Waveguide antenna with integrated temperature management

Abstract

An illustrative example embodiment of an antenna device includes: a substrate; a plurality of antenna elements supported on the substrate; an integrated circuit supported on one side of the substrate; and a metal waveguide antenna placed against the substrate. The metal waveguide antenna includes a heat sink portion in a thermally conductive relationship with the integrated circuit. The heat sink portion is configured to reduce a temperature of the integrated circuit.

Description

Background Art

[0001] Modern automobiles include an increasing amount of electronic technology, such as sensors, detectors, and cameras, which provide information about the environment near the vehicle to facilitate driver assistance or autonomous vehicle control. Radar detectors, for example, include antennas for transmitting and receiving signals. Some antenna configurations include arrays of antenna elements to achieve desired gain and directivity.

[0002] Some antenna configurations include a patch antenna element supported on a printed circuit board. An integrated circuit associated with the antenna element is typically supported on the printed circuit board. One disadvantage of this arrangement is that there is limited heat transfer from the integrated circuit to the board via the solder balls that typically secure the integrated circuit to the board. Summary of the invention

[0003] An illustrative example embodiment of an antenna device includes a substrate, a plurality of antenna elements supported on the substrate, an integrated circuit supported on one side of the substrate, and a metal waveguide antenna placed against the substrate. The metal waveguide antenna includes a heat sink portion in a thermally conductive relationship with the integrated circuit. The heat sink portion is configured to reduce a temperature of the integrated circuit.

[0004] In an embodiment having one or more features of the antenna device of the preceding paragraph, the heat dissipating portion includes a heat exchanger including a plurality of metal components arranged to allow fluid to flow between the metal components.

[0005] In an embodiment having one or more features of the antenna device of any of the preceding paragraphs, the metal member comprises a fin.

[0006] In an embodiment having one or more features of the antenna device of any preceding paragraph, the heat sink portion includes a chamber configured to contain a fluid for absorbing heat from the integrated circuit.

[0007] In an embodiment having one or more features of the antenna device of any preceding paragraph, the chamber defines a first volume within the chamber, the fluid is a liquid, and the liquid has a second volume less than the first volume.

[0008] In an embodiment having one or more features of the antenna device of any of the preceding paragraphs, the second volume is between 10% and 60% of the first volume.

[0009] In an embodiment having one or more features of the antenna device of any preceding paragraph, the second volume is 30% of the first volume.

[0010] In an embodiment having one or more features of the antenna device of any preceding paragraph, the liquid is at least one of water, ethylene glycol, and acetone.

[0011] An embodiment having one or more features of the antenna device of any preceding paragraph comprises a wicking structure located in the chamber, the wicking structure configured to promote circulation of an evaporated portion of the liquid back into the liquid.

[0012] In an embodiment having one or more features of the antenna device of any preceding paragraph, the metal waveguide antenna comprises copper, the wicking structure comprises a sintering paste or a copper etch, and the sintering paste or the copper etch is located on a surface of the chamber closer to the integrated circuit than the liquid.

[0013] In an embodiment having one or more features of the antenna device of any preceding paragraph, the metal waveguide antenna is on one side of the substrate, the metal waveguide antenna includes a cavity configured to receive the integrated circuit, and the cavity provides electromagnetic shielding around the integrated circuit.

[0014] In an embodiment having one or more features of the antenna device of any preceding paragraph, the metal waveguide antenna is on a second side of the substrate opposite the one side, and the heat sink portion includes a thermal interface material against the substrate and aligned with the integrated circuit.

[0015] In an embodiment having one or more features of the antenna device of any preceding paragraph, the metal waveguide antenna comprises multiple layers of metal material secured together, and at least one of the layers comprises a heat sink.

[0016] In an embodiment having one or more features of the antenna device of any preceding paragraph, the heat dissipation portion comprises a cavity, the at least one layer defines at least two interior surfaces of the cavity, and the at least one other layer defines at least one interior surface of the cavity.

[0017] An illustrative example embodiment of a method of manufacturing an antenna device includes: establishing a plurality of antenna elements on a substrate; securing an integrated circuit to one side of the substrate; forming a waveguide antenna by securing a plurality of metal layers together, including establishing at least one heat sink within at least one layer; and placing the waveguide antenna against the substrate to establish a thermally conductive relationship between the integrated circuit and the heat sink.

