Dispensing Flip Chip Underfill PRocess Problems and SOlutions

摘要

Although Flip Chip is not a new technology, over the laast few years we have seen this low cost interconnect solution applied ot substrates other than ceramic. It is now more and more common that bare die and flip chip are mounted onto FR4 and even flex substrates for low cost manufacturing of advanced electronics such as PDA's, pagers and mobile phones. Along with the use of these new substrates has arisen the need to "underfill" the die after reflow. This paper details the different hardware requirements as well as the process parameters involved and their effect on the final results obtained. Understanding each aprameter and the controls that are required in a production environment is key to ocrrect implementation of the process.