JP2008133456A - Adhesive composition for semiconductor, adhesive sheet for semiconductor, and semiconductor apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive composition for semiconductors having low melt viscosity and good adhesion strength and making it possible to improve the connection reliability of a semiconductor apparatus, an adhesive sheet for semiconductors, and a semiconductor apparatus obtained using them. <P>SOLUTION: This adhesive composition for semiconductors is an adhesive composition containing a thermoset resin and a filler, wherein the blending ratio of the filler to the thermoset resin ranges from 30 to 100 parts by mass to 100 parts by mass of the thermoset resin and the thermoset resin comprises (A) a high-molecular-weight component having a crosslinkable functional group, a weight average molecular weight ranging from 100,000 to 600,000, and a glass transition temperature ranging from -50 to 50°C, (B) a polyfunctional epoxy resin with a molecular weight of 500 or more, and (C) a phenol resin at a mass ratio of (A):(B):(C)=15 to 40:5 to 15:35 to 55. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an adhesive composition for a semiconductor used for manufacturing a semiconductor device, an adhesive sheet for a semiconductor, and a semiconductor device manufactured using them.

  Reliability is one of the most important characteristics as a mounting board on which various electronic components such as semiconductor elements are mounted. Among them, the connection reliability against thermal fatigue is a very important item because it is directly related to the reliability of the equipment using the mounting substrate. As a cause of lowering the connection reliability, there is a thermal stress generated by using various materials having different thermal expansion coefficients. Specifically, the thermal expansion coefficient of the semiconductor element is as small as about 4 ppm / ° C., whereas the thermal expansion coefficient of the wiring board on which the electronic component is mounted is as large as 15 ppm / ° C. or more. The thermal strain is generated by thermal shock, and thermal stress may be generated by the thermal strain.

  In recent years, a stacked MCP (Multi Chip Package) in which chips are stacked in multiple stages has become widespread. In such a package, mounting a chip without generating a gap on the bonding surface of the chip is one of the problems for improving connection reliability. In particular, when a chip is stacked on a substrate having wiring or the like, the embedding property of sufficiently embedding unevenness on the surface of the substrate is important for ensuring the connection reliability of the package. On the other hand, along with recent miniaturization and thinning of semiconductor devices, thinning of substrates and wafers has progressed, and warping of elements is likely to occur due to the above-described thermal stress. Therefore, mounting at lower temperature and lower load is strongly demanded.

  However, since it is difficult to sufficiently embed the above unevenness only by low temperature and low load crimp mounting, conventionally, the chip with the adhesive sheet is fixed by thermocompression bonding on the substrate, and the heat and pressure in the package sealing process The method of embedding irregularities was the mainstream. As an adhesive sheet used in such a method, for example, an adhesive film including an epoxy resin, a phenol resin, and an acrylic copolymer as described in Patent Document 1 is known.

JP 2002-220576 A

  By the way, the following problems exist in the above prior art. In other words, stacked MCPs are used as memory packages for mobile phones and mobile audio devices, but recently, with the increasing functionality of mobile phones and the like, the density and integration of packages has been further increased. Due to the progress, it is necessary to further increase the number of chips and reduce the thickness of the package. However, such multi-stage chip increases the number of processes that require heat treatment such as crimping and wire bonding processes, and promotes thermosetting of the adhesive before the sealing process. As a result, the embedding property such as unevenness derived from the substrate wiring is lowered, and a gap remains even after the sealing process, and sufficient connection reliability may not be obtained.

  On the other hand, due to diversification of chip sizes, there are also packages on which large-sized chips are mounted for the purpose of high package integration. However, when a large chip is mounted, it is difficult to completely eliminate the void inside the chip by the sealing process, and the void remaining at the end of the chip may reduce the connection reliability of the package.

  In addition, the method of raising the uneven | corrugated followable | trackability of an adhesive agent and reducing a space | gap by making the melt viscosity of an adhesive agent small can be considered. However, according to the study by the present inventors, the method of simply reducing the molecular weight of the high molecular weight component in order to reduce the melt viscosity of the conventional adhesive film also reduces the adhesive strength, which is important for the connection reliability of the package. It has been found that.

  The present invention has been made in view of the above-described problems of the prior art, and has a low melt viscosity and excellent adhesive strength, and can improve the connection reliability of a semiconductor device and a semiconductor. It is an object to provide an adhesive sheet for use, and a semiconductor device obtained using these.

  In order to solve the above problems, the present invention is an adhesive composition containing a thermosetting resin and a filler, and the blending ratio of the filler is 30 to 100 parts by mass with respect to 100 parts by mass of the thermosetting resin. And (A) a high molecular weight component having a crosslinkable functional group, a weight average molecular weight of 100,000 to 600,000 and a glass transition temperature of −50 ° C. to 50 ° C., (B) For semiconductors containing a polyfunctional epoxy resin having a molecular weight of 500 or more and (C) phenol resin in a mass ratio of (A) :( B) :( C) = 15-40: 5-15: 35-55 An adhesive composition is provided.

  The adhesive composition for a semiconductor of the present invention contains the thermosetting resin and the filler in the specific ratio, and contains the components (A) to (C) as the thermosetting resin in the specific ratio. By doing so, excellent adhesive strength can be expressed while having a low melt viscosity. According to such an adhesive composition for a semiconductor of the present invention, it is possible to sufficiently embed unevenness of a support member such as a wiring board or a semiconductor chip with good fluidity before curing, and support of an organic substrate or the like after curing. Since high adhesive strength can be exhibited with respect to a member, a silicon chip, etc., it becomes possible to improve the connection reliability of the mounting substrate.

  Moreover, according to the adhesive composition for semiconductors of this invention, the unevenness | corrugation of support members, such as a board | substrate, or a semiconductor chip can fully be embedded only by crimping mounting at low temperature (especially 100-120 degrees C or less). Furthermore, according to the adhesive composition for a semiconductor of the present invention, it is possible to obtain excellent heat resistance and moisture resistance after curing, so that the reflow resistance of the semiconductor device and the connection reliability under high temperature and high humidity can be improved. It becomes possible to plan.

  It is preferable that the adhesive composition for semiconductors of this invention contains 2 or more types of fillers from which an average particle diameter differs as said filler. In this case, it is possible to sufficiently retain the characteristics of having a low melt viscosity and an excellent adhesive strength after curing.

  Moreover, the adhesive composition for semiconductors of this invention is the 1st filler in which the average particle diameter exists in the range of 0.1-1.0 micrometer, and a primary particle diameter from a viewpoint which acquires said effect more reliably. It is preferable that the 2nd filler which exists in the range whose average particle diameter is 0.005-0.03 micrometer is included.

  Moreover, it is preferable that the adhesive composition for semiconductors of this invention further contains the thermopolymerizable compound which becomes high molecular weight by a polymerization reaction at 150 degreeC or more. Thereby, since melt viscosity can be lowered | hung, the fluidity | liquidity of a film can be improved. Moreover, the adhesive force to the organic substrate is also improved.

  The adhesive composition for a semiconductor of the present invention preferably has a melt viscosity at 80 ° C. before curing of 700 Pa · s to 5000 Pa · s.

  Moreover, it is preferable that the adhesive strength for semiconductors of this invention is 3.0 MPa or more of the adhesive strength after hardening with respect to an organic substrate.

  Moreover, this invention provides the adhesive sheet for semiconductors formed by shape | molding the adhesive composition for semiconductors of the said invention in the shape of a film.

  The present invention also includes a semiconductor element, a support member for mounting the semiconductor element, and an adhesive member that is provided between the semiconductor element and the support member and adheres the semiconductor element and the support member. Provided is a semiconductor device which is a cured product of the adhesive composition for a semiconductor of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, it is low melt viscosity, is excellent in adhesive strength, and can improve the connection reliability of a semiconductor device, the adhesive composition for semiconductors, the adhesive sheet for semiconductors, and the semiconductor obtained using these An apparatus can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as the case may be. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted. Note that the dimensional ratio in each 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 sheet for semiconductor of the present invention. The semiconductor adhesive sheet 1 shown in FIG. 1 includes a support 20 and an adhesive layer 10 provided on the support 20. The adhesive layer 10 is made of the adhesive composition for semiconductors of the present invention. In the adhesive sheet for semiconductor of the present invention, the opposite surface of the support 20 on the adhesive layer 10 may be covered with a protective film.

  First, the semiconductor adhesive composition of the present invention will be described.

  The adhesive composition for semiconductor of the present invention is an adhesive composition containing a thermosetting resin and a filler, and the blending ratio of the filler is 30 to 100 parts by mass with respect to 100 parts by mass of the thermosetting resin. And (A) a high molecular weight component having a crosslinkable functional group, a weight average molecular weight of 100,000 to 600,000 and a glass transition temperature of −50 ° C. to 50 ° C. ) A polyfunctional epoxy resin having a molecular weight of 500 or more and (C) a phenol resin in a mass ratio of (A) :( B) :( C) = 15-40: 5-15: 35-55 It is characterized by.

  Examples of the high molecular weight component (A) include polyimide resins having crosslinkable functional groups such as epoxy groups, alcoholic or phenolic hydroxyl groups, and carboxyl groups, (meth) acrylic resins, urethane resins, polyphenylene ether resins, and polyetherimide resins. , Phenoxy resin, modified polyphenylene ether resin, and the like. However, it is not limited to these.

  As the high molecular weight component (A) used in the present invention, an epoxy group-containing compound (meta) having a weight average molecular weight of 100,000 to 600,000 obtained by polymerizing a monomer containing a functional monomer such as glycidyl acrylate or glycidyl methacrylate is used. ) Acrylic copolymer is preferred. Furthermore, as the (meth) acrylic copolymer, 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, a copolymer such as ethyl acrylate and acrylonitrile, or the like.

  The glass transition temperature Tg of the high molecular weight component (A) needs to be in the range of −50 ° C. to 50 ° C. If the Tg of the high molecular weight component exceeds 50 ° C., the flexibility of the adhesive sheet for semiconductor becomes too low, and sufficient adhesion when laminated on the wafer tends to be difficult to obtain. On the other hand, if the Tg of the high molecular weight component is less than −50 ° C., the flexibility of the adhesive sheet for semiconductor becomes too high, so that the adhesive sheet is difficult to cut during dicing of the semiconductor wafer, and the dicing property deteriorates due to the generation of burrs. There is a case.

  Moreover, although the weight average molecular weight of a high molecular weight component (A) needs to exist in the range of 100,000-600,000, Preferably it is 200,000 or more and 500,000 or less. When the weight average molecular weight of the high molecular weight component is less than 200,000, the film moldability of the adhesive resin composition may be deteriorated, or the adhesive force and heat resistance of the adhesive sheet may be lowered, and the weight average molecular weight is 50. If it exceeds 10,000, the fluidity of the uncured adhesive sheet may decrease.

  In the present invention, the weight average molecular weight means a value measured by gel permeation chromatography (GPC) and converted using a standard polystyrene calibration curve.

  In addition, the high molecular weight component (A) used in the present invention is such that the adhesive sheet is easily cut at the time of semiconductor wafer dicing and resin waste is less likely to be generated, the fluidity of the uncured adhesive sheet is increased, and From the viewpoint of high adhesive strength and heat resistance, those having a Tg of −20 ° C. to 40 ° C. and a weight average molecular weight of 100,000 to 600,000 are preferable, and the Tg is −10 ° C. to 40 ° C. Those having a molecular weight of 200,000 to 500,000 are more preferred.

  The polyfunctional epoxy resin (B) having a molecular weight of 500 or more is not particularly limited as long as it is cured and has an adhesive action. For example, a novolac epoxy resin such as a phenol novolac epoxy resin or a cresol novolac epoxy resin Can be used. Moreover, what is generally known, such as a polyfunctional epoxy resin, a glycidyl amine type epoxy resin, a heterocyclic ring-containing epoxy resin, or an alicyclic epoxy resin, can be applied.

  The adhesive composition for semiconductor of the present invention preferably contains an epoxy resin represented by the following general formula (1) and having a molecular weight of 800 or more as the polyfunctional epoxy resin (B).

式（１）中、Ｒ^１は水素原子、ハロゲン原子、直鎖状、分岐状若しくは環状のアルキル基、アラルキル基、アルケニル基、水酸基、又は、アリール基を示し、ｌは１〜３の整数を示し、ｍは２〜４の整数を示す。

In the formula (1), R ¹ represents a hydrogen atom, a halogen atom, a linear, branched or cyclic alkyl group, an aralkyl group, an alkenyl group, a hydroxyl group, or an aryl group, and l represents an integer of 1 to 3. M represents an integer of 2 to 4.

  In addition, the polyfunctional epoxy resin represented by the general formula (1) and having a molecular weight of 800 or more has a water absorption of 2% by mass or less after being put into a constant temperature and humidity chamber at 85 ° C. and 85% RH for 48 hours. Those having a heating mass reduction rate (heating rate: 5 ° C./min, atmosphere: nitrogen) at 350 ° C. measured by a gravimetric analyzer (TGA) of less than 5% by mass can be preferably used. Examples of such polyfunctional epoxy resins include YDCN series manufactured by Toto Kasei Co., Ltd.

  The adhesive composition for a semiconductor of the present invention contains a polyfunctional epoxy resin having a molecular weight of 500 or more as an essential component. From the viewpoint of further improving the heat resistance of the cured product, the adhesive composition for a semiconductor is represented by the general formula (1) and has a molecular weight. It is especially preferable that the polyfunctional epoxy resin which is 800-3000 is contained.

  Moreover, in the adhesive composition for semiconductors of this invention, from a viewpoint of improving the flexibility of the film in a B-stage state, as an epoxy resin other than the polyfunctional epoxy resin (B) having a molecular weight of 500 or more, the molecular weight is less than 500. It is preferable that an epoxy resin is further contained, and it is more preferable that an epoxy resin having a molecular weight of 400 or less is further contained. As such an epoxy resin, a bifunctional epoxy resin such as bisphenol A type or bisphenol F type epoxy resin is preferably used.

  It is preferable that the adhesive composition for semiconductors of this invention contains the phenol resin represented by following General formula (2) as a phenol resin (C).

式（２）中、Ｒ^２は水素原子、ハロゲン原子、直鎖状、分岐状若しくは環状のアルキル基、アラルキル基、アルケニル基、水酸基、又は、アリール基を示し、ｑは１〜３の整数を示し、繰り返し単位の数を示すｐは１〜５０の範囲の整数を示す。

In the formula (2), R ² represents a hydrogen atom, a halogen atom, a linear, branched or cyclic alkyl group, an aralkyl group, an alkenyl group, a hydroxyl group, or an aryl group, and q is an integer of 1 to 3. P indicating the number of repeating units is an integer in the range of 1-50.

  In addition, the phenol resin represented by the general formula (2) has a water absorption rate of 2% by mass or less after being put into a constant temperature and humidity chamber of 85 ° C. and 85% RH for 48 hours, and is measured by a thermogravimetric analyzer (TGA). The measured heating mass reduction rate at 350 ° C. (temperature increase rate: 5 ° C./min, atmosphere: nitrogen) is preferably less than 5% by mass. Typical examples of such a phenol resin represented by the general formula (2) include the Mirex XLC-series and XL series manufactured by Mitsui Chemicals.

  The compounding ratio of the epoxy resin and the phenol resin in the adhesive composition for semiconductor of the present invention is such that the equivalent ratio of epoxy equivalent and hydroxyl equivalent is 0.70 / 0.30 to 0.30 / 0.70. It is preferable to set the value, more preferably 0.65 / 0.35 to 0.35 / 0.65, and 0.60 / 0.40 to 0.40 / 0.60. Is more preferable, and it is particularly preferable to set it to be 0.60 / 0.40 to 0.50 / 0.50. When the equivalent ratio of the epoxy equivalent and the hydroxyl equivalent is outside the above range, the curability of the adhesive sheet is inferior, or the viscosity of the uncured adhesive sheet is increased and the fluidity tends to be inferior.

  The semiconductor adhesive composition of the present invention contains a filler, thereby improving the dicing property of the adhesive sheet in the B-stage state, improving the handling property of the adhesive sheet, improving the thermal conductivity, and improving the melt viscosity. It is possible to adjust, impart thixotropic properties, and improve adhesion.

  The filler used in the present invention is preferably an inorganic filler. The inorganic filler is not particularly limited, and examples thereof include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, alumina, aluminum nitride, aluminum borate whisker, and boron nitride. Crystalline silica, amorphous silica, antimony oxide, and the like can be used. These can be used alone or in combination of two or more.

