Patent ID: 7040121

Claim:
A process for hermetically sealing a component to a lamp envelope of a lighting device made of glass having a CTE C 1 from 0 to 300° C., comprising the following steps: (i) providing a component assembly comprising the component to be sealed with the lamp envelope and an infrared absorbing solder glass preform enclosing and bonded to the portion of the component to be hermetically sealed and affixed to the glass lamp envelope, wherein solder glass of the preform has a before-sealing softening point T s over 500° C., an after-sealing CTE C 2 from 0 to 300° C. in the range of C 1 ±10×10 −7 ° C. −1 , and is capable of forming a hermetic sealing of the component with the lamp envelope upon being heated to a temperature over its before-sealing softening point; (ii) attaching the component assembly to a hole of the lamp envelope through which the component is to be sealed and affixed to the lamp envelope; and (iii) heating the solder glass preform locally using infrared radiation to a temperature higher than the before-sealing softening point T s of the solder glass to effect a hermetic sealing, wherein the solder glass preform is formed from a devitrifying solder glass consisting essentially of a B 2 O 3 —SiO 2 —PbO—ZnO glass containing CuO and/or Fe 2 O 3 , having a before-sealing softening point in the range of 550–700° C., an after-sealing CTE C 2 from 0 to 300° C. in the range of 32–40×10 −7 ° C. −1 and a devitrifying temperature T d in the range of 630–750° C.