For most printing factories in China, the printing method of printing text and images on paper or film can be divided into letterpress, lithographic, intaglio, and perforated plates according to the shape of the plate, and they are used according to the purpose. These common general printing technologies have been evolving from simulation to digital, and then connected to the network to change their appearance.

Let me focus on the strength of high-precision printing technology and its application in electronic engineering to analyze the current situation of offset printing (lithographic) and screen printing (serigraphy). In general, it can be considered that the ink viscosity is relatively high and the reproduction film thickness is relatively thin, and the fine line reproducibility seems to be better.

As the most popular example of offset printing in China printing factories, there have been cases where the color cover of a weekly magazine was printed with 700 lines overseas. Usually 175 lines are used for printing, but I suddenly decided to use 700 lines for printing. Of course, the expressiveness of fine parts will be improved. Images that are invisible to the naked eye can be clearly recognized by looking through a magnifying glass. Because it is a dot, although the thin line width is difficult to show, it can still show up to 20μ. However, this only illustrates the printed image. When it comes to model reproduction for electronic engineering applications, the requirements are much stricter. This is mainly due to insufficient ink film thickness.

In addition, as an example of intaglio printing, fine text and fine shading are printed for the anti-counterfeiting of stocks, securities, etc. If you look at this part of the image with a magnifying glass, you can probably see the reproduction of fine lines of 10-20μ. Generally speaking, compared with offset printing, gravure printing can enhance the thickness of the ink film, so it is beneficial to the application of electronic engineering.

Using gravure offset printing to print LCD color mirror

Here is an example of using gravure offset printing to print LCD color mirrors. A printing method in which ink is applied to the intaglio plate and transferred to the silicon blanket, and then the entire amount is transferred to the glass plate. At the time of mass production, according to the design size, a color mirror with a line width of 40 ~ 50 μ was printed and put on the market. However, the remaining issue is the flatness of the model surface.

As a method of improving the flatness, a reverse printing method has been developed. This is to first coat the ink directly on the blanket, remove the unnecessary parts with a negative relief plate, and finally transfer it to the plain glass plate in turn. The flatness of the model depends entirely on the uniformity and smoothness of the ink layer coated on the blanket. Therefore, it can be said that compared with the gravure offset printing method, this method focuses on the ease of flatness control.