JP3623079B2 - Dielectric filter and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dielectric filter formed by arranging a plurality of resonators, which is used in mobile communication devices such as automobile phones and mobile phones.
[0002]
[Prior art]
As shown in FIG. 5, a plurality of resonators b formed by forming a resonant conductor by covering the inner peripheral surface of the through hole on the dielectric ceramic block a in one direction, and a through-hole covers the grounding conductor c to the desired outer peripheral surface excluding the open end surface of the opening, formed on the side surfaces and divides the input terminal pads P ₁ to bind to one end of the resonator t the ground conductor c, other dielectric filter f to an output terminal pad P ₂ that binds an end side of the resonator t and divides the grounding conductor c obtained by forming the side surfaces have been proposed. In this configuration, as shown in the figure, each resonance is formed by covering the surface of the counterbore d formed at the mouth end of each through hole with a conductive film or printing a pattern conductor on the open surface. A conductive layer e connected to the resonant conductor of the container is formed, and the conductive layers e are coupled to each other, thereby forming a band-pass filter.
[0003]
[Problems to be solved by the invention]
By the way, in the conventional dielectric filter f, as described above, when a circuit for coupling resonators is formed by forming a counterbore or a pattern, there is a limit to a circuit constant obtained. Create constraints on the design. In order to solve this problem, a device using lumped constant parts such as a coil and a capacitor has been proposed. However, in the configuration according to this, the degree of freedom is given to the design, but the number of assembling steps is increased, and the form is not a uniform shape like a rectangular parallelepiped, the dimensions are large, and the circuit arrangement is cluttered. As a result, the circuit design is complicated, and the mechanical strength is also reduced.
[0004]
The above-mentioned dielectric filter f is formed by sintering a plurality of through holes in a rectangular parallelepiped dielectric ceramic block a having a single structure, and thereafter, a conductive layer is formed on the inner peripheral surface and the required outer peripheral surface of the through hole. The resonator b is configured by being deposited and baked, and it is necessary to form the dielectric ceramic block a into individual pieces. For this reason, it is difficult to take a large number of pieces, and it is necessary to perform baking of the conductive layer as a separate process after sintering, which is troublesome. Furthermore, it is necessary to form a resonant conductor by introducing a conductive material into the through hole by dipping or the like and applying it to the inner peripheral surface of the through hole, making it difficult to form a uniform conductive layer. There were also problems such as incurring variations.
The present invention aims to eliminate such problems.
[0005]
[Means for Solving the Problems]
The present invention relates to a dielectric filter formed by laminating a plurality of dielectric division layers, and a plurality of hollow-shaped resonances constituted by a set of division holes formed in advance in a required dielectric division layer A plurality of resonators are configured in which holes are arranged side by side, and a resonance conductor is formed on the inner peripheral surface of each resonance hole, and a conductive layer applied to the inner periphery of each divided hole portion is formed continuously. In addition to a resonator circuit, a pattern circuit is formed by connecting electrode patterns formed on the laminated surface of each dielectric division layer, and the required filtering circuit is configured by connecting this pattern circuit and the resonator circuit. It is characterized by doing so.
The present invention also provides a dielectric filter formed by forming a plurality of resonators by forming conductive layers on the inner peripheral surfaces of a plurality of resonance holes drilled in parallel in a dielectric member. The member is formed by laminating a plurality of dielectric sheets each having a shape obtained by dividing the dielectric filter into a plurality of layers along the parallel direction of the resonance holes, and the resonator is formed on at least one surface of each dielectric sheet. The electrode pattern combined with the conductive layer is formed so that a part of the electrode pattern is led out of the dielectric member to form a pattern circuit, and is applied continuously to the inner periphery of the divided hole portion constituting the resonance hole. It is characterized in that a divided conductive layer constituting the conductive layer is formed.
[0006]
In such a configuration, a resonator circuit and a pattern circuit are configured by a simple configuration in which a plurality of dielectric division layers are stacked, and a uniform shaped dielectric filter can be easily formed. At the same time, an arbitrary circuit constant can be configured by selecting the structure of the electrode pattern. Here, the divided hole portion refers to a member that forms a resonance hole by a set of the divided holes, and therefore, only a conductive layer is formed and no hole is formed as in the uppermost end or the lowermost divided hole portion. There is also.
