Systems and methods for acoustically isolating resonators

Abstract

Systems and methods disclosed herein include an apparatus having a bulk acoustic wave resonator and one or more grooves configured to impede flow of acoustic energy to the bulk acoustic wave resonator.

Description

Technical Field

[0001] The present disclosure relates to acoustically isolating resonators, and more particularly, to systems and methods for acoustically isolating bulk wave resonator gyroscopes. Background Art

[0002] The coupling of acoustic energy to the resonator can increase the noise of the resonator. Changes in the coupled acoustic energy can cause changes in the resonator output. This leads to a degradation in the performance of the resonator. These and other drawbacks exist. Summary of the invention

[0003] Embodiments of the present disclosure provide a device including a substrate. The device may include a bulk acoustic wave resonator arranged on at least a first surface of the substrate. The substrate may include one or more grooves configured to hinder acoustic energy from flowing to the bulk acoustic wave resonator.

[0004] Embodiments of the present disclosure provide a device including a plurality of device components. A first device component selected from the plurality of device components may include a plurality of grooves and / or cavities. A second device component selected from the plurality of device components may be sensitive to acoustic energy. The plurality of grooves are configured to obstruct the flow of acoustic energy to the second device component.

[0005] Embodiments of the present disclosure provide a device including a substrate. The device may include a resonator coupled to a first surface of the substrate. The resonator may include a bulk acoustic wave resonator gyroscope that performs capacitive transduction via one or more electrodes. The device may include a cover structure. The cover structure may include one or more grooves configured to obstruct acoustic energy from flowing to the resonator. The cover structure may include one or more cavities configured to obstruct acoustic energy from flowing to the resonator. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] [ Figure 1A ] Figure 1A A cross-sectional view of a device according to an example embodiment is shown.

[0007] [ Figure 1B ] Figure 1B A cross-sectional view of a device according to another example embodiment is shown.

[0008] [ Figure 2 ] Figure 2 A cross-sectional view of a device according to another example embodiment is shown.

[0009] [ Figure 3A ] Figure 3A A cross-sectional view of a device according to another example embodiment is shown.

[0010] [ Figure 3B ] Figure 3B A cross-sectional view of a device according to another example embodiment is shown.

[0011] [ Figure 4 ] Figure 4 A cross-sectional view of a device according to another example embodiment is shown.

[0012] [ Figure 5A ] Figure 5A Plan views of various patterns according to example embodiments are shown.

[0013] [ Figure 5B ] Figure 5B Plan views of various patterns according to example embodiments are shown.

[0014] [ Figure 5C ] Figure 5C Plan views of various patterns according to example embodiments are shown.

[0015] [ Figure 5D ] Figure 5D Plan views of various patterns according to example embodiments are shown.

[0016] [ Figure 5E ] Figure 5E Plan views of various patterns according to example embodiments are shown.

[0017] [ Fig. 5F ] Fig. 5F Plan views of various patterns according to example embodiments are shown.

[0018] [ Figure 5G ] Figure 5G Plan views of various patterns according to example embodiments are shown.

[0019] [ Figure 5H ] Figure 5H Plan views of various patterns according to example embodiments are shown.

[0020] [ Figure 6 ] Figure 6 A cross-sectional view of a device according to another example embodiment is shown.

[0021] [ Figure 7 ] Figure 7 A cross-sectional view of a device according to another example embodiment is shown.

[0022] [ Figure 8 ] Figure 8 A graph of quality factor and trench size according to example embodiments is shown.

[0023] [ Fig.9A ] Fig.9A A die attach pattern according to example embodiments is shown.

[0024] [ Fig. 9B] Fig. 9B A die attach pattern according to example embodiments is shown.

[0025] [ Fig. 9C ] Fig. 9C A die attach pattern according to example embodiments is shown. DETAILED DESCRIPTION

[0026] The following description of the embodiments provides non-limiting representative examples, with reference to numbers to specifically describe the features and teachings of different aspects of the present invention. It should be appreciated that the described embodiments can be implemented individually or in combination with other embodiments according to the description of the embodiments. Those of ordinary skill in the art who read the description of the embodiments should be able to learn and understand the different described aspects of the present invention. The description of the embodiments should facilitate understanding of the present invention, so that other implementations that are not specifically covered but within the knowledge of those skilled in the art who have read the description of the embodiments should be understood to be consistent with the application of the present invention.

