Electronic component

Abstract

An electronic component (100) includes a mounting substrate (200), and first and second devices (101, 102) each including a functional element. The first device (101) is separate from the mounting substrate (200) and is disposed opposite the mounting substrate (200). The second device (102) is disposed on the mounting substrate (200) opposite the first device (101). The functional element (120) of the first device (101) is disposed in the first device (101) at a first face (112) opposite the second device (102). The functional element (125) of the second device (102) is disposed in the second device (102) at a second face (116) opposite the first device (101).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an electronic component, and more particularly, to a technology for realizing miniaturization of a device having a WLP (Wafer Level Package) configuration. BACKGROUND

[0002] In recent years, in a communication device such as a portable terminal typified by a portable telephone and a smartphone, communication using a high-frequency signal of a plurality of frequency bands is performed. In the case where signals of a plurality of frequency bands are processed, a filter for selectively passing signals of each frequency band is used.

[0003] In the portable terminal as described above, the demand for further miniaturization and thinness is still high, and in conjunction therewith, further low-profile of a high-frequency device such as a filter arranged inside the device is also demanded.

[0004] In U.S. Patent No. 9660609 (Patent Literature 1), a duplexer in which two high-frequency devices (filters) having a WLP configuration are stacked is disclosed. In the stacked duplexer disclosed in U.S. Patent No. 9660609 (Patent Literature 1), since the substrate area for forming the filters can be reduced, miniaturization of the device can be realized.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: U.S. Patent No. 9660609 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] As a high-frequency device having a WLP configuration, an elastic wave device using an elastic wave resonator is known. In the elastic wave device, a hollow space for mechanically vibrating the elastic wave resonator needs to be provided.

[0010] In the case where the stacked configuration disclosed in U.S. Patent No. 9660609 (Patent Literature 1) is applied to an elastic wave device, the planar substrate area can be reduced, on the other hand, a space for exciting the resonator needs to be ensured, and thus, the reduction in the size in the thickness direction (height direction) of the device is limited. Here, in order to ensure the space for excitation and realize further low-profile, it is considered to make the piezoelectric substrate itself forming the elastic wave resonator thin. However, when the thickness of the substrate is thinned, the heat capacity of the substrate decreases, and thus, the substrate temperature rises by heat generated by excitation of the elastic wave resonator, and as a result, the power resistance performance of the device can significantly decrease.

[0011] The present disclosure has been made to solve such a problem, and aims to suppress a decrease in power resistance performance and achieve miniaturization and low-profile in an electronic component having a WLP configuration.

[0012] Means for solving the problem

[0013] The electronic component of the present disclosure includes a mounting substrate, and first and second devices each including a functional element. The first device is separated from the mounting substrate and disposed opposite the mounting substrate. The second device is disposed on the mounting substrate opposite the first device. The functional element of the first device is disposed in the first device at a first face opposite the second device. The functional element of the second device is disposed in the second device at a second face opposite the first device.

[0014] Effects of the Invention

[0015] In the electronic component of the present disclosure, the two devices (first and second devices) forming the functional elements are formed in a stacked configuration. One device (second device) is disposed on the mounting substrate, and the other device (first device) is disposed separately from the mounting substrate. Also, in the first and second devices, the functional elements are respectively disposed at mutually opposite faces. By adopting such a structure, the space formed between the first and second devices can be shared by the functional elements formed in each device. Therefore, the thickness direction dimension of the entire device can be reduced without thinning the substrate forming the functional elements. Thus, in the electronic component having a WLP configuration, a decrease in power resistance performance can be suppressed and miniaturization and low-profile can be achieved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a cross-sectional view of an electronic component of Embodiment 1.

[0017] Figure 2 is a diagram for explaining a modification example of the joining member.

[0018] Figure 3 is a cross-sectional view of an electronic component of a comparative example.

[0019] Figure 4 is a cross-sectional view of an electronic component of Embodiment 2.

[0020] Figure 5 is a cross-sectional view of an electronic component of Embodiment 3.

[0021] Figure 6 is a cross-sectional view of an electronic component of Embodiment 4.

[0022] Figure 7 is a cross-sectional view of an electronic component of Modification Example 1.

[0023] Figure 8is a cross-sectional view of the electronic component of Modification Example 2.

[0024] Figure 9 is a cross-sectional view of the electronic component of Embodiment 5.

[0025] Figure 10 is a cross-sectional view of the electronic component of Embodiment 6.

[0026] Figure 11 is Figure 10 is a plan view of the electronic component of

[0027] Figure 12 is a diagram showing an example of the modularization of the electronic component described above.

[0028] Figure 13 is a cross-sectional view of the electronic component of Modification Example 3 in a case where a BAW resonator is used as a functional element. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present disclosure will be explained in detail with reference to the drawings. Note that the same reference signs are assigned to the same or equivalent portions throughout the drawings, and the explanation thereof will not be repeated.

