Electronic module, intermediate connection member, and electronic apparatus

Abstract

To reduce a noise in an intermediate connection member.SOLUTION: An electronic module comprises: a first wiring board; a second wiring board that is arranged so as to be separated from the first wiring board in a first direction; and an intermediate connection member that is arranged between the first wiring board and the second wiring board. The intermediate connection member includes: an insulation body; a plurality of first wirings that are supported by the insulation body, and are arranged in a second direction crossing to the first direction with an interval; a plurality of second wirings that are supported by the insulation body, and are arranged in the second direction with an interval; and a metal layer that is supported by the insulation body, and is arranged between the plurality of first wirings and the plurality of second wirings so as to be opposite to the plurality of first wirings and the plurality of second wirings in a third direction crossing the first direction and the second direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a technique for stacking a first wiring board and a second wiring board. [Background technology]

[0002] Electronic devices equipped with electronic modules having multiple wiring boards are known. Demand for miniaturization of electronic devices has led to a demand for high-density packaging in electronic modules. One known structure that achieves high-density packaging is a three-dimensional packaging structure formed by stacking multiple wiring boards in multiple stages. Known three-dimensional packaging structures include a method of connecting two opposing wiring boards using solder balls and a method of connecting two opposing wiring boards using an intermediate connector having wiring. Patent Document 1 discloses a three-dimensional packaging structure formed by connecting two mounting boards with an intermediate connector. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-111232 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, the demand for further miniaturization of electronic devices has led to a demand for further miniaturization of electronic modules, i.e., intermediate connectors. As the miniaturization of intermediate connectors reduces the distance between the wirings in the intermediate connector, there is a demand for reducing noise generated in the wiring in the intermediate connector.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to reduce noise in intermediate connecting members. [Means for solving the problem]

[0006] The electronic module of the present invention comprises a first wiring board, a second wiring board arranged at a distance from the first wiring board in a first direction, and an intermediate connecting member arranged between the first wiring board and the second wiring board, wherein the intermediate connecting member has an insulator, a plurality of first wirings supported by the insulator and arranged at a distance from each other in a second direction intersecting the first direction, a plurality of second wirings supported by the insulator and arranged at a distance from each other in the second direction, and a metal layer supported by the insulator and arranged between the plurality of first wirings and the plurality of second wirings so as to face the plurality of first wirings and the plurality of second wirings in a third direction intersecting the first direction and the second direction.

[0007] The intermediate connection member of the present invention is an intermediate connection member arranged between a first wiring board and a second wiring board so as to space the first wiring board and the second wiring board apart in a first direction, and is characterized by comprising: an insulator; a plurality of first wirings supported by the insulator and arranged at intervals from each other in a second direction intersecting the first direction; a plurality of second wirings supported by the insulator and arranged at intervals from each other in the second direction; and a metal layer supported by the insulator and arranged between the plurality of first wirings and the plurality of second wirings so as to face the plurality of first wirings and the plurality of second wirings in a third direction intersecting the first direction and the second direction. [Effects of the Invention]

[0008] According to the present invention, noise can be reduced in the intermediate connection member. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram of a digital camera, which is an imaging device as an example of an electronic device according to a first embodiment. [Figure 2] 1A is a plan view of an imaging module, which is an example of an electronic module according to the first embodiment, and FIG. 1B is a cross-sectional view of the imaging module according to the first embodiment. [Figure 3]1A is a perspective view of an intermediate connecting member according to a first embodiment, and FIG. 1B is a cross-sectional view of the intermediate connecting member according to the first embodiment. [Figure 4] 3(a) to 3(c) are enlarged cross-sectional views of the connection structure between a wiring board and an intermediate connection member according to the first embodiment. [Figure 5] 3(a) to 3(c) are enlarged cross-sectional views of the connection structure between a wiring board and an intermediate connection member according to the first embodiment. [Figure 6] 5(a) to 5(d) are explanatory diagrams of a method for manufacturing an imaging module according to the first embodiment. [Figure 7] 5(a) to 5(c) are explanatory diagrams of a method for manufacturing an imaging module according to the first embodiment. [Figure 8] 10(a) is a perspective view of an intermediate connecting member according to a second embodiment, and (b) is an enlarged perspective view of a portion of the intermediate connecting member according to the second embodiment. [Figure 9] 10(a) and 10(b) are enlarged cross-sectional views of a connection structure between a wiring board and an intermediate connection member according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0011] [First embodiment] 1 is an explanatory diagram of a digital camera 600, which is an imaging device as an example of an electronic device according to the first embodiment. The digital camera 600 is an interchangeable lens digital camera and includes a camera body 601. A lens unit 602 including a lens is detachable from the camera body 601. The lens unit 602 is an interchangeable lens, i.e., a lens barrel.

[0012] The camera body 601 includes a housing 611, and an imaging module 200 and an image processing module 400 disposed inside the housing 611. The imaging module 200 and the image processing module 400 are electrically connected to each other via a flexible printed wiring board 950 so that they can communicate with each other. A signal representing image data generated in the imaging module 200 is transmitted to the image processing module 400 via the flexible printed wiring board 950. The signal representing the image data is a digital signal.

[0013] The imaging module 200 is an example of an electronic module and has a three-dimensional mounting structure. The imaging module 200 includes circuit units 201 and 202 and a plurality of intermediate connection members 300, which are an example of at least one intermediate connection member. The circuit unit 201 is an example of a first circuit unit, and the circuit unit 202 is an example of a second circuit unit.

[0014] The image processing module 400 includes a printed wiring board 401 and an image processing device 402, which is a semiconductor element mounted on the printed wiring board 401. The image processing device 402 is, for example, a digital signal processor. The image processing device 402 is configured to perform image processing on image data acquired from the imaging module 200.

[0015] Fig. 2(a) is a plan view of the imaging module 200, and Fig. 2(b) is a cross-sectional view of the imaging module 200. For the sake of explanation, the circuit unit 202 is omitted from Fig. 2(a). Fig. 2(b) is a cross-sectional view of the imaging module 200 taken along line IIB-IIB shown in Fig. 2(a).

[0016] The circuit unit 201 is a printed wiring board, a printed circuit board, or a semiconductor package, and is, for example, a printed circuit board in the first embodiment. The circuit unit 202 is a printed wiring board, a printed circuit board, or a semiconductor package, and is, for example, a semiconductor package in the first embodiment.

[0017] The circuit unit 201 and the circuit unit 202 are arranged at a distance from each other so as to face each other in the Z direction, which is the stacking direction. A plurality of intermediate connection members 300 are arranged between the circuit unit 201 and the circuit unit 202 as an example of at least one intermediate connection member.

