JP6868555B2 - Compositions for film-like adhesives, film-like adhesives, methods for manufacturing film-like adhesives, semiconductor packages using film-like adhesives and methods for manufacturing them. - Google Patents

Description

The present invention relates to a composition for a film-like adhesive having high thermal conductivity, a film-like adhesive, a method for producing a film-like adhesive, a semiconductor package using the film-like adhesive, and a method for producing the same.

In recent years, as electronic devices have become smaller and more sophisticated, the semiconductor packages mounted therein have also become more sophisticated, and the semiconductor wafer wiring rules have been miniaturized. Along with this, heat is likely to be generated on the surface of the semiconductor element, and the generated heat has problems such as a decrease in the operating speed of the semiconductor element and a malfunction of the electronic device.

In order to eliminate such an adverse effect of heat, the constituent members of the semiconductor package are required to have thermal conductivity to release the generated heat to the outside of the package. Further, in a so-called die attach material for joining between semiconductor elements and wiring boards, or between semiconductor elements, high thermal conductivity, sufficient insulating properties, and adhesive reliability are required.

Further, as such a die attach material, conventionally, it has often been used in the form of a paste. However, since high-density mounting inside the package is required as the functionality of the semiconductor package increases, it is necessary to prevent contamination of other members such as semiconductor elements and wire pads due to resin flow and resin rising. In recent years, it has become common to use it in a film form (diatach film).

In order to achieve high thermal conductivity of the die attach film, it is necessary to highly fill the high thermal conductivity filler. However, in general, increasing the filler filling amount tends to cause an increase in melt viscosity, and is used when the die attach film is attached to the back surface of the semiconductor wafer or in the so-called die attach process in which a semiconductor element provided with the die attach film is mounted. In the case of the bonding or the mounting, the adhesion between the die attach film and the adherend is lowered, and air is easily entrained at the interface between the two. This is based on the fact that the back surface of the semiconductor wafer and particularly the surface surface of the wiring board on which the semiconductor element is mounted are not necessarily in a smooth surface state. Here, the entrained air not only reduces the adhesive force of the die attach film after heat curing, but also causes package cracks. Therefore, in order to suppress the increase in melt viscosity, it is necessary to reduce the filling amount as much as possible to achieve high thermal conductivity, and it is necessary to select a filler having higher thermal conductivity.

Further, in the semiconductor package manufacturing process, in the so-called dicing process of cutting the die attach film and the semiconductor wafer on which the semiconductor element is formed at the same time, it is also necessary that the wear rate of the processing blade by the die attach film is small. When a high-hardness, high-thermal conductivity filler is selected, the wear rate of the processing blade due to the die-attach film increases, and although a predetermined cut can be performed for a while after the start of the cutting process (dicing process), the cutting amount of the die-attach film gradually increases. Will be inadequate. In addition, if the blades are replaced frequently to prevent this problem, the productivity will decrease and the cost will increase. On the other hand, if the blades with a small amount of wear are used, the wafer will be chipped. Since chipping and the like occur, the yield is lowered.

Further, in recent years, a copper material has been used for semiconductor members. For example, in the case of metal wires, in order to reduce the cost of assembling a semiconductor package, wires made of copper instead of gold, which have been conventionally used, are used. Further, in order to improve the processing capacity of the semiconductor element, a copper material having a smaller electric resistance than the conventionally used aluminum material is used as the semiconductor element circuit material. However, when the die attach film is adhered to such a semiconductor member made of copper material, it is necessary not to corrode it at the time of reliability test such as bias HAST (Highly Accelerated Stress Test) of the semiconductor package under high temperature and high humidity. is there. Therefore, it is necessary for the die attach film to have a small amount of ionic impurities.
As described above, the high thermal conductivity die attach film has i) low melt viscosity for exhibiting adhesion, ii) blade wear resistance in the dicing process, and iii) low ions for not corroding the copper material semiconductor member. Impervious properties are required.

Examples of materials that can be used as a high thermal conductivity die attach film include, in Patent Document 1, an epoxy resin, a polymer component having a glass transition temperature of 95 ° C. or higher, a polymer component having a glass transition temperature of −30 ° C. or lower, and a thermal conductivity of 10 W. A high thermal conductivity adhesive sheet made of an inorganic filler of / m · K or more has been proposed. However, although the high thermal conductivity adhesive sheet described in Patent Document 1 has thermal conductivity and low melt viscosity, it uses high hardness aluminum oxide and has blade wear resistance. It can be estimated that problems remain, and the study on ionic impurities was insufficient.

Further, Patent Document 2 proposes a high thermal conductive resin composition containing high thermal conductive particles, an epoxy resin having mesogen, and a high molecular weight component. However, although the high thermal conductivity resin composition described in Patent Document 2 has high thermal conductivity and adhesion, it is presumed that high hardness aluminum oxide remains, and that the problem of blade wear resistance remains. In addition, the study on ionic impurities was insufficient.

Further, Patent Document 3 proposes a heat conductive filler made of aluminum hydroxide and silicon dioxide and a sheet of a heat conductive member made of a silicon resin. However, although the sheet of the heat conductive member described in Patent Document 3 has a certain degree of high heat conductivity, there is still a problem in adhesion to the adherend, and ionic impurities. The examination of was also insufficient.

Japanese Patent No. 5451613 Japanese Unexamined Patent Publication No. 2013-6893 Japanese Unexamined Patent Publication No. 2009-286809

The present invention has been made in view of the above-mentioned problems of the prior art, and is for excellent adhesion to an adherend, a sufficiently small wear rate of a processed blade, and not corroding a copper material semiconductor member. A composition for a film-like adhesive, a film-like adhesive, a method for producing a film-like adhesive, which can obtain a film-like adhesive that retains low ion impurity properties and exhibits excellent thermal conductivity after thermosetting. An object of the present invention is to provide a semiconductor package using a film-like adhesive and a method for producing the same.

As a result of diligent research to achieve the above problems, the present inventors have found that the following configuration is achieved.
(1) A composition for a film-like adhesive containing an epoxy resin (A), an epoxy resin curing agent (B), a phenoxy resin (C) , an aluminum nitride filler (D) , and a phosphoric acid ester-based surfactant, respectively. And
The content of the aluminum nitride filler (D) is relative to the total amount of the epoxy resin (A), the epoxy resin curing agent (B), the phenoxy resin (C), and the aluminum nitride filler (D). 30-60% by volume,
The aluminum nitride filler (D) has a surface oxide layer formed on the surface of the filler, and has been subjected to a water resistant surface treatment with phosphoric acid or a phosphoric acid compound.
When the film-like adhesive obtained from the film-like adhesive composition was heated at a heating rate of 25 ° C. to 5 ° C./min, the minimum melt viscosity in the range of 200 to 10,000 Pa · s was obtained at 80 ° C. or higher. After reaching, a cured product having a thermal conductivity of 1.0 W / m · K or more is given after thermosetting, and the electric conductivity of the extracted water extracted into pure water at 121 ° C. for 20 hours after curing is 50 μS / cm or less. A composition for a film-like adhesive.
( 2 ) Further, an ion trap agent selected from a triazine thiol compound, a zirconium compound, an antimony bismuth compound and a magnesium aluminum compound is 1.0 to 3.0 mass by mass with respect to the aluminum nitride filler (D). The composition for a film-like adhesive according to (1 ), which contains%.
( 3 ) A film-like adhesive obtained by the film-like adhesive composition according to (1) or (2) above.
( 4 ) A film-like adhesive according to the above (1) or (2) , which is produced by coating and drying the composition for a film-like adhesive on a release-treated base film. Production method.
( 5 ) The first step of providing an adhesive layer on the back surface of a semiconductor wafer having at least one semiconductor circuit formed on the front surface by thermocompression bonding the film-like adhesive and dicing tape according to (3).
A second step of obtaining a semiconductor chip with an adhesive layer including the semiconductor wafer and the adhesive layer by dicing the semiconductor wafer and the adhesive layer at the same time.
A third step of removing the dicing tape from the adhesive layer and thermocompression bonding the semiconductor chip with the adhesive layer and the wiring substrate via the adhesive layer, and
Fourth step of thermosetting the adhesive layer,
A method for manufacturing a semiconductor package, which comprises.
( 6 ) A semiconductor package obtained by the manufacturing method according to (5 ) above.

