ADHESION OF METAL COATINGS ON CERAMICS DEPOSITED BY DIFFERENT TECHNIQUES

Copper layers deposited by vacuum arc deposition (VAD), magnetron sputtering (MS) and currentless chemical deposition (CCD) on oxide and non-oxide ceramics are compared by adhesion measurement using the direct pull-off test before and after thermal shock treatment. Variations of the inert gas pressure and the substrate temperature are considered in the case of VAD and MS and compared with the results of CCD. The highest adhesion strengths for VAD were achieved with a bulk substrate temperature in the range of 300-degrees-C, an arc current of 120 A and an argon pressure of 3 Pa. The adhesion strength reached values of about 35 MPa for soldered pins and exceeded the tensile strength of the glue (66 MPa) for glued pins. Thin films deposited by MS and CCD had adhesion strength maxima of 20 MPa and 39 MPa respectively for glued joints. A decreased film adhesion was measured after thermal shock treatment of the metallized ceramics.