Hydrogen vent for optoelectronic packages with resistive thermal device (RTD)

• US 7,377,961 B2
• Filed: 08/23/2004
• Issued: 05/27/2008
• Est. Priority Date: 01/12/2004
• Status: Active Grant

• Current Assignee: NeoPhotonics Corporation (Lumentum Holdings Inc.)
• Original Assignee: Intel Corporation
• Inventors: McDonald, Mark E.
• Primary Examiner(s): Smith; Duane
• Assistant Examiner(s): TURNER, SONJI LUCAS
• Application Number:
  US10/925,321
• Publication Number:
  US 20050156159A1
• Time in Patent Office: 1,373 Days
• Field of Search: 437/210, 437/209, 437/215, 437/217, 437/220, 437/221, 257/682, 257/279, 338/25, 95/55, 96/4, 438/115, 438/209, 438/210, 438/215, 438/217, 438/220, 438/221
• US Class Current: 96/4
• CPC Class Codes: G02B 6/4201 Packages, e.g. shape, construction, internal or external details
• CPC Class Codes: G02B 6/424 Mounting of the optical light guide
• CPC Class Codes: G02B 6/4271 with thermo electric cooling
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 23/564 Details not otherwise provided for, e.g. protection against moisture getters H01L23/26
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/1423 Monolithic Microwave Integrated Circuit [MMIC]
• CPC Class Codes: H01S 5/02216 Butterfly-type, i.e. with electrode pins extending horizontally from the housings
• CPC Class Codes: H01S 5/0222 Gas-filled housings
• CPC Class Codes: H01S 5/02251 using optical fibres
• CPC Class Codes: H01S 5/02325 Mechanically integrated components on mount members or optical micro-benches
• CPC Class Codes: H01S 5/0612 controlled by temperature

Abstract

Thermally tuned lasers may use a resistive thermal device (RTD), sensitive to hydrogen, within a hermetic enclosure. Over time, hydrogen trapped within the enclosure or out gassed from other components within the enclosure may degrade the accuracy of the RTD. A vent comprising a hydrogen selective permeable membrane, such as palladium or a palladium alloy, provided in the enclosure vents hydrogen to mitigate damage to the RTD.

Claims

1. An apparatus, comprising:

a resistive thermal device (RTD) sensitive to hydrogen;

a material to out gas trapped hydrogen;

a sealed enclosure housing the RTD and the material, the RTD comprising a platinum layer and one of a chromium and titanium adhesion layer;

an inert gas atmosphere within the sealed enclosure;

an opening in the sealed enclosure to form a vent; and

a hydrogen selective permeable membrane covering the vent to vent out gassed hydrogen from the sealed enclosure.

2. The apparatus as recited in claim 1 wherein the hydrogen permeable membrane comprises palladium (Pd).

3. The apparatus as recited in claim 1 wherein the hydrogen permeable membrane comprises a palladium alloy.

4. The apparatus as recited in claim 2 wherein the enclosure comprises an opto-electronic hermetic package.

5. The apparatus as recited in claim 1 wherein the hydrogen selective permeable membrane caps hydrogen within the enclosure at atmospheric levels.

6. The apparatus as recited in claim 1, wherein the sealed enclosure comprises:

a substrate;

a positioning floor on the substrate;

the RTD arranged in relation to the positioning floor, and a cap sealed over the substrate, wherein the vent is positioned on the cap.

7. A method, comprising:

sealing a resistive thermal device (RTD) sensitive to hydrogen in an enclosure, the RTD comprising a platinum layer and one of a chromium and titanium adhesion layer;

sealing a material out gassing trapped hydrogen in the enclosure;

filling the enclosure with an inert gas atmosphere;

providing a vent in the enclosure;

covering the vent with a hydrogen selective permeable membrane; and

diffusing out gassed hydrogen through the permeable membrane.

8. The method as recited in claim 7 wherein the hydrogen selective permeable membrane comprises palladium (Pd).

9. The method as recited in claim 7 wherein the enclosure comprises a microelectronic hermetic package.

10. An optical system comprising:

a hermetic package comprising an interior;

a temperature tuned laser within the interior;

a resistive thermal device (RTD) sensitive to hydrogen within the interior to measure temperature, the RTD comprising a platinum layer and one of a titanium and a chromium adhesion layer;

at least one material to outgas trapped hydrogen within the interior; and

a vent in the hermetic package comprising a hydrogen selective membrane to diffuse the outgas trapped hydrogen from the interior to an exterior of the hermetic package.

11. The system as recited in claim 10 wherein the hydrogen selective membrane comprises one of palladium and a palladium alloy.

12. The system as recited in claim 11 wherein the hermetic package comprises an optoelectronic package.

13. The system as recited in claim 12 wherein the optoelectronic package forms part of an optical communication system.

14. The system as recited in claim 13 further comprising an optical fiber extending from the hermetic package.