According to the present invention, the adhesion to the adherend is excellent, the wear rate of the processed blade is sufficiently small, and the low ion impurity property for not corroding the copper material semiconductor member is maintained, which is excellent after thermosetting. Compositions for film-like adhesives capable of obtaining highly thermally conductive film-like adhesives exhibiting thermal conductivity, film-like adhesives, methods for producing film-like adhesives, semiconductor packages using film-like adhesives, and It has become possible to provide the manufacturing method.
The above and other features and advantages of the present invention will become more apparent from the description below, with reference to the accompanying drawings as appropriate.

FIG. 1 is a schematic vertical sectional view showing a preferred embodiment of the first step of the method for manufacturing a semiconductor package of the present invention. FIG. 2 is a schematic vertical sectional view showing a preferred embodiment of the second step of the method for manufacturing a semiconductor package of the present invention. FIG. 3 is a schematic vertical sectional view showing a preferred embodiment of the third step of the method for manufacturing a semiconductor package of the present invention. FIG. 4 is a schematic vertical cross-sectional view showing a preferred embodiment of the step of connecting the bonding wires in the method for manufacturing a semiconductor package of the present invention. FIG. 5 is a schematic vertical sectional view showing an example of a multi-stage lamination embodiment of the method for manufacturing a semiconductor package of the present invention. FIG. 6 is a schematic vertical sectional view showing another example of a multi-stage laminated embodiment of the method for manufacturing a semiconductor package of the present invention. FIG. 7 is a schematic vertical sectional view showing a preferred embodiment of a semiconductor package manufactured by the method for manufacturing a semiconductor package of the present invention.

<< Composition for film-like adhesive >>
The composition for a film-like adhesive of the present invention (hereinafter referred to as a composition for a high thermal conductive film-like adhesive) includes an epoxy resin (A), an epoxy resin curing agent (B), a phenoxy resin (C), and aluminum nitride. Each of the fillers (D) is contained, and the content of the aluminum nitride filler (D) is the epoxy resin (A), the epoxy resin curing agent (B), the phenoxy resin (C), and the aluminum nitride filling. It is 30 to 60% by volume based on the total amount of the agent (D).
Further, the high thermal conductive film-like adhesive obtained by the composition for high thermal conductive film-like adhesive of the present invention is 200 at 80 ° C. or higher when the temperature is raised from 25 ° C. to 5 ° C./min. Extraction that reaches the minimum melt viscosity in the range of 10000 Pa · s, gives a cured product with a thermal conductivity of 1.0 W / m · K or more after thermosetting, and is extracted into pure water at 121 ° C. for 20 hours after thermosetting. The electrical conductivity of water is 50 μS / cm or less.
Here, the term "after thermosetting" in the measurement of thermal conductivity, electrical conductivity of extracted water, and ammonium ion concentration means after heating at at least 180 ° C. for 1 hour.

<Characteristics of film-like adhesive>
The minimum melt viscosity of the high thermal conductive film-like adhesive obtained by the composition for high thermal conductive film-like adhesive of the present invention is 80 ° C. or higher when the temperature is raised from 25 ° C. to 5 ° C./min. At, the minimum melt viscosity in the range of 200 to 10,000 Pa · s is reached. The minimum melt viscosity is preferably in the range of 200 to 3000 Pa · s, and particularly preferably in the range of 200 to 2000 Pa · s. If the melt viscosity is larger than this range, voids are likely to remain between the irregularities of the wiring board when the semiconductor chip provided with the film-like adhesive is thermocompression bonded onto the wiring board. On the other hand, if it is smaller than this range, the film-like adhesive tends to squeeze out when the semiconductor chip provided with the film-like adhesive is mounted on the wiring board. In the present invention, the melt viscosity is defined by measuring the change in viscosity resistance in a temperature range of 25 to 200 ° C. and a heating rate of 5 ° C./min using a rheometer (trade name: RS6000, manufactured by Hake). The viscous resistance when the temperature is 80 ° C. or higher in the obtained temperature-viscosity resistance curve.
In order to set the minimum melt viscosity within the above range, in addition to the content of the aluminum nitride filler (D) and the type of the aluminum nitride filler (D), an epoxy resin (A), an epoxy resin curing agent, etc. It can be adjusted by the type of coexisting compound or resin and the content thereof.

The high thermal conductivity film-like adhesive of the present invention has a thermal conductivity of 1.0 W / m · K or more after thermosetting. The thermal conductivity is preferably 1.5 W / m · K or more. If the thermal conductivity is less than the above lower limit, it tends to be difficult for the generated heat to escape to the outside of the package. Since the high thermal conductivity film-like adhesive of the present invention exhibits such excellent thermal conductivity after thermosetting, the high thermal conductivity film-like adhesive of the present invention adheres to an adherend such as a semiconductor wafer or a wiring substrate. By making it heat-cured, the heat dissipation efficiency to the outside of the semiconductor package is improved.
The upper limit of the thermal conductivity is not particularly limited, but is practically 5.0 W / m · K or less.
In the present invention, the thermal conductivity of such a heat-cured film-like adhesive is determined by using a thermal conductivity measuring device (trade name: HC-110, manufactured by Eiko Seiki Co., Ltd.). The value obtained by measuring the thermal conductivity by the method (based on JIS-A1412).
In order to keep the thermal conductivity within the above range, in addition to the content of the aluminum nitride filler (D) and the type of the aluminum nitride filler (D), the epoxy resin (A), the epoxy resin curing agent, etc. It can be adjusted by the type of coexisting compound or resin and the content thereof.

Further, the high thermal conductivity film-like adhesive of the present invention has an electric conductivity of 50 μS / cm or less of the extracted water extracted into pure water at 121 ° C. for 20 hours after thermosetting. The electrical conductivity is preferably 40 μS / cm or less. If the electrical conductivity exceeds the above upper limit, the copper material is likely to be corroded during a reliability test such as bias HAST under high temperature and high humidity of the semiconductor package.
The lower limit of the electric conductivity is not particularly limited, but is practically 0.1 μS / cm or more.
In the present invention, the electric conductivity means the electric conductivity of the extracted water obtained by putting the thermosetting film-like adhesive in pure water and extracting at 121 ° C. for 20 hours with an electric conductivity meter (trade name: AE). -200, a value measured using METTLER TOLEDO Co., Ltd.).
The electrical conductivity can be adjusted within the above range by using a surface-modified aluminum nitride filler (D) or a phosphoric acid ester-based surfactant or an ion trapping agent (ion scavenger) as an additive. ..

<Epoxy resin (A)>
The epoxy resin (A) contained in the composition for a high thermal conductive film-like adhesive of the present invention may be either a liquid, a solid or a semi-solid. In the present invention, a liquid means a softening point of less than 50 ° C., a solid means a softening point of 60 ° C. or higher, and a semi-solid means a softening point of the above liquid and a solid. It means that it is between the softening point of (50 ° C or higher and lower than 60 ° C). The epoxy resin (A) used in the present invention has a softening point of 100 ° C. from the viewpoint of obtaining a film-like adhesive capable of reaching a low melt viscosity in a suitable temperature range (for example, 60 to 120 ° C.). The following is preferable. In the present invention, the softening point is a value measured by a softening point test (ring-ball type) method (measurement conditions: based on JIS-2817).

