When selecting an NTC thermistor, resistance value, accuracy tolerance, or B constant are typically considered. While these parameters are important, the package type becomes equally crucial once the design enters the manufacturing stage. In practical applications, the package directly impacts reliability, ease of installation, and longterm performance.
Epoxy Coated Thermistors (MF52 Series)
Epoxy coated thermistors are the most commonly used type. Their core components are protected by an epoxy coating, maintaining a small size and fast response time.
This package is widely used in electronic thermometers, home appliances, HVAC systems, battery packs, and other fields. Epoxy coated thermistors perform well in relatively clean and dry environments and achieve a good balance between cost and response time.
Glass Encapsulated Thermistors (MF58/MF59 Series)
When high humidity, high temperature, or long lifespan is required, epoxy coating alone may not be sufficient. In such cases, glass encapsulated thermistors are often a more suitable choice.
Glass encapsulation offers excellent moisture resistance and anti‑aging properties, making it widely used in industrial and automotive electronics. While its response time is slightly slower, its excellent stability makes it suitable for harsh environments.
Glass Encapsulation: The Ultimate Moisture Barrier
SHENZHEN HENQYI's MF58 series solves these issues through high‑integrity glass encapsulation.
- Hermetic Protection: The sensing element is fully shielded from moisture, ensuring stable performance in 100% humidity.
- Operational Excellence:
- Insulation Resistance: 500 MΩ at 500V DC.
- Thermal Resilience: After 1,000 hours at 250°C/482°F, resistance drift remains within a remarkable 2%.
- Endurance: Capable of withstanding up to 100,000 high‑low temperature cycles.
Fast Response for Precise PID Control
Cooking consistency depends on how fast a sensor reacts to change. The MF58 features a 12‑second thermal time constant, allowing the oven’s control system to:
- Detect rapid heat spikes during startup.
- Transition smoothly from full‑power heating to stable PID modulation.
- Eliminate temperature "overshoot," protecting delicate fermented dough and high‑end proteins alike.
Surface Mount Chip Thermistors (CMF Series)
Surface mount NTC thermistors are ideal for compact designs and high‑volume production. SMD thermistors are designed to conform to standard SMT processes, making them easy to assemble on modern production lines.
They are widely used for PCB temperature monitoring, especially in applications with limited installation space and extremely high assembly consistency requirements, such as power electronics, control boards, and consumer electronics.
Probes and Metal Housing Assemblies (CWF Series and Custom Sensors)
Many applications require temperature measurement in specific locations rather than on the PCB. Typical examples include motors, battery modules, pipes, and heating elements.
Probes and metal housing assemblies integrate the thermistor with leads or cables into a protective structure. This approach improves mechanical strength and allows for precise placement of the sensor where temperature feedback is required.
Engineering Considerations for Package Selection
From an engineering perspective, there is no "best" package for NTC thermistors. Epoxy encapsulation is simple and quick, glass encapsulation offers excellent environmental resistance, SMD chips are compatible with small electronic devices, and probe assemblies provide flexible mounting options.
Choosing the appropriate package early in the design process helps avoid reliability issues, especially after mass production begins.
Therefore, electrical specifications must also be considered when selecting a package.