Antenna device and method for manufacturing antenna device

Abstract

This method for manufacturing an antenna device (100) includes a melting step and a removal step. The antenna device (100) comprises: an antenna section (20) on which is wound a coil wire (40) having a coil core (47) covered by an insulation film (46); and a base (30) having a pad section (331) for which a portion of the coil wire (40) is soldered using a brazing filler material (50). In the melting step, a laser is radiated on the brazing filler material (50) supplied onto the pad section (331), melting the brazing filler material (50). In the removal step, the coil wire (40) is immersed in the melted brazing filler material (50) and a portion of the insulation film (46) is removed from the coil wire (40), and the coil wire (40) and the pad section (331) are joined by the brazing filler material (50).

Description

Antenna device and method for manufacturing the same

[0001] The present invention relates to an antenna device and a method for manufacturing the antenna device.

[0002] Some antenna devices have an antenna wound with a coil wire, and the coil wire is electrically connected to a circuit by soldering or the like. Regarding this type of technology, Patent Document 1 below discloses a method for manufacturing an RFID transponder having an antenna (4) made of a winding wire (2), the winding wire (2) being soldered to a solderable contact area (12). Specifically, as shown in FIG. 1 of Patent Document 1, a solderable contact area (12) is provided on the top surface of a semiconductor die (6). The contact area (12) is a metal plating made of a nickel-based alloy or the like. The end of the winding wire (2) is soldered to the contact area (12). Specifically, a laser is irradiated onto the area to be soldered, and the solder is melted by the laser, joining the winding wire (2) and the contact area (12).

[0003] Special Publication No. 2014-505309

[0004] Generally, the coil wire wound around an antenna is covered with an insulating coating. To solder the winding wire (2) to the contact area (12) as in Patent Document 1, it is necessary to strip the insulating coating from at least the portion of the winding wire (2) to be soldered in advance. Patent Document 1 discloses that the same laser device used to solder the winding wire (2) to the contact area (12) is used to strip the insulating coating before the soldering process. In other words, the insulating coating needs to be stripped before the soldering process. This poses a problem in the manufacture of antenna devices, increasing the number of manufacturing steps. This problem is not limited to soldering, but occurs in general with brazing using other metallic brazing materials.

[0005] The present invention has been made in view of the above-mentioned problems, and provides an antenna device with fewer manufacturing steps and a method for manufacturing the antenna device.

[0006] The method for manufacturing an antenna device of the present invention is a method for manufacturing an antenna device having an antenna section in which a coil wire whose coil core is coated with an insulating coating is wound, and a base having a pad section to which a portion of the coil wire is soldered with a solder material, and is characterized by including a melting process in which a laser is irradiated onto the solder material supplied onto the pad section to melt the solder material, and a removal process in which the coil wire is immersed in the molten solder material to remove a portion of the insulating coating from the coil wire and join the coil wire and the pad section with the solder material.

[0007] The antenna device of the present invention is an antenna device having an antenna section wound with a coil wire having a coil core and an insulating coating covering the coil core, and a base having a pad section, wherein the coil wire has an exposed section where the coil core is exposed from the insulating coating, the coil wire and the pad section are joined with a solder material, a portion of the coil wire is embedded in the solder material, and a first boundary line which is the boundary between an internal region of the circumferential surface of the coil wire which is embedded in the solder material and an external region which is outside the solder material, and a second boundary line which is the boundary between the exposed section and a coated portion of the coil wire which is coated with the insulating coating, are aligned with each other.

[0008] According to the manufacturing method of the present invention, the insulating coating immersed in the brazing material is removed from the coil wire by the heat of the molten brazing material, which allows the brazing process and the process of removing the insulating coating from the coil wire to be performed simultaneously, thereby reducing the number of steps required to manufacture the antenna device.

[0009] The above-mentioned objects, as well as other objects, features and advantages, will become more apparent from the preferred embodiments described below and the accompanying drawings.

[0010] 4 is a perspective view showing an example of an antenna device according to a first embodiment of the present invention. FIG. 1 is a top view of a circuit portion of the antenna device according to the first embodiment. FIG. 2 is a longitudinal cross-sectional view of the antenna device according to the first embodiment, taken along the dashed dotted line shown in FIG. 2, as viewed in the direction of arrow III-III. FIG. 2 is an enlarged view of X shown in FIG. 2 of the antenna device according to the first embodiment. FIG. 4 is a longitudinal cross-sectional view of the antenna device according to the first embodiment, taken along the dashed dotted line shown in FIG. 4, as viewed in the direction of arrow V-V. FIG. 1 is a perspective view of an antenna device for illustrating an example of a manufacturing method of the antenna device according to the first embodiment. FIG. 2 is a top view of an antenna device for illustrating an example of a manufacturing method of the antenna device according to the first embodiment. FIG. 7 is a longitudinal cross-sectional view of the antenna device according to the first embodiment, taken along the dashed dotted line shown in FIG. 7, as viewed in the direction of arrow IX-IX. FIG. 1 is a perspective view of an example of a pressing jig used in the manufacturing method of the antenna device according to the first embodiment. FIG. 1 is a perspective view of an example of installation of a pressing jig in the manufacturing method of the antenna device according to the first embodiment.

[0011] The various components of the antenna device of the present invention do not need to be independent entities, and it is acceptable for multiple components to be formed as a single member, for one component to be formed from multiple members, for one component to be part of another component, or for part of one component to overlap with part of another component. Furthermore, although the manufacturing method for the antenna device of the present invention may be described using multiple steps listed in order, the order of the steps does not limit the order or timing of performing the multiple steps. Therefore, when implementing the manufacturing method for the antenna device of the present invention, the order of the multiple steps may be changed as long as it does not cause any problems in terms of the content, and some or all of the timing of performing the multiple steps may overlap with each other.

[0012] An embodiment of the present invention will be described below with reference to the drawings. In each drawing, corresponding components are designated by the same reference numerals, and redundant description will be omitted where appropriate. In this embodiment, the front, rear, left, right, top, and bottom directions will be defined as shown in the drawings. Furthermore, the front end of the base 30, the antenna unit 20, or the coil wire 40 may be referred to as the front end, and the rear end thereof may be referred to as the rear end. The left-right direction may be referred to as the width direction, and the top-bottom direction may be referred to as the height direction. The direction from the center line of the base to the left or right in the left-right direction is referred to as the outward or outward direction, and the direction from the left or right toward the center line of the base is referred to as the inward or inward direction. Furthermore, a direction perpendicular to the top-bottom direction, i.e., the left-right direction and the front-back direction, may be collectively referred to as the horizontal direction. However, these definitions are provided for convenience in order to easily explain the relative relationships between the components, and do not limit the orientation of a product embodying the present invention during manufacture or use. Furthermore, the term "plane" as used herein refers to a shape that is physically formed with a flat surface as the target, and naturally does not necessarily have to be a perfect geometric plane.

[0013] First Embodiment (Outline of Antenna Device) FIG. 1 is a perspective view showing an example of an antenna device 100 according to a first embodiment of the present invention.

[0014] First, an overview of the antenna device 100 of this embodiment will be described. The antenna device 100 has an antenna section 20 and a base (circuit section 33) having a pad section 331. The antenna section 20 is wound with a coil wire 40 having a coil core 47 and an insulating coating 46 that covers the coil core 47. The coil wire 40 and the pad section 331 are joined with a brazing material 50.

[0015] Next, details of the antenna device 100 of this embodiment will be described with reference to FIGS. 1 to 5 . The antenna device 100 can be used in a small, portable communication system, such as a transceiver / receiver for a keyless entry system, or as an RFID transponder for identifying an item such as a commodity. For example, the antenna unit 20 functions as an antenna for transmitting and receiving radio waves within the antenna device 100. In this embodiment, the antenna unit 20 has a winding core 21, and a coil wire 40 is wound around the winding core 21. As shown in FIG. 1 , both ends of the coil wire 40 are located on the base 30 side (rear end side) of the winding core 21. Furthermore, the coil wire 40 (coil portion 49) is wound around the winding core 21 in the axial direction. In other words, the coil wire 40 is not wound around a portion of the front end of the winding core 21. Note that in the coil portion 49 shown in FIG. 1 , each individual strand of the coil wire 40 wound around the winding core 21 is omitted from the illustration. This also applies to FIGS. 3 , 6 , 7 , 9 , and 11 . The antenna unit 20 is not limited to the shape of this embodiment, and may have various shapes that function as an antenna. For example, the antenna unit 20 may be an air-core coil in which the inside of the coil unit 49 is hollow without using a winding core 21. The coil wire 40 may also be wound so as to be arranged in a circular shape on a plane. Both ends of the coil wire 40 are drawn out toward the base 30.

[0016] The coil wire 40 is a conductive wire. In this embodiment, the coil wire 40 is formed by covering a coil core 47 (see FIG. 4) made of a conductive metal such as copper with an insulating coating 46 (see FIG. 4). Examples of materials for the insulating coating 46 include resins such as polyurethane and polyimide. In this embodiment, the winding core 21 is inserted into a winding core insertion hole 316 (see FIG. 3) provided on the front end side of the base 30 (described later) and fixed to the base 30. As shown in FIG. 3, a chamfered portion 316a is provided at the opening of the winding core insertion hole 316 to facilitate insertion of the winding core 21 into the winding core insertion hole 316. The end face (the surface facing the rear end) of the winding core 21 is in contact with the bottom face (the surface facing the rear end) of the winding core insertion hole 316.