[0027] Acoustic energy can couple into a resonator, degrading its performance. For example, acoustic energy can increase the noise of a resonator, or affect the zero-rate offset of a resonator-based gyroscope. In addition, temperature-dependent acoustic energy coupled to a resonator can produce temperature-dependent effects, such as high-order zero-rate offset vs. temperature behavior. In addition to temperature, unwanted acoustic energy coupling can also vary with other operating conditions, such as stress or external fields, which can degrade device performance. The source of unwanted acoustic energy can be internal or external to the device. Acoustic energy can be generated in resonators and electrodes due to electrostatic transduction. Therefore, in some examples, resonators and electrodes can act as serious sources of acoustic energy.

[0028] As used herein, unwanted acoustic energy may refer to acoustic energy that may or may not be external to the resonator 101 and coupled to the anchor 106, even if generated internal to the resonator 101. Thus, the unwanted acoustic energy may be generated from the environment within the resonator 101 and / or external to the resonator 101, and is therefore not limited to energy that is only external to the resonator 101, and the grooves (e.g., grooves 901) are configured to impede the flow of the unwanted acoustic energy when it rebounds (including, but not limited to, one or more flow paths), as further discussed herein. In some examples, the unwanted acoustic energy may be coupled into the resonator 101 via structures other than the anchor 106, including, but not limited to, the connection 1501 (e.g., such as Figure 7 ). In some examples, there may be unwanted acoustic energy coupled to the resonator 101 via the medium surrounding the resonator. For example, the medium may refer to a gas, a liquid, and / or any combination thereof located around the resonator 101. The medium may be, but is not limited to, external to the resonator 101.

[0029] To mitigate these issues, the grooves and / or cavities of the systems and methods disclosed herein can be arranged to obstruct flow (e.g., one or more flow paths) and reduce unwanted acoustic energy between the drive and sense modes of a gyroscope (e.g., a bulk acoustic wave resonator gyroscope). In addition, this arrangement reduces zero-rate offset and higher-order zero-rate offset vs. temperature behavior in the resonant gyroscope. As a result, this produces an enhancement in device performance.

[0030] Figure 1A A cross-sectional view of a device 100 according to an example embodiment is depicted. The device 100 may include a resonator 101, a substrate 102, an electrode 103, a transduction gap 104, a cover structure 105, an anchor 106, a bonding pad 107, a wire bond 108, and one or more trenches 901. Figure 1A A single instance of a component of device 100 is shown, but it should be understood that any number of components of device 100 may be included.

[0031] like Figure 1A As further shown, acoustic energy can be supplied from several sources (e.g., sources 110, 115, 120, and 125 external to device 100, source 130 due to movement of wire bonds 108, source 135 due to movement of bond pads 107, source 140 due to movement of substrate 102, source 145 due to movement of lid structure 105, source 150 due to movement of the resonator, source 155 due to movement of anchor 106, and source 160 due to movement of electrode 103). Arrows depict movement of sources 145, 150, 155, and 160, but not necessarily the direction of movement, as movement or vibration can occur in any direction, e.g., longitudinally, transversely, laterally, obliquely, flexurally, etc. As further described below, device 100 can be configured to isolate resonator 101 from unwanted acoustic energy and enhance its performance.

[0032] Resonator 101 may include a bulk acoustic wave resonator gyroscope. The bulk acoustic wave resonator may be arranged on at least a first surface of substrate 102. For example, resonator 101 may be connected to the first surface of substrate 102 via anchor 106. Resonator 101 may be capacitively transduced via one or more electrodes 103. In some examples, one or more electrodes 103 may include one or more peripheral electrodes. In other examples, one or more electrodes 103 may include one or more non-peripheral electrodes. In other examples, one or more electrodes 103 may include peripheral electrodes, non-peripheral electrodes, and / or any combination thereof. For example, Figure 1BDevice 100 is shown, which also includes non-peripheral electrode 109. In some examples, non-peripheral electrode 109 can include a planar electrode. Capacitive transduction can occur across gap 111 between non-peripheral electrode 109 and resonator 101. Although Figure 1B A single instance of a component of device 100 is shown, but it should be understood that any number of components of device 100 may be included. Figure 1B Please refer to the above Figure 1A The same components of the discussed device 100. A transduction gap 104 can separate the resonator 101 from the one or more electrodes 103. The transduction gap 104 can be disposed above the substrate 102. For example, the transduction gap 104 can be disposed above a first surface of the substrate 102.

[0033] Wire bonds 108 may be coupled to bonding pads 108. Bonding pads 108 may be disposed on a first surface of cap structure 105. In some examples, bonding pads 108 may be disposed on opposite ends of the first surface of cap structure 105.

