Hello Rick,

This has been done successfully by a number of contract assemblers. A
fixture is required for the second side assembly but no adhesive is used.
The surface tension of the solder holds the µBGA® CSPs in place dirong
second side reflow.

Kind regards,
J. Fjelstad  


At 03:03 PM 10/30/98 -0800, you wrote:
>We've been asked by a customer to run boards with Intel uBGA flash memory on
>both sides of the board. My first impression was that the mass of the part
>vs. the ball area would not provide sufficient tension to hold the bottom
>side parts in place when reflowing the top. However, the customer does not
>want epoxy used to attach the bottom side parts due to shock testing they
>have to perform.
>
>Question: Anyone using these parts successfully on bottom side SMT?
>Anything I should watch out for?  The components in question are 7.67mm x
>16.37mm with a 56 ball array in the center. Ball width is .35mm with a .75mm
>pitch.
>
>Thanks in advance.
>
>                Rick Thompson
>                Ventura Electronics Assembly
>                2665A Park Center Dr.
>                Simi Valley, CA 93065
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