Statistical process control application to weld process

Improving bonding strength of tape-automated bonding technology by implementing statistical process control: a case study

“…The results show that the control charts implemented on the probimer and step wedge lines, and probimer developer have provided an effective means of identifying a cause-and-effect relationship between the processes. Cook et al [6] mention that statistical data trend analysis of the parameters in the welding process performed by control charts is not only valuable as a quality assurance monitoring and documentation system, it is also valuable in providing diagnostic assistance in troubleshooting equipment and material problems. Fan et al [7] provide a combined Shewhart-exponentially weighted moving average (SHEWMA) scheme based on wafer acceptance test data.…”

Sensors for Quality Control in Welding

“…Different types of discontinuities have been categorized for this purpose, such as cracks, porosity, undercuts, microfissures, etc. (Cook, 1997). Generally, good quality GMA welds are uniform and contain little or no artifacts on the bead surface.…”

“…This control shows optimal results in the disturbances detection of both, electric arc voltage and welding current monitoring signals (Cook, 1995(Cook, , 1997. As already explain, the signature signals analysis was made on the 150 ms moving window.…”

“…The stability of the short circuit gas metal arc welding process is directly related to weld pool oscillations. Optimal process stability corresponds to maximum shortcircuit rate, minimum standard deviation of the short-circuit rate, a minimum mass transferred per short circuit and minimum spatter loss, (Cook, 1997;Adolfsson, 1999;Wu, 2007). In the present work, the welding stability was evaluated using the sound pressure through the acoustic ignition frequency (AIF) and sound pressure level (SPL) signatures.…”

“…A high quality weld would generally yield small variation in the weld profiles, while low quality weld profiles would vary substantially, as irregularities and various discontinuities are encountered in the distinct profile scans (Cook, 1997). The initial weld profiles tested were the arc sound ignitions frequency, the average sound pressure level and the power spectral density using the continuous and octave fraction frequency domain.…”