JPH0236148B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an epoxy resin composition for molding, and more specifically, it exhibits excellent mold releasability without mold staining during molding, and has excellent marking properties and
The present invention relates to a molding epoxy resin composition exhibiting adhesive properties, particularly for semiconductor encapsulation. Conventionally, methods such as transfer molding, injection molding, compression molding, and method molding have been adopted for molding epoxy resin compositions. In each of these molding methods, it is extremely important from the viewpoint of productivity to smoothly take out the molded product from the mold. To this end, when designing molds, measures are taken to create an incline in the mold cavity and increase the number of push-up pins.
However, although increasing the number of push-up pins improves the mold releasability, there are disadvantages in that the manufacturing cost of the mold increases significantly, resulting in economical constraints, and that alone does not provide sufficient mold releasability. Additionally, in order to improve mold releasability, a method has been implemented in which production is interrupted and a mold release agent is applied to the mold.
Repeated application of a mold release agent to a mold has a fatal drawback in that it reduces work efficiency and seriously impedes productivity. As a result, expectations have inevitably increased for improvement of the resin itself, that is, for the development of internal mold release agents. By the way, the role of the internal mold release agent is to improve mold release properties during molding, but it is also important that there is no bleed-off and that it does not interfere with the adhesion between the semiconductor component and the resin. It is. This is because the internal mold release agent pre-offs and accumulates as dirt in the mold as the number of molding increases, causing stains on the surface of the molded product. This is because when applying a stamp such as, the internal mold release agent oozes out and impedes the stamping performance. Furthermore, when the resin is used as a sealing material for semiconductors such as transistor ICs, its adhesion is important to prevent moisture from entering. Conventionally, metal salts of higher fatty acids such as calcium stearate and zinc stearate have been used as internal mold release agents, but although they have excellent mold release and marking properties, they have not been used as encapsulants for semiconductor devices. In addition, ester waxes such as carnauba wax and montan wax are known as internal mold release agents, but the adhesion when used as a sealant is comparatively poor. Although it has excellent properties, it has the disadvantage of poor releasability and imprintability. Further, dimethyl silicone oil is sometimes used, but although this oil has excellent mold releasability, it has the disadvantage of being inferior in imprintability and adhesion. As a result of extensive research into internal mold release agents for epoxy resin compositions, the present inventor found that by blending an organopolysiloxane with a specific group that can react with epoxy resins, the present inventors found that they are superior in that there is no bleed-off and no mold staining. We discovered that it has excellent mold releasability, as well as excellent imprintability on molded products and adhesion as a sealing material, and applied for a patent (Japanese Patent Application Laid-Open No. 58-69244).
did. As a result of continued research on internal mold release agents, the present inventor discovered an organopolysiloxane that has a specific group that can react with an epoxy resin and also has a polyoxyalkylene group that imparts affinity with the epoxy resin. We discovered that by blending, there is no bleed-off and mold release properties are further improved.
We have arrived at the present invention. That is, the present invention provides (A) an epoxy resin, and (B) a general formula [wherein R is the same or different monovalent hydrocarbon group, A is a group selected from R, D and G,
D is a monovalent organic group containing an epoxy group, an amino group, a hydroxyl group, a carboxyl group, or a carboxylic acid ester group, and G is (-R ¹ )-aO(-C ₂ H ₄ O)-b(-
C ₃ H ₆ O) - cR ² where R ¹ is a divalent organic group, R ² is a hydrogen atom or an end capping group, a is 0 or 1,
b and c are 0 to 50, but b+c is 1 to 100
), l is 0 to 1000, m and n are 0 to
100, where l+m+n is 1 to 1000. ], and has at least one D group and at least one G group in one molecule (However, the amount of component (B) added is based on the weight of component (A).