[0017] The base 30 (circuit unit 33) is a member for arranging a circuit main body 333 to which the coil wires 40a, 40b drawn out from the coil unit 49 are connected. In addition to the circuit unit 33, the base 30 may include a wire placement unit 31 used in a manufacturing method of the antenna device 100, which will be described later. Hereinafter, the circuit unit 33 may be referred to as the base 30, and the circuit unit 33 and the wire placement unit 31 may be collectively referred to as the base 30. In this embodiment, as shown in FIG. 1 , the circuit unit 33 has a cylindrical shape with a substantially semicircular bottom surface. The semicircular surface corresponding to the bottom surface of the cylinder faces the front-rear direction, the flat portion of the side surface of the cylinder (top surface 33a) faces upward, and the curved peripheral surface of the side surface of the cylinder faces downward. The shape of the circuit unit 33 is not limited to a cylinder with a semicircular bottom surface, and may be a flat plate, a rectangular pillar, a cylinder, or the like. In this embodiment, the upper surface 33a of the circuit unit 33 is provided with a mounting hole 334 (see FIGS. 3 and 8 ) recessed downward. In this embodiment, as shown in FIG. 3 , the mounting hole 334 is open at the top and rear end. The mounting hole 334 may also be open only at the top. The bottom of the mounting hole 334 has a size and shape sufficient for disposing the circuit main body 333 (described later). Specifically, in this embodiment, the mounting hole 334 also has a rectangular shape elongated in the front-rear direction to accommodate the rectangular circuit main body 333 elongated in the front-rear direction. Furthermore, the width and front-rear lengths of the mounting hole 334 are equal to or greater than the width and front-rear lengths of the circuit main body 333, respectively. In this embodiment, the width and front-rear lengths of the mounting hole 334 are greater than the width and front-rear lengths of the circuit main body 333, respectively. As shown in FIG. 2 , gaps exist between the circuit unit 33 and the circuit main body 333 at the front end, left side, and right side of the circuit main body 333. The circuit main body 333 is housed within the mounting hole 334. Being housed means that a part or all of the circuit main body 333 is disposed within the installation hole 334. In this embodiment, as will be described later, the upper surface 333a of the circuit main body 333 is lower than the upper surface 33a of the circuit part 33. That is, as shown in FIG. 3 , the entire circuit main body 333 is housed within the installation hole 334, but this is not limiting.The upper part of the circuit main body 333 may be located above the upper surface 33a of the circuit section 33. Alternatively, the circuit section 33 may not be provided with the mounting hole 334, and the circuit main body 333 may be disposed on the upper surface 33a of the circuit section 33.

[0018] The circuit body 333 is a component having pad portions 331 (see FIGS. 2 and 3 ) described below and connected to the coil wire 40, and is a circuit board on which semiconductor components and the like are mounted. The circuit board may be coated with resin or the like and may be housed, for example, inside a hollow component. In this embodiment, the circuit body 333 and the circuit section 33 on which the circuit body 333 is installed are separate components, but this is not limited thereto. The circuit body 333 and the circuit section 33 may be combined into a single component. Pad portions 331 are disposed on the upper surface 333 a of the circuit body 333. The pad portions 331 are portions to which a brazing filler metal 50 for brazing the coil wire 40 is supplied. Specifically, the pad portions 331 are portions plated with a thin film of a conductive metal such as copper or nickel. The pad portions 331 are connected to components constituting a circuit, such as a semiconductor substrate, and the coil wire 40 and the components constituting the circuit are electrically connected via the pad portions 331. It is preferable that the thickness (length in the height direction) of the pad portion 331 is smaller than the base height h2 (height to the upper surface 33a of the circuit portion 33 based on the upper surface 333a of the circuit main body 333) described below.

[0019] As shown in FIGS. 2 and 4 , in this embodiment, two pads 331 are provided at two locations on the top surface 333a of the circuit body 333. This is to bond both ends of the coil wire 40 to the respective pads 331. More specifically, in this embodiment, the pads 331 are located at two locations on the left and right sides of the rear end of the top surface 333a of the circuit body 333. The left and right pads 331 are located at positions symmetrical with respect to the center line of the circuit body 333 in the left-right direction and have symmetrical shapes. In this embodiment, both ends of the coil wire 40 are bonded to the pair of pads 331 provided on the base 30 with brazing material 50. Each of the pair of pads 331 is formed in a substantially rectangular shape with the longitudinal direction as the longitudinal direction. Furthermore, each of the rectangles has one of the inner corners of the pair of pads 331 chamfered to form a hypotenuse 331a (see FIG. 4 ). Specifically, the corner located on the inner side and the front end of the rectangle is chamfered. That is, the pad portion 331 has a pentagonal shape. The oblique side 331a is aligned with the extension direction of the coil wire 40. Here, the extension direction of the coil wire 40 is the axial direction of the coil wire 40. The expression "the extension direction of the coil wire 40 is aligned with the oblique side 331a" means that the extension direction of the coil wire 40 and the oblique side 331a are preferably approximately parallel, and that the acute angle between the extension direction of the coil wire 40 and the oblique side 331a is at least 45 degrees or less.

[0020] The coil wire 40 extending from the antenna unit 20 is disposed on the base 30 and joined to the pad unit 331. As shown in FIG. 1 , the corners at the boundaries between the side surface and the top surface 33a at the front end of the base 30 are chamfered to form inclined surfaces 33c. A pair of guide units 335 are provided at the front end of the base 30, spaced apart in the left-right direction and protruding beyond the top surface 33a of the circuit unit 33. As shown in FIG. 2 , the guide units 335 are disposed outward of the pair of pad units 331. The guide units 335 are generally rectangular and elongated in the front-rear direction, and the corners at the boundaries between the side surface at the rear end and the outer side are rounded. That is, the outer surface 335a (see FIG. 2 ) disposed outward of the guide units 335 has a partially curved circumferential surface. As shown in FIGS. 1 and 2 , the coil wire 40 extending toward the base 30 is disposed along the inclined surfaces 33c and the outer surfaces 335a of the guide units 335. Furthermore, the coil wire 40 is arranged along the upper surface 33a of the circuit portion 33 and the outer surface 335a of the guide portion 335. That is, the coil wire 40 is bent along the curved circumferential surface that is part of the outer surface 335a. One end of the coil wire 40 is brazed to the pad portion 331 that is arranged inward of the guide portion 335. Furthermore, as shown in Figures 2 and 4, in this embodiment, one end of the coil wire 40 partially protrudes from the brazing material 50 toward the rear end.

[0021] Examples of the brazing material 50 used to braze the coil wire 40 to the pad portion 331 include metal brazing materials such as solder and gold brazing. The brazing material 50 melts in a melting step described below, and the molten brazing material 50 comes into contact with the coil core 47 of the coil wire 40 and the pad portion 331 to form an alloy layer between the coil core 47 or the pad portion 331. The following description will be given assuming that the brazing material 50 is solder 50.

[0022] A portion of the coil wire 40 is embedded in the brazing material 50 (solder 50). Here, "a portion of the coil wire 40 is embedded in the solder 50" does not necessarily mean that the solder 50 covers the entire radial direction of the coil wire 40, and that the entire coil wire 40 is wrapped in the solder 50 in a partial length region of the coil wire 40, as in the solder 50a in FIGS. 4 and 5. For example, as in the solder 50b illustrated in FIGS. 4 and 5, there may not be a portion where the entire radial direction of the coil wire 40 is covered with the solder 50, and a portion of the radial direction of the coil wire 40 may be covered with the solder 50 while another portion of the radial direction is not covered with the solder 50. In other words, only a portion of the radial direction may be an outer region, as described below, and the other portion of the radial direction may be an inner region, as described below. Preferably, at a certain point on the coil wire 40, more than half of the circumferential length of the coil wire 40, more preferably three-quarters or more of the circumferential length, is covered with the solder 50. Here, the radial direction refers to a direction perpendicular to the axis of the coil wire 40, that is, a direction extending radially from the axis of the coil wire 40 toward the circumferential surface.

[0023] (Method for Manufacturing Antenna Device) Next, a method for manufacturing the antenna device 100 of this embodiment (hereinafter, sometimes referred to as the present method) will be described.

[0024] First, an overview of this method will be described. The antenna device 100 manufactured by this method includes an antenna section 20 wound with a coil wire 40 having a coil core 47 coated with an insulating coating 46, as described above, and a base 30 having a pad section 331 to which a portion of the coil wire 40 is brazed with a brazing material 50. This method includes a melting step and a removing step. In the melting step, a laser is irradiated onto the brazing material 50 supplied onto the pad section 331, melting the brazing material 50. In the removing step, the coil wire 40 is immersed in the molten brazing material 50, removing a portion of the insulating coating 46 from the coil wire 40, and the coil wire 40 and the pad section 331 are joined by the brazing material 50. Furthermore, in this method according to the present embodiment, a wire placement step is performed before the melting step and the removing step, and a cutting step is performed after the melting step and the removing step, as described below.

[0025] First, the base 30 used in this method will be described. In this method, the base 30 includes a circuit section 33 and a wire placement section 31, as shown in FIG. 6 . The wire placement section 31 is a portion of the base 30 for fixing the end of the coil wire 40. In this embodiment, the wire placement section 31 is a plate-like member elongated in the front-rear direction. That is, the wire placement section 31 extends in the front-rear direction. The main surface of the plate-like portion (flat section 315) of the wire placement section 31 faces the up-down direction. The shape of the wire placement section 31 is not limited to a flat plate and may be another shape, such as a pillar. Furthermore, the wire placement section 31 is located opposite the antenna section 20 in the circuit section 33, i.e., on the rear end side of the circuit section 33. In this embodiment, the wire placement section 31 is integrally formed with the circuit section 33. Furthermore, as shown in FIG. 9 , the upper surface 315 a of the flat section 315 is located below the upper surface 33 a of the circuit section 33. The base 30 (wire placement section 31) has a wire fixing section 312 for fixing the coil wire 40. The wire fixing section 312 is a portion to which an end of the coil wire 40 is fixed. In this embodiment, the wire fixing section 312 is a square prism that protrudes upward from the upper surface 315a of the flat plate section 315 at the rear end side. As described below, the coil wire 40 can be fixed by entwining the coil wire 40 around the protruding square prism. The coil wire 40 is not limited to a shape that protrudes upward, and may have any shape or function for fixing one end of the coil wire 40, such as a protrusion in the left-right direction, toward the rear end, or downward, or a hook shape. In addition, a rectangular hole 314 (see FIG. 7 ) that is elongated in the front-rear direction is provided between the support section 311 of the flat plate section 315 and the wire fixing section 312.

