Packaging is a form of protection for chips in the electronic field, according to the type of packaging materials, mainly metal packaging, plastic packaging, ceramic packaging and so on. Among them, ceramic packaging material is a commonly used electronic packaging material, ceramic packaging is air-tight packaging, its advantages are good moisture resistance, good thermal properties such as thermal expansion rate and thermal conductivity, high mechanical strength, chemical stability, excellent comprehensive performance. In addition to the ceramic substrate we are familiar with, the electronic ceramic packaging tube shell is also an important packaging material, which is an important bridge for the connection between the internal chip and the external circuit in high-end semiconductor components, and has an important role and influence on the performance of semiconductor components. It can be widely used as the shell of electric vacuum tube switches, high-frequency high-power electronic tubes, and large-scale integrated circuits. Terminal applications include 5G communications, aerospace, national defense and military industries.
Ceramic tube and shell products have a long history, usually with cylindrical, square and other shapes, its internal cavity and lead and other structures, to meet different packaging needs, ceramic tube and shell products packaging density, good electric heating performance, good air tightness, high reliability, compared to plastic, metal materials in the field of packaging has unique advantages:
1. Low dielectric constant, good high-frequency performance;
2. Good insulation and high reliability;
3. High strength, good thermal stability;
4. Low coefficient of thermal expansion and high thermal conductivity;
5. Good air tightness, stable chemical properties;
6. Good moisture resistance, not easy to produce micro-cracking phenomenon.
There are various types of ceramic shell, which can be divided into ceramic double-in-line package shell (CDIP), ceramic four-sided pin flat package shell (CQFP), ceramic pin grid matrix package shell (CPGA), ceramic small shape package shell (CSOP), etc. According to the different raw materials, it can be divided into alumina (Al2O3) ceramic shell, beryllium oxide (BeO) ceramic shell and aluminum nitride (AlN) ceramic shell.
At present, the most mainstream ceramic tube and shell material on the market is alumina. Alumina ceramic tube and shell has the advantages of good insulation, high electrical strength, high impact toughness, low high-frequency loss, etc., which is widely used in the field of high-power electronic packaging. Aluminum nitride ceramic shell is the most promising product segment in the ceramic shell market, which has better thermal conductivity, electrical properties, mechanical properties and so on.
The application of ceramic packaging shell usually needs to be metallized, among which, HTCC (high temperature co-fired multi-layer ceramic) packaging shell is the mainstream product of the metal ceramic packaging shell market at present, which is widely used in industrial lasers, solid state relays, optocouplers, microwave devices and other scenarios.