JPH07238123A - Resin composition for semiconductor sealing - Google Patents

Abstract

PURPOSE:To provide a resin compsn. which is excellent in flowability on molding and gives a cured item absorbing little moisture and excellent in mechanical characteristics by compounding a specific polymaleimide component with a specific compd. in a specified amt. CONSTITUTION:This compsn. comprises 5-20wt.% polymaleimide component contg. a bismaleimide of formula I (wherein R1 and R2 are each 1-4C alkyl; and R3 and R4 are each H, methyl, or ethyl), 4-15wt.% allylphenol compd. having at least two allyl groups in the molecule, 25-90wt.% silica particles, and 0.1-5wt.% peroxyketal compd. The polymaleimide component may be a mixture of the compds. of formulas I and II (wherein Y is a polyvalent aliph., arom., alicyclic, or heterocyclic residue; and n>=2), pref. contg. at least 10wt.% compd. of formula I.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a resin composition for semiconductor encapsulation. More specifically, the present invention relates to a resin composition for semiconductor encapsulation, which has excellent fluidity during molding, low hygroscopicity, and a cured molded article having excellent mechanical properties.

[0002]

2. Description of the Related Art Conventionally, resin compositions have been widely used for sealing semiconductor elements such as ICs and LSIs in view of characteristics, cost, etc. Among them, epoxy resin compositions are the mainstream. Is doing. Further, in recent years, the trend of mass production and high integration of electronic components, thinning of semiconductor elements, surface mounting, and the like has further advanced, and the demand for a resin composition for semiconductor encapsulation includes heat resistance and mechanical strength. Not only improvement, but also good moldability, low thermal stress, and low moisture absorption have been strictly required. In order to deal with these problems, various studies have been made on epoxy resin compositions, but there is a limit to the improvement as long as an epoxy resin is used.

Polymaleimide-based resins are known as thermosetting resins having heat resistance superior to that of epoxy resins. Generally, polymaleimide-based resins have a high melting point or softening temperature, and their moldability is not always good. It cannot be said that. Further, a cured molded article obtained from a polymaleimide resin has a high elasticity and a low elongation at break, so that the strength is low, and as a result, it is hard and brittle.

In order to improve the above-mentioned drawbacks, a resin composition comprising a polymaleimide resin and O, O'-diallylbisphenol A (Japanese Patent Publication No. 55-39242), a bismaleimide compound and a diallyl ether compound of bisphenol S. A resin composition containing
3-134099), and a resin composition (JP-A 62-11716) in which an allyl ether of phenol novolac is mixed with a bismaleimide compound has been proposed. In addition, a technique of adding silica particles having a low coefficient of thermal expansion to polymaleimide resin has been proposed for the purpose of reducing thermal stress on the surface of IC, LSI, etc. (Japanese Patent Laid-Open No. 63-230728, etc.). .

However, in the above-mentioned conventionally proposed polymaleimide resin compositions, even if any of the fluidity at the time of molding and the heat resistance of the cured product is improved, the required properties are generally I'm not satisfied with it. According to the knowledge of the present inventors, for the purpose of reducing the thermal stress of the obtained cured molded article, if a large amount of silica particles are blended with the resin composition, the coefficient of thermal expansion can be reduced, but on the other hand, the flow during molding When the thin IC package or the like is molded, the bonding wire may be broken or an unfilled portion may occur.
The desired molded article cannot be obtained. Further, when surface-mounting a thin IC package or the like, it is directly exposed to high-temperature solder heat in the solder reflow process, but a cured product having high hygroscopicity instantly releases a large amount of water vapor when exposed to high temperatures. When they occur, cracks occur in the package (cured molded product) and the sealing function is impaired.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned conventional technical problems and includes a maleimide resin having excellent heat resistance as a sealing resin component,
Good fluidity at the time of molding, low hygroscopicity, and a cured molded article excellent in mechanical properties such as bending strength can be obtained.
It is intended to provide a highly reliable resin composition for semiconductor encapsulation.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a polymaleimide compound containing a specific bismaleimide, a specific allylphenol compound, a silica particle, and a par The present invention has been completed by finding that the object of the present invention can be easily achieved by a resin composition containing a specific amount of an oxyketal compound.

