WO2006022350A1

WO2006022350A1 - Chip antenna and method for manufacturing the same

Info

Publication number: WO2006022350A1
Application number: PCT/JP2005/015472
Authority: WO
Inventors: Tetsuo Shinkai
Original assignee: Omron Corporation
Priority date: 2004-08-26
Filing date: 2005-08-25
Publication date: 2006-03-02
Also published as: JP2006067251A

Abstract

In a chip antenna (1), a power supply conductor (2) and a dielectric board (3) are integrally formed by insert-forming a taper slot shaped power supply electrode part (5) to be covered with board materials (3a, 3b), which constitute the dielectric board (3) and have different specific inductive capacities. Thus, a method for manufacturing the chip antenna which is small but can be easily manufactured, has excellent antenna characteristics and applicable to wide band is provided.

Description

Specification

Chip antenna and manufacturing method thereof

Technical field

TECHNICAL FIELD [0001] The present invention relates to a chip antenna and a manufacturing method thereof, and more particularly to a chip antenna that realizes downsizing of a chip antenna corresponding to a wide frequency band and improvement of productivity and a manufacturing method thereof. .

Background art

In recent years, portable information processing devices having a wireless communication function have been popularized. For wireless communication in such an information processing apparatus, it is essential to mount an antenna in the information processing apparatus. With the small size and light weight of such portable information processing devices, it is important to develop a small antenna.

Accordingly, various antennas have been proposed in response to the demand for miniaturization. For example, Patent Document 1 (Japanese Patent Laid-Open No. 2003-133842 (published on May 9, 2003)) proposes a monopole antenna that can be easily reduced in height and facilitates downsizing. The monopole antenna will be described below with reference to FIG.

FIG. 17 is a configuration diagram of the monopole antenna 200. The monopole antenna 200 includes a dielectric substrate 20 standing on the ground plane 100, and a radiation conductor 30 provided on the surface of the dielectric substrate 20 along the vertical direction. A wire 40 is connected to the lower end of the radiating conductor 30. In addition, a ground electrode portion 50 is provided at the lower end portion of the dielectric substrate 20, and the ground electrode portion 50 is soldered to a ground surface 100 made of a metal plate or the like.

[0005] The ground electrode unit 50 is connected to an input power source 60, and a high-frequency signal is fed from the input power source 60 to the radiation conductor 30 via the feeder line 40. In addition, the radiation conductor 30 has an upper portion 1Z3 far from the ground plane 100 as a wide portion 30a as shown in FIG. 17, and a lower portion 1Z3 near the ground plane 100 as a narrow portion 30b. Between the narrow portion 30b, the width dimension is intermediate between the two. As described above, changing the shape of the radiation conductor 30 between the upper side and the lower side of the radiation conductor 30 has the following effects. [0006] The upper side of the radiating conductor 30 is a capacitance region where the voltage changes greatly. Since this portion of the monopole antenna 200 is a wide portion 30a, the resonance frequency of the monopole antenna is reduced along with the increase in capacitance on the upper side of the radiating conductor 30.

[0007] The lower side of the radiating conductor 30 is an inductive region where the current changes greatly. Since the monopole antenna 200 has a narrow portion 30b, the inductance increases. As the inductance increases, the resonance frequency of the monopole antenna 200 decreases.

That is, when compared with a monopole antenna in which a strip-shaped radiation conductor having a constant width is formed on the surface of the dielectric substrate, the monopole antenna 200 has the same height dimension as that of the radiation conductor 30. If the resonant frequency force S is reduced, and therefore the resonance is performed at a desired frequency, a band-shaped radiation conductor having a constant width is formed, and the height dimension can be reduced as compared with the monopole antenna.

FIG. 18 shows a plan view of an antenna having a shape generally called a tapered slot shape. The tapered slot shape is a shape shown in the radiation conductor 300 of FIG. 18, and the radiation conductor 300 corresponds to the radiation conductor 30 shown in FIG. By having such a radiating conductor 300, the tapered slot-shaped antenna can obtain the same effect as the monopole antenna 200 including the radiating conductor 30 described above.

[0010] The graph of Fig. 19 shows the VSWR (Voltage Standing Wave Ratio) measurement results of the tapered slot antenna shown in Fig. 18. VSWR is a value indicating the degree of reflection. “1” indicates no reflection, which is the best antenna characteristic. In contrast, the higher the VSWR, the greater the reflection. In other words, the lower the VSWR, the better the antenna characteristics!

As described above, the VSWR value can be used as an index indicating the antenna characteristics. The graph in Fig. 19 shows the maximum value of VSWR.

[0012] From the graph of FIG. 19, this tapered slot antenna has a relatively low VSWR value for radio waves in the frequency band 3.1 to 10.6 GHz, so it has a wide frequency band of 3.1 to 10.6 GHz. It can be seen that it can be used to send and receive radio waves. [0013] In order to manufacture the antenna as described above, generally, a process of dicing a dielectric substrate into a predetermined shape, a process of masking the surface of the dielectric substrate, A manufacturing method including a step of plating a corresponding metal material on the surface of the dielectric substrate and a step of finally forming the power supply conductor on the dielectric substrate by etching to remove the mask portion is used.

However, the antenna as shown in the above prior art has the following problems regarding mass productivity.

[0015] That is, as described above, generally used antenna manufacturing methods including the monopole antenna 200 have complicated processes, and the mass productivity of the antenna and the mass production of the mounted equipment are difficult.

'It is difficult to improve sex.

In the monopole antenna 200, a material having a relatively high relative dielectric constant such as FR-4 (for example, ε r is about 4.8) is used as the dielectric substrate 20. Since FR-4 is inexpensive, it can contribute to the cost reduction of the monopole antenna 200.

[0017] However, the force that can be reduced in terms of cost by using an inexpensive material such as FR-4 while the force is FR-4 is a material having a relative dielectric constant of about 4.8. It is difficult to reduce the size further.

Furthermore, as shown in FIG. 19, the taper slot-shaped wideband antenna has a relatively low VSWR value in the frequency band 3.1 to 10.6 GHz. And in the frequency band around 7-8GHz (especially in the frequency band 7-8GHz), VS

WR is rising and antenna characteristics tend to deteriorate.

Accordingly, the present invention has been made in view of the above-described problems, and an object of the present invention is to realize a chip antenna that is easy to manufacture and has a wide antenna characteristic while realizing downsizing. It is in providing the manufacturing method of.

Disclosure of the invention

In order to solve the above problems, a method for manufacturing a chip antenna of the present invention includes a dielectric substrate made of a dielectric material, a terminal portion having a power feeding terminal, and a conductor portion that is electrically connected to the terminal portion. A method of manufacturing a chip antenna including a power supply conductor, wherein the dielectric substrate and the power supply conductor are arranged so that at least a part of the conductor portion is covered with the dielectric material. Is characterized by being integrally formed by insert molding. Specifically, the dielectric substrate is preferably a resin.

[0021] According to the above configuration, in the chip antenna manufacturing method according to the present invention, the dielectric substrate and the feed conductor are integrally formed by insert molding.

[0022] Thereby, the manufacturing becomes easier as compared with the conventional manufacturing method of the antenna. Therefore, mass productivity can be improved and a low-cost chip antenna can be provided.

[0023] Specifically, in the method for manufacturing a chip antenna according to the present invention, the power supply conductor having the terminal portion and the conductor portion is sandwiched, and at least a part of the conductor portion of the power supply conductor is dielectric. The dielectric substrate is integrally formed with the power supply conductor by insert molding so as to be covered with the dielectric material of the body substrate.

A general chip antenna manufacturing method requires many steps as described above.

