Silicon package with integral heater
A hermetic package for electronic components which is made of metallic silicon is disclosed. The package includes a plurality of silicon elements which are bonded together. A metallic layer of platinum or gold is bonded to an internal surface of the hermetically sealed enclosure. While either metallic layer may serve as a heating element by subjecting the electronic circuit connected thereto with a large current, the platinum layer can also be used as a thermal sensor by passing a lower current there through. An internal heater is included to stabilize the performance of the electronic components.
1. A hermetically packaged electronic device comprising
a) an enclosure of metallic silicon made of a plurality of elements including an upper element and a lower element, said enclosure maintaining a vacuum in a range between 1×10 −6 and 1×10 −11 torr;
b) means bonding said plurality of elements together, said bonding means securing a first silicon element directly to a second silicon element;
c) a piezoelectric device contained within said enclosure;
d) a metallic layer bonded to a lower surface of said upper element, said metallic layer functioning as a heating element;
e) control means positioned outside of said enclosure;
f) electrical circuitry interconnected between said metallic layer and said control means.
2. The device of claim 1 wherein said bonding means comprises thermo-compression bonding means performed at high temperature for securing said plurality of elements of said enclosure directly to each other.
3. The device of claim 2 wherein said plurality of elements include a base member and a cover configured to fit thereon.
4. The package of claim 3 wherein said base member and said cover directly provide means of electrical contact to said piezoelectric device obviating need for leads and wires within and protruding from said package.
5. The device of claim 3 wherein said base member and said cover are each comprised of single metallic silicon crystals.
6. The device of claim 3 wherein said heating element comprises a non-venting, electrically conductive element bonded to a nether surface of said cover.
7. The device of claim 6 further comprising thermo-compression bonding means between said heating element and said cover, the same bonding means used to secure said plurality of enclosure elements together.
8. The device of claim 6 wherein said heating element is made from the group consisting of platinum and gold.
9. The device of claim 8 wherein said heating element is made from platinum and also serves as said temperature sensing means.
10. The package of claim 2 wherein said thermo-compression bonding means is performed in a temperature range of between 300° C. and 800° C.
11. The device of claim 10 wherein said thermo-compression bonding means comprises brazing of said cover to said base member using gold indium eutectic alloy at 495° C.
12. The device of claim 1 wherein said piezoelectric device is an ultra-stable oscillator.
13. The device of claim 12 wherein said ultra-stable oscillator comprises a quartz crystal.
14. The device of claim 13 wherein said ultra-stable oscillator further comprises first and second gold plated electrodes spaced from opposing surfaces of said quartz crystal.
15. The device of claim 1 wherein said metallic layer is selected from the group consisting of platinum and gold.
16. The device of claim 15 wherein said metallic layer is platinum.
17. The device of claim 16 wherein said metallic layer serves as both a heating element and a thermal sensor.
18. The device of claim 15 wherein said metallic layer serves as a heating element to control the temperature within said enclosure.