[0007]
In such a configuration, a division hole is formed in a required dielectric division layer, and a conductive layer is formed on the inner periphery of each division hole, and an electrode pattern is formed by screen printing or the like. In addition, after forming a ground conductor at a predetermined distance from the divided hole portion, each dielectric divided layer is laminated, this laminated body is sintered, and each conductive layer is baked to manufacture. Can do. The ground conductor may be an outer peripheral surface or may be incorporated in the laminate. When it is formed on the outer peripheral surface, it may be formed on the exposed surface of each dielectric division layer in advance or after lamination of each dielectric division layer.
[0008]
In such a manufacturing process, since the dielectric layer can be formed by punching the sheet material or the like, a large number of dielectric layer layers can be taken from the sheet material. In addition, a conductive layer is coated on the inner peripheral surface of the divided hole portion formed in the required dielectric divided layer, and each dielectric divided layer is laminated to form a resonance hole by the divided hole portion group. Therefore, it is easy to form a resonant conductor. Therefore, the conductive layer can be easily formed by screen printing, brushing, or the like without requiring dipping or the like as in the conventional configuration, and the thickness management of the conductive layer is facilitated. Moreover, by sintering after lamination, the conductive layer can be baked simultaneously with the sintering, and the heating process is only required once. Moreover, because of the hollow shape in which the resonance hole is confined, it is close to an ideal TEM mode and the Q value is high.
[0009]
As the pattern circuit, a low pass filter circuit constituting a low pass filter, a band pass filter circuit constituting a band pass filter, or a high pass filter circuit constituting a high pass filter can be applied in combination with each resonator.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a dielectric filter 1 according to an embodiment of the present invention, which is formed by laminating rectangular dielectric divided layers 10a to 10g, and is integrally sintered to form a one-chip structure. Is formed. Each of the dielectric division layers 10a to 10g is made of glass ceramic, a composite material of glass and a dielectric ceramic material, or a dielectric ceramic material such as a low-melting point oxide. The pattern circuit Y composed of a low-pass filter circuit is carried, and the low-pass filter and the band-eliminate filter shown in FIG.
[0011]
The dielectric filter 1 having such a configuration has a hollow shape with non-penetrating long resonance holes 3A, 3B, 3C formed at the center thereof. The resonance holes 3A, 3B, 3C have a conductive layer formed on the inner peripheral surface thereof, which is used as the resonance conductor 4. Further, an earth conductor 7 is formed on the outer peripheral surface, and each resonance conductor 4 is connected to the earth conductor 7 at one end through a conductive layer 12 formed on the laminated surface, which will be described later. Open end. The lengths of the resonance holes 3A, 3B, and 3C are substantially matched to the resonance length dimension corresponding to λ / 4 of the resonance frequency.
[0012]
Next, the configuration of each of the dielectric division layers 10a to 10g will be described. As shown in FIGS. 2 and 3, the dielectric divided layers 10a to 10g constituting the dielectric filter 1 by stacking are provided in the portions corresponding to the resonant holes 3A, 3B, and 3C in the resonant holes 3A, 3B, and 3C. Divided hole portions 11 constituting a part are formed. The division hole 11 has the maximum width of the dielectric division layer 10d at the center, and the width gradually decreases in the vertical direction. In addition, conductive layers 12 are respectively formed on the inner peripheral edge of the divided hole portion 11. Note that the conductive layer 12 is formed so as to protrude from the inner surface of the divided hole portion 11 to the periphery thereof so that mutual electrical connection can be ensured in the laminated state.
[0013]
Further, no holes are formed in the divided hole portions 11 of the dielectric divided layers 10a and 10g at the upper and lower positions of the resonance holes 3A, 3B, and 3C, and only the conductive layer 12 is configured.
[0014]
Furthermore, the earth conductor 7 is formed in the surface which comprises the outer surface of the laminated body of each dielectric material division layer 10a-10g, respectively. In addition, a communication portion is formed at the front edge of each of the dielectric division layers 10a to 10g so as to be insulated from the ground conductor 7, and the communication portion is continuous in the stacking direction, so that the conductive path 8a, 8b and 8c are formed.
[0015]
On the other hand, pattern regions are secured in front portions of the divided hole portions 11 of the dielectric divided layers 10a to 10g, and electrode patterns made of conductive layers such as electrodes and inductors are formed in the required regions. Yes. And the pattern circuit Y is comprised by the connection of each electrode pattern. The configuration of each electrode pattern will be described.
[0016]
In the pattern region of the dielectric division layer 10b, an electrode pattern including capacitor electrodes 21a, 21b, and 21c connected to the conductive layer 12 of the division hole portion 11 is formed.
