JP2017045934A - Adhesive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive film including an adhesive layer excellent in embossability of concave and convex of a substrate in the sealing step, even if hardened completely in the die bonding step and wire bonding step.SOLUTION: An adhesive film is composed of an adhesive composition containing an epoxy resin, an epoxy resin hardener represented by following general formula (1), and an epoxy group-containing (meth) acrylic copolymer. When laminating the chips in multi-stage, the thickness of an adhesive film at the lowermost stage where the concave and convex of a substrate is embossed is 3-23 μm, the thickness of an adhesive film at the second and subsequent stages where the wires are embossed is 42-62 μm, and the storage modulus of the adhesive film after being hardened is 1-31 MPa at 175°C.SELECTED DRAWING: None

Description

  The present invention relates to an adhesive film.

  Conventionally, silver paste is mainly used for joining a semiconductor element and a wiring board for mounting a semiconductor element. However, with the recent miniaturization and high performance of semiconductor elements, there is a growing demand for miniaturization and miniaturization of wiring boards used. In bonding using silver paste, it is difficult to meet the above requirements due to occurrence of defects during wire bonding due to protrusion or inclination of semiconductor elements, difficulty in controlling the thickness of the adhesive layer, generation of voids in the adhesive layer, etc. ing. Therefore, in recent years, a film-like adhesive (adhesive film) has been used for joining a semiconductor element and a wiring board for mounting a semiconductor element (see, for example, Patent Documents 1 and 2).

  Generally, the mounting substrate manufacturing process is performed as follows. First, after bonding an adhesive film with a dicing tape, the other surface of the adhesive film is bonded to the back surface of the semiconductor wafer. Thereafter, the semiconductor wafer to which the adhesive film is attached in the dicing process is separated into semiconductor elements with an adhesive film. Next, the semiconductor element with the adhesive film separated in the die bonding step is picked up and bonded to the wiring board. Next, in order to prevent the semiconductor element bonded to the wiring board from being peeled off or removed during transportation, curing is performed in an oven for a short time. Thereafter, a mounting substrate is obtained through a wire bonding process, a sealing process, a sealing material curing process, and a reflow process for soldering.

  One of the most important characteristics of a mounting substrate on which various electronic components such as semiconductor elements are mounted is reliability. In order to improve the reliability of a semiconductor device to be manufactured, development of a film-like adhesive in consideration of heat resistance, moisture resistance and reflow resistance has also been performed. As such a film adhesive, for example, Patent Document 3 proposes an adhesive film containing an epoxy resin, a phenol resin, and an acrylic copolymer.

Japanese Patent Laid-Open No. 3-192178 JP-A-4-234472 JP 2002-220576 A

  In recent years, the capacity of a mounting substrate has been increased by laminating semiconductor elements with adhesive films on a wiring board in multiple stages, and a die bonding process and a wire bonding process have been repeatedly performed in order to stack semiconductor elements in multiple stages. Yes. The adhesive film attached to the upper surface of the wiring board in the die bonding process needs to bury the irregularities on the upper surface of the wiring board by the high temperature and pressure in the sealing process after the wire bonding process. However, in the conventional adhesive film, the adhesive film is hardened due to repeated heating in the die bonding process and the wire bonding process and becomes highly elastic, and it becomes difficult to embed irregularities on the wiring board in the sealing process. The reliability of the mounting board may be reduced.

  Therefore, there is a demand for an adhesive film having a low elastic modulus even when cured after heating in the die bonding step and the wire bonding step.

  Then, this invention aims at providing an adhesive film provided with the adhesive bond layer which is fully excellent in the uneven | corrugated embedding property in a sealing process, even if it hardens | cures with the heat | fever which generate | occur | produces in a die bonding process and a wire bonding process. .

  The present invention uses an adhesive film comprising an adhesive composition containing (a) an epoxy resin, (b) an epoxy resin curing agent, and (c) an epoxy group-containing (meth) acrylic copolymer, and multi-stages the chip. The thickness of the lowermost adhesive film for embedding the substrate irregularities when laminating is 3 to 23 μm, the thickness of the second and subsequent adhesive films for embedding the wire is 42 to 62 μm, and 175 ° C. after curing of the adhesive film The storage elastic modulus at 1 to 31 MPa, and the epoxy resin curing agent of the component (b) provides an adhesive film containing a phenol resin represented by the following general formula (1).

