An electrode is drawn at both ends of the PN junction and a tube case is added to form a semiconductor diode. The electrode drawn from one end of the P-type semiconductor of the PN junction is called the anode, and the electrode drawn from one end of the N-type semiconductor of the PN junction is called the cathode. According to different structures, semiconductor diodes can be divided into point contact type, surface contact type and planar type.
The point contact type semiconductor diode is made by a metal wire in contact with the surface of the semiconductor. After a special process, a PN junction is formed on the contact point, a lead is made, and a case is encapsulated. The point contact diode has a small PN junction area and good high-frequency performance. It is suitable for high-frequency detection circuits and switching circuits.
