Study on hermetic package of antiradiation direct-head transmitter

As an important component in antiradiation direct-head, the uniformity and reliability of transmitter paly the key role in the electrical performance. The characteristic of missile transmitter with high integration is plenty sidewall connectors, larger size, and the 4047 aluminum alloy plate is easy to cause weld airtight failure in helium leak detection process. To keep an excellent microwave properties and high reliability, it is of great importance to insure the gas tightness of transmitter. For this reason, higher requirements are proposed for the weld penetration and sealing quality, while the temperature rise should be under the melting point of low temperature brazing weld. In this paper, the laser welding technology in different energies was employed, weld penetration and sealing quality of the components were investigated after the laser welding process, meanwhile the temperature around the RF connector was also tested. On the basis of this, the appropriate weld penetration and corresponding laser energy for large-size transmitter are obtained, so that the gas tightness performance of the components is satisfied and superior to the requirements of GJB548B.