US6558780B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit board and method for manufacturing the same
Assignee: Panasonic Holdings Corp
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Filing: 2001-10-25
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Granted: 2003-05-06
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Expires: 2021-10-25
Abstract
Abstract A circuit board includes an electrical insulator layer formed of a reinforcer sheet with density distribution in its in-plane direction, an electrical conductor filled in a plurality of inner via holes provided in the electrical insulator layer in its thickness direction, and a wiring layer connected to the electrical conductor. The inner via holes provided in a high-density portion of the reinforcer sheet are formed to have a smaller cross-section than the inner via holes provided in a low-density portion of the reinforcer sheet. In this manner, it is possible to provide a circuit board that can achieve a high-density wiring and an inner via connection resistance with less variation, when a base material including a reinforcer sheet with density distribution in its in-plane direction such as a glass-epoxy base material is used for an insulator layer.
Inventors
- 👤 Takeshi Suzuki
- 👤 Toshihiro Nishii
- 👤 Satoru Tomekawa
- 👤 Fumio Echigo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:18
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/40; H05K3/4038; H05K3/4053; H05K3/4069; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/0353; H05K1/0366; H05K1/11; H05K1/115; H05K2201/00; H05K2201/02; H05K2201/0275; H05K2201/0287; H05K2201/029; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0355; H05K2201/09; H05K2201/09209; H05K2201/09372; H05K2201/094; H05K2203/00; H05K2203/14; H05K2203/1461; H05K3/0011; H05K3/0017; H05K3/0026; H05K3/0032; H05K3/0044; H05K3/0047; H05K3/46; H05K3/4611; H05K3/4614; H05K3/4644; H05K3/4652; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49126; Y10T29/49128; Y10T29/4913; Y10T29/49155; Y10T29/49165; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/24322; Y10T428/24802; Y10T428/24917; Y10T428/249921; Y10T428/249924; Y10T428/24994; Y10T428/249953
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
106 words
A circuit board comprising: an electrical insulator layer formed of a reinforcer sheet with density distribution in its in-plane direction; an electrical conductor filled in a plurality of inner via holes provided in the electrical insulator layer in its thickness direction; and a wiring layer connected to the electrical conductor; wherein the inner via holes provided in a high-density portion of the reinforcer sheet are formed to have a smaller cross-section than the inner via holes provided in a low-density portion of the reinforcer sheet, and wherein the larger cross-section of the inner via holes is 1.15 to 10 times as large as the smaller cross-section.
Claim 2
Dependent Claim
106 words
A circuit board comprising: an electrical insulator layer formed of a reinforcer sheet with density distribution in its in-plane direction; an electrical conductor filled in a plurality of inner via holes provided in the electrical insulator layer in its thickness direction; and a wiring layer connected to the electrical conductor; wherein the inner via holes provided in a high-density portion of the reinforcer sheet are formed to have a smaller cross-section than the inner via holes provided in a low-density portion of the reinforcer sheet, and wherein the larger cross-section of the inner via holes is 1.15 to 10 times as large as the smaller cross-section.
Claim 3
Dependent Claim
56 words
The circuit board according to claim 1 , wherein the reinforcer sheet with density distribution in its in-plane direction is at least one sheet selected from the group consisting of a woven fabric and a non-woven fabric formed of at least one fiber selected from the group consisting of a synthetic fiber and an inorganic fiber.
Claim 4
Dependent Claim
27 words
The circuit board according to claim 1 , wherein the reinforcer sheet with density distribution in its in-plane direction is a film formed of a synthetic resin.
Claim 5
Dependent Claim
28 words
The circuit board according to claim 2 , wherein the reinforcer sheet with density distribution in its in-plane direction is the woven fabric formed of a glass fiber.
Claim 6
Dependent Claim
47 words
The circuit board according to claim 4 , wherein the inner via holes provided in overlapping portions of warps and wefts of the woven fabric formed of the glass fiber have a smaller cross-section than the inner via holes provided in portions other than the overlapping portions.
Claim 7
Dependent Claim
39 words
The circuit board according to claim 1 , wherein the inner via holes having a larger cross-section have a smaller amount of protruding fibers on a side wall surface thereof than the inner via holes having a smaller cross-section.
Claim 8
Dependent Claim
31 words
The circuit board according to claim 1 , wherein a plurality of the wiring layers are provided, and at least one of the wiring layers is embedded in the insulator layer.
Claim 9
Dependent Claim
55 words
The circuit board according to claim 1 , wherein the cross-section of the inner via holes is tapered to vary continuously, and the inner via holes have a small cross-section in the high-density portion of the reinforcer sheet, while the inner via holes have a large cross-section in the low-density portion of the reinforcer sheet.
Claim 10
Dependent Claim
33 words
The circuit board according to claim 1 , wherein a circuit board formed of a compressible electrical insulating material further is laminated on one surface of the circuit board of claim 1 .
Claim 11
Dependent Claim
34 words
A circuit board assembly, comprising a circuit board formed of a compressible electrical insulating material as a core substrate, and a circuit board of claim 1 laminated on each side of the core substrate.
Claim 12
Dependent Claim
47 words
A circuit board assembly, comprising a circuit board of claim 1 as a core substrate, and at least one circuit board formed of an insulator layer thinner than the insulator layer of the core substrate further is laminated on at least one surface of the core substrate.
References Cited (Backward Citations)
US4980217A
Cited
US5346750A
Cited
JPH06268345A
Cited
US6207259B1
Cited
US6224965B1
Cited
US6459046B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2006-05-05 | 2006-11-04 | 2007-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-05-05 | 2010-11-04 | 2011-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-05-05 | 2014-11-04 | 2015-05-06 | $7700.00 | Window Closed / Lapsed |