JP7662410B2 - Electronic Components - Google Patents

Description

The present invention relates to electronic components.

It is known to seal a functional element in a gap (for example, see Patent Documents 1 to 3). Electronic components are known in which a lid is provided on a frame that surrounds the functional element, and the functional element is sealed in the gap between the lid and the substrate (for example, Patent Document 4). It is known to provide a columnar body between the substrate and the lid in the gap to prevent the lid from bending even when pressure is applied to the lid (for example, Patent Document 5).

JP 2001-102894 A JP 2006-196799 A JP 2018-160829 A JP 2016-152612 A JP 2021-52359 A

However, even when a columnar body is provided between the substrate and the lid as described in Patent Document 5, there is still room for improvement in terms of reducing the deflection of the lid.

The present invention was developed in consideration of the above problems, and aims to reduce lid deflection.

The present invention is an electronic component comprising: a substrate; a functional element provided on the substrate; a frame body provided on the substrate surrounding the functional element in a planar view; a lid provided on the frame body across a gap between the substrate and the lid, sealing the functional element within the gap; a pillar body provided within the gap between the substrate and the lid, supporting the lid against the substrate; a first reinforcing portion provided on the surface of the lid facing the gap, having an elongated shape in a planar view, a longitudinal length in a planar view longer than the length of the pillar body and a height shorter than the height of the pillar body ; and a second reinforcing portion provided on the surface of the lid facing the gap, intersecting the first reinforcing portion, having an elongated shape in a planar view, a longitudinal length in a planar view longer than the length of the pillar body and a height shorter than the height of the pillar body .

In the above configuration, at least one of the first reinforcement portion and the second reinforcement portion is arranged to overlap the columnar body when viewed in a planar view, and the columnar body can be configured to support the lid via at least one of the first reinforcement portion and the second reinforcement portion .

In the above configuration, the lid can be configured to be approximately rectangular in a planar view, and the longitudinal length of the first reinforcement portion and the second reinforcement portion can be more than half the length of the lid in the same direction as the longitudinal direction.

In the above configuration, the frame body can be configured as an approximately rectangular ring having four sides, the first reinforcing portion contacting both of two opposing sides of the frame body , and the second reinforcing portion contacting both of the other two opposing sides of the frame body .

In the above configuration, the first reinforcing portion and the second reinforcing portion may be configured to pass through a center of the lid in a plan view.

In the above configuration, the width of the first reinforcing portion and the second reinforcing portion may be 0.5 to 3 times the length of the columnar body.

In the above configuration, the columnar body may be provided between the substrate and a portion where the first reinforcing portion and the second reinforcing portion intersect .

In the above configuration, the functional element can be an elastic wave element.

In the above configuration, a filter may be formed by the acoustic wave element.

In the above configuration, the filter may form a multiplexer.

The present invention can reduce lid deflection.

FIG. 1A is a plan view of an acoustic wave device in accordance with a first embodiment, and FIG. 1B is a plan view of a lid in the first embodiment. 2A is a cross-sectional view taken along line AA in FIG. 1A, and FIG. 2B is a cross-sectional view taken along line BB in FIG. FIG. 3 is a plan view of the acoustic wave element in the first embodiment. FIG. 4(a) is a circuit diagram of a filter, and FIG. 4(b) is a block diagram of a diplexer. 5A to 5C are cross-sectional views (part 1) illustrating a method for manufacturing the acoustic wave device in accordance with the first embodiment. 6A and 6B are cross-sectional views (part 2) illustrating a method for manufacturing the acoustic wave device in accordance with the first embodiment. 7A to 7C are cross-sectional views of acoustic wave devices according to first to third modified examples of the first embodiment. 8A to 8C are cross-sectional views of acoustic wave devices according to Comparative Examples 1 to 3. FIG. FIG. 9 is a plan view of the model used in the simulation. 10A to 10G are cross-sectional views of models A to G taken along line AA in FIG. 11(a) to 11(c) are plan views of simulated lid models H, I, and J. 12(a) to 12(h) are plan views showing other examples of the columns and reinforcing portions. FIG. 13A is a cross-sectional view of an acoustic wave device in accordance with a second embodiment, and FIG. 13B is a cross-sectional view of an acoustic wave element in the second embodiment.

Below, an embodiment of the present invention will be described with reference to the drawings, using an acoustic wave device as an example of an electronic component.

1(a) is a plan view of an acoustic wave device 100 according to a first embodiment, and FIG. 1(b) is a plan view of a lid 30 in the first embodiment. FIG. 2(a) is a cross-sectional view taken along line A-A in FIG. 1(a), and FIG. 2(b) is a cross-sectional view taken along line B-B in FIG. 1(a). FIG. 1(a) mainly shows a support substrate 10, a piezoelectric layer 12, a via wiring 16, a frame body 18, wiring 20, a columnar body 26, a reinforcing portion 32, and an acoustic wave element 50, as seen through the lid 30. FIG. 1(b) illustrates the reinforcing portion 32, as seen through the lid 30. In FIG. 1(a), the frame body 18, wiring 20, reinforcing portion 32, and acoustic wave element 50 are hatched for clarity. As shown in Figures 1(a), 1(b), 2(a), and 2(b), the acoustic wave device 100 of Example 1 has a piezoelectric layer 12 bonded to the upper surface of a support substrate 10.

