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SMT chip processing is a very important processing, it is what we often call printed circuit board processing. When we carry out SMT patch processing, we attach great importance to the design of PCB pads, because it affects the link between the circuit components. Therefore, we have certain standards when designing. So, what are the design standards for PCB pads? Let's take a look.



 


1. Design standards for the shape and size of PCB pads: call the PCB standard package library, the minimum one side of the pad is not less than 0.25mm, the maximum diameter of the entire pad is not more than 3 times the diameter of the component, and try to ensure the edge of the two pads. Pads with a pitch greater than 0.4mm, a diameter of more than 1.2mm or a pad diameter of more than 3.0mm should be designed as diamond-shaped or plum-shaped pads. In the case of dense wiring, oval and oval connection pads are recommended. The diameter or minimum width of the single-sided pad is 1.6mm; the double-sided weak current circuit pad only needs to add 0.5mm to the hole diameter, and the pad is too large to cause unnecessary continuous welding.


2. PCB pad via hole size standard: the inner hole of the pad is generally not less than 0.6mm, because the hole smaller than 0.6mm is not easy to process when punching. Usually, the diameter of the metal pin plus 0.2mm is used as the inner diameter of the pad. The diameter of the hole, for example, when the diameter of the metal pin of the resistor is 0.5mm, the diameter of the inner hole of the pad corresponds to 0.7mm, and the diameter of the pad depends on the diameter of the inner hole.


After the above introduction, I believe you already know what the design standard of PCB pads is in SMT chip processing.

                   
                   
                   
                   
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