JP5186936B2 - Epoxy resin composition for semiconductor encapsulation and semiconductor device - Google Patents

Description

  The present invention relates to an epoxy resin composition for semiconductor encapsulation and a semiconductor device using the same.

  In recent years, along with market trends of downsizing, weight reduction, and high performance of electronic devices, higher integration of electronic components has progressed year by year, and surface mounting of packages has been promoted. On the other hand, corporate activities in consideration of the global environment are regarded as important, and in the field of electronic equipment, it is required to completely eliminate lead, which is a harmful substance, except for specific uses by 2006. Under such circumstances, the solder used for electronic parts is also required to be converted to lead-free solder. However, since the melting point of lead-free solder is higher than that of conventional lead / tin solder, the temperature at the time of solder mounting such as infrared reflow and solder immersion is increased from 220 to 240 ° C. to 240 to 260 ° C. Become. Due to such an increase in mounting temperature, there is a problem that the resin for sealing the semiconductor is easily cracked at the time of mounting, and it is difficult to guarantee the reliability of the semiconductor. Further, with respect to the lead frame, from the viewpoint that it is necessary to remove lead from the external solder plating, the use of a lead frame that has been subjected to nickel / palladium plating in advance instead of the external solder plating is being promoted. This nickel / palladium plating has low adhesion to a general sealing material, and there is a problem that peeling is likely to occur at the interface during mounting, and cracks are likely to occur in the resin portion.

In response to such a problem, by using a low water-absorbing epoxy resin or a curing agent as a sealing resin for improving the solder reflow property (for example, see Patent Documents 1 and 2), the mounting temperature rises. It has come to be able to take measures against. On the other hand, the epoxy resin composition exhibiting such low water absorption and low elastic modulus has a low crosslink density, and the molded product immediately after curing is soft, and in continuous production, there is a problem in moldability such as resin tray on the mold. There was a problem of lowering productivity.
In addition, as an effort to improve continuous moldability, the application of a release agent with a high mold release effect has been proposed, but a mold release agent with a high mold release effect is inevitably raised on the surface of the cured resin, When continuously produced, there is a drawback that the appearance of the cured resin surface and the mold surface are significantly stained. In addition, as an epoxy resin composition having an excellent appearance on the surface of a cured resin product, a method of adding a silicone compound having a specific structure has been proposed (for example, see Patent Documents 3 and 4), but the releasability is not good. In the continuous molding, there is a problem that the continuous moldability is deteriorated, for example, the resin adheres at the air vent portion and the air vent is blocked to cause molding defects such as unfilling. In view of the above, there is a demand for an epoxy resin composition for semiconductor encapsulation that meets all the problems of solder reflow, mold release, continuous moldability, appearance of the cured resin surface, and mold contamination.

Japanese Patent Laid-Open No. 9-3161 JP 9-235353 A JP 2002-97344 A JP 2001-310930 A

The present invention relates to an epoxy resin composition for semiconductor encapsulation excellent in balance with continuous moldability, solder reflow property, mold releasability at the time of element sealing molding, appearance of the surface of the cured resin, and mold contamination. The semiconductor device used is provided.

The epoxy resin composition for semiconductor encapsulation of the present invention is
(A) first epoxy resin, (B) phenol resin curing agent, (C) organopolysiloxane (c1) having a polycaprolactone group and / or organopolysiloxane (c1) having a polycaprolactone group A reaction product (c2) of 2 with an epoxy resin, and (D) a tolylene diisocyanate-modified oxidized wax.

The epoxy resin composition for semiconductor encapsulation of the present invention is an epoxy resin composition in which the organopolysiloxane (c1) having a polycaprolactone group is an organopolysiloxane represented by the following general formula (1). be able to.
(However, in the general formula (1), R1 is a group selected from hydrogen, a methyl group, a phenyl group, or R2, and may be the same or different from each other, but at least one of them is R2. The average value of n1 is a positive number of 1 to 50. In R2, the average value of a is a positive number of 1 to 20, and R3 is an organic group having a polycaprolactone group. Is an organic group having 1 to 30 carbon atoms.)

  The epoxy resin composition for semiconductor encapsulation of the present invention may be an epoxy resin composition in which the dropping point of the (D) tolylene diisocyanate-modified oxidized wax is 70 ° C or higher and 120 ° C or lower.

  The epoxy resin composition for semiconductor encapsulation of the present invention may be an epoxy resin composition in which the acid value of the (D) tolylene diisocyanate-modified oxidized wax is 10 mgKOH / g or more and 50 mgKOH / g or less. .

  In the epoxy resin composition for semiconductor encapsulation of the present invention, the (D) tolylene diisocyanate modified oxidized wax has an average particle size of 20 μm or more and 70 μm or less, and a particle size of 106 μm or more in all tolylene diisocyanate modified oxidized wax. The epoxy resin composition having a particle content ratio of 0.1% by weight or less can be used.

  The epoxy resin composition for semiconductor encapsulation of the present invention comprises a blending amount W (c1) of the organopolysiloxane (c1) having the polycaprolactone group and a blending amount W (D) of the (D) tolylene diisocyanate-modified wax. The weight ratio W (c1) / W (D) can be an epoxy resin composition in the range of 3/1 to 1/5.

