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Conversion to no-clean solder paste

Kris W


Conversion to no-clean solder paste | 24 January, 2000

To all,

This may appear to be laziness on my part, but I need to ask for some advice. We are in the process of qualifying no-clean solder paste to replace or current RMA paste. I have performed qualification runs and extensive reliability testing through our largest customer, but I need to put together an implementation plan for the big wigs at our company.

I am looking for a source for documentation that may describe some of the trials and tribulations that other companies have encountered during their no-clean conversions. It is important that I develop this plan quickly (by month end), but I have encountered a bit of a writer's block! I don't intend to plaigerize or plunder another company's confidential records, so I will only use publically available material.

Any help would be deeply appreciated!!!!

Kris W.

Any help would be deeply appreciated

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Re: Conversion to no-clean solder paste | 25 January, 2000

Kris: I can appreciate your hesitance. Done correctly with proper planting and fore thought, the change to no-clean affects every part of your operations operations from purchasing to receiving and on down the line. Two things:

1 Following with your thought about "not want to re-invent the wheel." Why doesn't your new flux, paste supplier provide you with a plan? They must have heard your story a billion times. Even if they don't have a nice plan for you, surely they can get-off their cans and get one (by tomorrow ;-)) from one of their other customers that already went through this ... for all the money they're going to be making off you. Yakno? 2 Look in your Combs "Printed Circuits Handbook." Chapter 30 addresses "No-Clean Assembly Process." Pages 30.4 through 30.10 talks to "Implementing No-Clean."

Y'all have fun writing your plan. I just love doing those things too!!!! ;-)

Dave F

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Re: Conversion to no-clean solder paste | 25 January, 2000

When switching from cleaning RMA to a no-clean flux, one area that is commonly overlooked is the stencil cleaning operation. Stencil cleaners that are effective in cleaning RMA often fail when cleaning no-clean (especially alcohol cleaners).

Pallets that were cleaned when the PCBs were cleaned are going to accumulate flux residue in a no-clean process.

What else are you cleaning in your PCB cleaner? How will these items be cleaned when the PCB cleaner goes away? What other waste streams might develop?

Like your solder paste supplier, I see it happen everyday.

Good luck. Bill

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Dave H


Re: Conversion to no-clean solder paste | 25 January, 2000

Kris, Weigh very carefully the above caveat with regard to IPA. I would ask for documentation to substantiate this claim, which likely stems from a desire to sell "his" chemistry, while "slamming" competition. I'll be happy to run some tests for you on various no cleans you may choose. Dave

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