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Forum: Reliability & Maintainability Questions and Answers

Topic: Reliability & Maintainability Questions and Answers

Topic Posted by: Reliability & Maintainability Forum (src_forum@alionscience.com )
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998

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Original Message:

Posted by: Richard Golek (rgolek@molex.com )
Organization:Molex
Date posted: Wed Jun 13 19:20:34 US/Eastern 2001
Subject: Solder of leads on low power VCSEL laser diodes
Message:
Hand soldering of 0.019 dia VCSEL laser diode pins (usually in TO-46 packages)to solder pads on small PC boards is a common practice. Some laser diode manufacturers however advise against this method and recommend using connectors, while others provide solderability specs. I am interested in hearing from anyone on laser diode reliability issues related to the use of hand soldering, and also any ESD damage observed due to this method. Thank you.


Reply:

Subject: Laser Diode Soldering
Reply Posted by: Bruce Dudley (bdudley@alionscience.com )
Organization: Reliability Analysis Center
Date Posted: Thu Jun 14 14:34:42 US/Eastern 2001
Message:
The reliability problem is not so much the diode, but is the hand soldering. Using hand solder techniques means that there is the possibility of significant temperature stresses (hundreds of degrees C) being applied to the device in question through the lead. Automated solder techniques can be regulated to minimize the temperature rise and the stress applied to any device. Hand soldering is a random time and heat variable, with over-heating being a real possibility. The use of connectors or sockets removes the possible temperature over-stress situation and should result in less failures. Sockets and connectors do introduce another possible failure mode; that is, lead mechanical fracturing as a result of handling during manufacturing.


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