Thanks to all who commented on my wave solder hole filling questions.  I've decided that filling the 40mil holes is not the "sure thing" I had assumed.  I've ordered new probes with tips that should work on both filled and empty holes.  I guess that even simple things get complicated when you make assumptions based on limited knowledge and experience.  

Thanks for sharing,
Carl


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of James, Susan CAR
Sent: Wednesday, January 25, 2012 5:51 AM
To: [log in to unmask]
Subject: Re: [TN] TechNet Digest - 24 Jan 2012 (#2012-30)

Hi Carl,

We run thru-hole wave here and have no problem consistently filling holes that are .035" to at least 75%.  I think you have to consider a few things in your case:

With respect to the board fab:

Is there adequate plating inside the holes?
Is there debris inside the holes?
Does this occur only on a specific lot or date code?

With respect to the assembly:

Is the wave solder process in control?
Are proper handling procedures being practiced?
How often is "occasionally"?
Do you specify that these holes must be filled with solder and if so, by what percentage?

I always thought that board fab and assembly was part science and part black magic.  I'm not an assembly expert but these are some things I would begin looking at if you want to keep your current testing process. 

Regards,
Sue

Susan James
Taylor Company


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Carl VanWormer
Sent: Tuesday, January 24, 2012 1:01 PM
To: [log in to unmask]
Subject: [TN] Wave solder - filling of "empty" holes

We have a PCB assembly with a 2x5 pin "engineering" header that is not populated on our production boards.  The normal results of our CM's wave solder process yields boards with the 10 holes (.040" dia.) filled with solder.  Our pointed spring-probe test fixture hits the centers of these solder-filled holes, and all is good with the world . . .

 

Occasionally, we have some boards that do not have all of the holes filled (I can provide a picture if it helps the discussion).  The test fixture spring-probes may penetrate into the unfilled holes, making only intermittent contact with the hole-walls.  My final solution may be to obtain spring-probes with wider tips to bridge the hole, making contact with the annular ring, but I'd like to get opinions from the group as to my expectations of hole-filling in the wave solder process.  

 

I'm sure that 10mil holes will always fill, and 1000mil holes, will never fill.  What expectations should I have with my 40mil holes (in my
62 mil thick PCB)?  If the consensus is that the holes should fill, what suggestions can I give to my CM to facilitate my desired hole filling?

 

Thanks,
Carl


______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________




---------------------------------------------------

Technet Mail List provided as a service by IPC using LISTSERV 16.0

To unsubscribe, send a message to [log in to unmask] with following text in

the BODY (NOT the subject field): SIGNOFF Technet

To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)

To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest

Search the archives of previous posts at: http://listserv.ipc.org/archives

For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815

-----------------------------------------------------