Browse Prior Art Database

Ion Extraction Technique

IP.com Disclosure Number: IPCOM000103720D
Original Publication Date: 1993-Jan-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 2 page(s) / 50K

Publishing Venue

IBM

Related People

Ameen, JG: AUTHOR [+3]

Abstract

To remove residues and thus increase the reliability of the printed circuit, a working tank containing 10 percent by volume isopropyl alcohol with water has 4, 8 or more fittings to which alcohol-resistant tubing (e.g., Bev a Line tubing) is attached. Half of these tubes feed the inputs to a recirculating pump. The other half of the tubes are return lines to the tank. The pumps cause the fluid to flow through an ion exchange column that may contain activated charcoal before being returned to the tank. The system works as follows: the working fluid (the alcohol/water) is recirculated through the ion exchange columns such that the fluid is continuously cleaned. A contaminated printed circuit is immersed into the tank into this clean fluid. Because the water is very pure (i.e.

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Ion Extraction Technique

       To remove residues and thus increase the reliability of
the printed circuit, a working tank containing 10 percent by volume
isopropyl alcohol with water has 4, 8 or more fittings to which
alcohol-resistant tubing (e.g., Bev a Line tubing) is attached.  Half
of these tubes feed the inputs to a recirculating pump.  The other
half of the tubes are return lines to the tank.  The pumps cause the
fluid to flow through an ion exchange column that may contain
activated charcoal before being returned to the tank.  The system
works as follows: the working fluid (the alcohol/water) is
recirculated through the ion exchange columns such that the fluid is
continuously cleaned.  A contaminated printed circuit is immersed
into the tank into this clean fluid.  Because the water is very pure
(i.e., greater than 20 megohms), residual ionic contamination is
exposed to a powerful driving force to dissolve.  These contaminants
are solvated and removed from the circuit and are delivered to the
mixed bed ion exchange columns where all cations are exchanged for
hydrogen ions and all anions are exchanged for hydroxide ions.  Pure
water is returned to the tank.  The system is monitored by means of a
conductivity probe in the tank and a resistivity meter.  To increase
the throughput through the machine, a nitrogen line is added to the
lid of the tank.  The nitrogen provides a positive pressure over the
solution and prevents carbon dioxide from diffusing...