[0030] [Embodiment 1]

[0031] Figure 1 is a cross-sectional view of the electronic component 100 of Embodiment 1. Referring to Figure 1 , the electronic component 100 includes a first device 101, a second device 102, and a mounting substrate 200. The first device 101 and the second device 102 each have a WLP configuration. Note that in the following explanation, the positive direction of the Z-axis in the drawing will be referred to as the upper surface side, and the negative direction will be referred to as the lower surface side.

[0032] In Embodiment 1, the first device 101 and the second device 102 are circuitry in which functional elements are formed, and specifically, are filter circuitry including elastic wave resonators. The first device 101 includes a piezoelectric substrate 110, and at least one functional element 120 formed on the lower surface 112 of the piezoelectric substrate 110. In addition, the second device 102 includes a piezoelectric substrate 115, and at least one functional element 125 formed on the upper surface 116 of the piezoelectric substrate 115.

[0033] The piezoelectric substrates 110, 115 are formed of, for example, a piezoelectric single crystal material such as lithium tantalate (LiTaO3), lithium niobate (LiNbO3), aluminum oxide, silicon (Si), and sapphire, or a piezoelectric laminated material including LiTaO3 or LiNbO3.

[0034] The functional element is an element that extracts a signal of a specific frequency band. The functional elements 120, 125 include a pair of comb-shaped IDT (Interdigital Transducer) electrodes formed using an electrode material including, for example, a single metal including at least one of aluminum, copper, silver, gold, titanium, tungsten, platinum, chromium, nickel, molybdenum, or an alloy having them as a main component. In the first device 101 and the second device 102, a surface acoustic wave (SAW: Surface Acoustic Wave) resonator is formed by a piezoelectric substrate and the IDT electrodes, respectively.

[0035] In the first device 101, a wiring pattern 160 for electrically connecting between the functional elements 120 and for electrically connecting the functional elements 120 and the columnar electrodes 130 is formed on the lower surface 112 of the piezoelectric substrate 110 in which the functional elements 120 are formed.

[0036] The columnar electrodes 130 are formed to protrude downward (negative direction of the Z axis) from the lower surface 112 of the piezoelectric substrate 110, and are connected to and fixed to the connection electrodes 150 on the mounting substrate 200 by the solder bumps 140. That is, the first device 101 is supported on the mounting substrate 200 by the solder bumps 140 and the columnar electrodes 130, and a hollow space 190 is formed by the first device 101 and the mounting substrate 200.

[0037] The second device 102 is disposed so that the lower surface 117 is in contact with the mounting substrate 200 in the hollow space 190 formed by the first device 101. Note that an adhesive layer can be provided between the second device 102 and the mounting substrate 200. In the second device 102, a wiring pattern 165 for electrically connecting between the functional elements 125 and for electrically connecting the functional elements 125 and the connection electrodes 135 formed on the side surface of the piezoelectric substrate 115 is formed on the upper surface 116 of the piezoelectric substrate 115 in which the functional elements 125 are formed. The connection electrodes 135 are connected to and fixed to the connection electrodes 155 on the mounting substrate 200 by the solder bumps 145. That is, the electronic component 100 is formed in a stacked structure in which the functional elements 120 in the first device 101 are disposed opposite to the second device 102, and the functional elements 125 in the second device 102 are disposed opposite to the first device 101.

[0038] The outer side of the first device 101 and the support body (the columnar electrode 130, the solder bump 140) supporting the first device 101 is covered by the sealing member 210 for sealing the first device 101 and the second device 102. The sealing member 210 is formed of a material obtained by mixing a metal or the like inorganic filler into a material having high waterproofness such as a silicon compound, an epoxy resin, a silicon resin, a fluorine resin, or an acrylic resin. By forming the sealing member 210 of such a material, the moisture resistance and the impact resistance of the electronic component 100 can be improved.

[0039] Note that, in Figure 1 , an example in which a solder ball in a spherical shape is used to connect the connection electrode 135 and the connection electrode 155 is shown, but the connection electrode 135 and the connection electrode 155 can be connected using a solder paste 145A in a paste shape as in the electronic component 100A which is a modification example of Figure 2 .

[0040] As described above, the electronic component 100, 100A of Embodiment 1 is a duplexer having the first device 101 and the second device 102 formed as filter circuits including an elastic wave resonator. Such a duplexer is applied, for example, to a communication device such as a portable terminal typified by a portable telephone and a smartphone, for separating a transmission signal and a reception signal.

[0041] In such a portable terminal, the demand for further miniaturization and thinning is still high, and in conjunction therewith, high-frequency devices such as filters disposed inside the device are also required to be further miniaturized and thinned. In response to such a demand, a structure in which two devices (filters) are provided in a stacked configuration to reduce the circuit area on a mounting substrate as shown in the comparative example of Figure 3 .