The epoxy resin composition for semiconductor encapsulation of the present invention is an epoxy resin composition in which the (A) first epoxy resin includes an epoxy resin (a1) represented by the following general formula (2). Can do.
(However, in the general formula (2), Ar1 and Ar2 are aromatic groups having 6 to 20 carbon atoms, and may be the same or different. R4 and R5 are carbonized groups having 1 to 6 carbon atoms. R6 and R7 are hydrogen, a hydrocarbon group having 1 to 4 carbon atoms or an aromatic group having 6 to 20 carbon atoms, and are the same as each other. R8 is a hydrocarbon group having 1 to 4 carbon atoms, W1 is an oxygen atom or a sulfur atom, OG is a glycidoxy group, b and c are integers of 0 to 10, and d is 0. Is an integer of -3, e is an integer of 1 to 3. m2 is an integer of 0 to 20, n2 is an integer of 1 to 20, and the average of m2 / n2 is 1/10 to 1/1. Even if m2 repeating units and n2 repeating units are continuously arranged, Each other may have lined up alternately or randomly, but takes a structure having always -CR6R7- between each.)

  The semiconductor device of the present invention is characterized in that an element is sealed using the above-described epoxy resin composition for sealing a semiconductor.

  According to the present invention, it exhibits excellent solder reflow resistance at the time of mounting an electronic component device, as well as mold release properties, continuous moldability, appearance of the cured resin surface, mold contamination, etc. An epoxy resin composition for semiconductor encapsulation excellent in balance and a semiconductor device using the same are obtained.

  The present invention provides (A) a first epoxy resin and (B) a phenol resin-based curing agent as an essential component, (C) an organopolysiloxane having a polycaprolactone group (c1), and / or By containing a reaction product (c2) of an organopolysiloxane (c1) having a polycaprolactone group and a second epoxy resin, and (D) a tolylene diisocyanate-modified oxidized wax, it is separated at the time of sealing molding of the device. Epoxy for semiconductor encapsulation with excellent moldability, continuous moldability, appearance of the cured resin surface and excellent moldability that prevents mold contamination, and excellent solder reflow when mounting electronic parts A resin composition and a semiconductor device using the resin composition are obtained.

  Hereinafter, the present invention will be described in detail.

  The (A) first epoxy resin used in the present invention is a monomer, oligomer or polymer in general having two or more epoxy groups in one molecule, and its molecular weight and molecular structure are not particularly limited. For example, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, stilbene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, triphenolmethane type epoxy resin, alkyl Modified triphenolmethane type epoxy resin, phenol aralkyl type epoxy resin having phenylene skeleton, phenol aralkyl type epoxy resin having biphenylene skeleton, naphthol type epoxy resin, naphthol having phenylene skeleton Aralkyl type epoxy resin, naphthol aralkyl type epoxy resin having biphenylene skeleton, triazine nucleus-containing epoxy resin, dicyclopentadiene modified phenol type epoxy resin, epoxy resin having anthracene or hydrogenated skeleton, hydroquinone type epoxy resin, phenolic Examples include epoxy resins obtained by glycidyl etherification of phenol resins obtained by co-condensing hydroxyl-containing aromatics, aldehydes, and aromatics containing alkoxy groups or thioalkyl groups with epichlorohydrin. One type may be used alone, or two or more types may be used in combination. Especially, from a viewpoint of solder reflow property and flame resistance, the epoxy resin (a1) represented by the following general formula (2) is preferable.

(However, in the general formula (2), Ar1 and Ar2 are aromatic groups having 6 to 20 carbon atoms, and may be the same or different. R4 and R5 are carbonized groups having 1 to 6 carbon atoms. R6 and R7 are hydrogen, a hydrocarbon group having 1 to 4 carbon atoms or an aromatic group having 6 to 20 carbon atoms, and are the same as each other. R8 is a hydrocarbon group having 1 to 4 carbon atoms, W1 is an oxygen atom or a sulfur atom, OG is a glycidoxy group, b and c are integers of 0 to 10, and d is 0. Is an integer of -3, e is an integer of 1 to 3. m2 is an integer of 0 to 20, n2 is an integer of 1 to 20, and the average of m2 / n2 is 1/10 to 1/1. Even if m2 repeating units and n2 repeating units are continuously arranged, Each other may have lined up alternately or randomly, but takes a structure having always -CR6R7- between each.)

  The epoxy resin (a1) represented by the general formula (2) is an aggregate of a plurality of components having different m2 and n2 values, and each component is an integer in which m3 is 0 to 20, and n3 is 1 to 1. It is an integer of 20, which may be the same or different for each component, but the average value of m3 / n3 as a whole is preferably 1/10 to 1/1, More preferably, it is 9 to 1/2. If the average value of m3 / n3 is not less than the above lower limit value, the effect of improving solder reflow property and flame resistance can be obtained. Moreover, if it is below the said upper limit, there is little possibility of causing the fall of the fluidity | liquidity of the resin composition by resin viscosity becoming high, and favorable fluidity | liquidity can be obtained.