The support substrate 10 is, for example, a sapphire substrate, an alumina substrate, a spinel substrate, a quartz substrate, a crystal substrate, a silicon carbide substrate, or a silicon substrate, and has a thickness of 50 μm to 300 μm. The sapphire substrate is a single crystal Al ₂ O ₃ substrate, the alumina substrate is a polycrystalline Al ₂ O ₃ substrate, and the spinel substrate is a single crystal or polycrystalline MgAl ₂ O ₄ substrate. The quartz substrate is an amorphous SiO ₂ substrate, and the crystal substrate is a single crystal SiO ₂ substrate. The silicon carbide substrate is a polycrystalline or single crystal SiC substrate, and the silicon substrate is a single crystal or polycrystalline Si substrate. The linear expansion coefficient of the support substrate 10 is smaller than that of the piezoelectric layer 12. This allows the frequency temperature dependency of the acoustic wave element 50 to be reduced.

The piezoelectric layer 12 is, for example, a single crystal lithium tantalate layer or a single crystal lithium niobate layer, and has a thickness of 0.5 μm to 30 μm. The thickness of the piezoelectric layer 12 is, for example, smaller than the wavelength of the main mode acoustic wave (for example, surface acoustic wave) excited by the acoustic wave element 50. An insulating layer such as silicon oxide, aluminum oxide, and/or aluminum nitride may be provided between the support substrate 10 and the piezoelectric layer 12. In this way, the piezoelectric layer 12 is directly or indirectly bonded to the support substrate 10.

One or more acoustic wave elements 50 are provided on the upper surface of the piezoelectric layer 12. A terminal 14 is provided on the lower surface of the support substrate 10. The terminal 14 is a foot pad for electrically connecting the acoustic wave element 50 to the outside. A via wiring 16 is provided that penetrates the support substrate 10. One end of the via wiring 16 is connected to the terminal 14. The other end of the via wiring 16 is connected to the wiring 20 that extends from the upper surface of the piezoelectric layer 12 to the upper surface of the support substrate 10. As a result, the acoustic wave element 50 is electrically connected to the terminal 14 through the wiring 20 and the via wiring 16. The terminal 14, the via wiring 16, and the wiring 20 are metal layers containing, for example, titanium, copper, aluminum, platinum, nickel, and/or gold. The terminal 14, the via wiring 16, and the wiring 20 may be a single metal layer or a laminated metal layer in which multiple layers are laminated.

The piezoelectric layer 12 is not provided in the peripheral region of the support substrate 10. In a plan view, a frame 18 is provided on the support substrate 10 so as to surround the piezoelectric layer 12 and the acoustic wave element 50. The frame 18 is provided on the support substrate 10 away from the piezoelectric layer 12. The frame 18 is, for example, a metal layer containing copper, kovar, gold, aluminum, and/or tungsten, or a silicon layer, or a resin layer. Kovar is an alloy of iron, nickel, and cobalt. The frame 18 may be a single layer, or multiple layers may be laminated. The height of the frame 18 is, for example, about 15 μm to 30 μm, and the width is, for example, about 10 μm to 40 μm.

The lid 30 is provided on the frame 18 so that a gap 22 is formed between the frame 18 and the support substrate 10. The frame 18 and the lid 30 are joined by a bonding layer such as solder. The acoustic wave element 50 is sealed in the gap 22 by the frame 18 and the lid 30. The lid 30 is made of a metal such as kovar, copper, gold, aluminum, and/or tungsten, or silicon. As mentioned above, kovar is an alloy of iron, nickel, and cobalt. The lid 30 may be a single layer, or multiple layers may be laminated. The thickness of the lid 30 is, for example, about 20 μm to 50 μm.

When the frame body 18 and the lid 30 are made of metal, the frame body 18 may be electrically connected to a ground terminal provided on the underside of the support substrate 10 through a via wiring that penetrates the support substrate 10. This allows a ground potential to be supplied to the frame body 18, thereby providing a shielding effect to the frame body 18 and the lid 30. Furthermore, when the frame body 18 and the lid 30 are made of metal, the acoustic wave element 50 can be hermetically sealed within the gap 22. Note that the frame body 18 and the lid 30 are not electrically connected to the acoustic wave element 50 on the support substrate 10.

