Problem of precision coincidence of multilayer blind buried pcb circuit boards

Problem of precision coincidence of multilayer blind buried circuit boards

Multi-layer blind-buried and blind-hole printed circuit boards are generally completed by "sub-board" production methods, which means that they must be completed through multiple pressing, drilling, and hole plating, so precise positioning is very important.

The high-precision printed circuit refers to the use of fine line width/spacing, micro holes, narrow ring width (or no ring width), and buried and blind holes to achieve high density. High precision means that the result of "fine, small, narrow, and thin" will inevitably lead to high precision requirements. Take the line width as an example: O.20mm line width, and the production of 0.16-0.24mm is qualified. The error is (O.20 soil 0.04) mm; and the line width of O.10mm, the error is (0.10±O.02) mm, obviously the accuracy of the latter is doubled, and so on is not difficult to understand, Therefore, the high-precision requirements will not be discussed separately.

Buried, blind, and through-hole (multi-layer blind-buried circuit boards) combined technology is also an important way to increase the density of printed circuits. Generally, the buried and blind holes are all tiny holes. In addition to increasing the number of wiring on the circuit board, the buried and blind holes are interconnected by the "nearest" inner layer, which greatly reduces the number of through holes formed, and the isolation disk is also set up. It will be greatly reduced, thereby increasing the number of effective wiring and inter-layer interconnections in the board, and increasing the density of interconnections.