JPH08213282A - Variable capacitance capacitor - Google Patents
Variable capacitance capacitorInfo
- Publication number
- JPH08213282A JPH08213282A JP7036189A JP3618995A JPH08213282A JP H08213282 A JPH08213282 A JP H08213282A JP 7036189 A JP7036189 A JP 7036189A JP 3618995 A JP3618995 A JP 3618995A JP H08213282 A JPH08213282 A JP H08213282A
- Authority
- JP
- Japan
- Prior art keywords
- movable electrode
- electrode
- fixed electrode
- fixed
- distance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000003990 capacitor Substances 0.000 title claims abstract description 43
- 238000005452 bending Methods 0.000 claims abstract description 11
- 238000004904 shortening Methods 0.000 claims description 4
- 230000015556 catabolic process Effects 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 5
- 238000006073 displacement reaction Methods 0.000 description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical group [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 4
- 229910052710 silicon Inorganic materials 0.000 description 4
- 239000010703 silicon Substances 0.000 description 4
- 239000010408 film Substances 0.000 description 3
- 238000007740 vapor deposition Methods 0.000 description 3
- 239000010409 thin film Substances 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000012888 cubic function Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G5/00—Capacitors in which the capacitance is varied by mechanical means, e.g. by turning a shaft; Processes of their manufacture
- H01G5/16—Capacitors in which the capacitance is varied by mechanical means, e.g. by turning a shaft; Processes of their manufacture using variation of distance between electrodes
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Micromachines (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、電圧容量変換素子とし
て用いられる可変容量コンデンサに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable capacitance capacitor used as a voltage capacitance conversion element.
【０００２】[0002]
【従来の技術】図６には、可変容量コンデンサの一例と
して、特開平５−７４６５５号公報に提案されている可
変容量コンデンサの要部構成が示されており、この可変
容量コンデンサは表面マイクロマシニング技術を用いて
形成されている。同図において、シリコンの支持台３に
は凹部８が形成されており、この凹部８の底面５の中央
領域に、アルミニウムの蒸着等によって薄膜体に形成さ
れた固定電極４が配設されている。また、凹部８の上端
には、凹部開口に掛け渡して、固定電極４と電極面11同
士を対向させた可動電極６が凹部開口端縁側で固定され
て形成されている。この可動電極６も固定電極４と同様
に、アルミニウムの蒸着等により薄膜体に形成されてい
る。2. Description of the Related Art FIG. 6 shows an essential part of a variable capacitance capacitor proposed in Japanese Patent Laid-Open No. 5-74655 as an example of the variable capacitance capacitor. It is formed using technology. In the figure, a concave portion 8 is formed in a silicon support base 3, and a fixed electrode 4 formed in a thin film body by vapor deposition of aluminum or the like is arranged in a central region of a bottom surface 5 of the concave portion 8. . Further, a movable electrode 6 is formed at the upper end of the concave portion 8 so as to be bridged over the concave portion opening so that the fixed electrode 4 and the electrode surface 11 are opposed to each other and fixed on the edge side of the concave portion opening. Like the fixed electrode 4, the movable electrode 6 is also formed into a thin film body by vapor deposition of aluminum or the like.
【０００３】可動電極６と固定電極４のそれぞれの一端
側からは、図示されていない端子部が引き出し形成され
ており、この端子部間にバイアス電圧を印加することに
より、固定電極４と可動電極６に電位差を与えて、可動
電極６を固定電極４側に撓み変形させる電圧印加手段
（図示せず）が設けられている。From the respective one ends of the movable electrode 6 and the fixed electrode 4, a terminal portion (not shown) is formed so as to extend. By applying a bias voltage between the terminal portions, the fixed electrode 4 and the movable electrode 4 are formed. A voltage applying means (not shown) for applying a potential difference to the movable electrode 6 to bend and deform the movable electrode 6 toward the fixed electrode 4 side is provided.
【０００４】この可変容量コンデンサにおいては、前記
電圧印加手段（図示せず）により、固定電極４と可動電
極６との間に外部バイアス電圧を印加して固定電極４と
可動電極６に電位差を与えると、可動電極６がクーロン
力の作用（静電力作用）により固定電極４側に撓み変形
し、図の一点鎖線に示すような状態となり、それによ
り、可動電極６と固定電極４との間の間隙、すなわち、
電極間距離が変化する。そうすると、可動電極６および
固定電極４における静電容量が、両電極間に印加した外
部バイアス電圧に対応して変化することとなり、印加し
た外部バイアス電圧に対応する静電容量が得られること
になる。In this variable capacitor, the voltage applying means (not shown) applies an external bias voltage between the fixed electrode 4 and the movable electrode 6 to give a potential difference to the fixed electrode 4 and the movable electrode 6. Then, the movable electrode 6 is flexed and deformed toward the fixed electrode 4 side by the action of Coulomb force (electrostatic force action), and the state shown by the one-dot chain line in the figure is brought about. The gap, that is,
The distance between the electrodes changes. Then, the electrostatic capacitances of the movable electrode 6 and the fixed electrode 4 change in accordance with the external bias voltage applied between both electrodes, and the electrostatic capacitance corresponding to the applied external bias voltage is obtained. .