[0042] Figure 3 is a cross-sectional view of the electronic component 100# of the comparative example. Referring to Figure 3 , in the electronic component 100#, like the electronic component 100 of Embodiment 1, a stacked configuration in which the second device 102 is disposed in the hollow space 190 formed between the first device 101 and the mounting substrate 200 is formed. However, in the case of the electronic component 100# of the comparative example, the second device 102 is configured to be supported on the mounting substrate 200 by the columnar electrode 135# and the solder bump 145 like the first device 101. In other words, the functional element 125 in the second device 102 is formed on the lower surface 117 of the piezoelectric substrate 115, and is disposed in the hollow space 195 formed between the piezoelectric substrate 115 and the mounting substrate 200. That is, the functional element 125 is not disposed opposite the functional element 120 of the first device 101, but is disposed opposite the mounting substrate 200.

[0043] In the case of such a structure of the comparative example, particularly with respect to the interval between the second device 102 and the mounting substrate 200, it is not possible to narrow the size below a prescribed size due to the limitation of the size of the solder bump 145. In addition, in order to secure the function element 120 of the first device 101, it is also necessary to secure the distance between the piezoelectric substrate 115 of the second device 102 and the function element 120 of the first device 101 to be prescribed or more. Therefore, as a result, the interval between the first device 101 and the mounting substrate 200 can also need to be a size prescribed or more. That is, in the structure of the comparative example, there is a limit to the low-profile of the entire device.

[0044] In order to address such a problem, it is considered to reduce the size of the entire device by thinning the piezoelectric substrate of each device. However, when the thickness of the piezoelectric substrate is thinned, the heat capacity of the substrate decreases, and therefore, the substrate temperature rises by the heat generated by the operation of the function element, and as a result, the power resistance performance of the device can significantly decrease. In addition, when the thickness of the piezoelectric substrate is thinned, the strength of the substrate itself decreases, and therefore, the piezoelectric substrate can be damaged during the operation of each component in the manufacturing process of the electronic component.

[0045] On the contrary, in the structure of Embodiment 1, the second device 102 is arranged to be in contact with the mounting substrate 200, and the second device 102 and the mounting substrate 200 are connected by the side surface of the second device 102, and therefore, the restriction of the interval between the second device 102 and the mounting substrate 200 is relaxed. In addition, the second device 102 is arranged in the hollow space 190 of the first device 101, and the function element 120 and the function element 125 are arranged to face each other, and therefore, the space between the first device 101 and the second device 102 can be shared by the function element 120 and the function element 125, and therefore, it is not necessary to secure a separate hollow space in each device. Thus, the electronic component 100 of Embodiment 1 can shorten the distance from the mounting substrate 200 to the first device 101 and the second device 102 compared to the electronic component 100# of the comparative example. Therefore, the distance H1 from the upper surface 201 of the mounting substrate 200 to the upper surface 111 of the first device 101 in the electronic component 100 of Embodiment 1 can be made shorter than the distance H1# from the upper surface 201 of the mounting substrate 200 to the upper surface 111 of the first device 101 in the electronic component 100# of the comparative example, and as a result, it is possible to achieve the low-profile and high power resistance of the entire device.

[0046] Note that the "solder bump 140" and the "solder bump 145" in Embodiment 1 correspond to the "first joining member" and the "second joining member" of the present disclosure, respectively. The "connection electrode 150" and the "connection electrode 155" in Embodiment 1 correspond to the "first electrode" and the "second electrode" of the present disclosure, respectively. The "lower surface 112" of the piezoelectric substrate 110 and the "upper surface 116" of the piezoelectric substrate 115 in Embodiment 1 correspond to the "first surface" and the "second surface" of the present disclosure, respectively.

[0047] [Embodiment 2]

[0048] In Embodiment 1, the structure in which the functional element 120 of the first device and the functional element 125 of the second device 102 are exposed in the hollow space 190 formed between the first device 101 and the mounting substrate 200 is described. In Embodiment 2, a structure in which a structure that forms a hollow space is separately provided in each device, and a functional element is formed in the hollow space, is described.

[0049] Figure 4 is a cross-sectional view of an electronic component 100B of Embodiment 2. Reference is made to Figure 4 In the electronic component 100B, a cover portion that covers the functional element is additionally provided in the first device 101 and the second device 102, respectively, on the basis of the structure of the electronic component 100 of Embodiment 1. Specifically, the first device 101 further includes a cover portion 170 formed of an insulating member and a plurality of support portions 171. The support portions 171 are disposed so as to protrude toward the lower side (negative direction of the Z axis) on the lower surface 112 of the piezoelectric substrate 110 or on the wiring pattern 160 formed on the lower surface 112 of the piezoelectric substrate 110. Further, the cover portion 170 is disposed so as to be supported by the support portions 171. A hollow space 191 is formed between the cover portion 170 and the piezoelectric substrate 110 by the cover portion 170 and the support portions 171. The functional element 120 of the first device 101 is formed in the hollow space 191 formed by the cover portion 170 and the piezoelectric substrate 110.