[0026] Next, this method will be described in detail, step by step, using FIGS. 6 to 11 . In this embodiment, solder 50 is applied to the surface of the pad portion 331 before the wire placement process described below. Specifically, as shown in FIG. 8 , the solder 50 is formed in a mountain-like shape having a slope 51 that slopes downward from the center of the pad portion 331 toward the periphery of the pad portion 331. The solder 50 contacts substantially the entire surface of the pad portion 331. The slope 51 of the solder 50 is arched upward, giving the entire solder 50 a dome-like shape. The solder 50 is cooled and solidified. At this time, the distance from the surface of the pad portion 331 to the highest point (vertex 52) of the solder 50 (thickness of the solder 50) is greater than the base height h2 (see FIG. 9 ), described below, and is preferably equal to or greater than the wire diameter of the coil wire 40.

[0027] Next, a wire placement process is performed in which an end of the coil wire 40 is placed on the base 30. In the wire placement process, one end (fixing portion 43) of the coil wire 40 is fixed to the wire fixing portion 312, and a portion of the coil wire 40 (on-pad portion placement portion 42) is placed on the brazing material 50 provided on the surface of the pad portion 331. Specifically, as shown in FIGS. 6 and 7 , one end of the coil wire 40 is pulled out from the antenna portion 20 around which the coil wire 40 is wound, and pulled out toward the circuit portion 33. As described above, the pulled-out coil wire 40 is placed along the inclined surface 33c, the upper surface 33a of the circuit portion 33, and the outer surface 335a of the guide portion 335. As the coil wire 40 moves along the rounded surface of the outer surface 335a of the guide portion 335, the pulling direction of the coil wire 40 is turned inward. As a result, the coil wire 40 is pulled out toward the pad portion 331. As shown in FIG. 7 , a partial length region (the on-pad portion placement portion 42) of the coil wire 40 is placed on the pad portion 331. Here, "a partial length region of the coil wire 40 being placed on the pad portion 331" means that a portion of the coil wire 40 overlaps a portion of the pad portion 331 when viewed from the height direction. It is preferable that a portion of the on-pad portion placement portion 42 is placed outward from the vertex 52 (see FIG. 8 ). In this embodiment, as shown in FIG. 8 , a portion of the on-pad portion placement portion 42 is placed above the pad portion 331 and does not contact the surface of the pad portion 331. Furthermore, the solder 50 and the on-pad portion placement portion 42 may or may not contact each other. As shown in FIG. 6 , when the on-pad portion placement portion 42 is placed on the pad portion 331, the end of the coil wire 40 is bound and fixed to the wire fixing portion 312. At this time, sufficient tension is applied to the coil wire 40 so that the coil wire 40, which is placed above the base 30, does not slacken.

[0028] In this embodiment, the base 30 has a support portion 311 against which the coil wire 40 is pressed to change the pull-out direction of the coil wire 40. During the wire placement process, as shown in FIG. 7 , a bent portion 45 located between a portion (on-pad portion placement portion 42) of the coil wire 40 and one end (fixed portion 43) of the coil wire 40 is pressed against the support portion 311 of the base 30 and bent. The bent portion 45 is a partial length region of the coil wire 40 between the on-pad portion placement portion 42 and the fixed portion 43. More specifically, the bent portion 45 is a length region of the coil wire 40 that is curved in contact with the support portion 311 and a length region adjacent to the region. The support portion 311 is a member that holds the coil wire 40 to maintain the pull-out direction of the coil wire 40. As shown in FIG. 6 , the support portion 311 is exemplified by a cylindrical protrusion that protrudes upward from an upper surface 315 a of the flat plate portion 315. As described below, the coil wire 40 is pressed inward against the support portion 311, thereby maintaining the pull-out direction of the coil wire 40 pulled out from the guide portion 335 at a predetermined angle. The support portion 311 may be a protruding portion in the shape of a rectangular pillar or a column with a semicircular bottom. The support portion 311 may also be a wall portion protruding from the base 30 and having a peripheral or flat surface with which the coil wire 40 contacts. The shape of the support portion 311 is not limited to the above-described shape as long as it has a structure for maintaining the pull-out direction of the coil wire 40. In this embodiment, the support portion 311 is disposed between the pad portion 331 and the wire fixing portion 312. In other words, the support portion 311 is disposed between the on-pad portion arrangement portion 42 and the fixing portion 43 when viewed in the height direction. Due to this arrangement, the bent portion 45 between the on-pad portion arrangement portion 42 and the fixing portion 43 is pressed against the side surface of the support portion 311 and bent. Specifically, a portion of the bent portion 45 is disposed along the peripheral surface of the support portion 311 and is curved. At this time, the coil wire 40 is pressed against the side surface of the support portion 311. More specifically, the coil wire 40 is pressed against the side surface of the support portion 311 on the side opposite in the left-right direction to the side where the coil wire 40 is pulled out from the coil portion 49. For example, as shown in Figure 7, the coil wire 40b (see Figure 1) pulled out from the coil portion 49 to the base 30 on the right side is pressed against the peripheral surface on the left side of the support portion 311.One end (fixing portion 43) of the coil wire 40 bent at the bending portion 45 is wound around the wire fixing portion 312 of the base 30 as described above.

[0029] In this embodiment, both ends of the coil wire 40 are disposed on the base 30 as described above. Furthermore, both ends of the coil wire 40 intersect above the base 30 as viewed in the height direction. Specifically, the pressure applying portions 44, 44 intersect above the pressure jig installation hole 313 as viewed in the height direction. The pressure applying portions 44 may or may not be in contact with each other. That is, the pressure applying portions 44 may be twisted relative to each other. By having portions of the coil wire 40 intersect at a single point as viewed in the height direction, it becomes easy to position the wire straddling portions 220 on both ends of the coil wire 40 when positioning the pressure jig 200, as described below. The pressure applying portions 44 of the two coil wires 40a, 40b overlap in the height direction at the intersection point described above. At the intersection point, the coil wire 40a may be located above or below the coil wire 40b. 8 and 9, the overlapping of the pressure applying portion 44 of the coil wire 40a and the pressure applying portion 44 of the coil wire 40b is not shown.

[0030] By pressing a portion of the coil wire 40 against the support portion 311 in this manner, the coil wire 40 pulled out from the antenna portion 20 can be pulled in any direction and positioned on the pad portion 331. Specifically, by changing the position of the support portion 311 in the front-rear direction or by changing the width (length in the left-right direction) of the support portion 311, the coil wire 40 can be adjusted to pass through any position. For example, by positioning the support portion 311 closer to the front end or by increasing the width of the support portion 311, the coil wire 40 is pulled out at a larger angle with respect to the front-rear direction, and the coil wire 40 is positioned further inward above the circuit main body 333. In this embodiment, the distance between the pad portion 331 and the support portion 311 is less than half the distance between the pad portion 331 and the wire fixing portion 312. Furthermore, the width of the support portion 311 (the diameter of the bottom surface if the support portion 311 is cylindrical) is greater than the width of the wire fixing portion 312.

[0031] In the wire placement process, when the coil wire 40 is placed on the base 30, the pressure applying unit 44 applies pressure toward the base 30, pressing the coil wire 40 against the brazing material 50 (solder 50). The pressure applying unit 44 is a partial length region between one end (fixed portion 43) of the coil wire 40 and a portion (on-pad portion placement portion 42). More specifically, the pressure applying unit 44 is a partial length region between the length region of the coil wire 40 that contacts the support portion 311 (part or all of the bent portion 45) and the on-pad portion placement portion 42, and is a partial length region that is positioned above a pressure jig installation hole 313 (described later). The direction in which the pressure applying unit 44 approaches the base 30 refers to the direction toward the pressure jig installation hole 313 if the base 30 has a hollow portion such as the pressure jig installation hole 313. In this embodiment, the pressure applying unit 44 applies pressure downward. As a result, the coil wire 40 contacts the solder 50 while exerting a resistance force against the solder 50. As will be described later, the coil wire 40 exerts downward, inward and forward resistance on the slope 51 of the solder 50 .

[0032] In this embodiment, a pressure jig 200 is used to apply pressure to the pressure member 44. As shown in FIG. 10 , the pressure jig 200 has an inverted U-shape overall. The pressure jig 200 has a rod portion 230. Arms 210 extend from both ends of the rod portion 230, and weight portions 211 are provided at the lower ends of the arms 210. In this embodiment, the rod portion 230 and the arms 210 are flat plate-like, and the weight portions 211 are generally cubic in shape. A wire-straddling portion 220 is provided at the center of the rod portion 230 in the extension direction. The wire-straddling portion 220 directly applies pressure to a portion of the coil wire 40 (pressure member 44) and has a pair of claws 221 spaced apart in the extension direction of the rod portion 230. The claws 221 protrude from the opposite side (lower side) of the rod portion 230. The shape of the pressure jig 200 is not limited to the above-described shape and may be any shape that can apply pressure to the coil wire 40.

[0033] As shown in FIG. 11 , the pressure jig 200 is disposed so as to straddle the wire placement portion 31. The pressure member 44 is disposed between a pair of claws 221, and the wire-straddling portion 220 straddles and contacts the pressure member 44. Specifically, the wire-straddling portion 220 straddles the pressure member 44 at a portion of the pressure member 44 where both ends of the coil wire 40 are close to each other or where they intersect, as viewed from the height direction. The pressure jig 200 disposed on the pressure member 44 sinks downward due to its own weight. At this time, the sunken wire-straddling portion 220 may be disposed within the pressure jig installation hole 313, and further, the lower surface of the rod portion 230 may or may not contact the upper surface of the flat portion 315. The weight of the pressure jig 200 is transmitted to the pressure member 44, which is in contact with the wire-straddling portion 220, thereby pressing the pressure member 44 downward. At this time, the pressing portion 44 is held between the pair of claws 221, 221, so that the pressing jig 200 is stably positioned on the coil wire 40. Furthermore, the distance between the pair of inner end surfaces 212 (see FIG. 10 ) of the pressing jig 200 is equal to or greater than the width of the flat plate portion 315. Preferably, the distance between the inner end surfaces 212 of the pressing jig 200 is equal to the width of the flat plate portion 315, so that when the pressing jig 200 is placed across the coil wire 40, the outer end surface 315 b of the flat plate portion 315 comes into contact with the inner end surface 212 of the pressing jig 200. This makes it easy to position the pressing jig 200 when it is placed across the wire placement portion 31, and also effectively prevents the pressing jig 200 from shifting when placed across the wire placement portion 31.

