Patent US5222902A successfully refreshed from Google Patents.
EP0402811A2
Expired / Lapsed
EP
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Method of manufacturing printed circuit boards
Assignee: Hewlett Packard GmbH Germany
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Filing: 1990-06-09
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Granted: —
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Expires: 2010-06-09
Abstract
Abstract In a method for manufacturing printed circuit boards, it is started from a carrier plate 1 of isolating material to which a metal foil 2 has been laminated. A pattern of conductive traces 8, 9 is produced from the metal foil 2, for example by a photographic method using a photoresist layer 3. The final conductor structures are produced by chemically depositing a metal layer 10, 11, on the pattern of conductive traces 8,9. The method can be used for manufacturing single-layer or multilayer printed circuit boards with or without through-holes and permits to create conductor structures in the range of 50 micrometers and below.
Inventors
- 👤 Albert Ott
- 👤 Werner Motz
- 👤 Werner Kornmayer
- 👤 Michael Dr. Moser
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 09:03
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/40; H05K3/42; H05K3/425; H05K3/427; H05K3/10; H05K3/108; H05K3/22; H05K3/24; H05K3/244; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0347; H05K2201/07; H05K2201/0753; H05K2201/0761; H05K2203/00; H05K2203/03; H05K2203/0361; H05K2203/05; H05K2203/0562; H05K2203/0571; H05K2203/07; H05K2203/0703; H05K2203/072; H05K3/02; H05K3/06; H05K3/061; H05K3/062; H05K3/243; H05K3/30; H05K3/32; H05K3/34; H05K3/3452; H05K3/46; H05K3/4611
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
139 words
A method of manufacturing printed circuit boards, wherein: metallic conductor structures (10,11; 39) according to a desired pattern are produced on a carrier board (1; 20) of isolating material, and the method starts with a metal foil (2; 23) laminated to the surface of the carrier board (1; 20), characterized in that - the final conductor structures (10,11; 39) are produced by chemical metal deposition on a pattern of conductive traces (8,9; 37) corresponding to the desired pattern, said traces (8,9; 37) having as a base layer (8,9; 45) portions of the metal foil (2; 23) laminated to the carrier board (1;20), and - a deactivation step is performed before the step of chemical metal deposition wherein any substances on the carrier board (1;20) at locations outside the desired pattern are removed to avoid metal deposition at such locations.
Claim 2
Independent Claim
139 words
A method of manufacturing printed circuit boards, wherein: metallic conductor structures (10,11; 39) according to a desired pattern are produced on a carrier board (1; 20) of isolating material, and the method starts with a metal foil (2; 23) laminated to the surface of the carrier board (1; 20), characterized in that - the final conductor structures (10,11; 39) are produced by chemical metal deposition on a pattern of conductive traces (8,9; 37) corresponding to the desired pattern, said traces (8,9; 37) having as a base layer (8,9; 45) portions of the metal foil (2; 23) laminated to the carrier board (1;20), and - a deactivation step is performed before the step of chemical metal deposition wherein any substances on the carrier board (1;20) at locations outside the desired pattern are removed to avoid metal deposition at such locations.
Claim 3
Dependent Claim
20 words
A method as in claim 1 wherein the deactivation step comprises rinsing of the carrier board (1) with hydrochloric acid.
Claim 4
Dependent Claim
86 words
A method as in claim 1 or 2 for manufacturing one-sided printed circuit-boards or inner layers of multilayer printed circuit boards without through-holes, wherein the pattern of conductive traces (8,9) is produced by the steps of: a) applying a photoresist layer (3) on the metal foil (2), b) exposing the photoresist layer (3) to radiation according to the desired pattern of conductor structures, c) developing the photoresist layer (3), and d) etching away the portions of the metal foil (2) which are not covered by photoresist.
Claim 5
Dependent Claim
52 words
A method as in claim 1 for manufacturing outer layers of multilayer printed circuit boards or inner layers having through-holes (28), wherein during the step of chemical metal deposition on the pattern of conductive traces (37) the walls of the through-holes (28) are covered with a layer (40) of chemically deposited metal.
Claim 6
Dependent Claim
42 words
A method as in claim 4, wherein the through-holes (28) are covered with a metal layer (46) by a step of electroplating before the step of chemical metal deposition on the conductive traces (37) and on the walls of the through-holes (28).
Claim 7
Dependent Claim
47 words
A method as in claim 4 or 5, wherein the pattern of conductive traces (37) is produced by means of the steps of applying a photoresist layer (31), exposing the photoresist layer to radiation according to the desired pattern of conductor structures, and developing the photoresist layer
Claim 8
Independent Claim
24 words
A method as in any of the preceding claims wherein the thickness of the metal foil (2; 23) is less than approximately 17 micrometers.
Claim 9
Independent Claim
22 words
A method as in any of the claims 3, 6 or 7, wherein the resist (3; 31) is a dry film resist.
Claim 10
Dependent Claim
21 words
A method as in claim 8, wherein the thickness of the resist layer (3; 31) is less than approximately 15 micrometers.
Claim 11
Independent Claim
24 words
A method as in any of the preceding claims wherein the metal (10,11; 39) chemically deposited on the conductive traces (8,9; 37) is copper.
Claim 12
Dependent Claim
40 words
A method as in claim 10 wherein the printed circuit board is immersed in an additive bath during the step of electroless metal deposition , said bath comprising a cupric salt in a concentration of less than about 0.05 mol/liter.
Claim 13
Independent Claim
31 words
A method as in any of the claims 1 to 9 , wherein the metal (8,9; 37) chemically deposited on the conductive traces (8,9; 37) is nickel or nickel and gold.
Claim 14
Independent Claim
79 words
A method as in any of the preceding claims, comprising the following steps after the step of chemical metal deposition on the pattern of conductive traces: a) applying a protective layer (solder mask) to the surface of the board, b) exposing and developing said soldermask according to a predetermined pattern, and c) electroless deposition of a metal on those portions (e.g., contact pads, through-holes) of the surface of the board which are not covered with the developed protective layer.
Claim 15
Dependent Claim
36 words
A method as in claim 13 wherein the metal which is electrolessly deposited in step c) is nickel, and wherein after the deposition of nickel a layer of gold is electrolessly deposited on the nickel layer.
References Cited (Backward Citations)
No citation records indexed.
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