Thermally Coupled NTC Chip Thermistors: Their Properties and Applications

• Published in: Sensors (Basel, Switzerland) Vol. 24; no. 11; p. 3547
• Main Authors: Bodić, Milan Z, Aleksić, Stanko O, Rajs, Vladimir M, Damnjanović, Mirjana S, Kisić, Milica G
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 31.05.2024; MDPI
• Subjects: chip thermistors; Epoxy resins; heat transfer; Semiconductors; Temperature; Temperature measurements; thermal junction; chip thermistors; heat transfer; thermal junction
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s24113547

Negative temperature coefficient (NTC) chip thermistors were thermally coupled to form a novel device (TCCT) aimed for application in microelectronics. It consists of two NTC chip thermistors Th and Th , which are small in size (0603) and power (1/10 W). They are in thermal junction, but concurrently they are electrically isolated. The first thermistor Th generates heat as a self-heating component at a constant supply voltage U (input thermistor), while the second thermistor Th receives heat as a passive component (output thermistor). The temperature dependence R(T) of NTC chip thermistors was measured in the climatic test chamber, and the exponential factor B of thermistor resistance was determined. After that, a self-heating current I of the input thermistor was measured vs. supply voltage U and ambient temperature T as a parameter. Input resistance R was determined as a ratio of U and I while output thermistor resistance R was measured by a multimeter concurrently with the current I . Temperatures T and T of both thermistors were determined using the Steinhart-Hart equation. Heat transfer, thermal response, stability, and inaccuracy were analyzed. The application of thermally coupled NTC chip thermistors is expected in microelectronics for the input to output electrical decoupling/thermal coupling of slow changeable signals.