[0018] In an embodiment having one or more features of the method of the above paragraph, establishing at least one heat dissipation portion includes forming at least a portion of a heat exchanger in at least one layer, and the heat exchanger includes a plurality of metal components arranged to allow fluid to flow between the metal components.

[0019] In an embodiment having one or more features of the method in any of the preceding paragraphs, establishing at least one heat dissipation portion includes forming at least a portion of a chamber configured to contain a fluid for absorbing heat from integrated circuits within at least one layer, the chamber defining a first volume within the chamber, the fluid being a liquid, and the liquid having a second volume that is less than the first volume.

[0020] In an embodiment having one or more features of the method of any of the preceding paragraphs, the second volume is between 10% and 60% of the first volume.

[0021] In an embodiment having one or more features of the method of any preceding paragraph, establishing the heat dissipation portion includes positioning a wicking structure in the chamber, and the wicking structure is configured to promote circulation of a vaporized portion of the liquid back into the liquid.

[0022] In an embodiment having one or more features of the method in any of the preceding paragraphs, placing the waveguide antenna on the substrate includes securing a first of the metal layers to one side of the substrate; forming the waveguide antenna includes establishing a cavity in the first metal layer, the integrated circuit being received in the cavity, and the cavity providing electromagnetic shielding around the integrated circuit.

[0023] Various features and advantages of at least one disclosed example embodiment will become apparent to those skilled in the art from the following Detailed Description The drawings accompanying the Detailed Description can be briefly described as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 An antenna arrangement designed according to an example embodiment is schematically shown.

[0025] Figure 2 yes Figure 1 An exploded view of an embodiment of the present invention shows the components prior to final assembly.

[0026] Figure 3 Another exemplary embodiment of an antenna arrangement is schematically shown.

[0027] Figure 4 is shown before final assembly Figure 3 An exploded view of the components of an embodiment of the present invention.

[0028] Figure 5 Another example antenna arrangement embodiment is schematically illustrated.

[0029] Figure 6 Another example antenna arrangement embodiment is schematically illustrated. DETAILED DESCRIPTION

[0030] Figure 1 The antenna device 20 is schematically shown. The substrate 22 supports a plurality of antenna elements 24 on at least one side of the substrate 22. The substrate 22 and antenna elements 24 in the example embodiment are of known construction and are manufactured using known production or manufacturing processes.

[0031] An integrated circuit 26 is secured to one side of the substrate 22. In the example shown, the integrated circuit 26 is secured to the substrate 22 by solder balls 28, which also establish conductive connections between the integrated circuit 26, the antenna element 24, and any other parts or elements supported on the substrate 22 as may be desired for a particular situation. The integrated circuit 26 in the example shown is a millimeter wave integrated circuit (MMIC), which is used, for example, in radar equipment.

[0032] The metal waveguide antenna 30 is placed against the substrate 22. The metal waveguide antenna 30 includes an integrated heat sink 32 in thermally conductive relationship with the integrated circuit 26. The heat sink 32 is configured to reduce the temperature of the integrated circuit 26 by absorbing heat from the integrated circuit 26.

[0033] exist Figure 1 In the exemplary embodiment of the present invention, the heat sink portion 32 includes a fluid 34 and a wicking structure 36 within a chamber 37 having a first volume defined between a side wall 40 and end walls 42 and 44. In the illustrated embodiment, the wicking structure 36 is supported on the end wall 44. In some embodiments, the wicking structure 36 includes a sintering paste, while in other embodiments, the wicking structure 36 includes etched copper. The wicking structure provides an increased surface area for heat exchange between the integrated circuit 26 and the fluid 34. The wicking structure promotes circulation of the evaporated fluid back into liquid form within the chamber of the heat sink portion 32.

[0034] In the example embodiment shown, the fluid 34 includes a liquid, such as water, ethylene glycol, acetone, or a combination thereof. The liquid has a second volume that is less than the first volume of the chamber. The liquid occupies between 10% and 60% of the first volume of the chamber 37. In some embodiments, the liquid 34 occupies 30% of the first volume of the chamber 37 defined between the sidewall 40 and the end walls 42 and 44. The example shown includes a fluid port 38 for selectively increasing or decreasing the amount of the fluid 34 within the heat dissipation portion 32.

