What aspect of the via is the ‘Capture Pad’?
The capture pad provides a landing area for the lasers. It connects the via with external traces, facilitating the transfer of electrical signals between PCB layers. The capture pad also enlarges the surface area around the via barrel, improving solderability and ensuring a robust and reliable connection.
The rule of thumb for capture pad diameter is 4 mil over the drill size. For example, if the drill diameter is 6 mil, the capture pad will be 10 mil.
Would the 3-6 drilled core vias enhance reliability?
Using a 3-6 drilled core for vias would indeed contribute to sub-assembly reliability.
Will you do 3D sip work?
Yes, we work on 3D system-in-package structure?
Is there a risk of oxidation when back drilling through the annular ring, given a drill size of 10 mils, finishing at 7 mils, and an annular ring size of 20 mils, resulting in a back drill diameter of 12 mils?
I don’t think there’s a significant risk of oxidation when back drilling through the annular ring with those dimensions. However, to ensure optimal reliability and performance, it’s advisable to consider filling the holes after back drilling. This helps to protect against potential oxidation and ensures better long-term stability of the via structure.