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:
Oct. 04, 1988
Filed:
Aug. 26, 1987
Applicant:
Inventor:
John L Cordani, Waterbury, CT (US);
Assignee:
MacDermid, Incorporated, Waterbury, CT (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C23F / ; B44C / ; C03C / ; C03C / ;
U.S. Cl.
CPC ...
156634 ; 156656 ; 1566591 ; 1566611 ; 156666 ; 156902 ; 148-62 ; 427 97 ;
Abstract
Printed circuit boards having copper circuit patterns coated with an adhesion promoter (e.g., copper oxide, tin) are subjected to the action of an aqueous chromic acid solution prior to incorporation in a multi-layer board by interposing layers of semi-cured polymeric non-conductive material between the individual boards and laminating the assembly using heat and pressure. The chromic acid treatment serves to improve adhesion between the layers and, in particular, to overcome or minimize the 'pink ring' effect which is frequently observed around holes drilled through multilayer boards.