In the epoxy resin (A) used in the present invention, the crosslink density of the cured product is increased, and as a result, the contact probability between the aluminum nitride fillers (D) to be blended is high and the contact area is widened, so that the heat is higher. From the viewpoint of obtaining conductivity, the epoxy equivalent is preferably 500 g / eq or less, and more preferably 150 to 450 g / eq. In the present invention, the epoxy equivalent means the number of grams (g / eq) of the resin containing 1 gram equivalent of the epoxy group.

The skeleton of the epoxy resin (A) includes phenol novolac type, orthocresol novolac type, cresol novolac type, dicyclopentadiene type, biphenyl type, fluorenbisphenol type, triazine type, naphthol type, naphthalenediol type, triphenylmethane type, Examples thereof include tetraphenyl type, bisphenol A type, bisphenol F type, bisphenol AD type, bisphenol S type, and trimethylolmethane type. Of these, the triphenylmethane type, bisphenol A type, cresol novolac type, and orthocresol novolac type are preferable from the viewpoint of obtaining a film-like adhesive having low crystallinity of the resin and having a good appearance.

The content of the epoxy resin (A) is preferably 3 to 30% by mass, more preferably 5 to 25% by mass, based on the total mass of the composition for a high thermal conductive film-like adhesive of the present invention. If the content is less than the above lower limit, the amount of the resin component that increases the crosslink density when cured is reduced, so that it tends to be difficult to improve the thermal conductivity of the film-like adhesive. On the other hand, if the content exceeds the above upper limit. Since the main component is an oligomer, the film state (film tackiness, etc.) tends to change easily even with a slight temperature change.

<Epoxy resin curing agent (B)>
As the epoxy resin curing agent (B) contained in the composition for a highly thermally conductive film-like adhesive of the present invention, known curing agents such as amines, acid anhydrides, and polyhydric phenols can be used. .. In the present invention, the epoxy resin (A) and the phenoxy resin (C) have a low melt viscosity, exhibit curability at a high temperature exceeding a certain temperature, have quick curability, and are further stored for a long period of time at room temperature. From the viewpoint of obtaining a composition for a film-like adhesive having high storage stability, it is preferable to use a latent curing agent.
Potential curing agents include dicyandiamides, imidazoles, curing catalyst complex polyhydric phenols, hydrazides, boron trifluoride-amine complexes, amineimides, polyamine salts, and modified products and microcapsules of these. Can be mentioned. In the present invention, the water absorption rate after thermosetting is low, and the elastic modulus after heat curing is also low, so that peeling failure is unlikely to occur in the moisture absorption reflow test after assembling the semiconductor package. It is more preferable to use valent phenols.
Examples of the curing catalyst composite polyhydric phenol include a novolak type phenol resin, a phenol aralkyl type phenol resin, a polyvinyl type phenol resin, and a resol type phenol resin.
These may be used individually by 1 type, or may be used in combination of 2 or more type.

The content of the epoxy resin curing agent (B) is preferably 0.5 to 100% by mass, more preferably 1 to 80% by mass, based on the epoxy resin (A). If the content is less than the above lower limit, the curing time tends to be long, while if it exceeds the above upper limit, an excess curing agent remains in the film-like adhesive and the residual curing agent adsorbs moisture, so that the film-like state is formed. In the reliability test after incorporating the adhesive into the semiconductor, defects tend to occur easily.

<Phenoxy resin (C)>
The phenoxy resin (C) contained in the composition for a highly thermally conductive film-like adhesive of the present invention is used to impart sufficient adhesiveness and film-forming property (film-forming property) to the film-forming layer. Since the phenoxy resin has a structure similar to that of the epoxy resin, it has good compatibility, low resin melt viscosity, and good adhesiveness. The phenoxy resin is obtained from bisphenol such as bisphenol A and epichlorohydrin, and in the present invention, a thermoplastic resin having a mass average molecular weight of 10,000 or more is preferable. By blending a phenoxy resin, it is effective in eliminating tackiness and brittleness at room temperature. Preferred phenoxy resins include bisphenol A type, bisphenol A / F type, bisphenol F type, and cardo skeleton type phenoxy resin. The phenoxy resin is 1256 (trade name: bisphenol A type phenoxy resin, manufactured by Mitsubishi Chemical Corporation), YP-70 (trade name: bisphenol A / F type phenoxy resin, manufactured by Shin Nikka Epoxy Manufacturing Co., Ltd.), FX. -316 (trade name: bisphenol F type phenoxy resin, manufactured by Shin Nikka Epoxy Manufacturing Co., Ltd.), FX-280S (trade name: cardo skeleton type phenoxy resin, manufactured by Shin Nikka Epoxy Manufacturing Co., Ltd.), etc. Commercially available phenoxy resin may be used.
Here, the mass average molecular weight is a value obtained in terms of polystyrene by GPC [Gel Permeation Chromatography].

The glass transition temperature (Tg) of the phenoxy resin is preferably less than 100 ° C, and more preferably less than 80 ° C.
The lower limit of the glass transition temperature (Tg) is preferably 0 ° C. or higher, more preferably 10 ° C. or higher.

The content of the phenoxy resin is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, still more preferably 4 to 13% by mass, based on the epoxy resin (A). By setting the content in such a range, the film state is good (the film tackiness is reduced), and the film brittleness can be suppressed.

<Aluminum nitride filler (D)>
The aluminum nitride filler (D) contained in the composition for a high thermal conductive film-like adhesive of the present invention contributes to high thermal conductivity of the film-like adhesive and reduction of the coefficient of linear expansion. If the value of the coefficient of linear expansion is high, the difference in the coefficient of linear expansion from the wiring board becomes large, so that the effect of suppressing the stress with these objects to be adhered is low, which leads to the occurrence of package cracks, which is not preferable.

In general, aluminum nitride has a low affinity with a resin, so that the thermal resistance at the interface with the resin tends to increase. Also. Since it is highly reactive with water, the surface is hydrolyzed by contact with water in the powder state, and ammonia is likely to be generated. This ammonia becomes ammonium ions, which easily corrodes the copper material during reliability tests such as bias HAST under high temperature and high humidity of the semiconductor package. Therefore, in the present invention, it is preferable that the aluminum nitride filler (D) is surface-modified. As a surface modification method for aluminum nitride, a method in which an oxide layer of aluminum oxide is provided on the surface layer to improve water resistance and surface treatment with phosphoric acid or a phosphoric acid compound is performed to improve the affinity with the resin is preferable. ..

The phosphoric acid used in the surface treatment is orthophosphoric acid (H ₃ PO ₄ ), pyrophosphoric acid (H ₄ P ₂ O ₇ ), metaphosphoric acid ((HPO ₃ ) n, n are integers representing the degree of condensation) or These metal salts can be mentioned. Examples of the phosphoric acid compound include organic phosphoric acids such as alkylphosphonic acid, arylphosphonic acid, alkylphosphoric acid, and arylphosphoric acid (for example, methylphosphonic acid, ethylphosphonic acid, hexylphosphonic acid, vinylphosphonic acid, phenylphosphonic acid, and methylphosphoric acid. Ethylphosphoric acid, hexylphosphoric acid) can be mentioned.

It is also preferable to surface-treat the surface of the aluminum nitride particles with a silane coupling agent.
It is also preferable to use an ion trap agent (ion scavenger) in combination.

In the present invention, the content of the aluminum nitride filler (D) is the total amount of the epoxy resin (A), the epoxy resin curing agent (B), the phenoxy resin (C), and the aluminum nitride filler (D). It is 30 to 60% by volume, more preferably 35 to 50% by volume. This is because the minimum melt viscosity value is controlled by the amount of the aluminum nitride filler compounded. If the blending amount is larger than the range, the minimum melt viscosity value becomes large, and when the semiconductor chip provided with this film-like adhesive is thermocompression bonded onto the wiring board, voids are likely to remain between the irregularities of the wiring board, and the film is fragile. The sex becomes stronger. If the blending amount is less than the range, the minimum melt viscosity value becomes small, and when the semiconductor chip provided with the film-like adhesive is mounted on the wiring board, the film-like adhesive tends to be poorly squeezed out.