It is 0.1-20% by weight. ) The present invention relates to an epoxy resin composition for molding containing as a main ingredient. The epoxy resin of component (A) used in the present invention is:
All conventionally known epoxy resins can be used as long as they have at least two epoxy groups in one molecule. For example, diglycidyl ether of bisphenol A or epibis type epoxy resin which is a polymer thereof, bisphenol F type epoxy resin, resorcin type epoxy resin, tetrahydroxyphenylethane type epoxy resin, phenol novolak type epoxy resin, Examples include various modified epoxy resins such as cresol novolac type epoxy resin, polyolefin type epoxy resin, alicyclic type epoxy resin, epoxidized soybean oil, silicone-modified epoxy resin, and halogenated products thereof. As the epoxy resin, one type or a mixture of two or more types may be used.
Also included are mixtures of epoxy resins and other thermosetting resins that do not have epoxy groups. Component (B) used in the present invention, organopolysiloxane, is blended with an epoxy resin to provide excellent mold release properties without mold staining during molding, as well as improve marking properties on molded products and as a sealant. It is an important component that provides adhesion. This organopolysiloxane has the general formula In the formula, R is the same or different monovalent hydrocarbon group, such as a methyl group, an ethyl group,
Examples include propyl group, octyl group, phenyl group, vinyl group, allyl group, 3-chloropropyl group, β-phenylethyl group, and 3,3,3-trifluoropropyl group. Among these, methyl group is generally used. D is a monovalent organic acid containing an epoxy group, an amino group, a hydroxyl group, a carboxyl group, or a carboxylic acid ester group. Since these groups react with the epoxy resin, (B)
Works to prevent ingredient bleed-off. Among these, amino groups in which one or two of the hydrogen atoms bonded to the nitrogen atom are substituted with an alkyl group or the like can also be used. The type of monovalent organic group to which these functional groups are bonded is not particularly limited, but examples include alkylene groups such as methylene group, ethylene group, propylene group, and butylene group, chloroethylene group, and fluoroethylene group. halogenated alkylene group, aliphatic cyclic body-containing alkylene group,
Phenylene group, alkylenearylene group, -
C ₆ H ₄ CO―, ―CO―, ―NHCO―, ―
CH ₂ OCH ₂ CH ₂ CH ₂ ―, ―CH ₂ CH ₂ OCH ₂ CH ₂ ―,

[Formula] - (CH ² ) _1-10 (NHCH ₂ CH ₂ ) _1-5 or a composite group consisting of a combination of these groups is exemplified, and preferably the above functional group is bonded to one end of the group. It is something. However, this does not exclude those in which the functional group is bonded in the middle of the molecule constituting the monovalent organic group. G is the formula (-R ¹ )- _a O(-C ₂ H ₄ O)- _b (-C ₃ H ₆ O)- _c R
It is a polyoxyalkylene group represented by ² . This polyoxyalkylene group is a group that imparts affinity with epoxy resins. Here, R ¹ is a divalent organic group, an alkylene group having 1 to 10 carbon atoms,
Examples include a -C ₆ H ₄ - group, a -CO- group, an -NHCO- group, and a composite group in which these groups are bonded together.
R ² is a hydrogen atom or a terminal blocking group, and examples of the terminal blocking group include a monovalent hydrocarbon group, an acyl group, and a carbonic acid monoester group; examples of the monovalent hydrocarbon group include a methyl group, an ethyl group, a propyl group, Examples of the acyl group include a dodecyl group, a cyclohexyl group, a phenyl group, and a β-phenylethyl group. Examples of the acyl group include an acetyl group, a propionyl group, and a benzoyl group. a is 0 or 1, b and c are 0~
50, where b+c is 1 to 100. Further, A is a group selected from R, D and G described above. l is 0-1000, m and n are 0-100, provided that l+m+n is 1-1000. This organopolysiloxane contains, in one molecule,
It is necessary to have at least one D group and at least one G group. The D and G groups may be present anywhere in the molecular structure of the organopolysiloxane. In addition, if the value of b + c of the polyoxyalkylene group is too large, there is a risk that the polyoxyalkylene group will branch during production.
A range of 50 is preferred. Further, the preferable ranges of each siloxane unit are 1 to 500 for l, 2 to 40 for m, 1 to 30 for n, and 10 to 500 for l+m+n. The blending ratio of component (B) is in the range of 0.1 to 20% by weight of the epoxy resin that is component (A), preferably 0.5 to 20% by weight.