The piezoelectric layer 12 has an opening 24 located near the center of the lid 30 and penetrating from the upper surface to the lower surface. In the opening 24, for example, the upper surface of the support substrate 10 is exposed. In the opening 24, a columnar body 26 is located near the center of the lid 30 between the support substrate 10 and the lid 30 and supports the lid 30 relative to the support substrate 10. The columnar body 26 is located in the gap 22, is provided away from the piezoelectric layer 12, and is in contact with the upper surface of the support substrate 10, for example. The columnar body 26 is, for example, a metal layer containing copper, kovar, gold, aluminum, and/or tungsten, or a silicon layer, or a resin layer. The columnar body 26 may be a single layer, or may be a laminate of multiple layers. In the first embodiment, the height of the columnar body 26 is lower than the height of the frame body 18, for example, about 10 μm to 25 μm, and the width of the columnar body 26 is larger than the width of the frame body 18, for example, about 30 μm to 60 μm. The number of pillars 26 provided between the support substrate 10 and the lid 30 is not limited to one, and two or more pillars may be provided.

A reinforcing portion 32 having an elongated shape is provided on the underside of the lid 30. The reinforcing portion 32 is, for example, bonded to the underside of the lid 30, or is formed by integral molding with the lid 30. In the first embodiment, the reinforcing portion 32 extends linearly in the longitudinal and lateral directions of the lid 30, which is substantially rectangular in plan view, and is provided on a line connecting the centers of the opposing sides of the lid 30, and is in contact with both side surfaces of the opposing sides of the frame body 18, which is substantially rectangular and annular and has four sides. Therefore, the two reinforcing portions 32 pass through the center 34 of the lid 30 in plan view and intersect at the center 34. A columnar body 26 is disposed at the point where the two reinforcing portions 32 intersect. Therefore, the reinforcing portion 32 overlaps with the columnar body 26 in plan view, and the columnar body 26 supports the lid 30 via the reinforcing portion 32. The reinforcing portion 32 and the columnar body 26 may be bonded by a bonding layer such as solder, or may be in contact without being bonded. The reinforcement section 32 has an elongated shape with its length measured along its longitudinal direction and its width measured along its lateral direction.

The reinforcing portion 32 is, for example, a metal layer containing copper, kovar, gold, aluminum, and/or tungsten, or a silicon layer, or a resin layer. The reinforcing portion 32 may be made of the same material as the lid 30, or may be made of a different material. When the lid 30 and the reinforcing portion 32 are made of the same material, they can be manufactured by integral molding. When the lid 30 and the reinforcing portion 32 are made of different materials, appropriate materials can be selected according to the usage situation and/or usage purpose. The height of the reinforcing portion 32 is lower than the height of the columnar body 26, for example, about 2 μm to 5 μm. The width of the reinforcing portion 32 is, for example, approximately the same as the width of the columnar body 26, for example, 30 μm to 60 μm. The term "approximately the same" here means that differences of the order of manufacturing error are allowed.

3 is a plan view of the acoustic wave element 50 in the first embodiment. As shown in FIG. 3, the acoustic wave element 50 is a surface acoustic wave resonator. An IDT (Interdigital Transducer) 51 and a reflector 52 are provided on the upper surface of the piezoelectric layer 12. The IDT 51 has a pair of opposing comb electrodes 53. The comb electrode 53 has a plurality of electrode fingers 54 and a bus bar 55 to which the plurality of electrode fingers 54 are connected. The reflectors 52 are provided on both sides of the IDT 51. The IDT 51 excites a surface acoustic wave in the piezoelectric layer 12. The pitch of the electrode fingers 54 of one of the pair of comb electrodes 53 is approximately the wavelength λ of the acoustic wave. The pitch D of the plurality of electrode fingers 54 is twice the pitch of one of the comb electrodes 53. The IDT 51 and the reflector 52 are formed of a metal film such as aluminum, copper, or molybdenum. A protective film or a temperature compensation film covering the IDT 51 and the reflector 52 may be provided on the upper surface of the piezoelectric layer 12. The comb electrode 53 may have dummy electrode fingers.

A filter or a duplexer may be formed by a plurality of acoustic wave elements 50 formed on the upper surface of the piezoelectric layer 12. FIG. 4(a) is a circuit diagram of a filter, and FIG. 4(b) is a block diagram of a diplexer.

As shown in FIG. 4(a), one or more series resonators S1 to S4 are connected in series between the input terminal Tin and the output terminal Tout. One or more parallel resonators P1 and P2 are connected in parallel between the input terminal Tin and the output terminal Tout. The series resonators S1 to S4 and the parallel resonators P1 and P2 form the acoustic wave element 50. The number of series resonators and parallel resonators can be set as appropriate. Although a ladder-type filter has been described as an example of the filter, the filter may also be a multimode filter.

As shown in FIG. 4(b), a transmission filter 60 is connected between the common terminal Ant and the transmission terminal Tx. A reception filter 62 is connected between the common terminal Ant and the reception terminal Rx. The transmission filter 60 passes the transmission band signal among the high frequency signals input from the transmission terminal Tx to the common terminal Ant as a transmission signal, and suppresses signals of other frequencies. The reception filter 62 passes the reception band signal among the high frequency signals input from the common terminal Ant to the reception terminal Rx as a reception signal, and suppresses signals of other frequencies. Note that although a duplexer is shown as an example of a multiplexer, a triplexer or a quadplexer may also be used.

