JPH0255409A - Manufacture of dielectric filter - Google Patents

Abstract

PURPOSE:To facilitate the manufacture by choking an entry of a throughhole acting like a coupling hole provided between resonator units of a dielectric block by an adhesive tape, immersing the block into a conductor paste thereby preventing the formation of the conductor film into the coupling hole. CONSTITUTION:Throughholes 11, 11 are provided to the dielectric block 10 at a prescribed interval. A coupling hole 12 in parallel with the throughholes 11 is provided between the throughoholes 11 and the entrance of the coupling hole 12 is choked by an adhesive tape 13. The block 10 is dipped into the conductor paste to form the conductor film to all parts of the block except the coupling hole 12, the block is lifted out of the paste 16 and dried and baked. In this case, the adhesive tape 13 is burned and the conductor film is coated to the place of the tape having been burned. The dielectric block at one end of the throughholes 11 is ground to expose the dielectric substance and the part is used for an end face. The grounding is being conducted till the size reaches a size in response to the wavelength of the prescribed resonance frequency. Thus, the manufacture process is simplified and the cost is reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a dielectric filter, and particularly to a method for manufacturing a conductive film of a block-type dielectric filter that integrates a plurality of resonator units. This relates to a forming method.

[Prior art]

A dielectric material in which through-holes are formed at predetermined intervals in a dielectric block, an inner conductor is formed on the surface of the dielectric block, an outer conductor is formed on the outer peripheral surface, and a conductive film is formed on one end of the through-hole to create a short-circuited end surface. Filters are now being used in various fields in the microwave band.

Such a block-shaped dielectric filter has the advantage of being easy to assemble and having excellent mechanical strength.

FIG. 3 is a perspective view of such a block-shaped dielectric filter. Two through holes 31 having a circular cross section are formed in a dielectric block 30 having a rectangular parallelepiped shape, and a conductive film is formed on the surface of the through holes 31 to serve as an inner conductor. A conductive film is also formed on the outer peripheral surface parallel to the through hole 31,
It is an outer conductor.

A conductive film is also formed on the top surface, making it a short-circuited end surface.
No conductor film is formed on only the bottom surface, which is an open end surface.

Two resonator units are formed by the inner conductor of the through hole 31 and the conductor film on the outer peripheral surface. A coupling hole 32 for adjusting coupling is formed between these resonator units, and no conductor film is formed on the surface of this coupling hole 32.
Dielectric is exposed.

〔assignment〕

As mentioned above, there are two types of through holes: those that require a conductive film and those that do not require a conductive film.

Therefore, formation of the conductive film requires work such as applying conductive paste to a predetermined surface and inside the through hole using a brush. Therefore, many man-hours are required to form the conductive film.

The present invention provides an efficient method for manufacturing a dielectric filter in which a dielectric block is immersed in a conductive paste to form a conductive film only on the surface and within predetermined through holes.

[Means to solve the problem]

In the present invention, a dielectric block is immersed in conductor paste with only the bonding hole portion covered with adhesive tape, and the adhesive tape is burned and removed when the conductor paste is baked onto the dielectric block. It is something that solves problems.

That is, in a method for manufacturing a dielectric filter in which a dielectric block having a plurality of through holes is immersed in a conductive paste to form a conductive film on the surface of the dielectric block and in predetermined through holes, the dielectric block Cover at least one end of the through hole, which serves as a coupling hole between the resonator units, with adhesive tape 1, and immerse the dielectric block in conductive paste to connect the surface of the dielectric block and the inner conductor of the resonator unit. It is characterized in that a conductive film is formed within the through hole, but no conductive film is formed within the coupling hole.

Furthermore, the conductor paste is baked to form the inner and outer conductors, the adhesive tape is burned and removed at the same time, a conductor film is applied as necessary to the part where the adhesive tape was removed, and the open end side is polished to the desired shape. A block-shaped dielectric filter is obtained.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view showing an embodiment of the present invention, in which both ends of the coupling hole are closed. The dielectric block 10 has a through hole 11 in which the inner conductor of the resonator unit is formed, and a coupling hole 12 for adjusting the coupling between the resonator units. Both ends of the coupling hole 12 , that is, the short-circuited end face and the open end face are closed with adhesive tape 13 and immersed in conductor paste 16 .

Since both ends are closed, the entire dielectric block 10 can be immersed so that a conductive film is formed on the entire surface.

The dielectric block with the conductive paste 1- formed on its entire surface is pulled up from the conductive paste, dried, and then fired to form an m-body paste. At that time, the adhesive tape burns and does not remain after firing.

As described above, any adhesive tape can be used as long as it burns during firing, and a commonly used adhesive tape may be used. It is not necessary to make the adhesive force very strong, and it is sufficient that it sticks only when immersed in the paste. When trafting tape for drafting was used, it was confirmed that it functioned satisfactorily.

