WO2016119418A1 - 一种加速度计中的z轴结构 - Google Patents

一种加速度计中的z轴结构 Download PDF

Info

Publication number
WO2016119418A1
WO2016119418A1 PCT/CN2015/084969 CN2015084969W WO2016119418A1 WO 2016119418 A1 WO2016119418 A1 WO 2016119418A1 CN 2015084969 W CN2015084969 W CN 2015084969W WO 2016119418 A1 WO2016119418 A1 WO 2016119418A1
Authority
WO
WIPO (PCT)
Prior art keywords
pole piece
electrode pole
axis
movable electrode
fixed electrode
Prior art date
Application number
PCT/CN2015/084969
Other languages
English (en)
French (fr)
Inventor
方华斌
宋青林
孙艳美
Original Assignee
歌尔声学股份有限公司
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 歌尔声学股份有限公司 filed Critical 歌尔声学股份有限公司
Priority to US15/542,761 priority Critical patent/US20170363656A1/en
Publication of WO2016119418A1 publication Critical patent/WO2016119418A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
    • G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
    • G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
    • G01P15/125—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by capacitive pick-up
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
    • G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
    • G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
    • G01P2015/0805—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration
    • G01P2015/0822—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining out-of-plane movement of the mass

Definitions

  • the invention belongs to the field of micro electromechanical (MEMS), and more particularly relates to a microelectromechanical inertial measurement module, in particular to a Z-axis structure in an accelerometer.
  • MEMS micro electromechanical
  • Z-axis accelerometers were all flat-plate capacitive, and the motion mode of the mass was a structure similar to a seesaw.
  • a first plate electrode 2 made of metal or polysilicon 2 on the substrate 4 below the mass 1, there are a first plate electrode 2 made of metal or polysilicon 2, a second plate electrode 3, and the mass 1 and the two electrodes respectively form two capacitors C1, C2.
  • the distance between the mass 1 and the first plate electrode 2 and the second plate electrode 3 is equal, and the values of C1 and C2 are equal at this time.
  • the mass 1 If there is acceleration input, the mass 1 is no longer balanced, and a flip similar to the seesaw occurs.
  • the mass 1 is side down and side up, at this time, between the mass 1 and the first plate electrode 2.
  • the distance from its distance to the second plate electrode 3 is no longer equal.
  • C1 decreases, and C2 increases, while the difference between C1 and C2 is proportional to the input acceleration, and the output is positive.
  • the negative sign reflects the direction of the input acceleration.
  • the Z-axis accelerometer of the above structure has the following drawbacks:
  • XY axial accelerometers are currently in-plane comb-tooth capacitance schemes, so for XY-axis accelerometers, it is not necessary to introduce a plate electrode on the substrate.
  • the scheme of the above Z-axis accelerometer is completely different, and it is necessary to have a plate electrode on the substrate. That is, in order to realize the design of the Z-axis accelerometer, an additional layer of plate electrodes is required to increase the complexity and cost of the process.
  • the plate electrode is on the substrate, so the parasitic capacitance of the Z-axis accelerometer is relatively large, which in turn affects the accuracy of the Z-axis accelerometer; while the XY-axis accelerometer, because the capacitor plate is suspended, the parasitic capacitance is generally better than the Z-axis. Accelerometers are less than half, so the accuracy of a typical XY-axis accelerometer is higher than the Z-axis.
  • the Z-axis accelerometer uses a flat-plate capacitor structure, which occupies a relatively large area. Generally, in a three-axis accelerometer, the Z-axis accelerometer occupies an area of more than 40%.
  • the present invention provides a Z-axis structure in an accelerometer.
  • a Z-axis structure in an accelerometer including a substrate, further comprising:
  • An elastic beam supported by the side wall supports a mass above the substrate, which is flattened in the Z-axis direction with respect to the substrate, wherein the sidewall of the mass is provided with a first movable electrode pole piece and a second Movable electrode pole piece;
  • first fixed electrode pole piece and a second fixed electrode pole piece disposed on the substrate, wherein the first fixed electrode pole piece and the second fixed electrode pole piece extend in a plane direction composed of an X axis and a Y axis;
  • the first movable electrode pole piece is opposite to the sidewall of the first fixed electrode pole piece to form a first Z-axis detecting capacitance;
  • the second movable electrode pole piece is opposite to the sidewall of the second fixed electrode pole piece, Forming a second Z-axis detection capacitor;
  • the end surface of one end of the first fixed electrode pole piece is lower than the end surface of the same end of the first movable electrode pole piece; and the end surface of the second fixed electrode pole piece at the same end as the first fixed electrode pole piece is higher than the first end An end surface of the second movable electrode pole piece that is at the same end as the first fixed electrode pole piece.
  • the mass is provided with a through hole, and the first movable electrode pole piece and the second movable electrode pole piece are disposed on the sidewall of the mass block through hole.
  • the upper end surface of the first fixed electrode pole piece is lower than the upper end surface of the first movable electrode pole piece; the upper end surface of the second fixed electrode pole piece is higher than the upper movable electrode pole piece End face.
  • the lower end surface of the first fixed electrode pole piece and the first movable electrode is flush; the lower end surface of the second fixed electrode pole piece is flush with the lower end surface of the second movable electrode pole piece.
  • the lower end faces of the first fixed electrode pole piece, the first movable electrode pole piece, the second fixed electrode pole piece, and the second movable electrode pole piece are all flush.
  • the lower end surface of the first fixed electrode pole piece is lower than the lower end surface of the first movable electrode pole piece; the lower end surface of the second fixed electrode pole piece is higher than the second movable electrode The lower end of the pole piece.
  • the first fixed electrode pole piece and the first movable electrode pole piece are provided in plurality, and the plurality of first movable electrode pole pieces are distributed along the sidewall of the mass; the plurality of first fixed electrode poles
  • the sheet and the first movable electrode pole piece constitute a comb-tooth capacitance structure.
  • the second fixed electrode pole piece and the second movable electrode pole piece respectively have a plurality of, and the plurality of second movable electrode pole pieces are distributed along the sidewall of the mass; the plurality of second fixed electrode poles
  • the sheet and the second movable electrode pole piece constitute a comb-tooth capacitance structure.