【０００５】この提案の可変容量コンデンサは、上記の
ように単一素子によって構成されており、従来用いられ
ていた可変空気コンデンサ（バリコン）のように回転機
構等の複雑な機構を必要としないために小型化が可能で
あるといった利点があり、また、バラクタダイオードの
ように耐圧が低く、耐圧の向上を図ろうとして内部抵抗
を大きくした場合にＱ値の低下が生じるといった問題も
なく、耐圧およびＱ値の高い優れた可変容量コンデンサ
として注目されている。The proposed variable capacitor is composed of a single element as described above, and does not require a complicated mechanism such as a rotating mechanism unlike the conventionally used variable air capacitor (varicon). In addition, it has a merit that it can be downsized, and has a low withstand voltage like a varactor diode, and there is no problem that the Q value is lowered when the internal resistance is increased in order to improve the withstand voltage. It is attracting attention as an excellent variable capacitor with a high Q value.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、上記提
案の可変容量コンデンサにおいては、可動電極６に加わ
るクーロン力と、そのクーロン力の作用により撓み変形
した可動電極６が変形前の元の位置に戻ろうとするばね
力との関係から、可動電極６の変位量に限界があり、し
たがって、可動電極６の撓み変形によって得られる容量
変化率を大きくすることができないといった問題があっ
た。However, in the above-mentioned proposed variable capacitor, the Coulomb force applied to the movable electrode 6 and the movable electrode 6 flexibly deformed by the action of the Coulomb force are returned to the original position before the deformation. There is a problem in that the displacement amount of the movable electrode 6 is limited due to the relationship with the spring force to be tried, and therefore the rate of change in capacitance obtained by the bending deformation of the movable electrode 6 cannot be increased.
【０００７】それというのは、可動電極６の変形量が、
固定電極４と可動電極６との電極間距離の１／３よりも
大きくなると、以下に述べる関係から、前記ばね力と前
記クーロン力との釣り合いがとれにくいために、容量変
化率を容易に大きくすることができないのである。This is because the amount of deformation of the movable electrode 6 is
When the distance becomes larger than 1/3 of the distance between the fixed electrode 4 and the movable electrode 6, it is difficult to balance the spring force and the Coulomb force from the relationship described below, so that the capacity change rate is easily increased. You cannot do it.
【０００８】以下、可動電極６の変化量と、そのときに
可動電極６に加わるクーロン力および、ばね力の関係を
述べる。可動電極６は、可動電極６と固定電極４に与え
られる電位差により可動電極６に加わるクーロン力と、
そのクーロン力の作用により可動電極６が撓み変形した
ときに可動電極６が元の位置（変形していないときの位
置）に戻ろうとするばね力とが釣り合った位置で固定さ
れることになるために、このとき、次式（１）の関係が
成り立つことが分かる。The relationship between the amount of change in the movable electrode 6 and the Coulomb force and spring force applied to the movable electrode 6 at that time will be described below. The movable electrode 6 has a Coulomb force applied to the movable electrode 6 due to a potential difference applied to the movable electrode 6 and the fixed electrode 4,
Since the movable electrode 6 is bent and deformed by the action of the Coulomb force, the movable electrode 6 is fixed at a position balanced with the spring force that tries to return to the original position (the position when it is not deformed). At this time, it can be seen that the relationship of the following expression (1) is established.
【０００９】 Ｆ＝ｋｘ＝１／２・εＳ｛Ｖ／（ｘ0 −ｘ）｝2 ・・・・・（１）F = kx = 1 / 2εS {V / (x 0 -x)} 2 (1)
【００１０】なお、式（１）において、ｋは可動電極６
のばね定数、Ｓは可動電極６の固定電極４との対向面
積、εは誘電率、Ｖは電極４と６との間の電位差、ｘ0
は可動電極６と固定電極４の電極間距離、ｘは可動電極
６の変位量である。ここで、ｕ＝ｘ／ｘ0 ，Ｋ＝εＳ／
２ｋｘ0 3 として上記式（１）を整理すると、次式
（２）となる。In the equation (1), k is the movable electrode 6
Spring constant, S is the area of the movable electrode 6 facing the fixed electrode 4, ε is the dielectric constant, V is the potential difference between the electrodes 4 and 6, and x 0
Is the distance between the movable electrode 6 and the fixed electrode 4, and x is the amount of displacement of the movable electrode 6. Here, u = x / x 0 , K = εS /
Rearranging the above formula (1) as 2kX 0 3, the following equation (2).
【００１１】ｕ（１−ｕ）2 ＝ＫＶ2 ・・・・・（２）U (1-u) 2 = KV 2 (2)
【００１２】この式（２）から、ｕ（１−ｕ）2 ＝ｆ
（ｕ）とすると、図７に示す関係が導かれ、関数ｆ
（ｕ）は、ｕ＝１／３のときにＫＶ2 が約0.15でピーク
を有する３次関数となる。この図からＶが大きくなり、
ｕが１／３を越えると前記ばね力とクーロン力との釣り
合いがとれなくなることが分かり、そうなると、可動電
極６は固定電極４に接触してしまう。また、ｕが１／３
を越えた状態で、ばね力とクーロン力との釣り合いをと
ることも可能であるが、この場合は、何らかの制御でバ
イアス電圧Ｖをばね力に応じてコントロールする必要が
ある。From this equation (2), u (1-u) 2 = f
(U) leads to the relationship shown in FIG. 7, and the function f
(U) is a cubic function having a peak at KV 2 of about 0.15 when u = 1/3. V becomes large from this figure,
It was found that when u exceeds 1/3, the spring force and the Coulomb force cannot be balanced, and then the movable electrode 6 comes into contact with the fixed electrode 4. Also, u is 1/3
It is possible to balance the spring force and the Coulomb force in a state of exceeding the above condition, but in this case, it is necessary to control the bias voltage V according to the spring force by some control.