However, the gist of the present invention is as follows.
A resin composition for semiconductor encapsulation, characterized in that each of the following components A, B, C, and D is contained in a predetermined amount. A component: 5 to 20% by weight of a polymaleimide compound containing a bismaleimide represented by the following general formula (I), B component: 4 to 15% by weight of an allylphenol compound having two or more allyl groups in the molecule. %, C component: 25 to 90% by weight of silica particles, D component: 0.1 to 5% by weight of peroxyketal compound.

[0009]

[Chemical 2] [In the formula (I), R ₁ and R ₂ represent the same or different alkyl groups having 1 to 4 carbon atoms, and R ₃ and R ₄ represent
The same or different hydrogen atom, methyl group or ethyl group are shown. ]

The present invention will be described in detail below. <Component A> The component A in the present invention is the above-mentioned general formula (I).
Is a polymaleimide compound containing a bismaleimide represented by the formula (1), wherein the component A is the bismaleimide alone represented by the general formula (I), or the bismaleimide and the polymaleimide represented by the following general formula (II). It may be any of a mixture with a compound.

[0011]

[Chemical 3] [In the formula, Y represents an aliphatic, aromatic, alicyclic, or heterocyclic divalent or higher polyvalent residue, and n represents an integer of 2 or more. ]

The bismaleimide having the above-mentioned specific structure exerts the effects of imparting good fluidity to the resin composition of the present invention at the time of molding and reducing the hygroscopicity of the obtained cured molded product. When selecting the above mixture as the component A,
This bismaleimide is contained in an amount of 10% by weight or more, preferably 20%.
It is preferable that the content is at least wt%. When the component A having a bismaleimide content of 10% by weight or more is used, a resin composition having better fluidity at the time of molding can be obtained, and a cured molded product obtained from this exhibits low hygroscopicity and flexural strength. The mechanical properties such as are excellent and are preferable.

The bismaleimide used as the component A can be easily obtained by reacting an aromatic diamine having at least one carbon atom adjacent to an amino group-substituted carbon of an aromatic ring with an alkyl substituent with maleic anhydride. . Examples of such bismaleimides include bis (3-methyl-4-maleimidophenyl) methane and bis (3,5-
Dimethyl-4-maleimidophenyl) methane, bis (3
-Ethyl-4-maleimidophenyl) methane, bis (3
-N-butyl-4-maleimidophenyl) methane, bis (3-ethyl-5-methyl-4-maleimidophenyl)
Examples thereof include methane and bis (3,5-diethyl-4-maleimidophenyl) methane.

The polymaleimide compound used by mixing with the bismaleimide can be easily obtained by reacting a diamine or polyamine with maleic anhydride. The diamine has the general formula (H ₂ N) _n Y [n is 2 and Y
Is a divalent residue having the same meaning as in formula (II). ] It is a compound represented by these. Specific examples of the polymaleimide compound obtained by the reaction of such a diamine and maleic anhydride include aliphatic polymaleimides such as 1,2-dimaleimidoethane and 1,3-dimaleimidopropane; bis (4 -Maleimidophenyl) methane, bis (3-ethyl-4-maleimidophenyl) methane, bis (3-ethyl-4-maleimido-5-methylphenyl) methane, 2,7-dimaleimidofluorene,
1,3-dimaleimidobenzene, 1,4-dimaleimidobenzene, 2,4-dimaleimidotoluene, bis (maleimidophenyl) sulfone, bis (maleimidophenyl) ether, 2,2-bis (4- (4 -Maleimidophenoxy) phenyl) propane, bis (4- (4-maleimidophenoxy) phenyl) sulfone, 1,3-bis (2- (3-maleimidophenyl) propyl) benzene (each containing isomers), etc. Examples thereof include aromatic polymaleimides; alicyclic polymaleimides such as 1,4-dimaleimide cyclohexane; and heterocyclic polymaleimides such as bis (maleimidophenyl) thiophene (including isomers). Among these, aromatic polymaleimide is particularly preferable from the viewpoint of heat resistance.

