Our screen printers help achieve to Progress in electronics!

TEL: 0081-473-50-5131

お問い合わせ

Practice of screen printing

 
1.Implementation of screen printing
The three conditions listed below are required for optimum screen printing.
1) The setting of the optimum conditions for the paste is important.
2) Optimized screen mask specifications
3) Optimized printing conditions by screen printing

condition

4) Doing screen printing.
Screen printing requires a paste, a screen, and a screen printer. The specifications of each of these items are shown below.
A. Paste : Type, ratios of filler, resin, solvent, additive, etc., viscosity
B. Screen : Silk gauze material, tension, type of silk gauze frame, bias
C. Screen printer : Type and hardness of squeegee, attack angle, clearance, squeegee and scraper speeds, pressure, back pressure

5) For better printing
What is most important for better printing is the rheology of the paste. Printing quality depends greatly on it. The next important factor is the proper specifications of the screen mask. Although the optimum paste and screen mask almost determine printing quality, there is one more requirement for better printing: the optimum printing conditions of the screen printer.
2. The basic concept of Micro-tec.
1) MICRO SQUEEGEE (Micro-tec’s original)
MICRO SQUEEGEE has the following advantages
A. The ink discharge force can be stabilized at a fixed angle.
B. It ensures higher printing accuracy under uniform pressure in combination with a low-pressure system.

Micro-squeegee

2) Vertical float type air balance system (Micro-tec’s original)
Our air balance system is proud of the following features
A. With a printing system designed for printing pressure, images can be printed with a high degree of reproducibility, irrespective of the operator’s skills or capability.
B. Images can be printed under low pressure (low-pressure system).
C. The optimum printing conditions are available in combination with MICRO SQUEEGEE.
D. High productivity: The air balance system imposes less burdens on the plate and the squeegee, enabling them to serve for many years to come.

squeege head

3) The printing conditions can be set digitally.
The squeegee pressure, the scraper pressure, and the back pressure can be individually set with the aid of a precision regulator and digital display.

pressure_settings

4) Low vibration
Adopted for squeegee travel is a linear travel mechanism comprising an AC servomotor and a steel belt (PAT・P), featuring low vibration and high linearity.
5) Highly rigid structure
To maintain the set optimum printing conditions and reduce the effect of the long secular change in machine accuracy on printing accuracy, the movement of the drive unit is minimized, and the printing plate frame is fastened to a highly rigid base supported by four columns.

structure

3. Four mechanisms of screen printing
Four steps are carried out in screen printing.

rolling

1) Rolling
2) Discharge

leveling

3) Plate separation
4) Leveling
4. Four conditions for proper printing
1) Attack angle
atack angle:large atack angle: small
2) Squeegee pressure
pressure
3) Clearance
4) Squeegee speed
  • Relationship with paste viscosity
    Paste viscosity   Squeegee speed
    High Reduce
    Low Increase
  • Relationship with plate separation
    Delayed plate separation Reduce the squeegee speed to enable plate separation to follow it.
 
5. Ideas for realizing high-accuracy printing (summary)
1) Low clearance
2) Quick plate separation: Use a high-tension plate.
3) High-strength plate frame
4) Printing under low pressure
5) Stabilized squeegee travel
6) Rigidity and accuracy of printer: Parallelism among the table, the squeegee, and the plate
7) Working environment: Environmental control by temperature regulation