面向即时检测芯片超声波精密键合的熔接结构及工艺参数

针对芯片即时检测(POCT)芯片对键合精度、键合强度、生产效率和生物兼容性的要求,基于超声波键合技术设计了结构化的导能筋布置形式和阻熔导能接头结构。研究了超声波键合时间和键合压力对微通道高度保持性能的影响,确定了精密超声波键合工艺参数。利用高精度显微镜、拉伸试验机和羊全血分别对键合后芯片的微通道高度、键合强度、微通道密闭性以及液体自驱动性能进行了测试。结果表明:所设计的导能筋布置形式合理可靠;利于芯片各功能的集成,阻熔导能接头结构能够较精确地控制键合后微通道的高度,键合精度达到2μm;全血驱动时间的极差在20s以内;所确定的键合工艺参数能够实现高强度的键合,键合强度不小于2.5 MPa。该熔接结构及工艺参数具有键合精度高、键合强度高、生物兼容性好和熔接均匀等优点,可应用于医用POCT芯片产品中。

Joint structure and processing parameters of ultrasonic precision bonding for point-of-care testing chips

For the requirements of Point-Of-Care Testing(POCT) chips for bonding precision, bonding strength, productivity and biological compatibility, this paper designs a structured energy director and a weld limited joint structure based on ultrasonic bonding. The influence of ultrasonic bonding time and bonding pressure on microchannel's height maintenance was researched, and the optimum processing parameters of precision ultrasonic bonding were determined. After ultrasonic bonding, a high precision microscope, a tensile testing machine and the whole sheep blood were applied to test the microchannel height, bonding strength, microchannel leakproofness and the whole blood driving performance of ultrasonically bonded POCT chips respectively. Experimental results demonstrate that the structured energy director is rational, reliable and easy to integrate each functions. The weld limited joint structure can control the height of microchannel accurately during ultrasonic bonding, the bonding precision of the microchannel is 2 μm, and the time range of whole blood driving test is less than 20 s. Moreover, the optimum processing parameters are conductive the realization of the high bonding strength more than 2.5 MPa. It concludes that the joint structure and processing parameters have the advantages of high bonding precision, high bonding strength, biological compatibility and uniform welding for POCT chips, and are suitable for the application to medical POCT chips.