and an adhesive layer on the adhesive layer,
(A) an epoxy resin that is in a solid state at 25 ° C. and has a viscosity at 50 ° C. of 10 mPa · s to 500 mPa · s,
(B) At least one thermoplastic resin selected from polyimide silicone resin or phenoxy resin having a functional group reactive with the epoxy resin (A), the amount of the epoxy group of the component (A) with respect to the amount of the functional group In an amount such that the molar ratio of
(C) a catalyst amount of an epoxy resin curing catalyst, and (D) an inorganic filler at 5 to 90% by mass of the adhesive composition,
An adhesive composition comprising. The adhesive composition according to claim 1, wherein the component (A) includes an epoxy resin having a polystyrene-equivalent weight average molecular weight of 600 or less and in a solid state at 25 ° C.   The adhesive composition of Claim 1 or 2 in which a component (A) contains a bisphenol F type epoxy resin.   The adhesive composition according to claim 2 or 3, wherein the component (A) further comprises an epoxy resin that is liquid at 25 ° C.   The adhesive composition according to any one of claims 1 to 4, wherein the adhesive layer contains a (meth) acrylic resin. The adhesive composition according to claim 1, wherein the functional group of component (B) is at least one selected from a phenolic hydroxyl group, an amino group, and an epoxy group. The polyimide silicone resin has the following formula (2):

(In the formula, R ^{4 s} are each independently a hydrogen atom, a halogen atom, or an unsubstituted or substituted monovalent hydrocarbon group having 1 to 8 carbon atoms)
Or the following formula (3):

The adhesive composition according to claim 1, wherein the adhesive composition is derived from a diamine represented by the formula:   A dicing die attach film, wherein the adhesive layer is made of the adhesive composition according to claim 1.

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