Radar device and method for manufacturing the same

Abstract

A radar device includes a circuit board and a signal generation circuit disposed at least indirectly on the circuit board and electrically coupled to the circuit board and configured to generate a radar signal. The radar device further includes a waveguide antenna device disposed at least indirectly on the circuit board and constructed at least in part from an injection molded plastic substrate. The radar device further includes a waveguide input device, the signal generation circuit disposed on or within the waveguide input device, and the waveguide input device configured to input a radar signal generated from the signal generation circuit to the waveguide antenna device.

Description

[Technical field]

[0001] The present invention relates to a radar device and a method for manufacturing a radar device, and more particularly to a radar device for use in an automobile. [Background technology]

[0002] Driver assistance systems can assist the driver or control the vehicle at least partially autonomously. For the functions offered, a good knowledge of the vehicle's surroundings is a fundamental prerequisite. To this end, driver assistance systems have access to sensor data generated by the vehicle's sensors. Representative sensors here include vehicle cameras, lidar sensors, infrared sensors and especially radar sensors.

[0003] Radar sensors must have high sensitivity and good resolution, which places high demands on the antenna field of the radar sensor. At the same time, costs need to be kept down, which can be achieved, for example, by integrating electrical signal generation, transmission, reception and processing into a single system-on-chip (SoC).

[0004] In addition to conventional patch antenna arrays, waveguide antennas can also be used. Patch antenna arrays are typically narrowband, whereas waveguide antennas can cover bandwidths up to about 10 GHz. Furthermore, waveguide antennas promise better efficiency, lower losses, and a larger field of view compared to modern patch antennas. An exemplary waveguide interface is known from US 2020 / 365971. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] US Patent Application Publication No. 2020 / 365971 Summary of the Invention [Means for solving the problem]

[0006] The invention provides a radar device and a method for manufacturing a radar device having the features of the independent claims. Preferred embodiments are the subject matter of the respective dependent claims.

[0007] According to a first aspect, the present invention provides a radar apparatus comprising a circuit board and a signal generation circuit at least indirectly disposed on the circuit board and electrically coupled to the circuit board and configured to generate a radar signal. The radar apparatus further includes a waveguide antenna apparatus at least indirectly disposed on the circuit board and constructed at least in part from an injection molded plastic substrate. The radar apparatus further includes a waveguide input apparatus, the signal generation circuit being disposed on or within the waveguide input apparatus, the waveguide input apparatus configured to input a radar signal generated from the signal generation circuit to the waveguide antenna apparatus.

[0008] According to a second aspect, the present invention provides a method for manufacturing a radar device. The method includes providing a circuit board, the signal generation circuit being at least indirectly disposed on the circuit board, the signal generation circuit being electrically coupled to the circuit board and configured to generate a radar signal. The method further includes at least partially overmolding the circuit board with the signal generation circuit with plastic in a mold patterned with a waveguide channel. The method further includes removing the mold and metallizing the waveguide channel to form a waveguide antenna device. The method further includes exposing an input element of a waveguide input device, the waveguide input device configured to input a radar signal generated from the signal generation circuit to the waveguide antenna device via the input element. Effect of the Invention

[0009] The present invention provides a radar device with a circuit board, a signal generating circuit, and a waveguide input element, which can be combined into a high frequency package with a waveguide antenna device injection molded using a plastic injection molding process. This allows the elimination of high frequency lamination on the circuit board for the radar device. It is possible to manufacture the adapter parts with low cost circuit board technology. By using a surface mount device (SMD) process combined with direct injection molding (DIM), the radar device can be manufactured at low cost.

[0010] By coupling the radar signal directly into the waveguide antenna, circuit board material costs can be optimized without mmWave requirements or constraints. According to a further embodiment of the radar device, the waveguide input device is configured to input the radar signal generated by the signal generation circuit directly into a waveguide channel of the waveguide antenna device, the waveguide antenna device being injection molded directly onto the waveguide input device in a connection area continuous with the waveguide channel.

[0011] In particular, no air gaps are formed in this connection area. Preferably, the plastic is directly injection molded onto the circuit board, the signal generating circuit or the waveguide input device. Only the input area (feed channel) remains for inputting the radar beam into the waveguide antenna device. The absence of air gaps makes it possible to omit the tolerance compensation area that is usually necessary and also makes it possible to avoid high frequency inputs into adjacent input areas.

[0012] According to a further embodiment of the radar device, the waveguide antenna arrangement is injection molded directly onto the signal generating circuit, which makes it possible to avoid additional separate remolding, thus simplifying production and reducing costs.

[0013] According to a further embodiment of the radar device, the waveguide input device comprises at least one metallized high frequency structure for inputting the radar signal generated by the signal generation circuit into the waveguide antenna device, the radar signal being input directly via the metallized high frequency structure.

