TMP103: ball size issue

Tommy Tzeng

Part Number: TMP103

Hi Sir,

may i know what the ball size of TMP103 is base on calculate the PCB_PAD size? have any specification or data for reference?

IC Ball size is Ø0.23, tolerance is +/-0.02 ? so we must be to reach 0.25 for maximum PCB_PAD size?right?

and could provide SMD and NSMD relate data or information?thanks for your great help.

over 5 years ago

0 Josh Wyatt over 5 years ago

TI__Guru* 91206 points

Dear Tommy -

the image you posted is the land pattern for the TMP103, which is the spec to follow for board layout - if you scroll back up to the page directly before where you found this, you will find the dimensioned drawing of the part, which includes the size of the balls on the device.

Further - on the product page, under CAD/CAE symbols tab, you will find this link, https://vendor.ultralibrarian.com/ti/embedded?vdrPN=TMP103AYFFR&sid=0160569dc37f001012e0fc60ef8004072002006a00978&c=1

this is offered online with the intent of making it easy to design the PCB.

0 Tommy Tzeng over 5 years ago in reply to Josh Wyatt

Genius 5780 points

Hi Josh,

thanks for your reply, there are define of SMD and NSMD in the datasheet,but is there a reason for this define or reference specification?

0 Josh Wyatt over 5 years ago in reply to Tommy Tzeng

TI__Guru* 91206 points

Dear Tommy -

The reason is for part connection reliability and reduce stress on the part from being attached. For additional reference, please see:

http://www.ti.com/lit/an/snva009ai/snva009ai.pdf

0 Tommy Tzeng over 5 years ago in reply to Josh Wyatt

Genius 5780 points

Hi Josh,

the Generally recommend PCB PAD size baes on the diameter or opening of the ball? which one?

0 Josh Wyatt over 5 years ago in reply to Tommy Tzeng

TI__Guru* 91206 points

Tommy -

The land pattern example should be followed. (this is towards the end of the datasheet, also at this direct link, second page: http://www.ti.com/lit/ml/mxbg345/mxbg345.pdf)

The recommendation is made for 0.23 size landing for the question you are asking. Hopefully you can see from that document that if the balls diameter is from 0.3 to 0.2 diameter, and the land is supposed to be 0.23+/-0.02, which results in the soldermask opening to be also 0.23, then that scenario is closer to ball opening diagram if balls on parts are >~0.25 and roughly the diameter if they are on the smaller side and that this covers the range of what is specified from the variation of a 300µm solder ball. hope that helps

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TMP103: ball size issue