【００１３】したがって、可動電極６の変位量は、可動
電極６と固定電極４との電極間距離の１／３までが限界
となり、この可変容量コンデンサの容量変化率は最大で
50％となり、これ以上大きな可変率を得ることができな
かった。Therefore, the displacement amount of the movable electrode 6 is limited to 1/3 of the distance between the movable electrode 6 and the fixed electrode 4, and the capacity change rate of this variable capacitor is maximum.
It was 50%, and it was not possible to obtain a larger variable rate.
【００１４】本発明は、上記課題を解決するためになさ
れたものであり、その目的は、大きな可変率（容量変化
率）を取ることができる可変容量コンデンサを提供する
ことにある。The present invention has been made to solve the above problems, and an object of the present invention is to provide a variable capacitor capable of achieving a large variable ratio (capacity change ratio).
【００１５】[0015]
【課題を解決するための手段】上記目的を達成するため
に本発明は次のように構成されている。すなわち、本発
明は、支持台に凹部が形成され、この凹部底面の中央領
域に固定電極が配設されており、前記凹部の上端には該
凹部開口に掛け渡して前記固定電極と電極面同士を対向
させて可動電極が凹部開口端縁側で固定されて形成され
ており、前記固定電極の両外側の凹部底面領域から凹部
上端の内端側にかけて前記可動電極の固定電極側への撓
み変形量が大きくなるにつれて支点間距離を順次短くし
て可動電極を支えるストッパー構造が形成されているこ
とを特徴として構成されている。In order to achieve the above object, the present invention is constructed as follows. That is, according to the present invention, a recess is formed in a support base, and a fixed electrode is disposed in a central region of the bottom surface of the recess. The fixed electrode and the electrode surface are connected to each other at the upper end of the recess so as to extend over the opening of the recess. And the movable electrode is formed so as to be fixed on the opening edge side of the recess, and the amount of bending deformation of the movable electrode toward the fixed electrode from the bottom surface region of the recess on both outer sides of the fixed electrode to the inner end side of the upper end of the recess. Is increased, the distance between the fulcrums is sequentially shortened to form a stopper structure for supporting the movable electrode.
【００１６】また、前記ストッパー構造は可動電極を支
える支点間距離を段階的に短くする１つ以上の段部を有
して構成されていること、前記ストッパー構造は可動電
極を支える支点間距離を連続的に短くするテーパ状のガ
イド面を有して形成されていることも本発明の特徴的な
構成とされている。Further, the stopper structure is configured to have one or more steps for gradually shortening the distance between fulcrums supporting the movable electrode, and the stopper structure defines the distance between fulcrums supporting the movable electrode. It is also a characteristic configuration of the present invention that it is formed with a tapered guide surface that is continuously shortened.
【００１７】[0017]
【作用】上記構成の本発明において、固定電極の両外側
の凹部底面領域から凹部上端の内端側にかけて前記可動
電極の固定電極側への撓み変形量が大きくなるにつれて
支点間距離を順次短くして可動電極を支えるストッパー
構造が形成されているために、可動電極は、固定電極側
への撓み変形量が大きくなるにつれて、ストッパー構造
により、支点間距離を順次短くして支えられることとな
る。In the present invention having the above structure, the distance between the fulcrums is gradually reduced as the amount of flexural deformation of the movable electrode toward the fixed electrode increases from the bottom surface region of the recess on both outer sides of the fixed electrode to the inner end side of the upper end of the recess. Since the stopper structure for supporting the movable electrode is formed, the movable electrode is supported by the stopper structure by sequentially shortening the distance between the fulcrums as the amount of bending deformation toward the fixed electrode increases.
【００１８】一般に、両持ち梁のばね定数は、次式
（３）によって表され、梁の長さＬが短くなるほどばね
定数が大きくなるために、可動電極の支点間距離が順次
短くなれば、可動電極のばね定数が大きくなる。Generally, the spring constant of a doubly supported beam is expressed by the following equation (3). Since the spring constant increases as the length L of the beam decreases, the distance between the fulcrums of the movable electrodes becomes shorter. The spring constant of the movable electrode becomes large.
【００１９】ｋ＝ＡＥＩ／Ｌ3 ・・・・・（３）K = AEI / L 3 (3)
【００２０】ただし、式（３）のＡは定数、Ｉは断面２
次モーメント、Ｌは梁の長さ、すなわち、支点間距離、
Ｅはヤング率である。In the equation (3), A is a constant and I is a cross section 2.
The second moment, L is the beam length, that is, the distance between fulcrums,
E is Young's modulus.
【００２１】したがって、可動電極の固定電極側への撓
み変形量が大きくなって、可動電極に加わるクーロン力
が大きくなっても、上記のように、クーロン力が大きく
なるにつれて可動電極を支える支点間距離が短くなれ
ば、クーロン力と可動電極のばね力とが釣り合った状態
で可動電極が固定されるようになる。そのため、可動電
極が固定電極側へ大きく撓み変形することが可能とな
り、その結果、可変容量コンデンサの容量変化率を大き
くすることが可能となる。Therefore, even if the amount of flexural deformation of the movable electrode toward the fixed electrode increases and the Coulomb force applied to the movable electrode increases, as described above, the fulcrum between the fulcrums supporting the movable electrode increases as the Coulomb force increases. When the distance is shortened, the movable electrode is fixed while the Coulomb force and the spring force of the movable electrode are balanced. Therefore, the movable electrode can be largely flexed and deformed toward the fixed electrode side, and as a result, the rate of change in capacitance of the variable capacitor can be increased.