In the present invention, the aluminum nitride filler (D) is preferably spherical from the viewpoint of high filling and fluidity. The average particle size is preferably 0.01 to 5 μm. If the particle size is smaller than 0.01 μm, the filler tends to aggregate, unevenness occurs during film production, and the uniformity of the film thickness of the obtained adhesive film may deteriorate. If the particle size is larger than 5 μm, when a thin film is produced by a coating machine such as a roll knife coater, the filler acts as a trigger to easily generate streaks on the film surface.

The aluminum nitride (D) used in the present invention preferably has a Mohs hardness of 7 to 8. When the Mohs hardness exceeds the above upper limit, the wear rate of the processed blade due to the film-like adhesive increases. In the present invention, the Mohs hardness is defined by using a 10-step Mohs hardness tester, rubbing the measured object in order from the mineral with the lowest hardness, and visually measuring whether the measured object is scratched or not, and the hardness of the measured object. Refers to the value at which is determined.

Further, in the present invention, the average particle size means the particle size when the total particle size is 100% and the total particle size is 50% in the particle size distribution, and the laser diffraction / scattering method (measurement condition: dispersion medium-. It can be obtained from the cumulative curve of the body integration rate of the particle size of the particle size distribution measured by sodium hexametaphosphate, laser wavelength: 780 nm, measuring device: Microtrac MT3300EX). Further, in the present invention, the spherical shape means a true sphere or a substantially true sphere having a roundness having substantially no corners.

As a method of blending the aluminum nitride filler (D) into the resin binder, a method of directly blending a powdered aluminum nitride filler with a silane coupling agent, phosphoric acid or a phosphoric acid compound or a surfactant, if necessary. (Integral blend method), or a slurry aluminum nitride filler in which an aluminum nitride filler treated with a surface treatment agent such as a silane coupling agent, phosphoric acid or a phosphoric acid compound or a surfactant is dispersed in an organic solvent. A compounding method can be used. In particular, when producing a thin film, it is more preferable to use a slurry aluminum nitride filler. This is a surface-treated aluminum nitride filler dispersion liquid dispersed in a smaller organic solvent, and a resin component such as an epoxy resin, an epoxy resin curing agent, and a polymer is mixed to form an aluminum nitride filler having a small particle size. This is because even if there is, it can be uniformly dispersed in the resin component without agglomeration, and the surface appearance of the obtained film-like adhesive is improved.

A silane coupling agent is one in which at least one hydrolyzable group such as an alkoxy group or an aryloxy group is bonded to a silicon atom, and in addition, an alkyl group, an alkenyl group, an alkenyl group and an aryl group are bonded. You may. The alkyl group is preferably substituted with an amino group, an alkoxy group, an epoxy group, or a (meth) acryloyloxy group, and is preferably an amino group (preferably a phenylamino group), an alkoxy group (preferably a glycidyloxy group), or a (meth) acryloyl. The one substituted with an oxy group is more preferable.
The silane coupling agent includes, for example, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldimethoxy. Silane, 3-glycidyloxypropylmethyldiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, N-phenyl-3-aminopropyltri Examples thereof include methoxysilane, 3-methacryloyl oxypropylmethyldimethoxysilane, 3-methacryloyl oxypropyltrimethoxysilane, 3-methacryloyl oxypropylmethyldiethoxysilane, and 3-methacryloyl oxypropyltriethoxysilane.

The surfactant may be anionic, cationic or nonionic, or may be a polymer compound.
In the present invention, anionic surfactants are preferable, and phosphoric acid ester-based surfactants are more preferable.
As the phosphoric acid ester-based surfactant, a phosphoric acid ester represented by the following general formula (1) is preferable.

In the general formula (1), R ¹ represents an alkyl group, an alkenyl group or an aryl group, L ¹ represents an alkylene group, m represents an integer of 0 to 20, and n represents 1 or 2.

R number of carbon atoms in the alkyl group in ¹ is preferably 1 to 20, more preferably 8 to 20, more preferably 8 to 18, for example, butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, Examples thereof include undecylic, dodecyl, hexadecyl, and octadecyl, with preference given to decyl, undecyl, and dodecyl, with undecy being preferred.
The carbon number of the alkenyl group in R ¹ is preferably 2 to 20, more preferably 8 to 20, and even more preferably 8 to 18, and examples thereof include allyl and oleyl.
The ^{number of carbon atoms of the aryl group in R 1} is preferably 6 to 20, more preferably 6 to 20, further preferably 6 to 18, and examples thereof include phenyl and nonylphenyl.

The ^{number of carbon atoms of the alkyl group in L 1} is preferably 2 or 3, more preferably 2, and examples thereof include ethylene and propylene.
m is preferably an integer from 0 to 10.
The phosphoric acid ester represented by the general formula (1) may be a mixture of n of 1 and 2.

As the phosphoric acid ester represented by the general formula (1), a commercially available phosphoric acid ester manufactured by Toho Chemical Industry Co., Ltd. can be used. For example, Phosphanol RS-410, 610, 710, Phosphanol RL-310, Phosphanol RA-600, Phosphanol ML-200, 220, 240, Phosphanol GF-199 (all trade names). Can be mentioned.

The silane coupling agent and the surfactant are preferably contained in an amount of 0.1 to 5.0% by mass with respect to the aluminum nitride filler (D).
If the content of the silane coupling agent or the surfactant is less than the above lower limit, the aluminum nitride filler (D) tends to aggregate and the appearance of the film surface deteriorates. On the other hand, if it is equal to or more than the above upper limit, excess silane coupling agent and surfactant remaining in the system volatilize in the semiconductor assembly heating step (for example, reflow step), which causes peeling at the bonding interface.

<Other additives>
The composition for a film-like adhesive of the present invention includes the epoxy resin (A), the epoxy resin curing agent (B), the phenoxy resin (C), and the aluminum nitride filler (D), as well as the present invention. Additives such as ion trapping agents (ion trapping agents), curing catalysts, viscosity modifiers, antioxidants, flame retardants, colorants, stress relieving agents such as butadiene rubbers and silicone rubbers, as long as the effects of the invention are not impaired. May be further contained.

Of these, it is particularly preferable to use an ion trap agent for the purpose of capturing ammonium ions generated by hydrolysis of aluminum nitride with water. Examples of the ion trapping agent include a triazine thiol compound, an inorganic ion trapping agent containing a zirconium compound, an antimony bismuth compound and a magnesium aluminum compound.
It is more preferable to use the ion trap agent in an amount of 1.0 to 3.0% by mass based on the aluminum nitride filler (D).
If the content of the ion trap agent is less than the above lower limit, the generated ammonium ions remain in the system and easily cause corrosion of the circuit member during the reliability test. On the other hand, if the above upper limit is exceeded, the excess ion trapping agent remaining in the system absorbs moisture, so that the adhesive force at the adhesive interface tends to decrease, which causes peeling during the reliability test.
In the present invention, the ammonium ion concentration is preferably 80 ppm or less, more preferably 70 ppm or less under the measurement conditions of the electric conductivity of discharged water.
If the ammonium ion concentration exceeds the above upper limit, the concentration of ammonium ions and other ionic impurities becomes high, and the circuit member is likely to be corroded during the reliability test.

