Residual Chlorine on Printed Circuit Boards
Q. We have found chlorine present on our printed circuit boards after ultrasonic cleaning and distilled water rinse. As ultrasonic cleaning detergent, we’re using either Liquinox or Detergent 8, but are unsure which one was used on affected boards. Could either be contributing to this issue?
A. It’s highly unlikely that either detergent, or your cleaning process, is the source of the chlorine residue. The cleaning process you described, if using detergent at recommended dilution levels, should successfully remove flux and process residues.
Replacing Hazardous Acids
Q: What can I use to replace hazardous acids below pH 1 cleaning?
A: Depending on exactly what you are using your acid cleaning to do, we may be able to help you.
Neutralizing Citranox for Waste Disposal
Q. We manufacture electronics and use Citranox to cleans oil off of a variety of machined parts. However, our Municipal Water District does not allow the disposal of spent Citranox. Can you recommend a neutralization procedure?
A. You will need 0.14 lbs, 0r 2 ¼ oz of baking soda (sodium bicarbonate) to neutralize a gallon of un-used 1% Citranox solution to a pH near 7. Note that some of the acidity in Citranox may be depleted …
Cleaning Glassware with Adhesives and APIs
Q. We have glassware that contains adhesive and API dissolved in organic solvents. If we do not do additional organic rinses prior to the aqueous rinses we have issues. Is there any way we can avoid the organic rinses?
A. To avoid organic rinses, you can soak in a high emulsifying cleaner such as a 1% Alconox solution (1.25 oz/gal or 10 g/L) prior to aqueous rinsing. Ideally soak in a warm or hot solution for fastest and most reliable results. The emulsifiers in Alconox will emulsify the solvents and active pharmaceutical ingredients (API). Be sure to rinse at the same temperature you are soaking at so you do not break the emulsion and redeposit the API or solvents. If you soak hot . . .
Cleaning Adhesive Residues off Medical Devices
Q: We are looking for recommendations on how to remove adhesive residue left on medical devices after pulling off labels or tape. A. We are aware of many other customers using Detergent 8 to successfully remove different kinds of tough adhesive residues. We suggest using…