EP0507043A2
Expired / Lapsed
EP
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Selective and precise etching and plating of conductive substrates
Assignee: Shipley Co Inc
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Filing: 1992-01-07
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Granted: —
•
Expires: 2012-01-07
Abstract
Abstract Method for selective and precise etching and plating of a conductive substrate through electrophoretic deposition of a photoresist composition. The invention enables chemical milling and plating of products useful in high performance applications such as lead frames with lead widths less than 1.0 mil and precisely plated lead faces.
Inventors
- 👤 Martin J. Harris
- 👤 Ivan K. Ho
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 07:06
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/01; H10W70/04; H10W70/042; C; C09; C09D; C09D5/00; C09D5/44; C09D5/4407; C09D5/4411; C23; C23F; C23F1/00; C23F1/02; C25; C25D; C25D5/00; C25D5/02; C25D5/022; G; G03; G03F; G03F7/00; G03F7/16; G03F7/164; H05; H05K; H05K3/00; H05K3/0073; H05K3/0079; H05K3/02; H05K3/06; H05K3/061; H05K3/064; H05K3/10; H05K3/20; H05K3/202
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
53 words
A process for precision manufacture of a three dimensional substrate by chemical etching, comprising the steps of: (a) electrophoretically applying a photoresist composition on a conductive substrate; (b) exposing and developing the photoresist on the conductive substrate; and (c) chemically etching the portions of the conductive substrate exposed by development of the photoresist.
Claim 2
Dependent Claim
23 words
The process of claim 1 where the conductive substrate is selected from the group consisting of a copper alloy and a nickel alloy.
Claim 3
Dependent Claim
24 words
The process of claim 1 where the photoresist composition comprises a solvent, an organic polymer, an unsaturated monomer, a photoinitiator, an electrolyte and water.
Claim 4
Dependent Claim
30 words
The process of claim 1 where the photoresist composition comprises dimethylamino methacrylate, methyl methacrylate, ethyl axcrylate, dipentaerythritol monohydroxy penta-acrylate, propylene glycol methylether, one or more photoinitiators, lactic acid and water.
Claim 5
Dependent Claim
13 words
The process of claim 1 where the photoresist composition includes a coalescing agent.
Claim 6
Dependent Claim
31 words
The process of claim 5 where the coalescing agent is selected from the group consisting of 1-nitropropane, 2-nitropropane, methyl pyrrolidone, ethylene glycol ethylhexylether, propylene glycol methylether, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, or mixtures thereof.
Claim 7
Dependent Claim
24 words
The process of claim 1 where the substrate is vibrated during application of the photoresist whereby gas bubbles adhereing to the substrate are dislodged.
Claim 8
Dependent Claim
13 words
The process of claim 1 used for the manufacture of a lead frame.
Claim 9
Dependent Claim
23 words
The process of claim 1 used to manufacture a lead frame having resolution of an element to a width of about 1.0 mil.
Claim 10
Dependent Claim
24 words
The process of claim 1 used to manufacture a lead frame, each lead of the lead frame having a width of about 0.5 mils.
Claim 11
Dependent Claim
12 words
The process of claim 1 where the conductive surface has irregular topography.
Claim 12
Dependent Claim
51 words
A process for selective and precise plating of a conductive substrate comprising the steps of: (a) electrophoretically applying a photoresist composition on the conductive substrate; (b) exposing and developing the photoresist on the conductive substrate; and c) metal plating the portions of the conductive substrate exposed by development of the photoresist.
Claim 13
Dependent Claim
24 words
The process of claim 12 where the photoresist composition comprises a solvent, an organic polymer, an unsaturated monomer, a photoinitiator, an electrolyte and water.
Claim 14
Dependent Claim
30 words
The process of claim 12 where the photoresist composition comprises dimethylamino methacrylate, methyl methacrylate, ethyl axcrylate, dipentaerythritol monohydroxy penta-acrylate, propylene glycol methylether, one or more photoinitiators, lactic acid and water.
Claim 15
Dependent Claim
13 words
The process of claim 12 where the photoresist composition includes a coalescing agent.