  Of the above inorganic fillers, alumina, aluminum nitride, boron nitride, crystalline silica, amorphous silica and the like are preferably used from the viewpoint of improving thermal conductivity. In terms of adjusting melt viscosity and imparting thixotropic properties, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, alumina, crystalline silica It is preferable to use amorphous silica or the like. From the viewpoint of improving dicing properties, it is preferable to use alumina or silica.

  The content of the filler is such that the dicing property of the adhesive sheet is improved, the storage elastic modulus after curing of the adhesive sheet is 20 to 1000 MPa at 170 ° C., and the wire bonding property is improved, and the thermosetting resin 100 mass. It is necessary that it is 30-100 mass parts with respect to a part, Furthermore, it is preferable that it is 35-100 mass parts.

  Further, if the filler content is too large, it tends to cause deterioration of film moldability, decrease in fluidity of an uncured adhesive sheet, excessive increase in storage elastic modulus of adhesive, and decrease in adhesive strength. It is preferable that a content rate is 80 mass parts or less with respect to 100 mass parts of thermosetting resins. On the other hand, if the filler content is small, resin burrs are likely to occur during semiconductor wafer dicing, and the adhesive force tends to decrease. Therefore, the filler content is 35 parts per 100 parts by mass of the thermosetting resin. It is preferable that it is more than a mass part.

  It is preferable that the adhesive composition for semiconductors of this invention contains 2 or more types of fillers from which an average particle diameter differs as said filler. In this case, compared to the case where a single filler is used, it becomes easier to prevent an increase or decrease in the viscosity of the raw material mixture before film formation, and good film formability can be easily obtained, and the adhesive sheet is cured. It becomes easy to obtain excellent adhesive strength later.

  Moreover, the adhesive composition for semiconductors of this invention is the 1st filler in which the average particle diameter exists in the range of 0.1-1.0 micrometer, and a primary particle diameter from a viewpoint which acquires said effect more reliably. It is preferable that the 2nd filler which exists in the range whose average particle diameter is 0.005-0.03 micrometer is included. Further, a dispersion in which the first filler is dispersed in cyclohexanone by bead mill treatment is dropped into acetone, and the average particle size in the dispersion of the first filler measured using this is 0.1 to 1. It is preferably 0 μm. Moreover, it is preferable that the average particle diameter of the dispersion liquid of the 2nd filler measured similarly is 0.05-0.3 micrometer.

  Furthermore, the adhesive composition for semiconductors of the present invention has an average particle diameter in the range of 0.1 to 1.0 μm and 99% or more of the particles have a particle diameter of 0 from the viewpoint of obtaining the above effect more reliably. The first filler distributed within the range of 0.1 to 1.0 μm, and the average primary particle size within the range of 0.005 to 0.03 μm and 99% or more of the particles have a particle size of 0.00. It is preferable that the 2nd filler distributed in the range of 005-0.1 micrometer is included.

  Moreover, it is preferable that the adhesive composition for semiconductors of this invention further contains the thermopolymerizable compound which becomes high molecular weight by a polymerization reaction at 150 degreeC or more.

  Examples of the thermopolymerizable compound that increases in molecular weight by a polymerization reaction at 150 ° C. or higher include polyfunctional (meth) acrylate monomers that increase in molecular weight when heated at high temperature in the presence of oxygen. Nippon Kayaku Co., Ltd. For example, KAYARAD DPHA manufactured by KK can be used.

  It is preferable that the content rate of the said thermopolymerizable compound in the adhesive composition for semiconductors of this invention is 3-10 mass parts with respect to 100 mass parts of thermosetting resins. When the content ratio is too high, the stickiness of the uncured adhesive sheet tends to increase.

  Moreover, the adhesive composition for semiconductors of the present invention comprises the above-mentioned thermosetting resin (high molecular weight component (A), epoxy resin (B), epoxy resin other than (B) and phenol resin (C)), filler, In addition to the thermopolymerizable compound, it may further contain a curing accelerator, a catalyst, an additive, a coupling agent and the like.

  In addition, the semiconductor adhesive composition of the present invention preferably has a melt viscosity at 80 ° C. before curing of 700 Pa · s to 6000 Pa · s, more preferably 700 Pa · s to 5000 Pa · s, and more preferably 1000 Pa · s. More preferably, it is s or more and 1900 Pa · s or less.

  Moreover, the adhesive composition for semiconductors of the present invention forms a circuit on an organic substrate (for example, copper-clad laminate “E-697FG” (manufactured by Hitachi Chemical Co., Ltd., 400 μm thickness)), and “AUS308” (solar ink ( It is more preferable that the adhesive strength after curing with respect to those coated with (made by Co., Ltd.) is 3.0 MPa or more.

  There is no restriction | limiting in particular as the support body 20, For example, a polyester film, a polypropylene film, a polyethylene terephthalate film, a polyimide film, a polyetherimide film, a polyether naphthalate film, a methylpentene film etc. are mentioned.

  The adhesive sheet 1 for semiconductors can be produced, for example, by the following method. First, each component constituting the above-described semiconductor adhesive composition of the present invention is mixed and kneaded in an organic solvent to prepare a varnish, and a layer of this varnish is formed on the support 20 and dried by heating. Thereby, the adhesive sheet 1 for semiconductors can be obtained. Alternatively, the support 20 may be removed after the varnish layer is dried to form an adhesive sheet for a semiconductor composed only of the adhesive layer 10. The above mixing and kneading can be carried out by appropriately combining dispersers such as ordinary stirrers, crackers, three rolls, and ball mills. The heating and drying conditions are not particularly limited as long as the used solvent is sufficiently volatilized, but the heating is usually performed at 60 to 200 ° C. for 0.1 to 90 minutes.

