Thick Film Sensors

Thick Film Sensors are sensor elements made using thick film technology to detect and measure physical parameters such as position, angle, temperature, pressure, humidity, and gas concentration; these sensors are produced through a cost-effective process in which thick film materials are applied to a circuit board to form functional sensing elements, ensuring high stability, durability, and widespread use in various industrial and commercial applications while maintaining cost-efficiency.

Thick Film Sensors are characterized by high reliability, low manufacturing costs, and customizable functionality. Thanks to the nature of thick film technology, the sensor elements can achieve large sizes and high resistance to interference without compromising accuracy. Additionally, thick film sensors can be tailored to meet different application needs, detecting various physical or chemical stimuli, such as changes in temperature, pressure, humidity, or the presence of specific chemicals. Their structure is typically simple, robust, and durable, making them suitable for use in harsh environments.

Thick Film Sensors operate based on the principle of resistance change. The thick film material applied to the sensor's surface undergoes physical property changes in response to environmental factors such as temperature, pressure, or humidity, resulting in variations in resistance. For example, when external pressure changes, the thick film material inside the sensor may deform or compress, leading to a corresponding change in resistance. The sensor's circuit system continuously monitors these changes and outputs signals that reflect the changes in environmental parameters.

Working Principle of Thick Film Sensors :

Thick Film Sensors operate based on changes in their electrical properties in response to specific physical or chemical stimuli. The working principle of a thick film sensor depends on the type of measurement it is designed for. Here are some common types of thick film sensors and their respective working principles:

1, Thick Film Electrochemical Sensors:
These sensors utilize the change in resistance of the thick film material for detection. When the sensor is exposed to a stimulus (e.g., temperature, pressure, or a specific liquid / gas), the physical or chemical properties of the thick film material alter, leading to a resistance change. This alteration can be measured to the intensity of the stimulus.

2, Thick Film Potentiometer Sensors:
Potentiometer Sensors operate based on the change in resistance caused by the movement of a wiper or sliding contact across a thick-film resistive element, which in turn alters the output voltage. The sensor typically consists of a thick-film resistive material, and the wiper or contact slides along this resistive element in a linear or rotational direction. As the position of the wiper changes, the resistance value varies, causing the sensor's output voltage to change in synchronization with the displacement of the contact. In this way, Potentiometer Sensors provide precise feedback on displacement or position.

3, Thick Film Flexible Sensors:
Flexible Sensors detect changes in pressure or strain by measuring the variation in resistance of a thick-film resistive material on a flexible substrate. As external forces deform the substrate, the resistance changes, and this is converted into a measurable signal, such as a voltage or current variation. These sensors are highly sensitive and flexible, making them ideal for applications in wearable devices, robotics, medical equipment, and automotive systems, where real-time monitoring of physical parameters is required. Their ability to operate on curved or irregular surfaces makes them versatile for a variety of industries.

4, Thick Film Resistive Sensors:
Variable Resistor Sensor PCB operates based on the characteristic that resistance changes in response to external factors. By adjusting parameters such as the length, width, or material of the resistor elements on the board, external environmental changes (such as temperature, pressure, humidity, or light) can influence the resistance value. As current flows through the resistor element, the resistance value changes in response to these external conditions, causing variations in the electrical output or voltage signal.

5, Thick Film Capacitive Sensors:
Capacitive Sensors rely on changes in capacitance between two conductive layers separated by a dielectric material. In thick film sensors, one or both of the conductive layers may consist of thick film materials. When a stimulus affects the dielectric properties of the material (such as humidity or a change in permittivity due to a chemical reaction), the capacitance between the layers changes. This alteration in capacitance is then measured to determine the presence or concentration of the target stimulus.

6, Thick Film Pressure Sensors:
Pressure Sensors are devices that convert pressure measurements into electrical signals by utilizing the unique properties of ceramic materials, such as durability, stability, and resistance to extreme conditions, with the ceramic substrate acting as the core element for pressure detection, ensuring accurate and reliable performance in various applications, and are highly valued for their ability to operate in challenging environments where other sensor materials may fail, making them an ideal choice for applications requiring high precision and robustness.

7, Thick Film Thermistors:
Thermistors are temperature-sensitive resistors. In thick film thermistors, the resistance of the thick film material varies with temperature. The thermistor's resistance can either increase or decrease with temperature, depending on the material's characteristics (NTC for negative temperature coefficient and PTC for positive temperature coefficient). By measuring the resistance, the temperature can be determined.

In all cases, the design of thick film sensors is tailored to respond to specific stimuli. The sensor's output, whether it's a change in resistance, capacitance, or potential difference, is then processed and converted into a readable signal for monitoring and controlling the environment or process being measured. The versatility of thick film technology allows for the creation of robust, cost-effective sensors suitable for a wide range of applications.

For more information, Please refer to Thick Film Resistor PCB.

Advantages of Thick Film Sensors :

1, Cost-Effectiveness: Thick film sensors are economically advantageous compared to alternatives like thin film sensors or MEMS sensors. Leveraging screen-printing techniques, the thick film technology enables cost-efficient mass production.

2, Versatility: Thick film sensors are versatile, capable of measuring various physical parameters such as temperature, pressure, humidity, and position. This versatility renders them suitable for a wide array of applications, from automotive to environmental monitoring.

3, Ruggedness and Reliability: Thick film sensors boast a sturdy construction that mitigates mechanical stress and physical damage, enhancing reliability and prolonging operational lifespan.

4, Customization and Flexibility: The thick film process facilitates tailoring sensor properties to specific application needs. This adaptability allows for the creation of sensors with unique sensitivity ranges or environmental adaptability.

5, Integration Capability: These sensors seamlessly integrate into complex systems. Utilizing thick film technology, manufacturers can incorporate multiple functionalities onto a single substrate, yielding compact and efficient sensor systems.

6, Simplicity of Processing: Processing thick film sensors is relatively straightforward compared to other sensor types. This simplicity expedites prototyping and development cycles, fostering rapid product innovation.

7, Robustness and Durability: Renowned for their resilience, thick film sensors excel in harsh environments, including extreme temperatures, humidity, and corrosive settings, making them ideal for industrial and automotive applications.

8, Low Power Consumption: Many thick film sensors operate with low power consumption, ideal for energy-efficient applications like wireless sensor networks or portable devices.

9, Ease of Fabrication: Fabricating thick film sensors is straightforward and doesn't demand the precision or cleanroom conditions necessitated by some other sensor technologies, streamlining production and reducing manufacturing complexity.

Thick Film Sensors offer a compelling combination of cost-effectiveness, robustness, integration capability, customization options, reliability, simplicity of processing, versatility, low power consumption, and ease of fabrication. These attributes position them as the preferred choice for applications requiring both performance and durability.

Why Do You Need to Customize Thick Film Sensors ?

● Performance Optimization: Customization allows for the optimization of sensor performance tailored to specific application needs, including enhanced sensitivity, response time, and stability.

● Cost-Effectiveness: Thick film technology is known for its simple manufacturing process, rapid and cost-effective tooling systems, economic viability, and quick prototyping capabilities, making it widely used in the electronics industry.

● Reliability: Thick film sensors are favored for their high reliability, especially in environments where long-term stable operation is required.

● Multifunctionality: The capability of thick film technology to create multilayer circuits means that multiple functions can be integrated into a single sensor, improving the system's comprehensiveness and efficiency.

● Adaptability: Thick film sensors can be adapted to various working environments, including high-temperature, high-pressure, or chemically corrosive conditions, making them highly useful in industrial applications.

● Miniaturization and Flexibility: With advancements in manufacturing technology, thick film sensors can be made smaller and more flexible, allowing for a wide range of applications and form factors.

● Integration with Other Systems: Custom thick film sensors can be designed to seamlessly integrate with other systems or components, enhancing the overall functionality of a device or process.

● Specific Environments: Sensors can be customized to withstand specific environmental conditions or to interact with particular types of materials.

● Rapid Prototyping and Development: The ability to quickly prototype and develop customized thick film sensors can significantly reduce time-to-market for new products.

● Quality Control: Customization often includes stringent quality control measures, ensuring that the sensors meet the exacting standards required for their intended applications.

Differences Between Thin Film Sensors and Thick Film Sensors :

1, Thick Film Sensors:
● Material Thickness: Thick Film Sensors are made with relatively thicker layers, typically ranging from several micrometers to tens of micrometers.

● Fabrication Process: Produced via screen-printing, a paste or ink containing sensor materials is applied to a substrate, then fired or sintered at high temperatures to remove binders and fuse metal particles.

● Materials: Commonly employ metal powders, glass frits, and organic binders in paste formulations.

● Advantages: Known for robustness, cost-effectiveness, and resilience to harsh environments. Compatible with various substrate materials and easy to integrate into complex systems.

