Semiconductor fuse is a current protection device mainly used to limit high current and protect sensitive semiconductor components such as thyristors, power supplies, SCRs, rectifiers, diodes and so on.

Semiconductor fuses are fast blowing fuses. Typically, semiconductor fuses are available in voltages ranging from 125 to 2,100V and are available in a wide range of sizes and shapes. Unlike ordinary industrial fuses, semiconductor fuses do not have an added time delay and are able to respond in 10ms or even less, resulting in more reliable protection.

Structural Characteristics

Semiconductor fuses are composed of a fuse element, a filler that surrounds the element, body, and mounting terminals.

Element:

Semiconductor fuses contain one or more current-sensitive elements. The resistance of each element and the number of elements used in each fuse typically determine the current rating of the fuse. Semiconductor fuses contain elements made of silver, silver-plated copper, brass, or other suitable materials.

Filler Material:

Semiconductor fuses contain filler, which is primarily used to eliminate the arc discharge that occurs during current breaking. The use of high grade quartz-silica crystal filler material helps to improve the current limiting capability of the fuse. In addition, the filler helps maintain thermal balance within the fuse while providing stability to the element. This stability allows for smaller element cross-sections, which improves short-circuit performance.

Body Material:

The most common body materials used in semiconductor fuses are glass-reinforced melamine and high-grade ceramics. Glass melamine is strong and break-resistant, while ceramic has high heat dissipation and high temperature resistance.

Mounting Terminals:

Typical semiconductor fuses terminals consist of copper alloy material. Some semiconductor fuses fuses with lower current ratings are made of drawn brass designed to properly relieve stress. The terminals of these fuses are also usually plated to minimize corrosion and provide a low resistance connection.