Standards Manage Your Business
We Manage Your Standards
Standards Manage Your Business
We Manage Your Standards
An In-Depth Look At Ionic Cleanliness Testing
INTRODUCTION
Many printed wiring assembly (PWA) failures that occur in the field can be attributed to manufacturing residues that were not properly removed. It is essential that the cleaning process be monitored to ensure proper removal of contaminants that may, when exposed to time, temperature, and humidity, lead to high defect rates.
The most common method for evaluating the cleanliness level of a PWA is a method called the Resistivity Of Solvent Extract (ROSE) test. The original procedure, developed in the early 1970s, used a laboratory squeeze bottle filled with a 75% isopropanol (lPA) and 25% deionized water solution to dissolve ionic contamination from the PWA into a beaker. The resistivity of the extract solution was then measured and assigned a value based on a sodium chloride (NaCl) standard. In the last 20 years; several manufacturers have developed and marketed equipment to perform this type of testing. During that time, radical changes have been made to the systems, such as the addition of solvent heaters, sprays and microprocessors. Recent studies have shown discrepancies among not only the different manufacturers, but also among different parameters such as solvent temperature and volume. To continue using this test to manage a process or to make decisions on what cleaning alternative works best, it became necessary to investigate what variables influence final results and standardize a test procedure.
Currently Viewing
Expand Your Knowledge and Unlock Your Learning Potential - Your One-Stop Source for Information!
© Copyright 2025 BSB Edge Private Limited.