Claim 16
Dependent Claim
31 words
The process of claim 15 where the coalescing agent is selected from the group consisting of 1-nitropropane, 2-nitropropane, methyl pyrrolidone, ethylene glycol ethylhexylether, propylene glycol methylether, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, or mixtures thereof.
Claim 17
Dependent Claim
24 words
The process of claim 12 where the substrate is vibrated during application of the photoresist whereby gas bubbles adhering to the substrate are dislodged.
Claim 18
Dependent Claim
29 words
The process of claim 12 where, prior to the metal plating step, the substrate portions exposed by development are cleaned to remove essentially all traces of organic substances thereon.
Claim 19
Dependent Claim
11 words
The process of claim 12 where the metal is electrolessly plated.
Claim 20
Dependent Claim
11 words
The process of claim 12 where the metal is electrolytically plated.
Claim 21
Dependent Claim
15 words
The process of claim 12 where the conductive surface is one or more lead frames.
Claim 22
Dependent Claim
29 words
The process of claim 21 where the edges of the one or more lead frame are substantially free of the metal plated on the one or more lead frames.
Claim 23
Dependent Claim
23 words
The process of claim 21 where the lead sidewalls are substantially free of the metal plated on the one or more lead frames.
Claim 24
Dependent Claim
24 words
The process of claim 21 where the lead frame is used for electrically connecting electronic devices operating at frequencies of 10 megahertz or greater.
Claim 25
Dependent Claim
102 words
A process for the selective and precise plating of a lead frame, the lead frame having a three dimensional conductive surface and leads laterally extending from a mounting area on which an integrated circuit or other electronic device can be mounted, the process comprising the steps of: (a) electrophoretically applying a photoresist composition on the lead frame whereby the photoresist is uniformly deposited on all conductive surfaces of the lead frame; (b) exposing and developing the photoresist whereby the top face of each of the leads are selectively bared; and (c) metal plating the bared top face of each of the leads.
Claim 26
Dependent Claim
25 words
The process of claim 25 where the lead frame is vibrated during application of the photoresist whereby gas bubbles adhering to the substrate are dislodged.
Claim 27
Dependent Claim
31 words
The process of claim 25 where, prior to the metal plating step, the top face of each of the leads are cleaned to remove essentially all traces of organic substances thereon.
Claim 28
Dependent Claim
11 words
The process of claim 25 where the metal is electrolessly plated.
Claim 29
Dependent Claim
11 words
The process of claim 25 where the metal is electrolytically plated.
Claim 30
Dependent Claim
26 words
The process of claim 25 where the metal plated on the conductive surface is selected from the group consisting of gold, silver, palladium, rhodium and ruthenium.
Claim 31
Dependent Claim
25 words
The process of claim 25 where the lead sidewalls are substantially free of the metal plated on the top face of each of the leads.
Claim 32
Dependent Claim
19 words
The process of claim 25 where the lead edges are substantially free of metal plated on the lead edges.
Claim 33
Dependent Claim
22 words
The process of claim 25 where the lead frame is used for electronic systems operating at frequencies of 10 megahertz or greater.
Claim 34
Dependent Claim
92 words
A lead frame where each lead of the lead frame has width of between about 0.5 and 1.0 mils and where the edges of the lead frame and lead sidewalls are substantially free of metal plated on the top surface of the leads, the lead frame produced by a process comprising the steps of: (a) electrophoretically applying a photoresist composition on a conductive metal foil substrate; (b) exposing and developing the photoresist on the conductive substrate; and (c) chemically etching the portions of the metal foil exposed by development of the photoresist.
Claim 35
Dependent Claim
70 words
A lead frame where the edges and lead sidewalls of the lead frame are substantially free of metal plated on the lead frame, the lead frame produced by a process comprising the steps of: (a) electrophoretically applying a photoresist composition on the lead frame; (b) exposing and developing the photoresist on the lead frame; and c) metal plating the portions of the lead frame exposed by development of the photoresist.
References Cited (Backward Citations)
No citation records indexed.
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