Therefore, it is difficult to improve the production efficiency of the chip antenna. Therefore, the chip antenna manufacturing method according to the present invention includes, as described above, integrally molding the dielectric substrate and the power supply conductor by insert molding, so that the above-described mask processing step and the mask are performed. It can be manufactured by a simple method without requiring a step of removing by partial etching. As the dielectric material of the dielectric substrate, a resin can be used.

That is, according to the chip antenna manufacturing method of the present invention, the mass productivity of the chip antenna can be improved.

[0026] Further, as the mass productivity is improved, the cost associated with the chip antenna can be reduced, so that a low-cost chip antenna can be provided.

[0027] Further, since at least a part of the conductor portion of the power supply conductor is insert-molded so as to be covered with the dielectric material, the portion of the conductor portion covered with the dielectric material is not exposed to the outside. Therefore, the conductor portion can be protected from the external environment such as oxidation.

Accordingly, the durability of the conductor portion with respect to the external environment and the durability of the entire chip antenna with respect to the external environment can be improved. [0029] In the present specification, "insert molding" means that a metal material such as a power supply conductor is placed in the mold using a mold, and further a dielectric material is placed in the mold. By introducing, a metal material such as a power supply conductor and a dielectric material are integrally formed.

[0030] Further, since the chip antenna manufactured by the chip antenna manufacturing method of the present invention has a chip shape, it is a thin antenna whose height from the ground plane is lower than that of a conventional monopole antenna. Can be provided.

[0031] Thus, it can be suitably used for thin devices such as various mopile devices that have been actively developed in recent years.

[0032] Further, in the method for manufacturing a chip antenna according to the present invention, the dielectric substrate has at least two dielectric material forces having different dielectric constants, and each dielectric material is in contact with the conductor portion. Is preferred. Specifically, the conductor part has a line-symmetric shape with respect to an axis of symmetry including the power supply terminal, and the dielectric substrate has a dielectric constant stepped toward a side farther from the side force closer to the axis of symmetry. It is preferable to be molded so as to be large. Specifically, it is preferable that at least one of the above-mentioned dielectric materials is rosin.

By adopting the above configuration, in addition to the above effects, it is possible to provide a chip antenna that can cope with a wider frequency band while keeping the maximum value of VSWR small.

[0034] As described above, the conventional broadband antenna having a tapered slot shape has an increased VSWR value in a specific frequency band. This is due to the reflection of electromagnetic waves propagating to the radiation conductor. Specifically, electromagnetic waves are reflected at the interface where the dielectric constant changes, such as the outer surface of the dielectric substrate. Here, the boundary surface is, for example, the boundary between the outer surface of the dielectric substrate and the external space where electromagnetic waves are radiated. The conventional taper slot shaped broadband antenna and the monopole antenna described in Patent Document 1 each have a single-layer dielectric substrate as shown in the figure. When the dielectric substrate is a single layer, the location where electromagnetic waves are reflected is only the boundary surface between the outer surface of the dielectric substrate and the external space where the electromagnetic waves are radiated. Waves will be generated. This increases the VSWR value. Therefore, according to the method for manufacturing a chip antenna of the present invention, each substrate material is configured to be in contact with at least the conductor portion, and the substrate materials have different dielectric constants. Thereby, the electromagnetic wave propagating from the feed line to the feed conductor inside the dielectric substrate is reflected on the boundary surface of each substrate material and the outer surface of the dielectric substrate according to the difference in the dielectric constant. It will be.

[0036] That is, in the above configuration, since at least two substrate materials constituting the dielectric substrate are substrate base materials having different dielectric constants, locations where electromagnetic waves are reflected are dispersed. Along with this, the reflected waves of the respective frequencies are also dispersed. Therefore, it is possible to avoid a problem that a reflected wave having a high intensity is generated concentrated on a predetermined frequency and the VSWR value at that frequency is increased.

[0037] In addition, as described above, the chip antenna manufacturing method of the present invention can make the dielectric substrate multi-layered, and even when multi-layered, each dielectric can be easily formed by insert molding. The material and the power supply conductor can be integrally formed.

[0038] Therefore, it is possible to provide a chip antenna that is easy to manufacture and that can handle a wide range of frequencies (radio waves).

[0039] Further, in the method for manufacturing a chip antenna of the present invention, the feeding conductor is disposed in the mold with reference to a positioning region provided in the chip-shaped mold, and the dielectric substrate and the insert are inserted. It is preferable to integrally mold by molding.

[0040] According to the above configuration, a chip antenna with high manufacturing accuracy can be manufactured. Specifically, a positioning region is provided in advance at a predetermined position of a mold used for insert molding. Thereby, the power supply conductor can be arranged in the mold with reference to the positioning region. The feeding conductor and the dielectric substrate can be accurately integrally formed.

[0041] Thus, the chip antenna manufacturing method of the present invention can be formed integrally with the feeding conductor and the dielectric substrate more accurately than simply with the conventional method. Compared with the conventional method, the manufacturing accuracy is high.

[0042] In the method for manufacturing a chip antenna of the present invention, it is preferable that the feeding conductor is formed by pressing a lead frame in accordance with a cut die.

[0043] With the above-described configuration, the manufacturing method of the chip antenna of the present invention can be simplified, and a conductor portion having a desired shape can be easily formed.

That is, in the conventional manufacturing method, as described above, the feed conductor (the conductor portion of the feed conductor) In order to form the film, a number of steps were required, such as a step of masking the dielectric substrate, a metal material corresponding to the power supply conductor, and finally removing the mask portion by etching. Therefore, the chip antenna manufacturing method of the present invention can form the power feeding conductor by press-carrying the lead frame in accordance with the cut mold, so that the conductor is very easily compared with the conventional method. The part can be formed.

[0045] Further, by changing the shape of the cut mold, it is possible to form a feed conductor having a desired shape. Therefore, it is possible to provide a chip antenna having a shape suitable for an apparatus or device on which the chip antenna manufactured by the manufacturing method of the present invention is mounted.

In the method for manufacturing a chip antenna of the present invention, it is preferable that the conductor portion has a tapered slot shape.

[0047] With the above configuration, the chip antenna manufactured by the manufacturing method of the present invention can be used for transmission / reception of radio waves in the wide frequency band 3.1 to: LO. 6 GHz.

[0048] In the method for manufacturing a chip antenna of the present invention, it is preferable that the terminal portion is bent after the dielectric substrate and the feed conductor are integrally formed by insert molding.

With the above configuration, the chip antenna manufactured by the chip antenna manufacturing method of the present invention can be formed into a surface-mounted shape.

[0050] Since the monopole antenna in the prior art has a structure that stands up with respect to the ground plane, it is difficult to automatically mount the ground pole on the ground plane as described above. On the other hand, in the chip antenna manufacturing method of the present invention, the terminal portion is bent after the dielectric substrate and the feed conductor are integrated by insert molding. Since the terminal portion is bent, the chip antenna manufactured by the chip antenna manufacturing method of the present invention is a surface mount type.

[0051] Note that the surface mount type refers to a state in which the surface of the power supply conductor of the chip antenna is configured to be horizontal with respect to the installation surface of the apparatus or device on which the chip antenna according to the present invention is mounted. It is.

[0052] Since this is a surface-mounted chip antenna, Rather than a standing structure, it can be surface mounted. As a result, it is possible to improve the productivity of devices equipped with chip antennas.

[0053] In the method for manufacturing a chip antenna of the present invention, it is preferable that the resin is a polyether sulfone or a liquid crystal polymer.

[0054] Polyethersulfone or liquid crystal polymer has a characteristic of having a high dielectric constant among rosins. When a material having a high dielectric constant is formed on the dielectric substrate, the feed conductor can be reduced in size due to the wavelength shortening effect. Therefore, it is possible to further reduce the size of the chip antenna manufactured by the chip antenna manufacturing method of the present invention.

