<lol>  - Well, teaches me not to be more specific!

     Thanks to all who replied about reversed and internally reversed
     (built backwards) capacitors... I've seen those, and, unfortunately
     that's not an issue here.

     Electrical surges, including negative spikes has also been ruled out.

     This issue is occurring on boards designed by different companies.

     The problems are either in the manufacture of the cap's themselves,
     or, our process is causing the failure mode of the caps either in
     creating the problem or by aggravating an existing defect.

     Thanks again!

     Rob Green




     ---------------- Original Message  -------------------------------

     We are currently experiencing a run of tantalum polarized capacitor
     failures. The caps are becoming resistive when voltage is aplied,
     drawing current, and cooking up. Sometimes this is immediate,
     sometimes over time.

     This issue primarily is affecting 12VDC power busses, and involves
     several different value and manufacturer caps.  Common threads: 12V
     circuits (the supplies themselves have been ruled out), polarized SMT
     tantalum capacitors, 35V rated.

     We have had the manufacturers involved and have exhaustively looked
     into the issue.  I know that there is a myriad amount of possible
     contributors to this problem.

     My question is simple:  Have any of you experienced this before with
     tantalum capacitors, and if so, what have you found?


     Thanks in advance!

     -------------------------------------------------------------
     Robert D. Green - Supervisor, Test Engineering
     Hadco - Value Added Manufacturing
     e-mail [log in to unmask]

################################################################
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's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################

################################################################
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's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################