PCB Via-in-Pad


What is the VIA-in-PAD?

When it comes to PCB design or PCB fabrication,Via In Pad is a special design technology to increase PCB density, to allows higher PCB component density(Especially in BGA area and SMT IC area). Many designers like to use via in pad to significantly save board space.


How to achieve the quality of VIA in PAD technology in PCB manufacturing process

Step 1: make the via holes as traditional via holes
Step 2: filling the via holes by resin(conductive resin or non-conducive resin)
Step 3: Plate copper over top side(or both side) of the via holes,to make sure the via hole to be plated as “Shut up”.
Step 4: Surface finishing treatment on the surface


Advantage features of via in pad technology in PCB design

1. Via in Pad can improved trace routing option
2. Via in PAD can help thermal dissipate performance
3. Via in pad can help reduce inductance in high frequency PCB board.
4. Via in pad can provide a flat surface for SMD component.

Dis-advantage features of via in pad technology in PCB design

1. It’s price is high comparing with normal PCB as it’s complexity manufacturing process.
2. Risk solder off of the BGA pad if you get low quality .

The manufacturing cost reference of Via in PAD technology to traditional via holes

Below is the cost reference from through via holes,tented via holes,blind via holes… to Via in Pad for PCB design reference.


The guidelines for design of Via-In-Pad

Via hole size (mm)PAD size (mm)Annular ring size (mm) per side
0.200.400.10

Remark: No matter how big size of your via holes and PAD size,but the minimum annular ring size must be no less than 0.1mm per side

For more knowledge about Via in PAD PCB design,you can contact us freely by email: service@wellerpcb.com, our engineer will provide professional consult to your design issues.