TW201903087A - Adhesive film, tape for processing semiconductor wafer, semiconductor package, and production method therefor - Google Patents

Abstract

The present invention relates to a bonding film, a semiconductor wafer processing tape, a semiconductor package, and a method for manufacturing the bonding film. The bonding film is composed of an adhesive layer containing a thermosetting resin, a thermoplastic resin, and a thermally conductive filler. Thermal conductivity is 12W / m. The content of K or more in the adhesive layer is 30 to 50% by volume, the thermoplastic resin contains at least one phenoxy resin, and the reliability of the cured adhesive layer is calculated by the following mathematical formula (1) The coefficient S1 is 50 ~ 220 (× 10 ^-6 GPa), the reliability coefficient S2 calculated from the following mathematical formula (2) is 10 ~ 120 (× 10 ^-8 GPa), and the thermal conductivity is 0.5 W / m. K or more.

S1 = (Tg-25 [℃]) × (CTEα1 [ppm / K]) × (Storage elastic modulus E '[GPa] at 260 ℃) ... (1)

S2 = S1 × (saturated water absorption rate WA [mass%]) ... (2)

In the formulas (1) and (2), S1, S2, Tg, CTEα1, storage elastic modulus E ', and saturated water absorption rate WA are for the adhesive layer after hardening. Tg is the glass transition temperature, CTEα1 is the coefficient of linear expansion below the glass transition temperature, and the storage elastic modulus E ′ is a value measured at 260 ° C. Units are indicated in [].

Description

   Adhesive film, tape for semiconductor wafer processing, semiconductor package, and manufacturing method thereof   

The present invention relates to an adhesive film, a tape for processing a semiconductor wafer, a semiconductor package, and a method for manufacturing the same.

In recent years, in the process of miniaturization, high functionality, and multifunctionalization of electronic devices, the semiconductor packages mounted on them have also been developed in terms of high functionality and multifunctionality. The microfabrication rules for semiconductor wafers are being refined. Into. Along with high functionality and multifunctionality, a multi-layer stacked MCP (Multi Chip Package) that stacks semiconductor wafers to achieve high capacity is becoming popular. Regarding the structure of semiconductor wafers, there are a method of directly mounting on a substrate or a semiconductor wafer [FOD (Film on Device) structure]; and a method of embedding and mounting a semiconductor wafer or a wire already mounted on a substrate [FOW ( Film on Wire). Wire-embedded semiconductor package (FOW structure) is a semiconductor package formed by crimping a high-fluid adhesive on a semiconductor wafer connected to the conductor and covering the conductor with the adhesive, and is used in mobile phones and portable audio-visual equipment. Memory packaging, etc.

As described above, with the rapid development of data processing of semiconductor devices, the amount of heat generated from semiconductor wafers has increased, and the importance of the design of semiconductor devices with heat dissipation has increased. It goes without saying that heat adversely affects the semiconductor device itself, and also has various adverse effects on the electronic device itself. As a countermeasure for heat dissipation, there are various methods considered, but the most important is heat dissipation through a printed circuit board or a substrate such as a lead frame.

Therefore, there have been cases where an adhesive having a high thermal conductivity is used for bonding a substrate to a semiconductor wafer. As such an adhesive, there is known a silver paste having a relatively high thermal conductivity, or a recently proposed sheet-shaped adhesive film (sticky film) (for example, refer to Patent Document 1).

Among them, the sheet-shaped adhesive film can suppress the cracking of the wafer, the inflow of the adhesive, and the tilt of the wafer, but its thermal conductivity is lower than that of the silver paste.

[Prior technical literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2008-218571

In a semiconductor package or a semiconductor device, a high-frequency device (RF device) generates a large amount of heat, and heat dissipation becomes a problem. On the other hand, for semiconductor packages or semiconductor devices such as high-frequency devices, reliability such as moisture sensitivity level (MSL, Moisture Sensitivity Levels) 1 of a moisture absorption reflow test (semiconductor heat resistance test) is required.

In addition, MSL1 is a grade specification specified by IPC / JEDEC (Common Electronic Equipment Technical Committee).

However, it is known that the adhesion of the adhesive film to the lead frame is not high, and peeling may occur between the adhesive film and the lead frame. As for the reliability of the semiconductor package as described above, it is important to have a higher level.

Therefore, the present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a bonding film having high heat dissipation and excellent reliability of a semiconductor package, and further, a semiconductor wafer processing tape having excellent semiconductor processability, A semiconductor package using the adhesive film or a tape for processing a semiconductor wafer and a manufacturing method thereof.

The present inventors have conducted diligent research repeatedly and found that: in addition to using a thermal conductivity of 12 W / m. In addition to thermal conductive fillers above K and thermosetting resins, phenoxy resins made of thermoplastic resins are used to make the cured adhesive layer have a coefficient of linear expansion below the glass transition temperature and a storage elastic modulus E 'at 260 ° C, In addition, the above-mentioned problem can be solved by satisfying a specific relationship including a saturated water absorption rate.

That is, it can be seen that the above-mentioned problem is achieved by the following configuration.

(1) An adhesive film comprising an adhesive layer containing a thermosetting resin, a thermoplastic resin, and a thermally conductive filler, characterized in that the thermal conductivity of the thermally conductive filler is 12 W / m. The content of K or more and the content in the adhesive layer is 30-50% by volume. The thermoplastic resin contains at least one phenoxy resin, and the reliability coefficient of the cured adhesive layer is calculated by the following mathematical formula (1). S1 is 50 ~ 220 (× 10 ^-6 GPa), the reliability coefficient S2 calculated from the following mathematical formula (2) is 10 ~ 120 (× 10 ^-8 GPa), and the thermal conductivity is 0.5W / m. Above K, S1 = (Tg-25 [℃]) × (CTEα1 [ppm / K]) × (Storage modulus E '[GPa] at 260 ℃) ... (1)

S2 = S1 × (saturated water absorption rate WA [mass%]) ... (2)

In the formulas (1) and (2), S1, S2, Tg, CTEα1, storage elastic modulus E ', and saturated water absorption rate WA are for the adhesive layer after hardening; Tg is the glass transition temperature, and CTEα1 is between The coefficient of linear expansion below the glass transition temperature and the storage elastic modulus E ′ are values measured at 260 ° C. In addition, the unit in [] is expressed.

(2) The adhesive film according to (1), wherein the glass transition temperature (Tg) of the phenoxy resin is -50 to 50 ° C, and the mass average molecular weight is 10,000 to 100,000.

(3) The adhesive film according to (1) or (2), wherein the phenoxy resin has a repeating unit represented by the following general formula (I),

In the general formula (I), L ^a represents a single bond or a divalent linking group, R ^a1 and R ^a2 each independently represent a substituent; ma and na each independently represent an integer of 0 to 4; X represents an alkylene group, and nb represents 1 An integer of ~ 10.

(4) The adhesive film according to any one of (1) to (3), wherein the thermosetting resin is an epoxy resin.

(5) The adhesive film according to any one of (1) to (4), wherein the thermally conductive filler is at least one selected from alumina and aluminum nitride.

(6) The adhesive film according to any one of (1) to (5), which contains a phenol resin as a hardener.

(7) The adhesive film according to any one of (1) to (6), which contains a sulfonium salt compound as a hardening accelerator.

(8) A tape for processing a semiconductor wafer, comprising: an adhesive layer on a base film; and the adhesive film according to any one of (1) to (7) on the adhesive layer.

(9) A semiconductor package using the adhesive film according to any one of (1) to (7) above.

(10) A method for manufacturing a semiconductor package, comprising the following steps: a first step of bonding any one of (1) to (7) to a back surface of a semiconductor wafer having at least one semiconductor circuit formed on its surface; A semiconductor wafer with an adhesive layer is obtained by adhering the adhesive layer of the film according to the item above, and the obtained semiconductor wafer with the adhesive layer and a wiring substrate are thermocompression-bonded via the adhesive layer; and a second step, The adhesive layer is thermally cured.

According to the present invention, a bonding film, a semiconductor wafer processing tape, a semiconductor package using the bonding film or a semiconductor wafer processing tape, and a method for manufacturing the same can be provided, which have high heat dissipation and excellent reliability of a semiconductor package.

In addition, the semiconductor wafer processing tape of the present invention has an adhesive film with high heat dissipation properties and excellent reliability of a semiconductor package. In addition to these properties, the semiconductor has excellent processability.

The above and other features and advantages of the present invention will be made clearer from the following description.

<< Adhesive film >>

The adhesive film of the present invention is composed of an adhesive layer containing at least a thermosetting resin, a thermoplastic resin, and a thermally conductive filler, and the adhesive layer after curing satisfies a specific range of reliability coefficient, and the thermal conductivity is 0.5 W / m. K or more.

In addition, in the present invention, the adhesive film refers to a film-like adhesive (hereinafter, also simply referred to as an adhesive or an adhesive layer), which may be a film composed of only the adhesive layer, or may be a release film. A film having an adhesive layer thereon.

<Composition of Adhesive Layer>

The adhesive film (adhesive layer) of the present invention contains at least a thermosetting resin, a thermoplastic resin, and a thermally conductive filler, and particularly preferably contains a curing agent and a curing accelerator.

(Thermoplastic resin)

Examples of the thermoplastic resin include natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, and polybutadiene. Polyolefin resin, polycarbonate resin, thermoplastic polyimide resin, polyimide resin such as 6-nylon or 6,6-nylon, phenoxy resin, acrylic resin, polyethylene terephthalate or polyparaphenylene Polyester resins such as succinate, polyimide resins, and fluororesins. These thermoplastic resins can be used alone or in combination of two or more.

In the present invention, at least one phenoxy resin among these thermoplastic resins is used. The phenoxy resin has high heat resistance and low saturated water absorption, and is also preferable in order to ensure the reliability of the semiconductor package. In addition, phenoxy resins have a similar structure to epoxy resins, so they have better compatibility, lower melt viscosity and better adhesion.

The phenoxy resin can be obtained by a reaction of a bisphenol or biphenol compound with an epihalohydrin such as epichlorohydrin, and a reaction of a liquid epoxy resin with a bisphenol or biphenol compound.

In any reaction, the bisphenol or biphenol compound is preferably a compound represented by the following general formula (A).

In the general formula (A), L ^a represents a single bond or a divalent linking group, and R ^a1 and R ^a2 each independently represent a substituent. ma and na each independently represent an integer from 0 to 4.

About L ^a, the divalent linking group is preferably alkylene, phenylene, -O -, - S -, - SO -, - SO 2 - , or a phenylene alkylene group and a combination of.

