JP7261666B2 - RADAR DEVICE AND METHOD FOR MANUFACTURING RADAR DEVICE - Google Patents

Description

The present invention relates to a radar device and a method of manufacturing a radar device.

Patent Document 1 below discloses an invention of a microwave/millimeter wave sensor device as a radar device for detecting obstacles around a vehicle. According to the microwave/millimeter wave sensor device disclosed in Patent Document 1 below, a three-electrode high-frequency amplification element is integrated so as to generate a negative resistance in the resonance cavity, and an antenna function for radiating electromagnetic waves into space is provided. A radiation type oscillator is configured to be shared, an oscillation radiation wave of the radiation type oscillator is a transmission RF signal, a reflected wave of the transmission RF signal by the device under test is a reception RF signal, and the reception RF signal is the above-mentioned An IF signal is received by a radiation-type oscillator and obtained by homodyne mixing by the radiation-type oscillator itself, and the IF signal amplified by the amplification gain in the IF band from the direct current of the three-electrode high-frequency amplifying element that is oscillating in the RF band. The object to be measured is detected based on the analysis and processing by the analysis processing means.

WO2008/120826

In the above Patent Document 1, a horn-shaped radiation structure (hereinafter simply referred to as a horn) is provided on the radiation surface side of the radiation oscillator substrate in order to secure a certain opening to sharpen the radiation beam and improve the detection sensitivity. However, if the entire horn is made of metal, the weight of the device increases. On the other hand, if the horn is made of lightweight resin, radio waves pass through the horn, weakening the directivity and strength of the radio waves. I had a problem.

The object of the present invention is to solve the above problems, without increasing the weight of the device, at a low cost, and improving the directivity and strength of radio waves, as well as improving the heat dissipation of heat generated by parts. It is another object of the present invention to provide a radar device that can be manufactured, and to provide a method for manufacturing the radar device.

In a radar device according to one aspect of the present invention, an antenna and an electronic component connected to the antenna are arranged on one main surface of a substrate, and a resin horn is arranged so as to overlap the antenna and the electronic component. In the radar device, the horn has a waveguide formed at a position corresponding to the antenna, the waveguide becoming wider with distance from one main surface of the substrate, a plating layer formed on an outer surface of the horn, and the A shield layer is formed by the plating layer on a wall surface of the horn that forms the waveguide, and a peripheral wall portion of the horn is formed on a surface of the horn that faces the substrate from a position that faces the electronic component of the horn. It is characterized in that the heat transfer layer is extended to.

According to the present invention, the directivity and strength of radio waves emitted from the waveguide are improved by the shield layer, and by adopting a resin horn, the amount of metal used can be suppressed and the weight of the radar device can be reduced. can be realized. Furthermore, by providing a heat transfer layer on the surface of the horn facing the board, the heat dissipation of the electronic component mounted on the board can be improved at a low cost. Further features related to the present invention will become apparent from the description of the specification and the accompanying drawings. Further, problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

1 is an exploded perspective view of a radar device according to a first embodiment; FIG. 1 is a schematic cross-sectional view of a radar apparatus having a plurality of antennas according to a first embodiment and showing a radiation state of radio waves; FIG. FIG. 3 is an enlarged schematic cross-sectional view showing one antenna of the radar device of FIG. FIG. 2 is a schematic plan view showing the arrangement of an MMIC chip (electronic component) and a heat transfer layer; FIG. 4 is a schematic cross-sectional view showing a manufacturing method for integrally molding a heat transfer layer with a horn. FIG. 4 is an enlarged schematic cross-sectional view corresponding to FIG. 3 when a heat transfer member is provided in the radar device according to the first embodiment; 7A is an explanatory diagram of a radio wave radiation state, a heat transfer path, and a heat radiation path according to a comparative example, and FIG. 7B is an explanatory diagram of a radio wave radiation state by a plurality of antennas according to the comparative example.

[First Embodiment]
A radar device 1 according to a first embodiment will be described below with reference to FIGS. 1 to 5. FIG. First, referring to FIG. 1, the overall configuration of the radar device according to the first embodiment will be described. FIG. 1 is an exploded perspective view of the radar device according to the first embodiment. In the following description, a millimeter wave radar will be exemplified as a radar device, but the technique of the present disclosure can be used for other radar devices that detect obstacles by emitting radio waves.

The radar device 1 is a millimeter wave radar device that emits radio waves in the millimeter wave band and receives reflected waves from obstacles to detect obstacles. As shown in FIG. 1, a plurality of antennas 13 and MMIC (Monolithic Microwave Integrated Circuit) chips 14 as a plurality of electronic components are provided on one main surface 11 of a substrate 10 of the radar device 1 . A plurality of antennas 13 are connected to each MMIC chip 14 via feeder lines (not shown). A radio wave is radiated from each antenna 13 by power supply from each MMIC chip 14, and the radio wave captured by each antenna 13 is sent to each MMIC chip 14 through a feeder line.

