Custom High Power Resistors

Ion Beam Milling builds high power Tantalum Nitride Chip resistors to customer specifications. We can manufacture resistors using a variety of substrates in various thicknesses to meet your specific needs.

Resistors can be produced with element features under 0.002 inch for high density or high value resistor applications. Low noise stable TCR and chip sizes under 0.010 inch x 0.020 inch are routinely processed in production quantities.

Our Chip Resistors Feature:

Single value or network applications available in chip sizes under 0.020" x 0.020"
Sheet resistivity from 25 to 200 ohms per square.
Long term stability is less than 0.5% change in value over 1000 hours at 125°C in air.
Tantalum Nitride is self passivating (moisture resistant). The tantalum pentoxide passivation is formed during our air anneal stabilization process.

For high power Chip Resistors, substrates of Aluminum Nitride and Beryllium Oxide are commonly used. When very high power is required, Ion Beam Milling can offer Chip Resistors on CVD Diamond that feature unsurpassed power handling.

Basic equation for calculating resistance

The resistance of a specific resistor depends on its aspect ratio (the ratio of its length to width) expressed as a number of “squares” (note: the term “square” is dimensionless).

R = s(L/W) where:

R = resistance in ohms
s = sheet resistance in ohms/sq
L = Length of the resistor
W = width of the resistor

Resistor “length” is always the dimension of the resistor parallel to the current flow.

Sample Characteristics of Various Substrates

Substrate & Thickness	Resistor Size (mils)	Max. Power Density (w/sq in.)	Resistor Temperature Rise above ambient (°C)
Aluminum Nitride	20 x 20	5000	<125 °C
BeO / 0.15”	20 x 20	10,000	<125 °C
CVD Diamond / 0.10”	20 x 20	20,000	<125 °C
Note: Testing performed with substrates attached to 3” x 3” x 0.25” Cu sink held at 25 °C ambient