Precise Solder Dispensing in High-Throughput Micro-Device Packaging Applications

摘要

Advanced micro-device packaging sets a high and dynamic standard for its supplier industries for speed, precision and flexibility. A high-precision and high-throughput solder paste dispensing process has been developed to fill the gap between novel packaging design and traditional processes oj stencil printing and slow dispensing. This process is being used in 35 PCBA production lines to package smart phones, MEMS devices and automobile control panels. These production lines are in full service 24/6 with each dispense system running at 2500 units per hour (UPH) for simple MEMS patterns, 144 UPH for complex smart phone patterns and 6 UPH of full automobile control panels. A well-controlled valve design is applied to achieve high dispensing accuracy at fast speeds. This has removed process design barriers related to dispensing and has matched the high-end platform capability. This process also provides packaging designers with a flexibility superior to the existing solder printing process. The dispense pattern and route can be modified at no cost, in minutes, and during any step in the design or the assembly stage. Dispensed shapes include dots, lines, rectangle frames and annular rings, with fine edge definition of 40um or less. This process can cover a wide range of pattern dimensions between 0.18mm and 100mm. Solder pastes that can be dispensed during this process have 80～90% metal content, type 4 to 6 mesh size. New processes are under development to further push limitations on throughput, dimension, flexibility and material dispensability.