This write-up begins by reviewing the fundamental building of a thick movie power resistor item. We after that cover the prospective performance constraints this building and construction can trigger and also review the concerns to consider when picking a power resistor for a particular application.
The building of a thick film resistor item is a serial procedure. A substratum (normally Alumina) is printed with a resistor paste that makes up metal oxides and also glass-based fillers, which along with a solvent kinds a paste. The substratum and also paste are then discharged to burn abnormalities and solvents and to solidify the substrate. The resistor element is after that sealed to prevent moisture as well as gas access.
Although thick movie resistors are frequently the most affordable components on a PCB a failure can be equally as tragic as the most expensive energetic part. Selecting the best quality for a thick film resistor begins by defining its use as follows:
– Explain the use and application.
– Define The environment for usage. The key problems to consider are temperature level, dampness, hostile gases, mechanical stress and anxieties as well as EMC needs.
– Long term integrity demands.
– Define the required quality requirement.
It may be the power resistor device is only needed for a customer application. In this case, the long term effect on performance as a result of electrical anxieties or environmental variables such as temperature may be irrelevant.
Quality requirements might not be a concern if the power resistor is for a low-priced product with an anticipated short lifespan. However, if the tool is for an armed forces application ecological factors and top quality levels will certainly be a significant problem.
In high-reliability applications, the storage of elements, traceability and also production techniques will be very important. Microcracking in the substratum as a result of improper handling or trimming can cause failure. As can failure to secure the device properly to avoid the ingress of dampness and also gases (especially sulphur and chlorine).
Thick movie power resistor gadgets are reasonably small, inexpensive and high dependability in the majority of applications. Yet some understanding of the production procedure as well as possible failure settings works to guarantee right element option. The quality in the accurate requirements for the gadget will maximise the chances of long-term element reliability.
When an application-specific resistor is the only solution, close collaboration with an expert resistor manufacturer can produce the most effective outcomes. Use the experience of the provider engineering groups to make certain the power resistor gadget is fit for purpose.