Welding method for semiconductor ceramic shell sealing cap

Abstract

The invention relates to a welding method for a semiconductor ceramic shell sealing cap and belongs to the technical field of semiconductor ceramic packaging. The welding method comprises the steps of pre-arranging a metal coating layer on the surface of a metal cover plate, and pre-arranging a coated metal seal frame in a ceramic shell welding area; enabling a solder ring to undergo spot welding on the metal coating layer of the metal cover plate; enabling the metal cover plate to be aligned with the metal seal frame of a ceramic shell under the atmosphere of nitrogen, utilizing a parallel seam welding device and a small-angle (5-degree) copper electrode to perform low-power welding, and enabling the solder ring to be fully molten and respectively welded to the metal coating layer of the metal cover plate and the metal seal frame of the ceramic shell to finish melting seal of a circuit. According to the welding method, the problems that pulse is too large and the local central heating temperature is too high in the parallel seam welding process are solved, the problem that chips inside the circuit and bonding positions are in a high-temperature state in a melting seal process is solved, and the maximum temperature of parallel seam welding is reduced.

Description

technical field [0001] The invention relates to a welding method for sealing caps of semiconductor ceramic shells, and belongs to the technical field of semiconductor ceramic packaging. Background technique [0002] With the rapid development of ceramic packaging, the requirements for airtightness of packaged circuits are getting higher and higher. Good airtight packaging can effectively ensure a good internal atmosphere, ensure long-term reliability of products, and achieve the goal of airtight packaging. The main methods are parallel seam welding and fusion sealing. [0003] In the ceramic packaging process using parallel seam welding, many companies use the direct welding of the metal cover plate and the cutting frame of the ceramic shell, and use two conical roller electrodes to press the metal cover plate to be packaged and the metal frame on the shell. Generally, it is a 15° electrode and a 10° electrode, and the power is 1750W. The high resistance of the entire circu...

AI Technical Summary

Problems solved by technology

It has the advantages of high yield (close to 100%), easy control of process parameters, and high reliability. However, this process uses a chain furnace to heat the circuit as a whole above the melting point of the solder. The melting point of gold is 1064°C, making the entire circuit in the setting At the same temperature, the internal chip of the device will also be affected by high temperature.