PCB Blog - What are the benefits of Mirror fr4 pcb board panel

In the electronic assembly manufacturing industry, we generally call Mirror fr4 pcb Board two types. The first type is the Mirror fr4 pcb Board with the reverse side of the mirror (different side mirror fr4 pcb Board), or the first side of one board and the second side of another board are displayed on the same side of the panel; The other type is the Mirror Board (Same side Mirror fr4 pcb Board) with all panels on the same side but reversed from left to right, such as the layout of pdpd. There are two reasons why electronic manufacturers will require Mirror fr4 pcb board design:

1. It can make full use of the advantages of SMT long line to achieve greater efficiency

The overall efficiency of an SMT can be determined by simply looking at whether there are machines waiting. If there is no time for machines to wait, we can say that the efficiency of this SMT line reaches 100%. But is it really so simple to achieve 100% efficiency? With the speed of SMT machine making parts faster and faster, SOC (System On Chip) parts become more and more popular, and the parts on a board become less and less, but there is no significant progress in the speed of solder paste printing machine, so now many bottlenecks of SMT lines appear in the solder paste printing machine, that is, the solder paste printing machine has no rest, while other more expensive machines are waiting. So let's say that it takes about 20 seconds to print the solder paste steel plate (depending on the length of printing), and that the next pick&place takes less than 20 seconds to complete, then the time left for this machine is idle, which is equivalent to buying a high-end Ferrari sports car, but it is not moving in the garage, because every machine on the SMT is very expensive, So we should make full use of their value as much as possible, and do not let them have any free time, so that we can make money with them. Therefore, some people think of using the method of panelization to increase the use time of the pasting machine, so as to greatly improve its use efficiency; However, the solder paste printing machine can not be left idle, so there is a positive and negative reverse combination of yin and yang, so that more different parts can appear on the same side of the board at the same time, so that the SMT long line, which originally has multiple printing and pasting machines, can give full play to its role. Another important purpose is that the upper and lower parts can be completed in one line, without wasting the time of changing lines.

2. It can save the space wasted by the blank board, that is, improve the use efficiency of the panel and save money

In order to produce in large quantities and reduce costs, general circuit boards manufacturers usually buy some basic standard size plates, which are priced by volume, such as 16.16 "x16.16", 18.32 "x18.32", 20.32 "x20.32". Some may also buy only a number of substrate sizes that are widely used, rather than a full range. The panel design of Mirror fr4 pcb board is carried out for some circuit boards that are not square in shape, so that one or two more circuit boards can be squeezed into the same circuit board, which can improve the use efficiency of the board and achieve the purpose of saving costs. Because the price of the circuit board is basically calculated by the utilization rate of the substrate. If the same size of the substrate is used, the appearance of Design A can only produce one circuit board, while Design B can produce two circuit boards, and the price of Board A will be twice that of Board B. Unfortunately, although the use of Mirror fr4 pcb board panel has the advantages of increasing efficiency and saving costs, the two designs of Mirror fr4 pcb board also have their own shortcomings and limitations.

The most common connecting board is composed of more than two identical circuit boards, such as 2 in 1 (two in one), 3 in 1 (three in one), 4 in 1 (four in one), etc; There are also cases where circuit boards of different shapes are combined into a large board, but it is rare, because it is difficult for the production management to match the right number of different boards when arranging production; There are also examples of using the same board as Mirror fr4 pcb board. Mirror fr4 pcb board mostly means the top and bottom side configurations. This is usually applied to circuit boards with fewer parts, such as mobile phone boards, because it can make full use of the SMT's long line marking function to increase efficiency, but the disadvantage is that it is limited in use and may cause uneven heating, For example, some circuit boards will focus on one side of the heavier parts, and then use this side as the second part to prevent the heavier parts from falling off. Of course, this kind of board cannot adopt the design of Mirror fr4 pcb board; Some boards may have heat-absorbing parts (such as large-area ATM card reading slot), and are not suitable for the design of Mirror fr4 pcb board.