1, engineering design line width compensation: due to the thick copper, the line width must be compensated, otherwise the line width is too poor after etching, the customer is not accepted, the line width compensation value must experience stacking.

　　2, the uniformity of print resistance welding: due to the ultra-normal copper thickness of the line after graphic etching, print resistance welding is very difficult, skip printing, too thick and too thin customers do not bear. How to print this layer of green oil is also one of the difficulties.

　　3. Etching: The line width after etching must meet the needs of customer drawings. The residual copper is not allowed, nor can the knife be scraped away, the knife will scratch the insulation layer, resulting in sparks and leakage in the voltage test.

　　4, mechanical processing: aluminum substrate drilling can be, but the drilling hole inside the hole edge is not allowed to have any burrs, which will affect the pressure test. Milling shape is very difficult. And the shape, the need to use high-grade molds, mold manufacturing is very skillful, which is also one of the difficulties of aluminum substrate. After the shape is washed, the marginal demand is very regular, without any burrs, and does not hurt the solder resistance layer on the edge of the plate. Generally, the use of soldier die, hole punching from the line, shape punching from the aluminum surface, the force of the circuit board punching is cut down, and so on are tricks. After punching the shape, the warpage of the board should be less than 0.5%.

　　5, the entire production process is not allowed to wipe the aluminum base: the aluminum base through hand contact, or by a certain chemical will occur appearance discoloration, blackening, which is definitely not acceptable, scratch the aluminum base from scratch customers do not accept, so the whole process does not hurt, do not touch the aluminum base is one of the difficulties in the production of aluminum substrate. Some companies choose passivation technology, and some paste protective films before and after hot air leveling (spraying tin)... Many tips, eight immortals across the sea, each show their magic.