JPH11340714A - Manufacture of dielectric resonance member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a dielectric resonance member with excellent mass productivity without dispersing input capacity components and coupling capacity components. SOLUTION: This manufacturing method of the dielectric resonance member 10 consists of a process for forming an organic resist film 6a in an area 6 for separating an outer conductor 4 from an input/output conductor 5 on the side face of a dielectric block 1, a process for baking conductor paste to at least the side face and the other end face of the dielectric block 1 and forming a conductor film 40 and a process for mechanically applying an impact to a conductor film 4a formed at the organic resist film 6a and separating the outer conductor 4 and the input/output conductor 5 from the conductor film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a dielectric resonance member in which at least an outer conductor is formed from a thick film conductor on the surface of a dielectric block.

[0002]

2. Description of the Related Art A dielectric resonance member is a dielectric resonator having a single resonance circuit portion in a single dielectric block or a dielectric filter in which a plurality of resonance circuit portions are produced in a single dielectric block. And the like. Note that the dielectric resonator is used as a resonance unit of a high-frequency oscillation circuit of a communication device, and the dielectric filter is used as an antenna filter and a high-frequency bandpass filter in transmission and reception of the communication device.

A dielectric resonator member, for example, a quarter-wavelength dielectric resonator 60 having a single resonance circuit portion in a single dielectric block generally has an external perspective view shown in FIG. 5 and FIG. As shown in the cross-sectional view, the cylindrical and prismatic dielectric block 61 has one end surface (the upper end surface in the drawing,
A through hole 62 penetrating from the open end face to the other end face is formed. A conductor is attached to the surface of the dielectric block 61 other than the open end surface.

For example, the inner conductor 6 is provided on the inner wall surface of the through hole 62.
3 is formed, and an outer conductor 64 is formed on the other end face and side face.

[0005] In such a dielectric resonator 60, the input / output conductor 65 is isolated on a part of the side surface so as to be electrically separated from the external conductor 64. This input / output conductor 65
When surface mounting the dielectric resonator 60 on the motherboard,
It is used as an input / output electrode with an external circuit when connecting to a predetermined wiring of a predetermined circuit. Further, when the inner conductors 62 of the dielectric resonator having such a structure are coupled to each other to form a dielectric filter, a junction capacitance between the inner conductor 62 and the inner conductor 62 of the adjacent dielectric resonator is formed. Is used as an input / output coupling electrode for a high-frequency signal between the dielectric resonators 60 to generate the electric field.

The point is that a part of the side surface of the dielectric resonator 60 is
It is necessary to form input / output conductors (input / output electrodes and input / output coupling electrodes) 65 that are isolated from the outer conductor 64.

As the inner conductor 63, the outer conductor 64, and the input / output conductor 65, a plated film of copper or the like formed by a plating method or a thick film of silver or the like formed by a thick film method is known. However, a thick conductor film such as silver is advantageous in consideration of manufacturing efficiency, environmental problems, and high current density capacity of the conductor.

A method of manufacturing such a dielectric resonator is generally manufactured by the following manufacturing method.

First, a ceramic powder of a predetermined dielectric material is press-molded into a predetermined shape having a through-hole 62 and fired to form a dielectric block 61.

Next, the inner conductor 63,
The outer conductor 64 and the input / output conductor 65 are formed. Specifically, a process of immersing the dielectric block 61 in a silver paste, shaking off excess paste by rotating the dielectric block 61 by centrifugal force, and drying the paste is repeated several times, and the thickness of the conductor is adjusted to a predetermined value. And baking to form an electrode over the entire surface.

Then, a part of the conductive film is removed from the conductive film formed on the side surface of the dielectric block 61 by using a cutting tool such as a diamond foil in order to isolate the outer conductor 64 and the input / output conductor 65 from each other. Thus, the isolation band 66 is formed.

Then, if necessary, the dielectric block 6
Unnecessary conductor films adhered on the open end face of the substrate 1 are removed by planar polishing.

It should be noted that, apart from the above-described method of forming the isolation band, the outer conductor 64 and the input / output conductor 6 on the side surface of the dielectric block 61 are provided.
The resist film is applied in a predetermined shape to the five regions, and the isolation band 66 exposed from the resist film by sandblasting.
There is also a method in which the conductive film adhered to the surface is scraped off and the resist is peeled off.

[0014]

However, in the above-described method of isolating the outer conductor 64 and the input / output conductor 65 on the side surface of the dielectric block 61, the conductor film attached to the isolation band 66 is mechanically removed. Was. For this reason, when the conductive film is removed, a part of the dielectric block 61 is also shaved at the same time, and the entire isolation band 66 is depressed from the surface of the dielectric block 61.

