Classification of Crystal Diodes 2

2. A key type diode is formed by fusing or silver filaments onto a single crystal of germanium or silicon. Its characteristics are between point contact diodes and alloy diodes. Compared with point contact type, although the PN junction capacity of key type diodes has slightly increased, their forward characteristics are particularly excellent. Commonly used as a switch, sometimes also applied to detection and power rectification (not greater than 50mA). In key type diodes, diodes with fused gold wires are sometimes referred to as gold bond type, while diodes with fused silver wires are sometimes referred to as silver bond type.

3. Alloy diodes are formed by fabricating PN junctions on N-type germanium or silicon single crystal wafers by alloying with metals such as indium and aluminum. Small forward voltage drop, suitable for high current rectification. Due to its high static capacitance when the PN junction is reversed, it is not suitable for high-frequency detection and rectification.