JPH1127016A - Production of dielectric cylindrical resonator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of a dielectric cylindrical resonator which does not grind a conductor pattern in a grinding process. SOLUTION: In regard to a dielectric resonator 50, an area A2 including no conductor pattern 5 at the side of an open end face 8 is set in the axial direction from the edge of the face 8 with prescribed width secured when the pattern 5 is formed. When the outer circumference 2 of a dielectric element set at the side of the face 8 is ground in a tapered shape by a grinding machine 21 of a grinding blade that is not vertical to a shaft and tilted in a grinding process, the circumference 2 is ground with a sufficient unground part (width L4) secured so that the grinding blade does not touch the boundary edge of the pattern 5. Therefore, the metal powder caused by grinding of the pattern 5 is never attached to the grinding blade nor a ground surface 9 of the dielectric element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is carried out it relates to a manufacturing method of a cylindrical dielectric resonator (dielectric cylindrical resonator), especially at the final stage of the manufacturing process in order to obtain the required resonant frequency f ₀ and Q values It is related to grinding.

[0002]

2. Description of the Related Art Needless to say, a coaxial line composed of a dielectric and a conductor is a distributed constant circuit. However, when this is cut to a certain size, high-frequency energy is confined in this line and a resonance reflecting material characteristics is caused. Container.

This is a cylindrical or columnar dielectric resonator (also referred to as a high-frequency dielectric resonator or a microwave dielectric ceramic). Various resonance types such as a TE mode, a TM mode, and a TEM mode are used depending on the resonance mode to be used. Among them, the TEM mode resonator is most suitable for miniaturization, and is used for an antenna duplexer, a bandpass filter, a VCO resonator, and the like in a high-frequency block of a mobile phone or the like.

A coaxial line type generally used as a TEM mode resonator has an outer peripheral surface 2 of a cylindrical dielectric element 1 having a resonator length L of 1/4 wavelength, as shown in FIG. The dielectric cylindrical resonator 10 in which the conductor patterns 5, 6, and 7 are formed by metallizing the inner peripheral surface 3 and the one end surface 4 (to be a short-circuit end surface) with silver or copper is a basic shape, but in the longitudinal direction of the resonator. As shown in FIG. 4, the outer peripheral surface 2 and the inner peripheral surface 3 of the cylindrical dielectric element body 1 and the electrodes on the one end surface 4 are used to shorten the length of the resonator and to adjust the Q of the resonator and the resonance frequency f ₀ . A layer having different impedances is formed by forming a layer and grinding the conductor pattern and the dielectric element body on the peripheral edge on the side of the open end face 8 stepwise using a grinding machine 11 of a grinding blade parallel or perpendicular to the axis. Dielectric cylindrical resonator 20 having a shape connected to
Have also been widely adopted and become common (for example,
(See FIG. 4 in the specification of JP-A-8-194406).

Japanese Patent Application Laid-Open No. 58-194406 mentioned above discloses a coaxial dielectric resonator as shown in FIG. 5 on the open end face 8 side of a cylindrical (or cylindrical) dielectric element 1. A dielectric cylindrical (cylindrical) resonator 30 in which a part of the conductor pattern 5 on the outer peripheral surface and a part of the dielectric element body 1 is tapered by a grinding machine 21 of a grinding blade which is not perpendicular to an axis is disclosed. I have.

In general, the Q of the dielectric resonator is increased in accordance with the outer diameter, contrary to the demand for miniaturization. Therefore, in practice, the size is determined from the balance between Q and miniaturization. Since Q and f ₀ depend on the grinding depth of the dielectric body and the length (L2) of the conductor pattern 5 on the outer peripheral surface after the grinding, various characteristics such as the required resonance frequency f ₀ and Q value can be obtained. The grinding at the final stage in the above-described production of the dielectric circular resonator, in which a part of the conductor pattern 5 on the outer peripheral surface is scraped, requires high grinding accuracy.

In this grinding process, for example, as shown in FIG. 6, the dielectric element 1 is supported by a pair of left and right chucks 12 and 13 so as to be fixed on one side, and the dielectric element 1 on which a conductor pattern is formed is ground. Grinding is performed by applying a grinding blade of the disk 21 (or the grinding machine 11) at a constant pressure at a rotation speed of several hundreds to several thousand rpm, and the required characteristics are obtained by sequentially monitoring the resonance frequency f _{0 and the} like.