The polyamine has the general formula (H ₂ N) _n Y
[N is an integer of 3 or more, and Y is a trivalent or higher polyvalent residue having the same meaning as in the general formula (II). ] It is a compound represented by these. Specific examples of the polymaleimide compound obtained by the reaction of such a polyamine and maleic anhydride include polyamine maleimide compounds obtained by polycondensation reaction of aniline or various derivatives thereof with formalin.

These polymaleimide compounds may be a combination of two or more kinds or a mixture of a plurality of diamines or polyamines and may be obtained by maleimidization, and further, they may have fluidity. For the purpose of further improving the above, a monomaleimide such as N-phenylmaleimide can be added within a range that does not impair the molding processability such as generation of burrs.

The proportion of component A contained in the resin composition of the present invention is in the range of 5 to 20% by weight, more preferably 5 to 15%.
It is in the range of% by weight. When the proportion of the component A exceeds 20% by weight, the moldability of the resin composition is improved, but the thermal expansion coefficient of the obtained cured molded article becomes large, which is not preferable. On the other hand, when it is less than 5% by weight, it is obtained. This is not preferable because the cured product may be insufficiently cured.

<Component B> The component B in the present invention is an allylphenol compound having two or more allyl groups in the molecule. The component B exhibits an effect of improving the mechanical properties of the obtained cured molded product by undergoing a crosslinking reaction with the component A during curing. The component B is preferably liquid in that it can smoothly react with the component A. However, even if it is solid at room temperature, it becomes liquid by heating during the mixing operation. Can be used. Specific examples of the B component include 2,2-bis (3-
Allyl-4-hydroxyphenyl) propane, 1,1,
1,3,3,3-hexafluoro-2,2-bis (3-
Allyl-4-hydroxyphenyl) propane, bis (3
-Allyl-4-hydroxyphenyl) sulfone, bis (3-allyl-4-hydroxyphenyl) sulfide,
Examples thereof include bis (3-allyl-4-hydroxyphenyl) ether, but are not limited to these exemplified ones. These may be used alone or as a mixture of two or more kinds.

The proportion of component B contained in the resin composition of the present invention is in the range of 4 to 15% by weight, more preferably 4 to 10%.
It is in the range of% by weight. When the proportion of the component B is less than 4% by weight, the obtained cured molded article becomes brittle and mechanical properties such as bending strength are deteriorated, while when it exceeds 15% by weight, the heat resistance of the obtained cured molded article is high. Is decreased, and both are not preferable.

The amount of the component B to be used can be selected from the above range by taking the ratio of the component A to the maleimide functional group as a guide, and in this case, the allyl group of the component B to 1 equivalent of the maleimide functional group of the component A is used. The ratio of 0.
It is preferably in the range of 5 to 1.5 equivalents. When the above-mentioned proportion of the allyl group of the component B is less than 0.5 equivalent, the obtained cured molded article tends to be brittle, and when it is more than 1.5 equivalent, the heat resistance of the obtained cured molded article tends to decrease.

<Component C> The component C in the present invention is silica particles. The silica particles are not particularly limited as long as they are in the form of particles, and the shape may be spherical, prismatic or crushed, and produced by either liquid phase synthesis or gas phase synthesis. It may have been done. The component C exerts the effect of reducing the coefficient of thermal expansion of the obtained cured molded product, and for this purpose, the proportion of the component C is
It is preferable to increase the amount as long as the fluidity of the resin composition is kept good.