In FIG. 1, two ladder-type filters 64 are formed by multiple acoustic wave elements 50. One of the two ladder-type filters 64 is a transmit filter 60, and the other is a receive filter 62.

[Production method]
5(a) to 6(b) are cross-sectional views showing a method for manufacturing the acoustic wave device 100 according to the first embodiment. As shown in FIG. 5(a), a via hole is formed on the upper surface of the support substrate 10 by irradiating the upper surface with, for example, a laser beam, and a metal layer such as copper is formed in the via hole by, for example, electrolytic plating. Then, the upper surface of the metal layer is planarized by, for example, CMP (Chemical Mechanical Polishing) so that the upper surface of the support substrate 10 is exposed. As a result, a via wiring 16 is formed in the support substrate 10. Next, a piezoelectric substrate is bonded to the upper surface of the support substrate 10 at room temperature by, for example, a surface activation method. The support substrate 10 and the piezoelectric substrate may be directly bonded via an amorphous layer of several nm, or may be indirectly bonded via an insulating layer. Then, the upper surface of the piezoelectric substrate is polished by, for example, CMP. As a result, a piezoelectric layer 12 is formed that is directly or indirectly bonded to the upper surface of the support substrate 10.

As shown in FIG. 5(b), a portion of the piezoelectric layer 12 is removed, for example, by etching. This removes the piezoelectric layer 12 from the peripheral region of the support substrate 10, exposing the via wiring 16. An opening 24 is also formed in the piezoelectric layer 12. For example, the upper surface of the support substrate 10 is exposed in the opening 24. Next, an acoustic wave element 50 is formed on the upper surface of the piezoelectric layer 12. A wiring 20 is formed that extends from the upper surface of the piezoelectric layer 12 to the via wiring 16 and electrically connects the acoustic wave element 50 and the via wiring 16.

As shown in FIG. 5(c), a frame 18 that surrounds the acoustic wave element 50 and the piezoelectric layer 12, and a columnar body 26 in an opening 24 formed in the piezoelectric layer 12 are formed on the support substrate 10. The frame 18 and the columnar body 26 are formed, for example, by electrolytic plating.

As shown in FIG. 6(a), a lid 30 provided with a reinforcing portion 32 is prepared, the reinforcing portion 32 is aligned so as to overlap with the columnar body 26, and the lid 30 is joined to the frame body 18 with a bonding layer such as solder. The reinforcing portion 32 and the columnar body 26 may be joined with a bonding layer such as solder, or may be in contact without being joined.

As shown in FIG. 6B, the bottom surface of the support substrate 10 is polished, for example, by CMP. This exposes the via wiring 16 from the bottom surface of the support substrate 10. Next, terminals 14 that connect to the via wiring 16 are formed on the bottom surface of the support substrate 10. In this manner, the acoustic wave device 100 according to the first embodiment is manufactured.

[Modification]
7(a) to 7(c) are cross-sectional views of acoustic wave devices 110 to 130 according to Modifications 1 to 3 of the first embodiment. FIGS. 7(a) to 7(c) are cross-sectional views of a portion corresponding to the B-B portion of FIG. 1(a). As shown in FIG. 7(a), in the acoustic wave device 110 according to Modification 1, the reinforcing portion 32 is inserted between the lid 30 and the frame 18, and the side surface of the reinforcing portion 32 perpendicular to the extension direction of the reinforcing portion 32 is flush with the side surface of the lid 30 and the outer surface of the frame 18. The side surface of the reinforcing portion 32 may be located between the inner surface and the outer surface of the frame 18, or may be located outside the outer surface of the frame 18. The other configurations are the same as those of the acoustic wave device 100 according to the first embodiment, and therefore will not be described.

As shown in FIG. 7(b), in the acoustic wave device 120 of the second modified example, the reinforcing portion 32 is not in contact with the frame body 18, and the side surface of the reinforcing portion 32 perpendicular to the extension direction of the reinforcing portion 32 is located closer to the frame body 18 than half the distance between the columnar body 26 and the frame body 18. Therefore, the length between the opposing sides of the lid 30 of the reinforcing portion 32 is at least half the distance between the opposing sides. The rest of the configuration is the same as that of the acoustic wave device 100 of the first embodiment, so a description thereof will be omitted.

As shown in FIG. 7(c), in the acoustic wave device 130 of the third modification, the side surface of the reinforcing portion 32 perpendicular to the extension direction of the reinforcing portion 32 is located closer to the columnar body 26 than half the distance between the columnar body 26 and the frame body 18. The rest of the configuration is the same as that of the acoustic wave device 100 of the first embodiment, so a description thereof will be omitted.

[Comparative Example]
8(a) to 8(c) are cross-sectional views of acoustic wave devices 500 to 520 according to Comparative Examples 1 to 3. FIGS. 8(a) to 8(c) are cross-sectional views of a portion corresponding to B-B in FIG. 1(a). As shown in FIG. 8(a), in the acoustic wave device 500 according to Comparative Example 1, the lid 30 is not provided with a reinforcing portion 32, and the pillar-shaped body 26 is not provided between the support substrate 10 and the lid 30 within the gap 22. The other configurations are the same as those of the acoustic wave device 100 according to Example 1, and therefore description thereof will be omitted.

