The Cause Of Frequent Failures Of Printing Presses Due To Static Electricity

- Jan 08, 2019-

Frequent crashes when the DEK press is used in a patch processing plant (the first press on the machine after unpacking)

After analysis, the reason for the frequent crashes of the printing press is that the PCB has a high static electricity. analyse as below:

(1) After 50 pieces of light plate are printed through the furnace, there is no problem; then the light plate without the furnace is printed, and the machine starts to crash frequently, indicating that it may be caused by static electricity.

(2) Static measurement of the light board that has just been removed from the package, the result is 105V, and the static electricity is only 4V after measuring the PCB after the furnace. Measure the light panels of other products that have just been unpacked, and the static electricity is 4V. Then re-measure the plate that was placed for a period of time (about 100 mils) after unpacking, and the static electricity was 45V.


pcb


Therefore, it can be judged that the packaging material of the board is not anti-static (high static electricity), resulting in abnormal equipment. The board is vacuum-packed with PVC bags, separated by white paper, and protected on both sides with glue board, as shown in Figure 10-4.

Reason for the printer crash:

After the screen stopper on the graphic recognition camera touches the electrostatically charged PCB, the static electricity is transmitted to the camera. The excessive static electricity interferes with the camera's imaging signal and the brightness of the light source, causing the camera to fail to recognize the Mark point. And there is a crash.

Production site:

(1) After unpacking the PCB, place it for 1-10h, then let the static discharge and then print.

(2) Or use an ion fan to blow off the packaged PCB for 2-20 minutes before printing.

(3) Temporarily attach an insulating tape to the board stopper.

This is a typical case where static electricity affects the normal operation of the equipment.


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