[0018] Each intermediate connection member 300 is disposed between the circuit unit 201 and the circuit unit 202 and is used to electrically and mechanically connect the circuit unit 201 and the circuit unit 202 together.

[0019] Circuit unit 202 has wiring board 221 including two main surfaces 2211 and 2212, and image sensor 222 arranged on main surface 2211 of wiring board 221. Main surface 2212 is the main surface facing wiring board 211. Main surface 2211 is the main surface on the back side of main surface 2212. Wiring board 221 is an example of a second wiring board and is a package substrate. Wiring board 221 is also a rigid printed wiring board. Image sensor 222 is an example of a second semiconductor element, such as a semiconductor chip. Circuit unit 202 also has frame 223 arranged on main surface 2211 of wiring board 221 to surround image sensor 222, and LID 224 arranged on frame 223 to face image sensor 222 with a gap therebetween. LID 224 is, for example, a glass substrate.

[0020] Wiring board 221 has a flat insulating substrate 220. The material of insulating substrate 220 is preferably a resin with a low thermal expansion coefficient. Principal surfaces 2211 and 2212 of wiring board 221 are also principal surfaces of insulating substrate 220.

[0021] The image sensor 222 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor. The image sensor 222 has a function of converting light incident via the lens unit 602 into an electrical signal and generating image data based on the electrical signal. As images become increasingly finer, the image sensor 222 is preferably sized to accommodate larger sizes such as APSC size or full size.

[0022] Circuit unit 201 includes wiring board 211 including two main surfaces 2111 and 2112, memory 212 arranged on main surface 2111 of wiring board 211, and electronic component 213 arranged on main surface 2111 of wiring board 211. Memory 212 is an example of a first semiconductor element. Main surface 2111 is a main surface facing wiring board 221. Main surface 2112 is a main surface on the back side of main surface 2111. Wiring board 211 is an example of a first wiring board, and is a rigid printed wiring board. Memory 212 is, for example, a semiconductor chip, and in the first embodiment, is capable of storing image data. Electronic component 213 is a chip component smaller in size than memory 212, and is, for example, a passive element such as a resistor, capacitor, or inductor, or an active element such as a semiconductor component. Thus, on main surface 2111 of wiring board 211, electronic component 213 and relatively large memory 212 are mounted as at least one mounted component.

[0023] Wiring board 211 has a flat insulating substrate 210. The material of insulating substrate 210 is preferably a resin such as an epoxy resin containing glass fiber. Principal surfaces 2111 and 2112 of wiring board 211 are also principal surfaces of insulating substrate 210.

[0024] In the first embodiment, main surface 2111 of wiring board 211 is disposed opposite main surface 2212 of wiring board 221 in the Z direction. Therefore, memory 212 and electronic components 213 are disposed between wiring board 211 and wiring board 221 in the Z direction. Multiple intermediate connection members 300 are disposed between wiring board 211 and wiring board 221 to maintain a distance between wiring board 211 and wiring board 221 and to prevent memory 212 and electronic components 213 from interfering with wiring board 221. In other words, multiple intermediate connection members 300 also serve as spacers.

[0025] A plurality of intermediate connection members 300 are arranged to surround memory 212 and electronic component 213. In the first embodiment, the number of intermediate connection members 300 is four. Each intermediate connection member 300 is configured to electrically connect the signal line, power line, and ground line of wiring board 211 to the signal line, power line, and ground line of wiring board 221.

[0026] Wiring board 221 has a plurality of pads 225 arranged at positions corresponding to intermediate connection members 300. The plurality of pads 225 are provided on main surface 2212. Each pad 225 is formed of a conductive material, for example, a metal such as copper. Each pad 225 is, for example, a signal pad, a power pad, a ground pad, or a dummy pad. Each intermediate connection member 300 is joined to a corresponding one of the plurality of pads 225 by a conductive joining member 352 such as solder. When joining member 352 joining intermediate connection member 300 and wiring board 221 is solder, intermediate connection member 300 can be said to be soldered to wiring board 221.

[0027] A solder resist film (not shown) may be provided on the main surface 2212. In this case, it is preferable that openings are formed in the solder resist film at positions corresponding to the pads 225. The shape of each pad 225 is not particularly limited, and may be, for example, circular or polygonal in plan view. The relationship between the solder resist film and the pads may be either SMD (Solder Mask Defined) or NSMD (Non Solder Mask Defined).

[0028] Wiring board 211 has a plurality of pads 215 arranged at positions corresponding to intermediate connection members 300, a plurality of pads 216 arranged at positions corresponding to memory 212, and a plurality of pads 217 arranged at positions corresponding to electronic components 213. These pads 215, 216, and 217 are provided on main surface 2111. Each of pads 215, 216, and 217 is formed of a conductive material, such as a metal such as copper. Each of pads 215, 216, and 217 is, for example, a signal pad, a power pad, a ground pad, or a dummy pad. Each intermediate connection member 300 is joined to a corresponding one of the plurality of pads 215 by a conductive joining member 351 such as solder. When joining member 351 joining intermediate connection member 300 and wiring board 211 is solder, intermediate connection member 300 can be said to be soldered to wiring board 221. Memory 212 is joined to the plurality of pads 216 by a conductive joining member such as solder. Each electronic component 213 is bonded to a corresponding one of the pads 217 with a conductive bonding material such as solder.

[0029] A solder resist film (not shown) may be provided on the main surface 2111. In this case, it is preferable that openings are formed in the solder resist film at positions corresponding to the pads 215, 216, and 217. The shape of the pads 215, 216, and 217 is not particularly limited, and may be, for example, circular or polygonal in plan view. The relationship between the solder resist film and the pads may be either SMD or NSMD.

[0030] The multiple intermediate connection members 300 have the same configuration. The following description focuses on one intermediate connection member 300. Fig. 3(a) is a perspective view of the intermediate connection member 300 according to the first embodiment. Fig. 3(b) is a cross-sectional view of the intermediate connection member 300.

[0031] The intermediate connection member 300 is, for example, a rectangular parallelepiped rigid wiring board. Here, the longitudinal direction of the intermediate connection member 300 is the X direction, and the width direction, i.e., thickness direction, of the intermediate connection member 300 is the Y direction. The height direction of the intermediate connection member 300, i.e., the short side direction of the intermediate connection member 300, is the Z direction. The Z direction is an example of a first direction, the Y direction is an example of a third direction, and the X direction is an example of a second direction. The X direction, Y direction, and Z direction intersect with each other. In this embodiment, the X direction, Y direction, and Z direction are perpendicular to each other. The intermediate connection member 300 preferably has a rectangular parallelepiped shape that is long in the X direction in order to electrically and mechanically connect the two circuit units 201 and 202, i.e., the two wiring boards 211 and 212, while maintaining the Z-direction spacing between the two opposing main surfaces 2111 and 2212.