The number of carbon atoms is preferably 1 to 10, more preferably 1 to 6, even more preferably 1 to 3, particularly preferably 1 or 2, and most preferably 1.

The alkylene group is preferably -C (R ^α ) (R ^β )-. Here, R ^α and R ^β each independently represent a hydrogen atom, an alkyl group, and an aryl group. R ^α and R ^β may be bonded to each other to form a ring. R ^α and R ^β are each independently, preferably a hydrogen atom or an alkyl group (e.g. methyl, ethyl, isopropyl, n-propyl, n-butyl, isobutyl, hexyl, octyl, 2-ethylhexyl ). Among them, the alkylene group is preferably -CH _2- , -CH (CH ₃ ), -C (CH ₃ ) _2- , more preferably -CH _2- , -CH (CH ₃ ), and even more preferably -CH. _2- .

The phenylene group preferably has a carbon number of 6 to 12, more preferably 6 to 8, and even more preferably 6. Examples of the phenylene group include p-phenylene, m-phenylene, and o-phenylene, and p-phenylene and m-phenylene are preferred.

As a group composed of an alkylene group and an alkylene group, alkylene-alkylene-alkylene group is preferred, and -C (R ^α ) (R ^β ) -phenylene-C (R ^α ) (R ^β )-.

The ring formed by bonding R ^α and R ^{β is} preferably a 5- or 6-membered ring, more preferably a cyclopentane ring, a cyclohexane ring, and even more preferably a cyclohexane ring.

L ^{a is} preferably a single bond or an alkylene group, -O-, -SO _2- , and more preferably an alkylene group.

In R ^a1 and R ^a2 , the substituent is preferably an alkyl group, an aryl group, an alkoxy group, an alkylthio group, or a halogen atom, more preferably an alkyl group, an aryl group, a halogen atom, and even more preferably an alkyl group.

ma and na are preferably 0 to 2, more preferably 0 or 1, and even more preferably 0.

Examples of the bisphenol or biphenol compound include bisphenol A, bisphenol AD, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, and bisphenol. G, bisphenol M, bisphenol S, bisphenol P, bisphenol PH, bisphenol TMC, bisphenol Z, or 4,4'-biphenol, 2,2'-dimethyl-4,4'-linked Phenol, 2,2 ', 6,6'-tetramethyl-4,4'-biphenol, etc., preferably bisphenol A, bisphenol AD, bisphenol C, bisphenol E, bisphenol F, 4, 4'-biphenol is more preferably bisphenol A, bisphenol E, bisphenol F, and particularly preferably bisphenol F.

On the other hand, the liquid epoxy resin is preferably a diglycidyl ether of an aliphatic diol compound, and more preferably a compound represented by the following general formula (B).

Formula (B)

In the general formula (B), X represents an alkylene group, and nb represents an integer of 1 to 10.

The carbon number of the alkylene group is preferably 2 to 10, more preferably 2 to 8, even more preferably 3 to 8, particularly preferably 4 to 6, and most preferably 6.

Examples include: ethylene, propyl, butyl, pentyl, hexyl, and octyl. Preferred are ethyl, trimethylene, tetramethylene, pentamethylene, and heptylene. Methyl, hexamethylene, octamethylene.

nb is preferably 1 to 6, more preferably 1 to 3, and even more preferably 1.

Here, when nb is 2 to 10, X is preferably ethylene or propyl, and more preferably ethylene.

Examples of the aliphatic diol compound in diglycidyl ether include ethylene glycol, 1,2-propylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, 1,3-propylene glycol, and 1,4 -Butanediol, 1,5-heptanediol, 1,6-hexanediol, 1,7-pentanediol, 1,8-octanediol.

In the above reaction, each of the bisphenol, biphenol compound, or aliphatic diol compound may be a phenoxy resin obtained by performing a reaction alone, or may be a phenoxy resin obtained by mixing two or more types of reaction. Examples of the reaction include a diglycidyl ether of 1,6-hexanediol and a reaction with a mixture of bisphenol A and bisphenol F.

In the present invention, the phenoxy resin is preferably a phenoxy resin obtained by the reaction of a liquid epoxy resin with a bisphenol or a biphenol compound, and more preferably one having the following general formula (I) Repeated units of phenoxy resin.

In the general formula ^{(I), L a, R} a1, R a2, ma and na general formula (A), the ^{L a, R a1, R a2} , ma and na same meaning, the preferred range is also the same. X and nb have the same meanings as X and nb in the general formula (B), and preferred ranges are also the same.

In the present invention, a polymer of diglycidyl ether of bisphenol F and 1,6-hexanediol is preferred among these.

The mass average molecular weight of the phenoxy resin is preferably 10,000 or more, and more preferably 10,000 to 100,000.

In addition, a small amount of epoxy groups remain, and the epoxy equivalent is preferably 5,000 g / eq or more.

Here, the mass average molecular weight is a value calculated in terms of polystyrene by GPC [Gel Permeation Chromatography].

The glass transition temperature (Tg) of the phenoxy resin is preferably less than 100 ° C, more preferably less than 80 ° C. In the present invention, it is particularly preferably -50 ° C to 50 ° C, and most preferably -50 ° C to 30 ° C. ℃.

The phenoxy resin can be synthesized by the method described above, and a commercially available product can also be used. Examples of commercially available products include: YX7180 (trade name: bisphenol F + 1,6-hexanediol diglycidyl ether phenoxy resin, manufactured by Mitsubishi Chemical Corporation), 1256 (trade name: Bisphenol A type phenoxy resin, manufactured by Mitsubishi Chemical (Co., Ltd.), YP-70 (Trade name: Bisphenol A / F type phenoxy resin, manufactured by Nisshin Chemical Epoxy (Co., Ltd.), FX-316 (Trade name: Bisphenol F-type phenoxy resin, manufactured by Nippon Epoxy Manufacturing Co., Ltd.), and FX-280S (Trade name: Cardo skeleton-type phenoxy resin, manufactured by Nippon Epoxy Corporation) (Manufactured by Co., Ltd.), 4250 (trade name: bisphenol A / bisphenol F mixed phenoxy resin, manufactured by Mitsubishi Chemical (Co., Ltd.)) and the like.

The content of the thermoplastic resin is preferably 10 to 500 parts by mass, more preferably 30 to 450 parts by mass, and still more preferably 60 to 400 parts by mass with respect to 100 parts by mass of the thermosetting resin (especially epoxy resin). By setting the content to such a range, the rigidity and flexibility of the adhesive film before curing can be adjusted.

(Thermosetting resin)

As thermosetting resins, epoxy resins, phenol resins, urea resins, melamine resins, unsaturated polyester resins, silicone resins, and polyurethane resins are known. In the present invention, epoxy resins are particularly preferred. .

The epoxy resin may be any of liquid, solid, or semi-solid. In the present invention, the so-called liquid system means that the softening point is less than 50 ° C, the so-called solid means that the softening point is above 60 ° C, and the so-called semi-solid means that the softening point is between the softening point of the liquid and the softening point of the solid (50 ° C Above and below 60 ° C). As the epoxy resin used in the present invention, from the viewpoint of obtaining an adhesive layer capable of achieving a low melt viscosity in a suitable temperature range (for example, 60 to 120 ° C), the softening point is preferably 100 ° C or lower. In the present invention, the softening point means a value measured by a softening point test (ring and ball method) method (measurement conditions: based on JIS-2817).

In the epoxy resin used in the present invention, the crosslinked density of the hardened body becomes higher, and as a result, a higher thermal conductivity is obtained from the viewpoint of higher contact probability between the fillers to be blended and wider contact area. In other words, the epoxy equivalent is preferably 600 g / eq or less, more preferably 150 to 550 g / eq, still more preferably 150 to 450 g / eq, even more preferably 150 to 300 g / eq, and most preferably 150 to 200 g / eq. In addition, in the present invention, the epoxy equivalent means the number of grams (g / eq) of a resin containing 1 gram equivalent of an epoxy group.

The molecular weight or mass average molecular weight of the epoxy resin is preferably less than 3,000, more preferably 150 or more and less than 3,000, still more preferably 200 to 2,000, particularly preferably 200 to 1,000, and most preferably 300 to 600.

Here, the mass average molecular weight is a value calculated in terms of polystyrene by GPC [Gel Permeation Chromatography].

Examples of the skeleton of the epoxy resin include phenol novolac type, o-cresol novolac type, cresol novolac type, dicyclopentadiene type, biphenyl type, perylene bisphenol type, and three Type, naphthol type, naphthalene glycol type, triphenylmethane type, tetraphenyl type, bisphenol A type, bisphenol F type, bisphenol AD type, bisphenol S type, trimethylol methane type, dimerization Ester type and so on. Among these, from the viewpoint that the resin has low crystallinity and an adhesive layer having a good appearance can be obtained, triphenylmethane type, bisphenol A type, bisphenol F type, cresol novolac type, The cresol novolac type is more preferably a triphenylmethane type, a bisphenol A type, or a bisphenol F type, and among these, a triphenylmethane type and a bisphenol A type are more preferred.

The epoxy resin may be used singly or in combination of two or more kinds.

The content of the epoxy resin is preferably 1 to 20 parts by mass, and more preferably 4 to 10 parts by mass with respect to 100 parts by mass of the total mass of the components constituting the adhesive film. By setting it as such a range, the cross-linking density becomes a better range during hardening, which can suppress the generation of resin components with high cross-linking densities, which is difficult to improve the thermal conductivity, and suppress the film state (film adhesion due to slight temperature changes). Properties, etc.), the generation of oligomer components is liable to change.

(Hardener and hardening accelerator)

In the present invention, in order to thermally harden the epoxy resin, it is particularly preferable to use a hardener or a hardening accelerator.

Examples of the hardener or hardening accelerator for thermally curing the epoxy resin include dicyandiamine resins, boron trifluoride complexes, organic hydrazine compounds, amines, polyamide resins, Imidazole compounds, urea or thiourea compounds, polythiol compounds, polysulfide resins with mercapto groups at the ends, acid anhydrides, curing catalyst composite polyphenols and other phenolic resins, light / ultraviolet curing agents, phosphorus-boron curing Accelerators (phosphonium salt compounds, etc.).

Among them, boron trifluoride complexes include boron trifluoride-amine complexes with various amine compounds (preferably primary amine compounds), and organic hydrazine compounds include difluorene isophthalate. Hydrazine.

