Recommended Land Pattern for LIS2HH12TR

[juliano]

Posted on August 09, 2016 at 00:05

What is the recommended land pattern for 

LIS2HH12TR (LGA12)?

[Miroslav BATEK]

Posted on August 09, 2016 at 09:49

Please see technical note TN0018

/resource/en/technical_note/cd00134799.pdf

On page 5 you can find basic rules for land pattern dimensions.

Best regards

Miroslav

[juliano]

Posted on August 09, 2016 at 19:03

Hi Miroslav,

Thanks. I designed the footprint as per the technical note, but the solder mask between the pads are overlapping. Is that ok? ________________ Attachments : SM_Overlap.png : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HyrN&d=%2Fa%2F0X0000000bK7%2FGBw5XBwl1cK61N9Lmip3lDYIh9OUL_1fjR9cmTagYvQ&asPdf=false

[Miroslav BATEK]

Posted on August 10, 2016 at 11:47

Basically it means, there won’t be any solder mask between the pads. It is ok for prototyping.

You should discuss it with your PCB manufacturer and assembly plant. If they are able to make narrow solder mask you can modify the solder mask expansion to have solder mask also between pads. For example I use following settings:

A = PCB land length = LGA solder pin length + 0.1 mm

B = PCB land width = LGA solder pin width + 0.05 mmC = Solder mask opening length = PCB land length + 0.05 mmD = Solder mask opening width = PCB land width + 0.05 mm

Best regards

Miroslav