JPH05167317A - Dielectric coaxial resonator - Google Patents

Abstract

(57) [Abstract] [Purpose] It is an object of the present invention to provide a dielectric coaxial resonator which is small in size, and particularly excellent in mass productivity even when the height is 3 mm or less. [Structure] A base 11 made of a dielectric material has a rectangular hole 11a, and a hole 11 having a rectangular cross section continuous with the hole 11a.
A through hole 11c constituted by b is provided, and a step portion K is formed at the boundary between the hole 11a and the hole 11b. The outer dimension of the hole 11a is 3 mm in width L4 and 1 in height L5.
mm and the length L6 are set to 2.5 mm. Also the hole 11
b is 1.2 mm in width L7 and 0.5 m in height L8
The length m and the length L9 are set to 2.5 mm. An outer conductor layer 12 is provided on the outer peripheral portion of the base 11, an inner conductor layer 13 is provided in the through hole 11c, and a connecting conductor layer 14 that connects the outer conductor layer 12 and the inner conductor layer 13 is provided on the end face 11d where the hole 11b is opened. It was

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric coaxial resonator used for mobile radio and the like.

[0002]

7 (a) and 7 (b) are a perspective view and a sectional view showing a conventional dielectric coaxial resonator, respectively.

In FIGS. 7 (a) and 7 (b), reference numeral 1 denotes a rectangular base body made of a dielectric material such as ceramics. The base body 1 has a rectangular hole 1a and a cylindrical shape continuous with the hole 1a. A through hole 1c composed of the hole 1b is provided. Reference numeral 2 is an outer conductor layer formed on the outer peripheral portion of the substrate 1, and 3 is a through hole 1c.
The inner conductor layers 4 formed on the end face 1 having the holes 1b opened
and a connecting conductor layer formed in d and connecting the outer conductor layer 2 and the inner conductor layer 3. The base 1 is exposed on the open end surface 1e.

8 (a) and 8 (b) are a perspective view and a sectional view, respectively, showing another conventional dielectric coaxial resonator.

In FIGS. 8 (a) and 8 (b), reference numeral 5 denotes a rectangular base made of a dielectric material such as ceramics. The base 5 has an open end surface 5a provided with an annular groove 5b. A protrusion 5c surrounded by the groove 5b is formed. A through hole 5d is formed in the center of the protrusion 5c. 6
Is an outer conductor layer formed on the outer peripheral portion of the substrate 5, and 7 is a groove 5b.
A groove conductor layer formed therein, 8 an internal conductor layer formed in the through hole 5d, 9 a connecting conductor layer formed on the upper surface of the protrusion 5c, connecting the groove conductor layer 7 and the internal conductor layer 8, Reference numeral 10 is a connecting conductor layer that connects the inner conductor layer 8 and the outer conductor layer 6 and is formed on the end face 5e opposite to the open end face 5a side.

The dielectric coaxial resonator configured as described above partially changes the line impedance,
The resonator length can be shortened compared to the 1/4 wavelength dielectric coaxial resonator, and the triple frequency spurious resonance frequency can be shifted to a frequency higher than the fundamental frequency, so the influence of the triple harmonic spurious is suppressed. be able to. The dielectric coaxial resonator having such characteristics has an outer diameter of 3 to 4 mm square and a hole 1b.
Or, the through hole 5d has an inner diameter of 1.0 to 1.5 mm and a Q value of 2
The size of 50 to 300 is the smallest size that can be mass-produced.

[0007]

As devices such as mobile radios are made smaller, it is desired to lower the height of the dielectric coaxial resonator mounted on the substrate. However, in the above-mentioned conventional configuration, there is a problem that processing becomes very difficult if the height is set to 3 mm or less. That is, if the height is set to 2 mm, the inner diameter of the hole 1b or the through hole 5d must be about 0.6 mm. Therefore, the diameter of the round pin for forming the hole 1b or the through hole 5d of the dry press die is It is 0.72 mm, but such a pin cannot be metal-processed, and even if such a pin can be made by a dry press die by another process, the pin is easily broken and mass productivity is high. Because there is no.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a dielectric coaxial resonator which is excellent in mass productivity even when miniaturized.

[0009]

In order to achieve this object, a through hole having a step portion is provided in a substrate made of a dielectric material, and the cross-sectional shape of the through hole opened on the side opposite to the open end surface is changed. It was square.

[0010]

With this structure, a flat plate can be used as the pin for forming the through hole.

[0011]

1 (a) and 1 (b) are a perspective view and a sectional view, respectively, showing an embodiment of the present invention.

