What are the advantages of using "yin and yang board" to join the PCB?
In the electronics assembly manufacturing industry, there are generally two types of "Mirror Boards" that we call. The first type is the Different side mirror board with the front and back sides reversed. There are also the first side and the other side of a board. The second side of a board is presented on the same side of the jigsaw; the other type is the same side mirror board (Same side mirror board) where all the jigsaws are on the same side but the left and right sides are reversed, such as pdpd typesetting.
The reasons why electronics manufacturers will require the "Yin Yang board" design are nothing more than the following two reasons:
1. Can make full use of the advantages of SMT long-term to achieve greater efficiency
The overall efficiency of an SMT can be judged simply by looking at whether there are machines waiting (idle). If there is no machine waiting at all, then we can say that the efficiency of this SMT line is up to 100%.
But is there such a simple way to achieve 100% efficiency? As the speed of SMT machine printing becomes faster and faster, SOC (System On Chip) parts are becoming more and more popular, and there are fewer and fewer parts on a board, but there is no solder paste printing machine (solder paste printing). machine) What's the speed improvement, so now many SMT line bottlenecks appear in the solder paste printing machine, that is, the solder paste printing machine has no rest, while other more expensive machines are waiting.
Let’s put it this way, assuming that the time to print a solder paste steel plate is about 20 seconds (depending on the length of the printing), and assuming that the pick & place immediately following takes less than 20 seconds. Finished, the remaining time of this machine is wasted idle, which is equivalent to buying a high-end Ferrari sports car, but it is parked in the garage and not moving, because every machine on the SMT Machines are very expensive, so make the most of their value as much as possible, and don't let them have any time to wait, so that you can use them to make money.
Therefore, some people have come up with the use of panelization/panelization to increase the use time of the placement machine to greatly improve its use efficiency; but it cannot be left empty for the solder paste printer, so there is a positive, The reversed yin and yang puzzles appear, so that more different parts can appear on the same side of the board at the same time, so that the SMT long line with multiple placement machines can fully play its role.
Another important purpose is that the upper and lower parts can be printed with only one line, so there is no need to waste time changing lines.
2. It can save the wasted space of bare board, that is, improve the use efficiency of panelization and save money
In order to mass-produce and reduce costs, general circuit board manufacturers usually buy some basic standard size plates, and price them in volume, such as 16.16"x16.16", 18.32"x18.32", 20.32"x20. 32"... etc. Some may only buy some larger substrate sizes instead of the entire series.
For some circuit boards with a non-square shape, the yin and yang board are designed to be assembled. There is a chance to squeeze one or two more circuit boards into the same circuit board, so that the use efficiency of the board can be improved, and the purpose of saving costs can be achieved. .
Because the price of the circuit board is calculated based on the utilization rate of the substrate, if the same size of the substrate is used, the appearance of the design A can only produce one circuit board, while the design B can produce two circuit boards. The price of the A board will be twice that of the B board.
It is a pity that although the use of "Yin-Yang Board" puzzle has the advantages of increasing efficiency and saving costs, the two designs of "Yin-Yang Board" also have their own shortcomings and limitations.