LM74: Pad layout and possible issues

Danilo A.

Part Number: LM74

Hi Team,

Our customer would like to consult the pads of LM74CITP-3 which they implemented on their board. According to our customer,

I am investigating a failure traced to LM74CITP-3 in a 5-Bump DSBGA package YTA0005. It appears that the board was designed with a modified 5 pin SOT pad layout. I can get accurate dimensions.

I am wondering if this modified pad layout could be causing an issue with the part?

Please let me know what information you may need.

Regards,

Danilo

over 3 years ago

0 Eddie LaCost over 3 years ago

TI__Mastermind 40400 points

Hi Danilo,

Can you please provide the footprint dimensions that the customer has used? Gerber files or PDF with dimensions will be fine.

Our recommended footprint can be found below.

https://vendor.ultralibrarian.com/TI/embedded/?gpn=LM74&package=YTA&pin=5&sid=017817f8a5430077b97d553b377803073001306b00bd0&c=1?

0 Danilo A. over 3 years ago in reply to Eddie LaCost

TI__Mastermind 27100 points

Hi Eddie,

Thank you for your response. We just received these files from our customer showing the dimensions of the footprint.

Footprint.zip

Regards,

Danilo

0 Eddie LaCost over 3 years ago in reply to Danilo A.

TI__Mastermind 40400 points

Hi Danilo,

This footprint looks quite different from the recommended land pattern shown below. They are using square pads for a BGA package. It is recommended to use the proper footprint from the Ultra librarian link above.

It is possible that the layout they are using is causing some problem. What type of issues are they seeing?

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LM74: Pad layout and possible issues