● Applications: Widely used in automotive, industrial, and consumer electronics, prioritizing durability and cost efficiency.

2, Thin Film Sensors:
● Material Thickness: Thin film sensors feature much thinner layers, typically ranging from nanometers to a few micrometers.

● Fabrication Process: Fabricated through techniques like sputtering, evaporation, or chemical vapor deposition, depositing a thin layer of sensing material onto a substrate.

● Materials: Often utilize high-purity materials, including semiconductors, conductive oxides, or advanced materials.

● Advantages: Offer high sensitivity, rapid response times, and precise control over layer thickness and composition. Enable creation of small, lightweight sensors.

● Applications: Commonly employed in high-precision measurement devices, microelectronics, and scenarios requiring limited space or demanding sensitivity and responsiveness.

The key disparities between Thin Film Sensors and Thick Film Sensors revolve around layer thickness, fabrication methods, materials employed, and their respective advantages and applications. Thick Film Sensors excel in durability and cost efficiency, while thin film sensors shine in sensitivity and precision.

Applications of Thick Film Sensors :

Thick Film Sensors are preferred in a variety of applications due to their unique combination of properties, such as robustness, cost-effectiveness, and the ability to operate in harsh environments. Here are some common applications where thick film sensors are often the preferred choice over other sensor types:

1, Automotive Industry:
Thick film sensors are widely used in the automotive industry for applications such as fuel level sensing, throttle position sensing, engine oil pressure sensing, accelerator pedal sensing, and airbag deployment sensors. Their resistance to harsh environmental conditions, such as temperature fluctuations and exposure to various chemicals, makes them ideal for these applications.

2, Environmental Monitoring:
Thick film sensors are used in environmental monitoring to detect various gases and pollutants. Their ability to operate in outdoor conditions and withstand weather extremes makes them a preferred choice for long-term, reliable data collection.

3, Medical Diagnostics:
In the medical field, thick film sensors are used in devices such as blood glucose monitors and other diagnostic equipment. The sensors' stability and precision are crucial for accurate readings, and the thick film technology provides these characteristics.

4, Consumer Electronics:
In consumer electronics, thick film sensors are used in a range of products, from temperature sensors in appliances to touch sensors in devices. Their compact size and low-cost manufacturing make them an attractive option.

5, Energy Management:
Thick film sensors are used in energy management applications, such as smart meters and solar panels, to monitor and control energy consumption and production. Their reliability and long-term stability are essential in these applications.

6, Smart Packaging:
In the packaging industry, thick film sensors enable smart packaging solutions that can monitor product freshness, temperature exposure, and other environmental factors. The sensors' ability to be integrated into packaging materials without compromising their functionality is a key advantage.

7, Aerospace and Defense:
The aerospace and defense sectors require sensors that can operate in extreme conditions, such as high altitudes, pressures, and temperatures. Thick film sensors meet these requirements and are used in various applications, including aircraft control systems and space probes.

8, Industrial Process Control:
Thick film sensors are used for monitoring and controlling parameters like pressure, temperature, and humidity. Their durability and reliability in extreme conditions, such as high temperatures and corrosive environments, make them suitable for these applications.

Thick Film Sensors are indispensable in modern technology due to their adaptability and cost-effectiveness across a broad range of industries. Their ability to operate reliably in extreme conditions (high temperatures, humidity, pressure, and mechanical stress) makes them ideal for use in automotive, industrial, medical, and consumer electronics applications. Whether for temperature control, pressure monitoring, environmental sensing, or human health monitoring, thick film sensors continue to enhance the performance and safety of many devices and systems.

Thick Film Sensors offer unique advantages in terms of cost, robustness, and versatility, making them a valuable component in modern technology applications across diverse sectors. Their ability to provide precise and reliable measurements in challenging environments ensures their continued relevance in future advancements.

Most Representative Applications of Thick Film Sensors :

1, Automotive Industry:
● Transmission Fluid Temperature Sensors: Thick film sensors gauge transmission fluid temperature in automatic transmissions. This information regulates transmission operation, prevents overheating, and ensures smooth gear shifting, improving driving experience and transmission longevity.

● EGR Position Sensors: Thick film sensors are part of EGR systems, monitoring the EGR valve's position. This data guides the engine control unit (ECU) in regulating exhaust gas recirculation, reducing nitrogen oxides (NOx) emissions, and enhancing engine efficiency.