  The organic solvent used for the preparation of the varnish is not particularly limited as long as the material can be uniformly dissolved, kneaded or dispersed, and conventionally known ones can be used. Examples of such a solvent 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.

  The thickness of the adhesive layer 10 is preferably 10 to 250 μm in order to fill unevenness such as a gold wire attached to the wiring circuit of the substrate or the lower chip. If the thickness is less than 10 μm, it is difficult to obtain sufficient filling of the unevenness, and the stress relaxation effect and adhesiveness tend to be reduced. If the thickness is more than 250 μm, it is not economical and the semiconductor device is small. It tends to be difficult to respond to the demands for making it easier. Furthermore, the thickness of the adhesive layer 10 is more preferably 20 to 100 μm, and even more preferably 40 to 80 μm, from the viewpoint that sufficient adhesiveness can be obtained and the semiconductor device can be thinned.

  From the viewpoint of excellent dicing properties, the storage elastic modulus at 25 ° C. before curing of the adhesive layer 10 (B stage state) is preferably 200 to 6000 MPa. Furthermore, the storage elastic modulus is more preferably 200 to 2000 MPa in terms of excellent dicing properties and excellent adhesion to a semiconductor wafer. Moreover, it is preferable that the storage elastic modulus in 80 degreeC before hardening of the adhesive bond layer 10 (B stage state) is 0.0001-10MPa. In this case, the laminating property to the semiconductor wafer becomes better. In particular, the storage elastic modulus at 80 ° C. is more preferably 0.001 to 5 MPa in terms of high adhesion to a semiconductor wafer.

  Further, from the viewpoint of obtaining good wire bonding properties, the storage elastic modulus at 170 ° C. after curing of the adhesive layer 10 (C-stage state) is preferably 20 to 1000 MPa.

  The storage elastic modulus of the adhesive layer 10 was measured using a dynamic viscoelasticity measuring device (“Rheogel-E4000” manufactured by UBM), sample size: length 20 mm, width 4 mm, temperature range: −30 to 200 ° C. It is measured under the measurement conditions of a temperature rate of 3 ° C./min, a tensile mode, 10 Hz, and an automatic static load.

  The melt viscosity at 80 ° C. before curing of the adhesive layer 10 is preferably 700 Pa · s or more and 6000 Pa · s or less, more preferably 700 Pa · s or more and 5000 Pa · s or less, and further preferably 1000 Pa · s or more and 1900 Pa · s or less. preferable. The melt viscosity at 80 ° C. is represented by a value calculated from the change in area when pressed for 3 seconds under the conditions of a temperature of 80 ° C. and a load of 3 kgf based on the parallel plate plastometer method.

  Moreover, it is more preferable that the adhesive strength of the adhesive layer 10 to the organic substrate after curing is 3 MPa or more. This adhesive strength means a value measured by the following procedure. First, the adhesive layer 10 is bonded to a semiconductor wafer having a thickness of 400 μm at 60 ° C. and diced to 5.0 mm square. The separated sample is pressure-bonded on a substrate coated with resist AUS308 for 1 second under conditions of a temperature of 120 ° C. and a load of 250 gf. Next, the substrate to which the sample is bonded is cured by step curing at 120 ° C. for 1 hour and 170 ° C. for 3 hours. The mounting board thus produced is left for 168 hours under the conditions of 85 ° C. and 60 RH%. Thereafter, the die shear strength at 250 ° C. is immediately measured, and this is used as the adhesive strength.

  The adhesive composition for semiconductors and the adhesive sheet for semiconductors of the present invention may be used as such, but as another embodiment, an adhesive layer comprising the adhesive composition for semiconductors of the present invention is conventionally known. It can also be used as a dicing / die bonding integrated adhesive sheet provided on the dicing tape. In this case, since the laminating process on the semiconductor wafer is performed only once, the work can be made more efficient. FIG. 2 is a schematic cross-sectional view showing the configuration of the adhesive sheet of the present embodiment. The adhesive sheet 2 shown in FIG. 2 includes a dicing tape 30 and an adhesive layer 10 provided on the dicing tape 30 and made of the adhesive composition for a semiconductor of the present invention.

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

  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. This pressure-sensitive adhesive layer can be formed by applying and drying a resin composition having an appropriate tack strength obtained by adjusting the ratio of the liquid component and the Tg of the high molecular weight component.

  When the adhesive sheet 2 is used for manufacturing a semiconductor device, it is preferable that the adhesive layer 10 has an adhesive force that prevents the semiconductor elements from scattering during dicing, and can be easily peeled off from the dicing tape during pickup. For example, if the adhesive layer is too sticky, picking up may be difficult. Therefore, it is preferable to appropriately adjust the tack strength of the adhesive layer. As its method, the adhesive strength and tack strength tend to increase when the flow of the adhesive layer at room temperature increases, while the adhesive strength and tack strength tend to decrease when the flow decreases. do it. Specifically, to increase the flow, for example, there are methods such as increasing the plasticizer content and increasing the tackifier content. Conversely, in order to reduce the flow, the content of the compound may be reduced. Examples of the plasticizer include monofunctional acrylic monomers, monofunctional epoxy resins, liquid epoxy resins, acrylic resins, and epoxy-based so-called diluents.

  As a method of providing an adhesive layer on a dicing tape, in addition to printing, a method of pressing an adhesive layer prepared in advance on a dicing tape and hot roll laminating can be mentioned. A method of providing an adhesive layer by hot roll lamination is preferred.

  The film thickness of the dicing tape is not particularly limited, and is determined based on the knowledge of those skilled in the art as appropriate depending on the film thickness of the adhesive layer and the application of the adhesive sheet. 60-150 micrometers is preferable at a good point, and 70-130 micrometers is more preferable.

