JP5841627B2 - Antenna component and antenna device - Google Patents

Description

  The present invention relates to a small antenna component and an antenna device.

  For example, as a small antenna device, an antenna device for keyless entry is known. Since the antenna device for keyless entry is used at frequencies such as 315MHz and 433MHz, the ideal dipole antenna is 1/2 wavelength 47.6cm (when 315MHz) or 34.6cm (when 433MHz) The antenna size is required. Therefore, in order to store this antenna device inside a small terminal such as a keyless entry, it is necessary to reduce the size of the antenna.

  As a means for downsizing the antenna, there is known an antenna device using a helical antenna and a wavelength shortening effect by using a high dielectric constant material (Patent Documents 1 and 2).

  This antenna device is configured such that an antenna component is mounted on a substrate. The antenna component has a configuration in which, for example, a plurality of metal antenna elements constituting a helical antenna are arranged on a resin holding member having a high dielectric constant. An antenna pattern constituting the other part of the helical antenna is formed on the substrate.

  Therefore, by mounting the antenna component on the substrate, the antenna element and the antenna pattern are connected to form a helical antenna.

JP 2009-296269 A JP 2004-120168 A

  The antenna component is surface-mounted on the substrate using solder. This soldering process is performed using a solder reflow furnace. In the solder reflow furnace, temperature control is performed in a solder melting process called a temperature profile. In this solder reflow furnace, for example, the antenna component and the substrate are heated up to about 250 ° C.

  Here, the antenna component is composed of a resin holding member and a metal antenna element having different thermal expansion coefficients. Specifically, the thermal expansion coefficient of the resin-made holding member is larger than the thermal expansion coefficient of the metal antenna element.

  For this reason, at the time of solder reflow, the antenna element may be deformed due to the difference in the coefficient of thermal expansion, and the antenna component and the board may not be properly soldered.

  An exemplary object of an aspect of the present invention is to provide an antenna component and an antenna device that can prevent deformation of an antenna element during heating.

According to one aspect of the invention,
An antenna component constituting a helical antenna by being mounted on a substrate,
A plurality of antenna elements having terminal portions connected to the wiring formed on the substrate at both ends, and constituting the helical antenna in cooperation with the wiring;
A holding member for holding the antenna element;
An antenna component provided with an engaging portion that engages with the holding member at at least one end of the antenna element ,
The terminal portion is formed by providing a bent portion in the antenna element,
The engaging portion has a first portion having a first width between a tip portion of the antenna element and the bent portion, and a second portion having a second width wider than the first portion. Having at least one set of two parts,
In addition, the second part is disposed on the tip side with respect to the first part.

  According to an aspect of the present invention, it is possible to prevent deformation of the antenna element during heating such as solder reflow.

FIG. 1 is an exploded perspective view of an antenna device according to an embodiment. FIG. 2 is a perspective view illustrating a state in which the holding member of the antenna device according to an embodiment is removed. FIG. 3 is an enlarged perspective view showing an antenna element of an antenna component according to an embodiment. FIG. 4 is a bottom view of an antenna component according to an embodiment. FIG. 5 is a cross-sectional view of an antenna component according to an embodiment. FIG. 6 is a cross-sectional view of an antenna component according to another embodiment. FIG. 7 is a cross-sectional view of an antenna component according to still another embodiment. FIG. 8 is a perspective view showing a conductive metal plate in which a plurality of antenna elements are integrally formed. FIG. 9 is a diagram for explaining notch folding. FIG. 10 is a diagram showing an engaging part of an antenna component according to still another embodiment.

  Reference will now be made to non-limiting exemplary embodiments of the invention with reference to the accompanying drawings.

  In the description of all attached drawings, the same or corresponding members or parts are denoted by the same or corresponding reference numerals, and redundant description is omitted. Also, the drawings are not intended to show relative ratios between members or parts unless otherwise specified. Accordingly, specific dimensions can be determined by one skilled in the art in light of the following non-limiting embodiments.

  In addition, the embodiments described below are examples, not limiting the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  FIG. 1 is an exploded perspective view of an antenna device 1 according to an embodiment of the present invention. The antenna device 1 can be applied to the antenna device in a small terminal such as a keyless entry.

  The antenna device 1 includes an antenna component 10 </ b> A and a substrate 30. The antenna component 10 </ b> A constitutes a helical antenna by being surface-mounted on the substrate 30.