Examples of the amines include chain aliphatic amine compounds (diethylene triamine, triethylene tetramine, hexamethylene diamine, N, N-dimethylpropylamine, dimethylbenzyl) Amine, 2- (dimethylamino) phenol, 2,4,6-tris (dimethylaminomethyl) phenol, m-xylylenediamine, etc.), cyclic aliphatic amine compound (N-aminoethyl) Pipe , Bis (3-methyl-4-aminocyclohexyl) methane, bis (4-aminocyclohexyl) methane, mentanediamine, isophoronediamine, 1,3-bis (aminomethyl) Cyclohexane, etc.), heterocyclic amine compounds (piper , N, N-dimethylpipe , Triethylenediamine, melamine, guanamine, etc.), aromatic amine compounds (m-phenylenediamine, 4,4'-diaminodiphenylmethane, diamine, 4,4'-diamine Diphenylsulfonium, etc.), polyamine resin (preferably polyamine, a condensation product of a dimer acid and a polyamine).

Examples of the imidazole compound include 2-phenyl-4,5-dihydroxymethylimidazole, 2-methylimidazole, 2,4-dimethylimidazole, 2-n-heptadecylimidazole, and 1-cyano Ethyl-2-undecyl imidazolium-trimellitate, epoxy-imidazole adduct, composite compound of imidazole compound and aromatic polycarboxylic acid compound, etc.

Examples of urea or thiourea compounds include N, N-dialkylurea compounds, N, N-dialkylthiourea compounds, and the like.

Examples of the acid anhydride include tetrahydrophthalic anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic dianhydride, and the like.

Examples of the curing catalyst composite polyphenols include novolac-type phenol resins, phenol-aralkyl-type phenol resins, polyethylene-type phenol resins, and cresol-type phenol resins.

Examples of the light / ultraviolet curing agent include diphenyliodonium hexafluorophosphate, triphenylphosphonium hexafluorophosphate, and the like.

Examples of the phosphorus-boron-based hardening accelerator include tetraphenylphosphonium tetraphenylborate (trade name: TPP-K), tetraphenylphosphonium tetra-p-tolylborate (trade name: TPP-MK), and three Phosphine-boron-based hardening accelerators such as phenylphosphine triphenylborane (trade name: TPP-S) (both manufactured by Beixing Chemical Industry Co., Ltd.). Among these, tetraphenylphosphonium tetraphenylborate and tetraphenylphosphonium tetra-p-tolylborate are preferred in terms of excellent latentness and good storage stability at room temperature.

In the present invention, the hardening agent is preferably a curing catalyst composite polyphenol, and the hydroxyl equivalent is preferably 100 to 150 g / eq.

In the present invention, the term “hydroxyl equivalent” means the number of grams (g / eq) of a resin containing 1 gram equivalent of a hydroxyl group.

Among the hardening catalyst composite polyphenols, a novolac phenol resin is preferred in the present invention, and a cresol novolac phenol resin is more preferred.

Moreover, as a hardening accelerator, a phosphorus-boron hardening catalyst or the encapsulated imidazole is preferable at the point which is excellent in latency and can maintain the reliability of an adhesive film for a long time.

In the present invention, the hardening accelerator is particularly preferably a phosphorus-boron hardening accelerator, and most preferably is tetraphenylphosphonium tetraphenylborate.

The content of the hardener or the hardening accelerator in the adhesive layer is not particularly limited, and the optimum content varies depending on the type of the hardener or the hardening accelerator.

The content of the hardener is preferably 0.5 to 80 parts by mass, and more preferably 1 to 70 parts by mass based on 100 parts by mass of the epoxy resin.

The content of the hardening accelerator is preferably less than the content of the hardener, and is preferably 0.1 to 50 parts by mass, more preferably 0.5 to 20 parts by mass, and even more preferably 1 to 15 parts by mass, with respect to 100 parts by mass of the hardener.

(Conductive filler)

In the present invention, the adhesive layer contains a thermal conductivity of 12 W / m. At least one thermally conductive filler above K.

If the thermal conductivity of the thermally conductive filler does not reach 12W / m. K, in order to obtain the target thermal conductivity, it is necessary to mix more thermally conductive fillers. As a result, the melt viscosity of the adhesive film is increased, and the unevenness of the substrate cannot be covered when the substrate is crimped, and the adhesion is reduced.

Regarding the thermal conductivity of 12W / m. The thermal conductive filler above K is preferably selected from the group consisting of alumina particles (thermal conductivity: 36 W / m · K), aluminum nitride particles (thermal conductivity: 150-290 W / m · K), and boron nitride particles (thermal conductivity: 60W / m · K), zinc oxide particles (thermal conductivity: 54W / m · K), silicon nitride filler (thermal conductivity: 27W / m · K), silicon carbide particles (thermal conductivity: 200W / m · K), and At least one filler in the group consisting of magnesium oxide particles (thermal conductivity: 59 W / m · K). In particular, alumina particles have high thermal conductivity and are preferred in terms of dispersibility and availability. The aluminum nitride particles or the boron nitride particles preferably have a higher thermal conductivity than the aluminum oxide particles. In the present invention, among them, alumina particles and aluminum nitride particles are preferred.

The aluminum nitride particles contribute to high thermal conductivity and reduction in linear expansion coefficient.

Although aluminum nitride particles are hydrolyzed on the surface due to contact with water in the powder state, ammonium ions are easily generated, but by using a phenol resin with a low hygroscopicity in the epoxy resin hardener, hydrolysis can be suppressed.

The thermally conductive filler may also be subjected to surface treatment or surface modification. Examples of such surface treatment or surface modification include a silane coupling agent, a phosphoric acid or a phosphoric acid compound, and a surfactant.

For example, the method for treating a thermally conductive filler with a silane coupling agent is not particularly limited, and examples thereof include a wet method in which a thermally conductive filler and a silane coupling agent are mixed in a solvent, and a thermally conductive particle and a silane coupling agent are mixed in a gas phase. A dry method in which the mixture is treated, an integral method in which a silane coupling agent is previously mixed with a thermoplastic resin as a binder resin, and the like.

In the case of aluminum nitride particles, in order to suppress hydrolysis, it is preferable to perform surface modification. As the surface modification method of aluminum nitride, a method of improving the water resistance by providing an oxide layer of aluminum oxide on the surface layer, and improving the affinity with the resin by performing surface treatment with phosphoric acid or a phosphoric acid compound are particularly preferred.

Examples of phosphoric acid used in the surface treatment of a thermally conductive filler containing aluminum nitride include orthophosphoric acid (H ₃ PO ₄ ), pyrophosphoric acid (H ₄ P ₂ O ₇ ), and metaphosphoric acid ((HPO ₃ ) n, n is an integer representing the degree of condensation) or a metal salt thereof. Examples of the phosphoric acid compound include organic phosphoric acids such as alkylphosphonic acid, arylphosphonic acid, alkylphosphoric acid, and arylphosphoric acid (for example, methylphosphonic acid, ethylphosphonic acid, hexylphosphonic acid, vinylphosphonic acid, and phenyl Phosphonic acid, methyl phosphoric acid, ethyl phosphoric acid, hexyl phosphoric acid).

It is also preferable to use a silane coupling agent to surface-treat the surface of the thermally conductive filler.

It is also preferable to use an ion trapping agent in combination.

The silane coupling agent is obtained by bonding at least one hydrolyzable group such as an alkoxy group or an aryloxy group to a silicon atom, and in addition to this, an alkyl group, an alkenyl group, or an aryl group may be bonded. The alkyl group is preferably substituted with an amine group, an alkoxy group, an epoxy group, and a (meth) acrylic acid alkoxy group, and more preferably an amine group (preferably a phenylamino group) or an alkoxy group ( A glycidyloxy group or a (meth) acryloxy group is preferable.

Examples of the silane coupling agent include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyl Triethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, dimethyldimethoxysilane, dimethyl Diethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxy Silane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxy Silyl, 3-methacryloxypropyltriethoxysilane, and the like.

The surfactant (dispersant) may be any of anionic, cationic, and nonionic, and may be a polymer compound.

In the present invention, an anionic surfactant is preferred, and a phosphate ester surfactant is more preferred.

As the phosphate ester surfactant, a commercially available Phosphanol series manufactured by Toho Chemical Co., Ltd. can be used. Examples include: Phosphanol RS-410, 610, 710, Phosphanol RL-310, Phosphanol RA-600, Phosphanol ML-200, 220, 240, and Phosphanol GF-199 (all are trade names).

The silane coupling agent or the surfactant preferably contains 0.1 to 2.0 parts by mass based on 100 parts by mass of the thermally conductive filler.

The shape of the thermally conductive filler is not particularly limited. For example, flake, needle, filament, sphere, and scale can be used. However, the contact area between the thermally conductive particles and the resin can be reduced, and the temperature can be increased by 120 ° C to 130. In terms of fluidity at a temperature of 0 ° C, spherical particles are preferred.

The average particle diameter is preferably 0.01 to 5 μm, and more preferably 0.1 to 5 μm. By setting the average particle diameter to such a range, no aggregation occurs between the fillers, and unevenness or streaks do not occur when the adhesive layer is provided, thereby maintaining the uniformity of the film thickness of the adhesive layer.

In addition, in the present invention, the "average particle diameter" refers to a particle diameter when the total volume of particles is 50% when the total volume of particles is set to 100% in the particle size distribution, and can be based on the laser diffraction-scattering method (measurement conditions). : Dispersion medium-sodium hexametaphosphate, laser wavelength: 780 nm, measuring device: Microtrac MT3300EX) Measured by the cumulative curve of the volume percentage of the particle size distribution of the particle size distribution. In the present invention, the term "spherical" refers to a true sphere or a substantially true sphere with radians and substantially no corners.

In the present invention, the content of the thermally conductive filler is 30-50% by volume relative to the total volume of the adhesive layer. By setting it as such a range, a semiconductor package manufactured by using an adhesive film not only has excellent heat dissipation properties but also excellent stress relaxation properties. It can relax internal stress generated by the semiconductor package during thermal changes, and can peel off the adherend. Become less prone to happen.

In addition, if the content of the thermally conductive filler is less than 30% by volume, the thermal conductivity of the adhesive layer becomes low, and the heat radiation effect of the heat from the semiconductor package is weakened. If the content of the thermally conductive filler exceeds 50% by volume, the stress relaxation is poor, and it is difficult to relax the internal stress generated by the semiconductor package during thermal changes, and the peeling from the adherend is liable to occur.

The lower limit of the content of the thermally conductive filler is preferably 35% by volume or more, and more preferably 40% by volume or more. The content of the thermally conductive filler with respect to the total volume of the adhesive layer is calculated based on the added amount and specific gravity of each component constituting the adhesive layer.