Further, the antenna 13 may be a flat antenna such as a patch antenna provided on the substrate 10 or may be a surface-mounted chip antenna provided on the substrate 10 . Although the MMIC chip 14 for transmission and reception is arranged as a semiconductor chip on the substrate 10, the MMIC chip 14 for transmission and the MMIC chip 14 for reception may be arranged separately. Other MIC (Microwave Integrated Circuit) chips may be used as semiconductor chips. Further, as the substrate 10, a glass epoxy substrate, a ceramic substrate, or the like may be used, or a high frequency substrate made of fluorine resin having a low dielectric constant may be used.

A rectangular horn 20 in plan view is arranged on one main surface 11 of the substrate 10 of the radar device 1 so as to overlap the antenna 13 and the MMIC chip 14 . The horn 20 is made of a resin material, and a plating layer 28 is formed on the outer surface 27 of the horn 20 so as to cover the entire horn 20 by metal plating. Waveguides 23 are formed in the horn 20 at positions corresponding to the plurality of antennas 13 on the substrate 10 . Furthermore, a heat transfer layer 80 extends from a position of horn 20 facing MMIC chip 14 to the peripheral wall portion of horn 20 on the surface of horn 20 facing substrate 10 . The heat transfer layer 80 is integrally molded in the vicinity of the surface facing the portion of the substrate 10 where the semiconductor chip such as the MMIC chip 14 is mounted (see FIG. 2). The waveguides 23 are classified into types for short distance, medium distance, and long distance. It is possible to detect obstacles at different distances from the radar device 1 by emitting radio waves from the plurality of waveguides 23 to the outside. Each waveguide 23 is formed, for example, in a pyramid shape or a conical shape by the tapered surface of the horn 20 so that the width (area increases) as it goes away from one main surface 11 of the substrate 10 .

Further, the horn 20 includes PBT (Polybutylene Terephthalate) resin, PPS (Poly Phenylene Sulfide) resin, PP (Poly Propylene) resin, ABS (Acrylonitrile Butadiene Styrene) resin, PS (Polystyrene) resin, PE (Poly Ethylene) resin, PVC (Polyvinyl Chloride) resin, PC (Polycarbonate) resin, PET (Polyethyleneterephthalate) resin, LCP (Liquid Crystal Polymer) resin, PPO (Polyphenyleneether) resin, Epoxy resin, Si (Silicone) resin, Polyester resin A thermoplastic resin or a thermosetting resin having a light weight and a low thermal conductivity may be used. In addition, the plating layer 28 (see FIG. 2) formed on the outer surface 27 of the horn 20 by metal plating includes silver (Ag), copper (Cu), gold (Au), which have high thermal conductivity and shielding properties. A metal containing at least one of nickel (Ni), tin (Sn), aluminum (Al), iron (Fe), and the like may be used. In addition to plating, the plating layer 28 on the outer surface 27 of the horn 20 may be formed by a sputtering method, an inkjet method, a screen printing method, a CVD (Chemical Vapor Deposition) method, a PVD (Physical Vapor Deposition) method, or the like. An alloy or pure metal can be used for the heat transfer layer 80 . Metal plates such as copper alloys, aluminum alloys, SUS, brass alloys, iron alloys, and magnesium alloys can be used as alloys. Also, these alloys may be used as thin metal foils. As pure metals, metal plates or metal foils such as silver (Ag), copper (Cu), gold (Au), nickel (Ni), tin (Sn), aluminum (Al), and iron (Fe) can be used. can.

The horn 20 is provided with a rectangular lens 30 in plan view so as to cover the plurality of waveguides 23 . A plurality of lens surfaces 31 (see FIG. 2) corresponding to the plurality of waveguides 23 of the horn 20 are formed on the rear surface of the lens 30 on the substrate 10 side. Then, the radio wave radially diffused in the waveguide 23 from the antenna 13 is converted into a plane wave by the lens 30 and emitted to the outside. Reflected waves from the outside are converged within the waveguide 23 by the lens 30 and received by the antenna 13 . Note that dielectric materials such as PBT resin and PPS resin may be used for the lens 30 .

The outer edges of the horn 20 and the lens 30 are held by a rectangular frame-shaped housing 35 . The housing 35 has an opening edge portion 36 that prevents the horn 20 and the lens 30 from coming off, and a side wall portion 37 that forms the side surface of the radar device 1 . A cover 39 forming the surface of the radar device 1 is fixed on the opening edge 36 of the housing 35 . The cover 39 bulges out except for the outer peripheral portion fixed to the housing 35, and functions as a radome that protects the inside of the device from the natural environment such as rain and wind. For the housing 35 and the cover 39, a resin material such as PBT resin or PPS resin may be used.