  The antenna component 10A includes a plurality of antenna elements 12A and a holding member 14. The antenna element 12 </ b> A includes a main body portion 16 and terminal portions 19 that are integrally formed at both ends of the main body portion 16.

  Each antenna element 12A is formed of a conductive metal. As a specific material of the antenna element 12A, various materials can be used. For example, copper or a copper alloy can be used.

  Further, the antenna element 12A has a quadrilateral shape by bending the four corner positions of the main body 16 as shown in an enlarged view in FIG. Further, a part of the lower side of the antenna element 12 </ b> A that is joined to the substrate 30 is cut to form a separation portion 17. In the following description, the lower two bending positions of the four bending positions of the antenna element 12 </ b> A are referred to as bending portions 15.

  The terminal part 19 to be soldered to the antenna pattern 32 of the board 30 when the antenna component 10A is mounted on the board 30 is formed so as to extend inward from the bent part 15. The terminal portion 19 is configured such that the surface is exposed from the holding member 14 in a state where the antenna element 12 </ b> A is mounted on the holding member 14.

  FIG. 2 shows a state where the antenna element 12 </ b> A is surface-mounted on the substrate 30. In FIG. 2, in order to show the connection state of the antenna element 12A and the antenna pattern 32, the holding member 14 is not shown.

Each of the plurality of antenna patterns 32 formed on the substrate 30 has a shape extending obliquely with respect to the side of the substrate 30. The antenna component 10 </ b> A is mounted on the substrate 30 by soldering the terminal portion 19 of the antenna element 12 </ b> A to the antenna pattern 32.
At this time, the plurality of antenna elements 12A are soldered to the antenna pattern 32 while being shifted by one pitch. Therefore, by mounting the antenna element 12A on the substrate 30, the antenna element 12A and the antenna pattern 32 cooperate to form a helical antenna.

  The type of the substrate 30 is not particularly limited, and various substrates such as a resin substrate, a glass epoxy substrate, and a ceramic substrate can be used as long as the antenna pattern 32 can be formed on the surface.

  The holding member 14 is made of a resin material. The antenna element 12A described above is held by the holding member 14. Specifically, the antenna element 12 </ b> A is insert-molded into the holding member 14 when the holding member 14 is molded. Thus, the antenna element 12A is embedded in the holding member 14, and thus the antenna element 12A is held by the holding member 14.

  The antenna element 12A needs to be accurately placed on the holding member 14 in order to form a helical antenna. However, the antenna element 12A can be easily and accurately disposed in the holding member 14 by using the insert molding method and molding the resin after the antenna element 12A is locked in advance in the insert mold.

  Further, when the antenna element 12 </ b> A is insert-molded into the holding member 14, the outer peripheral surface of the antenna element 12 </ b> A is configured to be exposed from the holding member 14. As a result, the antenna characteristics are stabilized and improved.

As the material of the holding member 14, a resin having a high dielectric constant of 2 or more can be used. As a specific example, in the present embodiment, a resin having a relative dielectric constant of 2 to 40 is used as the holding member 14.
As described above, when the holding member 14 serving as the base material of the antenna component 10A is formed of a high dielectric constant material, the wavelength of the high frequency current flowing through the antenna element 12A and the antenna pattern 32 constituting the helical antenna is shortened. For this reason, compared with the case where a low dielectric material is used for the holding member 14, the helical antenna comprised of the antenna element 12A and the antenna pattern 32 can be reduced in size.

  As described above, the antenna component 10A according to this embodiment includes the antenna element 12A made of metal and the holding member 14 made of resin. Therefore, the thermal expansion coefficients of the antenna element 12A and the holding member 14 are different. Specifically, the thermal expansion coefficient of the holding member 14 (resin) is larger than that of the antenna element 12A (metal).

  As described above, the antenna component 10A is surface-mounted on the substrate 30 using solder. This soldering process is performed by placing the antenna component 10A and the substrate 30 in a reflow furnace and heating to about 250 ° C., for example.

  For this reason, in the configuration in which the antenna element 12A is simply incorporated into the holding member 14 by insert molding, the antenna element 12A and the holding member 14 are different due to the difference in thermal expansion coefficient between the antenna element 12A and the holding member 14 during reflow processing (heating). Stress is generated between the two.

  FIG. 5 shows, by arrows, the stress generated between the antenna element 12A and the holding member 14 during heating. Since the thermal expansion coefficient of the holding member 14 is larger than the thermal expansion coefficient of the antenna element 12A, the stress acts outward as shown in FIG.