[0032] Intermediate connection member 300 has end face 300L and end face 300U spaced apart in the Z direction. End face 300L faces main surface 2111 of wiring board 211 in the Z direction. End face 300U faces main surface 2212 of wiring board 221 in the Z direction.

[0033] The intermediate connection member 300 includes a flat insulating substrate 310, which is an example of an insulator, a metal layer 309 disposed inside the insulating substrate 310, and a plurality of, for example, 16, wires 330 disposed on the insulating substrate 310 and each extending in the Z direction. Each wire 330 is supported by the insulating substrate 310. In this manner, a large number of wires 330 are densely arranged on the insulating substrate 310.

[0034] The material of insulating substrate 310 is preferably a resin such as glass fiber-containing epoxy resin. In consideration of increasing the density of mounted components in imaging module 200 and ensuring a sufficient mounting area, the Y-direction thickness of intermediate connection member 300 is preferably 5 mm or less, and therefore the Y-direction thickness of insulating substrate 310 is preferably 2 mm or less. The Y-direction thickness of metal layer 309 is preferably 0.5 mm or less, taking into consideration the Y-direction thickness of intermediate connection member 300, the Y-direction thickness of insulating substrate 310, the Y-direction thickness of wiring 330, and the X-direction pitch of wiring 330.

[0035] Each wiring 330 is electrically connected to a signal line, a power line, a ground line, or a dummy line of each of the wiring boards 211 and 221. Each wiring 330 extends from one end of the insulating substrate 310 to the other end in the Z direction. A dimension H11 of each wiring 330 in the Z direction is greater than a dimension L11 of each wiring 330 in the X direction. Of the two end faces 330L, 330U of each wiring 330 in the Z direction, the end face 330L is included in the end face 300L of the intermediate connection member 300. The end face 330L is joined to a corresponding one of the multiple pads 215 in FIG. 2(b) by a joining member 351. Of the two end faces 330L, 330U of each wiring 330 in the Z direction, the end face 330U is included in the end face 300U of the intermediate connection member 300. 2(b) with bonding members 352. As described above, pads 215 of wiring board 211 and wiring 330 of intermediate connection member 300 are electrically and mechanically connected with bonding members 351, and pads 225 of wiring board 221 and wiring 330 of intermediate connection member 300 are electrically and mechanically connected with bonding members 352.

[0036] Each of the bonding members 351, 352 is configured to include a conductive material, such as solder. The material of the bonding member 352 is the same as the material of the bonding member 351. The solder included in the bonding members 351, 352 is preferably solder such as Sn-Ag-Cu or Sn-Bi. Note that each of the bonding members 351, 352 preferably includes solder, but is not limited thereto. For example, each of the bonding members 351, 352 may include an inorganic material such as copper, silver, or aluminum, or an organic material such as conductive rubber. Furthermore, each of the bonding members 351, 352 may be, for example, a cured product of an organic conductive adhesive.

[0037] The insulating substrate 310 includes two insulating base materials 311 and 312. The insulating base material 311 is an example of a first insulating base material, and the insulating base material 312 is an example of a second insulating base material. Each of the insulating base materials 311 and 312 is a flat insulating member. The insulating base material 312 is disposed at a distance from the insulating base material 311 in the Y direction. Of the 16 wires 330, a plurality of wires, i.e., eight wires 3301 in this embodiment, are disposed on the insulating base material 311 of the insulating substrate 310. Of the plurality of wires 330, a plurality of wires other than the wire 3301, i.e., eight wires 3302 in this embodiment, are disposed on the insulating base material 312 of the insulating substrate 310. Each of the wires 3301 is an example of a first wire. Each of the wires 3302 is an example of a second wire. The plurality of wires 3301 are disposed at a distance from each other in the X direction. The plurality of wires 3302 are disposed at a distance from each other in the X direction.

[0038] Each wiring 330 and metal layer 309 is configured to include a conductive material, for example, an inorganic material such as copper, silver, or aluminum, or an organic material such as conductive rubber, etc. Each wiring 330 may be formed by pressing a metal foil, or may be formed by applying a conductive paste using a dispenser or the like and baking it.

[0039] The plurality of wirings 3301 are arranged on one of two outer surfaces of the insulating substrate 310 that are spaced apart in the Y direction, and the plurality of wirings 3302 are arranged on the other outer surface of the two outer surfaces. That is, the insulating base material 311 of the insulating substrate 310 is arranged between the plurality of wirings 3301 and the metal layer 309, and the insulating base material 312 of the insulating substrate 310 is arranged between the plurality of wirings 3302 and the metal layer 309.

[0040] Insulating base material 311 of insulating substrate 310 has surface 3111 facing insulating base material 312 and surface 3112 on the back side of surface 3111. Insulating base material 312 of insulating substrate 310 has surface 3121 facing insulating base material 311 and surface 3122 on the back side of surface 3121. Surfaces 3111 and 3121 face each other. Surfaces 3112 and 3122 are also outer surfaces of insulating substrate 310. That is, multiple wirings 3301 are arranged on surface 3112, and multiple wirings 3302 are arranged on surface 3122. Metal layer 309 is arranged between surface 3111 and surface 3121.

[0041] In this way, the metal layer 309 is disposed between the insulating base material 311 and the insulating base material 312, between the plurality of wirings 3301 and the plurality of wirings 3302 so as to be sandwiched between the plurality of wirings 3301 and the plurality of wirings 3302. As a result, the metal layer 309 faces the plurality of wirings 3301 and the plurality of wirings 3302 in the Y direction.

[0042] The metal layer 309 extends from one end to the other end of the insulating base materials 311, 312 in the Z direction. Two end faces 309L, 309U of the metal layer 309 in the Z direction are exposed to the outside. The end face 309L is included in the end face 300L of the intermediate connection member 300. The end face 309U is included in the end face 300U of the intermediate connection member 300.

[0043] Figures 4(a) to 4(c) are enlarged cross-sectional views of the connection structure between wiring board 211 and intermediate connection member 300 according to the first embodiment. Figures 5(a) to 5(c) are enlarged cross-sectional views of the connection structure between wiring board 221 and intermediate connection member 300 according to the first embodiment. Figures 4(a) to 5(c) show cross sections of the connection structure at different positions in the X direction.

