Localized Contamination Measurement System
Original Publication Date: 1987-Apr-01
Included in the Prior Art Database: 2005-Feb-01
A method is described of extracting and measuring ionic contamination left around and under the small, compact Surface-Mounted Technology (SMT) components after the flux-cleaning/removal process. One of the important considerations for all circuit cards assembled is how well they have been cleaned. If the cards are not cleaned sufficiently, their reliability will be compromised. The small clearances under SMT components makes flux removal/cleaning difficult. Current contaminant measurement equipment utilizes a sizable quantity (>1 liter) of a deionized water and isopropyl alcohol solution to completely submerge an entire circuit card. As the solution dissolves the residual contamination from the card, a very dilute, slightly conductive solution is formed.