JP2010222390A - Adhesive composition, adhesive sheet and method for producing semiconductor apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive composition that achieves high package reliability even if exposed to a severe reflow condition in a package packaging a semiconductor chip in thinning and especially achieves high package reliability even when allowed to stand high-temperature and high-humidity conditions and IR reflow is carried out after humidity absorption, an adhesive sheet having an adhesive layer composed of the adhesive composition, and a method for producing a semiconductor apparatus using the adhesive sheet. <P>SOLUTION: The adhesive composition comprises an acrylic polymer (A), an epoxy-based thermosetting resin (B) and a phenol-based thermosetting agent (C) having a molecular weight distribution (Mw/Mn) of ≤1.7 and a weight-average molecular weight of ≥770. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is particularly suitable for use in a step of die bonding a semiconductor element (semiconductor chip) to an organic substrate or a lead frame and a step of dicing a silicon wafer or the like and die bonding a semiconductor chip to an organic substrate or a lead frame. The present invention relates to an adhesive composition, an adhesive sheet having an adhesive layer made of the adhesive composition, and a method of manufacturing a semiconductor device using the adhesive sheet.

A semiconductor wafer made of silicon, gallium arsenide or the like is manufactured in a large diameter state, and this wafer is cut and separated (diced) into element pieces (semiconductor chips) and then transferred to the next mounting step. At this time, the semiconductor wafer is subjected to dicing, cleaning, drying, expanding, and pick-up processes in a state where it is adhered to the adhesive sheet in advance, and then transferred to the next bonding process.
In order to simplify the pick-up process and bonding process among these processes, various dicing / die bonding adhesive sheets having both a wafer fixing function and a die bonding function have been proposed (for example, Patent Documents). 1-4).

  Patent documents 1 to 4 disclose an adhesive sheet composed of an adhesive layer made of a specific composition and a base material. This adhesive layer has a function of fixing the wafer during wafer dicing, and further, the adhesive force is reduced by irradiation with energy rays and the adhesive force with the base material can be controlled. When done, the adhesive layer peels off with the chip. When the semiconductor chip with the adhesive layer is placed on the substrate and heated, the thermosetting resin in the adhesive layer develops an adhesive force, and the bonding between the semiconductor chip and the substrate is completed.

  The adhesive sheet disclosed in the above-mentioned patent document enables so-called direct die bonding, and the application process of the die bonding adhesive can be omitted. The adhesive disclosed in the above-mentioned patent document contains a low molecular weight energy ray curable compound as an energy ray curable component. By irradiation with energy rays, the energy ray curable compound is polymerized and cured, the adhesive force is lowered, and the adhesive layer is easily peeled from the substrate. The adhesive layer of the above-mentioned adhesive sheet cures all components after die bonding after energy ray curing and heat curing, and firmly bonds the chip and the substrate.

  In recent years, the required physical properties of semiconductor devices have become very strict. For example, package reliability in a severe hot and humid environment is required. However, as a result of thinning of the semiconductor chip itself, the strength of the chip is reduced, and it cannot be said that the package reliability in a severe heat and humidity environment is sufficient.

  Further, in recent surface mounting methods used for connecting electronic components, a surface mounting method (reflow method) in which the entire package is exposed to a temperature higher than the solder melting point is used. Recently, due to environmental considerations, mounting temperature has increased from 240 ° C to 260 ° C due to the shift to lead-free solder, increasing the stress generated inside the semiconductor package, further increasing the risk of package cracking. It has become.

  That is, the reduction in the thickness of the semiconductor chip and the increase in the mounting temperature cause a decrease in the reliability of the package.

JP-A-2-32181 JP-A-8-239636 Japanese Patent Laid-Open No. 10-8001 JP 2000-17246 A

  For this reason, it is required to realize high package reliability even in a case where a package in which a semiconductor chip that is becoming thinner is mounted, even when exposed to severe reflow conditions. Furthermore, it is required to have high package reliability even in the case where IR reflow is performed after leaving it under high temperature and high humidity conditions to absorb moisture.