The material used as the dielectric element 1 of the dielectric resonator is ceramics, and must be fired at a temperature lower than the melting point of the electrode material. Therefore, Bi-based materials, composite perovskite, (ZrSn) TiO ₄ -based, BaO-TiO _{2 and the} like.

In addition, silver and copper are used as the material of the conductor pattern. In general, various film forming techniques such as coating, dipping, and plating can be used in addition to being formed by vapor deposition or sputtering by a vacuum device. 2-40μm thick
It is about.

The dielectric cylindrical resonator described in detail above has an outer diameter of 2
３3 mm, length about 4-20 mm.

[0011]

However, in the grinding process of the conventional dielectric cylindrical resonators 20, 30, FIG.
As shown in (1), since the conductor pattern 5 on the outer peripheral surface is formed up to the peripheral portion (edge portion) of the cylindrical dielectric body 1 before grinding, grinding is performed on the outer peripheral surface of the dielectric body 1. This involves grinding and grinding of the conductor pattern 5 formed on the surface thereof.

As a result, the desired characteristics such as the reduction of Q due to the adhesion of the grinding metal powder W of the conductor pattern 5 to the grinding blades of the grinding machines 11 and 21 and the grinding portion 9 of the dielectric body 1 are caused. There is a problem in that it is no longer possible to obtain, and the reliability is poor.

The present invention has been made in view of the above circumstances, and provides a novel method of manufacturing a dielectric cylindrical resonator without grinding a conductive pattern.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method for forming a conductive pattern which is continuous on one end surface with an outer peripheral surface and an inner peripheral surface of a cylindrical dielectric element. A method of manufacturing a dielectric cylindrical resonator having a step of grinding a peripheral edge on an open end face side of an element body, wherein a region having no conductor pattern on an open end face side of an outer peripheral surface of the dielectric element body is axially moved from the open end face edge. Forming a conductor pattern on the outer peripheral surface in a part by setting a predetermined width to the outer peripheral surface of the dielectric element body. And a step of grinding into a stepped shape or a tapered shape while leaving the step of forming a dielectric cylindrical resonator.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a dielectric cylindrical resonator according to the present invention will be described in detail with reference to the drawings. The same members and locations as those in the conventional example are indicated by the same reference numerals.

FIG. 1 is a sectional view of a dielectric cylindrical resonator according to the present invention in a stepped grinding step.

FIG. 2 is a sectional view of the dielectric cylindrical resonator according to the present invention in a tapered grinding step.

In FIG. 1, a dielectric cylindrical resonator 40 has conductor patterns 5, 6, 7 which are continuous with an outer peripheral surface 2, an inner peripheral surface 3 and one end surface 4 of a cylindrical dielectric element 1 and are formed. The structure in which the outer peripheral surface 2 on the open end surface 8 side of the dielectric element body 1 is ground in a stepped manner is the same as that of the conventional dielectric cylindrical resonator 20 shown in FIG. The conductor pattern 5 formed on the outer peripheral surface 2 of the dielectric element body 1 before the processing step has a region A on the open end face 8 side where no conductor pattern exists.
1 is set to a predetermined width in the axial direction from the edge of the open end face, and the conductor pattern 5 formed on the outer peripheral face 2 is formed not on the entire surface but on a part near the short-circuit end face 4 side (an area of 70 to 95% of the whole is appropriate). It is that you are.

Then, in the grinding process, the grinding machine 11 places an unground portion (width L3) on the boundary A between the conductor pattern on the outer peripheral surface and the area A1 on the outer peripheral surface on the open end surface side of the dielectric element body 1 without the conductor pattern. Is characterized in that it is ground in a stepped shape while leaving the surface.

In FIG. 2, the dielectric cylindrical resonator 5
In the grinding process, similar to the conventional dielectric cylindrical resonator 30 shown in FIG. 5 described above, the outer peripheral surface 2 on the open end face 8 side of the dielectric element body 1 is inclined not perpendicular to the axis in the grinding process. Although the point of grinding in a tapered shape by the blade grinder 21 is common, a region A where there is no conductor pattern on the open end face 8 side is used.
2 is formed by setting a predetermined width in the axial direction from the edge of the open end face.