Further, in the present invention, it is also preferable to use a curing catalyst. Examples of the curing catalyst include phosphorus-boron type curing catalyst, triphenylphosphine type curing catalyst, imidazole type curing catalyst, and amine type curing catalyst, and phosphorus-boron type curing catalyst and triphenylphosphine type curing catalyst are preferable. A boron-type curing catalyst is particularly preferable.
Examples of the triphenylphosphine-type curing catalyst include triarylphosphine such as triphenylphosphine and tri-p-tolylphosphine, which are preferable.
Examples of the phosphorus-boron type curing catalyst include tetraphenylphosphonium tetraphenylborate (trade name; TPP-K), tetraphenylphosphonium tetra-p-triborate (trade name: TPP-MK), and triphenylphosphine triphenylborane (trade name). ; A phosphorus-boron-based curing accelerator such as TPP-S) can be mentioned (both manufactured by Hokuko Kagaku Kogyo Co., Ltd.). Among these, tetraphenylphosphonium tetraphenylborate and tetraphenylphosphonium tetra-p-triborate are preferable in the present invention because they have excellent potential and therefore have good storage stability at room temperature.

The curing catalyst is preferably contained in an amount of 0.1 to 5.0% by mass with respect to the epoxy resin curing agent (B).

<< Film-like adhesive and its manufacturing method >>
As a preferred embodiment of the method for producing a film-like adhesive of the present invention, the composition for a high thermal conductive film-like adhesive of the present invention is applied onto one surface of a release-treated base film. , A method of applying heat drying can be mentioned, but the method is not particularly limited to this method. As the release-treated base film, any known film may be used as long as it functions as a cover film for the obtained film-like adhesive. For example, release-treated polypropylene (PP), release-treated polyethylene (PE), and release-treated polyethylene terephthalate (PET) can be mentioned. As the coating method, a known method can be appropriately adopted, and examples thereof include a method using a roll knife coater, a gravure coater, a die coater, a reverse coater, and the like.

The film-like adhesive of the present invention thus obtained preferably has a thickness of 5 to 200 μm, and more preferably 5 to 40 μm from the viewpoint of being able to more sufficiently embed irregularities on the surfaces of the wiring board and the semiconductor chip. .. If the thickness is less than the above lower limit, unevenness on the surface of the wiring board or semiconductor chip cannot be sufficiently embedded, and sufficient adhesion cannot be ensured. On the other hand, if the thickness exceeds the above upper limit, the organic solvent is removed during manufacturing. Therefore, the amount of residual solvent increases and the film tackiness tends to be strong.

<< Semiconductor package and its manufacturing method >>
Next, a preferred embodiment of the semiconductor package of the present invention and a method for manufacturing the same will be described in detail with reference to the drawings. In the following description and drawings, the same or corresponding elements are designated by the same reference numerals, and duplicate description will be omitted. 1 to 7 are schematic vertical sectional views showing a preferred embodiment of each step of the method for manufacturing a semiconductor package of the present invention.

In the method for manufacturing a semiconductor package of the present invention, first, as a first step, as shown in FIG. 1, the film form of the present invention is formed on the back surface of a semiconductor wafer 1 in which at least one semiconductor circuit is formed on the front surface. The adhesive is thermocompression bonded to provide the adhesive layer 2, and then the semiconductor wafer 1 and the dicing tape 3 are provided via the adhesive layer 2. At this time, the product in which the adhesive layer 2 and the dicing tape 3 are integrated may be thermocompression bonded at once. As the semiconductor wafer 1, a semiconductor wafer having at least one semiconductor circuit formed on its surface can be appropriately used, and examples thereof include a silicon wafer, a SiC wafer, and a GaS wafer. As the adhesive layer 2, the high thermal conductive film-like adhesive of the present invention may be used alone or in layers of two or more. As a method of providing such an adhesive layer 2 on the back surface of the wafer 1, a method capable of laminating the film-like adhesive on the back surface of the semiconductor wafer 1 can be appropriately adopted, and the back surface of the semiconductor wafer 1 can be appropriately adopted. After laminating the film-like adhesive to the wafer, when laminating two or more layers, a method of sequentially laminating the film-like adhesive until the desired thickness is obtained, or laminating the film-like adhesive to a desired thickness in advance. After that, a method of bonding to the back surface of the semiconductor wafer 1 and the like can be mentioned. Further, the device used when providing such an adhesive layer 2 on the back surface of the semiconductor wafer 1 is not particularly limited, and for example, a known device such as a roll laminator or a manual laminator can be appropriately used.

Next, as a second step, as shown in FIG. 2, a semiconductor chip 5 with an adhesive layer including the semiconductor wafer 1 and the adhesive layer 2 is obtained by dicing the semiconductor wafer 1 and the adhesive layer 2 at the same time. .. The dicing tape 3 is not particularly limited, and a known dicing tape can be used as appropriate. Further, the device used for dicing is not particularly limited, and a known dicing device can be used as appropriate.

Next, as a third step, as shown in FIG. 3, the dicing tape 3 is detached from the adhesive layer 2, and the semiconductor chip 5 with the adhesive layer and the wiring substrate 6 are thermocompression bonded via the adhesive layer 2. , The semiconductor chip 4 with an adhesive layer is mounted on the wiring substrate 5. As the wiring board 5, a substrate having a semiconductor circuit formed on its surface can be appropriately used. For example, a printed circuit board (PCB), various lead frames, and electronic components such as a resistor element and a capacitor are mounted on the substrate surface. The substrate is mentioned.

The method of mounting the semiconductor chip 5 with an adhesive layer on such a wiring board 6 is not particularly limited, and the semiconductor chip 5 with an adhesive layer is mounted on the wiring board 6 or the surface of the wiring board 6 by using the adhesive layer 2. A conventional method capable of adhering to the electronic component mounted on the top can be appropriately adopted. As such a mounting method, conventionally known heating such as a method using a mounting technique using a flip-chip bonder having a heating function from the upper part, a method using a die bonder having a heating function only from the lower part, and a method using a laminator. , Pressurization method can be mentioned.

In this way, by mounting the semiconductor chip 5 with an adhesive layer on the wiring board 6 via the adhesive layer 2 made of the film-like adhesive of the present invention, the unevenness on the wiring board 5 caused by the electronic components is described above. Since the film-like adhesive can be made to follow, the semiconductor chip 4 and the wiring board 6 can be brought into close contact with each other and fixed.

Next, as a fourth step, the film-like adhesive of the present invention is thermoset. The thermosetting temperature is not particularly limited as long as it is equal to or higher than the thermosetting start temperature of the film-like adhesive of the present invention, and varies depending on the type of resin used. ~ 180 ° C. is preferable, and 140 to 180 ° C. is more preferable from the viewpoint that curing at a higher temperature is possible in a short time. If the temperature is lower than the thermosetting start temperature, the thermosetting does not proceed sufficiently and the strength of the adhesive layer 2 tends to decrease. On the other hand, if the temperature exceeds the above upper limit, the epoxy resin in the film-like adhesive during the curing process. , Hardeners, additives, etc. tend to volatilize and easily foam. The curing treatment time is preferably 10 to 120 minutes, for example. In the present invention, by thermosetting the film-like adhesive at a high temperature, a semiconductor package in which the wiring board 6 and the semiconductor chip 4 are firmly adhered can be obtained without generating voids even if the film-like adhesive is cured at a high temperature. be able to.

Next, in the method for manufacturing a semiconductor package of the present invention, as shown in FIG. 4, it is preferable to connect the wiring board 6 and the semiconductor chip 5 with an adhesive layer via a bonding wire 7. Such a connection method is not particularly limited, and a conventionally known method, for example, a wire bonding method, a TAB (Tape Automated Bonding) method, or the like can be appropriately adopted.

Further, a plurality of other semiconductor chips 4 can be laminated by thermocompression bonding, thermosetting, and reconnecting to the wiring board 6 by a wire bonding method on the surface of the mounted semiconductor chip 4. For example, there is a method of staggering and laminating semiconductor chips as shown in FIG. 5, or a method of laminating while embedding a bonding wire 7 by thickening the second adhesive layer 2 as shown in FIG.

