JP6213618B2 - Film adhesive, adhesive sheet and semiconductor device - Google Patents

Description

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

  Stacked MCP (Multi Chip Package), in which chips are stacked in multiple stages and increased in capacity with the increasing functionality of mobile phones and the like, has become widespread, and film adhesives that are advantageous in the mounting process for mounting semiconductor devices Is widely used as an adhesive for die bonding. An example of a multi-layer stacked package using such a film adhesive is a wire-embedded package. This is a package in which a wire connected to a chip to be crimped is crimped by using a high-flowing film adhesive, and the adhesive is covered with the adhesive. It is mounted on memory packages for devices.

One of the important characteristics required for semiconductor devices such as the above-mentioned stacked MCP is connection reliability. In order to improve connection reliability, a film that takes into consideration characteristics such as heat resistance, moisture resistance, and reflow resistance Development of adhesives is underway. As such a film adhesive, for example, Patent Document 1 includes a resin containing a high molecular weight component and a thermosetting component mainly composed of an epoxy resin and a filler having a thickness of 10 to 250 μm. Adhesive sheets have been proposed. Patent Document 2 proposes an adhesive composition containing a mixture containing an epoxy resin and a phenol resin and an acrylic copolymer.

Further, the connection reliability of the semiconductor device is greatly influenced by whether or not the chip can be crimped without generating a gap on the bonding surface. For this reason, a highly fluid film adhesive is used so that the chip can be crimped without generating voids, or a film with low elastic modulus so that the generated voids can be eliminated in the sealing process of the semiconductor element. Devises such as using an adhesive have been made. For example, Patent Document 3 proposes an adhesive sheet having low viscosity and low tack strength.

The adhesive film or the like of Patent Document 1 contains a large amount of epoxy resin or the like for the purpose of increasing fluidity because the wire is embedded at the time of pressure bonding. For this reason, thermosetting proceeds due to heat during the semiconductor device manufacturing process, resulting in high elasticity, so the film does not deform even under high temperature and high pressure conditions during sealing, and voids formed during crimping eventually disappear. do not do.
On the other hand, although the adhesive film of the above-mentioned patent document 2 has a low elastic modulus and can eliminate voids in the sealing process, it has a high viscosity and cannot embed a wire at the time of pressure bonding.

International Publication No. 2005/103180 JP 2002-220576 A JP 2009-120830 A

  In recent years, in order to achieve higher capacity and higher density of packages, attempts have been made to make the thickness of the chip as thin as possible. When assembling packages using such ultra-thin chips, Problems occur. For example, when a film adhesive is used, the chip with adhesive is adsorbed by a tool with a hole called a collet, lifted to be peeled off from the dicing tape, and pressed onto another semiconductor element or substrate. When the chip is thinned, the chip is easily bent in a convex shape due to the suction holes of the collet. As a result, the quality after the pressure bonding is deteriorated, and a void is easily generated in the chip. For this reason, even if a highly fluid film like the adhesive sheet of Patent Document 3 is used, voids tend to be generated at the time of pressure bonding, so that the characteristics of the film adhesive are improved.

  In this way, when an ultra-thin chip is crimped using a film-like adhesive for embedding wires, voids are generated during crimping and will not disappear thereafter, so that sufficient connection reliability cannot be obtained. There is.

  In addition, when an ultra-thin wafer with a film-like adhesive attached is cut into chips, the chip is likely to be cracked and chip is easily damaged by cutting with a normal rotary blade. For this reason, in recent years, a method has been devised and adopted in which an ultra-thin wafer to which a film-like adhesive has been attached is made into a chip size by a method other than the conventional rotary blade. For example, after a wafer is modified with a laser, it is stretched (expanded) so as to be fragmented together with a film adhesive, or after a film adhesive is pasted on a chip that has been fragmented in advance, a laser or The method of dividing a film adhesive by an expand is mentioned. For this reason, there exists a tendency for the film-like adhesive to require not only a cutting ability with a rotary blade but also a good cutting ability with an expand. However, it is difficult to achieve both the disappearance of the gap in the sealing step and the good splitting property by the expand, and the splitting property is not sufficient in the adhesive sheet of Patent Document 2.

  The present invention has been made in view of the above circumstances, and shows good breakability before curing, and can be embedded at the time of crimping with high flow, for example, heating at 150 ° C./1 hour in the wire bonding process. An object of the present invention is to provide a film-like adhesive that is low in elasticity and capable of eliminating voids at the time of sealing. Another object of the present invention is to provide an adhesive sheet using the film adhesive of the present invention and a semiconductor device manufactured using the film adhesive of the present invention.

  In order to achieve the above-mentioned object, the present inventors have conducted intensive research on selection of a resin used for a film adhesive and adjustment of physical properties. In particular, high fluidity is exhibited with an uncured film, and even when curing progresses partway through heating, the elastic modulus of the film adhesive is kept low and soft, and high adhesive strength is exhibited after complete curing. Is important. It has been found that this can be solved not only by the ratio of the thermosetting component and the flexible high molecular weight component but also by using a resin having a low molecular weight and a large amount of reactive functional groups as the high molecular weight component. Further, it has been found that in order to increase the breakability before curing, it can be solved by using a high molecular weight component having a lower molecular weight and using a filler having a larger particle size.

That is, the present invention is as follows.
(1) (a) Thermosetting containing 20% by mass or more of an epoxy resin having a softening point of 100 ° C. or less or becoming liquid at 100 ° C. or less and having an epoxy equivalent of 140 or more or a hydroxyl group equivalent of 140 or more. 100 parts by mass of resin,
(B) a first high molecular weight component having a crosslinkable functional group in a monomer ratio of 5 to 15%, a weight average molecular weight of 100,000 to 400,000 and a Tg of -50 to 50 ° C;
Alternatively, the first high molecular weight component and the second high molecular weight component having a crosslinkable functional group in a monomer ratio of 1 to 7%, a weight average molecular weight of 500,000 to 800,000, and Tg of −50 to 50 ° C. 30 to 100 parts by mass of any one of the mixed high molecular weight components wherein the first high molecular weight component is 50% by mass or more,
(C) including a first filler having an average particle diameter of 0.4 μm or more and a second filler having an average particle diameter of less than 0.4 μm, and particles having a particle diameter of 0.4 μm or more occupy 30% by volume or more. A film adhesive comprising 10 to 60 parts by mass of an inorganic filler and (d) 0 to 0.07 parts by mass of a curing accelerator.

(2) The shear viscosity at 80 ° C. before curing is 200 to 11000 Pa · s or less,
The tensile modulus at 180 ° C. after heating at 150 ° C. for 1 hour is 20 MPa or less, the adhesive breaking elongation at 25 ° C. is 350% or less, and the breaking strength is 6.0 MPa or less. Film adhesive.
(3) The film adhesive according to (1) or (2), wherein the adhesive strength of the silicon nitride formed on the semiconductor chip surface to the thin film is 1.0 MPa or more after the film adhesive is cured.

  (4) The adhesive sheet which has a base film and the film adhesive as described in any one of said (1)-(3) laminated | stacked on the single side | surface of this base film.

  (5) A semiconductor chip is laminated on a substrate having a step or another semiconductor chip that is wire-bonded via the film adhesive according to any one of (1) to (3). Or the semiconductor device by which the unevenness | corrugation by a wire is embedded in a film adhesive, and also at least a semiconductor chip and a wire are sealed with a sealing material.