● Fuel Level Sensors: These sensors are vital components in fuel monitoring and control systems for vehicles and machinery, offering accurate, real-time data on fuel levels to ensure efficient fuel management and optimized performance. Designed to endure harsh operating conditions, these sensors provide reliable readings in various applications, helping to prevent fuel shortages and optimize fuel consumption. Click Fuel Level Sensor PCB for more information.

● Throttle Position Sensors: TPSs are crucial for accurately monitoring the position of the engine's throttle valve, converting its mechanical movement into an electrical signal that is transmitted to the Engine Control Unit (ECU). This information enables the ECU to adjust engine performance, optimizing throttle response and improving fuel efficiency, The sensors play a key role in enhancing overall vehicle performance. Click Throttle Position Sensor PCB for more information.

● Accelerator Pedal Sensors: APSs transform the mechanical movement of the accelerator pedal into an electrical signal, which is transmitted to the ECU. This conversion allows for precise control of throttle position, enhancing acceleration accuracy, vehicle response time. The sensors play a crucial role in ensuring smoother driving experiences by providing real-time feedback to optimize throttle adjustments. Click Accelerator Pedal Sensor PCB for more information.

● Engine Oil Pressure Sensors: These sensors monitor the oil pressure in an engine's lubrication system, converting mechanical pressure into an electrical signal to help reduce friction, heat, and wear. Changes in oil pressure cause diaphragm deformation, which alters the thick-film resistors, creating a voltage signal. This signal is sent to the ECU, providing real-time oil pressure data for management. Click Engine Oil Pressure Sensor PCB for more information.

● Manifold Absolute Pressure (MAP Sensors): Thick film sensors, acting as MAP sensors, measure the intake manifold's absolute pressure. This data is vital for assessing engine load and optimizing fuel injection timing, enhancing engine performance and fuel efficiency.

● TPMS Sensors: Thick film sensors in TPMS monitor tire air pressure, alerting the driver to low pressure. This enhances vehicle safety, optimizes tire performance, and reduces fuel consumption by maintaining proper tire pressure.

2. Medical Diagnostics:
● Blood Glucose Sensors: Devices like the "Accu-Chek Sensor" leverage thick film sensors for accurate blood glucose monitoring, playing an essential role in diabetes management by offering reliable, real-time readings that enable timely interventions and better control of blood sugar levels.

● Temperature Sensors: "Infrared Thermometers" utilize thick film sensors to measure body temperature accurately and non-invasively. These sensors provide a fast and reliable way to monitor temperature, making them ideal for both clinical and home use, especially for quick health assessments in fever detection.

3. Industrial Products:
● Pressure Sensors: These sensors measure the force exerted by gases or liquids and are essential for monitoring pressure levels in a wide range of applications, from weather forecasting to automotive systems. By providing real-time data, they help ensure safety, performance, and efficiency in industrial environments such as manufacturing plants, oil rigs, and HVAC systems. Click Ceramic Pressure Sensors for more information.

● Humidity Sensors: These sensors monitor the moisture level in the air and play a crucial role in maintaining controlled environments. Widely used in weather stations, HVAC systems, and industrial applications, they help optimize conditions for processes such as food storage, pharmaceuticals, and electronics manufacturing, ensuring quality and reliability. Click Humidity Sensitive Ceramic Resistors for more information.

● Temperature Sensors: Designed to detect temperature changes, these sensors are vital in controlling industrial processes. Common types, such as thermocouples and RTDs, are widely used in HVAC systems, manufacturing, and power generation plants to maintain optimal operating conditions and prevent equipment failure.

4. Environmental Monitoring:
● Gas Sensors: These sensors detect the presence and concentration of gases, ensuring safety in various settings. Used in safety systems, environmental monitoring, and industrial applications, gas sensors provide critical data for preventing hazardous gas leaks and maintaining air quality in industries such as mining, manufacturing, and waste management. Click LP Gas Tank Gauges Ceramic PCB for more information.

5, Agriculture:
● Crop Moisture Sensors: Thick film sensors are integrated into agricultural irrigation systems to measure soil moisture levels in fields. These sensors help optimize irrigation schedules, conserve water, and enhance crop yield by ensuring optimal soil moisture levels for plant growth.

6, Aerospace:
● Engine Performance Sensors: Thick film sensors are utilized in aircraft engines to monitor various parameters such as engine temperature, pressure, and vibration. These sensors contribute to optimizing engine performance, ensuring safety.

