A study of the geometry of microball lens arrays using the novel batch-fabrication technique

The innovative concept of batch-fabrication of microball lenses not only reduces the cost of micro assembly, but also replaces conventional aspheric lenses or costly GRINs without sacrificing performance. The process of production is based on thermal reflow of dual-layer polymer systems to batch-fabricate microball lens arrays. The shape of the microball lens and neck width will affect the application of an optoelectronic product and its fabrication method, such as the alignment of the light source and the size of the holder. Therefore, this study focuses on the influence of the major factors of microball radius and neck width. The results reveal that the interactive relationship between the microball radius and neck width plays an important role in the formation of microball lens and application. In the dual-layer polymer system, the PI layer was used as a holder to prop up the AZ4620 layer, and the height of the PI layer was controlled by the reflow temperature. When the microball neck width is improperly controlled, it results in the microball peeling off from the interface between the two polymers.