(6) One side of the film-like adhesive according to any one of (1) to (3) above, or an exposed surface of the film-like adhesive in the adhesive sheet according to claim 4, and a semiconductor wafer or a semiconductor chip A laminating process for bonding the bottom surface;
A cutting step for obtaining a semiconductor chip with a film adhesive by cutting or stretching,
A die bonding step in which the semiconductor chip with the film adhesive is pressure-bonded to the upper surface of the substrate having a step or the upper surface of another semiconductor chip wire-bonded on the substrate, and the unevenness due to the step or the wire is embedded in the film adhesive. When,
A method of manufacturing a semiconductor device including a step of sealing with a sealing material.

(7) In the die bonding step, the pressure bonding conditions are 80 to 180 ° C., 0.01 to 0.50 MPa, 0.5 to 2.0 seconds,
The method for manufacturing a semiconductor device according to (6), wherein the sealing condition is 170 to 180 ° C./6.0 to 10.0 MPa / 90 seconds.

  According to the present invention, it has a low elastic modulus that enables mounting in a wire-embedded structure without causing voids in the bonding surface while suppressing damage to the chip, and has heat resistance, moisture resistance, and reflow resistance. An excellent film adhesive, an adhesive sheet, and a semiconductor device manufactured using the film adhesive can be provided.

  Thereby, the film adhesive of this invention can lose | disappear the space | gap produced at the time of pressure bonding at the time of sealing, ensuring favorable wire embedding property at the time of pressure bonding. Furthermore, when the film adhesive of the present invention is used for a wire embedded package using an ultrathin chip, it is difficult to achieve with a conventional film adhesive for embedding a wire while suppressing damage to the ultrathin chip. A semiconductor device free from voids on a certain bonding surface can be obtained.

(A)-(d) is a longitudinal cross-sectional schematic diagram which shows embodiment of the adhesive sheet which concerns on this invention, respectively. (A) is a longitudinal cross-sectional schematic diagram which shows one Embodiment of the semiconductor device of this invention, (b) is a longitudinal cross-sectional schematic diagram which shows another embodiment of the semiconductor device of this invention. (A) is the board | substrate for evaluation used in the Example of this invention, (b) is the sample produced using (a). It is a SEM photograph near the wire of the Example of this invention, Comprising: (a) is an example of embedding defect, (b) is an example of embedding good.

  Details of the present invention will be described below.

  The film adhesive of this invention is comprised from the thermosetting resin composition which can be in a completely hardened | cured material (C stage) state after a hardening process through a semi-hardened (B stage) state. The adhesive sheet of the present invention is obtained by laminating the film adhesive on one side of a base film. In this specification, “(meth) acryl” means “acryl” and “methacryl” corresponding to it.

  The film-like adhesive of the present invention has (1) a shear viscosity at 80 ° C. before curing of 200 to 11000 Pa · s, and after heating at 150 ° C. for 1 hour, (2) tensile at 180 ° C. It is preferable that the elastic modulus is 20 MPa or less, (3) 350% or less at 25 ° C., and (4) the breaking strength is 6.0 MPa or less.

  The more preferable range of the above (1) shear viscosity is 200 to 8000 Pa · s, (2) the more preferable range of the 180 ° C. tensile modulus is 15 MPa or less, and (3) the more preferable range of the adhesive breaking elongation is 330% or less, and (4) a more preferable range of the breaking strength is 5.7 MPa or less.

  The above shear viscosity is a measured value when measured using ARES (manufactured by Rheometric Scientific) and increasing the temperature at a temperature increase rate of 5 ° C./min while giving 5% strain to the film adhesive. Means. On the other hand, the tensile elastic modulus means a measured value when measured using a dynamic viscoelasticity measuring device (UBM) while increasing the temperature at a temperature increase rate of 3 ° C./min. The adhesive breaking elongation and breaking strength were tested when a 10 mm wide, 60 μm thick uncured film adhesive was set in a tensile tester with a chuck distance of 20 mm and pulled at a speed of 50 mm / min. It means the elongation and tensile strength until the piece breaks.

  (1) By setting the shear viscosity at 80 ° C. to 200 to 11000 Pa · s, it becomes possible to embed irregularities derived from voids under the wires or substrate steps in the adhesive. The pressure bonding at that time is preferably 80 ° C. or higher, 0.01 to 0.50 MPa, and 1 to 2 seconds.

  Further, (2) by setting the tensile elastic modulus at 180 ° C. after heating at 150 ° C. for 1 hour to 20 MPa or less, the remaining voids can be eliminated during curing of the sealing material. The sealing conditions at that time are preferably 175 ° C./6.7 MPa / 90 seconds.

  (3) When the adhesive breaking elongation at 25 ° C. is 350% or less, and (4) the breaking strength is 6.0 MPa or less, it can be cut together with an ultrathin chip by a cutting method such as expand. It can be used as an adhesive and can be made into small pieces while suppressing damage to the ultrathin chip.

In order for the film adhesive of the present invention to have the above characteristics (1) to (4), (a) an epoxy resin having a softening point of 100 ° C. or lower or a liquid at 100 ° C. or lower and an epoxy equivalent of 140 or higher. Alternatively, 100 parts by mass of a thermosetting resin containing 20% by mass or more of a phenol resin having a hydroxyl group equivalent of 140 or more,
(B) a first high molecular weight component having a crosslinkable functional group in a monomer ratio of 5 to 15%, a weight average molecular weight of 100,000 to 400,000, and a Tg of −50 to 50 ° C., or a crosslinkable functional group Is obtained by blending a second high molecular weight component and a first high molecular weight component having a weight average molecular weight of 500,000 to 800,000 and a Tg of −50 to 50 ° C. 30 to 100 parts by mass of any one of the high molecular weight components, wherein the molecular weight component is such that the ratio of the first high molecular weight component is 50% by mass or more,
(C) Consisting of a first filler having an average particle size of 0.4 μm or more and a second filler having an average particle size of less than 0.4 μm, and particles having a particle size of 0.4 μm or more occupy 30% by volume or more. 10 to 60 parts by mass of an inorganic filler characterized by
(D) It can produce by shape | molding the adhesive composition containing 0-0.07 mass part of hardening accelerators in a film form.

  More specifically, in order to set the shear viscosity at 80 ° C. to 200 to 11000 Pa · s, the content of the resin having a low molecular weight component, becoming liquid at 100 ° C. or lower, or having a softening point of 100 ° C. or lower. The composition may be changed in any one of increasing the filler and decreasing the filler content.

  In order to set the tensile modulus at 180 ° C. after heating at 150 ° C. for 1 hour to 20 MPa or less, increase the high molecular weight component, lower the monomer ratio of the crosslinkable functional group of the high molecular weight component, What is necessary is just to use the thermosetting resin with a larger epoxy equivalent and hydroxyl equivalent to lower.

  In order to set the adhesive elongation at break at 25 ° C. to 350% or less and the breaking strength to 6.0 MPa or less, the ratio of the first high molecular weight component is increased and the ratio of the second high molecular weight component is decreased. What is necessary is just to raise the ratio, raise the ratio of the filler whose particle size is 0.4 micrometer or more, and raise the ratio of the solid epoxy resin or phenol resin whose softening point is 25 degreeC or more.

The film-like adhesive of the present invention preferably has an adhesive force of 1.0 MPa or more after being pressed and cured on a silicon nitride thin film formed on the semiconductor chip surface (wiring side). In order for the film adhesive to have the above adhesive force, the adhesive composition may be configured as described above. A silicon nitride thin film is formed as a typical circuit protection material on a semiconductor chip.
From the viewpoint of obtaining sufficient adhesiveness, the adhesive composition may further include (e) an additive such as a coupling agent.
Moreover, adhesive force is obtained by measuring the die shear strength mentioned later.

