JP2007110768A - Forming method for electrode of dielectric filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a projecting conductor, an extended conductor on an opening end face, without generating exudation, friction, displacement at the boundaries of electrode layers. <P>SOLUTION: On the opening end face of the dielectric filter, planar-shaped depressed portions respectively corresponding to shapes and positions of the protruding conductor to be formed on the face are formed with a block outline by using press forming. The electrode layer is formed over the entire surface of the block through dipping. Then, the opening end face is ground to a grinding thickness of less than the depth of the depressed portions, such that only the electrode layers over internal surface of the depressed portions remain. Thus, the electrode layers over the internal surface of the depressed portions are used to form the protruding conductor. In addition, in order to make the insulating partitions between input/output pads and an outer-conductor via U-shaped exposed parts, appropriate U-shaped portions of the outer-conductor are removed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a dielectric filter having a plurality of resonators arranged in parallel.

  A plurality of resonators constructed by covering the inner peripheral surface of the through hole with the inner conductor on the dielectric ceramic block and covering the required outer peripheral surface excluding the open end surface where the through hole opens. Various dielectric filters have been proposed.

  In the above-described configuration, in order to couple the resonators to each other, the extension conductors extend from the open end edges of the adjacent resonators, and the insulating gaps are formed between the end edges of the extension conductors. The resonators are capacitively interstage-coupled by the insulating gap, and the input / output pads are arranged on the side surface facing the outermost resonator close to the open end, and the outer conductor and the insulating section. If necessary, an extension conductor is extended from the input / output pad to the open end face side, and the extension conductor is placed between the extension conductor via an insulation gap. The input / output pad and the outermost resonator are capacitively coupled. Thus, conductor patterns made of various conductors are formed on the open end surface.

Conventionally, the above-described conductor pattern has been performed by applying the electrode layer in a required shape by screen pattern printing. However, when screen pattern printing is performed in this way, blurring occurs on the boundary line of the electrode layer, blurring occurs due to variations in ink density, etc., and further, the screen positioning is incomplete. There is a problem that the relative position with respect to the surface fluctuates slightly, resulting in misalignment of the filter, resulting in large variations in filter characteristics, requiring a process for adjusting the characteristics, taking a lot of time, making mass production difficult, and yield. It was bad too.
The object of the present invention is to eliminate the problems of the conventional configuration.

  According to the present invention, in the dielectric filter described above, a planar concave portion corresponding to the shape and position of the overhang conductor formed on the open end surface is formed on the open end surface together with the outer shape of the block by press molding. An electrode layer is formed on the entire block by dipping, and then the open end surface is ground with a grinding thickness equal to or less than the depth of the recess so that the electrode layer remains only on the inner wall surface of the recess. An overhanging conductor is formed by the electrode layer on the wall surface, and further, in order to insulate the input / output pad from the outer conductor through the U-shaped exposed portion, the corresponding portion of the outer conductor is deleted in a U-shape. This is a method for forming an electrode of a dielectric filter, characterized in that it is configured as described above.

  In addition, even when an extended conductor extending from the input / output pad to the open end surface is formed, the open end surface is formed after forming a concave portion having a planar shape corresponding to the shape and position of the extended conductor, like the overhanging conductor. A method of grinding is included.

  In such a method, the electrode layer is left in the concave portion by forming the electrode on the entire open end surface by dotting or the like, and surface grinding thereof, thereby defining the shape of the electrode layer by the concave portion. Therefore, unlike screen printing, there is no blurring, blurring, misalignment, etc., and highly accurate pattern formation is possible.

  Further, the concave portion can be formed together with the outer shape of the block by press molding. In this case, the position and shape of the concave portion are determined in advance by the mold, and the concave portion can be formed with a highly reproducible position and high shape accuracy. It becomes possible.

  According to the present invention, a planar concave portion corresponding to a conductor pattern composed of an overhanging conductor or the overhanging conductor and an extension conductor is formed on an open end surface, and an electrode layer is formed on the entire open end surface by dotting or the like. Since the electrode layer is left only on the inner surface of the recess by grinding the open end face later, the shape of the electrode layer can be accurately defined by the recess. Therefore, a stable pattern can be formed.

