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not good soldering

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not good soldering | 29 August, 2018

Dear All

We are using structural similar type of connector in A & B product with same set parameter in selective soldering machine but result in B product is not good. Observation – Plating on A product Connector terminal done on all 4 side But In B product connector plating done on 2 side only, which may cause this solderbility issue.

Please suggest me how to improve soldering quality in B product, can we get result with more aggressive flux or else ………


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not good soldering | 29 August, 2018

What type of flux are you using today? - Obviously you have already outlined the difference in the parent materials and parent material preparation, so using the same program/profile will not work; the characteristics are different.

Try increasing preheat time or investing in an inexpensive solder pot and pre-tin them properly. - Was this how the supplier offered/sold them to you? or - did you switch suppliers?

- If they are from the same supplier, I would contact them and asked what changed within their process. They should simply be able to get you properly tinned pins and replace the defective ones.

You certainly could migrate to a more aggressive flux - but to what avail? - I do not know about your final product but I would be wary of changing fluxes so quickly without regards to other processes going on after soldering (eg. Conformal Coatings). Typically you will need to clean the part after soldering if you migrate to a more aggressive flux type. If your team is dead set on creating a "work around" rather than getting the "properly prepared parts", perhaps the first step would be to apply more flux (of the currently used flux chemistry) and increase preheat time. Then let us know the result.

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not good soldering | 7 September, 2018

thanks for your input

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not good soldering | 9 September, 2018

I have found the paste flux is the worst. It leaves a black residue that can corrode.

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not good soldering | 17 September, 2018

M_, the parts may be similar but the boards look to be different. Is the thermal relief for each lead on each board the same? what is the board finish, HASL, Enig, OSP or other? The part itself may not be your problem but the part that is partial plated is of concern and a check of your supplier should be done.

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