  • the first fixed electrode pole piece and the second fixed electrode pole piece are arranged in parallel on the substrate.
  • the first movable electrode pole piece and the second movable electrode pole piece are integrally formed with the mass.
  • the Z-axis accelerometer of the invention eliminates the structure of the lower plate, thereby eliminating the limitation of the lower plate to the Z-axis accelerometer, so that the motion mode of the mass is no longer a seesaw motion, but in the Z-axis direction.
  • the lower translation mode reduces the parasitic capacitance of the Z-axis accelerometer and improves the detection accuracy. Moreover, since the lower plate structure is discarded, the chip area occupied by the chip board is reduced, the complexity and cost of the manufacturing process are reduced, and the reliability of the chip is improved.
  • the Z-axis structure avoids the contact of the mass with the substrate and improves the reliability of the chip; since the mass and the fixed electrode are on the same layer, firstly, better consistency than the conventional Z-axis structure can be achieved, and Anchor points can be designed more concentrated, reducing the chip's sensitivity to temperature and stress changes.
  • Fig. 1 is a schematic view showing the structure of a Z-axis structure in the prior art.
  • Figure 2 shows a schematic view of the mass of Figure 1 when it is deflected.
  • Figure 3 shows a schematic view of the Z-axis structure of the present invention.
  • Figure 4a shows a schematic diagram of the motion modality of the mass of the invention in its initial state.
  • Figure 4b shows a schematic diagram of the motion pattern of the mass of the invention when subjected to acceleration in the negative direction of the Z-axis.
  • Figure 4c is a schematic illustration of the motion pattern of the mass of the present invention when subjected to a positive acceleration in the Z-axis.
  • FIGS 5a to 5c show schematic diagrams of the Z-axis detection capacitance of the present invention.
  • 6a to 6c are schematic views showing another embodiment of the Z-axis detecting capacitor of the present invention.
  • the accelerometer of the conventional structure adopts a translational mode in both the X-axis and the Y-axis direction, and the Z-axis adopts a seesaw-type deflection mode.
  • the present invention provides a Z in an accelerometer.
  • the shaft structure can be used to detect the Z-axis acceleration signal in the vertical direction.
  • a substrate 4 is included on which various functional components of the accelerometer, etc., can be arranged.
  • the mass 1 can be connected to the anchor point 6 on the substrate 4 by means of a spring beam 5, in particular the side wall of the mass 1 is connected to the anchor point 6 of the substrate 4 by means of a spring beam 5.
  • the anchor point 6 can also be raised by the spacer.
  • the mass 1 When the mass 1 is subjected to a corresponding force, it can move up and down with respect to the substrate 4, more precisely, when the mass 1 is subjected to acceleration in the Z-axis direction, the mass 1 can be moved in the Z-axis direction. Move up or down.
  • the upward direction is the positive direction of the Z axis
  • the downward direction is the negative direction of the Z axis.
  • the mass 1 is moved downward by the action of the elastic beam to perform the action of stretching the elastic beam downward, see Fig. 4b.
  • the mass 1 is moved upward by the action of the elastic beam to perform an action of stretching the elastic beam upward, with reference to Fig. 4c.
  • a plurality of elastic beams are provided for stable support, which will not be specifically described herein.
  • a first movable electrode pole piece 10, a second movable electrode pole piece 11, a first movable electrode pole piece 10, a second movable electrode pole piece 11 and a mass are disposed on a side wall of the mass 1
  • Block 1 is integral and is used as a common pole piece for differential sense capacitors.
  • the first movable electrode pad 10 and the second movable electrode pad 11 may be disposed at an edge of the mass 1.
  • the mass 1 is provided with a through hole, and the first movable electrode pad 10 is provided.
  • the second movable electrode pad 11 is disposed on the sidewall of the through hole of the mass 1.
  • a first fixed electrode 2 and a second fixed electrode 3 are further disposed on the substrate 4, and the first fixed
  • the edges of the electrode 2 and the second fixed electrode 3 are respectively provided with a first fixed electrode pole piece 20 and a second fixed electrode pole piece 30 extending outward.
  • the first fixed electrode 2 and the first fixed electrode pole piece 20 are integrally formed, and the second fixed electrode 3 and the second fixed electrode pole piece 30 are also integrally formed.
  • the first fixed electrode pole piece 20 and the second fixed electrode pole piece 30 are located in a plane direction formed by the X axis and the Y axis, that is, the first fixed electrode pole piece 20 and the second fixed electrode pole piece 30
  • the direction of extension is perpendicular to the direction of motion of the mass 1.
  • the first fixed electrode pole piece 20 may extend in the X-axis direction
  • the second fixed electrode pole piece 30 may also extend in the X-axis direction.
  • the first fixed electrode 2 is The second fixed electrodes 3 may be arranged in parallel on the substrate 4.
  • the second fixed electrode pole piece 30 may also extend in the Y-axis direction as long as it is substantially perpendicular to the moving direction of the mass block 1.
  • the first movable electrode pole piece 10 is opposite to the sidewall of the first fixed electrode pole piece 20 to constitute a first Z-axis detecting capacitance; that is, the sidewalls of the two pole pieces located in the XZ or YZ plane are opposite,
  • the first movable electrode pole piece 10 is displaced in the Z-axis direction as the mass 1 is displaced, the relative area and position between the two pole piece side walls are changed, so that the first Z-axis detecting capacitance changes.
  • the second movable electrode pole piece 11 is opposite to the side wall of the second fixed electrode pole piece 30 to constitute a second Z-axis detecting capacitance; that is, the two pole pieces are located in the XZ or YZ plane.
  • the side walls are opposite such that when the second movable electrode pole piece 11 is displaced in the Z-axis direction, the relative area and position between the two pole piece side walls are changed, so that the second Z-axis detection is performed.
  • the capacitance changes.
  • the end surface of one end of the first fixed electrode pole piece 20 is lower than the first movable electrode pole.
  • the end surface of the same end of the first fixed electrode pole piece 20 of the second fixed electrode pole piece 30 is higher than the end face of the second movable electrode pole piece 11 at the same end as the first fixed electrode pole piece 20.
  • the upper end surface of the first fixed electrode pole piece 20 is lower than the upper end surface of the first movable electrode pole piece 10; the upper end surface of the second fixed electrode pole piece 30 is higher than the second The upper end surface of the electrode electrode tab 11.
