Structure

Abstract

To improve heat radiation properties in a structure to which high power is input.SOLUTION: A structure (1) has a substrate (10), first wiring (41) and second wiring (42) that are provided directly or indirectly on a surface (11) of the substrate, and a heat radiation member (50) that is separated from and faces the surface above the surface. The heat radiation member includes a non-conducting material, and is in direct or indirect contact with the first wiring and second wiring.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to structures. [Background technology]

[0002] As structures such as acoustic wave devices become increasingly powerful, they tend to generate more heat. If the amount of heat generated is significant, the electrical characteristics of the acoustic wave device may change and the power resistance may decrease. As a result, the acoustic wave device may be destroyed.

[0003] Patent Document 1 discloses an acoustic wave device in which heat dissipation is promoted by a thermally conductive material layer formed on the electrodes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2016 / 017308 Summary of the Invention [Problem to be solved by the invention]

[0005] There is a demand for improved heat dissipation performance in structures into which high power is input.

[0006] One aspect of the present disclosure aims to improve the heat dissipation performance in a structure to which high power is input. [Means for solving the problem]

[0007] In order to solve the above problems, the structure disclosed herein comprises a substrate, a first wiring and a second wiring provided directly or indirectly on a surface of the substrate, and a heat dissipation member above the surface, spaced apart from and facing the surface, the heat dissipation member including a non-conductive material and directly or indirectly contacting the first wiring and the second wiring. Effect of the Invention

[0008] According to the present disclosure, a structure with high heat dissipation performance can be obtained.

[0009] According to one aspect of the present disclosure, even when high power is input to a structure, heat can be sufficiently dissipated, and power resistance performance is improved. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing the structure of a structure according to a first embodiment. [Diagram 2] 1 is a cross-sectional view illustrating a structure of a chip in an elastic wave device in accordance with a first embodiment. [Diagram 3] FIG. 2 is a plan view of a structure serving as an elastic wave device. [Figure 4] FIG. 2 is a plan view of a structure serving as an elastic wave device from which a heat dissipation member has been removed. [Diagram 5] FIG. 11 is a diagram showing the heat distribution in a comparative example in which the heat dissipation member is removed from the structure. [Figure 6] 11 is a cross-sectional view showing the structure of a structure in which a heat dissipation member according to a second embodiment contacts a bump at one point. FIG. [Figure 7] 11 is a cross-sectional view showing the structure of a structure according to a third embodiment in which a heat dissipation member contacts bumps at multiple points. FIG. [Figure 8] 11 is a cross-sectional view illustrating the structure of a chip in an elastic wave device according to a third embodiment. FIG. [Figure 9] 1A to 1C are schematic diagrams illustrating a method for manufacturing a structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] [Embodiment 1] Hereinafter, an embodiment according to one aspect of the present disclosure (hereinafter also referred to as "the present embodiment") will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and their description will not be repeated.

[0012] (Structure 1) 1 is a cross-sectional view showing the structure of a structure 1 according to embodiment 1. The structure 1 includes a substrate 10, an electrode 20, a protective film 30, a thick film wiring 40, a heat dissipation member 50, a bump 60, and a solder ball 70.

[0013] The substrate 10 has a piezoelectric body, and is, for example, a single plate of a piezoelectric body such as lithium tantalate (LT) or lithium niobate (LN). The substrate 10 is not limited to a single plate of a piezoelectric body, and may be a substrate in which SiO2 and Si are laminated and a piezoelectric body is added, or a substrate in which a multi-layer structure of SiO2 and HfO2 and Si are laminated and a piezoelectric body is added. The thickness of the substrate 10 is about 100 to 250 μm.

[0014] The electrode 20 is an electrode provided directly on the surface 11 of the substrate 10, and may be an IDT (Interdigital Transducer) electrode. The electrode 20 is an Al-Cu alloy (Cu: about 1%). The electrode 20 may be a laminated electrode containing Ti or the like as a base layer. The electrode 20 may be indirectly provided on the surface 11 of the substrate 10 via a layer made of various dielectric materials or the like.

[0015] The protective film 30 reduces the risk of the electrode 20 peeling off from the substrate 10. Alternatively, the protective film 30 reduces the risk of corrosion of the electrode 20. Examples of the protective film include silicon oxide, silicon nitride, and tantalum pentoxide.

[0016] The thick film wiring 40 is a thick film made of Al and formed on the electrode 20. The thickness of the thick film wiring 40 is about 3 μm.