  The antenna element 12A may be deformed by this stress. When the antenna element 12A is deformed, the antenna characteristics are deteriorated and a soldering failure may occur between the antenna element 12A and the substrate 30.

  On the other hand, the antenna component 10A is provided with engaging portions 18A at both ends of the antenna element 12A. The engaging portion 18A has a first portion having a first width between the tip portion 21 of the antenna element 12A and the bent portion 15 and a second width that is wider than the first portion. It has at least one set consisting of the second part.

  In this embodiment, as shown in FIG. 4, the shape of the engaging portion 18 </ b> A (terminal portion 19) is a triangular shape in which the width dimension gradually increases from the bent portion 15 toward the inside of the mounting surface 20. For this reason, in this embodiment, the bending part 15 becomes a 1st site | part, and all the site | parts by the side of the front-end | tip part 21 rather than this bending part 15 become a 2nd site | part.

  Accordingly, when the width dimension (first width dimension) of the bent portion 15 (first part) is W1, the width dimension (second width dimension) of the second part is the first in all the parts. It is larger than the width dimension W1. For example, taking the width dimension of the distal end portion 21 of the engaging portion 18A as an example, the width dimension W2 of the distal end portion 21 is larger than the width dimension W1 of the bent portion 15 (W2> W1). Furthermore, the second part is configured to be disposed on the tip part 21 side with respect to the bent part 15 serving as the first part.

  Therefore, even if a stress is generated between the antenna element 12A and the holding member 14 due to thermal expansion and a force is applied to the engaging portion 18A in a direction away from the holding member 14, the second portion is held. The member 14 is caught (bite in), and a so-called anchor effect is generated in the engaging portion 18A.

  For this reason, the antenna element 12A does not move from the normal position even if stress is applied to the antenna element 12A in the direction away from the holding member 14 due to the difference in thermal expansion coefficient, and the antenna element 12A Generation of a gap between the holding member 14 and the holding member 14 can be prevented. Moreover, since the positional deviation of the terminal part 19 is suppressed, the coplanarity (flatness) of the terminal part 19 is maintained, and therefore the terminal part 19 can be soldered to the antenna pattern 32 in a good state. Therefore, according to the antenna device 1 and the antenna component 10A according to the present embodiment, it is possible to prevent the antenna characteristics from being deteriorated.

  Next, another embodiment of the present invention will be described with reference to FIGS. 6 to 9, the same components as those of the antenna device 1 and the antenna component 10A according to the embodiment described with reference to FIGS. 1 to 5 are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 6 shows an antenna component 10B which is still another embodiment of the present invention. FIG. 6 is a cross-sectional view of the antenna component 10B.

  The antenna component 10 </ b> B according to the present embodiment is configured such that the engaging portion 18 </ b> B is provided on the tip portion 21 side of the antenna element 12 </ b> B, and the engaging portion 18 </ b> B is positioned inside the holding member 14 with respect to the terminal portion 19. Specifically, in this embodiment, the engaging portion 18B is bent inward with respect to the terminal portion 19.

  By adopting this configuration, when the antenna element 12B is insert-molded into the holding member 14, the engaging portion 18B bites into the holding member 14 and is engaged. Therefore, also in the antenna component 10B according to the present embodiment, an anchor effect is generated in the engaging portion 18B, and the engaging portion 18B (terminal portion 19) can be prevented from moving from the normal position of the holding member 14. Thereby, also in the antenna component 10B which concerns on this embodiment, degradation of an antenna characteristic can be suppressed.

  In addition, the process which bends the front-end | tip part of the terminal part 19 of the antenna element 12B inside can be easily performed by press work etc., Therefore The engaging part 18B can be formed easily.

  FIG. 7 shows an antenna component 10C according to still another embodiment of the present invention. FIG. 7 shows a cross section of the antenna component 10C.

  The antenna component 10 </ b> C according to this embodiment has an engaging portion 18 </ b> C formed on the distal end portion 21 side of the terminal portion 19 on the inner side of the holding member 14, similarly to the antenna component 10 </ b> B according to the embodiment shown in FIG. 6. The configuration is displaced.

  In the antenna component 10B shown in FIG. 6, the engaging portion 18B is formed by deforming the tip of the antenna element 12B inward by press working or the like. On the other hand, the antenna component 10C according to the present embodiment is characterized in that a burr generated at the time of notch folding performed in the manufacturing process of the antenna element 12C is used as the engaging portion 18C.

