1. Modulation of screen printing ink
The thick or thin screen printing ink will directly affect the quality of the screen printing. If the ink is too thin, the ink layer will become thinner, and the lines will become blurred. If the ink is too thick, it is easy to block the network. Therefore, the ink needs to be adjusted appropriately according to actual requirements.
2. Screen printing screen selection
It is accurate and consistent with the wire diameter cloth quality and Mesh number, and the quality is stable. The grid is generally selected from 450 to 500. For the thin, high-fineness, and ink absorption on the substrate, a large screen with a Mesh size should be used. On the contrary, a lower screen Mesh should be selected. The position on the screen and the screen size of the text for plate making should be determined according to the structure, size and substrate and position. If the design is not good, it will affect the print quality, and even screen printing is not possible. The choice of specific Mesh.
3. Scraper selection
Use polyurethane scraper material. The abrasion resistance, solvent resistance and toughness of the polyurethane rubber scraper are very good. In 60 ~ 80 Shore hardness. The tension of the large screen and the smooth surface of the substrate are good, and the hardness of the blade should be high. Squeegee for screen printing
4. Screen positioning
The fixture materials use metal, wood, plywood, and PVC transparent sheet. Due to the difficulty of positioning, the substrate and small-scale fixtures should be made of metal. As shown near the edge of the substrate, the wood on the flat surface should be fixed to the edge of a piece as high as easy to paste text. The network distance is usually 1 ~ 2.5mm. If the printed pattern is easy to paste or Mesh, it refers to the transfer distance of a large network.
5. Silk screen process
The squeegee pressure is high, so the ink volume, but the screen is easy to deform, so the squeegee pressure is not high. The squeegee speed is usually 60 ~ 200mm/s, the squeegee speed, the amount of ink is small, but it is not easy to block the network. Therefore, if the screen printing ink is clogged, the squeegee speed must be fast. Scrape the line, straight line and curve three. Should be selected according to the smoothness and image of the wiring board on the substrate. Squeegee long lines and ink consumption, the amount of scraping should be even greater, even if you scrape a layer of ink first, then scrape printing.