[0014] According to a further embodiment of the radar device, the metallized side walls of the waveguide channel of the waveguide antenna device are in contact with the metallized high-frequency structure, in this way the entire input area is metallized.

[0015] According to a further embodiment of the radar device, the metallized sidewall of the waveguide channel of the waveguide antenna device contacts a solder mask disposed between the waveguide antenna device and the waveguide input device, the solder mask separating the metallized sidewall of the waveguide channel from the waveguide input device.

[0016] According to a further embodiment of the radar device, the metallized high frequency structure is spaced apart from the solder mask. According to a further embodiment of the radar device, the metallized sidewall of the waveguide channel of the waveguide antenna device is spaced from the waveguide input device by an injection molded plastic part.

[0017] According to a further embodiment of the radar device, the metallized sidewall has a portion that runs parallel to the metallized high frequency structure at the transition to the waveguide input device. The input can be influenced by various configurations of the metallized sidewall.

[0018] In accordance with a preferred embodiment of the radar system, the waveguide input arrangement includes an interposer configured to conduct the radar signal generated from the signal generation circuitry to the waveguide antenna arrangement.

[0019] According to a further embodiment, the radar device comprises at least one heat sink at least indirectly connected to the signal generating circuit and / or the circuit board for dissipating heat, thereby making it possible to avoid overheating of the radar device.

[0020] According to a further embodiment of the radar device, the signal generation circuit is a system-on-chip circuit or a monolithic microwave integrated circuit (MMIC). Further advantages, features and details of the invention are set forth in the following description, in which various embodiments are detailed with reference to the drawings. [Brief description of the drawings]

[0021] [Figure 1] 1 is a schematic cross-sectional view of a radar device according to a first embodiment of the present invention. [Diagram 2] FIG. 5 is a schematic cross-sectional view of a radar device according to a second embodiment of the present invention. [Diagram 3] FIG. 11 is a schematic cross-sectional view of a radar device according to a third embodiment of the present invention. [Figure 4] FIG. 11 is a schematic cross-sectional view of a radar device according to a fourth embodiment of the present invention. [Diagram 5] 13A and 13B are schematic top and cross-sectional views of a radar device according to a fifth embodiment of the present invention. [Figure 6] FIG. 13 is a schematic cross-sectional view of a radar device according to a sixth embodiment of the present invention. [Figure 7] FIG. 13 is a schematic cross-sectional view of a radar device according to a seventh embodiment of the present invention. [Figure 8] FIG. 13 is a schematic cross-sectional view of a radar device according to an eighth embodiment of the present invention. [Figure 9] FIG. 13 is a schematic cross-sectional view of a radar device according to a ninth embodiment of the present invention. [Figure 10] FIG. 23 is a schematic cross-sectional view of a radar device according to a tenth embodiment of the present invention. [Figure 11] FIG. 23 is a schematic cross-sectional view of a radar device according to an eleventh embodiment of the present invention. [Figure 12] FIG. 26 is a schematic cross-sectional view of a radar device according to a twelfth embodiment of the present invention. [Figure 13] FIG. 4 is a flow diagram of a method for manufacturing a radar device.

[0022] In all figures, like or functionally similar elements and devices are labeled with the same reference numbers. Numbering of method steps is for clarity and generally does not imply a particular chronological order. In particular, multiple method steps may be performed simultaneously. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] 1 is a schematic cross-sectional view of a radar device 100. The radar device 100 includes a printed circuit board (PCB) 109 having a surface mount device (SMD) 110 and a plug contact 112.

[0024] A signal generation circuit 108 is coupled to the circuit board 109 and is integrated into a waveguide input device 103, which may also be referred to as a waveguide launcher. The waveguide input device 103 is integrated into the radar chip package such that the mmWave signal is not transmitted over the circuit board 109.

[0025] The waveguide input device 103 has a molding material 106 that surrounds the signal generating circuitry 108 on the side remote from the circuit board 109. According to a further embodiment, the molding material 106 may be absent.

[0026] The waveguide input device 103 further comprises an interposer 104. The interposer 104 is not surrounded by the molding material 103 in an outer region to allow for a low loss input from the waveguide input device 103 to the waveguide antenna device 102.

[0027] The signal generating circuit 108 is disposed on the interposer 104, which is connected to the circuit board 109 via solder balls or pads 107 to form a ball grid array (BGA) or land grid array (LGA) type package. The signal generating circuit 108 is a monolithic microwave integrated circuit (MMIC). According to a further embodiment, the signal generating circuit 108 may be a system-on-chip circuit. The signal generating circuit 108 is configured to generate and receive radar signals (radio frequency signals).