[0034] By applying pressure to the base 30 with the pressure member 44, the coil wire 40 bends toward the base 30, i.e., downward. This causes the over-pad portion 42 to approach the pad 331 and contact the solder 50 previously deposited on the pad 331 while being pressed against it. More specifically, as shown in FIG. 8 , the coil wire 40 is pressed against the slope 51 of the brazing filler metal 50 (solder 50). Specifically, the coil wire 40 is pressed against the slope 51 located outward from the peak 52 of the mountain-shaped deposited solder 50. More specifically, when viewed from above as shown in FIG. 7 , the coil wire 40, including the over-pad portion 42, is slightly curved and pressed outward at the portion that is pressed against the solder 50. Furthermore, a portion of the coil wire 40, including the over-pad portion 42, is disposed obliquely relative to the front end direction when viewed from above as shown in FIG. 7 . Therefore, the coil wire 40, including the on-pad portion disposition portion 42, is also expanded toward the rear end at the portion that is pressed against the solder 50. That is, when viewed from above as shown in FIG. 7, the on-pad portion disposition portion 42 is bent outward and toward the rear end along the slope of the solder 50. To summarize the above, the coil wire 40 applies not only a downward resistance to the solder 50, but also an inward resistance toward the front end. In other words, the coil wire 40 applies a resistance (resistance force T (see FIG. 8)) toward the center of the pad portion 331 to the slope 51 of the solder 50 while being pressed against the center of the pad portion 331. By pressing the coil wire 40 against the slope 51 of the solder 50 in this way, the direction of pressure of the coil wire 40 against the solder 50 can be controlled consistently. Furthermore, since the coil wire 40 does not contact the apex 52 of the solder 50 but contacts the slope 51 of the solder 50, the coil wire 40 is prevented from accidentally shifting left and right or front and rear on the solder 50.

[0035] As shown in FIG. 9 , the upper surface 333a of the circuit body 333 is positioned lower than the upper surface 33a of the circuit unit 33. Furthermore, the upper surface 333a of the circuit body 333 is positioned lower than the upper surface 33a of the circuit unit 33, which is positioned closer to the rear end than the circuit body 333. The height (base height h2) from the upper surface 333a of the circuit body 333 to the upper surface 33a of the circuit unit 33 is greater than the thickness of the pad unit 331, as described above. Because the upper surface 333a of the circuit body 333 is positioned lower than the upper surface 33a of the circuit unit 33, when the coil wire 40 is pressed downward, the coil wire 40 contacts the upper surface 33a of the circuit unit 33 on the rear end side, but does not contact the surface of the pad unit 331 or the circuit unit 33. This prevents the surface of the pad unit 331 and the circuit unit 33 from being damaged by the coil wire 40. Furthermore, the base height h2 is smaller than the height (solder height h1) of the highest point of the solder 50 relative to the top surface 333a of the circuit body 333. Preferably, the base height h2 is equal to or less than half the solder height h1. This allows the height of the on-pad portion 42 relative to the solder 50 to be adjusted to any position. In other words, by pressing the coil wire 40 against the middle portion of the slope 51 of the solder 50, the coil wire 40 can be sufficiently immersed in the solder 50 when the solder 50 melts, as described below.

[0036] After the wire placement process, the melting process is performed. In the melting process, a laser (not shown) is irradiated onto the solder 50 supplied onto the pad portion 331 from above, as described above. In this embodiment, a carbon dioxide laser is irradiated onto the solder 50. Here, "above the pad portion 331" includes the surface of the pad portion 331 and the space above the pad portion 331. In other words, irradiating the brazing filler metal 50 supplied onto the pad portion 331 with a laser does not necessarily mean irradiating the solder 50 formed and solidified on the surface of the pad portion 331 with a laser. As will be described later, this also includes irradiating the solder 50, such as a wire solder, arranged above the pad portion 331 with a laser. The solder 50 melts due to the heat applied by the laser. It is sufficient that the laser is irradiated onto the solder 50; the laser may or may not be irradiated onto the coil wire 40.

[0037] In this embodiment, in the melting step, the solder 50 is supplied to the surface of the pad portion 331 to a thickness equal to or greater than the wire diameter of the coil wire 40. In this embodiment, the solder 50 is formed in advance to a thickness equal to or greater than the wire diameter of the coil wire 40, and even after being melted by a laser, the thickness of the solder 50 remains equal to or greater than the wire diameter of the coil wire 40. When the solder 50 is supplied using wire solder or the like in the melting step, as described below, the thickness of the melted solder 50 applied to the surface of the pad portion 331 is equal to or greater than the wire diameter of the coil wire 40. By applying the solder 50 to the surface of the pad portion 331 to a sufficient thickness in this way, the coil wire 40 can be sufficiently immersed in the solder 50 in the removal step, which will be described later.

[0038] In this embodiment, in the melting process, the temperature of at least one of the coil wire 40 or the brazing filler metal 50 (solder 50) is measured, and the laser irradiation dose is controlled so that the temperature is within a predetermined range higher than the melting point of the brazing filler metal 50. Alternatively, the laser irradiation dose is controlled so that the temperature is within a predetermined range higher than the decomposition temperature of the insulating coating 46. The temperature of only the coil wire 40, only the brazing filler metal 50, or both the coil wire 40 and the brazing filler metal 50 may be measured. More specifically, the temperature of the brazing filler metal 50 irradiated with the laser, or a portion of the coil wire 40 immersed in the brazing filler metal 50 and a nearby length region thereof, is measured. The temperature measurement is preferably performed without contacting the solder 50, and an infrared thermometer is an example of a measuring device used for temperature measurement. Here, the lower limit of the predetermined range is the melting point of the solder 50, which is preferably higher than the melting point of the insulating coating 46 and more preferably higher than the decomposition temperature of the insulating coating 46. The upper limit of the predetermined range can be the lower limit of the temperature at which the insulating coating 46 in the portion of the coil wire 40 not immersed in the solder 50 (the outer region described below) becomes scorched or decomposed. If the temperature of the measurement site falls outside the predetermined range, the laser irradiation dose is immediately changed. Controlling the laser irradiation dose here includes increasing the laser irradiation dose when the temperature of the measurement site is lower than the predetermined range, and also includes decreasing the laser irradiation dose or interrupting laser irradiation when the temperature of the measurement site is higher than the predetermined range. Controlling the laser irradiation in this manner can sufficiently melt the solder 50 and raise the temperature high enough to remove the insulating coating 46 in the removal process described below. Furthermore, it is possible to prevent the insulating coating 46 covering the outer region of the coil wire 40 from deteriorating.

[0039] After the melting process, the removal process is performed. When the solder 50 melts and becomes liquid, a portion of the coil wire 40 that was pressed against the solder 50 becomes immersed in the molten solder 50. As described above, the coil wire 40 that was pressed against the center of the pad portion 331 penetrates into the solder 50 toward the center of the pad portion 331. Specifically, when viewed from the front-to-back direction as shown in FIG. 8 , the coil wire 40 (particularly the over-pad portion portion 42) that is pressed against the slope 51 of the solder 50 penetrates into the solder 50 while moving inward and downward (the coil wire 40a toward the lower right, and the coil wire 40b toward the lower left). Also, when viewed from above as shown in FIG. 7 , the coil wire 40 penetrates into the solder 50 while moving inward and toward the front end (the coil wire 40a toward the lower right on the paper, and the coil wire 40b toward the lower left on the paper). That is, the molten solder 50 envelops the coil wire 40 from the center side of the pad portion 331. Specifically, in FIG. 8, solder 50a envelops the coil wire 40 from the lower right of the coil wire 40a, and solder 50b envelops the coil wire 40 from the lower left of the coil wire 40b. As a result, as will be described later, a portion (the portion in the upper right corner of the drawing) of the side circumferential surface 40e of the coil wire 40b (see FIG. 5) is disposed outside the solder 50b. Alternatively, a portion of the coil wire 40 is completely immersed in the solder 50, as in the case of the coil wire 40a.

[0040] When the coil wire 40 is immersed in the molten solder 50, the liquid solder 50 on the surface of the pad portion 331 tends to spread laterally (left-right and front-back). In this embodiment, the solder 50 spreads only over the surface of the pad portion 331, which has good wettability, and does not spread beyond the pad portion 331. As described above, when viewed from above, the coil wire 40 moves inward and toward the front end while penetrating into the solder 50. This causes the solder 50 to be pushed out, particularly inward and toward the front end. Meanwhile, as described above, the pad portion 331 has a rectangular shape with missing corners on the inner and front end sides when viewed from above. This prevents the solder 50, which tends to spread inward and toward the front end when the coil wire 40 is immersed in the solder 50, from spreading out more flatly than necessary. Furthermore, the solder 50 that has been prevented from spreading tends to bulge upward and cover the coil wire 40, so that the upper peripheral surface 40c of the coil wire 40 (see FIG. 5) is covered with the solder 50. As a result, the coil wire 40 can be sufficiently immersed in the solder 50. As described above, the solder 50 does not easily wet and spread onto the upper surface 333a of the circuit body 333 that is not metal-plated, so it bulges upward on the pad portion 331. The bulged solder 50 is rounded due to surface tension, and as shown in FIG. 4, the solder 50 may appear to be located outside the pad portion 331 when viewed from above.

[0041] When the coil wire 40 is immersed in the solder 50 heated by laser irradiation, the insulating coating 46 on the surface of the coil wire 40 immersed in the solder 50 is heated by the heat of the molten solder 50. As a result of being heated, the insulating coating 46 in contact with the solder 50 is removed. Specifically, for example, the insulating coating 46 is decomposed and removed from the coil wire 40. When the temperature of the insulating coating 46 reaches its decomposition temperature, the insulating coating 46 is decomposed. The affinity between the coil core 47, which is made of a metal or other material, and the solder 50 is greater than the affinity between the decomposition products of the insulating coating 46, which is made of a resin or other material, and the coil core 47. As a result, the solder 50 wets the surface of the coil core 47, and the decomposition products of the insulating coating 46 are removed from the surface of the coil core 47 to the outside of the solder 50. The decomposition products of the insulating coating 46 precipitate on the surface of the solder 50. Alternatively, the decomposition products of the insulating coating 46 are sublimated by the heat of the molten solder 50. In this way, the insulating coating 46 is decomposed and removed from the surface of the coil wire 40, exposing the coil core 47. Alternatively, instead of being decomposed, the insulating coating 46 may be melted and removed from the coil wire 40. When the temperature of the insulating coating 46 reaches the melting point of the resin that forms the insulating coating 46, the insulating coating 46 melts, increasing its fluidity and turning into a liquid. The liquid insulating coating 46 is pushed out from the surface of the coil core 47 by the solder 50 that wets the surface of the coil core 47 and removed. The liquid insulating coating 46 floats to the surface of the solder 50. Alternatively, part of the insulating coating 46 may melt, and another part may be decomposed and removed from the coil wire 40.