A radiator plate 40 is provided on the other main surface 12 of the substrate 10 to release heat from the substrate 10 . A plurality of supports 41 are formed on the surface of the heat sink 40 on the side of the substrate 10 at positions corresponding to the plurality of MMIC chips 14 on the substrate 10 . The back surface of the heat sink 40 is supported by a base 45 that forms the back surface of the radar device 1 . The supporting surface of each support table 41 is in contact with the substrate 10 through the heat dissipation sheet S1, and the base 45 is in contact with the heat dissipation plate 40 through the heat dissipation sheet S2. In the radar device 1 , a heat dissipation path for releasing heat from the MMIC chip 14 is formed by the heat dissipation plate 40 and the base 45 . A material with high thermal conductivity such as aluminum may be used for the radiator plate 40 and the base 45 . Although not shown, the radiator plate 40 and the base 45 do not necessarily need to be separated as shown in FIG.

A detailed configuration of the radar apparatus according to the first embodiment will be described with reference to FIGS. 2 and 3. FIG. FIG. 2 is a schematic cross-sectional view of a radar apparatus having a plurality of antennas according to the first embodiment and showing a radiation state of radio waves. FIG. 3 is an enlarged schematic cross-sectional view showing one antenna of the radar device of FIG.

As shown in FIG. 2, an MMIC chip 14 is arranged on one main surface 11 of the substrate 10, and an antenna 13 is provided apart from the MMIC chip 14. As shown in FIG. A horn 20 is arranged on one main surface 11 of the substrate 10 . A peripheral wall portion 21 surrounding the outer edge of the substrate 10 is provided on the outer peripheral portion of the horn 20 . A horn body 22 having a waveguide 23 formed therein is provided inside the horn 20, and portions corresponding to the MMIC chip 14 and the antenna 13 partially protrude from the rear surface of the horn body 22 on the substrate 10 side. .

A contact portion 24 that contacts the surface of the MMIC chip 14 is provided on the rear surface of the horn body 22 at a location corresponding to the MMIC chip 14 . A thin guide portion 25 protruding along the waveguide 23 is provided on the rear surface of the horn body 22 at a location corresponding to the antenna 13 . The waveguide 23 is formed by the horn main body 22 and the tapered wall surface 26 of the guide portion 25 such that the distance between the waveguides 23 increases as the distance from the main surface 11 of the substrate 10 increases. A lens 30 is arranged on the front side of the horn main body 22, and a convex lens surface 31 is formed on the back side of the lens 30 with the center line of the waveguide 23 as the optical axis.

A heat sink 40 is provided on the other main surface 12 of the substrate 10 . A peripheral wall portion 42 that surrounds the outer edge of the substrate 10 is provided on the outer peripheral portion of the heat sink 40 , and a support base 41 that abuts on the substrate 10 at a portion corresponding to the MMIC chip 14 on the inner portion of the heat sink 40 . is provided. The peripheral wall portion 42 of the heat sink 40 is in contact with the peripheral wall portion 21 of the horn 20, and the support base 41 of the heat sink 40 is in contact with the substrate 10 via the heat sink sheet S1. The heat sink 40 is supported by the base 45 via the heat sink sheet S2. Since the base 45 is made of a metal having a high thermal conductivity like the heat sink 40, the base 45 also functions as a heat sink.

Further, in the horn 20, since the wall surface 26 of the horn 20 on which the waveguide 23 is formed is also covered with the plating layer 28, the wall surface 26 of the horn 20 is formed with a shield layer 29 for shielding radio waves by the plating layer 28. It is That is, the portion of the plated layer 28 covering the entire horn 20 that covers the wall surface 26 of the horn 20 constitutes a shield layer 29 that shields radio waves. The shielding layer 29 on the wall surface 26 ensures shielding of radio waves in the waveguide 23 and improves the directivity and strength of the radio waves. Also, since the contact portion 24 is in contact with the surface of the MMIC chip 14 via the plating layer 28, the plating layer 28 forms a heat transfer path R2 (see FIG. 3) from the MMIC chip 14 to the shield layer 29. At the same time, a heat dissipation path R3 (see FIG. 3) is formed from the MMIC chip 14 to the heat dissipation plate 40. As shown in FIG. As a result, the occurrence of dew condensation in the waveguide 23 is prevented, and the temperature rise of the MMIC chip 14 is suppressed.

Here, in order to efficiently transfer the heat generated by the MMIC chip 14 to the heat sink 40 through the heat dissipation path R3, the plating layer 28 must have a thickness of 10 μm or more even if copper, which has excellent thermal conductivity, is used as described above. thickness is required. In the case of plating with copper to a thickness of 10 μm or more, there is a problem that the manufacturing time is long and the cost is high.

