Abstract: die blanking can be used for PCB blanking, hole and shape processing. Blanking can be used for PCB with simple processing or PCB with low requirements. It is suitable for the production of low-level and large-scale PCB with low requirements and shape requirements is not very high, and its cost is low
Punching：
One or several pairs of dies are usually used for punching single-sided paper substrate and double-sided nonmetallic hole ring oxygen glass cloth substrate with large batch production, various types and quantities of holes and complex shape.
Shape processing：
PCB production of large quantities of single panel and double-sided board shape, usually using die stamping. According to the size of printed circuit board inch, it can be divided into up and down die.
Compound processing：
The hole and hole， between the hole and the shape of printed circuit board require high precision. At the same time, in order to shorten the manufacturing cycle and improve the production rate, compound die is used to process the hole and shape of single panel at the same time.
The key to processing printed boards with molds is the design and processing of molds, which require professional technical knowledge. In addition, mold installation and debugging are also very important. At present, most of the molds of PCB manufacturing plants are processed by outside factories.
Precautions for mold installation：
1.Select punch (including type, ton position) according to the blanking force calculated by die design, die size, closing height, etc.
2.Start the punch, and check whether the clutch, brake, slide block and other parts are normal, whether the operating mechanism is reliable, and there is no continuous impact phenomenon.
3.The pad iron under the die, generally two, must be ground out on the grinder at the same time to ensure that the die is installed parallel and vertical straight. The intercalation of the pad iron does not hinder the blanking, and at the same time, it should be as close to the center of the die as possible.
4.Prepare several sets of pressing plate and T-head pressing plate screw for corresponding use with the mold. The front end of the pressing plate should not touch the straight wall of the lower die. Sand cloth should be placed between the contact surfaces, and the screws must be tightened.
5.When installing the mold, pay great attention to the screws and nuts on the lower mold not to touch the upper mold (the upper mold drops and closes).
6.When adjusting the mould, try to use manual instead of motor
7.In order to improve the blanking performance of the substrate, the paper substrate should be heated. The best temperature is 70-90 ℃.
There are several quality defects in the hole and shape of the die blanking printed circuit board：
Bulge around the hole or copper foil warping or lamination; cracks between the holes; hole position deviation or hole itself is not vertical straight; burr is large; cross section is rough; the printed circuit board punched into pot bottom warping; waste jumping up; waste blocking.
The inspection and analysis steps are as follows：
Check whether the blanking force and rigidity of the punch are sufficient; whether the die design is reasonable and whether the rigidity is sufficient; whether the processing accuracy of the punch and female die, guide column and guide sleeve are up to standard, and whether the installation is concentric and vertical. Whether the fit clearance is even. If the gap between convex and concave is too small or too large, it will produce quality defects, which is the most important problem in mold design, processing, debugging and use. The edge of convex and concave die is not allowed to be rounded or chamfered. The taper of punch is not allowed, especially when punching, both positive cone and inverted cone are not allowed. In production, it is necessary to pay attention to whether the edge of punch and die is worn. Whether the discharge port is reasonable and the resistance is small. Whether the pushing plate and the rod are reasonable and the force is sufficient. The thickness of the sheet to be punched, the binding force and glue content of the substrate, the binding force with copper foil, the pre heat moisture degree and time are also the factors to be considered in the analysis of blanking quality defects.