[0017] The heat dissipation member 50 is a member joined to the thick film wiring 40 and includes a non-conductive material. The heat dissipation member 50 also includes a material with a higher thermal conductivity than the piezoelectric body. The heat dissipation member 50 includes, for example, any of silicon, alumina, sapphire, aluminum nitride, diamond, aluminum nitride doped with scandium, silicon oxide, and silicon nitride. The thickness of the heat dissipation member 50 is about 20 μm.

[0018] The bumps 60 are provided in plurality and are formed on the thick film wiring 40. In addition, solder balls 70 are placed on the bumps 60.

[0019] (Structure as an Elastic Wave Device 1) Next, a case where the structure 1 is an acoustic wave device will be described. That is, an IDT electrode 21 is formed on the electrode 20.

[0020] The thick film wiring 40 includes a first wiring 41 and a second wiring 42. The first wiring 41 and the second wiring 42 are formed on the upper surface of the electrode 20, that is, are indirectly provided on the surface 11 of the substrate 10. In addition, the first wiring 41 and the second wiring 42 are not limited to being indirectly provided on the surface 11 of the substrate 10, and may be directly provided on the surface 11 of the substrate 10.

[0021] The first wiring 41 and the second wiring 42 are connected to the first comb-tooth electrode 21a and the second comb-tooth electrode 21b, respectively, that constitute the IDT electrode 21. That is, the first wiring 41 is connected to the first comb-tooth electrode 21a, and the second wiring 42 is connected to the second comb-tooth electrode 21b. As a result, the IDT electrode 21 is located between the first wiring 41 and the second wiring 42.

[0022] The heat dissipation member 50 is in direct or indirect contact with the first wiring 41 and the second wiring 42. This allows the heat in the first wiring 41 and the second wiring 42 to be transferred to the heat dissipation member 50 and dissipated by the heat dissipation member 50.

[0023] The first wiring 41 is connected to any one of the plurality of bumps 60. The second wiring 42 is not connected to any one of the plurality of bumps 60.

[0024] Here, the first wiring 41 has a high heat dissipation performance because it has a heat capacity including the bump 60. Also, the first wiring 41 has a high heat dissipation performance because it can dissipate heat to the outside via the bump 60. In contrast, even though the second wiring 42 is not connected to the bump 60, almost the same energy as that input to the first wiring 41 is input to the second wiring 42. Therefore, the second wiring 42 is more likely to become hotter than the first wiring 41.

[0025] The thick film wiring 40 may further include a third wiring 43. The heat dissipation member 50 is in contact with the third wiring 43 directly or indirectly.

[0026] The first wiring 41 is a thick-film wiring 40 directly or indirectly connected to a transmitting terminal 61 described later. The third wiring 43 is a thick-film wiring 40 directly or indirectly connected to a receiving terminal 62 described later.

[0027] Generally, higher power is applied to the transmitting terminal 61 than to the receiving terminal 62, so the IDT electrode 21 and the like are more likely to generate heat.

[0028] Furthermore, the heat dissipation member 50 is located above the surface 11 of the substrate 10 and faces the surface 11 at a distance. That is, the heat dissipation member 50 overlaps the IDT electrode 21 in a plan view, and a gap exists between the heat dissipation member 50 and the electrode 20 which is the IDT electrode. Therefore, the heat dissipation member 50 is unlikely to inhibit the vibration of the IDT electrode 21. Even if the heat dissipation member 50 is provided, if the heat dissipation member 50 is made of a material that has a small electromagnetic field effect, the effect on the vibration characteristics (resonator characteristics) of the electrode 20 can be reduced.

[0029] (Structure of Chip 2 of Acoustic Wave Device) The following describes the case where electrode 20 is an IDT electrode 21, that is, where structure 1 is an acoustic wave device. Fig. 2 is a cross-sectional view showing the structure of chip 2 of the acoustic wave device according to embodiment 1. In chip 2, structure 1 is mounted on mounting substrate 80 after being turned upside down from the state shown in Fig. 1 so that solder balls 70 face downward. Bumps or patterns are formed on mounting substrate 80 and are bonded to solder balls 70. Structure 1 is then covered with resin 90 to form chip 2.

[0030] (Heat dissipation characteristics) Fig. 3 is a plan view of a structure 1 serving as an acoustic wave device. Fig. 4 is a plan view of the structure 1 serving as an acoustic wave device from which a heat dissipation member 50 has been removed. As shown in Fig. 4, the structure 1 is formed by collecting a large number of IDT electrodes.