Hereinafter, each component of the adhesive composition for obtaining the film adhesive will be described.
(A) Thermosetting component:
(A) As a thermosetting component, a thermosetting resin is preferable and an epoxy resin, a phenol resin, etc. which have the heat resistance and moisture resistance required when mounting a semiconductor element are preferable.

  In order to eliminate voids remaining at the time of sealing, it is necessary to lower the tensile elastic modulus during and after curing. For this purpose, the thermosetting resin has a softening point of 100 ° C. or lower or 100 ° C. It is necessary to contain 20% by mass or more of an epoxy resin that becomes liquid in the following (hereinafter, generically referred to as a softening point of 100 ° C. or less) and that has an epoxy equivalent of 140 or more or a phenol resin that has a hydroxyl equivalent of 140 or more. It is. Examples of such an epoxy resin include an epoxy resin represented by the general formula (1).

(In formula (1), R _{1 to} R ₄ are each independently a hydrogen atom, a linear, branched or cyclic alkyl group, a linear, branched or cyclic aralkyl group, a linear, branched or cyclic alkenyl group, a hydroxyl group, an aryl. A group or a halogen atom, k and m represent an integer of 1 to 4)

In the above formula (1), as preferred epoxy resins, R _{1 to} R ₄ are hydrogen atoms, and k = 4, m = 4 epoxy resin (if it is a commercial product, YDF-8170C manufactured by Toto Kasei Co., Ltd.) Etc.) or an epoxy resin in which R _{1 to} R ₂ are methyl groups, R _{3 to} R ₄ are hydrogen atoms, k = 2, m = 2 in the above formula (1) (Tohto Kasei is a commercial product) YSLV-80XY etc. made by Corporation | KK) etc. are mentioned.

  The epoxy resin other than the above general formula (1) is not particularly limited as long as it has a softening point of 100 ° C. or lower and an epoxy equivalent of 140 or higher, and has an adhesive action when cured, bisphenol A type epoxy resin, bisphenol F Type epoxy resin, bifunctional epoxy resin obtained by modifying bisphenol E type epoxy resin, novolac type epoxy resin such as phenol novolac type epoxy resin and cresol novolac type epoxy resin, and the like can be used. Examples of bifunctional epoxy resins obtained by modifying bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, etc. include R710 (liquid, epoxy equivalent 170), R1710 (liquid) manufactured by Printec Co., Ltd. , Epoxy equivalent 175), R2710 (liquid, epoxy equivalent 180) and the like (see the following general formula (2)).

(In formula (2), n represents 0 to 5)

  Moreover, you may use together epoxy resin other than an epoxy resin with a softening point of 100 degrees C or less and an epoxy equivalent of 140 or more as (a) thermosetting resin. As such an epoxy resin, generally known ones such as a polyfunctional epoxy resin, a glycidylamine type epoxy resin, a heterocyclic ring-containing epoxy resin or an alicyclic epoxy resin can be used.

  In addition, any epoxy resin preferably has a weight average molecular weight of 1000 or less, more preferably 500 or less, from the viewpoint of enhancing the flexibility of the film in the B-stage state. Examples of the epoxy resin having a weight average molecular weight of 500 or less that is excellent in flexibility include bisphenol A type or bisphenol F type epoxy resin.

  Examples of the phenol resin having a softening point of 100 ° C. or lower and a hydroxyl group equivalent of 140 or higher as the thermosetting resin include phenol resins represented by the general formulas (3) and (4).

(In the formula (3), each R ₅ is independently a hydrogen atom, a linear, branched or cyclic alkyl group, a linear, branched or cyclic aralkyl group, a linear, branched or cyclic alkenyl group, a hydroxyl group, an aryl group, or Represents a halogen atom, n represents an integer of 1 to 4, and p represents an integer in the range of 1 to 50.)

(In formula (4), q represents an integer in the range of 1-50.)

Typical examples of the phenolic resin represented by the general formula (3) include the Millex XLC-series and XL series (for example, the Millex XLC-LL (in the general formula (3), R ₅ is a hydrogen atom, and n = 3))) and the like.
Moreover, there exists HE series (for example, HE200C-10) by Air Water, etc. as a typical thing as a phenol resin represented by General formula (4).

  In addition to those represented by the above general formulas (3) and (4), in addition to the above, as a phenol resin having a softening point of 100 ° C. or lower and a hydroxyl group equivalent of 140 or higher, a naphthol resin SN series manufactured by Toto Kasei Co., Ltd. is used. May be.

  In addition, you may use together phenol resin other than a phenol resin with a softening point of 100 degrees C or less and a hydroxyl equivalent of 140 or more as a thermosetting resin. Other phenolic resins are not particularly limited as long as they are cured and have an adhesive action. For example, Phenolite LF, KA, TD series, etc. manufactured by DIC Corporation may be mentioned.

  From the viewpoint of heat resistance, both the phenol resin having a softening point of 100 ° C. or less and a hydroxyl group equivalent of 140 or more and other phenol resins have a water absorption rate of 2 mass after being put into a constant temperature and humidity chamber of 85 ° C. and 85% RH for 48 hours. %, And the heating mass reduction rate (temperature increase rate: 5 ° C./min, atmosphere: nitrogen) at 350 ° C. measured with a thermogravimetric analyzer (TGA) is preferably less than 5% by mass.

When both an epoxy resin and a phenol resin are included as the thermosetting component, the compounding amounts of the epoxy resin and the phenol resin are 0.70 / 0.30 to 0.30 / 0. 70 is preferable, 0.65 / 0.35 to 0.35 / 0.65 is more preferable, and 0.60 / 0.40 to 0.40 / 0.60 is still more preferable. 0.60 / 0.40 to 0.50 / 0.50 is particularly preferable.
If the blending ratio exceeds the above range, the produced film adhesive may be inferior in curability, or the viscosity of the uncured film adhesive may be high and fluidity may be inferior.

  In addition to epoxy resins having a softening point of 100 ° C. or lower and an epoxy equivalent of 140 or higher, other epoxy resins, phenol resins having a softening point of 100 ° C. or lower and a hydroxyl equivalent of 140 or higher, and other phenol resins, (a) thermosetting As a component, a resin having a functional group such as a (meth) acryl group that is polymerized by heating can be used.

(B) High molecular weight component:
(B) As the high molecular weight component, a combination of a high molecular component having a high crosslinkable functional group ratio and a low molecular weight and a high molecular component having a low crosslinkable functional group ratio and a high molecular weight is preferable. It is preferable that the component is contained in a certain amount or more.
That is, a first high molecular weight component containing a crosslinkable functional group in a monomer ratio of 5 to 15%, a Tg (glass transition temperature) of −50 ° C. to 50 ° C., and a weight average molecular weight of 100,000 to 400,000 ,
Containing a crosslinkable functional group in a monomer ratio of 1 to 7%, a second high molecular weight component having a Tg (glass transition temperature) of -50 ° C to 50 ° C and a weight average molecular weight of 500,000 to 800,000. The ratio of the first high molecular weight component is preferably 50% by mass or more.
In the present invention, both the first and second high molecular weight components are preferably acrylic resins, and the Tg (glass transition temperature) is −50 ° C. to 50 ° C., and an epoxy group or glycidyl group such as glycidyl acrylate or glycidyl methacrylate. An acrylic resin such as an epoxy group-containing (meth) acrylic copolymer obtained by polymerizing a functional monomer having a crosslinkable functional group is more preferred.

