Luobin Zhang,Jintao Wang,Sheng Zhou,Xiaojia Luo,Yufeng Li
This research is an attempt to apply the silver thick-film metallization and the soft soldering process to the ultra-high vacuum packaging of atom chips with through silicon via (TSV). During the packaging process, a vacuum environment is used to avoid oxidation of the Cu layer on the chip during heating. At the same time, tin foil is used to protect the inner wall of the glass cell to prevent the gas emitted by the solder from polluting the inner wall. In general, by the adoption of screen printing, sintered surface metallization at a constant temperature of 450–500 °C for 5 min, combined with soft soldering, the packaging of an atom chip with TSV and a silica glass cell is realized. The weld gap is less than 50 μm, the airtightness can reach 8.5 × 10 −13 Pa m 3 /s, and the vacuum degree can reach 2.18 × 10 −8 Pa. That can meet the requirements of cold atom experiment for light path and vacuum degree.
Fan Guo,Rui Yuan,Yun-Ling Yang,Jing-Tai Zhao,Hui Lin,Zhi-Jun Zhang
Phosphor-in-glass (PiG) is one of the most important spectral converters to overcome thermal effect in high-power white light-emitting diodes (LEDs). The Al 2 O 3 –SiO 2 –B 2 O 3 –ZnO–Na 2 O–Li 2 O glass was designed and sintered with Y 3 Al 5 O 12 :Ce 3+ (YAG: Ce) phosphors at the low temperature of 650 °C to obtain YAG: Ce-PiG. The optimized YAG: Ce-PiG shows the white light of the luminous efficiency (LE), correlated color temperature (CCT) and chromaticity coordinate (CIE) of 177.5 lm/W, 6410 K and (0.31,0.34), respectively. The white LEDs (WLED) were fabricated by coupling the YAG: Ce-PiG with a blue light emitting chip, and the correlation between the luminescence properties , the thickness of PiG and the ratio of phosphors was investigated. More importantly, the WLEDs of a maximum luminous efficiency can reach up to 199.5 lm/W with the thickness of 0.35 mm. In addition, a structure with vacuum packaging technique based on the WLEDs lighting combined with sapphire as substrate was fabricated, which can effectively reduce the heat accumulation during the working process of WLEDs. Compared with normal non-vacuum packaging, the working temperature of WLEDs was reduced by about 35%, from 359.2 to 232.2 °C, with the novel vacuum packaging technique under 30W high-power chip and the luminous performance can still be maintained at 94.7%. In a word, the prepared YAG: Ce-PiG exhibits a great potential for application in high-power solid-state WLEDs.
危险品化学品经营许可证（带存储）