Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


upinder singh

#14837

Pin in hole process problem | 28 July, 1998

Hello everybody. Remember I posted some questions on the smtnet regarding placing the thru hole connector using paste and reflow(pin in hole). I have able to accomplish the process succcesfully.....but I have a problem. The boards are failing at the in-circuit testing due to flux build up on the connector pins because of the paste process. If u clean wash the board..it passes. Can anybody help me in this , other than recommending the cleaning .....like any special testing probes available or anything else. Need help desperately. Rgds Upinder

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Steve Gregory

#14839

Re: Pin in hole process problem | 28 July, 1998

| Hello everybody. | Remember I posted some questions on the smtnet regarding placing the thru hole connector using paste and reflow(pin in hole). I have able to accomplish the process succcesfully.....but I have a problem. The boards are failing at the in-circuit testing due to flux build up on the connector pins because of the paste process. If u clean wash the board..it passes. | Can anybody help me in this , other than recommending the cleaning .....like any special testing probes available or anything else. | Need help desperately. | Rgds | Upinder Hi there Upinder! Yep, that's the one pain-in-the-you-know-what with no clean...ICT problems. The residue is insulative, so when it builds up on the probes you can't test...but who really needs test anyway, we always build things right...right? (snicker..) Your problem is not all that unusual, it happens to everybody. No clean requires more maintenance on your fixtures just for that reason. There's a company called Ingun that makes some good probes. They have all kinds of styles of tips, and they have this trademarked plating they call "Aurun" that is supposed to be more chemical resistant than any other type. They also do the "twist-style" plungers that were made for no-clean or heavily oxidized boards. When the board is placed into the fixture, and the vacuum turned on, the probe socket has a little spiral keyway that a key, or nub from the probe goes into, and as the board is sucked down, the probe rotates breaking through any residue, oxidation, or contamination to ensure good contact. They have a office in Charlotte North Carolina (Phone number: 704-329-0444) and they have a WEB site too: www.ingun.com I've put the link below.... -Steve Gregory-

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David Spilker

#14838

Re: Pin in hole process problem | 29 July, 1998

| Hello everybody. | Remember I posted some questions on the smtnet regarding placing the thru hole connector using paste and reflow(pin in hole). I have able to accomplish the process succcesfully.....but I have a problem. The boards are failing at the in-circuit testing due to flux build up on the connector pins because of the paste process. If u clean wash the board..it passes. | Can anybody help me in this , other than recommending the cleaning .....like any special testing probes available or anything else. | Need help desperately. | Rgds | Upinder

Check your solder paste to be sure it is considered a no clean paste. You can also try high pressure contacts on your ICT fixture for the pins in question. Also, you can consider creating test pads for these points.

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