  As such a resin, an epoxy group-containing (meth) acrylic acid ester copolymer, an epoxy group-containing acrylic rubber or the like can be used, and an epoxy group-containing acrylic rubber is more preferable. The epoxy group-containing acrylic rubber is a rubber having an epoxy group mainly composed of an acrylate ester and mainly composed of a copolymer such as butyl acrylate and acrylonitrile, a copolymer such as ethyl acrylate and acrylonitrile, or the like. .

  In the present invention, the crosslinkable functional group of the high molecular weight component includes not only an epoxy group but also a crosslinkable functional group such as an alcoholic or phenolic hydroxyl group or a carboxyl group.

The weight average molecular weight is a polystyrene conversion value using a standard polystyrene calibration curve by gel permeation chromatography (GPC).
The glass transition temperature is measured using a DSC (thermal differential scanning calorimeter) (for example, “Thermo Plus 2” manufactured by Rigaku Corporation).

  If the molecular weight of the first high molecular weight component is not too low to such an extent that the moldability of the film and the adhesive strength after curing can be maintained, the first high molecular weight component alone can be used. Or when it uses together with the 2nd high molecular weight component with larger molecular weight, and the ratio of a 1st high molecular weight component shall be 50 mass% or more, it exists in the tendency for the fracture property of a film to become further favorable. The first high molecular weight component is more preferably 60% by mass or more.

  Further, if the Tg of the high molecular weight component is 50 ° C. or lower, the flexibility of the film adhesive is sufficient, and if the Tg is −50 ° C. or higher, the flexibility of the film adhesive is not too high. The film adhesive can be easily cut during wafer dicing, and the occurrence of burrs that affect dicing can be suppressed.

  If the weight average molecular weight of the first high molecular weight component is less than 100,000, the film-forming property may be deteriorated or the adhesive strength and heat resistance of the film-like adhesive may be lowered, and the weight average molecular weight may be 400,000. If it exceeds 1, the breakability of the uncured film adhesive tends to deteriorate, and the elongation and the breaking strength tend to increase. From such a viewpoint, the weight average molecular weight of the first high molecular weight component is preferably 100,000 or more and 400,000 or less.

  In addition, if the weight average molecular weight of the second high molecular weight component is 500,000 or more, the effect of improving film-forming properties by blending with the first high molecular weight component tends to be sufficiently exhibited, and the weight average molecular weight Is 800,000 or less, the machinability and breakability of the uncured film adhesive do not deteriorate, so that the quality of dicing can be maintained. In these respects, the weight average molecular weight of the second high molecular weight component is preferably 500,000 or more and 800,000 or less.

  Furthermore, it is easy to cut the film adhesive at the time of wafer dicing, it is difficult to generate resin waste, high adhesive strength and heat resistance, and high fluidity of the uncured film adhesive. ) The high molecular weight component is preferably a high molecular weight component having a Tg of -20 ° C to 40 ° C as a whole, and a high molecular weight component having a Tg of -10 ° C to 30 ° C.

  The (b) high molecular weight component is preferably contained in an amount of 30 to 100 parts by mass with respect to 100 parts by mass of the (a) thermosetting component. If it is 30 parts by mass or more, the flexibility of the film is sufficient. At the same time, there is a tendency that the elasticity can be increased after heating to prevent the voids from being embedded at the time of sealing. On the other hand, if it is 100 parts by mass or less, the fluidity of the uncured film is sufficient, and the adhesive strength after curing tends not to decrease. More preferably, it is 30-60 mass parts.

  Furthermore, in order to express high adhesive strength, the monomer ratio of the functional monomer such as glycidyl acrylate or glycidyl methacrylate as the first high molecular weight component used mainly is (weight of functional monomer used) / (total monomer used). 5 to 15% is preferable, and from the viewpoint of maintaining a low tensile elastic modulus after heating at 150 ° C./1 hour, 5 to 10% is more preferable.

  The high molecular weight component (b) used in the present invention can also be obtained as a commercial product. For example, trade name “acrylic rubber HTR-860P-30B-CHN” manufactured by Teikoku Chemical Industry Co., Ltd. can be used. This compound has a glycidyl moiety as a crosslinkable functional group and is a compound based on an acrylic rubber made of an acrylic acid derivative and has a weight average molecular weight of 100,000 to 300,000 and a glass transition temperature Tg (−7 ° C.). It is.

(C) Inorganic filler:
(C) As an inorganic filler, the improvement of the dicing property of the film adhesive in the B stage state, the improvement of the handling property of the film adhesive, the improvement of the thermal conductivity, the adjustment of the melt viscosity, the provision of thixotropic property, the adhesion From the viewpoint of improving the force, it is preferable to add a silica filler.

  In the adhesive composition of this embodiment, from the viewpoint of controlling the fluidity and breakability of the uncured film adhesive and the tensile modulus and adhesive force of the film adhesive after curing, (a) a thermosetting component It is preferable to mix 10 to 60 parts by mass of an inorganic filler with respect to 100 parts by mass. When an inorganic filler lower than the above lower limit is blended, the breakability and dicing properties of the uncured film adhesive may be deteriorated and the adhesive strength after curing may be reduced. On the other hand, when an inorganic filler exceeding the upper limit is blended, the fluidity of the uncured film adhesive is lowered, and the tensile modulus after curing tends to be increased. A more preferable blending amount is 15 to 50 parts by mass.

  The inorganic filler is preferably mixed with two or more kinds of fillers having different average particle diameters for the purpose of improving the breakability of the uncured film adhesive and sufficiently exhibiting the adhesive strength after curing. That is, the first particle diameter is 0.4 μm or more for the purpose of improving the breakability of the uncured film adhesive, and the average particle diameter for the purpose of fully expressing the adhesive strength after curing. It is preferable that particles containing a second filler of less than 0.4 μm and having a particle size of 0.4 μm or more occupy 30% by volume or more. When the content of the first filler is less than 30% by volume, the breakability of the film deteriorates and the fluidity of the uncured film adhesive tends to deteriorate. Here, the “average particle size” is a value obtained when acetone is used as a solvent in a laser diffraction particle size distribution analyzer. Moreover, it is more preferable that the difference between the average particle diameters of the fillers of each type is so large that each average particle diameter can be discriminated with a particle size distribution measuring apparatus.

(D) Curing accelerator:
(D) The curing accelerator is preferably an imidazole compound from the viewpoint of reactivity.
A curing accelerator that is too reactive causes a rapid curing of the film-like adhesive during the manufacturing process of the semiconductor device, particularly in the heat history of the wire bonding process, and has a tensile modulus after heating at 150 ° C./1 hour. It tends to be higher. On the other hand, a curing accelerator having a reactivity that is too low makes it difficult for the film-like adhesive to be completely cured by the thermal history in the manufacturing process of the semiconductor device, and it is mounted in the product uncured, There is a risk of inducing subsequent device failures.

  If the amount of curing accelerator added is too small, it will be difficult to completely cure the film adhesive due to the heat history in the semiconductor device manufacturing process, and it will be mounted in the product uncured. Then, there is a risk of inducing subsequent device failures. On the other hand, when the addition amount of the curing accelerator is too large, the film-like adhesive is rapidly cured during the manufacturing process of the semiconductor device, and the tensile elastic modulus after heating at 150 ° C./1 hour tends to increase. . From such a viewpoint, the curing accelerator is preferably contained in an amount of 0 to 0.07 parts by mass with respect to 100 parts by mass of the thermosetting resin.

(E) Other ingredients:
In addition to the above (a) to (d), the adhesive composition of the present embodiment preferably contains a coupling agent from the viewpoint of improving adhesiveness. Examples of the coupling agent include γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, and the like.

