JP5828442B2 - Dielectric resonant component - Google Patents

Description

  The present invention relates to a dielectric resonant component such as a dielectric filter or a dielectric duplexer, which is formed by forming a plurality of resonators in a dielectric block and used in a high frequency band such as a microwave band.

  2. Description of the Related Art Conventionally, mobile communication devices such as mobile phones are configured so that signals transmitted and received by an antenna can be transmitted and received only in a desired frequency band through a filter such as a passband filter. Dielectric resonance parts such as dielectric filters and dielectric duplexers, which are functional electronic parts, are often of an integrated type that uses a dielectric block and is formed with a plurality of resonators. Used.

  However, in recent years, there has been a demand for higher performance in mobile communication devices, particularly those for base stations. Accordingly, there is also a demand for higher performance in dielectric resonant components used in mobile communication devices. Therefore, higher performance is achieved by making more resonators in a single dielectric block. In this case, there was a problem that the dielectric block becomes too long in the longitudinal direction and the mechanical strength tends to decrease. Recently, a dielectric resonant component having a high mounting efficiency has been demanded, and a dielectric resonant component that is too long in the longitudinal direction has a problem that the mounting efficiency is lowered.

  In order to avoid such a problem, for example, Patent Document 1 proposes a method in which two dielectric filters are divided and manufactured, and each is electrically and mechanically joined.

  Further, Patent Document 2 proposes to improve the mounting efficiency by bending the dielectric block in the middle to form a U shape.

Registered Utility Model No. 3010568 JP 62-73801 A

  However, in the method described in Patent Document 1, the number of parts increases, and there is a problem of cost increase due to assembly work. In addition, there is a problem that electrical matching is difficult to achieve and the characteristics of the dielectric resonant component vary. For example, when applied to a high frequency dielectric resonant component, the inductance component of the metal terminal deteriorates the impedance matching, and the high frequency leaks from the metal terminal portion to deteriorate the performance.

  On the other hand, the method described in Patent Document 2 still does not solve the problem of lowering mechanical strength.

  The present invention has been made in view of the above circumstances, and even when the number of resonators of a dielectric resonant component is increased in order to meet high performance, a reduction in mechanical strength is prevented, and the mounting efficiency is reduced at a low cost. An object of the present invention is to provide a high-frequency dielectric resonant component.

According to the present invention, the object as described above is achieved.
A dielectric block having first and second surfaces parallel to each other having a corresponding elongated shape and having an elongated shape corresponding to the elongated shape of the first surface and the second surface; A plurality of through holes formed from the first surface of the body block to the second surface and arranged along a longitudinal direction of the dielectric block; an inner conductor formed in the through hole; and the through hole A coupling electrode extending from the inner conductor on the first surface so as to couple the resonators formed corresponding to the holes, and an outer conductor formed on the outer surface of the dielectric block. A dielectric resonant component comprising:
The dielectric block has a U-shaped portion in at least a part of the longitudinal direction, and the surfaces to which the outer conductors are attached at both ends of the U-shaped portion are joined together by a joined body. A dielectric resonant component characterized by
Is provided.

  In one aspect of the present invention, the joined body includes a joining agent and a joining member joined to both ends of the U-shaped portion by the joining agent. In one aspect of the present invention, the dielectric resonant component further includes an electromagnetic shield cover disposed so as to substantially cover the first surface. In one aspect of the present invention, the dielectric resonant component includes an electromagnetic shield cover disposed so as to substantially cover the first surface instead of the joining member, and a part of the electromagnetic shield cover includes It joins with the surface where the said outer conductor was attached | subjected of the both ends of the said U-shaped part via the said bonding agent. In one aspect of the present invention, the electromagnetic shield cover has a dielectric resonant component fixing protrusion that extends along substantially the same surface as the second surface of the dielectric block.

  In one aspect of the present invention, the surfaces of both end portions of the U-shaped portion joined together by the joined body are both end surfaces in the longitudinal direction of the dielectric block. In one aspect of the present invention, the surfaces of both ends of the U-shaped portion joined together by the joined body are the first surfaces of the dielectric block.

  In one aspect of the present invention, the surfaces of both ends of the U-shaped portion joined together by the joined body are the outer surfaces of the dielectric block and the inner surfaces facing each other.