  This invention is made | formed in view of the above prior arts, Comprising: It aims at meeting the said request | requirement by examining the adhesive agent used for die bonding.

The gist of the present invention aimed at solving such problems is as follows.
(1) A phenolic thermosetting agent having an acrylic polymer (A), an epoxy thermosetting resin (B) and a molecular weight distribution (Mw / Mn) of 1.7 or less and a weight average molecular weight of 770 or more ( C) is contained, The adhesive composition characterized by the above-mentioned.
(2) The adhesive composition according to claim 1, wherein the phenol-based thermosetting agent (C) is a novolac-type phenol-based thermosetting agent.
(3) An adhesive sheet in which an adhesive layer made of the adhesive composition according to (1) or (2) is formed on a substrate.
(4) A semiconductor wafer is adhered to the adhesive layer of the adhesive sheet described in (3) above, the semiconductor wafer is diced into semiconductor chips, and the adhesive layer is fixed and left on the back surface of the semiconductor chip to form a base material A method for manufacturing a semiconductor device, comprising: a step of peeling off the semiconductor chip and thermally bonding the semiconductor chip onto a die pad portion through the adhesive layer.

  According to the present invention, a package mounted with a semiconductor chip that is becoming thinner can achieve high package reliability even when exposed to severe reflow conditions, and more particularly, under conditions of high temperature and high humidity. An adhesive composition that can achieve high package reliability even when IR reflow is performed after leaving it to absorb moisture and an adhesive sheet having an adhesive layer made of the adhesive composition and the adhesive sheet A method for manufacturing a semiconductor device is provided.

Hereinafter, the present invention will be described more specifically.
The adhesive composition according to the present invention has an acrylic polymer (A), an epoxy thermosetting resin (B), a molecular weight distribution (Mw / Mn) of 1.7 or less, and a weight average molecular weight of 770 or more. The phenol-based thermosetting agent (C) is an essential component and may contain other components as necessary in order to improve various physical properties. Hereinafter, each of these components will be described in detail.

Acrylic polymer (A)
A conventionally known acrylic polymer can be used as the acrylic polymer.
The weight average molecular weight of the acrylic polymer is preferably from 10,000 to 2,000,000, and more preferably from 100,000 to 1,500,000. If the weight average molecular weight of the acrylic polymer is too low, the peeling force from the base material may be high and pick-up failure may occur. If it exceeds 2 million, the adhesive layer may not be able to follow the substrate irregularities. It becomes an occurrence factor.

  The glass transition temperature of the acrylic polymer is preferably in the range of −10 ° C. to 50 ° C., more preferably 0 ° C. to 40 ° C., and particularly preferably 0 ° C. to 30 ° C. If the glass transition temperature is too low, the peeling force between the adhesive layer and the substrate may increase, resulting in chip pick-up failure. If it is too high, the adhesive force for fixing the wafer may be insufficient. .

  Moreover, as a monomer of this acrylic polymer, a (meth) acrylic acid ester monomer or its derivative is mentioned. For example, (meth) acrylic acid alkyl ester having 1 to 18 carbon atoms in the alkyl group, such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, etc. Is mentioned. Moreover, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, acrylic acid, methacrylic acid, itaconic acid, glycidyl methacrylate, glycidyl acrylate, and the like can be given. Also, (meth) acrylic acid esters having a cyclic skeleton such as (meth) acrylic acid cycloalkyl ester, (meth) acrylic acid benzyl ester, isobornyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxy Examples include ethyl acrylate and imide acrylate.

  Vinyl acetate, acrylonitrile, styrene or the like may be copolymerized. It is preferable to use an acrylic polymer monomer having a hydroxyl group because the compatibility between the acrylic polymer and the epoxy resin is good.

