As few or no failures occur during accelerated life test,it is difficult to assess reliability for long-life products with traditional life tests.Reliability assessment using degradation data of product performance ov...As few or no failures occur during accelerated life test,it is difficult to assess reliability for long-life products with traditional life tests.Reliability assessment using degradation data of product performance over time becomes a significant approach.Aerospace electrical connector is researched in this paper.Through the analysis of failure mechanism,the performance degradation law is obtained and the statistical model for degradation failure is set up; according to the research on statistical analysis methods for degradation data,accelerated life test theory and method for aerospace electrical connector based on performance degradation is proposed by improving time series analysis method,and the storage reliability is assessed for Y11X series of aerospace electrical connector with degradation data from accelerated degradation test.The result obtained is basically consistent with that obtained from accelerated life test based on failure data,and the two estimates of product＇s characteristic life only have a difference of 8.7%,but the test time shortens about a half.As a result,a systemic approach is proposed for reliability assessment of highly reliable and long-life aerospace product.展开更多
A GaN-based light-emitting diode (LED) with reflective current blocking layer (CBL) underneath p-electrode pad and backside hybrid reflector was fabricated and investigated. With a 20 mA injection current, the LED wit...A GaN-based light-emitting diode (LED) with reflective current blocking layer (CBL) underneath p-electrode pad and backside hybrid reflector was fabricated and investigated. With a 20 mA injection current, the LED with SiO2 /ITO/Al reflective CBL deposited on naturally textured p-InGaN/p-GaN surface exhibited a light output power that was 7.6% and 18.5% higher than those of the textured LEDs with SiO2 CBL and without SiO2 CBL, respectively. The LED with backside hybrid reflector exhibited a light output power that was 30% higher than that of LED without the hybrid reflector. The enhancement in light output power is attributed to the improved current spreading performance via the SiO2 CBL, the Al omnidirectional metal reflector to prevent the light absorption by the opaque p-electrode pad, and the backside hybrid reflector to extract bottom-emitting light.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 50935002,Grant No. 51075370,Grant No. 51105341)National Hi-tech Research and Development Program of China (863 Program,Grant No. 2007AA04Z409)Civil Aerospace Science and Technology Pre-research Project of China (Grant No. B122006 2302)
文摘As few or no failures occur during accelerated life test,it is difficult to assess reliability for long-life products with traditional life tests.Reliability assessment using degradation data of product performance over time becomes a significant approach.Aerospace electrical connector is researched in this paper.Through the analysis of failure mechanism,the performance degradation law is obtained and the statistical model for degradation failure is set up; according to the research on statistical analysis methods for degradation data,accelerated life test theory and method for aerospace electrical connector based on performance degradation is proposed by improving time series analysis method,and the storage reliability is assessed for Y11X series of aerospace electrical connector with degradation data from accelerated degradation test.The result obtained is basically consistent with that obtained from accelerated life test based on failure data,and the two estimates of product＇s characteristic life only have a difference of 8.7%,but the test time shortens about a half.As a result,a systemic approach is proposed for reliability assessment of highly reliable and long-life aerospace product.
基金supported by the Postdoctoral Science Foundation of Shanghai (Grant No. 12R21413900)the National Basic Research Project of China ("973" Project) (Grant No. 2011CB013103)
文摘A GaN-based light-emitting diode (LED) with reflective current blocking layer (CBL) underneath p-electrode pad and backside hybrid reflector was fabricated and investigated. With a 20 mA injection current, the LED with SiO2 /ITO/Al reflective CBL deposited on naturally textured p-InGaN/p-GaN surface exhibited a light output power that was 7.6% and 18.5% higher than those of the textured LEDs with SiO2 CBL and without SiO2 CBL, respectively. The LED with backside hybrid reflector exhibited a light output power that was 30% higher than that of LED without the hybrid reflector. The enhancement in light output power is attributed to the improved current spreading performance via the SiO2 CBL, the Al omnidirectional metal reflector to prevent the light absorption by the opaque p-electrode pad, and the backside hybrid reflector to extract bottom-emitting light.
