RiversideME
Mechanical
Hello,
I am replacing a 30 YO Ionic contamination tester in our electronics assembly facility with a newer model and am creating a validation procedure for that tester. We produce electronics to IPC-A-610 Class 3. The tester is used to read the ionic contamination of CCAs with a ROSE(resistivity of solvent extract) method. This ensures the washing process is up to par. Cleanliness is important for conformal coating adhesion on the assemblies. My tentative plan to validate this unit is to introduce several specimens with the same amounts of contamination. If the results are a certain percentage difference, then the validation will fail. My question is what variation of results shall be acceptable? This is difficult because the MFR doesn’t publish what precision their tester is capable of. Is there a rule of thumb for acceptability in this situation? It isn’t critical that the results read within 10% of each other but I don’t want to pick a percentage out of thin air for this.
I am replacing a 30 YO Ionic contamination tester in our electronics assembly facility with a newer model and am creating a validation procedure for that tester. We produce electronics to IPC-A-610 Class 3. The tester is used to read the ionic contamination of CCAs with a ROSE(resistivity of solvent extract) method. This ensures the washing process is up to par. Cleanliness is important for conformal coating adhesion on the assemblies. My tentative plan to validate this unit is to introduce several specimens with the same amounts of contamination. If the results are a certain percentage difference, then the validation will fail. My question is what variation of results shall be acceptable? This is difficult because the MFR doesn’t publish what precision their tester is capable of. Is there a rule of thumb for acceptability in this situation? It isn’t critical that the results read within 10% of each other but I don’t want to pick a percentage out of thin air for this.