Epoxy thermosetting resin (B)
Various conventionally known epoxy resins can be used as the epoxy thermosetting resin.

  The epoxy thermosetting resin is preferably contained in an amount of 1 to 1500 parts by weight, more preferably 3 to 1000 parts by weight, based on 100 parts by weight of the acrylic polymer (A). If the amount is less than 1 part by weight, sufficient adhesiveness may not be obtained. If the amount exceeds 1500 parts by weight, the peel strength from the substrate may be increased, resulting in pickup failure.

  Epoxy thermosetting resins include polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and hydrogenated products thereof, orthocresol novolac epoxy resins, dicyclopentadiene type epoxy resins, biphenyl type epoxy resins, and bisphenol A. Examples thereof include epoxy compounds having two or more functional groups in the molecule, such as type epoxy resin and bisphenol F type epoxy resin. These can be used individually by 1 type or in combination of 2 or more types.

Phenolic thermosetting agent (C)
The phenolic thermosetting agent (C) is a phenolic thermosetting agent having a molecular weight distribution (Mw / Mn) of 1.7 or less and a weight average molecular weight (Mw) of 770 or more, and an epoxy thermosetting agent. Since it has a phenolic hydroxyl group capable of reacting with the epoxy group in the resin (B), it can react with the epoxy thermosetting resin (B) by heating to function as a thermosetting agent.

  The molecular weight distribution (Mw / Mn) of the phenol-based thermosetting agent (C) is 1.7 or less and the weight average molecular weight is 770 or more, but the molecular weight distribution (Mw / Mn) is 1.6 or less and the weight average molecular weight is 780. The molecular weight distribution (Mw / Mn) is preferably 1.0 to 1.6, and more preferably a weight average molecular weight 780 to 2000. By taking such molecular weight distribution (Mw / Mn) and weight average molecular weight range, when the adhesive composition is used as the adhesive layer of the pressure-sensitive adhesive sheet, the unreacted phenolic thermosetting agent (C). Since the low molecular weight component does not ooze out from the adhesive layer or vaporize at the time of heat curing to reduce the adhesiveness of the adhesive layer, the package reliability can be improved.

  In addition, the said weight average molecular weight (Mw) and number average molecular weight (Mn) obtain | require the elution curve of standard molecular weight polystyrene based on the following conditions, and are calculated | required by the obtained elution curve. The molecular weight distribution is weight average molecular weight (Mw) / number average molecular weight (Mn).

(GPC conditions)
Column: KF-801, KF-802, KF-803 (made by Showa Denko KK)
Solvent: tetrahydrofuran (THF)
Molecular weight reference material: Polystyrene resin (manufactured by Tosoh Corporation)
Detector: UV-8011 (manufactured by Tosoh Corporation)

  The phenol-based thermosetting agent (C) is not particularly limited as long as it has the molecular weight distribution (Mw / Mn) and the weight average molecular weight. For example, specific examples thereof are represented by the following formula (1). Such a novolak-type phenol resin, a dicyclopentadiene-based phenol resin represented by the following formula (2), a polyfunctional phenol resin represented by the following formula (3), and the following formula (4) Aralkylphenol resin etc. are mentioned, These can be used individually by 1 type or in mixture of 2 or more types.

この中でも、エポキシ系熱硬化性樹脂（Ｂ）中のエポキシ基との反応性が良好であるという観点から、ノボラック型フェノール樹脂が好ましい。

Among these, from the viewpoint of good reactivity with the epoxy group in the epoxy thermosetting resin (B), a novolac type phenol resin is preferable.

  The adhesive composition according to the present invention is a phenolic polymer having an acrylic polymer (A), an epoxy resin (B) and a molecular weight distribution (Mw / Mn) of 1.7 or less and a weight average molecular weight of 770 or more. Although the thermosetting agent (C) is contained as an essential component, in order to improve various physical properties, the components described later may be included.