<Method for producing film adhesive>
A film adhesive can be produced from the varnish of the adhesive composition described above.
Specifically, first, (a) a thermosetting resin containing the epoxy resin and the phenol resin, (b) a high molecular weight component, (c) an inorganic filler, (d) a curing accelerator, if necessary Then, other additive components such as the above coupling agent are mixed and kneaded in an organic solvent to prepare a varnish.

  Next, a layer of the varnish is formed by applying the obtained varnish on the base film. Next, after removing a solvent from a varnish layer by heat drying, a film adhesive is obtained by removing a base film.

  The above mixing and kneading can be performed by using a normal stirrer, a raking machine, a three-roller, a ball mill, or other disperser and appropriately combining them. The above-mentioned heat drying is not particularly limited as long as the solvent used is sufficiently volatilized, but it can be usually performed by heating at 60 ° C. to 200 ° C. for 0.1 to 90 minutes.

  The organic solvent for producing the varnish is not particularly limited as long as it can uniformly dissolve, knead or disperse the above components, and a conventionally known one can be used. Examples of such solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, dimethylformamide, dimethylacetamide, N methylpyrrolidone, toluene, xylene, and the like. It is preferable to use methyl ethyl ketone, cyclohexanone, etc. in terms of fast drying speed and low price.

  There is no restriction | limiting in particular as said base film, For example, a polyester film, a polypropylene film (OPP film etc.), a polyethylene terephthalate film, a polyimide film, a polyetherimide film, a polyether naphthalate film, a methylpentene film etc. are mentioned. .

<Embodiments of Film Adhesive and Adhesive Sheet of the Present Invention>
The film thickness of the film adhesive is preferably 5 to 200 μm in order to sufficiently fill unevenness such as a wire for connecting a semiconductor element and a wiring circuit of a substrate. If the film thickness is less than 5 μm, the adhesive force tends to be poor. If the film thickness is more than 200 μm, it is not economical and it is difficult to meet the demand for miniaturization of the semiconductor device. In addition, 10-100 micrometers is more preferable, and 20-75 micrometers is still more preferable from the point which has high adhesiveness and can make a semiconductor device thin.

The film adhesive of this invention can be used as an adhesive sheet by laminating | stacking on a base film. Moreover, what apply | coated the said varnish on the base film and dried may be used as an adhesive sheet as it is.
(A) of FIG. 1 is a schematic longitudinal cross-sectional view which shows one Embodiment of the adhesive sheet which concerns on this invention.
The adhesive sheet 100 shown in FIG. 1 is comprised from the base film 2 and the film adhesive 1 of this invention provided on one surface of this.

  The film adhesive 1 can be provided by laminating the base film 2 with the film adhesive according to the present invention obtained in advance. Further, as one method for producing a thicker film adhesive 1, it can be formed by bonding the film adhesive 1 obtained in advance with the film adhesive 1 of the adhesive sheet 100.

  FIG. 1B is a schematic longitudinal sectional view showing another embodiment of the adhesive sheet according to the present invention. The adhesive sheet 110 shown in (b) has a structure in which a cover film 3 is further provided on the side surface opposite to the base film 2 of the film adhesive 1 provided on the base film 2.

  Examples of the cover film 3 include a PET film, a PE film, and an OPP film.

  The film adhesive of the present invention may be used by itself, but as one embodiment, as a dicing / die bonding integrated adhesive sheet in which the film adhesive of the present invention is laminated on a conventionally known dicing tape. It can also be used. In this case, the efficiency of the operation can be improved in that the laminating process on the wafer is performed only once.

  Examples of the dicing tape include plastic films such as a polytetrafluoroethylene film, a polyethylene terephthalate film, a polyethylene film, a polypropylene film, a polymethylpentene film, and a polyimide film. In addition, the dicing tape may be subjected to surface treatment such as primer coating, UV treatment, corona discharge treatment, polishing treatment, and etching treatment as necessary.

  Further, the dicing tape preferably has adhesiveness, and the above-mentioned plastic film provided with adhesiveness may be used, or an adhesive layer may be provided on one side of the above-mentioned plastic film.

Examples of such a dicing / die bonding integrated adhesive sheet include those having the configuration shown in FIGS. 1C and 1D. The adhesive sheet 120 shown in (c) uses a dicing tape in which an adhesive layer 6 is provided on a substrate film 7 that can ensure elongation when a tensile tension is applied as a supporting substrate, and the adhesive layer of the dicing tape. 6 has a structure in which a film adhesive 1 is provided.
As for the adhesive sheet 130 shown to (d), the base film 2 is provided in the surface of the film adhesive 1 of the adhesive sheet shown to (c).

Examples of the base film 7 include the above-described plastic film described for the dicing tape.
Examples of the pressure-sensitive adhesive layer 6 include a resin composition containing a liquid component and a high molecular weight component and having an appropriate tack strength. The dicing tape can be formed by applying the adhesive layer 6 on the base film 7 and drying, or by bonding the adhesive layer 6 applied to the base film such as a PET film and drying to the base film 7. is there. The tack strength is set to a desired value, for example, by adjusting the ratio of the liquid component and the Tg of the high molecular weight component.

  When the dicing / die bonding integrated adhesive sheet is used in the manufacture of a semiconductor device, it must have an adhesive force that prevents the semiconductor elements from scattering during dicing, and can be easily peeled off from the dicing tape during subsequent pick-up.

  Such characteristics can be obtained by adjusting the tack strength of the pressure-sensitive adhesive layer as described above, and changing the tack strength by photoreaction, etc., but if the tackiness of the film adhesive is too high, picking up becomes difficult. Sometimes. Therefore, it is preferable to appropriately adjust the tack strength of the film adhesive of the present invention. As the method, for example, when the flow of the film adhesive at room temperature (25 ° C.) is increased, the adhesive strength and tack strength tend to increase, and when the flow is decreased, the adhesive strength and tack strength tend to decrease. You can use something.

  For example, when increasing the flow, a method such as increasing the content of a compound that functions as a plasticizer can be used. In the case of reducing the flow, for example, a method of reducing the content of a compound that functions as a plasticizer can be mentioned. Examples of the plasticizer include monofunctional acrylic monomers, monofunctional epoxy resins, liquid epoxy resins, and acrylic resins.

  As a method of laminating the film-like adhesive of the present invention on the dicing tape, a varnish of the adhesive composition described above was applied to the entire surface and dried, or in addition to a method of partially coating by printing, it was prepared in advance. A method of laminating the film adhesive of the present invention on a dicing tape by pressing or hot roll laminating is mentioned. In the present embodiment, a hot roll laminating method is preferable because it can be continuously manufactured and is efficient.

  The film thickness of the dicing tape is not particularly limited, and can be appropriately determined based on the knowledge of those skilled in the art depending on the film thickness of the film adhesive and the application of the dicing / die bonding integrated adhesive sheet. When the thickness of the dicing tape is less than 60 μm, the handleability is poor, and the dicing tape tends to be broken by the expansion in the process of peeling the chips diced by dicing from the dicing tape. On the other hand, 180 μm or less is desirable from the viewpoint of economy and good handleability. From the above viewpoint, the film thickness of the dicing tape is preferably 60 to 180 μm.