  • the thickness of the first movable electrode pad 10 and the like can be reduced by etching.
  • the lower end faces of the pole pieces may be flush or uneven. Now we will introduce each case separately.
  • the lower end surface of the first fixed electrode pole piece 20 is flush with the lower end surface of the first movable electrode pole piece 10; the lower end surface of the second fixed electrode pole piece 30 is the second end The lower end surface of the movable electrode pole piece 11 is flush. That is, in this embodiment, referring to FIG.
  • the upper end surface of the first fixed electrode pole piece 20 is lower than the upper end surface of the first movable electrode pole piece 10, and the lower end faces of the two pole pieces are flush;
  • the upper end surface of the second fixed electrode pole piece 30 is higher than the upper end surface of the second movable electrode pole piece 11, and the lower end faces of the two pole pieces are flush; in a preferred embodiment of the present invention, the first The lower end faces of the fixed electrode pole piece 20, the first movable electrode pole piece 10, the second fixed electrode pole piece 30, and the second movable electrode pole piece 11 are all flush.
  • the mass 1 When the mass 1 receives the acceleration in the negative direction of the Z-axis, referring to FIG. 4b and FIG. 5b, the tensile elastic beam of the mass 1 is displaced downward. At this time, the first movable electrode pole piece 10 and the second movable electrode pole The sheet 11 is displaced downward with the mass 1 . Since the area facing the second movable electrode pad 11 and the second fixed electrode pad 30 is reduced, the second Z-axis detecting capacitance C2 is decreased; and the first movable electrode pad 10 is generated downward.
  • the displacement is such that more electric field lines intersect between the lower end of the first fixed electrode pole piece 20 and the first movable electrode pole piece 10, so that the edge capacitance at the point increases, and finally the first movable electrode pole piece 10 is
  • the first Z-axis detection capacitor C1 composed of the first fixed electrode pad 20 is integrally increased.
  • a differential capacitance structure is formed between the first Z-axis detection capacitor C1 and the second Z-axis detection capacitor C2 for detecting an acceleration signal in the negative direction of the Z-axis.
  • the opposing area between the electrode pole pieces 20 is reduced, so that the first Z-axis detecting capacitance C1 is decreased; and since the second movable electrode pole piece 11 is displaced upward, the lower end of the second movable electrode pole piece 11 is There are more electric field lines intersecting between the second fixed electrode pole pieces 30, so that the edge capacitance at the place increases, and finally the second Z axis composed of the second movable electrode pole piece 11 and the second fixed electrode pole piece 30 is finally obtained.
  • the detection capacitor C2 is increased as a whole.
  • a differential capacitance structure is formed between the first Z-axis detection capacitor C1 and the second Z-axis detection capacitor C2 for detecting an acceleration signal in the positive direction of the Z-axis.
  • the Z-axis structure of the invention eliminates the structure of the lower plate, thereby getting rid of the limitation of the lower plate to the Z-axis accelerometer, so that the motion mode of the mass is no longer a seesaw motion, but in the Z-axis direction, Lower translation reduces the parasitic capacitance of the Z-axis accelerometer and improves the accuracy of detection. Moreover, since the lower plate structure is discarded, the chip area occupied by the chip is reduced, and the complexity and cost of the manufacturing process are reduced.
  • the Z-axis structure avoids the contact of the mass with the substrate and improves the reliability of the chip; since the mass and the fixed electrode are on the same layer, firstly, better consistency than the conventional Z-axis structure can be achieved, and Anchor points can be designed more concentrated, reducing the chip's sensitivity to temperature and stress changes.
  • the lower end faces of the first fixed electrode pad 20, the first movable electrode pad 10, the second fixed electrode pad 30, and the second movable electrode pad 11 are not flush. flat.
  • the lower end surface of the first fixed electrode pole piece 20 is lower than the lower end surface of the first movable electrode pole piece 10; the lower end surface of the second fixed electrode pole piece 30 is higher than the second movable electrode pole piece 11 The lower end face.
  • the upper end surface of the first fixed electrode pole piece 20 is lower than the upper end surface of the first movable electrode pole piece 10, and the lower end surface of the first fixed electrode pole piece 20 is lower than the first movable end a lower end surface of the electrode pole piece 10; an upper end surface of the second fixed electrode pole piece 30 is higher than an upper end surface of the second movable electrode pole piece 11, and a lower end surface of the second fixed electrode pole piece 30 is higher than the second movable electrode pole The lower end surface of the sheet 11.
  • the opposing area between the first movable electrode pad 10 and the first fixed electrode pad 20 is increased, so that the first Z-axis detecting capacitance C1 is increased; and the second movable electrode pad 11 and the second fixed electrode are The facing area between the sheets 30 is reduced, thereby The second Z-axis detection capacitor C2 is reduced, and finally a differential capacitance structure is formed between the first Z-axis detection capacitor C1 and the second Z-axis detection capacitor C2 for detecting an acceleration signal in the positive direction of the Z-axis.
  • the opposing area between the first movable electrode pad 10 and the first fixed electrode pad 20 is reduced, so that the first Z-axis detecting capacitance C1 is decreased; and the second movable electrode pad 11 is fixed to the second fixed
  • the facing area between the electrode pole pieces 30 is increased, so that the second Z-axis detecting capacitance C2 is increased, and finally the differential capacitance structure is formed between the first Z-axis detecting capacitor C1 and the second Z-axis detecting capacitor C2.
  • the first fixed electrode pole piece 20 and the first movable electrode pole piece 10 may have a plurality of respectively, respectively distributed along the sidewalls of the first fixed electrode 2 and the mass block 1;
  • the electrode pole piece 20 and the first movable electrode pole piece 10 form a comb-tooth capacitance structure, which improves the detection accuracy.
  • the second fixed electrode pole piece 30 and the second movable electrode pole piece 11 may also be respectively disposed, and distributed along the sidewalls of the second fixed electrode 3 and the mass block 1 respectively;
  • the second fixed electrode pole piece 30 and the second movable electrode pole piece 11 constitute a comb-toothed capacitor structure, which improves the accuracy of detection.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Pressure Sensors (AREA)

