Some Measures to Reduce PCB Reverse Production Costs
As a measure to reduce the cost of manufacturing a rigid multilayer printed circuit board PCB Reverse, it is possible to proceed from various angles such as the type, size, processing technology and materials of printed circuit boards. The following are the same as the "
First, the printed circuit board PCB Reverse size design of the impact of the cost of noon
The original size of the copper plate is too large, it is inconvenient to process, and sometimes can not even into the printed circuit board PCB Reverse processing equipment for processing, so you need to first cut it into a number of pieces of processing size of the copper plate. As for the specific size of the processing size, it is necessary to determine the size of each printed circuit board according to the processing equipment of the printed circuit board and some process parameters. In addition to the length and width required to print the circuit pattern itself, these process parameters include the width of the screw holes that are fixed to the printed circuit board on the electronic product frame, the amount of process, the electroless plating, the plating and the corrosion When the clamp holding capacity, multi-layer printed circuit board when the number of positioning pin, the amount of the alignment between the layers, printed circuit board manufacturers to keep the mark, printed circuit board width, etc., of which Some process parameters can be recommended to the copper plate manufacturers or distributors to obtain. Printed wire production and processing, according to the above data to determine a large original size of the copper plate cut into the number of pieces of processing size of the copper plate, is the vertical cutting or horizontal cutting, can be cut and so on. The following are the same as the "
Figure 4.86 is an example of cutting the original size of copper. It is a piece of the original size of the copper plate cut into four processing size of the copper plate, and each processing size of the copper plate contains six printed circuit boards. If the longitudinal dimension of the printed circuit board is increased by 1 mm, then each of the machined copper sheets can only be cut into four printed circuit boards, which will undoubtedly increase the cost of the printed circuit board to six prints 150% of the circuit board. It can be seen, according to the original size of the copper plate, the rational design of the size of printed circuit board importance. The following are the same as the "
The original size of the copper plate and the size of the printed circuit board
Second, the printed circuit board PCB Reverse the number of layers on the impact of the cost
Printed circuit boards with the increase in the number of layers, the production costs will increase dramatically, so there may be a difference between the cost caused by significant differences in costs. If you design a 6-layer printed circuit board in the face of difficulties, must not give up, perhaps a lot of economic benefits in your efforts to insist on; but it is also very easy to reluctantly, because when Encounter this kind of thing, in most cases the designer may not hesitate to choose to design an 8-layer printed circuit. The following are the same as the "
Third, CEM-3 material
In addition to the widely used double-sided epoxy glass cloth, there is also a low-cost CEM-3 material, see Figure 4.87. The structure is to use the original double-sided printed circuit board There are double-sided epoxy glass cloth made of copper as a substrate thicker epoxy glass cloth made into a very thin two sheets, this time due to the strength is not enough, and between the two sheets of epoxy glass cloth Sandwiched epoxy glass nonwovens, thus reducing the cost. CEM-3 material texture is soft, in addition to can be used alone, but also can be used as a multi-layer rigid printed circuit board core material used. The following are the same as the "
The structure of the CEM-3 material
Fourth, the conductor line width and gap width ratio of the impact of the cost of noon
If the width of the guide pattern in the printed circuit board is represented by L, the gap width between the conductor patterns is represented by S, then the LIS represents the ratio of the width of the conductive tape to the gap width. With this reduction in the ratio, the production rate of printed circuit boards will be drastically reduced and the cost will rise. This phenomenon is more obvious when the circuit density is relatively high. Therefore, the value of LIS can not be arbitrarily reduced. The following are the same as the "
Fifth, the aperture of the hole on the cost of the impact of noon
In the case of punching a printed circuit board with a drill bit, the drilling depth of the drill bit drastically decreases when the aperture is below a certain value. In other words, the same hole to play a hole, drilling a small hole, the drill need to quit many times the heat, so it will reduce the production efficiency and increase costs. Therefore, do not arbitrarily reduce the aperture of the through hole; but also as much as possible to reduce the number of through-holes. The following are the same as the "
6, filled with silver paste through the hole
For the double-sided printed circuit board through-hole, without copper method to achieve the connection of the two sides of the circuit, but the use of through-hole filled with silver paste method, you can also reduce the cost of double-sided printed circuit board. A detailed schematic representation of the process is shown in Figure 4. 88. This method is generally used for double-sided copper ordinary phenolic resin cardboard. The method firstly firstly performs the surface cleaning treatment of the ordinary phenolic resin board with copper on both sides, then printing the resist pattern on both sides with the screen printing method, forming the conductor pattern after etching, removing the resist layer and then through the through hole, and then Paste the silver paste into the hole. In order for the silver paste to be in good contact with the conductor pattern on both sides, the silver paste should be perforated through the through hole and the diameter of the silver paste pattern in the bulged portion is larger than the diameter of the through hole. In order to block the migration of silver ions, a layer of overlay is capped by screen printing on the surface of the bulb portion of the silver paste. Then, on both sides of the screen printing resistance welding pattern, isolation graphics, stamping or drilling fixed printed circuit board screw hole, processing shape. Finally, through the inspection, silver paste filled through the double-sided printed circuit board on the production was completed. The following are the same as the "
Silver paste filled through hole process
In general, double-sided printed circuit boards filled with through-holes of this silver paste are not suitable for use in highly reliable circuits due to the substrate. In addition, because the silver paste in addition to conductive substances, there are a lot of non-conductive material, so the conductivity of silver paste conductivity of copper foil as good as good.