IP Library Granted Patent US 12,351,698
Granted Patent B2
US 12,351,698 · App. 17/442,339 · Granted Jul 8, 2025

Resin composition, copper foil with resin, dielectric layer, copper-clad laminate, capacitor element, and printed wiring board with built-in capacitor

Inventors: Toshihiro Hosoi (Ageo, JP); Kenshiro Fukuda (Ageo, JP); Yoshihiro Yoneda (Ageo, JP); Tomohiro Ishino (Ageo, JP); Tetsuro Sato (Ageo, JP)
Assignee: MITSUI MINING & SMELTING CO., LTD.
C08K3/22B32B15/043B32B15/20C08L63/00H01G4/14B32B2255/06B32B2255/26B32B2307/204B32B2307/732B32B2457/08B32B2457/16C08K2003/2206C08K2003/2237C08L2203/20
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Quick Facts
Patent No.
US 12,351,698
App. No.
17/442,339
Granted
Jul 8, 2025
Kind
B2
Abstract

There is provided a resin composition that can greatly improve voltage endurance while ensuring high capacitance and excellent circuit adhesion, when used as the dielectric layer of a capacitor. This resin composition includes a binder component including bisphenol S, an epoxy resin curing agent having a phenolic hydroxyl group, and an epoxy resin; and a dielectric filler.

Claims (26)

1. A resin composition comprising:

a binder component consisting of:

bisphenol S blended in the resin composition as an unreacted monomer,

an epoxy resin curing agent having a phenolic hydroxyl group,

optionally, a polymer component, and

an epoxy resin; and

a dielectric filler;

wherein

the polymer component content is 0 parts by weight or more and 15 parts by weight or less based on 100 parts by weight of the binder component, and

the polymer component is selected from the group consisting of polyimide resins, polyamide resins, and polyamide-imide resins.

2. The resin composition according to claim 1 , wherein the epoxy resin curing agent having a phenolic hydroxyl group has three or more phenolic hydroxyl groups per molecule.

3. The resin composition according to claim 1 , wherein the binder component comprises 20 parts by weight or more and 40 parts by weight or less of the bisphenol S based on 100 parts by weight of the binder component.

4. The resin composition according to claim 1 , comprising at least one polymer component selected from the group consisting of polyimide resins, polyamide resins, and polyamide-imide resins.

5. The resin composition according to claim 1 , wherein the dielectric filler is a complex metal oxide comprising at least two selected from the group consisting of Ba, Ti, Sr, Pb, Zr, La, Ta, and Bi, in an amount of 70 parts by weight or more and 85 parts by weight or less based on 100 parts by weight of solids of the resin composition.

6. The resin composition according to claim 5 , wherein the complex metal oxide comprises at least one selected from the group consisting of BaTiO 3 , SrTiO 3 , Pb(Zr,Ti)O 3 , PbLaTiO 3 , PbLaZrO, and SrBi 2 Ta 209 .

7. The resin composition according to claim 5 , comprising 75 parts by weight or more and 85 parts by weight or less of the complex metal oxide based on 100 parts by weight of the solids of the resin composition.

8. The resin composition according to claim 1 , wherein the binder component comprises 1 part by weight or more and 25 parts by weight or less of the epoxy resin curing agent having a phenolic hydroxyl group based on 100 parts by weight of the binder component.

9. The resin composition according to claim 1 , wherein the epoxy resin has two or more epoxy groups per molecule.

10. The resin composition according to claim 1 , wherein the binder component comprises 30 parts by weight or more and 80 parts by weight or less of the epoxy resin based on 100 parts by weight of the binder component.

11. The resin composition according to claim 1 , wherein a copper-clad laminate obtained using the resin composition has a peel strength of 0.8 kgf/cm or more.

12. A resin-attached copper foil comprising a copper foil and the resin composition according to claim 1 provided on at least one surface of the copper foil.

13. A dielectric layer being a layer of the resin composition according to claim 1 that is cured.

14. The dielectric layer according to claim 13 , having a thickness of 0.2 μm or more and 30 μm or less.

15. A copper-clad laminate comprising a first copper foil, the dielectric layer according to claim 13 , and a second copper foil in sequence.

16. A capacitor element comprising the dielectric layer according to claim 13 .

17. A capacitor-built-in printed wiring board comprising the dielectric layer according to claim 13 .

Assignments (2)
CHANGE OF NAME Recorded Mar 31, 2026
From: MITSUI MINING AND SMELTING COMPANY, LIMITED
To: MITSUI KINZOKU COMPANY, LIMITED
Reel/Frame 075357/0342 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 23, 2021
From: HOSOI, TOSHIHIRO; FUKUDA, KENSHIRO; YONEDA, YOSHIHIRO; ISHINO, TOMOHIRO; SATO, TETSURO
To: MITSUI MINING & SMELTING CO., LTD.
Reel/Frame 057579/0648 →
Priority Claims (1)
JP 2019-059816 · Mar 27, 2019 · national
Continuity (1)
Related Publication 20220162418A1 · May 26, 2022
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