Kohler Fabian, Kiele Patrick, Ordonez Juan S, Stieglitz Thomas, Schuettler Martin
Annu Int Conf IEEE Eng Med Biol Soc. 2014;2014:3981-4. doi: 10.1109/EMBC.2014.6944496.
In this paper, we introduce a technique for double-sealed ceramic packages for the long-term protection of implanted electronics against body fluids. A sequential sealing procedure consisting of a first step, during which the package is sealed with epoxy, protecting the implant electronics from aggressive flux fumes. These result from the application of the actual moisture barrier which is a metal seal applied in a second step by soft soldering. Epoxy sealing is carried out in helium atmosphere for later fine leak testing. The solder seal is applied on the laboratory bench. After the first sealing step, a satisfactory barrier for moisture is already achieved with values for helium leakage of usually LHe = 6·10(-8) mbar 1 s(-1). After solder sealing, a very low leakage rate of LHe ≤ 1·10(-12) mbar 1 s(-1) was found, which was the lower detection limit of the measurement setup, suggesting excellent hermeticity and hence moisture barrier. Presuming an implant package volume of V ≥ 0.5 cm(3), the time to reach a critical humidity of p = 5000 ppm H2O inside the package will be longer than any anticipated average life of human patients.
在本文中，我们介绍了一种用于双密封陶瓷封装的技术，以长期保护植入式电子设备免受体液影响。一种顺序密封程序包括第一步，在此期间用环氧树脂密封封装，保护植入式电子设备免受腐蚀性助焊剂烟雾的影响。这些烟雾来自实际防潮层的应用，该防潮层是在第二步通过软钎焊施加的金属密封。环氧树脂密封在氦气气氛中进行，以便稍后进行精细泄漏测试。钎焊密封在实验室工作台上进行。在第一步密封之后，通常氦气泄漏率为LHe = 6·10(-8) mbar 1 s(-1)，已经实现了令人满意的防潮效果。钎焊密封后，发现泄漏率非常低，LHe≤1·10(-12) mbar 1 s(-1)，这是测量装置的检测下限，表明具有出色的气密性，因此具有防潮性。假设植入式封装体积V≥0.5 cm(3)，封装内部达到临界湿度p = 5000 ppm H2O的时间将长于人类患者任何预期的平均寿命。
