| | | I believe that gold fingers on my circuit boards are being | | | contaminated and need to clean them with some chemical | | | solution. Any recommendations. | | | | | Chuck: What is the type and source of your contamination? Dave F | | We are using a silicone uv cure for die wire bond encapsulant. | also a kapton tape with silicone adhesive to protect fingers through wave solder. Also possible contamination due to oxidation through time.
Chuck:
I think IPC has some spec. on adhesive used for kapton (for masking/laminating [flex] purpose) tape. we had a lot of problem on the gold fingers as we were using normal 3M tape (yes ! from the drug store) for gold peel test which in turn leaves the adhesive residue behind, contaminating the fingers itself. Our rework process was to wash it with a non-aggresive cleaning solution (Isopropanol) (depents on your facility and cust. qual/cert reqrmnt.) and lint-free material. Level of contamination can be found out by using any method stated in IPC -TM 650.
An eraser can help you a lot but can be used only in moderation and is not recommended (in some facilities and application) for immersion gold or plating under 10 u inches.
Re-plating can be done by using any gold contact plating system(CEPS-connector edge plating system) can be found in IPC -R 700 or Circuit technology center - Document # CRC-20.
I think gold plating and surface cleanliness requirement spec for bonding (gold purity) is different than edge connector but dont quote me on that.
Hope that helps.
Regards Kc. | |
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