Alumina direct copper-bonded

For a copper sheet direct-bonded to a 96% alumina substrate, the spreading angle is calculated as follows ... 

When aluminum nitride (AIN) is bonded to copper with the DBC process, the surface of the ceramic first needs to be converted with heat and oxygen to alumina. This results in a thin layer (1-2 /xm) of oxygen-bearing alumina. The cross section of copper direct bonded to AIN is shown in Figure 8.11 [11]. The oxidized AIN is then placed in the furnace with the copper foil in the same maimer as with alumina and beryllium oxide. The process flow for DBC on AIN is shown in Figure 8.12. 

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