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Solderability Issues

Solderability Issues

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Recently we have expereinced solder issues with our reflow p... - Jul 20, 2010 by Craig

It is likely that the pads that will not solder have been co... - Jul 22, 2010 by dyoungquist

by viewing your posting i came to know this is solder abili... - Jul 23, 2010 by JOSEPH PJ

> by viewing your posting i came to know this is > ... - Jul 28, 2010 by Craig

I took a pad that did not have any solder flow (wetting issu... - Jul 28, 2010 by Craig

What surface finish are you using? ... - Jul 28, 2010 by brad

I believe it is LF HASL. I will need to double check. ... - Aug 02, 2010 by Craig

Craig, If it is LF Hasl it sounds like it applied too thi... - Aug 03, 2010 by brad

IPC TM 650- Solderability of Metallic Surfaces ... - Aug 09, 2010 by Mark

Types of PCB Finish ... - Aug 09, 2010 by Mark

Try tinning pads with a high pH water soluble flux like Kest... - Aug 09, 2010 by Dennis O'Donnell

Boards with the LF hasl finish applied too thin will genrall... - Aug 13, 2010 by brad

Craig

#62284

Solderability Issues | 20 July, 2010

Recently we have expereinced solder issues with our reflow process. The issue is random and doesn't effect every assembly.

I'm seeing extreme solder wicking, no solder flow onto the pads, only onto the leads of the components.

I have tried to hand solder and am unable to hand solder. The same solder wick issue occurs. Due to this fact, I'm leaning away from process. I have not checked a board that has not gone through reflow soldering.

Any ideas are greatly appreciated.

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dyoungquist

#62298

Solderability Issues | 22 July, 2010

It is likely that the pads that will not solder have been contaminated. There is something on the surface that is preventing the solder from flowing.

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JOSEPH PJ

#62299

Solderability Issues | 23 July, 2010

by viewing your posting i came to know this is solder ability issue which is because of marginable solder ability of PCB / components,

just ensure that issue due to PCB or component . check the msl of of substrate / component. verify the baking requirement . with regards joseph

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Craig

#62333

Solderability Issues | 28 July, 2010

> by viewing your posting i came to know this is > solder ability issue which is because of > marginable solder ability of PCB / > components, > > just ensure that issue due to > PCB or component . check the msl of of substrate > / component. verify the baking requirement . > with regards joseph

I have another thread going about warp issues from our supplier. It is possible they have tried to correct the issue by baking and have caused these effects we are seeing.

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Craig

#62334

Solderability Issues | 28 July, 2010

I took a pad that did not have any solder flow (wetting issue with pad) and not reworkable with soldering iron, and scraped with an exacto knife. After scraping the pad soldered fine.

Any suggestions?

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brad

#62335

Solderability Issues | 28 July, 2010

What surface finish are you using?

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Craig

#62352

Solderability Issues | 2 August, 2010

I believe it is LF HASL. I will need to double check.

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brad

#62375

Solderability Issues | 3 August, 2010

Craig,

If it is LF Hasl it sounds like it applied too thin exposing the intermetallic layer wich is not solderable. We call out a minimum thickness of 80 microinches and have good results. We have had shops in the past that did not control the Hasl thickness and had the problems you are describing.

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Mark

#62402

Solderability Issues | 9 August, 2010

IPC TM 650- Solderability of Metallic Surfaces http://www.shanelo.co.za/List%20of%20articles/IPC%202.4.14%20Solderability%20of%20Metalic%20Surfaces.pdf

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Mark

#62403

Solderability Issues | 9 August, 2010

Types of PCB Finish http://www.shanelo.co.za/types_of_pcb_finishes.htm

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Dennis O'Donnell

#62405

Solderability Issues | 9 August, 2010

Try tinning pads with a high pH water soluble flux like Kester 2331-ZX or Alpha Metals 3355-HB is what we use. It will remove the contamination quick;y without having to scrape with a blade. If you have a large number of bare boards you can run them through a wave solder machine with said flux and tin pads in high volume. I send them out to get Air Solder Leveled and specify the flux I want used.

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brad

#62436

Solderability Issues | 13 August, 2010

Boards with the LF hasl finish applied too thin will genrally pass the IPC test. That is some pretty agressive flux they call out. The boards usually wave solder just fine as well. Reflow is where the you see the problem.

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