| The increasing market scale of the radio frequency identification (RFID) brings forth a great challenge for the RFID package equipment. The peeling of the die from the wafer is completed by the ejector of the bonding module. The stress distribution and displacement of the chip under the contact force between the piercer and the chip is the key of a successful die-peeling process. It is necessary to analyze the die peeling process and the important factors that may cause die failure in this process.The main content of the research in this paper includes: classification of the die peeling modes, the detail of the die peeling process, analysis of important factors causing die failures, the structural design of an ejector.First, four standards are applied to classify the die peeling modes appears in practice, the application situation is also discussed. There are two stages in the die peeling process.The details are described to show the very moment that chip failure happens. The factors causing die failures are summarized. Two important factors about the structural design are picked out as the research issue of the paper.Second, the stress distribution and displacement of the chip under different speeds of the piercer and different vacuum areas are analyzed through static FEM. Some conclusions about the die failure are obtained after the comparison of the maximum stress of the chip. A few tests are carried out to get the properties of the material and the boundary conditions. A FEM-TEST method is supplied to get the maximum pierce speed.Finally, the structural design of the ejector is depicted. It has been proved that the design can perfectly suits the practice demand. The contour curve of the cam and the vacuum parts are so important that the design processes are detailed in this paper.The achievements in the paper are very helpful for the analysis of chip failure and the parameter optimization of the design and the remission of the ejector. |
