KR100555967B1 - Variable capacitor - Google Patents

Abstract

The present invention relates to a variable capacitor and a method of manufacturing the same, in particular, to extend the variable range of capacitance, to reduce the sensitivity of the capacitance, and to implement a low capacitance, while reducing the equivalent series resistance by increasing the effective electrode area To increase the inverse (Q) value of the dielectric loss to minimize the loss at high frequencies and to provide a method for manufacturing the capacitor. The variable capacitor of the present invention for this purpose includes a stator including a ceramic element inserted therein and an electrode connectable to the outside, and a mover movably mounted on an upper surface of the stator opposite to the electrode of the stator. The mover is provided with an electrode on a part of the surface of the mover facing the upper surface of the stator, and the electrode of the stator includes a portion having a different distance from the electrode to the upper surface of the stator.

Stator, rotor, capacitor, dielectric, ceramic sheet, dielectric loss, low capacitance

Description

Variable Capacitors {VARIABLE CAPACITOR}

1 is a schematic exploded perspective view of a stepped stacked trimmer capacitor according to the present invention;

FIG. 2 is a bottom view of the rotor of the stepped stacked trimmer capacitor shown in FIG. 1; FIG.

3 is a cross-sectional view taken along line III-III of the stepped stacked trimmer capacitor shown in FIG.

4 is a view showing a manufacturing process of the stator of the stepped stacked trimmer capacitor shown in FIG.

5 is a diagram showing the rate of change of capacitance according to the rotation angle of the rotor of the stepped stacked trimmer capacitor and the general single plate trimmer capacitor according to the present invention shown in FIG.

6 is a sectional view of another example of a stator of a stepped stacked trimmer capacitor;

7 is a schematic exploded perspective view of a floating electrode type trimmer capacitor.

FIG. 8 shows a bottom surface of the stator of the floating electrode type trimmer capacitor shown in FIG.

Fig. 9 is a sectional view taken along line IX-IX of the floating electrode type trimmer capacitor shown in Fig. 7;

Fig. 10 is an equivalent circuit diagram of the floating electrode type trimmer capacitor shown in Fig. 7;

11 is a schematic exploded perspective view of a stacked floating electrode type trimmer capacitor.

FIG. 12 is a cross-sectional view taken along lines XII-XII of the stacked floating electrode type trimmer capacitor shown in FIG.

FIG. 13 is a view showing a manufacturing process of the stacked floating electrode type trimmer capacitor shown in FIG.

14 is a schematic exploded perspective view of a modification in which the laminated floating electrode type trimmer capacitor shown in FIG. 11 is modified;

FIG. 15 shows a bottom surface of the rotor of the capacitor shown in FIG.

FIG. 16 is a sectional view of the capacitor shown in FIG.

Fig. 17 is a sectional view and an equivalent circuit diagram of a trimmer capacitor of the present invention in which a low dielectric constant layer is inserted between a stator and a rotor of a typical single plate type trimmer capacitor in series with the low dielectric constant layer in a single plate type trimmer capacitor.

FIG. 18 is a sectional view and equivalent circuit diagram of another modification of the capacitor shown in FIG. 17; FIG.

Fig. 19 is a sectional view and an equivalent circuit diagram of a trimmer capacitor in which a capacitor of a low dielectric constant layer is formed in series with a floating electrode type trimmer capacitor.

Fig. 20 is a sectional view and an equivalent circuit diagram of a trimmer capacitor in which a capacitor of a low dielectric constant layer is formed in series with a laminated floating electrode type trimmer capacitor.

FIG. 21 is a sectional view and equivalent circuit diagram of another modification of the capacitor shown in FIG. 20; FIG.

Fig. 22 is a schematic cross sectional view of a modification of the stepped stacked trimmer capacitor shown in Fig. 1;

Figure 23 is a schematic exploded perspective view of a conventional conventional single-plate trimmer capacitor.

Fig. 24 is a view showing the bottom face of the rotor of the conventional single plate type trimmer capacitor shown in Fig. 23;

FIG. 25 shows a bottom surface of a stator of the conventional single plate type trimmer capacitor shown in FIG. 23; FIG.

FIG. 26 is a cross sectional view taken along line XXVI-XXVI of the conventional single-plate trimmer capacitor shown in FIG. 23; FIG.

Fig. 27 is a schematic exploded perspective view of a multilayer trimmer capacitor of Murata Corporation.

FIG. 28 is a sectional view of the stacked trimmer capacitor shown in FIG. 27; FIG.

<Explanation of symbols for the main parts of the drawings>

110, 210, 310, 410, 610, 710, 810: Stator

112a, 112b, 112c, 212a, 212b, 312a, 312b, 412a, 412b, 612a, 612b, 612c, 712, 812: stator electrodes

120, 220, 320, 420, 720, 820: rotor

122, 222a, 222b, 322a, 322b, 422a, 422b, 722, 822: rotor electrodes

130, 230, 330, 730: frames

440, 840: metal cover

500: low dielectric constant layer

620: mover

622: mover electrode

The present invention relates to a variable capacitor and a method of manufacturing the same, in particular, to extend the variable range of capacitance, to reduce the sensitivity of the capacitance, and to implement a low capacitance, while reducing the equivalent series resistance by increasing the effective electrode area The present invention relates to a variable capacitor and a method of manufacturing the same to minimize the loss at high frequencies by increasing the inverse (Q) value of the dielectric loss.

