This posting commences by talking about the primary construction of a thick film ability resistor product or service. We then protect the possible efficiency limitations this building can trigger and examine the concerns to think about when choosing a ability resistor for a unique software.
The design of a thick movie resistor merchandise is a serial course of action. A substrate (typically Alumina) is printed with a resistor paste that comprises metal oxides and glass-centered fillers, which collectively with a solvent forms a paste. The substrate and paste are then fired to burn off off irregularities and solvents and to harden the substrate. The resistor element is then sealed to protect against dampness and gasoline ingress.
Even though thick movie resistors are typically the lowest priced components on a PCB a failure can be just as catastrophic as the most high priced lively ingredient. Choosing the right excellent for a thick movie resistor starts off by describing its use as follows:
– Describe the use and software.
– Describe The ecosystem for use. The crucial difficulties to look at are temperature, moisture, aggressive gases, mechanical stresses and EMC necessities.
– Long time period reliability needs.
– Specify the required high quality conventional.
It might be the electrical power resistor device is only necessary for a shopper software. In this scenario, the extended expression effect on general performance due to electrical stresses or environmental elements this sort of as temperature might be irrelevant.
High quality requirements may not be an problem if the electricity resistor is for a low-cost products with an predicted quick lifespan. Nonetheless, if the system is for a military services application environmental elements and excellent stages will be a serious issue.
In significant-dependability apps, the storage of elements, traceability and output techniques will be crucial. Microcracking in the substrate owing to inappropriate dealing with or trimming can cause failure. As can failure to seal the machine correctly to stop the ingress of humidity and gases (particularly sulphur and chlorine).
Thick movie power resistor devices are fairly little, lower expense and higher dependability in the vast majority of applications. But some expertise of the production system and potential failure modes is practical to make certain right element choice. The clarity in the precise requirements for the machine will maximise the probabilities of extensive phrase ingredient reliability.
When an software-certain resistor is the only answer, shut cooperation with a expert resistor company can yield the greatest effects. Utilise the expertise of the provider engineering groups to make certain the electricity resistor product is suit for purpose.