Curing agent (D)
The curing agent (D) is a curing agent other than the phenol thermosetting agent (C), and functions as a curing agent for the epoxy thermosetting resin (B) together with the phenol thermosetting agent (C). Thus, with respect to the case of only the phenol-based thermosetting agent (C), by using the curing agent (D), physical properties such as adjustment of the rate of the curing reaction and the elastic modulus of the cured product of the adhesive are preferable. Can be adjusted.

  Preferred curing agents include compounds having two or more functional groups capable of reacting with an epoxy group in one molecule. The functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and acid anhydrides. Examples include physical groups. Of these, an amino group and an acid anhydride group are preferable, and an amino group is more preferable. Specific examples thereof include amine curing agents such as DICY (dicyandiamide). These curing agents can be used alone or in combination of two or more.

  In the adhesive composition of the present invention, the total content of the phenolic thermosetting agent (C) and the curing agent (D) is 0.1 to 500 with respect to 100 parts by weight of the epoxy thermosetting resin (B). It is preferable that it is a weight part, and it is more preferable that it is 1-100 weight part. If the total amount of the phenol-based thermosetting agent (C) and the curing agent (D) is excessively small, adhesiveness may not be obtained due to insufficient curing, and if it is excessive, the moisture absorption rate increases and the reliability of the package decreases. Sometimes.

  Further, the ratio (C) / (D) (weight ratio) of the content of the phenol-based thermosetting agent (C) and the content of the curing agent (D) is preferably 1 or more, and is 2 or more. More preferably, it is 5 or more. If (C) / (D) (weight ratio) is too small, the effects of the present invention may not be sufficiently obtained.

Curing accelerator (E)
The curing accelerator is used to adjust the curing rate of the adhesive composition. Preferred curing accelerators include compounds that can promote the reaction between an epoxy group and a phenolic hydroxyl group or amine.

  Specifically, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4- Examples include imidazoles such as methylimidazole, organic phosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine, and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphinetetraphenylborate. These can be used individually by 1 type or in mixture of 2 or more types.

  It is preferable that 0.01-100 weight part is contained with respect to 100 weight part of epoxy-type thermosetting resins (B), and, as for a hardening accelerator (E), 0.1-50 weight part is more preferable, and 1-30. Part by weight is more preferred.

Coupling agent (F)
The coupling agent (F) is used to improve the adhesion and adhesion of the adhesive composition to the adherend. Moreover, the water resistance can be improved by using a coupling agent (F), without impairing the heat resistance of the hardened | cured material obtained by hardening | curing adhesive composition.

  As the coupling agent, a compound having a group that reacts with a functional group of the above component (A), component (B), component (C), component (D), or the like is preferably used. As the coupling agent (F), a silane coupling agent is preferable.

  Such coupling agents include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- (methacrylopropyl). ) Trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-6- (aminoethyl) -γ-aminopropylmethyldiethoxysilane, N- Phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfane, methyltrimethoxy Silane, methylto Examples include reethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazolesilane. These can be used individually by 1 type or in mixture of 2 or more types.

  When these coupling agents (F) are used, they are usually 0.1 to 20 parts by weight, preferably 0.5 to 15 parts by weight, more preferably 100 parts by weight of the epoxy thermosetting resin (B). Is used in a proportion of 1 to 10 parts by weight. If it is less than 0.1 part by weight, the effect cannot be obtained, and if it exceeds 10 parts by weight, it may cause outgassing.

Inorganic filler (G)
By blending the inorganic filler (G) into the adhesive, the thermal expansion coefficient can be adjusted, and the package is obtained by optimizing the thermal expansion coefficient of the adhesive layer after curing with respect to the semiconductor chip or organic substrate. The heat resistance of can be improved. Moreover, it becomes possible to reduce the moisture absorption rate after hardening of an adhesive bond layer. Preferable inorganic fillers (G) include silica, alumina, talc, calcium carbonate, titanium white, bengara, silicon carbide, boron nitride and the like, spherical beads of these, single crystal fibers, glass fibers, and the like. . These can be used individually by 1 type or in mixture of 2 or more types. In the present invention, among these, the use of silica powder and alumina powder is preferable.
The inorganic filler (G) can be adjusted in the range of usually 0 to 80% by weight with respect to the entire adhesive.

