Brazing of alumina ceramics modified by pulsed plasma beams combined with arc PVD treatment


Brazing of alumina ceramics modified by pulsed plasma beams combined with arc PVD treatment

Piekoszewski, J.; Krajewski, A.; Prokert, F.; Senkara, J.; Stanislawski, J.; Walis, L.; Werner, Z.; Wlosinski, W.

A new method of preparing alumina ceramic surface for brazing it to kovar with conventional Ag-Cu eutectic brazes is presented. The key concept of this approach consists in formation of two inter-layers on the ceramic surface: (i) thin (in nm scale) layer of TiOx using pulse plasma beams, and (ii) thicker (about 2 µm) layer of TiOx or metallic Ti using arc PVD technique. Grazing incidence X-ray diffraction (GXRD) analysis shows that the first layer consists most likely of Ti7O13, whereas the second is either Ti2O, or metallic Ti - depending on the deposition conditions. Commercial housings of semiconductor diodes have been used as the samples. Brazed housings were tested under routine industrial conditions. The ultimate tensile strength (UTS) of joints reaches the average value of 90 MPa. Vacuum tightness is better than 5x10-6 mbar l/s. The values of parameters are sufficient to pass the production requirements.

Keywords: Brazing of alumina; Pulsed plasma treatment

  • Vacuum 70 (2003) 307-312

Permalink: https://www.hzdr.de/publications/Publ-5371
Publ.-Id: 5371