[0050] Similarly, the second device 102 further includes a cover portion 175 formed of an insulating member and a plurality of support portions 176. The support portions 176 are disposed so as to protrude toward the upper side (positive direction of the Z axis) on the upper surface 116 of the piezoelectric substrate 115 or on the wiring pattern 165 formed on the upper surface 116 of the piezoelectric substrate 115. Further, the cover portion 175 is disposed so as to be supported by the support portions 176. A hollow space 196 is formed between the cover portion 175 and the piezoelectric substrate 115 by the cover portion 175 and the support portions 176. The functional element 125 of the second device 102 is formed in the hollow space 196 formed by the cover portion 175 and the piezoelectric substrate 115.

[0051] Note that part of the first device 101 and the second device 102 can be hollow or can be filled with the sealing member 215. The sealing member 215 can be the same material as the sealing member 210 that covers the outer periphery of the first device 101 or can be a different material from the sealing member 210.

[0052] As above, by providing each device in which a functional element is formed with a structure for forming a hollow space, the degree of freedom of selection of a sealing method can be increased. Further, even in a case where deformation occurs due to a force in the Z-axis direction acting on each device as a result of sealing, since direct contact of the functional element of the first device with the functional element of the second device is suppressed, the mold resistance can be improved.

[0053] Note that in the electronic component 100B, a structure in which a cover portion is provided on both the first device 101 and the second device 102 is described, but a structure in which a cover portion is provided on either the first device 101 or the second device 102 can also be employed. In this case, the sealing member 215 is not used.

[0054] [Embodiment 3]

[0055] In Embodiment 3, a structure in which a shield structure is formed on the cover portion described in Embodiment 2 is described.

[0056] Figure 5 is a cross-sectional view of the electronic component 100C of Embodiment 3. The same components as those of the electronic component 100A of Embodiment 1 are denoted by the same reference numerals, and a description thereof will not be repeated. Figure 5 In the electronic component 100C, the cover portion 175 described in Embodiment 2 is formed on the second device 102, and a shield layer 185 formed of a conductive member is disposed on the upper surface (a surface facing the first device 101) of the cover portion 175. Although not shown in Figure 5 , the shield layer 185 is connected to a ground potential.

[0057] By providing such a shield layer 185, an electromagnetic field that can be generated by the functional element 125 of the second device 102 is shielded. Thus, electromagnetic field coupling between the functional element 120 of the first device 101 and the functional element 125 of the second device 102 can be prevented, and thus, a decrease in filter characteristics caused by the electromagnetic field coupling can be suppressed.

[0058] Note that in Figure 5 , an example in which a cover portion is formed only on the second device 102 side is shown, but a structure in which a cover portion is formed only on the first device 101 side and a shield layer is formed on the cover portion can also be employed. Alternatively, cover portions can be formed on both the first device 101 and the second device 102 as in Figure 4 . In a case where cover portions are formed on both sides, the shield layer can be formed on at least one of the cover portions.

[0059] [Embodiment 4]

[0060] In each of the above-described embodiments, the structure in which the first device and the second device are arranged on the flat mounting substrate is described. In Embodiment 4, the structure in which the second device is arranged in a recess formed on the mounting substrate is described.

[0061] Figure 6 is a cross-sectional view of an electronic component 100D of Embodiment 4. The same components as those of the electronic component 100 of Embodiment 1 are denoted by the same reference numerals, and the description thereof is omitted. Figure 6 In the electronic component 100D, instead of the mounting substrate 200, the first device 101 and the second device 102 are arranged on a mounting substrate 200D. As in the above-described embodiments, the first device 101 is supported to the mounting substrate 200D by the columnar electrode 130 and the solder bump 140.

[0062] In the mounting substrate 200D, a recess 205 is formed in a portion of a surface opposite to the functional element 120 formed in the first device 101, that is, the upper surface facing the hollow space 190. The recess 205 is formed to be at least a size in which the second device 102 can be arranged inside. Further, from the bottom surface of the recess 205 through the wall portion to the upper surface 201 of the mounting substrate 200D, the connection electrode 155D is formed. That is, at least a portion of the connection electrode 155D is farther from the first device 101 in the Z-axis direction than the connection electrode 150 for the first device 101 to the first device 101.

[0063] The second device 102 is arranged in the above-described recess 205. Further, the connection electrode 135 formed on the side surface of the second device 102 and the connection electrode 155D formed on the bottom surface of the recess 205 are connected by the solder bump 145, and thereby the second device 102 is fixed to the mounting substrate 200D.

