Testing of Ionic Contamination
Converting ROSE to PICT
For many years, military (e.g. MIL-STD-2000) and commercial (e.g. IPC-J-STD-001) manufacturing standards have required manufactured printed circuit assemblies (PCAs) to meet an ionic cleanliness requirement of 1.56 microgram (μg) of sodium chloride (NaCl) equivalence (μg) per square centimetre (cm2) of extracted surface.
This technique, originally developed in the 1970's, became known as Resistivity of Solvent Extract (ROSE) testing, and is documented today in IPC-TM-650, method 2.3.25.
The ROSE technique measures dissolvable ionic residues. There are today however, undetectable non-ionic residues that contribute to reliability issues. These non-ionic residues are a cleanliness issue but, not being detectable by the ROSE system, it means that a cleanliness measurement is totally inappropriate in this context.
A new standard is being written, adopting a similar approach and using the measurement methodology to previous ROSE methods, but now the new test method approaches the subject from a process control perspective, and the test will be known as "Process Ionic Contamination Testing" (PICT).
Gen3 Systems Production Manager, Mark Routley, will present the paper titled "Process Control of Ionic Contamination achieving 6-Sigma Criteria in the assembly of Electronic Circuits" alongside Dr Pierre Eckold of Robert Bosch at the upcoming IPC APEX EXPO. The presentation will be held during the session titled "Corrosion/Cleanliness/SIR Reliability" on Wednesday the 15th February between 10:30 - 12:00pm in location 3.
The CM Series is the World's first and only combined ROSE and PICT tester
and Gen3 Systems will be exhibiting their NEW CM22+ System at the IPC Apex Exhibition on booth 3136.
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