  When the antenna element 12C is manufactured, so-called multi-cavity manufacturing is performed in which a plurality of antenna elements 12C are manufactured collectively from a single sheet metal. FIG. 8 shows a conductive metal plate 51 on which a plurality of antenna elements 12C are formed.

  As shown in the figure, in a state immediately after the plurality of antenna elements 12C are formed from one conductive metal plate 51, the plurality of antenna elements 12C are connected and integrated by a connecting portion 52. Yes.

  In this way, by connecting the plurality of antenna elements 12C at the connection portion 52, a plurality of antenna elements 12C having a small shape can be collectively handled, and handling becomes easy.

  Further, when the antenna element 12 </ b> C is manufactured, the connection portion 52 is formed so as to be located on the inner side with respect to the terminal portion 19. Specifically, the connection portion 52 is formed so as to be located on the inner side with respect to the terminal portion 19 by a dimension indicated by an arrow ΔH in FIG. Further, at the time of this pressing, a notch 54 (V-shaped groove) is formed at the boundary portion between the terminal portion 19 and the connection portion 52.

  When the antenna element 12C shown in FIG. 8 is formed, the conductive metal plate 51 on which the antenna element 12C is formed is mounted on a mold, and the holding member 14 is molded. FIG. 9A is a cross-sectional view showing a state in which the conductive metal plate 51 (antenna element 12C) is inserted into the holding member 14. FIG. 9A to 9C are cross-sectional views of the holding member 14 cut at the position where the antenna element 12C is formed.

  In the state shown in FIG. 9A, each antenna element 12C does not function as an antenna because it is also electrically connected by the connecting portion 52. Therefore, as shown in FIG. 9B, the antenna element 12C is individually separated by bending and cutting the connecting portion 52 at the position where the notch 54 is formed (the bending and cutting process in the notch 54). Is called notch folding).

  When this notch folding is performed, burrs 56 are generated at the cut portion. The burr generated by the notch folding is conventionally removed by performing a burr removing process after the notch folding. In contrast, the present embodiment is characterized in that the burr 56 is used as the engaging portion 18C.

  If the notch fold is performed with the terminal portion 19 and the connection portion 52 being flush with each other (the same plane), the burr 56 protrudes downward from the terminal portion 19 and the coplanarity (flatness) of the terminal portion 19 is lowered. The solderability with the antenna pattern 32 is reduced.

  Therefore, in the present embodiment, the connection portion 52 is shifted (shifted) inward with respect to the terminal portion 19. Further, the shift amount ΔH to the inside of the connection portion 52 with respect to the terminal portion 19 is set to be larger than the downward protrusion amount of the burr 56 generated.

  Therefore, even if notch folding is performed at the position where the notch 54 is formed, the burr 56 does not protrude downward from the terminal portion 19. Thereby, the coplanarity of the terminal part 19 is maintained and the terminal part 19 and the antenna pattern 32 can be soldered satisfactorily.

  As described above, the antenna element 12C according to the present embodiment uses the burr 56 generated when the notch folding is performed as the engaging portion 18C. For this reason, when the antenna element 12C is insert-molded into the holding member 14, the engaging portion 18C is engaged with the holding member 14.

  Therefore, the antenna component 10C according to the present embodiment also has an anchor effect at the engaging portion 18C. Therefore, it can prevent that the engaging part 18C (terminal part 19) moves from the normal position of the holding member 14, and can suppress degradation of an antenna characteristic.

  FIG. 10 shows engaging portions 18D to 18I as still another embodiment. Note that each of the engaging portions 18 </ b> D to 18 </ b> I illustrated in FIG. 10 is configured integrally with the terminal portion 19.

  In FIG. 10A, a circular engagement portion 18 </ b> D is formed between the bent portion 15 and the distal end portion 21. A diameter W2 (second width dimension) of the engaging portion 18D is set to be larger than a width dimension W1 (first width dimension) of the terminal portion 19. The engaging portion 18 </ b> D is disposed on the tip portion 21 side with respect to the terminal portion 19.

  10B, a rectangular engaging portion 18E is formed between the bent portion 15 and the distal end portion 21, and the entire portion including the terminal portion 19 has a substantially T shape. A width dimension W2 (second width dimension) of the engaging portion 18E is set larger than a width dimension W1 (first width dimension) of the terminal portion 19. Further, the engaging portion 18 </ b> E is disposed on the tip portion 21 side with respect to the terminal portion 19.

