Application of Screen Printing in PCB Manufacturing

With the continuous development of screen printing technology, the new screen printing materials, screen printing process and testing equipment used in the PCB industry have been perfected day by day, making the current screen printing technology suitable for high-density PCB production. The application of screen printing in PCB manufacturing mainly includes the following three aspects:

• Application of PCB surface solder mask
• PCB pattern transfer process and application of anti-corrosion and anti-plating layer
• Application of PCB surface marking symbols

Because the first two applications are technically difficult to achieve, this article will introduce them in a targeted manner, and at the same time make a brief introduction to the screen printing materials of the PCB process.

Screen Printing Materials

1. Wire Mesh

Screen is the most important part of screen printing plate, because it is the key to control the fluidity and printing thickness of ink, and determines the durability of the screen and is widely used in quality switch manufacturing technology. In addition, the excellent combination of screen and screen photosensitive material is also an important factor in making high-quality, high-precision screen printing plates. In order to ensure a good combination of the screen and the photosensitive material, the traditional method is to roughen and degrease the new screen, which can ensure the quality of the screen and prolong the service life of the screen.

2. Printing Plate Photosensitive Material

Commonly used photosensitive materials for printing plates include diazo sensitizers and photosensitive films. Diazo emulsions are commonly used in screen printing screen production. The photosensitive film has the characteristics of uniform and controllable film thickness, high resolution, high definition, wear resistance, and strong adhesion to the screen. It has been widely used in character printing on printed boards.

3. Screen Frame

The material of the screen frame and the shape of the cross section are very important. Compared with a screen frame of a certain size, if the screen frame strength is not enough, the consistency of the tension cannot be guaranteed. Nowadays, high-tensile aluminum mesh frames are generally used.

With the development of screen printing technology, screen printing technology occupies an increasingly important position in the printed circuit manufacturing industry. Its application not only improves the production efficiency of printed circuits, reduces the production cost of printed circuits, but also improves the processing quality of printed circuit boards. On the other hand, due to the research, development and application of screen printing materials, especially the development of functional inks, the application field of screen printing has become more diversified and has been continuously expanded, such as silver paste printing in membrane switch manufacturing technology. Printing and stencil manufacturing of solder paste in SMT manufacturing technology; Application of PCB strippable ink, etc.