  Specific examples of the epoxy resin (a1) having the structure represented by the general formula (2) include a phenol aralkyl type epoxy resin having a phenylene skeleton (in the general formula (2), -Ar1-: phenylene group, -Ar2- : Phenylene group, R6: hydrogen, R7: hydrogen, b = 0, c = 0, d = 0, e = 1, m2 / n2 average value: 1), phenol aralkyl type epoxy resin having a biphenylene skeleton (general formula In (2), -Ar1-: biphenylene group, -Ar2-: phenylene group, R6: hydrogen, R7: hydrogen, b = 0, c = 0, d = 0, e = 1, m2 / n2 average value: 1), a naphthol aralkyl type epoxy resin having a phenylene skeleton (in the general formula (2), -Ar1-: naphthalene group, -Ar2-: phenylene group, R6: hydrogen, R7: hydrogen, b = 0 c = 0, d = 0, e = 1, m2 / n2 average value: 1), epoxidized resin of novolak type phenol resin obtained by cocondensation of methoxynaphthalene, phenol and formaldehyde (in general formula (2)) , -Ar1-: naphthalene group, -Ar2-: phenylene group, R6: hydrogen atom, R7: hydrogen atom, R8: methyl group, W1: oxygen atom, b = 0, c = 0, d = 1, e = 1 Epoxide resin of a novolak-type phenolic resin obtained by cocondensation of methoxynaphthalene, cresol and formaldehyde (general formula (2)) -Ar1-: naphthalene group, -Ar2-: phenylene group, R5: methyl group, R6: hydrogen atom, R7: hydrogen atom, R8: methyl group, W1: oxygen atom, = 0, c = 1, d = 1, e = 1, average value of m @ 2 / n2 in the average value of the whole: 1 / 10-1 / 1), and the like. These may be used alone or in combination of two or more.

  Although it does not specifically limit about the lower limit of the compounding ratio of the whole (A) 1st epoxy resin used by this invention, It is preferable that it is 3 weight% or more in all the epoxy resin compositions, and 5 weight% or more. It is more preferable that When the lower limit of the blending ratio is within the above range, the resin composition has excellent fluidity during molding. In addition, the upper limit value of the blending ratio of the entire first epoxy resin (A) is not particularly limited, but is preferably 12% by weight or less and preferably 10% by weight or less in the total epoxy resin composition. Is more preferable. When the upper limit of the blending ratio is within the above range, the resin composition has excellent solder reflow properties.

  The (B) phenolic resin-based curing agent used in the present invention is a monomer, oligomer or polymer in general having two or more phenolic hydroxyl groups in one molecule, and its molecular weight and molecular structure are not particularly limited. For example, phenol novolak resin, cresol novolak resin, naphthol novolak resin, dicyclopentadiene modified phenol resin, terpene modified phenol resin, triphenolmethane type resin, phenol aralkyl resin having phenylene skeleton and / or biphenylene skeleton, phenylene and / or Examples thereof include a naphthol aralkyl resin having a biphenylene skeleton, a bisphenol compound, and the like. These may be used alone or in combination of two or more. Among these, the hydroxyl equivalent is preferably 90 g / eq or more and 250 g / eq or less from the viewpoint of curability.

  Although it does not specifically limit about the lower limit of the compounding ratio of the (B) phenol resin hardening | curing agent used by this invention, It is preferable that it is 2 weight% or more in all the epoxy resin compositions, and is 4 weight% or more. More preferably. When the lower limit of the blending ratio is within the above range, the resin composition has excellent fluidity during molding. Moreover, about the upper limit of the mixture ratio of (B) phenol resin type hardening | curing agent, it is preferable that it is 10 weight% or less, and it is more preferable that it is 8 weight% or less. When the upper limit of the blending ratio is within the above range, the resin composition has excellent solder reflow properties.

  Moreover, as a compounding ratio of (A) 1st epoxy resin and (B) phenol resin type hardening | curing agent, the number of epoxy groups (EP) of all the epoxy resins, the number of phenolic hydroxyl groups (OH) of all the phenol resin type hardening | curing agents, and The ratio (EP) / (OH) is preferably 0.8 or more and 1.3 or less. When the equivalent ratio is within this range, the curability of the epoxy resin composition can be maintained, or the physical properties of the resin cured product can be kept good.

  In the present invention, (C) an organopolysiloxane (c1) having a polycaprolactone group and / or a reaction product (c2) of an organopolysiloxane (c1) having a polycaprolactone group and a second epoxy resin, (D) Tolylene diisocyanate-modified oxidized wax is preferably used in combination. Thereby, since the epoxy resin matrix and the (D) tolylene diisocyanate-modified oxidized wax can be compatibilized in an appropriate state, the epoxy resin composition using these in combination is formed on the surface of the cured resin product at the time of molding. Appearance and releasability can both be achieved, and continuous formability is improved.

  On the other hand, (D) an organopolysiloxane (c1) having a polycaprolactone group and / or an organopolysiloxane (c1) having a polycaprolactone group without using a tolylene diisocyanate-modified oxidized wax, and When only the reaction product (c2) with epoxy resin No. 2 is used, the releasability becomes insufficient and the continuous moldability is lowered. On the contrary, (C) the organopolysiloxane (c1) having a polycaprolactone group and / or the reaction product (c2) of the organopolysiloxane (c1) having a polycaprolactone group and the second epoxy resin is not used. In addition, when only (D) tolylene diisocyanate-modified oxidized wax is used, compatibilization of (D) tolylene diisocyanate-modified oxidized wax in the epoxy resin matrix becomes insufficient, and the appearance of the resin cured product surface is deteriorated. The weight ratio W (c1) / W (D) of the blending amount W (c1) of the organopolysiloxane having a polycaprolactone group (c1) and the blending amount W (D) of the (D) tolylene diisocyanate-modified oxidized wax is The range of 3/1 to 1/5 is preferable, and when it is within this range, the effect of using both in combination is the highest. The amount of the organopolysiloxane (c1) having a polycaprolactone group when the reaction product (c2) of the organopolysiloxane (c1) having a polycaprolactone group and the second epoxy resin is used as the component (C). W (c1) means the compounding quantity with respect to all the epoxy resin compositions of the organopolysiloxane (c1) which has a polycaprolactone group before making it react with a 2nd epoxy resin.

