A fixed welding method without tooling for high-power igbt modules

Abstract

The invention discloses a fixed welding method for high-power IGBT modules without tooling. The polymer adhesive is sprayed on the back of the primary welding piece and placed on the surface of the copper-clad ceramic liner; the polymer is sprayed on the back of the chip for bonding. agent, and placed on the surface of the primary welding sheet, assembled into a lining subunit, put the lining subunit into the welding furnace to complete the primary welding; coat the surface of the substrate with organic silica gel, and the coating shape is a rectangular frame, and the size of the rectangular frame is greater than two The size of the secondary welding piece; place the secondary welding piece in the rectangular frame of organic silica gel; spray the polymer adhesive on the back of the lining subunit, and place it on the surface of the secondary welding piece, and put it into the welding piece after assembly The furnace completes the secondary welding. The invention does not require tooling to be fixed, can ensure welding reliability, and does not need to be cleaned. The organic silica gel in the secondary welding can not only fix the solder tabs, but also avoid solder overflow and short circuit on the surface of the substrate caused by the melting of large-size solder tabs.

Description

technical field [0001] The invention relates to the technical field of IGBT module welding, in particular to a method for fixing and welding high-power IGBT modules without frocks. Background technique [0002] Insulated Gate Bipolar Transistor (IGBT) is the most advanced power semiconductor device in the third generation of power electronic devices. It has the advantages of high frequency, high voltage and high current. The core devices in the fields of energy power generation and power quality management have been widely used in related industries. In the IGBT module packaging, the welding of the chip and the copper-clad ceramic lining (Direct Bonding Copper, DBC) is usually called the first welding; the welding of the lining subunit composed of the chip and the DBC lining and the copper or composite material substrate is called the second welding. First soldering, primary soldering and secondary soldering are key processes that affect the quality of module packaging. ...

AI Technical Summary

Problems solved by technology

[0004] For the solder paste process, there is no need for additional tooling during the soldering process, and the soldering efficiency is high. However, the solder paste contains a large amount of flux, which needs to be cleaned after soldering, and flux residues are likely to exist, which will seriously affect large-scale applications with high reliability requirements. Long-term service reliability of power IGBT modules

For the solder tab process, there is no need to use flux during the welding process, and the post-solder cleaning process is exempted, but the solder tab has no adhesion, and the relative position of the chip, solder tab, and liner subunits is likely to move during the assembly process, affecting the final welding quality. , it is necessary to design corresponding welding fixtures for each IGBT module, which reduces production efficiency and increases tooling management costs

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