[0034] The substrate 102 may include one or more grooves 901 configured to obstruct the flow of unwanted acoustic energy to the bulk acoustic wave resonator. For example, one or more grooves 901 may be symmetrically disposed within the substrate 102. In another example, one or more grooves 901 may be asymmetrically disposed within the substrate 102. In addition, one or more grooves 901 may have the same or different shapes as another groove 901. In addition, the size of one or more grooves 901 may be the same or different from another groove 901. For example, at least one groove 901 may extend more than halfway into the substrate 102, including but not limited to along a direction perpendicular to the substrate 102. The length of the groove 901 may exceed the width of the groove 901. In other examples, the length of the groove 901 may be equal to or less than the width of the groove 901.

[0035] One or more grooves 901 can be configured to block unwanted acoustic energy from flowing toward resonator 101. In some examples, the presence of one or more grooves 901 can be configured to block unwanted acoustic energy from flowing toward resonator 101 (e.g., one or more flow paths 302, 303, 304, and / or 305) via anchor 106. Figure 1A to Figure 1BAs shown, acoustic energy originating from one or more of the electrodes 103 or the cover structure 105 can reach the resonator 101 through the corresponding direct flow paths 303, 305. The acoustic energy originating from one or more of the electrodes 103 or the cover structure 105 can reach the resonator 101 through the corresponding flow paths 302, 304 after one or more reflections (e.g., reflections against the second surface (e.g., the bottom surface) of the substrate 102). It should be understood that the reflection is not limited to only a single reflection or against the second surface of the substrate 102, and additionally or alternatively, reflections can be made for any number of reflections and / or any number of surfaces of the substrate 102 to constitute a flow path for the acoustic energy to pass through the resonator 101.

[0036] One or more grooves 901 can be formed by one or more processes, including but not limited to dry etching, wet etching, cutting, laser ablation, milling and / or any combination thereof. In addition, any number of walls of the groove 901 can be straight, tapered, rounded, corrugated, wavy, and / or any combination thereof.

[0037] Resonator 101 may be configured to resonate in multiple modes (e.g., a first mode and a second mode). In the first mode (e.g., a drive mode), this may correspond to vibration along a first axis, while in the second mode (e.g., a sense mode), this may correspond to vibration along a second axis, so that the modes are orthogonal to each other. It is generally desirable that the frequencies of the drive mode and the sense mode match, as this can often increase the signal-to-noise ratio of resonator 101. For example, an angular rate gyroscope may be configured to operate under mode matching conditions, such that the drive mode is configured to have the same resonant frequency as the sense mode. In some examples, unwanted acoustic coupling between the drive mode and the sense mode may occur via flow path 301. In this way, acoustic energy originating from resonator 101 due to excitation of the drive mode may pass through flow path 301 and couple back to the sense mode of resonator 101. The effects of such coupling are particularly detrimental in a mode-matched configuration, as the two modes are nominally at approximately the same frequency, resulting in effective coupling of unwanted acoustic energy.

[0038] The cover structure 105 can be configured to at least partially surround the resonator 101. The transduction gap 104 can include a space or gap between the resonator 101 and the one or more electrodes 103. In some examples, the device 100 can include two or more transduction gaps 104. For example, two transduction gaps 104 can be diametrically opposed to each other, and each can be opposite to the resonator 101 and a different electrode 103. The resonator 101 and the one or more electrodes 103 can be formed in, for example, a base portion of the device 100, and the base portion can be bonded to the cover structure 105. The cover structure 105 can be disposed above the substrate 102. For example, the cover structure 105 can be disposed above the first surface of the substrate 102.

[0039] Figure 2 A cross-sectional view of a device 100 is depicted according to another example embodiment. Figure 2 Please refer to the above Figure 1A to Figure 1B For the sake of brevity, the above description of the same components of the device 100 is omitted. Figure 1A to Figure 1B Application of the components of the apparatus 100 discussed herein Figure 2 Although Figure 2 A single example of a component of the device 100 is shown, but it should be understood that any number of components of the device 100 may be included. The device 100 may include one or more attachment structures 401. For example, at least one of the attachment structures 401 may be disposed below the second surface (e.g., bottom surface) of the substrate 102. The one or more attachment structures 401 may include one or more selected from the group of: a soft core attachment, a hard die attachment, an adhesive, a stud bump, an interposer, and / or any combination thereof. In particular, soft materials (including but not limited to soft cores) may be used to avoid the accumulation of stress when the temperature changes. For example, a soft core attachment material may be utilized to minimize thermal and packaging stresses acting on the MEMS die. When selecting a type of die attachment, a trade-off between stress effects and reliability needs to be considered, as the softer the die attachment, the lower the reliability may be. If the grooves in the resonator 101 are not used, there are issues associated with unwanted acoustic energy (as discussed herein), but factors that need to be considered when selecting a soft core attachment include lower stress during packaging and operation over a certain temperature range. In some examples, the die attach thickness value may range from a few microns to hundreds of microns. For example, the die attach thickness value may include 50 microns.

