The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 07, 2004
Filed:
May. 07, 2002
Tomoo Iijima, Tokyo, JP;
Masayuki Ohsawa, Tokyo, JP;
North Corporation, Tokyo, JP;
Abstract
The present invention prepares a member having a conductor-circuit-forming copper foil formed on a protrusion-forming copper layer via an etching-barrier layer formed of a different metal. Etching is selectively performed for the protrusion-forming copper foil by using etchant that does not etch the etching-barrier layer, and protrusions are thereby formed. Then, the etching-barrier layer is removed using etchant that does not etch the copper foil and using the protrusions as masks. An interlayer-insulating layer is formed on a surface of the copper foil, on which the protrusions are formed, so that the protrusions are connected to the conductor circuit. Thereby, heights of the protrusions are uniformed, and the reliability of connections can be improved.