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 >>
> 

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