No conductor film is formed on the area where the adhesive tape is applied. Therefore, the firing ends with no conductor film formed around the bonding hole on the short-circuited end face. In order to prevent leakage of magnetic flux, it is preferable to form a conductive film on this portion by printing or the like.

By polishing the surface of the dielectric block at one end of the through hole to expose the dielectric, this surface can be made into an open end surface. Polishing is performed until the dimensions correspond to the wavelength of a predetermined resonance frequency.

FIG. 2 shows an example in which the coupling hole is immersed in conductor paste (.) with only one end thereof closed. The dielectric block 20 has a through hole 21 in which the inner conductor of the resonator unit is formed;
A coupling hole 22 is formed to adjust the coupling between the resonator units. One end of the coupling hole 22 , that is, the lower surface side serving as the short-circuited end surface is closed with an adhesive tape 23 and immersed in a conductive paste 26 .

Since the top surface is not covered, the dielectric block 2o must be immersed without the conductive paste 16 being applied to the top surface.

As a result, a conductive film is formed inside the through hole 21, but no conductive film is formed inside the through hole 22.

Although there is a slight portion where the conductive film is not formed on the upper end of the side surface of the through hole 21 and the dielectric block 20, there is no problem because this surface will be polished as an open end surface in a later step.

Thereafter, the dielectric filter is completed through steps such as firing, printing, and polishing, as in the previous example.

〔effect〕

According to the present invention, a conductive film can be easily formed by dipping into a conductive paste. Therefore, the manufacturing process of the dielectric filter can be greatly simplified, and a low-cost dielectric filter can be obtained.

Furthermore, the step of removing the tape is not required, which is advantageous in terms of reducing the number of man-hours.

[Brief explanation of the drawing]

1 and 2 are front views showing an embodiment of the present invention,
FIG. 3 is a perspective view of a dielectric filter to which the present invention is applied. 10.20...Dielectric block 11, 21...Through hole 12.22...Coupling hole 13.23...Adhesive tape 16.26...Conductor paste

Claims (6)

[Claims] (1) A method for manufacturing a dielectric filter, in which a dielectric block having a plurality of through holes is immersed in a conductive paste to form a conductive film on the surface of the dielectric block and in predetermined through holes. Covering at least one end of the through hole that serves as the coupling hole between the resonator units of the block with adhesive tape,
The dielectric block is immersed in a conductive paste to form a conductive film on the surface of the dielectric block and in the through hole that will become the inner conductor of the resonator unit, and that no conductive film is formed in the coupling hole. A method for manufacturing a featured dielectric filter. (2) The method for manufacturing a dielectric filter according to claim 1, wherein both ends of the through hole which becomes the coupling hole are covered with adhesive tape. (3) Covering one end of the through hole that will become the coupling hole with adhesive tape, and immersing the dielectric block in the conductive paste with the covered side facing down to a depth that does not allow the conductive paste to adhere to the opposite surface. A method for manufacturing a dielectric filter as described in . (4) A method for manufacturing a dielectric filter, in which a dielectric block having a plurality of through holes is immersed in a conductive paste to form a conductive film on the surface of the dielectric block and in predetermined through holes. Covering at least one end of the through hole that serves as the coupling hole between the resonator units of the block with adhesive tape,
The dielectric block is immersed in a conductive paste, a conductor is baked onto the dielectric block, and the adhesive tape is burned to form a conductive film on the surface of the dielectric block and in the through-hole that will become the inner conductor of the resonator unit. A method for manufacturing a dielectric filter, characterized in that a conductive film is not formed within the coupling hole. (5) A method for manufacturing a dielectric filter, in which a dielectric block having a plurality of through holes is immersed in a conductive paste to form a conductive film on the surface of the dielectric block and in predetermined through holes. Covering at least one end of the through hole that serves as the coupling hole between the resonator units of the block with adhesive tape,
immersing the dielectric block in a conductive paste, baking a conductor onto the dielectric block and burning the adhesive tape to form a conductive film on the portion covered with the adhesive tape;
A method for manufacturing a dielectric filter, characterized in that a conductor film is formed on the surface of the dielectric block and in the through-hole that becomes the inner conductor of the resonator unit, but no conductor film is formed in the coupling hole. (6) A method for manufacturing a dielectric filter, in which a dielectric block having a plurality of through holes is immersed in a conductive paste to form a conductive film on the surface of the dielectric block and in predetermined through holes. Covering at least one end of the through hole that serves as the coupling hole between the resonator units of the block with adhesive tape,
immersing the dielectric block in a conductive paste, baking a conductor onto the dielectric block and burning the adhesive tape to form a conductive film on the portion covered with the adhesive tape;
The open end surface side of the dielectric block is polished to a predetermined length, a conductor film is formed on the surface of the dielectric block and in the through hole that will become the inner conductor of the resonator unit, and a conductive film is formed in the coupling hole. A method for manufacturing a dielectric filter, characterized in that a conductive film is not formed.