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:
Mar. 15, 1994
Filed:
Oct. 29, 1992
Harry D Boersen, Holland, MI (US);
John M Eldred, Holland, MI (US);
Robert K Hayes, Fruitport, MI (US);
Vince J Jasinski, Grand Rapids, MI (US);
Kim A Pattee, Holland, MI (US);
Clinton A Peterson, Holland, MI (US);
David L Walcott, Zeeland, MI (US);
Venturedyne, Ltd., Milwaukee, WI (US);
Abstract
The invention is an improvement in a thermal stress screening system of the type using a single type of liquid for alternately transferring heat to and from the product. In the improvement, the product is confined in a single chamber during alternate heat transfer. That is, the system provides 'one chamber' thermal stress screening. The system includes a plurality of tanks, one each for hot and cold liquid, and a heat exchanger associated with each tank so that the liquid in a tank is maintained at the proper temperature for stress screening. An improved method for thermally stress screening products, e.g., printed circuit boards, includes the steps of placing the product in a chamber, flowing cold liquid into the chamber, draining the cold liquid from the chamber and flowing hot liquid into the same chamber.