  Next, a method for manufacturing a semiconductor device using the adhesive sheet 2 will be described.

  FIGS. 3A to 3D and FIG. 4 are cross-sectional views for explaining a preferred embodiment of a method for manufacturing a semiconductor device using the adhesive sheet 2. The manufacturing method of the semiconductor device according to the present embodiment includes a bonding process (wafer laminating process) in which the adhesive layer of the above-mentioned adhesive sheet 2 is bonded to a semiconductor wafer, and dicing the semiconductor wafer and the adhesive layer together. A dicing process for obtaining a semiconductor element having an adhesive layer attached thereto, a pickup process for picking up the semiconductor element having an adhesive layer attached thereto from a dicing tape, and the semiconductor element being bonded to a support member for mounting the semiconductor element through the adhesive layer. An adhesion step. Hereinafter, each process will be described with reference to the drawings.

(Attaching process)
First, as shown in FIG. 3A, the adhesive sheet 2 is attached to the main surface of the semiconductor wafer W via the adhesive layer 10.

  The semiconductor wafer W used in the manufacture of the semiconductor device using the adhesive sheet according to this embodiment includes single crystal silicon, polycrystalline silicon, various ceramics, and compound semiconductors such as gallium arsenide.

  The temperature at which the adhesive sheet 2 is attached to the semiconductor wafer W, that is, the laminating temperature, is preferably 0 to 90 ° C, more preferably 15 to 80 ° C, and even more preferably 20 to 70 ° C. When the laminating temperature exceeds 90 ° C., the warp of the semiconductor wafer after the adhesive sheet is attached tends to increase. Moreover, when affixing with a dicing tape, it is preferable to carry out at room temperature (25 degreeC)-40 degreeC.

  In addition, when using the adhesive sheet formed by shape | molding the adhesive composition for semiconductors of this invention into a film form instead of the adhesive sheet 2, after bonding an adhesive sheet to a semiconductor wafer first, the semiconductor wafer of an adhesive sheet is then used. What is necessary is just to affix a dicing tape on the surface on the opposite side. When the semiconductor adhesive sheet 1 is used instead of the adhesive sheet 2, the adhesive sheet is bonded to the semiconductor wafer, the support 20 is peeled off, and then the adhesive layer 10 is placed on the surface opposite to the semiconductor wafer. A dicing tape may be attached. The laminating temperature for attaching the adhesive sheet and dicing tape in these cases is preferably the above temperature.

(Dicing process)
Next, as shown in FIG. 3B, the semiconductor wafer W and the adhesive layer 10 are diced. At this time, the dicing tape 30 may be diced halfway. Dicing can be performed with a rotary blade or a laser.

(Pickup process)
After the dicing step, as shown in FIG. 3C, the dicing tape 30 is expanded (expanded) so that the semiconductor elements 40 obtained by cutting are separated from each other, and the pick-up tool is used from the dicing tape 30 side. 42 (push-up of a needle or a slide-type unit) or the like promotes peeling of the adhesive layer 10a and the dicing tape 30, and the semiconductor element 40 with the adhesive layer is sucked and picked up by the suction collet 44. The semiconductor element 40 with an adhesive layer includes a semiconductor element Wa and an adhesive layer 10a. The semiconductor element Wa is obtained by dividing the semiconductor wafer W, and the adhesive layer 10a is obtained by dividing the adhesive layer 10. In the pick-up process, it is not always necessary to perform expansion, but the pick-up performance can be further improved by expanding.

  Further, it is preferable that the needle 42 is pushed up as necessary. Furthermore, from the viewpoint of ensuring sufficient pickup performance even for an ultra-thin wafer, for example, a two-stage or three-stage pickup method may be performed.

In the present embodiment, the semiconductor element 40 can be picked up by a method other than the suction collet 44.

(Adhesion process)
After picking up the semiconductor element 40 with the adhesive layer, as shown in FIG. 3D, the semiconductor element 40 with the adhesive layer is bonded to the semiconductor element mounting support member via the adhesive layer 10a by thermocompression bonding. Adhere to 50.

  The load for pressure bonding is preferably 0.001 to 1 MPa, more preferably 0.01 to 0.5 MPa, and still more preferably 0.01 to 0.3 MPa. If the load is less than 0.001 MPa, voids are generated and the heat resistance tends to be reduced, and if it exceeds 1 MPa, the chip tends to be damaged.

  Moreover, it is preferable that it is 60-240 degreeC, and, as for heating temperature, it is more preferable that it is 80-180 degreeC. When the temperature is lower than 60 ° C., the embedding property of the unevenness tends to be lowered, and when the temperature exceeds 240 ° C., the support member such as the substrate is deformed and warpage tends to increase. Examples of the heating method include a method of bringing a supporting member or a semiconductor element into contact with a heated hot plate, irradiating the supporting member or the semiconductor element with infrared rays or microwaves, and blowing hot air. In this embodiment, it is desirable to heat the support member which is an adherend, the semiconductor element with an adhesive layer, or both.

  After mounting the semiconductor element 40 with the adhesive layer on the support member 50 through the adhesive layer 10a, the semiconductor element 40 with the adhesive layer is again bonded to the semiconductor element Wa through the adhesive layer 10a by thermocompression bonding. You may do that. Thereby, a plurality of semiconductor elements Wa can be mounted on the support member 50. In this case, the thermal history of the adhesive layer 10a is increased, but the adhesiveness between the semiconductor element Wa and the support member 50 can be sufficiently maintained according to the adhesive layer 10a according to the present embodiment.

