What Is Blind Via Technology?
Blind vias are vias that connect the surface layer and the inner layer without penetrating the entire board. Blind holes are located on the top and bottom surfaces of the printed circuit board and have a certain depth for the connection of the surface layer and the underlying inner layer. The depth of the hole usually does not exceed a certain ratio (diameter).
Therefore, since the opposite side cannot be seen, it is called a blind hole.
More Detailed Explanation
Blind holes are located on the top and bottom surfaces of the circuit board and have a certain depth. They are used for the connection of the surface layer circuit to the inner layer circuit below. The depth of the hole generally has a specified ratio.
This kind of production method requires special attention. The drilling depth must be just right. If you don’t pay attention, it will cause difficulties in electroplating the hole.
Blind vias do not run through the PCB, so few factories use this method of fabrication. It is also possible to drill holes for the circuit layers that are connected first, and then glue them together at the end of the individual circuit layers but requires a more precise positioning and alignment device.
Blind vias connect one outer layer and at least one inner layer; each connected hole is defined as a separate drill file. And the ratio of hole diameter to hole depth must be 1:1 or greater. The smaller the hole, the smaller the distance between the outer and inner layers.
Advantages of Blind Vias
the application of blind vias can greatly reduce the size and quality of the PCB, reduce the number of layers, improve electromagnetic compatibility, increase the characteristics of electronic products, reduce costs, and also make the design work easier and faster.
In traditional PCB design and processing, holes pose many problems, and they use a lot of available space. Secondly, a large number of through-hole dense places also cause obstacles to the inner layers of multi-layer PCBs.
These vias take up the space required for traces, they pass densely through the surface of the power and ground layers, and they also destroy the impedance characteristics of the power ground layer, making the power ground layer ineffective. And conventional mechanical drilling will be several times the workload of using non-penetrating hole technology.
Blind vias also free up space, which is essential for fine-pitch BGA components. Increased costs, but also allowed many requirements to be met.
Metallized Hole
Metallized holes are one of the important elements of PCB design. In the double-sided and multi-layer boards, in order to connect the printed wires between the layers, a common hole, that is, a via hole, is drilled at the intersection of the wires that need to be connected on each layer. There are three types of vias, namely blind vias, buried vias and through vias.
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