[0042] To sufficiently remove the insulating coating 46, a coil wire 40 having an insulating coating 46 with a low heat resistance temperature may be used. An example of such an insulating material is polyurethane, which has a heat resistance of 120°C or less. It is also preferable to use a coil wire 40 having an insulating coating 46 that is thin enough to make it easy to remove. It is also preferable that the insulating coating 46 be transparent or white, and not colored. This keeps the laser absorption rate of the insulating coating 46 low, preventing the insulating coating 46 from being directly peeled off by laser irradiation or the insulating coating 46 not covered by solder 50 from being denatured by laser irradiation.

[0043] In this manner, substantially all of the insulating coating 46 covered by the solder 50 is removed from the coil wire 40, but this is not limited to this. A small amount of the insulating coating 46 may remain in a portion of the coil wire 40 that was immersed in the solder 50. For example, as shown in FIG. 4 , a portion of the inner region (the region inside the first boundary line 48) covered with the solder 50b (described later) also constitutes a covered portion 473 (described later) where the insulating coating 46 remains. This is because the heat of the solder 50b is not sufficiently transferred to the periphery of the inner region (the portion close to the first boundary line 48). Furthermore, as described later, a small amount of the insulating coating 46 may remain in the center of the inner region without being completely decomposed or melted. Furthermore, a portion of the exterior of the solder 50 on the coil wire 40 may not be covered with the insulating coating 46. For example, in the outer region (described later) of the coil wire 40a shown in FIG. 4 , a portion of the insulating coating 46 close to the solder 50a has been removed, resulting in an exposed portion 471 (described later). This is because the heat of the molten solder 50 is also transferred to the insulating film 46 that is located outside the solder 50 and in close proximity to the solder 50 .

[0044] When the insulating coating 46 is removed from the coil wire 40, the coil core 47 comes into contact with the solder 50. The metal constituting the coil core 47 and the metal constituting the solder 50 form an alloy, thereby joining the coil wire 40 and the pad portion 331. The molten solder 50 cools and solidifies.

[0045] In this embodiment, a portion of the melting process and a portion of the removing process are performed at overlapping times. Performing these processes at overlapping times means that all of the processes may be performed at the same time, or that some of the processes may be performed simultaneously. Specifically, when the solder 50 begins to melt in the melting process, the removing process is initiated, and the coil wire 40 begins to be immersed in the solder 50. That is, the coil wire 40 is immersed in the solder 50 while the solder 50 is melted by the laser. The melting process is completed by the time the removing process is completed. In this embodiment, the coil wire 40 is continuously pressed toward the base before and during laser irradiation. That is, the pressurization and some of the melting processes in the wire placement process are performed at overlapping times. As a result, the coil wire 40 is immersed simultaneously with the melting of the solder 50.

[0046] In this embodiment, in the melting process, an inert gas (not shown) is supplied to the brazing filler metal 50 (solder 50) along the direction in which pressure is applied to the coil wire 40. It is also preferable to supply an inert gas in the removal process following the melting process. The direction in which the inert gas is supplied is preferably approximately parallel to the direction in which pressure is applied to the coil wire 40. That is, in the melting process, the inert gas is supplied to the solder 50 from above. As the inert gas, a gas that is less reactive with the solder 50 is used, and examples of such gases include noble gases such as nitrogen and argon. By supplying the inert gas to the solder 50, oxygen-containing air surrounding the solder 50 can be removed. This prevents the solder 50 from oxidizing, improving the wettability of the solder 50 on the circumferential surface of the coil wire 40 and the surface of the pad portion 331. Furthermore, by supplying the inert gas along the direction in which pressure is applied to the coil wire 40, oxygen surrounding the solder 50 can be sufficiently removed over a wide area. That is, because the solder 50 is piled up in a mountain-like shape that protrudes upward, supplying the inert gas from above supplies the inert gas to the entire slope 51 of the solder 50. Instead of supplying the inert gas in the direction that pressurizes the coil wire 40, the inert gas may be supplied along the direction of the resistance that the coil wire 40 exerts on the solder 50. That is, the inert gas may be supplied from two directions, from the upper right toward the solder 50 and from the upper left toward the solder 50. This ensures that the inert gas is sufficiently supplied, especially around the coil wire 40 that is buried in the solder 50. The wettability of the solder 50 on the circumferential surface of the coil wire 40 is maintained well, and the coil wire 40 is sufficiently immersed in the solder 50.

[0047] This method includes a cutting step that is performed after the pad portion 331 and the coil wire 40 are joined with the brazing filler metal 50 (solder 50) in the removing step. In the cutting step, the coil wire 40 and the base 30 are cut, and a portion of the coil wire 40 including one end (fixing portion 43) and a portion of the base 30 including the wire fixing portion 312 are removed. In this embodiment, the coil wire 40 and the base 30 are cut along a plane that is approximately perpendicular to the front-rear direction. It is preferable that the coil wire 40 and the base 30 are cut along the same plane. Specifically, the coil wire 40 and the base 30 are cut along the cut plane indicated by the dashed dotted line Y in FIG. 9 . That is, in this embodiment, the cut plane along which the coil wire 40 and the base 30 are cut is a plane that is located rearward of and parallel to the side end surface 333b on the rear side of the circuit body 333. More specifically, the cut plane includes the installation hole 334. Alternatively, the cut plane may be flush with the side end surface 333b of the circuit body 333. Alternatively, in the removal step, the circuit portion 33 may not be cut, but the flat portion 315 of the wire placement portion 31 and the coil wire 40 may be cut. In this case, the cut surface may be flush with the rear end side surface 33d located on the rear end side of the circuit portion 33 (the boundary surface between the wire placement portion 31 and the circuit portion 33).

[0048] Both ends of the coil wire 40 located forward of the cut surface are removed. Specifically, the ends of the coil wire 40 including the pressure section 44, the bent section 45, and the fixed section 43 are removed. In addition, a portion of the base 30 located forward of the cut surface is also removed. Specifically, the end of the base 30 including the wire placement section 31 is removed.

[0049] The antenna device 100 is manufactured through the above steps. In manufacturing the antenna device 100, the melting step of melting the solder 50 by irradiating a laser and the step of immersing the coil wire 40 in the molten solder 50 to remove a portion of the insulating coating 46 from the coil wire 40 are essential steps. It is optional to include other steps or other components. According to this method, when the coil wire 40 is immersed in the solder 50 for soldering, the insulating coating 46 is removed from the coil wire 40. In other words, this method allows the insulating coating 46 to be peeled off during the brazing step, eliminating the need to perform a step of peeling off the insulating coating 46 from the coil wire 40 before the brazing step. This reduces the number of steps required to manufacture the antenna device 100.

[0050] (Details of the Antenna Device) Next, the features of the antenna device 100 manufactured in this embodiment will be described in detail. The coil wire 40 has an exposed portion 471 where the coil core 47 is exposed from the insulating coating 46. A first boundary line 48, which is the boundary between the internal region of the circumferential surface of the coil wire 40 that is buried in the solder 50 and the external region that is exposed outside the solder 50, and a second boundary line 472, which is the boundary between the exposed portion 471 and a coated portion 473 of the coil wire 40 that is coated with the insulating coating 46, run parallel to each other.

[0051] "A portion of the circumferential surface of the coil wire 40 is embedded in the solder 50" means that a portion of the circumferential surface of the coil wire 40 is covered with the solder 50. The internal region is a portion of the circumferential surface of the coil wire 40 that is embedded in the solder 50 and is the region inside the first boundary line 48 (see FIG. 4). The external region is a portion of the circumferential surface of the coil wire 40 that is not covered with the solder 50 and is the region outside the first boundary line 48. As shown in FIG. 4, two first boundary lines 48 are arranged on the circumferential surface of the coil wire 40a, spaced apart in the front-to-rear direction. Each first boundary line 48 on the coil wire 40a goes around the coil wire 40a in the circumferential direction. Here, the internal region (the region inside the first boundary lines 48) is a portion of the circumferential surface of the coil wire 40a that is sandwiched between a pair of first boundary lines 48. In other words, the internal region of the coil wire 40a extends throughout the entire radial direction of the coil wire 40a. On the other hand, a substantially elliptical first boundary line 48 is disposed on the circumferential surface of the coil wire 40b shown in Figure 4. The inner region of the coil wire 40b is the substantially elliptical region inside the first boundary line 48. More specifically, the inner region of the coil wire 40b covers a portion of the lower circumferential surface of the coil wire 40b (a lower circumferential surface 40d described below), and extends over only a portion of the radial direction of the coil wire 40b.

[0052] The exposed portion 471 is a partial region of the circumferential surface of the coil wire 40 that is not covered with the insulating coating 46 and exposes the coil core 47. As described above, the insulating coating 46 may not be sufficiently removed during the removal process, leaving a small amount of the insulating coating 46 in the center of the inner region. That is, the insulating coating 46 may be present only in a small portion of the center of the exposed portion 471. In this case, the region where the insulating coating 46 is present inside the inner region, excluding the periphery, is also referred to as the exposed portion 471. Preferably, the insulating coating 46 is completely peeled off over the entire exposed portion 471. Meanwhile, a partial region of the circumferential surface of the coil wire 40, excluding the exposed portion 471, is covered with the insulating coating 46. The region of the circumferential surface of the coil wire 40 that is covered with the insulating coating 46 is referred to as the covered portion 473. In the coil wire 40a, the exposed portion 471 extends along the entire circumference of the coil wire 40a. The exposed portion 471a is a region sandwiched between a pair of second boundary lines 472a, 472a spaced apart in the front-to-rear direction. Each of the second boundary lines 472a extends around the circumferential surface of the coil wire 40a in the circumferential direction. Furthermore, in the coil wire 40b, the exposed portion 471b is generally elliptical and includes a portion of the lower circumferential surface 40d (described later), and extends only along a portion of the radial direction of the coil wire 40b. In other words, the exposed portion 471b is the region inside the generally elliptical second boundary lines 472.