Other components In addition to the above, various additives may be blended in the adhesive composition of the present invention as necessary. For example, a flexible component can be added to maintain the flexibility after curing. The flexible component is a component having flexibility at normal temperature and under heating, and a component that is not substantially cured by heating or energy ray irradiation is selected. The flexible component may be a polymer made of a thermoplastic resin or an elastomer, or may be a polymer graft component or a polymer block component. Moreover, the modified resin by which the flexible component was previously modified | denatured by the epoxy resin may be sufficient.

  Moreover, in order to adjust the initial adhesive force and cohesion force of an adhesive composition, a crosslinking agent can also be added. Examples of the crosslinking agent include organic polyvalent isocyanate compounds and organic polyvalent imine compounds.

  Examples of the organic polyvalent isocyanate compounds include aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, alicyclic polyvalent isocyanate compounds, trimers of these polyvalent isocyanate compounds, And a terminal isocyanate urethane prepolymer obtained by reacting a polyvalent isocyanate compound with a polyol compound.

  Furthermore, as various additives of the adhesive composition, energy ray polymerizable compounds, photopolymerization initiators, plasticizers, antistatic agents, antioxidants, pigments that are polymerized and cured by irradiation with energy rays such as ultraviolet rays and electron beams A dye or the like may be used.

Adhesive composition The adhesive composition comprising the above components has pressure-sensitive adhesiveness and heat-curing property, and has a function of temporarily holding various adherends in an uncured state. Finally, a cured product with high impact resistance can be obtained through thermosetting, and the balance between shear strength and peel strength is excellent, and sufficient adhesive properties can be maintained even under severe heat and humidity conditions. .
The adhesive composition according to the present invention is obtained by mixing the above-described components at an appropriate ratio. In mixing, each component may be diluted with a solvent in advance, or a solvent may be added during mixing.

Adhesive Sheet The adhesive sheet according to the present invention is formed by laminating an adhesive layer made of the above adhesive composition on a substrate. The shape of the adhesive sheet according to the present invention can be any shape such as a tape shape or a label shape.

  Examples of the base material of the adhesive sheet include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, fluororesin film, polyethylene terephthalate film, polyethylene naphthalate. Film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, A transparent film such as a polyimide film is used. These crosslinked films are also used. Furthermore, these laminated films may be sufficient. In addition to the transparent film described above, a film obtained by coloring these, an opaque film, or the like can be used.

  The adhesive sheet according to the present invention is affixed to various adherends, and after subjecting the adherend to required processing, the adhesive layer is peeled off from the substrate while remaining adhered to the adherend. That is, it is used in a process including a step of transferring an adhesive layer from a substrate to an adherend. For this reason, the surface tension of the surface in contact with the adhesive layer of the substrate is preferably 40 mN / m or less, more preferably 37 mN / m or less, and particularly preferably 35 mN / m or less. Such a substrate having a low surface tension can be obtained by appropriately selecting the material, and can also be obtained by applying a release agent to the surface of the substrate and performing a release treatment.

  As the release agent used for the substrate release treatment, alkyd, silicone, fluorine, unsaturated polyester, polyolefin, wax, etc. are used, and in particular, alkyd, silicone, fluorine release agents. Is preferable because it has heat resistance. In particular, an alkyd resin is preferred because of its high adhesion to the substrate film and easy adjustment of the surface tension.