[0064] By adopting such a structure, compared with the case of the electronic component 100 of Embodiment 1, the distance from the upper surface 201 of the mounting substrate 200D to the upper end of the second device 102 can be shortened, and thereby the interval between the functional element 120 and the functional element 125 can be ensured. Thereby, the electromagnetic field coupling between the functional element 120 and the functional element 125 is relaxed. Or, when the interval between the functional element 120 and the functional element 125 is set to be the same as that of the electronic component 100, the distance of the mounting substrate 200D from the first device 101 can be shortened, and thereby the size of the device as a whole in the Z-axis direction can be reduced, and further low-profile can be achieved. In addition, by enlarging the interval between the functional element 120 and the functional element 125, the thickness of the piezoelectric substrate can be increased. Thereby, the breakage of the device due to the operation in the manufacturing process is suppressed, and thereby the operability can be improved.

[0065] Further, since the second device 102 is arranged in the determined recess 205, it is possible to improve the positioning accuracy of the second device 102 on the mounting substrate 200D. Thus, it is possible to suppress an electrical failure due to "solder spreading" in which the solder bump 140 of the first device 101 and the solder bump 145 of the second device 102 are brought into contact with each other accompanying a positional displacement of the second device 102.

[0066] Note that the following Figure 7 and Figure 8 A modification of the structure for suppressing the positional displacement of the second device 102 is shown.

[0067] (Modification 1)

[0068] Figure 7 is a cross-sectional view of an electronic component 100E of Modification 1. Reference is made to Figure 7 In the electronic component 100E, the mounting substrate 200E is formed with a plurality of protrusions 206 protruding upward (positive direction of the Z axis) from the upper surface 201 of the mounting substrate 200E, and the columnar electrode 130E and the solder bump 140 for supporting the first device 101 are formed on the protrusions 206. Note that the upper surface of the protrusion 206 on which the connection electrode 150 is formed is elevated compared with the upper surface 201 of the mounting substrate 200E, and thus the dimension of the columnar electrode 130E in the Z axis direction is shorter than that of the columnar electrode 130 in the electronic component 100 of Embodiment 1.

[0069] In the electronic component 100E of Modification 1, the distance in the Z axis direction from the connection electrode 155 for the second device 102 to the first device 101 is also farther than the distance in the Z axis direction from the connection electrode 150 for the first device 101 to the first device 101.

[0070] The second device 102 is arranged in the region surrounded by the protrusions 206 in the mounting substrate 200E. In the electronic component 100E of Modification 1, the protrusions 206 function as a guide mechanism for the second device 102, and thus it is possible to suppress the positional displacement of the second device 102.

[0071] Further, as described above, the dimension of the conductive member (columnar electrode + solder bump) in the support portion of the first device 101 is shortened by the protrusions 206. Thus, it is possible to reduce the inductance component of the support portion, and thus it is possible to reduce the influence of the inductance component on the filter characteristics.

[0072] (Modification 2)

[0073] Figure 8 is a cross-sectional view of an electronic component 100F of Modification 2. Reference is made toFigure 8 In the electronic component 100F, the mounting substrate 200 having a flat surface is used as in Embodiment 1. However, in the hollow space 190 formed between the first device 101 and the mounting substrate 200, the positioning member 187 for positioning the second device 102 is formed on the mounting substrate 200. The positioning member 187 is formed on the mounting substrate 200, for example, by copper (Cu) plating. In the manufacturing process of the electronic component 100F, the second device 102 is positioned to a prescribed position by being arranged in accordance with the positioning member 187.

[0074] Note that, in the example of the electronic component 100F, Figure 8 In the example of the electronic component 100F, the dimension of the connecting electrode 150F of the connection solder bump 140 in the Z-axis direction is the same as the dimension of the positioning member 187 in the Z-axis direction. In this way, in the manufacturing process of the electronic component 100F, the positioning member 187 can be formed at the same time as the connecting electrode 150F is formed on the mounting substrate 200. Therefore, in Modified Example 2, the positioning accuracy can be improved without an increase in cost accompanying the addition of a new process.

[0075] In the electronic component 100F of Modified Example 2, the distance from the connecting electrode 155 for the second device 102 to the first device 101 in the Z-axis direction is farther than the distance from the connecting electrode 150F for the first device 101 to the first device 101 in the Z-axis direction.

[0076] [Embodiment 5]

[0077] In the above-described embodiments, the second device is formed in the region between the first device and the mounting substrate. Therefore, for the second device, heat generated by the functional element easily accumulates, and the temperature of the piezoelectric substrate easily rises. As described above, when the temperature rises, the withstand voltage performance of the device decreases, and this can be a major cause of a decrease in device characteristics and failure or damage of the device.

[0078] Therefore, in Embodiment 5, a structure for suppressing a decrease in the withstand voltage performance of the device by forming a heat dissipation mechanism for the second device on the mounting substrate is described.

