Suspended resonator

Abstract

To provide a suspended resonator which can effectively avoid an issue where it comes into contact with an adjacent component due to an excessive amount of deformation in a vibration structure.SOLUTION: A suspended resonator includes a vibration structure 200, a first electrode 260, and a second electrode 270. The vibration structure includes a vibration region 202, a frame part 210, and a connection part. The vibration region includes a flat plate part 220 and a thickened part 230. The flat plate part includes a first surface 222 and a second surface 224 facing each other. The thickened part surrounds a center portion 221 of the flat plate part, and a peripheral portion of the flat plate part is sandwiched by the thickened part. A thickness T1 of the thickened part is thicker than a thickness T2 of the flat plate part. The frame part surrounds the vibration region, and it keeps a gap G with the vibration region. The connection part connects the thickened part to the frame part. The first electrode is disposed on the first surface. The second electrode is disposed on the second surface.SELECTED DRAWING: Figure 2C

Description

Technical Field

[0001] The present invention relates to a resonator, and particularly to a suspended resonator.

Background Art

[0002] A resonator is an electronic component that utilizes the piezoelectric characteristics of a material and the natural resonance frequency of the material. The resonance frequency is related to the thickness of the resonator chip. Therefore, in high-frequency applications, a general flat-plate resonator chip is very thin. For example, the thickness of a flat-plate resonator chip having a resonance frequency of 300 MHz is less than 5 microns. The thin-plate resonator chip has low structural rigidity and weak strength. Due to external forces or inertial forces of mechanical vibration, the chip is likely to be excessively deformed and collide with adjacent components above and below.

Summary of the Invention

Problems to be Solved by the Invention

[0003] As the resonance frequency increases, how to improve the problem that the resonator chip is too thin and easily collides with adjacent components above and below has become an important issue that researchers in this field should actively study.

Means for Solving the Problems

[0004] The present invention provides a suspended resonator that can effectively avoid the problem that the deformation amount of the vibration structure becomes too large and collides with adjacent components.

[0005] One embodiment of the present invention provides a suspension resonator including a vibrating structure, a first electrode, and a second electrode. The vibrating structure includes a vibrating region, a frame, and a connector. The vibrating region includes a plate portion and a reinforced portion. The plate portion includes a first surface and a second surface facing each other, a central portion, and a peripheral portion. The reinforced portion surrounds the central portion of the plate portion. The peripheral portion of the plate portion is sandwiched within the reinforced portion, and the thickness of the reinforced portion is greater than the thickness of the plate portion. The frame portion surrounds the vibrating region and maintains a gap between it and the vibrating region. The connector connects the reinforced portion to the frame portion. The first electrode is located on the first surface, and the second electrode is located on the second surface. [Effects of the Invention]

[0006] In the suspension-type resonator of the embodiment of the present invention, the thickness of the reinforced portion in the vibration region is greater than the thickness of the flat plate portion. Therefore, the amount of deformation of the vibration region during vibration is reduced, thereby effectively avoiding the problem of the vibration structure becoming too deformed due to external forces or inertial forces of mechanical vibration, causing it to collide with adjacent parts. [Brief explanation of the drawing]

[0007] The accompanying drawings are included to further illustrate the principles of the present invention, are incorporated herein, and constitute part thereof. The drawings illustrate embodiments of the present invention and, together with the description, serve to illustrate the principles of the present invention.

[0008] [Figure 1] This is an enlarged view of a suspension-type resonator according to one embodiment of the present invention. [Figure 2A] Figure 1 shows the vibration structure and a schematic three-dimensional view of the first electrode. [Figure 2B] Figure 2A shows the vibration structure and a schematic top view of the first electrode. [Figure 2C] Figure 2B shows a schematic cross-sectional view of the vibration structure and the first electrode along line II, as well as the second electrode located below the vibration structure. [Figure 2D] Figure 2B is a schematic cross-sectional view of the vibration structure along line II-II. [Figure 3]This curve shows the change in the amount of deformation of the vibration structure of the suspension-type resonator in Figure 1 during vibration, relative to the height of the protrusion of the thickened portion relative to the first surface. [Modes for carrying out the invention]

[0009] Figure 1 is an enlarged view of a suspension resonator according to one embodiment of the present invention. Figure 2A is a schematic three-dimensional view of the vibration structure and first electrode of Figure 1. Figure 2B is a schematic top view of the vibration structure and first electrode of Figure 2A. Figure 2C is a schematic cross-sectional view of the vibration structure and first electrode along line II of Figure 2B, and a second electrode located below the vibration structure. Figure 2D is a schematic cross-sectional view of the vibration structure along line II-II of Figure 2B. Referring to Figures 1 and 2A to 2D, the suspension resonator 100 of this embodiment includes a vibration structure 200, a first electrode 260, and a second electrode 270 (shown in Figure 2C). The vibration structure 200 includes a vibration region 202, a frame portion 210, and a connecting portion 240. The vibration region 202 includes a flat plate portion 220 and a thickened portion 230. The flat plate portion 220 includes a first surface 222 and a second surface 224 facing each other, a central portion 221, and a peripheral portion 223. The reinforced portion 230 surrounds the central portion 221 of the flat plate portion 220. The peripheral portion 223 of the flat plate portion 220 is sandwiched within the reinforced portion 230, and the thickness T1 of the reinforced portion 230 is greater than the thickness T2 of the flat plate portion 220. The frame portion 210 surrounds the vibration region 202 and maintains a gap G between the vibration region 202 and the frame portion 210. The connecting portion 240 connects the reinforced portion 230 to the frame portion 210. The first electrode 260 is located on the first surface 222, and the second electrode 270 is located on the second surface 224.

