HOME FAQs BOOKS JOBS: Help Wanted Suggestions you are here: Hotline/Forum => Letter 27074

Solderability problem with tin plating

++++

We know that tin plating gives excellent solderability but recently we have encountered difficult solderability at our tin plating (iron base substrate) electrical terminal. I would like to know what has caused the difficult solderability of the tin plating? I do not reckon is the formation of oxide layer as our SEM/EDX result does not detect the presence of oxygen.

Thank you.

Maung San Zaw
Engineer - Singapore

++++

It would be handy to see the parts concerned, but if this is not possible, so be it. I am surprised there is no evidence of oxygen on the tin because tin easily forms an oxide. What other elements have been detected? I wonder if insufficient tin has been put down and when you have heated the tinned substrate as you solder, the tin has diffused into the iron base to form iron-tin alloys. This could easily cause problems with solder as the iron-tin alloy does not wet as easily as iron.

Trevor Crichton
R&D practical scientist The Pheasantries - Chesham, U.K.

ANSWER or FOLLOW UP POST an unrelated QUESTION HOT Topics

Disclaimer: It is not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information
presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The
internet is largely anonymous; some names may be fictitious and some recommendations may be deliberately harmful.

If you are seeking a product or service related to metal finishing, please check these Directories: