Hi Erat,

Here is a list of things that could be done pending the customers concurrence.
These are my suggestions which I'm sure someone will have issue with; so for
what it's worth here goes:

Reduce board thickness.
Use a Higher Tg laminate such as a High Tg tetrafunctional epoxy or Polyimide.
Try smaller pads on the holes.
Utilize a higher tensile strength copper.
Reduce the hole size.
Lower the copper concentration in the plating bath (acid copper). I have seen
this have an impact on corner cracking.

In my estimation these are somwhat in a prioritized order.

Good luck,
Les Connally
[log in to unmask]
>  From: "Erat, Wolfgang" <[log in to unmask]>, on 2/27/98 2:36 PM:
>  We have a customer which is very sensitive to separation between plated
>  copper and outerlayer foil copper (doublesided product). This condition
>  is especially visible at high pad rotation after thermal shock. What can
>  be  done to minimize / avoid this issue ?
>
>  Wolfgang Erat / Viasystems Canada
>
>  ################################################################
>  TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional
>  information.
>  For the technical support contact Dmitriy Sklyar at [log in to unmask] or
>  847-509-9700 ext.311
>  ################################################################
>
>

################################################################
TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
################################################################