[0055] Still other objects, features, and advantages of the present invention will be fully understood from the following description. The benefits of the present invention will become apparent from the following description with reference to the accompanying drawings.

Brief Description of Drawings

FIG. 1 is a perspective view showing the shape of a chip antenna in an embodiment according to the present invention.

FIG. 2 is a perspective view showing the configuration of the chip antenna in the embodiment according to the present invention.

FIG. 3 is a cross-sectional view of the chip antenna shown in FIG. 1 cut along line AA ′.

4 is a cross-sectional view of the chip antenna shown in FIG. 1 cut along a line BB ′.

FIG. 5 (a) is a plan view showing a structure of a feed conductor composed of a feed electrode portion and a feed terminal portion provided in the chip antenna according to the embodiment of the present invention.

FIG. 5 (b) is a perspective view of the feed conductor shown in FIG. 5 (a).

FIG. 6 is a schematic diagram showing a method for manufacturing a chip antenna according to an embodiment of the present invention, and in particular, a method for manufacturing a chip antenna when a dielectric substrate is made of one type of substrate material.

FIG. 7 is a schematic diagram showing a method for manufacturing a chip antenna according to an embodiment of the present invention, and in particular, a method for manufacturing a chip antenna when the dielectric substrate is made of two types of substrate materials.

FIG. 8 is a perspective view showing a modification of the structure of the chip antenna according to the embodiment of the present invention.

[FIG. 9] As a characteristic evaluation of the chip antenna in the embodiment according to the present invention, 3.1˜: LO. It is a graph which shows the measurement result which measured VSWR in a 6GHz band.

[Fig. 10] —Cross-sectional view showing the structure of a general tapered slot antenna and a graph showing the measurement results of VSWR in the 3.1 to 10.6 GHz band for each dielectric constant of the dielectric substrate. is there.

FIG. 11 (a) is a cross-sectional view showing a configuration of a chip antenna according to an embodiment of the present invention.

[FIG. 11 (b)] FIG. 11 (b) is a graph showing measurement results obtained by measuring VSWR in the 3.1 to 10.6 GHz band of the chip antenna shown in FIG. 11 (a).

FIG. 12 is a perspective view showing a modification of the structure of the chip antenna according to the embodiment of the present invention.

FIG. 13 (a) is a perspective view showing a modification of the configuration of the chip antenna according to the embodiment of the present invention.

[FIG. 13 (b)] is a cross-sectional view of the chip antenna shown in FIG. 13 (a) cut along line CC ′.

14 is a sectional view showing a modification of the configuration of the chip antenna shown in FIG.

FIG. 15 is a cross-sectional view showing the configuration of the chip antenna used in this example.

FIG. 16 is a graph showing the measurement results of measuring VSWR in the 3.1 to: LO. 6 GHz band as a characteristic evaluation of the chip antenna used in this example.

FIG. 17 is a configuration diagram showing a configuration of a monopole antenna in the prior art.

FIG. 18 is a cross-sectional view showing a configuration of a general tapered slot antenna.

[Fig.19] 3.1-10.6G as characteristics evaluation of general tapered slot antenna

It is a graph which shows the measurement result which measured VSWR in the Hz band.

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1]

Embodiments according to the present invention will be described with reference to FIGS. 1 to 14 as follows.

FIG. 1 is a perspective view showing the shape of chip antenna 1 in the present embodiment. As shown in Fig. 1, chip antenna 1 is a chip-shaped antenna whose outer shape is dielectric. The body substrate 3 is formed.

In the present embodiment, as shown in FIG. 1, dielectric substrate 3 is composed of two types of substrate materials, substrate materials 3a and 3b. However, the present invention is not limited to this. Even when the dielectric substrate 3 is composed of only one kind of substrate material, it is possible to construct two or more kinds of substrate material forces. It may be.

In the present specification, the dielectric constant of the substrate materials 3a and 3b of the dielectric substrate 3 with respect to the dielectric constant ε 0 in the space (external space, usually the air layer) from which the electromagnetic waves are radiated from the chip antenna 1 The ratio of ε 1 ε 1 / ε 0 is defined as the relative dielectric constant of dielectric substrate 3 (substrate materials 3a and 3b).

FIG. 2 is a perspective view of the chip antenna 1 illustrated in FIG. In FIG. 2, the substrate materials 3a and 3b of the dielectric substrate 3 are omitted for convenience of explanation.

As shown in FIG. 2, the chip antenna 1 includes a feeding conductor 2, a dielectric substrate 3, and ground electrodes 4a and 4b.

The power supply conductor 2 includes a power supply electrode portion 5 (conductor portion) and a power supply terminal portion 6 (terminal portion). As shown in FIG. 2, the power supply conductor 2 is sandwiched between the dielectric substrates 3. In particular, the power supply electrode portion 5 is completely covered with the dielectric substrate 3. A part of the power feeding terminal 6 is exposed to the outside of the dielectric substrate 3, and has a power feeding terminal 7 at the end of the exposed power feeding terminal 6.

FIG. 3 is a cross-sectional view showing a state where the chip antenna 1 is cut along a line segment AA ′ in FIG. As shown in FIG. 3, the feed conductor 2 has a line-symmetric shape with respect to the symmetry axis S.

The feeding electrode portion 5 is an electrode made of a conductor, and this shape is generally called a taper slot shape. The feeding electrode portion 5 is connected to the feeding terminal portion 6 in the region V.

[0066] The power supply terminal portion 6 is a terminal made of a conductor, and the shape thereof is a flat plate. The power feeding terminal portion 6 is disposed between the ground electrodes 4a and 4b so as to be separated from each other, and is electrically insulated from the ground electrodes 4a and 4b by being separated. One of the opposing ends of the feeding terminal portion 6 is connected to the region V of the feeding electrode portion 5. And electrically connected to the feeding electrode portion 5. At the other end, a power supply terminal 7 is provided and connected to a power supply line (not shown).

[0067] As described above, the power supply terminal 7 of the power supply terminal portion 6 is exposed to the outside of the dielectric substrate 3, and the exposed portion is shown in FIG. 1 and FIG. It is bent like this. Since the feeding terminal 7 portion of the feeding terminal portion 6 is bent, the chip antenna i of the present embodiment is suitable for surface mounting. The power supply terminal portion 6 can be made of, for example, a metal material.

As shown in FIG. 17, the monopole antenna 200 according to the prior art has a structure in which the monopole antenna 200 stands up on the ground plane 100. In its manufacture, the monopole antenna 200 is self-supported on the ground plane 100. That is, it is difficult to automatically mount the monopole antenna 200 on the ground plane 100. Therefore, in order to stand on the ground plane 100, it is necessary to perform soldering manually. Therefore, the monopole antenna 200 is compared with a monopole antenna in which a strip-shaped radiation conductor having a constant width is formed. Although it can be downsized, mounting on mounting devices was complicated. Further, as described above, the monopole antenna 200 is configured to stand on the ground plane 100, and thus has a predetermined height in the height direction. Therefore, the monopole antenna 200 is mounted on a thin device such as a mopile device. It is difficult to let On the other hand, the chip antenna 1 according to the present embodiment has a structure suitable for surface mounting by bending the feeding terminal 7 portion of the feeding terminal portion 6, so that the mass productivity of the chip antenna is improved. Thus, it is possible to improve the mass productivity of the mounting device on which the chip antenna is mounted.

