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:
May. 03, 2005
Filed:
Nov. 25, 2002
Ashwinkumar C. Bhatt, Endicott, NY (US);
Brant S. Blomberg, Endicott, NY (US);
Ross W. Keesler, Endicott, NY (US);
Michael V. Longo, Glen Aubrey, NY (US);
Eboney J. N. Smith, Johnson City, NY (US);
Ashwinkumar C. Bhatt, Endicott, NY (US);
Brant S. Blomberg, Endicott, NY (US);
Ross W. Keesler, Endicott, NY (US);
Michael V. Longo, Glen Aubrey, NY (US);
Eboney J. N. Smith, Johnson City, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A hybrid photolithography process for printed circuit board patterning combines two types of photoresist applications to achieve superior protection of printed circuit board (PCB) 'plated through holes' (PTH). In a first step, electro-deposited (ED) photoresist (also known as 'ED resist') is applied to a fully copper plated PCB including the 'plated through holes' to protect the outer layers and the ‘plated through holes’ from copper etchant solution. In a second step, the electro-deposited photoresist is imaged (exposed) and patterned (developed). In a third step, after developing the circuit image, a layer of Dry Film resist is applied to the panel of the PCB on top of the developed electro-deposited (ED) photoresist. This Dry Film resist layer will ‘tent’ the plated through holes by adding an extra layer of protection to the plated through holes. In a fourth step, the dry film resist is then exposed and developed. At this point, the PCB is etched as normal and all subsequent processing remains unchanged.