Film capacitor packaging naming

Film capacitors are commonly seen in our daily lives, appearing in LED energy-saving lamps, TV set-top boxes, camera flashes, electricity meters, computers, and peripheral equipment. But do you know how they are named? What are the naming conventions? This article will provide a detailed introduction to the naming conventions of film capacitor packaging and the significance of packaging.

Film Capacitor Packaging Naming Conventions

Film capacitors are generally available in voltage ratings of 6.3V, 10V, 16V, 25V, and 50V. Domestic capacitor models typically consist of four parts (excluding varistors, variable capacitors, and vacuum capacitors). These parts represent the name, material, classification, and serial number, respectively.

Part 1: Name, expressed in English letters; capacitors are represented by C.

Part 2: Raw materials, expressed in English letters.

Part 3: Classification, generally represented by numbers, sometimes by English letters.

Part 4: Number, represented by numbers.

The raw materials of the products are represented by the following letters: A - Tantalum electrolysis, B - Non-polar plastic films such as polyethylene, C - High-frequency ceramics, D - Aluminum electrolysis, E - Electrolysis of other raw materials, G - Aluminum alloy electrolysis, H - Composite materials, I - Laminated glass glaze, J - Metallized paper, L - Optically active organic chemical plastic films such as polyester fabric, N - Niobium electrolysis, O - Film coating, Q - Paint layer, T - High-frequency ceramics, V - Biotite paper, Y - Biotite, Z - Paper media

The practical significance of film capacitor packaging

1. Electrolytic capacitors are generally composed of a metal foil (aluminum/tantalum) as the positive electrode, and an insulating plastic film or electrolyte solution polymer.

2. The negative electrode of a tantalum electrolytic capacitor is typically made of manganese dioxide. Because it uses an electrolyte solution as the negative electrode (note the difference from the electrolytic medium), electrolytic capacitors are known for this.

3. Optically active electrolytic capacitors are generally used in switching power supply principles or high-frequency power circuits for functions such as power supply filtering, decoupling, signal coupling, time constant setting, and DC blocking. They are generally not used in AC switching power supply principles. When used as filter capacitors in DC regulated power supply circuits, their anode (positive terminal) should be connected to the positive terminal of the power supply voltage, and their negative terminal (negative terminal) should be connected to the negative terminal of the power supply voltage. Incorrect connection will damage the capacitor.

4. Electrolytic capacitors are widely used in electrical products and various electronic devices. Their capacitance range is very large, generally 1~1000μF, and their rated operating frequency range is 6.3~450V. Their disadvantages are dielectric loss, large capacitance deviation (maximum allowable error of +100% and -20%), weak heat resistance, and easy failure after long storage time.

Common packaging types of film capacitors

Film capacitors are generally classified into three types according to their specifications and dimensions: lead type (also called through-hole type), buffalo horn type (also called solder pin type), and anchor bolt type.

The most common type of welding needle is the two-corner welding needle, but there are also triangular welding needles, four-corner welding needles, and irregularly shaped multi-corner welding needles.

In addition, there is a type called the welding plate type, which is less common and has similar dimensions to the buffalo horn type.

Common types: Wire-type aluminum electrolytic capacitors, solder-pin type aluminum electrolytic capacitors (two-corner and four-corner), anchor bolt type aluminum electrolytic capacitors

Uncommon types: Triangular solder-pin type aluminum electrolytic capacitors, solder tab type aluminum electrolytic capacitors

How are film capacitors composed?

Electrolytic capacitors have optical activity, so why do they also have optical activity?

Generally, electrolytic capacitors are used in rectifier circuits but not in AC circuits. Therefore, a certain difference in their optical rotation is necessary. If differentiation is needed at the component level, it can be done as follows: The longer side of the lead pin is the positive terminal (○+), and the shorter side is the negative terminal (○). A thick black line on the waterproof sleeve indicates the negative terminal.

The following distinctions are made regarding raw materials:

Aluminum foil: Aluminum foil with formed and unformed aluminum foil.

Formed foil: Used on the positive electrode.

Specifically refers to aluminum foil that can be printed with working voltage. Foil used for different specifications and working voltages is generally distinguishable.

Unformed foil: Used on the negative electrode.

Unformed foil is aluminum foil that has not been formed; in other words, it refers to aluminum foil that cannot be printed with working voltage.

Why is electrolytic paper used?

Electrolytic paper:

1. It is sandwiched between the formed foil and the unformed foil and is used as an insulator. In other words, it is placed in order to prevent short circuit faults between the positive foil and the negative foil.

2. Absorb and preserve lithium battery electrolyte.

What are the other raw materials and parts used for?

Lithium battery electrolyte, also known as lithium battery driver electrolyte, is a mixture of various chemicals and can be differentiated based on the operating voltage, temperature characteristics, and type of capacitor used.

After the rubber rewinding machine, the raw material is soaked in the lithium battery electrolyte and the aluminum shell is wetted. If it is left in the air, the wetted material will evaporate. Therefore, the raw material is put into the aluminum shell, covered with rubber, and the aluminum shell is tightened to ensure complete sealing.