A thin prepreg layer is the most common HDI substrate. It provides good reliability, process-ability and reasonable cost.
The typical thickness of a prepreg HDI layer is 60u +/-20u. Typical laser hole diameter (drilled top) is 100 – 150u.
![](https://aspocomp.com/wp-content/uploads/2020/03/prepreg1.gif)
A thin prepreg layer is the most common HDI substrate. It provides good reliability, process-ability and reasonable cost.
The typical thickness of a prepreg HDI layer is 60u +/-20u. Typical laser hole diameter (drilled top) is 100 – 150u.