Cleaning and liquid contact with solids – Apparatus – Automatic controls
Patent
1991-06-14
1993-09-21
Stinson, Frankie L.
Cleaning and liquid contact with solids
Apparatus
Automatic controls
134109, 134111, 134902, B08B 302
Patent
active
052460231
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.
REFERENCES:
patent: 3871914 (1975-03-01), Goffredo et al.
patent: 3880685 (1975-04-01), Rehm et al.
patent: 3964956 (1976-06-01), Snyder
patent: 3973572 (1986-08-01), Brous
patent: 4682615 (1987-07-01), Burkman
patent: 4731154 (1988-03-01), Hausman Hazlitt et al.
patent: 4977688 (1990-12-01), Roberson, Jr. et al.
patent: 5022419 (1991-06-01), Thompson et al.
Austen Paul M.
Breunsbach Rex
Electronic Controls Design, Inc.
Stinson Frankie L.
LandOfFree
Method and apparatus to clean and cleanliness test printed circu does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus to clean and cleanliness test printed circu, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus to clean and cleanliness test printed circu will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1044031