Among the representative passive electronic components such as capacitor (C), resistor (R), and inductor (L), capacitors apply the basic characteristics of charge accumulation and discharge, which eliminates time constant circuits and noise in circuits, and coupling capacitors. It is the most widely used electronic component that plays many roles such as configuration of calculus and calculus. Such capacitors may be divided into ceramic capacitors, film capacitors, mylar capacitors, tantalum capacitors, and aluminum electrolytic capacitors according to materials, and may be classified into lead type and surface mount type (SMD) depending on the structure. In general, most capacitors are fixed capacitance capacitors with fixed capacitance values, and capacitors used in frequency adjustment circuits and the like are variable capacitance capacitors capable of changing capacitance values to adjust frequency.

Recently, as the popularity of portable electronic devices has increased, almost all electronic components have been implemented in surface-mounted type due to their volume and weight problems. Accordingly, the variable capacitor is also mounted in a surface mount type. Surface-mounted trimmer capacitors are actively engaged in various companies, mainly Murata, Japan. Especially, in Murata, the ceramic body of a conventional trimmer capacitor is a single plate type, whereas the ceramic body is stacked and patented. The application is of course mass-produced and marketed.

Fig. 23 shows a typical conventional single plate type trimmer capacitor. A typical single plate trimmer capacitor includes a stator 710, a rotor 720, and a frame 730. In the stator 710 made of a ceramic element, the stator electrode 712 is printed in a semicircular shape on the lower surface thereof as shown in FIG. The rotor 720 is made of metal (which is a conductor), and as shown in Fig. 25, a rotor electrode 722 and a support protrusion 726 protruding in a semicircular shape are formed. 23 and 26, the stator electrode is fixedly mounted in the frame 730, and the rotor 720 is rotatably mounted on the stator 710 in the frame 730, thereby stator electrodes. 712 and rotor electrode 722 face to face with the ceramic element therebetween. At this time, the stator terminal 711 and the rotor terminal 721 fixed to the frame 730 are connected to the stator electrode 712 and the rotor electrode 722, respectively. A support protrusion 726 formed on the lower surface of the rotor 720 supports the electrode 722 of the rotor to rotate while always in contact with the upper surface of the stator. When the rotor 720 rotates on the stator 710 by inserting a driver or the like into the groove 725 formed on the upper surface of the rotor, the area where the stator electrode 712 and the rotor electrode 722 face each other. This change causes the capacitance of the capacitor to change.

As another prior art, Figures 27 and 28 show Murata's stacked trimmer capacitors (see US Pat. Nos. 6,134,097, 5,424,906 and 5,424,930). The stator 810 is composed of a ceramic body in which ceramic sheets are laminated. The electrode 812 of the stator is printed on either sheet in the middle of the ceramic body, with a portion of the electrode printed so as to be exposed to the side of the ceramic body. Above this stator 810 is placed a metal rotor 820 similar to that shown in Figure 24, which is covered by a metal cover 840 which also functions as a terminal of the rotor. The exposed stator electrode 812 is connected to a terminal 811 printed on one side of the stator 810. The terminal 812 printed on the other side of the stator 810 opposite the one side of the stator 810 is connected to a part of the metal cover 840 that covers the rotor 820 and is connected to a part of the metal cover 840 by means of a metal rotor. ). The rotor 820 thus rotates over the stator 810 within the metal cover 840 to change the capacitance of the capacitor. In this case, the gap between the electrode and the electrode can be made as thin as at least one sheet thickness to realize a high value of capacitance.

The conventional single-plate trimmer capacitor and Murata's multilayer trimmer capacitor described above replace the ceramic element between the electrodes with a different dielectric constant to adjust the sensitivity of the capacitance to the rotation angle of the rotor or the range of the capacitance. The thickness must be changed. However, these design changes do not vary the sensitivity or range of capacitance as desired. After the capacitor is actually mounted in the electronic circuit, it is necessary to relax the sensitivity of the capacitance to the rotation angle of the rotor in order to fine tune the frequency. In addition, a low capacitance capacitor having a high Q value, which is the inverse of the dielectric loss Df, is required for use in a high frequency circuit.

To achieve low capacitance, the area facing the stator electrode and the rotor electrode should be reduced or the distance between the electrodes should be increased. Since the conventional trimmer capacitor changes the capacitance by adjusting the area where the stator electrode and the rotor electrode face each other, it is not meaningful to reduce the area where the stator electrode and the rotor electrode face each other. You have to increase the distance between them. However, increasing the distance between the electrodes increases the thickness of the capacitor, making it difficult to miniaturize it.

Disclosure of Invention An object of the present invention is to provide a variable capacitor having excellent frequency characteristics and a method for manufacturing the same, which can be applied to various circuits by minimizing energy loss at high frequencies.

Another object of the present invention is to provide a variable capacitor and a method of manufacturing the same, which can finely adjust the frequency by relaxing the sensitivity of the capacitance to the rotation angle of the rotor after mounting the capacitor in an electronic circuit.

It is still another object of the present invention to provide a small variable capacitance capacitor having a low capacitance characteristic which can be used in a high frequency circuit by increasing the Q value, which is the inverse of the dielectric loss Df, and a method of manufacturing the same.

