JPH08217974A - Cyanate resin composition - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a semiconductor device having high heat resistance and low water absorption, and having excellent package crack resistance after immersion in a solder bath when, for example, a semiconductor is encapsulated using the same. Providing a cyanate resin composition. [Structure] The following general formula [I]: [In the formula, A represents an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group or an alkenyl group, a phenyl group or a halogen group, and X is a single bond, a saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms. , A carbonyl group, a sulfone group, a divalent sulfur atom or an oxygen atom, and i represents an integer value of 0 or more and 4 or less. ] A cyanate ester represented by or a prepolymer thereof, a curing accelerator for the cyanate ester, and a filler, and the ratio of the filler to the entire composition is 80% by weight or more and 94% by weight or less. Cyanate resin composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filler-containing cyanate resin composition suitable for injection molding and transfer molding, and particularly useful as a sealing material for electronic parts, a molding material and an adhesive. It relates to a composition.

[0002]

2. Description of the Related Art Recently, LSIs, ICs, transistors, etc.
Transfer molding of an economically useful epoxy resin composition is performed for sealing a semiconductor. In particular, recently, the surface mounting of LSIs has been performed, and the number of cases in which a semiconductor package is directly immersed in a solder bath at the time of mounting on a semiconductor substrate is increasing. At this time, the sealed package is 2
Since it is exposed to a high temperature of 00 ° C. or higher, cracks are generated inside the sealed package and peeling occurs between the element or the metal frame and the sealing material interface. Therefore, the resin sealing material is strongly required to have heat resistance and package crack resistance. At present, an epoxy resin is usually used as a sealing resin. However, there is a limit to improving the heat resistance of the epoxy resin, and a highly reliable epoxy resin has not been obtained when it is directly exposed to a solder bath. Cyanate resin is known as a resin having high heat resistance as an alternative to the epoxy resin. This resin has a high Tg and a relatively low moisture absorption when it is press-molded for a long time like a laminated plate. However, when this is used for short-time molding of a sealing material or the like, unreacted cyanate groups remain in the cured product, and when a large amount of moisture is absorbed, it is decarboxylated via hydrolysis (USP5195299). However, there are problems such as cracks in the sealed package.

[0003]

In view of the above-mentioned problems, the object of the present invention is to have high heat resistance and low water absorption.
It is an object of the present invention to provide a cyanate resin composition which, when used for sealing a semiconductor, provides a semiconductor device having excellent resistance to package cracks after immersion in a solder bath.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a resin composition containing a filler having a specific composition achieves the object of the present invention, and completes the present invention. Came to. That is, the present invention provides the following general formula [I]

[0005]

[Chemical 4] [In the formula, A represents an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group or an alkenyl group, a phenyl group or a halogen group. A may be different from each other (A
If there are multiple in the same nucleus or different nuclei). X is a single bond, a saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms,
A carbonyl group, a sulfone group, a divalent sulfur atom or an oxygen atom is shown. i represents an integer value of 0 or more and 4 or less. i may be different from each other. ] A cyanate ester represented by or a prepolymer thereof, a curing accelerator for the cyanate ester, and a filler, and the ratio of the filler to the entire composition is 80% by weight or more and 94% by weight or less. Cyanate resin composition.

Any cyanate compound can be used as long as it satisfies the general formula [I]. In the general formula [I], A is a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a t-butyl group, a hydrocarbon group such as a cyclohexyl group, an allyl group or a phenyl group, and a halogen atom such as fluorine, chlorine or bromine. Examples of X include a biphenyl type single bond, an isopropylidene group, a cyclohexylene group, a vinylene group and a sulfide group.

