chip resistor (thin film resistor)   

    The chip resistor (thin film resistor) adopts vacuum evaporation, magnetron sputtering and other process methods. Thin film resistance can achieve 0.01% accuracy of one ten thousandth, 0.1% accuracy of one thousandth, etc. Thin film resistance can achieve a very low temperature coefficient, so that the resistance value changes very little with temperature, and the resistance value is stable and reliable. Therefore, thin film resistors are commonly used in various instruments, medical devices, power supplies, power equipment, electronic and digital products, etc.

    The film resistance has the best thickness of temperature sensitive deposition layer, but the resistance value produced by the best film thickness seriously limits the possible range of resistance value. Therefore, different resistance ranges can be achieved by using various deposition layer thicknesses. The stability of thin film resistance is affected by temperature rise. The aging process of film resistance stability is different due to the film thickness required to achieve different resistance values, so it is variable in the whole resistance range. This chemical / mechanical aging also includes high temperature oxidation of resistance alloys. In addition, changing the optimal film thickness will seriously affect TCR. Because the thinner deposition layer is easier to oxidize, the resistance degradation rate of high resistance films is very high.

     TCR is a small parameter that can not be ignored. Its unit is ppm / ℃ (the resistance value caused by temperature change per ℃ changes by parts per million). The TCR coefficient of 1% ordinary resistance is in the range of thousands of PPM / ° C. The change of the overall resistance is related to the material, actual power and physical size of the resistance.