Manufacture of pc board

Abstract

Abstract PURPOSE: To ensure a resist which is prevented from being etched with nitric acid and is stable and removable with a commercial removing agent without giving damage to a junction between it and a copper foil or a substrate thereof by adding a tin-nickel alloy, a semiglossy nickel, or a combination thereof to a copper part to be held, and removing remaining copper with a nitric acid etching solution. CONSTITUTION: In a method of assembling a printed circuit board by selectively removing copper from an insulating substrate, a semiglossy nickel layer is formed on a copper part to be held. A tin-nickel alloy layer is formed on the semiglossy nickel. For etching thereafter the substrate is exposed to a nitric acid etching solution in order to remove the copper part not covered with the semiglossy nickel and the tin-nickel alloy. Herein, the semiglossy nickel layer is preferably at least 0.2mil in thickness in order to ensure a proper isolation between the copper and the tin-nickel. Hereby, when nickel is used as an etching resist, the difficulties and limitation caused until now can be eliminated.

Inventors

• 👤 Jiei Baanetsuto Danieru
• 👤 Ei Deiiru Pauro
• 👤 Jiei Neruson Noobueru

Bibliographic Details