New twist to water cleaning guarantees reliability

Abstract

The author previously showed how different types of testers can be used to monitor wet processes and determine the amount of ionic residues being left on a printed circuit. In the present work, it is shown how this type of technology can be upscaled so that substrates, cards, and boards can be cleaned to levels cleaner than that required of integrated circuits using mostly water. Cleaning circuits beyond the 18.3-M Omega resistivity endpoint of water is easily accomplished producing reliable circuits, which can easily pass insulation resistance testing. The units considered are characterized by relatively low cost, low pollution, and low water usage. These units are particularly desirable where pollution criteria and water usage are severely restricted.<>