（一般式（１）中、ｎは１〜２０の整数である。）

(In general formula (1), n is an integer of 1-20.)

  The adhesive film of the present invention includes (a) an epoxy resin and (c) an epoxy group-containing (meth) acrylic copolymer, and (b) a phenol resin having a specific structure represented by the general formula (1). By including the adhesive layer formed from the adhesive composition, it is not easily affected by the heat generated in the die bonding step and the wire bonding step, and is sufficiently excellent in the unevenness embedding property in the sealing step. .

  The adhesive film of the present invention is derived from the monomer having the epoxy group-containing (meth) acrylic copolymer (c) having a glass transition temperature (Tg) of −50 to 30 ° C. and having an epoxy group. It is preferable that the copolymer contains 0.5 to 3.0% by mass of structural units and has a weight average molecular weight of 100,000 or more.

  Moreover, the adhesive film of the present invention comprises a total mass A of the (a) epoxy resin and the (b) epoxy resin curing agent, and a mass B of the (c) epoxy group-containing (meth) acrylic copolymer. The ratio A / B is preferably 0.1 to 4.1.

In the adhesive film of the present invention, the adhesive composition further includes (d) an inorganic filler having an average particle diameter of 0.005 to 0.5 μm in total of (a), (b), and (c). It is preferable to contain 1 to 50 parts by volume with respect to 100 parts by volume.
The adhesive film of the present invention preferably has an adhesive film having a melt viscosity at 80 ° C. of 500 to 10,000 Pa · s.
The adhesive film of the present invention is sufficiently excellent in embeddability and insulation properties by the adhesive composition further containing an inorganic filler and having a melt viscosity within the range, and improves the reliability of the semiconductor device to be manufactured. be able to.

  According to the present invention, it is possible to provide an adhesive film including an adhesive layer that is hardly affected by the heat generated in the die bonding step and the wire bonding step and that is sufficiently excellent in the unevenness embedding property in the sealing step. .

It is a schematic cross section which shows suitable one Embodiment of the adhesive film of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as the case may be. Note that the dimensional ratio in the drawing is exaggerated for the sake of explanation and does not necessarily match the actual dimensional ratio.

  FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the adhesive film of the present invention. The adhesive film 1 shown in FIG. 1 includes a base film 20 and an adhesive layer 10 provided on the base film 20. The adhesive layer 10 is made of the adhesive composition according to the present invention. The adhesive film of this invention may coat | cover the surface of the other side of the base film 20 on the adhesive bond layer 10 with a protective film.

  The adhesive film of the present invention uses an adhesive film comprising an adhesive composition containing (a) an epoxy resin, (b) an epoxy resin curing agent, and (c) an epoxy group-containing (meth) acrylic copolymer, The thickness of the lowermost adhesive film for embedding the substrate unevenness when stacking chips in multiple stages is 3 to 23 μm, the thickness of the second and subsequent adhesive films for embedding wires is 42 to 62 μm, and after the adhesive film is cured The storage elastic modulus at 175 ° C. is 1-31 MPa, and the epoxy resin curing agent of component (b) contains a phenol resin represented by the general formula (1).

  First, each component which comprises the adhesive composition which concerns on this invention is demonstrated in detail.

((A) Epoxy resin)
The epoxy resin of component (a) according to this embodiment is not particularly limited as long as it has at least two epoxy groups in the molecule. Epoxy resins include bifunctional epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin and bisphenol S type epoxy resin, novolac type epoxy resins such as phenol novolac type epoxy resin and cresol novolac type epoxy resin, and polyfunctional epoxy. Examples thereof include resins and alicyclic epoxy resins. These can be used alone or in combination of two or more.

((B) Epoxy resin curing agent)
The epoxy resin curing agent of component (b) according to this embodiment contains a phenol resin represented by the following formula (1).