[0017]
In addition, an electrode pattern including capacitor electrodes 22a, 22b, and 22c is formed in the pattern region of the dielectric division layer 10c, and the capacitor electrodes 21a, 21b, and 21c are connected to the capacitor electrodes via the thickness of the dielectric division layer 10b. 22a, 22b, and 22c face each other to form capacitors C ₁ , C ₂ , and C ₃ shown in FIG. The capacitor electrodes 22a, 22b, and 22c are connected to the conduction paths 8a, 8b, and 8c through the communication portion at the front edge.
[0018]
In the pattern region of the dielectric division layer 10e, an electrode pattern composed of rectangular electrodes 23 extending over the entire width is formed. The electrode 23 is electrically connected to the ground conductor 7 so that the capacitor electrodes 22a, 22b, 22c and the electrode 23 are opposed to each other through the thicknesses of the dielectric division layer 10c and the dielectric division layer 10d. Thus, capacitors C ₄ , C ₅ , C _{6 are} formed.
[0019]
The pattern area of the dielectric division layer 10f, respectively end and a front edge of the communicating portion conduction path 8b through, the electrode pattern made of a meandering line like inductors Y ₂ to be connected to 8c are formation.
[0020]
Similarly, the pattern area of dielectric split layer 10 g, each of the end portions of the conductive path 8a through the communicating portion of the leading edge, the electrode pattern made of a meandering line like inductors Y ₁ to be connected to 8b is formed Yes.
[0021]
Thus, the conductive paths 8a, and the capacitor electrode 22a, and one end of the inductor _{Y 1} is connected to the conductive paths 8b, the capacitor electrode 22b, the other end and one end of the inductor _{Y 2} of the inductor _{Y 1} is connected , the conduction path 8c, and the capacitor electrode 22c, and the other end of the inductor _{Y 2} are connected.
[0022]
Thus, each electrode pattern is connected to form a pattern circuit Y (low-pass filter circuit) composed of capacitors C _{1 to} C ₃ , C _{4 to} C ₆ , inductors Y ₁ and Y ₂ , and the pattern circuit Y is connected to the resonator circuit X via the capacitor electrodes 21a, 21b and 21c, and the low pass filter and the band eliminate filter shown in FIG. 4 are configured.
[0023]
In the dielectric filter 1 according to the above-described configuration, each of the dielectric division layers 10a to 10g corresponds to the shape of each dielectric division layer 10a to 10g, for example, by punching a raw sheet-like sheet material. Formed. The sheet material thus punched is coated with the conductive layer 12 and the extended conductive layer 13 on the inner peripheral surface of the divided hole portion 11 and the required electrode pattern in each pattern region in the raw sheet state. Further, the ground conductor 7 is applied to the required outer peripheral surface. These coatings can be performed by screen printing or the like.
[0024]
And after laminating | stacking each of these dielectric material division layers 10a-10g, it sinters. Accordingly, each conductive layer is baked simultaneously with the sintering.
[0025]
Thus, by laminating a large number of dielectric division layers 10a to 10g, the elongated resonance holes 3A, 3B, 3C in which the division hole portions 11 are gathered to approximate a circle are formed, and as described above, Resonant conductors 4 in which the conductive layers 12 are continuously formed are formed on the inner peripheral surfaces of the elongated resonant holes 3A, 3B, 3C. When the resonant length of the resonant conductor 4 is set to λ / 4 of the operating frequency, as shown in the above example, one end is connected to the ground conductor 7 and the other end is not connected to the ground conductor 7. And Note that the conductive layer 12 is not necessarily formed at the open end. Further, when the operating frequency is set to λ / 2, both ends of the resonant conductor 4 are connected to the ground conductor 7, or both ends are connected to the ground conductor 7, or both ends are open. Further, the pattern circuit Y is carried by the laminate.
[0026]
In this configuration, each of the dielectric division layers 10a to 10g is easily formed by punching a sheet material or the like, and the electrode layer applied to the division hole portion 11 or the like is a special layer such as dipping. There is no need to take any means, and the conductive layer can be easily formed by screen printing or burn coating. As a result, there is no thickness unevenness, whereby the long resonance holes 3A, 3B, 3C having the resonance conductor 4 of uniform thickness can be formed, and the characteristics are stabilized. Further, by sintering after lamination, the conductive layer can be baked simultaneously with the sintering, and the heating process is reduced. Furthermore, since the long resonance holes 3A, 3B, and 3C are confined in the dielectric filter 1, they are close to an ideal TEM mode and have a high Q value. Further, the pattern circuit Y is also integrally formed in the manufacturing process.
