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:
Jul. 27, 2004
Filed:
Aug. 07, 2002
Toshihisa Shimo, Kariya, JP;
Kyoko Kumagai, Kariya, JP;
Toshiki Inoue, Kariya, JP;
Yoshifumi Kato, Kariya, JP;
Takashi Yoshida, Kariya, JP;
Masanobu Hidaka, Kariya, JP;
Kabushiki Kaisha Toyota Jidoshokki, Kariya, JP;
Abstract
An aqueous solution containing sulfuric acid and hydrogen peroxide is used for a soft etchant in a soft etching step in a smear removing process performed prior to a catalyst applying process for chemical copper plating after formation of via holes through an insulating layer of a multi-layer substrate by irradiation of laser. The concentration of sulfuric acid is 2.4 times or less than the concentration of hydrogen peroxide. Preferably, the concentration of sulfuric acid is in a range of 9 to 90 g/l, and the concentration of sulfuric acid is lower than the concentration of hydrogen peroxide. More preferably, the concentration of sulfuric acid is in a range of 9 to 18 g/l, and the concentration of hydrogen peroxide is in a range of 33 to 38.5 g/l. As a result, smear can be certainly removed without excessively etching a conductive layer in the smear removing process.