7, Food and Beverage Industry:
● pH Sensors: Thick film sensors are used in food processing and beverage production to measure pH levels in liquids. These sensors ensure quality control and consistency in food and beverage products by monitoring acidity or alkalinity.

8. Consumer Electronics:
● Touch Sensors: Widely integrated into various devices, including "Capacitive Touch Sensors" in smart appliances and gadgets, these sensors enable intuitive, touch-based interfaces that enhance user experience by offering smooth and responsive control. Their versatility is crucial for modern devices such as smartphones, tablets, and home automation systems, providing seamless interaction.

9. Energy Management:
● Smart Meter Sensors: Products like "Energy Monitoring Sensors" incorporate thick film technology to measure and manage energy consumption in both residential and commercial buildings. By providing real-time data on energy usage, these sensors help users optimize consumption, reduce costs, and contribute to energy conservation efforts, supporting both environmental sustainability and cost savings.

10, Building Automation:
● Occupancy Sensors: Thick film sensors are utilized in building automation systems for occupancy detection in rooms and spaces. These sensors contribute to energy conservation by automatically adjusting lighting, heating, and ventilation based on occupancy status.

11, Industrial Automation:
● Conveyor Belt Tension Sensors: Thick film sensors are employed in industrial conveyor systems to measure the tension of conveyor belts. These sensors ensure proper belt tension, preventing slippage and enhancing conveyor efficiency in manufacturing and logistics operations.

12, Marine Industry:
● Bilge Pump Sensors: Thick film sensors are employed in marine vessels to detect water levels in the bilge area. These sensors trigger bilge pumps to remove excess water and prevent flooding, enhancing the safety of the vessel.

13. Smart Packaging:
● Freshness Indicators: Often known as "Freshness Indicator Labels," these sensors are integrated into packaging to provide real-time information about the freshness and quality of the product inside. By detecting changes in environmental conditions such as temperature or humidity, these sensors help consumers make informed decisions, enhancing product safety and reducing waste in industries like food and pharmaceuticals.

14. Oil and Gas Industry:
● Tank Level Sensors: Thick film sensors are essential in oil and gas storage tanks for accurate fluid level monitoring. These sensors offer reliable measurements that ensure effective inventory management, prevent overflows, and optimize process control in petroleum refining and distribution facilities. By maintaining precise level readings, they contribute to safety and efficiency in the storage and transportation of hazardous materials.

Multi-Wire Wipers Used For Thick Film Sensors :

Multi-Wire Wipers are crucial components designed to transmit voltage and signals. They perform linear or rotational sliding over the surfaces of resistive materials (thick film resistors) to adjust resistance values and act as contact elements in voltage dividers.

The design of the contact wiper is extremely important for the efficiency and lifespan of the sensor assembly. When designing the wiper, factors such as contact resistance, operating height (load), repeatability, hysteresis, the type of resistive material, and especially the wiper’s material, shape, and applied pressure must be carefully considered.

We also offer custom Multi-Contact Wipers tailored to customer needs. We can manufacture wipers based on your specific requirements or specifications. For more detailed information about wipers, please refer to our Multi-Wire Wipers section.

Design Guidelines of Thick Film Sensors :

We compiled a Thick Film Sensors-Design Guidelines as attached for you to download, It is to better support our customers' needs in designing and applying Thick Film Sensors, This guide covers detailed information on product solutions, engineering design specifications, material properties, available manufacturing processes, and more.

We hope that this guide will assist customers in standardizing their design process while ensuring the manufacturability of the design data, ultimately improving product reliability and production efficiency. Customers are encouraged to refer to the guide when designing Thick Film Sensors to ensure adherence to best practices.

Engineering Specification of Thick Film Sensors :

Items :

Typical Values

Advanced Capabilities

1, Substrates :

FR4, Ceramic ( AI203, ALN, BeO, ZrO2), Polyimide (Flexible PI), Stainless Steel (SUS304), Mica

FR4, Ceramic ( AI203, ALN, BeO, ZrO2), Polyimide (Flexible PI), Stainless Steel (SUS304), Mica

2, Conductor (Paste) Materials :

Copper, Silver , Gold , Silver-Palladium, Palladium-Gold, Platinum-Silver, Platinum-Gold

Copper, Silver , Gold , Silver-Palladium, Palladium-Gold, Platinum-Silver, Platinum-Gold

3, Thick Film Carbon Thickness (Height) :

