US5035939A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of printed circuit boards
Assignee: Sarnoff Corp
•
Filing: 1990-02-09
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Granted: 1991-07-30
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Expires: 2010-02-09
Abstract
Abstract In the manufacture of printed circuit boards, a first photoresist post is patterned on the substrate where via holes are to be made. A dielectric layer is put down, a second photoresist layer patterned so as to have openings over and in alignment with the photoresist posts, and the dielectric removed from the via holes. Barrier layers to reduce interaction between layers of copper, dielectric and photoresist during filling of the via holes with a conductor via fill ink are also described.
Inventors
- 👤 Edward J. Conlon
- 👤 Ashok N. Prabhu
- 👤 Simon M. Boardman
- 👤 Valerie A. Pendrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:33
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/0011; H05K3/0017; H05K3/0041; H05K3/40; H05K3/4038; H05K3/4053; H05K3/4061; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K1/09; H05K1/092; H05K2201/00; H05K2201/01; H05K2201/0137; H05K2201/0166; H05K2203/00; H05K2203/03; H05K2203/0384; H05K2203/05; H05K2203/0562; H05K2203/0582; H05K2203/30; H05K2203/308; H05K3/002; H05K3/46; H05K3/4644; H05K3/4664; H05K3/4667; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/24322; Y10T428/24802; Y10T428/24917; Y10T428/24926; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
29 words
A substrate having a first patterned photoresist layer thereon, a dielectric layer thereof, and a patterned photoresist layer having openings over and aligned with said first patterned photoresist layer.
Claim 2
Dependent Claim
29 words
A substrate having a first patterned photoresist layer thereon, a dielectric layer thereof, and a patterned photoresist layer having openings over and aligned with said first patterned photoresist layer.
Claim 3
Dependent Claim
20 words
A substrate having a patterned copper layer thereon, a dielectric layer thereover and a barrier layer contacting said dielectric layer.
Claim 4
Dependent Claim
20 words
A substrate having a patterned copper layer thereon, a dielectric layer thereover and a barrier layer contacting said dielectric layer.
Claim 5
Dependent Claim
17 words
A substrate according to claim 2 wherein said dielectric layer is patterned to have via holes therein.
Claim 6
Dependent Claim
16 words
A substrate according to claim 2 wherein a photoresist layer is deposited over said barrier layer.
Claim 7
Dependent Claim
42 words
An unfired printed circuit board having a patterned copper circuit thereon, a dielectric layer thereover having via holes therein of between about 50 and 125 micrometers in diameter, and a photoresist post at the bottom of one or more said via holes.
Claim 8
Dependent Claim
42 words
An unfired printed circuit board having a patterned copper circuit thereon, a dielectric layer thereover having via holes therein of between about 50 and 125 micrometers in diameter, and a photoresist post at the bottom of one or more said via holes.
Claim 9
Dependent Claim
18 words
A printed circuit board according to claim 5 wherein a barrier layer is deposited over said dielectric layer.
Claim 10
Dependent Claim
55 words
An unfired printed circuit board having a patterned copper circuit thereon, a dielectric layer thereover having via holes therein between about 50 and 125 micrometers in diameter, a first barrier layer over said dielectric layer, a conductor via fill ink filling said via holes, and a second barrier layer over said conductor via fill ink.
Claim 11
Dependent Claim
55 words
An unfired printed circuit board having a patterned copper circuit thereon, a dielectric layer thereover having via holes therein between about 50 and 125 micrometers in diameter, a first barrier layer over said dielectric layer, a conductor via fill ink filling said via holes, and a second barrier layer over said conductor via fill ink.
Claim 12
Dependent Claim
17 words
A printed circuit board according to claim 7 having a photoresist layer over said second barrier layer.
Claim 13
Dependent Claim
13 words
A printed circuit board according to claim 7 wherein said conductor is copper.
Claim 14
Independent Claim
95 words
A method of making small via holes of high aspect ratio on a substrate which comprises 1) applying a first patterned photoresist layer on said substrate such that the photoresist is situated where the via hole is to be made, 2) depositing a dielectric ink layer thereover, 3) subjecting the dielectric layer to an oxygen plasma treatment, 4) applying a second photoresist layer over said dielectric layer, 5) patterning said second photoresist layer so that it has an opening over and aligned with said first photoresist layer, and 6) removing said dielectric in said opening.
Claim 15
Independent Claim
95 words
A method of making small via holes of high aspect ratio on a substrate which comprises 1) applying a first patterned photoresist layer on said substrate such that the photoresist is situated where the via hole is to be made, 2) depositing a dielectric ink layer thereover, 3) subjecting the dielectric layer to an oxygen plasma treatment, 4) applying a second photoresist layer over said dielectric layer, 5) patterning said second photoresist layer so that it has an opening over and aligned with said first photoresist layer, and 6) removing said dielectric in said opening.
Claim 16
Dependent Claim
18 words
A method according to claim 10 wherein a barrier layer is deposited prior to the first photoresist layer.
Claim 17
Dependent Claim
16 words
A method according to claim 10 wherein a barrier layer is deposited over the dielectric layer.
Claim 18
Dependent Claim
17 words
A method according to claim 10 wherein a barrier layer is deposited over the second photoresist layer.
Claim 19
Dependent Claim
17 words
A method according to claim 10 wherein a conductor via fill ink is deposited in said opening.
Claim 20
Dependent Claim
18 words
A method according to claim 14 wherein a barrier layer is deposited over said via fill ink layer.
Claim 21
Dependent Claim
20 words
A method according to claim 10 wherein a barrier layer is deposited over a pattern copper layer on said substrate.
Claim 22
Dependent Claim
11 words
A method according to claim 14 wherein said conductor is copper.
References Cited (Backward Citations)
US4902610A
Cited
US4897338A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-29 | 1995-01-28 | 1995-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-29 | 1999-01-28 | 1999-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-29 | 2003-01-28 | 2003-07-30 | $7700.00 | Window Closed / Lapsed |