One aspect of the present invention for achieving the above object comprises a stator including a ceramic element inserted therein and an electrode connectable to the outside, and a mover movably mounted on an upper surface of the stator opposite the electrodes of the stator. In addition, the mover is provided with an electrode on a part of the surface of the mover facing the upper surface of the stator, the electrode of the stator relates to a variable capacitance capacitor comprising a portion different in distance from the electrode to the upper surface of the stator. .

The variable capacitance capacitor of the present invention includes a plurality of electrodes in the stator, and these electrodes have portions that do not overlap each other when projected on the upper surface of the stator, and the plurality of electrodes are each at the upper surface of the stator. It can be arranged at different distances and connected to each other electrically. One side of the stator may further include an electrode. The stator may include a ceramic body in which a plurality of ceramic sheets are stacked, and the plurality of electrodes may be interposed between the ceramic sheets.

In such a variable capacitance capacitor, the mover may be a trimmer capacitor which is a rotor rotatably mounted on the top surface of the stator. The electrode of the stator may include a printed electrode printed between each ceramic sheet, the rotor may include a conductor, and the surface on which the electrode of the rotor is provided may be a protruding conductor. The surface where the stator and the rotor face each other is circular around the axis of rotation, and the electrodes of the stator and the rotor may be concentric with the axis of rotation of the rotor, and the electrodes of the stator are projected in the direction of the axis of rotation. The electrodes of the stator and the rotor which are not overlapping and are fan-shaped may have the same center angle. In addition, a frame on which the stator and the rotor are mounted and a terminal for the stator and the rotor provided in the frame and connected to the electrodes of the stator and the rotor, respectively, wherein the plurality of electrodes of the stator are electrically connected through the stator. It can be connected to the stator terminal of the frame.

Another aspect of the present invention provides a stator comprising a ceramic body having two electrodes insulated from each other and connected to the outside on a lower surface thereof, and a mover mounted to the upper surface of the stator opposite the lower surface of the stator. The mover includes a variable capacitance capacitor provided on a face of the mover, the two electrodes corresponding to two electrodes of the stator and electrically connected to each other, respectively.

The mover of such a variable capacitor capacitor may be a trimmer capacitor which is a rotor rotatably mounted on the top surface of the stator. The stator electrode includes a printed electrode, the rotor includes a conductor, and the rotor may be an integral electrode covering a portion of the top surface of the stator, and the top surface of the stator facing the rotor may have a rotation axis. It is circular in the center, and the two electrodes of the stator are concentric with the axis of rotation of the rotor, the edges are spaced apart from each other, and the ends of the center axis are removed, and the two electrodes of the rotor are concentric with the axis of rotation of the rotor. And the sides may be fan-shaped apart from each other. Preferably, the electrodes do not overlap when the electrodes are projected in the direction of the rotation axis, and the fan-shaped electrodes have the same center angle. The apparatus may include a frame on which the stator and the rotor are mounted, and terminals provided on the frame and connected to two electrodes insulated from each other of the stator.

Still another aspect of the present invention provides a stator comprising a ceramic body having two mutually insulated electrodes connectable to the outside and a ceramic body inserted therein, and a movable member movably mounted to an upper surface of the stator opposite the electrodes of the stator. And wherein the mover has two electrodes electrically connected to the two electrodes of the stator, respectively, on the face of the mover facing the stator, and project the electrodes of the stator perpendicularly to the upper surface of the stator. Relates to a variable capacitor which does not overlap when.

In such a variable capacitance capacitor, the two electrodes of the stator may be spaced at the same distance in parallel to the top surface of the stator, and in particular may be a trimmer capacitor which is a rotor rotatably mounted to the top surface of the stator. . The electrode of the stator includes a printed electrode, the rotor may comprise a conductor, and the rotor may be an integral electrode covering a portion of the top surface of the stator. The upper surface of the stator facing the rotor is circular around the axis of rotation, the two electrodes of the stator are concentric with the axis of rotation of the rotor and are truncated fan-shaped with the sides spaced apart from each other and the ends of the center axis being removed. The two electrodes of the rotor may be truncated fan-shaped concentric with the axis of rotation of the rotor, the sides of which are spaced apart from one another, and the ends of the central axis side removed, preferably the sector-shaped electrodes have the same center angle. The variable capacitor includes a frame in which the stator and the rotor are mounted, and two terminals provided in the frame, and two insulated electrodes of the stator may be connected to terminals provided in the frame through the stator. . The electrodes of the rotor may be conductors and protruding surfaces, as described above. In this case, the two electrodes of the stator may be connected to the outside through the side of the stator, respectively.

Another aspect of the invention is a stator comprising a ceramic body having an electrode provided on a portion of the lower surface, and a surface movably mounted on the upper surface of the stator opposite the lower surface of the stator and facing the upper surface of the stator. The present invention relates to a variable capacitor including a mover having an electrode provided in a part thereof, and a dielectric inserted between the stator and the mover. Similarly, in the above-described variable capacitor capacitor, it may further include a dielectric inserted between the stator and the mover. The dielectric preferably comprises a low dielectric constant polymer.

