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Solder mask bridge issue

From what I understand, PCB manufacturing has a limitation on the minimum width of the solder resist—it cannot be too thin, typically not less than 5 mil. In many components, including those with a 0.65 mm pitch, the spacing between pads can become smaller than 5 mil.

This reduction in spacing is due not only to the proximity of the pads but also to the **solder mask opening**—the larger it is (e.g., a common value is 4 mil), the smaller the remaining solder mask bridge. However, this issue persists even when the solder mask opening is as small as 2 mil.

For example, I am currently working with the **NCP730BMT280TBG** (LDO, see two images below) and the **PMPB15XP** (P-channel MOSFET, see last image below). Both of these components have tight pad spacing, making it difficult to maintain a sufficient solder mask bridge between them.

Is my understanding correct? If so, how is this issue typically addressed?

Additionally, I'd like to clarify terminology: Does "SM bridge" mean the same as "SM sliver," and is this the issue I am describing here?

What are the recommended design practices for professional manufacturing (without strict compliance to specific standards)? What is commonly accepted in various industries?

Thanks in advanced to any answer,

Eyal





![NCP730 recommended footprint](https://electrical.codidact.com/uploads/wvgnrb7znok7rtvw2pp0dul7e0ha)




![NCP730 measurement between pad and EP = 4.47 mil](https://electrical.codidact.com/uploads/6fb5mspaicszlkifhwsefgjzzo7p)




![PMPB15XP recommended footprint](https://electrical.codidact.com/uploads/q1zzvte9e9i4jbtwquqv4hpxbkaj)