Therefore, in this embodiment, in addition to the plating layer 28, a heat transfer layer 80 having higher thermal conductivity than the plating layer 28 is provided to improve the thermal conductivity of the heat dissipation path R3. The heat transfer layer 80 is formed by integrally molding a plate-shaped member made of a metal material having a greater thickness than the shield layer 29 (plated layer 28 ) and the horn 20 .

The heat transfer layer 80 is integrally formed with the horn 20 so as to be positioned near the surface facing the portion of the substrate 10 on which the semiconductor chip such as the MMIC chip 14 is mounted (see FIG. 2). As shown in FIG. 3, the heat transfer layer 80 extends from a position facing the MMIC chip 14, which is a heat generating component, to the peripheral wall portion (21) of the horn (20). The heat transfer layer 80 can satisfy the heat dissipation performance if the thickness is 50 μm or more regardless of the material as long as it is a metal material. A metal foil having a thickness of 10 μm or more can be used as long as it is a material having excellent heat conductivity such as a copper alloy.

In this embodiment, the heat transfer layer 80 and the plating layer 28 covering the surface of the heat transfer layer 80 form the heat dissipation path R3. The heat transfer layer 80 is formed integrally with the heat transfer layer mounting portion 27 a on the surface of the horn 20 so that at least a portion of the heat transfer layer 80 is arranged at a position facing the MMIC chip 14 . The surface side 82 of the heat transfer layer 80 is covered with the plating layer 28 while being attached to the heat transfer layer attachment portion 27a. The heat transfer layer 80 is in contact with the heat sink 40 via the plating layer 28 at the mating surfaces of the peripheral wall portion 21 of the horn 20 and the peripheral wall portion 42 of the heat sink 40 . The heat generated by the MMIC chip 14 is transmitted to the peripheral wall portion 42 of the heat sink 40 through the heat radiation path R3 composed of the heat transfer layer 80 and the plating layer 28, and is also transmitted from the heat sink 40 to the base 45 via the heat radiation sheet S2. . In this way, in addition to the heat radiation path R1 from the MMIC chip 14 in the thickness direction of the substrate 10, the heat radiation path R3 from the MMIC chip 14 through the heat transfer layer 80 and the plating layer 28 on the outer surface 27 of the horn 20 heats the MMIC chip 14. Temperature rise can be suppressed.

In order to improve the heat dissipation of the MMIC chip 14, it is effective to increase the installation area of the heat transfer layer 80, but this increases the weight of the device. Therefore, the heat transfer layer 80 is not limited to covering the entire MMIC chip 14, but is an upper portion facing the MMIC chip 14, as in the arrangement of the MMIC chip (electronic component) 14 and the heat transfer layer 80 shown in FIG. It suffices if it is installed so as to connect at least a part of the position and the peripheral wall portion 21 of the horn 20 . With this configuration, a heat dissipation path R3 (see FIG. 3) is formed through which the heat generated from the MMIC chip 14 is dissipated through the heat transfer layer 80, which is thicker and has excellent heat dissipation properties than in the case where the heat is dissipated only by the plating layer 28. can.

As a method for manufacturing the horn 20 integrally molded with the heat transfer layer 80, for example, it can be manufactured by insert molding as shown in FIG. As shown in FIG. 5, the method of manufacturing the horn 20 includes inserting a heat transfer layer 80 into a mold 70 for resin molding, filling the mold 70 with a resin material 81 while the mold is closed, and forming the horn 20. is integrally molded with the heat transfer layer 80 exposed to the heat transfer layer mounting portion 27a on the surface. After that, the plating layer 28 is formed on the surface side 82 of the heat transfer layer 80 removed from the mold 70 and the outer surface 27 of the horn 20 integrally formed with the heat transfer layer 80 . The plated layer 28 on the surface side 82 of the heat transfer layer 80 is formed continuously with the shield layer 29 of the waveguide 23 . By forming this continuous plating layer, a heat transfer path R2 to the shield layer 29 of the waveguide 23 is formed. Moreover, the manufacturing cost of a heat transfer layer having a thickness of about 100 μm is generally lower than the cost of forming a Cu plating having a thickness of about 10 μm. Assembling the horn 20 having the heat transfer layer 80 manufactured in this way, the substrate 10 provided with the separately manufactured antenna 13, etc., the lens 30, the housing 35, the cover 39, the radiator plate 40, the base 45, etc. to manufacture the radar device 1 of the first embodiment.

Further, as shown in FIG. 5, by forming the horn 20 integrally molded with the heat transfer layer 80 by a resin molding method using a mold 70, the work of assembling the heat transfer layer to the horn is omitted. Further cost reduction can be achieved. Also, the cost of a heat transfer layer with a thickness of about 100 μm is generally lower than the cost of forming Cu plating (shield layer 29) with a thickness of about 10 μm, and the thickness of the shield layer 29 of the waveguide is generally 0.1 μm. ~1 μm is sufficient. Therefore, in order to transfer the heat generated by the MMIC chip 14, the heat transfer layer 80 is partially used to form the heat dissipation path R3, and the overall thickness of the shield layer 29 is reduced to further reduce the cost. can be done.