[0040] In some examples, one or more attachment structures 401 can be disposed at opposite ends of the substrate 102. For example, one or more attachment structures 401 can be disposed symmetrically with respect to opposite ends of the substrate 102. The width of one or more attachment structures 401 can be shorter than the end of the substrate 102 to which it is coupled. In other examples, the width of one or more attachment structures 401 can be longer than the end of the substrate 102 to which it is coupled. In some examples, one or more attachment structures 401 can be disposed adjacent to or closer to the outer edge of one or more grooves 901 (rather than the inner edge).

[0041] The device 100 may include one or more underlying support structures 402. In some examples, the device 100 may include a single underlying support structure 402. For example, the underlying support structure 402 may be disposed between one or more attachment structures 401. In some examples, the underlying support structure may extend longer than the length of each of the substrate 102 and the cover structure 105. The one or more underlying support structures 402 may include at least one selected from the group of an integrated circuit, a printed circuit board, a package, an interposer, etc.

[0042] like Figure 2 As further shown, the first dimension 1201 can be smaller than the second dimension 1202 and relative to a direction parallel to the one or more underlying support structures 402. For example, the first dimension 1201 can be defined by a first distance from a first end (e.g., an outer edge) of the first groove 901 to a second end (e.g., an outer edge) of the second groove 901. In some examples, the outer edge of the groove 901 can include an edge farthest from the resonator 101. The second dimension 1202 can be defined by a second distance from a third end (e.g., an inner end of the first electrode 103) to a fourth end (e.g., an inner end of the second electrode 103). In some examples, the inner end of the electrode 103 can include an end proximate to the resonator 101. In some examples, the device 100 can include two or more transduction gaps 104, which can be diametrically opposed to each other and each can be relative to the resonator 101 and a different electrode 103. In some examples, selecting the first dimension 1201 to be smaller than the second dimension 1202 can hinder the flow of unwanted acoustic energy via the flow paths 302, 303, and 305.

[0043] FIG. 3A to FIG. 3B Each depicts a cross-sectional view of a device 200 according to an example embodiment. FIG. 3A to FIG. 3B Please refer to Figure 1 and Figure 2 For the sake of brevity, the above description of FIG. 1 and FIG. Figure 2 The components of the apparatus 100 discussed apply to the description of FIG. 3. Although FIG. 3A to FIG. 3B A single instance of components of device 200 is shown, but it should be understood that any number of components of device 200 may be included.

[0044] like Figure 3A As shown, device 200 may include multiple device components 801, 802, and 803. For example, device component 801 and device component 803 may be disposed on the same surface of device component 802. In some examples, device component 801 and device component 803 may be disposed on opposite ends of a first surface of device component 802.

[0045] At least one of the device components (e.g., device component 802) selected from the plurality of device components 801, 802, and 803 may include a plurality of grooves 901, 902, 903, and 904. At least one of the device components (e.g., device component 801) may be sensitive to unwanted acoustic energy. A plurality of grooves 901, 902, 903, and 904 may be configured to obstruct unwanted acoustic energy from flowing to device component 801. Device component 801 may be separated from device component 803 by at least one groove (e.g., groove 902). In some examples, groove 901 may have a different size and / or shape than grooves 902, 903, and 904. As previously described, the unwanted acoustic energy may be supplied from any of a number of sources located outside and / or inside device 200.

[0046] A plurality of grooves 901, 902, 903 and 904 may be formed by one or more processes, including but not limited to dry etching, wet etching, cutting, laser ablation, milling and / or any combination thereof. In addition, any number of walls of the grooves 901, 902, 903 and 904 may be straight, tapered, rounded, corrugated, wavy and / or any combination thereof.