[0035] The metal waveguide antenna 30 includes air waveguides 52 and 54 through which radiation from the antenna element 24 is emitted, for example, during signal transmission.

[0036] Figure 2 Shown before final assembly Figure 1 The metal waveguide antenna 30 is made of multiple layers of metal, such as copper. The illustrated example includes three layers 62, 64, and 66. Each layer comprises a stamped or punched metal sheet. The layers 62, 64, and 66 are secured together. In embodiments where the layers comprise copper, a solder reflow process secures the layers together.

[0037] Layer 66 defines cavity 50 which receives integrated circuit 26. One feature of cavity 50 is that it provides electromagnetic shielding for integrated circuit 26.

[0038] The air guides 52 and 54 are created by stamping the layers together when the layers are secured together. Figure 2 In the example of , layer 62 includes a surface that establishes end wall 42 of chamber 37. Layer 64 defines side wall 40 of the chamber, and layer 66 defines end wall 44. Wicking structure 36 is secured to layer 66 or otherwise formed thereon before the layers are secured together. Once layers 62-66 are secured together, fluid 34 may be introduced into chamber 37 of heat dissipation portion 32 through fluid port 38.

[0039] Despite Figure 1 and Figure 2 Although three layers are shown in the exemplary embodiment of FIG. 3 , other embodiments may include more layers or only two layers of metal material to form a metal waveguide antenna with an integrated heat sink 32 .

[0040] Figure 3 and Figure 4 Another example embodiment is shown in FIG. In this example, the heat dissipation portion 32 includes a heat exchanger including a plurality of metal members 70 arranged to allow fluid to flow between them to facilitate heat exchange between the integrated circuit 26 and the heat dissipation portion 32. In some embodiments, the fluid within the heat exchanger includes air. Other embodiments may include a liquid or gel to facilitate heat transfer for reducing the temperature of the integrated circuit 26.

[0041] from Figure 4 It will be appreciated that the metal member 70 may be formed as part of the layer 64. Alternatively, a set of pins, posts or fins are located in the section of the assembly that will establish the heat sink portion 32. In some embodiments, the metal member 70 will be formed using an etching process or during stamping of the layer 64.

[0042] In some embodiments, the antenna assembly includes or has an associated fan or blower that moves air through the heat exchanger heat sink portion 32 so that the metal member 70 more effectively provides cooling for the integrated circuit 26 .

[0043] Figure 5 Another example embodiment is schematically shown. Figure 1-4 In the illustrated embodiment, the metal waveguide antenna 30 is located on the same side of the substrate 22 as the integrated circuit 26. Figure 5 In the embodiment of FIG. 1 , the metal waveguide antenna 30 is located on the opposite side of the substrate 22. In this embodiment, similar to Figure 1In an embodiment of the present invention, the heat sink portion 32 contains a fluid such as water or acetone. Since the metal waveguide antenna 30 is on the opposite side of the substrate 22, a thermal interface material 80 is included between the substrate 22 and the heat sink portion 32 to promote heat transfer for maintaining a desired temperature of the integrated circuit 26. In this embodiment, the heat sink portion 32 is located between air waveguides 82.

[0044] exist Figure 6 , where the metal waveguide antenna 30 is located on the side of the substrate 22 opposite the integrated circuit 26. A thermal interface material 80 is located between the metal base that serves as the heat sink 32 and the substrate 22. The metal base is located between air waveguides 82.

[0045] The example embodiment shown includes an integrated heat sink within a metal waveguide antenna. Using multiple stampings or metal layers to manufacture the waveguide antenna provides an economical and lightweight arrangement that can meet the needs of, for example, automotive radar detectors. The example antenna device includes a low-loss package and a low-loss routing line. The embodiments described above provide a low-loss antenna with enhanced heat dissipation characteristics.

[0046] The various features of the disclosed embodiments are not necessarily limited to the arrangements shown. Other combinations of the disclosed features may realize additional or different embodiments.

[0047] The foregoing description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples will become apparent to those skilled in the art without necessarily departing from the essence of the invention. The scope of legal protection afforded this invention can only be determined by studying the following claims.

