US4908940A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing two-layer printed circuit sheet
Assignee: Furukawa Electric Co Ltd
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Filing: 1988-12-12
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Granted: 1990-03-20
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Expires: 2008-12-12
Abstract
Abstract An insulating sheet having through holes formed therein at positions where circuit patterns formed on its both surfaces are electrically connected is prepared. A sheet for forming a hole bottom is attached to one surface of the insulating sheet. Subsequently, a first-layer circuit pattern is printed on the other surface of the insulating sheet to which the hole-bottom sheet is not attached, and a conductive paste is filled into the holes. Thereafter, the hole-bottom sheet is removed. Then, a second-layer circuit pattern is printed on the surface of the insulating sheet, from which the hole-bottom sheet is removed. With this process, a two-layer printed circuit sheet is manufactured.
Inventors
- 👤 Toshiaki Amano
- 👤 Tomoya Kato
- 👤 Kenzo Kobayashi
- 👤 Yoshihiro Onuma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 06:34
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/40; H05K3/4038; H05K3/4053; H05K3/4069; H05K1/00; H05K1/02; H05K1/03; H05K1/0393; H05K1/09; H05K1/092; H05K1/095; H05K2203/00; H05K2203/01; H05K2203/0147; H05K2203/0156; H05K2203/07; H05K2203/0756; H05K2203/0769; H05K2203/14; H05K2203/1453; H05K2203/1476; H05K3/22; H05K3/28; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49155; Y10T29/49165
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
130 words
A method of manufacturing a two-layer printed circuit sheet, comprising the steps of: preparing an insulating sheet, on both surfaces of which circuit patterns are formed, said insulating sheet having a through hole formed therein in advance at a position where the circuit patterns are electrically connected to each other; forming a bottom of the through hole by attaching a releasable hole-bottom sheet to one of the surfaces of said insulating sheet; filling a conductive paste into the through hole from an open end thereof; printing a first-layer circuit pattern on the other surface of said insulating sheet to which said hole-bottom sheet is not attached; removing said hole-bottom sheet; and printing a second-layer circuit pattern on the surface of said insulating sheet, from which said hole-bottom sheet is removed.
Claim 2
Independent Claim
130 words
A method of manufacturing a two-layer printed circuit sheet, comprising the steps of: preparing an insulating sheet, on both surfaces of which circuit patterns are formed, said insulating sheet having a through hole formed therein in advance at a position where the circuit patterns are electrically connected to each other; forming a bottom of the through hole by attaching a releasable hole-bottom sheet to one of the surfaces of said insulating sheet; filling a conductive paste into the through hole from an open end thereof; printing a first-layer circuit pattern on the other surface of said insulating sheet to which said hole-bottom sheet is not attached; removing said hole-bottom sheet; and printing a second-layer circuit pattern on the surface of said insulating sheet, from which said hole-bottom sheet is removed.
Claim 3
Dependent Claim
25 words
A method according to claim 1, wherein said hole-bottom sheet comprises a water-soluble resin composition and is removed by dissolving said resin composition in water.
Claim 4
Dependent Claim
19 words
A method according to claim 1, wherein said hole-bottom sheet comprises an adherent sheet and is removed by peeling.
Claim 5
Dependent Claim
27 words
A method according to claim 1, wherein the step of filling said conductive paste into the through hole is performed after printing of said first-layer circuit pattern.
Claim 6
Dependent Claim
27 words
A method according to claim 1, wherein the step of filling said conductive paste into the through hole is performed before printing of said first-layer circuit pattern.
Claim 7
Dependent Claim
23 words
A method according to claim 1, wherein at least one of said first- and second-layer circuit patterns comprises a conductive paste allowing soldering.
Claim 8
Dependent Claim
14 words
A method according to claim 1, wherein said insulating sheet comprises a resin film.
Claim 9
Dependent Claim
15 words
A method according to claim 1, wherein said insulating sheet comprises a polyethylene terephthalate film.
Claim 10
Dependent Claim
14 words
A method according to claim 1, wherein said insulating sheet comprises a polyimide film.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-03-19 | 1993-09-18 | 1994-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-19 | 1997-09-18 | 1998-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-19 | 2001-09-18 | 2002-03-20 | $7700.00 | Window Closed / Lapsed |