[0047] like Figure 3B As shown, the device 200 may include a plurality of device components 801, 802, and 803. Figure 3A As shown. In addition, at least one of the device components 801 may include a bulk acoustic wave resonator 905 that performs capacitive transduction through one or more electrodes. Therefore, the device 200 may include a bulk acoustic wave resonator 905 that performs capacitive transduction through one or more electrodes (e.g., one or more peripheral electrodes). In addition, the device 200 may include a cavity 904. For example, the device component 802 may be configured to include a cavity 904 disposed below the bulk acoustic wave resonator 905. The cavity 904 may be configured to hinder the flow of acoustic energy into the bulk acoustic wave resonator 905. The cavity 904 may be adjacent to at least one of the grooves (e.g., the groove 902). The cavity 904 may have any size and / or shape. In fact, the plurality of grooves 901, 902, 903, and 904 and the one or more cavities 904 may be configured to mitigate the unwanted acoustic energy that flows into the bulk acoustic wave resonator 905.

[0048] Figure 4 Depicted is a cross-sectional view of a device 200 according to an example embodiment. Figure 4 Please refer to Figure 1 and Figure 2 The same components of the device 100 discussed above and the FIG. 3A to FIG. 3B For the sake of brevity, the above description of FIG. 1 and FIG. Figure 2 The components of the device 100 discussed above and FIG. 3A to FIG. 3B Application of the components of the apparatus 200 discussed herein Figure 4 Although Figure 4 A single instance of components of device 200 is shown, but it should be understood that any number of components of device 200 may be included.

[0049] Device 200 may include multiple device components 801, 802, and 803, one or more attachment structures 401, and one or more underlying support structures 402. For example, device component 801 and device component 803 may be disposed on the same surface of device component 802. In some examples, device component 801 and device component 803 may be disposed on opposite ends of a first surface of device component 803.

[0050] Device component 802 may include one or more grooves, such as groove 901. For example, at least one groove 901 may extend more than halfway into device component 802, including but not limited to along a direction perpendicular to underlying support structure 402. The length of groove 901 may exceed the width of groove 901. In other examples, the length of groove 901 may be equal to or less than the width of groove 901.

[0051] Grooves 901 can be configured to impede the flow of unwanted acoustic energy from device component 803 and energy reflected from one or more attachment structures 401. For example, as shown by flow path 808, unwanted acoustic energy can originate from device component 803, be reflected by one or more attachment structures 401, and then be impeded by grooves 901, ultimately reaching device component 801.

[0052] As shown by flow path 807 , unwanted acoustic energy may originate from device component 803 , then be blocked by groove 901 , and ultimately reach device component 801 .

[0053] As shown by flow path 805 , unwanted acoustic energy may originate from device component 802 , be reflected by a surface (eg, a bottom surface) of device component 802 , and ultimately reach device component 801 .

[0054] If the reflectivity of acoustic energy at one or more attachment structures 401 is high or varies significantly with operating conditions (e.g., temperature, stress, external magnetic field, etc.), one or more attachment structures 401 can be configured to have a smaller discrete geometry. In this way, the configuration can mitigate unwanted acoustic energy coupled to the device component 801 and the variation of acoustic energy coupled to the device component 801 over a range of operating conditions.

[0055] One or more attachment structures 401 may be disposed on a first surface (e.g., a bottom surface) of the second device component 802. In some examples, one or more attachment structures 401 may be disposed adjacent to each other on the same side of the device component 802. In some examples, one or more attachment structures 401 may have the same size and / or shape. One or more attachment structures 401 may be disposed below the device component 803. At least one of the one or more attachment structures 401 may be disposed adjacent to, below, and / or near the outer edge of the groove 901. In some examples, there may be no attachment structure 401 located within a direct line of sight of the device component 801. In this way, the configuration may reduce the intensity of acoustic energy passing through the flow path 805 and / or mitigate variations in unwanted acoustic energy coupled to the device component 801 over a range of operating conditions.

[0056] The underlying support structure 402 may be coupled to a first surface (eg, a bottom surface) of the second device component 802 via one or more attachment structures 401 .

[0057] FIG. 5A to FIG. 5H Various designs of grooves in plan views according to example embodiments are shown. The grooves may refer to the grooves described above with respect to FIGS. Figure 4 Any of the same grooves previously described in any of the above. Any number of these groove designs and any combination of these groove designs can be used for the grooves associated with any of the figures disclosed herein. As shown in these figures, the groove area 901 can be surrounded by one or more solid areas 1301 of the device 100 or device 200.