A further aspect of the present invention provides a method of fabricating a first ceramic sheet, the method comprising: (a) providing a first ceramic sheet and printing a first electrode on a portion of the first ceramic sheet; and (b) enabling the first electrode to be electrically connected to the outside. (C) laminating a second ceramic sheet on the first ceramic sheet and printing a second electrode on a portion of the second ceramic sheet; and (d) electrically connecting the second electrode to the first electrode. And (e) repeating the steps (c) and (d) a plurality of times, and then laminating a cover ceramic sheet, and (f) pressing, debindering and firing the laminate of the ceramic sheet. Forming a ceramic body, and (g) movably mounting a mover provided with an electrode on the upper surface of the ceramic body, the electrode being provided on a part of the surface of the ceramic body facing the upper surface of the ceramic body; In the ceramic body Electrodes when the projection on the top surface of the ceramic body relates to a variable capacitance capacitor manufacturing method of the portion which does not overlap with each other exists.

In such a method of manufacturing a variable capacitor, the step of making the first electrode connectable to the outside includes forming a through hole in contact with the first electrode in the first ceramic sheet to fill a conductor in the through hole, Electrically connecting the second electrode to the first electrode may include forming a through hole in contact with the first electrode and the second electrode in the second ceramic sheet to fill a conductor in the through hole.

Another further aspect of the present invention provides a method of preparing a ceramic body and printing two electrodes insulated on the bottom surface of the ceramic body, and capable of moving the mover on the top surface of the ceramic body opposite the bottom surface of the ceramic body. And a mounting step, wherein the mover is provided with two electrodes electrically connected to a surface of the mover facing the upper surface of the ceramic element.

Another further aspect of the present invention provides a method of forming two through holes in a ceramic sheet, and printing two insulated electrodes on one surface of the ceramic sheet respectively covering the two through holes and connected to the outside. Laminating an additional ceramic sheet on one surface of the ceramic sheet, compressing, debindering and firing the laminate of the ceramic sheet to form a ceramic body, and further ceramic sheet of the ceramic body And a method of movably mounting a mover on an upper surface of the side, wherein the mover is provided with two electrodes electrically connected to a surface of the mover facing the upper surface of the ceramic element. will be.

In addition, another additional aspect of the present invention is to print two electrodes each connected to the outside and insulated on one surface of the ceramic sheet, the step of laminating an additional ceramic sheet on one surface of the ceramic sheet, the lamination Exposing a portion of the two electrodes between the formed ceramic sheets, squeezing, debindering and firing the laminate of the ceramic sheets to form a ceramic body, and an upper side of the ceramic body being the further ceramic sheet. And a method of movably mounting a mover on a surface, wherein the mover is provided with two electrodes provided with two electrodes electrically connected to a face of the mover facing the upper surface of the ceramic element.

In the above-described method of manufacturing a variable capacitor capacitor, the method further comprises inserting a dielectric between the mover and the ceramic body, wherein inserting the dielectric material on the top surface of the ceramic body or the top surface of the ceramic body. Coating a dielectric on the face of the movable mover.

First Embodiment-Stepped Stacked Trimmer Capacitor

1 is a schematic exploded perspective view of a stepped stacked trimmer capacitor according to a first embodiment of the present invention. This looks similar to the conventional conventional single-plate trimmer capacitor shown in FIG. 23, but the configuration of the electrodes provided on the stator 110 and the rotor 120 and the manufacturing method of the stator 110 are different from each other. As shown in FIG. 2, the lower surface of the rotor 120 according to the present embodiment has a fan shape having a center angle of 90 and two support protrusions 126. The conventional capacitor shown in FIG. Is the same as the rotor 720. However, in the case of the stator 110, as shown in Figs. 1, 3 and 4 (FIG. 4 will be described again as the manufacturing process of the stator), three fan-shaped shapes having three central angles of 90 respectively. Internal electrodes are arranged in different layers in the stator. Referring to FIG. 4, which illustrates a manufacturing process of the stator 110, the configuration of the rotor 110 may be more easily understood.

First, a slurry is prepared using a ceramic powder having a desired dielectric constant, and then a ceramic sheet is manufactured by a method such as Dr. blade. A first through hole 113a is formed in the first ceramic sheet 110a thus manufactured, and a conductive paste such as Ag is filled in the first through hole 113a. This is to form a passage in which internal electrodes to be printed between the sheets are connected to the terminal 111 provided in the frame. Next, a second through hole 113b connected to the first through hole 113a is formed in the second ceramic sheet 110b, the conductive paste is filled, and the first inside is connected to the conductive paste in the through hole 113b. The electrode 112a is printed. The third and fourth ceramic sheets 110c and 110d are prepared in the same manner as the second ceramic sheet 110b, and then the cover sheets 110e are stacked to complete the green bar. In actual production, the green bar is manufactured by manufacturing a sheet printed with internal electrodes such that the unit structure is repeatedly printed and laminated by thousands or more. Since three internal electrodes 112a, 112b, and 112c are formed in the unit stator 110 so as not to overlap each other by 90 degrees on different layers, these three internal electrodes 112a, 112b, and 112c each have a range of 270 degrees. At different distances from the top surface of the stator over.

The manufactured green bar is cut into a desired shape by pressing and punching. Then, a binder and firing are performed to produce a stepped ceramic body. Debinding is performed at about 300 to about 20 hours, and ceramic firing is performed at about 1200 to 1300 degrees.

