초록 ▼

Disclosed is a process for sealing component assembly to an electrical lighting device using induction healing. The assembly comprises the component, such as an electrode lead wire, and a solder glass perform. The process is useful, for example, in hermetically sealing and affixing lamp components,

Disclosed is a process for sealing component assembly to an electrical lighting device using induction healing. The assembly comprises the component, such as an electrode lead wire, and a solder glass perform. The process is useful, for example, in hermetically sealing and affixing lamp components, such as electrical lead wires and exhaust tubulation, to a low-pressure fluorescent discharge lamp envelope having phosphor coating already applied thereto without causing to damage other lamp components sensitive to high temperature. The present invention is particularly suitable for lamp envelopes made of borosilicate glass having a CTE form 0 to 300° C. in the range of 30?45×10?7° C.?1.

대표청구항 ▼

1. A process for hermetically sealing a component to a lamp envelope of a lighting device made of glass having a CTE C1 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 a solder glass preform enclosi

1. A process for hermetically sealing a component to a lamp envelope of a lighting device made of glass having a CTE C1 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 a solder glass preform enclosing and bonded to the portion of the component to be hermetically sealed and affixed to the glass lamp envelope, wherein the solder glass of the preform has a before-sealing softening point Ts over 500° C., an after-sealing CTE C2 from 0 to 300° C. in the range of C1±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 a hole of the lamp envelope through which the component is to be sealed and affixed to the lamp envelope; and(iii) allowing the solder glass preform to proximate a succeptor die, which is heated by induction, of an induction heating device to heat the solder glass preform to a temperature higher than the before-sealing softening point Ts 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 B2O3?SiO2?PbO?ZnO glass containing CuO and/or Fe2O3, having a before-sealing softening point in the range of 550?700° C., an after-sealing CTE C2 from 0 to 300° C. in the range of 32?40×10?7° C.?1 and a devitrifying temperature Td in the range of 630?750° C.2. A process in accordance with claim 1, wherein in step (iii), (a) the die does not contact the solder glass preform directly; (b) the distance between the succeptor die and the solder glass preform when the preform is heated is less than 5 mm, and (c) the solder glass preform is heated by the radiation emitted from the heated succeptor die.3. A process in accordance with claim 2, wherein the distance between the succeptor die and the solder glass preform when the preform is heated is less than 3 mm.4. A process in accordance with claim 3, wherein the distance between the succeptor die and the solder glass preform when the preform is heated is between 1 and 2 mm.5. A process in accordance with claim 2, wherein the solder glass of the preform is infrared absorbing.6. A process in accordance with claim 1, wherein the glass envelope is made of borosilicate glass having a CTE C1 in the range of 30?45×10?7°C.?1 from 0 to 300° C., and a phosphor coating has been applied to the glass envelope before sealing thereof.7. A process in accordance with claim 1, wherein the solder glass preform is formed from a solder glass consisting essentially, by weight percentage on an oxide basis, of: 0?2% of Al2O3, 15?25% of B2O3, 1?5% of CuO, 0?5% of Fe2O3, 0?7% of PbO, 10?16% of SiO2 and 55?65% ZnO, and having a before-sealing softening point in the range of 600?650° C., an after-sealing CTE C2 from 0 to 300° C. in the range of 34?38×10?7° C.?1 and a devitrifying temperature Td in the range of 650?700° C.8. A process in accordance with claim 1, wherein the glass envelope is made of a borosilicate glass having the following composition, expressed in terms of weight percentage on an oxide basis calculated from the glass batch: 77.4% SiO2, 15.4% B2O3, 1.9% Al2O3 and 5.3% Na2O, and has a CTE of approximately 38×10?7° C.?1 from 0 to 300° C.9. A process in accordance with claim 6, wherein the glass envelope is preheated to a temperature below 600° C. before step (iii).10. A process in accordance with claim 9, wherein the glass envelope is preheated to a temperature between about 550?585° C.11. A process in accordance with claim 1, wherein the component to be sealed and affixed to the glass envelope is a beaded electrode lead wire.12. A process in accordance with claim 11, wherein the beaded electrode lead wire has an inner lead, an outer lead and an intermediate lead, and the intermediate lead has a hermetically sealed solder glass bead therewith.13. A process in accordance with claim 12, wherein the solder glass bead of the beaded lead wire is bonded and attached to the solder glass preform by sintering at a temperature lower than the before-sealing softening point Ts of the solder glass preform.14. A process in accordance with claim 13, wherein the solder glass preform has a shape directly receivable by or capable of covering the hole of the glass envelope through which the solder glass preform beaded electrode wire assembly is to be sealed and affixed to the lamp envelope.15. A process in accordance with claim 14, wherein the solder glass preform enclosing the lead wire consists of two integrated parts P1 and P2 having different cross-sectional sizes, P1 has a smaller cross-sectional size receivable by the hole of the lamp envelope through which the component assembly is to be sealed and affixed, and part P2 has a larger cross-sectional size capable of covering the hole when P1 is inserted into and received by the hole.16. A process in accordance with claim 6, wherein the component to be sealed and affixed is a borosilicate glass tubulation having a CTE C3 in the range of C1±10×10?7.17. A process in accordance with claim 16, wherein the tubulation is bonded to the solder glass preform by sintering at a temperature below the before-sealing softening temperature Ts of the solder glass of the preform.18. A process in accordance with claim 17, wherein the component enclosed by the solder glass preform is to be affixed to the lamp envelope as an exhaust tubulation.19. A process in accordance with claim 17, wherein the solder glass preform enclosing the tubulation has a shape receivable by or capable of covering the hole of the lamp envelope through which the component assembly is to be sealed and affixed.20. A process in accordance with claim 17, wherein the solder glass preform enclosing the tubulation consists of two integrated parts P1 and P2 having different cross-sectional sizes, P1 has a smaller cross-sectional size receivable by the hole of the lamp envelope through which the component assembly is to be sealed and affixed, and part P2 has a larger cross-sectional size capable of covering the hole when P1 is inserted into and received by the hole.21. A process in accordance with claim 19 or 20, wherein the component assembly to be sealed and affixed to the lamp envelope further comprises a beaded electrode lead wire placed inside the tubulation, the beaded lead wire and the tubulation are chosen and placed in a manner such that upon prior or further heating of the tubulation, a hermetic seal can be effected between the beaded lead wire and the tubulation without causing substantial heating to the glass envelope to which the assembly is to be sealed and affixed.22. A process in accordance with claim 1, wherein step (iii) is carried out in less than 5 minutes.23. A process in accordance with claim 15, wherein step (iii) is carried out in less than 3 minutes.24. A process in accordance with claim 16, wherein step (iii) is carried out in less than 1 minute.25. A process in accordance with claim 17, wherein step (iii) is carried out in less than 30 seconds.