[0015] In the figure, the depression is indicated by H. As a result, the input coupling capacitance component and the coupling capacitance component generated between the inner conductor 63 and the input / output conductor 65 vary. This is because the capacitance between the outer conductor 64 and the inner conductor 63 changes due to the depression H when a part of the surface of the dielectric block 61 is removed.

Therefore, if the input / output coupling capacitance component and the coupling capacitance component fluctuate, as a result, the filter characteristics are greatly affected.

Further, in the above-mentioned manufacturing process, management costs such as diamond foil and sand blast are required, and mass productivity is extremely poor.

The present invention has been devised in view of the above-mentioned problems, and has as its object to provide a dielectric resonance member which does not vary the input capacitance component and the coupling capacitance component and has good mass productivity. It is to provide a manufacturing method.

[0019]

According to the present invention, a through hole is formed from one end face to the other end face of a columnar dielectric block, and an inner conductor made of a conductive film is formed on an inner wall surface of the through hole. An outer conductor made of a conductive film is formed on the other end face and the side face of the body block, and an input / output conductor is formed on at least a part of the side face, which is isolated from the outer conductor and performs input / output of an external circuit signal. A method of manufacturing a dielectric resonance member, comprising: forming an organic resist film on an isolation band on a side surface of the dielectric block for isolating the outer conductor and the input / output conductor; and A step of applying a conductive paste to at least the side surface and the other end surface of the dielectric block including the surface, and baking the conductive paste to form a conductor on at least the side surface and the other end surface of the dielectric block. Together with the baking, the steps of the organic resist film is carbonized or burned, the conductive film existing on the isolation zone, and removing by mechanical impact,
It is a manufacturing method of the dielectric resonance member containing.

[0020]

According to the present invention, an input / output conductor formed in an island shape by being separated from an outer conductor on a side surface of a dielectric block is formed on the side surface of the dielectric block before the formation of the conductor film. An organic resist is applied to the area (isolation zone) that isolates the input / output conductors, then silver paste is applied and baked, and then the conductor film on the organic resist is mechanically applied using a water jet or rotating barrel. It is removed by a gentle shock and is formed separately from the outer conductor formed on the side surface of the dielectric block.

As a result, since the dielectric block itself is not removed, there is no variation in the coupling capacitance component and the input / output capacitance component as in the prior art.

Thus, a dielectric resonance member capable of minimizing fluctuations in resonance characteristics and filter characteristics can be obtained.

Since a portion separating the outer conductor and the input / output conductor is coated with an organic resist film, it is carbonized and burned off when it is baked to form a conductor film. At this time, since the organic resist film is carbonized between the conductor film and the dielectric block and burned out to form a cavity, only the isolated portion is peeled off very easily by applying a mechanical shock. it can.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a dielectric resonator according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is an external perspective view of a general dielectric resonator, for example, a dielectric resonator in which one resonance circuit is formed in a dielectric block, and FIG. 2 is a sectional view thereof.

The dielectric resonator 10 is configured such that an inner conductor 3, an outer conductor 4, and an input / output conductor 5 are attached to the surface of a dielectric block 1.

The dielectric block is made of, for example, BaO-Ti
O ₂ system, ZrO ₂ —SnO ₂ —TiO ₂ system, BaO—S
m ₂ O ₃ —TiO ₂ , BaO—Nd ₂ O ₃ —TiO ₂
And a ceramic having a predetermined dielectric constant of a CaO-TiO ₂ —SiO ₂ system and having a prismatic shape having a predetermined length (corresponding to １ ／ or 共振 of the resonance wavelength λ) according to the resonance frequency. For example, the end face dimensions, for example, 2 mm × 2 mm, length,
For example, it is 4.6 mm.

That is, the dielectric block 1 has end faces at both ends in the longitudinal direction (one end face is an open end face and the other end face is a short-circuit end face) and four side faces.

In the dielectric block 1, a cylindrical through hole 2 is formed in the longitudinal direction from the open end face to the short-circuit end face. An inner conductor 3 is formed on the inner wall surface of the through hole 2.

An outer conductor 4 is formed on the outer peripheral surface of the dielectric block except for the open end surface.

Further, when the dielectric resonator 10 is independently surface-mounted on a mounting board or a circuit board, the dielectric resonator 10 serving as a mounting surface is connected to at least an external circuit of the dielectric block 1. An input / output coupling electrode (input / output conductor 5) independent of the outer conductor 4 and formed in an island shape is formed on the side surface of the ten.

In the dielectric resonator in which the two dielectric resonators are joined to each other to form a filter, an island-shaped input / output coupling electrode (separated from the outer conductor 4) is provided on the side surface serving as the joining surface. Input / output conductors 5) are formed.