The rotor 120 is mounted on the stator 110 such that the electrodes 122 of the rotor 120 do not face each other with the electrodes 112a, 112b, and 112c of the stator 110. When rotated, the area of the facing electrodes changes up to 90 degrees, the distance between the electrodes changes from 90 degrees to 270 degrees, and the facing areas of the electrodes change again from 270 to 360 degrees. Therefore, while the conventional trimmer capacitor is configured to change only the area of the facing electrodes in order to change the value of the capacitance, the stepped stacked trimmer capacitor of the present embodiment changes the distance between the electrodes as well as the large area of the facing electrodes. The value of the capacitance can be changed.

FIG. 5 shows the change of capacitance value according to the rotor rotation angle of the stepped stacked trimmer capacitor of this embodiment and the general single plate trimmer capacitor shown in FIG. The stepped stacked trimmer capacitor according to the present embodiment can be seen that the sensitivity of the capacitance value to the rotation angle of the rotor is reduced compared to the general single-plate trimmer capacitor. That is, the change in capacitance value is small when the rotor is rotated at the same angle. This has the advantage of allowing finer control when adjusting the frequency after the trimmer capacitor is mounted in the actual electronic circuit.

The internal electrodes of the stator of the present embodiment may be two or four or more than three, and the shape and size of these and the rotor electrodes may be changed as necessary. In addition, although the internal electrodes of the stator have been described as not overlapping each other when projecting the upper surface of the stator, the present invention does not need to be so limited, and some overlapping parts may exist.

Meanwhile, the first through third ceramic sheets 110b, 110c, and 110d are penetrated through the second through fourth ceramic sheets 110b, 110c, and 110d without laminating the first and fifth ceramic sheets 110a and 110e among the laminated ceramic sheets shown in FIG. 4. After forming only the holes 113b, 113c, and 113d and the first to third internal electrodes 112a, 112b, and 112c, the inverter may be inverted and then pressed, cut, debindered, and fired to manufacture the stator. Thus, one of the internal electrodes in the stator may be formed on the bottom surface of the stator.

In addition, as shown in FIG. 6, the internal electrode 112 is formed on the stator 110 only in one layer, and the ceramic body itself is obliquely cut so that the internal electrode 112 of the stator is inclined in the stator 110. It is also possible to simultaneously change the area between the stator electrode and the rotor electrode and the area between them facing each other.

Second Embodiment-Floating Electrode Trimmer Capacitor

7 is a schematic exploded perspective view of a floating electrode type trimmer capacitor. In the stator 210 of the floating electrode type trimmer capacitor of the present embodiment, a bow-shaped electrode 212a and 212b as shown in FIG. 8 is used instead of the electrode pattern of the lower surface of the stator 710 of the conventional conventional single plate type trimmer capacitor shown in FIG. ) Is printed, and a rotating shaft support hole 215 into which the rotating shaft 225 of the rotor 220 is not connected is formed. The electrodes 212a and 212b are connected to terminals 211a and 211b provided at the upper portion of the frame, respectively. In the rotor 220 which is a metal, the electrodes 212a and 212b of the stator 210 and the two electrodes 222a and 222b corresponding to each other are connected to each other by the electrode connection part 226. The rotor 220 is provided with a rotating shaft 225 perpendicular to the surfaces of the electrodes 222a and 222b and fitted into the rotating shaft support hole 215 of the stator, so that the rotor 220 is rotatably mounted with respect to the stator 210. do. That is, in the floating electrode type trimmer capacitor of the present embodiment, the rotor 220 serves as a floating electrode. The floating electrode type trimmer capacitor of this embodiment has a structure in which two trimmer capacitors are connected in series, which can be easily seen from an equivalent circuit diagram of FIG.

The total capacitance in series and parallel connection of the capacitor is:

In parallel connection: Ct = C1 + C2

In series connection: 1 / Ct = 1 / C1 + 1 / C2

Since the capacitance is greatly reduced when the capacitors are connected in series in the electric circuit, the floating electrode type trimmer capacitor of the present embodiment uses the same to realize low capacitance.

In the case of the high-frequency trimmer capacitor, as the capacitance increases, the resonant frequency decreases, and above the resonant frequency, the function of the capacitor is lost. Therefore, a capacitor having a low capacitance is required. However, in the case of the conventional trimmer capacitor, it is difficult to implement a low capacitance of less than 1 pF due to structural problems (floating capacity) that occur during assembly with the rotor and the limit that the dielectric constant can no longer be lowered due to the characteristics of the material. Therefore, the floating electrode type trimmer capacitor of the present exemplary embodiment has a structure in which two capacitors are connected in series to realize low capacitance. In addition, the equivalent series resistance (esr) value due to the increase of the effective electrode area is reduced to increase the Q value, which is the inverse of the dielectric loss, thereby minimizing the loss at high frequencies.

Third Embodiment-Multilayer Floating Electrode Trimmer Capacitor

11 and 12 are schematic perspective views and cross-sectional views of the stacked floating electrode type trimmer capacitor. The stacked floating electrode type trimmer capacitor of this embodiment is the same except for the stator and the floating electrode type trimmer capacitor described in the second embodiment. Whereas the electrode of the stator 210 of the floating electrode type trimmer capacitor of the second embodiment is printed on the bottom surface of the ceramic element, the electrode 312 of the laminated floating electrode type trimmer capacitor stator 310 of the present embodiment performs the first embodiment. Similar to the stator of the example is an internal electrode inserted inside the stator 310.

