Patent EP0158536A2 successfully refreshed from Google Patents.
EP0158536A2
Expired / Lapsed
EP
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Methods of and apparatus for forming conductive patterns on a substrate
Assignee: Individual
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Filing: 1985-04-09
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Granted: —
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Expires: 2005-04-09
Abstract
Abstract A method of forming an electrically conductive pattern on a substrate includes the steps of forming a layer of gold (6) on an electrically insulating substrate (2) and coating the gold layer (6) with a photo-resist (8). The resist (8) is exposed to light through a photo mask and the exposed portions of the photo-resist (8) are selectively removed by etching. The now exposed parts of the gold layer (6) are coated with copper (12) and the remaining photo-resist (8) is removed. The exposed parts of the gold layer (6) and the copper (12) are subjected to molten tin (14) which simultaneously acts to dissolve the exposed parts of the gold layer (6) and to form an electrically conductive coating on the copper (12).The process enables the formation of a precise conductive pattern with enhanced reliability.
Inventors
- 👤 Peter Leslie Moran
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 08:17
CPC Classifications
C; C23; C23F; C23F4/00; C23F4/04; C23C; C23C2/00; C23C2/02; H; H05; H05K; H05K3/00; H05K3/10; H05K3/108; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; H05K3/3468; H05K2201/00; H05K2201/03; H05K2201/0302; H05K2201/0305; H05K2203/00; H05K2203/04; H05K2203/044; H05K2203/07; H05K2203/0703; H05K2203/0723; H05K3/02; H05K3/06; H05K3/067; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49155; Y10T428/00; Y10T428/12; Y10T428/12389; Y10T428/12396; Y10T428/12493
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
121 words
A metnod of forming a conductive pattern on a substrate comprising: the steps of coating the substrate with a first electrically conductive material, to form a first layer; forming a resist pattern on the first layer; depositing a second electrically conductive material on the parts of the first layer not covered by the resist pattern; removing the resist pattern; and temporarily subjecting the now exposed parts of the first layer and the deposits of said second conductive material with a third electrically conductive material in its molten state, the third electrically conductive material being such that when in its molten state it acts simultaneously to dissolve the first conductive material and to provide a coating on said second electrically conductive material.
Claim 2
Dependent Claim
121 words
A metnod of forming a conductive pattern on a substrate comprising: the steps of coating the substrate with a first electrically conductive material, to form a first layer; forming a resist pattern on the first layer; depositing a second electrically conductive material on the parts of the first layer not covered by the resist pattern; removing the resist pattern; and temporarily subjecting the now exposed parts of the first layer and the deposits of said second conductive material with a third electrically conductive material in its molten state, the third electrically conductive material being such that when in its molten state it acts simultaneously to dissolve the first conductive material and to provide a coating on said second electrically conductive material.
Claim 3
Dependent Claim
18 words
A method according to Claim 1, wherein said first electrically conductive layer comprises gold or an alloy thereof.
Claim 4
Dependent Claim
18 words
A method according to Claim 1, wherein said first electrically conductive layer comprises silver or an alloy thereof.
Claim 5
Independent Claim
15 words
A method according to any preceding Claim, wherein said second electrically conductive material comprises copper.
Claim 6
Independent Claim
41 words
A method according to any preceding Claim, wherein said third electrically conductive material is selected from the group consisting of tin, an --alloy of tin and silver; an alloy of tin and lead, and an alloy of lead silver and tin.
Claim 7
Independent Claim
75 words
A method according to any preceding Claim, including the steps of: increasing the thickness of selected parts of the deposited second electrically conductive material by forming a further resist pattern following the deposit of the second electrically conductive matpriai, but prior to the removal of the resist pattern; and subjecting the parts of the second electrically conductive material not covered by the further resist pattern, to a further deposit of said second electrically conductive material.
