EP0189975A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Manufacture of printed circuit boards
Assignee: Prestwick Circuits Ltd
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Filing: 1986-01-09
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Granted: —
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Expires: 2006-01-09
Abstract
Abstract A double sided lamination of dielectric substrate and copper foil is processed to give a p.c.b. having conductor tracks (18) formed by the original copper, and holes (16) and pads (22) plated relatively thickly. The process comprises - negative imaging - etching, to give track pattern - electroless copper plating all over - positive pad imaging - electroplating with copper-tin/lead or copper-nickel-tin/lead - etching to remove unplated electroless copper
Inventors
- 👤 Christopher Rivett
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 06:13
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/40; H05K3/42; H05K3/425; H05K3/428; H05K3/22; H05K3/24; H05K3/243; H05K1/00; H05K1/02; H05K1/09; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0341; H05K2203/00; H05K2203/05; H05K2203/0502; H05K2203/0542; H05K3/244; H05K3/30; H05K3/32; H05K3/34; H05K3/3452; H05K3/3465; H05K3/3473
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
1 words
Claims
Claim 2
Independent Claim
121 words
A method of manufacturing a printed circuit board comprising: providing a board having at least one face covered with a conductive foil, and drilling the board with a predetermined hole pattern; characterised by the steps of: removing the foil except in the desired track areas by application of an etch resist pattern followed by etching and removal of the resist, coating the board including the holes with a relatively thin layer of conductive material by electroless deposition, applying a plating resist to mask all areas except holes, pads and any other desired functional areas, depositing a relatively thick layer of conductive material on the unmasked areas, including the holes, by electroplating, removing the mask material, and etching away the electroless layer.
Claim 3
Dependent Claim
32 words
The method of claim 1, in which the etch resist pattern is created by applying a negative photoresist material, exposing thereon a negative image of the desired pattern, and developing the photoresist.
Claim 4
Dependent Claim
36 words
The method of claim 1 or claim 2, in which the plating resist mask is created by applying a negative photoresist material, exposing thereon a positive image of the desired pad pattern, and developing the photoresist.
Claim 5
Dependent Claim
14 words
4 . The method of any preceding claim, in which the foil is copper.
Claim 6
Independent Claim
18 words
The method of any preceding claim, in which the electroless layer is copper, preferably about 2.5 µm thick.
Claim 7
Independent Claim
21 words
The method of any preceding claim, in which the electroplating step comprises electroplating copper, nickel, and tin/lead in three successive stages.
Claim 8
Dependent Claim
20 words
The method of claim 6, in which a further layer of copper is electroplated between the nickel and the tin/lead.
Claim 9
Dependent Claim
42 words
The method of claim 6 or claim 7, in which the electroplated copper layer is about 20-25 µm thick, and the nickel and tin/lead layers are each about 8-12 µm thick, the further copper layer if present being about 5 um thick.
Claim 10
Dependent Claim
21 words
The method of any of claim 1 to 5, in which the electroplating step comprises plating copper about 30-35 µm thick.
References Cited (Backward Citations)
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