Hi,
We have been having some problesm with pinholes and they don't seem
to go away. We've tried different boards, different components,
checked the RH in the facility, checked the oven profiles.
Still we have not been able to determine the root cause of the
problem. The experiments point towards a few components, but
we're not sure as the problem is widespread over all components.
I would assume the problem is with an organic film forming on the
component film which results in outgassing during wave-solder.
Now how this film gets onto the leads is unclear, is from the
manufacturing process from the component vendor, or is it from
our process in house.
Would moisture be a major contributor to this problem. The air
we have actually is very dry running at around 40-50% RH.
Could we anticipate a problem with the quality of the Solder paste
from our vendor. Although we have tried different solder pastes
and we have the same results.
Anybody out there with experience with pinholes.
AN.
>From: "Dieselberg, Ron" <[log in to unmask]>
>Reply-To: "TechNet E-Mail Forum." <[log in to unmask]>, "Dieselberg,
>Ron" <[log in to unmask]>
>To: [log in to unmask]
>Subject: Re: [TN] Blow Holes
>Date: Thu, 10 Aug 2000 06:32:12 -0400
>
>Yes, Cara, if the board has not been properly cleaned and baked prior to
>assembly you will get blow holes! Check the holes, (assume PTH) with a good
>high power stereo microscope, for foreign material. Taping a small ball
>bearing to the backside of the board and viewing into the topside of the
>hole will give you a "fish eye" view of the entire barrel. If you find
>"crud" in the holes determine what the material is and clean it out. (After
>solvent cleaning blow dry the holes with dry Nitrogen.) It works for us :-)
>
>Ron Dieselberg
>BAE SYSTEMS
>Cincinnati Electronics Corp.
>
>-----Original Message-----
>From: Cara.Startek [mailto:[log in to unmask]]
>Sent: Wednesday, August 09, 2000 14:52
>To: [log in to unmask]
>Subject: [TN] Blow Holes
>
>
>I'm having a problem with blow holes occurring in a thick board that I'm
>running on a wave solder machine. As a test I am going to bake the boards
>for 24hrs to remove moisture from the board and eliminate this as a cause
>of
>the problem. Is there any thing else that cold be causing blow holes?
>
>Cara Startek
>
>Process Engineering
>http://www.leitch.com
>
>##############################################################
>TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
>##############################################################
>To subscribe/unsubscribe, send a message to [log in to unmask] with following
>text in
>the body:
>To subscribe: SUBSCRIBE TECHNET <your full name>
>To unsubscribe: SIGNOFF TECHNET
>##############################################################
>Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
>additional
>information.
>If you need assistance - contact Keach Sasamori at [log in to unmask] or
>847-509-9700 ext.5315
>##############################################################
>
>##############################################################
>TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
>##############################################################
>To subscribe/unsubscribe, send a message to [log in to unmask] with following
>text in
>the body:
>To subscribe: SUBSCRIBE TECHNET <your full name>
>To unsubscribe: SIGNOFF TECHNET
>##############################################################
>Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
>additional
>information.
>If you need assistance - contact Keach Sasamori at [log in to unmask] or
>847-509-9700 ext.5315
>##############################################################
________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe: SUBSCRIBE TECHNET <your full name>
To unsubscribe: SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
##############################################################
|