<Semiconductor device obtained using the film adhesive or adhesive sheet of the present invention>
The film adhesive and adhesive sheet of the present invention are preferably used for the production of semiconductor devices. More preferably, a step of bonding an adhesive sheet and a dicing tape or a dicing die bonding integrated adhesive sheet to a wafer, a step of obtaining a chip with an adhesive by cutting with a rotary blade, laser or stretching, a chip with the adhesive A semiconductor device including a die-bonding step of filling a semiconductor element connected by a wire or a substrate having a step, filling the unevenness due to the wire or the step and embedding in an adhesive, and a step of sealing with a sealing material Used. Note that the wafer may be diced and thinned by grinding to obtain a fragmented chip, and then bonded to the adhesive sheet.
In the manufacture of the semiconductor device of the present invention, it is preferable that the thermal history in the wire bonding step, for example, is 150 ° C./1 hour or less between the die bonding step and the sealing step. The bonding is preferably performed at 0 ° C to 90 ° C.

  “Thermal history is 150 ° C./1 hour or less” indicates that the heat treatment temperature does not exceed 150 ° C. and the heat treatment time is 1 hour or less between the die bonding step and the sealing step. For example, even if it is less than 150 ° C., it may not be preferable to exceed 1 hour.

  In this invention, it is preferable that it is 0.01-0.50 MPa, and, as for the load in the pressure bonding conditions of a die-bonding process, it is more preferable that it is 0.02-0.2 MPa. If the load is less than 0.01 MPa, there are excessive unfilled parts, and the chip moves due to the pressure at the time of sealing, which may deteriorate the quality of the semiconductor device. On the other hand, when the pressure bonding load exceeds 0.50 MPa, the chip tends to be damaged. Further, when the chip with film adhesive is pressure-bonded to a substrate having irregularities, it is desirable to heat the adherend, the chip with film adhesive, or both.

The heating temperature in the pressure bonding condition is preferably 80 to 180 ° C, and more preferably 80 to 160 ° C. If the temperature is less than 80 ° C., the embedding property of the unevenness tends to be lowered, and if it exceeds 180 ° C., the substrate tends to be deformed and warpage tends to increase. Examples of the heating method include a method of bringing the substrate into contact with a heated hot plate, irradiating infrared rays or microwaves, and blowing hot air.
The crimping time is preferably 0.5 to 2.0 seconds.

  Examples of the wafer include single crystal silicon, polycrystalline silicon, various ceramics, and compound semiconductors such as gallium arsenide.

  When the film adhesive of the present invention is used alone, the film adhesive is bonded to the wafer, and then a dicing tape is bonded to the film adhesive surface.

  The temperature at which the film adhesive is affixed to the wafer, that is, the laminating temperature, is usually 0 to 90 ° C, preferably 15 to 80 ° C, and more preferably 40 to 80 ° C. When the temperature exceeds 90 ° C., a change in thickness due to excessive melting of the film adhesive may become remarkable. The dicing tape or the dicing / die bonding integrated adhesive sheet is also preferably applied at the above temperature.

  The sealing conditions in the sealing step are preferably 170 to 180 ° C./6.0 to 10.0 MPa / 90 seconds. You may implement the heat processing process for hardening a sealing material further after a sealing process.

  As a use of the film adhesive of the present invention, a semiconductor device provided with a film adhesive will be specifically described with reference to the drawings. In recent years, semiconductor devices having various structures have been proposed, and the use of the film adhesive of the present invention is not limited to the semiconductor devices having the structure described below.

FIG. 2A is a schematic longitudinal sectional view showing an embodiment of the semiconductor device of the present invention.
In the semiconductor device 200 shown in (a), the first-stage semiconductor element 9a is bonded to the semiconductor element mounting support member 10 on which the terminals 13 are formed by the cured product 1a (adhesive member) of the film adhesive of the present invention. The second-stage semiconductor element 9b is further bonded onto the first-stage semiconductor element 9a by the cured product 1a (adhesive member) of the film adhesive of the present invention. Connection terminals (not shown) of the first-stage semiconductor element 9 a and the second-stage semiconductor element 9 b are electrically connected to external connection terminals via wires 11 and are sealed with a sealing material 12. Thus, the film adhesive of the present invention can be suitably used for a semiconductor device having a structure in which a plurality of semiconductor elements are stacked.

FIG. 2B is a schematic longitudinal sectional view showing another embodiment of the semiconductor device of the present invention.
In the semiconductor device 210 shown in (b), the semiconductor element 9 is bonded to the semiconductor element mounting support member 10 by the cured product 1a (adhesive member) of the film adhesive of the present invention, and a connection terminal (not shown) of the semiconductor element 9 is shown. Is electrically connected to an external connection terminal (not shown) via a wire 11 and sealed with a sealing material 12.

  In the semiconductor device (semiconductor package) shown in FIG. 2, for example, the above-described chip with film adhesive is bonded to the semiconductor element mounting support member or the semiconductor element by thermocompression bonding, and then the wire bonding process and the sealing material are used. It can be obtained through a process such as a sealing process.

  By manufacturing a semiconductor device using the film-like adhesive or adhesive sheet of the present invention, it is possible to embed irregularities derived from voids or substrate steps under the wire during crimping, and even if voids remain after crimping, the film Since the adhesive has a low elastic modulus at 180 ° C. after heating at 150 ° C. for 1 hour, voids disappear during sealing.

  Note that the film adhesive provided by the present invention is not limited to wire embedding applications, and is also used in applications for bonding semiconductor elements to metal substrates such as substrates having irregularities due to wiring, lead frames, etc. Is possible.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.
(Examples 1-5 and Comparative Examples 1-2)
The product name and composition ratio (unit: part by mass) shown in Table 1 or Table 2 (a) epoxy resin and phenol resin as thermosetting resin, (c) cyclohexanone was added to the composition consisting of inorganic filler and mixed with stirring. . To this, (b) acrylic rubber as a high molecular weight component, which is similarly shown in Table 1 or Table 2, is added and stirred, and further, a coupling agent similarly shown in Table 1 or Table 2 and (d) a curing accelerator are added. In addition, varnish was obtained by stirring until each component was uniform.

  In addition, the symbol of each component in Table 1 and Table 2 means the following.

(Epoxy resin)
R710: (trade name, manufactured by Printec Co., Ltd., bisphenol type epoxy resin, epoxy equivalent 170, liquid at room temperature, weight molecular weight of about 340). In addition, it is an epoxy resin represented by the general formula (2).
YDCN-700-10: (trade name, manufactured by Tohto Kasei Co., Ltd., cresol novolac type epoxy resin, epoxy equivalent 210, softening point 75 to 85 ° C.).

(Phenolic resin)
Millex XLC-LL: (trade name, manufactured by Mitsui Chemicals, Inc., phenol resin, hydroxyl group equivalent 175, softening point 77 ° C., water absorption 1 mass%, heating mass reduction rate 4 mass%). In the above general formula (3), R ₅ is a hydrogen atom and is a phenol resin in which n = 3.
HE200C-10: (trade name, manufactured by Air Water Co., Ltd., phenol resin, hydroxyl group equivalent 200, softening point 65-76 ° C., water absorption 1 mass%, heating mass reduction rate 4 mass%). In addition, it is a phenol resin represented by the said General formula (4).
HE910-10: (trade name, manufactured by Air Water Co., Ltd., phenol resin, hydroxyl group equivalent 101, softening point 83 ° C., water absorption 1 mass%, heating mass reduction rate 3 mass%). The phenol resin represented by the following general formula (5). In general formula (5), m and n are 0-20, respectively. Preferably, m and n are 1-5.

(Inorganic filler)
SC2050-HLG: (trade name, manufactured by Admatechs Co., Ltd., silica filler dispersion, average particle size 0.50 μm).
SC1030-HJA: (trade name, manufactured by Admatechs Co., Ltd., silica filler dispersion, average particle size of 0.25 μm).
Aerosil R972: (trade name, manufactured by Nippon Aerosil Co., Ltd., silica, average particle size 0.016 μm).