[0058] Figure 5A Square-shaped trench regions 901 disposed between solid regions 1301 are shown. Figure 5B Circular trench regions 901 disposed between solid regions 1301 are shown. Figure 5C An intersecting trench region 901 disposed between solid regions 1301 is shown. Figure 5D A square-shaped trench region 901 disposed inside the solid region 1301 is shown. Figure 5E 1 shows a partially circular groove region 901 disposed between solid regions 1301. For example, Figure 5E As shown, the convex groove pattern can be configured to reduce the amplitude of unwanted acoustic energy at the device component 801, the resonator 101, or the capacitive transducer BAW resonator 905. Fig. 5F Hexagonal trench regions 901 disposed between solid regions 1301 are shown. Figure 5G A polygonal groove region 901 disposed between solid regions 1301 is shown. Figure 5H1 shows example dimensions of a square trench region 901 disposed between solid regions 1301. The trench region 901 and the solid region 1301 may be Figure 5A 1. In some examples, the square groove region 901 may include about 775 microns on the first x dimension and about 175 microns on the second x dimension. The solid region 1301 may include about 2300 microns on the third x dimension. In some examples, the groove 901 region may be about 10 to 500 microns deep. For example, the range of the ratio of the area inside the region 901 to the area outside the region 901 may include about 0.03 to 0.09. However, it should be understood that other values ​​of the ratio of the corresponding areas inside the region 901 and outside the region 901 can be envisioned.

[0059] It should be understood that FIG. 5A to FIG. 5H The groove region 901 and the solid region 1301 are not limited to these groove patterns and / or shapes and / or sizes, and any other groove patterns and / or shapes and / or sizes may be used to at least partially eliminate sound waves that may or may not be reflected. In some examples, FIG. 5A to FIG. 5H The groove pattern can be symmetrical with respect to the device component 801, the resonator 101, or the capacitive transducer BAW resonator 905. For example, by contacting one or more attachment structures 401 (including but not limited to hose core attachment) with the area 1301 outside the groove area 901, the flow of unwanted acoustic energy from the one or more attachment structures 401 to the resonator 101 can be hindered. In other examples, FIG. 5A to FIG. 5H The groove pattern of the device component 801 can be asymmetric with respect to the device component 801, the resonator 101, or the capacitive transducer BAW resonator 905. For example, the asymmetric groove pattern can be configured to partially cancel the reflected acoustic waves at the device component 801, the resonator 101, or the capacitive transducer BAW resonator 905 by destructive interference, such as Figure 5G In some examples, such as Figure 5G As shown, the asymmetric arrangement of the groove pattern can achieve destructive interference of acoustic waves entering the resonator 101 via the anchor 106 , and this destructive interference can result in further mitigation of unwanted acoustic energy coupled to the resonator 101 .

[0060] Figure 6 A cross-sectional view of a device 300 is shown according to an example embodiment.

[0061] Figure 6 Please refer to Figure 1 and Figure 2 The same components of the device 100 discussed above with respect to FIG. 3A to FIG. 3B as well as Figure 4The same components of the device 200 discussed herein, and the groove patterns discussed above with respect to FIG. 5 , are omitted for the sake of brevity. Figure 2 The components of the device 100 discussed above FIG. 3A to FIG. 3B The components of the discussed device 200 and the application of the groove pattern of FIG. 5 to Figure 6 Although Figure 6 A single instance of a component of device 300 is shown, but it should be understood that any number of components of device 300 may be included.

[0062] While device 300 may include many of the same components as device 100 and / or device 200, it may differ in some respects. Specifically, substrate 102 may be disposed above resonator 101. Cover structure 105 may be disposed below resonator 101. Cover structure 105 may include one or more grooves 901 and one or more cavities 904, which may be configured to each obstruct one or more flow paths of unwanted acoustic energy that may or may not include reflections to resonator 101. For example, grooves 901 and cavities 904 may be configured to mitigate unwanted acoustic energy from flowing to resonator 101 via flow paths 603 and 602, respectively. Cavity 904 may be at least in the cover structure and at least partially below the resonator.

[0063] In some examples, unwanted acoustic energy can originate from one or more bonding pads 107, which can be reflected against a surface (e.g., a side surface) of the cap structure 105. The grooves 901 can be disposed at corners of the cap structure 105. The grooves 901 can be disposed at opposite ends of the cavity 904. In some examples, acoustic energy coupling can be reflected from the electrode 103 through the flow path 601, from a surface (e.g., a top surface) of the substrate 102, and into the resonator 101.

