Let´s revise the ASTM method F.459 for wirebonding process control

Wire pull testing cannot be used to monitor wirebonding process control as the X-bar and R charts of row pull strength data routinely demonstrate wide variations. The bonding process appears to be out-of-control; indeed, the testing methodology and data collection itself are inaccurate in representing the process. Many factors, which are difficult to control in production, can subtly affect the raw SPC data. This paper reviews the pull test method used to identify the potential variation(s) that causes the errors and are misleading in the process control. The paper also includes the efforts to revise the ASTM´s method F.459 for its pull test in making the data collected using this method applicable in the statistic process control (SPC) chart