As shown in FIG. 8(b), in the acoustic wave device 510 of Comparative Example 2, no pillars 26 are provided between the support substrate 10 and the lid 30 within the gap 22. The reinforcing portion 32 provided on the lid 30 is inserted between the lid 30 and the frame 18, as in the acoustic wave device 110 of Modification Example 1. The rest of the configuration is the same as that of the acoustic wave device 100 of Example 1, so a description thereof will be omitted.

As shown in FIG. 8(c), in the acoustic wave device 520 of Comparative Example 3, the reinforcing portion 32 is not provided on the lid 30. The pillars 26 are approximately the same height as the frame 18 and are provided between the support substrate 10 and the lid 30 within the gap 22. The rest of the configuration is the same as that of the acoustic wave device of Example 1, so a description thereof will be omitted.

[Simulation 1]
The deformation amount of the lid 30 when a uniform external force is applied to the upper surface of the lid 30 was simulated. Fig. 9 is a plan view of a model used in the simulation. Figs. 10(a) to 10(g) are cross-sectional views of models A to G taken along the line A-A in Fig. 9. Note that Fig. 9 illustrates model A in Fig. 10(a) as an example, but models B to G in Figs. 10(b) to 10(g) are the same except for the presence or absence and shape of the reinforcing portion 32 and the presence or absence of the columnar body 26. The normal direction of the lid 30 is the Z direction, and the side directions of the lid 30 are the X direction and the Y direction.

As shown in FIG. 9, the simulation was performed using a 1/4 symmetrical model of the lid 30. That is, the frame 18 is not provided on the +X side surface and the -Y side surface of the lid 30, and the boundary conditions of these surfaces are mirror conditions. The lengths of the lid 30 in the X direction and the Y direction are D1 and D2. The width of the frame 18 is D3. The length of the columnar body 26 and the width of the reinforcing part 32 are D4. As shown in FIG. 10(a) to FIG. 10(g), the thickness of the lid 30 is T1, and the thickness of the reinforcing part 32 is T2. In the models A, C, D, E, and G of FIG. 10(a), FIG. 10(c), FIG. 10(d), FIG. 10(e), and FIG. 10(g), the thickness of the frame 18 is T3. In the models B and F of FIG. 10(b) and FIG. 10(f), the thickness of the frame 18 is T3'. In models A, B, C, and D of Figures 10(a), 10(b), 10(c), and 10(d), the thickness of the columnar body 26 is T4. In model G of Figure 10(g), the thickness of the columnar body 26 is T4'. In model C of Figure 10(c), the distance between the reinforcing portion 32 and the frame body 18 is W1. In model D of Figure 10(d), the distance between the reinforcing portion 32 and the frame body 18 is W2.

Model A in FIG. 10(a) corresponds to Example 1, Model B in FIG. 10(b) corresponds to Variation 1 of Example 1, Model C in FIG. 10(c) corresponds to Variation 2 of Example 1, and Model D in FIG. 10(d) corresponds to Variation 3 of Example 1. Model E in FIG. 10(e) corresponds to Comparative Example 1, Model F in FIG. 10(f) corresponds to Comparative Example 2, and Model G in FIG. 10(g) corresponds to Comparative Example 3.

The simulation conditions are as follows.
Lid 30: Kovar Frame 18: Copper (Cu)
Column 26: Copper (Cu)
Reinforcement portion 32: Kovar D1: 442 μm
D2: 542 μm
D3: 23 μm
D4: 23 μm
T1: 30 μm
T2: 4 μm
T3: 20.5 μm
T3': 16.5 μm
T4: 16.5 μm
T4': 20.5 μm
W1: 5 μm
W2: 390 μm

Table 1 shows the Young's modulus, Poisson's ratio, bulk modulus, and shear modulus of the materials used in the simulation.

To estimate the deformation of the lid 30, we assumed that the bottom surfaces of the frame 18 and the columnar body 26 were fixed to immovable objects, and simulated the maximum displacement of the bottom surface of the lid 30 when a force of 6 MPa was applied uniformly to the entire top surface of the lid 30 in this state.

Table 2 shows the simulation results. As shown in Table 2, in model G corresponding to comparative example 3, the maximum displacement of the lid 30 was significantly reduced compared to model E corresponding to comparative example 1 due to the provision of the pillars 26. However, in models A to D corresponding to example 1 to modified example 3 of example 1 in which the reinforcing portion 32 was provided in addition to the pillars 26, the maximum displacement of the lid 30 was further reduced compared to model G. Note that in model F corresponding to comparative example 2 in which only the reinforcing portion 32 was provided without the pillars 26, the maximum displacement of the lid 30 was hardly reduced. From this, it can be seen that the maximum displacement of the lid 30 can be reduced by providing both the pillars 26 and the reinforcing portion 32.