  In order to release the surface of the substrate using the above release agent, the release agent can be applied directly with a gravure coater, Mayer bar coater, air knife coater, roll coater, etc. without solvent, or by solvent dilution or emulsion. The laminate may be formed by normal temperature or heating or electron beam curing, wet lamination, dry lamination, hot melt lamination, melt extrusion lamination, coextrusion processing, or the like.

  The film thickness of the substrate is usually about 10 to 500 μm, preferably about 15 to 300 μm, and particularly preferably about 20 to 250 μm. The thickness of the adhesive layer is usually 1 to 500 μm, preferably 5 to 300 μm, particularly preferably about 10 to 150 μm.

  The method for producing the adhesive sheet is not particularly limited, and the adhesive sheet may be produced by applying and drying a composition constituting the adhesive layer on the substrate, and the adhesive layer is provided on the release film. You may manufacture by transferring to the said base material. In addition, in order to protect an adhesive bond layer before using an adhesive sheet, you may laminate | stack a peeling film on the upper surface of an adhesive bond layer. Moreover, in order to fix other jigs, such as a ring frame, the adhesive layer and the adhesive tape may be separately provided in the surface outer periphery part of the adhesive bond layer.

Manufacturing Method of Semiconductor Device Next, a method for using the adhesive sheet according to the present invention will be described taking as an example the case where the adhesive sheet is applied to the manufacture of a semiconductor device.

  In the semiconductor device manufacturing method according to the present invention, first, the semiconductor wafer and the ring frame are placed on the tape mounter device, and the adhesive layer of the adhesive sheet according to the present invention is placed on one surface of the semiconductor wafer and the ring frame. The semiconductor wafer and the ring frame are fixed to the adhesive sheet by lightly pressing so as to come into contact.

  Next, the silicon wafer is cut using a cutting means such as a dicing saw to obtain a semiconductor chip. The cutting depth at this time is set to a depth that takes into account the total thickness of the silicon wafer and the adhesive layer and the wear of the dicing saw.

  Then, if necessary, when the adhesive sheet is expanded, the interval between the semiconductor chips is expanded, and the semiconductor chips can be picked up more easily. At this time, a deviation occurs between the adhesive layer and the base material, the adhesive force between the adhesive layer and the base material is reduced, and the pick-up property of the chip is improved.

When the semiconductor chip is picked up in this manner, the cut adhesive layer can be fixedly left on the back surface of the semiconductor chip and peeled off from the substrate.
Next, the semiconductor chip is placed on the die pad portion through the adhesive layer. The die pad part is heated before placing the semiconductor chip or immediately after placing. The heating temperature is usually 80 to 200 ° C., preferably 100 to 180 ° C., the heating time is usually 0.1 seconds to 5 minutes, preferably 0.5 seconds to 3 minutes, and the chip mount pressure is Usually, it is 1 kPa to 200 MPa.

  After the semiconductor chip is chip-mounted on the die pad portion, further heating may be performed as necessary. The heating conditions at this time are in the above heating temperature range, and the heating time is usually 1 to 180 minutes, preferably 10 to 120 minutes.

Alternatively, the heat treatment after the chip mounting may not be performed, and the adhesive layer may be cured by using the heat in resin sealing performed in a subsequent process.
Through such a process, the adhesive layer is cured and the semiconductor chip and the die pad portion can be firmly bonded. Since the adhesive layer is fluidized under die-bonding conditions, the adhesive layer is sufficiently embedded in the unevenness of the die pad portion, and generation of voids can be prevented.

  That is, in the obtained mounting product, the adhesive that is a fixing means of the chip is cured and is sufficiently embedded in the unevenness of the die pad portion, so that a sufficient package even under severe conditions Reliability and board mountability are achieved.

  In addition, the adhesive composition and adhesive sheet of this invention can also be used for adhesion | attachment of a semiconductor compound, glass, ceramics, a metal other than the usage method as mentioned above.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.
In the examples and comparative examples, “surface mountability evaluation” was performed as follows.

