A self bonding wire process

In the past few years many companies have been experimenting with the use of bondable wire processes. The advantages to this type of process include reduced cycle times, less handling, and virtually no environmental impact. Using a bondable wire process can allow a manufacturer to completely build a product on one line without a lot of work in process. The process can be set to supply a product off a line in less than 10 seconds. The systems can be designed with tooling to form the product, test the product, and bond the product in one station. In some cases the product could be packaged immediately after this station. This paper investigates the use of DC power sources to thermally activate the bondable adhesive. The methodology of determining how much power is needed to heat the coil in the required time is investigated. A theoretical approach of estimated power verses bond time is supported by an experimental approach. A method for determining final temperature and temperature overshoot is presented. We discuss the advantages of using a constant voltage source compared to a constant current source.