(Other additives)

In the present invention, the adhesive layer preferably contains a hardening agent and a hardening accelerator in addition to a thermoplastic resin, a thermosetting resin, and a thermally conductive filler. In addition to these, the adhesive layer may be further within a range not hindering the effects of the present invention. Contains additives such as viscosity modifiers, antioxidants, flame retardants, colorants, stress relief agents such as butadiene-based rubber or silicone rubber.

(Content of resin component)

In the present invention, the content of the resin component including at least the thermoplastic resin and the thermosetting resin in the adhesive layer is preferably 50% by volume or more. The upper limit of the content of the resin component in the adhesive layer is preferably 70% by volume or less, more preferably 65% by volume or less, and still more preferably 60% by volume or less.

In addition, as the blending ratio of the thermosetting resin to 100 parts by mass of the total amount of the thermosetting resin and the thermoplastic resin, as long as the adhesive film (adhesive layer) is used as a thermosetting type when heating under specific conditions, The degree of the function is not particularly limited. In terms of improving the fluidity at 120 ° C to 130 ° C, a range of 10 to 80 parts by mass is preferable, and a range of 20 to 70 parts by mass is more preferable.

On the other hand, the blending ratio of the thermoplastic resin is preferably 20 to 100 parts by mass based on the total amount of the thermosetting resin and the thermoplastic resin in terms of improving the fluidity at 120 ° C to 130 ° C. A range of 90 parts by mass, more preferably a range of 30 to 80 parts by mass.

(Thickness of adhesive film (adhesive layer))

Next, the thickness of the film is preferably 5 to 200 μm, and from the viewpoint that the unevenness on the surface of the wiring substrate and the semiconductor wafer can be more fully covered, it is more preferably 10 to 40 μm. By setting the thickness to the above range, the unevenness on the surface of the wiring substrate and the semiconductor wafer can be sufficiently covered, and sufficient adhesion can be ensured. The organic solvent can be easily removed, and the amount of the residual solvent is small, so that no tackiness is generated. The problem of getting stronger.

<Release Film>

The release film is a release-treated film that functions as a cover film for an adhesive film (adhesive layer) and is peeled off when the adhesive layer as an adhesive film is attached to an adherend, and is used for Then the operability of the film is improved.

The demoulding treatment may be any treatment, and a representative treatment is a polysiloxane treatment.

Examples of the release film include a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, and polyterephthalene. Ethylene formate film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate copolymer film, ionic polymer resin film, ethylene- (meth) acrylic acid Release films such as copolymer films, ethylene- (meth) acrylate copolymer films, polystyrene films, polycarbonate films, polyimide films, and fluororesin films. Alternatively, such a crosslinked film may be used. Furthermore, such a laminated film may be used.

Of these, release-treated polyethylene, release-treated polypropylene, and release-treated polyethylene terephthalate are preferred, and release-treated polyethylene terephthalate is preferred. Ethylene formate.

The surface tension of the release film is preferably 40 mN / m or less, and more preferably 35 mN / m or less.

The film thickness of the release film is usually 5 to 300 μm, preferably 10 to 200 μm, and particularly preferably about 20 to 150 μm.

<Characteristics of Adhesive Film (Adhesive Layer)>

The adhesive layer (adhesive layer) of the present invention exhibits the following properties after being cured (hereinafter, also simply referred to as "post-hardened"), that is, the cured layer.

In addition, the measurement of the hardened | cured material of an adhesive layer was calculated | required about the hardened | cured material which had been heat-processed at 180 degreeC for 1 hour.

(Reliability Factor)

In the present invention, the reliability coefficient S1 calculated from the following mathematical formula (1) of the adhesive layer after curing is 50 to 220 (× 10 ^-6 GPa), and the reliability calculated from the following mathematical formula (2) The coefficient S2 is 10 to 120 (× 10 ^-8 GPa).

S1 = (Tg-25 [℃]) × (CTEα1 [ppm / K]) × (Storage elastic modulus E '[GPa] at 260 ℃) ... (1)

S2 = S1 × (saturated water absorption rate WA [mass%]) ... (2)

In the formulas (1) and (2), S1, S2, Tg, CTEα1, storage elastic modulus E ', and saturated water absorption rate WA are for the adhesive layer after hardening. Tg is the glass transition temperature, CTEα1 is the coefficient of linear expansion below the glass transition temperature, and the storage elastic modulus E ′ is a value measured at 260 ° C. In addition, the unit is shown in [].

Here, the reliability coefficients S1 and S2 include the 260 ° C heating step of the simulated moisture absorption step and the reflow step, and whether the peeling between the wafer and the substrate of the semiconductor package caused by deformation due to temperature change or moisture evaporation occurs. Evaluate.

When the glass transition temperature (Tg) of the adhesive layer after hardening is lower than the temperature, deformation will occur due to temperature change, and strain will occur. The amount of deformation due to temperature change is calculated by (Tg-25 [° C]) × (CTEα1 [ppm / K]) of the above-mentioned mathematical formula (1).

When the temperature is higher than the glass transition temperature (Tg), since the rubber is in a rubber state, the deformation can be eased.

In addition, if the storage elastic modulus E ′ at 260 ° C. is small, the strain relief accumulated from normal temperature (25 ° C.) to 260 ° C. due to internal stress is excellent.

The reliability coefficient S1 is a relational expression obtained by considering the above.

On the other hand, the reliability coefficient S2 is a relational expression obtained by further considering that, if the saturated water absorption is large, the moisture is evaporated in the heating step at 260 ° C. and the adhesion is easily generated inside the semiconductor package. Delamination at the interface of the agent layer.

(Saturated water absorption rate WA)

In the present invention, the saturated water absorption rate WA of the cured adhesive layer is preferably 1.0% by mass or less, and more preferably 0.7% by mass or less. If the saturated water absorption rate WA exceeds 1.0% by mass, in the reliability test including the moisture absorption step, there is a tendency that when the semiconductor package is soldered by the reflow method, due to the explosive vaporization of the moisture inside the film, Easy to produce package cracks. In addition, the saturated water absorption rate WA can be measured using a constant temperature and humidity device to measure the mass of the film after heat curing and before the film absorbs water, and the quality of moisture absorption to saturation at a temperature of 85 ° C and a relative humidity of 85%. Figure it out.

The saturated water absorption rate WA can be adjusted by changing the content ratio of the resin component and the thermally conductive filler, and the type and content of the resin component.

(Glass transition temperature (Tg) of the adhesive layer after hardening)

In the present invention, the glass transition temperature (Tg) of the adhesive layer after curing is preferably 80 ° C or higher.

If the glass transition temperature (Tg) is 80 ° C or higher, rapid changes in the physical properties of the semiconductor package in the normal use temperature range and the temperature range of the thermal cycle reliability test can be suppressed, and the saturation water absorption rate WA can be suppressed from increasing. The glass transition temperature (Tg) of the cured adhesive layer is more preferably 85 ° C or higher, and even more preferably 100 ° C or higher. On the other hand, the upper limit of the glass transition temperature (Tg) of the adhesive layer after curing is preferably 200 ° C or lower. If it is 200 ° C or lower, strain caused by temperature change can be suppressed. The upper limit of the glass transition temperature (Tg) of the adhesive layer after curing is more preferably 180 ° C or lower, and further preferably 150 ° C or lower.

The glass transition temperature (Tg) of the adhesive layer after curing can be adjusted by changing the type and content of the resin component and the curing conditions.

(Storage elastic modulus E ')

In the present invention, the storage elastic modulus E ′ of the adhesive layer after curing at 260 ° C. is preferably 1 GPa or less. When the storage elastic modulus E ′ at 260 ° C. is 1 GPa or less, the stress relaxation property is excellent, internal stress generated by the semiconductor device can be relaxed during thermal changes, and peeling from the adherend becomes difficult to occur. The lower limit of the storage elastic modulus E 'at 260 ° C is preferably 1 MPa or more. If the storage elastic modulus E 'at 260 ° C is 1 MPa or more, it is difficult to cause aggregation failure at high temperatures, and the reflow resistance is excellent. The storage elastic modulus E 'at 260 ° C is more preferably 0.01 GPa or more.

The storage elastic modulus E ′ can be adjusted by changing the content ratio of the resin component and the thermally conductive filler and the type and content of the resin component.

(Linear expansion coefficient CTEα1 below glass transition temperature (Tg))

In the present invention, the linear expansion coefficient CTEα1 of the adhesive layer after curing at a glass transition temperature (Tg) or lower is preferably 40 ppm / K or lower. If the linear expansion coefficient CTEα1 below the glass transition temperature (Tg) is 40 ppm / K or less, at the bonding interface between the adhesive layer and the adherend, it is possible to prevent the aggregate layer from being damaged due to the peeling stress generated by the heat. . The lower limit of the linear expansion coefficient CTEα1 below the glass transition temperature (Tg) is preferably 5 ppm / K or more. If the linear expansion coefficient CTEα1 below the glass transition temperature (Tg) is 5 ppm / K or more, at the bonding interface between the adhesive layer and the adherend, the adhesive layer can relax and absorb the peeling stress generated when heat is absorbed, and prevent Then the interface is peeled off.

The coefficient of linear expansion CTEα1 below the glass transition temperature (Tg) can be adjusted by changing the type and content of the resin component.

(The thermal conductivity of the adhesive layer after curing)

In the present invention, the thermal conductivity of the adhesive layer after curing is 0.5 W / m. Above K, preferably 1.2W / m. Above K, more preferably 1.5W / m. K or more. If the thermal conductivity of the adhesive layer after curing is 0.5 W / m. Above K, the semiconductor package manufactured using the adhesive film is excellent in heat dissipation. In addition, although the thermal conductivity of the adhesive layer after curing is higher, the better, but the upper limit is, for example, 20 W / m. K or less.

The thermal conductivity of the cured adhesive layer can be adjusted by changing the type and content of the resin component, and the type and content of the thermally conductive filler.

The glass transition temperature (Tg), the linear expansion coefficient CTEα below the glass transition temperature (Tg), the storage elastic modulus E 'at 260 ° C, the saturated water absorption rate WA, and the thermal conductivity of the cured adhesive layer can be determined by It measured by the method described in an Example.

<< Semiconductor Wafer Processing Tape and Manufacturing Method >>

The adhesive film of the present invention may be used alone as the adhesive film of the present invention, or it may have an adhesive layer on the base film and an adhesive layer (hereinafter referred to as adhesive for short) as the adhesive film of the present invention on the adhesive layer. (Adhesive layer) is used in the form of a semiconductor wafer processing tape (cut-to-die film).