【００２２】[0022]
【実施例】以下、本発明に実施例を図面に基づいて説明
する。なお、本実施例の説明において、図６に示した可
変容量コンデンサと同一名称部分には同一符号を付し、
その重複説明は省略する。図１には、本発明に係わる可
変容量コンデンサの第１の実施例の要部構成が断面図に
より示されている。本実施例が図６に示した可変容量コ
ンデンサと異なる特徴的なことは、固定電極４の両外側
の凹部底面領域から凹部上端の内端13側にかけて、１つ
以上（図では２つ）の段部９ａ，９ｂを形成し、これら
の段部９ａ，９ｂにより、可動電極６の固定電極４側へ
の撓み変形量が大きくなるにつれて支点間距離を順次短
くして可動電極６を支えるストッパー構造10を形成した
ことである。なお、本実施例のそれ以外の構成は、図６
に示した可変容量コンデンサと同様に構成されている。Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same name parts as those of the variable capacitor shown in FIG.
The duplicate description will be omitted. FIG. 1 is a sectional view showing the configuration of the essential parts of a first embodiment of a variable capacitor according to the present invention. The present embodiment is different from the variable capacitance capacitor shown in FIG. 6 in that one or more (two in the figure) are provided from the bottom surface region of the recess on both outer sides of the fixed electrode to the inner end 13 side of the upper end of the recess. A stopper structure in which stepped portions 9a and 9b are formed, and the stepped portions 9a and 9b support the movable electrode 6 by sequentially shortening the distance between fulcrums as the amount of bending deformation of the movable electrode 6 toward the fixed electrode 4 increases. That is the formation of 10. It should be noted that the other configuration of this embodiment is similar to that of FIG.
It has the same structure as the variable capacitor shown in FIG.
【００２３】本実施例では、可動電極６と固定電極４の
電極間距離はｈとなっており、前記段部９ａは、固定電
極４の電極面11から２／３・ｈの高さに形成されてお
り、段部９ｂは固定電極４の電極面11から４／９・ｈの
高さに形成されている。そして、これらの段部９ａ，９
ｂを有してストッパー構造10を構成することにより、ス
トッパー構造10は可動電極６を支える支点間距離を段階
的に短くするように構成されている。In this embodiment, the distance between the movable electrode 6 and the fixed electrode 4 is h, and the step 9a is formed at a height of 2/3 · h from the electrode surface 11 of the fixed electrode 4. The step portion 9b is formed at a height of 4/9 · h from the electrode surface 11 of the fixed electrode 4. And these step parts 9a, 9
By configuring the stopper structure 10 with b, the stopper structure 10 is configured to gradually reduce the distance between fulcrums supporting the movable electrode 6.
【００２４】本実施例は以上のように構成されており、
次のその動作について説明する。本実施例でも、図６に
示した可変容量コンデンサと同様に、図示されていない
電圧印加手段により可動電極６と固定電極４にバイアス
電圧が印加されて電位差が与えられ、その電位差に応じ
て、可動電極６が固定電極４側に撓み変形するが、本実
施例では、可動電極６の固定電極４側への撓み変形量が
大きくなるにつれて、支点間距離を順次短くして可動電
極６を支えるストッパー構造10が段部９ａ，９ｂにより
形成されており、図２の（ａ）に示すように、可動電極
６が撓み変形していき、段部９ａに接触すると、可動電
極６は段部９ａにより、Ａ−Ａ間で支えられることとな
る。こうなると、可動電極６を支える支点距離（Ａ−
Ａ）が可動電極６の変形前（図１に示す状態のとき）の
支点（内端13）間距離よりも短くなることから、前記式
（３）から明らかなように、可動電極６のばね定数が大
きくなり、可動電極６は大きく変位することが可能とな
る。This embodiment is constructed as described above,
The operation will be described below. Also in this embodiment, similarly to the variable capacitor shown in FIG. 6, a bias voltage is applied to the movable electrode 6 and the fixed electrode 4 by a voltage applying means (not shown) to give a potential difference, and in accordance with the potential difference, The movable electrode 6 flexibly deforms toward the fixed electrode 4 side, but in this embodiment, as the amount of flexural deformation of the movable electrode 6 toward the fixed electrode 4 increases, the distance between the fulcrums is gradually shortened to support the movable electrode 6. The stopper structure 10 is formed by the step portions 9a and 9b. As shown in FIG. 2A, when the movable electrode 6 is flexibly deformed and comes into contact with the step portion 9a, the movable electrode 6 is moved to the step portion 9a. As a result, it is supported between A and A. Then, the fulcrum distance (A- that supports the movable electrode 6)
Since (A) is shorter than the distance between the fulcrums (inner ends 13) before the movable electrode 6 is deformed (in the state shown in FIG. 1), the spring of the movable electrode 6 can be clearly understood from the above formula (3). The constant becomes large and the movable electrode 6 can be largely displaced.
