宇航级晶体管寿命试验

Life Test of Aerospace Grade Level Transistors

选取美国宇航级晶体管2N2219AL同批次的4组(分别为A,B,C和D组)样品进行了寿命试验。A组样品在额定功率P CM为800 mW下进行了6 000 h的工作寿命试验;B,C和D组样品分别在试验应力P为1 200,1 400和1 600 mW下,进行了恒定应力加速寿命试验。对样品电参数直流共发射极电流增益h FE的测试结果表明,h FE呈先增后减的缓慢退化趋势,同时I CBO远小于5 nA的失效标准。试验后,A组样品又在北方实验室环境下贮存了14年,距其制造日期已有32年。对其电参数复测,并与1998年的测试结果对比,没有明显的变化。揭示了高可靠性晶体管在长期工作寿命试验中电参数的变化规律,为其极长的贮存寿命提供了有力的证据。

Four groups of american JANS level transistors 2N2219AL from the same lot were chosen to take the life test. The group A was in operation life test for 6 000 h at the rated power of 800 mW, and the group B, C and D were in accelerated life test with P of 1 200, 1 400 and 1 600 mW, separately. The DC common emitter current gain （hrE） was tested at several time points using high precision equipment. The test reslts show that the value of hFE increased firstly and then decreased continuously, while Icso was far less than the fail criteria of 5 nA. Subsequently, the transistors were stored for 14 years in the lab of north of China, 32 years after their fabrication. The electrical parameters were tested again, and there was no obvious change compared with the parameters tested in 1998. The variety law of the electrical parameters of the high reliability transistors during the long term operation life test was discovered, which can give a strong evidence for their extremely long storage life.