LMT70: Recommended Solder Mask Opening

Art Mecina

Genius 16585 points

Part Number: LMT70

Hello Guys,

Good day.

Our customer wanted to know the recommended Solder Mask Opening for LMT70YFQR (DSBGA) package.

This is not included in the device datasheet. Is there anything they could use as a reference?

Thanks in advance!

Art

over 4 years ago

0 Ren Schackmann over 4 years ago

TI__Mastermind 40575 points

Hi Art,

TI recommends a Non-Solder Mask Defined (NSMD) land pattern. See ti.com/lit/snva009 page 9. Under these guidelines, the opening size is not very important. I'm sorry this isn't the answer you were looking for, but I don't think we have another published statement on this topic.

thanks,

ren

0 Art Mecina over 4 years ago in reply to Ren Schackmann

TI__Genius 16585 points

Thanks Ren!

Customer made a clarification that what he is looking for is the BGA SRO (Solder Resist Opening). It should be some reduced diameter of the BGA true ball diameter.

Is this one available?

Art

0 Ren Schackmann over 4 years ago in reply to Art Mecina

TI__Mastermind 40575 points

Hi Art,

Solder Resist and Solder Mask is the same thing. Could you please ensure customer has reviewed the information in this image? Also, ball diameter is shown on page 28 of the datasheet to be 0.25-0.28mm.

thanks,

ren

0 Art Mecina over 4 years ago in reply to Ren Schackmann

TI__Genius 16585 points

Hi Ren,

Good day.

Upon reviewing by the customer, the information, according to them won't be enough. They have sent me an image. Hopefully this will clarify it. Is this available for LMT70YFQR?

Thanks!

Art

0 Josh Wyatt over 4 years ago in reply to Art Mecina

TI__Guru* 91206 points

Art -

See page 8 of this app note, https://www.ti.com/lit/an/snva009ai/snva009ai.pdf

It has the dimensions (I think) they are asking about and it is the page prior to the one with the image that Ren shared previously.

the image posted above is referring to the connection that we take care of and should not concern them.

0 Art Mecina over 4 years ago in reply to Josh Wyatt

TI__Genius 16585 points

Thanks Josh!

I will relay the information to the customer. I will inform them of this e2e-thread in case of further inquiries.

Art

0 Collin Russell over 4 years ago in reply to Art Mecina

Prodigy 20 points

Hey Josh.

I am the one who was in contact with Art. Apparently what you guys most recently submitted still isn't sufficient for our DFM. We dont want what TI suggests as the land pattern, as we want to define our own, based on the UBM (Under Bump Metal) or SRO (Solder Resist Opening) value of the BGA itself.

Thanks,

Collin

0 Josh Wyatt over 4 years ago in reply to Collin Russell

TI__Guru* 91206 points

Collin -

Thanks for posting and welcome to E2E!

Ren is doing the research on that internally and will respond with the detail. If its not too much trouble, can you explain why you want to define this yourself? The team has seen similar requests like this in the last few months, so i am curious to know, from a customer perspective.

0 Ren Schackmann over 4 years ago in reply to Collin Russell

TI__Mastermind 40575 points

Hi Colin, Art,

As you've seen, TI doesn't publish UBM diameter. The only way I know to retrieve this information is to contact the assembly site. I did this yesterday, and got the following response overnight. There are some internal email chains circulating on this topic; hopefully we can find a way to better serve customers in this regard.

UBM diameter is 240um.

Solder ball size used is 250um diameter

thanks,

ren

0 Collin Russell over 4 years ago in reply to Ren Schackmann

Prodigy 20 points

Thank you so much Ren!

Collin

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LMT70: Recommended Solder Mask Opening