Blind Via Hole Board Feature!

Blind Via Hole which connects the outermost circuit of the blind and buried via circuit board with the adjacent inner layer with plated holes. Because the opposite side cannot be seen, it is called "blind via". In order to increase the space utilization of the PCB circuit layer, the "blind via" process came into being. This production method requires special attention to the depth of the drilling (Z axis) to be just right. This method often causes difficulties in electroplating in the hole, so it is almost used by no manufacturer; it is also possible to place the circuit layers that need to be connected in advance on the individual circuit layers. When the time is required, the holes are drilled first, and then glued together, but a relatively precise positioning and alignment device is required.

Blind holes are located on the top and bottom surfaces of the printed circuit board, with a certain depth, and are used for the connection of the surface circuit and the underlying inner circuit. The depth of the hole usually does not exceed a certain ratio (diameter).

In the non-through via technology, the application of blind vias and buried vias can greatly reduce the size and quality of blind and buried via circuit boards, reduce the number of layers, improve electromagnetic compatibility, increase the characteristics of electronic products, and reduce costs. Makes design work easier and faster. In traditional PCB design and processing, through-holes present many problems. First of all, they occupy a large amount of effective space, and secondly, a large number of through holes are densely packed in one place, which also causes huge obstacles to the inner layer routing of multi-layer PCBs. These through holes occupy the space required for routing, and they densely pass through power and ground. The surface of the wire layer will also destroy the impedance characteristics of the power ground wire layer, making the power ground wire layer ineffective. And conventional mechanical drilling will be 20 times the workload of using non-penetrating hole technology.

In PCB design, although the size of pads and vias has been gradually reduced, if the thickness of the board layer is not proportionally reduced, the aspect ratio of the vias will increase, and the increase in the aspect ratio of the vias will reduce reliability. With the maturity of advanced laser drilling technology and plasma dry etching technology, it is possible to apply non-penetrating small blind holes and small buried holes. If the hole diameter of these non-penetrating holes is 0.3mm, the parasitic parameters brought by them are The original conventional hole is about 1/10, which improves the reliability of the PCB.

Due to the use of non-through via technology, there will be few large vias on the blind buried via circuit board, which can provide more space for wiring. The remaining space can be used for large area shielding to improve EMI/RFI performance. At the same time, more remaining space can also be used for the inner layer to partially shield the device and key network cables, so that it has the best electrical performance. The use of non-through vias makes it easier to fan out device pins, making it easy to route high-density pin devices (such as BGA packaged devices), shortening the wiring length, and meeting high-speed circuit timing requirements.