  In one aspect of the present invention, the joined body is composed only of a bonding agent.

  In one aspect of the present invention, the dielectric block is made of a dielectric ceramic.

  According to the present invention, even when the number of resonators is increased by joining the surfaces to which the outer conductors are attached at both ends of the U-shaped portion of the dielectric block with the joined body, the mechanical strength is increased. Is prevented, and a dielectric resonant component with low mounting cost and high mounting efficiency is provided.

1 is a schematic exploded perspective view showing a first embodiment of a dielectric resonant component according to the present invention. It is a typical perspective view which shows the dielectric resonance component of 1st Embodiment. It is a typical partial enlarged plan view showing the dielectric resonance component of the first embodiment. It is a typical partial enlarged plan view showing a second embodiment of a dielectric resonant component according to the present invention. FIG. 6 is a schematic partially enlarged plan view showing a third embodiment of a dielectric resonant component according to the present invention. FIG. 9 is a schematic exploded perspective view showing a fourth embodiment of a dielectric resonant component according to the present invention. It is a typical perspective view which shows the dielectric resonance component of 4th Embodiment. It is a typical fragmentary expanded sectional view which shows an example of the connection form with the external circuit in 4th Embodiment. It is a typical perspective view which shows 5th Embodiment of the dielectric resonance component by this invention. FIG. 10 is a schematic exploded perspective view showing a sixth embodiment of a dielectric resonant component according to the present invention. It is a typical fragmentary sectional view showing the dielectric resonance component of a 4th embodiment. FIG. 10 is a schematic exploded perspective view showing a seventh embodiment of a dielectric resonant component according to the present invention. FIG. 3 is a schematic plan view showing a second surface of the dielectric resonant component according to the first embodiment. It is the typical top view seen from the 1st surface which shows the dielectric resonance component of 3rd Embodiment. It is the typical top view seen from the 2nd surface which shows the dielectric resonance component of 3rd Embodiment.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic exploded perspective view showing a first embodiment of a dielectric resonant component according to the present invention, and FIG. 2 is a schematic perspective view of the dielectric resonant component of the present embodiment. FIG. 3 is a schematic partial enlarged plan view of the dielectric resonant component of the present embodiment. In the present embodiment, the dielectric resonant component is a dielectric filter. FIG. 13 is a schematic plan view showing a second surface of the dielectric resonant component of the present embodiment.

The dielectric filter of this embodiment has a dielectric block 2. As a material of the dielectric block 2, for example, a dielectric ceramic can be used, and in particular, a forsterite ceramic having a relative dielectric constant ε _r of about 10 can be used.

  The dielectric block 2 has a first surface 21 and a second surface 22. The first surface 21 is an upper surface. The second surface 22 is a lower surface, is located opposite to and parallel to the first surface 21 with a distance H from the first surface 21, and has a shape corresponding to the first surface 21. The shape of the first surface 21 and the second surface 22 is an elongated shape, specifically, a U-shape. The U-shape referred to in the present invention refers to a shape in which one end of two portions extending substantially parallel to each other is connected by a connecting portion, and the shape of the connecting portion is also a curved shape. Shall also be included. In the figure, the connection portion has a curved shape (arc shape). This is a shape close to a U-shape, but is included in the U-shape referred to in the present invention.

  Thus, the dielectric block 2 has an elongated shape corresponding to the elongated shape of the first surface 21 and the second surface 22. The portion of the dielectric block 2 having such a U shape is referred to as a U shape portion. In the present embodiment, the U-shaped portion occupies the entire region in the longitudinal direction of the dielectric block 2.

  The dielectric block 2 has a surface connecting the peripheral edges of the first surface 21 and the second surface 22. This surface includes two end surfaces 23 and 24 in the longitudinal direction of the dielectric block, and an outer surface 25 and an inner surface 26 having a U-shape. The two end surfaces 23 and 24 are located on the same plane. Thus, the outer surface of the dielectric block 2 includes the first surface 21, the second surface 22, the end surfaces 23 and 24, the outer surface 25 and the inner surface 26.

