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EP0572121A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Method of making circuit board

Assignee: Sumitomo Electric Industries Ltd
•
Filing: 1993-04-30
•
Granted: —
•
Expires: 2013-04-30
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Abstract

Abstract A method of making circuit boards in which the thickness of an insulating layer (2) is held constant to ensure the fine configuration and dimensions of wiring lines and further to prevent variations in wiring intervals and wiring grounds due to unevenness of the insulating layer, thereby preventing electric characteristics from varying. The method comprising the steps of stacking an insulating layer (2) on an insulating substrate (1), and engraving the insulating layer into a wiring configuration, for example by exposure and development. A metal layer (3) is formed thereon, and photoresist is removed. This sequence of steps can be repeated as necessary obtaining a layer-structure wiring board. <IMAGE>

Inventors

  • 👤 Tomohiko C/O Itami Works Ihara
  • 👤 Hiroshi Sumitomo Electric Ind.Ltd. Yoshino
  • 👤 Hisao C/O Itami Works Hattori
  • 👤 Shosaku C/O Itami Works Yamanaka

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-25 22:13
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/46; H05K3/4644; H05K3/465; H05K3/467; H10; H10W; H10W70/00; H10W70/01; H10W70/05; H10W70/095; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0364; H05K2201/0376; H05K2201/09; H05K2201/09009; H05K2201/09036; H05K3/0011; H05K3/0017; H05K3/0023; H05K3/0041; H05K3/02; H05K3/06; H05K3/061; H05K3/064; H05K3/10; H05K3/107; H05K3/14; H05K3/16

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 75 words
A method of making circuit boards having a single wiring layer or alternating wiring layers and insulating layers, the wiring layers being connected one to another with via holes or through holes, the method comprising the steps of: stacking an insulating layer (2) on a substrate (1); engraving the layer according to the wiring configuration forming a metal layer (3) all over or partially over the engraved layer; and thereafter forming wiring patterns by etching.
Claim 2
Dependent Claim 26 words
A method as claimed in claim 1, wherein the insulating layer (2) is made of any one of a polyimide resin, epoxy resin, and polytetrafluorethylene resin.
Claim 3
Dependent Claim 30 words
A method as claimed in claim 2, wherein at least one resin of the insulating layer (2) is photosensitive, and the engraving process is in combination of exposure and development.
Claim 4
Dependent Claim 18 words
A method as claimed in claim 1 or claim 2, wherein the engraving process involves liquid phase etching.

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