FIG. 13 shows a process for manufacturing the stator 310 of the stacked floating electrode type trimmer capacitor. First, a slurry is prepared using a ceramic powder having a desired dielectric constant, and then a ceramic sheet is manufactured by a method such as a doctor blade. The shaft hole 315a of the rotor 320 and the through-holes 313a and 313b for exposing the inner electrode of the rotor 320 are formed in the first ceramic sheet 310a thus manufactured, and Ag is provided in the through-holes for exposing the internal electrodes 313a and 313b. Electroconductive pastes, such as these, are filled. The conductive paste in the through holes 313a and 313b is connected to the terminals 311a and 311b provided in the frame, respectively. Next, the first and second internal electrodes 312a and 312b are printed on the first ceramic sheet 310a so as to be connected to the conductive paste in the through holes 313a and 313b, and the first and second internal electrodes 312a are provided. , 312b) each form a passageway connected to the outside. Next, after forming the rotor shaft hole 315b in the second ceramic sheet 310b, the green bar is completed by laminating the first ceramic sheet 310a. In actual production, the green bar is manufactured by manufacturing a sheet printed with internal electrodes such that the unit structure is repeatedly printed and laminated by thousands or more. As described in the first embodiment, the manufactured green bar is pressed, punched, cut into desired shapes, and then debindered and fired to produce a stepped multilayer ceramic body. Debinding is performed at about 300 to about 20 hours, and ceramic firing is performed at about 1200 to 1300 degrees.

Similarly to the second embodiment, the laminated floating electrode type trimmer capacitor of the present embodiment can also implement a desired low capacitance by connecting two trimmer capacitors in series. That is, by adjusting the thickness of the laminated sheet can be adjusted to various capacitance values. In addition, the equivalent series resistance (esr) value due to the increase of the effective electrode area is reduced to increase the Q value which is the inverse of the dielectric loss, thereby minimizing the loss at the high frequency.

Fourth Embodiment-Modification of Multi-Layered Floating Electrode Trimmer Capacitor

14 to 16 are stacked floating trimmer capacitors that do not use a separate frame, such as Murata's stacked trimmer capacitor described with reference to FIGS. 27 and 28. (Refer to Korean Patent Application Publication No. 10-2003-1148 for the manufacturing method of such a stacked trimmer capacitor.) The capacitor according to the present embodiment shows the internal electrodes 412a and 412b of the stator 410, as shown in FIG. Unlike the internal electrode 812 of the stator 810, as shown in FIG. 14, a bow tie shape is provided. The internal electrodes 412a and 412b of the stator 410 are connected to terminals 411a and 411b printed on the side of the stator, respectively. The electrodes 422a and 422b of the rotor 420 also protrude in a bowtie shape so as to correspond to the internal electrodes 412a and 412b of the stator 410. The stator 410 also serves as a frame, and the internal electrodes 412a and 412b are exposed to the sides of the stator 410 to facilitate connection with the outside. Moreover, the trimmer capacitor of the present embodiment can also realize low capacitance and high Q by connecting two trimmer capacitors in series.

Example 5 Low Dielectric Constant Polymer Layer Insertion Trimmer Capacitor

FIG. 17 is a sectional view and an equivalent circuit diagram of a trimmer capacitor of the present invention in which a low dielectric constant layer is inserted between the stator 710 and the rotor 810 of the general single plate type trimmer capacitor shown in FIGS. 23 to 26. When the low dielectric constant polymer material 500 is inserted between the stator and the rotor of a typical single plate type trimmer capacitor, as shown in the equivalent circuit diagram of FIG. 17, the low dielectric constant layer capacitor is formed in series in the single plate type trimmer capacitor. do. Therefore, two capacitors can be connected in series to reduce the capacitance value. In particular, by utilizing the excellent low dielectric loss characteristics of the polymer material, it is possible to manufacture a trimmer capacitor having a high Q value even at high frequencies.

Low dielectric constant polymer materials such as parylene can be made into discs and inserted between the stator and the rotor, which are ceramic bodies. Alternatively, the polymeric material can be formed and inserted into a film on a facing surface of the stator or rotor by a method such as thin film coating.

FIG. 18 is a sectional view and an equivalent circuit diagram of an embodiment in which a low dielectric constant layer 500 is inserted between a stator 810 and a rotor 820 of Murata's stacked trimmer capacitor shown in FIGS. 27 and 28. FIGS. 21 is a cross-sectional view of an embodiment in which the low dielectric constant layer 500 is inserted between the stators 210, 310, 410 and the rotors 220, 320, 420 of the trimmer capacitors according to the second to fourth embodiments, respectively. Equivalent circuit diagram.

In particular, the capacitors shown in Figs. 19 to 21 have a low dielectric constant between the stators 210, 310, 410 and the rotors 220, 320, 420 of the (laminated) floating electrode type trimmer capacitors in which the rotor electrodes are floating. In this case, the layer 500 is inserted. In this case, two capacitors are connected in series due to the floating electrode, and two capacitors are connected in series by the low dielectric constant layer, and the four capacitors are connected in series to further increase capacitance. Can be lowered.

Although not shown, the insertion of the low dielectric constant layer into the stepped trimmer capacitor of the first embodiment may not only reduce the sensitivity of the capacitance value to the rotation angle of the rotor, but also lower the capacitance.