  As shown in FIG. 2, the dielectric block 2 has a height of H, a length of L, and a width of W in the outer dimensions. However, considering the elongated U-shape, the dimension of the cross section perpendicular to the longitudinal direction is H in height and W 'in width. The lengths of the portions extending in parallel with each other are L ′. It is preferable that H is 4 mm to 25 mm, L is 60 mm to 130 mm, W is 25 mm to 60 mm, W 'is 9 mm to 25 mm, and L' is 50 mm to 115 mm. As a more specific form, L is, for example, about 70 mm, W is, for example, about 35 mm, and H is, for example, about 10 mm. L 'is about 55 mm, for example, and W' is about 15 mm, for example. L is preferably within 3W. Further, W is preferably within 3W '.

  As shown in FIG. 3, the longitudinal ends of the dielectric block 2 are separated by a distance D. That is, at the end of the dielectric block 2 in the longitudinal direction, the interval between the inner side surfaces 26 facing each other is D. D is, for example, about 4 mm.

  As shown in FIG. 1, the dielectric block 2 is formed with a plurality of through holes 30 having a circular cross section formed from the first surface 21 to the second surface 22. Each through-hole 30 extends in the vertical direction along the outer surface 25, the inner surface 26, and the end surfaces 23 and 24. The plurality of through holes 30 are arranged in a U shape along the longitudinal direction of the dielectric block, that is, along the outer surface 25 and the inner surface 26. An inner conductor 31 is attached to the inner surface of each through hole 30.

  An outer conductor 32 is attached to the outer surface of the dielectric block 2 excluding the first surface 21. Thus, the first surface 21 is an open surface and the second surface 22 is a short-circuit surface, and a quarter wavelength resonator is formed corresponding to each of the through holes 30. The first surface 21 is provided with a coupling electrode 33 connected to each inner conductor 31 (that is, extending from each inner conductor 31). The shape of the coupling electrode 33 is not limited to that shown in the figure, and may be appropriately changed as long as a required coupling is obtained. The first surface 21 may be provided with a coupling adjustment electrode (not shown) connected to the outer conductor 32. The coupling between the resonators adjacent to each other is established by the coupling electrode 33 and the coupling adjustment electrode.

  On the first surface 21 of the dielectric block 2, input / output electrodes 34 and 35 are formed in the vicinity of both ends of the dielectric block 2, that is, in the vicinity of the end surfaces 23 and 24. The input / output electrodes 34 and 35 are respectively coupled to the resonators at both ends via the coupling electrode 33 and are connected to an external circuit.

  In the present embodiment, both end portions of the dielectric block 2 are joined to each other by the joined body 50. Specifically, the end faces 23 and 24 provided with the outer conductors 32 at both ends of the dielectric block 2 are joined to each other by the joined body 50. That is, in the present embodiment, both end surfaces of the U-shaped portion joined together by the joined body 50 are both end surfaces 23 and 24 in the longitudinal direction of the dielectric block 2.

  As shown in FIG. 3, the joined body 50 includes a joining agent 51 and a joining member 52 joined to the both end faces 23 and 24 by the joining agent. As the bonding agent 51, for example, an adhesive or solder can be used. As the joining member 52, for example, an iron-based metal plate having a thickness of about 1 mm can be used. The size of the joining member 52 can be, for example, height H × width W or slightly smaller than that. However, the bonding agent 51 and the bonding member 52 are not limited to those shown above.

  By adopting such a structure, even if the number of resonators is increased in order to obtain a high function, the increase in L can be suppressed by making the dielectric block 2 U-shaped. Since the end faces 23 and 24 to which the outer conductors 32 at both ends are joined are joined to each other by the joined body 50, a decrease in mechanical strength is prevented. Thus, a dielectric filter having a low cost and high mounting efficiency is provided.

[Second Embodiment]
FIG. 4 is a schematic partially enlarged plan view showing a second embodiment of the dielectric resonant component according to the present invention. FIG. 4 shows the same part as FIG. 3 according to the first embodiment.

  This embodiment is the same as the first embodiment except for the specific configuration of the joined body 50 that joins both ends of the dielectric block 2 to each other.

  In the second embodiment, the surfaces of the both ends of the U-shaped portions joined together by the joined body 50 are the outer surfaces of the dielectric block 2 and the inner side surfaces 26 facing each other. The joined body 50 is the same as that of the first embodiment except for the shape and dimensions of the joining member 52.

  By adopting such a structure, in addition to the operational effects obtained in the first embodiment, it is not necessary to position both end faces 23 and 24 on the same plane, and the degree of freedom in the shape of the dielectric block 2 is increased. The effect of doing is also obtained.