In FIGS. 1 (a) and 1 (b), reference numeral 11 is a base having a rectangular cross section made of a dielectric material such as ceramics.
The outer dimensions of the base 11 are 4 mm in width L1 and 2 mm in height L2,
The length L3 is set to 5 mm. Further, the base 11 is provided with a through hole 11c composed of a square hole 11a and a rectangular hole 11b which is continuous with the hole 11a, and a step portion K is formed at the boundary between the hole 11a and the hole 11b. Has been done. The outer dimensions of the hole 11a are such that the width L4 is 3 mm, the height L5 is 1 mm, and the length L6 is 2.5 mm. Hole 1
1b has external dimensions of 1.2 mm in width L7 and 0.5 in height L8.
The length L9 is 2.5 mm. Reference numeral 12 is an outer conductor layer formed on the outer peripheral portion of the base 11, and 13 is a through hole 1.
Reference numeral 14 denotes an inner conductor layer formed on 1c, and reference numeral 14 denotes a connecting conductor layer formed on the end surface 11d where the hole 11b is opened and connecting the outer conductor layer 12 and the inner conductor layer 13. Each of the above conductor layers is A
It is made of a conductive material such as g or Cu and has a film thickness of 4 to 5 μm. Also open end face 11
The base 11 is exposed at e.

A method of manufacturing the dielectric coaxial resonator having the above structure will be described below with reference to FIG.

FIG. 2 is a process chart showing the manufacturing method. First, in the mixing step, a predetermined amount of raw materials such as BaO, TiO ₂ , Nd ₂ O _{3 and the} like are mixed. Next, in the mixing step, the above-mentioned compounds are mixed by using a mill or the like, and in the granulation step, the particle size is adjusted and the binder is added by using a spray dryer or the like. Next, in a molding step, a predetermined shape, that is, the shape of the substrate 11 is molded using a dry press. FIG. 3 is a side view showing the dry press. In FIG. 3, numeral 15 is a us having a rectangular cross section, and the us 15 is provided with a through hole 16. 1
Reference numeral 7 denotes an upper punch that can be inserted into the through hole 16, and the upper punch 17 is provided with a convex portion 18 on the side to be inserted into the through hole 16. Further, 19 is a lower punch inserted into the through hole 16. The upper punch 17 and the lower punch 19 are respectively provided with through holes 21 and 22 each having a rectangular cross section into which a pin 20 is inserted at their central portions. As shown in FIG. 4, the pin 20 is composed of a disk-shaped base 20a and a flat plate 20b erected on the base 20a. The flat plate 20b is designed so that the width L10 is 1.44 mm and the height L11 is 0.6 mm. The raw material 23 of which the grain size is adjusted is filled in the uss 15, and the lower punch 19 and the upper punch 17 are used to form the raw material 23 shown in FIG.
As described above, the substrate 11 is prepared by applying a pressure of ² kg / cm ² . At this time, the pin 20 is pressed while penetrating the upper punch 17 and the lower punch 19. Next, each conductive layer is formed on the base 11 in the electrode forming step. At this time, when the conductive layer is made of Cu, first, a thin copper layer is formed on the substrate 11 by an electroless plating method, and a copper layer is further laminated on the copper layer by an electrolytic plating method. A conductive layer is formed. In addition, the conductive layer is Ag
In the case of (1), Ag paste is formed on the substrate 11 by printing and dipping, and then the Ag film is baked at 800 ° C. to 900 ° C. in the next step of electrode baking. This baking step is unnecessary when the conductive layer is made of Cu. Finally, in the polishing step, the open end face side is polished to form a dielectric coaxial resonator as shown in FIG.

The dielectric coaxial resonator thus constructed uses the pin 20 having the flat plate 20b when forming the hole 11b by forming the hole 11b into a rectangular shape instead of the conventional cylindrical shape. Since the pin strength can be made extremely large, there is no possibility that the pin cannot be machined as in the conventional case or the pin is broken immediately so that the productivity is not deteriorated. Further, conventionally, a dielectric coaxial resonator having a length L3 of 5 mm or more could not be produced because the pin would be easily broken. This is because when the length L3 of the dielectric coaxial resonator becomes long, a large force is applied to the pin when the raw material is pressed when the base material 11 is formed by the dry press, and the pin is easily broken. However, in this embodiment, the flat plate 21b can be used for the pin 20,
Since the pin strength can be made very large, the length L3
Even if the length is increased, it does not break when the raw material is pressed.

Further, as can be seen from (Table 1), the Q value is equal to or higher than that of the conventional example (height is 3 mm) and this example.