【００２５】そして、図２の（ｂ）に示すように、可動
電極６の固定電極４側への撓み変形量がさらに大きくな
り、可動電極６が段部９ｂに接触すると、可動電極６
は、図のＢ−Ｂ間で支えられるようになり、支点間距離
はさらに短くなる。そうすると、前記式（３）から明ら
かなように、可動電極６のばね定数はさらに大きくな
り、可動電極６はさらに大きく変位することが可能とな
る。実際に、本実施例では、可動電極６が変形前の位置
（図１に示す状態での位置）から電位差に対応して21／
27・ｈまで変位することが確認された。Then, as shown in FIG. 2B, when the amount of flexural deformation of the movable electrode 6 toward the fixed electrode 4 side further increases and the movable electrode 6 contacts the step 9b, the movable electrode 6
Will be supported between BB in the figure, and the distance between fulcrums will be further shortened. Then, as is clear from the above formula (3), the spring constant of the movable electrode 6 is further increased, and the movable electrode 6 can be displaced further largely. Actually, in the present embodiment, the movable electrode 6 has a potential difference of 21 / corresponding to the potential difference from the position before the deformation (the position in the state shown in FIG. 1).
It was confirmed that the displacement was up to 27 h.
【００２６】本実施例によれば、上記動作により、可動
電極６の固定電極４側への撓み変形量が大きくなるにつ
れて、段部９ａ，９ｂにより、支点間距離を順次短くし
て可動電極６が支えられ、それにより、段部９ａ，９ｂ
に支えられている可動電極６のばね定数を大きくするこ
とができるために、可動電極６の撓み変形量が大きくな
り、可動電極６に働くクーロン力が大きくなっても、そ
のクーロン力と可動電極６が元の位置に戻ろうとするば
ね力との釣り合いを保つことができるようになり、可動
電極６を固定電極４側に大きく変位させることができ
る。そのため、可変容量コンデンサの可変率（容量変化
率）を大きくすることが可能となり、図２の（ｂ）に示
したように、可動電極６を変形前の位置から最大21／27
・ｈ撓み変形させることにより、容量変化率を最大350
％とすることができる。According to this embodiment, as the amount of flexural deformation of the movable electrode 6 toward the fixed electrode 4 increases due to the above operation, the distance between the fulcrums is gradually reduced by the step portions 9a and 9b. Is supported thereby, by which the steps 9a, 9b
Since the spring constant of the movable electrode 6 supported by the movable electrode 6 can be increased, even if the amount of bending deformation of the movable electrode 6 increases and the Coulomb force acting on the movable electrode 6 increases, the Coulomb force and the movable electrode 6 also increase. It becomes possible to maintain the balance with the spring force of 6 to return to the original position, and the movable electrode 6 can be largely displaced to the fixed electrode 4 side. Therefore, it becomes possible to increase the variable ratio (capacity change ratio) of the variable capacitor, and as shown in (b) of FIG.
・ Maximum capacity change rate of 350 by flexing and deforming
It can be%.
【００２７】また、本実施例によれば、上記段部９ａ，
９ｂを有するストッパー構造10が形成されている以外
は、図６に示した可変容量コンデンサと同様に構成され
ているために、図６の可変容量コンデンサと同様に、単
一素子でありながらも耐圧およびＱ値が高いという特長
を有することが可能となる。したがって、本実施例の可
変容量コンデンサは、単一素子でありながらも耐圧およ
びＱ値が高く、しかも、大きな可変率を取ることができ
る非常に優れた可変容量コンデンサとすることができ
る。Further, according to this embodiment, the step 9a,
6 is the same as the variable capacitance capacitor shown in FIG. 6 except that the stopper structure 10 having 9b is formed, the same as the variable capacitance capacitor of FIG. Also, it becomes possible to have a feature that the Q value is high. Therefore, the variable capacitance capacitor of the present embodiment can be a very excellent variable capacitance capacitor which has a high withstand voltage and a high Q value even though it is a single element and can have a large variable ratio.
【００２８】図３には、本発明に係わる可変容量コンデ
ンサの第２の実施例の要部構成が断面図により示されて
いる。本実施例が上記第１の実施例と異なる特徴的なこ
とは、ストッパー構造10が、可動電極６を支える支点間
距離を連続的に短くするテーパ状のガイド面12を有して
形成されていることである。FIG. 3 is a sectional view showing the structure of the essential part of the second embodiment of the variable capacitor according to the present invention. This embodiment is different from the first embodiment in that the stopper structure 10 is formed with a tapered guide surface 12 that continuously shortens the distance between fulcrums supporting the movable electrode 6. It is that you are.
【００２９】本実施例は以上のように構成されており、
本実施例も上記第１の実施例とほぼ同様に動作し、電圧
印加手段（図示せず）により、固定電極４と可動電極６
に電位差が与えられると、可動電極６が固定電極４側に
撓み変形していき、この撓み変形量が大きくなるにつれ
て、ストッパー構造10としてのガイド面12により、支点
間距離を順次短くして可動電極６が支えられるが、本実
施例では、ストッパー構造10が可動電極６を支える支点
間距離を連続的に短くするテーパ状のガイド面12を有し
て形成されているために、可動電極６は、その撓み変形
量が大きくなるにつれて、ガイド面12に支えられて連続
的にばね定数が大きくなる。This embodiment is constructed as described above,
This embodiment also operates in substantially the same manner as the first embodiment, and the fixed electrode 4 and the movable electrode 6 are operated by the voltage applying means (not shown).