[0069] The ground electrodes 4a and 4b are electrodes made of a conductor, and the shape thereof is a flat plate. The ground electrodes 4a and 4b are perpendicular to the symmetry axis S formed by the feed electrode section 5, and the ground electrode 4a and the ground electrode 4a are arranged so that the feed terminal section 6 is spaced from the ground electrodes 4a and 4b. And it is arranged at a certain distance from 4b. The ground electrodes 4a and 4b can be made of, for example, a metal plate material.

[0070] Dielectric substrate 3 is made of a dielectric material, and is interposed between feeding electrode portion 5 and ground electrodes 4a and 4b, and fills between feeding electrode portion 5 and ground electrodes 4a and 4b. It is a member. The outer shape of the dielectric substrate 3 corresponds to the outer shape of the chip antenna 1, and as shown in FIG. It has a shape. The dielectric substrate 3 is composed of substrate materials 3a and 3b. The substrate materials 3a and 3b will be described in detail below based on FIG.

FIG. 4 is a cross-sectional view showing a state where the chip antenna 1 is cut along the line BB ′ in FIG. As shown in FIG. 4, the dielectric substrate 3 is composed of substrate materials 3a and 3b, and both are configured to be in contact with the feeding electrode portion 5. Specifically, the substrate material 3a is arranged in a region including the symmetry axis S of the feeder conductor 2, and the substrate material 3b is arranged in a region far from the symmetry axis S without including the symmetry axis S. !

[0072] The substrate materials 3a and 3b are dielectrics having dielectric constants ε3a and ε3b, respectively, and their relative dielectric constant forces S are adjusted so as to increase in this order. Specifically, the substrate material 3b has a higher dielectric constant than the substrate material 3a so that the relative dielectric constant increases as the distance from the symmetry axis S increases.

[0073] The dielectric constant of each substrate material is not particularly limited as long as such a condition is satisfied. For example, a substrate material 3a having a dielectric constant ε = 4 and a substrate material 3b having a dielectric constant ε = 16 can be used. In the following description, a case where the substrate material 3a having a dielectric constant ε = 4 and the substrate material 3b having a dielectric constant ε = 16 is used will be described.

[0074] As a substrate material having such a dielectric constant, a resin is preferable. The reason is that, as will be described later, the chip antenna according to the present invention is manufactured by integrally molding the feeding conductor 2 and the dielectric substrate 3 by insert molding. Therefore, a resin having thermoplasticity, that is, a thermoplastic cured resin is preferable.

[0075] Examples of the resin include polyethersulfone (PPS), liquid crystal polymer (LCP), syndiotactic polystyrene (SPS), polycarbonate (PC), polyethylene terephthalate (PET), epoxy resin (EP ), Polyimide resin (PI), polyetherimide resin (PEI), phenol resin (PF), and the like.

[0076] Among the above resins, PPS or LCP is particularly preferable because it can have a high dielectric constant among the resins.

[0077] The specific forming width W of the substrate material 3a, that is, the forming width W of the substrate material 3a in the direction perpendicular to the symmetry axis S shown in FIG. 3, is appropriately determined depending on the size of the chip antenna. Can be set. For example, the area of the cross section corresponding to the cross section shown in FIG. In the case of a chip antenna of m × 15 mm and a thickness of lmm, the forming width W of the substrate material 3a can be set in the range of 7 mm to: L lmm, and is preferably about 9 mm. In the following description, a case where the forming width W is 9 mm will be described.

[0078] By setting the molding width in the above range, as an index indicating the antenna characteristics, the maximum value of VSWR in the frequency band of 3.1 to 10.6 GHz is shown on the vertical axis as shown in FIG. In addition, it is possible to reduce the increase in the VSWR maximum value that occurs in a wide band antenna with a general tapered slot shape, and to stabilize the VSWR maximum value in the frequency band from 3.1 to 10.6 GHz. .

When electromagnetic waves are transmitted / received using the chip antenna 1, a cable such as a coaxial cable (not shown) is connected to the center of the chip antenna 1 from the ground electrode 4a side. At this time, the inner conductor (core wire) of the coaxial cable is connected to the feeding terminal 7, and the outer conductor (shield) of the coaxial cable is connected between the ground electrodes 4a and 4b. For this purpose, the ground electrodes 4a and 4b are provided with connectors (not shown) for connection to the coaxial cable. A coaxial cable without a connector may be directly attached to the ground electrodes 4a and 4b.

It should be noted that the chip antenna 1 in the present embodiment shown in FIGS. 1 to 3 is configured to include ground electrodes 4a and 4b. The present invention is not limited to this. Absent. That is, the ground electrode may be provided on the substrate side on which the chip antenna 1 is mounted. In the following description of the manufacturing method of the chip antenna 1 according to the present embodiment, the description will be given based on a configuration not provided with the ground electrodes 4a and 4b for convenience of explanation.

[0081] When the ground electrode is provided on the substrate side on which the chip antenna 1 is mounted, when the ground electrode is prepared in advance on the substrate side to be mounted and the coaxial cable is connected, the internal conductor Connect the (core wire) in the same way as above, and connect the outer conductor (shield) of the coaxial cable to the ground electrode fabricated on the board side.

Next, a method for manufacturing the chip antenna 1 having the above configuration will be described with reference to FIGS.

[0083] First, in order to explain the outline of the manufacturing method of the chip antenna of the present invention, a dielectric substrate is used. The case where only the force S i of the substrate material is also described will be described, and then the manufacturing method of the chip antenna 1 in this embodiment having the substrate materials 3a and 3b on the dielectric substrate will be described. Note that the member numbers in FIGS. 1 to 4 are used as they are for the convenience of explanation also when the case where the dielectric substrate is made of only one kind of substrate material is described.

First, a method for manufacturing the feed conductor 2 will be described with reference to FIGS. 5 (a) and 5 (b).

The power supply electrode portion 5 can be formed into a taper slot-shaped power supply electrode portion 5 as shown in FIG. 5 (a) by placing a lead frame in a taper slot-shaped cut die and pressing it. it can. For example, gold, silver, copper, or the like can be used as a material constituting the feeding electrode portion 5. The power feeding terminal portion 6 is formed by soldering. Since the feeding electrode unit 5 and the feeding terminal unit 6 are electrically connected, the feeding terminal 7 can be electrically connected to the feeding electrode unit 5. FIG. 5 (b) is a perspective view of the power supply conductor 2 in which the connection portion of the power supply terminal portion 6 is cut from the structure in the state of FIG. 5 (a).

Next, the power supply conductor 2 manufactured as described above is used to be integrally formed with the dielectric substrate 3 by insert molding to form a chip antenna.

A method for manufacturing a chip antenna by insert molding will be described below with reference to FIGS. 6 (a) to 6 (f).

[0088] The chip antenna is manufactured by insert molding by insert molding using the first die 8 having a chip shape. FIG. 6 (a) is a perspective view showing the shape of the first mold 8. For convenience of explanation, FIG. 6A shows only one side of the first mold 8. Therefore, when the substrate material is introduced, the first metal mold 8 on the other side is also used so that the power supply conductor 2 is sandwiched from both sides.

[0089] As shown in FIG. 6 (a), the first mold 8 is provided with a first positioning region 8a at a predetermined position. Examples of the first positioning region 8a include those in which a depression is formed in the shape of the power supply terminal portion 6 of the power supply conductor 2 as in the first positioning region 8a. By forming the depression, the feeding terminal portion 6 can be fitted into the depression and the feeding conductor 2 can be aligned. In addition, it is possible to align the feed conductor 2 even if a rod-like projection is formed at a predetermined position and the feed terminal 6 is brought into contact with the projection. If it is a thing, it will not specifically limit. As described above, since the first mold 8 is provided with the first positioning region 8a, the power supply conductor 2 shown in FIG. 5 (b) has the first positioning region 8a. 1 can be accurately placed in the mold 8 and the feeding conductor 2 and the dielectric substrate 3 can be integrally formed with high accuracy.