  Further, the concave portion can be formed together with the outer shape of the block by press molding. In this case, the position and shape of the concave portion are determined in advance by a mold, and the concave portion is formed with a highly reproducible position and high shape accuracy. Is possible.

  Accordingly, there is an excellent effect that the input / output coupling capacitance and the interstage coupling capacitance are constant, and a dielectric filter having stable filter characteristics can be configured.

  Embodiments of the present invention will be described with reference to the accompanying drawings. In addition, about the common part, the same code | symbol is attached | subjected and description is simplified.

  1 and 2 show an embodiment in which a two-stage dielectric filter 1 comprising two resonators 3 and 3 is constructed. Here, the dielectric ceramic block 2 has a substantially rectangular parallelepiped shape made of a titanium oxide ceramic dielectric, and the resonators 3 and 3 are arranged in parallel to each other. The resonators 3 and 3 are formed by coating the through-holes 4 and 4 with the inner conductors 5 and 5, respectively, and the outer conductor is provided on the required outer peripheral surface excluding the open end face 8 where the through-holes 4 and 4 are opened. 7 is covered and used as a shield electrode. The resonators 3 and 3 are substantially matched with the resonance length corresponding to λ / 4 of the resonance frequency.

Next, the main part of the present invention will be described. On the open end face 8 side of the dielectric porcelain block 2, as shown in FIG. 1, extending from the end portions of the through holes of the resonators 3 and 3 are formed extending coupling conductors 6 and 6, respectively. The inner conductors 5 and 5 of the through holes 4 and 4 are connected. The resonators 3 and 3 are coupled to each other via the capacitor C ₁ (see FIG. 4) by the insulating gap g ₁ between the coupling extending conductors 6 and 6.

On the other hand, in the dielectric filter 1 having this configuration, the input / output pads 9 and 9 are formed on the side surfaces facing the resonators 3 and 3 close to the open end, and are insulated from the outer conductor 7. The pads 9 and 9 can be electrically connected to the electric circuit on the printed circuit board. The input / output pads 9 and 9 extend the extension conductors 10 and 10 to the open end face side, and the extension conductors 10 and 10 are opposed to the extension conductors 6 and 6 via the insulating gaps g ₂ and g ₂ . Thus, capacitances C ₀ and C ₀ (see FIG. 4) are generated between the resonators 3 and 3 and the input / output pads 9 and 9. If the input / output pads 9 and 9 are composed of three or more stages of resonators, the input / output pads 9 and 9 are opposed to the outermost resonator.

  In this configuration, the overhanging conductors 6 and 6 and the extension conductors 10 and 10 are formed by the following electrode forming method shown in FIG.

  First, titanium oxide ceramic dielectric powder is put into a mold, and the outer shape of the dielectric ceramic block 2 is determined by pressing. As shown in FIG. In addition, concave portions 20a and 20b having a pattern in which the planar shape and the position coincide with the coupling extending conductors 6 and 6 and the extended conductors 10 and 10 formed on the surface are formed.

  And after taking out from a type | mold, after forming the through-holes 4 and 4, it is sintered. Next, the sintered body is subjected to dotting (dipping) or the like to form an electrode layer 21 as shown in FIG.

  Thereafter, as shown in FIG. 3C, the surface of the open end face 8 is ground. This grinding is performed at a cutting position (see line II in FIG. 3) that is less than the depth of the recesses 20a and 20b, thereby leaving the electrode layers in the recesses 20a and 20b on the surface of the open end surface 8. Then, only the electrode layer 21 on the surface is removed. Thereby, the overhanging conductors 6 and 6 and the extended conductors 10 and 10 are formed by the electrode layer 21 in the recesses 20a and 20b. Further, in order to insulate and partition the outer conductor 7 through the U-shaped exposed portions 23 and 23, the input / output pads 9 and 9 that are continuous with the extended conductors 10 and 10 at the side surface positions, Delete in U-shape.