[0064] In addition, the cover structure 105 can be coupled to the underlying support structure 402 via the bonding pad 107 and the one or more attachment structures 401. The one or more attachment structures 401 can be disposed on a first surface (e.g., a top surface) of the underlying support structure 402. The one or more attachment structures 401 can be disposed on a second surface (e.g., a bottom surface) of the bonding pad 107. The bonding pad 107 can be disposed on a surface (e.g., a bottom surface) of the cover structure 105. At least one of the one or more attachment structures 401 and / or the bonding pad 107 can be disposed adjacent to an outer edge of the groove 901, disposed below an outer edge of the groove 901, and / or disposed closer to an outer edge of the groove 901.

[0065] Figure 7 A cross-sectional view of a device 300 is shown according to an example embodiment.

[0066] Figure 7 Please refer to Figure 1 and Figure 2 The device 100 discussed above FIG. 3A to FIG. 3B as well as Figure 4 The device 200 discussed above, the groove pattern discussed above with respect to FIG. 5, and the groove pattern discussed above with respect to FIG. Figure 6 For the sake of brevity, the above description of FIG. 1 and FIG. Figure 2 The components of the device 100 discussed above FIG. 3A to FIG. 3B as well as Figure 4 The components of the discussed device 200, the groove pattern of FIG. 5, and the application of the device 300 to Figure 7 Although Figure 7 A single instance of a component of device 300 is shown, but it should be understood that any number of components of device 300 may be included.

[0067] Although the device 300 may include Figure 6 100 and 105. The resonator 101 may include many of the same components as the device 300, but it may differ in some respects. The resonator 101 may be doubly connected to the substrate 102 and the cover structure 105. For example, the resonator 101 may be coupled to the substrate 102 via an anchor 106, e.g., coupled to the bottom surface of the substrate 102 via the anchor 106. In addition, the resonator 101 may be coupled to the cover structure 105 via a connection 1501, e.g., coupled to the upper surface of the cover structure 105 via the connection 1501. For example, the connection 1501 may refer to an electrical connection. In some examples, the connection 1501 may include a columnar structure, which may be configured to provide an anchor point and an electrical connection. In some examples, the connection 1501 may be integrated with the cover structure 105.

[0068] In addition, the present disclosure also contemplates the design and configuration of optimal groove dimensions that minimize unwanted acoustic energy to the resonator 101. For certain device parameters, a simulated optimal value for the groove 901 width is approximately 50 microns. Figure 8 As shown, graph 800 shows the quality factor and the width of the groove region 901. For example, the simulations performed show an optimal value for the groove width that minimizes unwanted acoustic coupling. In some examples, the actual groove width used may be different from the optimal value for the simulated groove width. More specifically, under simulated operation, the drive mode is excited and the sensing mode is measured as a function of the material properties of one or more attachment structures 401. When the material properties of one or more attachment structures 401 are changed, the acoustic reflectivity is changed, and therefore the amplitude of the sensing mode changes.

[0069] Since the flexible tube core attach material has a low Young's modulus, the wavelength of the acoustic waves in the die attach can be comparable to the die attach thickness. Therefore, under certain conditions, the acoustic film interference effect can be prominent, which leads to higher acoustic reflections and unwanted acoustic coupling. In some examples, the die attach can be distributed as a continuous pattern. In other examples, the die attach can be distributed as a set of discrete lines or points. 9A to 9C An exemplary die attach pattern is shown in . Note that the area coverage of the die attach is a trade-off between mechanical reliability of the attachment and unwanted acoustic coupling. Fig.9A A plan view of a trench region 901 disposed between solid regions 1301 is shown, wherein a die attach pattern 905 is continuously disposed around the trench region 901 . Fig. 9B A plan view of a trench region 901 disposed between solid regions 1301 is shown, wherein a die attach pattern 915 is disposed at one or more edges or corners of the solid regions 1301 . Fig. 9C A plan view of a trench region 901 disposed between solid regions 1301 is shown, wherein a die attach pattern 910 is disposed at one or more sides relative to the trench region 901 .

[0070] Throughout the specification and claims, the following terms have at least the meanings explicitly associated herein unless the context clearly dictates otherwise. The term "or" is intended to mean an inclusive "or". In addition, the terms "a", "an", and "the" are intended to mean one or more, unless otherwise specified or clear from context to indicate a singular form.

[0071] In this specification, many specific details have been set forth. However, it should be understood that the embodiments of the disclosed technology can be practiced even without these specific details. In other instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description. References to "some examples", "other examples", "one example", "example", "various examples", "one embodiment", "embodiment", "some embodiments", "example embodiments", "various embodiments", "one implementation", "implementation", "example implementation", "various implementations", "some implementations", etc. indicate that the embodiments of the disclosed technology described in this way may include specific features, structures, or characteristics, but not every implementation necessarily includes specific features, structures, or characteristics. In addition, the repeated use of the phrases "in one example", "in one embodiment", or "in one implementation" does not necessarily refer to the same example, embodiment, or implementation, although it may be so referred to.