[0010] In this embodiment, the material of the vibrating structure 200 is a piezoelectric material, such as quartz or another piezoelectric material. When a voltage difference is applied between the first electrode 260 and the second electrode 270, the flat plate portion 220 deforms in response to it due to the inverse piezoelectric effect. Then, when the voltage difference is removed, the flat plate portion 220 vibrates in response. Furthermore, as a result of the vibration, a voltage change occurs between the first electrode 260 and the second electrode 270 due to the piezoelectric effect, and the first electrode 260 and the second electrode 270 output a voltage signal.

[0011] In this embodiment, the connection portion 240 includes two connection sections 242 connected to two opposing sides of the vibration region 202, so that the vibration region 202 forms a suspension structure. In one embodiment, the connection line C of the connection section 242 is offset from the center of the vibration region 202. Furthermore, in this embodiment, the thickness T3 of the connection portion 240 is greater than the thickness T2 of the flat plate portion 220. In one embodiment, the thickness T3 of the connection portion 240 may be approximately the same as the thickness T1 of the thickened portion 230.

[0012] In this embodiment, the suspension resonator 100 further includes a base 110, a first seal ring 130, a second seal ring 140, and an upper cover 120. The first seal ring 130 is positioned on the base 110, and the vibrating structure 200 is positioned on the first seal ring 130. The upper and lower sides of the first seal ring 130 lean against the edges of the vibrating structure 200 and the suspension resonator 100, respectively. The second seal ring 140 is positioned on the vibrating structure 200, and the upper cover 120 is positioned on the second seal ring 140. The upper and lower sides of the second seal ring 140 lean against the edges of the upper cover 120 and the edges of the vibrating structure 200, respectively. In this embodiment, the first seal ring 130 and the second seal ring 140 are rectangular rings. Furthermore, in this embodiment, the suspension resonator 100 further includes a plurality of pads 150 positioned below the base 110 and electrically connected to the first electrode 260 and the second electrode 270, respectively. For example, the pads 150 are electrically connected to the first electrode 260 and the second electrode 270, respectively, via a conductive trace 250 and another conductive trace located behind the connection section 242 in Figure 2A. The conductive trace 250 may extend from the first electrode 260 to the surface of the frame section 210 via the surface of one of the connection sections 242 (the connection section 242 on the right side in Figure 2A). The other conductive trace described above may extend from the second electrode 270 to the surface of the frame section 210 via the surface of another connection section 242 located behind the base in Figure 2A (the connection section 242 on the left side in Figure 2A).

[0013] In the suspended resonator 100 of the present embodiment, the thickness T1 of the thickened portion 230 of the vibration region 202 is greater than the thickness T2 of the flat plate portion 220 of the vibration region 202, and the thickness T3 of the connecting portion 240 may also be greater than the thickness T2 of the flat plate portion 220. Therefore, the structural rigidity and strength are enhanced, the deformation amount of the vibration region 202 during vibration is reduced, and thereby, the problem that the deformation amount of the vibration structure 200 becomes too large due to the external force or inertial force of mechanical vibration and hits adjacent components (for example, the upper cover 120 and the base 110) can be effectively avoided. Also, since the vibration region 202 and the frame portion 210 are connected via the connecting portion 240, the effect of isolating the thermal stress generated by the process from being transmitted to the vibration region 202 can be maintained.

[0014] In the present embodiment, the protrusion height of the thickened portion 230 facing the first surface 222 is H, the length of the vibration region 202 in the arrangement direction of the two connection sections 232 (that is, the extending direction of the connection line C) is L, and the suspended resonator 100 satisfies 0.01 < H / L < 0.8. Also, the height of the thickened portion 230 protruding relative to the second surface 224 is H'. In the present embodiment, H = H'. FIG. 3 is a curve showing the change in the deformation amount of the vibration structure of the suspended resonator of FIG. 1 during vibration relative to the protrusion height of the thickened portion facing the first surface. As can be seen from FIG. 3, in the comparative example, when the protrusion height H of the thickened portion 230 facing the first surface 222 is 0, the deformation amount of the vibration structure 200 during vibration is as high as about 28 microns (μm). At this time, the deformation amount of the vibration structure 200 becomes too large due to the external force or inertial force of mechanical vibration and hits adjacent components (for example, the upper cover 120 and the base 110). However, when the protrusion height H of the thickened portion 230 facing the first surface 222 is greater than 4 microns, the deformation amount of the vibration structure 200 during vibration decreases to 1 micron or less. Therefore, the problem that the deformation amount of the vibration structure 200 becomes too large due to the external force or inertial force of mechanical vibration and hits adjacent components (for example, the upper cover 120 and the base 110) can be effectively avoided. At this time, the deformation amount of the vibration structure 200 during vibration decreases to 1 micron or less.