When a potential difference is applied to the movable electrode 6, the movable electrode 6 flexibly deforms toward the fixed electrode 4 side, and as the amount of flexural deformation increases, the guide surface 12 as the stopper structure 10 sequentially shortens the distance between the fulcrums to move the movable electrode 6. Although the electrode 6 is supported, in the present embodiment, the stopper structure 10 is formed with the tapered guide surface 12 that continuously shortens the distance between the fulcrums supporting the movable electrode 6, so that the movable electrode 6 is supported. As the amount of flexural deformation increases, the spring constant is continuously increased by being supported by the guide surface 12.
【００３０】そのため、可動電極６は、前記電位差に対
応して滑らかに変位することが可能となり、本実施例の
可変容量コンデンサは、上記第１の実施例と同様の効果
に加え、上記第１の実施例の可変容量コンデンサよりも
滑らかに容量の可変を行うことが可能な、より優れた可
変容量コンデンサとすることができる。Therefore, the movable electrode 6 can be smoothly displaced in accordance with the potential difference, and the variable capacitance capacitor of the present embodiment has the same effect as that of the first embodiment, and the first capacitor described above. It is possible to obtain a more excellent variable capacitance capacitor that can change the capacitance more smoothly than the variable capacitance capacitor of the above embodiment.
【００３１】なお、本発明は上記実施例に限定されるこ
とはなく、様々な実施の態様を採り得る。例えば、上記
第１の実施例では、ストッパー構造10は、２つの段部９
ａ，９ｂを有して構成されていたが、ストッパー構造10
は、１つの段部を有して構成されていてもよく、３つ以
上の段部を有して構成されていてもよい。また、段部９
ａ，９ｂの形状を、図４の（ａ），（ｂ）に示すような
形状に構成してもよく、このように、段部の形状や配設
数、大きさ等は適宜設定されるものである。The present invention is not limited to the above-mentioned embodiment, and various embodiments can be adopted. For example, in the above-described first embodiment, the stopper structure 10 has two steps 9
Although it was configured with a and 9b, the stopper structure 10
May have one step, or may have three or more steps. Also, the step 9
The shapes of a and 9b may be configured as shown in FIGS. 4 (a) and 4 (b). In this way, the shape, the number of arrangements, the size, etc. of the stepped portion are appropriately set. It is a thing.
【００３２】また、上記実施例では、凹部８の内端13や
ストッパー構造10により、可動電極６を両端側でのみ支
えるように構成したが、例えば、図５に示すように、可
動電極６をその外周側の複数の箇所で支えるように構成
してもよい。Further, in the above-mentioned embodiment, the movable electrode 6 is supported only on both end sides by the inner end 13 of the recess 8 and the stopper structure 10. However, for example, as shown in FIG. It may be configured to be supported at a plurality of locations on the outer peripheral side.
【００３３】さらに、上記第２の実施例のように、スト
ッパー構造10をテーパ状のガイド面12を有して構成する
ときのガイド面12の角度等は特に限定されるものではな
く、適宜設定されるものである。Further, when the stopper structure 10 is constructed to have the tapered guide surface 12 as in the second embodiment, the angle and the like of the guide surface 12 are not particularly limited and may be set appropriately. It is what is done.
【００３４】さらに、上記実施例では、ストッパー構造
10は、段部９ａ，９ｂとガイド面12のいずれか一方によ
り構成されていたが、ストッパー構造10は、段部とガイ
ド面12の両方を有する構成としてもよい。Further, in the above embodiment, the stopper structure is used.
Although 10 is constituted by either one of the step portions 9a, 9b and the guide surface 12, the stopper structure 10 may be constituted by having both the step portion and the guide surface 12.
【００３５】さらに、上記実施例では、可動電極６と固
定電極４は、いずれもアルミニウムの蒸着等により形成
したアルミニウム電極により構成したが、可動電極６と
固定電極４の材質や形状、形成方法等は特に限定される
ものではなく、適宜設定されるものである。Furthermore, in the above embodiment, the movable electrode 6 and the fixed electrode 4 were both formed of aluminum electrodes formed by vapor deposition of aluminum, but the material, shape, forming method, etc. of the movable electrode 6 and the fixed electrode 4 etc. Is not particularly limited and is set appropriately.
【００３６】さらに、上記実施例では、支持台３として
シリコンからなるものを示したが、支持台３は必ずしも
シリコンにより形成するとは限らず、どのような絶縁体
により形成された支持台としてもよく、また、表面側に
絶縁膜を形成したもの、例えば、シリコンの表面側にシ
リコン酸化膜やシリコン窒化膜を形成したものとしても
よい。Further, in the above embodiment, the support base 3 made of silicon is shown, but the support base 3 is not necessarily made of silicon, and a support base made of any insulator may be used. Alternatively, an insulating film may be formed on the front surface side, for example, a silicon oxide film or a silicon nitride film may be formed on the front surface side of silicon.