In the method for manufacturing a semiconductor package of the present invention, as shown in FIG. 7, it is preferable to seal the wiring board 6 and the semiconductor chip 5 with an adhesive layer with a sealing resin 8, and thus the semiconductor package 9 is sealed. Obtainable. The sealing resin 8 is not particularly limited, and an appropriately known sealing resin that can be used for manufacturing a semiconductor package can be used. Further, the sealing method using the sealing resin 8 is not particularly limited, and a known method can be appropriately adopted.

According to the method for manufacturing a semiconductor package of the present invention, it is possible to provide an adhesive layer 2 which is excellent in adhesion to an adherend, has a sufficiently small wear rate of a processing blade, and does not corrode a copper material semiconductor member. Further, by exhibiting excellent thermal conductivity after thermosetting, the heat generated on the surface of the semiconductor chip 4 can be efficiently dissipated to the outside of the semiconductor package 9.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited to the following Examples. In each Example and Comparative Example, the melt viscosity, thermal conductivity, electric conductivity of extracted water, blade wear rate, and corrosiveness evaluation were carried out by the methods shown below.

(Measurement of minimum melt viscosity)
The film-like adhesives obtained in each Example and Comparative Example were cut into a size of 5.0 cm × 5.0 cm, laminated, and bonded on a hot plate at a stage of 70 ° C. with a hand roller to increase the thickness. A test piece having a size of about 1.0 mm was obtained. This test piece was measured for changes in viscous resistance in a temperature range of 20 to 250 ° C. and a heating rate of 5 ° C./min using a rheometer [RS6000, manufactured by Hake], and from the obtained temperature-viscosity resistance curve. The minimum melt viscosity (Pa · s) was calculated.

(Void evaluation)
First, the film-like adhesive obtained in each Example and Comparative Example was used as a dummy silicon wafer at a temperature of 70 ° C. and a pressure of 0.3 MPa using a manual laminator [trade name: FM-114, manufactured by Technovision Co., Ltd.]. After adhering to one surface of a glass substrate (10 × 10 cm, thickness 50 μm), using the same manual laminator, what is the glass substrate as the dummy silicon wafer of the film-like adhesive at room temperature and pressure of 0.3 MPa? A dicing tape [trade name: K-13, manufactured by Furukawa Denki Kogyo Co., Ltd.] and a dicing frame [trade name: DTF2-8-1H001, manufactured by DISCO] were adhered on the opposite surface. Next, a dicing device [trade name: DFD-6340, manufactured by DISCO] equipped with a two-axis dicing blade [Z1: NBC-ZH2050 (27HEDD), manufactured by DISCO / Z2: NBC-ZH127F-SE (BC), manufactured by DISCO]. A glass chip, which is a dummy semiconductor chip, was obtained by dicing to a size of 10 mm × 10 mm using [manufactured by DISCO Corporation].

Next, the glass chip was placed on a wiring board (FR) under the conditions of a temperature of 120 ° C., a pressure of 0.1 MPa (load 1000 gf), and a time of 1.0 second with a die bonder [trade name: DB-800, manufactured by Hitachi High-Technologies Corporation]. -4 substrate, thickness 200 μm) was thermocompression bonded. The state of the film-like adhesive after thermocompression bonding was observed from the back surface of the glass substrate. The void evaluation was evaluated according to the following evaluation criteria.

〔Evaluation criteria〕
A: No voids C: With voids

(Thermal conductivity)
The obtained film-like adhesive is cut into square pieces having a side of 50 mm or more, the samples cut so as to have a thickness of 5 mm or more are superposed, placed on a disk-shaped mold having a diameter of 50 mm and a thickness of 5 mm, and a compression press. Using a molding machine, the film-like adhesive is thermoset by heating at a temperature of 150 ° C. and a pressure of 2 MPa for 10 minutes and then heating in a dryer at a temperature of 180 ° C. for 1 hour to obtain a thickness of 50 mm in diameter. A disk-shaped test piece having a size of 5 mm was obtained. Regarding this test piece, the thermal conductivity (W / m · K) was measured by the thermal flow metering method (based on JIS-A1412) using a thermal conductivity measuring device (trade name: HC-110, manufactured by Hideko Seiki Co., Ltd.). Was measured.

(Extracted water electrical conductivity, ammonium ion concentration)
About 10 g of the film-like adhesive before thermosetting was cut out and heat-treated at a temperature of 180 ° C. for 1 hour using a hot air oven to prepare a sample after thermosetting. Approximately 2 g of the thermosetting sample and 50 mL of pure water are placed in a container and heat-treated at a temperature of 121 ° C. for 20 hours, and the electric conductivity of the obtained extracted water is transferred to an electric conductivity meter [CYBERSCAN PC300 manufactured by EUTECH INSTRUMENTS]. Was measured. Moreover, the ammonium ion concentration of the obtained extracted water was measured by ion chromatography [HIC-SP, manufactured by Shimadzu Corporation].

(Corrosiveness evaluation)
First, the obtained film-like adhesive was attached to a dummy silicon wafer (8 inch size, thickness 100 μm) at a temperature of 70 ° C. and a pressure of 0.3 MPa using a manual laminator [trade name: FM-114, manufactured by Technovision Co., Ltd.]. Then, using the same manual laminator, dicing tape [trade name: K-13, manufactured by Furukawa Denki Kogyo] and dicing frame on the side opposite to the dummy silicon wafer of the film adhesive at room temperature and pressure of 0.3 MPa. [Product name: DTF2-8-1H001, manufactured by DISCO] was bonded to prepare a test piece. For this test piece, a dicing device [trade name] equipped with a 2-axis dicing blade [Z1: NBC-ZH2030-SE (DD), manufactured by DISCO / Z2: NBC-ZH127F-SE (BB), manufactured by DISCO]. : DFD-6340, manufactured by DISCO] was diced to a size of 7.5 × 7.5 mm to prepare a semiconductor chip with a film-like adhesive.

Next, the semiconductor chip with a film-like adhesive was used in a die bonder [trade name: DB-800, manufactured by Hitachi High-Technologies Corporation] under the conditions of a temperature of 120 ° C., a pressure of 0.1 MPa (load 1000 gf), and a time of 1.0 second. Was mounted on a lead frame substrate [material: 42Arroy-based metal, thickness: 125 μm, manufactured by Letterpress Printing Co., Ltd.], and the film-like adhesive was thermoset by heating at 150 ° C. for 1 hour. Then, using a wire bonder [trade name: UTC-3000, manufactured by Shinkawa Co., Ltd.], the semiconductor chip and the lead frame substrate were connected to a copper wire [trade name: EX-1, 18umΦ, Nippon Steel Materials Co., Ltd.] at a stage temperature of 200 ° C. Zu Co., Ltd.]. Further, the semiconductor chip with the film-like adhesive was mounted so as to be stacked on the previously mounted semiconductor chip, and the film-like adhesive was thermoset by heating at 150 ° C. for 1 hour.

After that, these semiconductor chips are sealed with a molding agent [trade name: KE-3000F5-2, manufactured by Kyocera Corporation] with a molding device [trade name: Y1E, manufactured by TOWA], and at a temperature of 180 ° C. 5 After heat treatment for a period of time, the molding agent was cured to obtain a semiconductor package sample.

After performing a bias HAST test (temperature: 130 ° C., relative humidity: 85%, time: 100 hours) on the obtained semiconductor package sample, a cross section of this semiconductor package sample is subjected to a desktop scanning electron microscope [trade name: Pro, manufactured by Jasco International Co., Ltd.], the degree of corrosion of the copper circuit and copper wire part on the surface of the semiconductor chip was observed.
As a result of the observation, when no corrosion was observed, it was judged as "A (good corrosiveness)", and when corrosion was observed, it was judged as "C (bad corrosiveness)".