FIG. 6B is a perspective view showing a state in which the power supply conductor 2 is arranged in the first mold 8. Fig 6

(c) is a schematic view showing a state in which the feeding conductor 2 is sandwiched between the first molds 8 on both sides. The dielectric substrate 3 and the feed conductor 2 are integrated by introducing the substrate material of the dielectric substrate 3 having thermoplasticity into the first mold 8 from an introduction port (not shown) and insert molding. To do.

FIG. 6 (d) shows the chip antenna 1 after insert molding. As shown in FIG. 6 (d), the substrate material of the dielectric substrate 3 is formed integrally with the power supply conductor 2 so as to completely cover the surface of the power supply electrode portion 5 of the power supply conductor 2.

The integrally formed chip antenna 1 is cut with the length of the feeding terminal portion 6 shortened as shown in FIG. 6 (e). Next, as shown in FIG. 6 (f), the feeding terminal portion 6 exposed to the outside of the dielectric substrate 3 is bent.

[0094] By the method as described above, a chip antenna in the case where the dielectric substrate 3 has one type of substrate material can be manufactured.

In the case of manufacturing using two or more kinds of substrate materials as in the chip antenna 1 in the present embodiment, each substrate material only needs to have different thermoplasticity. In this case, unlike the above, the number of molds corresponding to the type of substrate material can be used to sequentially change the molds.

[0096] Next, a manufacturing method of the chip antenna 1 including the dielectric substrate 3 composed of the substrate materials 3a and 3b shown in FIGS. 1 and 3 will be described with reference to FIG.

FIG. 7 is a schematic diagram for explaining a manufacturing method of the chip antenna 1. Since the manufacturing method of the feeding conductor 2 is the same as described above, the description thereof is omitted.

Specifically, in the manufacturing method in the case of the chip antenna 1 shown in FIGS.

Then, the second mold 9 formed in the size of the substrate material 3a is used. FIG. 7 (a) is a perspective view showing the shape of the second mold 9. For convenience of explanation, FIG. 7 (a) shows the shape of the second mold 9. Only one side is shown. Therefore, when introducing the substrate material,

The metal mold 9 of 2 is also used so that the feeder conductor 2 is sandwiched from both sides.

[0099] As with the first mold 8, the second mold 9 is also provided with a second positioning region 9a at a predetermined position. The feeding conductor 2 manufactured by the above method can be aligned based on the second positioning region 9a, and can be accurately placed in the second mold 9. FIG. 7B is a perspective view showing a state in which the power supply conductor 2 is arranged in the second mold 9. FIG. 7 (c) is a schematic diagram showing a state in which the feeding conductor 2 is sandwiched between the second molds 9 on both sides. The substrate material 3a of the dielectric substrate 3 having thermoplasticity is introduced into the second mold 9 from an introduction port (not shown), and insert molding is performed to integrally mold the substrate material 3a and the power supply conductor 2. .

[0100] Next, the integrally formed substrate material 3a and the feeding conductor 2 are taken out from the second mold 9, and this is taken out of the mold corresponding to the substrate material 3b, that is, the first size of the dielectric substrate 3. Based on the first positioning region 8 a of the first mold 8, the first mold 8 is installed in the first mold 8. FIG. 7 (d) is a perspective view showing a state in which the substrate material 3a and the feed conductor 2 integrally formed in the first mold 8 are arranged. FIG. 7 (e) is a schematic diagram showing a state in which the feeding conductor 2 is sandwiched between the first molds 8 on both sides. A substrate material 3b having thermoplasticity is introduced into the first mold 8 through an introduction port (not shown), and insert molding is performed. FIG. 7 (f) is a perspective view showing a state in which the substrate material 3a, the power supply conductor 2, and the substrate material 3b are integrally formed.

Note that, as described above, the chip antenna 1 shown in FIGS. 1 to 3 has a configuration in which the ground electrodes 4a and 4b are provided. In the case of the configuration in which the ground electrodes 4a and 4b are provided, the manufacturing method is as shown in FIG. 7 (b), in which a positioning region for arranging the ground electrodes 4a and 4b is provided in the second mold 9, Together with the conductor 2, the substrate material 3 a of the dielectric substrate 3 having thermoplasticity and insert molding are performed. Similarly, in FIG. 7 (d), a positioning region for arranging the ground electrodes 4a and 4b is provided in the first mold 8, and the substrate material 3b having thermoplasticity and the substrate material 3a are fed. Conductor 2 and ground electrodes 4a and 4b are insert-molded.

[0102] By the above method, the chip antenna 1 including the dielectric substrate 3 having the two types of substrate materials shown in FIGS. 1 and 3 can be manufactured. [0103] As described above, if the molds corresponding to the respective substrate materials are used, the chip antenna 1 can be manufactured using two or more kinds of substrate materials.

[0104] In the above manufacturing method, the feeder conductor 2 having the structure shown in Fig. 5 (b) is used! However, the present invention is not limited to this! /.

That is, FIG. 8 is a perspective view showing a state in which the power supply conductor 2 having the structure shown in FIG. 5 (a) is integrally formed by insert molding with the power supply conductor 2, the dielectric substrate 3, and the like. . In this way, it can also be manufactured using the feed conductor having the structure shown in FIG.

[0106] As described above, the chip antenna manufacturing method according to the present embodiment is formed by integrally forming the dielectric substrate 3 and the feed conductor 2 by insert molding. In comparison, manufacturing is facilitated.

In addition, as shown in FIG. 17, the prior art monopole antenna 200 has a radiating conductor 30 connected to a feeding line 40 such as a coaxial cable provided on the surface of the dielectric substrate 20.ヽ. That is, the radiation conductor 30 is exposed to the outside. For this reason, the radiation conductor 30 has poor resistance to the external environment such as oxidation, and as a result, the durability of the monopole antenna 200 with respect to the external environment has occurred. On the other hand, in the chip antenna manufacturing method according to the present embodiment, since the feeding electrode portion 5 is covered with the substrate materials 3a and 3b, the above-described problem of resistance to the external environment can be solved. Therefore, the chip antenna 1 having high durability can be provided.

Next, characteristics and the like of the chip antenna 1 manufactured by the manufacturing method described with reference to FIG. 7 will be described.

In the following, for convenience of explanation, it is assumed that electromagnetic waves are transmitted using the chip antenna 1, and the force for explaining the characteristics of the chip antenna, etc. The same holds true for reception. That is, the chip antenna 1 can be used for both electromagnetic wave transmission and reception.

[0110] In the following, it is assumed that the chip antenna 1 is used to transmit a high frequency band of 3.1 to 10.6 GHz, which corresponds to the frequency band of UWB communication.

[0111] In the chip antenna 1 of the present embodiment, as described above, the antenna can be downsized by providing the dielectric substrate. The reason is that the dielectric substrate 3 is This is because a wavelength shortening effect is obtained by providing them. Therefore, for example, an electromagnetic wave having a longer wavelength, that is, an electromagnetic wave having a lower frequency can be transmitted as compared with a chip antenna of the same size without a dielectric substrate. On the other hand, if the limits on the low frequency side are the same, chip antenna 1 is larger in size than a chip antenna without a dielectric substrate.

/ J, you can do it.

Further, in the present embodiment, as shown in FIG. 2, by providing the feeding electrode portion 5 having a tapered slot shape, a wide band in a frequency band can be realized.

[0113] Therefore, for the chip antenna 1 manufactured by the above-described manufacturing method, based on FIGS. 9 and 11, a substrate material having a different dielectric constant is used for the dielectric substrate 3, and the arrangement thereof is described above. The effect on the antenna characteristics by setting as above will be explained in detail.