In the two embodiments, the former forms a coupling capacitance between a predetermined circuit and an input / output electrode and the inner conductor 2, and the latter forms a coupling capacitance between the adjacent resonator and the dielectric resonator. A coupling capacitance is formed between the input / output electrode and the inner conductor 2. Although the purpose of each of the capacitance components is different, when viewed from one resonator, it is a portion where signals are input / output. Further, since the manufacturing steps are the same, the present invention is described as the input / output conductor 5.

The inner conductor 3, the outer conductor 4, and the input / output conductor 5 are formed, for example, by baking a conductive paste containing silver as a main component.

In the above embodiment, the shape of the dielectric block 1 may be a columnar shape other than a prismatic shape. At the same time, the opening shape of the through hole 2 is not limited to a circular shape.
The through hole 2 may have a rectangular shape, and a step may be formed at the opening on the open end face side of the through hole 2.

Such a dielectric resonator is manufactured by the steps shown in FIG.

First, the dielectric block 1 in which the through holes 2 are formed is formed. Specifically, it is formed by press molding and firing of a ceramic powder of a predetermined dielectric material having the above-described composition component.

Next, as shown in FIG. 4A, an organic resist film is formed. The organic resist film 6a is formed on a part of the side surface of the dielectric block 1 at a portion which becomes an isolation band (hereinafter, referred to as an isolation region) 6 for finally separating the outer conductor 4 and the input / output conductor 5 from each other. Is applied and cured.
This organic resist material is an epoxy resist or the like.
It is desirable that the solvent evaporate at a temperature of 00 ° C. or higher, and it is necessary to use a solvent that does not elute with a solvent when immersed in a conductive paste in the next step. Note that this resist film 6
“a” is formed on a part of the side surface of the dielectric block 1 by printing in a predetermined shape by screen printing, and by heating and curing.

Next, a coating film of a conductive paste is formed on the entire surface of the dielectric block 1. Specifically, the entire dielectric block 1 is immersed in, for example, a conductive paste tank containing silver as a main component, and excess paste is shaken off by centrifugal force caused by rotation of the dielectric block 1 and dried. This process is repeated several times to make the thickness of the coating film a predetermined thickness.
The predetermined thickness is about three times the thickness at which a high-frequency current easily flows due to the skin effect.

Next, the coating film applied on the surface of the dielectric block 1 is baked to form a conductor film 40. Specifically, the baking treatment is performed in an air atmosphere at a peak temperature of 850 to 950 ° C.

This state is shown in FIG. Due to this baking treatment, the above-mentioned organic resist film is carbonized and burnt out. Since the organic resist film is coated with a coating film of a conductive paste, the portion where the resist film is formed has a cavity between the dielectric block 1 and the fired conductive film, and the portion floats. State.

Next, the conductor film 40a coated on the organic resist film 6a is removed to form an isolation region 6. Specifically, a mechanical shock is applied to the conductor film located at a portion to be the separation region 6 to separate the outer conductor and the input / output conductor from the conductor film. Examples of the mechanical impact include a water jet and a rotating barrel.

As described above, the conductor film in the isolation region 6 can be removed by relatively simple mechanical impact because the organic resist film 6a is carbonized when the conductor film 40a is baked at 850 to 900 ° C. This is because the portion where the organic resist film has been burned out and the organic resist film is present becomes substantially hollow.

Finally, the open end face of the dielectric block 1 is polished. This polishing of the open end face is performed when the coating film is intentionally formed up to the open end face during the process of forming the coating film on the surface of the dielectric block 1 described above, or the coating film adheres to the open end face unexpectedly. This is what you do if you do.

In this method, the surface to be the open end face of the dielectric resonator 10 is planarly subjected to lapping polishing or the like, and the conductor film adhered to the open end face is removed. The polishing of the open end face assumes a quarter-wavelength type dielectric resonator. For example, in a half-wavelength type dielectric resonator, both end faces need to be open end faces. Polish both end faces.

The conductive film formed on the outer periphery of the dielectric block 1 by the above manufacturing process is subjected to a mechanical shock to form the isolation region 6, and a part of the conductive film on the side surface is removed. Thus, at least the outer conductor 4 and the input / output conductor 5 are completely separated from each other, and the inner conductor 3 and the outer conductor 4 are completely distinguished by polishing the open end face. Has been stipulated.

In the dielectric resonator 10 having such a structure, a capacitance component is formed between the inner conductor 2 and the outer conductor 3, and is determined by the length of the current path between the inner conductor 2 and the outer conductor 3. Is formed, and an L-C resonance circuit is formed by the entire dielectric resonator.

Also, a capacitance component is formed between the inner conductor 2 and the input / output conductor 5. When this capacitance component is connected to the signal wiring of the external circuit board,
It becomes an input / output coupling capacitance component, and when a dielectric filter is formed by joining two dielectric resonance members, it forms a coupling capacitance that couples two resonance circuits.

