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Cleaning under LCC's

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SteveH

#44256

Cleaning under LCC's | 2 October, 2006

We are having issues with cleaning underneath leadless chip carriers due to their extreme low lying nature and I wondered if anyone else had any experience of this. Our process for years has been vapour degreasing with Triklone N, which works, but we are now trying to eliminate the use of Trike in our plant and instead would like to run them through our Aquastorm 200 inline cleaner with all our other SMT products. However, trials in the inline cleaner thus far using 'fine pitch' cleaning agents such as Aquanox 4520T and Circuitkleen CK1305 have been unsuccessful. We have explored different concentration levels, temperatures and conveyor speeds but we cannot get underneath these devices. Our solder paste is Alpha RMA390 DH3 (15% rosin based).

Does anyone know of a more suitable saponifier that is able to get underneath LCC's or are we just banging our heads?

Thanks in advance

Steve

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#44271

Cleaning under LCC's | 2 October, 2006

Choices are: * Buying a helmet. * Using a paste with low residue flux.

Where are you located that you can use Triklone N [1,1,2-trichloroethene, CAS No: 79-01-6, C2HCl3]?

As a solvent replacement for Triklone, several companies offer proprietary blends based on n-propyl bromide.

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SteveH

#44314

Cleaning under LCC's | 4 October, 2006

Thanks Dave.

We are UK based which is why we are still allowed to use Trike and our product is for an aerospace application so changing a cleaning chemical is much easier than requalifying a new flux. This was pretty much what I thought my options would be though.

Steve

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RDR

#44326

Cleaning under LCC's | 4 October, 2006

Cannot see you cleaning under this type of part with aqueous no matter what you try

Russ

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Steve Gregory

#44474

Cleaning under LCC's | 11 October, 2006

Don't think there's any easy way to clean under a LCC, but you might want to consider this:

http://www.winslowautomation.com/ccmd.asp

A dead simple way to mount solder columns onto LCC's and then solder the part to the PCB with a stand-off of about .050" up off the board.

You can then clean beneath it with the added benefit of improved reliability from TCE mis-matches.

-Steve Gregory-

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#44584

Cleaning under LCC's | 17 October, 2006

Hi Steve,

I agree with you that cleaning under LCC's is often difficult but its not impossible. In order to clean the residues, the most important thing to consider is the right compatibility of the fluxes with the cleaning chemistry. There are several companies who manufacturer cleaning agents especially for cleaning under low stand-offs. The high precision cleaning agents provided by companies such as Zestron, Petroferm, Kyzen do have the ability to fulfill your requirements. Since you mentioned that you are involved with Aerospace; it offcourse is much easier to change the chemistry as compared to the flux itself. Perhaps, it wont hurt to contact other cleaning agent manufacturer's and get their opinions too. Regards, Jovial_Guy23

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