The proportion of component C contained in the resin composition of the present invention is in the range of 25 to 90% by weight, preferably 60 to 88.
It is in the range of% by weight. When the proportion of the C component is less than 25% by weight, the thermal expansion coefficient of the obtained cured molded article cannot be sufficiently lowered, and when it exceeds 90% by weight, the fluidity of the resin composition is lowered and the moldability is deteriorated. Is damaged. When blending at a higher ratio within the above range, it is preferable to use a plurality of types of silica particles having different average particle sizes. When using a plurality of types of silica particles, it is preferable to prepare and use mixed silica in which they are premixed. Regarding the particle size of the silica particles used, those having a particle size of 200 μm or more are 0.1% by weight or less, and those having a particle size of 0.01 μm or less have a particle size distribution of 0.1% by weight or less.

If necessary, a particulate or fibrous inorganic filler other than silica particles can be used in combination with the resin composition of the present invention. Specific examples of the filler that can be used in combination include particles of alumina powder, mica, titania, zirconia and the like; and inorganic fibers such as glass fiber, carbon fiber and boron fiber, and heat resistant fibers such as aramid fiber. Good. Further, it is desirable that the silica particles and other inorganic fillers used together therewith have a low content of radioactive elements such as uranium and thorium. Α from these radioactive elements
This is because the line may induce a malfunction of the semiconductor to be sealed due to, for example, destruction of the memory.

In addition, a silane coupling agent can be used for the surface treatment of the silica particles. The amount of the silane coupling agent used varies depending on the type of the silane coupling agent and the surface properties of the silica particles, but is generally in the range of 0.1 to 5 parts by weight, preferably 0.5 to 100 parts by weight with respect to 100 parts by weight of the silica particles. It is preferable that the range is 3 parts by weight. This silane coupling agent may be added to only the silica particles in advance, or may be added when the C component (silica particles) is mixed with the A component, B component and D component described later. As the silane coupling agent, an organosilane compound having an amino group is particularly effective,
Suitable silane coupling agents include 3-aminopropyltriethoxysilane, 3- (N- (2-aminoethyl)) aminopropyltrimethoxysilane, 3- (N-
Allyl-N- (2-aminoethyl)) aminopropyltrimethoxysilane, 3- (N-allyl-N-chrysidylmethyl) aminopropyltrimethoxysilane, 3- (N
Examples thereof include-(2-aminoethyl)) aminopropylmethyldimethoxysilane and 3- (N-phenyl) aminopropyltrimethoxysilane. These may be used alone or as a mixture of two or more kinds.

<Component D> The component D in the present invention is a peroxyketal compound, which means a compound in which two peroxy groups are bonded to one carbon atom. It has the effect of promoting the curing of the resin composition. Examples of peroxyketal compounds suitable as the component D include ethyl levulinate tert-butyl peroxyketal, butyl levulinate tert-butyl peroxyketal, cyclohexanone tert-butyl peroxyketal, and the like. It is not limited to.

The proportion of the component D contained in the resin composition of the present invention is in the range of 0.1 to 5% by weight, and within this range, the curing conditions such as temperature and speed at the time of curing are adjusted. , Can be selected. If the ratio of the D component is less than 0.1% by weight, curing will be insufficient, and the content will be 5% by weight.
If it exceeds, the fluidity is remarkably reduced, and an unfilled portion may occur in the cured molded product, which is not preferable. When the ratio of the D component is within the above range, curing can be sufficiently promoted while maintaining good fluidity at the time of molding, and the target cured molded article can be obtained.

In the resin composition of the present invention, an organic peroxide other than the D component can be used in combination with the D component for the purpose of lowering the coefficient of thermal expansion of the cured molded product. As the organic peroxide that can be used in combination with the D component, 1,4-bis (2-
(2- (tert-butylperoxy) propyl)) benzene, tert-butylperbenzoate, dicumylhaloxide, and the like. The amount of the organic peroxide used in combination with these D components may be individually determined depending on the type, purpose of addition, etc.
Ingredient) It is preferable that the amount is 0.05 to 2 parts by weight with respect to 100 parts by weight.