  In general formula (1), n shows the integer of 1-20.

  The phenol resin is a biphenylene dimethylene type phenol resin (phenol biphenyl aralkyl resin), and is available as a commercial product. be able to.

  The compounding amount of the epoxy resin and the phenol resin is preferably an equivalent ratio of epoxy equivalent and hydroxyl equivalent from the viewpoint of curability when used as an adhesive, preferably 0.70 / 0.30 to 0.30 / 0.70. More preferably 0.65 / 0.35 to 0.35 / 0.65, still more preferably 0.60 / 0.40 to 0.40 / 0.60, particularly preferably 0.55 / 0.45. 0.45 / 0.55.

((C) Epoxy group-containing (meth) acrylic copolymer)
The epoxy group-containing (meth) acrylic copolymer of component (c) according to this embodiment can be obtained by polymerizing a monomer containing a functional monomer such as glycidyl acrylate or glycidyl methacrylate. Since the functional monomer is incompatible with the epoxy resin, the epoxy resin and the (meth) acrylic copolymer are separated from each other after curing, and the reflow crack resistance and heat resistance of the adhesive layer can be improved. .
Here, the (meth) acrylic copolymer means an acrylic copolymer, a methacrylic copolymer corresponding to the acrylic copolymer, or a mixture thereof.

  As the (meth) acrylic copolymer, for example, a (meth) acrylic acid ester copolymer, acrylic rubber or the like can be used, and acrylic rubber is more preferable. Acrylic rubber is a rubber mainly composed of an acrylate ester and mainly composed of a copolymer such as butyl acrylate and acrylonitrile, or a copolymer such as ethyl acrylate and acrylonitrile.

  That is, as an epoxy group-containing (meth) acrylic copolymer, a copolymer of a functional monomer such as glycidyl acrylate or glycidyl methacrylate and butyl acrylate, ethyl acrylate, acrylonitrile, or the like can be used. The polymerization method of the epoxy group-containing (meth) acrylic copolymer is not particularly limited, and pearl polymerization, solution polymerization and the like can be used.

  The structural unit derived from the monomer having an epoxy group in the epoxy group-containing (meth) acrylic copolymer is 0.5 to 3.0% by mass from the viewpoint of ensuring adhesion and preventing gelation. It is preferable that it is 2.0 to 3.0% by mass.

  The epoxy group-containing (meth) acrylic copolymer can be obtained as a commercial product, for example, trade name “HTR-860P-3” manufactured by Nagase ChemteX Corporation.

  The glass transition temperature (Tg) of the epoxy group-containing (meth) acrylic copolymer is preferably -50 to 30 ° C, and more preferably -30 to 30 ° C. When the Tg of the epoxy group-containing (meth) acrylic copolymer is less than -50 ° C, the flexibility of the adhesive layer tends to be too high as compared with the case where the Tg is in the range of -50 to 30 ° C. . Thereby, it becomes difficult to cut the adhesive layer during wafer dicing, and as a result, burrs are generated and the dicing property tends to be lowered. Moreover, when Tg exceeds +30 degreeC, it exists in the tendency for the softness | flexibility of an adhesive bond layer to fall compared with the case where it exists in the range of -50-30 degreeC.

  The weight average molecular weight (Mw) of the epoxy group-containing acrylic copolymer is preferably 100,000 to 3,000,000, and more preferably 500,000 to 2,000,000. When the Mw of the epoxy group-containing acrylic copolymer is within this range, the strength, flexibility, and tackiness of the film and film can be appropriately controlled, and the reflow property is excellent and the embedding property is improved. can do. Here, Mw means a value measured by gel permeation chromatography (GPC) and converted using a standard polystyrene calibration curve.

  The blending amount of the epoxy group-containing (meth) acrylic copolymer is preferably 24-1000 parts by mass with respect to 100 parts by mass in total of (a) epoxy resin and (b) epoxy resin curing agent, More preferably, it is part by mass. That is, the ratio (A / B) of the total mass (A) of (a) epoxy resin and (b) epoxy resin curing agent to the mass (B) of the epoxy group-containing (meth) acrylic copolymer is 0. 0.1 to 4.1 is preferable, and 0.6 to 4.1 is more preferable. Within this range, it is possible to further improve the control of fluidity during molding, the handleability at high temperatures, and the embedding property.

