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With the development of the wireless body area network, the demand for medical monitoring is getting higher and higher. A series of wearable devices have now emerged as a means of medical monitoring to detect human bioelectrical signals. This article mainly contains three parts, which are wireless body area network, Electrocardiograph(ECG) signal and Electroencephalogram(EEG) signal acquisition, and the design of wearable acquisition system based on wireless body area network. The first part starts with the performance requirements of the wireless body area network, introduces the performance required for medical monitoring, emphasizes the transmission reliability, and focuses on the key issue of wireless body area network research - energy conservation. The second part introduces the non-contact sensor, and expounds the selection of electrode materials. The design of the acquisition circuit and noise cancellation are mainly discussed. The third part puts forward the structural design of the wearable acquisition system based on wireless body area network, and expounds the data transmission system of the system. Finally, it puts forward suggestions and ideas for the design of body-area network-based wearable EEG and ECG acquisition systems.

This paper presents a novel die attach material that withstands high working temperature of at least 415 °C after low temperature liquid bonding at 250 °C. The die attach material was preform compressed with Cu@Sn core-shell microparticles, which were produced using an electroless process. When the reflow temperature reached Sn melting point, the outer Sn layer melted and connected the inner Cu cores. After reflow soldering at 250 °C for 4 min, the outer Sn completely transformed into tri-dimensional network-like structure intermetallic compounds (IMCS) Cu 6 Sn 5 and Cu 3 Sn, the inner Cu cores were interconnected by the formed network-like Cu-Sn IMCS, with a high remelting temperature (415°C for Cu 6 Sn 5 and 676°C for Cu 3 Sn). With reflow time increased, more Cu 6 Sn 5 layer transformed into Cu 3 Sn, and voids increased with Cu atom diffusing to Cu 6 Sn 5 layer. Consequently, the joint with little Cu 3 Sn has the potential to fulfill the requirements of high temperature die attach. The surface morphology of the produced Cu@Sn microparticles and cross section morphology of the joint was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis was performed to investigate the structure and phases of Cu@Sn particles and the joint. The voids rate of the joint was studied by X-ray.