Hereinafter, a semiconductor wafer processing tape will be described.

(Base film)

The material of the substrate film can usually be used by the users of adhesive tapes for semiconductor wafer processing. Examples include polyethylene, polypropylene, ethylene-propylene copolymer, polybutene, ethylene-vinyl acetate copolymer, and ethylene. -Homopolymers or copolymers of α-olefins such as acrylic copolymers, ethylene-acrylic copolymers, ionic polymers, engineering plastics such as polyethylene terephthalate, polycarbonate, polymethyl methacrylate, Thermoplastic elastomers such as polyurethane, styrene-ethylene-butene, or pentene-based copolymers may be those obtained by mixing two or more kinds selected from these groups.

In the present invention, from the viewpoints of holding the adhesive film and the semiconductor wafer at the time of dicing, and uniform expansion of the semiconductor wafer at the time of picking up, a crosslinkable resin is preferable, and for example, ethylene- (a (Meth) acrylic acid binary copolymer or ethylene- (meth) acrylic acid- (meth) acrylic acid is an ionic polymer cross-linked by metal ions.

The base film may be a single-layer film or a base film formed by laminating two or more films.

The thickness of the base film is preferably 50 to 200 μm.

(Adhesive layer)

The adhesive for forming the adhesive layer is not particularly limited. For example, it can be a general pressure-sensitive adhesive such as an acrylic adhesive, a rubber adhesive, or a radiation-curable adhesive that is hardened by irradiation with ultraviolet rays. Either. The pressure-sensitive adhesive used in the processing of semiconductor wafers is usually an acrylic adhesive and is preferred.

In the present invention, a radiation-curable adhesive is better than a pressure-sensitive adhesive.

The radiation-curable adhesive may be any one as long as it has a radiation-curable functional group such as a carbon-carbon double bond and exhibits adhesion.

For example, the following examples include radiation-curable adhesives, which are prepared by mixing a radiation-curable monomer component or an oligomer component with a general pressure-sensitive adhesive such as an acrylic adhesive to form a radiation-curable adhesive or base. A polymer having a carbon-carbon double bond at the side chain, main chain, or main chain end of the polymer. A radiation-curable adhesive having a carbon-carbon double bond in the base polymer (hereinafter, a polymer having a carbon-carbon double bond is referred to as a radiation-curable polymer). Containing these ingredients does not contain much, so oligomer ingredients and the like do not move in the adhesive layer with time, and can form an adhesive layer with a stable layer structure, so it is preferred.

In a case where a radiation-curable monomer component in which a radiation-curable monomer component or an oligomer component is blended into a general pressure-sensitive adhesive such as an acrylic adhesive, as the radiation-curable monomer component, for example, Examples: amine oligomers, amine (meth) acrylates, trimethylolpropane tris (meth) acrylates, tetramethylolmethane tetras (meth) acrylates, neopentaerythritol tris (methyl) ) Acrylate, neopentaerythritol tetra (meth) acrylate, dinepentaerythritol monohydroxypenta (meth) acrylate, dinepentaerythritol hexa (meth) acrylate, 1,4-butane Alcohol di (meth) acrylate and the like. Examples of the radiation-curable oligomer component include various oligomers such as amine ester-based, polyether-based, polyester-based, polycarbonate-based, and polybutadiene-based. These molecular weights are generally 100 to 30,000, and contain 5 to 500 parts by mass with respect to 100 parts by mass of the base polymer such as the acrylic polymer constituting the adhesive.

In the case where the base polymer has a carbon-carbon double bond radiation-hardening adhesive, the radiation-hardening polymer is a carbon-carbon double bond (hereinafter referred to as an ethylenic compound) which is polymerized and hardened by irradiation of radiation. Saturated groups) include vinyl, allyl, styryl, (meth) acrylfluorenyloxy, (meth) acrylfluorenylamino, and the like.

The radiation-curable polymer is not particularly limited, and examples thereof include a (meth) acrylic copolymer, a polyester, an ethylene or styrene copolymer, and a polyurethane, and a (meth) acrylic copolymer is preferable.

The (meth) acrylic acid in the (meth) acrylic copolymer includes acrylic acid or methacrylic acid, and may be either or both of them.

As a method for synthesizing a radiation-hardenable polymer, for example, (a) in the case of a polymer having an ethylenically unsaturated group, a compound having an ethylenically unsaturated group is reacted with the polymer to obtain the introduction of an ethylenically unsaturated group; A method of a polymer of a saturated group; and (b) a method of using an oligomer having an ethylenically unsaturated group [for example, a (meth) acrylate oligomer as a crosslinking agent, etc.]; these methods It is simple and easy, so it is preferable, and the method (a) is preferable among them.

In the method (a), as the compound having an ethylenically unsaturated group, a compound having a structure different from the ethylenically unsaturated group (referred to as a reactive group α) is used as the ethylenically unsaturated compound. The unsaturated polymer is a polymer containing a structure having a reactive group β that reacts with a reactive group α of a compound having the ethylenically unsaturated group (hereinafter referred to as a “polymer having a reactive group β” ), And the reactive groups α and β react.

Such reactive groups α and β are preferably set such that one is a base for performing a nucleophilic attack, and the other is a base subjected to a nucleophilic attack or a base subjected to an addition reaction. Examples of such a reactive group include a hydroxyl group, an amino group, a mercapto group, a carboxyl group, an epoxy group, an oxetanyl group, an isocyanate group, a group forming a cyclic acid anhydride, a halogen atom, an alkoxy group, or an aromatic group. Oxycarbonyl and the like.

Here, when any of the reactive groups α and β is a hydroxyl group, an amine group, a mercapto group, or a carboxyl group, the other reactive group may be an epoxy group, an oxetanyl group, an isocyanate group, A cyclic acid anhydride group, a halogen atom, an alkoxy group, or an aryloxycarbonyl group.

The reactive group α of the compound having an ethylenically unsaturated group is preferably a group subjected to a nucleophilic attack or a group subjected to an addition reaction. For example, an epoxy group, an oxetanyl group, or an isocyanate group is preferred. A cyclic acid anhydride-forming group, a halogen atom, an alkoxy group, or an aryloxycarbonyl group, more preferably an epoxy group, an oxetanyl group, an isocyanate group, or a cyclic acid anhydride-forming group, and more preferably a cyclic acid anhydride group An oxy group, an oxetanyl group, or an isocyanate group, among which an isocyanate group is preferable.

On the other hand, the reactive group β possessed by the polymer into which the ethylenically unsaturated group is introduced is preferably a group for conducting a nucleophilic attack, for example, a hydroxyl group, an amino group, a mercapto group, or a carboxyl group is more preferable, and a hydroxyl group or an amine is more preferable A hydroxy group or a mercapto group is more preferably a hydroxy group, an amine group, or a carboxyl group, and still more preferably a hydroxy group or a carboxyl group, and among these, a hydroxy group is more preferable.

Examples of the compound having an ethylenically unsaturated group and a reactive group α or a monomer having a reactive group β for synthesizing a polymer having a reactive group β include the following compounds.

-A compound having a reactive carboxyl group-

(Meth) acrylic acid, cinnamic acid, itaconic acid, fumaric acid, etc.

-A compound having a reactive group as a hydroxyl group-

Hydroxyalkyl (meth) acrylate having a hydroxyl group in the alcohol part [e.g. 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, trimethylolpropane mono (meth) acrylate Ester, ethylene glycol mono (meth) acrylate, diethylene glycol mono (meth) acrylate], N- (hydroxyalkyl) alkyl (meth) propylene, which is an alkylamine having a hydroxyl group in the amine portion Ammonium [eg N-methylol (meth) acrylamide, N, N-bismethylol (meth) acrylamide], allyl alcohol, etc.

-Compound having a reactive group as an amine group-

Aminoalkyl (meth) acrylates having an amine group in the alcohol portion [e.g. 2- (alkylamino) ethyl (meth) acrylate, 3- (alkylamino) propyl (meth) acrylate ], (Meth) acrylamide, etc.

-The compound whose reactive group is a cyclic acid anhydride-

Maleic anhydride, itaconic anhydride, fumaric anhydride, phthalic anhydride, etc.

-Compounds having a reactive group as an epoxy group or an oxetanyl group-

Glycidyl (meth) acrylate, allyl glycidyl ether, 3-ethyl-3-hydroxymethyloxetane, etc.

-The compound whose reactive group is isocyanate-

(Meth) acryloxyalkyl isocyanate [e.g. 2- (meth) acryloxyethyl isocyanate, 2- (meth) acryloxypropyl isocyanate], use A compound having a hydroxyl group or a carboxyl group and an ethylenically unsaturated group is obtained by amine esterifying a part of the isocyanate group of the polyvalent isocyanate compound [for example, 2 to 10 functional groups (meth) acrylic acid acrylate oligomers物] 等

In addition, as the amine acrylate oligomer, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, neopentaerythritol tri (meth) acrylate, and the like are preferred. Hydroxyalkyl (meth) acrylate having a hydroxyl group in the alcohol portion, and toluene diisocyanate, methylene biphenyl diisocyanate, hexamethylene diisocyanate, naphthalene diisocyanate, methylene dicyclohexyl isocyanate, isophorone An oligomer having at least one isocyanate group obtained by reacting a diisocyanate such as a diisocyanate or an isocyanate having three or more functional groups. In addition, it may be an oligomer obtained by reacting a polyol compound, a polyether diol compound, or a polyester diol compound in addition to a hydroxyalkyl (meth) acrylate and a polyisocyanate.

-Compound having a reactive group as a halogen atom-

2,4,6-trichloro-1,3,5-tri , 2,4-dichloro-6-methoxy-1,3,5-tri Isohalide III Wait

As the compound having an ethylenically unsaturated group and a reactive group α, a compound having the aforementioned reactive group as an isocyanate group is preferred, and as a monomer for synthesizing a polymer having a reactive group β A compound having a reactive group as a carboxyl group or a compound having a reactive group as a hydroxyl group is preferred, and a compound having a reactive group as a hydroxyl group is more preferred.

Among them, in the present invention, a (meth) acryloxyalkyl isocyanate is preferred, and a 2- (meth) acryloxyethyl isocyanate is particularly preferred.