The organopolysiloxane (c1) having a polycaprolactone group used in the present invention is obtained by mixing polycaprolactone and organopolysiloxane and reacting them at 50 to 100 ° C. under a platinum catalyst. Although it does not specifically limit as organopolysiloxane (c1) which has a polycaprolactone group, The organopolysiloxane represented by following General formula (1) is preferable.
(However, in the general formula (1), R1 is a group selected from hydrogen, a methyl group, a phenyl group, or R2, and may be the same or different from each other, but at least one of them is R2. The average value of n1 is a positive number of 1 to 50. In R2, the average value of a is a positive number of 1 to 20, and R3 is an organic group having a polycaprolactone group. Is an organic group having 1 to 30 carbon atoms.)

  In the general formula (1), R1 is a group selected from hydrogen, a methyl group, a phenyl group, or R2, and may be the same or different from each other, but at least one is represented by R2. An organic group having a polycaprolactone group. In R2, the average value of a is a positive number of 1 or more and 20 or less, and R3 is an organic group having 1 to 30 carbon atoms. When the carbon number of the organic group having a polycaprolactone group is within the above range, the compatibility with the epoxy resin matrix becomes appropriate, and the appearance of the cured resin surface becomes good. In the general formula (1), the average value of n1 is a positive number of 1 or more and 50 or less. When the average value of n1 is within the above range, the viscosity of the organopolysiloxane itself is in an appropriate range, and the fluidity is good.

  When the organopolysiloxane (c1) having a polycaprolactone group (C) and / or the reaction product (c2) of an organopolysiloxane (c1) having a polycaprolactone group and a second epoxy resin is used, fluidity Even when a release agent having poor compatibility with the resin, such as (D) tolylene diisocyanate-modified oxidized wax, is used, the appearance of the cured resin surface can be improved.

  (C) The method for producing the reaction product (c2) of the organopolysiloxane (c1) having a polycaprolactone group and the second epoxy resin is not particularly limited, but for example, an organopolysiloxane having a polycaprolactone group Siloxane (c1) can be obtained by melting and reacting with the second epoxy resin together with a curing accelerator. The curing accelerator referred to here may be anything that promotes the curing reaction between the polycaprolactone group of the organopolysiloxane (c1) and the epoxy group of the second epoxy resin, and will be described later (A) the first epoxy. The same thing as the hardening accelerator which accelerates | stimulates the hardening reaction of the epoxy group of resin and the phenolic hydroxyl group of (B) phenol resin-type hardening | curing agent can be used. The second epoxy resin referred to here is a monomer, oligomer or polymer in general having two or more epoxy groups in one molecule, and the same one as the above-mentioned (A) first epoxy resin can be used. it can. (C) When the reaction product (c2) of an organopolysiloxane (c1) having a polycaprolactone group and a second epoxy resin is used, mold stains after continuous molding hardly occur and continuous moldability is extremely high. Become good.

(C) The compounding amount of the reaction product (c2) of the organopolysiloxane (c1) having a polycaprolactone group and / or the organopolysiloxane (c1) having a polycaprolactone group and the second epoxy resin is The blending amount of the organopolysiloxane (c1) having a caprolactone group is preferably 0.01% by weight or more and 3% by weight or less in the total epoxy resin composition. When the blending amount is within the above range, (D) the appearance stain on the surface of the cured resin by the tolylene diisocyanate-modified oxidized wax can be suppressed, and a good appearance can be obtained. Moreover, when the blending amount is within the above range, deterioration of the appearance of the cured resin surface due to the organopolysiloxane (c1) itself having a polycaprolactone group can be suppressed, and a good appearance can be obtained.
The reaction product (c2) of (C) the organopolysiloxane (c1) having a polycaprolactone group and / or the organopolysiloxane (c1) having a polycaprolactone group and the second epoxy resin used in the present invention. Other organopolysiloxanes can be used in combination within a range that does not impair the effect of the addition of).

  The (D) tolylene diisocyanate-modified oxidized wax used in the present invention is obtained by modifying an oxidized wax with tolylene diisocyanate, and has excellent release properties. The (D) tolylene diisocyanate modified oxidized wax used in the present invention is not particularly limited. For example, tolylene diisocyanate modified oxidized wax, tolylene diisocyanate modified polyethylene wax, tolylene diisocyanate modified oxidized paraffin wax, for example. Is mentioned. Of these, tolylene diisocyanate-modified oxidized polyethylene wax and tolylene diisocyanate-modified oxidized paraffin wax are more preferable from the viewpoints of releasability of the epoxy resin composition and appearance of the cured resin surface. These tolylene diisocyanate-modified oxidized waxes may be used alone or in combination of two or more.

  The dropping point of the (D) tolylene diisocyanate-modified oxidized wax used in the present invention is preferably 70 ° C. or higher and 120 ° C. or lower, more preferably 80 ° C. or higher and 110 ° C. or lower. The dropping point can be measured by a method based on ASTM D127. Specifically, using a metal nipple, it is measured as the temperature at which molten wax first drops from the metal nipple. In the following examples, it can be measured by the same method. When the dropping point is within the above range, (D) tolylene diisocyanate-modified oxidized wax is excellent in thermal stability, and (D) tolylene diisocyanate-modified oxidized wax is difficult to seize at the time of continuous molding. Therefore, it is excellent in the mold release property of the resin cured material from a metal mold | die, and is excellent in continuous moldability. Furthermore, when the epoxy resin composition is cured within the above range, (D) tolylene diisocyanate-modified oxidized wax is sufficiently melted. Thereby, (D) tolylene diisocyanate modified oxidized wax is dispersed substantially uniformly in the cured resin. Therefore, segregation of the (D) tolylene diisocyanate-modified oxidized wax on the surface of the cured resin can be suppressed, and the deterioration of the appearance of the mold and the surface of the cured resin can be reduced. Become.

