Metalized Ceramic

Thick Film Resistors: Introduction, Characteristics, and Applications

Thick film resistors are passive electronic components that have become fundamental elements in modern electronics. These resistors are created by depositing a resistive paste (typically a mixture of metal oxides and glass frit) onto a ceramic substrate, usually alumina (Al₂O₃), and then firing it at high temperatures (typically 850-1000°C) to form a durable resistive layer. The thickness of this layer typically ranges from 10 to 50 micrometers, significantly thicker than their thin-film counterparts (which are about 0.1 micrometer thick).

The manufacturing process allows for precise control of resistance values by adjusting the composition of the resistive paste, the dimensions of the printed pattern, and the firing conditions. Thick film technology emerged in the 1960s as a cost-effective alternative to other resistor technologies and has since evolved to offer excellent performance characteristics for a wide range of applications.

Characteristics of Thick Film Resistors

1. **Resistance Range**: Thick film resistors are available in a broad resistance range, typically from 1 ohm to 10 megohms, making them suitable for diverse circuit requirements.

2. **Tolerance**: Standard tolerances range from ±1% to ±5%, with precision versions available at ±0.5% or better for specialized applications.

3. **Temperature Coefficient of Resistance (TCR)**: Typically between ±100 ppm/°C to ±250 ppm/°C, though advanced formulations can achieve ±50 ppm/°C or better.

4. **Power Rating**: Available in various power ratings from 0.1W to several watts, depending on size and design.

5. **Voltage Rating**: Can withstand relatively high voltages, often up to 200V or more for standard sizes.

6. **Frequency Response**: While not as good as thin film resistors at high frequencies, thick film resistors perform adequately for most applications below several hundred MHz.

7. **Noise Characteristics**: Generate more current noise than thin film resistors but less than carbon composition types.

8. **Pulse Handling**: Demonstrate good pulse handling capabilities due to their thermal mass and construction.

9. **Environmental Stability**: Exhibit good resistance to humidity and environmental contaminants when properly protected.

10. **Cost-Effectiveness**: One of the most economical resistor technologies for general-purpose applications.

Applications of Thick Film Resistors

Thick film resistors find widespread use across virtually all segments of the electronics industry:

1. **Consumer Electronics**: Used extensively in televisions, audio equipment, home appliances, and mobile devices due to their reliability and cost-effectiveness.

2. Automotive Electronics: Employed in engine control units, sensors, lighting systems, and infotainment systems where they must withstand harsh environments.

3. Industrial Controls: Found in motor drives, power supplies, and control systems where their robustness is valued.

4. Medical Equipment: Used in patient monitoring systems, diagnostic equipment, and therapeutic devices where reliability is critical.

5. Telecommunications: Applied in base stations, routers, and network equipment for signal processing and power management.

6. Power Supplies: Serve in voltage regulation, current limiting, and feedback circuits in both linear and switching power supplies.

7. Hybrid Circuits: Commonly used in hybrid microcircuits where components are directly printed onto substrates.

8. Surface Mount Technology (SMT): The majority of surface mount chip resistors are thick film types, populating virtually every modern PCB.

9. Resistor Networks: Multiple thick film resistors can be printed on a single substrate to create compact resistor arrays.

10. Specialized Sensors: Some thick film compositions are used in strain gauges, pressure sensors, and other transducer applications.

Advantages Over Other Resistor Technologies

Compared to other resistor types, thick film resistors offer several distinct advantages:

- **Manufacturing Efficiency**: The screen printing process allows for high-volume production with excellent consistency.
- **Design Flexibility**: Resistance values can be easily adjusted by modifying the printed pattern geometry.
- **Miniaturization**: Can be made in very small sizes (down to 0201 metric packages - 0.6mm × 0.3mm).
- **Integration**: Can be combined with other thick film elements (capacitors, conductors) to create complete circuits.
- **Durability**: The fired ceramic structure provides mechanical strength and environmental resistance.

Our main Resistor:
Far-infrared Microcrystalline Ceramic Glass Heating Plate 
The far-infrared glass-ceramic heating plate is a combination of non-metallic conductive materials and infrared radiation materials through printing, high-temperature sintering and other processes on the outer surface of the glass-ceramic plate, which is permanently integrated with the glass-ceramic plate to form a layer of inorganic conductive The resistive film layer emits infrared heat after being energized and heated to form a heat radiation source and conduction and convection heating.

Far-infrared glass-ceramic heating plate
Security:
There is no open flame and no oxidation when working, and the service life is 50 times longer than that of ordinary heating wires.
far-infrared glass-ceramic heating plate
Health:
It Using glass-ceramics as the carrier, the expansion coefficient is small, the infrared radiation is strong, and its far-infrared wavelength is 2-15um, which is good for human health
Energy saving:
High energy conversion rate (no loss of other forms of energy such as noise, visible light, etc.). High heat absorption rate (covered heating, wide absorption area)..
Heating:
The heating is stable and uniform, and the heat is emitted by infrared radiation, with strong penetrating power and good baking effect
Wide range of applications and long service life (This data is an average value and does not represent all values)

●Using voltage range: 110v, 220V,.

●Power density range: 1w～30w/cm2

●Application temperature range: 40℃～600℃.

●The service life is more than 10,000 hours.

Thick-film resistor technology is used to produce electronic devices such as resistor card, surface mount devices, hybrid integrated circuits and sensors by silk Screen printing technology and following process drying/curing, firing, and laser trimming of resistors.

FEATURES:
1. Ultra-precision pitch printing between 0.18mm and 0.25mm
2. Perfect stability and high accuracy
3. Wear-resisting frequency range: 300,000 times to 2,000,000 times
4.Other sizes or other types are also available if requested

Thick film circuit board Applications:
Thick film circuit board specially designed for throttle position sensor of various direct injection automobile and motorcycle engine; The product has strong corrosion resistance to oil, lubricating oil and salinization fog in industrial environment. The output linear characteristic curve is good, the wear resistance is strong, the service life is long, can be used for the throttle
position sensor such as the German BOSCH system and the American DELPHI system.

Other high voltage resistor :
Plug-in high-voltage resistor, surface-mount megohm resistor, cylindrical high-voltage resistor 

Thick film resistor future developments
The thick film resistor industry continues to evolve with:
- Improved materials for better TCR and stability
- Advanced trimming techniques for higher precision
- Nanotechnology-enhanced pastes for superior performance
- Environmentally friendly formulations eliminating lead and other hazardous materials

In conclusion, thick film resistors represent an optimal balance of performance, reliability, and cost that has secured their position as the most widely used resistor technology in the electronics industry. Their versatility and continuous improvement ensure they will remain essential components in electronic designs for the foreseeable future.