((D) inorganic filler)
The adhesive composition of the present embodiment can further contain (d) an inorganic filler. Examples of the inorganic filler include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whisker, boron nitride and crystals. And non-crystalline silica. These can use together 1 type (s) or 2 or more types. From the viewpoint of improving the thermal conductivity of the adhesive layer, it is preferable to contain aluminum oxide, aluminum nitride, boron nitride, crystalline silica, or amorphous silica as the inorganic filler. From the viewpoint of adjusting the melt viscosity of the adhesive layer and imparting thixotropic properties to the adhesive composition, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, It is preferable to contain magnesium oxide, aluminum oxide, crystalline silica, or amorphous silica.

The average particle diameter of the inorganic filler is preferably 0.005 to 0.5 μm, and more preferably 0.01 to 0.1 μm, from the viewpoint of improving adhesiveness.
Here, the average particle diameter is a particle diameter at a point corresponding to a volume of 50% when the cumulative frequency distribution curve by the particle diameter is obtained with the total volume of the particles being 100%, and the particle size using the laser diffraction scattering method. It can be measured with a distribution measuring device or the like.

  The blending amount of the inorganic filler is preferably 1 to 50 parts by volume with respect to 100 parts by volume of the adhesive composition excluding the inorganic filler (total of (a), (b) and (c)), and 10 to 40 parts by volume. Is more preferable. When the compounding quantity of an inorganic filler exists in this range, sufficient storage elasticity, adhesiveness, and an electrical property of an adhesive bond layer can be ensured.

  Moreover, a hardening accelerator can also be added to the adhesive composition of this embodiment. The curing accelerator is not particularly limited, and various imidazoles can be used. Examples of imidazoles include 2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, etc., and these include one kind or two or more kinds. It can also be used together.

  The addition amount of the curing accelerator is preferably 0.04 to 5 parts by mass and more preferably 0.04 to 0.2 parts by mass with respect to 100 parts by mass in total of (a) epoxy resin and (b) epoxy resin curing agent. preferable. When the addition amount of the curing accelerator is within this range, both curability and reliability can be achieved.

  The adhesive composition may further contain various additives such as a catalyst, an additive, and a coupling agent as necessary in addition to the above-described components. From the viewpoint of improving the adhesive strength to the adherend, it is preferable to include a coupling agent. Examples of the coupling agent include a silane coupling agent, a titanate coupling agent, and an aluminum coupling agent, and among them, a silane coupling agent can be preferably used.

  There is no restriction | limiting in particular as the base film 20, For example, a polytetrafluoroethylene, a polyethylene film, a polypropylene film, a polymethylpentene film, a polyethylene terephthalate film, a polyimide film etc. are used.

  These films may be subjected to surface treatment such as primer application, UV treatment, corona discharge treatment, polishing treatment, etching treatment, etc., as necessary. The thickness of the base film 20 is not particularly limited and is appropriately selected depending on the thickness of the adhesive layer 10 and the use of the adhesive film 1.

  The adhesive film 1 of this invention can be produced as follows, for example. First, each component which comprises the above-mentioned adhesive composition is mixed and knead | mixed in a solvent, a varnish is prepared, the layer of this varnish is formed on the base film 20, and the adhesive film 1 is dried by heating. Can be obtained. Alternatively, the base film 20 may be removed after the varnish layer is dried to form an adhesive film composed only of the adhesive layer 10.

  Although it does not specifically limit as a solvent used for preparation of the said varnish, Considering the volatility at the time of film preparation, etc., methanol, ethanol, 2-methoxyethanol, 2-butoxyethanol, methyl ethyl ketone, acetone, methyl isobutyl ketone, 2- It is preferable to use a solvent having a relatively low boiling point such as ethoxyethanol, toluene, and xylene. In order to improve the coating property, a solvent having a relatively high boiling point such as dimethylacetamide, dimethylformamide, N-methylpyrrolidone, cyclohexanone can be added.