It is in the range of 15% by weight. If the blending ratio is less than 0.1% by weight, the effect as an internal mold release agent will not be sufficient, and if it exceeds 20% by weight, it will affect the properties of the molded product after curing, such as mechanical strength, electrical properties, and chemical properties. This is because it affects Furthermore, two or more types of component (B) may be blended as long as there is no problem. In addition to the above-mentioned components (A) and (B), this composition uses an epoxy resin curing agent. This curing agent may be a conventionally known one, such as acid anhydrides such as phthalic anhydride, pyromellitic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, succinic anhydride, and benzophenonetetracarboxylic anhydride. Curing agents, amine-based curing agents such as dicyandiamide, diaminodiphenylmethane, diaminodiphenyl sulfone, metaphenylenediamine, bis(3-methyl-4-aminophenyl)methane, bis(4-amino-cyclohexyl)methane, or phenols. A novolak type curing agent or the like is used. This blending amount varies depending on the type of curing agent and is therefore not particularly limited. In addition to this curing agent, curing accelerators typified by imidazole and tertiary amines can also be used. Furthermore, this composition may optionally contain fatty acid metal salts, ester waxes, conventionally known internal mold release agents such as liquid organopolysiloxanes other than component (B), fumed silica, fused silica, crystalline silica, crystalline silica, etc. silica, alumina, alumina hydrate,
Inorganic fillers such as talc, diatomaceous earth, mica, asbestos, calcium carbonate, and glass fiber; flame retardants such as antimony oxide, halogen compounds, and phosphorus compounds; and silane coupling agents (containing component (B)). (including a silane coupling agent having the same functional group as the functional group), pigments, etc. can be blended. The amount of inorganic filler added varies depending on the purpose, but it is usually 5 to 1000% of component (A).
Add in a range of % by weight. The epoxy resin composition for molding of the present invention exhibits extremely excellent mold releasability without mold staining during molding by transfer, compression, injection, casting, etc., and its molded products have excellent marking properties and are suitable for semiconductor encapsulation. When used for purposes, it can improve adhesion to semiconductor components. Furthermore, powdered epoxy resin mixed with component (B) or treated epoxy resin powder with component (B) can improve anti-blocking properties and fluidity. It can be used as a paint for electrical insulation coatings and corrosion-resistant coatings.
In addition, it can be used as a general molding material, heat-resistant varnish, casting resin, impregnating resin, and coating material. Next, the present invention will be explained with reference to examples. Parts in Examples and Comparative Examples mean parts by weight, and viscosity is the value at 25°C. In each of the Examples and Comparative Examples, the following methods were used to determine the characteristics of the present invention: "mold releasability", "mold staining", "imprintability", and "adhesion". "Mold releasability" In a mold with a cylindrical cavity with a cross-sectional area of 1 ^cm2 , 1.5 g of each composition was compression molded at 175°C for 2 minutes, and the extrusion force (Kg )
was measured with a push-pull gauge. This was repeated 10 times and the lowest and highest values were taken. "Mold stains" Using a mold for 20 To-202 transistors,
Transfer molding was performed continuously at 175°C for 2 minutes 500 times, and stains on the mold after molding were visually observed. If the mirror surface of the mold was not cloudy, tranfer molding was continued 500 times and dirt on the mold was visually observed.
The mirror surface of the mold should not be cloudy even after 1000 moldings.
A mark was given as △ if there was no clouding after 500 moldings, but clouding occurred after 1000 moldings, and an x mark if clouding occurred after 500 moldings or less. "Stampability" Using a mold for 20 To-202 transistors,
Markem 7261 ink was stamped on the molded surface which was transfer molded at 175℃ for 2 minutes, and then transferred at 150℃ for 1 minute.
