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. 05, 1989
Filed:
Oct. 15, 1987
Edward J Choinski, Wayland, MA (US);
Epicor Technology, Inc., Wayland, MA (US);
Abstract
A method for temporarily sealing holes in a printed circuit board laminate during processing is disclosed. A sheet of deformable material is placed on one side of the PCB and then deformed so that the material extends into each hole to form a protectively sealing plug therein. Thereafter, the other side of the PCB is coated with a suitable resist for subsequent processing. The resist can be either photo-imagable or non-photo-imagable, such as silk screening inks, lacquers and varnishes. After conventional processing of the resist coated PCB, the deformed sheet material that forms the protectively sealing plugs is removed from the PCB. In the preferred embodiment, deformation of the sheet material is accomplished by thermally deforming a thermodeformable sheet material with a pressure differential applied across the thickness of the sheet material. The thermodeformable sheet material preferably comprises either a low or high density polyethylene of polypropylene that can be re-used many times in order to reduce the material costs of practicing the method of the invention.