Printed circuit of high precision refers to the fine line / space, micro hole, narrow the width of ring (or no ring width) and buried and blind hole technology has reached the high density. And high precision is refers to "thin, small, narrow and thin" the results will inevitably bring about the high precision requirements, the linewidth, for example: linewidth O.20mm, according to the provisions of the production out O.16-0.24mm as qualified, the error is (soil O.20 0.04 mm; and O.10mm linewidth. Similarly the error for (0.10 mm + 02), apparently the accuracy increase 1 times, the analogy is not difficult to understand, so high precision no longer separate discussion. But it is a prominent problem in production technology.
The functional hole of the printed board which is installed on the surface of the micro hole technology is mainly the function of the electric connection, so the application of the micro hole technology is more important. Using conventional drill material and numerical control drilling machine to produce micro holes with high cost and multiple faults. So the printed circuit board of high density of mostly in wires and welding compact disc of efforts, although made great achievements, but its potential is limited, it is necessary to further improve the fine (such as less than O.08mm wire, a sharp rise in the cost of, and steering with micropore to improve fine.
In recent years, CNC drilling machine and micro drill technology has made a breakthrough, so micro hole technology has a rapid development. This is the main highlight of the current production of printed boards. In micro hole formation technology mainly depends on the advanced CNC drilling machine and excellent small head, and laser technology formation of holes, from the point of view of quality cost and the hole of the see is still inferior to CNC drilling machine and the formation of holes.
Buried, blind, through hole technology, blind hole, through hole combination technology is also an important way to improve the high density of printed circuit. General buried, blind hole is a small hole, in addition to increase the number of the upper surface of the wiring, buried and blind hole is "recently" inner interconnection, greatly reducing the number of through hole is formed and isolating disc is provided with a will greatly reduce the, thus increasing the interconnection between plate and efficient routing and layer number and improve the high interconnection density. So buried and blind, through combining hole multilayer board than conventional allpass orifice plate structure, in the same size and the number of layers, the interconnect density increased by at least 3 times, if under the same technical indicators, buried and blind, hole combination of printed circuit board, its size will be greatly reduced or significantly reduced the number of layers. So high density surface mount printed board, buried, more and more blind hole technology has been applied in, not only in large computers, communications equipment and other surface mount printed circuit board in the and in the field of civil and industrial use has also been widely used, even in some thin plate can be applied, such as PCMCIA, Smard, IC cards, such as the thin six storeys above the board.
Buried and blind hole structure of the printed circuit board, typically use the "plate" mode of production to complete, which means to go through the multiple plate, drilling, hole plating, etc. in order to complete and precise positioning is very important.