[0031] Of the bumps 60 , the bump 61 is a transmitting terminal 61 , the bump 62 is a receiving terminal 62 , and the bump 63 is an antenna terminal 63 .

[0032] The IDT electrode 21 located between the transmitting terminal 61 and the antenna terminal 63 is the transmitting filter 22. The second wiring 42 is located in the transmitting filter 22. The IDT electrode 21 located between the receiving terminal 62 and the antenna terminal 63 is the receiving filter 23. The third wiring 43 is located in the receiving filter 23.

[0033] Fig. 5 is a diagram showing the heat distribution in a comparative example in which the heat dissipation member 50 has been removed from the structure 1. As shown in Fig. 5, the area indicated by the reference numeral 51 is hot. In comparison with the case in which the heat dissipation member 50 is not present, the maximum temperature of the area indicated by the reference numeral 51 can be reduced by 26% when the heat dissipation member 50 is present. In other words, the heat dissipation performance is improved by the heat dissipation member 50. As a result, the power resistance of the structure 1 is also improved.

[0034] The area of ​​the portion of front surface 11 of substrate 10 facing heat dissipation member 50 is 50% or more of the area of ​​front surface 11. This ensures a sufficient heat dissipation area in heat dissipation member 50. Here, heat dissipation member 50 faces IDT electrode 21 of electrode 20 with a gap therebetween.

[0035] Here, the heat dissipation member 50 may be preferentially arranged on the side where the transmitting terminal 61 is located, compared to the side where the receiving terminal 62 is located. As a result, heat is generated more severely on the transmitting terminal 61 side than on the receiving terminal 62 side, and this can be dealt with by dissipating heat only on the transmitting terminal 61 side. Therefore, the cost of the heat dissipation member 50 can be reduced.

[0036] [Embodiment 2] Other embodiments of the present disclosure will be described below. For convenience of explanation, the same reference numerals will be given to components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0037] (Contact between heat dissipation member 50 and bump 60) In the first embodiment, the heat dissipation member 50 is in contact only with the thick film wiring 40, and receives and dissipates heat from the thick film wiring 40. In contrast, in the present embodiment, the heat dissipation member 50 is in contact with any of the bumps 60, and receives and dissipates heat from the bumps 60 as well.

[0038] Fig. 6 is a cross-sectional view showing the structure of structure 3 when heat dissipation member 51 according to embodiment 2 contacts bump 60 at one point. Fig. 7 is a cross-sectional view showing the structure of structure 4 when heat dissipation member 52 according to embodiment 3 contacts bump 60 at multiple points.

[0039] The bump 60 has a larger volume per unit area in a plan view than the thick film wiring 40, and therefore has a larger heat capacity. Therefore, the bump 60 efficiently absorbs the heat generated in the electrode 20. Here, by the heat dissipation member 50 being in contact with any one of the multiple bumps 60, the heat of the bump 60 can be efficiently transferred to the heat dissipation member 50. Therefore, the heat dissipation efficiency is improved.

[0040] (Holes in heat dissipation member 50) Also, holes corresponding to the bumps 60 may be formed in the heat dissipation member 50. The bumps 60 are then arranged to pass through the holes in the heat dissipation member 50. This not only increases the area of ​​the heat dissipation member 50 and improves the heat dissipation performance, but also has the effect of fixing the positions of the solder balls 70 placed on the bumps 60 to some extent by the heat dissipation member 50. In other words, it is possible to reduce the risk of the solder balls 70 being misaligned. The shape of the holes is not limited.

[0041] [Embodiment 3] Other embodiments of the present disclosure will be described below. For convenience of explanation, the same reference numerals will be given to components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0042] 8 is a cross-sectional view showing the structure of chip 5 of the elastic wave device according to Preferred Embodiment 3. Unlike chip 2, chip 5 has thermal grease 53 applied between heat dissipation member 50 and mounting substrate 80.

[0043] The heat dissipation grease 53 allows the heat generated in the structure 1 to be easily transferred to the mounting board 80 via the heat dissipation member 50 and the heat dissipation grease 53. Therefore, efficient heat dissipation is achieved by dissipating heat from the mounting board 80 having a large heat dissipation area.

[0044] [Embodiment 4] Other embodiments of the present disclosure will be described below. For convenience of explanation, the same reference numerals will be given to components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0045] (Method of Manufacturing Structure 1) Fig. 9 is a schematic diagram showing a method for manufacturing the structure 1. As shown in Fig. 9, the structure 1 is manufactured by forming and laminating each layer in order.