[Third Embodiment]
FIG. 5 is a schematic partially enlarged plan view showing a third embodiment of the dielectric resonant component according to the present invention. FIG. 5 shows the same parts as FIG. 3 according to the first embodiment and FIG. 4 according to the second embodiment. FIG. 14 is a schematic plan view seen from the first surface showing the dielectric resonant component of the third embodiment. Further, FIG. 15 is a schematic plan view seen from the second surface showing the dielectric resonant component of the third embodiment.

  This embodiment is the same as the second embodiment except for the shape of both end portions of the dielectric block 2 and the specific configuration of the joined body 50 that joins the both end portions to each other.

  In the third embodiment, the both ends of the dielectric block 2 have protruding portions 27 protruding so as to be close to each other. The distance between the inner side surfaces 26 in the protruding portion is, for example, 1 mm. Moreover, the distance of the longitudinal direction (left-right direction in FIG.5, FIG.14 and FIG.15) of the protrusion part 27 can be 2 mm-15 mm, for example.

  The joined body 50 can be composed of a joining agent 51 and a joining member 52. In addition, since the distance between the inner side surfaces 26 is shortened by providing the protruding portion 27, it is possible to configure only the bonding agent 51 without using the bonding member 52.

  By adopting such a structure, in addition to the operational effects obtained in the second embodiment, the configuration of the joined body 50 can be simplified, and the operational effect that the number of parts can be reduced is also obtained.

[Fourth Embodiment]
FIG. 6 is a schematic exploded perspective view showing a fourth embodiment of the dielectric resonant component according to the present invention, and FIG. 7 is a schematic perspective view of the dielectric resonant component of the present embodiment. FIG. 8 is a schematic partial enlarged sectional view of the dielectric resonant component of the present embodiment.

  The present embodiment is the same as the first embodiment except that an electromagnetic shield cover is provided and a part of the electromagnetic shield cover functions as a joining member.

  The electromagnetic shield cover 10 is disposed so as to substantially cover the first surface 21 of the dielectric block 2. Specifically, the electromagnetic shield cover 10 is disposed so as to be separated from the open area (area part where the outer conductor is not formed) of the first surface 21 of the dielectric block 2 and to cover the open area. For example, it is made of a metal plate having a thickness of about 0.3 mm to 0.8 mm. The electromagnetic shield cover 10 may be made of a conductive material. For example, iron-based metal, particularly iron whose surface is tin-plated can be used. The electromagnetic shield cover 10 includes a first portion 101 positioned horizontally above the first surface 21, a second portion 102 extending downward from a part of an edge of the first portion 101, and a first portion 101. And a third portion 103 extending downward from the other part of the edge. The second portion 102 is connected to the outer conductor 32 attached to the outer side surface 25 and the inner side surface 26 of the dielectric block 2, whereby the radio wave from the first surface (open area) 21 by the first portion 101. The effect | action which suppresses a leak is acquired.

  On the other hand, the third portion 103 is positioned so as to face the end faces 23 and 24 of the dielectric block 2 and has the same function as the bonding member 52 of the first embodiment. That is, the third portion 103 is joined to the end faces 23 and 24 of the dielectric block 2 by an adhesive, and thus constitutes the joined body 50.

  By providing such an electromagnetic shield cover 10, a good electromagnetic shielding effect is exhibited to obtain high electrical characteristics, and a dielectric filter with increased mechanical strength is provided at a low cost with a small number of parts. be able to.

  FIG. 8 is a schematic partial cross-sectional view showing an example of a connection form with an external circuit in the present embodiment. As shown in FIG. 8, the inner conductor of the coaxial connection cable 12 is connected to the input / output electrode 34, and the dielectric filter is connected to an external circuit by the connection cable 12. The outer conductor of the connection cable 12 is connected to, for example, the third portion 103 of the electromagnetic shield cover 10.

  The connection method between the dielectric filter and the external circuit is not limited to the above, and other known methods may be used as necessary, using a coaxial connection connector or using a lead pin. But it ’s okay.

