Buried Via Holes Affect PCB Thickness
Using buried via holes in your PCB can provide several advantages like improved signal performance and enhanced board density. However, the use of these vias can have some drawbacks too. The main ones are manufacturing challenges, rework considerations, and cost.
Vias are barrel shaped vertical conductive holes that make connections between layers of a multi-layer PCB. They can be classified into two types: blind and buried. The former connects outer layers to inner layers and doesn’t go through the entire board, while a buried via does.
Typically, these holes are plated and filled with conductive material either before or after the multilayer lamination process. The conductive filling improves current flow through the hole and ensures that no voids remain. The choice of the conductive filling depends on your design. Conductive epoxy (copper or silver) is ideal for these applications as it can be applied in thin layers and offers superior thermal conductivity.
How Does the Use of Buried Via Holes Affect PCB Thickness?
Since the use of buried via hole requires drilling and copper plating in the inner layer core, it can be more challenging to produce a quality PCB than a standard plated through-hole (PTHO) board. This is because the drill depth has to be very precise, and if it’s too shallow it may not provide a good connection. On the other hand, if it’s too deep it may result in signal degradation or distortion.
To prevent this, the PCB manufacturer must have a well-defined drill calibration and quality control system in place. In addition, they must use the best available PCB materials for the process and ensure that their design and fabrication specifications are compatible with buried vias.
Another issue is that buried vias require more layer space, which can raise production costs. Moreover, they can cause problems in the case of mismatched signals as they create a path between different layers, resulting in crosstalk and electromagnetic interference (EMI). Hence, it’s important to consider these factors when designing your PCB.
Whether you’re working on an automotive, aerospace, or defence project, it’s essential to keep these issues in mind when using buried vias in your PCB. This will ensure that your circuit boards are able to function properly and meet the required standards. Additionally, they will also be able to deliver higher functionality without increasing the overall thickness of the board. So, if you want to get the most out of your PCB, be sure to incorporate buried vias in your design. It will help you avoid costly mistakes and improve your product’s reliability.
