With the continuous development of touch screen technology, lithography technology plays an increasingly important role in touch screen production. Among many lithography processes, yellow light process (also known as visible light lithography) has become a key technology that cannot be ignored because of its wide application in capacitive touch screen manufacturing. As a mature manufacturing method, the yellow light process provides important support for the production of touch screen with its stability, cost effectiveness and operability. In the production of capacitive touch screens, the yellow light process plays a vital role, especially in efficient production, precision machining and cost control.
1. Overview of yellow light process
Yellow light process is a lithography technology based on visible light sources (mainly yellow light). In the manufacture of capacitive touch screen, it is mainly used to make the electrode pattern of touch sensor. The basic principle is to use ultraviolet or visible light to shine on the substrate coated with photosensitive glue, and through the steps of exposure, development and etching, the circuit pattern is accurately transferred to a transparent conductive film (usually ITO film).
One of the advantages of the yellow light process is that it uses visible light, rather than higher precision ultraviolet light, which makes the process relatively simple and low cost, but also easy to promote in industrial production.
2. Advantages of yellow light process
Cost effective
Compared with ultraviolet lithography (UV lithography) and deep ultraviolet lithography, the production cost of the yellow light process is relatively low. This is mainly reflected in the following aspects:
Low cost of light source: The light source used in the yellow light process belongs to the visible range, and the cost of yellow light source is lower than the deep ultraviolet (DUV) light source used in ultraviolet lithography, thus greatly reducing equipment procurement and maintenance costs.
Wide selection of photoresist: The photoresist used in the yellow light process has a wide variety of photoresist (photoresist), and the price is relatively low, suitable for large-scale industrial production.
Strong adaptability: The yellow light process can adapt to a wider range of production needs, especially for low-end touch screen products, can achieve higher manufacturing accuracy at a lower cost.
Therefore, the yellow light process still occupies a large share in the price-sensitive market and the low-end market.
Easy to operate, easy to achieve mass production
Compared with the ultraviolet process, the operation process of the yellow light process is relatively simple. Although the accuracy is not as good as ultraviolet lithography, in touch screen production, the yellow light process can meet the requirements of many application scenarios.
Simple process flow: the steps of Huang Guang lithography include exposure, development, etching, etc., the process chain is short, the operation is simple, and it is easy to train workers, which reduces the technical difficulty in the production process.
High yield: Because the operation is relatively simple and the equipment is mature, the yellow light process can achieve a high yield in actual production, reducing the product defect rate.
These characteristics make the yellow light process particularly suitable for small and medium-sized production lines, especially in the initial production stage of touch screen panels.
Suitable for mass production
Another advantage of the yellow light process is that it is suitable for large-scale industrial production. Because of its simple process, stability and efficient operation of the equipment, it is very suitable for mass production.
High production efficiency: The Yellow Light process is able to support fast production cycles, which is especially important for large-scale production needs. Achieve mass production in a short period of time to meet market demand.
Strong stability: The yellow light process is highly stable and can provide consistent and predictable results in large-scale production. Even in the production process, the operation and adjustment of the lithography machine is relatively simple, and it can maintain a high accuracy.
Therefore, the yellow light process is one of the mainstream processes chosen by many touch screen manufacturers, especially in the middle and low-end touch screen market.
Moderate accuracy to meet the needs of low-end applications
Although the resolution of the yellow light process is not as good as that of the ultraviolet light process, it can still meet the accuracy requirements of most of the low-end capacitive touch screens. Especially in application scenarios where touch accuracy requirements are more relaxed, the yellow light process is sufficient to provide good capacitive touch performance.
Adapt to low and medium resolution requirements: for some low-end intelligent equipment, POS machines, ticketing machines, industrial control equipment and other applications, the resolution of the yellow light process is enough to meet its needs, so it is still the first choice for the production process of many equipment.
Reduce costs and adapt to market demand: with the popularity of electronic equipment and the increase in cost pressure, many manufacturers choose the yellow light process to produce capacitive touch screens, which can not only ensure the basic touch accuracy, but also control costs, to achieve the most cost-effective production mode.
Flexible application scenarios
Another advantage of the yellow light process is its wide applicability. In addition to capacitive touch screens, this technology is also widely used in the production of other display devices and electronic components, such as OLED displays, sensors, circuit boards, etc. With the diversification of the demand for various electronic products in the market, the yellow light process can also flexibly adapt to different manufacturing needs.
3. Limitations of yellow light process
Although the yellow light process has many advantages, it still has certain limitations, especially in some high-end applications, its limitations are particularly obvious.
Low resolution: The resolution of the yellow light process is usually lower than that of the ultraviolet light process, so for some high-precision, high-resolution capacitive touch screens, the yellow light process may not meet the requirements. For products requiring ultra-high resolution, multi-touch and high sensitivity, UV processes still dominate.
Limited applicability: In high-end touch screen applications that require higher touch sensitivity, thinner electrode layers, and greater transparency, the yellow light process may not provide sufficient precision and performance.
Therefore, the yellow light process is usually more suitable for low-cost, mass-produced low-end touch screens, and still faces some technical challenges in the high-end market.
Step 4 Summarize
As an important technology in capacitive touch screen production, yellow light process is widely used in the manufacturing of middle and low end touch screen with its advantages of low cost, easy operation and strong adaptability. Its outstanding performance in production efficiency, cost control and large-scale production has become one of the preferred processes for many manufacturers. However, in touch screen applications with high resolution and precision, the UV process is still more competitive. In the future, with the continuous progress of technology, the yellow light process may also further enhance its application scope and accuracy through improvement and innovation to meet more complex market needs.