【００３７】[0037]
【発明の効果】本発明によれば、固定電極の両外側の凹
部底面領域から凹部上端の内端側にかけて前記可動電極
の固定電極側への撓み変形量が大きくなるにつれて支点
間距離を順次短くして可動電極を支えるストッパー構造
が形成されていることにより、ストッパー構造に支えら
れている可動電極のばね定数を大きくして、可動電極が
変形前の元の位置に戻ろうとするばね力を大きくするこ
とが可能となり、可動電極の撓み変形量が大きくなるに
つれて可動電極に働くクーロン力が大きくなっても、そ
のクーロン力と前記ばね力との釣り合いを保つことが可
能となる。したがって、本発明とほぼ同様の構成で前記
ストッパー構造を備えていない従来提案の可変容量コン
デンサにおいては、可動電極の撓み変形量が可動電極と
固定電極との電極間距離の１／３が限界であったのに比
べ、本発明の可変容量コンデンサにおいては可動電極の
撓み変形量を格段に大きくすることが可能となり、非常
に大きな可変率を取ることができる。According to the present invention, the distance between fulcrums is gradually shortened as the amount of bending deformation of the movable electrode toward the fixed electrode increases from the bottom surface regions of the recesses on both outer sides of the fixed electrode to the inner end side of the upper end of the recess. By forming a stopper structure that supports the movable electrode by increasing the spring constant of the movable electrode supported by the stopper structure, the spring force that tries to return the movable electrode to its original position before deformation is increased. Therefore, even if the Coulomb force acting on the movable electrode increases as the amount of bending deformation of the movable electrode increases, it is possible to maintain the balance between the Coulomb force and the spring force. Therefore, in the conventionally proposed variable capacitor having substantially the same structure as the present invention and not including the stopper structure, the amount of bending deformation of the movable electrode is limited to 1/3 of the distance between the movable electrode and the fixed electrode. On the contrary, in the variable capacitor of the present invention, the amount of bending deformation of the movable electrode can be significantly increased, and a very large variable rate can be obtained.
【００３８】そして、本発明の可変容量コンデンサは、
上記ストッパー構造を除く構成が同様の前記提案の可変
容量コンデンサの特長を生かし、単一素子でありながら
も耐圧およびＱ値が大きいという前記従来の可変容量コ
ンデンサの特長と、本発明の特長である大きな可変率を
取ることができる特長とを併せ持つ非常に優れた可変容
量コンデンサとすることができる。The variable capacitor of the present invention is
Taking advantage of the features of the proposed variable capacitance capacitor having the same configuration except for the stopper structure, the features of the conventional variable capacitance capacitor having a large withstand voltage and a large Q value even though it is a single element are the features of the present invention. It is possible to make a very excellent variable capacitance capacitor that also has the feature that a large variable ratio can be obtained.
【図面の簡単な説明】[Brief description of drawings]
【図１】本発明に係わる可変容量コンデンサの第１の実
施例を示す要部構成図である。FIG. 1 is a main part configuration diagram showing a first embodiment of a variable capacitor according to the present invention.
【図２】上記第１の実施例の動作を示す説明図である。FIG. 2 is an explanatory diagram showing an operation of the first embodiment.
【図３】本発明に係わる可変容量コンデンサの第２の実
施例を示す要部構成図である。FIG. 3 is a main part configuration diagram showing a second embodiment of the variable capacitor according to the present invention.
【図４】本発明の可変容量コンデンサの他の実施例を示
す説明図である。FIG. 4 is an explanatory view showing another embodiment of the variable capacitor of the present invention.
【図５】本発明の可変容量コンデンサのさらに他の実施
例を示す説明図である。FIG. 5 is an explanatory diagram showing still another embodiment of the variable capacitor of the present invention.
【図６】従来の可変容量コンデンサの一例を示す説明図
である。FIG. 6 is an explanatory diagram showing an example of a conventional variable capacitor.
【図７】図６に示した可変容量コンデンサにおける可動
電極の変位率とばね力との関係を示すグラフである。7 is a graph showing the relationship between the displacement rate of the movable electrode and the spring force in the variable capacitor shown in FIG.
３ 支持台 ４ 固定電極 ６ 可動電極 ８ 凹部 ９ａ，９ｂ 段部 10 ストッパー構造 12 ガイド面 3 Support base 4 Fixed electrode 6 Movable electrode 8 Recesses 9a, 9b Step 10 Stopper structure 12 Guide surface
Claims (3)
の中央領域に固定電極が配設されており、前記凹部の上
端には該凹部開口に掛け渡して前記固定電極と電極面同
士を対向させて可動電極が凹部開口端縁側で固定されて
形成されており、前記固定電極の両外側の凹部底面領域
から凹部上端の内端側にかけて前記可動電極の固定電極
側への撓み変形量が大きくなるにつれて支点間距離を順
次短くして可動電極を支えるストッパー構造が形成され
ていることを特徴とする可変容量コンデンサ。1. A recess is formed in a support base, and a fixed electrode is disposed in the central region of the bottom surface of the recess. The fixed electrode and the electrode surface are laid over the recess opening at the upper end of the recess. The movable electrodes are formed so as to face each other and are fixed at the opening edge side of the concave portion, and the amount of bending deformation of the movable electrode toward the fixed electrode side from the bottom surface regions of the concave portions on both outer sides of the fixed electrode to the inner end side of the upper end of the concave portion is reduced. A variable capacitance capacitor characterized in that a stopper structure for supporting a movable electrode is formed by sequentially shortening the distance between fulcrums as the size increases.
間距離を段階的に短くする１つ以上の段部を有して構成
されていることを特徴とする請求項１記載の可変容量コ
ンデンサ。2. The variable capacitor according to claim 1, wherein the stopper structure is configured to have one or more steps that stepwise shorten a distance between fulcrums supporting the movable electrode.
