This technical paper presents the resolution of high leakage current failures on QFN-mr （Quad-Flat No-leads Multi-Row） LF （leadframe） devices by optimizing the waterjet deflash process and eliminating the ESD （el...This technical paper presents the resolution of high leakage current failures on QFN-mr （Quad-Flat No-leads Multi-Row） LF （leadframe） devices by optimizing the waterjet deflash process and eliminating the ESD （electrostatic discharge） events. ESD damage to units can cause permanent or latent product failures which results in low final test yield, and worse, possible external customer complaints. The use of CO2 （carbon dioxide） bubbler was able to reduce the DI （deionized） water’s equivalent resistivity from 17 M？ to 0.30 M？, minimizing the tribocharging effect produced during the waterjet deflash process. Moreover, ESD events were eliminated by grounding the floating assembly equipment parts and installing appropriate ESD controls. It is of high importance to reduce or eliminate the leakage current failures to ensure the product quality, especially as the market becomes more demanding. After the optimization and implementation of the corrective and improvement actions, high leakage current occurrence was significantly reduced from baseline of 5,784 ppm to 20 ppm.展开更多
As power system interconnections become more prevalent, there has been an increase in use of thyristor controlled shunt connected compensation devices for dynamic power compensation and enhancement of real power trans...As power system interconnections become more prevalent, there has been an increase in use of thyristor controlled shunt connected compensation devices for dynamic power compensation and enhancement of real power transmission capacity. In this paper, an enhancement technique of real power transfer capacity of transmission lines is presented. A SVC （static var compensator） is designed and applied to a simple power system for this purpose. Increase in power flow and improvement in bus voltage profile are observed after using the SVC. Stability analysis of the system after experiencing fault as well as consequent fault clearance by time domain analysis has also beeu performed and satisfactory results are obtained.展开更多
文摘This technical paper presents the resolution of high leakage current failures on QFN-mr （Quad-Flat No-leads Multi-Row） LF （leadframe） devices by optimizing the waterjet deflash process and eliminating the ESD （electrostatic discharge） events. ESD damage to units can cause permanent or latent product failures which results in low final test yield, and worse, possible external customer complaints. The use of CO2 （carbon dioxide） bubbler was able to reduce the DI （deionized） water’s equivalent resistivity from 17 M？ to 0.30 M？, minimizing the tribocharging effect produced during the waterjet deflash process. Moreover, ESD events were eliminated by grounding the floating assembly equipment parts and installing appropriate ESD controls. It is of high importance to reduce or eliminate the leakage current failures to ensure the product quality, especially as the market becomes more demanding. After the optimization and implementation of the corrective and improvement actions, high leakage current occurrence was significantly reduced from baseline of 5,784 ppm to 20 ppm.
文摘As power system interconnections become more prevalent, there has been an increase in use of thyristor controlled shunt connected compensation devices for dynamic power compensation and enhancement of real power transmission capacity. In this paper, an enhancement technique of real power transfer capacity of transmission lines is presented. A SVC （static var compensator） is designed and applied to a simple power system for this purpose. Increase in power flow and improvement in bus voltage profile are observed after using the SVC. Stability analysis of the system after experiencing fault as well as consequent fault clearance by time domain analysis has also beeu performed and satisfactory results are obtained.