Further, as shown in FIG. 5, by forming the horn 20 integrally molded with the heat transfer layer 80 by a resin molding method using a mold 70, the work of assembling the heat transfer layer 80 to the horn 20 is simplified. By omitting, further cost reduction can be achieved.

Alternatively, as in the radar device 1 shown in FIG. 6, the MMIC chip 14 may be coated with the heat transfer member A1, and the MMIC chip 14 may be connected to the heat dissipation path R3 via the heat transfer member A1. Note that the heat transfer member A1 is composed of a component containing a polymer material that has a heat dissipation effect, and an adhesive, grease, or the like can be used. As a result, even when a gap is formed between the MMIC chip 14 and the heat dissipation path R3, heat dissipation failure can be prevented by filling the gap with the heat transfer member A1.

Alternatively, the heat transfer layer 80 may completely cover the upper portion of the MMIC chip 14 and form the heat transfer path R2 together with the plating layer 28. FIG. As a result, the heat generated by the MMIC chip 14 can heat the shield layer 29 through the heat transfer path R2 in a shorter time, and dew condensation can be reliably prevented.

In the above-described first embodiment, the substrate 10 is provided with a plurality of antennas 13 and the horn 20 is provided with a plurality of waveguides 23. However, the substrate 10 is provided with a single antenna 13. , a single waveguide 23 may be formed in the horn 20 .

In the above-described first embodiment, the plating layer 28 is formed on the entire outer surface 27 of the horn 20, and the shield layer 29, the heat transfer path R2, and the heat dissipation path R3 are formed. Not limited. That is, the plated layer 28 may be partially formed on the outer surface 27 of the horn 20 to form the shield layer 29, the heat transfer path R2, and the heat dissipation path R3. At this time, the plating layer 28 may be formed at least in the portion where the heat transfer layer 80 is provided in the heat dissipation path R3. Conversely, the heat transfer layer 80 may be formed at the position where the plating layer 28 is formed in the heat dissipation path R3.

In addition, in the above-described first embodiment, after the heat transfer layer 80 is integrally formed with the horn 20, the plating layer 28 is provided on the surface side 82 of the horn 20 and the heat transfer layer 80, but this is not the only option. Alternatively, after the plating layer 28 is formed on the horn 20 , the heat transfer layer 80 may be provided on the surface of the plating layer 28 and exposed from the outer surface 27 of the horn 20 . The plating layer 28 may be omitted from the portion exposed from 27 .

Furthermore, in the above-described first embodiment, the case where the horn 20 and the heat transfer layer 80 are integrally molded is shown, but this is not limiting, and the horn 20 and the heat transfer layer 80 are separately formed and then combined. may

Next, effects of the radar device 1 of the first embodiment will be described with reference to FIGS. 2, 3, 7A and 7B. FIG. 7A is an explanatory diagram of a radio wave radiation state, a heat transfer path, and a heat dissipation path according to a comparative example, and FIG. 7B is an explanatory diagram of a radio wave radiation state by a plurality of antennas according to the comparative example. The radar device of the comparative example differs from the radar device of the present embodiment in that the outer surface 27 of the resin horn is not plated with metal and that the heat transfer layer 80 is not provided. .

First, with reference to FIG. 3 of the first embodiment and FIG. 7A of the comparative example, the directivity and intensity of radio waves of the radar device will be described.

As shown in FIG. 7A, in the radar device 50 according to the comparative example, when power is supplied from the MMIC chip 53 to the antenna 52, radio waves are radiated from the antenna 52 to the outside. A radio wave directed from the antenna 52 toward the inside of the waveguide 55 is guided through the waveguide 55 to the lens surface 57, converted into a plane wave by the lens surface 57, and used to detect obstacles. However, radio waves directed from the antenna 52 to the outside of the waveguide 55 go straight through the resin-made horn 54 and are emitted to the outside, and are not used for detecting obstacles. Therefore, although the weight of the horn 54 can be reduced, the radio wave utilization efficiency is lowered, and the directivity and strength of the radio wave are lowered.

On the other hand, as shown in FIG. 3, in the radar device 1 according to the first embodiment, a shield layer 29 is formed of a plated layer 28 on the tapered wall surface 26 of the horn 20 on which the waveguide 23 is formed. Shielding properties of the wave path 23 are ensured. Therefore, both the radio wave from the antenna 13 to the inside of the waveguide 23 and the radio wave from the antenna 13 to the outside of the waveguide 23 are guided to the lens surface 31 by the shield layer 29 of the horn 20 and converted into plane waves by the lens surface 31. used for obstacle detection. Therefore, the weight of the horn 20 can be reduced, the radio wave utilization efficiency is increased, the directivity and strength of the radio wave are improved, and the detection accuracy is improved.