間距離を連続的に短くするテーパ状のガイド面を有して
形成されていることを特徴とする請求項１記載の可変容
量コンデンサ。3. The variable capacitor according to claim 1, wherein the stopper structure is formed to have a tapered guide surface that continuously shortens a distance between supporting points supporting the movable electrode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7036189A JPH08213282A (en) | 1995-02-01 | 1995-02-01 | Variable capacitance capacitor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7036189A JPH08213282A (en) | 1995-02-01 | 1995-02-01 | Variable capacitance capacitor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08213282A true JPH08213282A (en) | 1996-08-20 |
Family
ID=12462788
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7036189A Pending JPH08213282A (en) | 1995-02-01 | 1995-02-01 | Variable capacitance capacitor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08213282A (en) |
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| WO2004000717A3 (en) * | 2002-06-19 | 2004-10-28 | Filtronic Compound Semiconduct | A micro-electromechanical variable capactitor |
| FR2862806A1 (en) * | 2003-11-25 | 2005-05-27 | St Microelectronics Sa | Variable capacitor for e.g. resonator, has flexible conducting membrane placed above groove portion, where depth of groove portion increases continuously from one of two lateral edges of portion to base of groove portion |
| US7082024B2 (en) | 2004-11-29 | 2006-07-25 | Stmicroelectronics S.A. | Component comprising a variable capacitor |
| JP2006310854A (en) * | 2005-04-25 | 2006-11-09 | Commissariat A L'energie Atomique | Variable capacitance electromechanical micro capacitor and method of manufacturing same |
| WO2009028269A1 (en) * | 2007-08-31 | 2009-03-05 | Omron Corporation | Element assembly, and its manufacturing method |
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| WO2011152192A1 (en) * | 2010-05-31 | 2011-12-08 | 株式会社村田製作所 | Variable capacitance element |
| JP2012531122A (en) * | 2009-06-19 | 2012-12-06 | クアルコム，インコーポレイテッド | Adjustable MEMS resonator in cavity |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004000717A3 (en) * | 2002-06-19 | 2004-10-28 | Filtronic Compound Semiconduct | A micro-electromechanical variable capactitor |
| GB2406716A (en) * | 2002-06-19 | 2005-04-06 | Filtronic Compound Semiconduct | A micro-electromechanical variable capactitor |
| GB2406716B (en) * | 2002-06-19 | 2006-03-01 | Filtronic Compound Semiconduct | A micro-electromechanical variable capactitor |
| FR2862806A1 (en) * | 2003-11-25 | 2005-05-27 | St Microelectronics Sa | Variable capacitor for e.g. resonator, has flexible conducting membrane placed above groove portion, where depth of groove portion increases continuously from one of two lateral edges of portion to base of groove portion |
| EP1536439A1 (en) * | 2003-11-25 | 2005-06-01 | St Microelectronics S.A. | Component comprising a variable capacitor |
| US8340615B2 (en) | 2004-09-27 | 2012-12-25 | Qualcomm Mems Technologies, Inc. | Selectable capacitance circuit |
| US7881686B2 (en) | 2004-09-27 | 2011-02-01 | Qualcomm Mems Technologies, Inc. | Selectable Capacitance Circuit |
| US7657242B2 (en) | 2004-09-27 | 2010-02-02 | Qualcomm Mems Technologies, Inc. | Selectable capacitance circuit |
| US7200908B2 (en) | 2004-11-29 | 2007-04-10 | Stmicroelectronics S.A. | Method of making a variable capacitor component |
| US7082024B2 (en) | 2004-11-29 | 2006-07-25 | Stmicroelectronics S.A. | Component comprising a variable capacitor |
| JP2006310854A (en) * | 2005-04-25 | 2006-11-09 | Commissariat A L'energie Atomique | Variable capacitance electromechanical micro capacitor and method of manufacturing same |
| JP2009059866A (en) * | 2007-08-31 | 2009-03-19 | Omron Corp | Element assembly and its manufacturing method |
| WO2009028269A1 (en) * | 2007-08-31 | 2009-03-05 | Omron Corporation | Element assembly, and its manufacturing method |
| JP2012531122A (en) * | 2009-06-19 | 2012-12-06 | クアルコム，インコーポレイテッド | Adjustable MEMS resonator in cavity |
| US8981875B2 (en) | 2009-06-19 | 2015-03-17 | Qualcomm Incorporated | Tunable MEMS resonators |
| JP2015136162A (en) * | 2009-06-19 | 2015-07-27 | クアルコム，インコーポレイテッド | Tunable mems resonators in cavity |
| JP2011205761A (en) * | 2010-03-25 | 2011-10-13 | Panasonic Electric Works Co Ltd | Non-contact power feeding system and drive method thereof |
| WO2011152192A1 (en) * | 2010-05-31 | 2011-12-08 | 株式会社村田製作所 | Variable capacitance element |
| WO2015186728A1 (en) * | 2014-06-05 | 2015-12-10 | 株式会社村田製作所 | Mems device |
| CN106458567A (en) * | 2014-06-05 | 2017-02-22 | 株式会社村田制作所 | MEMS device |
| US10287159B2 (en) | 2014-06-05 | 2019-05-14 | Murata Manufacturing Co., Ltd. | MEMS device |
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