Further, the resin composition of the present invention may contain, if necessary, natural wax, synthetic wax, organic fatty acid, or organic wax thereof, as long as the fluidity at the time of molding, the curing characteristics, and the various properties of the cured molded article are not impaired. Internal release agents such as esters or metal salts; halogenated compounds such as brominated epoxy compounds and brominated phenols, or flame retardants such as antimony oxide; coloring agents such as carbon black; nitrile rubber, polydimethylsiloxane, etc. A flexibility-imparting agent such as a silicone compound may be added, and each function can be improved.

To produce the resin composition of the present invention, the above components A to D are uniformly mixed. The mixing method at this time is not particularly limited, but the mixing temperature is 9
It preferably does not exceed 0 ° C. As the mixer, a conventionally known mixer can be used, and specific examples thereof include a hot roll, an extruder, a kneader, and a mixer. The resin composition thus obtained can be easily cured by heating from the outside to obtain the desired cured molded article.

[0030]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the description of the following Examples unless it exceeds the gist. In the following examples, "part" and "%" are based on weight unless otherwise specified.

In the following examples (including Table 1),
The abbreviations for the raw materials used have the following meanings. Maleimide a: Bis (3-ethyl-5-methyl-4-maleimidophenyl) methane Maleimide b: Bis (4-maleimidophenyl) methane Allylphenol a: 2,2-bis (3-allyl-4-)
Hydroxyphenyl) propane silica particles a: spherical silica having an average particle diameter of 18 μm Silica particles b: spherical silica having an average particle diameter of 1 μm Silica particles c: crushed silica having an average particle diameter of 7 μm Coupling agent a: 3-aminopropyltriethoxysilane Oxide a: butyl levulinate tert-butyl peroxyketal peroxide b: 1,4-bis (2- (2- (tert-butylperoxy) propyl)) benzene peroxide c: tert-butyl peroxide

Example 1 45 parts of maleimide a (component A), allylphenol a
28 parts of (Component B) was charged into a mixer and stirred at 150 ° C. for 20 minutes to obtain a mixed composition. Next, after cooling this, to this mixed composition were added 378 parts of silica particles a, 42 parts of silica particles b (component C), and a coupling agent a4.2.
Parts, peroxide a (D component) 1.5 parts, peroxide b0.4
Part, and 0.7 part of carnauba wax were added, and the mixture was melt-kneaded at 75 ° C. for 30 minutes using a two-roll mill, cooled, and pulverized to obtain a resin composition. The spiral flow of this resin composition was measured to evaluate the fluidity during molding. Then, a crushed product of the obtained resin composition is transferred to a transfer molding machine (KTS15, manufactured by Kotaki Co., Ltd.).
(Mold), injection was carried out at an injection pressure of 100 kg / cm ² , and the temperature was kept at 180 ° C. for 3 minutes, and then the cured molded product was taken out from the mold. The moisture absorption rate and bending strength of this cured molded article were measured. The results are shown in Table 1 together with the composition of raw materials.

Each of the above measurements was carried out by the following method. 1) Spiral flow (cm) of resin composition Using a transfer molding die conforming to the EMMI method (EMMI 1-66), a portion under sufficient pressure under a molding pressure of 70 kg / cm ² and a molding temperature of 180 ° C. Was measured. 2) Moisture absorption rate (%) After the weight (Wd) of the cured molded product immediately after molding was measured, the cured molded product was allowed to stand for 20 hours in a moisture absorbing atmosphere at a temperature of 85 ° C. and a relative humidity of 85% to absorb moisture. Then, the weight (Ww) after moisture absorption was measured and calculated from the following formula.

Moisture absorption rate (%) = (Ww-Wd) x 100 / Wd 3) Bending strength (kg / mm ² ) According to JIS K 6911, length 100 mm, width 10
It measured using the test piece of 0 mm and thickness 4 mm.

Example 2 A resin composition and a cured molded article were prepared in the same manner as in Example 1 except that the type and amount of peroxide were changed as shown in Table 1 in the example described in Example 1. Obtained and various measurements were performed. The results are also shown in Table 1.

