A Comparison of Film Capacitors and Safety Capacitors

We know that capacitors are used in electrical appliances, yet many people may not be very familiar with them. There is a wide variety of capacitors on the market, each with its own distinct characteristics and advantages—such as "safety capacitors," which are currently very popular and widely used in appliance switches with great success. Since many people are unaware of their specific advantages, let’s look at a comparison shared by the team at Furuixin: Safety capacitors versus film capacitors—which one comes out on top?

Determining whether safety capacitors are superior to film capacitors cannot be done based on simple criteria alone; they serve different purposes and are suited to different application scenarios. Ultimately, which one is "better" depends on the specific use case. However, we can start by examining the differences between safety capacitors and film capacitors, which are outlined below:

1. Regarding Certification

Safety capacitors are categorized into X-capacitors and Y-capacitors; Y-capacitors, for instance, utilize ceramic materials, making them fundamentally different from film capacitors in terms of composition. Regarding safety certification, safety capacitors are required to undergo a certification process. There are numerous available certifications, and the specific qualifications obtained—as well as the number of certifications held—can vary by manufacturer. Generally speaking, the more certifications a safety capacitor has, the better; without such certification, a component cannot be classified or used as a safety capacitor. In contrast, film capacitors do not require any certification prior to market launch and promotion. Based on these certification requirements alone, one can infer that safety capacitors are superior to film capacitors, as certified products inherently offer a higher level of safety assurance.

2. Regarding Brand Marking

We know that many products feature printed information on their exteriors—such as brand details. For safety-rated capacitors, printing the brand is mandatory, as it is a requirement for certain certifications. In contrast, film capacitors generally have no such requirement; unless a manufacturer chooses to print such information for promotional purposes, brand details are rarely found on the exterior of film capacitors.

3. Performance Characteristics

As they are two different types of capacitors, their performance characteristics naturally differ. For instance, the materials used in X-class safety capacitors differ from those in standard film capacitors; X-class safety capacitors are encapsulated in plastic housings, whereas standard film capacitors utilize polyolefin film. Generally speaking, the plastic-encapsulated safety capacitors offer superior high-temperature resistance; furthermore, the plastic housing enables them to withstand high humidity.