Illustrating the cyanate ester represented by the general formula [I], 4,4'-dicyanate diphenyl,
4,4'-dihydroxybenzophenone, 4,4'-dihydroxy-3,5-dimethylbenzophenone, 1, 2
-Bis (4-cyanatephenyl) ethene, 1,2-bis (4-cyanate-3,5-dimethylphenyl) ethene, 3,3 ', 5,5'-tetramethyl-4,4'-dicyanate diphenyl, bis (cyanate) Phenyl) methane, bis (4-cyanate-3,5-dimethylphenyl) methane, bis (2-cyanate-3-t-butyl-)
5-methylphenyl) methane, bis (4-cyanatephenyl) ethane, 2,2-bis (4-cyanatephenyl) propane, 2,2-bis (3,5-dimethyl-4-)
Cyanate phenyl) propane, 2,2-bis (3-methyl-4-cyanatephenyl) propane, 2,2-bis (4-cyanate-3-t-butylphenyl) propane, 2,2-bis (4-cyanate) -3-t-butyl-
6-methylphenyl) propane, 2,2-bis (3-allyl-4-cyanatephenyl) propane, 1,1-bis (4-cyanate-3-t-butyl-6-methylphenyl) butane, 1,1 -Bis (4-cyanatephenyl) cyclohexane, 1,1-bis (4-cyanate-)
3-Methylphenyl) cyclohexane, 1,1-bis (4-cyanate-3-cyclohexyl-6-methyl)
Butane, bis (4-cyanatephenyl) menthane, bis (4-cyanate-3,5-dimethyl) menthane, bis (4-cyanate-3-t-butyl-6-methylphenyl) mentane, bis (4-cyanatephenyl) ) Tricyclo [5,2,1,0 ^2,6 ] decane, bis (4-cyanate-3,5-dimethylphenyl) tricyclo [5
2,1,0 ^2,6 ] decane, bis (4-cyanate-3-)
t-butyl-6-methylphenyl) tricyclo [5,5
2,1,0 ^2,6 ] decane, bis (4-cyanatephenyl) sulfide, bis (4-cyanate-3,5-dimethylphenyl) sulfide, bis (4-cyanate-3)
Examples thereof include -t-butyl-6-methylphenyl) sulfide, bis (4-cyanatephenyl) sulfone, bis (4-cyanatephenyl) carbonyl, bis (4-cyanatephenyl) ether and the like. In particular, 2,2-bis (4-cyanatephenyl) propane is industrially easily available and is preferable. In addition, 1,1-bis (4-cyanine)
To-3-methylphenyl) cyclohexane is preferable because it has a high curing rate, heat resistance and low hygroscopicity.

If the viscosity of the cyanate ester is low and the workability during molding is impaired, the cyanate ester may be prepolymerized if necessary. That is, it is possible to adjust a desired viscosity by heating or adding a slight amount of a cyanate ester curing accelerator to convert a part of the cyanate ester into polytriazine.

As the curing accelerator used in the cyanate resin composition of the present invention, known ones can be used. For example, a protic acid represented by hydrochloric acid or phosphoric acid;
Lewis acid represented by aluminum chloride, boron trifluoride complex, zinc chloride; aromatic hydroxy compound represented by phenol, pyrocatechol, nonylphenol, dihydroxynaphthalene; zinc naphthenate, cobalt naphthenate, tin octylate, octylate Organometallic salts typified by cobalt; tertiary amines typified by triethylamine, tributylamine, pyridine and quinoline; imidazoles; quaternary ammonium salts typified by tetraethylammonium chloride, tetramethylammonium bromide and benzylammonium chloride A metal hydroxide typified by sodium hydroxide; a metal alcoholate typified by sodium methoxide; triphenylphosphine; diazabicyclo- (2,2,2) -octane. Particularly, metal salts of naphthenic acid and metal salts of octanoic acid are preferable because they have a high curing rate and are easily available.

Examples of the filler used in the present invention are silica, alumina, aluminum nitride, silicon nitride, silicon carbide, silica sand, silica stone, talc, white carbon, aerosil, wollastonite, mica, clay,
There are glass spheres, metal spheres and the like. From the viewpoint of the coefficient of thermal expansion and high purity, the spherical powder is preferably fused silica powder, crystalline silica powder, alumina powder or the like, and the crushed powder is preferably fused silica powder.

The blending amount of the filler used in the present invention is preferably 80% by weight or more and 94% by weight or less, more preferably 85% by weight or more and 94% by weight or less, based on the whole composition. If the amount of the filler used is less than this range, the heat resistance after moisture absorption is lacking, and if the amount of the filler compounded is more than this range, the flowability during heating and melting of the sealing material is impaired, Difficult to mold.

