WDM add/drop multiplexer module

• US 6,804,116 B2
• Filed: 12/18/2002
• Issued: 10/12/2004
• Est. Priority Date: 12/21/2001
• Status: Expired due to Fees

• Current Assignee: Avery Group Limited, Hiyes International Co., Ltd.
• Original Assignee: Redfern Broadband Networks, Inc. (Comtek Network Systems (UK) Ltd.)
• Inventors: Brown, Brian Robert, Owens, Mark J., Seiler, Chia, Halgren, Ross, Bonwick, Mark Henry, Scott, Quentin, Goh, Robert
• Primary Examiner(s): CHERVINSKY, BORIS LEO
• Application Number:
  US10/323,870
• Publication Number:
  US 20030128512A1
• Time in Patent Office: 664 Days
• Field of Search: 361/677, 361/678, 361/687-690, 361/694-704, 361/705-721, 361/725, 361/727, 361/728, 361/729, 361/732, 174/15.1, 174/15.2, 174/16.1, 174/16.3, 165/80.4, 165/122, 165/133.04, 459/184
• US Class Current: 361/700
• CPC Class Codes: G02B 6/293 with wavelength selective means
• CPC Class Codes: G02B 6/29383 Adding and dropping
• CPC Class Codes: G02B 6/29398 Temperature insensitivity
• CPC Class Codes: G02B 6/4452 Distribution frames
• CPC Class Codes: G02B 6/44526 Panels or rackmounts covering a whole width of the frame or rack
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/0201 Add-and-drop multiplexing

Abstract

A chassis member for carrying at least one circuit board for use in a WDM add/drop multiplexer unit, wherein the chassis member is adapted, in use, to function as a heatsink for a heat generating component mounted on the circuit board.

Claims

1. A chassis member for carrying at least one circuit board for use in a WDM add/drop multiplexer unit, wherein the chassis member is adapted to function as a heatsink for a heat generating component mounted on the circuit board, the chassis member comprising:

at least one thermally conductive member of higher thermal conductivity than the chassis member in thermal communication with a main body of the chassis member,

wherein a portion of the thermally conductive member extends beyond the main body of the chassis member for facilitating heat dissipation to an ambient around the extending portion of the thermally conductive member.

2. The chassis member as claimed in claim 1, wherein the main body of the chassis member is contoured or shaped in a manner such that, in use, a distance between the heat generating component and a region of the main body facing the heat generating component is reduced compared to other components on the at least one circuit board.

3. The chassis member as claimed in claims 1 or 2, wherein the chassis member comprises sidewalls formed around the peripheral region of the main body and adapted to function, in use, as at least a portion of housing sidewalls of a housing structure for the at least one circuit board.

4. The chassis member as claimed in claim 1, wherein the chassis member is adapted, in use, to carry at least one circuit board above and at least one circuit board below of the main body.

5. The chassis member as claimed in claim 1, wherein the at least one thermally conductive member comprises heat pipes containing a working fluid.

6. The chassis member as claimed in claim 5, wherein the working fluid is water.

7. The chassis member as claimed in claims 5 or 6, wherein the heat pipe is mounted on a surface of the main body or embedded in the main body.

8. The chassis member as claimed in claim 1, wherein the chassis member is formed from a plurality of pieces and at least one of the pieces comprises at least one capillary member, wherein when the chassis member is assembled the at least one capillary member comprises the at least one thermally conductive member.

9. The chassis member as claimed in claim 1, wherein the chassis member comprises a malleable thermal pad element disposed such that, when the chassis member is inserted into a casing for operation, the thermal pad abuts a heatsink structure of the casing, whereby a relative movement between the chassis member and the heatsink structure caused by different thermal expansion coefficients is accommodated over a temperature range.

10. The chassis member as claimed in claim 9, arranged such that the thermal connection of the thermal pad to the heatsink structure is poorer at lower temperatures compared to higher temperatures.

11. The chassis member as claimed in claim 10, wherein one or more of a group consisting of the thermal pad, the heatsink structure and the chassis member are arranged, in use, to effect the poorer thermal connection at lower temperatures.

12. The chassis member as claimed in claims 10 or 11, wherein loss of contact occurs, in use, between the heat sink structure and the thermal pad below a threshold temperature.

13. The chassis member as claimed in claim 1, wherein the chassis member further comprises a locking element for locking the chassis member into position when inserted in a casing for operation.

14. The chassis member as claimed in claim 13, wherein the locking element is arranged such that the chassis member is biased when inserted into position in the casing, whereby a thermal connection between the chassis member and a heatsink structure of the casing is maintained over a temperature range by accommodating relative movement between the chassis member and the heatsink structure caused by different thermal expansion coefficients.

15. The chassis member as claimed in claim 14, wherein loss of contact occurs between the chassis member and the heatsink structure at temperatures below a threshold temperature.

16. A WDM multiplexer module comprising:

a housing,

a chassis member located substantially inside the housing and adapted to function as a heat sink,

a heat sink structure extending from the housing and in thermal communication with the chassis member,

at least one heat generating electrical component in thermal communication with the chassis member, and

a control unit for maintaining a controlled temperature environment inside the housing utilising the heat sink structure and the heat generating electrical component and utilising the chassis member as a thermal communication medium, and

wherein the module is adapted for plug-in connection to an external backplane.

17. The module as claimed in claim 16, wherein the module further comprises at least one thermally conductive member having a thermal conductivity higher than the chassis member formed in or on the chassis member to facilitate the heatsink functionality of the chassis member.

18. The module as claimed in claim 16, wherein the module further comprises a local thermal environment structure located inside the housing and a TE device is in thermal communication with the chassis member and the local thermal environment structure,

whereby, in use, a second stage controlled temperature environment is created substantially inside the local thermal environment structure, and

wherein temperature variations in the second stage controlled temperature environment are smaller than temperature variations inside the housing.

19. The module as claimed in claim 18, wherein the module comprises at least one laser source disposed in a manner such that, in use, the source temperature of the laser source is substantially governed by the second stage controlled temperature environment.

20. The module as claimed in claim 19, wherein the laser source is a semiconductor laser source, and a junction of the laser source is located substantially inside the local thermal environment structure.

21. The module as claimed in claim 20, wherein a the laser driver associated with the laser source is located substantially outside the local thermal environment structure, whereby the thermal environment around the laser driver is governed by the controlled temperature environment inside the housing.

22. The module as claimed in claim 16, wherein the module comprises a plurality of electrical components, and the control unit sequentially switches on the electrical components based on operating temperature specifications and heat generating characteristics of the electrical components to facilitate creation of the controlled temperature environment during start-up or re-start of the module.

23. The module as claimed in claim 17, wherein the at least one thermally conductive member comprises at least one heat pipe.

24. The module as claimed in claim 23, wherein the at least one heat pipe has a working fluid characterised by a freezing temperature above −

40°

C., whereby a discontinuity in heat transfer to and from the heat sink structure is created for temperatures below the freezing temperature of the working fluid in the heat pipe for reducing heat loss from the inside of the housing.

25. The module as claimed in claim 24, wherein the freezing temperature is about zero °

C.

26. The module as claimed in claim 16, wherein the chassis member comprises side walls formed around the peripheral region of a main body of the chassis member, and said side walls form at least a portion of housing side walls of the housing.

27. The module as claimed in claim 16, wherein the housing is adapted to function as an electro-magnetic induction (EMI) shield.

28. The module as claimed in claim 16, wherein the module further comprises biasing means for biasing the chassis member with respect to the heatsink structure.

29. The module as claimed in claim 16, wherein the module further comprises a first key member arranged, in use, to cooperate with a second key member formed on a casing into which the module is inserted, to prevent the module from making contact with a backplane of the casing when the module is inserted upside down into a slot of the casing for which the module is not intended.

30. A WDM multiplexer module comprising:

a housing,

at least one laser source located substantially inside the housing,

a chassis member located substantially inside the housing and adapted to function as a heat sink,

a heat sink structure extending from the housing and in thermal communication with the chassis member,

at least one laser driver for the at least one laser source in thermal communication with the chassis member,

a control unit for maintaining a controlled temperature environment inside the housing utilizing the heat sink structure, and heat generated by the at least one laser driver and utilizing the chassis member as a thermal communication medium, and

wherein the at least one laser driver is exposed to the controlled temperature environment inside the housing of the module.