Antenna device

Abstract

This antenna device comprises a base (4b) that has a mounting unit (land (16a)), and a chip electronic component (capacitor chip (12)). The land (16a) has at least a pair of mounting terminals (16c) for mounting the capacitor chip (12). The base (4b) has uneven sections (20) formed at edge portions (4g) of an opening (4e). The uneven sections (20) are each configured by a recess section (21) and a protruding section (22) that respectively protrude from and are recessed into the edge portions (4g) of the opening (4e) in the direction in which the mounting terminals (16c) that form a pair are aligned. The protruding sections (22) demarcate mounting spaces at positions where at least a pair of terminals (12a) of the capacitor chip (12) face the mounting terminals (16c) that form a pair.

Description

Antenna device

[0001] The present invention relates to an antenna device on which a chip electronic component is mounted.

[0002] In recent years, keyless entry systems capable of transmitting and receiving radio signals when locking and unlocking doors of vehicles, houses, etc., have been put into practical use. To realize keyless entry systems, antenna devices such as low frequency (LF) transmitting antennas capable of transmitting and receiving radio signals are widely adopted.

[0003] For example, the antenna device disclosed in Patent Document 1 includes a base having a through opening, a coil, a terminal member, and a capacitor. The terminal member has a chip support piece that is partially exposed from the opening in the base. The capacitor is mounted on the chip support piece by reflow soldering. Furthermore, to prevent the capacitor from shifting position during reflow (to maintain physical and electrical connection with the mounting terminal), the terminal member itself is provided with multiple protrusions.

[0004] JP 2017-103549 A

[0005] However, in the antenna device disclosed in Patent Document 1, in order to provide a protrusion on the terminal member, it was necessary to select a material with appropriate plasticity and toughness, and the material itself also needed to be thick.

[0006] The present invention has been made in view of the above-mentioned problems, and has as its object to provide an antenna device that can suitably maintain physical and electrical connection with a mounting terminal.

[0007] According to the present invention, there is provided an antenna device comprising a base having an opening and a mounting portion within the opening, and a chip electronic component mounted on the mounting portion, wherein the mounting portion has at least a pair of mounting terminals for mounting the chip electronic component, the base has a concave-convex portion formed on the edge portion of the opening, the concave-convex portion being composed of a concave portion and a convex portion and protruding and recessed at the edge portion of the opening in the arrangement direction of the pair of mounting terminals, the convex portion defining a mounting space for the chip electronic component, and at least a pair of terminals of the chip electronic component defining the mounting space at a position facing the pair of mounting terminals.

[0008] According to the present invention, an antenna device can be provided in which a protrusion is provided on the base portion, thereby positioning a chip electronic component and suitably maintaining physical and electrical connection with the mounting terminal.

[0009] 2 is a perspective view of an antenna device; FIG. 2 is an enlarged view of a portion II in FIG. 1, and is a front view showing an opening; FIG. 3 is a front view showing an opening with a capacitor chip provided therein that is in a state where it is in contact with a protrusion; FIG. 4 is a schematic cross-sectional view showing the IV-IV cross section of FIG. 2; FIG. 5 is a front view showing an opening in a state where a fillet is formed between a terminal of the capacitor chip and a mounting terminal; FIG. 6 is a front view showing an opening with a protrusion according to a first modified example provided therein; and FIG. 7 is a schematic cross-sectional view corresponding to FIG. 4, showing a protrusion according to a second modified example. Detailed Description of the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are merely examples for facilitating understanding of the present invention and are not intended to limit the present invention. In other words, the shapes, dimensions, arrangements, etc. of the components described below may be changed or improved without departing from the spirit of the present invention, and the present invention naturally includes equivalents thereof. Furthermore, the various components of the present invention do not necessarily have to exist independently. It is acceptable for multiple components to be configured as a single component, for one component to be divided into multiple components, for one component to be part of another component, or for part of one component to overlap with part of another component, etc.

[0011] In addition, in all drawings, like elements are denoted by like reference numerals, and redundant explanations are omitted where appropriate. Furthermore, although the present specification may refer to an up-down direction, this is set for the sake of convenience in explaining the relative relationships between elements, and does not limit the directions when manufacturing or using the product according to the present invention.

[0012] <Overview of Antenna Device> First, an overview of the antenna device 1 will be described mainly with reference to Figures 1 and 2. Figure 1 is a perspective view of the antenna device 1, and Figure 2 is an enlarged view of part II in Figure 1, showing the opening 4e. Note that in Figure 2 and Figure 3 described below, the fillet 19 shown in Figure 5 is omitted.

