JPS6173725A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:An epoxy resin composition having low internal stress, excellent heat shock resistance and excellent moisture resistance reliability, comprising a phenol-modified silicone compound, an epoxy resin, a phenolic resin and a filler. CONSTITUTION:A phenol-modified silicone compound is obtained by reacting an organosilicone compound of the formula [wherein R is H, methyl, ethyl or phenyl, X is an epoxy group-containing organic group, Y is a group of an oxyethylene polymer, a group of an acrylamide polymer, or a like group, lis 0.1-0.98 (a molar fraction of siloxane units), m is 0.01-0.5and n is 0.01-0.7] with a phenolic resin and extracting an unreacted organic silicone compound. An epoxy resin is mixed with said compound, a phenol curing agent and an inorganic filler such as silica. The obtained resin composition is suitably used in sealing semiconductor electronic parts.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an epoxy resin composition for encapsulating electronic components such as semiconductors, which has particularly low internal stress, excellent heat shock resistance, and reliable moisture resistance. The present invention relates to an epoxy resin composition for encapsulating semiconductor electronic components, which has good properties.

(Prior art) In recent years, most semiconductors (hereinafter referred to as ICs) have been encapsulated with resin, and epoxy resin compositions have become mainstream due to their close relationship with elements and cost. It has become. These require technical improvements necessary to maintain the characteristics of semiconductors. Among these, two important issues are improving moisture resistance reliability and reducing internal stress generated from distortion caused by curing shrinkage of the resin and the difference in coefficient of thermal expansion between the resin and the element. In particular, due to the recent increase in the degree of integration of electronic devices, the size of devices has increased, and cracks in the resin due to internal stress and internal stress at the time of zero thermal shock have become a major problem.

For this reason, various studies have recently been conducted with the aim of reducing this internal stress.The methods for reducing internal stress include: - lowering the coefficient of thermal expansion of the resin to bring it close to the coefficient of thermal expansion of the element; ?Lower, etc.

The former is generally achieved by adding an inorganic photonic agent with a small coefficient of thermal expansion to the resin, but on the other hand, the elastic modulus increases, so if the internal stress is not sufficiently reduced and the resin is filled with a higher This causes problems of poor moldability and decreased fluidity. The latter is achieved by adding a flexibility imparting agent to the resin. This can be done by adding a comb component (Japanese Unexamined Patent Publication No. 5
No. 7-151226, etc.), it has been carried out to add a silicone compound having a pentate property.

In particular, silicone compounds hold great promise as they have superior heat resistance and less impurities than ordinary rubber.

The conventional technology for silicone compounds is to add silicone compounds that are not reactive with resins (Japanese Unexamined Patent Publication No. 58
-219218, etc.) or a silicone compound having a functional group reactive with the resin (Japanese Unexamined Patent Application Publication No. 56-1989).
145942, JP-A-58-158730, etc.). However, from these results, no significant reduction in internal stress was observed - this is thought to be due to the following problems. In other words, a silicone compound that is not reactive with a resin has a weak bonding force at the interface with the resin (Also, silicone compounds and resins are inherently not compatible with each other, so they do not disperse well. It is thought that silicone compounds that have a functional group that reacts with the resin also have poor compatibility with the resin, and therefore cannot produce significant effects.

(Problems to be Solved by the Invention) The present invention solves these drawbacks, and solves the problems by solving the following formula [1
By using a phenol-modified silicone compound and an epoxy resin composition, which are obtained by reacting an organic silicone compound represented by An object of the present invention is to provide an epoxy resin composition for encapsulating semiconductor electronic components that also has good properties.

(In formula (2), R represents hydrogen, a methyl group, an ethyl group, or a phenyl group, X represents an epoxy group-containing organic group, Y represents a polyoxyethylene polymer, a polyoxypropylene polymer,
Indicates polyacrylamide polymer, polyvinyl alcohol polymer, and polydioxolane polymer. 13 + m +
n indicates the mole fraction of each xylochitin unit, A = 0.1
~0.98, m50.01~0.5, n=0.01~0
．． It is 7. ) (Means for Solving the Problems) That is, the present invention involves reacting an organic silicone compound represented by the following formula CI with a phenol resin in advance in the absence of a solvent, and removing the unreacted organic silicone compound represented by the following formula CI and a phenol resin. It is characterized by consisting of a phenol-modified silicone compound extracted and removed with water, an epoxy resin, a phenol resin, and a filler.

(In formula (2), R represents hydrogen, a methyl group, an ethyl group, or a phenyl group, X represents an epoxy group-containing organic group, Y represents a polyoxyethylene polymer, a polyoxypropylene polymer,
073. indicates a polyacrylamide polymer, a polyvinyl alcohol polymer, and a polydioxolane polymer. m and n indicate the mole fraction of each siloxane unit, n = 0.1 to 0.9
8, m=0.01~0.5, n=0.01~0-7
It is. ) The present invention will be explained in detail below.

