System and device for coupling electromagnetic waves into and / or out of a waveguide and method for producing same

Abstract

The invention relates to a coupling structure for coupling electromagnetic waves into and / or out of a waveguide. The coupling structure comprises a substrate which comprises a pot-shaped, electrically hollow structure having an oval basic shape, wherein the electrically hollow structure is defined on one side of the substrate and is terminated on the opposite side of the substrate.

Description

[0001] Description

[0002] title

[0003] System and device for coupling electromagnetic waves into and / or out of a waveguide and method for producing the same

[0004] The present invention relates to a system and a device for coupling electromagnetic waves into and / or out of a waveguide and a method for manufacturing the same.

[0005] State of the art

[0006] To couple high-frequency electromagnetic waves from a source or sink into a waveguide, there are numerous known approaches such as tapered transitions or X / 4 coupling pins.

[0007] DE 10 2021 204296 discloses a radar device comprising a printed circuit board, a signal generation circuit which is at least indirectly arranged on the printed circuit board, is electrically coupled to the printed circuit board and is configured to generate a radar signal, a waveguide antenna device which is at least indirectly arranged on the printed circuit board, and a device for coupling a waveguide, wherein the signal generation circuit is arranged on or in the device for coupling a waveguide, and wherein the device for coupling a waveguide is configured to couple the radar signal generated by the signal generation circuit into the device for coupling a waveguide.

[0008] US 2020 / 0176393 Al discloses a monolithically integrated microwave circuit with embedded transmission line and grounding shield.

[0009] Disclosure of the invention: The invention provides a system and a device for coupling electromagnetic waves into and / or out of a waveguide and a method for manufacturing the same device with the features of the independent claims.

[0010] Preferred embodiments are the subject of the respective dependent claims.

[0011] The coupling structures according to the invention have high efficiency and good transmission, while reflection is reduced compared to conventional coupling structures. The feed path is shortened and can be implemented in different layers, allowing the coupling structure to be implemented very compactly and with fewer sources of interference. Undesirable influences from backside structures and / or materials, such as the silicon of a chip, can be avoided.

[0012] According to a first aspect, the invention relates to a coupling structure for coupling electromagnetic waves into and / or out of a waveguide. The coupling structure comprises a substrate comprising a pot-shaped electrically hollow structure with an oval base shape, wherein the electrically hollow structure is defined on one side of the substrate and closed on the opposite side of the substrate.

[0013] According to further training, a form of electrically hollow structure includes, in addition to the oval basic shape, at least one corner that protrudes from the oval basic shape.

[0014] According to a further development, the coupling structure further comprises a patch, wherein the patch is positioned on a far side of a bottom surface of the oval pot-shaped electrically hollow structure and preferably does not close off the electrically hollow structure.

[0015] According to further training, the coupling structure also includes a signal line with a feed finger.

[0016] According to a further development, the coupling structure further comprises a patch that is positioned on a far side of a bottom surface of the oval pot-shaped electrically hollow structure and preferably does not close off the electrically hollow structure; wherein the coupling structure further comprises a signal line with a feed finger; and wherein the feed finger runs along a side of the patch facing away from the patch and the bottom surface and is configured to electromagnetically excite the patch.

[0017] According to further training, the substrate comprises a metallic layer on the side of the hollow body.

[0018] According to further training, the coupling structure also includes solder balls that are positioned around the electrically hollow structure on the side of the substrate opening, which is defined by the electrically hollow structure.

[0019] According to a second aspect, the invention relates to a system comprising the coupling structure as described above and an electronic chip which is connected to the substrate on the side of the substrate facing away from the electrically hollow structure, wherein the electronic chip is preferably electronically connected to the signal line.

[0020] According to further training, the system includes the waveguide into which input / output occurs.

[0021] According to a third aspect, the invention relates to a method for providing a coupling structure for coupling electromagnetic waves into and / or out of a waveguide, comprising the following steps: providing a substrate; and forming an oval pot-shaped electrically hollow structure, wherein the electrically hollow structure is defined on one side of the substrate and is closed off on the opposite side by the substrate.

[0022] Brief description of the drawings

[0023] It shows:

[0024] Figure 1 shows a schematic representation of a coupling structure (also called a coupling structure) on the back side of a chip substrate according to an exemplary embodiment; Figure 2 shows a schematic representation of a cross-section through a launcher according to an exemplary embodiment;

[0025] Figure 3 shows a schematic representation of an exemplary embodiment of a launcher; and

[0026] Figure 4 shows a schematic representation of a mold with a chip over a plurality of launchers in an interposer according to an exemplary embodiment.

[0027] In all figures, identical or functionally equivalent elements and devices are designated with the same reference numerals. The numbering of process steps serves for clarity and generally does not imply a specific chronological order. In particular, several process steps can be performed simultaneously.

[0028] Description of the exemplary implementations

[0029] Figure 1 shows a coupling structure 12, also called a coupling structure, on the back side of a substrate 24 of a chip 10. The coupling structure 12 comprises a launcher 14 and solder balls 28, also called solder balls, solder balls, and / or pads, surrounding the launcher 14. The launcher 14 includes a signal line 16 with a feed finger 18 at the leading edge of the signal line 16, a patch 20, and a bounded and electrically hollow structure 22. The electrically hollow structure 22 is enclosed in the back side of the chip 10 with metallic bounding (usually vias) and consists only of interposer material, vias or other planar bounding elements, and the metallic coupling structure elements.