[0027]
Although the low-pass filter circuit is exemplified as the pattern circuit Y described above, various circuits such as a band-pass filter circuit or a high-pass filter circuit can be applied.
[0028]
【The invention's effect】
In the present invention, as described above, a required filtering circuit including the resonator circuit X and the pattern circuit Y is configured by laminating a plurality of dielectric division layers 10a to 10g.
1) The whole can be made into a simple and simple shape, which can be downsized and save space. Moreover, since it is based on integral sintering of a simple laminated body, mechanical strength improves.
2) Since the resonator circuit X and the pattern circuit Y are confined in the dielectric division layers 10a to 10g, they are cut off from the external atmosphere and are not easily affected by external influences such as humidity and mechanical shock. Stabilize.
3) Since an electrode pattern is formed on the laminated surface of the dielectric division layers 10a to 10g and the pattern circuit Y is configured by connecting the circuit patterns, it is easy to set an arbitrary circuit constant only by pattern setting. It can be configured and gives freedom in the design of the filter.
4) Each dielectric layer is made of the same material in the form of a sheet, each of which is formed by laminating and forming the required conductive layers, and then sintered together, making it easy to manufacture and mass-productive Rich.
5) A dielectric division layer can be formed by punching a sheet material. In this case, a large number of pieces can be easily obtained, and productivity is further improved.
6) When the conductive layer is baked at the same time as the sintering after lamination, the heating process is reduced.
7) Unlike a configuration in which a conductive layer is introduced into the resonance hole by dipping, the thickness of the conductive layer can be easily managed, and a resonant conductor having a uniform thickness can be formed.
8) Since each resonance hole has a non-penetrating hollow shape, each resonator has an ideal TE.
Close to M mode and high Q value.
[Brief description of the drawings]
FIG. 1 is a perspective view of a dielectric filter 1 according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of the dielectric filter 1;
FIG. 3 is a longitudinal sectional view of a dielectric filter 1;
FIG. 4 is an equivalent circuit diagram of the dielectric filter 1;
FIG. 5 is a perspective view of a conventional dielectric filter f.
[Explanation of symbols]
First dielectric filter 3A, 3B, 3C resonance holes 4 resonant conductor 7 grounding conductor 10a~10g dielectric split layer 11 dividing holes 12 conductive layer 13 extending conductive layer X resonator circuit Y pattern circuit _C 1 _-C 3, _{C 4} -C ₆ capacitor _Y 1, _{Y 2} inductor

Claims (4)

A dielectric filter formed by laminating a plurality of dielectric division layers,
A plurality of hollow-shaped resonance holes constituted by a set of division holes formed in advance in a required dielectric division layer are arranged in parallel, and the inner peripheral edge of each division hole is formed on the inner peripheral surface of each resonance hole. Comprising a resonator circuit comprising a plurality of resonators formed by forming a resonant conductor in which a conductive layer applied to is continuous, and
A pattern circuit formed by connecting electrode patterns formed on the laminated surface of each dielectric division layer,
A dielectric filter characterized in that a required filtering circuit is configured by connecting the pattern circuit and a resonator circuit. A dielectric filter formed by forming a plurality of resonators by forming conductive layers on the inner peripheral surfaces of a plurality of resonance holes drilled in parallel in a dielectric member,
  The dielectric member is formed by laminating a plurality of dielectric sheets having a shape obtained by dividing the dielectric filter into a plurality of layers along a parallel direction of the resonance holes.
  On at least one surface of each dielectric sheet, an electrode pattern coupled to the conductive layer of the resonator is formed so that a part of the electrode pattern is led out of the dielectric member to form a pattern circuit. The divided conductive layer that is applied to the inner peripheral edge of the divided hole portion that constitutes the resonance hole and that continuously forms the conductive layer is formed.
A dielectric filter characterized by the above. The pattern circuit, a dielectric filter according to any one of claims 1 and 2, characterized in that a low-pass filter circuit, a bandpass filter circuit, or a high-pass filter circuit associated with each resonator. In the required dielectric division layer, division holes are formed, a conductive layer is applied to the inner periphery of each division hole, and an electrode pattern is applied to the laminated surface, and then each dielectric division layer is formed. The method for manufacturing a dielectric filter according to claim 1, wherein each conductive layer is baked by laminating and laminating the laminate.

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