[0079] Figure 9is a cross-sectional view of the electronic component 100G of Embodiment 5. The electronic component 100G is configured such that a metal layer 220 is formed between the second device 102 and the mounting substrate 200 on the basis of the electronic component 100 of Embodiment 1. The metal layer 220 is arranged so as to be in contact with the piezoelectric substrate 115 of the second device 102. The metal layer 220 is formed of s metal having a higher thermal conductivity than the mounting substrate 200, for example, using copper or aluminum or the like. By arranging such a metal layer 220, heat generated by the second device 102 is rapidly transferred to the metal layer 220 and dissipated to the mounting substrate 200. Note that by extending the metal layer 220 to a portion of the mounting substrate 200 where heat generation is less, it is possible to further improve the heat dissipation efficiency.

[0080] Note that the metal layer 220 is not limited to Figure 9 The structure of the rectangular parallelepiped-shaped conductive member, for example, can also be a structure in which a plurality of conductive vias connected to a ground potential are arranged.

[0081] [Embodiment 6]

[0082] In the electronic component of the above-described embodiments, a structure in which the second device arranged in contact with the mounting substrate is disposed in the hollow space formed between the first device and the mounting substrate is adopted. In this case, the joining members (solder bumps) for fixing the second device to the mounting substrate are also located in the hollow space. In this way, the joining members for the first device and the joining members for the second device are densely arranged in a narrow region, and thus the wiring patterns on the mounting substrate connected to the joining members also need to be formed in close proximity to each other. Therefore, the degree of freedom in the design of the wiring in the mounting substrate can be greatly restricted. In addition, when the joining members are arranged in close proximity, the possibility of short-circuiting between electrodes increases due to "solder spreading" caused by the expansion of the solder upon melting of the solder.

[0083] Thus, in Embodiment 6, a structure in which the arrangement of the joining members of the first device and the second device is designed so as to suppress the dense arrangement of the joining members of the two devices is described.

[0084] Figure 10 is a cross-sectional view of the electronic component 100H of Embodiment 6. In addition, Figure 11 is a plan view of the electronic component 100H as viewed from the lower surface (negative direction of the Z axis). Note that in the plan view of Figure 10 , the mounting substrate 200 is omitted in order to make the description easier. Figure 11

[0085] Reference is made to Figure 10 ​The electronic component 100H includes the first device 101H and the second device 102H. Like the electronic component 100 of Embodiment 1, the second device 102H is arranged so that the lower surface 117 is in contact with the mounting substrate 200. The second device 102H is fixed to the mounting substrate 200 by connecting the connecting electrode 135 formed on the side surface of the second device 102H to the connecting electrode 155 formed on the upper surface 201 of the mounting substrate 200 with the solder bump 145. In addition, the first device 101H is supported by the support body including the columnar electrode 130 and the solder bump 140, and is arranged apart from the second device 102H in the positive direction of the Z axis. Further, the hollow space 190 is formed between the first device 101H and the second device 102H.

[0086] In the piezoelectric substrate 110 of the first device 101H, the functional element 120 is formed on the lower surface 112 facing the hollow space 190. In addition, in the piezoelectric substrate 115 of the second device 102H, the functional element 125 is formed on the upper surface 116 facing the hollow space 190.

[0087] Referring to Figure 11 When the electronic component 100H is viewed from the normal direction of the mounting substrate 200, the first device 101H and the second device 102H are formed in a rectangular shape. The first device 101H and the second device 102H each have a side parallel to the X axis direction (first direction) and a side parallel to the Y axis direction (second direction). The first device 101H and the second device 102H are arranged so that the center of the piezoelectric substrate 110 of the first device 101H overlaps the center of the piezoelectric substrate 115 of the second device 102H.

[0088] The size of the first device 101H in the X axis direction is smaller than the size of the second device 102H in the X axis direction. On the other hand, the size of the second device 102H in the Y axis direction is smaller than the size of the first device 101H in the Y axis direction. In other words, the side parallel to the X axis direction in the first device 101H is positioned outward of the side parallel to the X axis direction in the second device 102H. In addition, the side parallel to the Y axis direction in the second device 102H is positioned outward of the side parallel to the Y axis direction in the first device 101H.

[0089] Further, the solder bump 140 of the first device 101H is arranged along the side parallel to the X axis direction of the first device 101H. On the other hand, the solder bump 145 of the second device 102H is arranged along the side parallel to the Y axis direction of the second device 102H.

[0090] Thus, in the first device 101H and the second device 102H having a rectangular shape, the solder bumps (joining members) are arranged along the sides located outward of the opposite sides, respectively, whereby the distance between the solder bump 140 of the first device 101H and the solder bump 145 of the second device 102H can be secured, and the density of the solder bumps can be reduced. Thus, the occurrence of solder spreading can be suppressed, and malfunction due to electrical contact between the solder bumps can be suppressed.

