Power Metal Film Chip Resistors (SMF)

In the metal layer to achieve a homogenous crystalline structure, Direct Electronics' surface mount power type metal film package resistor (SMF) benefits from the key advantages of today's sputtering technology for the tight control of metal film thickness.

By photolithography, the same length and width of the resistive element can be controlled by the same precision and accuracy as the thickness of the sputtered metal film layer.

Surface Mounted Power Metal Film Resistors (SMF) have good accuracy tolerances, good stability and low TCR characteristics. In addition, due to the low voltage coefficient, the resistor has low noise characteristics and high linearity. Thus, in important circuits, (SMF) power chip resistors are commonly used in active filters or bridge circuits.

Direct (SMF) power-type metal film molded resistors provide three power, 2W, 3W, and 5W. Resistance range of 10Ω ~ 2MΩ, and the maximum working voltage up to 500V. The tolerance accuracy has two options ±1% (F), and ±5% (J) with temperature coefficient of ±100ppm/°C.

(SMF) series are available in tapes, RoHS compliant and 100% lead free. For conventional parameters, specifications outside the parameters, or technical requirements, please contact Direct.

Download complete PDF Power Metal Film Chip Resistors.

Features :
  1. Automatic surface mount special design. Lower assembly costs.
  2. Excellent electrical stability and mechanical strength.
  3. Flameproof UL94V0 Resin molded package.
  4. Heat resistant, moisture resistant, insulated.
Applications :
  1. Consumer electronics, computers.
  2. Telecommunications, control equipment and so on.
Construction & Dimensions (Unit: mm) (SMF)
Surface Mounted Power Metal Film Resistor Dimensions (SMF)
Rated Wattage A ±0.3 B ±0.3 C ±0.3 D ±0.3 E Max. F ±0.3 Resistance Range (Ω) Max. Working Voltage (V)
2W 4.0 6.7 1.4 3.55 7.9 1.5 10 ~ 2M 300
3W 5.5 10.5 1.7 5.0 12 2.3 10 ~ 2M 500
5W 7.3 13.5 1.7 6.8 17 2.5 10 ~ 2M 500
Note:
  • Rated Continuous Working Voltage (RCWV) = ( P × R ) , or Max. Operating Voltage listed in above table whichever is lower.
  • Resistance or specifications outside the parameters can be on request.
Electrical And Mechanical Performance (SMF)
Characteristics Standards Test Methods
Resistance Tolerance ±5% (J) or ±1% (F) -
TCR ±100ppm/°C -55°C ~ 200°C
Power Rating Load Surface temp. 275°C Max. Rated voltage for 30 minutes
Short Time Overload ±(1% + 0.05Ω) 5 times rated power with applied voltage not to exceed 2 times maximum continuous operating voltage for 5 seconds.
Dielectric Withstanding Voltage No evidence of mechanical damage or insulation breakdown. AC 500V for 1 minutes
Insulation Resistance 10,000MΩ DC 500V megger
Solder-ability Minimum 95% coverage 235 ± 5°C for 2 seconds
Resistance to Soldering Heat No evidence of mechanical damage. ±(1% + 0.05Ω) 270 ± 5°C for 10±1 seconds

Environmental Characteristics (SMF)
Characteristics Standards Test Methods
Temp. Cycle ±(1% + 0.05Ω) -55°C (30min.) → Room Temp. (3min.) → +200°C (30min.) → Room Temp. (3min.)/(5cycles)
Load Life ±(1% + 0.05Ω) Rated power load 90 minutes ON 30 minutes OFF 70°C 1000 hours
Moisture-proof Load Life ±(1% + 0.05Ω) Rated power load 90 minutes ON 30 minutes OFF 40°C 95% RH 500 hours
Derating Curve (SMF)
For resistors operated in ambient temperatures above 20°C, power rating must be derated in accordance with the curve below.
Precision Chip Resistor (SMF) Recommend Land Pattern

Surface Temperature Rise (SMF)
Precision Chip Resistor (SMF) Recommend Land Pattern
Order Codes (SMF)
SMF 2W 10Ω J
Part Number
SMF
Rated Wattage (W)
2W
3W
5W
Resistance (Ω)
10 10Ω
1K1 1.1KΩ
110K 110KΩ
1M1 1.1MΩ
Tolerance (%)
F ±1.00%
J ±5.00%