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 more particularly to a suspended resonator.

Background Art

[0002] A resonator is an electronic component that utilizes the piezoelectric properties 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 hit the 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 hits the 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 hits the adjacent components.

[0005] One embodiment of the present invention provides a suspended resonator including a vibrating structure, a first electrode, and a second electrode. The vibrating structure includes a vibrating region, a frame portion, and a connecting portion. The vibrating region includes a flat plate portion and a thickening portion. The flat plate portion includes a first surface and a second surface facing each other, a central portion, and an edge portion. The thickening portion surrounds the central portion of the flat plate portion. The edge portion of the flat plate portion is sandwiched within the thickening portion, and the thickness of the thickening portion is greater than the thickness of the flat plate portion. The frame portion surrounds the vibrating region and maintains a gap with the vibrating region. The connecting portion connects the thickening portion to the frame portion. The first electrode is disposed on the first surface, and the second electrode is disposed on the second surface.

Advantages of the Invention

[0006] In the suspended resonator according to the embodiment of the present invention, the thickness of the thickening portion of the vibrating region is greater than the thickness of the flat plate portion. Therefore, the amount of deformation of the vibrating region during vibration is reduced, thereby effectively avoiding the problem that the amount of deformation of the vibrating structure becomes too large due to the external force or inertial force of mechanical vibration and hits adjacent components.

Brief Description of the Drawings

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

[0008]

Figure 1

Figure 2A

Figure 2B

Figure 2C

Figure 2D

Figure 3

DETAILED DESCRIPTION OF THE INVENTION

[0009] FIG. 1 is an enlarged view of a suspended resonator according to an embodiment of the present invention. FIG. 2A is a three-dimensional schematic view of the vibration structure and the first electrode of FIG. 1. FIG. 2B is a schematic top view of the vibration structure and the first electrode of FIG. 2A. FIG. 2C is a schematic cross-sectional view of the vibration structure and the first electrode along line I-I of FIG. 2B, and the second electrode below the vibration structure. FIG. 2D is a schematic cross-sectional view of the vibration structure along line II-II of FIG. 2B. Referring to FIGS. 1 and 2A to 2D, the suspended resonator 100 of the present embodiment includes a vibration structure 200, a first electrode 260, and a second electrode 270 (shown in FIG. 2C). The vibration structure 200 includes a vibration region 202, a frame portion 210, and a connection portion 240. The vibration region 202 includes a flat plate portion 220 and a build-up 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 an edge portion 223. The build-up portion 230 surrounds the central portion 221 of the flat plate portion 220. The edge portion 223 of the flat plate portion 220 is sandwiched within the build-up portion 230, and the thickness T1 of the build-up 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 with the vibration region 202. The connection portion 240 connects the build-up portion 230 to the frame portion 210. The first electrode 260 is disposed on the first surface 222, and the second electrode 270 is disposed on the second surface 224.

[0010] In the present embodiment, the material of the vibration structure 200 is a piezoelectric material, for example, quartz or other piezoelectric materials. When a voltage difference is applied between the first electrode 260 and the second electrode 270, the flat plate portion 220 deforms due to the inverse piezoelectric effect in response thereto. Then, when the voltage difference is removed, the flat plate portion 220 vibrates in response thereto. Further, since a voltage change occurs between the first electrode 260 and the second electrode 270 due to the piezoelectric effect accompanying the vibration, the first electrode 260 and the second electrode 270 output a voltage signal.

[0011] In this embodiment, since the connection part 240 includes two connection sections 242 respectively connected to two opposite sides of the vibration region 202, the vibration region 202 forms a suspended structure. In one embodiment, the connection line C of the connection section 242 diverges from the center of the vibration region 202. Further, in this embodiment, the thickness T3 of the connection part 240 is greater than the thickness T2 of the flat plate part 220. In one embodiment, the thickness T3 of the connection part 240 may be substantially the same as the thickness T1 of the build-up part 230.

