Dear Technos,

 

What is the rationale behind the 100% wetting on the termination edges, as required by 8.2.14 of IPC-A-610D? I see the request is still there in rev E.

 

Here's my case: due to window panning of the stencil apertures on the thermal planes, often one could see a discontinuity in the end joint, where there's no paste printed. Then, if the DPAKs are on the first reflowed side, when they go in the oven upside down, for the second reflow, they tend to lift slightly, leaving occasional blow holes.

Due to the 100% wetting requirement, all the above discontinuities are reasons for reject by our or our customers QC departments, so we waste our time touching up.

 

I mean, we only deal with a thermal connection over a large surface and signs of good wetting should be enough, even if there are discontinuities in the end joint.

 

How do you deal with this?

 

Thanks,

 

Ioan Tempea, ing.
Ingénieur Principal de Fabrication / Senior Manufacturing Engineer
T | 450.967.7100 ext.244
E | [log in to unmask] <mailto:[log in to unmask]>  
W | www.digico.cc <http://www.digico.cc/> 

 
 N'imprimer que si nécessaire - Print only if you must

 


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

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------