Ten Points to Note About Assembled PCB Board

Here are 10 things to pay attention to:

1. The outer frame (clamping edge) of the PCB assembled board should adopt a closed-loop design to ensure that the PCB assembled board will not be deformed after being fixed on the fixture.

2. PCB panel width ≤260mm (SIEMENS line) or ≤300mm (FUJI line). If automatic dispensing is required, PCB panel width×length ≤125 mm×180 mm.

3. The PCB board shape should be as close as possible to the square. It is recommended to use 2×2, 3×3.

4. The center distance between the small plates is controlled between 75 mm and 145 mm.

5. When setting the reference positioning point, usually leave a non-resistance area 1.5 mm larger than it around the positioning point.

6. There should be no large devices or protruding devices near the connection points between the outer frame of the panel and the inner small board, and between the small board and the small board, and there should be a space greater than 0.5mm between the components and the edge of the PCB board. To ensure the normal operation of the cutting tool.

7. Four positioning holes are made in the four corners of the outer frame of the assembled board panel, with a diameter of 4mm±0.01mm. The strength of the holes should be moderate to ensure that they will not break during the upper and lower boards. The precision of the hole diameter and position should be high, and the hole wall should be smooth and free of burrs.

8. Each small board in the PCB assembled board must have at least three positioning holes, 3≤aperture ≤6 mm, and no wiring or patching is allowed within 1mm of the edge positioning hole.

9. The reference symbols are used for the positioning of the entire PCB and the positioning of fine-pitch devices. In principle, the QFP with a pitch less than 0.65mm should be set in its diagonal position. The positioning reference symbols used for the imposition PCB sub-board should be paired used, arranged at the opposite corner of the positioning element.

10. Large components should have positioning posts or positioning holes, such as I/O interface, microphone, battery interface, micro switch, earphone interface, motor, etc.