[0030] The metallic layer, or the entire metallic boundary of the hollow body, does not necessarily have to be continuous. The metallic layer can also be formed similarly to a wire mesh fence, for example, using vias and / or a perforated surface, or a combination thereof. The metallic layer can be geometrically arbitrary, as long as it represents an electrical short circuit or reflection with respect to the operating frequencies.

[0031] The electrically hollow structure is usually not hollow and therefore, for example, air-filled, but rather filled with a dielectric.

[0032] The solder balls 28 are located laterally next to the electrically hollow structure 22 and can project from the plane of the chip 10 towards a printed circuit board. The view in Figure 1 is from the direction of the printed circuit board. The printed circuit board can include a waveguide into which or from which the coupling structure 12 couples a signal, an electromagnetic wave, and / or out. Alternatively or additionally, the structure 22 can also couple directly into / out of a waveguide.

[0033] On the side of chip 10 facing away from the viewer, an electronic structure such as parts of chip 10 and / or a silicon chip may be located. The chip may also be a substrate 24 such as a printed circuit board or, more generally, silicon from the chip. Electronic components of this structure are electronically connected to the signal line 16 and thus also to the feed finger 18. The signal line 16 may be a microstrip line, a coplanar line, a triplate, depending on its position, or another type of line, or a combination thereof. The feed finger 18 of the signal line 16 may extend into the launcher 14, and / or run near patch 20, and / or be connected to patch 20. Patch 20 can be excited by the feed finger 18.

[0034] The electrically hollow structure 22 has a specially shaped, pot-like structure with a boundary geometry. This boundary geometry characterizes the launcher, see Figure 3 and the accompanying description. The boundary geometry can be represented in the launcher 14 with very closely spaced vias. Within the pot-like structure, the patch 20 is located in an inner layer of the launcher 14 and is excited by a feed finger 18, for example, in the outermost layer of the launcher 14. The excitation side of the feed finger 18 can be coupled in various ways, i.e., in different positions such as an inner or outer layer. The electromagnetic wave is emitted from the launcher 14 past boundary solder balls 28 and into a waveguide. During coupling, the radiation occurs in the reverse direction.

[0035] The electrically hollow structure 22 is bounded on the side facing the substrate 24, i.e., in the opposite direction to the waveguide, by a metallic termination. The metallic termination can be a metal layer. The metallic termination can be part of the substrate 24 and / or the chip 10.

[0036] Figure 2 shows a section through the launcher 14. The lower part of Figure 2 shows portions of the solder balls 28. In this embodiment, the feed finger 18 runs parallel to and close to the patch 20 without touching it or having direct contact with it. The signal conductor 16 also runs through the substrate 24 and is connected on the other (upper) side to the electronic structure, which sends a signal to generate an electromagnetic wave or receives a signal from a received electromagnetic wave. The connection between the electronic structure and the feed finger 18 is therefore short. It can be seen that the electrically hollow structure 22 extends between the patch 20 and the substrate 24. The electrically hollow structure 22 can extend uniformly, e.g., like a cylinder, within the substrate 24.

[0037] It is possible that the feed finger 18 and the patch 20, also called the radiation patch, comprise multiple layers and / or a triplate. An example is four copper layers of RF-suitable material. The feed finger 18 can be part of an outer layer of the copper layers, and the patch 20 can be located in an inner layer of the copper layers.

[0038] Figure 3 shows the launcher 14. The pot-like structure of the electrically hollow structure 22 is preferably oval in cross-section along the plane of the substrate. More preferably, the oval cross-section has corners. Other boundary geometries are also possible. The electrically hollow structure 22 is preferably uniformly embedded in the chip 10 or the substrate 24, e.g., similarly to a cylinder. It is possible that no corners, or one or more corners, are included in the boundary geometry (possibly approximated by appropriately placed vias), in particular two near the exit of the signal line 16 and / or two away from the passage 26 of the signal line 16, as shown. The first corner 30 near the passage 26 of the signal line 16 can be optional. If the signal line 16 exits further inward, it is possible that the first corner 30 is omitted. The second corner 32, third corner 34, fourth corner 36, and fifth corner 38 can also be optional.One or more of these four corners (32 to 38) may be present. In a preferred embodiment, the fourth corner 36 and the fifth corner 38 (with or without a first corner 30) are present.

[0039] In a more preferred embodiment, the second corner 32 and the third corner 34 (with or without the first corner 30) are present. In a further preferred embodiment, the second corner 32, the third corner 34, the fourth corner 36, and the fifth corner 38 (with or without the first corner 30) are present. The corners can be interpreted as additional angular electrically hollow structures to the oval electrically hollow structure. All electrically hollow structures together can also be interpreted as a single electrically hollow structure. Preferably, the shape of the single electrically hollow structure is substantially oval.

