Resistance Heated Evaporation Boat
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09
Titanium is evaported by means of a resistance-heated evaporation boat 1 to which a heating current is applied through connecting tags 2 and 3. The titanium is contained in a cavity 4. Boat 1 is made of tungsten. Commercially available boats of this kind have not proved satisfactory, as they lead to titantium splashes and thus to process problems. Apart from this, the service life of the boats is short, as normally a boat cannot be used for more than two to three evaporation runs. Boat 1, shown in the plan view of Fig. 1 and the sectional view of Fig. 2, is tapered in the region of cavity 4 at a ratio of about 3:5 relative to connecting tags 2 and 3. This tapering keeps the molten titanium within cavity 4 and prevents splashes during evaporation.