Next, with reference to FIG. 3 of the first embodiment and FIG. 7A of the comparative example, a heat transfer path and a heat dissipation path of the radar system will be described.

As shown in FIG. 7A, in the radar device 50 according to the comparative example, when the air inside the device is warmed by the heat generated by the MMIC chip 53, dew condensation occurs on the tapered wall surface 58 of the horn 54 due to the temperature difference between the inside and the outside, and radio waves are emitted. It can get messy. Heat generated by the MMIC chip 53 is transmitted to the support base 61 of the heat sink 60 through the substrate 51 and the heat sink sheet S1, and further from the heat sink 60 to the base 62 through the heat sink sheet S2. However, it is difficult to effectively suppress the temperature rise of the MMIC chip 53 only with the heat radiation path R1 extending from the MMIC chip 53 in the thickness direction of the substrate 51 .

On the other hand, as shown in FIG. 3, in the radar device 1 according to the first embodiment, a heat transfer path R2 from the MMIC chip 14 to the shield layer 29 is formed on the outer surface 27 of the horn 20 . The heat transfer path R2 is formed by the plating layer 28 covering the outer surface 27 of the horn 20 from the contact portion 24 to the guide portion 25, and the plated layer 28 of the heat transfer path R2 and the shield layer 29 are formed at the tip portion of the guide portion 25. The plated layers 28 are continuous. Therefore, the heat generated by the MMIC chip 14 is transmitted to the shield layer 29 through the heat transfer path R2, and the shield layer 29 is heated to suppress the occurrence of dew condensation. In this way, the heat generated by the MMIC chip 14 is used to suppress the occurrence of dew condensation on the waveguide 23 .

At this time, the heat generated by the MMIC chip 14 is easily transferred to the plated layer 28 on the outer surface 27 of the horn 20, but since the resin-molded portion of the horn 20 has a low thermal conductivity, the resin inside the plated layer 28 on the outer surface 27 of the horn 20 is heated. It is difficult for heat to be transmitted to the molded part. Therefore, heat is intensively transferred from the MMIC chip 14 to the plated layer 28, which has a high thermal conductivity and a small heat capacity. can. Therefore, the shield layer 29 can be warmed immediately after the radar device 1 is activated, and the disturbance of radio waves due to dew condensation can be effectively suppressed. Furthermore, by providing the heat transfer layer 80 in addition to the plating layer 28, heat can be efficiently transferred to the shield layer 29, so that the occurrence of dew condensation in the waveguide can be further suppressed. .

Further, in the radar device 1 according to the first embodiment, a heat radiation path R3 is formed on the outer surface 27 of the horn 20 from the MMIC chip 14 toward the peripheral wall portion 21 of the horn 20 . The heat dissipation path R3 is formed by the plating layer 28 and the heat transfer layer 80 covering the outer surface 27 of the horn 20 from the contact portion 24 to the peripheral wall portion 21, and the peripheral wall portion 21 of the horn 20 and the peripheral wall portion 42 of the heat sink 40 are aligned. The plated layer 28 of the heat dissipation path R3 is in contact with the heat dissipation plate 40 on the surface. Therefore, the heat generated by the MMIC chip 14 is transferred to the peripheral wall portion 42 of the heat dissipation plate 40 through the heat dissipation path R3, and is transferred from the heat dissipation plate 40 to the base 45 via the heat dissipation sheet S2. Thus, in addition to the heat radiation path R1 from the MMIC chip 14 in the thickness direction of the substrate 10, the heat radiation path R3 from the MMIC chip 14 passing through the outer surface 27 of the horn 20 and the plated layer 28 and the heat transfer layer 80 also heats the MMIC chip 14. temperature rise can be suppressed.

Although the shield layer 29, the heat transfer path R2, and the heat dissipation path R3 are formed of the plated layer 28 of the same material here, the configuration is not limited to this. That is, the shield layer 29 is formed of a plated layer having a higher shielding property than the heat transfer path R2 and the heat dissipation path R3, and the heat transfer path R2 and the heat dissipation path R3 are formed of a plated layer having a higher thermal conductivity than the shield layer 29. may For example, nickel with high shielding properties may be used for the shield layer 29, and copper with high thermal conductivity may be used for the heat transfer path R2 and the heat dissipation path R3. In this case, a thickness of 0.021 μm or more is required to ensure shielding properties with nickel, and a thickness of 10 μm or more is necessary to ensure heat conductivity with copper.