[0012] In this embodiment, the suspended 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 disposed on the base 110, and the vibration structure 200 is disposed on the first seal ring 130. The upper and lower sides of the first seal ring 130 respectively abut against the edge of the vibration structure 200 and the edge of the suspended resonator 100. The second seal ring 140 is disposed on the vibration structure 200, and the upper cover 120 is disposed on the second seal ring 140. The upper and lower sides of the second seal ring 140 respectively abut against the edge of the upper cover 120 and the edge of the vibration structure 200. In this embodiment, the first seal ring 130 and the second seal ring 140 are rectangular rings. Also, in this embodiment, the suspended resonator 100 further includes a plurality of pads 150 disposed 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 behind the connection section 242 in FIG. 2A. The conductive trace 250 may extend from the first electrode 260 to the surface of the frame part 210 through the surface of one of the connection sections 242 (the right connection section 242 in FIG. 2A). The above-mentioned another conductive trace may extend from the second electrode 270 to the surface of the frame part 210 through the surface of another connection section 242 (the left connection section 242 in FIG. 2A) behind FIG. 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 the adjacent components (for example, the upper cover 120 and the base 110) can be effectively avoided. Further, 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 opposite to 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 opposite to the first surface. As can be seen from FIG. 3, in the comparative example, when the protrusion height H of the thickened portion 230 opposite to 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 the adjacent components (for example, the upper cover 120 and the base 110). However, when the protrusion height H of the thickened portion 230 opposite to 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 the 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 extension 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 extension sub-section 244, and the fourth end E4 of the extension 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 the external force or inertial force of mechanical vibration and hits the adjacent components.

Industrial Applicability

[0017] By applying the suspended resonator of the present invention, the problem that the amount of deformation of the vibration structure becomes too large and hits the adjacent components can be avoided.

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 Central Portion 222 First Surface 223 Edge Portion 224 Second Surface 230 Fleshing part 240 Connection part 242 Connection section 243 Gentle slope sub-section 244 Extension sub-section 245 V-shaped concave surface 250 Conductive trace 260 First electrode 270 Second electrode C Connection wire E1 First end E2 Second end E3 Third end E4 Fourth end G Gap H, H’ Height L Length T1, T2, T3 Thickness

Claims

1. a plate portion including opposing first and second surfaces, a central portion, and a peripheral portion; A thickened portion surrounding the central portion of the flat plate portion; a vibration structure including: a peripheral portion of the flat plate portion is sandwiched within the thickened portion; and a thickness of the thickened portion is greater than a thickness of the flat plate portion; a frame portion surrounding the vibration region and maintaining a gap between the vibration region and the frame portion; a connection portion that connects the thickened portion to the frame portion; a vibrating structure including: a first electrode disposed on the first surface; a second electrode disposed on the second surface; A suspended resonator comprising:

2. 2. The suspended resonator according to claim 1, wherein the connection portion includes two connection sections respectively connected to two opposite sides of the vibration region.

3. 3. The suspended resonator according to claim 2, wherein the connection lines of the connection sections are offset from the center of the vibration region.

4. 3. The suspended resonator according to claim 2, wherein a protrusion height of the thickened portion relative to the first surface is H, a length of the vibration region in an arrangement direction of the two connection sections is L, and the suspended resonator satisfies 0.01<H / L<0.

8.

5. Each of the two connection sections is a gentle slope subsection having a first end connected to the frame portion; an extension subsection; 3. The suspended resonator of claim 2, comprising: a second end of the shallow subsection connected to a third end of the extending subsection and a fourth end of the extending subsection connected to the thickened portion, the first end facing the second end, the third end facing the fourth end, and a thickness of the shallow subsection decreasing from the first end to the second end.

6. 2. The suspended resonator of claim 1, wherein the material of the vibrating structure is a piezoelectric material.

7. With the base, a first seal ring disposed on the base and having the vibration structure disposed thereon; a second seal ring disposed on the vibrating structure; an upper cover disposed on the second seal ring; The suspended resonator of claim 1 further comprising:

8. 8. The suspended resonator of claim 7, further comprising a plurality of pads disposed below the base and electrically connected to the first electrode and the second electrode, respectively.

9. 2. The suspended resonator according to claim 1, wherein the thickness of said connection portion is greater than the thickness of said flat plate portion.

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