A thermal sensor integrated with its driving circuit by using Cu on polyimide (COP) as a substrate was developed. A heater, working as the thermal flow sensor and constant temperature circuit (CTC), working as its driving feedback circuit, were successfully integrated on the COP substrate by photolithography, metal deposition, and sacrificial selective etching in the Cu layer. The Cu layer works to form a cavity that acts thermal isolation for the heater and electrical feedthroughs in the CTC. The electrical components, i.e., resistors, capacitors, and operational amplifiers, were mounted on the electrical pads using low-temperature solder paste of Sn–Bi at the CTC area. The areas of the thermal sensor and CTC were 11 × 23 mm and 16 × 24 mm, respectively. The area of the thermal sensor was inserted into a tube with a diameter of 5 mm acting as the flow sensor. The sensor outputs increased along with the airflow rate up to 10.0 L/min, and the calibration curve as the airflow-rate sensor was experimentally derived. The fabricated sensor outputs were not affected by variations in the airflow temperature and only depended on the airflow rate thanks to the added temperature compensation function, and a response time of 0.095 s was obtained.

通过在聚酰亚胺（COP）上使用Cu作为基底，开发了一种集成了其驱动电路的热传感器。通过光刻，金属沉积和在Cu层中进行选择性牺牲蚀刻，将用作热流量传感器和恒温电路（CTC）的加热器（用作其驱动反馈电路）成功集成到COP基板上。铜层用于形成空腔，该空腔对CTC中的加热器和电气馈通孔起到热隔离作用。使用CTC区域的Sn-Bi低温焊膏将电气组件（即电阻器，电容器和运算放大器）安装在电气焊盘上。热传感器和CTC的面积分别为11×23 mm和16×24 mm。将热传感器的区域插入直径为5 mm的管中，用作流量传感器。传感器的输出随着风量的增加而增加，最高达到10.0 L / min，并通过实验得出了作为风量传感器的校准曲线。由于增加了温度补偿功能，所制造的传感器输出不受气流温度变化的影响，而仅取决于气流速率，并且获得了0.095 s的响应时间。