Power Chip Resistors on Aluminium‑Nitride Substrates (AlN)

The SRT Resistor Technology CHP Series are power chip resistors manufactured in thick-film technology on aluminium-nitride (AlN) substrates to deliver high thermal conductivity for compact power designs. The AlN substrate allows heat to be conducted efficiently into the solder pads or mounting surface, supporting reliable operation at specified power ratings when pad dimensions are chosen to secure sufficient heat conduction.

The series covers chip sizes 1216, 2010, 2040, 2512 and 4020, with continuous power ratings at 70 °C from 0.75 W up to 2.5 W depending on size, and P200 = 0 W. Maximum working voltages for trimmed standard versions range from 200 V to 500 V, while untrimmed “NA” versions with tolerance above 5 % offer higher maximum working voltages from 600 V up to 1500 V, depending on size. Resistance ranges from 1 Ω to 1.6 kΩ are available with temperature coefficients of resistance (TCR) of 250 ppm/K or 100 ppm/K, depending on the resistance range.

With an operating temperature range from -55 °C to +200 °C and climatic category 55/200/56, the CHP Series is suited to demanding environments where high substrate thermal conductivity, long-term stability and high-temperature behaviour are important. The parts use PtAg thick-film terminations suitable for soldering or conductive gluing and are designed without organic materials, making them suitable for high-vacuum applications. Long-term stability is specified with typical changes under defined storage, load and environmental test conditions.

Key Features

• Resistor technology: thick-film power chip resistors on aluminium-nitride substrates
• Chip sizes: 1216, 2010, 2040, 2512, 4020
• Power rating at 70 °C (P70), P200 = 0 W:
  1216: 0.75 W; 2010: 1.0 W; 2040: 2.5 W; 2512: 1.5 W; 4020: 2.0 W
• Maximum working voltage (V), standard trimmed:
  1216: 200 V; 2010: 250 V; 2040: 250 V; 2512: 300 V; 4020: 500 V
• Maximum working voltage (V), NA untrimmed (Tol. > 5 %):
  1216: 600 V; 2010: 900 V; 2040: 900 V; 2512: 1200 V; 4020: 1500 V
• Resistance ranges and TCR:
  1 Ω to < 10 Ω: TCR 250 ppm/K, tolerance 1 %–20 %;
  10 Ω to 1.6 kΩ: TCR 100 ppm/K, tolerance 1 %–20 %
• Operating temperature range: −55 °C to +200 °C; climatic category 55/200/56
• Terminations: PtAg (platinum-silver) thick-film terminations for soldering or conductive gluing
• High-vacuum suitability: no organic materials, suitable for high vacuum applications
• Moisture Sensitivity Level: MSL 1 (unlimited) to J-STD-020
• Long-term stability and endurance: defined limits under storage, load, overload and damp-heat conditions

Application Industries and Use Cases

• Power Electronics: Power resistors in converters, inverters and power supplies where high thermal conductivity of AlN supports efficient heat spreading.
• Industrial Control and Drives: Damping, load and snubber resistors mounted on thermally optimised PCB areas operating up to 200 °C.
• Measurement and Test Equipment: Power resistors in instrumentation requiring stable behaviour under long-term storage, overload and damp-heat conditions.
• High-Temperature and Harsh Environments: Resistors in circuits exposed to elevated temperatures and climatic conditions consistent with climatic category 55/200/56.
• High-Vacuum Systems: Resistive elements in high-vacuum applications where the absence of organics and PtAg terminations are advantageous.