[0053] 4, the exposed portion 471 and the internal region are generally coincident, but they do not need to be perfectly coincident with each other. For example, the exposed portion 471 may include the external region, and the internal region may include the coated portion 473. In the coil wire 40a, most of the exposed portion 471 is covered with the solder 50 and coincides with the internal region, but part of the exposed portion 471 is outside the solder 50 and is the external region. In the coil wire 40b, most of the internal region is the exposed portion 471 that exposes the coil core 47, but the remaining part of the internal region is the coated portion 473 that is covered with the insulating coating 46.

[0054] Here, "the first boundary line 48 and the second boundary line 472 are aligned" means that the convex portions and concave portions of the first boundary line 48 and the second boundary line 472 correspond to each other. That is, the shapes of the first boundary line 48 and the second boundary line 472 are substantially identical to each other. Preferably, the acute angle formed by the tangent to a portion of the first boundary line 48 and the tangent to a portion of the second boundary line 472 adjacent to that portion of the first boundary line 48 is smaller than the acute angle formed by the first boundary line 48 and a plane perpendicular to the extension direction of the coil wire 40. Also, it is desirable that the first boundary line 48 and the second boundary line 472 are sufficiently close to each other. Specifically, the distance between a portion of the first boundary line 48 and a portion of the second boundary line 472 adjacent to that portion is preferably equal to or less than the wire diameter of the coil. More preferably, the distance between a portion of the first boundary line 48 and a portion of the second boundary line 472 adjacent to that portion is zero, and the first boundary line 48 and the second boundary line 472 substantially coincide with each other.

[0055] Furthermore, the first boundary line 48 may be located inside or outside the exposed portion 471. For example, the first boundary line 48a in the solder 50a is located on the exposed portion 471a, i.e., located closer to the inside of the second boundary line 472a in the exposed portion 471a. On the other hand, a partial length region (first boundary line 48b) of the first boundary line 48 in the solder 50b is located outside the exposed portion 471b, i.e., located further outward from the exposed portion 471b than the second boundary line 472b. Furthermore, another partial length region (first boundary line 48c) of the first boundary line 48 in the solder 50b approximately coincides with a portion of the second boundary line 472 (second boundary line 472c). Furthermore, the second boundary line 472 and the first boundary line 48 may intersect. That is, a partial length region of the first boundary line 48 may be located outside the exposed portion 471, and another partial length region of the first boundary line 48 may be located inside the exposed portion 471, and the second boundary line 472 and the first boundary line 48 may intersect.

[0056] By configuring the solder 50 in a shape that encases the coil wire 40 so that the first boundary line 48 and the second boundary line 472 are aligned, the antenna device 100 can be manufactured using the manufacturing method described above. That is, the antenna device 100 of this embodiment has a structure that can be manufactured with few manufacturing steps. Furthermore, by aligning the first boundary line 48 and the second boundary line 472 with each other, substantially the entire exposed portion 471 is covered with the solder 50, and the area of ​​the exposed portion 471 that is not covered with the solder 50 (the area where the coil core is exposed) can be minimized. This prevents the coil core 47 from being exposed more than necessary, thereby improving the insulation of the coil wire 40. Furthermore, since the coil core 47 is only exposed to a small amount, deterioration of the coil core 47 due to wear and oxidation can be prevented. The antenna device 100 in which the coil wire 40 is enclosed in the solder 50 so that the first boundary line 48 and the second boundary line 472 are aligned can be manufactured without using the manufacturing method described above. For example, the insulating coating may be removed after previously masking the circumferential surface of the coil wire 40 except for the area to be covered with the solder 50 .

[0057] In this embodiment, the thickness (height direction) of the brazing filler metal 50 (solder 50) is greater than the wire diameter of the coil wire 40. The thickness of the solder 50 here refers to the maximum height of the solder 50, measured from the surface of the pad portion 331 at a point in the area where the solder 50 is disposed in the height direction and where the coil wire 40 and the solder 50 do not overlap. In other words, the thickness of the solder 50 here refers to the thickness of the solder 50 alone, excluding the thickness of the coil wire 40. For example, as shown in FIG. 5 , the solder 50 is formed in a generally mountain-like shape with its apex above the coil wire 40. In this case, the highest point of the solder 50 is above the coil wire 40, but the thickness of the solder 50 is smaller than the height of the solder 50 (the distance from the surface of the pad portion 331 to the highest point of the solder 50). In this case, the thickness of the solder 50 is the height of the solder 50 at a point close to the side of the coil wire 40.

[0058] By forming the solder 50 to a sufficient thickness equal to or greater than the wire diameter of the coil wire 40, the coil wire 40 can be sufficiently immersed in the solder 50 in the manufacturing method of the antenna device 100, which will be described later. Furthermore, by piling up the solder 50 to a thickness equal to or greater than the wire diameter of the coil wire 40, it is possible to bury almost the entire radial direction of the coil wire 40 in the solder 50. This makes the bond between the solder 50 and the coil wire 40 physically strong, and also improves the electrical connection between the solder 50 and the coil wire 40.

[0059] In the present embodiment, in a partial length region of the coil wire 40b (the buried portion 42a, which is a partial length region having the exposed portion 471 when viewed radially of the coil wire 40), a radial portion is the exposed portion 471, and another radial portion is the covered portion 473. The radial portion being the exposed portion 471 and another radial portion being the covered portion 473 means that, in a cross section at a certain point in the buried portion 42a, a portion of the circumference (arc) of the cross-sectional circle is not covered with the insulating coating 46, and the coil core 47 is exposed, while another portion is covered with the insulating coating 46. In the present embodiment, as in the coil wire 40b illustrated in FIGS. 4 and 5 , a radial portion of the entire region of the buried portion 42a is the exposed portion 471, and another radial portion is the covered portion 473. In other words, the insulating coating 46 is not divided by the exposed portion 471. That is, the first insulating coating 46a and the second insulating coating 46b cover the entire radial area of ​​the first and second length regions of the coil wire 40, sandwiching the buried portion 42a (a partial length region buried in the brazing filler metal 50). The first and second insulating coatings 46a and 46b are connected by a bridge portion 461 that has a width smaller than the wire diameter of the coil wire 40 and extends along the extension direction of the coil wire 40. Here, the first and second length regions are regions outside the brazing filler metal 50 and are partial length regions of the coil wire 40 that are located forward or rearward of the pad portion 331 in the height direction, respectively. As shown in FIG. 4 , the first insulating coating 46a covers the entire circumference of the coil wire 40 (first length region) that is located forward of the buried portion 42a. The second insulating coating 46b covers the entire circumference of the coil wire 40 (second length region) that is located rearward of the buried portion 42a. A bridge portion 461 connecting the first insulating coating 46a and the second insulating coating 46b is disposed on the circumferential surface of the buried portion 42a. The bridge portion 461 is a part of the insulating coating 46, and is narrow and elongated in the axial direction of the coil wire 40. The longitudinal direction of the bridge portion 461 and the extension direction of the coil wire 40 are aligned with each other. Here, the width of the bridge portion 461 refers to the minimum length of the bridge portion 461 in the circumferential direction.Furthermore, the longitudinal direction of the bridge portion 461 and the extending direction of the coil wire 40 being aligned with each other means that the acute angle formed when a virtual center line connecting the centers of the bridge portions 461 in the width direction is projected onto the axis of the coil wire 40 is at least 30 degrees or less. Preferably, the center line of the bridge portion 461 and the axis of the coil wire 40 are substantially parallel to each other.

[0060] Furthermore, in this embodiment, in the partial length region (embedded portion 42a) of the coil wire 40, a portion of the upper side (upper circumferential surface 40c) opposite the side where the pad portion 331 is disposed and a portion of the lower side (lower circumferential surface 40d) facing the pad portion 331 are exposed portions 471 where the insulating coating 46 has been removed and are in contact with the brazing material 50. Furthermore, a portion of the side of the partial length region is a coated portion 473 covered with the insulating coating 46 and is not in contact with the brazing material 50. Here, the upper circumferential surface 40c is a region of a predetermined width on the circumferential surface of the buried portion 42a that includes the upper end of the coil wire 40, as shown in FIG. 5 . That is, the upper circumferential surface 40c may be a substantially linear region that includes only the upper end of the coil wire 40, or may be an elongated region that includes the upper end of the coil wire 40 and its vicinity. Furthermore, the lower circumferential surface 40d is a region of a predetermined width on the circumferential surface of the buried portion 42a that includes the lower end of the coil wire 40. Like the upper circumferential surface 40c, the lower circumferential surface 40d may be a substantially linear region including only the lower end, or may have an elongated shape with a certain width. The width of the upper circumferential surface 40c or the lower circumferential surface 40d may be less than or more than half the wire diameter of the coil wire 40. Here, "a portion of the side of the coil wire 40 is the coated portion 473" means that at least a portion of the side surface is the coated portion 473. The side surface 40e refers to the circumferential surface of the coil wire 40 excluding the upper circumferential surface 40c and the lower circumferential surface 40d. Furthermore, in this embodiment, a portion of the upper side of the partial length region (embedded portion 42a) of the coil wire 40 is the coated portion 473 covered with the insulating coating 46 and not in contact with the brazing filler metal 50, while the entire lower side of the partial length region (embedded portion 42a) is the exposed portion 471 from which the insulating coating 46 has been removed and which is in contact with the brazing filler metal 50. That is, the outer and upper region of the side circumferential surface 40e is the covered portion 473, and the lower region of the side circumferential surface 40e is the exposed portion 471. Here, the upper side of the side circumferential surface 40e refers to the region of the side circumferential surface 40e that is located above the center of the cross section of the coil wire 40, and the lower side of the side circumferential surface 40e refers to the region that is located below this center of the cross section and faces the pad portion 331. The upper circumferential surface 40c and the lower circumferential surface 40d over the entire length of the buried portion 42a are not necessarily the exposed portion 471.The upper circumferential surface 40c or the lower circumferential surface 40d may be an exposed portion 471 in a partial length region of the buried portion 42a, and the upper circumferential surface 40c or the lower circumferential surface 40d may be a covered portion 473 in the remaining length region.