Example 6-Translationally Variable Variable Capacitor

So far, the variable capacitance capacitor has basically described a trimmer capacitor in which the rotor rotates on the stator. However, the present invention is to form an internal electrode of the stator in a stepped stack, to provide a floating electrode in the rotor, or to insert a low dielectric constant polymer layer between the rotor and the stator, and to limit the trimmer capacitor in which the rotor rotates on the stator. It doesn't work. For example, in the stepped stacked trimmer capacitor presented in the first embodiment, instead of rotating the metal rotor over the stator, the metal mover 620 translates the capacitance value while performing translational motion. In this case, the internal electrodes 612a, 612b, 612c of the stator are arranged in parallel to each layer of the ceramic sheet in a non-square rectangle, and the electrode 622 of the mover is in contact with the rotor 610. Becomes the bottom surface of itself. Figure 22 shows a schematic cross section of such a translational variable capacitance capacitor. As the mover 620 starts at point A and reaches point B as shown in Fig. 22, the facing area between the electrode 612a and the electrode 622 changes, and from the point B to the point D, the electrode 612a , 612b, 612c and the distance between the electrode 622 are changed. Therefore, this embodiment can achieve the same effect as the above-described first embodiment. This translational variable capacitance capacitor is equally applicable to other embodiments of the present invention.

The variable capacitance capacitor of the present invention according to the above-described configuration is relaxed the sensitivity of the capacitance to the rotation angle of the rotor can be finely adjusted the frequency after mounting the capacitor in the electronic circuit.

In addition, it is possible to implement a low capacitance, it is possible to increase the Q value which is the inverse of the dielectric loss (Df) when used in a high frequency circuit. In this case, a low dielectric constant layer may be inserted into the capacitor, or the capacitor may be connected in series by using the electrode of the rotating body of the capacitor and the internal electrode of the stator, thereby minimizing the size of the capacitor while implementing low capacitance.

As such, since the range and sensitivity of the capacitance can be adjusted in a wide range, the degree of freedom in design is increased. In addition, the stator is manufactured by printing internal electrodes on a ceramic sheet and simply laminating them, and the sensitivity and range of the capacitance can be adjusted by coating a polymer having a low dielectric constant on the stator or the rotor. The manufacturing cost can be reduced.

Claims (38)