  Subsequently, as shown in FIG. 4, it is preferable to electrically connect the semiconductor element Wa and the support member 50 by wire bonding 60 as necessary. At this time, the semiconductor element Wa, the adhesive layer 10a, and the support member 50 are heated at a predetermined temperature for a predetermined time. Furthermore, after connecting by wire bonding, the semiconductor element Wa is preferably resin-sealed as necessary. At this time, the resin sealing material 70 is formed on the surface (semiconductor mounting surface) of the support member 50, but the resin sealing material may be formed on the surface of the support member 50 opposite to the semiconductor mounting surface.

  Through the above steps, the semiconductor device 100 can be manufactured using the adhesive sheet 2. The semiconductor device 100 obtained in this way has a cured product of the above-described adhesive composition for a semiconductor of the present invention as an adhesive member for adhering a semiconductor element and a support member, and thus has excellent connection reliability, particularly high temperature. Excellent connection reliability under high humidity conditions.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

(Example 1)
6.2 parts by mass of epoxy resin “YDCN-700-10” (manufactured by Tohto Kasei Co., Ltd., cresol novolac type epoxy resin, epoxy equivalent 210), phenol resin “Mirex XLC-LL” (trade name, manufactured by Mitsui Chemicals, Inc.) , Phenol resin, hydroxyl group equivalent 175) 51.8 parts by mass, epoxy resin “YDF-8170C” (trade name, manufactured by Tohto Kasei Co., Ltd., bisphenol F type epoxy resin, epoxy equivalent 159, molecular weight 312) 41.9 parts by mass, 81.5 parts by mass of “SC2050-HLG” (trade name, manufactured by Admatechs Co., Ltd., average particle size 0.500 μm) which is a dispersion of silica filler, and “Aerosil R972” which is silica filler (Nippon Aerosil Co., Ltd.) ) Product name, average particle size of primary particle size 0.016 μm) Cyclohexanone in a composition comprising 2.9 parts by mass The mixture was stirred and mixed to obtain a uniform composition.

  To this, 23.0 parts by mass of acrylic rubber “HTR-860P-230k” (trade name, Teikoku Chemical Industry Co., Ltd., weight average molecular weight 230,000), “NUC A-1160” (Nihon Unicar ( Co., Ltd. product name, γ-ureidopropyltriethoxysilane) 0.3 parts by mass and “NUC A-189” (trade name, γ-mercaptopropyltrimethoxysilane) manufactured by Nippon Unicar Co., Ltd. In addition, 0.1 part by mass of “Curazole 2PZ-CN” (trade name, 1-cyanoethyl-2-phenylimidazole, manufactured by Shikoku Kasei Co., Ltd.) as a curing accelerator was added and mixed with stirring until uniform. Furthermore, this was filtered with a 100-mesh filter and vacuum degassed to obtain an adhesive composition varnish.

  This varnish is applied on a polyethylene terephthalate (PET) film having a thickness of 38 μm, and dried by heating at 140 ° C. for 5 minutes, so that the B-stage adhesive layer (film thickness 40 μm) is PET. An adhesive sheet formed on the film was obtained.

(Example 2)
In the composition of Example 1, 8.4 parts by mass of “KAYARAD DPHA” (trade name, manufactured by Nippon Kayaku Co., Ltd., dipentaerythritol hexaacrylate) which is a thermosetting compound was further blended, and “Aerosil R972” was added. The adhesive sheet was produced through the same process as Example 1 except not mix | blending and having changed the mixture ratio of each component as shown in Example 2 of Table 1. FIG.

(Example 3)
In the composition of Example 1, 8.3 parts by mass of “KAYARAD DPHA” (trade name, manufactured by Nippon Kayaku Co., Ltd., dipentaerythritol hexaacrylate), which is a thermosetting compound, was further blended, and the blending ratio of each component The adhesive sheet was produced through the process similar to Example 1 except having changed as shown in Example 3 of Table 1.

(Examples 4 and 5)
In the composition of Example 1, “Aerosil R972” was not blended, and the blending ratio of each component was changed as shown in Examples 4 and 5 of Table 2, followed by the same steps as in Example 1 for adhesion. A sheet was produced.

(Comparative Example 1)
In the composition of Example 1, "Aerosil R972" was not blended, and the adhesive sheet was subjected to the same steps as in Example 1 except that the blending ratio of each component was changed as shown in Comparative Example 1 of Table 2. Produced.

(Comparative Example 2)
In the composition of Example 1, an adhesive sheet was produced through the same steps as in Example 1 except that the blending ratio of each component was changed as shown in Comparative Example 2 of Table 2.

[Measurement of melt viscosity]
For the adhesive sheets of Examples 1 to 5 and Comparative Examples 1 and 2, the melt viscosity of the adhesive layer in the B stage state was measured by the following procedure based on the parallel plate plastometer method. First, three adhesive layers were bonded at 60 ° C. to form a film having a thickness of 120 μm, and this was punched into a circle having a diameter of 6 mm. The obtained circular film was sandwiched between two glass slides having a thickness of 150 μm to obtain a measurement sample. Using a crimping machine that can be set to a predetermined temperature during crimping, the measurement sample was crimped for 3 seconds at a temperature of 80 ° C. and a load of 3 kgf. The melt viscosity was calculated from the change in the area of the film due to the pressure bonding at this time. The obtained results are shown in Table 3.