[0013] The antenna device 1 includes a base 4b having mounting portions (lands 16a) within an opening 4e, and a chip electronic component (capacitor chip 12) mounted on the lands 16a. The lands 16a have at least a pair of mounting terminals 16c for mounting the capacitor chip 12. The base 4b has an uneven portion 20 formed on an edge portion 4g of the opening 4e. The uneven portion 20 is composed of a recessed portion 21 and a protruding portion 22, and protrudes and recesses at the edge portion 4g of the opening 4e in the direction in which the paired mounting terminals 16c are aligned.

[0014] The protrusions 22 define a mounting space for the capacitor chip 12, and define the mounting space at a position where at least one pair of terminals 12a of the capacitor chip 12 faces a pair of mounting terminals 16c. Specifically, the position where the pair of terminals 12a faces the pair of mounting terminals 16c may be a position where any portion of one of the pair of mounting terminals 16c contacts any portion of one of the pair of terminals 12a of the capacitor chip 12, and where any portion of the other of the pair of mounting terminals 16c contacts any portion of the other of the pair of terminals 12a of the capacitor chip 12.

[0015] 2, specifically, the uneven portions 20 are provided on the opposing surfaces of the edge portion 4g of the opening 4e that face each other in the arrangement direction of the pair of mounting terminals 16c. Note that in this specification, "facing" is not limited to facing by extending parallel to each other, but also includes facing at an angle of 0 degrees or more but less than ±90 degrees when the parallel state is defined as 0 degrees.

[0016] In the arrangement direction of the paired mounting terminals 16c, the recessed portions 21 are recessed farther from the center of the opening 4e than the protruding portions 22. In contrast, in the arrangement direction of the paired mounting terminals 16c, the protruding portions 22 protrude further toward the center of the opening 4e than the recessed portions 21. In addition to the capacitor chip 12 described in this embodiment, examples of chip electronic components include resistor chips.

[0017] According to the above configuration, the protrusions 22 provided on the base 4b allow each of the pair of terminals 12a provided on the chip electronic component (capacitor chip 12) to be suitably positioned opposite the corresponding pair of mounting terminals 16c. Furthermore, since the uneven portion 20 is provided on a part of the base 4b rather than on the mounting terminals 16c, the material of the mounting terminals 16c can be freely selected from among conductive materials, and the material can be made thinner, thereby reducing material costs.

[0018] [Overall Configuration] Next, we will explain the overall configuration of the antenna device 1. As shown in Fig. 1, the antenna device 1 mainly includes a long, plate-shaped core 3, a base 4 that holds the core 3, a coil 5 that is wound spirally around the periphery of the base 4 at intervals, and a capacitor chip 12.

[0019] The core 3 amplifies the magnetic field generated by the coil 5 and is housed in the base 4 (a bobbin 4a, which will be described later) with a portion exposed. The core 3 is formed long and has a flattened cross-sectional shape (rectangular) in a cross section perpendicular to the long direction.

[0020] Materials for the core 3 include those made of ceramics primarily composed of iron oxide (ferrite core), those made of amorphous alloys (amorphous core), those made by compressing and molding metal powder (dust core), and those made by electrically insulating multiple electromagnetic steel sheets and forming a laminated structure (laminated core).

[0021] The coil 5 is a main inductance element in the series resonant circuit of the antenna device 1. The coil 5 according to this embodiment is spirally wound at four intervals around the periphery of the base portion 4 (a bobbin 4a described later). Ends of the coil 5 are connected to the lead frame 16 shown in FIG.

[0022] The base portion 4 according to this embodiment is made of an insulating material such as resin, and insulates the core 3 housed therein from the coil 5 wound around the bobbin 4a, as shown in Fig. 1. The base portion 4 continuously comprises a bobbin 4a located in the center in the longitudinal direction and around which the coil 5 is wound spirally, and bases 4b formed on both sides of the bobbin 4a, each having an opening 4e on one side within which the capacitor chip 12 is attached.

[0023] [Opening] Next, the opening 4e provided in the base portion 4 will be described in detail. In the antenna device 1 according to this embodiment, the opening 4e is provided in the base 4b to expose the mounting terminals 16c (lands 16a) from the base 4b and to mount the capacitor chip 12. The opening 4e does not penetrate the base 4b in the thickness direction. In other words, the opening 4e is formed thinner than the surrounding area of ​​the base 4b, exposes the lands 16a, and forms a mounting space for the capacitor chip 12.