A stator including a ceramic element inserted therein with an electrode connectable to the outside; A mover movably mounted on an upper surface of the stator opposite the electrodes of the stator, The mover is provided with an electrode on a part of the surface of the mover facing the upper surface of the stator, the electrode of the stator includes a portion of the distance from the electrode of the stator to the upper surface is different. 2. The stator of claim 1, wherein the stator includes a plurality of electrodes, and these electrodes have portions that do not overlap each other when projected on the top surface of the stator, and the plurality of electrodes are different from each other on the top surface of the stator. A variable capacitance capacitor arranged at a distance and electrically connected to each other. The stator of claim 1, wherein the stator includes a plurality of electrodes and one electrode on a lower surface of the stator, and these electrodes have portions that do not overlap each other when projected on the upper surface of the stator. And the electrodes are arranged at different distances from the upper surface of the stator and are electrically connected to each other. 3. The variable capacitance capacitor of claim 2, wherein the stator includes a ceramic body in which a plurality of ceramic sheets are stacked, and the plurality of electrodes are interposed between the ceramic sheets. 5. The variable capacitance capacitor of claim 4 wherein the mover is a rotor rotatably mounted on the top surface of the stator. The method of claim 5, wherein the electrode of the stator includes a printed electrode printed between each ceramic sheet, the rotor comprises a conductor, the surface provided with the electrode of the rotor is a protruding conductor Variable capacitance capacitor. 7. The variable capacitance capacitor of claim 6, wherein a surface of the stator and the rotor facing each other is circular around a rotation axis, and electrodes of the stator and the rotor are concentric with the rotation axis of the rotor. 8. The variable capacitor capacitor as claimed in claim 7, wherein the stator and the rotor electrodes which are not overlapped when the electrodes of the stator are projected in the direction of the rotational axis, have the same center angle. 9. The apparatus of claim 8, further comprising a frame on which the stator and the rotor are mounted, and terminals for the stator and the rotor provided in the frame and connected to the electrodes of the stator and the rotor, respectively. And electrically connected to the terminal for stator of the frame. A stator including a ceramic body having two electrodes insulated from each other and insulated from each other on a lower surface thereof, and having a rotating shaft support hole; A rotor including a rotating shaft and the rotating shaft mounted to the rotating shaft support hole so as to be rotatable on an upper surface of the stator; And the rotor has two electrodes corresponding to two electrodes of the stator, and electrically connected to each other, on the side of the rotor facing the upper surface of the stator. delete 11. The variable capacitance capacitor of claim 10 wherein the electrode of the stator comprises a printed electrode, the rotor comprises a conductor, and the rotor is an integral electrode covering a portion of the top surface of the stator. The method of claim 12, wherein the upper surface of the stator facing the rotor is circular about the axis of rotation, the two electrodes of the stator are concentric with the axis of rotation of the rotor and the sides are spaced apart from each other and the side of the center axis A truncated fan shape with the ends removed, and the two electrodes of the rotor are fan shapes concentric with the rotation axis of the rotor and spaced apart from each other. The variable capacitor of claim 13, wherein the electrodes do not overlap when the electrodes are projected in the direction of the rotation axis, and the fan-shaped electrodes have the same center angle. 15. The variable capacitor capacitor as claimed in claim 14, comprising a frame on which the stator and the rotor are mounted, and terminals provided on the frame and connected to two electrodes insulated from each other of the stator. A stator including a ceramic body having two mutually insulated electrodes each connected to the outside and inserted therein; A mover movably mounted on an upper surface of the stator opposite the electrodes of the stator, The mover is provided with two electrodes electrically connected to the two electrodes of the stator, respectively, on the face of the mover facing the stator, and do not overlap when the electrodes of the stator are projected perpendicularly to the upper surface of the stator. Variable capacitance capacitor. 17. The variable capacitor capacitor of claim 16 wherein the two electrodes of the stator are spaced at equal distances parallel to the top surface of the stator. 18. The variable capacitance capacitor of claim 17 wherein the mover is a rotor rotatably mounted on an upper surface of the stator. 19. The method of claim 18, wherein the stator electrode comprises a printed electrode, the rotor comprises a conductor, and the rotor is an integral electrode covering a portion of the top surface of the stator or the electrodes of the rotor are the conductors. Variable capacitance capacitor, characterized in that the protruding surface. 20. The rotor of claim 19, wherein the upper surface of the stator facing the rotor is circular about the axis of rotation, and the two electrodes of the stator are concentric with the axis of rotation of the rotor and the sides are spaced apart from one another and the ends on the central axis side are removed. And a truncated fan shape, wherein the two electrodes of the rotor are concentric with the rotation axis of the rotor and the edges are spaced apart from each other and the ends of the central axis are removed. 21. The variable capacitance capacitor of claim 20, wherein the fan-shaped electrodes have the same center angle. 22. The apparatus of claim 21, further comprising a frame on which the stator and the rotor are mounted, and two terminals provided in the frame, wherein two insulated electrodes of the stator are connected to terminals provided in the frame through the stator. Variable capacitance capacitor. delete delete delete 19. The variable capacitor of claim 18 wherein the two electrodes of the stator are each connectable to the outside through the side of the stator.  27. A variable capacitance capacitor according to any one of claims 1 to 10, 12 to 22 and 26, further comprising a dielectric interposed between the stator and the mover. delete A stator including a ceramic element provided with an electrode on a part of a lower surface thereof, A mover mounted to an upper surface of the stator opposite the lower surface of the stator and provided with an electrode on a part of the surface facing the upper surface of the stator; And a dielectric interposed between the stator and the mover. 30. The variable capacitance capacitor of claim 29 wherein the mover is a rotor rotatably mounted to an upper surface of the stator. 31. The variable capacitance capacitor of claim 29 or 30 wherein the dielectric comprises a polymer of low dielectric constant. (a) preparing a first ceramic sheet and printing a first electrode on a portion of the first ceramic sheet; (b) enabling the first electrode to be electrically connected to the outside; (c) laminating a second ceramic sheet on the first ceramic sheet and printing a second electrode on a portion of the second ceramic sheet; (d) electrically connecting the second electrode with a first electrode; (e) repeating steps (c) and (d) a plurality of times and then laminating a cover ceramic sheet; (f) pressing the laminate of the ceramic sheets, debindering and firing to form a ceramic body, (g) movably mounting a mover provided with an electrode on the upper surface of the ceramic body, the electrode being provided on a part of the surface of the ceramic body facing the upper surface of the ceramic body, wherein the electrodes in the ceramic body are ceramic bodies; And a part which does not overlap each other when projected on the upper surface of the variable capacitor capacitor manufacturing method. 33. The method of claim 32, wherein enabling the first electrode to be externally accessible includes forming a through hole in the first ceramic sheet contacting the first electrode to fill a conductor in the through hole, wherein the second electrode Electrically connecting the first electrode to the first electrode includes filling the conductor in the through hole by forming a through hole in contact with the first electrode and the second electrode in the second ceramic sheet. Manufacturing method. Providing a ceramic body and printing two insulated electrodes on the bottom surface of the ceramic body; Movably mounting a mover on an upper surface of the ceramic body opposite the lower surface of the ceramic body, And the mover is provided with two electrodes electrically connected to a surface of the mover facing the upper surface of the ceramic element. Forming two through holes in the ceramic sheet, Printing two insulated electrodes on one surface of the ceramic sheet respectively covering the two through holes and connected to the outside; Laminating an additional ceramic sheet on one surface of the ceramic sheet; Pressing the laminate of the ceramic sheets, debindering and firing to form a ceramic body, Movably mounting a mover on an upper surface which is a side of a further ceramic sheet of said ceramic body, And the mover is provided with two electrodes electrically connected to a surface of the mover facing the upper surface of the ceramic element. Printing two insulated and insulated electrodes on one surface of the ceramic sheet, respectively; Laminating an additional ceramic sheet on one surface of the ceramic sheet; Exposing a portion of two electrodes between the laminated ceramic sheets; Pressing the laminate of the ceramic sheets, debindering and firing to form a ceramic body, Movably mounting a mover on an upper surface which is a side of a further ceramic sheet of said ceramic body, And the mover is provided with two electrodes electrically connected to a surface of the mover facing the upper surface of the ceramic element. 37. The method of any one of claims 32 to 36, further comprising inserting a dielectric between the mover and the ceramic body. 38. The method of claim 37, wherein inserting the dielectric comprises coating the dielectric on the top surface of the ceramic body or on the face of the mover facing the top surface of the ceramic body. .

Images