[0015] In this embodiment, each of the two connection sections 242 includes a gentle slope sub-section 243 and an extended sub-section 244. The first end E1 of the gentle slope sub-section 243 is connected to the frame portion 210, the second end E2 of the gentle slope sub-section 243 is connected to the third end E3 of the extended sub-section 244, and the fourth end E4 of the extended sub-section 244 is connected to the thickening portion 230. The first end E1 faces the second end E2, the third end E3 faces the fourth end E4, and the thickness of the gentle slope sub-section 243 decreases from the first end E1 towards the second end E2. As shown in FIGS. 2A and 2D, a V-shaped concave surface 245 is provided at the joint portion between the second end E2 and the third end E3. The gentle slope sub-section 243 is configured to reduce stress concentration.

[0016] As described above, in the suspended resonator according to the embodiment of the present invention, the thickness of the thickening portion in the vibration region is greater than the thickness of the flat plate portion. Therefore, the amount of deformation of the vibration region during vibration is reduced, thereby effectively avoiding the problem that the amount of deformation of the vibration structure becomes too large due to an external force or inertial force of mechanical vibration and hits adjacent components.

Industrial Applicability

[0017] By applying the suspended resonator of the present invention, it is possible to avoid the problem that the amount of deformation of the vibration structure becomes too large and hits adjacent components.

Explanation of Reference Numerals

[0018] 100 Suspended Resonator 110 Base 120 Upper Cover 130 First Seal Ring 140 Second Seal Ring 150 Pad 200 Vibration Structure 202 Vibration Region 210 Frame Portion 220 Flat Plate Portion 221 Center Portion 222 First Surface 223 Edge Portion 224 Second Surface 230 Thickening section 240 Connection part 242 Connection Sections 243 Gentle gradient sub-section 244 Extension Subsection 245 V-shaped concave 250 conductive traces 260 1st electrode 270 2nd electrode C connection wire E1 1st end E2 2nd end E3 3rd end E4 End 4 G gap H, H' Height L Length T1, T2, T3 thickness

Claims

1. A flat plate portion including a first surface and a second surface facing each other, a central portion, and a peripheral portion, The thickened portion surrounding the central portion of the flat plate, The vibration region includes the following: the edge portion of the flat plate is sandwiched within the thickened portion, the total thickness of the edge portion of the flat plate and the thickened portion sandwiching the edge portion is greater than the thickness of the flat plate, and the edge portion and the thickened portion are not an integral structure. A frame portion that surrounds the vibration region and maintains a gap with the vibration region, A connecting portion for connecting the thickened portion to the frame portion, A vibration structure including, A first electrode disposed on the first surface, A second electrode disposed on the second surface, Includes, The connection portion includes two connection sections connected to two opposing sides of the vibration region, the two connection sections are arranged in the gap, and connect the reinforced portion and the frame portion. Each of the two aforementioned connection sections is A gently sloping sub-section having a first end connected to the frame portion, The extended sub-section and The gently sloping subsection includes a second end connected to the third end of the extended subsection, the fourth end of the extended subsection connected to the thickened portion, the first end facing the second end, the third end facing the fourth end, the thickness of the gently sloping subsection decreasing from the first end to the second end, the gently sloping subsection connecting the frame portion and the extended subsection, and having two opposing inclined surfaces inclined with respect to the flat plate portion. A suspension resonator in which the height of the projection of the thickened portion relative to the first surface is H, the length of the vibration region in the direction of arrangement of the two connection sections is L, and 0.01 < H / L < 0.

8.

2. The suspension resonator according to claim 1, wherein the imaginary line connecting the two connection sections is offset from the center of the vibration region.

3. The suspension resonator according to claim 1, wherein the material of the vibration structure is a piezoelectric material.

4. Bass and, A first seal ring, on which the vibration structure is arranged, is disposed on the base, A second seal ring is arranged on the aforementioned vibration structure, The upper cover is positioned on the second sealing ring, The suspension resonator according to claim 1, further comprising:

5. The suspension resonator according to claim 4, further comprising a plurality of pads positioned below the base and electrically connected to the first electrode and the second electrode, respectively.

6. The suspension resonator according to claim 4, wherein the thickness of the connecting portion is greater than the thickness of the flat plate portion.

7. The suspension resonator according to claim 1, wherein the height of the projection of the thickened portion relative to the first surface is H, and the height of the thickened portion protruding relative to the second surface is H', and H = H'.

Images