  The acid value of (D) tolylene diisocyanate-modified oxidized wax used in the present invention is preferably 10 / mg or more and 50 mgKOH / g or less, more preferably 15 mgKOH / g or more and 40 mgKOH / g or less. The acid value affects the compatibility with the cured resin. The acid value can be measured by a method based on JIS K 3504. Specifically, it is measured as the number of milligrams of potassium hydroxide required to neutralize free fatty acids contained in 1 g of waxes. In the following examples, it can be measured by the same method. When the acid value is within the above range, the (D) tolylene diisocyanate-modified oxidized wax is in a compatible state with the epoxy resin matrix in the cured resin. Thereby, (D) tolylene diisocyanate modified oxide wax and epoxy resin matrix do not cause phase separation. Therefore, segregation of the (D) tolylene diisocyanate-modified oxidized wax on the surface of the cured resin is suppressed, and deterioration of the appearance of the mold stain and the surface of the cured resin can be reduced, and the resin composition has a good appearance. . Furthermore, since the (D) tolylene diisocyanate-modified oxidized wax exists on the surface of the cured resin, the cured resin is excellent in releasability from the mold. On the other hand, if the compatibility with the epoxy resin matrix is too high, the (D) tolylene diisocyanate-modified oxidized wax cannot ooze out on the surface of the cured resin, and sufficient releasability may not be ensured. .

  The average particle size of the (D) tolylene diisocyanate-modified oxidized wax used in the present invention is preferably 20 μm or more and 70 μm or less, more preferably 30 μm or more and 60 μm or less. The average particle diameter can be measured as a 50% particle diameter based on weight using, for example, a laser diffraction particle size distribution measuring apparatus such as SALD-7000 manufactured by Shimadzu Corporation as a solvent. In the following examples, it can be measured by the same method. Within the above range, (D) the tolylene diisocyanate-modified oxidized wax is in a compatible state with the epoxy resin matrix in the cured resin. As a result, (D) tolylene diisocyanate-modified oxidized wax is present on the surface of the resin cured product, and is excellent in releasability of the cured product from the mold. On the other hand, if the compatibility with the epoxy resin matrix is too high, it cannot be oozed out on the surface of the cured resin and sufficient releasability cannot be ensured. Furthermore, since (D) tolylene diisocyanate-modified oxidized wax and epoxy resin matrix are in a preferable compatible state, segregation of (D) tolylene diisocyanate-modified oxidized wax on the surface of the cured resin is suppressed, and mold contamination And the appearance of the cured resin surface can be improved. Furthermore, when it exists in the said range, when hardening an epoxy resin composition, (D) tolylene diisocyanate modification | denaturation wax will fully fuse | melt. Therefore, the epoxy resin composition is excellent in fluidity.

  Further, the content ratio of particles having a particle size of 106 μm or more in all (D) tolylene diisocyanate-modified oxidized wax is preferably 0.1% by weight or less. This content ratio can be measured using a standard sieve of 106 μm openings according to JIS Z8801. In the following examples, it can be measured by the same method. If it is said content ratio, (D) tolylene diisocyanate modification | denaturation wax will disperse | distribute substantially uniformly in an epoxy resin composition, and the deterioration of the external appearance of a mold | die stain | pollution | contamination and resin cured | curing material can be suppressed. In addition, when the epoxy resin composition is cured, (D) the tolylene diisocyanate-modified oxidized wax is sufficiently melted, so that the fluidity is excellent.

  The lower limit of the blending amount of (D) tolylene diisocyanate-modified oxidized wax used in the present invention is preferably 0.01% by weight or more, more preferably 0.03% by weight or more in the epoxy resin composition. . When the lower limit value of the blending amount is within the above range, the release property of the cured resin from the mold is excellent. Moreover, about the upper limit of the compounding quantity of (D) tolylene diisocyanate modified oxidation wax, 1 weight% or less is preferable in an epoxy resin composition, More preferably, it is 0.5 weight% or less. When the upper limit of the blending amount is within the above range, the adhesion with the lead frame member becomes good, and peeling between the cured resin of the epoxy resin composition and the lead frame member during the soldering process can be suppressed. Furthermore, it is possible to suppress the mold stains and the deterioration of the appearance of the cured resin surface and obtain a good appearance.

The (D) tolylene diisocyanate-modified oxidized wax used in the present invention is commercially available, and can be used after adjusting the particle size if necessary.
Other mold release agents can be used in combination as long as the effects of using the (D) tolylene diisocyanate-modified oxidized wax used in the present invention are not impaired. Examples of release agents that can be used in combination include natural waxes such as carnauba wax, and metal salts of higher fatty acids such as zinc stearate.

  The epoxy resin composition of the present invention comprises (A) a first epoxy resin, (B) a phenol resin curing agent, (C) an organopolysiloxane (c1) having a polycaprolactone group, and / or a polycaprolactone group. The reaction product (c2) of organopolysiloxane (c1) and the second epoxy resin, and (D) tolylene diisocyanate-modified oxide wax are essential components, but (E) curing acceleration as other main constituent components An agent, (F) an inorganic filler, etc. can be mix | blended.

