Flux residual on joints of PIH

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Hello everyone, During our PIH process we found much flux r... - Apr 27, 2005 by

You will probably need to change paste. If I remember corre... - Apr 27, 2005 by RDR

Have you examined what type of residue is present? It is po... - Apr 27, 2005 by sarag

Hi Sarag, We share Sara's described experience with clean... - Apr 27, 2005 by

Bryan

#33911

Flux residual on joints of PIH | 27 April, 2005

Hello everyone, During our PIH process we found much flux residual around or on the joints of PIH after reflow.We use the Indium smq92j no clean solder paste.but the residual is too much to be accepted.can anybody share with me some ideas to solve the issue? Thanks a lot Regards!

Bryan

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RDR

#33915

Flux residual on joints of PIH | 27 April, 2005

You will probably need to change paste. If I remember correctly the SMQ92J has a post reflow residue of 40%. This is one of the highest post reflow residue levels available. PIH uses a lot of paste which means a lot of flux residue. There are other Mfgr that have less residue. Alpha om5100 is one example.

Russ

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sarag

#33917

Flux residual on joints of PIH | 27 April, 2005

Have you examined what type of residue is present? It is possible that what you are seeing is benign, though flux that is not fully activated often leaves harmful residue species such as chloride or weak organic acids. If you don't want to change pastes, you could look at modifying your profile to make sure the flux residues are fully heat activated, or you could even look at cleaning these residues if they are harmful or don't pass your visual criterion. No clean boards are more challenging to clean, but are indeed cleanable. If you have any other questions about the issues you are having, please contact us offline.

Regards, Sara Gorcos Foresite Inc. 1982 S. Elizabeth St. Kokomo, IN 46902 (765)457-8095 www.residues.com

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Shean Dalton

#33922

Flux residual on joints of PIH | 27 April, 2005

Hi Sarag,

We share Sara's described experience with cleaning No-Clean/Low Residue flux residues. We can add that of the Low Residue residues, Indium SMQ92J is one of the more challenging flux residues to clean. That said, we have had repeated success with this cleaning process. Should you decide to consider cleaning as a standard process or for the batch of boards produced so far, we would be happy to speak with you about our experiences and try to help you with this application.

Thanks and Have a Great Week!

Shean Dalton Austin American Technology www.aat-corp.com (512) 335-6400

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