[0024] In this embodiment, the opening 4e is formed in a double rectangular shape in a plan view, and is formed so as to flare out in the depth direction toward the opening tip (the front side in the paper direction of FIG. 2). In other words, the edge portion 4g of the opening 4e is formed to be inclined with respect to the opening and a land 16a (described later) on the opposite side of the opening. In a plan view, a pair of lands 16a (described later) are provided on the bottom surface of the opening 4e.

[0025] [Unevenness] Next, the unevenness 20 that defines the mounting position of the capacitor chip 12 and ensures a formation area for the fillet 19 will be described with reference mainly to FIGS. 3 and 4 in addition to FIGS. 1 and 2. FIG. 3 is a front view showing the opening 4e provided therein with the capacitor chip 12 in a position where it is in contact with the protrusion 22. FIG. 4 is a schematic cross-sectional view showing the IV-IV cross section of FIG. 2. Note that in FIG. 4 and FIG. 7 described later, the cross section of the capacitor chip 12 is shown in a simplified form, and unlike FIGS. 2 and 3, the fillet 19 is shown.

[0026] 2 to 4, the concave-convex portion 20 is provided on each of the surfaces of the edge portion 4g of the opening 4e that face each other in the arrangement direction of the pair of mounting terminals 16c. Of the concave-convex portion 21 and the convex portion 22 that make up the concave-convex portion 20, the convex portion 22 functions as a positioning portion that determines the position of the capacitor chip 12.

[0027] In this specification, "convex and concave" are relative terms, and when only convex portions are formed on the side (more precisely, the surface) of the opening 4e in a plan view, the portion other than this convex portion is called a concave portion. Conversely, when only concave portions are formed on this side (more precisely, the surface), the portion other than this concave portion is called a convex portion. In other words, it is not the case that only one of the concave and convex portions is formed.

[0028] The concave-convex portion 20 may be provided on one of the opposing surfaces of the pair of mounting terminals 16c in the arrangement direction. Even in this case, the chip electronic component (capacitor chip 12) can be positioned on the side where the concave-convex portion 20 is provided, and an area for forming the fillet 19 shown in FIG. 5 can be secured.

[0029] However, by providing fillets 19 on both opposing surfaces, that is, on both sides, the capacitor chip 12 can be positioned on both sides in the direction of arrangement of the paired mounting terminals 16c. This makes it possible to ensure areas for forming fillets 19 on both sides of the capacitor chip 12, which is more preferable because it prevents a tombstone state (where one side is joined but the other is separated) caused by a tensile force generated from one side during reflow due to an uneven amount of solder.

[0030] In this embodiment, the protrusions 22 are disposed in the central portion of the mounting surface 16 e in the direction (width direction) perpendicular to the arrangement direction of the paired mounting terminals 16 c in a plan view of the opening 4 e. The "central portion of the mounting surface 16 e in the direction perpendicular to the arrangement direction of the paired mounting terminals 16 c" where the protrusions 22 are disposed refers to, for example, within an area that occupies 40 percent of the central portion of the entire length of the mounting surface 16 e in the perpendicular direction.

[0031] According to the above configuration, since the convex portion 22 is arranged in the central portion of the mounting surface 16e, fillets 19 can be formed on both sides of the convex portion 22 on the mounting surface 16e, thereby increasing the bonding strength between the terminal 12a of the capacitor chip 12 and the mounting terminal 16c.

[0032] 3, the pair of protrusions 22 are formed in the center of the mounting area in the width direction, and the width dimension of the capacitor chip 12 is larger than half of the opening 4e. With this configuration, no matter how much the capacitor chip 12 moves in the left-right direction (width direction), the upper edge of the capacitor chip 12 abuts against the protrusions 22, and the capacitor chip 12 is positioned by the protrusions 22.

[0033] However, the present invention is not limited to this configuration, and it is preferable that the protrusions 22 are provided on each of the opposing surfaces of the pair of mounting terminals 16c that face each other in the arrangement direction of the mounting terminals 16c, and the arrangement and number of the protrusions 22 can be set arbitrarily. However, by reducing the number of protrusions 22, a wide area for forming the fillet 19 can be secured, and the occurrence of solder cracks can be suppressed.

[0034] By forming the recess 21 at the edge 4g of the opening 4e, the fillet 19 is formed smoothly and continuously so as to become thinner in a skirt shape from the terminal 12a of the capacitor chip 12 toward the edge 4g of the opening 4e of the land 16a. By forming the fillet 19 in this way, stress concentration is reduced, making it less likely for solder cracks to occur.