[Simulation 2]
11(a) to 11(c) are plan views of simulated models H, I, and J of the lid 30. Although Fig. 11(a) to 11(c) show plan views of the entire lid 30, the simulation was performed using a 1/4 symmetrical model of the lid 30, as in simulation 1 in Fig. 9.

As shown in FIG. 11(a), model H is a model corresponding to a modified example of Example 1 in which three reinforcing parts 32 are provided. One of the three reinforcing parts 32 extends between opposing sides in the longitudinal direction of the lid 30, positioned on a line connecting the bisecting points of each side, and is provided so as to overlap with the columnar body 26. The remaining two of the three reinforcing parts 32 extend between opposing sides in the lateral direction of the lid 30, positioned on a line connecting the trisecting points of each side.

As shown in FIG. 11(b), model I is a model corresponding to a modified example of example 1 in which four reinforcing parts 32 are provided. Two of the four reinforcing parts 32 extend between opposing sides in the longitudinal direction of the lid 30, positioned on a line connecting the third dividing point of each side. The remaining two of the four reinforcing parts 32 extend between opposing sides in the lateral direction of the lid 30, positioned on a line connecting the third dividing point of each side. All four reinforcing parts 32 are provided without overlapping with the columnar body 26.

As shown in FIG. 11(c), model J is a model that does not have a reinforcing portion 32 and corresponds to comparative example 3.

The simulation conditions were the same as in Simulation 1 above, except that the length of the pillars 26 and the width D4 of the reinforcing portion 32 were 12.5 μm. The Young's modulus, Poisson's ratio, bulk modulus, and shear modulus of elasticity of the materials used in the simulation were the values in Table 1. As with Simulation 1 above, the deformation amount of the lid 30 was simulated by assuming that the bottom surfaces of the frame 18 and pillars 26 were fixed to immovable fixed objects, and the maximum displacement of the bottom surface of the lid 30 when a force of 6 MPa was applied uniformly to the entire top surface of the lid 30 in this state.

The simulation results are shown in Table 3. As shown in Table 3, in models H and I provided with reinforcing parts 32 and columns 26, the maximum displacement of the lid 30 was reduced compared to model J provided with columns 26 alone, both in the case where the columns 26 supported the lid 30 via the reinforcing parts 32 (model H) and in the case where the columns 26 supported the lid 30 without the reinforcing parts 32 (model I). From the viewpoint of reducing the maximum displacement of the lid 30, the results showed that it was preferable for the reinforcing parts 32 to be provided overlapping the columns 26, and for the columns 26 to support the lid 30 via the reinforcing parts 32.

According to Example 1 and its modified example, a pillar 26 is provided between the support substrate 10 and the lid 30 in the gap 22 to support the lid 30 relative to the support substrate 10. A reinforcing portion 32 having an elongated shape in a plan view and a length longer than the length of the pillar 26 is provided on the surface of the lid 30 facing the gap 22. As a result, as shown in the results of Simulations 1 and 2 above, even if an external force is applied to the lid 30, the deflection of the lid 30 can be reduced.

When the overall thickness of the lid 30 is increased in an attempt to reduce the bending of the lid 30, the distance between the lid 30 and the acoustic wave element 50 is reduced, which may result in electrical coupling and degradation of the characteristics. However, in the first embodiment and its modified example, the lid 30 is simply provided with an elongated reinforcing portion 32, which prevents the distance between the lid 30 and the reinforcing portion 32 and the acoustic wave element 50 from being reduced, thereby preventing degradation of the characteristics.

It is preferable that the reinforcing portion 32 overlaps with the columnar body 26 in a plan view, and the columnar body 26 supports the lid 30 via the reinforcing portion 32. This makes it possible to effectively reduce the deflection of the lid 30, as shown in the results of Simulation 2 above.

It is preferable that the reinforcing portion 32 has an elongated shape in which the length between the opposing sides of the lid 30, which is approximately rectangular in plan view, is at least half the distance between the opposing sides. In other words, it is preferable that the longitudinal length of the reinforcing portion 32 is at least half the length of the lid 30 in the same direction as the longitudinal direction. This makes it possible to effectively reduce the deflection of the lid 30, as shown in the results of Simulation 1 above. In terms of reducing the deflection of the lid 30, it is preferable that the longitudinal length of the reinforcing portion 32 is at least 2/3 the length of the lid 30 in the same direction as the longitudinal direction, and more preferably at least 3/4.

In order to reduce the deflection of the lid 30, the reinforcing portion 32 is preferably in contact with both opposing sides of the frame 18, which is an approximately rectangular ring-shaped frame, and may be inserted between the frame 18 and the lid 30.

It is preferable that the reinforcing portion 32 is provided through the center of the lid 30 in a plan view. This makes it possible to effectively reduce the deflection of the lid 30. Here, the center of the lid 30 corresponds to the center of gravity when the lid 30 is observed in a plan view.