Claims

1. An antenna device, comprising: substrate; a plurality of antenna elements supported on the substrate; an integrated circuit supported on one side of the substrate; as well as A metal waveguide antenna comprising an air waveguide, the metal waveguide antenna comprising a first layer, a second layer and a third layer, wherein when the first layer, the second layer and the third layer are fixed together, the first layer, the second layer and the third layer establish an air waveguide, wherein the first layer is placed against the substrate and the second layer is between the first layer and the third layer, The waveguide antenna has a heat sink portion within the metal waveguide antenna in a thermally conductive relationship with the integrated circuit, the heat sink portion includes a chamber defined by the second layer for containing a liquid or a heat exchanger formed as part of the second layer, and the heat sink portion is configured to reduce the temperature of the integrated circuit.

2. The antenna device according to claim 1, characterized in that The heat exchanger includes a plurality of metal components arranged to allow a fluid to flow between the metal components.

3. The antenna device according to claim 2, characterized in that The metal member includes a fin.

4. The antenna device according to claim 1, wherein: The chamber is configured to contain a fluid for absorbing heat from the integrated circuit.

5. The antenna device according to claim 4, characterized in that The chamber defines a first volume within the chamber; The fluid is a liquid; and The liquid has a second volume that is smaller than the first volume.

6. The antenna device according to claim 5, characterized in that The second volume is between 10% and 60% of the first volume.

7. The antenna device according to claim 6, characterized in that The second volume is 30% of the first volume.

8. The antenna device according to claim 5, characterized in that The liquid is at least one of water, ethylene glycol and acetone.

9. The antenna device according to claim 5, characterized in that: A wicking structure is included within the chamber, the wicking structure being configured to promote circulation of a vaporized portion of the liquid back into the liquid.

10. The antenna device according to claim 9, characterized in that The metal waveguide antenna comprises copper; The wicking structure comprises a sintering paste or a copper etch; and The sintering paste or the copper etch is located on a surface within the chamber that is closer to the integrated circuit than the liquid.

11. The antenna device according to claim 1, wherein: The metal waveguide antenna is on one side of the substrate; The metal waveguide antenna includes a cavity configured to receive the integrated circuit; and The cavity provides electromagnetic shielding around the integrated circuit.

12. The antenna device according to claim 1, wherein: the metal waveguide antenna is on a second side of the substrate opposite the one side, wherein the one side is the first side; and The heat sink portion includes a thermal interface material against the substrate and aligned with the integrated circuit.

13. The antenna device according to claim 1, wherein: The metal waveguide antenna comprises multiple layers of metal material fixed together; and At least one of the layers includes the heat dissipation portion.

14. The antenna device according to claim 13, characterized in that The heat dissipation portion includes a chamber; The at least one layer defines at least two interior surfaces of the chamber; and At least one other of the layers defines at least one interior surface of the chamber.

15. A method for manufacturing an antenna device, the method comprising: establishing a plurality of antenna elements on a substrate; securing an integrated circuit to one side of the substrate; forming a waveguide antenna comprising an air waveguide by securing together a first metal layer, a second metal layer and a third metal layer, comprising establishing at least one heat sink portion in at least one of said layers, said heat sink portion comprising a chamber defined by said second metal layer for containing a liquid or a heat exchanger formed as part of said second metal layer, and said second metal layer being between said first metal layer and said third metal layer; as well as The first metal layer of the waveguide antenna is placed against the substrate to establish a thermally conductive relationship between the integrated circuit and the heat sink.

16. The method according to claim 15, characterized in that The heat exchanger includes a plurality of metal components arranged to allow a fluid to flow between the metal components.

17. The method according to claim 15, characterized in that The chamber is configured to contain a fluid for absorbing heat from the integrated circuits in the at least one layer, The chamber defines a first volume within the chamber; The fluid is a liquid; and The liquid has a second volume that is smaller than the first volume.

18. The method according to claim 17, characterized in that The second volume is between 10% and 60% of the first volume.

19. The method according to claim 17, characterized in that Establishing the heat dissipation portion includes placing a wicking structure in the chamber; and The wicking structure is configured to promote circulation of a vaporized portion of the liquid back into the liquid.

20. The method of claim 15, wherein: Positioning the waveguide antenna against the substrate includes securing a first metal layer of the metal layers against the side of the substrate; forming the waveguide antenna including a cavity established within the first metal layer; The integrated circuit is received in the cavity; as well as The cavity provides electromagnetic shielding around the integrated circuit.

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