  The above mixing and kneading can be carried out by appropriately combining dispersers such as a normal stirrer, a raking machine, a triple roll, a ball mill, and a bead mill. In the production of the varnish when the inorganic filler is added, it is preferable to use a raking machine, a three roll, a ball mill or a bead mill in consideration of the dispersibility of the inorganic filler. Moreover, after mixing an inorganic filler and a low molecular weight component previously, the time to mix can also be shortened by mix | blending a high molecular weight component. Further, after the varnish is formed, the bubbles in the varnish can be removed by vacuum degassing or the like.

  An adhesive film is obtained by applying the prepared varnish on the base film 20 and heating and drying to form the adhesive layer 10. As a method for applying the varnish to the support, known methods can be used, and examples thereof include a knife coating method, a roll coating method, a spray coating method, a gravure coating method, a bar coating method, and a curtain coating method. The conditions for the heat drying are not particularly limited as long as the solvent used is sufficiently volatilized, but it is usually carried out by heating at 50 to 200 ° C. for 0.1 to 90 minutes.

  The thickness of the adhesive layer 10 is 3 to 23 μm at the bottom adhesive film for embedding the substrate unevenness when the chips are stacked in multiple stages, and the thickness of the adhesive film after the second stage for embedding the wire is 42 to 42 μm. 62 μm, preferably 3 to 62 μm. When the thickness is within this range, it is possible to sufficiently exhibit the unevenness embedding property of the wiring board and it is economical. Also, two or more adhesive layers 10 can be bonded to obtain a desired thickness.

  The adhesive film of the present invention may be used by itself, but can also be used as a dicing tape-integrated adhesive film in which the adhesive layer in the adhesive film of the present invention is laminated on a conventionally known dicing tape. As a method of laminating the adhesive layer on the dicing tape, in addition to printing, a pre-manufactured adhesive film can be pressed on the dicing tape, a hot roll laminating method, etc., but it can be manufactured continuously and is efficient. A hot roll laminating method is preferred. In addition, the film thickness of a dicing tape does not have a restriction | limiting in particular, According to the film thickness of an adhesive bond layer, and the use of a dicing tape integrated adhesive film, it determines suitably based on the knowledge of those skilled in the art. From the viewpoint of economy and film handling, the thickness of the dicing tape is preferably 60 to 200 μm, more preferably 70 to 170 μm.

  The adhesive film of the present invention is hardly affected by curing due to heat generated in the die bonding step and the wire bonding step, and has good embeddability in the uneven portion of the semiconductor element or the wiring substrate in the sealing step. Therefore, by using the adhesive film of the present invention, a semiconductor device that is sufficiently excellent in connection reliability can be manufactured.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

Example 1
Each component was mix | blended with the mixture ratio (mass part) shown in Table 1, and the adhesive composition was prepared. First, as the epoxy resin of component (a), a cresol novolac type epoxy resin (manufactured by Tohto Kasei Co., Ltd. (Nippon Steel & Sumikin Chemical Co., Ltd.), trade name: YDCN-700-10, epoxy equivalent: 210 g / eq) 100.0 mass Part and bisphenol F-type epoxy resin (manufactured by DIC Corporation, trade name: EXA830-CRP, epoxy equivalent: 155 g / eq), 100.0 parts by mass, (b) as an epoxy resin curing agent of component (1) 15-part by mass of a biphenylene dimethylene type phenolic resin (trade name: HE200C-10, hydroxyl group equivalent: 204 g / eq) having a structure represented by 3-mercaptopropyl as a silane coupling agent Trimethoxysilane (Momentive Performance Materials Japan Product name: A-189) 0.6 parts by mass and 3-ureidopropyltriethoxysilane (Momentive Performance Materials Japan G.K., product name: A-1160) 1.2 parts by mass As an inorganic filler, 200.0 parts by mass of spherical silica (manufactured by Admatechs, trade name: Admanano, average particle size: about 0.050 μm) and 1000 parts by mass of cyclohexanone were mixed with stirring. Here, as an epoxy group-containing (meth) acrylic copolymer of component (c), acrylic rubber (manufactured by Nagase Chemtech Co., Ltd., trade name: HTR-860P-3, Mw: 800,000, Tg: 15 ° C., butyl (Mass ratio of acrylate / ethyl acrylate / acrylonitrile / glycidyl methacrylate: 39.4 / 29.3 / 30.3 / 3) 110.0 parts by mass are added and mixed, then vacuum degassed to varnish the adhesive composition Got.