The organic silicone compound used in the phenol-modified silicone compound of the present invention is represented by the general formula. Moreover, R is hydrogen, a methyl group, an ethyl group, or a phenyl group, and X represents an organic group containing an epoxy group, and there is no particular restriction as long as it has an epoxy group. For example, etc.

Y represents a functional group that is compatible with the phenolic resin, and examples thereof include polyoxyethylene, polyoxynolopyrene, polyacrylic acid amide group, polyvinyl alcohol, and polydioxolane, and the degree of polymerization of these polymers is 5 to 500. Preferably it is 10-600. When the degree of polymerization is less than 5, a compatibility effect is observed; when it exceeds 500, the strength of the epoxy resin itself decreases, causing problems.

d, m, and n are the mole fractions of each block of each siloxane unit, and l is 0.1 to 0.98; if it is less than this, the original characteristics of the silicone compound will not be exhibited, and if it exceeds this, The compatibility between the resin and the resin is poor.

m is 0.01 to 0.5; if it is less than this, the reactivity with the resin will be poor (if it exceeds this, gelation will occur during the preliminary reaction).

n is 0.01 to 0.7; if it is less than this, the compatibility with the resin will be poor (if it exceeds this, the strength of the resin itself will decrease, which is a problem)
The method for producing a phenol-modified silicone compound involves first heating and melting a phenol resin at a temperature of 120 to 16[]°C without removing it, and preferably adding a catalyst such as triphenylphosphine and an organic silicone compound thereto. do,
Allow to react while stirring.

After a predetermined period of time has elapsed, remove the compound from the container.
If any unreacted substances remain, the heat resistance reliability will decrease, so next, transfer to an autoclave, add water at high temperature and high pressure, extract and remove unreacted organosilicone compounds, thoroughly dry water, and remove the product. Smash. The obtained compound is dispersed in the epoxy resin, is well miscible at the interface between the resin and the compound, and has strong adhesion due to chemical bonds.

The amount of the phenol-modified silicone compound added is preferably 2 to 40 parts by weight per 100 parts by weight of the epoxy resin.
It is 5 to 60 parts by weight. If the amount added is less than 2 parts by weight, moisture resistance reliability and low internal stress cannot be obtained, and if it exceeds 40 parts by weight, the moldability and strength of the resin composition will deteriorate, which is not preferable.

The epoxy resin used in the present invention is not particularly limited in molecular structure, molecular weight, etc., as long as it has at least two or more epoxy bonds in its molecule.

Examples include bisphenol A type epoxy resin, phenol novolak type epoxy resin, cresol novolac type epoxy resin, etc., but in this case, it is preferable to use one with less impurities and hydrolyzable chlorine.

Examples of the curing agent include phenolic curing agents such as phenol novolac resins and cresol novolac resins, amine curing agents, and acid anhydride curing agents. There are no particular restrictions on the amount of these used, but
It is necessary to add stoichiometric amounts of epoxy groups and curing agent.

Examples of inorganic photonic agents include powders such as crystalline silica, fused silica, calcium silicate, alumina, calcium carbonate, talc, and barium sulfate, or glass fibers, but usually crystalline silica or , fused silica is used. The blending ratio of these inorganic photonic agents to the total varies depending on the selected resin content, but
Generally, the amount may be about 150 to 450 parts by weight per 100 parts by weight of the resin. If it is less than 150 parts by weight, the coefficient of thermal expansion and molding shrinkage will be high, and the thermal conductivity will be low, and if it is more than 450 parts by weight, there will be disadvantages such as decreased fluidity and increased mold wear.

Other components that may be added as necessary include silane coupling agents such as γ-glycidomizolopyltrimethoxysilane, curing accelerators such as imidazoles, phosphines, preferably triphenylphosphine, and carbon black. Examples include pigments, release agents such as Montana wax, carnauba wax, or Hoechst wax, and flame retardants such as brominated epoxy resins and antimony trioxide.

The resin composition of the present invention can be obtained by stirring and mixing each component and additives in a lamixer, mixing with a heated roll, cooling, and pulverizing.

(Example) Examples 1 to 10 60 parts by weight of a phenol novolac resin, 60 parts by weight of an organic silicone compound having the structure shown in the table, and the added amount shown in the table, respectively.
0.2 parts by weight of triphenylphosphine are reacted at 140 DEG C. for 6 hours and the resulting product 'r is extracted with 500 ml of water in an autoclave at 110 DEG C. for 6 hours. The extraction residue was dried under reduced pressure at 80° C. and 30 Hg for 16 hours, pulverized with a Henschel mixer, and then mixed with other materials in the proportions (parts by weight) shown in the table using a mixer.