[0035] The protrusion 22 is narrowed on the protruding side in a plan view relative to the opening 4e. In this embodiment, the protrusion 22 is narrowed on the protruding side because the protruding end is formed in a semicircular shape in a plan view relative to the opening 4e. However, the configuration is not limited to this as long as the protruding side is narrow, and the protrusion may be formed in a stepped shape. With the above configuration, the narrowed protrusion 22 allows the fillet 19 formed between the terminal 12a and the mounting terminal 16c of the chip electronic component (capacitor chip 12) to be wider in the width direction of the protrusion 22.

[0036] Furthermore, it is preferable that the protrusion 22 according to this embodiment is formed to gradually narrow on the protruding side in a plan view relative to the opening 4e. As described above, the protrusion 22 according to this embodiment has a semicircular portion protruding from the recess 21 in a plan view relative to the opening 4e, and is formed to smoothly narrow on the protruding side. The above-mentioned "gradually narrowing" means that the width is smoothly narrowed, and is not limited to a semicircular protrusion 22 in which the surface on the protruding side is formed to be curved.

[0037] The gradually narrowing convex portion 22 includes a convex portion 22 that is formed so as to be inclined so as to become narrower in the protruding direction of the convex portion 22 when viewed in a plane relative to the opening 4e, for example, a convex portion 22 that is formed in a trapezoidal shape.

[0038] According to the above configuration, the convex portion 22 gradually narrows on the protruding side, making it easier to form the fillet 19 formed between the terminal 12a and the mounting terminal 16c of the chip electronic component (capacitor chip 12) continuously along the convex portion 22.

[0039] 4, the upper surface 22a of the protrusion 22 (the surface opposite to the surface facing the mounting surface 16e) is perpendicular to the mounting surface 16e of the mounting terminal 16c and is inclined toward the center of the opening 4e within an imaginary plane including the direction in which the pair of mounting terminals 16c are aligned, so that the upper surface 22a approaches the mounting surface 16e. The "upper surface" refers to the surface opposite to the surface facing the mounting terminal 16c, and "upper" and "lower" are unrelated to the direction of gravity.

[0040] This configuration prevents the protrusion 22 from interfering with the placement of the chip electronic component (capacitor chip 12) toward the center of the opening 4 e. Specifically, the upper surface 22 a of the protrusion 22 is inclined downward so as to approach the mounting surface 16 e toward the center of the opening 4 e, as described above, so that the capacitor chip 12 can be oriented toward the center of the opening 4 e.

[0041] More specifically, even if the capacitor chip 12 is dropped onto the upper surface 22a of the convex portion 22, the capacitor chip 12 can slide along the upper surface 22a of the convex portion 22 due to the reaction force applied to the central side of the opening 4e from the convex portion 22 or due to the capacitor chip 12's own weight, and the capacitor chip 12 can be directed toward the central side of the opening 4e where the mounting terminals 16c are exposed.

[0042] 3, in a plan view of the opening 4e, the length W1 of the protrusion 22 is shorter than the length W2 of the mounting terminal 16c in a direction perpendicular to the arrangement direction of the pair of mounting terminals 16c. With the above configuration, the region of the fillet 19 provided between the terminal 12a of the chip electronic component (capacitor chip 12) and the mounting terminal 16c can be secured in a portion of the mounting terminal 16c that does not overlap with the protrusion 22.

[0043] [Mounting Portion] Next, the mounting portion (lands 16a and mounting terminals 16c) will be described with reference to Fig. 5 in addition to Fig. 3 and Fig. 4. Fig. 5 is a front view showing the opening 4e in a state where a fillet 19 is formed between the terminal 12a of the capacitor chip 12 and the mounting terminal 16c.

[0044] The lands 16a are part of the lead frame 16 and serve as mounting terminals 16c to which the terminals 12a of the capacitor chip 12 are soldered. Another part of the lead frame 16 is disposed inside the base 4, and the pair of lands 16a are exposed to the outside from the base 4.

[0045] 3, the length L1, which is the sum of the length of the protrusion 22 from the recess 21 into the mounting space and the longitudinal dimension of the chip electronic component (capacitor chip 12), is longer than the shortest length L2 from the recess 21 to the mounting terminal 16c that is distal to the gap 16d among the pair of mounting terminals 16c.

