Introduction


This is a 30-month research project supported by the Innovation and Technology Fund (ITF), Hong Kong University of Science and Technology (HKUST), and industrial sponsorship. The ITF and industrial sponsorship supports over HK$ 9 millions.

This project intends to develop new low cost flip chip technologies with intent to transfer these low-cost technologies to Hong Kong companies. Low-cost and lead-free flip chip technologies include 1) developing electro less processes for under bump metallization; 2) depositing bumps by stencil printing of solder paste (which can be lead-free) directly onto silicon wafers; 3) elimination of some other process steps that are cost intensive such as underfilling; 4) development of new material processes for redistribution, which will allow wafers from any foundry to be bumped so they can be applied to flip chip modules.

This project also intends to develop and disseminate lower cost and lead-free flip-chip technology, and its associated wafer level packaging technologies to various Hong Kong industries. This project will also provides 1) know-how; 2) pilot line; 3) bumped and redistributed samples; 4) reliability data, for Hong Kong companies involved in high density interconnects of silicon wafers to packaging substrates. Dissemination will be both on an ongoing engineer-in-residence basis as well as formal classes.

This project will definitely drive down the cost of high density interconnect which will results in 1) lowering the production cost of the company resulting in better leverage during sales negotiations; 2) having a higher level of readiness with faster prototypes and faster qualification samples and more information of product reliability; 3) more easy to the companies that need a subcontractor for flip chip work to find a local source; 4) Hong Kong subcontractors can have a higher level of independence and flexibility as having the ability to redistribute at the wafer level.