PCB News - PCB multilayer circuit board manufacturers: what is via plug oil

PCB multilayer circuit board manufacturers: what is via plug oil

In double-sided circuit boards and PCB multilayer circuit boards, in order to connect the printed wires between the various layers of circuit boards, a common hole, that is, a via hole, is drilled at the intersection of the wires that need to be connected in each layer. In the process of PCB multilayer circuit board manufacturing, the via holes must be plugged. The via plug oil process is one of the via processing methods. Let’s talk with the editor of Shenzhen Electronics to understand what is the via plug oil for PCB multilayer circuit boards.

Through hole plug oil guides the hole of the through hole to be plugged with ink, emphasizing the quality and density of the plug hole. What is the inspection standard for the handling of via plug oil? The first is to be opaque, and there must be ink covering and clogging on it. The second is that the orifice should not show yellowing, and it should not be stained with tin.

The via plugging oil process is an important supplement to the via cover oil. Generally, high-quality PCB multilayer circuit boards will require via plugging oil, especially for vias like BGA, the requirements are more demanding. The via plugging oil first fills all the vias with ink to block the vias, so that the ink on the solder mask will not flow into the vias, thus achieving the effect of no yellowing of the vias. The smaller the via hole of the circuit board is, the easier it is to plug it. The via hole of fortress oil is not easy to be too large. The maximum value is 0.5mm. It is recommended to cover oil for holes larger than 0.5mm.

In addition, for those with stricter technological requirements, those who have made via-hole cover oil, usually the cover oil is not full or yellowish, and can be changed to via-hole plug oil later. Engineers should pay attention to the following points when docking the via plugging process with the PCB multi-layer circuit board factory (multi-layer circuit board batch manufacturer):

1. The attributes of the vias when placing an order must be consistent with the attributes of the file, so that the time for mutual confirmation with PCB multilayer circuit board manufacturers can be reduced.

2. If windows are required, the corresponding solder mask must be clearly drawn.

3. If the circuit board has a large number of pads that need to be soldered later, it is recommended to cover the via hole with oil, which can reduce the chance of short circuit.

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