PCBA Tech - Reasons and solutions for high smt throwing rate

In the process of smt patch processing, the problem of throwing may occur. If it is within the range of the normal value, it is a normal problem. If the value of the throwing rate is relatively high, then there is a problem, then the production Line engineers or operators should immediately stop the line to check the reasons for throwing materials, so as not to waste electronic materials and affect production capacity. Then, what are the reasons for the throwing of the placement machine and how to solve them, let me tell you about this problem.

1. The problem of electronic materials

If the electronic material itself is ignored in the PMC inspection, and the electronic material flows to the production line for use, it may lead to increased throwing, because some electronic materials may be squeezed and deformed during transportation or handling,

or when they leave the factory. There are problems with electronic materials due to production reasons, so this needs to be solved in coordination with the electronic material supplier, and new materials are issued and tested before being used on the production line.

2. The location of the feeder feeder is wrong

Some production lines work in two shifts, and some operators may be tired or negligent and cause the feeder station to be mistaken. Then the placement machine will throw a lot of material and give an alarm. At this time, the operator needs to check and replace the feeder. Material station.

3. Reasons for the picking position of smt placement machine

The placement of the placement machine relies on the suction nozzle on the placement head to sequentially suck the corresponding materials for placement. Some throwing materials are caused by the trolley or feeder and the material is not in the position of the suction nozzle or does not reach the suction height. The placement machine will fake picking and fake mounting, and there will be a lot of empty stickers. In this case, it is necessary to calibrate the feeder or adjust the suction height of the suction nozzle.

4. The nozzle problem of the placement machine

Some placement machines run efficiently and quickly for a long time, the suction nozzle will be worn, resulting in the material being sucked and falling or failing to pick up, and a large amount of throwing will occur. In this case, the placement machine needs to be maintained in time. Change the nozzle frequently.

5. The negative pressure problem of the placement machine

The placement machine can absorb components and place them, mainly relying on the internal vacuum to generate negative pressure for suction and placement. If the vacuum pump or the air pipe is damaged or blocked, the air pressure will be too small or insufficient, and the components will not be absorbed. Or drop during the moving process of the placement head. In this case, the throwing material will increase. In this case, the air pipe or vacuum pump needs to be replaced.

6. The visual recognition error of the placement machine image

The placement machine can mount the specified component to the specified pad position, mainly due to the visual recognition system of the placement machine. The placement machine visually recognizes the part number, size, and size of the component, and then passes through the placement machine. Machine algorithm, the component is mounted on the designated PCB pad. If the vision is dusty or dusty, or is damaged, there will be recognition errors and lead to errors in picking materials, resulting in increased throwing. In this case, you need to replace the vision recognition system.