LMR38020: solder skip

Allan Fan

Part Number: LMR38020

Tool/software:

Hi expert,

Customer used LMR38020 and report there are some solder empty issue for thermal PAD due to the small 0.25mm height from the pin leg.

Would you please provide any advice to improve the assembly?

Regards,

Allan

7 months ago

0 Richard Fu22 7 months ago

TI__Mastermind 27740 points

Hi Allan,

Can you clarify the issue a bit more? Is the customer not able to solder the thermal pad?

Regards,

Richard

0 Ryan Chen 7 months ago

Prodigy 20 points

Hi Richard

The SMT factory reported that because there is a 0.1mm drop between the Pin and the E-pad in the Z-axis height, the E-pad will be partially soldered.

0 David Baba 7 months ago in reply to Ryan Chen

TI__Mastermind 36040 points

Hello Ryan,

Apologies for the delay, someone will respond in 24 hours, as its a public holiday today in the USA. Thanks.

David.

0 Richard Fu22 7 months ago in reply to Ryan Chen

TI__Mastermind 27740 points

Hi Ryan,

I'm afraid it is not entirely clear to me, since the LMR38020 should not require any different reflow profile than what is usually used for conventionally packaged parts. TI recommends a minimum solder joint area of 50% of the package thermal area. The performance improvement from there is usually negligible. Please see section 3 of this app note: https://www.ti.com/lit/an/slma002h/slma002h.pdf?ts=1725402766242&ref_url=https%253A%252F%252Fwww.google.com%252F

Thanks,

Richard

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LMR38020: solder skip