The average particle size and the compounding ratio of the filler used in the present invention are arbitrary, but in order to obtain the desired compounding amount of the filler without impairing the flowability during heating and melting, the following average values are given. Particle size and blending ratios are recommended. That is, spherical powder having an average particle size of 0.1 μm or more and 1.5 μm or less (x component), spherical powder having an average particle size of 2 μm or more and 15 μm or less (y component), and spherical powder having an average particle size of 20 μm or more and 70 μm or less ( z component) and a crushed powder (m component) are contained, and the proportions of x, y and z components with respect to the total composition are 10% by volume or more and 24% by volume or less, respectively.
0.1 volume% or more and 36 volume% or less, 57 volume% or more 76
It is preferably not more than volume%.

Additives such as epoxy resin, imide resin, petroleum resin, coumarone resin and polybutadiene resin may be added to the cyanate ester.

[0014]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. The characteristics of the cured resin were evaluated as follows.・ Spiral flow: According to EMMI-1-66, 190 ℃ / 70kg /
It was carried out under the condition of cm ² . -Barcol hardness: According to ASTM D-648, it was measured with a 958 type hardness meter under the condition of 190 ° C / 90 seconds.・ Glass transition temperature: Thermomechanical analyzer (SHIMADZU DT-3
0) was used for the measurement.・ Flexural strength, flexural modulus, flexural modulus: 240 according to JIS K-6911 using a tensile tester (SHIMADZU IS-10T)
It was measured at ° C.・ Water absorption: Constant temperature and humidity chamber (Advantech Toyo AGX-326)
Was used to measure the weight change under the conditions of 85 ° C./85% RH / 24 hours. -Solder crack resistance: Simulated IC (52-pin QFP package thickness 2.05 mm) is allowed to absorb moisture under the conditions of 85 ° C / 85% RH / 24 hours, and immediately immersed in a solder bath at 240 ° C for 30 seconds. The number of cracked ICs. 8 test individuals.

Reference Example 1 2,2-bis (4-hydroxyphenyl) propane (manufactured by Mitsui Toatsu Chemicals, Inc.) in a reactor equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser under a nitrogen atmosphere. ) 11
4.2 g (0.5 mol), methyl isobutyl ketone 6
After charging 85 g and dissolving at room temperature, the solution was cooled to 0 ° C. Next, 67.7 g (1.1 mol) of cyanogen chloride was added dropwise over 2 hours. 5 minutes after the start of dropwise addition of cyanogen chloride, 111.2 g (1.1 mol) of triethylamine was added to 0 to 6
The mixture was added dropwise at 2 ° C. for 2 hours and 30 minutes and kept at the same temperature for 30 minutes. During the dropwise addition, the pH of the reaction solution was adjusted to 5-6. After washing with 300 g of 3% hydrochloric acid water, 300 g of water
It was washed twice with water and separated. The obtained organic layer was concentrated under reduced pressure to 178 g, 228 g of isopropyl alcohol was added dropwise, and the mixture was cooled to 5 ° C. and stirred for 3 hours. The obtained slurry was filtered, washed with 114 g of isopropyl alcohol, and then air-dried to obtain 121.1 g of white crystals having a melting point of 80 ° C. (yield 87%). LC (liquid chromatographic analysis)
The purity of the dicyanate product was 99.3%. The obtained white crystals were analyzed by GC (gas chromatograph), but diethylcyanamide was not detected. An attempt was made to analyze chloride ion by potentiometric titration using silver nitrate, but the content of chloride ion was 10 ppm or less.

Reference Example 2 In Reference Example 1, 148.2 g (0.5 mo) of 1,1-bis (4-cyanate-3-methylphenyl) cyclohexane was used.
1) White crystals were prepared under exactly the same conditions except that 1) was used.
55.9 g was obtained (yield 90%). The purity of the dicyanate body by LC was 99.5%. The obtained white crystals were analyzed by GC, but no diethylcyanamide was detected. An attempt was made to analyze chloride ion by potentiometric titration using silver nitrate, but the content of chloride ion was 10 ppm or less.

