US4526859A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metallization of a ceramic substrate
Assignee: International Business Machines Corp
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Filing: 1983-12-12
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Granted: 1985-07-02
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Expires: 2003-12-12
Abstract
Abstract There is disclosed a method of selectively metallizing a ceramic substrate provided with a metallization pattern according by photoresist processing. A first layer of photoresist is blanket deposited over the substrate exposed through a coarse block out mask, and developed in order to protect those areas of the metallization pattern not to be covered with metal. A blanket metal layer is then formed over the entire substrate surface. A second layer of photoresist is deposited, exposed through a customized mask of the metallization pattern, and developed. The exposed metal is etched and the remaining first and second photoresist layers are removed, leaving a coating of metal only at desired locations. The method may be used for the heavy gold deposition over the Engineering change pads used as a standard in multilayer ceramic substrates.
Inventors
- 👤 Richard G. Christensen
- 👤 Robert L. Moore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:23
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/24; H05K3/243; G; G03; G03F; G03F7/00; G03F7/0035; H10; H10W; H10W70/00; H10W70/01; H10W70/05; H10W70/60; H10W70/611; H10W70/62; H10W70/641; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K3/02; H05K3/04; H05K3/046; H05K3/048; H05K3/06; H05K3/061; H05K3/064; H05K3/10; H05K3/14; H05K3/143; H05K3/244
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
177 words
A process for depositing metal at only selected subdivided portions of a metallization pattern pre-existing on a substrate comprising the steps of: (A) providing a substrate having said metallization pattern at a major surface; (B) blanket depositing a first photoresist layer to cover the said substrate major surface and said metallization pattern; (C) selectively exposing and developing the first photoresist layer on a pattern forming a first mask opposite to and only over a subdivided region of said metallization pattern; (D) depositing a blanket layer of said metal, over the entire substrate major surface; (E) depositing a second blanket layer of photoresist over the substrate major surface; (F) selectively exposing though a second mask and developing the second photoresist layer to define a second resist mask over and opposite to a second subdivided region of said metallization pattern; (G) etching the portions of the deposited metal layer which remain exposed; and, (H) solvating the resist masks for removal thereof together with overlying layers of said metal thereon over the first said subdivided region of said metallization pattern.
Claim 2
Dependent Claim
177 words
A process for depositing metal at only selected subdivided portions of a metallization pattern pre-existing on a substrate comprising the steps of: (A) providing a substrate having said metallization pattern at a major surface; (B) blanket depositing a first photoresist layer to cover the said substrate major surface and said metallization pattern; (C) selectively exposing and developing the first photoresist layer on a pattern forming a first mask opposite to and only over a subdivided region of said metallization pattern; (D) depositing a blanket layer of said metal, over the entire substrate major surface; (E) depositing a second blanket layer of photoresist over the substrate major surface; (F) selectively exposing though a second mask and developing the second photoresist layer to define a second resist mask over and opposite to a second subdivided region of said metallization pattern; (G) etching the portions of the deposited metal layer which remain exposed; and, (H) solvating the resist masks for removal thereof together with overlying layers of said metal thereon over the first said subdivided region of said metallization pattern.
Claim 3
Dependent Claim
26 words
The process of claim 1 wherein said substrate is a multilayer ceramic substrate provided with both engineering change pads and input/output pads comprising said metallization pattern.
Claim 4
Dependent Claim
18 words
The process of claim 2 wherein said metallization pattern comprises gold coated nickel and said metal is gold.
Claim 5
Dependent Claim
29 words
The process of claim 1 wherein said first mask is a coarse block out mask which leaves hardened photoresist over the first said subdivided region comprised of input/output pads.
Claim 6
Dependent Claim
18 words
The process of claim 4 wherein said second mask is a custom mask conforming to said metallization pattern.
Claim 7
Dependent Claim
22 words
The process of claim 4 wherein said depositing system is selected from the group comprised of magnetron sputtering and ion plating systems.
Claim 8
Dependent Claim
25 words
The process of claim 5 wherein said metal is deposited in a system selected from the group comprised of magnetron sputtering and ion plating systems.
Claim 9
Dependent Claim
25 words
The process of claim 2 wherein said metal is deposited in a system selected from the group comprised of magnetron sputtering and ion plating systems.
Claim 10
Dependent Claim
25 words
The process of claim 3 wherein said metal is deposited in a system selected from the group comprised of magnetron sputtering and ion plating systems.
Claim 11
Dependent Claim
29 words
The process of claim 3 wherein said first mask is a coarse block out mask which leaves hardened photoresist over the first said subdivided region comprised of input/output pads.
Claim 12
Dependent Claim
18 words
The process of claim 10 wherein said second mask is a custom mask conforming to said metallization pattern.
Claim 13
Dependent Claim
25 words
The process of claim 11 wherein said metal is deposited in a system selected from the group comprised of magnetron sputtering and ion plating systems.
Claim 14
Dependent Claim
25 words
The process of claim 10 wherein said metal is deposited in a system selected from the group comprised of magnetron sputtering and ion plating systems.
Claim 15
Dependent Claim
29 words
The process of claim 2 wherein said first mask is a coarse block out mask which leaves hardened photoresist over the first said subdivided region comprised of input/output pads.
Claim 16
Dependent Claim
18 words
The process of claim 14 wherein said second mask is a custom mask conforming to said metallization pattern.
Claim 17
Dependent Claim
25 words
The process of claim 15 wherein said metal is deposited in a system selected from the group comprised of magnetron sputtering and ion plating systems.
Claim 18
Dependent Claim
25 words
The process of claim 14 wherein said metal is deposited in a system selected from the group comprised of magnetron sputtering and ion plating systems.
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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) | 1988-07-01 | 1988-12-31 | 1989-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-01 | 1992-12-31 | 1993-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-01 | 1996-12-31 | 1997-07-02 | $7700.00 | Window Closed / Lapsed |