[0091] In addition, as shown in FIG. 10, in a plan view of the electronic component 100H, the solder bumps are not formed in the portions in which the piezoelectric substrate 110 of the first device 101H and the piezoelectric substrate 115 of the second device 102H overlap. Thus, in each of the piezoelectric substrates, the area in which the functional elements and the wiring patterns can be formed can be enlarged, and thus, the degree of freedom of the wiring can be improved. Figure 11

[0092] [Application Example]

[0093] Figure 12 FIG. 11 is a diagram illustrating an example of a high-frequency device 10 obtained by modularizing electronic components 100X1 and 100X2 to which features of each of the embodiments described above are applied. As a representative, the high-frequency device 10 is a front-end circuit of a communication device.

[0094] Referring to FIG. 11, the high-frequency device 10 includes a mounting substrate 200, the electronic components 100X1 and 100X2, a chip component 20, and an integrated circuit (IC) 30. The electronic components 100X1 and 100X2 and the chip component 20 are mounted on an upper surface 201 of the mounting substrate 200. The integrated circuit 30 is mounted on a lower surface 202 of the mounting substrate 200 by solder bumps 40. Figure 12 In addition, a columnar electrode 50 for connection with an external device is formed on the lower surface 202 of the mounting substrate 200. The upper surface 201 and the lower surface 202 of the mounting substrate 200 are molded by a sealing member 210.

[0095] The chip component 20 is, for example, an independent component such as a transformer, an inductor, a capacitor, or the like. The integrated circuit 30 is a circuit for supplying a high-frequency signal to the electronic components 100X1 and 100X2 and / or for processing a high-frequency signal received from the electronic components 100X1 and 100X2.

[0096] The electronic components 100X1 and 100X2 are components having the same functions as those of each of the embodiments described above, and have a structure in which two devices including functional elements are stacked.

[0097]

[0098] ​​The electronic component 100X1 is a structure including the features of the above-described Embodiment 1, Embodiment 2, Embodiment 3, Modification 1 of Embodiment 4, Embodiment 5, and Embodiment 6. Specifically, the electronic component 100X1 includes the second device 102 disposed on the mounting substrate 200, and the first device 101 disposed opposite the second device 102 and separately from the mounting substrate 200. The first device 101 is supported on the connection electrode 150 formed on the convex portion 206 of the upper surface 201 of the mounting substrate 200 via the columnar electrode 130 and the solder bump 140. The first device 101 includes the piezoelectric substrate 110, the plurality of functional elements 120, and the cover portion 170. The plurality of functional elements 120 are disposed on a surface of the piezoelectric substrate 110 opposite the second device 102. The cover portion 170 covers the plurality of functional elements 120. The functional elements 120 are disposed in a hollow space formed between the piezoelectric substrate 110 and the cover portion 170.

[0099] The second device 102 includes the piezoelectric substrate 115, the plurality of functional elements 125, and the cover portion 175. The piezoelectric substrate 115 is disposed so as to be in contact with the mounting substrate 200. The plurality of functional elements 125 are disposed on a surface of the piezoelectric substrate 115 opposite the first device 101. The cover portion 175 covers the plurality of functional elements 125. The functional elements 125 are disposed in a hollow space formed between the piezoelectric substrate 115 and the cover portion 175. In the second device 102, a shielding layer 185 formed of a conductive member is disposed on the upper surface side of the cover portion 175. In addition, a metal layer 220 for heat dissipation is formed between the piezoelectric substrate 115 and the mounting substrate 200.

[0100] When viewed from the normal direction of the electronic component 100X1, the piezoelectric substrates of the first device 101 and the second device 102 each have a rectangular shape including a side parallel to the X-axis and a side parallel to the Y-axis. The side of the piezoelectric substrate 110 of the first device 101 parallel to the X-axis is located outward of the side of the piezoelectric substrate 115 of the second device 102 parallel to the X-axis. In addition, the side of the piezoelectric substrate 115 of the second device 102 parallel to the Y-axis is located outward of the side of the piezoelectric substrate 110 of the first device 101 parallel to the Y-axis. The second device 102 is fixed to the mounting substrate 200 by connecting the connection electrode 135 formed on the side of the piezoelectric substrate 115 parallel to the Y-axis to the connection electrode 155 formed on the mounting substrate 200 using the solder paste 145A. In addition, the solder bump 140 supporting the first device 101 is disposed along the side of the piezoelectric substrate 110 parallel to the X-axis.

[0101] Note that, in the above-described embodiments, the piezoelectric substrate is formed of a piezoelectric material. However, the piezoelectric substrate can be formed of a piezoelectric material or a piezoelectric ceramic material. Figure 12In the example of the high-frequency device 10, the electronic component 100X2 has the same structure as the electronic component 100X1. Therefore, the description of the structure of the electronic component 100X2 will not be repeated.

[0102] In the high-frequency device 10, by arranging the electronic components 100X1 and 100X2 in the structure described above, it is possible to suppress the decline in power resistance and achieve miniaturization and low backlighting. Furthermore, the electromagnetic field coupling between the first and second devices is reduced by forming a shielding layer. In addition, by arranging the bonding members of the first and second devices on different sides, solder spreading can be suppressed, and the freedom of wiring design on the mounting substrate can be increased.

