PRINTED WIRING BOARD AND SEMICONDUCTOR PACKAGE

• US 20190315094A1
• Filed: 11/09/2017
• Published: 10/17/2019
• Est. Priority Date: 11/09/2016
• Status: Active Grant

• Current Assignee: Resonac Corp. (Resonac Holdings Corp.)
• Original Assignee: Hitachi Chemical Company Limited (Resonac Holdings Corp.)
• Inventors: SAITOH, Takeshi, NAKAMURA, Yukio, SASAKI, Ryohta, SOMEKAWA, Junki, TOSAKA, Yuji, SHIMIZU, Hiroshi, UCHIMURA, Ryoichi
• Granted Patent: US 11,040,517 B2
• Time in Patent Office: Days
• CPC Class Codes: B32B 15/08 of synthetic resin
• CPC Class Codes: C08J 2379/08 Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: C08J 2463/04 Epoxynovolacs
• CPC Class Codes: C08J 5/043 with glass fibres
• CPC Class Codes: C08J 5/244 using glass fibres
• CPC Class Codes: H01L 23/3114 the device being a chip scale package, e.g. CSP
• CPC Class Codes: H05K 1/0271 Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion
• CPC Class Codes: H05K 1/0298 Multilayer circuits
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 1/036 Multilayers with layers of different types
• CPC Class Codes: H05K 1/0366 reinforced, e.g. by fibres, fabrics H05K1/036 takes precedence
• CPC Class Codes: H05K 2201/0191 wherein the thickness of the dielectric plays an important role

Abstract

Provided are a printed circuit board in which warps are effectively suppressed, and a semiconductor package having a semiconductor device mounted on said printed circuit board, even though circuit patterns of different amounts of metal are formed on both sides of one cured product of a prepreg. Specifically, said printed circuit board is a printed circuit board which comprises a cured product of a prepreg comprising a fiber base material and a resin composition, in which circuit patterns of different amounts of metal are formed on both sides of one cured product of the prepreg, in which said prepreg has layers on the front and back of said fiber base material, wherein said layers comprise resin compositions having different heat curing shrinkage rates, in which among these layers, the layer made of the resin composition having a smaller heat curing shrinkage rate is present on the side on which the circuit pattern with a smaller amount of metal is formed.

Claims

1. A printed circuit board comprising a cured product of a prepreg comprising a fiber base material and a resin composition, in which circuit patterns of different amounts of metal are formed on both sides of one cured product of the prepreg, respectively, in which

said prepreg has layers on the front and back of said fiber base material, wherein said layers comprise resin compositions having different heat curing shrinkage rates, in which among these layers, the layer made of the resin composition having a smaller heat curing shrinkage rate is present on the side on which the circuit pattern with a smaller amount of metal is formed.

2. The printed circuit board according to claim 1, wherein the layers comprising the resin compositions having different heat curing shrinkage rates on said each of the front and back of said fiber base material in said prepreg comprises different types of resin compositions.

3. The printed circuit board according to claim 1, wherein the difference between the heat curing shrinkage rates of the resin compositions forming the layers on each of the front and back of said fiber base material is 0.3% or above.

4. The printed circuit board according to claim 1, wherein the difference in the amount of metal between the circuit patterns on both sides is 15% by volume or above.

5. The printed circuit board according to claim 1, wherein said prepreg satisfies a following formula (1) as well as a following formula (2):

0.12<

{(a1+a2)/2}/B<

0.32 

 

(1)

0.8≤

a1/a2≤

1.25 

 

(2)

wherein a1 represents an average thickness of the resin composition after being cured which is present on one surface of the fiber base material;

a2 represents an average thickness of the resin composition after being cured which is present on other surface of the fiber base material; and

B represent an average thickness of the fiber base material.

6. The printed circuit board according to claim 1, wherein the thickness of the prepreg is 30 to 170 μ

m.

7. The printed circuit board according to claim 1, wherein the stress generated by the difference in the amount of metal of one circuit pattern and the amount of metal of the other circuit pattern on said both sides is compensated by the stress generated by the difference in heat curing shrinkage rates of said resin compositions.

8. The printed circuit board according to claim 1, wherein the amount of the warps, which is measured according to the measurement method described in section 2.4.22.1C of IPC-TM-650, is 60 mm or less.

9. A semiconductor package comprising a semiconductor device mounted on the printed circuit board according to claim 1.