(High molecular weight component)
Acrylic rubber HTR-860P-30B-CHN: (sample name, manufactured by Teikoku Chemical Industry Co., Ltd., weight average molecular weight 230,000, glycidyl functional group monomer ratio 8%, Tg: −7 ° C.).
Acrylic rubber HTR-860P: (sample name, manufactured by Teikoku Chemical Industry Co., Ltd., weight average molecular weight 800,000, glycidyl functional group monomer ratio 3%, Tg: −7 ° C.).

(Coupling agent)
NUC A-1160: (trade name, manufactured by GE Toshiba Corporation, γ-ureidopropyltriethoxysilane).
NUC A-189: (trade name, manufactured by GE Toshiba Corporation, γ-mercaptopropyltrimethoxysilane).

(Curing accelerator)
Cureazole 2PZ-CN: (trade name, manufactured by Shikoku Kasei Kogyo Co., Ltd., 1-cyanoethyl-2-phenylimidazole).

  Next, the obtained varnish was filtered through a 100-mesh filter and vacuum degassed. The varnish after vacuum defoaming was applied onto a polyethylene terephthalate (PET) film having a thickness of 38 μm as a base film. The applied varnish was heat-dried in two stages of 90 ° C. for 5 minutes, followed by 140 ° C. for 5 minutes. Thus, an adhesive sheet provided with a film adhesive having a thickness of 60 μm in a B-stage state on a PET film as a base film was obtained.

<Evaluation of various physical properties>
About the film-like adhesive of the obtained adhesive sheet, elongation at 25 ° C./breaking strength, splitting property with ultra-thin wafer attached product, shear viscosity at 80 ° C., wire embedding, 150 ° C./1 hour Measurement of tensile modulus, mold embedding property, adhesion strength after heat treatment, and evaluation of reflow resistance were performed.

[Measurement of elongation and breaking strength]
The elongation rate and breaking strength of the film adhesive were evaluated by the following methods.
The adhesive sheet having a thickness of 60 μm was cut into a strip shape having a width of 10 mm and a length of 50 mm, and the cover film and the base film were peeled off. This was set in a tensile pressure bonding tester (product name: SL-2001, manufactured by Imada Seisakusho Co., Ltd.) so that the distance between chucks was 20 mm, and a tensile test was performed at 25 ° C. and a tensile speed of 50 mm / min. . The tensile strength when the film adhesive broke was defined as the breaking strength. The elongation was calculated by dividing the amount of elongation of the film adhesive until it broke by the distance between chucks of 20 mm. Four samples were measured and the average value was recorded as the measured value.

[Evaluation of severability with ultra-thin wafers]
The severability in an ultra-thin wafer pasted product was evaluated by the following method.
A semiconductor wafer (12 inches) having a thickness of 625 μm was half cut into a 10 mm square size, a BG tape was attached to the wafer surface, and then the wafer back surface was polished to reduce the thickness to 50 μm. The film-like adhesive (thickness 60 μm) of the adhesive sheet obtained above was pasted at 70 ° C. on the back surface of this wafer. The wafer-bonded product was treated with an expanding cutting device (product name: DDS2300, manufactured by Disco Corporation) under the conditions of 0 ° C., a pushing speed of 200 mm / second, and a pushing amount of 6 mm, to cut the film adhesive. Three wafers were evaluated, and when the film-like adhesive was divided without any problem, “◯” was given as good dividing property, and “×” was given when the portion that was not well divided exceeded 5%.

[Shear viscosity measurement]
The shear viscosity at 80 ° C. of the film adhesive was evaluated by the following method.
After peeling and removing the base film from the three adhesive sheets, three film adhesives were bonded at 70 ° C. to obtain a laminate having a thickness of 180 μm. Next, the laminate was punched into a 10 mm square in the thickness direction to obtain a square laminate having a 10 mm square and a thickness of 180 μm. A circular aluminum plate jig having a diameter of 8 mm was set in a dynamic viscoelastic device ARES (manufactured by Rheometric Scientific), and a laminate of a film-like adhesive punched out was set here. Then, it measured, raising temperature at a temperature increase rate of 5 degree-C / min, giving a distortion of 5% at 35 degreeC, and recorded the value of the shear viscosity of 80 degreeC as a measured value.

[Evaluation of wire embedding]
The wire embedding property of the film adhesive was evaluated by the following method.
The film-like adhesive (thickness 60 μm) of the adhesive sheet obtained above was attached to a semiconductor wafer (8 inches) having a thickness of 50 μm at 70 ° C. Next, they were diced into 7.5 mm squares to obtain chips.

The sample chip adhesive shown in FIG. 3B was obtained by pressing the separated chip adhesive onto the evaluation substrate 300 shown in FIG. 3A under the conditions of 120 ° C., 0.10 MPa, and 1 second. . In addition, in the evaluation substrate 300 shown in (a), the first-stage semiconductor element 9a is formed by a general conventional film adhesive 1b for semiconductor (FH-900-20 manufactured by Hitachi Chemical Co., Ltd.). The semiconductor element mounting support member 10 is bonded. A wire 11 is connected to the semiconductor element 9a.
A sample 310 shown in (b) is obtained by pressure-bonding a chip (second-stage semiconductor element 9b + film adhesive 1 (before curing)) to an evaluation substrate 300.

  Regarding the obtained sample, the lower part of all the wires was observed by SEM as shown in FIG. If the wire is 90% or more of the total number of wires (total of 64) and the lower part is well filled with a film adhesive as shown in (b), the wire embedding property is good and “○” is given. In the case where the number of well-filled wires is less than 90%, “x” is given. An example of not being filled well is shown in (a).

[Measurement of tensile modulus after heating at 150 ° C./1 hour]
The tensile modulus of the film adhesive after heating at 150 ° C./1 hour was evaluated by the following method.
After peeling off and removing the base film from the two adhesive sheets, two film adhesives were bonded at 70 ° C. to obtain a laminate having a thickness of 120 μm. Next, the laminate was cut into a thickness of 4 mm and a length of 30 mm in the thickness direction, and heated in an oven at 150 ° C. for 1 hour. The obtained sample was set in a dynamic viscoelastic device (product name: Rheogel-E4000, manufactured by UMB Co., Ltd.), subjected to a tensile load, measured at a frequency of 10 Hz, and a temperature rising rate of 3 ° C./min, 180 ° C. The measured value was recorded as the tensile elastic modulus after heating at 150 ° C./1 hour.

[Evaluation of mold embedding]
The mold embedding property of the film adhesive was evaluated by the following method.
Similar to the sample obtained in [Evaluation of wire embedding], a film adhesive 60 μm of the adhesive sheet obtained above was attached to a semiconductor wafer having a thickness of 50 μm at 70 ° C. Next, they were diced into 7.5 mm squares to obtain chips. A chip 310 (FIG. 3B) was obtained by pressure-bonding the separated chip adhesive to the evaluation substrate 300 shown in FIG. 3A under the conditions of 120 ° C., 0.10 MPa, and 1 second. .

  The obtained sample was heated at 125 ° C. for 60 minutes, and a thermal history equivalent to wire bonding (150 ° C., 1 hour) was given to the sample using a hot plate. Subsequently, resin sealing was performed under conditions of 175 ° C./6.7 MPa / 90 seconds using a mold sealing material (Hitachi Chemical Industry Co., Ltd., trade name “CEL-9750ZHF10), and conditions of 175 ° C. for 5 hours. Then, the sealing material was cured to obtain a package.