In order to reduce the deflection of the lid 30, the width of the reinforcing portion 32 is preferably 0.5 times or more, more preferably 1 time or more, and even more preferably 1.5 times or more, the length of the columnar body 26. The width of the reinforcing portion 32 is preferably 1/30 or more, more preferably 1/20 or more, and even more preferably 1/15 or more of the narrower distance between the two pairs of opposing sides of the lid 30. On the other hand, as the width of the reinforcing portion 32 increases, the distance between the reinforcing portion 32 and the elastic wave element 50 tends to become closer, so the width of the reinforcing portion 32 is preferably 3 times or less, more preferably 2.5 times or less, and even more preferably 2 times or less, the length of the columnar body 26. The width of the reinforcing portion 32 is preferably 1/6 or less, more preferably 1/8 or less, and even more preferably 1/10 or less, the narrower distance between the two pairs of opposing sides of the lid 30. It is preferable that the width of the reinforcing portion 32 is approximately the same as the length of the columnar body 26. "Approximately the same" means that a difference of the order of manufacturing error is allowed. The length of the columnar body 26 refers to the length in the longitudinal direction when the columnar body 26 has a short side direction and a long side direction in a plan view.

To prevent the distance between the reinforcing portion 32 and the elastic wave element 50 from becoming too close, the height of the reinforcing portion 32 is preferably 1/2 or less of the distance between the lid 30 and the piezoelectric layer 12, more preferably 1/3 or less, and even more preferably 1/4 or less. In order to reduce the deflection of the lid 30, the height of the reinforcing portion 32 is preferably 1/10 or more of the distance between the lid 30 and the piezoelectric layer 12, more preferably 1/8 or more, and even more preferably 1/5 or more.

It is preferable that the lid 30, the columns 26, and the reinforcing portion 32 are formed mainly from metal or silicon. This can prevent the lid 30 from bending. Being mainly composed means that the ratio of metal or silicon to the total of the elements contained in the lid 30, the columns 26, and the reinforcing portion 32 is 50 at% (atomic percent) or more, and may be 80 at% or more.

In the first embodiment, the pillar 26 is provided at the center 34 of the lid 30, and the reinforcing portion 32 is provided between the central portions of the opposing sides of the lid 30, extending linearly in the longitudinal and lateral directions of the lid 30, but this is not limited to the above case. FIGS. 12(a) to 12(h) are plan views showing other examples of the pillar 26 and the reinforcing portion 32. As shown in FIG. 12(a), the reinforcing portion 32 may be provided extending only in the longitudinal direction of the lid 30. As shown in FIG. 12(b), the reinforcing portion 32 may be provided with one extending in the longitudinal direction of the lid 30 and two extending in the lateral direction, as in model H of the above simulation 2. As shown in FIG. 12(c), the reinforcing portion 32 may be provided with two extending in each of the longitudinal and lateral directions of the lid 30, as in model I of the above simulation 2.

As shown in FIG. 12(d), the reinforcing portion 32 may be provided only in the longitudinal direction of the lid 30, and two pillars 26 may be provided point-symmetrically with respect to the center 34 of the lid 30 on a line connecting the centers of the sides facing each other in the longitudinal direction of the lid 30. Even if two pillars 26 are provided point-symmetrically with respect to the center 34 of the lid 30, as shown in FIG. 12(e), the reinforcing portion 32 may be provided so that one extends in each of the longitudinal and lateral directions of the lid 30. As shown in FIG. 12(f), the reinforcing portion 32 may be provided so that one extends in the longitudinal direction of the lid 30 and two extend in the lateral direction. As shown in FIG. 12(g), the reinforcing portion 32 may be provided so that two extend in each of the longitudinal and lateral directions of the lid 30. Also, as shown in FIG. 12(h), the reinforcing portion 32 may be provided so that it extends on the diagonal line of the lid 30. The reinforcing portion 32 may be interrupted midway along the extension direction.

The pillars 26 are preferably located on a line connecting the centers of the opposing sides in the longitudinal direction of the lid 30, on a line connecting the centers of the opposing sides in the lateral direction, or on a diagonal line. When only one pillar 26 is provided, it is preferably provided at the center 34 of the lid 30, and when multiple pillars 26 are provided, it is preferably provided approximately point-symmetrically with respect to the center 34 of the lid 30. The reinforcing portion 32 is preferably provided linearly through the center 34 of the lid 30 in a plan view and/or approximately point-symmetrically with respect to the center 34 of the lid 30. The reinforcing portion 32 is not limited to being provided in a straight line, and may be provided in a curved line. Approximately point-symmetrical is not limited to being in a completely point-symmetrical position, but allows for a deviation from the point-symmetrical position to an extent that the deflection of the lid 30 can be effectively reduced.

In the first embodiment, the piezoelectric layer 12 is provided on the support substrate 10, but the piezoelectric layer 12 may be a thick piezoelectric substrate without the support substrate 10.

