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LM317L: mechanical stress LM317LITP (6-Pin DSBGA)

Nico Lichtenstein
Prodigy 10 points
Part Number: LM317L

Tool/software:

Hello,

we use the LM317LITP component (DSBGA (YPB) with 6 pins). The first samples have been manufactured, but unfortunately, there are problems with the component's soldering. Under slight mechanical stress, the balls detach from the package. However, the tin remains on the PCB. Are there any information how much mechanical stress the component can withstand?

Is there a technical report that shows how much force the component can exert? We need this to discuss it with the end customer.

Thank you

  • 0
    TI__Expert 4891 points

    Hey Nico,

    Reaching out the packaging team to get an answer for you, please allow 2 business days for an update. 

    Thanks,

    Vahnroy

  • 0 in reply to Vahnroy Hosear
    TI__Expert 4891 points

    Hey Nico,

    This is what I recieved from the packaging team

    More information on this issue would be required to make a proper assessment, but answering the question:

    At the device level, all wafer lots have a solder ball shear test after bump to validate the process.  The min ball shear that a ball should report is 3182 gf/mm2.  

    The device also goes through a qualification process where the package is stressed to different conditions.  The details on the qualification can be found at this  link

     

    In order to do a better assessment, answers to the following questions would be helpful:

    • What is the stress condition used and referred as “slight mechanical stress”?
    • When the solder balls were detached from the package
      • What solder balls were detached from the package ( ll the solder balls, some of them, only corner balls? 
      • What type of failure was observed (cohesive or adhesive)  and what is the interphase of separation?
        • Are there any  images of this (Cross section, and image of the ball and the device post separation?
      • What was the reflow profile used for SMT?
      • Have the guidelines for PCB design  been followed? 
        • A much larger land pad size in the PCB to the recommended  would result in a stress concentration at the die size; 
      • Does the device shows some damage (like die crack, chipping,  ball dents,  etc)  near the area where the ball separated ?

    Thanks,

    Vahnroy