[0046] In a step indicated by reference numeral 101, the electrode 20 is formed on the substrate 10 by a method such as sputtering. In a step indicated by reference numeral 102, a photoresist 20a is formed on the electrode 20. In a step indicated by reference numeral 103, the electrode 20 is etched using the photoresist 20a. In a step indicated by reference numeral 104, the photoresist 20a is ashed to expose the electrode 20. As a result, the electrode 20 is formed as an IDT electrode.

[0047] Next, in the step indicated by reference numeral 105, a protective film 30 is formed on the electrode 20 to reduce the possibility of the IDT electrode falling off. The protective film 30 needs to be present only at the portion of the electrode 20 where the IDT electrode is located, and must not be present at the portion where the thick film wiring 40 is to be located. Therefore, in the step indicated by reference numeral 106, a photoresist 30a is formed on the protective film 30. In the step indicated by reference numeral 107, the protective film 30 is etched using the photoresist 30a.

[0048] In the step indicated by reference numeral 108, the thick film wiring 40 is formed. The thick film wiring 40 is formed on the electrode 20 in the area where the photoresist 30a is not present, and is formed on the photoresist 30a in the area where the photoresist 30a is present. The thickness of the photoresist 30a is set to be thicker than that of the thick film wiring 40. In the step indicated by reference numeral 109, the photoresist 30a is lifted off.

[0049] In the step indicated by reference numeral 110, a photoresist 60a is formed, and the protective film 30 is etched using the photoresist 60a. As a result, the protective film 30 is peeled off at the location where the bump 60 is located, so that the bump 60 can come into contact with the electrode 20.

[0050] In a step indicated by reference numeral 111, the bump 60 is formed on the electrode 20 and the photoresist 60a. In a step indicated by reference numeral 112, the photoresist 60a is lifted off. As a result, the bump 60 is formed.

[0051] In the step indicated by reference numeral 113, solder balls 70 are placed on the bumps 60. Furthermore, in the step indicated by reference numeral 114, the heat dissipation member 50 is bonded onto the thick film wiring 40. Furthermore, in the step indicated by reference numeral 115, the structure 1 is cut and divided into single elements.

[0052] The order of the steps 111 to 115 may be reversed. In other words, the structure 1 on which the bumps 60 are formed may be cut, and then the heat dissipation members 50 may be bonded to the respective elements, and then the solder balls 70 may be placed thereon.

[0053] (Manufacturing method of chip 2) Thereafter, in a step not shown, the structure 1 is turned upside down and placed on the mounting substrate 80, and the solder balls 70 are melted and bonded.

[0054] In order to reduce the risk of impurities entering the inside of the structure 1, the mounting substrate 80 to which the structure 1 is connected is molded with resin 90.

[0055] [Modifications] (Type of structure 1) The structure 1 is not limited to an acoustic wave device, and may be, for example, a printed circuit board.

[0056] 〔summary〕 A structure according to a first aspect of the present disclosure comprises a substrate, a first wiring and a second wiring provided directly or indirectly on a surface of the substrate, and a heat dissipation member above and facing the surface, the heat dissipation member including a non-conductive material and directly or indirectly contacting the first wiring and the second wiring.

[0057] According to the above configuration, a structure with high heat dissipation performance can be obtained.

[0058] A structure according to aspect 2 of the present disclosure may be configured as in aspect 1 above, further comprising an IDT electrode provided directly or indirectly on the surface, the substrate including a piezoelectric material, the IDT electrode being located between the first wiring and the second wiring, and the heat dissipation member overlapping the IDT electrode in a planar view.

[0059] With the above configuration, an acoustic wave device with high heat dissipation performance can be obtained.

[0060] A structure according to aspect 3 of the present disclosure may be configured as in aspect 2 above, where the first wiring is connected to a first comb-tooth electrode of the IDT electrode, and the second wiring is connected to a second comb-tooth electrode of the IDT electrode.

[0061] According to the above configuration, a pair of bus bars of the IDT electrode can be used as the first wiring and the second wiring.

[0062] The structure according to aspect 4 of the present disclosure may be configured as any one of aspects 1 to 3 above, further comprising a plurality of bumps provided on the surface of the substrate, the first wiring being connected to any one of the plurality of bumps, and the second wiring not being connected to any one of the plurality of bumps.

[0063] According to the above configuration, the second wiring is more likely to reach a high temperature than the first wiring.

[0064] A structure according to a fifth aspect of the present disclosure is any one of the first to fourth aspects, wherein a transmit filter is configured in the structure, and the second wiring is located in the transmit filter.