"Evaluation of surface mountability"
(1) Manufacture of semiconductor chip # 2000 polished silicon wafer (150 mm diameter, 150 μm thick) was bonded to the adhesive sheets of Examples and Comparative Examples with a tape mounter (Lintech Co., Adwill RAD2500) Fixed to a ring frame for wafer dicing. Next, dicing was performed using a dicing apparatus (manufactured by Tokyo Seimitsu Co., Ltd., AWD-4000B) to obtain an 8 mm × 8 mm size chip. The amount of cut during dicing was such that the substrate was cut by 20 μm.

(2) Manufacturing of semiconductor package A circuit pattern is formed on the copper foil of a copper foil-clad laminate (CCL-HL830 manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a substrate, and a solder resist (PSR4000 AUS5 made by Taiyo Ink) is 40 μm thick on the pattern The BT substrate possessed by the company was used (made by Chino Giken Co., Ltd.). The chip on the adhesive sheet obtained in the above (1) was picked up from the base material together with the adhesive layer, and pressed onto the BT substrate via the adhesive layer under the conditions of 120 ° C., 100 gf, and 1 second.

  Then, it is sealed with a mold resin (KE-1100AS3 manufactured by Kyocera Chemical Co., Ltd.) so as to have a sealing thickness of 400 μm (sealing device MPC-06M Trial Press manufactured by Apic Yamada Co., Ltd.), and the resin is cured at 175 ° C. for 5 hours. It was. Next, the sealed BT substrate is affixed to a dicing tape (Adwill D-510T manufactured by Lintec Corporation), and diced to a size of 12 mm × 12 mm using a dicing apparatus (AWD-4000B manufactured by Tokyo Seimitsu Co., Ltd.). A semiconductor package for reliability evaluation was obtained.

(3) Evaluation of semiconductor package surface mountability The obtained semiconductor package was left to stand for 168 hours at 85 ° C. and 85% RH to absorb moisture, and then subjected to IR reflow with a maximum temperature of 260 ° C. and a heating time of 1 minute (reflow oven: Scanning ultrasonic flaw detector (Hy-Focus, manufactured by Hitachi Construction Machinery Finetech Co., Ltd.) for the presence or absence of floating / peeling of joints and the occurrence of package cracks when Sagami Riko WL-15-20DNX type) is performed three times. ) And cross-sectional observation. The case where peeling of 0.5 mm or more was observed at the substrate / semiconductor chip junction was judged as peeling, and 25 packages were put into the test, and the number of peeling did not occur was counted.

Moreover, each component which comprises an adhesive composition is as follows.
(A) Acrylic polymer: Coponil N-2359-6 (Mw: about 300,000, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
(B) Epoxy resin:
(B-1) Liquid epoxy resin: bisphenol A type epoxy resin (Epicoat 828 (epoxy equivalent 189 g / eq, manufactured by Japan Epoxy Resin Co., Ltd.))
(B-2) Solid epoxy resin: bisphenol A type epoxy resin (EPICRON 1055 (epoxy equivalent 850 g / eq, manufactured by Dainippon Ink & Chemicals, Inc.))
(B-3) Solid epoxy resin: dicyclopentadiene (DCPD) type epoxy resin (EPICRON HP-7200HH (epoxy equivalent 278 g / eq, manufactured by Dainippon Ink & Chemicals, Inc.))
(C) Phenolic thermosetting agent:
(C-1) Novolac-type phenol resin (PAPS-PN2 (weight average molecular weight: 784, molecular weight distribution 1.2, manufactured by Asahi Organic Materials Co., Ltd.))
(C-2) Novolac-type phenol resin (PAPS-PN4 (weight average molecular weight: 1035, molecular weight distribution 1.5, manufactured by Asahi Organic Materials Co., Ltd.))
(D) Curing agent:
(D-1) Novolac type phenolic resin (Shonol BGR556 (weight average molecular weight: 800, molecular weight distribution 1.8, manufactured by Showa Polymer Co., Ltd.))
(D-2) Novolac type phenolic resin (Shonol BGR557 (weight average molecular weight: 1000, molecular weight distribution 2.0, manufactured by Showa Polymer Co., Ltd.))
(D-3) Novolac type phenol resin (H-4 (weight average molecular weight: 767, molecular weight distribution 1.37, manufactured by Meiwa Kasei Co., Ltd.))
(D-4) Dicyandiamide (Hardener 3636AS, manufactured by ADEKA Corporation)
(E) Curing accelerator: Imidazole (Cureazole 2PHZ, manufactured by Shikoku Kasei Kogyo Co., Ltd.)
(F) Coupling agent: Silane coupling agent (MKC silicate MSEP2 (Mitsubishi Chemical Corporation))
(G) Inorganic filler: spherical silica (Admafine SC2050, manufactured by Admatechs Co., Ltd.)
(H) Thermoplastic resin: polyester resin (Byron 220, manufactured by Toyobo Co., Ltd.)
Further, a polyethylene film (thickness: 100 μm, surface tension: 33 mN / m) was used as the base material of the adhesive sheet.