[0061] By having only a radial portion of the coil wire 40 embedded in the solder 50 and another portion positioned outside the solder 50, the coil wire 40 and the pad portion 331 can be joined with a small amount of solder 50. Furthermore, because the radial portion not covered by the solder 50 is covered with the insulating coating 46, the coil core 47 of the buried portion 42a is covered with the insulating coating 46 or the solder 50 over its entire circumference. This prevents the coil core 47 from being exposed to the outside, preventing deterioration of the coil core 47 due to oxidation, wear, or the like, which could lead to breakage. Furthermore, because the radial portion of the buried portion 42a is not covered with the solder 50 over its entire length, the thermal fatigue resistance of the joint between the pad portion 331 and the coil wire 40 is improved. For example, when the coil wire 40 is immersed in molten solder 50, air adhering to the coil wire 40 may enter the solder 50. In contrast, according to the present embodiment, a radial portion of the coil wire 40 is not covered with solder 50 over the entire length of the buried portion 42a, so that any air that enters the solder 50 at any position moves upward along the surface of the coil wire 40 and easily escapes from the solder 50. This prevents voids from forming inside the solder 50 and prevents deterioration of the joint over time due to contraction and expansion of the air within the solder 50 caused by temperature changes around the joint. Furthermore, by covering the upper circumferential surface 40c of the circumferential surface of the coil wire 40 with the brazing material 50, the upper circumferential surface 40c, which is prone to wear due to interference with other components, can be protected by the brazing material 50.

[0062] As shown in FIG. 4 , the buried portion 42a of the coil wire 40a embedded in the solder 50a has an exposed portion 471 in which the insulating coating 46 has been removed over substantially the entire radial length. In this embodiment, both ends of the buried portion 42a protrude from the solder 50a at an angle relative to the circumferential direction of the coil wire 40a. The first insulating coating 46a covering a first length region of the coil wire 40a that is forward of the buried portion 42a and the second insulating coating 46b covering a second length region of the coil wire 40a that is rearward of the buried portion 42a are separated from each other by the exposed portion 471. Furthermore, at parts of both ends of the buried portion 42a, only a portion of the radial length is an internal region covered with solder 50, and the other portion of the radial length is an external region not covered with solder 50. In this embodiment, at both ends of the buried portion 42a, the region of the outer circumferential surface of the coil wire 40a that is close to the solder 50a is an exposed portion 471a where the insulating coating 46 has been peeled off. Alternatively, the region of the outer circumferential surface of the coil wire 40a that is close to the solder 50a may be covered with the insulating coating 46 to form a coated portion 473. That is, the second boundary line 472 and the first boundary line 48 may be substantially aligned, or the second boundary line 472 may be located inside the exposed portion 471. In this case, at both ends of the buried portion 42a, a portion in the radial direction is covered with the solder 50, and another portion in the radial direction is covered with the insulating coating 46. This prevents the coil core 47 from deteriorating and breaking due to oxidation, wear, or the like at both ends of the buried portion 42a, as described above. In the present embodiment, in only one of the left and right coil wires 40a, 40b, a radial portion of the entire length region of the buried portion 42a is the exposed portion 471 and the other portion is the covered portion 473, but this is not limited to this. In both of the left and right coil wires 40a, 40b, a radial portion of the entire length region of the buried portion 42a may be the exposed portion 471 and the other portion may be the covered portion 473. Furthermore, in both of the left and right coil wires 40a, 40b, the entire radial portion of the partial length region may be the exposed portion 471.

[0063] In this embodiment, as shown in FIGS. 2 and 3 , the end faces 41 of the coil wire 40 and the side end faces 33 b of the base 30 (circuit portion 33) are arranged on the same plane. Here, the end faces 41 of the coil wire 40 refer to cross sections resulting from cutting the coil wire 40 in the cutting process described below. In this embodiment, the coil wire 40 is arranged at an angle to the cut surface, so the end faces 41 of the coil wire 40 are elliptical. Here, the side end faces 33 b of the circuit portion 33 refer to surfaces facing the rear end of the circuit portion 33 and are cross sections resulting from cutting the base 30 in the cutting process described above. In other words, the side end faces 33 b of the circuit portion 33 are on the same plane as the surface indicated by the dashed line Y in FIG. 9 . Instead of this embodiment, the coil wire 40 and the circuit portion 33 may be cut along surfaces along the side end faces 333 b of the circuit body 333 in the cutting process. In this case, the end surface 41 of the coil wire 40, the side end surface 33b of the circuit portion 33, and the side end surface 333b of the circuit main body 333 are all arranged on the same plane. Furthermore, in the cutting step, the base 30 may be cut on the same plane as the boundary surface between the circuit portion 33 and the wire placement portion 31 (the same plane as the rear end side surface 33d in FIG. 9). In this way, the coil wire 40 and the circuit main body 333 do not protrude rearward beyond the side end surface 33b of the circuit portion 33, thereby preventing deterioration of the coil wire 40 and the circuit main body 333 due to wear.

[0064] <Modifications> The present invention is not limited to the above-described embodiment, and includes various modifications and improvements as long as the object of the present invention is achieved. The following modifications can be combined as appropriate.

[0065] For example, in this embodiment, the solder 50 is formed in a mountain-shaped shape on the surface of the pad portion 331 in advance and solidified, but this is not limited to this. The solder 50 does not have to be formed on the surface of the pad portion 331 in advance. For example, as described above, in the melting process, the solder 50 supplied above the pad portion 331 may be melted by a laser, and the molten solder 50 may fall onto the surface of the pad portion 331. If the solder 50 is not formed on the surface of the pad portion 331 in advance and the molten solder 50 is applied to the surface of the pad portion 331 in the melting process, the wire placement process may be performed after the melting process. That is, after liquid solder 50 is supplied onto the surface of the pad portion 331, the coil wire 40 may be placed above the pad portion 331 and the coil wire 40 may be immersed in the solder 50 by applying downward pressure to the solder 50. In other words, the melting process and the removal process may be performed at different times.

[0066] In this embodiment, the solder 50 is formed in advance on the pad surface in a mountain-like shape with an arched slope 51, but this is not limited to this. For example, the slope 51 of the solder 50 may be straight or may be concave downward. Furthermore, the apex 52 of the solder 50 is not limited to being a point. The highest points of the solder 50 may be connected on a line, or may be a surface. For example, the solder 50 may be formed in a trapezoidal shape when viewed from the front-to-back direction.

[0067] In this embodiment, in order to press the coil wire 40 against the solder 50, one end of the coil wire 40 is fixed to the rear end side of the base 30, and the pressure jig 200 is placed on the coil wire 40 to press the coil wire 40 downward, but this is not limited to this. For example, without using a pressure jig, the coil wire 40 may be brought closer to the solder 50 and pressed against it by a mechanism that pulls or pushes the coil wire 40 downward. Alternatively, when the coil wire 40 is placed above the pad portion 331 in the wire placement process and then pulled out toward the rear end, the coil wire 40 may be pulled out downward and fixed so that the coil wire 40 is pressed against the solder 50.

[0068] As described above, in this embodiment, the depth (height) of the installation hole 334 is greater than the thickness (height) of the circuit body 333, so that the entire upper surface 33a of the circuit unit 33 is positioned higher than the upper surface 333a of the circuit body 333. Alternatively, only the upper surface 33a of the circuit unit 33 positioned toward the rear end of the circuit body 333 may be positioned higher than the upper surface 333a of the circuit body 333. For example, a protrusion that protrudes upward from the upper surface 33a of the circuit unit 33 may be provided nearer the rear end of the circuit body 333, and the upper surface of the protrusion may be higher than the upper surface 333a of the circuit body 333. This prevents the coil wire 40, which is pressurized and approaches the pad portion 331, from contacting the pad portion 331 and damaging the pad portion 331. In this case, substantially the entire upper surface 33a of the circuit unit 33, excluding the protrusion, may be positioned lower than the upper surface 333a of the circuit body 333.

[0069] In this embodiment, the pressure jig installation hole 313 is disposed between the circuit portion 33 and the support portion 311, but is not limited to this. The pressure jig installation hole 313 may be provided between the support portion 311 and the wire fixing portion 312. In this case, the pressure portion 44 is a partial length region between the bent portion 45 and the fixing portion 43.