The above (b) method is one in which the above (meth) acrylic acid amine oligomer is used (the oligomer is also a kind of crosslinking agent as described later), and the (meth) acrylic copolymer and The acrylate oligomers coexist to form a UV-curable adhesive layer. The (meth) acrylic copolymer is preferably obtained by polymerizing (meth) acrylic acid and (meth) acrylate. A preferred form of the (meth) acrylic acid ester component constituting the (meth) acrylic acid copolymer is the same as that described as a copolymerization component in the polymer having a reactive group β described below.

The monomer having a reactive group β for synthesizing a polymer having a reactive group β is preferably a hydroxyalkyl (meth) acrylate or (meth) acrylic acid having a hydroxyl group in the alcohol portion.

In the case of a hydroxyalkyl (meth) acrylate having a hydroxyl group in the alcohol portion, the above-mentioned monomer component having a reactive group β accounts for the total monomer component constituting the polymer having a reactive group β. The ratio is preferably 5 to 50 mole%, more preferably 20 to 40 mole%, and still more preferably 20 to 35 mole%.

On the other hand, in the case of (meth) acrylic acid, the proportion of acrylic acid or methacrylic acid in the total monomer component is preferably 0.1 to 3 mole%, more preferably 0.5 to 2.5, and even more preferably 0.5 ~ 2.

In addition, it is preferable when a compound having an ethylenically unsaturated group and a reactive group α and a polymer having a reactive group β are reacted to introduce an ethylenically unsaturated group into a polymer having a reactive group β. It is 5 to 40 parts by mass, more preferably 10 to 30 parts by mass, and still more preferably 10 to 20 parts by mass relative to 100 parts by mass of the polymer having a reactive group β. .

Since the unreacted reactive group β remains after the reaction of the reactive groups α and β, the resin characteristics can be adjusted by using the following crosslinking agents and the like.

The polymer having a reactive group β is preferably a monomer component having a reactive group β as a constituent component thereof, and a (meth) acrylate component as a copolymerization component.

The (meth) acrylic acid ester is preferably one or two or more kinds of (meth) acrylic acid alkyl esters. The alcohol part of the (meth) acrylate does not have the above-mentioned reactive group β. It is preferable that the alcohol part of the said (meth) acrylate is unsubstituted.

As such a (meth) acrylate, the carbon number of the alcohol part is preferably 1 to 12. The carbon number of the alcohol part is more preferably from 1 to 10, and even more preferably from 4 to 10. Among them, the alcohol part is preferably a branched alkyl group, and particularly preferably 2-ethylhexyl (meth) acrylate.

In the case where the radiation-curable polymer contains a plurality of types of (meth) acrylate components as constituent components, the (meth) acrylate component preferably contains a carbon number of 1 to 8 (a (Meth) acrylate component, among them, it is preferable to contain a methyl (meth) acrylate component or a butyl (meth) acrylate component.

Specific examples of the monomer added to the polymer as the copolymerization component are listed below.

-(Meth) acrylic acid alkyl ester-

The alkyl ester of (meth) acrylic acid is preferably one having 1 to 12 carbon atoms in the alcohol portion, and examples thereof include methyl (meth) acrylate, ethyl (meth) acrylate, and (meth) acrylic acid. Propyl ester, butyl (meth) acrylate, isobutyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ( Isooctyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, and the like. These can be used alone or in combination of two or more. By using two or more types in combination, various functions as an adhesive can be exerted, and the followability to the step of the surface of the semiconductor wafer and the non-contamination property including the prevention of paste residue can be taken into consideration.

-Monomers other than (meth) acrylic acid alkyl esters-

Examples of the monomer other than the alkyl ester of (meth) acrylic acid include vinyl acetate, styrene, and (meth) acrylamide, for example, N, N-diethylacrylamide, N, N-di Ethacrylamide, N-isopropylacrylamide, N-acrylamide Porphyrin, etc. These can be used alone or in combination of two or more.

In the present invention, as a monomer of a copolymerization component combined with a monomer having a reactive group β, (meth) acrylate and (meth) acrylic acid are preferred.

The ratio of the copolymerization component to all the polymer components constituting the polymer having the reactive group β is preferably 5 to 85 mol%, more preferably 20 to 80 mol%, and still more preferably 55. ~ 75 mole%, particularly preferably 60 ~ 75 mole%.

In addition, although the amount of the reactive group β remaining in the radiation-curable polymer also depends on the compounding amount of the compound having the reactive group α, it can also be performed by the types and blending amounts of the following crosslinking agents Adjustment.

The hydroxyl value of the radiation-hardenable polymer is preferably 5 to 70 mgKOH / g, the acid value is preferably 0 to 10 mgKOH / g, the glass transition temperature (Tg) is preferably -40 to -10 ° C, and the mass average molecular weight is preferably 150,000 to 1.3 million.

The acid value is measured based on JIS K5601-2-1: 1999, and the hydroxyl value is measured based on JIS K 0070.

Here, the glass transition temperature refers to a glass transition temperature measured by a DSC (differential scanning calorimeter) at a temperature increase rate of 0.1 ° C / minute.

The mass average molecular weight was calculated by dissolving a 1% solution obtained by dissolving in tetrahydrofuran with a gel permeation chromatography (manufactured by Waters, trade name: 150-C ALC / GPC). It measured, and calculated the value based on the mass average molecular weight of polystyrene conversion.

(Photopolymerization initiator)

The radiation-curable adhesive is particularly preferably a photopolymerization initiator. The adhesive force after crosslinking can be controlled by adjusting the blending amount of the photopolymerization initiator in the adhesive. Specific examples of such a photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl diphenyl sulfide, and tetramethylthiuram monosulfide. , Azobisisobutyronitrile, bibenzyl, diacetamidine, β-chloroanthraquinone, benzophenone, Michelin, chloro 9-oxosulfur , Biphenyl acetol, α-hydroxycyclohexylphenyl ketone, 2-hydroxymethylphenylpropane and the like. These can be used alone or in combination.

The photopolymerization initiator is usually used in a ratio of 0.1 to 10 parts by mass based on 100 parts by mass of the total amount of the radiation-curable polymer (the polymer having an ethylenically unsaturated group) and the compound having an ethylenically unsaturated group. In addition, it is preferably 0.1 to 10 parts by mass, and more preferably 1 to 6 parts by mass, with respect to 100 parts by mass of the matrix resin constituting the adhesive.

By irradiating the radiation-curable adhesive layer thus formed with radiation such as ultraviolet rays, the adhesive force can be greatly reduced, and the adhesive tape can be easily peeled from the adhesive layer.

(Crosslinking agent)

In the present invention, a crosslinking agent is preferably contained in the adhesive. The crosslinkable group, that is, the reactive group, of the crosslinker is preferably a crosslinker that reacts with the reactive group β of a polymer having a reactive group β.

For example, when the reactive group β of a resin having a reactive group β is a carboxyl group or a hydroxyl group, the crosslinkable group, that is, the reactive group, is preferably a cyclic acid anhydride, isocyanate group, epoxy group, The halogen atom is more preferably an isocyanate group or an epoxy group.

By using such a crosslinking agent, the residual amount of the reactive group β of the polymer having the reactive group β can be adjusted by its blending amount, and the tackiness can also be controlled.

In addition, by using a crosslinking agent, the cohesive force of the adhesive (adhesive layer) can also be controlled.

Examples of the crosslinking agent include polyisocyanate compounds, polyepoxide compounds, polyaziridine compounds, and chelate compounds. Specific examples of the polyvalent isocyanate compound include a tolyl diisocyanate, a diphenylmethane diisocyanate, a hexamethylene diisocyanate, an isophorone diisocyanate, and an adduct type thereof.

Examples of the polyvalent epoxy compound include ethylene glycol diglycidyl ether, terephthalic acid diglycidyl acrylate, and the like. Examples of the polyaziridine compound include tri-2,4,6- (1-aziridinyl) -1,3,5-tris. , Tris [1- (2-methyl) -aziridinyl] phosphine oxide, hexa [1- (2-methyl) -aziridinyl] triphosphotris Wait. Examples of the chelate compound include ethyl aluminum diisopropylacetate, aluminum tris (ethyl acetate), and the like.

In addition, in the adhesive, a crosslinking agent having at least two ethylenically unsaturated groups in the molecule, preferably an oligomer or polymer, may be used, and the crosslinking agent itself may be used as radiation. Hardening resin.

Examples of the low-molecular compound having at least two ethylenically unsaturated groups in the molecule include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, neopentaerythritol triacrylate, Neopentaerythritol tetraacrylate, dipentaerythritol monohydroxy pentaacrylate, dinepentaerythritol hexaacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, Polyethylene glycol diacrylate, oligoester acrylate, and the like.

In addition, amine acrylate oligomers can also be used, and specifically, they can be widely used in which a polyol compound such as a polyester type or a polyether type and a polyisocyanate compound [for example, 2, 4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate, etc.] A terminal isocyanate amine prepolymer is obtained, and the terminal isocyanate amine prepolymer and a (meth) acrylate having a hydroxyl group [for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate] Ester, polyethylene glycol (meth) acrylate].

The content of the cross-linking agent may be adjusted in such a manner that the adhesive force and the tackiness of the adhesive become the required ranges. It is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 100 parts by mass of the matrix resin. 5 to 5 parts by mass, more preferably 0.6 to 5 parts by mass, and even more preferably 0.7 to 3 parts by mass.

(Additive)

The adhesive may contain additives in addition to the above.

Examples of such additives include polysiloxane (for example, polysiloxane and polysiloxane) and radiation hardening accelerators as additives for preventing wetting and improving slippage. In addition, an amino acrylate as a waterproofing agent may be contained as an additive. In addition, a plasticizer may be contained as an additive. It may also contain a surfactant used in polymerizing the polymer.

(Thickness of adhesive layer)

The thickness of the adhesive layer is not particularly limited, but is preferably 3 to 300 μm, more preferably 3 to 100 μm, and still more preferably 5 to 50 μm.

(Other layers)

In the present invention, an intermediate layer such as a primer layer may be provided on the adhesive layer as needed.

<< Applications for Adhesive Film and Tape for Semiconductor Wafer Processing >>

The adhesive film and the semiconductor wafer processing tape of the present invention are preferably used for manufacturing a semiconductor package in a FOD structure. In addition, it is also suitable to set the adhesive of the wiring substrate and the semiconductor wafer to the same adhesive as the adhesive between the multi-layer laminated semiconductor wafers, instead of a different adhesive, to manufacture a semiconductor package.