[0028] The waveguide antenna device 102 is disposed on a circuit board 109 and surrounds the waveguide input device 103 and the signal generation circuitry 108 incorporated therein. The waveguide antenna device 102 is formed by overmolding the circuit board 109, which includes the waveguide input device 103 and the signal generation circuitry 108, with a plastic 1022, such as a thermoset or thermoplastic.

[0029] The waveguide antenna arrangement 102 includes a waveguide channel 1021 with metallized sidewalls 105. Aperture plate 101 is disposed on the waveguide channel 1021. A waveguide input arrangement 103 is configured to input a radar signal generated from a signal generation circuit 108 to the waveguide antenna arrangement 102. The radar signal is transmitted through an opening in the perforated plate 101.

[0030] The transition to the waveguide antenna arrangement 102 is preferably realized in the portion of the interposer 104 that is not surrounded by the molding material 103, thereby reducing high frequency losses and ensuring a high bandwidth. Input is via a metallized high frequency structure 111.

[0031] FIG. 2 is a schematic cross-sectional view of the details of the radar device 200. The signal generating circuit 108 is attached to the interposer 104 using flip-chip technology and is connected to the interposer 104 by contacts 213. The signal generating circuit 108 is not surrounded by a molding material. It is therefore a bare die configuration. The high frequency (HF) structures 211 are realized in conductive layers in the side regions of the circuit board. They are configured to input the radar signal generated from the signal generating circuit 108 to a subsequent (not shown) waveguide antenna device. Between the signal generating circuit 108 and the interposer 104, a capillary underfill (CUF) or molded underfill (MUF) 212 is formed. In the radar device 200, the waveguide input device 203 is formed by the interposer 104 with the CUF or MUF 212, the contacts 213 and the high frequency structures 211. The circuit board 109 is not shown. The illustrated components of the radar device 200 can be called a launcher-on-package. A waveguide antenna device (not shown) is attached by injection molding. In Fig. 2 and the following Figs. 3 to 11, as in Fig. 1, components (not shown) may be provided.

[0032] 3 is a schematic cross-sectional view of a launcher-on-package of a radar device 300. The configuration corresponds generally to the configuration shown in FIG. 2, particularly with respect to the waveguide input device 303. Furthermore, the signal generation circuit 108 is partially surrounded by the molding material 303. However, the lateral regions of the interposer 104 are not surrounded by the molding material 303.

[0033] 4 is a schematic cross-sectional view of a launcher-on-package of a radar device 400. A signal generating circuit 108 is disposed on the lower surface of an interposer 104 of a waveguide input device 403 and is surrounded by a molding material 403. A high frequency structure 211 is disposed on the upper surface of the interposer 104, and a high frequency signal is radiated upward and input to a waveguide antenna device (not shown).

[0034] 5 is a schematic plan view (top) and cross-sectional view (bottom) of a launcher-on-package of a radar device 500. A molding material 501 is also formed on the outer region on the interposer 104, and high frequency signals are input from a waveguide input device 503 to a waveguide antenna device (not shown) by through holes (vias) 515. The through holes 515 extend through the molding material 501 and are fabricated using through-mold via technology.

[0035] 6 is a schematic cross-sectional view of a launcher-on-package for a radar device 600, in which a waveguide input device 603 is provided surrounded by a molding material 601, with a high frequency structure 211 exposed or at least partially covered by a thin molding material layer.

[0036] 7 is a schematic cross-sectional view of a launcher-on-package of a radar device 700. This radar device 700 differs from the radar device 600 shown in FIG. 6 in that the high frequency structure 211 of the waveguide input device 703 is not exposed to the molding material 701. A beam shaping element 702 is formed above the high frequency structure 211.

[0037] 8 is a schematic cross-sectional view of a detail of a radar device 800, i.e., an input structure. The radar device 800 includes a waveguide channel 1021 with metallized sidewalls 105 that contact a metallized high frequency structure 211. A solder mask 802 is disposed on the outside of the input structure between the waveguide antenna device 102 and the waveguide input device 103.

[0038] 9 is a schematic cross-sectional view of the input structure of a radar device 900, in which the metallized sidewall 105 of the waveguide channel 1021 of the waveguide antenna device 102 is in contact with a solder mask 802 disposed between the waveguide antenna device 102 and the waveguide input device 103. The metallized high frequency structure 211 is spaced from the solder mask 802.

[0039] 10 is a schematic cross-sectional view of an input structure of a radar device 1000. Unlike the input structure shown in FIG.

[0040] 11 is a schematic cross-sectional view of the input structure of a radar device 1100. The metallized sidewall 105 of the waveguide channel 1021 of the waveguide antenna device 102 is spaced from the waveguide input device 103 by an injection molded plastic part 1101. The spacing may be, for example, between 20 pm and 100 pm-500 pm. The injection molded plastic part 1101 may be made of a thermosetting or thermoplastic material, such as the same material that constitutes the rest of the waveguide 102. However, a further dielectric material may be provided.

