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Select SMD or NSMD pad type for BGA package - KBA233770

Chelladurai
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Select SMD or NSMD pad type for BGA package - KBA233770

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Two types of land pad patterns are solder mask defined (SMD) pad and non-solder mask defined (NSMD) pad. The land pad pattern type differs depending on the solder mask opening.

Consider the following table to select a PCB land pad pattern type when designing hardware with BGA package FAB024. See Figure 1.

Solder mask defined (SMD) pad type

Non-solder mask defined (NSMD) pad type

In SMD pad type, the solder mask opening is smaller than the metal ball land pad.

In NSMD pad type, the solder mask opening is bigger than the metal ball land pad.

Select the SMD pad type to minimize underfill issues during the surface mount assembly process.

Select the NSMD pad type when board-level mechanical performance is important.

The solder mask prevents solder to spill over the pad’s edge.

There is a gap between solder pad and solder mask in which the solder flows and strengthens the bond.

 

Chelladurai_1-1631534189526.png

 

Figure 1

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‎Sep 13, 2021 05:01 AM
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