<< Semiconductor Package and Manufacturing Method >>

In the present invention, the semiconductor package is preferably manufactured by the following manufacturing method. The manufacturing method includes at least: a first step of bonding the present invention to the back surface of a semiconductor wafer having at least one semiconductor circuit formed on the surface; The adhesive layer of the film is used to obtain a semiconductor wafer with an adhesive layer, and the obtained semiconductor wafer with an adhesive layer and a wiring substrate are thermocompression bonded via the adhesive layer; and the second step is the adhesive The layer is thermally hardened.

As the semiconductor wafer, a semiconductor wafer having at least one semiconductor circuit formed on the surface can be suitably used, and examples thereof include a silicon wafer, a SiC wafer, and a GaS wafer. The device used when the adhesive layer of such a semiconductor wafer processing tape is provided on the rear surface of the semiconductor wafer is not particularly limited, and for example, a well-known roll bonding machine, a manual bonding machine, or the like can be suitably used. Of the device.

When a semiconductor wafer processing tape is used, first, the semiconductor wafer processing tape of the present invention is provided on the adhesive layer side by thermal compression bonding to the back surface of a semiconductor wafer having at least one semiconductor circuit formed on the surface. The device used when the adhesive layer of such a semiconductor wafer processing tape is provided on the rear surface of the semiconductor wafer is not particularly limited, and for example, a well-known roll bonding machine, a manual bonding machine, or the like can be suitably used. Of the device.

Secondly, the semiconductor wafer and the adhesive layer are simultaneously crystallized to obtain a semiconductor wafer including the semiconductor wafer and the adhesive layer and an adhesive layer attached thereto. The device used for cutting the crystal is not particularly limited, and a known cutting device can be suitably used.

Next, the dicing tape (the portion having the adhesive layer on the base film) is detached from the adhesive layer, the semiconductor wafer with the adhesive layer and the wiring substrate are thermally compression-bonded via the adhesive layer, and the adhesive layer is detached. The semiconductor wafer is mounted on a wiring substrate. As the wiring substrate, a substrate on which a semiconductor circuit is formed can be suitably used, and examples thereof include a printed circuit board (PCB), various lead frames, and a substrate on which electronic components such as a resistance element or a capacitor are mounted on the surface of the substrate.

As a method of constructing a semiconductor wafer with an adhesive layer on such a wiring substrate, there is no particular limitation, and a semiconductor wafer with an adhesive layer can be suitably used on the wiring substrate or the surface of the wiring substrate by using an adhesive layer. How to know the electronic components on board. Examples of such a mounting method include a method using a mounting technology using a flip chip bonding machine having a heating function from above, a method using a die attaching machine having a heating function only from below, and a bonding machine. Methods such as the conventionally known heating and pressing methods.

By mounting the semiconductor wafer with the adhesive layer on the wiring substrate through the adhesive layer of the adhesive film of the present invention as described above, the adhesive layer can follow the unevenness on the wiring substrate generated by the electronic component, so that the semiconductor can be made. The wafer and the wiring substrate are in close contact and fixed.

Next, the adhesive layer is thermally hardened. The heat curing temperature is not particularly limited as long as it is equal to or higher than the heat curing starting temperature of the adhesive layer, and it differs depending on the type of resin used, and is not general. For example, it is preferably 100 to 180 ° C. From the viewpoint of curing in a short time when curing at a higher temperature, it is more preferably 140 to 180 ° C. If the temperature does not reach the starting temperature of thermal curing, the thermal curing may not be sufficiently performed, and the strength of the adhesive layer may decrease. On the other hand, if the above upper limit is exceeded, the epoxy in the adhesive layer may harden during the curing process. Resins, hardeners, additives, and the like tend to evaporate and tend to foam. The time for the hardening treatment is preferably, for example, 10 to 120 minutes. In the present invention, the film-shaped adhesive is thermally hardened at a high temperature, and no void is generated even if the film-shaped adhesive is cured at a high temperature, so that a semiconductor package in which a wiring substrate and a semiconductor wafer are firmly bonded can be obtained.

Secondly, it is preferable to connect the wiring substrate and the semiconductor wafer with the adhesive layer through a bonding wire. The connection method is not particularly limited, and a conventionally known method such as a wire bonding method or a TAB (Tape Automated Bonding) method can be suitably used.

In addition, it is also possible to laminate multiple layers by thermally crimping, hardening other semiconductor wafers by the surface of the mounted semiconductor wafer, and connecting them again to the wiring substrate by wire bonding. For example, there is a method of staggering a semiconductor wafer, or a method of laminating a bonding wire while inserting a bonding wire by thickening a second-layer adhesive layer.

In the present invention, it is preferable to seal the wiring substrate and the semiconductor wafer with the adhesive layer by a sealing resin, thereby obtaining a semiconductor package. The sealing resin is not particularly limited, and a known sealing resin that can be used for manufacturing a semiconductor package can be appropriately used. In addition, the sealing method using a sealing resin is not particularly limited, and a known method can be appropriately used.

[Example]

Hereinafter, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the following examples.

The materials used are the following.

[Thermoplastic resin]

． Phenoxy resin A1: YP-70

Product name of Nisshin Chemical Epoxy Co., Ltd., bisphenol A / bisphenol F copolymerization type, mass average molecular weight about 55,000, glass transition temperature (Tg) 60 ° C

． Phenoxy resin A2: YX7180

Manufactured by Mitsubishi Chemical Co., Ltd. Trade name, bisphenol F + 1,6-hexanediol diglycidyl ether type phenoxy resin, mass average molecular weight about 55,000, glass transition temperature (Tg) 15 ° C

[Thermosetting resin]

． Epoxy resin B1: RE-310S

Manufactured by Nippon Kayaku Co., Ltd. Trade name, bisphenol A liquid epoxy resin (bisglycidyl ether of bisphenol A), epoxy equivalent 185g / eq

． Epoxy resin B2: EPPN-501H

Manufactured by Nippon Kayaku Co., Ltd. Trade name, Triphenylmethane type epoxy resin (triglycidyl ether of tris (4-hydroxyphenyl) methane), epoxy equivalent 164g / eq

． Epoxy resin B3: JER871

Product name of Mitsubishi Chemical Corporation, a dimer-type epoxy resin (diglycidyl dimer), epoxy equivalent 390 ~ 470g / eq

[hardener]

． Dicyanodiamine resin: DICY-7

Product name of Mitsubishi Chemical Corporation, NH2-C (= NH) -NH-CN

． Phenolic resin: PSM-4271

Product name: Qunrong Chemical Industry Co., Ltd. Trade name, Cresol novolac hardener, hydroxyl equivalent 106g / eq

[Hardening accelerator]

．鏻 Salt: TPP-K

Manufactured by Beixing Chemical Industry Co., Ltd. Trade name, tetraphenylphosphonium tetraphenylborate

[Stress reliever]

． Epoxy Modified Polybutadiene: E-1800-6.5

Manufactured by Nippon Petrochemical Co., Ltd. Trade name, number average molecular weight 1,800, epoxy equivalent 250g / eq

[Conductive filler]

． Alumina: Thermal conductivity 36W / m. K, spherical particles with an average particle diameter of 2 to 3 μm

． Aluminum nitride: thermal conductivity 150W / m. K, spherical particles with an average particle diameter of 1.0 to 1.5 μm

Example 1

1. Follow the production of the film

70 parts by mass of phenoxy resin A2 (YX7180 manufactured by Mitsubishi Chemical Corporation) and 18 parts by mass of epoxy resin B1 (RE-31OS manufactured by Nippon Kayaku Co., Ltd.) were used. Qunrong Chemical Industry Co., Ltd. PSM-4271) with 11 parts by mass, hardening accelerator (Beiping Chemical Industry Co., Ltd. TPP-K) with 1.0 part by mass, and thermally conductive filler (alumina) with 329 A ratio of parts by mass was mixed into 30 mL of cyclopentanone to prepare an adhesive composition varnish, and the adhesive composition varnish was applied to a 38 μm-thick polyethylene terephthalate film (PET film) after being subjected to a release treatment. Then, heating and drying (holding at 130 ° C. for 10 minutes) were performed to volatilize the cyclopentanone, and an adhesive film having a thickness of 20 μm was prepared.

Examples 2 to 7 and Comparative Examples 1 to 9

In Example 1, a thermoplastic resin, an epoxy resin, a hardener, a hardening accelerator, a stress relieving agent, and a thermally conductive filler were changed in accordance with Tables 1 and 2 below, except that the same method as in Example 1 was used. Each of the adhesive films of Examples 2 to 7 and Comparative Examples 1 to 9 was produced.

[The performance evaluation of the film]

Using the adhesive films prepared in Examples 1 to 7 and Comparative Examples 1 to 9, the thermal conductivity after heat curing, the chloride ion concentration of the extracted water, the glass transition point, the storage elastic modulus at 260 ° C, and the glass transition temperature were measured. The following coefficients of linear expansion and saturated water absorption.

In addition, using the obtained glass transition temperature, a storage elastic modulus of 260 ° C, a linear expansion coefficient below the glass transition temperature, and a saturated water absorption, the reliability coefficients S1 and S2 were calculated from the above mathematical formulas (1) and (2). .

Furthermore, each of the produced adhesive films and the semiconductor package reliability test (MSL) and the semiconductor processing tape [(Furukawa Electric Industry Co., Ltd.]) were bonded at room temperature to prepare cut crystals. A die-bonding film is used to evaluate the semiconductor wafer processability (crystallinity and pick-up property).

(Measurement of thermal conductivity)

From each of the adhesive films produced above, a test piece of 12 mm × 12 mm × 2 mm was produced by forming processing, and the test piece was heated and hardened at 180 ° C. for 1 hour to obtain a measurement sample. The thermal diffusivity of the test piece was measured by a laser flash method [LFA447, manufactured by Netch (Co., Ltd., 25 ° C)], and then based on the thermal diffusivity and a differential scanning thermal measurement device [Pyris 1, PerkinElmer ( Co., Ltd.), the product of the specific heat capacity obtained and the specific gravity obtained by the Archimedes method, to calculate the thermal conductivity (W / m · K) at 25 ° C.

(Determination of chloride ion concentration in extracted water)

About 10 g of each adhesive film before heat curing was cut out, and heat-treated at 180 ° C for 1 hour using a hot air oven to prepare a sample after heat curing. 2 g of the heat-cured sample and 50 mL of pure water were placed in a container, and heat-treated at a temperature of 121 ° C. for 20 hours. The chloride ion concentration of the extracted water.