(Evaluation of blade wear resistance)
First, the obtained film-like adhesive was attached to a dummy silicon wafer (8 inch size, thickness 100 μm) at a temperature of 70 ° C. and a pressure of 0.3 MPa using a manual laminator [trade name: FM-114, manufactured by Technovision Co., Ltd.]. Then, using the same manual laminator, dicing tape [trade name: G-11, manufactured by Lintec Co., Ltd.] and dicing frame on the side opposite to the dummy silicon wafer of the film adhesive at room temperature and pressure of 0.3 MPa. [Product name: DTF2-8-1H001, manufactured by DISCO] was bonded to prepare a test piece. A dicing device [trade name] equipped with a 2-axis dicing blade [Z1: NBC-ZH2030-SE (DD), manufactured by DISCO / Z2: NBC-ZH127F-SE (BB), manufactured by DISCO] for this test piece. : DFD-6340, manufactured by DISCO] Dicing was performed to a size of 1.0 × 1.0 mm. Setup is performed before dicing (before dicing) and at the time of cutting 150 m (after machining), and the amount of blade edge extension is measured by a non-contact type (laser type), and the amount of blade wear after dicing (blade edge before machining). The amount of feeding-the amount of cutting edge of the blade after processing) was calculated. The calculated amount was evaluated according to the following evaluation criteria.

〔Evaluation criteria〕
A: Wear amount is less than 10 μm C: Wear amount is 10 μm or more

(Example 1)
Novolak type phenol resin [trade name: PS-4271, mass average molecular weight: 400, softening point: 70 ° C, solid, hydroxyl group equivalent: 105 g / eq, manufactured by Gunei Chemical Co., Ltd.] 29 parts by mass, bisphenol A type epoxy resin [Product name: YD-128, mass average molecular weight: 400, softening point: 25 ° C or less, liquid, epoxy equivalent: 190, manufactured by Shin Nikka Epoxy Mfg. Co., Ltd.] 49 parts by mass and bisphenol A / bisphenol F Copolymerization type phenoxy resin [trade name: YP-70, mass average molecular weight: 55,000, Tg: 70 ° C., manufactured by Shin Nikka Epoxy Mfg. Co., Ltd.] 30 parts by mass, epoxy-based silane coupling agent [trade name: S-510, 3-glycidyloxypropyltrimethoxysilane, manufactured by JNC Co., Ltd.] Weigh 3 parts by mass and heat in a 500 ml separable flask using 79 parts by mass of cyclopentanone as a solvent at a temperature of 110 ° C. for 2 hours. The mixture was stirred to obtain a resin varnish.

Next, 190 parts by mass of this resin varnish was transferred to an 800 ml planetary mixer, and phosphoric acid water resistant treatment aluminum nitride [trade name: HF-01A, average particle size 1.1 μm, moth hardness 8, thermal conductivity 200 W / m · K. , Tokuyama Co., Ltd.] 273 parts by mass, phosphorus-boron type curing catalyst [trade name: TPP-K, manufactured by Hokuko Chemical Co., Ltd., tetraphenylphosphonium tetraphenylborate] 0.8 parts by mass was added at room temperature. After stirring and mixing for a time, vacuum defoaming was performed to obtain a mixed varnish. Next, the obtained mixed varnish was applied onto a mold-released polyethylene terephthalate film (PET film) having a thickness of 38 μm, dried by heating (held at 130 ° C. for 10 minutes), and adhered to a film having a thickness of 20 μm. I got the agent. The melt viscosity and thermal conductivity of the obtained film-like adhesive, the electrical conductivity of the extracted water, the corrosiveness evaluation, and the blade wear resistance evaluation were carried out. The results obtained are shown in Table 1 together with the composition of the film-like adhesive.

(Example 2)
Epoxy-based silane coupling agent [trade name: S-510, 3-glycidyloxypropyltrimethoxysilane, JNC Co., Ltd.] Phosphophosphate-based surfactant instead of 3 parts by mass [trade name: Phosphanol RS- 710, manufactured by Toho Kagaku Co., Ltd.] Using 3 parts by mass of water-resistant aluminum nitride [trade name: HF-01A, average particle size 1.1 μm, moth hardness 8, thermal conductivity 200 W / m · K, ( Made by Tokuyama Co., Ltd.]) Water-resistant untreated aluminum nitride filler instead of 273 parts by mass [Product name: HF-01, average particle size 1.1 μm, moth hardness 8, thermal conductivity 200 W / (m ・ K), Co., Ltd. ) Tokuyama] A composition for a film-like adhesive and a film-like adhesive were obtained in the same manner as in Example 1 except that 273 parts by mass was used.

(Example 3)
Water-resistant untreated aluminum nitride filler [Product name: HF-01, average particle size 1.1 μm, moth hardness 8, thermal conductivity 200 W / mK, manufactured by Tokuyama Co., Ltd.] Phosphorus as aluminum nitride instead of 273 parts by mass Acid water resistant aluminum nitride [trade name; HF-01A, average particle size 1.1 μm, moth hardness 8, thermal conductivity 200 W / (mK), manufactured by Tokuyama Co., Ltd.] 273 parts by mass was used. A film-like adhesive composition and a film-like adhesive were obtained in the same manner as in Example 2.

(Example 4)
283 parts by mass of phosphoric acid-treated water-resistant aluminum nitride [trade name: HF-01A, average particle size 1.1 μm, Mohs hardness 8, thermal conductivity 200 W / mK, manufactured by Tokuyama Co., Ltd.], and an ion trap agent. [Product name: IXE-6107, bismuth / zirconium type, manufactured by Toa Synthetic Co., Ltd.] A film-like adhesive composition and a film-like adhesive in the same manner as in Example 3 except that 4.3 parts by mass was used. Got

(Example 5)
Phosphoric acid treatment Water resistant treatment Aluminum nitride [trade name; HF-01A, average particle size 1.1 μm, Mohs hardness 8, thermal conductivity 200 W / mK, manufactured by Tokuyama Co., Ltd.] by 283 parts by mass, and an ion trap agent [Product name: IXE-100, zirconium-based, manufactured by Toa Synthetic Co., Ltd.] A film-like adhesive composition and a film-like adhesive were obtained in the same manner as in Example 3 except that 4.3 parts by mass was used. It was.

(Example 6)
Phosphoric acid treatment Water resistant treatment Aluminum nitride [trade name; HF-01A, average particle size 1.1 μm, Mohs hardness 8, thermal conductivity 200 W / mK, manufactured by Tokuyama Co., Ltd.] 490 parts by mass, and an ion trap agent [Product name: IXE-100, zirconium-based, manufactured by Toa Synthetic Co., Ltd.] A film-like adhesive composition and a film-like adhesive were obtained in the same manner as in Example 3 except that 7.4 parts by mass was used. It was.

(Example 7)
169 parts by mass of phosphoric acid-treated water-resistant aluminum nitride [trade name: HF-01A, average particle size 1.1 μm, Mohs hardness 8, thermal conductivity 200 W / mK, manufactured by Tokuyama Co., Ltd.], and an ion trap agent. [Product name: IXE-100, zirconium-based, manufactured by Toa Synthetic Co., Ltd.] A film-like adhesive composition and a film-like adhesive were obtained in the same manner as in Example 3 except that 2.5 parts by mass was used. It was.

(Example 8)
Hydronic acid-treated water-resistant aluminum nitride [trade name: HF-01A, average particle size 1.1 μm, Mohs hardness 8, thermal conductivity 200 W / mK, manufactured by Tokuyama Co., Ltd.] by 134 parts by mass, and an ion trap agent [Product name: IXE-100, zirconium-based, manufactured by Toa Synthetic Co., Ltd.] 2.1 A film-like adhesive composition and a film-like adhesive were obtained in the same manner as in Example 3 except that 2.1 parts by mass was used. It was.

