Enhancing the Fracture Resistance of Medium/Small-Sized TFT-LCDs Using the Six Sigma Methodology

Maintaining satisfactory fracture resistance of medium/small-sized thin-film transistor liquid crystal displays (TFT-LCDs) imposes additional challenges with the demand for thinner and larger display screens from customers. This paper presents a case study on the application of DMAIC-based Six Sigma methodology for improving the fracture resistance of medium/small-sized TFT-LCDs of display panels manufactured by a company. Analyses show that, in this case, the unsatisfactory fracture resistance reflected by bending strength was related to the defective TFT-LCD cutting plane. Therefore, the objective of the improvements was to reduce variations in the cutting process and to find solutions to control the process factors that influence the same, such as operators, scribing parameters, and scribing wheels. We obtained significant bending strength increases of 35% in the
x
-axis and 16% in the
y
-axis of medium/small-sized TFT-LCDs with the application of DMAIC. The quality performance was enhanced from lower than 1-sigma level to higher than 4-sigma level, in addition to a financial impact that translated into extra business revenue of at least 15.4%.