(Measurement of glass transition point and measurement of storage elastic modulus at 260 ° C)

The PET film was peeled from each of the adhesive films produced above, and the adhesive layer was laminated to form a laminated body having a thickness of 1000 μm. After the laminated body was heated at 180 ° C. for 1 hour to harden, a measurement sample having a length of 20 mm × a width of 5 mm was cut out of the cured product. Regarding this heat-cured sample, a solid viscoelasticity measuring device [Rheogel-E4000, manufactured by UBM (Co., Ltd.)] was used to measure the storage elastic modulus and loss elastic modulus at 25 ° C to 300 ° C. The measurement conditions were set to a frequency of 10 Hz and a heating rate of 5 ° C / minute. Furthermore, the value of tan δ [E "(loss elastic modulus) / E '(storage elastic modulus)] was calculated to obtain a glass transition point (Tg).

(Measurement of linear expansion coefficient)

A 5 mm corner post was produced from each of the adhesive films produced as described above by a molding process, and the corner post was heated at 180 ° C. for 1 hour to harden to obtain a measurement sample. The measurement sample was placed in a measurement jig of a thermomechanical analysis device [TMA7100, manufactured by Hitachi High-Tech Science (Co., Ltd.)], and a pressure of 0.02N was applied in a temperature range of -50 ° C to 300 ° C. The expansion coefficient was measured under the conditions of a probe diameter of 3 mm Φ and a heating rate of 7 ° C./minute, and a linear expansion coefficient (CTEα1) below the glass transition temperature (Tg) was calculated.

(Determination of saturated water absorption)

The PET film was peeled from each of the adhesive films prepared above, and formed into a disc shape with a diameter of 50 mm and a thickness of 3 mm. The PET film was heat-treated at 180 ° C for 1 hour using a hot air oven to prepare test pieces after heat curing. After measuring the mass (W ₁ ) before water absorption of the test piece, use a constant temperature and humidity device (trade name: SH-222, manufactured by ESPEC (Co., Ltd.)) to make it absorb water at a temperature of 85 ° C and a relative humidity of 85%. The time point when the mass of the test piece after the absorption of water was confirmed to be water absorption for more than 24 hours at a temperature of 85 ° C. and a relative humidity of 85% and the mass increase rate was 10% by mass or less was determined as the water absorption after measurement. The subsequent mass (W ₂ ) was determined by the following equation.

Saturated water absorption rate WA (mass%) = ((W ₂ -W ₁ ) / W ₁ ) × 100

(Semiconductor Wafer Processability: Crystallization, Pickup)

1) Crystalline

Each of the produced adhesive films was bonded to a dicing tape with an ionic polymer resin as a base film and an acrylic adhesive layer provided at room temperature to prepare a dicing-sticking film. Next, at a temperature of 70 ° C, it was bonded to a polished surface (roughness: # 2,000) of a silicon wafer cut and polished to a thickness of 50 μm, and a semiconductor with an attached film of 8 mm in width and 9 mm in length was formed by cutting the crystal. Wafer. The phenomenon that the wafer cut at this time is peeled off from the processing belt during the dicing process and scatters is referred to as "wafer splashing". In addition, the phenomenon of angular defects when the cut surface of the diced wafer is observed with a microscope is referred to as "" "Cracking". Regarding wafer spatter, if the number of wafers generated is less than 10% of the total number of wafers (140 to 160), it is set to "pass", and if it is more than 10%, it is set to "not qualified". Regarding chipping, randomly select 20 wafers after dicing, and if the maximum height of the defect under the microscope observation is 50% or less (that is, 25μm or less) with respect to the thickness of the wafer, it is set to "pass", and when it is 50% or more Set to "Fail".

2) Picking

When picking the cut-to-crystal film cut in 1) above, the phenomenon that the interface between the bonding film and the processing belt fails to peel off and the sticking device stops is called "pickup error". A part of the phenomenon remaining on the processing tape is called "DAF residue", and a case where the number of generated wafers (72 to 96) is 10% or more is set to "qualified" and 10% The following cases are set as "failed".

(Reliability test: MSL)

The solder heat resistance test MSL (Moisture Sensitivity Level) (wet reflow resistance) was evaluated in the following manner.

The semiconductor wafer with the dicing die-adhesive film produced as described above was bonded to an organic substrate via an adhesive film. The joining conditions were set to a temperature of 140 ° C, a pressure of 0.1 MPa, and 1 second. Next, the lead frame to which the semiconductor wafer was bonded was heat-treated at 120 ° C for 1 hour with a dryer, 150 ° C for 1 hour, and then 180 ° C for 1 hour. Thereafter, a sealing resin is used for packaging, thereby obtaining a semiconductor package. The sealing conditions were set to a heating temperature of 175 ° C and 120 seconds. Thereafter, it was dried at 125 ° C for 24 hours, and then subjected to moisture absorption under the conditions of 85 ° C, 85% relative humidity, and 168 hours, and then loaded in an IR reflow furnace set to hold at 260 ° C or higher for 10 seconds. A semiconductor package was placed, and this reflow test (held at 260 ° C or higher for 10 seconds) was performed three times. Thereafter, the semiconductor package was observed with an ultrasonic microscope, and it was confirmed whether or not peeling occurred at the interface between the adhesive film and the organic substrate. The verification was performed on eight semiconductor wafers. The case where there were zero peeled semiconductor wafers was set to "Pass", and the case where one or more semiconductor wafers were peeled was set to "Fail".

In addition, MSL1 described in Tables 1 and 2 is a grade specification specified by IPC / JEDEC (Common Electronic Equipment Technical Committee).

The obtained results are collectively shown in Tables 1 and 2 below.

In addition, Comparative Example 9 has a thermal conductivity of 0.4 W / m. K, does not meet the specified 0.5W / m. K or more, although the evaluation of the semiconductor wafer processability was performed, the remaining evaluations were not performed.

Here, the number which shows the compounding quantity of a material is a mass part. In addition, "-" in the table indicates unused. The semiconductor wafer processability is represented by "semiconductor processability".

From the above-mentioned Tables 1 and 2, the following can be known.

The hardened adhesive films (adhesive layers) of Examples 1 to 7 of the present invention have high thermal conductivity, excellent heat dissipation, and excellent reliability test (MSL) for solder heat resistance. In addition, the semiconductor has excellent processability.

Here, as in Comparative Example 9, if the content of the thermally conductive filler is less than 30% by volume, the thermal conductivity of the adhesive film (adhesive layer) after hardening does not reach 0.5 W / m. K, while heat dissipation is reduced.

If the content of the thermally conductive filler is 30% by volume or more, the thermal conductivity becomes 0.5 W / m. K or more.

However, as in Comparative Examples 1 to 8, as long as the reliability coefficient S1 does not satisfy the range of 50 to 220 × 10 ^-6 GPa and the reliability coefficient S2 does not satisfy the range of 10 to 120 × 10 ^-8 GPa, it is reliable in solder heat resistance. In the property test (MSL), peeling occurred at the interface between the adhesive film and the organic substrate.

In addition, when the content of the thermally conductive filler exceeds 70% by volume, if either of the reliability coefficients S1 and S2 does not satisfy the above range specified in the present invention, the processability of the semiconductor is often deteriorated. Here, in Comparative Example 1, since the phenoxy resin used is a phenoxy resin having a repeating unit represented by the general formula (I), especially two of bisphenol F and 1,6-hexanediol A polymer of glycidyl ether is considered to be excellent in semiconductor processability.

The invention has been described together with its embodiments, but it is believed that as long as the inventor does not specify otherwise, the invention of the inventor is not limited to any details of the description, and it should be within the scope of the patent application that does not violate it The scope of the illustrated spirit and scope of the invention is broadly interpreted.

This application claims priority based on Japanese Patent Application No. 2017-091351 for which a patent application was filed in Japan on May 1, 2017, which is hereby incorporated by reference as a part of the content described in this specification. .

Claims (10)

An adhesive film composed of an adhesive layer containing a thermosetting resin, a thermoplastic resin, and a thermally conductive filler, characterized in that the thermal conductivity of the thermally conductive filler is 12 W / m. The content of K or more in the adhesive layer is 30 to 50% by volume, the thermoplastic resin contains at least one phenoxy resin, and the reliability of the cured adhesive layer is calculated by the following mathematical formula (1) The coefficient S1 is 50 ~ 220 (× 10 ^-6 GPa), the reliability coefficient S2 calculated from the following mathematical formula (2) is 10 ~ 120 (× 10 ^-8 GPa), and the thermal conductivity is 0.5 W / m. Above K; S1 = (Tg-25 [℃]) × (CTEα1 [ppm / K]) × (Storage elastic modulus E '[GPa] at 260 ℃)… (1) S2 = S1 × (Saturated water absorption rate WA [Mass%]) ... (2) In the formulas (1) and (2), S1, S2, Tg, CTEα1, storage elastic modulus E ', and saturated water absorption rate WA are for the adhesive layer after curing; Tg is the glass transition temperature, CTEα1 is the coefficient of linear expansion below the glass transition temperature, and the storage elastic modulus E ′ is a value measured at 260 ° C. In addition, the unit in [] indicates the unit.     The adhesive film according to claim 1, wherein the glass transition temperature (Tg) of the phenoxy resin is -50 to 50 ° C, and the mass average molecular weight is 10,000 to 100,000.     The adhesive film according to claim 1 or 2, wherein the phenoxy resin has a repeating unit represented by the following general formula (I); In the general formula (I), L ^a represents a single bond or a divalent linking group, R ^a1 and R ^a2 each independently represent a substituent; ma and na each independently represent an integer of 0 to 4; X represents an alkylene group, and nb represents 1 An integer of ~ 10.     The adhesive film according to any one of claims 1 to 3, wherein the thermosetting resin is an epoxy resin.         The adhesive film according to any one of claims 1 to 4, wherein the thermally conductive filler is at least one selected from alumina and aluminum nitride.         The adhesive film according to any one of claims 1 to 5, which contains a phenol resin as a hardener.         The adhesive film according to any one of claims 1 to 6, which contains a sulfonium salt compound as a hardening accelerator.         A tape for processing a semiconductor wafer, which has an adhesive layer on a base film and an adhesive film according to any one of claims 1 to 7 on the adhesive layer.         A semiconductor package using the adhesive film according to any one of claims 1 to 7.         A method for manufacturing a semiconductor package, comprising the following steps: a first step of bonding the adhesive film according to any one of claims 1 to 7 on a back surface of a semiconductor wafer having at least one semiconductor circuit formed on its surface; The adhesive layer is followed to obtain a semiconductor wafer with an adhesive layer, and the obtained semiconductor wafer with an adhesive layer and a wiring substrate are thermocompression-bonded via the adhesive layer; and the second step is to perform the adhesive layer described above. Heat hardened.