[0044] The wiring board 211 includes a ground line 211G, a plurality of signal lines 211S1, 211S2, and 211S3, and a power line (not shown). The ground line 211G is an example of a first ground. Each of the signal lines 211S1, 211S2, and 211S3 is used to transmit a digital signal. The ground line 211G includes a plurality of ground pads 215G1 and 215G2. Each of the ground pads 215G1 and 215G2 is an example of a first ground pad. The signal line 211S1 includes a signal pad 215S1. The signal line 211S2 includes a signal pad 215S2. The signal line 211S3 includes a signal pad 215S3.

[0045] The wiring board 221 includes a ground line 221G, a plurality of signal lines 221S1, 221S2, and 221S3, and a power line (not shown). The ground line 221G is an example of a second ground. Each of the signal lines 221S1, 221S2, and 221S3 is used to transmit digital signals. The ground line 221G includes a plurality of ground pads 225G1 and 225G2. Each of the ground pads 225G1 and 225G2 is an example of a second ground pad. The signal line 221S1 includes a signal pad 225S1. The signal line 221S2 includes a signal pad 225S2. The signal line 221S3 includes a signal pad 225S3.

[0046] The multiple wirings 330, i.e., the multiple wirings 3301 and the multiple wirings 3302, include at least one signal wiring, at least one ground wiring, and at least one power wiring. In the example of FIGS. 4(a) to 5(c), the multiple wirings 3301 include multiple ground wirings 330G11, 330G21, 330G31, and 330G41, and multiple signal wirings 330S11 and 330S21. The multiple wirings 3302 include multiple ground wirings 330G12 and 330G22, and multiple signal wirings 330S12, 330S22, 330S32, and 330S42. Each of the signal wirings 330S11, 330S21, 330S12, 330S22, 330S32, and 330S42 is used to transmit a digital signal. The ground wirings 330G11 and 330G21 are an example of a first ground wiring. The ground wiring 330G12 is an example of a second ground wiring. The ground wirings 330G31 and 330G41 are an example of a third ground wiring. The ground wiring 330G22 is an example of a fourth ground wiring.

[0047] Signals transmitted through each of the signal wirings 330S11 to 330S42 are subject to interference noise such as mutual interference, radiation noise, or conduction noise. The metal layer 309 is wider in the X direction than each of the signal wirings 330S11 to 330S42. According to the first embodiment, the metal layer 309 disposed near each of the signal wirings 330S11 to 330S42 reduces these noises, improving the quality of the transmitted signals.

[0048] Specifically, since the metal layer 309 is disposed between the signal wiring 330S11 and the signal wiring 330S22, interference noise between the signal wiring 330S11 and the signal wiring 330S22 can be reduced. Similarly, since the metal layer 309 is disposed between the signal wiring 330S21 and the signal wiring 330S42, interference noise between the signal wiring 330S21 and the signal wiring 330S42 can be reduced. Furthermore, interference noise between each of the signal wirings 330S11 to 330S42 and another signal wiring or a power wiring adjacent to it in the X direction can also be reduced. Furthermore, since the metal layer 309 is disposed near each of the signal wirings 330S11 to 330S42, radiation noise and conduction noise in each of the signal wirings 330S11 to 330S42 can be reduced.

[0049] When the bonding members 351 and 352 include solder, the metal layer 309 is preferably soldered to at least one of the wiring board 211 and the wiring board 221. In the first embodiment, the metal layer 309 is soldered to both the wiring board 211 and the wiring board 221. In the first embodiment, the metal layer 309 is bonded to the ground pads 215G1 and 215G2 with bonding members 351G1 and 351G2, respectively, so as to be electrically connected to the ground line 211G. In the first embodiment, the end surface 309L of the metal layer 309 is exposed to the outside, and therefore the end surface 309L is bonded to the ground pads 215G1 and 215G2 with bonding members 351G1 and 351G2, respectively. This causes the metal layer 309 to have the same potential as the ground line 211G. The ground pads 215G1 and 215G2 face the end surface 309L of the metal layer 309 in the Z direction.

[0050] The ground wiring 330G11 is joined to the ground pad 215G1 with a joining member 351G1, thereby being electrically connected to the metal layer 309 and the ground line 211G and having the same potential as the metal layer 309 and the ground line 211G. The ground pad 215G1 faces the end surface 330L of the ground wiring 330G11 in the Z direction.

[0051] In the first embodiment, the ground pad 215G1 faces the end surface 309L of the metal layer 309 and the end surface 330L of the ground wiring 330G11 in the Z direction.

[0052] The ground wiring 330G21 is joined to the ground pad 215G2 by a joining member 351G2, thereby being electrically connected to the metal layer 309 and the ground line 211G and having the same potential as the metal layer 309 and the ground line 211G. The ground pad 215G2 faces the end surface 330L of the ground wiring 330G21 in the Z direction.

[0053] The ground wiring 330G12 is joined to the ground pad 215G2 with a joining member 351G2, thereby electrically connecting to the metal layer 309, the ground line 211G, and the ground wiring 330G21. Therefore, the ground wiring 330G12 has the same potential as the metal layer 309, the ground line 211G, and the ground wiring 330G21. The ground pad 215G2 faces an end surface 330L of the ground wiring 330G12 in the Z direction.

[0054] In the first embodiment, the ground pad 215G2 has a larger area than the ground pad 215G1 when viewed in the Z direction. The ground pad 215G2 faces the end face 300L of the metal layer 309, the end face 330L of the ground wiring 330G21, and the end face 330L of the ground wiring 330G12 in the Z direction.

[0055] The signal wiring 330S12 is electrically connected to the signal line 211S1 by being joined to the signal pad 215S1 with a joining member 351S1. The signal wiring 330S11 is electrically connected to the signal line 211S2 by being joined to the signal pad 215S2 with a joining member 351S2. The signal wiring 330S22 is electrically connected to the signal line 211S3 by being joined to the signal pad 215S3 with a joining member 351S3.

[0056] In the first embodiment, the metal layer 309 is joined to the ground pads 225G1 and 225G2 by respective joining members 352G1 and 352G2 so as to be electrically connected to the ground line 221G. In the first embodiment, an end surface 309U of the metal layer 309 is exposed to the outside, and therefore the end surface 309U is joined to the ground pads 225G1 and 225G2 by respective joining members 352G1 and 352G2. This sets the metal layer 309 at the same potential as the ground line 221G. The ground pads 225G1 and 225G2 face the end surface 309U of the metal layer 309 in the Z direction.