[0017]

[Table 1]

FIGS. 6A and 6B are a perspective view and a sectional view showing a dielectric coaxial resonator showing another embodiment, respectively.

In FIGS. 6 (a) and 6 (b), reference numeral 24 is a rectangular base made of a dielectric material such as ceramics. An open end face 24a of the base 24 is provided with a groove 24b in an annular shape. A protrusion 24c surrounded by 24b is formed. A through hole 24d having a rectangular cross section is formed in the center of the protrusion 24c. Reference numeral 25 is an outer conductor layer formed on the outer peripheral portion of the substrate 24, 26 is a groove conductor layer formed in the groove 24b, 27 is an inner conductor layer formed in the through hole 24d, and 28 is a groove conductor layer 26 and the inside. A connecting conductor layer which connects the conductor layer 27 and is formed on the upper surface of the protrusion 24c, and 29 connects the inner conductor layer 27 and the outer conductor layer 25, and has an open end face 24.
The connecting conductor layer is formed on the end surface 24e on the side opposite to the a side. Each conductor layer is made of the same material as the dielectric coaxial resonator shown in FIG. 1 and is made by the same manufacturing method.

In this other embodiment as well, since a flat pin can be used when forming the through hole 24d, a dielectric coaxial resonator having a very low height and a long length can be obtained. it can.

[0021]

According to the present invention, a through hole having a step portion is provided in a substrate made of a dielectric material, and the through hole opened on the side opposite to the open end face has a rectangular cross-sectional shape. Since a flat plate can be used for the pins to be created, the through holes can be surely created even if the size is reduced, especially when the height is reduced, and the productivity is not deteriorated due to the pins breaking. Absent.

[Brief description of drawings]

FIG. 1A is a perspective view showing a dielectric coaxial resonator according to an embodiment of the present invention. FIG. 1B is a sectional view showing a dielectric coaxial resonator according to an embodiment of the present invention.

FIG. 2 is a process diagram showing the manufacturing process of the present embodiment.

FIG. 3 is a side sectional view showing a dry press used in the manufacturing process of this embodiment.

FIG. 4 is a perspective view showing pins of a dry press.

FIG. 5 is a side sectional view showing a dry press used in the manufacturing process of this embodiment.

FIG. 6A is a perspective view showing a dielectric coaxial resonator according to another embodiment of the present invention. FIG. 6B is a sectional view showing a dielectric coaxial resonator according to another embodiment of the present invention.

FIG. 7A is a perspective view showing a conventional dielectric coaxial resonator, and FIG. 7B is a sectional view showing a conventional dielectric coaxial resonator.

FIG. 8A is a perspective view showing another conventional dielectric coaxial resonator. FIG. 8B is a sectional view showing another conventional dielectric coaxial resonator.

[Explanation of symbols]

 11 Base Body 11a Hole 11b Hole 11c Through Hole 12 Outer Conductor Layer 13 Inner Conductor Layer 14 Connecting Conductor Layer 24 Base Body 24a Open End Face 24b Groove 24c Projection 24d Through Hole 25 External Conductor Layer 26 Groove Part Conductor Layer 27 Inner Conductor Layer 28 Connecting Conductor Layer 29 Connection conductor layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiromitsu Taki 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. A base body made of a dielectric material is provided with a through hole having a step portion, an outer conductor layer is provided on an outer side portion of the base body, and an inner conductor layer is provided on an inner side portion of the base body. Is a dielectric coaxial resonator in which a connecting conductor layer for connecting the inner conductor layer and the outer conductor layer is provided on one end surface where the through hole is opened, the through hole being opened on the side where the connecting conductor layer is provided. A dielectric coaxial resonator having a rectangular cross section. 2. The dielectric coaxial resonator according to claim 1, wherein the through hole opened on the side where the connecting conductor layer is provided has a rectangular cross-sectional shape. 3. A base made of a dielectric material is provided with an annular groove on one end surface thereof, a through hole is provided in a portion surrounded by the groove, and an outer conductor layer is provided on an outer portion of the base. An in-groove conductor portion is provided in the groove of the base body, an internal conductor layer is provided inside the base body, and the inner conductor layer and the outer conductor layer are connected to the end surface of the base body opposite to the side where the groove is provided. A dielectric coaxial resonator comprising a first connecting conductor layer, and a second connecting conductor layer connecting the inner conductor layer and the in-groove conductor layer in a portion surrounded by the groove of the base, A dielectric coaxial resonator characterized in that the through-hole has a rectangular cross-sectional shape. 4. The dielectric coaxial resonator according to claim 3, wherein the through-hole has a rectangular cross-sectional shape.