XC5VLX50T-1FF665I FPGA - Metal shield torn off part

[jace_astro]

Hello,

In our application, we add a thermal pad to the top of this part and then apply a cover on top of the pad. The pad then compresses on top of the component. When we have removed the cover, we found that the shield was torn off the part. I have attached some images showing the issue. Is there a specification for the pressure that we can apply to the top of this component? 

[bpatil]

Hello @jace_astro 

Kindly check https://www.xilinx.com/support/documentation/application_notes/xapp426.pdf (Page 13).

[tenzinc]

@jace_astro , Page 11 of the XAPP426 maybe more applicable as it references removal of the HS including recommending heating the HS to loosen the any TIM material between the HS and the package lid. Other than that in regards to the package pressure handing capacity I'd recommend using a screwdriver with “smart torque” to assemble which should help limit the over stress during assembly but also the amount of pressure is related to how fast the case is assembled. Slowing that down helps flatten the pressure curve. You could also perform strain gauge testing and limit the strain. It may also be worthwhile to use a die and pry technique to ensure the balls do not crack or show other abnormalities.

Regards,

T