  In FIG. 10C, a rectangular engaging portion 18 </ b> F is formed between the bent portion 15 and the distal end portion 21, and the entire portion including the terminal portion 19 has a substantially L shape. A width dimension W2 (second width dimension) of the engaging portion 18F is set to be larger than a width dimension W1 (first width dimension) of the terminal portion 19. Further, the engaging portion 18 </ b> F is disposed on the tip portion 21 side with respect to the terminal portion 19.

  FIG. 10D includes a first portion having a width dimension W1 (first width dimension) and a second portion having a triangular shape between the bent portion 15 and the tip portion 21. An engaging portion 18G is formed. In addition, the maximum width dimension W2 (second width dimension) in the second part is set to be larger than the first width dimension.

  Further, the second portion having the width dimension W2 is disposed on the distal end portion 21 side with respect to the first portion having the width dimension W1.

  FIG. 10E shows a first portion having a width dimension W1 (first width dimension) and a width dimension W2 (second width dimension) wider than that between the bent portion 15 and the tip portion 21. A pair of second portions having) indicates a plurality of engaging portions 18H formed. The engaging portion 18H shown in the present embodiment shows an example in which three sets of the first part and the second part are formed. Further, in each set, the second portion having the width dimension W2 is disposed on the distal end portion 21 side with respect to the first portion having the width dimension W1.

  FIG. 10F shows a configuration in which an engaging portion 18I having a zigzag shape is formed between the bent portion 15 and the distal end portion 21.

  Even when the engagement portions 18D to 18I shown in FIGS. 10A to 10F are formed at the end of the antenna element, stress is generated between the antenna element and the holding member due to thermal expansion. In the case, the anchor effect is generated in the engaging portions 18D to 18I as well as the engaging portion 18A (see FIGS. 1 to 5). Therefore, it is possible to prevent a gap from being generated between the antenna element and the holding member, and it is possible to maintain the coplanarity because the positional deviation of the terminal portion 19 is suppressed. Thereby, the antenna component 10A having the engaging portions 18D to 18I shown in FIGS. 10A to 10F can prevent the deterioration of the antenna characteristics.

  As described above, the antenna components 10A to 10C according to the present embodiment can maintain predetermined antenna characteristics without deformation of the antenna elements 12A to 12C even when heat treatment is performed as in the substrate mounting. it can. Therefore, it is possible to improve the characteristics and the reliability of the antenna device on which the antenna components 10A to 10C are mounted.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments described above, and various modifications can be made within the scope of the present invention described in the claims. It can be modified and changed.

DESCRIPTION OF SYMBOLS 1 Antenna apparatus 10A-10C Antenna components 12A-12C Antenna element 14 Holding member 15 Bending part 16 Main-body part 18A-18I Engagement part 19 Terminal part 20 Mounting surface 21 Tip part 30 Substrate 32 Antenna pattern 50 Frame member 52 Connection part 54 Notch

Claims (3)

An antenna component constituting a helical antenna by being mounted on a substrate,
A plurality of antenna elements having terminal portions connected to the wiring formed on the substrate at both ends, and constituting the helical antenna in cooperation with the wiring;
A holding member for holding the antenna element;
An antenna component provided with an engaging portion that engages with the holding member at at least one end of the antenna element ,
The terminal portion is formed by providing a bent portion in the antenna element,
The engaging portion has a first portion having a first width between a tip portion of the antenna element and the bent portion, and a second portion having a second width wider than the first portion. Having at least one set of two parts,
An antenna component , wherein the second part is disposed on the tip side with respect to the first part. An antenna component constituting a helical antenna by being mounted on a substrate,
A plurality of antenna elements having terminal portions connected to the wiring formed on the substrate at both ends, and constituting the helical antenna in cooperation with the wiring;
A holding member for holding the antenna element;
An antenna component provided with an engaging portion that engages with the holding member at at least one end of the antenna element,
The engaging portion, antenna parts and having a zigzag shape. The antenna component according to claim 1 or 2 ,
A board on which connection wiring for connecting the end of the antenna element is formed,
The antenna device, wherein the antenna component is mounted on the substrate, whereby the antenna element and the connection wiring are connected to constitute the helical antenna.

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