Thick Film v Wirewound Power Resistors – A Comparison

There are many power resistor technologies available but the most common are Wirewound and Thick Film with other technologies reserved for specialist applications

Power Resistor Design Considerations

For any resistor technology, the four main design considerations are:

-Resistance value

-The resistor power handling capability

-The change in the resistance value over time

-The change in the resistance value with temperature

Passive Electronic Component Obsolescence Solutions

Resistors and other passive electronic components can often become difficult to source or obsolete at short notice causing delays to production schedules, upsetting important customers and wasting resources. Often, an attempt may be made to purchase residual stock from distribution or component brokers but this can lead to issues with quality or counterfeit components. As many manufacturers may be chasing the same solution the correct component can be both difficult and expensive to source.

The Main Causes Of Thick Film Resistor Failure

Thick film resistor failures are often caused by external environmental factors such as electrical and mechanical stresses and handling issues but seldom occur due to a failure of the resistive element itself. Failures are either classed as a degradation of performance or complete failure (usually as an open rather than a short circuit).

We consider several common causes of thick film resistor failure, many of which may not be immediately obvious to the circuit designer. Failure modes include:

·         Mechanical stress