[0057] The ground wiring 330G31 is joined to the ground pad 225G1 by a joining member 352G1, thereby being electrically connected to the metal layer 309 and the ground line 221G and having the same potential as the metal layer 309 and the ground line 221G. The ground pad 225G1 faces an end surface 330U of the ground wiring 330G31 in the Z direction.

[0058] In the first embodiment, the ground pad 225G1 faces an end surface 309U of the metal layer 309 and an end surface 330U of the ground wiring 330G31 in the Z direction.

[0059] The ground wiring 330G41 is joined to the ground pad 225G2 by a joining member 352G2, thereby being electrically connected to the metal layer 309 and the ground line 221G and having the same potential as the metal layer 309 and the ground line 221G. The ground pad 225G2 faces an end surface 330U of the ground wiring 330G41 in the Z direction.

[0060] The ground wiring 330G22 is joined to the ground pad 225G2 with a joining member 352G2, thereby electrically connecting to the metal layer 309, the ground line 221G, and the ground wiring 330G41. Therefore, the ground wiring 330G22 has the same potential as the metal layer 309, the ground line 221G, and the ground wiring 330G41. The ground pad 225G2 faces an end surface 330U of the ground wiring 330G22 in the Z direction.

[0061] In the first embodiment, the ground pad 225G2 has a larger area than the ground pad 225G1 when viewed in the Z direction. The ground pad 225G2 faces an end face 300U of the metal layer 309, an end face 330U of the ground wiring 330G41, and an end face 330U of the ground wiring 330G22 in the Z direction.

[0062] The signal wiring 330S32 is electrically connected to the signal line 221S1 by being bonded to the signal pad 225S1 with a bonding member 352S1. The signal wiring 330S21 is electrically connected to the signal line 221S2 by being bonded to the signal pad 225S2 with a bonding member 352S2. The signal wiring 330S42 is electrically connected to the signal line 221S3 by being bonded to the signal pad 225S3 with a bonding member 352S3.

[0063] As described above, since the metal layer 309 is at ground potential, noise in signals transmitted through each signal wiring can be effectively reduced.

[0064] 4(a) may be joined by a bonding member to a ground pad (not shown) of ground line 221G of wiring board 221 together with metal layer 309, as in the case of FIG. 5(a). Furthermore, signal line 330S12 shown in FIG. 4(a) may be joined by a bonding member to a signal pad (not shown) of a signal line (not shown) of wiring board 221, as in the case of FIG. 5(a).

[0065] 4(b) may be joined to a ground pad (not shown) of ground line 221G of wiring board 221 together with metal layer 309 by a joining member, as in FIG. 5(b).

[0066] 4(c) may be joined by a joining member to a signal pad (not shown) of a signal line (not shown) on the wiring board 221, similar to FIG. 5(c). Further, signal wiring 330S22 shown in FIG. 4(c) may be joined by a joining member to a signal pad (not shown) of a signal line (not shown) on the wiring board 221, similar to FIG. 5(c).

[0067] 5(a) may be joined by a bonding member to a ground pad (not shown) of ground line 211G of wiring board 211 together with metal layer 309, similar to FIG. 4(a). Further, signal line 330S32 shown in FIG. 5(a) may be joined by a bonding member to a signal pad (not shown) of a signal line (not shown) of wiring board 211, similar to FIG. 4(a).

[0068] 4(b), the ground wirings 330G41 and 330G22 shown in FIG. 5(b) may be joined to a ground pad (not shown) of the ground line 211G of the wiring board 211 together with the metal layer 309 by a joining member.

[0069] 5(c) may be joined by a joining member to a signal pad (not shown) of a signal line (not shown) on the wiring board 211, similar to FIG. 4(c). Further, signal wiring 330S42 shown in FIG. 5(c) may be joined by a joining member to a signal pad (not shown) of a signal line (not shown) on the wiring board 211, similar to FIG. 4(c).

[0070] 4(a) to 5(c), the signal wirings 330S11, 330S21, 330S12, 330S22, 330G32, and 330G42 may be replaced with power wirings, and the corresponding pads may be power pads. Also, any of these wirings may be joined to a dummy pad.

[0071] A larger current flows through the ground wirings 330G11, 330G21, 330G31, 330G41, 330G12, and 330G22 included in the intermediate connection member 300 than through the signal wirings. For this reason, each of the ground wirings 330G11 to 330G22 is required to have lower resistance. Therefore, each of the ground wirings 330G11 to 330G22 may be made of a conductive material with lower resistance or a wire with a larger diameter.

[0072] The width in the X direction and the thickness in the Y direction of each wiring 330 can be determined depending on the purpose of the wiring and the purpose of the electronic component 320 to be connected, but is preferably 0.01 mm or more and 2 mm or less. In consideration of increasing the density of the multiple wirings 330, the width in the X direction and the thickness in the Y direction of each wiring 330 are more preferably 0.5 mm or less. The width (thickness) in the Y direction of the metal layer 309 is preferably wider than the distance D2 in the X direction between two adjacent wirings 3301 among the multiple wirings 3301.

[0073] The length of intermediate connection member 300 in the X direction is preferably shorter than the length of one side of each wiring board 211, 221. The width of intermediate connection member 300 in the Y direction is preferably as thin as possible to maximize the mounting area available for mounting components on wiring board 211. The height of intermediate connection member 300 in the Z direction is preferably greater than the height of the tallest mounted component, such as memory 212. For example, if a mounted component with a height of 1.6 mm is mounted on wiring board 211, the height of intermediate connection member 300 in the Z direction is preferably 1.6 mm or greater. The number and pitch of wires 330 of intermediate connection member 300 depend on the number of pads on wiring boards 211, 221 and the pitch between the pads. The pitch of multiple wires 3301 and the pitch of multiple wires 3302 may be the same or different.

[0074] The distance D0 in the Y direction between any one of the plurality of signal wirings 330S11 to 330S42, for example, signal wiring 330S12, and the metal layer 309 is preferably equal to or less than the distance D1 between the two nearest wirings among the plurality of wirings 3301 and the plurality of wirings 3302. In the first embodiment, the two nearest wirings among the plurality of wirings 3301 and the plurality of wirings 3302 are one wiring 3301 and one wiring 3302 that are adjacent to each other in the Y direction with the metal layer 309 sandwiched between them. Also, in the first embodiment, the distance D0 is preferably equal to or less than the distance D2 between two wirings 3301 that are adjacent to each other in the X direction among the plurality of wirings 3301. In this way, by arranging each of the signal wirings 330S11 to 330S42 close to the metal layer 309, noise in the signal can be more effectively reduced.

