Epoxy resin composition for semiconductor encapsulation and semiconductor device
Provided are an epoxy resin composition for semiconductor encapsulation; and a semiconductor device having a cured product of such composition. The composition has a superior curability, and a metal layer (plated layer) can be selectively and easily formed on the surface of or inside the cured product of this composition via an electroless plating treatment. The composition of the present invention contains: (A) an epoxy resin; (B) a phenolic curing agent; (C) a curing accelerator having a urea structure; (D) a laser direct structuring additive; and (E) an inorganic filler.
1. An epoxy resin composition for semiconductor encapsulation, comprising:
(A) an epoxy resin;
(B) a phenolic curing agent;
(C) a curing accelerator having a urea structure selected from at least one of N, N,N′, N′-tetramethylurea, N′-phenyl-N, N-dimethylurea, N, N-diethylurea, N′-[3-[[[(dimethylamino) carbonyl] amino] methyl]-3,5,5-trimethylcyclohexyl]-N,N-dimethylurea, and N, N″-(4-methyl-1,3-phenylene)bis(N′, N′-dimethylurea);
(D) a laser direct structuring additive; and
(E) an inorganic filler, wherein
a ratio (epoxy group/phenolic hydroxyl group), in terms of an equivalent ratio, between the (A) epoxy resin and (B) the phenolic curing agent, is 0.5 to 1.5, and an amount of the component (C) added is 0.5 to 10.0 parts by mass per a total of 100 parts by mass of the components (A) and (B), an amount of the component (D) added is 20 to 100 parts by mass per a total of 100 parts by mass of the components (A) and (B), an amount of the component (E) added is 50 to 1,500 parts by mass per a total of 100 parts by mass of the components (A) and (B), wherein
the component (D) is a metal oxide having a spinel structure, and is represented by the following average composition formula (1):
AB 2 O 4 (1)
wherein A represents one or more metal elements selected from iron, copper and manganese, B represents iron or chromium, provided that A and B do not both represent iron, and
the component (D) is such that after an aqueous dispersion of the component (D) is prepared by immersing 10 parts by mass of the component (D) in 50 parts by mass of pure water, and then left to stand at 125±3° C. for 20±1 hours, a sodium ion concentration in the aqueous dispersion of the component (D) is not higher than 50 ppm, and a chloride ion concentration in the aqueous dispersion of the component (D) is not higher than 50 ppm.
2. The epoxy resin composition for semiconductor encapsulation according to claim 1 , wherein the component (D) is added in an amount of 30 to 80 parts by mass per a total of 100 parts by mass of the components (A) and (B).
3. The epoxy resin composition for semiconductor encapsulation according to claim 1 , wherein the component (D) has an average particle size of 0.01 to 5 μm.
4. The epoxy resin composition for semiconductor encapsulation according to claim 1 , wherein the component (D) is such that after an aqueous dispersion of the component (D) is prepared by immersing 10 parts by mass of the component (D) in 50 parts by mass of pure water, and then left to stand at 125±3° C. for 20±1 hours, a sodium ion concentration in the aqueous dispersion of the component (D) is not higher than 16 ppm, and a chloride ion concentration in the aqueous dispersion of the component (D) is not higher than 14 ppm.
5. The epoxy resin composition for semiconductor encapsulation according to claim 1 , wherein a top cut particle size of the component (E) in a wet sieve method is 5 to 25 μm, and an average particle size of the component (E) is 0.5 to 10 μm.
6. A semiconductor device having a cured product of the epoxy resin composition for semiconductor encapsulation according to claim 1 .
7. The semiconductor device according to claim 6 , wherein at least part of the cured product is plated.
8. A method for producing the semiconductor device according to claim 7 , wherein parts that have been irradiated with a laser are plated.
9. A method for encapsulating a semiconductor device, comprising the steps of:
preparing the epoxy resin composition for semiconductor encapsulation according to claim 1 ;
encapsulating the semiconductor device by molding and curing the epoxy resin composition to form a cured product of the epoxy resin composition;
irradiating a surface or inner region of the cured product with a laser; and
plating the parts that have been irradiated with the laser.
10. The method according to claim 9 , wherein the plating properties wherein the epoxy resin composition has plating properties that include that plated areas are formed in a continuous and uniform manner in a surface plating property evaluation or an inner plating property evaluation,
wherein for the surface plating property evaluation, a YVO 4 laser marker at 1064 nm in a test mode is used to perform marking on the surface of a test specimen prepared under a condition of 175° C., 300 seconds, wherein the test specimen is then immersed in a Ni plating solution for 30 minutes with the temperature thereof being maintained at 80° C. so as to observe a plating property of the test specimen, wherein the Ni plating solution is prepared by mixing 75 ml of a makeup CNN-mod; 30 ml of an Aurotech CNN Part A; 395 ml of pure water; and 8 ml of an ammonia water,
wherein for the inner plating property evaluation, a laser substrate cutting device is used to form 10 through holes of a size of 200 μmφ in a cured product having a thickness of 0.20 mm, wherein the cured product is then immersed in the Ni plating solution at 65° C. for 30 minutes so as to plate the through holes, wherein an inner plating property is confirmed by polishing the sections of these through holes, and then using a microscope to observe a plating property therein.
11. The method for according to claim 9 , wherein the epoxy resin composition has plating properties include suppressing an impaired electric property in a high-temperature and high-humidity environment, which causes the metal parts of a semiconductor device to be corroded.
12. The method for according to claim 9 , wherein the component (D) is such that after an aqueous dispersion of the component (D) is prepared by immersing 10 parts by mass of the component (D) in 50 parts by mass of pure water, and then left to stand at 125±3° C. for 20±1 hours, a sodium ion concentration in the aqueous dispersion of the component (D) is not higher than 16 ppm, and a chloride ion concentration in the aqueous dispersion of the component (D) is not higher than 14 ppm.
13. The method for according to claim 9 , wherein the component (D) is added in the epoxy resin composition in an amount of 30 to 80 parts by mass per a total of 100 parts by mass of the components (A) and (B).
14. The method for according to claim 9 , wherein the component (D) has an average particle size of 0.01 to 5 μm.
15. The method for according to claim 9 , wherein a top cut particle size of the component (E) in a wet sieve method is 5 to 25 μm, and an average particle size of the component (E) is 0.5 to 10 μm.