Summary for tin plating pinholes Discussion
Tin plating pinholes are the central concern here: Pankaj Agarwal asked why tin-coated copper-clad steel transformer pins solder fine by hand but show pinholes during customer wave soldering, especially during the rainy season. He also asked whether finished parts can be deoxidized and retinned, how to check tin-plating porosity in-house, and whether salt spray can predict high-humidity/high-temperature life. The thread excerpt provided does not include any answers, so no corrective method or test recommendation is stated in the source. The practical issue raised is that the parts may have surface oxidation or plating porosity that only becomes visible under wave soldering conditions, and the user is seeking a non-destructive way to verify plating quality on finished components.
July 26, 2018
Q. We manufacture PCB mountable transformers.The wire is terminated on tin plated pins with diameter 0.7mm and length 6mm. The pins are tin coated CCS i.e Copper Clad Steel. I am not sure of the thickness of copper cladding and tin plating.
When we do soldering at our works, the wire gets soldered properly to the pins and the surface looks smooth with naked eye. However when my customer puts our component on PCB and does wave soldering, pin holes appear in the solder indicating corrosion of the pins at the point of pin hole.
It is to be noted that this has happened for the first time in this month and the reason for this is rainy season.
I have following queries:
1.) I am desperately looking out for a way to reuse this material. Is there a way I can remove this oxidation and do tinning again. We cannot wet these pieces as in doing electroplating again as these are finished pieces we are talking about.
2.) Is there a way to check for porosity in tin plating in house?
3.) How do I check the quality of tin plating for life / corrosion in High Humidity High Temperature condition, does salt spray test work for testing this condition?
Thanks
Pankaj Agarwal
– Ghaziabad, UP, India