Some customers don't understand why the price of PCB board with blind via and buried via is slightly higher. In a word, the workload of PCB board with blind via and buried via is relatively larger and the technology is a little more complicated. There may also be more problems in removing and grinding boards (more detailed which takes more time in dismantling and grinding). How the board with blind via and buried via consumes time can be seen from the process of blind via and buried via, which are as follows:
Generally, PCB with blind via and buried via is multilayer board. Blind via refers to the through hole that only extends to one surface of PCB board. Generally, the via diameter is ≤ 0.4mm, which is plated-through hole (PTH). Buried via refers to the through hole that does not extend to the surface of PCB board. Usually, the hole diameter is ≤ 0.4mm, which is plated-through hole.
Based on the miniaturization of electronic equipment, the integration of components and the high density of IC, many multilayer PCB boards are designed as blind and buried vias multilayer boards. Adopting blind via and buried via is an effective method to increase the density, reduce the number of layers and reduce the size of the board surface, and it greatly reduces the number of plated through holes.
Most of the blind vias and buried vias are small holes with a diameter of 0.05 ~ 0.15 mm. During processing, the holes are embedded in the inner thin board, and the double-sided board manufacturing process is used for manufacturing. In the manufacture of blind holes, the CNC machine for drilling small holes with z-axis depth control has been used. Now, laser drilling, plasma etching and photoionization drilling are widely used.