Abstract

一种加速度计中的Z轴结构，包括相对于衬底（4）在Z轴方向上来回移动的质量块（1），所述质量块（1）的侧壁上设置有第一可动电极极片（10）、第二可动电极极片（11）；还分别设有朝由X轴、Y轴组成的平面方向伸出的第一固定电极极片（20）、第二固定电极极片（30）。Z轴加速度计，摒弃了下极板结构，从而摆脱了下极板对Z轴加速度计的限制，使质量块（1）的运动模式不再是跷跷板式的运动，而是在Z轴方向上、下平动，减小了Z轴加速度计的寄生电容，提高了检测的精度；避免可动质量块（1）与衬底（4）的接触，提高了芯片的可靠性；由于质量块（1）和固定电极在同一层上，首先可以达到比传统Z轴结构更好的一致性，而且可以将锚点设计的更为集中，降低芯片对温度和应力变化的敏感度。

Description

一种加速度计中的Z轴结构 技术领域
本发明属于微机电(MEMS)领域，更准确地说，涉及一种微机电的惯性测量模块，尤其涉及一种加速度计中的Z轴结构。
背景技术
以往的Z轴加速度计都是平板电容式的，质量块的运动模式是类似跷跷板的结构。参考图1，在质量块1下方的衬底4上，会有金属或多晶硅做的第一平板电极2、第二平板电极3，质量块1与两块电极分别形成两个电容C1、C2。在无加速度输入的情况下，质量块1与第一平板电极2、第二平板电极3之间的距离均相等，此时C1和C2的值相等。
如有加速度输入的情况下，质量块1不再平衡，会发生类似跷跷板一样的翻转，所述质量块1一边向下，一边向上，此时，质量块1到第一平板电极2之间的距离，与其到第二平板电极3之间的距离不再相等，参考图2的视图方向，C1减小，而C2增大，而C1和C2的差值与输入的加速度成正比，输出的正负号反映输入加速度的方向。
上述结构的Z轴加速度计存在以下几个缺陷：
a)工艺复杂度和成本：XY轴向的加速度计，目前都是平面内的梳齿电容方案，所以对于XY轴加速度计来说，不用引入衬底上的平板电极。上述Z轴加速度计的方案完全不同，一定要有衬底上的平板电极。也就是，为了实现Z轴加速度计的设计，要多加一层平板电极，增加工艺的复杂度和成本。
b)精度：平板电极在衬底上，所以Z轴加速度计寄生电容比较大，进而影响Z轴加速度计的精度；而XY轴加速度计，由于电容极板悬空，所以寄生电容一般会比Z轴加速度计小一半以上，所以一般XY轴加速度计的精度会比Z轴高。
c)可靠性：Z轴加速度计的可靠性一直是一个比较棘手的问题，由于下极板是Z轴加速度计必需的一部分，必须将质量块与下极板的间距控制在很小的尺寸内，结果造成质量块很容易接触到衬底或下电极，甚至粘在衬底上，不能分开，导致芯片完全的失效。
d)芯片面积：Z轴加速度计使用平板电容结构，会占用比较大的面积，一般在三轴加速度计中，Z轴加速度计占用的面积在40％以上。
发明内容
本发明为了解决现有技术中存在的问题，提供了一种加速度计中的Z轴结构。
为了实现上述的目的，本发明的技术方案是：一种加速度计中的Z轴结构，包括衬底，还包括：
通过侧壁连接的弹性梁支撑在衬底上方，相对于衬底在Z轴方向上来回平动的质量块，其中所述质量块的侧壁上设置有第一可动电极极片、第二可动电极极片；
设置在衬底上的第一固定电极极片、第二固定电极极片，所述第一固定电极极片、第二固定电极极片朝由X轴、Y轴组成的平面方向延伸；
所述第一可动电极极片与第一固定电极极片的侧壁相对，构成第一Z轴检测电容；所述第二可动电极极片与第二固定电极极片的侧壁相对，构成第二Z轴检测电容；
其中，初始状态下，第一固定电极极片其中一端的端面低于第一可动电极极片相同端的端面；而第二固定电极极片中与第一固定电极极片相同端的端面高于第二可动电极极片中与第一固定电极极片相同端的端面。
优选的是，所述质量块上设置有通孔，第一可动电极极片、第二可动电极极片设置在质量块通孔的侧壁上。
优选的是，初始状态下，第一固定电极极片的上端面低于第一可动电极极片的上端面；第二固定电极极片的上端面高于第二可动电极极片的上端面。
优选的是，初始状态下，第一固定电极极片的下端面与第一可动电极 极片的下端面齐平；第二固定电极极片的下端面与第二可动电极极片的下端面齐平。
优选的是，初始状态下，所述第一固定电极极片、第一可动电极极片、第二固定电极极片、第二可动电极极片的下端面均齐平。
优选的是，初始状态下，所述第一固定电极极片的下端面低于第一可动电极极片的下端面；所述第二固定电极极片的下端面高于第二可动电极极片的下端面。
优选的是，所述第一固定电极极片、第一可动电极极片设有多个，多个第一可动电极极片沿着质量块的侧壁分布；多个第一固定电极极片、第一可动电极极片构成梳齿电容结构。
优选的是，所述第二固定电极极片、第二可动电极极片分别有多个，多个第二可动电极极片沿着质量块的侧壁分布；多个第二固定电极极片、第二可动电极极片构成梳齿电容结构。
优选的是，所述第一固定电极极片、第二固定电极极片在衬底上平行布置。
优选的是，所述第一可动电极极片、第二可动电极极片与质量块一体成型。