  In this electrode forming method, since the recesses 20a and 20b are formed simultaneously with the outer shape of the dielectric ceramic block 2 by pressing, the position relative to the outer shape is always constant, and the reproducible recesses 20a and 20b are formed. 20b can be formed. Accordingly, the overhanging conductors 6 and 6 and the extended conductors 10 and 10 formed in the recesses 20a and 20b are defined by the recesses 20a and 20b, and can be formed in an accurate position and shape, and also by dipping. Since the conductors 6, 6, 10, and 10 can be formed, the conductor pattern does not become distorted as in screen printing, and the boundary line becomes clear and there is no blurring. Accordingly, there is no blurring, blurring, misalignment, etc., and a highly accurate pattern can be formed, and stable capacitive coupling can be generated.

  Furthermore, in this method, the recesses 20a and 20b are formed simultaneously with the outer shape of the dielectric porcelain block 2 by press working, so that there is an advantage that a manufacturing process is not required and manufacturing is easy. .

  In addition, after forming the dielectric ceramic block 2 by pressing, the recesses 20a and 20b may be formed by milling or the like together with the formation of the through holes 4 and 4. In this case as well, it is possible to form the coupling overhanging conductors 6 and 6 that are free from blemishes and blurring.

Further, extension conductors 10, 10 from the input-output pads 9, 9 are not necessarily required, the edge directly insulating gap _{g 2} of the input and output pads 9, 9 by further extending the edge of the overhanging conductor 6,6 , G ₂ may be capacitively coupled. In this case, only the portion forming the overhanging conductor is recessed.

1 is a perspective view of a dielectric filter 1 according to an embodiment of the present invention. 1 is a plan view of a dielectric filter 1. FIG. It is explanatory drawing which shows the formation process of the said overhanging conductors 6, 6, 10, and 10, and shows the upper part of the dielectric filter 1 longitudinally, respectively. It is an equivalent circuit diagram.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dielectric filter 2 Dielectric ceramic block 3, 3 Resonator 4 Through-hole 5 Inner conductor 6, 6 Overhang conductor 7 Outer conductor 8 Open end surface 9, 9 Input / output pad 10, 10 Extension conductor 20a, 20b Recessed part

Claims (2)

A plurality of resonators constructed by covering the inner peripheral surface of the through hole with the inner conductor on the dielectric ceramic block and covering the required outer peripheral surface excluding the open end surface where the through hole opens. Further, on the open end surface, an overhanging conductor connected to the inner conductor of each resonator formed on the surface is formed, and the input / output pad is arranged on the side surface facing the outermost resonator near the open end. A method for forming an electrode of a dielectric filter having a structure formed by insulating and partitioning a conductor,
On the open end surface, planar recesses corresponding to the shape and position of the overhang conductor formed on the surface are formed together with the outer shape of the block by press molding, and an electrode layer is formed on the entire block by dipping Then, the open end face is ground with a grinding thickness equal to or less than the depth of the recess so that the electrode layer remains only on the inner wall surface of the recess, so that the electrode layer on the inner wall surface of the recess A conductor is formed, and further, the input / output pad is insulated from the outer conductor via the U-shaped exposed portion, and this portion of the outer conductor is deleted in a U-shape. A method for forming an electrode of a dielectric filter. A plurality of resonators constructed by covering the inner peripheral surface of the through hole with the inner conductor on the dielectric ceramic block and covering the required outer peripheral surface excluding the open end surface where the through hole opens. Further, on the open end surface, an overhanging conductor connected to the inner conductor of each resonator formed on the surface is formed, and the input / output pad is arranged on the side surface facing the outermost resonator near the open end. A method for forming an electrode of a dielectric filter having a structure in which an extended conductor is extended from the input / output pad to the open end face side, and the extended conductor is opposed to the extended conductor via an insulating gap. Because
On the open end surface, a planar recess corresponding to the shape and position of the extension conductor formed on the surface and the extension conductor extending from the input / output pad to the surface is formed by press molding. The electrode layer is formed on the entire block by dipping, and then the open end surface is ground with a grinding thickness equal to or less than the depth of the recess, so that the electrode layer is formed only on the inner wall surface of the recess. Thus, an overhang conductor and an extension conductor are formed by the electrode layer on the inner wall surface of the recess, and an input / output pad continuous with the extension conductor at the side surface position is connected to the outer conductor via the U-shaped exposed portion. A method for forming an electrode of a dielectric filter, wherein the portion of the outer conductor is deleted in a U shape in order to insulate.

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