[0072] As used herein, unless otherwise specified, the use of ordinal adjectives "first," "second," "third," etc. to describe common objects indicates merely that different instances of similar objects are being referenced and is not intended to imply that the objects so described must be in a given order, whether temporally, spatially, in ranking, or in any other manner.

[0073] Although certain embodiments of the disclosed technology have been described in conjunction with what are currently considered to be the most practical and various embodiments, it should be understood that the disclosed technology is not limited to the disclosed embodiments, but rather the disclosed technology is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims. Although specific terms are used herein, they are used in a general and descriptive sense and not for limiting purposes.

[0074] This written description uses examples to disclose certain embodiments of the disclosed technology, including the best mode, and also to enable any person skilled in the art to practice certain embodiments of the disclosed technology, including making and using any devices or systems and performing any incorporated methods. The patentable scope of certain embodiments of the disclosed technology is defined in the claims, and may include other examples that occur to one skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims.

Claims

1. A device comprising: substrate; as well as A BAW resonator is disposed on at least a first surface of the substrate, wherein the substrate comprises one or more grooves configured to impede acoustic energy from flowing toward the BAW resonator.

2. The device according to claim 1, wherein: The BAW resonator includes a BAW gyroscope.

3. The device according to claim 2, further comprising one or more electrodes, wherein: The BAW resonator gyroscope is capacitively transduced via the one or more electrodes.

4. The device according to claim 3, wherein: The one or more electrodes include one or more peripheral electrodes.

5. The apparatus of claim 1, further comprising one or more attachment structures, the attachment structures comprising one or more selected from the group consisting of a soft tube die attach, a hard tube die attach, an adhesive, a stud bump, or an interposer.

6. The device according to claim 1, wherein: The one or more attachment structures are disposed below the substrate.

7. The device according to claim 1, wherein: The first dimension is smaller than a second dimension, the first dimension being defined by a first distance from a first end of the first trench to a second end of the second trench, and the second dimension being defined by a second distance from a third end of the first electrode to a fourth end of the second electrode.

8. The apparatus of claim 2, further comprising an attachment structure comprising one or more selected from the group consisting of a soft tube die attach, a hard tube die attach, an adhesive, a stud bump, or an interposer.

9. The device according to claim 2, wherein: The one or more attachment structures are disposed below the substrate.

10. The device according to claim 2, wherein: The first dimension is smaller than a second dimension, the first dimension being defined by a first distance from a first end of the first trench to a second end of the second trench, and the second dimension being defined by a second distance from a third end of the first electrode to a fourth end of the second electrode.

11. A device comprising: A plurality of equipment components, wherein A first device component selected from the plurality of device components includes a plurality of grooves, and A second device component selected from the plurality of device components is sensitive to acoustic energy, wherein the plurality of grooves are configured to impede the acoustic energy from flowing to the second device component.

12. The device according to claim 11, wherein The second device component is mounted on the first surface of the first device component.

13. The apparatus according to claim 11, further comprising: an attachment structure that is not in direct line of sight of the second equipment component; as well as An underlying support structure is coupled to the first device component via the attachment structure.

14. The device according to claim 11, wherein: The first device component includes a cavity disposed below the second device component, and wherein the second device component includes a bulk acoustic wave resonator.

15. The device according to claim 14, wherein: The BAW resonator performs capacitive transduction via one or more electrodes.

16. A device comprising: substrate; a resonator coupled to the first surface of the substrate, the resonator comprising a BAW resonator gyroscope that is capacitively transduced via one or more electrodes; as well as A cover structure, wherein the cover structure comprises: one or more grooves configured to impede the flow of acoustic energy toward the resonator; and one or more cavities configured to impede the flow of acoustic energy toward the resonator.

17. The apparatus according to claim 16, wherein: At least one groove selected from the one or more grooves is disposed near a corner of the cover structure.

18. The apparatus according to claim 16, wherein: At least one cavity selected from the one or more cavities is disposed in the cover structure at least partially beneath the resonator.

19. The apparatus according to claim 16, wherein: The cover structure is disposed below the substrate.

20. The apparatus of claim 16, wherein: The resonator is coupled to the first surface of the cover structure.

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