DBC (Direct Bonded Copper) substrate surface treatment process based on nano-silver soldering paste connecting chip

Abstract

The invention discloses a DBC (Direct Bonded Copper) substrate surface treatment process based on a nano-silver soldering paste connecting chip. The process solves the technology that not only the copper on the DBC substrate surface is prevented from bleeding out of a silver plating surface, but also the combination strength between the nano-silver soldering paste connecting chip and the DBC substrate is ensured. The DBC substrate surface treatment process comprises the following steps of: firstly carrying out cleaning pretreatment on the surface of a DBC substrate; then carrying out electronickelling treatment on the pretreated DBC substrate; and finally, after thorough cleaning, carrying out silverplating treatment on the surface of the electronickelled DBC substrate by using a magnetron sputtering method. The DBC substrate surface treatment process based on the nano-silver soldering paste connecting chip has the following beneficial effects: when the electronickelled DBC substrate subjected to magnetron sputtering silver is sintered at high temperature by using a nano-silver soldering paste, the metal copper on the surface of the DBC substrate does not oxidize, i.e. the metal copper does not permeate the surface of a silvering layer; after being sintered, the nano-silver soldering paste has good bonding strength with the electronickelled DBC substrate subjected to magnetron sputtering silver; and the DBC substrate surface treatment process is green and environment-friendly and has no adverse effect on the environment.

Description

technical field [0001] The invention relates to a surface treatment process of a direct copper-clad (DBC) substrate, in particular to a surface treatment process of a DBC substrate connected to chips based on nano-silver solder paste. Background technique [0002] In high-power insulated-gate bipolar transistor (IGBT) modules, the DBC substrate provides functions such as point connection, thermal spreading, and mechanical support for the chip. The traditional process of device connection is to connect the terminal of the chip to the DBC substrate through conductive glue or solder, and connect the other end with a thin aluminum wire. However, traditional conductive glue or solder has disadvantages such as short service life, low melting point, and poor heat dissipation. As a result, the working temperature of the connection point between the high-power chip and the DBC substrate cannot exceed 150°C, which limits the practical application of high-power IGBT modules. [0003] ...

AI Technical Summary

Problems solved by technology

The traditional silver plating process that can achieve this function uses cyanide, but cyanide is very harmful to the environment; when using cyanide-free electroplating silver plating formula, the silver plating layer is not dense enough, and the metallic copper on the surface of the DBC substrate will ooze out of the silver plating The surface of the layer affects the bonding strength of the nano-silver solder paste connecting the chip and the DBC substrate