Multilayer interconnection substrate

Abstract

Abstract PURPOSE:To improve the solderability of a connecting terminal and to obtain an integrated circuit multilayer interconnection substrate adapted for transmitting a high speed signal by forming part or all of soldering electrode terminals formed on an organic insulating layer of the substrate for forming an electric circuit with a nickel-copper alloy. CONSTITUTION:A polyimide surface insulating layer 4 having through holes 3 is formed on the top of wirings 2 made or Cu for connecting to a soldering terminal on the substrate 1 made of multilayer circuit substrate or ceramics having an insulating layer made of organic material. Then, a Cr film 51 is formed in a predetermined thickness by a method, such as vacuum depositing or sputtering, and an Ni-Cu alloy film 52 is formed in a predetermined thickness. After the film forming step is finished, a desired soldering terminal 6 is formed by photoetching. Cupric iodide or chloride solution is used to etch the film 52 at this time, caustic potash solution is used for the film 51 to obtain a multilayer interconnection substrate to be soldered in high reliability and repetition.

Inventors

• 👤 Akira Murata
• 👤 Yasunori Narizuka
• 👤 Mitsuru Usui
• 👤 Minoru Tanaka

Bibliographic Details