[0046] The "longitudinal dimension of the chip electronic component" here refers to the dimension from the end of the chip electronic component (capacitor chip 12) that abuts against the protrusion 22 to the distal end (lower end in FIG. 3) of the distal terminal 12a. The relationship between the lengths L1 and L2 described above applies not only to the relationship between the upper protrusion 22 and the lower mounting terminal 16c shown in FIG. 3, but also to the relationship between the lower protrusion 22 and the upper lower mounting terminal 16c.

[0047] In the above, the mounting terminal 16c on the "distal side" for determining the length L2 refers to the mounting terminal 16c on the side away from the recess 21 that was used as the reference when determining the length L1.

[0048] According to the above configuration, the chip electronic component (capacitor chip 12), the uneven portion 20 (the concave portion 21 and the convex portion 22), and the mounting terminal 16c have the above-mentioned length relationship, so that the pair of terminals 12a of the capacitor chip 12 positioned on the convex portion 22 is always positioned on the mounting terminal 16c.

[0049] The mounting terminal 16c is preferably a metal terminal that is insert-molded into the base 4b. According to the above configuration, the mounting terminal 16c is formed by insert molding when the base portion 4 is injection-molded, so that the mounting terminal 16c can be easily disposed within the opening 4e.

[0050] The mounting terminals 16c may be made of a thin film of conductive material printed on the base 4b. According to the above configuration, since the protrusions 22 are formed on the base 4b, it is not necessary to thicken a portion of the mounting terminals 16c for positioning purposes, and the mounting terminals 16c can be formed into a thin film by printing. For example, the mounting terminals 16c may be formed into a thin film by forming a land pattern including the mounting terminals 16c with a conductive paste or by plating the base 4b with resin, and the manufacturing method is not critical.

[0051] (First Modification) Next, a protrusion 32 according to a first modification will be described with reference to Fig. 6. Fig. 6 is a front view showing an opening 4e in which a protrusion 32 according to the first modification is provided.

[0052] In this example, the protrusion 22 has a rectangular protrusion at the protruding end that is narrower than the base end when viewed from above relative to the opening 4e, so that it is narrower on the protruding side. In other words, the protrusion 32 gradually narrows on the protruding side when viewed from above relative to the opening 4e. According to the above configuration, the narrowed protrusion 22 allows the fillet 19 formed between the terminal 12a and the mounting terminal 16c of the chip electronic component (capacitor chip 12) to be wider in the width direction of the protrusion 22. The protrusion 22 may have multiple steps.

[0053] (Second Modification) Next, a convex portion 42 according to a second modification will be described with reference to Fig. 7. Fig. 7 is a schematic cross-sectional view showing the convex portion 42 according to the second modification, corresponding to Fig. 4.

[0054] 7, the protrusion 42 according to this example is disposed at a distance from the mounting terminal 16c in the mounting direction (the direction perpendicular to the mounting surface 16e). Specifically, a gap 42a is formed between the protrusion 42 and the mounting terminal 16c. Solder penetrates into this gap 42a to form a fillet 19, and the protrusion 42 and the mounting terminal 16c are joined together via the fillet 19 in the gap 42a, forming an integral unit.

[0055] In this way, by having the protrusions 42 spaced apart from the mounting terminals 16c (protruding like eaves), the protrusions 42 spaced apart from the mounting terminals 16c can be prevented from interfering with the formation of the fillets 19. In particular, since the fillets 19 tend to be biased toward the mounting terminals 16c due to their own weight, providing the gaps 42a between the protrusions 42 and the mounting terminals 16c can effectively prevent the protrusions 42 from interfering with the formation of the fillets 19. If it is difficult to form the protrusions 42 when injection molding the base 4b, the protrusions 42 may be attached to another portion of the base 4b later.

