Subject: | |
From: | |
Reply To: | TechNet E-Mail Forum. |
Date: | Wed, 10 Nov 1999 15:44:19 -0500 |
Content-Type: | text/plain |
Parts/Attachments: |
|
|
Paul:
Anytime I've seen volcanic type voids as you have described generally points
to moisture trapped inside the board near the plated thru hole. Try baking a
board for a couple of hours at 225° - 250°F, then re-run. If the problem
persists then all I can say is that there are volitiles trapped inside your
PWB and nothing can be done to remove them except to talk to your board
supplier. (or find a new one !)
Bill Kasprzak
Moog Inc.
> -----Original Message-----
> From: Paul Tomlinson [SMTP:[log in to unmask]]
> Sent: Wednesday, November 10, 1999 10:57 AM
> To: [log in to unmask]
> Subject: [TN] Voids after Wave-Soldering!
>
> Hi folks,
>
> I am just learning about these matters, and this is THE place where
> knowledge and experience abounds so please somebody help me with this.
>
>
> I have just had my first ever boards waved and the results are not
> encouraging. What could be the cause of a volcano shaped void between the
> component leads being soldered and the main body of the solder?
>
>
> There is perfect continuity, the area at the tip and that around the board
> are well wetted, but mechanically the joints are very weak and prone to
> failure, the parts can actually be pulled out of the board without being
> damage.
>
>
> Could this be simply the result of a too low temperatured wave? They used
> 465F.
>
> | |
> | |
> | |
> --------------------- | | -------------------
> | | | |
> | | | |
> | | | |
> --------------------- | | -------------------
> * * | | * *
> * *V | | V * *
> * * O | | O * *
> * * I | | I * *
> * * D | | D * *
> * * | | * *
> * * | | * *
> * *| | * *
> * | | *
> *| |*
> ---------
>
> This ASCII art is extremely crude so I have attached both JPG and BMP
> files
> of a much better drawing.
>
> Tia,
>
> Paul. << File: lead.bmp >> << File: lead.jpg >> << File: ATT15807.txt >>
>
##############################################################
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 Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################
|
|
|