  According to FIG. 6, the shape of the part of the electromagnetic shield cover 10 corresponding to the connecting part that connects the ends of the two parts of the U-shape extending substantially parallel to each other is substantially trapezoidal. That is, the shape of the portion of the electromagnetic shield cover 10 corresponding to the connection portion is defined by two inclined sides extending so as to approach each other from the two portions and a straight line connecting the tips of the inclined sides. It has a mountain shape. However, the shape of the portion of the electromagnetic shield cover 10 corresponding to the connection portion is not limited to this, and for example, the shape is smooth so as to correspond to the curved shape (arc shape) of the connection portion of the dielectric block 2. It may be arcuate. Moreover, when the connection part of the dielectric block 2 is linear, it may be linear.

[Fifth Embodiment]
FIG. 9 is a schematic perspective view showing a fifth embodiment of a dielectric resonant component according to the present invention.

  This embodiment is the same as the fourth embodiment except that the electromagnetic shield cover has a dielectric resonant component fixing protrusion extending along substantially the same surface as the second surface of the dielectric block. is there.

  In the fifth embodiment, the second portion 102 of the electromagnetic shield cover 10 has a dielectric resonant component fixing protrusion 104. The dielectric resonant component fixing protrusion 104 extends along substantially the same surface as the second surface 22 of the dielectric block 2 and is provided with an opening that allows passage of fixing means such as screws.

  The dielectric filter is mounted on a mounting substrate (for example, a circuit board of a communication device) with the second surface 22 of the dielectric block 2 as a mounting surface (that is, with the second surface 22 facing the mounting substrate).

  By mounting the electromagnetic shield cover 10 as described above, when mounting the dielectric filter, the electromagnetic shield cover 10 can be directly fixed to the mounting substrate by the fixing means. Thus, it is not necessary to attach a new fixing bracket, the number of parts is reduced, and the cost can be reduced.

[Sixth Embodiment]
FIG. 10 is a schematic exploded perspective view showing a sixth embodiment of the dielectric resonant component according to the present invention, and FIG. 11 is a schematic partial enlarged sectional view of the dielectric resonant component of the present embodiment.

  In the present embodiment, the outer conductor 32 extends to the first surface 21 of the dielectric block 2 to a region adjacent to the end surfaces 23 and 24, and the outer conductor 32 on the first surface 21 is electromagnetically coupled. Except that the joined body 50 including the third portion 103 of the shield cover 10 is joined, it is the same as the fourth embodiment. In the sixth embodiment, the electromagnetic shield cover 10 also serves as the joining member 52.

  That is, the lower end edge of the third portion 103 of the electromagnetic shield cover 10 is bent horizontally and outward, and the lower surface of the lower end edge extends to the first surface 21 of the dielectric block 2 by the bonding agent 51. The outer conductor 32 is joined.

  By adopting such a structure, in addition to the operational effects obtained in the fourth embodiment, it is not necessary to position both end faces 23 and 24 on the same plane, and the degree of freedom in the shape of the dielectric block 2 is increased. The effect of doing is also obtained. Moreover, it is not necessary to prepare the joining member 52 separately, and the number of parts can be further reduced.

[Seventh Embodiment]
FIG. 12 is a schematic exploded perspective view showing a seventh embodiment of the dielectric resonant component according to the present invention. In the present embodiment, the dielectric resonant component is a dielectric duplexer.

  In the present embodiment, the transmission-side filter Ft is formed by four resonators on one side of two portions of the U-shaped dielectric block 2 extending substantially parallel to each other, and on the other side. A reception-side filter Fr is formed by four resonators. In the connection part that connects the two parts of the U-shaped dielectric block 2, a transmission / reception common electrode 36 that is coupled to both the transmission filter Ft and the reception filter Fr is formed on the first surface 21. Yes. The input / output electrode 34 functions as a transmission signal input electrode, the input / output electrode 35 functions as a reception signal output electrode, and the transmission / reception common electrode 36 functions as a transmission signal output electrode and a reception signal input electrode. The transmission / reception common electrode 36 is connected to transmission / reception means such as an antenna.

  The material of the dielectric block 2 is the same as that of the first embodiment and the fourth embodiment. The dimensions of the dielectric block 2 are 4 mm to 25 mm, L is 60 mm to 130 mm, W is 25 mm to 60 mm, W ′ is 9 mm to 25 mm, and L ′ is 50 mm to 115 mm according to the notation shown in FIG. Preferably there is. As a more specific form, L is, for example, about 70 mm, W is, for example, about 35 mm, and H is, for example, about 10 mm. L 'is about 55 mm, for example, and W' is about 15 mm, for example. L is preferably within 3W. Further, W is preferably within 3W '.