[Measurement of adhesive strength]
About the adhesive sheet of Examples 1-5 and Comparative Examples 1 and 2, adhesive strength was measured with the following procedures. First, the adhesive layer of the adhesive sheet was bonded to a semiconductor wafer having a thickness of 400 μm at 60 ° C. and diced to 5.0 mm square to obtain individual semiconductor chips with an adhesive layer. Next, the semiconductor chip with the adhesive layer was pressure-bonded on a substrate coated with the resist “AUS308” for 1 second under the conditions of a heating temperature of 120 ° C. and a load of 250 gf to prepare a semiconductor device sample. Subsequently, the adhesive layer of the sample was cured by step curing at 120 ° C./1 hour and 170 ° C./1 hour. Next, the sample of the semiconductor device after curing was left under conditions of 85 ° C. and 60 RH% for 168 hours. Immediately thereafter, the die shear strength at 250 ° C. of the sample was measured and used as the adhesive strength. The obtained results are shown in Table 3.

[Reflow resistance evaluation test]
The reflow resistance of the adhesive sheets of Examples 1 to 5 and Comparative Examples 1 and 2 was evaluated by the following procedure. First, the adhesive sheet was bonded to a 75 μm-thick wafer at 60 ° C. and diced to 7.5 mm square to obtain individual semiconductor chips with an adhesive layer. Next, a semiconductor chip with an adhesive layer is pressure-bonded on a substrate coated with a resist “AUS308” (manufactured by Taiyo Ink Co., Ltd.) for 1 second under conditions of a heating temperature of 120 ° C. and a load of 0.05 MPa. A sample was created. Next, this sample was subjected to a heat treatment at 120 ° C. for 60 minutes, followed by a heat treatment equivalent to wire bonding, and a mold sealing material (trade name “CEL-9700HF” manufactured by Hitachi Chemical Co., Ltd.). And cured at 175 ° C. for 5 hours to obtain a package. Next, after absorbing this package under JEDEC's prescribed moisture absorption conditions, it was passed through 260 ° C reflow (maximum temperature 265 ° C) three times in an IR reflow oven, causing damage to the package, changes in thickness, peeling of the interface, etc. The most severe moisture absorption condition among the conditions in which none was observed was regarded as the reflow resistance level. The JEDEC predetermined moisture absorption condition at this time is defined as level 3 where the package is moisture absorbed for 192 hours in a constant temperature and humidity chamber having a temperature of 30 ° C. and a humidity of 60%. Similarly, level 2 is a condition of 85 ° C., 60%, and 168 hours. The obtained results are shown in Table 3.

  As is clear from the results shown in Table 3, the adhesive sheets according to the present invention (Examples 1 to 5) have lower melt viscosity and higher adhesive strength than the adhesive sheets of Comparative Examples 1 and 2. It was confirmed that the balance was high. Moreover, even if it was a case where the adhesive sheet (Examples 1-5) based on this invention was exposed to high temperature, high humidity conditions after hardening, it turned out that sufficient adhesive strength is shown. Furthermore, it was confirmed that the adhesive sheets (Examples 1 to 5) according to the present invention are excellent in reflow resistance. According to the adhesive composition for semiconductor and the adhesive sheet for semiconductor according to the present invention, it is possible to improve the reliability of the semiconductor device.

It is a schematic cross section which shows suitable one Embodiment of the adhesive sheet for semiconductors of this invention. It is a schematic cross section which shows other suitable embodiment of the adhesive sheet for semiconductors of this invention. It is sectional drawing for demonstrating suitable one Embodiment of the manufacturing method of the semiconductor device using the adhesive sheet for semiconductors concerning this invention. 1 is a schematic cross-sectional view showing a preferred embodiment of a semiconductor device of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, ... Semiconductor adhesive sheet, 10 ... Adhesive layer, 20 ... Support, 30 ... Dicing tape, 40 ... Semiconductor element with adhesive layer, 50 ... Support member, 60 ... Wire bonding, 70 ... Resin sealing material , 100... Semiconductor device.

Claims (8)

An adhesive composition containing a thermosetting resin and a filler,
The blending ratio of the filler is 30 to 100 parts by mass with respect to 100 parts by mass of the thermosetting resin, and
As the thermosetting resin, (A) a high molecular weight component having a crosslinkable functional group, a weight average molecular weight of 100,000 to 600,000 and a glass transition temperature of −50 ° C. to 50 ° C., (B) a molecular weight of 500 Adhesion for semiconductors containing the above polyfunctional epoxy resin and (C) phenol resin in a mass ratio of (A) :( B) :( C) = 15-40: 5-15: 35-55 Agent composition.   The adhesive composition for semiconductor according to claim 1, comprising two or more fillers having different average particle diameters as the filler.   Including a first filler having an average particle diameter in the range of 0.1 to 1.0 μm and a second filler having an average particle diameter of the primary particle diameter in the range of 0.005 to 0.03 μm. The adhesive composition for semiconductors of Claim 1.   The adhesive composition for semiconductors as described in any one of Claims 1-3 which further contains the thermopolymerizable compound which becomes high molecular weight by a polymerization reaction at 150 degreeC or more.   The adhesive composition for semiconductors as described in any one of Claims 1-4 whose melt viscosity in 80 degreeC before hardening is 700 Pa.s or more and 5000 Pa.s or less.   The adhesive composition for semiconductors as described in any one of Claims 1-5 whose adhesive strength after hardening with respect to an organic substrate is 3.0 Mpa or more.   The adhesive sheet for semiconductors provided with the adhesive bond layer formed by shape | molding the adhesive composition for semiconductors as described in any one of Claims 1-4 in a film form. A semiconductor element; a support member for mounting the semiconductor element; and an adhesive member that is provided between the semiconductor element and the support member and bonds the semiconductor element and the support member.
The said adhesive member is a semiconductor device which is a hardened | cured material of the adhesive composition for semiconductors as described in any one of Claims 1-6.

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