  The (E) curing accelerator that can be used in the present invention is one that promotes the curing reaction between (A) the epoxy group of the first epoxy resin and (B) the phenolic hydroxyl group of the phenol resin curing agent. What is necessary is just to use what is generally used for a sealing material. For example, diazabicycloalkenes such as 1,8-diazabicyclo (5,4,0) undecene-7 and derivatives thereof; organic phosphines such as triphenylphosphine and methyldiphenylphosphine; imidazole compounds such as 2-methylimidazole; tetra Examples thereof include tetra-substituted phosphonium and tetra-substituted borates such as phenylphosphonium and tetraphenylborate, and these may be used alone or in combination of two or more.

  The lower limit of the blending ratio of the (E) curing accelerator that can be used in the present invention is not particularly limited, but is preferably 0.05% by weight or more in the total epoxy resin composition for semiconductor encapsulation, and 0 More preferably, it is 1% by weight or more. When the lower limit of the blending ratio is within the above range, there is little risk of causing a decrease in curability. Further, the upper limit of the blending ratio of the (E) curing accelerator is not particularly limited, but it is preferably 1% by weight or less, and 0.5% by weight or less in the total epoxy resin composition for semiconductor encapsulation. It is more preferable. When the upper limit of the blending ratio is within the above range, there is little possibility of causing a decrease in fluidity.

  As the inorganic filler (F) that can be used in the present invention, those generally used for epoxy resin compositions for semiconductor encapsulation can be used. For example, fused silica, crystalline silica, talc, alumina, silicon nitride and the like can be mentioned, and the most preferably used is spherical fused silica. These (F) inorganic fillers may be used alone or in combination of two or more. These may be surface-treated with a coupling agent. (F) The shape of the inorganic filler is preferably as spherical as possible and the particle size distribution is broad from the viewpoint of fluidity.

  About the lower limit of content of the (F) inorganic filler which can be used for this invention, it is preferable that it is 80 weight% or more in all the epoxy resin compositions, and it is more preferable that it is 84 weight% or more. When the lower limit of the content is within the above range, sufficient fluidity at the time of molding can be obtained. Moreover, about the upper limit of content of (F) inorganic filler, it is preferable that it is 92 weight% or less in all the epoxy resin compositions, and it is more preferable that it is 90 weight% or less. When the upper limit of the content is within the above range, good solder reflow properties at the time of mounting can be obtained.

  In addition to the above components (A) to (F), the epoxy resin composition of the present invention, if necessary, silane coupling agents such as epoxy silane, mercapto silane, amino silane, alkyl silane, ureido silane, vinyl silane, Titanate coupling agents, aluminum coupling agents, coupling agents such as aluminum / zirconium coupling agents; colorants such as carbon black; low-stress additives such as silicone oil and rubber; brominated epoxy resins, antimony trioxide, water Additives such as flame retardants such as aluminum oxide, magnesium hydroxide, zinc borate, zinc molybdate, and phosphazene may be appropriately blended.

  In addition, the epoxy resin composition of the present invention is a mixture in which the above components (A) to (F) and other additives are sufficiently uniformly mixed using a mixer or the like, and then further heated rolls, kneaders, extrusions. It is possible to use a material in which the degree of dispersion, fluidity, and the like are appropriately adjusted as necessary, such as those obtained by melt-kneading with a kneading machine such as a machine and pulverizing after cooling.

  The element for sealing is not particularly limited to, for example, an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, a solid-state imaging element, and the like, and a form of a semiconductor device obtained by sealing the element is also possible. There is no particular limitation. A semiconductor device sealed by a method such as low-pressure transfer molding is mounted on an electronic device or the like as it is or after being completely cured at a temperature of 80 to 200 ° C. for 15 seconds to 10 hours.

  As a form of the semiconductor device of the present invention, for example, dual in-line package (DIP), chip carrier with plastic lead (PLCC), quad flat package (QFP), small outline package (SOP), Small outline J lead package (SOJ), thin small outline package (TSOP), thin quad flat package (TQFP), tape carrier package (TCP), ball grid array (BGA), A chip size package (CSP), etc. are mentioned.

  FIG. 1 is a cross-sectional view showing a cross-sectional structure of an example of a semiconductor device using the epoxy resin composition for semiconductor encapsulation according to the present invention. The semiconductor element 1 is fixed on the die pad 3 via the die bond material cured body 2. The electrode pad of the semiconductor element 1 and the lead frame 5 are connected by a gold wire 4. The semiconductor element 1 is sealed with a cured body 6 of an epoxy resin composition for semiconductor sealing.

Conventional molding such as transfer molding, compression molding, injection molding, etc., is used to manufacture semiconductor devices by sealing various electronic components such as semiconductor elements using the epoxy resin composition for semiconductor sealing of the present invention. It may be cured by the method.

  Examples of the present invention are shown below, but the present invention is not limited thereto. The blending ratio is parts by weight.

