Faults and Countermeasures in the hottest PCB scre

2022-08-14
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Faults and Countermeasures in PCB Printing (IV)

5 Common faults and causes of mechanical printing countermeasures

5.1 causes and Countermeasures:

1) there is a gap in the blade edge of the scraper - grinding the scraper

2) the pressure of the scraper is too small - increase the pressure of the scraper

3) the distance between the plate and the printed board is too large - adjust the distance

4) the warping of the frame causes uneven pressure on the scraper - the replacement frame is often used in metal material experiments, and it is necessary to stretch and make plates again

5) the printing material viscosity is too high - mix the printing material and reuse it after stabilizing for a period of time after mixing

6) the plate making mask is too thick, the amount of transmitted printing material is small, and the printing wire is too thin - the mask thickness should be controlled during plate making (direct method)

7) printing speed is too fast - slow down the printing speed appropriately

8) improper selection of printing materials and high number of silk meshes - replace the printing materials and select the silk version with a slightly lower number of meshes

9) uneven pushing back printing material - adjust the doctor blade

5.2 inking

1) the blade edge becomes round - sharpen the blade edge

2) the angle of the scraper print is too small - appropriately increase the angle of the scraper print

3) printing material viscosity is too low - change 3. Sensor 1 uses only printing material with high viscosity

4) poor mixing of solvent and printing material - print after fully stirring the printing material

5) wipe the plate with solvent, and print it before the solvent completely volatilizes - after scrubbing the plate, print it after the solvent volatilizes

6) the number of silk meshes is too low - choose High-Purpose silk plate

5.3 poor printing patterns, spots, uneven coating of printing materials

1) poor thixotropy of printing materials - prepare printing materials according to data or replace with new printing materials

2) slow start of the post press version - adjust the viscosity of the printing material, increase the tension, and enhance the elasticity of the wind

3) the plate figure is too close to the edge of the frame - use a large frame for plate making, and make the smaller figure in the center of the plate

4) poor image formation of printing materials caused by static electricity - eliminate static electricity

5) the scraper angle is too small - adjust the scraper angle

6) uneven printing speed - adjust the scraper speed or repair the printing machine

5.4 the printing pattern has pinholes

1) during plate making, the coating of the plate mask is uneven, and the plate pattern has pinholes - repair the plate with sericin

2) impurities are mixed in the printing material to plug the hole - scrubbing version

3) dust in the air adheres to the plate graphics - scrub the plate to remove dust

4) the surface of the printed board is not cleaned, and there is dust attached to the plate - clean the plate, and the surface of the printed board is fully cleaned

when wiping the trial version, the version is accidentally scratched into small pinholes - for the repair version, wipe it gently with a soft cloth

5.5 version has short service life

1) the surface of the printed board is uneven or has burrs. During the printing process, the version is in contact with it, causing deformation of the version graphics or small holes - surface treatment

2) inappropriate plate tension - adjust the tension (self tensioning), and the fixed tension must be stretched again for plate making

3) improper selection of plate making emulsion) -- select the appropriate plate making emulsion according to the printing conditions

5.6 precautions for printing machine operation

1) the printing material dripping on any part of the printing machine must be wiped immediately

2) the moving parts of the printer must be lubricated every day

3) after adjusting the machine, the screws must be tightened

4) the printing machine must be installed horizontally

places with low humidity

5) suction cups are very important in printing and must not be bruised

6) it is not allowed to get the solvent on the suction cup

7) the vacuum pump dust collector must be cleaned once a month to ensure suction and prolong the service life of the pump

8) the operator must master the use rules of the printing machine. (1) (II) (III) (IV) (V)

2. Then check whether the serial port cable is connected to the computer

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