Regarding the phenolic resin, the missing amount was added to the amount shown in the table. Thereafter, this mixture was kneaded with a heating roll, cooled, and then crushed to produce 10 types of molding materials.

Comparative Examples 1 to 8 Regarding the various silicone compounds shown in the table, eight types of molding materials were added in the proportions shown in the table in the same manner as in the examples,
evaluated. At that time, regarding the manufacturing method, for comparison,
As shown in the table, phenol-modified silicone compounds that were not subjected to preliminary reaction or water extraction were also tested at °C.

1) Stress evaluation In order to evaluate the internal stress applied to the semiconductor element, a piezoresistive element (a piezoresistor whose resistance value changes depending on stress is formed on a semiconductor chip) was set in the frame of a 16-bin DIP type IC, and each composition was The stress applied to the element was measured from the change in resistance.

2) For evaluation of heat shock resistance? A 16-pin R frame with size 4 x 7.51!11 was transfer molded using each composition,
The 16-pin DIP molded body - 196°C liquid and +
The molded product was repeatedly immersed in a liquid for 50 seconds each time, and the crack occurrence rate on the surface of the molded product was determined from 50 samples.

5) Moisture resistance evaluation Using each composition, a device having aluminum wire electrodes facing each other was transfer molded, and for this sealed sample, a direct current was applied between the electrodes at a temperature of 125°C and under a steam pressure of 2.5 atm. A bias voltage of 20 V was applied, and the open failure rate of the aluminum wire over time was determined from 50 samples. This test is called Y BPCT (Bias Pressure Test). Similarly, a test v was conducted under non-bias conditions, and this test) r(PC
It is called T (pressure test).

(Effects of the Invention) As explained above, the present invention provides a composition of an epoxy resin, a phenol resin, a filler, and a phenol-modified silicone compound, which reduces internal stress and improves moisture resistance reliability of a sealed molded product. Furthermore, the moldability and strength of the composition are not reduced (and it exhibits an excellent effect in sealing electronic components such as semiconductors).

Patent Applicant Denki Kagaku Kogyo Co., Ltd. Procedural Amendment November 2, 1980 1, Indication of the Case 1982 Patent Application No. 195826 2, Name of the Invention Epoxy Resin Composition 6, Person Making the Amendment Relationship to the Case Address of patent applicant: 1-4-1 Yurakucho, Chiyoda-ku, Tokyo The table in column 5 of the detailed description of the invention and page 14 of the detailed description of the amendment is corrected as shown in the attached sheet.

Procedural amendment 1. Description of the case 1982 Patent Application No. 195826 2 Name of the invention Epoxy resin composition 6 Person making the amendment Relationship to the case Patent applicant address 1-4-1 Yurakucho, Chiyoda-ku, Tokyo Patent claim in the specification Scope column and Detailed description of the invention column 5, Contents of amendment 1) The scope of claims is corrected as shown in the attached sheet.

Ru.

"The group Y is a functional group having a repeating unit and represents an oxypropylene polymer, an acrylamide polymer, a vinyl alcohol polymer, or a dioquinrane polymer. l, m, and n are each siloxane unit." 3) Specification page 6 Proof that "extraction removal" in the first line is "extraction removal".

4) "Heat-resistance reliability" on the bottom line of page 8 of the specification is corrected to "humidity-resistance reliability."

(2. Claims: ``An organic silicone compound represented by the following formula [I] and a phenol resin are reacted in advance in the absence of a solvent, and the unreacted large organic silicone compound represented by the following formula [I] is extracted and removed with water. An epoxy resin composition for encapsulating semiconductor electronic components, comprising a phenol-modified silicone compound, an epoxy resin, a phenol resin, and a filler.

Claims (1)

[Claims] A phenol-modified product in which an organic silicone compound represented by the following formula [I] and a phenol resin are reacted in advance in the absence of a solvent, and the unreacted organic silicone compound represented by the following formula [I] is extracted and removed with water. An epoxy resin composition for encapsulating semiconductor electronic components, comprising a silicone compound, an epoxy resin, a phenol resin, and a filler. ▲There are mathematical formulas, chemical formulas, tables, etc.▼Formula [I] (In formula I, R represents hydrogen, methyl group, ethyl group, or phenyl group, X represents an epoxy group-containing organic group, and Y represents a polyoxyethylene polymer. , polyoxypropylene polymer, polyacrylamide polymer, polyvinyl alcohol polymer, polydioxolane polymer. l, m, n represent the mole fraction of each siloxane unit, l = 0.1 to 0.9
8, m=0.01-0.5, n=0.01-0.7. )