Why do PCB production panelization and board edge? And then the sub-board (de-panel)?

Why "Mosaic" in PCB production? So after SMT and wave soldering still have to go through the trouble of the panel? pcb stackup calculator What does PCB separation/coupons do? Isn't it true that the less boards you use, the cheaper the price? How about plate utilization?

Why do panel work in PCB production?

A typical PCB manufacturing process is called "Mosaic", which is designed to increase the productivity of SMT or wave soldering production lines.

PCB usually has the so-called "multi-in-one" board, 1 oz vs 2 oz such as 2-in-1 (2-in-1), 4-in-1 (4-in-1), 6-in-1 (6-in-1) and so on. It means to combine several boards into one big board.

If you have the opportunity to visit the SMT production line, you will find that the biggest bottleneck of the SMT production line is actually solder paste printing, because no matter the size of the PCB, the time required for printing is almost 25 seconds, which means that the unit price of the quick patch printer behind it is higher, if less than the screen printer, idle and so on. From an economic point of view, leisure is a waste.

In fact, the speed of the chip machine is very fast, and several parts can be hit in one second. Some mounters even have several mouthpieces that punch parts at the same time. Judging from the number of parts on the PCBA of the mobile phone, if there is only a single board, all the mounting operations should be completed in less than 10 seconds. Therefore, the PCB is made into a puzzle to increase the number of parts of the placement machine, which can increase the utilization rate of the placement machine and improve efficiency. Of course, it is best to achieve a "line balance" so that each device can play its full role.

In addition, in some special design requirements, there will be a large part on the same side of the PCB, and the other side only a few parts, you can consider using the mirror board to increase the number of parts on the side of the PCB, but the use of the mirror board also has limitations.

PCB splicing has another benefit. The PCBA can save time when taking and placing PCBA, because multiple boards can be taken and placed at the same time, and the subsequent board step test can also greatly save the wasted time when the fixture is taken and placed.

Finally, some circuit board design will show an irregular shape, such as this [L] shape of the board, if not made into "scheme 1", the upper left corner of the place will be a piece of waste, if we can change it into the upper and lower upside down the board, the waste can be greatly reduced, which is the concept of PCB board material utilization.

PCB production SMT production line

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