Many people know that the hole above the circuit board is processed by CNC drilling, but few people know the difference between single-sided circuit board drilling and double-sided circuit board drilling. The following is a simple introduction to the difference between single-sided circuit board drilling and double-sided circuit board drilling.
In fact, the difference between single-sided circuit board and double-sided circuit board is very big when drilling, single-sided circuit board can directly drill the circuit board according to the drawings or circuit board files provided by the customer, while double-sided circuit board is different, because the double-sided circuit board needs to be sunk after drilling. A layer of copper is plated on the hole wall of the circuit board after drilling the hole, and a layer of tin will be sprayed on the hole wall of the circuit board after drilling the hole when the hot air is leveled, so the double-sided circuit board should be increased by 0.1-0.2mm on the basis of the hole size of the circuit board on the drawing when drilling, if it is not increased, the aperture of the double-sided circuit board produced will be smaller.
PCB single-sided circuit board Two methods of circuit board line imaging and the difference
There are two ways of single-sided circuit board line imaging, one is exposure imaging and the other is screen printing line imaging. The following is a simple explanation of the two line imaging methods and the difference.
Exposure imaging: The main processing step of single-sided circuit board exposure imaging is to print wet film and then enter the oven to dry, and then paste the dried circuit board with the circuit board negative after exposure machine exposure, after the development machine to remove all the wet film outside the line, and finally through the corrosion machine corrosion. Circuit board factory exposure imaging processing of single-sided circuit boards will be relatively high cost, but this method can process high-density circuit boards, and the processed circuit board lines are more symmetrical.
Screen printing lines: The method of screen printing lines is relatively simple, first of all, the stains, impurities and oxidation layers on the copper foil on the circuit board are cleaned up by the brush machine, and then the lines are printed on the circuit board through the screen printing machine or the screen printing network. The above can be seen that the cost of screen printing lines is relatively low, but the quality of the processed circuit board will be much lower than that of the exposed circuit board.
Usually, the circuit board factory processes single-sided circuit boards, and if exposure imaging is used, the minimum line gap of the circuit board can be about 0.15mm, and the minimum line width can be about 0.15mm. The minimum line width of the circuit board of the screen printing line can only be 0.25mm, the minimum gap can only be 0.25mm, if it is lower than this value, then the processed circuit board will appear a lot of waste products.
PCB single-sided circuit board features and uses
Single-sided circuit board is the most basic PCB circuit board, the parts are concentrated on one side, the wire is concentrated on the other side, because the wire appears on one side of the reason we call it single-sided circuit board. Because single-sided circuit boards have many strict restrictions on the design circuit.
The single-sided circuit board substrate is mainly composed of paper copper-phenol laminated board and paper epoxy resin copper-laminated board. Single-sided circuit board is mostly used in radio, heater, refrigerator, washing machine and other home appliances, as well as printers, vending machines, circuit machines, electronic components and other commercial machines, single-sided circuit board advantage is low price.
PCB single-sided circuit board refers to a copper foil on one side of the circuit board, PCB single-sided circuit board is generally divided into two kinds, one is PCB single-sided aluminum substrate and PCB single-sided ordinary board circuit board. PCB single-sided aluminum substrate is more complex than the ordinary material single-sided PCB board, it is composed of aluminum plate, isolation layer and copper foil, and the ordinary plate single-sided circuit board is mainly composed of epoxy resin or flame retardant plate and copper foil. PCB single-sided aluminum substrate and ordinary PCB single-sided circuit board in addition to the difference in material in processing and price are very big differences, PCB single-sided aluminum substrate mechanical properties are very strong, so in CNC drilling and molding than ordinary PCB single-sided circuit board is much more difficult. Therefore, even in the case of the same raw materials, the price of PCB single-sided aluminum substrate is relatively higher than the price of ordinary PCB single-sided circuit boards.