[0070] The above embodiments encompass the following technical concepts: (1) A method for manufacturing an antenna device having an antenna section in which a coil wire having a coil core coated with an insulating coating is wound, and a base having a pad section to which a portion of the coil wire is brazed with a brazing material, the method comprising: a melting step in which the brazing material supplied onto the pad section is irradiated with a laser to melt the brazing material; and a removal step in which the coil wire is immersed in the molten brazing material to remove a portion of the insulating coating from the coil wire and join the coil wire to the pad section with the brazing material. (2) The method for manufacturing an antenna device according to (1), in which a portion of the melting step and a portion of the removal step are performed at an overlapping time. (3) The method for manufacturing an antenna device according to (1) or (2), in which, in the melting step, the brazing material is supplied to the surface of the pad section in a thickness equal to or greater than the wire diameter of the coil wire. (4) The method for manufacturing an antenna device according to any one of (1) to (3), in which, in the removal step, the insulating coating is decomposed and removed from the coil wire. (5) The method for manufacturing an antenna device according to any one of (1) to (4), wherein in the melting step, the temperature of at least one of the coil wire or the brazing filler metal is measured, and the amount of irradiation of the laser is controlled so that the temperature is within a predetermined range higher than the melting point of the brazing filler metal. (6) The method for manufacturing an antenna device according to (5), wherein the amount of irradiation of the laser is controlled so that the temperature is within a predetermined range higher than the decomposition temperature of the insulating coating. (7) The method for manufacturing an antenna device according to any one of (1) to (6), further comprising a wire placement step performed before the melting step, wherein the base has a wire fixing portion for fixing the coil wire, and in the wire placement step, one end of the coil wire is fixed to the wire fixing portion and a portion of the coil wire is placed on the brazing filler metal provided on the surface of the pad portion, and in the wire placement step, a pressing portion which is a partial length region between the one end and the portion of the coil wire is pressed toward the base, so that the coil wire is pressed against the brazing filler metal.(8) The method for manufacturing an antenna device according to (7), wherein, in the wire placement step, the brazing material is formed on the surface of the pad portion in a mountain shape having a slope sloping downward from the center of the pad portion toward the periphery, and the coil wire is pressure-welded to the slope of the brazing material. (9) The method for manufacturing an antenna device according to (8), wherein the coil wire is pressure-welded to the slope toward the center of the pad portion against the slope. (10) The method for manufacturing an antenna device according to any one of (7) to (9), including a cutting step in which, after the pad portion and the coil wire are joined with the brazing material, the coil wire and the base are cut to remove a portion of the coil wire including the one end and a portion of the base including the wire fixing portion. (11) The method for manufacturing an antenna device according to any one of (7) to (10), wherein the base has a support portion against which the coil wire is pressed to change the direction of drawing out the coil wire, and in the wire placement step, a bent portion located between the portion and the one end of the coil wire is pressed against the support portion of the base to be bent, and the one end of the coil wire bent at the bent portion is entangled with the wire fixing portion of the base. (12) The method for manufacturing an antenna device according to any one of (7) to (11), wherein in the melting step, an inert gas is supplied to the brazing material in a direction in which pressure is applied to the coil wire. (13) An antenna device having an antenna section wound with a coil wire having a coil core and an insulating coating covering the coil core, and a base having a pad section, wherein the coil wire has an exposed section where the coil core is exposed from the insulating coating, the coil wire and the pad section are joined with a brazing material, a part of the coil wire is embedded in the brazing material, and a first boundary line which is a boundary between an internal region of the circumferential surface of the coil wire embedded in the brazing material and an external region protruding from the brazing material, and a second boundary line which is a boundary between the exposed section and a coated portion of the coil wire that is coated with the insulating coating, are aligned with each other. (14) The antenna device described in (13), wherein a thickness of the brazing material is greater than a wire diameter of the coil wire.(15) The antenna device according to (13) or (14), wherein in the partial length region of the coil wire, a radial portion is the exposed portion and another radial portion is the covered portion. (16) The antenna device according to (15), wherein in the partial length region of the coil wire, a portion of an upper side opposite to the side on which the pad portion is arranged and a portion of a lower side facing the pad portion are the exposed portion and are in contact with the brazing material, and a portion of a side of the partial length region is the covered portion and is not in contact with the brazing material. (17) The antenna device according to (16), wherein a portion of an upper side of the side of the partial length region is the covered portion and is not in contact with the brazing material, and the entire lower side of the side of the partial length region is the exposed portion and is in contact with the brazing material. (18) The antenna device according to any one of (15) to (17), wherein a first insulating coating and a second insulating coating, which cover the entire radial extent of each of a first length region and a second length region sandwiching the partial length region embedded in the brazing material of the coil wire, are connected by a bridge portion having a width smaller than the wire diameter of the coil wire and extending along the coil wire. (19) The antenna device according to any one of (13) to (18), wherein end faces of both ends of the coil wire and side end faces of the base are arranged on the same plane. (20) The antenna device according to any one of (13) to (19), wherein both ends of the coil wire are joined by the brazing material to a pair of pad portions provided on the base, respectively, (21) An antenna device, wherein the insulating coating is transparent or white in color.

[0071] 100 Antenna device 20 Antenna section 21 Winding core 30 Base 31 Wire placement section 311 Support section 312 Wire fixing section 313 Pressurizing jig installation hole 314 Hole 315 Flat section 315a Upper surface 315b Outer end surface 316 Winding core insertion hole 316a Chamfered section 33 Circuit section 33a Upper surface 33b Side end surface 33c Inclined surface 33d Rear end side surface 331 Pad section 331a Hypothetical side 333 Circuit body 333a Upper surface 333b Side end surface 334 Installation hole 335 Guide section 335a Outer surface 40, 40a, 40b Coil wire 40c Upper peripheral surface 40d Lower peripheral surface 40e Side peripheral surface 41 End surface 42 Pad portion upper arrangement portion 42a Buried portion 43 Fixed portion 44 Pressure portion 45 Bent portion 46 Insulating coating 46a First insulating coating 46b Second insulating coating 461 Bridge portion 47 Coil core 471, 471a, 471b Exposed portion 472, 472a, 472b, 472c Second boundary line 473 Covering portion 48, 48a, 48b, 48c First boundary line 49 Coil portion 50 Brazing filler metal 50, 50a, 50b Solder 51 Slope 52 Vertex 200 Pressure jig 210 Arm 211 Weight portion 212 Inner end surface 220 Wire straddling portion 221 Claw 230 Rod portion

Claims

1. A method for manufacturing an antenna device, comprising: an antenna portion in which a coil wire coated with an insulating film is wound; and a base having a pad portion to which a part of the coil wire is brazed with a brazing material, a melting step of irradiating the brazing material supplied onto the pad portion with a laser to melt the brazing material; a removing step of dipping the coil wire into the melted brazing material, removing a part of the insulating film from the coil wire by the heat of the brazing material, and joining the coil wire and the pad portion with the brazing material.

2. The method for manufacturing an antenna device according to claim 1, wherein a part of the melting step and a part of the removing step are performed at overlapping timings.

3. The method for manufacturing an antenna device according to claim 1, wherein in the melting step, the brazing material is supplied onto the surface of the pad portion with a thickness equal to or greater than the wire diameter of the coil wire.

4. The method for manufacturing an antenna device according to any one of claims 1 to 3, wherein in the removing step, the insulating film is decomposed and removed from the coil wire.

5. The method for manufacturing an antenna device according to any one of claims 1 to 3, wherein in the melting step, the temperature of at least one of the coil wire and the brazing material is measured, and the irradiation amount of the laser is controlled so that the temperature falls within a predetermined range higher than the melting point of the brazing material.

6. The method for manufacturing an antenna device according to claim 5, wherein the irradiation amount of the laser is controlled so that the temperature falls within a predetermined range higher than the decomposition temperature of the insulating film.

7. further including a wire arranging step performed before the melting step, the base having a wire fixing portion for fixing the coil wire, in the wire arranging step, one end of the coil wire is fixed to the wire fixing portion, and a part of the coil wire is arranged on the brazing material provided on the surface of the pad portion, The method for manufacturing an antenna device according to any one of claims 1 to 3, wherein in the wire arranging step, a pressurized portion, which is a partial length region between the one end and the part of the coil wire, is pressurized toward the base so that the coil wire is in pressure contact with the brazing material.

8. In the wire arrangement step, the brazing material is formed in a mountain shape having an inclined surface that slopes downward from the center to the periphery of the pad portion on the surface of the pad portion, and the coil wire is in pressure contact with the inclined surface of the brazing material. The method of manufacturing an antenna device according to claim 7.

9. The method of manufacturing an antenna device according to claim 8, wherein the coil wire is in pressure contact with the inclined surface toward the center of the pad portion.

10. The method of manufacturing an antenna device according to claim 7, including a cutting step in which after the pad portion and the coil wire are joined by the brazing material, the coil wire and the base are cut, and a part including one end portion of the coil wire and a part including the wire fixing portion of the base are removed.

11. The base has a support portion against which the coil wire is pressed to deflect the pulling direction of the coil wire. In the wire arrangement step, a bent portion located between the part and the one end portion of the coil wire is pressed against the support portion of the base and bent. The method of manufacturing an antenna device according to claim 7, wherein one end portion of the coil wire bent at the bent portion is wound around the wire fixing portion of the base.

12. In the melting step, an inert gas is supplied to the brazing material along the direction in which the coil wire is pressurized. The method of manufacturing an antenna device according to claim 7.

13. An antenna device having an antenna portion around which a coil wire having a coil core and an insulating film covering the coil core is wound, and a base having a pad portion. The coil wire has an exposed portion where the coil core is exposed from the insulating film. The coil wire and the pad portion are joined by a brazing material. A part of the coil wire is buried in the brazing material. An antenna device in which a first boundary line, which is a boundary between an internal region buried in the brazing material and an external region protruding outside the brazing material on the circumferential surface of the coil wire, and a second boundary line, which is a boundary between the exposed portion and a covered portion covered by the insulating film of the coil wire, are along each other.

14. The antenna device according to claim 13, wherein the thickness of the brazing material is larger than the wire diameter of the coil wire.

15. The antenna device according to claim 13, wherein in a partial length region of the coil wire, a part in the radial direction is the exposed portion, and another part in the radial direction is the covered portion.

16. In the partial length region of the coil wire, an upper part on the side opposite to the side where the pad portion is disposed and a lower part on the side facing the pad portion are the exposed portions and are in contact with the brazing material, and a side part in the partial length region is the covered portion and is not in contact with the brazing material. The antenna device according to claim 15.

17. An upper part on the side of the side part of the partial length region is the covered portion and is not in contact with the brazing material, and the entire lower part on the side of the side part of the partial length region is the exposed portion and is in contact with the brazing material. The antenna device according to claim 16.

18. A first insulating film and a second insulating film that cover the entire radial direction of the first length region and the second length region sandwiching the partial length region of the coil wire embedded in the brazing material are connected by a bridge portion having a width smaller than the wire diameter of the coil wire and extending along the extending direction of the coil wire. The antenna device according to claim 15.

19. The antenna device according to any one of claims 13 to 18, wherein the end faces of both ends of the coil wire and the side end face of the base are arranged on the same plane.

20. Both ends of the coil wire are joined to the respective pair of pad portions provided on the base by the brazing material. The pair of pad portions are each formed in a rectangular shape. Each of the rectangles has a shape in which one of the corners on the inner side of the pair of pad portions is chamfered to form a hypotenuse. The hypotenuse is along the extending direction of the coil wire. The antenna device according to any one of claims 13 to 18.