Further, when forming the shield layer 29 and the heat transfer path R2 and the heat dissipation path R3 with the same plating layer 28, the plating layer of the heat transfer path R2 and the heat dissipation path R3 is thicker than the thickness of the plating layer 28 of the shield layer 29. The thickness of 28 may be formed large. For example, when the shield layer 29, the heat transfer path R2, and the heat dissipation path R3 are formed of a copper film, the shield layer 29 is formed of a copper film having a thickness of 0.24 μm or more, and the heat transfer path R2 and the heat dissipation path R3 are formed of a copper film having a thickness of 10 μm. It may be formed of a copper film having a thickness equal to or greater than the above thickness. As a result, the heat of the MMIC chip 14 can be easily transferred to the plated layer 28 by the thickness of the plated layer 28 of the heat transfer path R2 and the heat dissipation path R3. Moreover, the shield layer 29 may be formed with a multi-layer structure, for example, it may be formed with a two-layer structure of nickel with high shielding properties and copper with high thermal conductivity.

As described above, in the radar device 1 of the first embodiment, the plating layer 28 secures the shielding property in the waveguide 23, improves the directivity of the radio wave emitted from the waveguide 23, and increases the radio wave intensity. Increased. Moreover, by adopting the resin horn 20, the amount of metal used can be reduced, and the weight of the radar device 1 can be reduced. Furthermore, the heat transfer path R2 passing through the outer surface 27 of the horn 20 makes it possible to use the heat generated by the MMIC chip 14 to suppress the occurrence of dew condensation on the waveguide 23. FIG. Furthermore, the heat of the MMIC chip 14 is released to the heat sink 40 through the heat radiation path R3 passing through the outer surface 27 of the horn 20 formed by the plating layer 28 and the heat transfer layer 80, thereby suppressing the temperature rise of the MMIC chip 14. can.

Next, with reference to FIGS. 2 and 7B, radio wave interference of the radar device will be described.

As shown in FIG. 7B, a radar device 50 according to the comparative example has a plurality of waveguides 55 corresponding to a plurality of antennas 52, and radio waves are radiated from each antenna 52 at the same time. Radio waves directed from each antenna 52 toward the inside of each waveguide 55 are guided to the lens surface 57 through the waveguide 55, converted into plane waves by the lens surface 57, and used to detect obstacles. However, radio waves traveling from each antenna 52 to the outside of each waveguide 55 go straight through the resin-made horn 54 and enter the adjacent waveguide 55, causing radio wave interference. Therefore, the radio wave interference deteriorates the obstacle detection performance.

On the other hand, as shown in FIG. 2 , in the radar device 1 according to the first embodiment, even if radio waves are radiated from the plurality of antennas 13 at the same time, the shield layer 29 of the horn 20 prevents the radio waves from reaching the outside of the waveguide 23 . Leakage is prevented. Further, both the radio wave from the antenna 13 to the inside of the waveguide 23 and the radio wave from the antenna 13 to the outside of the waveguide 23 are guided to the lens surface 31 by the shield layer 29 of the horn 20 and converted into plane waves by the lens surface 31. used for obstacle detection. Therefore, radio wave interference does not occur between the plurality of waveguides 23, and obstacle detection performance does not deteriorate due to radio wave interference.

As described above, the radar device (1) according to this embodiment includes an antenna (13) on one main surface (11) of a substrate (10) and an electronic component (MMIC chip 14) connected to the antenna (13). ) are arranged, and a resin horn (20) is arranged so as to overlap an antenna (13) and an electronic component (MMIC chip 14), wherein the horn (20) has an antenna A waveguide (23) is formed at a position corresponding to (13) and becomes wider as it goes away from one main surface (11) of the substrate (10), and a plating layer (28) is formed on the outer surface (27) of the horn (20). ) is formed, and a shield layer (29) is formed by a plating layer (28) on the wall surface (26) forming the waveguide (23) of the horn (20), facing the substrate (10) of the horn (20). A heat transfer layer (80) extends from a position facing the electronic component (MMIC chip 14) of the horn (20) to the peripheral wall (21) of the horn (20) on the facing surface.

According to this configuration, the directivity and strength of radio waves emitted from the waveguide (23) are improved by the shield layer (29), and the use of the resin horn (20) reduces the amount of metal used. can be suppressed and the weight of the radar device (1) can be reduced. Furthermore, by providing a heat transfer layer (80) on the opposite surface of the horn (20) facing the substrate (10), the heat dissipation of the electronic component (MMIC chip 14) mounted on the substrate (10) can be improved at low cost. can be improved.

In the radar device (1) according to this embodiment, the antenna (13) is a plurality of antennas (13) provided on one main surface (11) of the substrate (10), and the waveguide (23) is a horn. A plurality of waveguides (23) formed at positions corresponding to the plurality of antennas (13) of (20).