After the ink was cured for a period of time, cellophane tape was brought into close contact with the surface of the ink, and when the tape was rapidly peeled off, the transferability of the ink to the tape side was visually judged. Repeat this 10 times, and in 10 cases, there is no transfer at all to the tape side, marked with ○, cases where even a portion of the transfer is on the tape side, at least once, is marked, and cases where there is transfer to almost the entire surface of the tape, marked at least once. I marked the items with an x. "Adhesion" Using a mold for 20 To-202 transistors,
The semiconductor was sealed by transfer molding at 175° C. for 2 minutes. Ten pieces of each of these molded products were immersed in Red-Check solution, boiled for 12 hours, taken out, and the extent to which Red-Check solution penetrated into the interface between the molded product and the lead frame was observed using a microscope.
Mark ○ if no infiltration is observed in any of the 10 items, and mark △ if there are 5 or less infiltrates.
Mark, all 10 items have no infiltration, even the slightest.
It was marked as a mark. Example 1 75 parts of cresol novolak epoxy resin with an epoxy equivalent of 220 and a softening point of 80°C, an epoxy equivalent of 400,
25 parts of brominated bisphenol A type epoxy resin with a softening point of 70°C and a bromine content of 45% by weight, 50 parts of a phenolic novolac resin with a softening point of 90°C as a hardening agent, 420 parts of fused silica powder as an inorganic filler, and hardening accelerator. 1 part of 2-methyl-4-imidazole as agent, 2 parts of carbon black as pigment, 20 parts of antimony trioxide, and formula as internal mold release agent. 2 parts of an organopolysiloxane containing an epoxy group and a polyoxyalkylene group having a viscosity of 3,500 centistokes are added, kneaded with heated rolls at 80 to 90°C, cooled and crushed to form an epoxy resin composition for molding. did. Using this composition, the mold releasability, mold staining, stamping performance, and adhesion were evaluated as described above, and the results are shown in Table 1. Comparative Example 1 An epoxy resin composition for molding was prepared in exactly the same manner as in Example 1, except that 2 parts of carnauba wax was used instead of the internal mold release agent used in Example 1, and the same evaluation was carried out. I did it. The results are shown in Table 1. Comparative Example 2 An epoxy resin composition for molding was prepared in exactly the same manner as in Example 1, except that 2 parts of calcium stearate was used instead of the internal mold release agent used in Example 1, and the same evaluation was performed. Ta. The results are shown in Table 1. Comparative Example 3 Instead of the internal mold release agent used in Example 1, a viscosity product in which both ends of the molecular chain were blocked with trimethylsilyl groups
An epoxy resin composition for molding was prepared in exactly the same manner as in Example 1, except that 2 parts of 1000 centistokes dimethylpolysiloxane was used, and the same evaluation was performed. The results are shown in Table 1. Comparative Example 4 Instead of the internal mold release agent used in Example 1, the formula An epoxy resin composition for molding was prepared in exactly the same manner as in Example 1, except that 2 parts of epoxy group-containing dimethylpolysiloxane having a viscosity of 8000 centistokes was used, and the same evaluation was performed.
The results are shown in Table 1. Comparative Example 5 Instead of the internal mold release agent used in Example 1, the formula Polyoxyalkylene group-containing dimethylpolysiloxane 2 with a viscosity of 1200 centistokes expressed by
An epoxy resin composition for molding was prepared in exactly the same manner as in Example 1, except that 100% of the epoxy resin composition was used, and the same evaluation was performed. The results are shown in Table 1.

[Table] As is clear from Table 1, Example 1 has extremely superior mold releasability compared to the comparative example using a conventionally known internal mold release agent, has no mold stains, and has excellent marking properties. This shows that it has excellent adhesion to semiconductor components, so it has great reliability when used as a semiconductor encapsulating material. Example 2 Instead of the organopolysiloxane containing epoxy groups and polyoxyalkylene groups of the internal mold release agent used in Example 1, the formula Example 1 except that 2 parts of an organopolysiloxane containing an amino group and a polyoxyalkylene group having a viscosity of 4000 centistokes represented by
An epoxy resin composition for molding was prepared in exactly the same manner as above, and the same evaluation was performed. The results are shown in Table 2. Comparative Example 6 Instead of the internal mold release agent used in Example 2, the formula An epoxy resin composition for molding was prepared in exactly the same manner as in Example 1, except that 2 parts of amino group-containing dimethylpolysiloxane having a viscosity of 1100 centistokes was used, and the same evaluation was performed. The results are shown in Table 2. Results similar to those in Example 1 were obtained.