In the former case, the input / output conductors 5 of the dielectric resonator are simultaneously connected to the mounting substrate (the case where the dielectric resonator is mounted) or the predetermined signal wiring conductor of the wiring board. The outer conductor 4 is soldered to the ground potential wiring conductor.

In the latter case, the input / output conductors 5 and the outer conductor 4 are joined to each other via solder and a conductive resin adhesive on the side surfaces of the two dielectric resonators where the input / output conductors 5 are formed. I do.

The characteristic point of the present invention is, as described above,
Separation portion regions 6 in which the input / output conductors 5 formed on a part of the side surface of the dielectric resonator are separated from the outer conductors 4 are formed as organic resist films before forming conductor films to be the conductors 4 and 5. After the conductive film is baked on the resist film, the conductive film on the resist film is removed by mechanical shock using a low-pressure water jet or a rotating barrel.

That is, since unnecessary conductor films can be easily removed by low-pressure mechanical impact, the porcelain on a part of the surface of the dielectric block (the part to be an isolation region) is not deleted. is there. In addition, since the shape of the input / output conductor 5 is restricted by the shape of the organic resist film, the control of the shape becomes very simple.

As a result, variation in the capacitance component between the inner conductor 2 and the input / output conductor 5 can be effectively suppressed.

Since the outer conductor 4 and the input / output conductor 5 are formed of a conductor film by a thick film method, the thickness can be made proportional to the number of times of immersion in the conductive paste.
That is, it is possible to control the film thickness so that the most efficient characteristics can be derived by a simple conductor film deposition process.

In the above-described embodiment, the description has been made of the dielectric resonator in which the resonance circuit having one through hole is formed in one dielectric block or the dielectric resonance member joining the same. Form multiple through holes in the block,
The present invention can also be applied to a dielectric resonance member (dielectric filter) in which a resonance circuit having the number of through holes is internally produced. In this case, since the junction capacitance between the resonance circuits uses a capacitance component between adjacent inner conductors in the dielectric block, an input connected to a predetermined wiring of a mounting board (case) or a wiring board by surface mounting. The electrode corresponds to the input / output conductor 5 of the present invention.

[0056]

According to the present invention, the separation region for separating the outer conductor and the input / output conductor is formed by forming the organic resist film previously formed on the dielectric block by using the conductor serving as the outer conductor and the input / output conductor. The conductive film is formed by removing unnecessary portions of the conductive film due to carbonization and burning during baking of the film and subsequent mechanical impact.

Accordingly, the dielectric block at the separation portion is not removed at all, and the control of the shapes of the input / output conductor and the outer conductor is extremely stabilized. For this reason, since the capacitance component between the inner conductor and the input / output conductor does not vary, very stable characteristics can be derived.

An outer conductor formed by a conventional plating plating film,
Compared with the input / output conductor, the manufacturing method is excellent in mass productivity and easy to control the film thickness.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a general dielectric resonator.

FIG. 2 is a sectional view of a dielectric resonator which is an example of the dielectric resonator of the present invention.

FIG. 3 is a process diagram illustrating a method for manufacturing a dielectric resonator which is an example of the dielectric resonator member of the present invention.

FIGS. 4A and 4B are perspective views showing main steps of a method for manufacturing a dielectric resonator according to the present invention.

FIG. 5 is an external perspective view of a conventional dielectric resonator.

FIG. 6 is a cross-sectional view of a conventional dielectric resonator.

[Explanation of symbols]

 10 dielectric dielectric 1 dielectric block 2 through hole 3 inner conductor 4 outer conductor 5 input / output conductor 6・ Isolation area 6a ・ ・ ・ Organic resist film 4a ・ ・ ・ Unnecessary conductor film in isolation area

Claims (1)

[Claims] 1. A through hole penetrating from one end surface to the other end surface of a columnar dielectric block, and an inner conductor made of a conductive film is formed on an inner wall surface of the through hole on the other end surface and a side surface of the dielectric block. An outer conductor made of a conductive film is formed, and at least a part of the side surface is separated from the outer conductor, and an input / output conductor for inputting / outputting an external circuit signal is formed. A method of manufacturing, comprising: a step of forming an organic resist film on an isolation band separating the outer conductor and the input / output conductor on a side surface of the dielectric block; and at least a dielectric block including the surface of the organic resist film. A step of applying a conductive paste on the side surface and the other end surface, and baking the conductive paste, together with baking of a conductive film on at least the side surface and the other end surface of the dielectric block,
A method for manufacturing a dielectric resonance member, comprising: a step of carbonizing or burning out the organic resist film; and a step of removing a conductor film present in the isolation band by mechanical impact.