本发明的Z轴加速度计，摒弃了下极板结构，从而摆脱了下极板对Z轴加速度计的限制，使质量块的运动模式不再是跷跷板式的运动，而是在Z轴方向上、下平动，减小了Z轴加速度计的寄生电容，提高了检测的精度。而且，由于摒弃了下极板结构，减小了其占用的芯片面积，降低了制造工艺的复杂程度和成本,提高了芯片的可靠性。而且，该Z轴结构，避免了质量块与衬底的接触，提高了芯片的可靠性；由于质量块和固定电极在同一层上，首先可以达到比传统Z轴结构更好的一致性，而且可以将锚点设计的更为集中，降低芯片对温度和应力变化的敏感度。
附图说明
图1示出了现有技术中Z轴结构的结构示意图。
图2示出了图1中质量块发生偏转时的示意图。
图3示出了本发明Z轴结构的示意图。
图4a示出了本发明质量块位于初始状态时的运动模态示意图。
图4b示出了本发明质量块受到Z轴负方向加速度时的运动模式示意图。
图4c示出了本发明质量块受到Z轴正方向加速度时的运动模式示意图。
图5a至图5c示出了本发明Z轴检测电容的原理图。
图6a至图6c示出了本发明Z轴检测电容另一实施结构的原理图。
具体实施方式
为了使本发明解决的技术问题、采用的技术方案、取得的技术效果易于理解，下面结合具体的附图，对本发明的具体实施方式做进一步说明。
传统结构的加速度计，其X轴、Y轴方向均采用平动方式，而Z轴均采用跷跷板式的偏转方式，相对于传统Z轴加速度计结构，本发明提供了一种加速度计中的Z轴结构，可以用来检测垂直方向上的Z轴加速度信号。参考图3、图4a，包括衬底4，在该衬底上可以排布加速度计的各功能部件等。质量块1可以通过弹性梁5连接到在衬底4上的锚点6上，具体地，所述质量块1的侧壁通过弹性梁5连接在衬底4的锚点6上。在具体工艺中，为了使质量块1与衬底4之间具有足够的间隙，还可通过隔离部将锚点6垫高。当质量块1在受到相应的力时，可以相对于衬底4上、下移动，更准确地说，当质量块1受到Z轴方向的加速度时，使得质量块1可以在Z轴方向上往上或往下移动。
以图4a的视图方向为参考，往上为Z轴的正方向，往下则为Z轴的负方向。当质量块1受到Z轴负方向的力时，质量块1在弹性梁的作用下往下移动，做向下拉伸弹性梁的动作，参考图4b。当质量块1受到Z轴正方向的力时，则质量块1在弹性梁的作用下往上移动，做向上拉伸弹性梁的动作，参考图4c。为了防止质量块1发生偏转，以设置多个弹性梁进行稳定地支撑，在此不再具体说明。
在所述质量块1的侧壁上设置有第一可动电极极片10、第二可动电极极片11，该第一可动电极极片10、第二可动电极极片11和质量块1是一体的，作为差分检测电容的公用极片使用。当质量块1受到外力朝向Z轴 方向发生位移时，第一可动电极极片10、第二可动电极极片11随着质量块1同步运动。该第一可动电极极片10、第二可动电极极片11可以设置在质量块1的边缘，优选的是，所述质量块1上设置有通孔，第一可动电极极片10、第二可动电极极片11设置在质量块1通孔的侧壁上。
为了能与第一可动电极极片10、第二可动电极极片11分别组成检测电容，在衬底4上还设置有第一固定电极2、第二固定电极3，所述第一固定电极2、第二固定电极3的边缘分别设有向外延伸的第一固定电极极片20、第二固定电极极片30。该第一固定电极2与第一固定电极极片20是一体成型，第二固定电极3与第二固定电极极片30也是一体成型的。其中，第一固定电极极片20、第二固定电极极片30位于由X轴、Y轴构成的平面方向内，也就是说，第一固定电极极片20、第二固定电极极片30的延伸方向与质量块1的运动方向是垂直的。
例如，在本发明一个具体的实施例中，第一固定电极极片20可以在X轴方向延伸，第二固定电极极片30也可以在X轴方向延伸，此时，第一固定电极2、第二固定电极3可以是平行地布置在衬底4上。当然第二固定电极极片30也可以在Y轴方向延伸，只要是与质量块1的运动方向基本垂直即可。
其中，第一可动电极极片10与第一固定电极极片20侧壁相对，构成第一Z轴检测电容；也就是说，两个极片中位于XZ或者YZ平面内的侧壁相对，使得第一可动电极极片10随着质量块1在Z轴方向发生位移时，两个极片侧壁之间相对的面积与位置会发生变化，从而使得第一Z轴检测电容发生变化。
基于同样的道理，第二可动电极极片11与第二固定电极极片30的侧壁相对，构成第二Z轴检测电容；也就是说，两个极片中位于XZ或者YZ平面内的侧壁相对，使得第二可动电极极片11随着质量块1在Z轴方向发生位移时，两个极片侧壁之间相对的面积与位置会发生变化，从而使得第二Z轴检测电容发生变化。
为了使第一Z轴检测电容、第二Z轴检测电容可以构成差分电容结构，在初始状态下，第一固定电极极片20其中一端的端面低于第一可动电极极 片10相同端的端面；而第二固定电极极片30中与第一固定电极极片20相同端的端面高于第二可动电极极片11中与第一固定电极极片20相同端的端面。
例如在本发明一个具体的实施例中，第一固定电极极片20的上端面低于第一可动电极极片10的上端面；第二固定电极极片30的上端面高于第二可动电极极片11的上端面。例如可以通过刻蚀的方式，来减小第一可动电极极片10的厚度等。
此时，各极片的下端面可以是齐平的，也可以是层次不齐的。现在针对两种情况分别进行介绍。