(4) Measurement of weight average molecular weight and number average molecular weight By gel permeation chromatography (GPC) method under the following conditions, an elution curve of standard molecular weight polystyrene was obtained, and based on the obtained elution curve, The weight average molecular weight and number average molecular weight (converted value of standard molecular weight polystyrene resin) were determined. Moreover, molecular weight distribution (Mw / Mn) was made into the weight average molecular weight (Mw) / number average molecular weight (Mn).

(GPC conditions)
Column: KF-801, KF-802, KF-803 (made by Showa Denko KK)
Solvent: tetrahydrofuran (THF)
Molecular weight reference material: Polystyrene resin (manufactured by Tosoh Corporation)
Detector: UV-8011 (manufactured by Tosoh Corporation)

(5) Examples and Comparative Examples Adhesive compositions having the compositions described in Table 1 were used. In the table, the numerical values indicate parts by weight in terms of solid content. The adhesive composition having the composition shown in Table 1 was applied on a silicone-treated release film (SP-PET3811 (S) manufactured by Lintec Corporation) so that the film thickness after drying was 30 μm, and dried (drying conditions: After drying in an oven at 100 ° C. for 1 minute and then at 120 ° C. for 2 minutes), the substrate was bonded to the substrate, and the adhesive layer was transferred onto the substrate to obtain an adhesive sheet.

  A semiconductor package was manufactured using the obtained adhesive sheet, and the surface mountability of the obtained semiconductor package was evaluated. The results are shown in Table 2.

  According to the present invention, an adhesive composition capable of achieving high package reliability even when exposed to severe reflow conditions in a package mounted with a semiconductor chip that is becoming thinner, and an adhesive composed of the adhesive composition An adhesive sheet having an agent layer and a method for manufacturing a semiconductor device using the adhesive sheet are provided.

Claims (4)

  Acrylic polymer (A), epoxy thermosetting resin (B), and phenolic thermosetting agent (C) having a molecular weight distribution (Mw / Mn) of 1.7 or less and a weight average molecular weight of 770 or more. An adhesive composition comprising:   The adhesive composition according to claim 1, wherein the phenol-based thermosetting agent (C) is a novolac-type phenol-based thermosetting agent.   An adhesive sheet in which an adhesive layer made of the adhesive composition according to claim 1 or 2 is formed on a substrate.   A semiconductor wafer is attached to the adhesive layer of the adhesive sheet according to claim 3, the semiconductor wafer is diced into a semiconductor chip, and the adhesive layer is fixed and left on the back surface of the semiconductor chip and peeled off from the substrate. The manufacturing method of the semiconductor device including the process of thermocompression bonding the said semiconductor chip on a die pad part via the said adhesive bond layer.