Claim 8
Independent Claim
140 words
A method of forming an electrically conductive pattern on a substrate comprising the steps of: forming a layer of gold or silver on an electrically insulating substrate; coating said gold or silver layer with a photo-resist; exposing the photo-resist to light through a photo mask; selectively removing the exposed portions of the photo-resist; coating the now exposed parts of the gold or silver layer with a second electrically conductive material other than gold or silver; removing the remaining photo-resist; and subjecting the exposed parts of the gold or silver layer and the said second electrically conductive material to a third electrically conductive material in molten form, the third electrically conductive material being such that it simultaneously acts to dissolve the exposed parts of the gold or silver layer and form an electrically conductive coating on the second electrically conductive material.
Claim 9
Independent Claim
140 words
A method of forming an electrically conductive pattern on a substrate comprising the steps of: forming a layer of gold or silver on an electrically insulating substrate; coating said gold or silver layer with a photo-resist; exposing the photo-resist to light through a photo mask; selectively removing the exposed portions of the photo-resist; coating the now exposed parts of the gold or silver layer with a second electrically conductive material other than gold or silver; removing the remaining photo-resist; and subjecting the exposed parts of the gold or silver layer and the said second electrically conductive material to a third electrically conductive material in molten form, the third electrically conductive material being such that it simultaneously acts to dissolve the exposed parts of the gold or silver layer and form an electrically conductive coating on the second electrically conductive material.
Claim 10
Dependent Claim
32 words
A method according to Claim 7, wherein the step of coating the exposed parts of the gold or silver layer with said second electrically conductive material is performed by an electro-plating method.
Claim 11
Dependent Claim
33 words
A method according to Claim 7, wherein the step of coating the exposed parts of the gold or silver layer with said second electrically conductive material is performed by an electroless plating method.
Claim 12
Independent Claim
68 words
A method according to any one of Claims 7 to 9, wherein the step of forming a layer of gold or silver comprises the steps of: screen printing a mixture of a gold or silver metallorganic and a metal oxide forming material on said substrate and then heating to fire said mixture, whereby the metal oxide formed upon firing adheres said gold or silver layer to said substrate.
Claim 13
Dependent Claim
28 words
A method according to Claim 10, wherein said step of forming the gold or silver layer comprises forming a gold or silver layer less than 0.5 micrcn thick.
Claim 14
Independent Claim
76 words
A method according to any one of Claims 7 to 11, wherein the step of subjecting the exposed parts of the gold or silver layer and the second electrically conductive material to said third electrically conductive material comprises the steps of: pre-heating the substrate and all that it carries, in an atmosphere which inhibits oxidation; immersing the substrate in a molten bath of said third electrically conductive material; and withdrawing the substrate back through said atmosphere.
Claim 15
Dependent Claim
22 words
A method according to Claim 12, wherein said atmosphere is used to heat said third electrically conductive material to its molten state.
Claim 16
Independent Claim
35 words
A method according to any one of Claims 7 to 13, wherein said third electrically conductive material is selected from the group consisting of tin, a tin/lead alloy, a tin/silver alloy and a tin/leac/silver alloy.
Claim 17
Dependent Claim
117 words
Apparatus for treating a substrate carrying an electrically conductive pattern comprising: a container for containing an oxidation inhibiting vapourisable liquid; heating means for heating the container to a level at which the liquid therein vapourises; a vessel for holding a molten electrically conductive material; means supporting the vessel in the container to be above the liquid phase of the vapourisable liquid; and means for displacing said substrate along a predetermined path through the container to the vessel, whereby when the heater is operative it will cause the vapourisable liquid to vapourise and the vapour to heat the material in the vessel to its molten state, and to form a preheating oxidation inhibiting environment around the said path.
Claim 18
Dependent Claim
117 words
Apparatus for treating a substrate carrying an electrically conductive pattern comprising: a container for containing an oxidation inhibiting vapourisable liquid; heating means for heating the container to a level at which the liquid therein vapourises; a vessel for holding a molten electrically conductive material; means supporting the vessel in the container to be above the liquid phase of the vapourisable liquid; and means for displacing said substrate along a predetermined path through the container to the vessel, whereby when the heater is operative it will cause the vapourisable liquid to vapourise and the vapour to heat the material in the vessel to its molten state, and to form a preheating oxidation inhibiting environment around the said path.
References Cited (Backward Citations)
No citation records indexed.
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