Fabrication Process of Micro-Lens Arrays

Micro-lens array, as an important component in optical systems, its processing technology directly affects the performance and application of the final product. Currently, the industry has developed various methods for fabricating micro-lens arrays, including the photoresist thermal reflow technique, laser direct writing technology, fabrication of photoresist micro-lens arrays, and Argon ion beam etching method for quartz micro-lens arrays. This article will detail these widely used micro-lens array processing technologies and their advantages and disadvantages.

Photoresist Thermal Reflow Technique

The photoresist thermal reflow technique is a commonly used micro-lens array processing technology. Its main steps include exposure, cleaning, and thermal forming. First, a mask is used to expose the photoresist to form the desired pattern, such as hexagonal, rectangular, or circular shapes. Next, the residual debris is cleaned off, and it is thermally formed on a heating platform. The advantage of the photoresist thermal reflow technique lies in its simple process, low material and equipment requirements, easy scalability, and controllable process parameters. However, the disadvantages of this method are also quite apparent. Due to the limitations of the process itself, the fabricated micro-lens arrays may have certain defects, and the mechanical and chemical properties of the materials may also affect the optical performance. Therefore, although the photoresist thermal reflow technique is widely used in production, its applicability may be somewhat limited.

Laser Direct Writing Technology

Laser direct writing technology is a high-precision micro-lens array fabrication method. The steps include designing the exposure structure, inputting the design pattern into the laser direct writing system, and laser etching on a substrate with photoresist. The advantages of laser direct writing technology are its high precision and high quality, suitable for model making, and the ease of scaling up the production, with relatively low costs. Laser direct writing allows precise processing of micro-lens arraysand obtaining good product quality. This method is particularly suitable for the production of micro-lens arrays requiring high precision and complex patterns. It is a crucial technology in current micro-lens array manufacturing.

Fabrication of Quartz Micro-Lens Array

The fabrication process of quartz micro-lens arrays involves the application of photoresist and Argon ion beam etching techniques. First, by selecting a suitable substrate material and coating photoresist on a quartz substrate, ultraviolet light is used to create a photomask on the photoresist. After exposing and developing with a chromium mask, the photomask pattern is obtained. Then, through thermal treatment, the surface forms a photoetched microlens pattern. Quartz micro-lens arrays can also be fabricated using Argon ion beam etching. This method utilizes energized ion beams to bombard the target material surface, performing sputter etching. The advantage of Argon ion beam etching technology is that it allows efficient pattern transfer. By optimizing the etching conditions, the processing accuracy and efficiency of micro-lens arrays can be improved. However, this method requires high standards for equipment and processes, necessitating strict control of the ion beam's energy, angle, and other conditions.

Micro-lens array processing technology plays an important role in optical systems. The photoresist thermal reflow technique, laser direct writing technology, the fabrication of photoresist micro-lens arrays, and Argon ion beam etching for quartz micro-lens arrays each have their unique advantages and disadvantages. Choosing the appropriate processing technique not only improves the production efficiency of micro-lens arrays but also optimizes their optical performance and application effects. With the development of technology, these processing techniques will play an increasingly important role in the manufacturing of micro-lens arrays, providing strong support for the innovation and development of optical systems.