IMPROVED VDM AND/DROP MULTIPLEXER MODULE

• US 20030128512A1
• Filed: 12/18/2002
• Published: 07/10/2003
• Est. Priority Date: 12/21/2001
• Status: Active Grant

• 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
• Granted Patent: US 6,804,116 B2
• Time in Patent Office: Days
• US Class Current: 361/689
• 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, in use, to function as a heatsink for a heat generating component mounted on the circuit board.

2. A chassis member as claimed in claim 1, wherein a main body of the chassis 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 circuit board.

3. A 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 circuit board.

4. A 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. A chassis member as claimed in claim 1, wherein the chassis member comprises one or more highly thermally conductive members for facilitating the heatsink functionality.

6. A chassis member as claimed in claim 5, wherein the one or more highly thermally conductive members are in the form of heat pipes containing a working fluid.

7. A chassis member as claimed in claim 6, wherein the working fluid is water.

8. A chassis member as claimed in claims 6 or 7, wherein the heat pipe is mounted on a surface of the chassis element or embedded in the chassis element.

9. A chassis member as claimed in claim 5, wherein the chassis is formed from two or more pieces and one or more of the pieces comprises one or more capillary members, wherein when the chassis member is assembled the capillary members can function as the highly thermally conductive members

10. A 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 mounting for operation, the thermal pad abuts a heatsink structure of the mounting unit, whereby a relative movement between the chassis member and the heatsink structure caused by different thermal expansion co-efficients is accommodated over a temperature range.

11. A chassis member as claimed in claim 10, arranged, in use, such that the thermal connection to the heatsink structure is poorer at lower temperatures compared to higher temperatures.

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

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

14. A 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 mounting unit for operation.

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

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

31. An optical network node incorporating a chassis member for carrying at least one circuit board as claimed in claims 1 or 2.

33. An optical network incorporating an optical network node as claimed in claim 31.

17. 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,

a thermoelectric (TE) device 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 arranged, in use, to maintain a controlled temperature environment inside the housing utilising the heat sink structure, the TE device, and the heat generating electrical component and utilising the chassis member as a thermal communication medium.

18. A module as claimed in claim 17, wherein the module further comprises one or more highly thermally conductive members formed in or on the chassis member to facilitate the heatsink functionality of the chassis member.

19. A module as claimed in claim 17, wherein the module further comprises a local thermal environment structure located inside the housing and the 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.

20. A module as claimed in claim 19, 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.

21. A module as claimed in claim 20, 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.

22. A module as claimed in claim 21, wherein a 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.

23. A module as claimed in claim 17, wherein the module comprises a plurality of electrical components, and the control unit is further arranged, in use during start-up or re-start of the module, to sequentially switch 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.

24. A module as claimed in claim 17, wherein the beat sink structure comprises at least one heat pipe.

25. A module as claimed in claim 24, wherein the 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.

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

C.

27. A module as claimed in claim 17, 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.

28. A module as claimed in claim 17, wherein the housing is adapted to function as an electromagnetic induction (EMI) shield.

29. A module as claimed in claim 17, wherein the module further comprises biasing means for biasing the chassis member with respect to the heatsink structure.

30. A module as claimed in claim 17, wherein the module further comprises a first key member arranged, in use, to cooperate with a second key member formed on a casing member into which the module is inserted, to prevent the module from making contact with a backplane of the casing member when the module is inserted upside down into a slot of the casing member for which the module is not intended.

32. An optical network node incorporating a WDM multiplexer module as claimed in claims 17 or 18.

34. An optical network incorporating an optical network node as claimed in claim 32.