According to this configuration, radio wave interference can be suppressed between the plurality of waveguides (23). In addition, by emitting radio waves from the plurality of waveguides (23) to the outside, it becomes possible to detect obstacles at different distances from the radar device (1).

In the radar device (1) according to this embodiment, the horn (20) has a heat transfer path (R2) from the electronic component (MMIC chip 14) to the shield layer (29). It is formed by a layer (28).

According to this configuration, the heat transfer path (R2) passing through the outer surface (27) of the horn (20) utilizes the heat generated by the electronic component (MMIC chip 14) to suppress the occurrence of dew condensation on the waveguide (23). be able to. The horn (20) is made of resin with low thermal conductivity, and the heat from the electronic component (MMIC chip 14) is intensively transferred to the metal with high thermal conductivity, so that the shield layer (29) can be warmed in a short time. can.

The radar device (1) according to this embodiment comprises a heat sink (40) or a base (45) provided on the other main surface (12) of the substrate (10), and the horn (20) has an electronic A heat dissipation path (R3) from the component (MMIC chip 14) to the heat dissipation plate (40) or base (45) is formed by the heat transfer layer (80) and the plating layer (28).

According to this configuration, the heat of the electronic component (MMIC chip 14) is released to the heat sink (40) or the base (45) through the heat radiation path (R3) passing through the outer surface (27) of the horn (20), thereby (MMIC chip 14) temperature rise can be suppressed.

In the radar device (1) according to this embodiment, the thickness of the heat transfer layer (80) is formed to be greater than the thickness of the plating layer (28).

According to this configuration, since the thickness of the heat transfer layer (80) is large, the heat of the electronic component (MMIC chip 14) can be effectively released to the plating layer (28).

In the radar device (1) according to this embodiment, the horn (20) is integrally formed with the heat transfer layer (80).

With this configuration, further cost reduction can be achieved by omitting the work of assembling the heat transfer layer (80) to the horn (20).

In the radar device (1) according to this embodiment, the heat transfer layer (80) or the plating layer (28) is made of metal containing at least one of silver, copper, gold, nickel, tin, aluminum and iron. be.

According to this configuration, the heat transfer layer (80) or the plated layer (28) can be formed from a metal having high thermal conductivity and shielding properties.

The manufacturing method of the radar device (1) according to the present embodiment comprises: a substrate (10) having an electronic component (MMIC chip 14) arranged on one main surface (11); 11), and a radiator plate (40) or base (45) arranged on the other main surface (12) of the substrate (10). In the manufacturing method, the horn (20) is formed in a state in which the heat transfer layer (80) is exposed by filling a resin (81) in a mold (70) in which the heat transfer layer (80) is installed. The surface of the horn (20) integrally molded with the heat transfer layer (80) is plated.

According to this configuration, the work of assembling the heat transfer layer (80) to the horn (20) is omitted, so that further cost reduction can be achieved. heat dissipation can be improved.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the invention described in the claims. Changes can be made. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with another configuration.

1 radar device 10 substrate 11 one main surface 12 the other main surface 13 antenna 14 MMIC chip (electronic component)
20 horn 23 waveguide 26 horn wall surface 27 horn outer surface 28 plating layer 29 shield layer 40 radiator plate R2 heat transfer path R3 heat dissipation path 70 mold 80 heat transfer layer 81 resin material 82 surface side A1 heat transfer member

Claims (6)

A radar device in which an antenna and an electronic component connected to the antenna are arranged on one main surface of a substrate, and a resin horn is arranged so as to overlap the antenna and the electronic component,
The horn is formed with a waveguide at a position corresponding to the antenna, the waveguide becoming wider as the distance from one main surface of the substrate increases,
A plating layer is formed on the outer surface of the horn,
A shield layer is formed by the plating layer on the wall surface forming the waveguide of the horn,
A heat transfer layer extends from a position of the horn facing the electronic component to a peripheral wall portion of the horn on a surface of the horn facing the substrate,
The radar device, wherein the horn is integrally formed with the heat transfer layer. The antennas are a plurality of antennas provided on one main surface of the substrate, and the waveguides are a plurality of waveguides formed at positions corresponding to the plurality of antennas of the horn. The radar device according to claim 1. 2. The radar device according to claim 1 , wherein the heat transfer path from the electronic component to the shield layer is formed in the horn by the heat transfer layer and the plating layer. A heat sink or base provided on the other main surface of the substrate,
2. The radar apparatus according to claim 1 , wherein the horn includes the heat transfer layer and the plated layer forming a heat dissipation path from the electronic component to the heat dissipation plate or the base. 2. The radar device according to claim 1 , wherein the thickness of said heat transfer layer is formed to be greater than the thickness of said plating layer. 2. The radar device according to claim 1, wherein the heat transfer layer or the plated layer is made of metal containing at least one of silver, copper, gold, nickel, tin, aluminum, and iron.

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