The key to equipment selection for SMT production line

1. Plan the PCB processing capacity of the entire SMT production line: such as PCB size, thickness, weight, requirements of the board edge, positioning requirements (fiducial marking, positioning holes, thickness of edge connector, and warp and twist restrictions, etc.), must have detailed and accurate planning. These plans should be carried out at the level of the entire line of equipment. If there are multiple lines with different specifications, they shall be standardized.

2. The overall production line required mounting capacity (chips/hour); the components range from 0402-55mm*55mm devices, CSP, QFP, BGA, UBGA, chip electrolytic capacitors, potentiometers, inductors, 50*150mm connectors , The component height is 25mm; the placement accuracy is ±0.08mm/Chip, ±0.05mm/QFP; the maximum PCB area is 510mmx460mm. With good compatibility for subsequent added equipments.

3. For the placement machine, you must pay attention to selecting an integral casting frame to ensure the placement accuracy of CHIP and QFP; select a placement machine with flying centering system, and with CCD mounted on the placement head to ensure the accuracy of the placement position; configure offline programming equipment and software to shorten the preparation time required for line change, so as to optimize the speed of the entire line; the feeder should be configured according to the circuit board product with the largest number of components, and a few more feeder should be configured for preparing components or replacement components, so as not to affect the mounting speed.

4. For the solder paste printing machine, choose automatic vision to ensure printing accuracy, so as to reduce the defective rate of circuit board soldering; especially pay attention to selecting equipment with a printing cycle of about 10S, which can eliminate the bottleneck effect of the whole line production. Finally, select equipment can change line within a short line time to ensure continuous production.

5. For reflow soldering, the length of the heating zone should be more than 1.8M, with 8 temperature zones or more, cooling zone, temperature curve test function etc., and with UPS power supply to ensure the quality of reflow soldering.

6. For AOI optical inspection machine, chooses CCD camera, coaxial bowl-shaped light source, equipment with stable and reliable misjudgment rate to ensure the quality and speed of inspection.