[0103] It should be noted that the above embodiments describe the use of a SAW resonator as a functional element, but any functional element formed within a hollow space is acceptable. Figure 13 Other elastic wave devices, such as the BAW resonator shown, can also be small sensors or actuators called microelectromechanical systems (MEMS).

[0104] exist Figure 13 In the electronic component 100J, the first device 101J and the second device 102J have functional elements 120J and 125J that form a BAW resonator. In the first device 101J, a recess 113 is formed on the lower surface 112 of the silicon substrate 110J, and a piezoelectric film 123 sandwiched between two wiring layers 121 and 122 is disposed thereon, thereby covering the recess 113. Similarly, in the second device 102J, a recess 118 is formed on the upper surface 116 of the silicon substrate 115J, and a piezoelectric film 128 sandwiched between two wiring layers 126 and 127 is disposed thereon, thereby covering the recess 113.

[0105] The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of this disclosure is set forth in the claims, rather than in the description of the embodiments above, and is intended to include all modifications within the same meaning and scope as the claims.

[0106] Explanation of reference numerals in the attached figures

[0107] 10 high frequency device, 20 sheet type component, 30 integrated circuit, 40, 140, 145 solder bump, 50, 130, 130E, 135 columnar electrode, 100, 100A-100H, 100J, 100X1, 100X2, 100 electronic component, 101, 101H, 101J first device, 102, 102H, 102J second device, 110, 115 piezoelectric substrate, 110J, 115J silicon substrate, 120, 120J, 125, 125J functional element, 113, 118, 205 recess, 121, 122, 126, 127 wiring layer, 123, 128 piezoelectric film, 135, 150, 150F, 155, 155D connecting electrode, 145A solder paste, 160, 165 wiring pattern, 170, 175 cover portion, 171, 176 support portion, 185 shielding layer, 187 positioning member, 190, 191, 196 hollow space, 200, 200D, 200E mounting substrate, 206 protrusion, 210, 215 sealing member, 220 metal layer.

Claims

1. An electronic component comprising: a mounting substrate; a first device separate from the mounting substrate and disposed opposite the mounting substrate; and a second device disposed on the mounting substrate opposite the first device, the first device and the second device each including a functional element, the functional element of the first device being disposed in the first device at a first surface opposite the second device, the functional element of the second device being disposed in the second device at a second surface opposite the first device, the first device being connected to a first electrode on the mounting substrate via a first joining member, the second device being connected to a second electrode on the mounting substrate via a second joining member, at least a portion of the second electrode being farther from the first surface of the first device than a distance from the first electrode to the first surface of the first device in a normal direction of the mounting substrate.

2. The electronic component according to claim 1, wherein the first joining member is connected to a wiring pattern formed on the first surface of the first device via a columnar electrode.

3. The electronic component according to claim 1 or 2, wherein the second joining member is connected to an electrode formed on a side surface of the second device.

4. The electronic component according to claim 1 or 2, wherein a recess is formed on a surface of the mounting substrate opposite the first device, and the second device is disposed in the recess of the mounting substrate.

5. The electronic component according to claim 4, wherein at least a portion of the second electrode is formed in the recess.

6. The electronic component according to claim 1 or 2, wherein a protrusion is formed on a surface of the mounting substrate opposite the first device, and the second device is disposed in a region on the mounting substrate surrounded by the protrusion.

7. The electronic component according to claim 6, wherein the first electrode is formed on the protrusion.

8. The electronic component according to claim 1 or 2, further comprising a positioning member disposed on the mounting substrate for positioning the second device.

9. The electronic component according to claim 1 or 2, wherein the first device and the second device each have a rectangular shape having a side parallel to a first direction and a side parallel to a second direction orthogonal to the first direction when viewed from a normal direction of the mounting substrate, the first joining member is disposed in the first device along the side parallel to the first direction, and the second joining member is disposed in the second device along the side parallel to the second direction.

10. The electronic component according to claim 9, wherein the side parallel to the first direction in the first device is located farther outward than the side parallel to the first direction in the second device when viewed from the normal direction of the mounting substrate. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The edge in the second device that is parallel to the second direction is positioned more outward than the edge in the first device that is parallel to the second direction.

11. The electronic component according to claim 1 or 2, wherein At least one of the first device and the second device further includes: a support portion; and a cover portion supported by the support portion, the functional element is formed in a space formed by the support portion and the cover portion.

12. The electronic component according to claim 11, wherein The electronic component further includes a shield layer formed on the cover portion.

13. The electronic component according to claim 1 or 2, wherein A metal layer is further included between the second device and the mounting substrate, the metal layer being in contact with the second device.

14. The electronic component according to claim 1 or 2, wherein The electronic component further includes a sealing member that seals the first device and the second device.

15. The electronic component according to claim 1 or 2, wherein The functional element includes a surface acoustic wave element.

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