Reflow soldering process flow
Printing quality inspection inspect the printed pcb (Inspect the printing quality, and there must be no missing printing, printing offset, etc.)
SMT quality inspection (check component placement quality, and correct defects)
The first piece inspection check the components (check the parameters, specifications, polarity process requirements, etc. of all mounted components according to the process instructions. The first piece can be mass-produced after the first piece is confirmed OK)
AOI automated optical inspection (use AOI for reflow soldering or curing products using optical contrast inspection. After defective products need to be repaired, perform AOI inspection again)
The process flow of the SMT placement machine is relatively complicated. Simply put, it is the process of using placement technology to remove the components from its packaging structure, and then placement to the designated position set by the system. Many placement machine manufacturers will use simple hand tools or simple mechanical devices for manual placement. If we want to achieve fully automatic and intelligent placement, we can use the following methods to operate.
The basic process flow of SMT placement machine
1. System setting: Set up all the parameters we need to fill in the placement machine system, which must be accurate.
2. PCB loading: the PCB board we need to mount is automatically loaded through the automatic board loading machine; in this way, the PCB board we need to mount will be automatically transferred to the placement machine workbench and automatically positioned to the system In the coordinate system
3. Pick and place: The feeder of the placement machine provides the components (materials) we have prepared in advance to the placement machine. The placement machine captures the current component position through the positioning system, and then sucks the component through the suction nozzle. Then the center of the component is coincident with the center position set by the system (X-axis, Y-axis coincide), and finally the original is accurately mounted to this position.
4. PCB unloading: When our current PCB boards are all mounted, they will be automatically transferred from the placement machine to the next position through the automatic unloading machine for subsequent operations, and at this time, the automatic loading in front of the placement machine The board machine will also provide the new PCB board to the placement machine
5. Silk screen printing: its effect is to print solder paste or patch glue onto the PCB pads to prepare for the soldering of components. The equipment used is a screen printing machine (screen printing machine), located at the forefront of the SMT production line.
6. Dispensing: It is to point the glue to the solid position of the PCB, and its important effect is to solidify the components on the PCB. The equipment used is a dispenser, located at the forefront of the SMT production line or in front of the inspection equipment.