A part of the obtained package was analyzed with an ultrasonic imaging apparatus SAT (manufactured by Hitachi Construction Machinery, product number FS200II, probe: 120 MHz) to confirm the embeddability after sealing. The evaluation criteria for embeddability are as follows.
○: Void ratio is less than 15%.
X: The void ratio is 15% or more.

[Measurement of adhesive strength]
The die shear strength (adhesion strength) of the film adhesive was measured by the following method.
First, the film adhesive 60 μm of the adhesive sheet obtained above was attached to a semiconductor wafer having a thickness of 400 μm at 70 ° C. Next, they were diced to 5.0 mm square to obtain chips. A sample was obtained by thermocompression bonding at 120 ° C., 0.1 MPa for 5 seconds on a 625 μm-thick semiconductor chip whose surface was treated with silicon nitride on the film adhesive side of the singulated chip. Thereafter, the adhesive of the obtained sample was cured by step cure in order of 125 ° C. for 1 hour, 150 ° C. for 1 hour, and 170 ° C. for 3 hours. Further, the sample after curing of the adhesive was allowed to stand for 168 hours under the conditions of 85 ° C. and 60 RH%. Thereafter, the sample was allowed to stand for 30 minutes under conditions of 25 ° C. and 50% RH, and the die shear strength was measured at 250 ° C., and this was taken as the adhesive strength.

[Evaluation of reflow resistance]
The reflow resistance of the film adhesive was evaluated by the following method.
Similar to the sample obtained in [Evaluation of wire embedding], a film adhesive 60 μm of the adhesive sheet obtained above was attached to a semiconductor wafer having a thickness of 50 μm at 70 ° C. Next, they were diced into 7.5 mm squares to obtain chips. A chip 310 (FIG. 3B) was obtained by pressure-bonding the chip adhesive to the evaluation substrate 300 shown in FIG. 3A under the conditions of 120 ° C., 0.10 MPa, and 1 second. .

  The obtained sample was heated at 125 ° C. for 60 minutes, and a thermal history equivalent to wire bonding (150 ° C., 1 hour) was given to the sample using a hot plate. Next, resin sealing was performed using a mold sealing material (trade name “CEL-9750ZHF10” manufactured by Hitachi Chemical Co., Ltd.) under the conditions of 175 ° C./6.7 MPa / 90 seconds, and 175 ° C. for 5 hours. The package was obtained by curing the sealing material under the following conditions.

  Twenty-four packages described above were prepared, and these were exposed to the environment (level 3, 30 ° C., 60 RH%, 192 hours) determined by JEDEC to absorb moisture. Subsequently, the package after moisture absorption was passed through an IR reflow furnace (260 ° C., maximum temperature 265 ° C.) three times. The case where none of the breakage of the package, the change in thickness, the peeling at the interface between the film adhesive and the semiconductor element was observed was evaluated as “◯”, and the case where even one was observed was evaluated as “X”. The results are shown in Table 3.

  As is clear from the results shown in Table 3, the adhesive sheets of Examples 1 and 2 are superior in wire embedding properties to the adhesive sheets of Comparative Examples 1 and 2, and heat at 150 ° C./1 hour or less. Even after the history, it was confirmed that the gap disappeared by sealing under a sealing condition of 175 ° C./6.7 MPa / 90 seconds, and the reflow resistance was excellent.

  According to the present invention, even a semiconductor element made of an ultra-thin chip can be mounted with a wire embedded structure without causing a gap on the bonding surface, and has a film shape excellent in heat resistance, moisture resistance and reflow resistance. An adhesive, an adhesive sheet, and a semiconductor device manufactured using the film adhesive can be provided.

100, 110 Adhesive sheet 120, 130 Dicing / die bonding integrated adhesive sheet 200, 210 Semiconductor device 300 Evaluation substrate 310 Sample 1 Film adhesive 1a of the present invention Cured product 1b of the film adhesive of the present invention Conventional film Cured product 2 of adhesive adhesive Base material film 3 Cover film 6 Adhesive layer 7 Base material films 9, 9a, 9b Semiconductor element 10 Supporting member 11 for mounting semiconductor element Wire 12 Sealing material 13 Terminal

Claims (7)

(A) A thermosetting resin having a softening point of 100 ° C. or less or becoming liquid at 100 ° C. or less and containing 20% by mass or more of an epoxy resin having an epoxy equivalent of 140 or more or a phenol resin having a hydroxyl group equivalent of 140 or more. Parts by mass,
(B) a first high molecular weight component having a crosslinkable functional group in a monomer ratio of 5 to 15%, a weight average molecular weight of 100,000 to 400,000 and a Tg of -50 to 50 ° C;
Alternatively, the first high molecular weight component and the second high molecular weight component having a crosslinkable functional group in a monomer ratio of 1 to 7%, a weight average molecular weight of 500,000 to 800,000, and Tg of −50 to 50 ° C. 30 to 100 parts by mass of any one of the mixed high molecular weight components wherein the first high molecular weight component is 50% by mass or more,
(C) including a first filler having an average particle diameter of 0.4 μm or more and a second filler having an average particle diameter of less than 0.4 μm, and particles having a particle diameter of 0.4 μm or more occupy 30% by volume or more. 10-60 parts by mass of inorganic filler, and (d) 0-0.07 parts by mass of curing accelerator ,
The (a) thermosetting resin contains a bifunctional epoxy resin in which a softening point is 100 ° C. or lower or becomes liquid at 100 ° C. or lower, and an epoxy equivalent is 140 or more, which is a modified bisphenol E type epoxy resin.
Film adhesive. The shear viscosity at 80 ° C. before curing is 200-11000 Pa · s or less,
The film according to claim 1, wherein the tensile modulus at 180 ° C after heating at 150 ° C for 1 hour is 20 MPa or less, the elongation at break at 25 ° C is 350% or less, and the breaking strength is 6.0 MPa or less. Adhesive.   The film adhesive according to claim 1 or 2, wherein the adhesive force of the silicon nitride formed on the semiconductor chip surface to the thin film is 1.0 MPa or more after the film adhesive is cured.   The adhesive sheet which has a base film and the film adhesive as described in any one of Claims 1-3 laminated | stacked on the single side | surface of this base film.   A semiconductor chip is laminated on a substrate having a step or another semiconductor chip bonded by wire via the film adhesive according to any one of claims 1 to 3, and the unevenness due to the step or the wire is a film. A semiconductor device embedded in an adhesive, and at least a semiconductor chip and a wire are sealed with a sealing material. The laminate which bonds the single side | surface of the film adhesive as described in any one of Claims 1-3, or the exposed surface of the film adhesive in the adhesive sheet of Claim 4, and the bottom face of a semiconductor wafer or a semiconductor chip. Process,
A cutting step for obtaining a semiconductor chip with a film adhesive by cutting or stretching,
A die bonding step in which the semiconductor chip with the film adhesive is pressure-bonded to the upper surface of the substrate having a step or the upper surface of another semiconductor chip wire-bonded on the substrate, and the unevenness due to the step or the wire is embedded in the film adhesive. When,
A method of manufacturing a semiconductor device including a step of sealing with a sealing material. In the die bonding step, the pressure bonding conditions are 80 to 180 ° C., 0.01 to 0.50 MPa, 0.5 to 2.0 seconds,
The method for manufacturing a semiconductor device according to claim 6, wherein the sealing condition is 170 to 180 ° C./6.0 to 10.0 MPa / 90 seconds.