A metal-ceramic interface Cu-AIN in a copper implanted and annealed AIN matrix is analyzed by HRTEM techniques. The precipitation in AIN matrix after an appropriate annealing treatment yields metallic particles all exhibiting the same low energy orientation relationship with the ceramic matrix. At an early stage of the precipitation, the small coppr paritcles are constrained by the matrix and are described by a near rhombohedral disturbance. The copper precipitates were often observed in twin-related palte-like shape which is determined by low energy interfaces, especially on the meta side. In the case of the interface parallel to (11ⅰ)Cu, the contrast at the interface is associated to a quasi-low energy configuration and gave us some crystal information for geometric and structural modelizations. The atomic structure at the interface is modelled according to these informations ; experimental and simulated images ahve been qualitatively compared.