  Next, the varnish was applied on a base film made of a polyethylene terephthalate film having a thickness of 38 μm and subjected to heat drying at 90 ° C. for 5 minutes and 130 ° C. for 5 minutes to form an adhesive layer in a B stage state. An adhesive film having a film thickness of 20 μm was formed on the base film.

(Comparative Example 1)
The epoxy resin curing agent HE200C-10 is blended in an amount of 100.0 parts by mass, XLC-LL (xylylene phenol resin, Millex XLC-LL (trade name, manufactured by Mitsui Chemicals), softening point 78 ° C., hydroxyl group equivalent 172 g. / Eq, number average molecular weight of about 1,050) was changed to 50.0 parts by mass, and an adhesive film was prepared in the same manner as in Example 1.

(Comparative Example 2)
An adhesive film was produced in the same manner as in Example 1 except that the amount of the epoxy resin curing agent HE200C-10 was changed to 50.0 parts by mass and the amount of XLC-LL was changed to 100.0 parts by mass.

(Comparative Example 3)
The adhesive film was produced like Example 1 except having changed the compounding quantity of XLC-LL which does not have a structure represented by General formula (1) into 150.0 mass parts for the epoxy resin hardening | curing agent.

*（ａ）エポキシ樹脂及び（ｂ）エポキシ樹脂硬化剤の合計質量Ａと、（ｃ）エポキシ基含有（メタ）アクリル共重合体(アクリルゴム）の質量Ｂとの比率。

* Ratio of the total mass A of (a) epoxy resin and (b) epoxy resin curing agent and mass B of (c) epoxy group-containing (meth) acrylic copolymer (acrylic rubber).

<Measurement of melt viscosity>
The melt viscosity of the adhesive layer of the adhesive film was measured using a rotational viscoelasticity measuring apparatus (trade name: ARES-RDA, manufactured by TA Instruments Japan Co., Ltd.).

After peeling the base film from the adhesive film, the adhesive layer was laminated at 70 ° C. to form a film with a film thickness of 100 to 300 μm, and punched into a circle with a diameter of 8 mm. The produced circular film was also sandwiched between two jigs with a diameter of 8 mm to produce a sample, jig: parallel plate, frequency: 1 Hz, strain: 5.0%, set temperature: 10 ° C. from 50 ° C. to 150 ° C. The temperature was raised at / min and the melt viscosity was measured. Table 2 shows the melt viscosity at 80 ° C.
The melt viscosity at 80 ° C. assumes the heating temperature applied in the die bonding process. A lower viscosity is preferred. This means a viscosity that allows the lower wire to be embedded during the die bonding process.

<Measurement of storage modulus>
The storage elastic modulus of the adhesive layer of the adhesive film was measured using a dynamic viscoelasticity measuring apparatus (manufactured by Rheology, trade name: DVE Leospectra).
After peeling the base film from the adhesive film, the adhesive layer was laminated at 70 ° C. to form a film with a film thickness of 100 to 300 μm, and cut into strips having a length of 50 mm and a width of 4 mm. The produced strip-shaped film was cured at 175 ° C., and the storage elastic modulus from room temperature (25 ° C.) to 270 ° C. was measured at a distance between chucks of 10 mm and a heating rate of 10 ° C./min. Table 2 shows the storage elastic modulus at 175 ° C.

  Curing at a set temperature of 175 ° C. is a heating condition sufficient for complete curing. By measuring the storage elastic modulus of the cured film, the time for the die bonding process and the wire bonding process for laminating semiconductor chips in multiple stages It is assumed that the elastic modulus is large enough to fill the groove of the substrate in the sealing process and the solder ball reflow process even when the length of the substrate becomes longer.