(Comparative Example 1)
Phosphoric acid water resistant aluminum nitride [trade name: HF-01A, average particle size 1.1 μm, moth hardness 8, thermal conductivity 200 W / mK, manufactured by Tokuyama Co., Ltd.] Water resistant untreated aluminum nitride instead of 273 parts by mass Example 1 except that an aluminum filler [trade name: HF-01, average particle size 1.1 μm, moth hardness 8, thermal conductivity 200 W / (m · K), manufactured by Tokuyama Co., Ltd.] 273 parts by mass was used. A composition for a film-like adhesive and a film-like adhesive were obtained in the same manner as in the above.

(Comparative Example 2)
Phosphoric acid water resistant aluminum nitride [trade name: HF-01A, average particle size 1.1 μm, Mohs hardness 8, thermal conductivity 200 W / m · K, manufactured by Tokuyama Co., Ltd.] Spherical alumina filler instead of 273 parts by mass [ Product name: AX3-15R, average particle size 3.0 μm, Mohs hardness 9, thermal conductivity 36 W / (m · K), manufactured by Nippon Steel Materials Co., Ltd.] In the same manner, a composition for a film-like adhesive and a film-like adhesive were obtained.

(Comparative Example 3)
Water-resistant treated aluminum nitride [Product name: HF-01A, average particle size 1.1 μm, Mohs hardness 8, thermal conductivity 200 W / mK, manufactured by Tokuyama Co., Ltd.] Boron nitride filler instead of 273 parts by mass [ Product name: UHP-01, average particle size 8.0 μm, Mohs hardness 2, thermal conductivity 60 W / m · K, manufactured by Showa Denko KK] 92 parts by mass in the same manner as in Example 1. A composition for a film-like adhesive and a film-like adhesive were obtained.

(Comparative Example 4)
Phosphoric acid treatment Water resistant treatment Aluminum nitride [trade name: HF-01A, average particle size 1.1 μm, Mohs hardness 8, thermal conductivity 200 W / mK, manufactured by Tokuyama Co., Ltd.] is 79 parts by mass, and an ion trap agent. [Product name: IXE-100, zirconium-based, manufactured by Toa Synthetic Co., Ltd.] A film-like adhesive composition and a film-like adhesive were obtained in the same manner as in Example 8 except that 1.2 parts by mass was used. ..

(Comparative Example 5)
Phosphoric acid treatment Water resistant treatment Aluminum nitride [trade name: HF-01A, average particle size 1.1 μm, Mohs hardness 8, thermal conductivity 200 W / mK, manufactured by Tokuyama Co., Ltd.] 605 parts by mass, and an ion trap agent [Product name: IXE-100, zirconium-based, manufactured by Toa Synthetic Co., Ltd.] A film-like adhesive composition and a film-like adhesive were obtained in the same manner as in Example 8 except that 9.0 parts by mass was used. ..

The results obtained are summarized in Tables 1 and 2 below.
The number indicating the blending amount of the material is a mass part.

The following points are clear from Tables 1 and 2 above.
As shown in Examples 1 to 8, each of the epoxy resin, the epoxy resin curing agent, the phenoxy resin and the aluminum nitride filler is contained, and the content of the aluminum nitride filler is the total amount of these resins and the filler. On the other hand, it is 30 to 60% by volume, and by satisfying all the characteristics of the film-like adhesive specified in the present invention, the generation of voids is suppressed while maintaining high thermal conductivity, and corrosion resistance and blade friction resistance. Excellent for.

On the other hand, in Comparative Example 1, the value of the electric conductivity of the extracted water was high and the corrosiveness was inferior as compared with Examples 1 and 2. It is presumed that this is a result of the difference in the combination of the surface treatment agent and the aluminum nitride having a large effect on the amount of ammonium ions generated during the bias HAST test.
On the other hand, in Comparative Examples 2 and 3 in which spherical alumina and boron nitride were used without using the aluminum nitride filler, spherical alumina was used even though all of the characteristics of the film-like adhesive specified in the present invention were satisfied. In Comparative Example 2, the blade friction property was inferior. Further, in Comparative Example 3 using boron nitride, voids were generated. It is presumed that this is because boron nitride has a scaly shape, so that the melt viscosity after being mixed with the resin binder tends to increase as compared with the spherical shape.

In Comparative Example 4 in which the content of the aluminum nitride filler with respect to the total amount of the epoxy resin, the epoxy resin curing agent, the phenoxy resin and the aluminum nitride filler was less than 30% by volume, the minimum melt viscosity and the thermal conductivity were low. As a result, when the semiconductor chip provided with the film-like adhesive is mounted on the wiring board, the film-like adhesive tends to squeeze out, and the generated heat does not easily escape to the outside of the package.
On the contrary, in Comparative Example 5 in which the content of the aluminum nitride filler exceeds 60% by volume, the minimum melt viscosity and the electric conductivity of the extracted water were high, voids were generated, and the corrosiveness was also inferior.

Although the present invention has been described with its embodiments and examples, we do not intend to limit our invention in any detail of the description unless otherwise specified, and in the spirit of the invention set forth in the appended claims. I think that it should be widely interpreted without going against the scope.

The present application claims priority based on Japanese Patent Application No. 2016-51630 filed in Japan on March 15, 2016, which is referred to herein and is described herein. Incorporate as a part.

1 Semiconductor wafer 2 Film-like adhesive layer 3 Dicing tape 4 Semiconductor chip 5 Semiconductor chip with film-like adhesive 6 Wiring substrate 7 Bonding wire 8 Encapsulating resin 9 Semiconductor package

Claims (6)

A composition for a film-like adhesive containing an epoxy resin (A), an epoxy resin curing agent (B), a phenoxy resin (C) , an aluminum nitride filler (D) , and a phosphoric acid ester-based surfactant, respectively. ,
The content of the aluminum nitride filler (D) is relative to the total amount of the epoxy resin (A), the epoxy resin curing agent (B), the phenoxy resin (C), and the aluminum nitride filler (D). 30-60% by volume,
The aluminum nitride filler (D) has a surface oxide layer formed on the surface of the filler, and has been subjected to a water resistant surface treatment with phosphoric acid or a phosphoric acid compound.
When the film-like adhesive obtained from the film-like adhesive composition was heated at a heating rate of 25 ° C. to 5 ° C./min, the minimum melt viscosity in the range of 200 to 10,000 Pa · s was obtained at 80 ° C. or higher. When the film is heat-cured, a cured film having a thermal conductivity of 1.0 W / m · K or more is given, and the electrical conductivity of the extracted water extracted into pure water at 121 ° C. for 20 hours after the thermosetting is 50 μS / cm or less. A composition for a film-like adhesive, which is characterized by being present. Further, an ion trap agent selected from a triazine thiol compound, a zirconium compound, an antimony bismuth compound and a magnesium aluminum compound is contained in an ion trapping agent in an amount of 1.0 to 3.0% by mass based on the aluminum nitride filler (D). The composition for a film-like adhesive according to claim 1. A film-like adhesive obtained by the film-like adhesive composition according to claim 1 or 2. A method for producing a film-like adhesive, which comprises coating and drying the composition for a film-like adhesive according to claim 1 or 2 on a release-treated base film. The first step of providing an adhesive layer on the back surface of a semiconductor wafer having at least one semiconductor circuit formed on the front surface by heat-bonding the film-like adhesive and dicing tape according to claim 3.
A second step of obtaining a semiconductor chip with an adhesive layer including the semiconductor wafer and the adhesive layer by dicing the semiconductor wafer and the adhesive layer at the same time.
A third step of removing the dicing tape from the adhesive layer and thermocompression bonding the semiconductor chip with the adhesive layer and the wiring substrate via the adhesive layer, and
Fourth step of thermosetting the adhesive layer,
A method for manufacturing a semiconductor package, which comprises. A semiconductor package obtained by the manufacturing method according to claim 5.

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