Flexible Hybrid Electronics with 3DIC

In recent years, wearable devices, implantable devices, and the Internet of Things have become increasingly popular as such devices have become smaller and lighter, and the development of wireless communications has made it easier for device-to-device connection, thus diversifying the applications of electronic devices. Although conventional devices are limited by the shape of their internal printed circuit boards (PCBs), making them impossible to bend, lots of flexible devices based on organic semiconductors and thin film transistors (TFT) [1] using flexible substrates instead of rigid PCBs have been reported. However, there are several issues with conventional flexible devices using organic semiconductors. First, carrier mobility of organic semiconductors’ is lower than inorganic single-crystal semiconductors such as Si. Since carrier mobility is an important factor in determining the operation speed and power consumption of an IC, it is challenging to construct high-performance devices with organic semiconductors compared to those with inorganic single-crystal semiconductors. The second problem is the difficulty of manufacturing high-density wiring. The wiring width of typical printed electronics is several millimeters to several tens of micrometers, making it challenging to achieve highly integrated and high-performance flexible devices.