US4908689A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Organic solder barrier
Assignee: International Business Machines Corp
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Filing: 1988-06-27
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Granted: 1990-03-13
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Expires: 2008-06-27
Abstract
Abstract A system for defining a solder barrier using a silylated positive photoresist. This layer replaces the top chrome layer previously employed and defines the C4 and I/O select patterns. The personality pattern in the Cr-Cu layers is defined by the use of a positive photoresist which is etched to provide the copper etch mask. The etched copper is then used to etch the chrome. This avoids the incompatibility of the positive photoresist with the alkaline chromium etchant.
Inventors
- 👤 Donald G. McBride
- 👤 Jane M. Shaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:03
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/075; G03F7/0755; H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3452; H10; H10W; H10W72/00; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
63 words
An electrical connection between a semiconductor chip and a carrier, comprising: a reflow solder ball contacting said chip and said carrier; and a positive photoresist layer comprising a reaction product of a polymeric material containing reactive hydrogen with a silyl group containing multifunctional organometallic material, said layer surrounding said solder ball on the surface of said carrier to act as a solder dam.
Claim 2
Dependent Claim
63 words
An electrical connection between a semiconductor chip and a carrier, comprising: a reflow solder ball contacting said chip and said carrier; and a positive photoresist layer comprising a reaction product of a polymeric material containing reactive hydrogen with a silyl group containing multifunctional organometallic material, said layer surrounding said solder ball on the surface of said carrier to act as a solder dam.
Claim 3
Dependent Claim
16 words
The electrical connector of claim 1, wherein said layer covers the entire surface of said carrier.
Claim 4
Dependent Claim
20 words
The electrical connector of claim 1, wherein said layer covers only conductive circuit lines on the surface of said carrier.
Claim 5
Dependent Claim
43 words
An electrical connection between a semiconductor chip and a carrier, comprising: a reflow solder ball contacting said chip and said carrier; and a silylated positive photoresist layer surrounding said solder ball on the surface of said carrier to act as a solder dam.
Claim 6
Dependent Claim
43 words
An electrical connection between a semiconductor chip and a carrier, comprising: a reflow solder ball contacting said chip and said carrier; and a silylated positive photoresist layer surrounding said solder ball on the surface of said carrier to act as a solder dam.
Claim 7
Dependent Claim
18 words
The electrical connector of claim 4, wherein said silylated positive photoresist covers the entire surface of said carrier.
Claim 8
Dependent Claim
22 words
The electrical connector of claim 4, wherein said silylated positive photoresist covers only conductive circuit lines on the surface of said carrier.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-03-12 | 1993-09-11 | 1994-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-12 | 1997-09-11 | 1998-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-12 | 2001-09-11 | 2002-03-13 | $7700.00 | Window Closed / Lapsed |