  According to the present embodiment, even in an integrated dielectric duplexer having a large number of resonators, as in the fourth embodiment, the increase in L can be suppressed by making the dielectric block 2 U-shaped. In addition, the end faces 23 and 24 to which the outer conductors 32 are attached at both ends of the dielectric block 2 are joined to each other by the joined body, so that the mechanical strength is prevented from being lowered and the electromagnetic functioning as a joining member is also achieved. By using the shield cover 10, a good electromagnetic shielding effect can be obtained to obtain high electrical characteristics, and a high-efficiency dielectric transfer duplexer with increased mechanical strength can be obtained at a low cost with a small number of parts. Can be provided.

[Other Embodiments]
In the above embodiments, specific ones are described with respect to dimensions, number, shape, and the like, but the present invention is not limited to these, and can be changed as appropriate.

  For example, the number of resonators formed in the dielectric block 2 can be set to, for example, 7 or 8 when the length L is about 70 mm, but is not limited thereto, and can be changed as appropriate. .

  In addition to the end surface, the inner surface, or the first surface as described above, the end surface of the dielectric block 2 to which the bonded body 50 is bonded includes the second surface, the end surface, and the inner surface. Two or more of the side surface, the first surface, and the second surface may be used in combination.

  The contents of the embodiment relating to the above dielectric filter can also be applied to the dielectric duplexer.

  Further, in the above embodiment, the U-shaped portion occupies the entire area in the longitudinal direction of the dielectric block 2 (the shape is limited to the U-shape, and the other portion connected to the tip of the U-shape. However, the present invention is not limited to this, and the dielectric block only needs to have a U-shaped portion in at least a part of the region in the longitudinal direction. That is, the dielectric block may have another portion connected to the U-shaped portion. Examples of the other part include a bulging part connected to the end of the U-shaped part. A resonator and an input / output electrode can be disposed on the bulging portion.

2 Dielectric block 21 1st surface 22 2nd surface 23,24 End surface 25 Outer side surface 26 Inner side surface 27 Protrusion part 30 Through-hole 31 Inner conductor 32 Outer conductor 33 Coupling electrode 34, 35 Input / output electrode 36 Transmission / reception common electrode 50 Bonded body 51 Bonding agent 52 Bonding member 10 Electromagnetic shield cover 101 First portion 102 Second portion 103 Third portion 104 Protruding portion 12 for fixing the dielectric resonant component Coaxial connection cable Ft Transmission side filter Fr Reception side filter

Claims (5)

A dielectric block having first and second surfaces parallel to each other having a corresponding elongated shape and having an elongated shape corresponding to the elongated shape of the first surface and the second surface; A plurality of through holes formed from the first surface of the body block to the second surface and arranged along a longitudinal direction of the dielectric block; an inner conductor formed in the through hole; and the through hole A coupling electrode extending from the inner conductor on the first surface so as to couple the resonators formed corresponding to the holes, and an outer conductor formed on the outer surface of the dielectric block. A dielectric resonant component comprising:
An electromagnetic shield cover arranged to substantially cover the first surface;
The dielectric block has a U-shaped portion in at least a part of the longitudinal direction, and the surfaces to which the outer conductors are attached at both ends of the U-shaped portion are joined together by a joined body. Tei Te, dielectric resonator apparatus, wherein Rukoto the electromagnetic shield cover is also used as the conjugate. The bonded body has a bonding agent,
2. The dielectric resonance according to claim 1 , wherein a part of the electromagnetic shield cover is bonded to the surfaces to which the outer conductors are attached at both ends of the U-shaped portion via the bonding agent. parts. 3. The dielectric resonant component according to claim 1, wherein surfaces of both end portions of the U-shaped portion joined to each other by the joined body are the first surfaces of the dielectric block. . Surfaces of both end portions of the U-shaped portion joined to each other by the joining member is characterized by a outer surface of the dielectric block is an inner surface opposed to each other, according to claim 1 or 2 Dielectric resonant component. The dielectric resonant component according to claim 4 , wherein the bonded body is made of only a bonding agent.

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