15um +/-5 um

30um +/-5 um

4, Conductor Thickness (Height) :

12um+/-5um

20um+/-5um

5, Min Width of Thick Film Line :

0.30 mm +/-0.05 mm

0.20 mm +/-0.05 mm

6, Min Space of Thick Film Line :

0.30 mm +/-0.05 mm

0.20 mm +/-0.05 mm

7, Min Overlap (Carbon to Conductor) :

No less than 0.25mm

0.20mm (Minimum)

8, Sheet Resistivity (ohms/square):

Printed resistors in milli ohm to mega ohm range (Customizable) with tolerances of 1-10% are fabricated and protected with overglaze materials.

Printed resistors in milli ohm to mega ohm range (Customizable) with tolerances of 0.5-10% are fabricated and protected with overglaze materials.

9, Resistor Value Tolerance (ohms) :

+/-10.0% (Standard) (Customizable)

+/-0.5% (Laser trimming)

10, Linearity :

+/-1.0% (Standard) (Customizable)

+/-0.2 ~ +/-0.5% (Laser trimming)

11, Synchronism of Double Channels :

+/-2.0% (Standard) (Customizable) (Potentiometers)

+/-1.0% (Laser trimming) (Potentiometers)

12, Durability of Carbon Ink (Life time) :

0.5 Million (Min), 2.0 Million (Standard)

5.0-10.0 Million (Max) with Surface Polishing

13, Working Temperature :

－ 40ºC /＋150ºC

－ 40ºC /＋180ºC

Test Characteristics of Fuel Level Sensor PCB :

Test Item

Standard

Test Method

Wear Life (Durability)

Contact wiper without break, Resistance within tolerances.

Materials used for the beryllium bronze (Wipers) sliding contact area in sliding contact with the conductor layer, with the contact area pressure at 0.25 N ± 0.05 N. The test requires at least 2 million cycles in the air or 5 million cycles when immersed in gasoline or diesel.

Resistance to Organic Solvents (Corrosion)

(△R/R)≤ 1%

Solvent: 85% diesel (or 92# gasoline) + 15% ethyl alcohol. Solvent temperature: (23 ± 5)°C. Soaking time: (10 ± 1) hours.

Resistance to Soldering Heat

(△R/R)≤ 1%

Soldering PAD is completely immersed in a 270°C ± 5°C tin bath, maintaining (5 ± 1) seconds. Recovery time: (24 ± 4) hours.

Temperature Coefficient (T.C.R)

Within specified T.C.R

As per IEC 60115-1 4.8, tested across the temperature range of +25°C/-55°C/+25°C/+125°C/+25°C.

Rapid Temperature Changing

(△R/R)≤ 1%

-40°C for 30 minutes - normal temperature for 5 minutes - 85°C for 30 minutes, repeated for 5 cycles.

Short Time Overload

(△R/R)≤ 1%

Apply 2.5 times rated voltage or maximum overload voltage (whichever is lower) for 5 seconds, as per IEC 60115-1 4.13.

Endurance at 70°C

(△R/R)≤ 1%

70°C ± 2°C for 1000 hours with rated voltage 1.5 hours ON / 0.5 hours OFF, as per IEC 60115-1 4.25.1.

Damp Heat Steady State

(△R/R)≤ 1%

As per IEC 60115-1 4.24, tested at 40°C ±2°C, 93% ±3%RH for 1000 hours.

Low Temperature Storage

(△R/R)≤ 1%

Place the Fuel Level Sensor PCB in the low-temperature storage chamber at (-55 ± 1)°C, duration: 1000 hours.

High Temperature Storage

(△R/R)≤ 1%

Place the Fuel Level Sensor PCB in the high-temperature storage chamber at (125 ± 1)°C, continuous for 1000 hours.

Test Characteristics of Throttle Position Sensor PCB :

Test Item

Standard

Test Method

Linearity of Output Voltage

Should be ≤ 1%

Throttle Position Sensor PCB must maintain a linearity of output voltage that should not exceed ±1% to ensure precise throttle angle measurements. This linearity is tested by recording the sensor's output voltage in relation to the throttle's angular position over multiple full-range cycles.

Wear Life (Durability)

Over 5 million cycles

Throttle Position Sensor PCB utilizes a platinum-palladium alloy wire sliding contact wiper, which ensures durability and reliability. The contact pressure with the resistive body is maintained at 0.15 N ± 0.05 N, and the sensor is designed to endure at least 5 million cycles of operation.

Temperature Coefficient

Within specified T.C.R

Throttle Position Sensor PCB's resistive temperature coefficient is kept within specified limits as per IEC 60115-1 4.8, ensuring stable performance across a range of temperatures from +25°C to -40°C, and up to +125°C.

Short Time Overload

(△R/R)≤ 5%

The sensor PCB is tested for short time overload conditions by applying a voltage of 16V for a period of 60 minutes, ensuring it can handle temporary voltage spikes.

Rapid Temperature Changing

(△R/R)≤ 5%

Throttle Position Sensor PCB is subjected to rapid temperature changes, with cycles of -40°C for 30 minutes, a transition to normal temperature for 5 minutes, and then 125°C for 30 minutes, repeated for 5 cycles.

Low Temperature Operation

(△R/R)≤ 5%

Throttle Position Sensor PCB's low-temperature operation is tested by placing it in a low-temperature chamber at -40°C, maintaining the temperature for 1 hour, and then applying a nominal voltage of (5 ± 0.1) V for 48 hours.

Endurance at 70°C

(△R/R)≤ 5%

Throttle Position Sensor PCB's endurance is evaluated at a constant temperature of 70°C ± 2°C for 1000 hours, with a cycle of 1.5 hours ON and 0.5 hours OFF, using the rated voltage or the limiting element voltage, whichever is lower.

Damp Heat Steady State

(△R/R)≤ 5%

Throttle Position Sensor PCB's performance in damp heat conditions is assessed at 40°C ±2°C and 93% ±3%RH for 1000 hours.

Low Temperature Storage

(△R/R)≤ 5%

Thick Film Resistor is tested for storage at low temperatures of -40°C ±1°C for 1000 hours to ensure long-term stability.

High Temperature Storage

(△R/R)≤ 5%

Thick Film Resistor is also tested for storage at high temperatures of 150°C ±1°C for 1000 hours to evaluate its resistance to prolonged exposure to heat.

Test Characteristic of Engine Oil Pressure Sensor PCB:

Test Item

Standard

Test Method

Wear Life (Durability)

Contact wiper without break, and the resistance value must be still within the requirement.

The sliding contact (wiper) made of beryllium bronze in the conductor layer area maintains contact with the conductor layer under a pressure of 0.25 N ± 0.05 N, rubbing back and forth with each cycle. The test requires a minimum of 2 million cycles in the air or 5 million cycles when immersed in gasoline or diesel oil.

Resistance to Organic Solvents

The solvent temperature is maintained at (23±5)°C, and the soaking time is (10±1) hours.

The test uses a solvent mixture of 85% diesel (or 92# gasoline) and 15% ethanol. The corrosion index (△R/R) must be ≤1%.

High Temperature Welding

Resistance to soldering heat (△R/R) must be ≤1%.

The soldering PAD is fully immersed in a tin bath at 270°C ± 5°C for a duration of (5±1) seconds. Recovery time is (24±4) hours.

Temperature Coefficient

Follows IEC60115-1 4.8.

Must be within the specified T.C.R across the temperature range of +25°C/-55°C/+25°C/+125°C/+25°C.

Rapid Change of Temperature

Resistance change (△R/R) must be ≤1% as per IEC 60115-1 4.19.

The test involves cycles of -40°C for 30 minutes, normal temperature for 5 minutes, and 85°C for 30 minutes, with 5 cycles in total.

Short Time Overload

Resistance change (△R/RI) must be ≤1% as per IEC60115-1 4.13.

The test applies 2.5 times the rated voltage or the maximum overload voltage (whichever is lower) for 5 seconds.

Endurance at 70°C

Resistance change (△R/R) must be <1%.

The test involves maintaining 70°C ± 2°C for 1000 hours with the rated voltage on for 1.5 hours and off for 0.5 hours continuously.

Steady State Damp Heat

Resistance change (△R/R) must be ≤1% as per IEC60115-1 4.24.

The test is conducted at 40°C ±2°C and 93% ±3% RH for 1000 hours.

Low Temperature Storage

Resistance change (△R/R) must be ≤1%.

Pressure Sensors PCB is placed in a low-temperature storage chamber at (-55±1)°C for 1000 hours.

High Temperature Storage

Resistance change (△R/R) must be ≤1%.

Pressure Sensors PCB is placed in a high-temperature storage chamber at (125±1)°C for 1000 hours.