FIG. 9 shows the antenna characteristics of the chip antenna 1 according to this embodiment as 3.1 to 10.

VSWR is measured in the frequency region of the 6GHz band, and the maximum value is graphed. As described above, the chip antenna 1 of the present embodiment uses the substrate material 3a having the dielectric constant ε = 4 and the substrate material 3b having the dielectric constant ε = 16 as the dielectric substrate 3. The forming width of a is 9mm. Further, in FIG. 9, for comparison, the measurement result of a chip antenna having a dielectric substrate made up of only one type of substrate material and having a tapered slot-shaped power supply electrode is shown by a broken line. The substrate material for this chip antenna is one with a dielectric constant ε = 16.

[0115] As shown in Fig. 9, the VSWR of the chip antenna (general tapered slot antenna) formed using only the substrate material with dielectric constant ε = 16 on the dielectric substrate is around 3.1 GHz frequency. It can be seen that the VSWR maximum value in the frequency band of 7 to 8 GHz is getting worse, that is, the VSWR maximum value is rising.

[0116] On the other hand, in the chip antenna 1 of the present embodiment shown by the solid line in FIG. 9, the increase in the maximum VSWR value is reduced in the vicinity of the frequency of 3.1 GHz and in the frequency region of 7 to 8 GHz. I can tell you.

[0117] The reason why the chip antenna 1 of the present embodiment was able to reduce the increase in the VSWR maximum value in the vicinity of the frequency of 3.1 GHz and the frequency of 7 to 8 GHz is as follows. It can be considered.

[0118] In general, the relationship between the length of the antenna, the dielectric constant, and the frequency is in the "tilt I port where the following equation applies".

λ = C / if ε eff

Where λ is the length of the antenna, C is the speed of light, f is the frequency, and ε eff is the effective dielectric constant.

[0119] Figure 10 shows a plan view of a tapered slot antenna with a dielectric substrate consisting of one type of substrate material, and the maximum value of VSWR in the antenna frequency band 3.1 to 10.6 GHz. It is the graph which measured. This antenna has a chip shape as in the present embodiment. In the following, the frequency band of each of the three types of tapered slot chip antennas is changed for this antenna by changing the relative dielectric constant of the substrate material to high, medium, and low, respectively. 10. Measure the maximum value of VSWR at 6GHz. In the graph of FIG. 10, the one-dot chain line has a high dielectric constant, a chip antenna formed by using a substrate material, the solid line has a chip antenna formed by using a substrate material having an intermediate dielectric constant, and the two-dot chain line is electrically charged. A low-rate chip antenna formed using a substrate material is shown.

[0120] As shown in Fig. 10 (b), chip antennas with tapered slot-shaped feed conductors usually have poor VSWR near 3.1 GHz and between 3.1 and 10.6 GHz. That is, the maximum value of VSWR tends to increase or become unstable.

[0121] Therefore, as shown by the alternate long and short dash line in the graph of FIG. 10, when the dielectric constant is increased, the lower limit frequency is lower for the same size antenna due to the wavelength shortening effect according to the above equation. Since it becomes smaller, the maximum VSWR at 3.1 GHz will be lower.

[0122] By the way, the tapered slot antenna has an antenna structure that lowers the VSWR maximum value over a wide band. If the antenna has the same size, the larger the dielectric constant of the base material, the shorter the wavelength. The maximum frequency tends to decrease.

[0123] Therefore, as shown by the dashed line in the graph of Fig. 10, when the dielectric constant is increased, the VSWR maximum value on the lower frequency side, which is 3.1 GHz, decreases. On the other hand, such a tapered slot Due to the shape of the antenna, the upper limit frequency (10.6 GHz) in the 3.1 to 10.6 GHz band is exceeded. The VSWR on the frequency side tends to deteriorate.

[0124] On the contrary, as indicated by the two-dot chain line in the graph of FIG. 10, the lower the dielectric constant, the lower the lower limit frequency for the same size antenna due to the wavelength shortening effect according to the above equation. Therefore, the maximum VSWR value at 1 GHz is high. However, the VSWR maximum value in the frequency range where the intermediate VSWR maximum value is bad is also shifted to the upper limit frequency side of 10.6 GHz, and depending on the conditions, the VSWR maximum value is higher than 10.6 GHz as shown in the figure. Shifting to a higher frequency side can solve the above-mentioned problem regarding the adverse effect of the intermediate maximum VSWR value.

[0125] The chip antenna 1 of the present embodiment has the advantages described based on the graph of FIG.

FIG. 11 (a) is a schematic diagram showing the relationship between the frequency and the antenna length in the chip antenna 1 of the present embodiment. In Fig. 11 (a), the length of the antenna corresponding to the length a defines the upper limit frequency. The length of the antenna corresponding to length b defines the lower limit frequency. 3. 1 ~: LO. In the frequency region of the 6 GHz band, the upper limit frequency is 10.6 GHz, and the lower limit frequency is 3.1 GHz. This relationship between the frequency and the antenna length applies not only to the chip antenna 1 but also to all tapered slot antennas.

[0127] As described above, the chip antenna of the present invention may have a configuration in which the ground electrode is not provided but the ground electrode is provided on the substrate side on which the chip antenna is mounted. In this case, the length a of the antenna that defines the upper limit frequency is the length of the boundary portion of the chip antenna with the mounting substrate, and the length b of the antenna that defines the lower limit frequency is similarly mounted on the chip antenna. The length is from the boundary with the substrate.

[0128] Based on the graph of Fig. 10, the chip antenna 1 of the present embodiment increases the dielectric constant of the substrate material 3b of the dielectric substrate 3 corresponding to the length b of the antenna length that defines the lower limit frequency. The dielectric material corresponding to the antenna length corresponding to the portion of the substrate material 3a of the dielectric substrate 3 corresponding to the length a of the antenna length that defines the limiting frequency and the VSWR maximum value in the middle of the above band is bad. It is considered that the advantages shown in the graph of Fig. 10 could be achieved by making the dielectric constant higher than that of the substrate 3 part. Specifically, the graph shown in FIG. 11 (b) is a graph obtained by measuring the maximum value of the VSWR of the chip antenna 1 in the frequency range of 3.1 to 10.6 GHz band. . In Fig. 11 (b), the measurement result of the maximum value of VSWR of chip antenna 1 is shown by a solid line, and for comparison, the VSWR of the chip antenna with an intermediate dielectric constant shown in the graph of Fig. 10 is shown. The measurement result of the maximum value is shown as a broken line.

[0130] As described above, the chip antenna 1 of the present embodiment has the dielectric constant ε on the dielectric substrate 3.

= 4 substrate material 3a and dielectric constant ε = 16 substrate material 3b.

[0131] As shown by the solid line in Fig. 11 (b), the VSWR maximum value of the chip antenna 1 of this embodiment is 3.1 ~: LO. Since the dielectric substrate corresponding to the length b, that is, the substrate material 3b, has a high relative dielectric constant, the maximum VS WR value on the lower limit frequency side corresponding to 3.1 GHz is It will be lower than the maximum VSWR value shown in.

[0132] As shown by the solid line in Fig. 11 (b), the maximum VSWR value of the chip antenna 1 of this embodiment is 3.1 to: LO. The upper limit frequency is defined in the frequency region of 6 GHz band. The relative dielectric constant of the substrate material 3a of the dielectric substrate corresponding to the antenna length length a is high, and the antenna length corresponding to the portion where the VSWR maximum value has increased in the middle of the above band The relative dielectric constant of the corresponding dielectric substrate is high. Therefore, the increase in the maximum VSWR value that occurred in the middle part of the above band shifts to the higher frequency side from the upper limit frequency side (10.6 GHz side) and disappears from the 3.1 to 10.6 GHz band.

