Paul

If you are using standard FR4 you probably have reason for concern. You may want to review some other material options, those with elevated Tg and Td properties. There is quite a bit of data on the web about these materials.

Best regards

Lee

J. Lee Parker, Ph.D.
JLP Consultants LLC
804 779 3389
  ----- Original Message ----- 
  From: Black, Paul<mailto:[log in to unmask]> 
  To: [log in to unmask]<mailto:[log in to unmask]> 
  Sent: Thursday, July 21, 2005 5:34 PM
  Subject: [TN] BGA's and Lead free


  Hi Everyone,

  We are starting to redesign a product for RoHS compliance and one of our engineers has a concern. Due to the higher oven temps, he is afraid that excess warpage may occur to the board and large components, particularly the BGA's, and the resulting stress will lead to failures. He is considering increasing the thickness of the board, which would be an expensive proposition. Our largest BGA is a 19 x 19, 357 pin 1.27mm pitch part on a 7" x 9" .062" board. I know that a number of you have been working with lead free for a while. Have you had a need to increase the thickness of the board?

  Thank you, 
  Paul Black 
  Manufacturing Engineer 
  Kronos 
  E-mail: [log in to unmask]<mailto:[log in to unmask]> 

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