13(a) is a cross-sectional view of an acoustic wave device 200 according to a second embodiment, and FIG. 13(b) is a cross-sectional view of an acoustic wave element 50a in the second embodiment. As shown in FIG. 13(a) and FIG. 13(b), in the acoustic wave device 200 of the second embodiment, an acoustic wave element 50a is provided on a support substrate 10 instead of an acoustic wave element 50. The acoustic wave element 50a is a piezoelectric thin film resonator. The acoustic wave element 50a includes a piezoelectric layer 72 provided on the support substrate 10, and a lower electrode 70 and an upper electrode 74 sandwiching the piezoelectric layer 72. A gap 76 is formed between the lower electrode 70 and the support substrate 10. The region where the lower electrode 70 and the upper electrode 74 face each other, sandwiching at least a portion of the piezoelectric layer 72, is a resonance region 78. In the resonance region 78, the lower electrode 70 and the upper electrode 74 excite an acoustic wave in a thickness longitudinal vibration mode in the piezoelectric layer 72. In addition, an insertion film may be inserted in the outer peripheral region of the resonance region 78 of the piezoelectric layer 72 to increase the Q value or for temperature compensation.

The lower electrode 70 and the upper electrode 74 are metal films, for example, including a ruthenium film. The piezoelectric layer 72 is, for example, an aluminum nitride layer or a zinc oxide layer. An acoustic reflection film that reflects elastic waves may be provided instead of the gap 76. The elastic wave element 50a is manufactured by a commonly known method.

As in Example 1, the functional element provided on the support substrate 10 may be an elastic wave element 50 including a comb-shaped electrode 53 provided on a piezoelectric layer 12 that is a single crystal lithium tantalate layer or a single crystal lithium niobate layer. As in Example 2, the functional element may be an elastic wave element 50a that is a piezoelectric thin film resonator in which a lower electrode 70 and an upper electrode 74 are provided with a piezoelectric layer 72 sandwiched therebetween. The functional element may also be something other than an elastic wave element, such as a piezoelectric element such as a MEMS (Micro Electro Mechanical System) element, or something else.

Although the embodiment of the present invention has been described in detail above, the present invention is not limited to such a specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention as described in the claims.

REFERENCE SIGNS LIST 10 Support substrate 12 Piezoelectric layer 14 Terminal 16 Via wiring 18 Frame body 20 Wiring 22 Air gap 24 Opening 26 Column body 30 Lid 32 Reinforcement portion 34 Center 50, 50a Elastic wave resonator 51 IDT
52 reflector 53 comb-shaped electrode 54 electrode finger 55 bus bar 60 transmission filter 62 reception filter 64 ladder filter 70 lower electrode 72 piezoelectric layer 74 upper electrode 76 gap 78 resonance region 100, 110, 120, 130, 200, 500, 510, 520 acoustic wave device

Claims (10)

A substrate;
A functional element provided on the substrate;
a frame provided on the substrate so as to surround the functional element in a plan view;
a lid that is provided on the frame with a gap between the substrate and the lid and seals the functional element in the gap;
a pillar-shaped member provided in the gap between the substrate and the lid, the pillar-shaped member supporting the lid relative to the substrate;
a first reinforcing part provided on a surface of the lid facing the gap, the first reinforcing part having an elongated shape in a plan view, the length of the first reinforcing part in a longitudinal direction in a plan view being longer than the length of the columnar body and the height of the first reinforcing part being shorter than the height of the columnar body ;
an electronic component comprising: a second reinforcing portion that is provided on the gap-side surface of the lid so as to intersect with the first reinforcing portion, has an elongated shape in a planar view, has a longitudinal length in a planar view that is longer than the length of the columnar body, and has a height that is shorter than the height of the columnar body . At least one of the first reinforcing portion and the second reinforcing portion is provided so as to overlap with the columnar body in a plan view,
The electronic component according to claim 1 , wherein the columnar body supports the lid via at least one of the first reinforcing portion and the second reinforcing portion . The lid has a substantially rectangular shape in a plan view,
3 . The electronic component according to claim 1 , wherein a length in a longitudinal direction of the first reinforcing portion and the second reinforcing portion is equal to or greater than half a length of the lid in the same direction as the longitudinal direction. The frame is annular and has a substantially rectangular shape having four sides,
The first reinforcing portion is in contact with both of two opposing sides of the frame body ,
The electronic component according to claim 1 , wherein the second reinforcing portion is in contact with both of the other two opposing sides of the frame . The electronic component according to claim 1 , wherein the first reinforcing portion and the second reinforcing portion are provided passing through a center of the lid in a plan view. The electronic component according to claim 1 , wherein a width of the first reinforcing portion and the second reinforcing portion is 0.5 to 3 times a length of the columnar body. The electronic component according to claim 1 , wherein the columnar body is provided between the substrate and a portion where the first reinforcing portion and the second reinforcing portion intersect . The electronic component according to any one of claims 1 to 7, wherein the functional element is an acoustic wave element. The electronic component according to claim 8, wherein the acoustic wave element forms a filter. The electronic component according to claim 9, wherein the filter forms a multiplexer.

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