The parameter setting of film capacitors is determined based on product design and application requirements. Here are some of the main parameters of film capacitors and how they are set:
1. Capacitance value: Capacitance value is a key parameter of film capacitors and indicates the ability of the capacitor to store charge. Capacitance value is usually expressed in Farad (F). According to the specific application requirements and circuit design, select the appropriate capacitance value to meet the required capacitance capacity.
2. Rated voltage: The rated voltage is the maximum voltage value at which the film capacitor can work normally. Selecting the appropriate rated voltage should consider the maximum voltage value in the circuit and the safety margin to ensure that the capacitor will not be damaged by overvoltage during operation.

3. Capacitance tolerance: Capacitance tolerance indicates the deviation range between the capacitance value and the nominal value. Capacitance tolerance is usually expressed as a percentage, such as ±5% or ±10%. Selecting the appropriate capacitance tolerance should consider the accuracy requirements and cost factors of the circuit.

4. Temperature coefficient: The temperature coefficient indicates the degree to which the film capacitance value changes with temperature. It is usually expressed as a percentage per degree Celsius (ppm/°C) or a percentage per Kelvin (ppm/K). To select the appropriate temperature coefficient, the stability and performance of the circuit under different temperature conditions should be considered.
5. Operating temperature range: The operating temperature range refers to the temperature range in which the safety film capacitor can work normally. According to the actual application environment and requirements, select a suitable operating temperature range to ensure that the capacitor can work normally under various temperature conditions.
6. Size and packaging: Film capacitors have different sizes and packaging forms for different applications. Choosing the appropriate size and packaging form should consider the design and installation requirements of the circuit board.
The above are some of the main parameters of film capacitors and how to set them. When selecting and setting the parameters of film capacitors, it is necessary to comprehensively consider factors such as circuit design, application requirements, cost and quality to ensure that film capacitors can work normally and meet performance requirements in specific applications.