[0075] The metal layer 309 is preferably a solid metal member, but is not limited to this. For example, the metal layer 309 may be a mesh-like metal member, or a metal member in which multiple metal plates arranged at intervals in the X direction are connected by wiring. The metal layer 309 is preferably a continuous metal member.

[0076] Next, a description will be given of a method for manufacturing the imaging module 200. Figures 6(a) to 7(c) are explanatory diagrams of the individual steps of the method for manufacturing the imaging module 200.

[0077] 6(a), a wiring board 211 is prepared. The wiring board 211 has a plurality of pads 215, a plurality of pads 216, and a plurality of pads 217.

[0078] Next, in the step shown in FIG. 6(b), a conductive paste PA is placed on each of the pads 215-217. The conductive paste PA is preferably a conductive adhesive such as solder paste or silver paste. The conductive paste PA may also be a sheet-like conductive adhesive. The conductive paste PA is preferably a solder paste containing solder powder and flux. The conductive paste PA can be applied by, for example, screen printing or a dispenser. The conductive paste PA may be applied so as to cover the entire exposed portion of each of the pads 215-217, or may be applied so as to cover only a portion of the exposed portion of each of the pads 215-217, as in offset printing.

[0079] 6(c), wiring board 211 is placed in a predetermined position with pads 215-217 on wiring board 211 facing vertically upward. Then, memory 212, electronic component 213, and intermediate connection member 300 are placed on main surface 2111 of wiring board 211. That is, memory 212 is placed on pad 216 while in contact with conductive paste PA, and electronic component 213 is placed on pad 217 while in contact with conductive paste PA. Intermediate connection member 300 is placed on pad 215 by bringing each wiring 330 into contact with the corresponding conductive paste PA. Memory 212, electronic component 213, and intermediate connection member 300 are placed on wiring board 211 by a mounter (not shown).

[0080] Next, the conductive paste PA is heated to a temperature equal to or higher than the melting point of the metal powder, e.g., solder powder, contained in the conductive paste PA. This melts the solder powder and causes the molten solder to coagulate. The molten solder is then cooled and solidified. As a result, the memory 212, electronic component 213, and intermediate connection member 300 are joined to the wiring board 211, as shown in FIG. 6(d). The heating step of heating and melting the conductive paste PA and the cooling step of cooling and solidifying the molten metal, both shown in FIG. 6(d), can be performed in a reflow furnace, for example. The intermediate connection member 300 is joined to the corresponding pad 215 by the corresponding joining member 351.

[0081] Next, in the step shown in FIG. 7(a), a conductive paste PB is placed on each pad 225 of the wiring board 221. The conductive paste PB is preferably a conductive adhesive such as solder paste or silver paste. The conductive paste PB may also be a sheet-like conductive adhesive. The conductive paste PB is preferably a solder paste containing solder powder and flux, and is preferably made of the same material as the conductive paste PA described above. The conductive paste PB can be applied by, for example, screen printing or a dispenser. The conductive paste PB may be applied so as to cover the entire exposed portion of each pad 225, or may be applied so as to cover only a portion of the exposed portion of each pad 225, as in offset printing.

[0082] Then, wiring board 221 is placed on end surface 300U of intermediate connection member 300 with each pad 225 on wiring board 221 facing vertically downward. That is, conductive paste PB on pad 225 is brought into contact with end surface 330U (FIG. 3(a)) of the corresponding wiring 330. Circuit unit 202 is placed on intermediate connection member 300 by a mounter (not shown).

[0083] Next, the conductive paste PB is heated to a temperature equal to or higher than the melting point of the metal powder, e.g., solder powder, contained in the conductive paste PB. This melts the solder powder and causes the molten solder to coagulate. The molten solder is then cooled, causing it to solidify. As a result, as shown in FIG. 7(b), the intermediate connection member 300 and the wiring board 221 are joined by the corresponding joining members 352. The steps of heating and cooling the conductive paste PB can be performed, for example, in a reflow furnace.

[0084] 7(c), the image sensor 222, the frame 223, and the LID 224 are mounted on the wiring board 221 to fabricate the circuit unit 202. This completes the imaging module 200. Pads (not shown) for bonding to the image sensor 222 with wires such as gold are formed in advance on the wiring board 221.

[0085] The imaging module 200 can be manufactured through the above-described process. This enables high-density packaging in the imaging module 200. Furthermore, it becomes possible to manufacture a miniaturized imaging module 200 with high precision.

[0086] [Second embodiment] Next, an intermediate connecting member according to a second embodiment will be described. Fig. 8(a) is a perspective view of an intermediate connecting member 300A according to the second embodiment. Fig. 8(b) is an enlarged perspective view of a portion of the intermediate connecting member 300A. The electronic module of the second embodiment is obtained by replacing the intermediate connecting member 300 shown in Fig. 2(a) etc. in the imaging module 200 of the first embodiment with the intermediate connecting member 300A. In the second embodiment, the same components as those in the first embodiment will be designated by the same reference numerals and will not be described again.

[0087] The intermediate connection member 300A is, for example, a rectangular parallelepiped rigid wiring board. The longitudinal direction of the intermediate connection member 300A is the X direction, and the width direction, i.e., thickness direction, of the intermediate connection member 300A is the Y direction. The height direction of the intermediate connection member 300A, i.e., the short side direction of the intermediate connection member 300A, is the Z direction. The Z direction is an example of the first direction, the Y direction is an example of the third direction, and the X direction is an example of the second direction. The X direction, Y direction, and Z direction intersect with each other. In this embodiment, the X direction, Y direction, and Z direction are perpendicular to each other.

[0088] The intermediate connection member 300A includes an insulating substrate 310A, which is an example of an insulator, a metal layer 309A, and a plurality of wirings 330A extending in the Z direction. Each wiring 330A is supported by the insulating substrate 310A. The insulating substrate 310A includes an insulating substrate 311A, which is an example of a first insulating substrate, an insulating substrate 312A, which is an example of a second insulating substrate, and an insulating layer 313A disposed between the insulating substrates 311A ​​and 312A. The metal layer 309A is disposed inside the insulating substrate 310A, between the insulating substrates 311A ​​and 312A in the second embodiment. The plurality of wirings 330A are disposed between the insulating substrates 311A ​​and 312A. The plurality of wirings 330A are arranged in a staggered pattern with the metal layer 309A sandwiched between them. The plurality of wirings 330A includes a plurality of wirings 330A1 arranged on insulating base material 311A ​​and a plurality of wirings 330A2 arranged on insulating base material 312A. Each wiring 330A1 is an example of a first wiring. Each wiring 330A2 is an example of a second wiring. The material of each of insulating base materials 311A, 312A is preferably a resin such as an epoxy resin containing glass fiber.