Examples 1 to 3 and Comparative Examples 1 and 2 The amounts (g) shown in Table 1 were blended, kneaded by heating with a roll, and then transfer molding was carried out. The properties of the obtained cured resin are also summarized in Table 1.

The cured resins of Examples 1 to 3 have a silica content of 90%, a high Tg, and a high bending strength at the time of heating, and have a low water absorption rate at 85 ° C / 85% RH / 24 hours. The resistance to solder cracking after the moisture absorption treatment is also good.

The cured resins of Comparative Examples 1 and 2 have a silica content of 75%, and the characteristics of the cured products are the same as those of the examples. However, the water absorption was high, and the solder crack resistance after the moisture absorption treatment at 85 ° C / 85% RH / 24 hours was poor.

[0020]

[Table 1] (Note) * 1.2,2-bis (4-cyanatephenyl) propane (obtained in Reference Example 1) * 2.1,1-bis (4-cyanatephenyl) cyclohexane (obtained in Reference Example 2) ) * 3. Petroleum hydrocarbon resin (trade name, manufactured by Nippon Steel Chemical Co., Ltd.) * 4. Crushed silica (average particle size 13 μm, manufactured by Denki Kagaku Kogyo Co., Ltd., trade name) * 5. Crushed silica (average particle size 30 μm, manufactured by Denki Kagaku Kogyo KK, trade name) * 6. Crushed silica (average particle size 5.6 μm, manufactured by Denki Kagaku Kogyo Co., Ltd., trade name) * 7. Crushed silica (average particle size 0.4 μm, manufactured by Admatech Co., Ltd., trade name) * 8. Crushed silica (average particle size 4.9 μm, manufactured by Nippon Chemical Industry Co., Ltd., trade name) * 9. Crushed silica (average particle size 40.4 μm, manufactured by Tokuyama Soda Industry Co., Ltd., trade name)

[0021]

The cyanate resin composition of the present invention has a high T
g, high elastic modulus and high bending strength, low water absorption rate, good package crack resistance by immersion in solder bath after moisture absorption treatment at 85 ℃ / 85% RH / 24 hours, for semiconductor encapsulant It is suitable as a resin composition.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noriaki Saito 6 Kitahara, Tsukuba, Ibaraki Sumitomo Chemical Co., Ltd.

Claims (5)

[Claims] 1. The following general formula [I]: [In the formula, A represents an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group or an alkenyl group, a phenyl group or a halogen group. A may be different from each other. X
Represents a single bond, a saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms, a carbonyl group, a sulfone group, a divalent sulfur atom or an oxygen atom. i represents an integer value of 0 or more and 4 or less.
i may be different from each other. ] A cyanate ester represented by the formula, a curing accelerator for the cyanate ester, and a filler, and the ratio of the filler to the entire composition is 80.
A cyanate resin composition, characterized in that the content is not less than 94% by weight. 2. A prepolymer obtained by adjusting the viscosity of the cyanate ester represented by the general formula [I] to 20 poise or less at 150 ° C., a cyanate ester curing accelerator and a filler. A cyanate resin composition, characterized in that the proportion of the whole composition is 80% by weight or more and 94% by weight or less. 3. A spherical powder having an average particle size of 0.1 μm to 1.5 μm (x component), a spherical powder having an average particle size of 2 μm to 15 μm (y component), and an average particle size of 20 μm to 7
A filler comprising a spherical powder (z component) of 0 μm or less and a crushed powder (m component) is contained, and the ratio of x, y, and z components to the entire composition is 10% by volume or more and 24 respectively.
The cyanate resin composition according to claim 1 or 2, wherein the content is not more than 0.1% by volume, not less than 0.1% by volume and not more than 36% by volume, and not less than 57% by volume and not more than 76% by volume. 4. The cyanate resin composition according to claim 3, wherein the cyanate ester represented by the general formula [I] is represented by the following formula. Embedded image 5. The cyanate resin composition according to claim 3, wherein the cyanate ester represented by the general formula [I] is represented by the following formula. Embedded image