Another response,

Does the board drawing specify for etchback be used in the fabrication of
the board?  Is this implied by some other specification.  We had a similar
problem years ago and found that this was the best solution to prevent
barrel seperation.

                                        Mark Spintale
                                        Hughes Defense Communications


At 08:50 AM 9/2/97 -0500, you wrote:
>>Return-Path: <[log in to unmask]>
>>Date:         Fri, 29 Aug 1997 10:34:00 -0600
>>Reply-To: "TechNet Mail Forum." <[log in to unmask]>,
>>        Richard MacCutcheon <[log in to unmask]>
>>Sender: TechNet Mail Forum<[log in to unmask]>
>>From: Richard MacCutcheon <[log in to unmask]>
>>Organization: BFGoodrich Data Systems
>>Subject:      [TECHNET] PCB Failures
>>X-To:         [log in to unmask]
>>To: [log in to unmask]
>>
>>======== Original Message ========
>>I work in a material and failure analysis lab for Lockheed Martin.
>>        We have a set of PCBs that are failing after hand soldering
>>operations.
>>Similar hand soldering operations on other boards are successful. Cross
>>sections of the failed areas shows pad lifting and a seperation of the
>>barrel and innerconnection on layer 5. The board is a 6 layer glass
>>epoxy GFG board. Suspect problem with board material between layers 5 &
>>6.
>>        Looking for information on types of tests to run, printed material
>>relating to testing PCBs, or other sources for information.
>>        Thank You.
>>
>>        Russ Salvo
>>======== Fwd by: Richard MacCu ========
>>Is there only one operator doing the soldering or many?
>>
>>If there are many, check all iron temps and specifically check the operator
>>who incurred the failure.  I have experienced a case where one employee was
>>not following correct procedure even after seven years of service.
>>
>>The other item to check is if there were mixed lots of laminate involved.
>>If so have the vendor of the laminate retest a sample for cure of the resin.
>>
>>
>
>
----------------------------------
Mark W. Spitnale                Phone: (219) 429-5992   Fax: (219) 429-4688
Hughes Defense Communications                           Mail Stop: 25-31
1010 Production Road, Fort Wayne, IN 46808-4106
Email: [log in to unmask]