Square ceramic tube shell and preparation process

Abstract

The invention relates to a square ceramic tube shell. The square ceramic tube shell comprises an upper cover and a ceramic base, wherein the ceramic base is covered with the upper cover, the upper cover comprises a cathode square electrode and a cathode split type flange, the cathode split type flange comprises a cathode thick ring and a cathode thin ring, the inner edge of the cathode thick ringis concentrically welded to the outer edge of the cathode thin ring, and the inner edge of the cathode thin ring is concentrically welded to the outer edge of the cathode square electrode; the ceramicbase comprises an anode square electrode, an anode sealing ring, a square ceramic ring, an anode split flange and a lead tube which are concentrically welded from bottom to top; the lead tube is connected to the square ceramic ring in a penetrating mode, the anode split type flange comprises an anode thick ring and an anode thin ring, the inner edge of the anode thick ring is concentrically welded to the outer edge of the anode thin ring, and the inner edge of the anode thin ring is concentrically welded to the outer edge of the anode square electrode. The stress difference problem of the welding area of the square tube shell is well solved by adopting the split type flanges and the precise welding temperature control curve.

Description

technical field [0001] The invention relates to a square ceramic shell and a preparation process, belonging to the technical field of power electronics. Background technique [0002] Power semiconductor devices used to be mainly rectifiers and thyristors, and their chips are usually in the shape of wafers, which determines that the ceramic shells for packaging are all circular structures. At present, the circular structure ceramic shells and the preparation process have been basically Mature. [0003] With the rapid development of new devices represented by insulated gate bipolar transistors (IGBTs) in recent years, new requirements are also put forward for packaging carriers. The traditional plastic module packaging method restricts the application of IGBT in high-voltage and high-current fields, and the pressure-connected ceramic package IGBT based on double-sided heat dissipation has obvious technical advantages in high-power fields such as flexible DC transmission. Sin...

AI Technical Summary

Problems solved by technology

Compared with ordinary circular ceramic shells, the welding stress distribution of square ceramic shells is uneven, and the welding stress at the 4 rounded corners and the 4 sides is quite different, which is the cause of the shell welding failure and the failure of the temperature shock resistance. main reason

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