<Evaluation of embedding of substrate irregularities>
A dicing sheet is attached to the adhesive layer surface of the adhesive film, the base film is peeled off, and then a semiconductor wafer having a thickness of 100 μm is laminated on the other adhesive layer surface on a hot plate. Thereafter, the semiconductor wafer was separated into pieces through a dicing process to obtain a semiconductor chip with an adhesive layer having a length of 7.5 mm and a width of 7.5 mm.

A sample in which the semiconductor chip with an adhesive layer is attached to a substrate (400 μm thick silicon wafer) having unevenness with a width of 30 μm and a depth of 50 μm under conditions of 120 ° C., 0.1 MPa, and 1 second is prepared on a hot plate. It heat-processed for 30 minutes at 0 degreeC. Thereafter, sealing was performed using a mold sealing material (trade name: CEL-9700HF, manufactured by Hitachi Chemical Co., Ltd.) under the conditions of 175 ° C., 6.9 MPa, and 120 seconds to prepare an evaluation package. The fillability of the top and bottom of the substrate (width 30 μm, depth 50 μm) is observed with a cross-sectional observation and an ultrasonic microscope, and “A” indicates that there are no voids in the uneven portions, and “B” indicates that there are voids. The embedding property of the substrate unevenness was evaluated.
The above measurement and evaluation results are summarized in Table 2.

The adhesive films of Comparative Examples 1 to 3 do not have a storage elastic modulus at 175 ° C. within the range of 1 to 31 MPa, and Example 1 has a storage elastic modulus lower than that of the Comparative Example within the range. Thereby, Example 1 is excellent in the embedding property of the substrate unevenness. This storage elastic modulus can be achieved by a combination using the components (a) to (c).
When the adhesive film of the present invention was used, it was confirmed that the wire embedding property was maintained and the embedding property of the uneven portion on the wiring board was sufficiently excellent. That is, the adhesive layer according to the present invention has a low-viscosity property that can be embedded in a wire, and is added in a die bonding process or a wire bonding process, and has a low-elastic property even when curing progresses. Even when semiconductor chips are stacked in multiple stages, it has excellent filling properties on the wiring substrate in the sealing process, and according to the adhesive film of the present invention, while improving the reliability of the semiconductor device, the processing speed of the semiconductor device, It is possible to improve the yield.

  DESCRIPTION OF SYMBOLS 1 ... Adhesive film, 10 ... Adhesive layer, 20 ... Base film.

Claims (5)

When using an adhesive film comprising an adhesive composition comprising (a) an epoxy resin, (b) an epoxy resin curing agent, and (c) an epoxy group-containing (meth) acrylic copolymer, when stacking chips in multiple stages The thickness of the lowermost adhesive film for embedding the substrate unevenness is 3 to 23 μm, the thickness of the second and subsequent adhesive films for embedding the wire is 42 to 62 μm, and the storage elasticity at 175 ° C. after curing of the adhesive film The adhesive film containing a phenol resin having a rate of 1 to 31 MPa and wherein the epoxy resin curing agent of the component (b) is represented by the following general formula (1)

(In general formula (1), n is an integer of 1-20.)   The structural unit derived from the monomer which the epoxy group containing (meth) acrylic copolymer of said (c) component has a glass transition temperature (Tg) of -50-30 degreeC and has an epoxy group is 0.5. The adhesive film according to claim 1, which is a copolymer containing ˜3.0 mass% and having a weight average molecular weight of 100,000 or more.   The ratio A / B between the total mass A of the (a) epoxy resin and the (b) epoxy resin curing agent and the mass B of the (c) epoxy group-containing (meth) acrylic copolymer is 0.1. It is-4.1, The adhesive film of Claim 1 or Claim 2.   The adhesive composition further comprises (d) an inorganic filler having an average particle size of 0.005 to 0.5 μm in an amount of 1 to 50 with respect to a total of 100 parts by volume of (a), (b) and (c). The adhesive film according to claim 1, comprising a volume part.   The adhesive film according to claim 1, wherein the adhesive film has a melt viscosity at 80 ° C. of 500 to 10,000 Pa · s.

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