[0065] According to the above configuration, since the second wiring is located in the high-temperature transmitting filter, heat can be dissipated from the high-temperature transmitting filter.

[0066] A structure according to a sixth aspect of the present disclosure may be configured in any one of the first to fifth aspects above, such that the structure includes a receiving filter and further includes a third wiring located within the receiving filter, and the heat dissipation member is in direct or indirect contact with the third wiring.

[0067] According to the above configuration, heat can also be dissipated from the third wiring located in the receiving filter, which has a lower temperature than the transmitting filter.

[0068] The structure according to a seventh aspect of the present disclosure is any one of the first to sixth aspects, further comprising a plurality of bumps, and the heat dissipation member may be in contact with any one of the plurality of bumps.

[0069] According to the above-mentioned configuration, the bumps and the heat dissipation member are in contact with each other, so that heat is also transferred to the heat dissipation member from the bumps, thereby improving the heat dissipation performance.

[0070] The structure according to aspect 8 of the present disclosure is any one of aspects 1 to 7 above, wherein the area of ​​the portion of the surface of the substrate that faces the heat dissipation component is 50% or more of the area of ​​the surface.

[0071] According to the above configuration, the heat dissipation member has a sufficient area, so that sufficient heat dissipation performance can be obtained.

[0072] A structure according to a ninth aspect of the present disclosure, in any one of the second to eighth aspects, may be configured such that the heat dissipation member includes a material having a higher thermal conductivity than the piezoelectric body.

[0073] According to the above configuration, the heat dissipation member has a higher thermal conductivity than the substrate, which is a piezoelectric body, and therefore heat can be dissipated efficiently.

[0074] A structure according to aspect 10 of the present disclosure is any one of aspects 1 to 9 above, wherein the heat dissipation member includes any one of silicon, alumina, sapphire, aluminum nitride, diamond, scandium-doped aluminum nitride, silicon oxide, and silicon nitride.

[0075] According to the above-mentioned configuration, a material capable of efficiently dissipating heat can be used as the heat dissipation member.

[0076] [Additional Notes] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. [Explanation of symbols]

[0077] 1, 3, 4 structures 2, 5 chips 10 Substrate 11 Surface 20 electrodes 21 IDT electrode 21a 1st comb electrode 21b 2nd comb electrode 22 Transmission Filter 23 Receiving Filter 30 Protective film 40 Thick film wiring 41 1st wiring 42 2nd wiring 43 3rd wiring 50, 51, 52 Heat dissipation member 53 Thermal grease 60 Bump 61 Transmission terminal 62 Receiving terminal 63 Antenna terminal 70 Solder ball 80 Mounting Board 90 Resin

Claims

1. A substrate; a first wiring and a second wiring provided directly or indirectly on a surface of the substrate; a heat dissipation member above the surface and spaced apart from and facing the surface; The heat dissipation member is Contains a non-conductive material, A structure that directly or indirectly contacts the first wiring and the second wiring.

2. The semiconductor device further includes an IDT electrode provided directly or indirectly on the surface, the substrate includes a piezoelectric material, the IDT electrode is located between the first wiring and the second wiring, The structure according to claim 1 , wherein the heat dissipation member overlaps the IDT electrode in a plan view.

3. the first wiring is connected to a first comb-tooth electrode of the IDT electrode, The structure according to claim 2 , wherein the second wiring is connected to a second comb-teeth electrode of the IDT electrode.

4. a plurality of bumps disposed on the surface of the substrate; the first wiring is connected to any one of the plurality of bumps, The structure according to claim 1 , wherein the second wiring is not connected to any of the plurality of bumps.

5. A transmit filter is configured in the structure, The structure of claim 4 , wherein the second wiring is located in the transmit filter.

6. A receive filter is configured in the structure, a third wiring located within the receiving filter; The structure according to claim 5 , wherein the heat dissipation member is in direct or indirect contact with the third wiring.

7. Further comprising a plurality of bumps; The structure according to claim 1 , wherein the heat dissipation member is in contact with any one of the plurality of bumps.

8. The area of ​​the portion of the surface of the substrate facing the heat dissipation member is 50% or more of the area of ​​the surface.

2. The structure of claim 1 ,

9. The structure according to claim 2 , wherein the heat dissipation member includes a material having a higher thermal conductivity than the piezoelectric body.

10. 2. The structure of claim 1, wherein the heat dissipation member comprises any of silicon, alumina, sapphire, aluminum nitride, diamond, scandium-doped aluminum nitride, silicon oxide, and silicon nitride.

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