[0041] Figure 12 is a schematic cross-sectional view of the input structure of a radar device 1200. It differs from the input structure shown in Figure 11 in that the metallized sidewall 105 has a portion 1202 that runs parallel to the metallized high frequency structure 211 at the transition to the waveguide input device 103.

[0042] FIG. 13 is a flow diagram of a manufacturing method for a radar device. In a first method step S1, a circuit board 109 is provided and a signal generating circuit 108 is at least indirectly disposed on the circuit board 109. The signal generating circuit 108 is electrically coupled to the circuit board 109 and configured to generate a radar signal.

[0043] In a second method step S2, a circuit board 109 with signal generating circuitry 108 is placed into the mold patterned with the waveguide channels and is at least partially overmolded with a plastic, such as a thermoset or thermoplastic, the transition areas to the waveguide channels may be free.

[0044] In step S3, the mould is removed. In step S4, the waveguide channels are metallised, thereby forming the waveguide antenna arrangement 102. This may be done, for example, by using a mask so that the metallic transition is not metallised in the input region. Alternatively, metal deposition may be performed on the metallic structure in the input region. The metal is then removed again.

[0045] Metallization can be done physically, chemically, or galvanically. Metals can be removed by lasers, wet chemical etching, or dry etching processes.

[0046] In step S5, the input element of the waveguide input device 103 is exposed, and the waveguide input device 103 is configured to input the radar signal generated from the signal generating circuit 108 to the waveguide antenna device 102 via the input element.

Claims

1. a circuit board (109), a signal generation circuit (108) at least indirectly arranged on and electrically coupled to said circuit board (109) and configured to generate a radar signal; a waveguide antenna arrangement (102) arranged at least indirectly on said circuit board (109) and at least partly made of an injection-molded plastic substrate; a waveguide input device (103), the signal generation circuit (108) being arranged on or within the waveguide input device (103), the waveguide input device (103) being configured to input a radar signal generated from the signal generation circuit (108) to the waveguide antenna device (102), Radar equipment (100-1200).

2. The radar device (100-1200) of claim 1, wherein the waveguide input device (103) is configured to directly input the radar signal generated from the signal generating circuit (108) into a waveguide channel (1021) of the waveguide antenna device (102), and the waveguide antenna device (102) is injection molded directly onto the waveguide input device (103) in a connection region continuous with the waveguide channel (1021).

3. The radar device (100-1200) of claim 1 or 2, wherein the waveguide antenna device (102) is injection molded directly onto the signal generating circuit (108).

4. The radar device (100-1200) according to any one of claims 1 to 3, wherein the waveguide input device (103) has at least one metallized high frequency structure (111; 211) for inputting the radar signal generated from the signal generating circuit (108) to the waveguide antenna device (102).

5. 5. The radar device (800) of claim 4, wherein the metallized sidewalls (105) of the waveguide channel (1021) of the waveguide antenna device (102) contact the metallized high frequency structure (111; 211).

6. 5. The radar device (900; 1000) of claim 4, wherein the metallized sidewall (105) of the waveguide channel (1021) of the waveguide antenna device (102) contacts a solder mask (802) disposed between the waveguide antenna device (102) and the waveguide input device (103).

7. 7. The radar device (900) of claim 6, wherein the metallized high frequency structure (111; 211) is spaced from the solder mask (802).

8. 5. A radar device (1100; 1200) as claimed in claim 4, wherein the metallized sidewall (105) of the waveguide channel (1021) of the waveguide antenna device (102) is spaced from the waveguide input device (103) by an injection molded plastic part (1101).

9. A radar device (1200) according to any one of claims 5 to 8, wherein the metallized side wall (105) has a portion (1202) that extends parallel to the metallized high frequency structure (111; 211) at the transition to the waveguide input device (103).

10. - providing (S1) a circuit board (109), the signal generating circuit (108) being at least indirectly arranged on said circuit board (109), the signal generating circuit (108) being electrically coupled to said circuit board (109) and configured to generate a radar signal; - at least partially overmolding (S2) said circuit board (109) comprising said signal generating circuit (108) with plastic in a mold patterned with waveguide channels (1021); - a step (S3) of removing said mould; - a step (S4) of metallizing said waveguide channel (1021) to form a waveguide antenna device (102); a step (S5) of exposing an input element of a waveguide input device (103), said waveguide input device (103) being configured to input a radar signal generated by said signal generating circuit (108) to said waveguide antenna device (102) via said input element; A method for manufacturing a radar device, comprising:

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