Title: KOA Resistance Category Analysis: Selection Guide from Thick Film to Special Resistors
Introduction: In the field of electronic components, resistance is a fundamental and critical component. As one of the world's leading resistor manufacturers, KOA Speer Electronics offers an extremely rich and reliable line of resistor products. Understanding the detailed categories of KOA resistors is crucial for engineers to select, make purchasing decisions, and ensure the reliability of circuit design. This article will systematically sort out the main categories and characteristics of KOA resistors to help you accurately match your needs.
Core advantage: KOA is renowned for its excellent manufacturing processes and strict quality control. The typical manufacturing density (failure rate) of its main products (such as general thick film chip resistors) is controlled at an excellent level of around 6%, which represents extremely high production consistency and reliability, making it an ideal choice for industrial and automotive applications.
Main classification dimensions of KOA resistors
The categories of KOA resistors can be divided into multiple dimensions, and the most common and practical classification methods include:
Classified by Function and Characteristics (Core Dimensions)
Fixed Resistors:
Thick Film Chip Resistors: This is the category with the highest production volume and widest application by KOA. Small size, low cost, and mature production technology. Covering various specifications such as standard type, high-precision type, sulfur resistant type, high-voltage type, array resistor, etc. Its high manufacturing density (low loss efficiency, about 6%) is mainly reflected in the large-scale stable production of this category.
Thin Film Chip Resistors: Provides higher precision, lower temperature coefficient (TCR), and better long-term stability than thick films. Commonly used in high demand fields such as precision instruments, measuring equipment, and medical electronics.
Metal Film Resistors MELF (Axial): including cylindrical MELF (surface mount) and axial lead type. The performance is between thick film and thin film, with good accuracy, stability, and pulse loading capability. MELF is particularly suitable for high reliability applications.
Metal Plate/Current Sensing Resistors: Made of low resistance alloy materials (such as manganese copper alloy). The core features are extremely low resistance value (milliohm level), high precision, extremely low TCR, and high power density. Specially designed for precise measurement of current in circuits (shunt).
Wirewound Resistors: Use resistance alloy wires wound around ceramics or other frameworks. Capable of withstanding high power and high pulse, with excellent stability. Divided into power type winding resistors (plug-in and patch) and precision winding resistors. Commonly used in high-power applications such as power supply, motor control, and braking.
Metal Oxide Film Resistors: The plug-in axial lead type is the main type. It has good high temperature resistance, moisture resistance, and high power, with high cost-effectiveness, and is commonly used in power supplies, household appliances, etc.
Carbon Film Resistors: Plug in axial lead type. The lowest cost, relatively average accuracy and stability, commonly used in consumer electronic products with low performance requirements.
Glaze Resistors/High Voltage Resistors: Surface covered with a glass glaze layer, with high voltage resistance, high insulation, and high temperature resistance characteristics, suitable for high-voltage power supplies, X-ray equipment, laser equipment, etc.
Variable Resistors:
Potentiometers: provide continuously adjustable resistance values. KOA offers rotating, sliding, and fine tuning materials, including carbon film, conductive plastic, and ceramic metal (Cermet), to meet different precision, lifespan, and environmental requirements.
Trimmer Resistors: Miniature potentiometers used for precise fine-tuning (such as calibration) after circuit board installation. Both patch type and plug-in type are available.
Special Resistors:
Fusible Resistors: They will melt like fuses during overcurrent, providing overcurrent protection and resistance function.
PTC Thermistors (Positive Temperature Coefficient Thermistors): The resistance value increases sharply with increasing temperature. Used for overcurrent protection, temperature sensing, demagnetization, etc.
NTC Thermistors (Negative Temperature Coefficient Thermistors): The resistance value decreases with increasing temperature. Widely used for temperature measurement, compensation, and surge current suppression.
Varistors Metal Oxide Varistors (MOV): The resistance value changes with voltage and is mainly used to absorb transient overvoltages (such as surges and ESD) and protect circuits.
Other special resistors: such as surge resistors, array resistors, etc.
Classified by packaging form and installation method
Chip/SMD resistors: mainstream packaging, directly mounted on the surface of PCB. Standardization of dimensions (such as 0201, 0402, 0603, 0805, 1206, 2010, 2512, etc.). Including thick film, thin film, metal plate (current detection) MELF、 Partial winding resistance, etc.
Through Hole Resistors: With axial or radial pins, they need to be inserted into PCB through holes for soldering. Including metal film, oxide film, carbon film, winding resistor, potentiometer, fine-tuning resistor, etc.
Power resistor packaging: It has a special heat dissipation structure, such as TO packaging with heat sinks, aluminum shell packaging, cement packaging, etc., mainly used for high-power wound resistors or metal plate resistors.
Classified by materials and technology
Thick film technology: cost-effective and widely used.
Thin Film Technology: High precision and high stability.
Metal Alloy Technology: Used for current detection resistors, precision winding resistors, etc.
Wirewound technology: high power, high stability.
Ceramic/Metal Oxide technology: used for high-voltage resistors, varistors, and oxide film resistors.
Carbon Film Technology: Economical.
Conductive plastic/Cremet technology: used for high-performance potentiometers/fine tuned resistors.
How to choose the appropriate KOA resistor?
When selecting KOA resistors, the following key parameters need to be considered comprehensively:
Resistance Value
Accuracy (tolerance)
Rated Power
Temperature coefficient (TCR)
Working Voltage/Max Voltage
Package Size
Special requirements: such as sulfur resistance, high reliability (automotive grade AECQ200), pulse resistance, low noise, high frequency characteristics, flame retardant rating, etc.
KOA Speer Electronics, with its comprehensive product line, leading technology (such as thick film processes that achieve approximately 6% high manufacturing density), and relentless pursuit of quality, can provide suitable resistance solutions for almost all electronic application scenarios. Understanding the different categories and core characteristics of KOA resistors is a crucial first step in efficient and reliable circuit design, whether it is consumer electronics, industrial control, automotive electronics, medical equipment, or communication base stations. It is recommended to obtain the latest and most detailed technical specifications and application support through the KOA official website's product catalog, selection guide, or consulting authorized distributors.