[0089] Each wiring 330A is electrically connected to a signal line, a power line, or a ground line of each of wiring boards 211 and 221 in FIG. 2(b). Each of insulating base materials 311A ​​and 312A is a flat insulating member. Insulating base material 312A is disposed at a distance from insulating base material 311A ​​in the Y direction. The multiple wirings 330A1 are disposed at a distance from each other in the X direction. The multiple wirings 330A2 are disposed at a distance from each other in the X direction.

[0090] Each wiring 330A and metal layer 309A is configured to include a conductive material, for example, an inorganic material such as copper, silver, or aluminum, or an organic material such as conductive rubber, etc. Each wiring 330A may be formed by pressing a metal foil, or may be formed by applying a conductive paste with a dispenser or the like and baking it.

[0091] The plurality of wirings 330A1 are disposed between the insulating substrate 311A ​​and the metal layer 309A, and the plurality of wirings 330A2 are disposed between the insulating substrate 312A and the metal layer 309A. The insulating substrate 311A ​​has a surface 3111A facing the insulating substrate 312A. The insulating substrate 312A has a surface 3121A facing the insulating substrate 311A. That is, the surfaces 3111A and 3121A face each other. The surface 3111A has a plurality of grooves formed therein in which the plurality of wirings 330A1 are disposed. The surface 3121A has a plurality of grooves formed therein in which the plurality of wirings 330A2 are disposed. The metal layer 309A is disposed between the surfaces 3111A and 3121A via the insulating layer 313A. The insulating layer 313A is a cured product such as an adhesive, and is formed of a material different from the insulating substrates 311A ​​and 312A.

[0092] In this way, the metal layer 309A is disposed between the insulating base material 311A ​​and the insulating base material 312A, between the plurality of wirings 330A1 and the plurality of wirings 330A2 so as to be sandwiched between the plurality of wirings 330A1 and the plurality of wirings 330A2, so that the metal layer 309A faces the plurality of wirings 330A1 and the plurality of wirings 330A2 in the Y direction.

[0093] The metal layer 309A extends from one end to the other end of the insulating base materials 311A, 312A in the Z direction. Two end faces 309LA, 309UA of the metal layer 309A in the Z direction are exposed to the outside.

[0094] The plurality of wirings 330A1 and the plurality of wirings 330A2 include at least one signal wiring 330SA. In the example of Fig. 8(a), the signal wiring 330SA is included in the plurality of wirings 330A2. Because the signal wiring 330SA is disposed near the metal layer 309A, noise in the signal transmitted through the signal wiring 330SA is reduced, improving the quality of the transmitted signal.

[0095] In the second embodiment, each wiring 330A is a wire with a diameter of, for example, 0.2 mm. The pitch between the multiple wirings 330A is, for example, 0.4 mm. The thickness of the metal layer 309A is, for example, 0.02 mm. The thickness of the insulating layer 313A is, for example, 0.02 mm.

[0096] The distance D10 in the Y direction between the signal wiring 330SA and the metal layer 309A is preferably equal to or less than the distance D11 between the two nearest wirings among the plurality of wirings 330A1 and the plurality of wirings 330A2. In the second embodiment, the two nearest wirings among the plurality of wirings 330A1 and the plurality of wirings 330A2 are one wiring 330A1 and one wiring 330A2 adjacent to each other with the metal layer 309A interposed therebetween. This wiring 330A2 is, for example, the signal wiring 330SA. Furthermore, in the second embodiment, the distance D10 is preferably equal to or less than the distance D12 between the two nearest wirings 330A1 in the X direction among the plurality of wirings 330A1. In this way, by arranging the signal wiring 330SA close to the metal layer 309A, noise in the signal can be more effectively reduced.

[0097] The metal layer 309A is preferably a solid metal member, but is not limited to this. For example, the metal layer 309A may be a mesh-like metal member, or a metal member in which multiple metal plates arranged at intervals in the X direction are connected by wiring. The metal layer 309A is preferably a continuous metal member.

[0098] An imaging module including intermediate connection member 300A is free from solder joint defects and can fully guarantee the optical performance of image sensor 222. Furthermore, in intermediate connection member 300A, metal layer 309A sandwiched between multiple wirings 330A reduces noise in transmitted signals, improving the quality of the transmitted signals.

[0099] [Third embodiment] Next, an intermediate connection member according to a third embodiment will be described. Figures 9(a) and 9(b) are enlarged cross-sectional views of the connection structure between wiring board 221 and intermediate connection member 300B according to the third embodiment. Figures 9(a) and 9(b) show cross sections of the connection structure at different positions in the X direction. In the third embodiment, the same components as in the first embodiment will be designated by the same reference numerals, and descriptions thereof will be omitted.

[0100] In the first embodiment, the metal layer 309 is bonded to the ground pad together with the ground wiring, but this is not limiting. In the third embodiment, the connection structure shown in FIGS. 5(a) and 5(b) described in the first embodiment is modified to the connection structure shown in FIGS. 9(a) and 9(b). Similar to the first embodiment, the intermediate connection member 300B of the third embodiment includes an insulating substrate 310 including insulating base materials 311 and 312, a metal layer 309, and a signal wiring 330S32. Although not shown, the intermediate connection member 300B also includes a plurality of first wirings arranged on the insulating base material 311 and a plurality of second wirings arranged on the insulating base material 312. The first wirings are spaced apart from one another in the X direction, and the second wirings are spaced apart from one another in the X direction. Similar to the first embodiment, the first wirings are arranged on the main surface 3112 of the insulating base material 311. Similar to the first embodiment, the plurality of second wirings are arranged on the main surface 3122 of the insulating substrate 312. The signal wiring 330S32 shown in Fig. 9(a) is, for example, one of the plurality of second wirings.

[0101] 9(a), the signal wiring 330S32 is joined to the signal pad 225S1 by a joining member 352S1. The end surface 309U of the metal layer 309 is joined to the ground pad 225G1 of the wiring board 221 by a joining member 352GB1. Neither the multiple first wirings nor the multiple second wirings of the intermediate connection member 300B are joined to the ground pad 225G1.

[0102] 9(b), end surface 309U of metal layer 309 is joined to ground pad 225G2 of wiring board 221 by joining member 352GB2. Neither the multiple first wirings nor the multiple second wirings of intermediate connection member 300B are joined to ground pad 225G2.

[0103] Even with the above configuration, noise in the transmitted signal is reduced and the quality of the transmitted signal is improved. Note that the connection structure between the intermediate connection member 300B and the wiring board 211 shown in Figure 2(b) may also be the same as the connection structure shown in Figures 9(a) and 9(b).