That is, the chip antenna 1 of the present embodiment can stabilize the VSWR as a whole by making use of wavelength shortening on the lower limit frequency side and not performing wavelength shortening on the middle to upper limit frequency side. It is possible and considered.

As described above, the chip antenna 1 includes the dielectric substrate 3 having the substrate materials 3a and 3b having different relative dielectric constants, whereby the above-described antenna characteristics can be obtained.

In the examples to be described later, a chip antenna having the same configuration as the chip antenna 1 is used, the molding width W of the substrate material 3a is changed, and the VSWR value is measured for each of them. We will evaluate the characteristics.

[0136] As described above, according to the chip antenna manufacturing method of the present invention, it is possible to perform insert molding. Thus, the feeding conductor 2 and the dielectric substrate 3 are integrally formed.

[0137] This makes it easier to manufacture as compared with conventional chip antenna manufacturing methods.

[0138] Accordingly, mass productivity can be improved, and the cost associated with the chip antenna can be reduced along with the improvement of mass productivity, so that a low-cost chip antenna can be provided.

[0139] The dielectric substrate 3 is composed of two substrate materials 3a and 3b having different thermoplasticity, and the substrate materials 3a and 3b are in contact with the surface of the conductor portion. Has been.

[0140] As described above, even when the dielectric substrate is composed of a plurality of substrate materials, these substrate materials have thermoplasticity different from each other. The feeding conductor can be integrally formed.

[0141] Also, according to the method for manufacturing a chip antenna of the present invention, since the substrate materials 3a and 3b have different relative dielectric constants, the maximum value of VSWR can be kept small, and a wider frequency band can be handled. A chip antenna can be provided.

[0142] That is, since the substrate materials 3a and 3b constituting the dielectric substrate have different relative dielectric constants, the locations where the electromagnetic waves are reflected are dispersed. The reflected wave of the frequency is also dispersed. Therefore, it is possible to avoid the problem that a reflected wave with strong intensity is generated concentrated on a predetermined frequency and the VSWR value at that frequency rises.

[0143] Also, according to the method for manufacturing a chip antenna of the present invention, the dielectric substrate 3 has a relative dielectric constant that increases stepwise toward the symmetrical axis S, toward the side, and toward the side. It is shaped like this. Specifically, the dielectric constant of the substrate material 3b of the dielectric substrate 3 corresponding to the antenna length length b that defines the lower limit frequency is defined as the dielectric substrate 3 corresponding to the antenna length length a that defines the upper limit frequency. It is higher than the substrate material 3a.

[0144] Thus, the VSWR can be stabilized as a whole by making use of the wavelength reduction on the lower limit frequency side and not performing the wavelength reduction on the middle to upper limit frequency side.

That is, according to the chip antenna manufacturing method of the present invention, it is easy to manufacture. In addition, it is possible to manufacture a chip antenna that can sufficiently handle a wide range of frequencies (radio waves).

[0146] Also, according to the method for manufacturing a chip antenna of the present invention, since the feed electrode portion 5 of the feed conductor 2 is insert-molded so as to be covered with the substrate materials 3a and 3b, the conductor feed electrode portion 5 Is not exposed to the outside. For this reason, contact of the power supply electrode portion 5 with the external environment can be avoided.

Therefore, the durability of the power feeding electrode portion 5 with respect to the external environment and the durability of the entire chip antenna 1 with respect to the external environment can be improved.

However, the present invention is not limited to this, and for example, a structure in which a part of the feeding electrode portion 5 is exposed to the outside may be used.

[0149] Further, since the chip antenna 1 has a chip shape, it can provide a thin antenna having a lower height from the ground plane than a conventional monopole antenna. It can be suitably used for thin devices such as various mopile devices that are actively used.

[0150] Further, according to the method for manufacturing a chip antenna of the present invention, the feed electrode portion 5 can be formed by pressing a lead frame in accordance with a cut mold.

Thereby, the manufacturing method of the chip antenna 1 can be further facilitated. That is, in the conventional manufacturing method, as described above, in order to form the conductor portion of the power supply conductor, the process of masking the dielectric substrate and the metal material corresponding to the power supply conductor are measured, and finally, Required many processes such as etching to remove the mask portion. Therefore, according to the method for manufacturing a chip antenna of the present invention, the power supply electrode portion 5 is formed by pressing a lead frame, so that the power supply electrode portion 5 can be manufactured more easily than in the past. .

[0152] Further, it is possible to easily form the feeding electrode portion 5 having a desired shape. Therefore, it is possible to form the feeding electrode portion 5 having a desired shape by changing the shape of the cut mold. Therefore, it is possible to provide a chip antenna 1 having a shape suitable for an apparatus or device on which the chip antenna 1 manufactured by the manufacturing method of the present invention is mounted.

[0153] Also, according to the manufacturing method of the chip antenna of the present invention, the feed electrode portion 5 is tapered. The chip antenna 1 can be used for transmission / reception of radio waves in a wide frequency band of 3.1 to: LO. 6 GHz.

[0154] Also, according to the method for manufacturing a chip antenna of the present invention, the feed terminal 2 is bent after the feed conductor 2 and the dielectric substrate 3 are integrally formed by insert molding.

[0155] Thereby, the chip antenna 1 can be formed into a surface-mounted shape. That is, the chip antenna 1 manufactured by the method for manufacturing a chip antenna of the present invention can cope with surface mounting that does not have a structure that stands up with respect to a device on which the chip antenna is to be mounted. Therefore, the difficulty of standing up and manufacturing which has been a problem in the past does not occur in the chip antenna manufacturing method of the present invention, and the chip antenna 1 can be automatically mounted.

[0156] As a result, it is possible to improve the productivity of a device to be mounted with a chip antenna.

In addition, according to the method for manufacturing a chip antenna of the present invention, it is preferable to use PPS or LCP as the substrate material of the dielectric substrate 3 of the chip antenna 1. PPS or LCP has a special property that it can have a higher dielectric constant than conventionally known resins. When a material having a high relative dielectric constant is formed on the dielectric substrate, the feed conductor can be downsized due to the wavelength shortening effect, and as a result, the chip antenna 1 itself can be downsized.

[0158] In the present embodiment, the chip antenna 1 having a rectangular parallelepiped shape has been described. However, the present invention is not limited to this, and is not limited to a rectangular parallelepiped shape as long as it can be surface-mounted as described above.

Specifically, the shape shown in FIG. 12 may be used. That is, in the chip antenna 1 shown in FIG. 12, the width of the dielectric substrate 3 increases from the feeding electrode portion 5 of the feeding conductor 2 toward the feeding terminal portion 6, and as a whole, the chip antenna 1 has a trapezoidal shape. Is in shape

[0160] Although the dielectric substrate 3 whose dielectric constant changes stepwise has been described in the present embodiment, the dielectric substrate 3 may be one whose dielectric constant changes continuously.

[0161] In addition, in the method for manufacturing a chip antenna of the present invention, ceramic is applied to the substrate material of the dielectric substrate 3. Even when a rack is used, it can be applied. The case where ceramic is used will be described below. Fig. 13 (a) is a perspective view showing the chip antenna 1 in which the ceramic 33a is used as the substrate material of the dielectric substrate 3, and Fig. 13 (b) shows the chip antenna 1 shown in Fig. 13 (a) as a line segment. It is sectional drawing which showed the state cut | disconnected by CC '. Even when the ceramic 33a is used, if the arrangement shown in FIG. 13 (b) is adopted, the substrate material having thermoplasticity as described above (for example, resin) is disposed around the ceramic 33a. Therefore, it is possible to integrally form the feeder conductor 2 by insert molding as described above.

