Researchers have developed a method to produce arrays of pure gold microspheres for advanced electronics; This method has improved the connection reliability and performance of microdisplays, with promising applications in high-resolution displays.

A research team led by experts from the Institute of Solid State Physics at the Hefei Institute of Physical Sciences, part of the Chinese Academy of Sciences, has successfully developed an effective method to create a series of gold-based anisotropic conductive adhesive films (ACFs). microspheres for advanced packaging applications.

The results of the research were published at: Nature Communication.

As electronic devices become smaller, it becomes increasingly difficult to obtain high-quality connections that are reliable and short-circuit-proof. In 2014, a Japanese company developed array-ACF, which uses arrays of metal-coated polymer microspheres to form these connections; however, the bond between the metal and the polymer may crack under pressure, affecting performance.

In this study, researchers developed a new approach to produce arrays of pure gold microspheres within 1 min using positional self-assembly and laser-assisted maturation strategy. This technique is based on a rapid, layer-by-layer laser-induced melting and fusion process, effectively avoiding the principle of anisotropic growth.

The main advantage of this strategy lies in the shaped size of the gold microsphere, which is determined by the initial patterned microholes and precisely positioned within them. This feature not only facilitates precise control but also ensures compatibility with industrial lithography techniques.

Versatility and advantages of the material

This technique is also flexible and can be used to create different types of microspheres, including microspheres made from gold and other metal alloys. When these microspheres are processed with a laser, they come together seamlessly to form stable and strong materials.

Compared to commercial gold-plated microspheres, pure gold microspheres are much more flexible and resistant to electrical problems under pressure. These gold microsphere arrays could help improve the bonding of microdisplays such as those used in μLED chips, which is key to creating high-resolution displays. This breakthrough could have a huge impact on the future of electronics and display technology.