Printing Technology Applied in Electronic Engineering (I)

In the field of electronic engineering, high-precision manufacturing methods are used in the actual production industry, mostly using photolithography.

Table 1 summarizes the minimum line width of commercially available electronic engineering components and optical components. From the point of view of mass production processing methods, the photomask model must have a photolithographic plate making process because of the nanoscale level, but 10μ The above-mentioned line-width picture tube barriers and printed circuit board models are currently also mass-produced using a photolithographic process. The reason is that this method is highly reliable.

In spite of this, due to the widespread use of optical components in the field of electronic engineering and the requirement to further reduce the cost of processing methods, it is being explored to replace other processes such as printing, inkjet, and electrophotography.

This is due to limited space. It can only briefly introduce the high degree of fineness that can be achieved by adopting printing processing methods, and several examples of its production and application.

Table 1 Mass production processes of various electronic engineering components and optical media

Various ways of printing

The printing method for printing characters and images onto paper or film can be divided into relief, lithographic, gravure, and stencil depending on the shape of the layout. These common general printing technologies have been evolving, moving from simulation to digital, and then connected to the Internet to change the appearance.

Here, we focus on the strength of high-precision printing technology and its application in electronic engineering to analyze the status of offset printing (lithography) and screen printing (hole printing) (see Table 2). In general, it can be considered that the viscosity of the ink is relatively high, and when the thickness of the reproduced film is relatively thin, the fine line reproducibility seems to be better.

Table 2 Various printing methods and reproduction film thickness

What kind of high precision can be achieved in plate printing and gravure printing?

As an example of the most popular offset printing, the overseas color covers of weekly magazines have been printed on 700 lines. Usually printed on 175 lines, and suddenly decided to use 700 lines of printing, the expressiveness of the subtle parts of course will increase. Unclear images can be clearly seen by looking through a magnifying glass. Because it is a dot, although the thin line width is difficult to show, it can still show a degree of 20μ. However, this is just a description of the printed image. When it comes to the reproduction of models for electrical engineering applications, the requirements are much more stringent. This is mainly due to the lack of ink film thickness.

In addition, as an example of gravure printing, fine text and subtle shading printed for the security of stocks, securities, and the like, if a magnifying glass is used to look at this part of the image, the reproduction of a thin line of 10 to 20 μm can be seen. . Generally speaking, compared with offset printing, gravure printing can enhance ink film thickness, so it is advantageous for the application of electronic engineering.

Using gravure offset printing LCD LCD mirror

Here is an example of the use of gravure offset printing LCD garnet mirror. After the gravure printing ink was transferred to the silicon blanket, the entire amount was transferred to the printing method on the glass plate (see Figure 1). At the time of mass production, according to the design size, the dichroic mirror with a line width of 40 to 50 μm was put into the market. However, the remaining problem is the flatness of the model surface.

As a method of improving the flatness, a flip printing method has been developed. This is done by first applying the ink directly to the blanket, removing the unwanted part with a negative relief, and finally transferring it to a clear glass plate. The flatness of the model is entirely dependent on the evenness 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 fact that the control of flatness is easy to accomplish. (To be continued)

Note: The table in the text is omitted

Reprinted from: Graphic Arts