In PCB design and final PCB mass production, PCB assembly is also a very important thing, which not only involves the quality standards of PCB circuit boards, but also affects the cost of PCB production. On the premise of ensuring the quality of PCB circuit boards, how to carry out reasonable and effective assembly, so as to save raw materials, is a problem that the production company pays great attention to solving.
01 Imposition connection method
There are two ways to connect PCB boards, one is V-cut, and the other is stamp hole connection. V-cut is generally suitable for PCBs with a rectangular shape. It is characterized by neat edges after separation and low processing costs. It is recommended to use it first.
Stamp holes are generally suitable for irregular layouts. For example, the "L" frame structure of MID often adopts the connection method of stamp holes for panelization.
02 Number of impositions
The size of the entire panel must be calculated based on the size of a single PCB, and must not exceed the maximum size range of the PCB (the length of the PCB panel must not exceed 250mm). In addition, too many panels will affect the accuracy of the panel position and affect the placement accuracy. Generally, the main board of the MID type is 2 panels, and the sub-boards of the keypad and LCD boards do not exceed 6 panels. The sub-boards with special areas are determined according to the specific situation.
03 Requirements for Stamp Hole Links
In a PCB jigsaw panel, the number of link bars should be appropriate, generally 2 to 3 link bars, so that the strength of the PCB meets the requirements of the production process, and it should not be broken easily. When designing the link bar, it is generally necessary to design a length of 4-5mm. The hole is non-metallized, the size is generally 0.3mm-0.5mm, and the distance between the holes is 0.8-1.2mm.
04 craft edge
When the board is relatively dense in components and the space on the edge of the board is limited, it is necessary to increase the process edge, which is used for the transmission edge of the PCB board when it is used for SMT, generally 3-5mm. Generally, a positioning hole is added to each of the 4 corners of the process side, and optical positioning points are added to the three corners to strengthen the positioning of the machine.