Example 1
Epoxy resin 1: a phenol aralkyl type epoxy resin having a biphenylene skeleton which is an epoxy resin having a structure represented by the following general formula (2) (however, in the following general formula (2), an average value of m2 / n2: 1, Ar1 = biphenyl group, Ar2 = phenyl group, R6 = hydrogen, R7 = hydrogen, b = 0, c = 0, d = 0, e = 1, manufactured by Nippon Kayaku Co., Ltd., NC-3000P, epoxy equivalent 275, Softening point 60 ° C.) 8.64 parts by weight

Phenol resin curing agent 1: phenol novolak resin represented by the general formula (3) (Sumitomo Bakelite Co., Ltd., Sumilite Resin (registered trademark) PR-HF-3. In the formula (3), the average value of n3 : 3.0, hydroxyl equivalent 104, softening point 80 ° C.) 3.26 parts by weight

Organopolysiloxane 1: Organopolysiloxane represented by the following formula (4) (obtained by mixing polycaprolactone and organopolysiloxane and reacting them at 80 ° C. under a platinum catalyst) 0.20 parts by weight

  Release agent 1: Tolylene diisocyanate-modified oxidized paraffin wax (tolylene diisocyanate-modified oxidized paraffin wax prepared by the above-mentioned method, particle size adjusted by turbo mill. Dropping point 80 ° C., acid value 30 mg KOH / g, number average molecular weight 2000, 0.2% by weight of particles having an average particle size of 35 μm and particles having a particle size of 106 μm or more.)

Curing accelerator 1: 1,8-diazabicyclo (5,4,0) undecene-7 (hereinafter referred to as DBU) 0.20 parts by weight

  Inorganic filler 1: fused spherical silica (average particle size 21 μm) 87.00 parts by weight

  Silane coupling agent 1: γ-glycidoxypropyltrimethoxysilane 0.20 parts by weight

  Colorant 1: Carbon black 0.30 parts by weight

The epoxy resin 1, the phenol resin-based curing agent 1, the organopolysiloxane 1, the release agent 1, the curing accelerator 1, the inorganic filler 1, the silane coupling agent 1, and the colorant 1 described above are mixed and heated. Using a roll, the mixture was melt kneaded at 95 ° C. for 8 minutes, cooled and pulverized to obtain an epoxy resin composition. The obtained epoxy resin composition was evaluated by the following methods. The results are shown in Table 1.

Evaluation method Spiral flow: Using a low-pressure transfer molding machine (KTS-15, manufactured by Kotaki Seiki Co., Ltd.), a mold for spiral flow measurement according to EMMI-1-66, a mold temperature of 175 ° C., an injection pressure of 6 The epoxy resin composition was injected under the conditions of .9 MPa and curing time of 120 seconds, and the flow length was measured. The unit is cm. The criteria for the evaluation were less than 70 cm, and 70 cm or more.

  Continuous moldability: 80 pink quad flat package with a mold temperature of 175 ° C., injection pressure of 9.8 MPa, curing time of 70 seconds using a low-pressure transfer automatic molding machine (GP-ELF manufactured by Daiichi Seiko Co., Ltd.) 80pQFP: Cu lead frame, package outer dimensions: 14 mm x 20 mm x 2 mm thickness, pad size: 6.5 mm x 6.5 mm, chip size 6.0 mm x 6.0 mm x 0.35 mm thickness), epoxy resin composition Thus, sealing molding was continuously performed up to 700 shots. Judgment criteria were ◎ for those that could be continuously molded up to 700 shots without any problems such as unfilled, ◯ for those that could be continuously molded up to 500 shots without any problems such as unfilled, and x otherwise.

  Package appearance and mold stain resistance: In the evaluation of the continuous moldability, the package surface and mold surface after 300, 500 and 700 shot molding were visually evaluated for stain. The package appearance judgment and mold contamination criteria are ◎ for those that are not dirty up to 700 shots, ◯ for those that are not dirty up to 500 shots, △ that are not dirty up to 300 shots, and × that are dirty. Represent. In addition, in the above-mentioned continuous formability, those that could not be continuously formed up to 300 shots were judged based on the package appearance and mold contamination status when the continuous forming was abandoned.

  Solder reflow property: The package molded in the above-described evaluation of continuous formability is subjected to post-curing by heat treatment at 175 ° C. for 8 hours, and then humidified for 168 hours at 85 ° C. and 60% relative humidity, and then a solder bath at 260 ° C. The package was immersed for 10 seconds. The adhesion state of the interface between the 20 semiconductor elements immersed in the solder and the cured epoxy resin composition was observed with an ultrasonic flaw detector (manufactured by Hitachi Construction Machinery Finetech Co., Ltd., mi-scope 10). Then, the occurrence rate of peeling [(number of peeling occurrence packages) / (total number of packages) × 100] was calculated. Units%. The criteria for determining the solder reflow characteristics are ◎ for the case where peeling did not occur, ◯ for the case where the peeling occurrence rate was 5% or more and less than 10%, △, 10% or more, less than 20%, △, 20% or more. The thing was set as x.

Examples 2-10, Comparative Examples 1-4
According to the composition of Tables 1 and 2, an epoxy resin composition was obtained in the same manner as in Example 1, and evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

The raw materials used other than Example 1 are shown below.
Epoxy resin 2: Epoxy resin having a structure represented by the following general formula (2) (however, in the following general formula (2), average value of m / n: 1/4, Ar1 = naphthalene group, Ar2 = phenyl group) R5 = methyl group, R6 = hydrogen, R7 = hydrogen, R8 = methyl group, W1 = oxygen, b = 0, c = 1, d = 1, e = 1, manufactured by Dainippon Ink & Chemicals, EXA- 7320. Epoxy equivalent 251, melting point 58 ° C.)

  Epoxy resin 3: Orthocresol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., EOCN-1020 62. Epoxy equivalent 200 g / eq, softening point 62 ° C.)

  Phenol resin curing agent 2: Phenol aralkyl resin having a phenylene skeleton (Mitsui Chemicals Co., Ltd., Milex (registered trademark) XLC-4L. Hydroxyl equivalent 165, softening point 65 ° C.)

