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:
Sep. 21, 1993
Filed:
Jun. 14, 1991
Rex Breunsbach, Clackamas, OR (US);
Paul M Austen, Milwaukie, OR (US);
Electronic Controls Design, Inc., Milwaukie, OR (US);
Abstract
The present invention is an apparatus to clean and cleanliness test printed circuit wiring boards and includes an inner chamber and an outer enclosure encasing the inner chamber. A rack within the chamber is adapted to hold a plurality of PCBs having electronic components assembled thereon. An operator programmable microprocessor controller causes a saponifier solution to be introduced into the interior chamber. The saponifier solution is pumped through a diffusion assembly in the chamber to spray the solution onto the PCBs. Upon completion of this cleaning cycle, the saponifier solution is drained by gravity out of the chamber. This is followed by a water rinsing cycle utilizing the same hardware and procedure. Once the rosin saponification cleaning cycle and water rinsing cycle are complete, the system controller empties the wash chamber and pumps in a standard resistivity test mixture of 75% isopropyl alcohol (IPA) and 25% water. A MIL-P-28809 cleanliness test is then performed on the PCBs. The PCBs are rinsed in the test IPA mixture by the diffusion assembly at a set temperature for a set time. If the test IPA mixture has a resistivity of .ltoreq.2 M.OMEGA./cm.sup.3, the PCBs are determined to be contaminated and are rejected for re-cleaning.