[0056] The above embodiments and modifications encompass the following technical concepts: (1) An antenna device comprising: a base having an opening and a mounting portion within the opening; and a chip electronic component mounted on the mounting portion, wherein the mounting portion has at least a pair of mounting terminals for mounting the chip electronic component, the base having a concave-convex portion formed on an edge of the opening, the concave-convex portion being composed of a concave and a convex portion and protruding and recessed at the edge of the opening in the direction of arrangement of the pair of mounting terminals, the convex portion defining a mounting space for the chip electronic component, and at least one pair of terminals of the chip electronic component defining the mounting space at a position facing the pair of mounting terminals. (2) The pair of mounting terminals are arranged with a gap between them, and the sum of the length of the convex portion protruding from the concave into the mounting space and the longitudinal dimension of the chip electronic component is longer than the shortest length from the concave portion to the mounting terminal of the pair that is distal to the gap. (3) The antenna device according to (1) or (2), wherein the concave-convex portion is provided on each of the surfaces of the edge portion of the opening that face each other in the arrangement direction of the pair of mounting terminals. (4) The antenna device according to any one of (1) to (3), wherein the convex portion is formed to be narrower on the protruding side in a plan view of the opening. (5) The antenna device according to (4), wherein the convex portion is formed to be gradually narrower on the protruding side in a plan view of the opening. (6) The antenna device according to any one of (1) to (5), wherein the upper surface of the convex portion is perpendicular to the mounting surface of the mounting terminal and slopes downwardly toward the mounting surface toward the center of the opening in an imaginary plane that includes the arrangement direction of the pair of mounting terminals. (7) The antenna device according to any one of (1) to (6), wherein the convex portion is arranged spaced apart from the mounting terminal in the mounting direction. (8) The antenna device according to any one of (1) to (7), wherein the length of the protrusion is shorter than the length of the mounting terminal in a direction perpendicular to the arrangement direction of the pair of mounting terminals in a plan view of the opening.(9) The antenna device according to (8), wherein the protrusion is disposed in a central portion of the mounting surface in a direction perpendicular to an arrangement direction of the pair of mounting terminals in a plan view of the opening. (10) The antenna device according to any one of (1) to (9), wherein the mounting terminal is a metal terminal insert-molded into the base. (11) The antenna device according to any one of (1) to (10), wherein the mounting terminal is a thin-film conductive material printed on the base.

[0057] REFERENCE SIGNS LIST 1 Antenna device 3 Core 4 Base portion 4a Bobbin 4b Base 4e Opening 4g Edge portion 5 Coil 12 Capacitor chip (chip electronic component) 12a Terminal 16 Lead frame 16a Land (mounting portion) 16c Mounting terminal 16d Gap 16e Mounting surface 19 Fillet 20 Concave / convex portion 21 Concave portion 22, 32, 42 Convex portion 22a Upper surface 42a Gap

Claims

1. a base having an opening and a mounting portion within the opening; a chip electronic component mounted on the mounting portion, the mounting portion has at least a pair of mounting terminals for mounting the chip electronic component; the base has an uneven portion formed on an edge portion of the opening, The uneven portion is constituted by a concave portion and a convex portion, and protrudes and is recessed at an edge portion of the opening portion in an arrangement direction of the pair of mounting terminals, The antenna device is characterized in that the convex portion defines a mounting space for the chip electronic component, and at least a pair of terminals of the chip electronic component define the mounting space at a position opposite the pair of mounting terminals.

2. The pair of mounting terminals are arranged with a gap therebetween, 2. The antenna device according to claim 1, wherein the sum of the length of the protrusion from the recess into the mounting space and the longitudinal dimension of the chip electronic component is longer than the shortest length from the recess to the mounting terminal of the pair that is distal to the gap.

3. The antenna device according to claim 1 , wherein the uneven portion is provided on each of the surfaces of the edge portion of the opening portion that face each other in an arrangement direction of the pair of mounting terminals.

4. The antenna device according to claim 1 , wherein the protrusion is narrower on a protruding side in a plan view with respect to the opening.

5. The antenna device according to claim 4 , wherein the protrusion is formed so as to gradually narrow on the protruding side in a plan view with respect to the opening.

6. 4. The antenna device according to claim 1, wherein an upper surface of the convex portion is perpendicular to a mounting surface of the mounting terminal and, within an imaginary plane including an arrangement direction of the pair of mounting terminals, slopes downward so as to approach the mounting surface as it moves toward the center of the opening.

7. The antenna device according to claim 1 , wherein the protrusion is disposed away from the mounting terminal in a mounting direction.

8. The antenna device according to claim 1 , wherein a length of the protrusion is shorter than a length of the mounting terminal in a direction perpendicular to an arrangement direction of the pair of mounting terminals in a plan view of the opening.

9. The antenna device according to claim 8 , wherein the protrusion is disposed in a central portion of the mounting surface in a direction perpendicular to an arrangement direction of the pair of mounting terminals in a plan view of the opening.

10. The antenna device according to claim 1 , wherein the mounting terminal is a metal terminal that is insert-molded into the base.

11. The antenna device according to claim 1 , wherein the mounting terminal is a thin film of conductive material printed on the base.