Organopolysiloxane 2: Organopolysiloxane represented by the following formula (5) (obtained by mixing polycaprolactone and organopolysiloxane and reacting at 80 ° C. under a platinum catalyst)

Organopolysiloxane 3: Organopolysiloxane represented by the following formula (6) (GE Toshiba Silicones Co., Ltd., SILSOFT034)

  Reaction product A: Bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin, YL-6810, epoxy equivalent 170 g / eq, melting point 47 ° C.) 66.1 parts by weight was heated and melted at 140 ° C. to obtain organopolysiloxane 1 (formula Organopolysiloxane represented by (4)) 33.1 parts by weight and 0.8 parts by weight of triphenylphosphine were added and melt mixed for 30 minutes to obtain a reaction product A.

  Release agent 2: Tolylene diisocyanate-modified polyethylene oxide wax (tolylene diisocyanate-modified polyethylene oxide wax prepared by the above-mentioned method, adjusted in particle size by a hammer mill. Dropping point 90 ° C., acid value 30 mg KOH / g, number average molecular weight 1800 (The average particle size is 33 μm, the particle size is 106 μm or more, 0.0% by weight.)

  Release agent 3: Tolylene diisocyanate-modified oxidized polypropylene wax (tolylene diisocyanate-modified oxidized polypropylene wax prepared by the above-mentioned method, whose particle size was adjusted by a jet mill. Drop point: 102 ° C., acid value: 15 mg KOH / g, number average molecular weight: 3500 (The average particle size is 40 μm, the particle size is 106 μm or more, 0.0% by weight.)

  Release agent 4: Carnauba wax (manufactured by Nikko Fine Products Co., Ltd., trade name Nikko Carnauba, drop point 83 ° C., acid value 5 mg KOH / g, number average molecular weight 650, average particle size 38 μm, particle size 106 μm or more. 0% by weight.)

  In Examples 1 to 10, the reaction product (c2) of (C) the organopolysiloxane (c1) having a polycaprolactone group and / or the organopolysiloxane (c1) having a polycaprolactone group and the second epoxy resin was used. ), And (D) a tolylene diisocyanate-modified oxide wax, and (C) the amount and type of component changed, (D) the amount and type of component changed, or the type of epoxy resin In either case, the result is an excellent balance of fluidity (spiral flow), continuous formability, package appearance, mold contamination, and solder reflow. It was.

  According to the present invention, the epoxy resin composition is excellent in fluidity, and has a balance of continuous formability, solder reflowability, mold releasability at the time of device sealing molding, appearance of the surface of the cured resin, and mold dirtiness. Since a product can be obtained, it is suitable for sealing a semiconductor device.

It is sectional drawing which showed the cross-section about an example of the semiconductor device using the epoxy resin composition which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor element 2 Die-bonding material hardening body 3 Die pad 4 Gold wire 5 Lead frame 6 Hardening body of epoxy resin composition for semiconductor sealing

Claims (2)

(A) a first epoxy resin,
(B) a phenolic resin-based curing agent,
(C) Reaction product of organopolysiloxane (c1) having a polycaprolactone group represented by the following general formula (1) and / or organopolysiloxane (c1) having a polycaprolactone group and a second epoxy resin Object (c2),
And (D) include tolylene diisocyanate modified oxidized waxes, viewed contains said (A) a first epoxy resin is represented by the following general formula epoxy resin represented by (2) (a1),
The (D) tolylene diisocyanate-modified oxidized wax has a dropping point of 70 ° C. or more and 120 ° C. or less, an acid value of 10 mg KOH / g or more and 50 mg KOH / g or less, and an average particle size of 20 μm or more and 70 μm or less. Yes, the content ratio of particles having a particle size of 106 μm or more in all tolylene diisocyanate-modified oxidized wax is 0.1% by weight or less, and the blending amount in all epoxy resin compositions is 0.01% by weight or more and 1% by weight. And
Weight ratio W (c1) / W (D) of blending amount W (c1) of organopolysiloxane (c1) having a polycaprolactone group and blending amount W (D) of (D) tolylene diisocyanate-modified oxide wax An epoxy resin composition for encapsulating a semiconductor, wherein the range is from 3/1 to 1/5 .

(However, in the general formula (1), R1 is a group selected from hydrogen, a methyl group, a phenyl group, or R2, and may be the same or different from each other, but at least one of them is R2. The average value of n1 is a positive number of 1 to 50. In R2, the average value of a is a positive number of 5 to 20, and R3 is an organic group having a polycaprolactone group. Is an organic group having 1 to 30 carbon atoms.)


(However, in the general formula (2), Ar1 and Ar2 are aromatic groups having 6 to 20 carbon atoms, and may be the same or different. R4 and R5 are carbonized groups having 1 to 6 carbon atoms. R6 and R7 are hydrogen, a hydrocarbon group having 1 to 4 carbon atoms or an aromatic group having 6 to 20 carbon atoms, and are the same as each other. R8 is a hydrocarbon group having 1 to 4 carbon atoms, W1 is an oxygen atom or a sulfur atom, OG is a glycidoxy group, b and c are integers of 0 to 10, and d is 0. Is an integer of -3, e is an integer of 1 to 3. m2 is an integer of 0 to 20, n2 is an integer of 1 to 20, and the average of m2 / n2 is 1/10 to 1/1. Even if m2 repeating units and n2 repeating units are continuously arranged, Each other may have lined up alternately or randomly, but takes a structure having always -CR6R7- between each.)   A semiconductor device, wherein an element is sealed using the epoxy resin composition for semiconductor sealing according to claim 1.