PCB using "yin and yang" what is the benefit of the board?

Manufactured in electronic assembly In the industry, we generally call [Mirror Board] there are two types, the first type is a differential side mirror board, and there is also the first side of a board and the second side of another board. The two sides are presented on the same side of the panel; the other type is the same side mirror board where all the panels are on the same side but reversed left and right, such as pdpd's typesetting.

Electronic manufacturers will require the use of [yin and yang] design for the following two reasons:

1. Can be fully Take advantage of SMT long lines to achieve greater printing efficiency

Whether the overall efficiency of an SMT is good or not can be judged simply by seeing if there is a machine waiting (idle), if it can be done completely There is no machine waiting time, then we can say that the efficiency of this SMT line is 100%.

But is it really that simple to achieve 100% efficiency? As the speed of SMT machine printing is getting 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) has made great progress, so now the bottleneck of many SMT lines appears in the solder paste printing machine, that is, the solder paste printing machine has no rest, while other more expensive machines are waiting.

Well, let’s assume that the time for printing a solder paste steel plate is about 20 seconds (depending on the length of the printing), and assuming that the following stickers (pick & place ) takes less than 20 seconds to complete, the rest of the machine is wasted idle, and it's like buying a fancy Ferrari, but it's parked in the garage Also, because every machine on SMT is very expensive, make the most of their value and don't let them have any idle time so that you can use it to make money.

So some people came up with the use of splicing/plying (Panelization) to increase the use time of the placement machine, so as to greatly improve its use efficiency; but it can't make the solder paste printing machine empty. , So there is a yin and yang jigsaw panel with the front and back reversed, so that more different parts can appear on the same side of the board at the same time, so that the long SMT line with multiple pasting machines can give full play to its role.

Another important purpose is that the upper and lower parts can be completed with only one line, and there is no need to waste time for changing lines.

2. It can save the wasted space of the bare board, that is, improve the efficiency of the panelization and save money

In order to mass-produce and reduce costs, general circuit board manufacturers usually purchase some basic standard-sized boards, and set the price based on quantity, such as 16.16"x16 .16", 18.32"x18.32", 20.32"x20.32"...etc. Some may also only purchase some of the larger base plate sizes, rather than the full range.

For some circuit boards that are not square in shape, the yin and yang boards are designed, and there is a chance to squeeze one or two more circuit boards into the same circuit substrate, so that It can improve the efficiency of the use of the board and achieve the purpose of saving costs.

Because the price of the circuit board is calculated based on the utilization rate of the substrate, if the same size substrate is used, the appearance of design A can only produce one circuit board, and design B can produce two circuit boards, and the price of the A board will be twice that of the B board. For more information, please refer to "How to choose the number of PCB connections".

Unfortunately, although the use of [yin-yang board] panel has the advantages of increasing efficiency and saving costs, the designs of these two [yin-yang board] also have their own Disadvantages and limitations.