Method and apparatus for the quantitative measurement of the corrosivity effect of residues present on the surface of electronic circuit assemblies

摘要

An apparatus and test method for determining the cleanliness (based on corrosivity) of a specific area on an electronic circuit assembly, such as the area between holes or pads on a single side of an assembly. The apparatus includes: (1) an extraction cell for providing an extraction fluid to an electronic circuit assembly ("ECA") area to be measured; (2) an extraction fluid for extracting residue from the ECA area to be measured; (3) a test cell with two or more electrodes and a voltage source for providing a voltage to the electrodes; and (4) a timer for measuring the time between the application of the voltage and an electrical short between the electrodes. The method includes: (1) positioning an extraction cell over an electronic circuit assembly area to be measured; (2) dispensing an extraction fluid into the extraction cell; (3) contacting the ECA area to be measured with the extraction fluid for a time sufficient to extract residue from the ECA area; (4) transferring the extraction fluid to a test cell made of two or more electrodes; (5) applying a voltage to the electrodes; and (6) measuring the time between the application of the voltage and an electrical short between the electrodes.