PCB Tech - Should the PCB design reserve the edges and grooves?

How does Router (path cutting machine, forming machine) cut (depanel) circuit board jigsaw? And does the PCB design need to reserve the break-away for the Router machine?

Q1: When using the Router cutting machine to cut the connecting plate, do I need to reserve a groove such as V-Cut on the edge of the connecting plate?

A1: Before answering this question, it is necessary to clarify why some boards need to reserve edges? This is because the circuit board automated assembly process will use mechanical devices such as chains to transfer the semi-finished products of the circuit board assembly. Paste printing is sent to the pick & place machine (Pick & Place machine), and how to pass through the reflow oven (reflow oven), these transfer devices are almost completed by the use of chains, and the chains must be set in advance of the board The left and right ends, and this is the biggest reason why the circuit board needs the edge of the board, because with the current mechanism technology, the parts are not allowed to be placed in the place where the chain is used, and the parts must be placed a certain distance from the edge of the chain. In order to prevent the parts from being knocked off by the chain or affect its reliability. Another device that will use the edge of the board is the PCB magazine rack (Magazine Rack), which uses multiple slot-shaped sockets to store the assembled circuit boards.

Therefore, if PCB company's circuit board assembly does not need a chain to transport the circuit board at all, nor does it need to use a magazine rack, then why does your company's circuit board need a board edge? But this seems a little impractical. There is a chance to save the edge of the board. Usually there is enough space on the board, and all the parts can avoid the position of the chain, so there is no need to use the edge of the board, but it is still necessary. Measure that some punching machines/placement opportunities have special needs such as digging and positioning.

So come back to answer when using the Router machine to cut the connecting plate, do I need to reserve a groove like V-Cut on the edge of the connecting plate? When using the Router machine to cut the connecting plate, the need to leave the edge of the plate depends on the situation of the above answer. As for the need to leave the V-cut groove, it is definitely not necessary, because the Router machine uses the computer preset path To define the cutting board, it is not positioned by grooves such as V-cut, so the problem is that since it is positioned by the computer, the path of each cutting will be exactly the same, at least roughly the same! Therefore, we must prepare a fixed fixture for the circuit board that uses the Router machine to cut and split the board, so that the circuit board will appear in a fixed position when the circuit board is cut and split, so that the Router machine will not cut the wrong position.

Q2: What are the requirements for the circuit board fixing of the Router machine?

A2: When using the Router machine to cut the circuit board, you need to use a fixed jig to make the position of each cut consistent, and the Router uses a cutter head like a milling cutter, and the depth of the cutter head must be greater than the thickness of the circuit board when cutting. Therefore, it is best to reserve some hollowed-out space on the cutting path of the circuit board, so that the milling cutter can be placed to a fixed depth in advance before starting to cut, and the jig must also avoid the walking path of the milling cutter, so as to prevent the milling cutter from cutting directly to the treatment. Tool, causing damage to the jig or milling cutter. In addition, each veneer must be fixed when cutting and splitting the board. The purpose is to avoid the problem that the veneer directly falls between the fixtures after all the indirect boards are cut. The other purpose of fixing the veneer is because of milling. When the knife is cutting and walking, there will be an outward swinging force. If the veneer is not fixed, it will deflect and cause the problem of cutting the board.

Since most circuit boards are designed with screw holes or other round holes, most fixtures use positioning posts to pass through these round holes to fix the single board. If it is really impossible to design the round hole in the single board, you can also consider using the outer frame of the circuit board to fix it, but the outer frame size and tolerance of the circuit board must be specially marked and defined, and at least three points or more are required to be fixed. Live the circuit board.

The universal fixing fixture of Router cutting machine is designed with many positioning posts to fix the circuit board.

The partial enlarged view of the positioning column on the universal fixing fixture of the Router cutting machine, you can see that the end of the positioning column is made into a cone shape to facilitate the picking and placing and taking of the circuit board.

Circuit board design needs to reserve board edges and grooves for router (path cutting machine/forming machine)? Circuit board design needs to reserve board edges and grooves for router (path cutting machine/forming machine)?