When Making PCB Panel Design, Please Consider The Production Factors
In order to facilitate production, PCB board impositions produced by PCB manufacturers often require the design of marking points, V-grooves and process edges.
First, the imposition shape
1. The outer frame (clamping edge) of the PCB panel should be closed-loop designed to ensure that the PCB panel does not deform after it is attached to the fixture.
2, PCB board width ≤ 260mm (SIEMENS line) or ≤ 300mm (FUJI line); if automatic dispensing is required, PCB board width × length 125 mm × 180 mm.
3, PCB layout as close to the square as possible, it is recommended to use 2 × 2, 3 × 3, ... puzzle; but do not spell into yin and yang;
Second, V-shaped groove
1. After opening the V-groove, the remaining thickness X should be (1/4 to 1/3) plate thickness L, but the minimum thickness X must be ≥ 0.4 mm. For heavy plates, the upper limit can be used and the lower limit of the lighter plate can be used.
2. The deviation S of the upper and lower sides of the V-shaped groove should be less than 0.1mm; due to the limitation of the minimum effective thickness, the plate with a thickness less than 1.2mm should not adopt the V-groove method.
Third, Mark points
1. When setting the reference positioning point, usually leave a non-resistive area 1.5 mm larger than the positioning point.
2, used to help the optical positioning of the placement machine and the diagonal of the chip device at least two asymmetric reference points, the entire PCB optical positioning reference point is generally located at the corresponding position of the entire PCB diagonal; the reference point of the block PCB optical positioning Usually located at the corresponding position on the diagonal PCB board.
3, PCB manufacturer is QFP (square flat package), pin pitch ≤ 0.5mm, BGA (ball grid array package), ball spacing ≤ 0.8mm, in order to improve the placement accuracy, you need to set two pairs of IC dot angles in the reference line.
Fourth, the process aspect
1. There should be no large devices or protruding devices near the connection point between the panel outer frame and the inner small plate, small plate and small plate. The spacing between the component and the PCB board should be greater than 0.5 mm. Make sure the cutting tool is working properly.
Five, board positioning hole
1. Reference symbols for PCB board integral board positioning and fine pitch device positioning. In principle, QFPs with a pitch of less than 0.65 mm should be placed at their diagonal positions; the positioning reference symbols for the imposition PCB daughter boards should be used and placed diagonally to the positioning function.
2. Large components should be left with positioning posts or positioning holes, such as I / O interface, microphone, battery interface, micro switch, headphone interface, motor and so on.
A good PCB manufacturer should consider the factors of production when designing impositions to facilitate processing, increase production efficiency and reduce production costs.