[0040] The signal conductor 16 traverses the substrate 24 at the passage 26. The passage 26 terminates the substrate 24 and couples the electromagnetic wave to a conductor outside the electrically hollow structure. The electrically hollow structure 22 preferably has no opening facing the electronic structure, i.e., opposite to the waveguide. Preferably, the chip 10 and / or the substrate 24 have no opening facing the electronic structure, i.e., opposite to the waveguide. The passage 26 can be a separate element or part of the substrate 24. In this sense, the electrically hollow structure can be pot-shaped, e.g., open at the top, closed at the bottom, and with straight sides. The passage 26 does not have to be located at the top of the electrically hollow structure but can also run laterally.

[0041] The disclosed coupling structure 12 can be incorporated into various products. These include microchips with different types of chip packaging, such as "System on Chip" (SoC), "Land Grid Array" (LGA), "Ball Grid Array" (BGA), and similar silicon substrates with interposer-like structures, for example, in automotive radar applications at 77 GHz, e.g., launchers for 77 GHz radar chip packages. It is also possible to use a coupling structure oriented in the opposite direction, i.e., from the chip upwards instead of downwards towards the circuit board as previously described. This structure also utilizes the same launcher structure with an analogous mechanical design, but directly into an antenna or waveguide, as shown by way of example in Figures 1 and 2, using solder balls for coupling.Since the geometry is arbitrarily scalable with respect to frequency and / or wavelength, it can also be used in analog design and form in frequency ranges other than between 76 and 81 GHz, for example at 2.45 GHz or 5.8 GHz, if a low height is important.

[0042] The disclosed systems and devices enable increased efficiency and improved transmission. Furthermore, improved high-frequency matching, resulting in reduced reflection, can be achieved. Feeding from different positions within the launcher is also possible. Additionally, the coupling structure can be implemented with a very low profile, making it more compact. Finally, undesirable influences from rearward structures and / or materials, such as the silicon of the chip, can be avoided.

[0043] A coupling structure for coupling electromagnetic waves into and / or out of a waveguide can be provided using a method. The method comprises, in one step, the provision of a substrate. In a further step, an oval, pot-shaped, electrically hollow structure is formed within the substrate by introducing electrically conductive structures. The electrically hollow structure is defined on one side of the substrate and closed on the opposite side to enable a compact design and / or reduced interference due to shortened signal lines.

[0044] Figure 4 shows a schematic representation of a mold 41 with a chip 42 above a plurality of launchers 44 in an interposer 43. The chip 42 is formed directly above at least one launcher 44 to enable a compact design and / or reduced interference due to shortened signal lines.

Claims

Claims 1. Coupling structure (12) for coupling electromagnetic waves into and / or out of a waveguide, the coupling structure (12) comprising: a substrate (24) comprising a pot-shaped electrically hollow structure (22) with an oval base shape, wherein the electrically hollow structure (22) is defined on one side of the substrate (24) and is closed on the opposite side of the substrate (24).

2. Coupling structure (12) according to claim 1, wherein a form of the electrically hollow structure (22) comprises, in addition to the oval basic shape, at least one corner that protrudes from the oval basic shape.

3. Coupling structure (12) according to any one of claims 1 to 2, wherein the coupling structure (12) further comprises a patch (20), wherein the patch (20) is positioned on the far side of a bottom surface of the oval pot-shaped electrically hollow structure (22) and preferably does not close off the electrically hollow structure (22).

4. Coupling structure (12) according to any one of claims 1 to 3, wherein the coupling structure (12) further comprises a signal line (16) with a feed finger (18).

5. Coupling structure (12) according to any one of claims 1 to 2, wherein the coupling structure (12) further comprises a patch (20), wherein the patch (20) is positioned on the far side of a bottom surface of the oval, pot-shaped, electrically hollow structure (22) and preferably does not close off the electrically hollow structure (22); wherein the coupling structure (12) further comprises a signal line (16) with a feed finger (18); and wherein the feeding finger (18) runs along a side of the patch (20) facing away from the patch and the floor surface and is configured to electromagnetically excite the patch (20).

6. Coupling structure (12) according to one of claims 1 to 5, wherein the substrate (24) comprises a metallic layer on the side of the hollow body.

7. Coupling structure (12) according to any one of claims 1 to 6, wherein the coupling structure (12) further comprises solder balls (28) which are positioned around the electrically hollow structure (22) on the side of the opening of the substrate (24) which is defined by the electrically hollow structure (22).

8. System comprising the coupling structure (12) according to one of claims 1 to 7 and an electronic chip which is connected to the substrate (24) on the side of the substrate (24) facing away from the electrically hollow structure (22), wherein the electronic chip is preferably electronically connected to the signal line (16).

9. System according to claim 8, wherein the system comprises the waveguide into which coupling in and / or out takes place.

10. Method for providing a coupling structure (12) for coupling electromagnetic waves into and / or out of a waveguide, comprising the following steps: Providing a substrate (24); Forming an oval pot-shaped electrically hollow structure (22) in the substrate (24) by introducing electrically conductive structures into the substrate, wherein the electrically hollow structure (22) is defined on one side of the substrate (24) and is closed off on the opposite side of the substrate (24).

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