[Table] Examples 3 to 5 Molding was carried out in exactly the same manner as in Example 1, except that 2 parts of each internal mold release agent represented by the chemical formula below was used instead of the internal mold release agent used in Example 1. An epoxy resin composition was prepared and evaluated in the same way.
The results are shown in Table 3. An organopolysiloxane containing a carboxyl group and a polyoxyalkylene group and having a viscosity of 8,500 centistokes (Example 3). An organopolysiloxane containing a carboxylic acid ester group and a polyoxyalkylene group and having a viscosity of 780 centistokes (Example 4). An organopolysiloxane containing a carbinol group and a polyoxyalkylene group and having a viscosity of 350 centistokes (Example 5). Comparative Examples 7-9 Instead of the internal mold release agent used in Examples 3-5,
Epoxy resin compositions for molding were prepared in exactly the same manner as in Example 1, except that two parts of each internal mold release agent represented by the following chemical formula were used, and the same evaluations were performed. The results are also listed in Table 3. Carboxy group-containing dimethylpolysiloxane having a viscosity of 2500 centistokes (Comparative Example 7). A carboxylic acid ester group-containing dimethylpolysiloxane having a viscosity of 2300 centistokes (Comparative Example 8). A carbinol group-containing dimethylpolysiloxane having a viscosity of 50 centistokes (Comparative Example 9).

[Table] Implementation 6 Epoxy equivalent: 220, 50 parts of cresol novolak epoxy resin with a softening point of 80°C, epoxy equivalent: 500,
Bisphenol A type epoxy resin 25 with a softening point of 70℃
25 parts of brominated bisphenol A type epoxy resin with a bromine content of 35% by weight, an epoxy equivalent of 280 and a softening point of 85°C, and tetrahydrophthalic anhydride as a curing agent.
30 parts, crystalline silica powder 420 as inorganic filler
1 part of 2-methyl-4-imidazole as a curing accelerator, 2 parts of carbon black as a pigment, 20 parts of antimony trioxide, and Example 1 as an internal mold release agent.
0.5 part of the organopolysiloxane containing epoxy groups and polyoxyalkylene groups used in
The mixture was kneaded in varying amounts of 1 part, 3 parts, 5 parts, 10 parts, and 15 parts, and pulverized to obtain an epoxy resin composition for molding. Regarding this, the same evaluation as in Example 1 was carried out, and the results are shown in Table 4. All had extremely good mold releasability, mold staining, imprintability, and adhesion.

[Table] Example 7 Instead of the internal mold release agent used in Example 6, the formula An epoxy resin composition for molding was prepared in exactly the same manner as in Example 6, except that 3 parts of organopolysiloxane containing an epoxy group and a polyoxyalkylene group with a viscosity of 14,500 centistokes was used, and molded and evaluated. As a result, the mold releasability was 2 to 3 kg, there was no mold staining, and the stamping performance and adhesion were both extremely good.

Claims (1)

[Claims] 1(A) Epoxy resin, and (B) General formula [wherein R is the same or different monovalent hydrocarbon group, A is a group selected from R, D and G,
D is a monovalent organic group containing an epoxy group, an amino group, a hydroxyl group, a carboxyl group, or a carboxylic acid ester group, and G is (-R ¹ )-aO(-C ₂ H ₄ O)-b(-
C ₃ H ₆ O) - cR ² (where R ¹ is a divalent organic group, R ²
is a hydrogen atom or a terminal capping group, a is 0 or 1, b and c are 0 to 50, but b+c is 1 to
100), l is 0 to 1000, m and n are 0 to
100, where l+m+n is 1 to 1000. ], and has at least one D group and at least one G group in one molecule (However, the amount of component (B) added is based on the weight of component (A).
It is 0.1-20% by weight. ) is the main ingredient of an epoxy resin composition for molding.