Example 3 In the example described in Example 1, 45 parts of maleimide a, 22.5 parts of maleimide a and b2 of maleimide in the same example were used.
A resin composition and a cured molded product were obtained and various measurements were performed in the same manner as in the same example except that the mixture was changed to 2.5 parts. The results are also shown in Table 1.

Example 4 A resin composition and a cured molded product were obtained in the same manner as in Example 3 except that the kind and amount of silica particles were changed as shown in Table 1. , Various measurements were performed. The results are also shown in Table 1.

Comparative Example 1 In the example described in Example 1, a resin composition and a cured molded product were obtained and various measurements were performed in the same manner as in the same example except that the maleimide a was changed to the maleimide b. The results are also shown in Table 1.

Comparative Example 2 In the example described in Example 1, except that the amounts of maleimide a and allylphenol a were changed as shown in Table 1,
In the same manner as in the example, a resin composition and a cured molded product were obtained and various measurements were performed. The results are also shown in Table 1.

Comparative Example 3 A resin composition and a cured molded article were prepared in the same manner as in Example 1 except that the type and amount of peroxide were changed as shown in Table 1 in the example described in Example 1. Obtained and various measurements were performed. The results are also shown in Table 1.

Comparative Example 4 A resin composition and a cured molded product were prepared in the same manner as in Example 1 except that the kind and amount of peroxide were changed as shown in Table 1 in the example described in Example 1. Obtained and various measurements were performed. The results are also shown in Table 1.

[0041]

[Table 1]

As is clear from Table 1, the resin composition containing the components A to D defined in the present invention in a predetermined ratio is:
The fluidity at the time of molding is excellent, and from these resin compositions, cured molded products having a low moisture absorption rate and good bending strength can be obtained (Examples 1 to 4). In contrast,
The resin composition not containing the essential components specified in the present invention (Comparative Examples 1, 3 and 4) or the resin composition not containing the components A to D in a predetermined ratio (Comparative Example 2) has a flow property at the time of molding. It is inferior in properties, or cured products having a low moisture absorption rate and good bending strength cannot be obtained from them, and both cannot be satisfied at the same time.

[0043]

INDUSTRIAL APPLICABILITY The present invention has the following particularly advantageous effects, and its industrial utility value is extremely large. (1) Since the resin composition for semiconductor encapsulation of the present invention has excellent fluidity at the time of molding, it can be molded as desired even when used for molding a thin IC package or the like. (2) When the resin composition for semiconductor encapsulation of the present invention is used, a cured molded article having low hygroscopicity, excellent bending strength, and good mechanical properties can be obtained. (3) Since a cured product having low hygroscopicity is obtained from the resin composition for semiconductor encapsulation of the present invention, this is used as a surface mount type I
Even when used for molding a C package or the like, there is no concern about cracks or the like in the solder flow process. (4) Since the resin composition for semiconductor encapsulation of the present invention uses a polymaleimide compound as a resin main component, a cured molded article having excellent heat resistance can be obtained from this resin composition.

Claims (2)

[Claims] 1. A resin composition for semiconductor encapsulation, comprising each of the following components A, B, C, and D in predetermined amounts. A component: 5 to 20% by weight of a polymaleimide compound containing a bismaleimide represented by the following general formula (I), B component: 4 to 15% by weight of an allylphenol compound having two or more allyl groups in the molecule. %, C component: 25 to 90% by weight of silica particles, D component: 0.1 to 5% by weight of peroxyketal compound, [In the formula (I), R ₁ and R ₂ represent the same or different alkyl groups having 1 to 4 carbon atoms, and R ₃ and R ₄ represent
The same or different hydrogen atom, methyl group or ethyl group are shown. ] 2. The semiconductor encapsulating resin according to claim 1, wherein the component A is a polymaleimide compound containing 10% by weight or more of the bismaleimide represented by the general formula (I). Composition.