Ten precautions for PCB imposition

1、The outer frame (clamping edge) of the PCB board should adopt closed-loop design to ensure that the PCB board will not be deformed after it is fixed on the fixture;

2, PCB board width ≤ 260mm (SIEMENS line) or ≤ 300mm (FUJI line); if you need automatic dispensing, PCB board width × length ≤ 125mm × 180mm;

3, PCB splicing board shape as close as possible to the square, recommended 2 × 2, 3 × 3, ...... splicing board; but do not put together into a yin and yang board;

4, the center distance between the small board control between 75mm ~ 145mm;

5, set the benchmark positioning point, usually around the positioning point to leave a non-resistance welding area 1.5mm larger than it;

6, the outer frame of the patchwork board and the internal small boards, small boards and small boards can not be near the connection point of large devices or outstretched devices, and components and PCB board edges should be left greater than 0.5mm space to ensure that the cutting tool operates normally;

7, four positioning holes in the four corners of the outer frame of the patchwork board, aperture 4mm ± 0.01mm; hole strength should be moderate, to ensure that in the process of up and down the board will not break; aperture and positional accuracy should be high, the hole wall is smooth and hairless;

8, PCB board within each small board at least three positioning holes, 3 ≤ aperture ≤ 6mm, edge positioning holes within 1mm does not allow wiring or patch;

9, used for PCB board positioning and positioning for fine-pitch device datum symbols, in principle, the pitch is less than 0.65mm QFP should be set in its diagonal position; used to spell PCB sub-panel positioning datum symbols should be used in pairs, arranged in the positioning elements of the diagonal;