By Ultrasonic Systems, Inc. (USI)
Polyimides are high performance insulating materials used in may applications including the fabrication of multi-layer high-density interconnects for advanced packaging. In the case of wafer-level and panel-level packaging a photoimageable polyimide is used to provide the passivation layer that enables connections between layers. The polyimide must be applied in a uniform layer to ensure that the inter-layer connections can be properly formed. In the following example, the USI Prism 800 system was used to produce 7.5 micron diameter vias in a 10 micron thick layer of polyimide using a 300 mm diameter silicon wafer as the test substrate. The polyimide layer thickness was measured across the surface of a 300 mm diameter wafer. A statistical analysis of the polyimide film thickness data is presented above. 7.5 micron vias are produced in a ployimide layer applied with USI’s nozzle-less ultrasonic spray technology. The same results have also been achieved on panel size substrates up to 650 mm x 650 mm. Please contact us directly to receive a detailed technical presentation and paper on this promising new process. Contact us to discuss your coating requirements.