[0162] Ceramic has a very high dielectric constant ε = about 80 compared to the above resin. Therefore, such a ceramic is configured to provide a wavelength shortening effect and further reduce the size of the feed conductor 5 as described above. Therefore, further miniaturization of the chip antenna 1 itself can be realized. The chip antenna 1 using ceramic may be a chip antenna having a cross-sectional structure as shown in FIG.

[0163] It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the claims, and the technical means disclosed in the different embodiments can be appropriately used. Embodiments obtained by combining are also included in the technical scope of the present invention.

[0164] Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited thereto.

[Example]

In the following description, a chip antenna manufactured by the chip antenna manufacturing method of the present invention will be described.

In this example, the same configuration of the chip antenna 1 as in FIG. 3 in the above-described embodiment is provided. The chip antenna of this example will be described as follows based on FIG.

As shown in FIG. 15, in the configuration of the chip antenna 1, PPS having a dielectric constant of 16 was used for the substrate material 3a of the dielectric substrate 3, and PPS having a dielectric constant of 16 was used for the substrate material 3b.

The shape of the chip antenna 1 is such that the cross-sectional area corresponding to the cross-sectional view shown in FIG. 3 is 14 mm × l 5 mm, and the thickness is lmm. A conductive material (eg For example, ground electrodes 4a and 4b made of a copper alloy thin plate material are formed. Furthermore, a tapered slot-shaped power supply conductor 4 having a power supply terminal portion 6 made of a conductive material (for example, a copper alloy thin plate material) and having a width of 2 mm is separated from each of the ground electrodes 4a and 4b by 1.1 mm. Is formed. The feed electrode portion 5 of the feed conductor 2 has a tapered slot shape, and is formed by pressing a lead frame made of a conductive material (for example, a copper alloy thin plate material). The feeding electrode part 5 and the feeding terminal part 6 were connected by silver paste. The ground electrodes 4a and 4b have a length of lmm along a side having a length of 15mm.

[0169] Using the chip antenna 1 having the above-mentioned shape and material strength, the molding width W of the substrate material 3a of the dielectric substrate 3 is appropriately changed, and the antenna characteristics are set to the VSWR maximum value in each case. Was evaluated by measuring. Substrate material 3b forming width W is ί, W = 0, 3, 5, 7, 9, 11, 13mm. A chip antenna of W = Omm is a chip antenna having a dielectric substrate composed only of PPS with a dielectric constant of 16 of the substrate material 3b formed by the substrate material 3a. It corresponds to an antenna.

[0170] Figures 16 (a) and (b) are: 3.1-: LO. Forming width W of various substrate materials 3b in the frequency band of 6 GHz (W = 0, 3, 5, 7, 9, 11 and 13 mm are graphs showing the measurement results of the maximum value of VSW R of a chip antenna having a diameter of 13 mm. For convenience of explanation, the measurement results for the seven types of chip antennas are shown in two parts in FIGS. 16 (a) and 16 (b). In Figs. 16 (a) and (b), the measurement results of a chip antenna with W = 0 (general tapered slot antenna) are shown in the graph with broken lines as an index. Fig. 16 (a) shows the measurement results of the maximum VSWR value of the tapered slot antenna with W = 7, 9, 11 mm and the index W = 0. In Fig. 16 (b), W = 3, The measurement results of the maximum VSWR value of the tip antenna with 5 and 13 mm and the index W = 0 were shown.

[0171] From the measurement results shown in FIGS. 16 (a) and 16 (b), the chip antenna of this example has a molding width W = 7 of the substrate material 3b in the frequency band of 3.1 to 10.6 GHz. 9 and 11mm (Fig. 16 (a)), the increase in the VSWR maximum value near the frequency 3.1 GHz and the frequency band 7 to 8 GHz is reduced and the VSWR maximum value is observed when W = Omm. Is stable You can see that In particular, the increase in the maximum VSWR value in the frequency band of 7 to 8 GHz is effectively reduced. Furthermore, it can be seen that when the forming width of the substrate material 3b is 9 mm, the increase in the maximum VSWR near the frequency of 10.6 GHz, as seen when W = Omm, can be reduced. When the substrate material 3b has a forming width W = 3, 5, 13 mm (Fig. 16 (b)), the VSWR with a frequency of around 3.1 GHz and a frequency band of 7 to 8 GHz is seen when W = Omm. The force that could not reduce the rise in the maximum value.

Therefore, among the measurement results of the present example, the chip antenna force having the molding width W = 9 mm, which is preferable for the chip antenna having the molding width W = 7˜: L lmm of the substrate material 3b, as described above. It is clear that the antenna characteristics are the best, so it is more preferable.

[0173] As described above, the chip antenna according to the present invention includes a dielectric substrate made of substrate materials having different relative dielectric constants, and therefore, compared with a general tapered slot antenna, 3.1 to : LO. It is possible to provide a chip antenna with good and stable antenna characteristics by reducing the deterioration of antenna characteristics, which has been a problem when dealing with a broadband of 6 GHz.

Industrial applicability

The chip antenna manufacturing method according to the present invention can be easily manufactured because the dielectric substrate and the feed conductor can be integrally formed by insert molding. In addition, the chip antenna to be manufactured is a surface-mount type chip that can cope well with a wide band of LO. 6 GHz by constructing a dielectric substrate from substrate materials with different relative dielectric constants. An antenna can be provided.

[0175] Therefore, for example, it can be widely applied to thin terminals such as information terminals such as mobile phones and PDAs, PC card type radios, CF (compact flash (registered trademark)) type radios, IEEE1394 type radios, etc. it can.

Claims

The scope of the claims

[1] a dielectric substrate made of a dielectric material;

A method of manufacturing a chip antenna comprising a power supply conductor having a terminal portion having a power supply terminal and a conductor portion conducted to the terminal portion,

A method for manufacturing a chip antenna, wherein the dielectric substrate and the feed conductor are integrally formed by insert molding so that at least a part of the conductor portion is covered with the dielectric material.

[2] The chip antenna according to [1], wherein the dielectric substrate is made of at least two dielectric materials having different dielectric constants, and the dielectric materials are in contact with the conductor portion. Manufacturing method.

[3] The conductor portion has a line-symmetric shape with respect to an axis of symmetry including the feeding terminal,

3. The method for manufacturing a chip antenna according to claim 2, wherein the dielectric substrate is shaped so that a dielectric constant increases stepwise from a side closer to the axis of symmetry to a side farther from the side.

[4] The feed conductor is disposed in the mold with reference to a positioning region provided in the chip-shaped mold, and the feed conductor and the dielectric substrate are integrally formed by insert molding. 2. The method for manufacturing a chip antenna according to claim 1, wherein:

5. The chip antenna manufacturing method according to claim 1, wherein the feed conductor is formed by pressing a lead frame in accordance with a cut die.

6. The method for manufacturing a chip antenna according to claim 1, wherein the terminal portion is bent after the dielectric substrate and the feed conductor are integrated by insert molding.

7. The method for manufacturing a chip antenna according to claim 1, wherein the dielectric substrate is a resin.

[8] The method for manufacturing a chip antenna according to [2], wherein at least one of the dielectric materials is a resin.

[9] The method for manufacturing a chip antenna according to claim 7 or 8, wherein the resin is polyether sulfone or a liquid crystal polymer.

10. The chip according to claim 1, wherein the conductor portion has a tapered slot shape. A method of manufacturing a antenna.

[11] A chip antenna manufactured by the chip antenna manufacturing method according to any one of [1] to [10].

12. The chip antenna according to claim 11, wherein the chip antenna is a surface mount type.