在本发明的一个具体的实施例中，第一固定电极极片20的下端面与第一可动电极极片10的下端面齐平；第二固定电极极片30的下端面与第二可动电极极片11的下端面齐平。也就是说，在该实施例中，参考图5a，第一固定电极极片20的上端面低于第一可动电极极片10的上端面，两个极片的下端面齐平；而第二固定电极极片30的上端面高于第二可动电极极片11的上端面，两个极片的下端面齐平；在本发明一个优选的技术方案中，为了便于制造，所述第一固定电极极片20、第一可动电极极片10、第二固定电极极片30、第二可动电极极片11的下端面均齐平。
当质量块1受到Z轴负方向的加速度时，参考图4b、图5b，质量块1拉伸弹性梁向下发生位移，此时，第一可动电极极片10、第二可动电极极片11随着质量块1向下发生位移。由于第二可动电极极片11与第二固定电极极片30之间正对的面积减小，故第二Z轴检测电容C2减小；而由于第一可动电极极片10向下发生位移，使得第一固定电极极片20的下端与第一可动电极极片10之间具有更多的电场线相交，使得该处的边缘电容增加，最终使得由第一可动电极极片10、第一固定电极极片20组成的第一Z轴检测电容C1整体增加。第一Z轴检测电容C1与第二Z轴检测电容C2之间构成了差分电容结构，用于检测Z轴负方向的加速度信号。
当质量块1受到Z轴正方向的加速度时，参考图4c、图5c，质量块1拉伸弹性梁向上发生位移，此时，第一可动电极极片10、第二可动电极极片11随着质量块1向上发生位移。由于第一可动电极极片10与第一固定 电极极片20之间正对的面积减小，故第一Z轴检测电容C1减小；而由于第二可动电极极片11向上发生位移，使得第二可动电极极片11的下端与第二固定电极极片30之间具有更多的电场线相交，使得该处的边缘电容增加，最终使由第二可动电极极片11、第二固定电极极片30组成的第二Z轴检测电容C2整体增加。第一Z轴检测电容C1与第二Z轴检测电容C2之间构成了差分电容结构，用于检测Z轴正方向的加速度信号。
本发明的Z轴结构，摒弃了下极板结构，从而摆脱了下极板对Z轴加速度计的限制，使质量块的运动模式不再是跷跷板式的运动，而是在Z轴方向上、下平动，减小了Z轴加速度计的寄生电容，提高了检测的精度。而且，由于摒弃了下极板结构，减小了其占用的芯片面积，降低了制造工艺的复杂程度和成本。而且，该Z轴结构，避免了质量块与衬底的接触，提高了芯片的可靠性；由于质量块和固定电极在同一层上，首先可以达到比传统Z轴结构更好的一致性，而且可以将锚点设计的更为集中，降低芯片对温度和应力变化的敏感度。
在本发明的另一实施例中，所述第一固定电极极片20、第一可动电极极片10、第二固定电极极片30、第二可动电极极片11的下端面不是齐平的。
例如，所述第一固定电极极片20的下端面低于第一可动电极极片10的下端面；所述第二固定电极极片30的下端面高于第二可动电极极片11的下端面。参考图6a，在初始状态时，第一固定电极极片20的上端面低于第一可动电极极片10的上端面，而第一固定电极极片20的下端面低于第一可动电极极片10的下端面；第二固定电极极片30的上端面高于第二可动电极极片11的上端面，第二固定电极极片30的下端面高于第二可动电极极片11的下端面。
当质量块1受到Z轴负方向的加速度时，参考图4b、图6b，质量块1拉伸弹性梁向下发生位移，此时，第一可动电极极片10、第二可动电极极片11随着质量块1向下发生位移。第一可动电极极片10与第一固定电极极片20之间正对的面积增加，从而使得第一Z轴检测电容C1增加；而第二可动电极极片11与第二固定电极极片30之间的正对面积减小，从而使 得第二Z轴检测电容C2减小，最终使得第一Z轴检测电容C1与第二Z轴检测电容C2之间构成了差分电容结构，用于检测Z轴正方向的加速度信号。
当质量块1受到Z轴正方向的加速度时，参考图4c、图6c，质量块1拉伸弹性梁向上发生位移，此时，第一可动电极极片10、第二可动电极极片11随着质量块1向上发生位移。第一可动电极极片10与第一固定电极极片20之间正对的面积减小，从而使得第一Z轴检测电容C1减小；而第二可动电极极片11与第二固定电极极片30之间的正对面积增加，从而使得第二Z轴检测电容C2增大，最终使得第一Z轴检测电容C1与第二Z轴检测电容C2之间构成了差分电容结构，用于检测Z轴正方向的加速度信号。
本发明中，所述第一固定电极极片20、第一可动电极极片10可以分别有多个，分别沿着第一固定电极2、质量块1的侧壁分布；多个第一固定电极极片20、第一可动电极极片10之间构成了梳齿电容结构，提高了检测的精度。基于同样的道理，所述第二固定电极极片30、第二可动电极极片11也可以分别设置多个，分别沿着第二固定电极3、质量块1的侧壁分布；该多个第二固定电极极片30、第二可动电极极片11构成梳齿电容结构，提高了检测的精度。
本发明已通过优选的实施方式进行了详尽的说明。然而，通过对前文的研读，对各实施方式的变化和增加对于本领域的一般技术人员来说是显而易见的。例如上述中“上端面”、“下端面”都时相对的概念，只是便于描述才进行了区分，在本说明书中，不应该用来限定本申请的保护范围，申请人的意图是所有的这些变化和增加都落在了本发明权利要求所保护的范围中。

Claims (10)

  1. 一种加速度计中的Z轴结构，包括衬底(4)，其特征在于，还包括：
    通过侧壁连接的弹性梁(5)支撑在衬底(4)上方，相对于衬底(4)在Z轴方向上来回平动的质量块(1)，其中所述质量块(1)的侧壁上设置有第一可动电极极片(10)、第二可动电极极片(11)；
    设置在衬底(4)上的第一固定电极极片(20)、第二固定电极极片(30)，所述第一固定电极极片(20)、第二固定电极极片(30)朝由X轴、Y轴组成的平面方向延伸；
    所述第一可动电极极片(10)与第一固定电极极片(20)的侧壁相对，构成第一Z轴检测电容；所述第二可动电极极片(11)与第二固定电极极片(30)的侧壁相对，构成第二Z轴检测电容；
    其中，初始状态下，第一固定电极极片(20)其中一端的端面低于第一可动电极极片(10)相同端的端面；而第二固定电极极片(30)中与第一固定电极极片(20)相同端的端面高于第二可动电极极片(11)中与第一固定电极极片(20)相同端的端面。
  2. 根据权利要求1所述的Z轴结构，其特征在于：所述质量块(1)上设置有通孔，第一可动电极极片(10)、第二可动电极极片(11)设置在质量块(1)通孔的侧壁上。
  3. 根据权利要求1所述的Z轴结构，其特征在于：初始状态下，第一固定电极极片(20)的上端面低于第一可动电极极片(10)的上端面；第二固定电极极片(30)的上端面高于第二可动电极极片(11)的上端面。
  4. 根据权利要求3所述的Z轴结构，其特征在于：初始状态下，第一固定电极极片(20)的下端面与第一可动电极极片(10)的下端面齐平；第二固定电极极片(30)的下端面与第二可动电极极片(11)的下端面齐平。
  5. 根据权利要求4所述的Z轴结构，其特征在于：初始状态下，所述第一固定电极极片(20)、第一可动电极极片(10)、第二固定电极极片 (30)、第二可动电极极片(11)的下端面均齐平。
  6. 根据权利要求3所述的Z轴结构，其特征在于：初始状态下，所述第一固定电极极片(20)的下端面低于第一可动电极极片(10)的下端面；所述第二固定电极极片(30)的下端面高于第二可动电极极片(11)的下端面。
  7. 根据权利要求1至6任一项所述的Z轴结构，其特征在于：所述第一固定电极极片(20)、第一可动电极极片(10)设有多个，多个第一可动电极极片(10)沿着质量块(1)的侧壁分布；多个第一固定电极极片(20)、第一可动电极极片(10)构成梳齿电容结构。
  8. 根据权利要求7所述的Z轴结构，其特征在于：所述第二固定电极极片(30)、第二可动电极极片(11)分别有多个，多个第二可动电极极片(11)沿着质量块(1)的侧壁分布；多个第二固定电极极片(30)、第二可动电极极片(11)构成梳齿电容结构。
  9. 根据权利要求8所述的Z轴结构，其特征在于：所述第一固定电极极片(20)、第二固定电极极片(30)在衬底(4)上平行布置。
  10. 根据权利要求1所述Z轴结构，其特征在于：所述第一可动电极极片(10)、第二可动电极极片(11)与质量块(1)一体成型。
PCT/CN2015/084969 2015-01-30 2015-07-23 一种加速度计中的z轴结构 WO2016119418A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US15/542,761 US20170363656A1 (en) 2015-01-30 2015-07-23 Z-axis structure in accelerometer

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201510051755.9A CN104614553A (zh) 2015-01-30 2015-01-30 一种加速度计中的z轴结构
CN201510051755.9 2015-01-30

Publications (1)

Publication Number Publication Date
WO2016119418A1 true WO2016119418A1 (zh) 2016-08-04

Family

ID=53149091

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2015/084969 WO2016119418A1 (zh) 2015-01-30 2015-07-23 一种加速度计中的z轴结构

Country Status (3)

Country Link
US (1) US20170363656A1 (zh)
CN (1) CN104614553A (zh)
WO (1) WO2016119418A1 (zh)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104614553A (zh) * 2015-01-30 2015-05-13 歌尔声学股份有限公司 一种加速度计中的z轴结构
CN107782914B (zh) * 2016-08-27 2021-07-09 深迪半导体(绍兴)有限公司 一种三轴加速计
DE102017211080B3 (de) * 2017-06-29 2018-11-08 Infineon Technologies Dresden GmbH & Co. KG Mikromechanischer Sensor und Verfahren zum Herstellen eines mikromechanischen Sensors und eines mikromechanischen Sensorelements
US11255873B2 (en) * 2018-09-12 2022-02-22 Analog Devices, Inc. Increased sensitivity z-axis accelerometer
GB2579057A (en) * 2018-11-16 2020-06-10 Atlantic Inertial Systems Ltd Accelerometer
JP7134931B2 (ja) * 2019-08-28 2022-09-12 株式会社東芝 センサ
CN110879303B (zh) * 2019-10-23 2022-01-04 杭州士兰微电子股份有限公司 一种惯性传感器及其控制方法
CN114280331B (zh) * 2021-12-16 2024-05-17 绍兴圆方半导体有限公司 一种z轴加速度计
CN114609413A (zh) * 2022-05-11 2022-06-10 绍兴圆方半导体有限公司 三轴加速度计

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1605871A (zh) * 2004-10-18 2005-04-13 北京大学 梳齿电容式z轴加速度计及其制备方法
CN1828223A (zh) * 2005-02-28 2006-09-06 北京大学 一种水平轴微机械陀螺及其制备方法
WO2006098794A2 (en) * 2005-03-09 2006-09-21 Honeywell International Inc. Mems device with thinned comb fingers
US20060272414A1 (en) * 2005-06-03 2006-12-07 Farrokh Ayazi Capacitive microaccelerometers and fabrication methods
CN102798734A (zh) * 2011-05-24 2012-11-28 中国科学院上海微***与信息技术研究所 Mems三轴加速度计及其制造方法
CN104614553A (zh) * 2015-01-30 2015-05-13 歌尔声学股份有限公司 一种加速度计中的z轴结构

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6571628B1 (en) * 2000-10-16 2003-06-03 Institute Of Microelectronics Z-axis accelerometer
US7516661B2 (en) * 2006-02-23 2009-04-14 Honeywell International Inc. Z offset MEMS device
FR2898683B1 (fr) * 2006-03-14 2008-05-23 Commissariat Energie Atomique Accelerometre triaxial a membrane
WO2009099123A1 (ja) * 2008-02-07 2009-08-13 Alps Electric Co., Ltd. 物理量センサ及びその製造方法
DE102009028343B4 (de) * 2009-08-07 2022-12-15 Robert Bosch Gmbh Sensorelement und Verfahren zum Betrieb eines Sensorelements
CN203705471U (zh) * 2014-01-26 2014-07-09 歌尔声学股份有限公司 一种z轴加速度计
CN203825034U (zh) * 2014-04-01 2014-09-10 南京信息工程大学 一种z轴电容式微机械加速度计
CN204439662U (zh) * 2015-01-30 2015-07-01 歌尔声学股份有限公司 一种加速度计中的z轴结构

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1605871A (zh) * 2004-10-18 2005-04-13 北京大学 梳齿电容式z轴加速度计及其制备方法
CN1828223A (zh) * 2005-02-28 2006-09-06 北京大学 一种水平轴微机械陀螺及其制备方法
WO2006098794A2 (en) * 2005-03-09 2006-09-21 Honeywell International Inc. Mems device with thinned comb fingers
US20060272414A1 (en) * 2005-06-03 2006-12-07 Farrokh Ayazi Capacitive microaccelerometers and fabrication methods
CN102798734A (zh) * 2011-05-24 2012-11-28 中国科学院上海微***与信息技术研究所 Mems三轴加速度计及其制造方法
CN104614553A (zh) * 2015-01-30 2015-05-13 歌尔声学股份有限公司 一种加速度计中的z轴结构

Also Published As

Publication number Publication date
CN104614553A (zh) 2015-05-13
US20170363656A1 (en) 2017-12-21

Similar Documents

Publication Publication Date Title
WO2016119418A1 (zh) 一种加速度计中的z轴结构
US11105829B2 (en) MEMS accelerometer
TWI417547B (zh) Capacitive sensor
US9476903B2 (en) Accelerometer and its fabrication technique
JP4605087B2 (ja) 静電容量式センサ
US20120160029A1 (en) Acceleration sensor
JP6260063B2 (ja) 平行板コンデンサ及びこれを含む加速度センサ
WO2014203896A1 (ja) Ｍｅｍｓセンサ用モジュール、振動駆動モジュール及びｍｅｍｓセンサ
TW201922610A (zh) 微機械ｚ軸慣性感測器
JP2012163507A (ja) 加速度センサ
CN204439662U (zh) 一种加速度计中的z轴结构
JP2000019198A (ja) 加速度センサ
JP5083635B2 (ja) 加速度センサ
US10544037B2 (en) Integrated semiconductor device and manufacturing method
JP2012185040A (ja) 静電容量型加速度センサ
JP2010127648A (ja) 加速度センサ
JP4775412B2 (ja) 半導体物理量センサ
WO2009099124A1 (ja) 物理量センサ
JP2013217844A (ja) Ｍｅｍｓデバイス
US20150123219A1 (en) Electrode system for a micromechanical component
US9702894B2 (en) Monolithic z-axis torsional CMOS MEMS accelerometer
JP2012247193A (ja) Ｍｅｍｓデバイス
JP2014190806A (ja) 容量式物理量センサ
JP2011049211A (ja) 静電容量式センサおよびその製造方法
KR20130118029A (ko) 정전 용량 압력 센서

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15879617

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 15542761

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15879617

Country of ref document: EP

Kind code of ref document: A1

122 Ep: pct application non-entry in european phase

Ref document number: 15879617

Country of ref document: EP

Kind code of ref document: A1

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 13/02/2018)

122 Ep: pct application non-entry in european phase

Ref document number: 15879617

Country of ref document: EP

Kind code of ref document: A1