Patent EP0246447A2 successfully refreshed from Google Patents.
EP0246447A2
Expired / Lapsed
EP
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Organic solder dam for a semiconductor device
Assignee: International Business Machines Corp
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Filing: 1987-04-14
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Granted: —
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Expires: 2007-04-14
Abstract
Abstract A method for defining a solder barrier using a silylated positive photoresist is disclosed. The silylated positive photoresist layer (24) replaces the top chrome layer previously employed and defines the solder barriers and I/O select patterns. The personality pattern in the Cr-Cu layers (14, 16) 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 Gene Mcbride
- 👤 Jane Margaret Shaw
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 21:21
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: 13
Claim 1
Independent Claim
42 words
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 2
Dependent Claim
42 words
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 3
Dependent Claim
17 words
Electrical connection of claim 1, wherein said silylated positive photoresist covers the entire surface of said carrier.
Claim 4
Dependent Claim
21 words
Electrical connection of claim 1, wherein said silylated positive photoresist covers only conductive circuit lines on the surface of said carrier.
Claim 5
Dependent Claim
102 words
Method of making a solder barrier for a chip carrier comprising the steps of: blanket coating said carrier with layers of chromium and copper, blanket coating said copper layer with a positive photoresist, exposing and developing said photoresist to define a personality pattern followed by etching said copper layer, etching said chromium layer using said etched copper layer as a mask, applying a second blanket layer of positive photoresist on to said etched copper and chrome layers, exposing and developing said second layer of positive photoresist to define a select pattern, and silylating said second layer of positive photoresist followed by baking.
Claim 6
Dependent Claim
102 words
Method of making a solder barrier for a chip carrier comprising the steps of: blanket coating said carrier with layers of chromium and copper, blanket coating said copper layer with a positive photoresist, exposing and developing said photoresist to define a personality pattern followed by etching said copper layer, etching said chromium layer using said etched copper layer as a mask, applying a second blanket layer of positive photoresist on to said etched copper and chrome layers, exposing and developing said second layer of positive photoresist to define a select pattern, and silylating said second layer of positive photoresist followed by baking.
Claim 7
Dependent Claim
17 words
Method of claim 4 further comprising the step of placing solder at locations on the select pattern.
Claim 8
Dependent Claim
15 words
Method of claim 5 further comprising the step of joining a chip to said carrier.
Claim 9
Dependent Claim
18 words
Method of claim 6, wherein said chip is joined by the controlled collapse chip connection of the solder.
Claim 10
Dependent Claim
20 words
Method of claim 4 further comprising the step of removing the silylated photoresist from selected portions on the chip carrier.
Claim 11
Dependent Claim
22 words
Method of claim 4 further comprising the step of removing the first layer of positive photoresist prior etching of the chromium layer.
Claim 12
Dependent Claim
14 words
Method of claim 4, wherein said copper layer is etched with FeCl₃/HCl or CuCl₂.
Claim 13
Dependent Claim
12 words
Method of claim 4, wherein said chromium layer is etched with KMnO₄.
References Cited (Backward Citations)
No citation records indexed.
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