In the grinding step, the grinding blade is tapered while leaving a sufficient unground portion (width L4) so as not to touch the boundary edge of the conductor pattern 5.

After all, when the conductor pattern 5 is formed on the surface of the dielectric element 1, the dielectric element 1 is not exposed to a predetermined width (about 5 to 20% of the resonator length L) from the periphery of the open end face 8 in advance. The conductor pattern 5 is formed not as the entire surface of the outer peripheral surface 2 but as a part of the short-circuit end surface 4 side as the conductor pattern portions A1 and A2 so that the grinding blade does not touch the conductor pattern 5 to open the dielectric body 1. Only the non-conductor pattern portions A1 and A2 on the end face 8 are ground into a stepped or tapered shape while leaving the unground portions (widths L3 and L4).

As a result, the dielectric cylindrical resonators 40 and 50
In the above-mentioned grinding process in the final stage in the manufacturing process of
The metal powder W does not grind the conductor pattern 5 formed on the entire outer peripheral surface 2 of the dielectric body 1 together with the dielectric body 1 as in the conventional grinding process, and the metal powder W is ground by the grinding blade or the dielectric body 1. Does not adhere to the surface.

Since there is no grinding of the conductor pattern, the reliability of the interface between the conductor and the dielectric element is improved, and the deterioration of Q and the deterioration of reliability due to the adhesion of metal powder are prevented. Will be.

The manufacturing method of the dielectric resonators 40 and 50 in the embodiment of the present invention is the same as the conventional manufacturing method except for the forming method of the conductive pattern and the grinding method of the grinding process. Needless to say, there is no limitation on the method of attaching the grinding blade or the like.

[0026]

Since the dielectric resonator according to the present invention is configured as described above, it has the following effects.

(1) Since the conductive pattern is not ground during the grinding process and the metal powder does not adhere to the grinding surface of the grinding blade or the dielectric body, the Q is reduced and the reliability is reduced due to the adhesion of the metal powder. Deterioration problems are prevented.

(2) Since the conductor pattern on the outer peripheral surface is not damaged during the grinding process, the reliability of the interface between the conductor and the dielectric element is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a dielectric cylindrical resonator according to the present invention during a stepped grinding process.

FIG. 2 is a sectional view of a dielectric cylindrical resonator according to the present invention during a tapered grinding step.

FIG. 3 is a cross-sectional view of a TEM mode quarter-wave dielectric cylinder resonator.

FIG. 4 is a cross-sectional view of a conventional dielectric cylindrical resonator ground into a step shape.

FIG. 5 is a sectional view of a conventional dielectric cylindrical resonator ground into a tapered shape.

FIG. 6 is a perspective view showing a cutting state in a grinding step of the dielectric cylindrical resonator.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 dielectric body 2 outer peripheral surface 3 inner peripheral surface 4 one end surface (short-circuit end surface) 5, 6, 7 conductive pattern 8 open end surface 9 ground surface 10, 20, 30, 40, 50 dielectric cylindrical resonator 11, 21 grinding Boards 12, 13 Chuck A1, A2 Unconductor pattern portion W Metal powder L Resonator length L2 Conductor pattern length on outer peripheral surface after grinding L3, L4 Width of unground portion

Claims (1)

[Claims] 1. A step of forming a continuous conductor pattern on an outer peripheral surface, an inner peripheral surface, and one end surface of a cylindrical dielectric element body, and then grinding the peripheral edge of the dielectric element body on an open end surface side. In the method for manufacturing a dielectric cylindrical resonator, a region having no conductor pattern on the open end surface side of the outer peripheral surface of the dielectric element body is set to a predetermined width in the axial direction from the edge of the open end surface to partially form the conductor pattern on the outer peripheral surface. And a step of grinding in a stepped or tapered shape while leaving an ungrounded portion at the boundary between the conductor pattern on the outer peripheral surface and a region having no conductor pattern on the outer peripheral surface on the open end surface side of the dielectric element body, A method for manufacturing a dielectric cylindrical resonator, comprising: