Metal film resistors are one of the most widely used types of resistors in electronic circuits, and their core advantages lie in:
High precision: accuracy can reach 0.01% or even higher;
Low temperature drift: Temperature coefficient (TCR) can be as low as ± 5ppm/℃;
Low noise: Extremely low current noise, suitable for sensitive scenes such as audio and sensors;
Excellent stability: Long term resistance change rate<0.1%, with a lifespan of over 10 years.
The following is a detailed classification and technical analysis of metal film resistors:
1、 Classified by accuracy level
Ordinary precision type (1%~5%)
Application: General electronic devices, consumer electronics products.
Features: Low cost, meeting basic circuit requirements.
High precision type (0.1%~0.5%)
Applications: Industrial instruments, communication equipment, medical equipment.
Features: High precision, suitable for scenarios with high stability requirements.
Ultra high precision type (<0.01%)
Applications: Quantum computing, satellite navigation, precision laboratory instruments.
Features: High precision, annual resistance change rate<5ppm.
2、 Classified by Temperature Coefficient (TCR)
Low temperature float type (± 5ppm/℃~± 25ppm/℃)
Applications: Precision temperature control, climate monitoring, laser temperature control.
Material: Usually manganese copper alloy or special nickel chromium alloy is used.
Ordinary temperature drift type (± 50ppm/℃~± 100ppm/℃)
Application: General industrial control, consumer electronics.
Features: Low cost, suitable for scenarios with low temperature stability requirements.
3、 Classified by power level
Low power type (1/16W~1/8W)
Applications: portable devices, wearable devices, miniaturized PCBs.
Packaging: 0201, 0402, 0603.
Medium power type (1/4W~1/2W)
Application: General electronic devices, household appliances.
Packaging: 0805, 1206, 1210.
High power type (1W~5W)
Applications: power modules, motor drives, electric vehicles.
Encapsulation: 2010, 2512, plug-in (such as TO-220).
4、 Classified by packaging form
Surface mount (SMD)
Features: Surface mount, suitable for automated production.
Packaging examples: 0201, 0402, 0603, 0805, 1206, 2512.
Plug in (Through Hole)
Features: Pin soldering, suitable for high-power or high-voltage scenarios.
Packaging examples: TO-220, TO-247, axial lead packaging.
5、 Classified by special functions
Anti Sulfur
Features: Surface coating (such as gold plating) prevents corrosion by sulfur elements and avoids resistance drift.
Application: Automotive electronics (engine compartment), chemical environment.
Certification standard: Passed AEC-Q200 (automotive grade) or GJB 150A (military grade) testing.
Anti Surge type
Features: Enhanced structural design, capable of withstanding transient overcurrent (such as motor start-up shock).
Applications: Motor drives, inverters, industrial robots.
Technical parameters: The surge current withstand capacity can reach more than 10 times the rated current.
Pulse Load Type
Features: Optimized design to withstand high-frequency pulse currents.
Applications: Switching power supply, laser driver, pulse generator.
6、 Classified by material and process
Nickel chromium alloy film resistor
Features: Low cost, TCR of about ± 25ppm/℃, suitable for general high-precision scenarios.
Application: Industrial instruments, communication equipment.
Representative models: Vishay DAL series, ROHM MCR series.
Manganese copper alloy film resistor
Features: Extremely low TCR (± 5ppm/℃), excellent long-term stability.
Applications: Quantum computing, satellite navigation.
Representative models: Vishay VHP series, Caddock USF series.
7、 Typical application scenarios
precise measurement
Example: In a six and a half digit multimeter, a 0.01% precision metal film resistor is used as the standard resistor.
EADS
Example: In satellite attitude control systems, ultra-high precision resistors ensure gyroscope stability.
medical equipment
Example: In magnetic resonance imaging (MRI), low noise resistance reduces image artifacts.
Automotive Electronics
Example: In the ECU (Engine Control Unit), the anti sulfurization resistor is suitable for high temperature and high humidity environments.
8、 Selection Guide
Precision priority: Choose models with 0.01% or higher precision, paired with low TCR materials (such as manganese copper).
High power scenario: Prioritize plug-in packaging and confirm whether the rated power meets P=Imax2 × R.
Harsh environment: Choose models that are resistant to vulcanization or surges, and obtain AEC-Q200 (automotive grade) certification.
Low temperature float requirement: Choose TCR<± 10ppm/℃ models, such as Vishay VHP series.
9、 Brand and representative model
brand
series
characteristic
Vishay
DAL、VHP
Ultra high precision, TCR as low as ± 5ppm/℃
ROHM
MCR
Thin film process with an accuracy of 0.1%
Yageo
AC
Copper alloy, resistant to sulfurization
KOA
RK73H
Nickel chromium alloy, high temperature resistant
Metal film resistors are the core components of precision electronic devices, and their selection requires comprehensive accuracy TCR、 Power, packaging, and special functional requirements. In cutting-edge fields such as quantum computing and satellite navigation, manganese copper alloys and ultra-high precision models are preferred; The anti sulfurization/anti surge characteristics need to be considered in automotive electronics or chemical environments; Portable devices require patch packaging to save space.