[0104] Example 1 A specific example of a manufacturing method for the imaging module 200 described in the first embodiment will be described. The thickness of the metal layer 309 in the Y direction was 0.2 mm. The intermediate connection member 300 was a strip-like member with a length in the X direction of 41.0 mm, a width (thickness) in the Y direction of 1.0 mm, and a height in the Z direction of 1.8 mm. The pitch in the X direction of the multiple wirings 3301 and the pitch in the X direction of the multiple wirings 3302 were 0.4 mm. The total number of the multiple wirings 330 was 140. A substrate with a low thermal expansion coefficient was used for the insulating substrate 310. The external dimensions of the insulating substrate 310 were a length in the X direction of 41.0 mm, a height in the Z direction of 1.8 mm, and a thickness in the Y direction of 0.4 mm. Each wiring 330 was made of copper and had a thickness of 0.015 mm and a width of 0.2 mm. The number of the multiple wirings 3301 was 70, and the number of the multiple wirings 3302 was 70. The pitch of the wiring 330 in the X direction was 0.4 mm. A copper plate with a length in the X direction of 41.0 mm, a height in the Z direction of 1.8 mm, and a thickness in the Y direction of 0.2 mm was used as the metal layer 309. This metal layer 309 was sandwiched between insulating base materials 311 and 312 and bonded together, resulting in an intermediate connection member 300 with a thickness of 1.0 mm. An intermediate connection member 300 with the above configuration was prepared.

[0105] 6(a) was prepared. A solder resist (not shown) was formed on a main surface 2111 of the wiring board 211, partially covering each of the pads 215 to 217. Openings were formed in the solder resist at positions corresponding to each of the pads 215 to 217, and each of the pads 215 to 217 was partially exposed.

[0106] Insulating substrate 210 of wiring board 211 was made of FR-4. The external dimensions of wiring board 211 in a plan view were 50.0 mm × 50.0 mm. Furthermore, electronic components such as capacitors and resistors (not shown) were pre-mounted on main surface 2112 of wiring board 211. Each of pads 215 to 217 of wiring board 211 was made of copper. Pads 215, excluding ground pads 215G1 and 215G2 to which intermediate connection member 300 was connected, had a width of 0.2 mm and a length of 0.3 mm. Pads 215 were arranged at a pitch of 0.4 mm. Pads 216 and 217 had a width of 0.2 mm and a length of 0.2 mm. Ground pad 215G1 had a width of 0.2 mm and a length of 0.6 mm. Ground pad 215G2 had a width of 0.2 mm and a length of 1.2 mm.

[0107] As shown in FIG. 6(b), each conductive paste PA was screen-printed onto each pad 215-217 of the wiring board 211. A printing plate with a thickness of 0.02 mm was used for the screen printing. The conductive paste PA was a solder paste containing Sn-Ag-Cu solder powder and flux. The alloy composition of the solder powder contained in the solder paste was tin, balance silver, 3 parts copper, and 3 parts copper, and the melting point of the solder powder was 220°C. The average particle size of the solder powder was 40 μm.

[0108] A memory 212 was prepared with solder balls already connected to its back surface. Each pad 216 of the wiring board 211 was arranged in a position corresponding to a solder ball of the memory 212. The external dimensions of the memory 212 were 16.0 mm in length, 16.0 mm in width, and 1.6 mm in height. Four intermediate connection members 300 were also prepared.

[0109] 6(c), memory 212, electronic components 213, and intermediate connection members 300 were placed using a mounter on wiring board 211 to which conductive pastes 615 to 617 had been applied. The four intermediate connection members 300 were placed on wiring board 211 so as to surround memory 212 and electronic components 213.

[0110] In each of the four intermediate connection members 300, end face 330L of each wiring 330 was aligned with each pad 215 of wiring board 211, and each intermediate connection member 300 was placed on wiring board 211. Furthermore, solder balls (not shown) of memory 212 were aligned with pads 216 of wiring board 211, and memory 212 was placed on wiring board 211. The width of insulating substrate 310 of intermediate connection member 300 was 1.0 mm, and intermediate connection member 300 was freestanding on wiring board 211.

[0111] Next, the wiring board 211 with these components mounted thereon was placed in a reflow furnace, and the conductive paste PA was heated to a temperature above the melting point of the solder powder. After the solder powder melted and the molten solder coagulated, the molten solder was cooled to a temperature below the melting point of the solder and solidified. This joined the memory 212, electronic component 213, and intermediate connector 300 to the wiring board 211, as shown in FIG. 6(d).

[0112] Next, as shown in FIG. 7(a), a conductive paste PB was screen-printed onto each pad 225 of the wiring board 221. The conductive paste PB was a solder paste containing Sn-Ag-Cu solder powder and flux. The alloy composition of the solder powder contained in the solder paste was tin, balance silver, 3 copper, and 3, and the melting point of the solder powder was 220°C. The average particle size of the solder powder was 40 μm.

[0113] Next, each pad 225 of wiring board 221 supplied with conductive paste PB was aligned with end face 330U of each wiring 330 of each intermediate connection member 300, and wiring board 221 was placed on four intermediate connection members 300. A solder resist (not shown) partially covering each pad 225 was formed on main surface 2212 of wiring board 221. Openings were formed in the solder resist at positions corresponding to each pad 225, exposing a portion of each pad 225.

[0114] An insulating substrate with a low thermal expansion coefficient was used for insulating substrate 220 of wiring board 221. The external dimensions of wiring board 221 in a plan view were 52.0 mm × 52.0 mm. Each pad 225 of wiring board 221 was made of copper. Pads 225 to which intermediate connection member 300 was connected were 0.2 mm wide and 0.3 mm long, and were arranged at a pitch of 0.4 mm.

[0115] 7(b), the assembly, in which wiring board 221 was mounted on intermediate connection member 300, was placed in a reflow furnace, and conductive paste PB was heated to a temperature equal to or higher than the melting point of the solder powder. After the solder powder melted and the molten solder coagulated, the molten solder was cooled to a temperature below the melting point of the solder and solidified. This joined wiring board 221 to intermediate connection member 300.

[0116] 7(c), the image sensor 222, frame 223, and LID 224 were mounted on the wiring board 221 to fabricate the circuit unit 202, thereby obtaining the imaging module 200. The imaging module 200 fabricated through the above process had no solder joint defects and was able to fully guarantee the optical performance of the image sensor 222. Furthermore, the metal layer 309 of the intermediate connector 300 reduced noise in the transmitted signal, improving the quality of the transmitted signal.

[0117] The present invention is not limited to the above-described embodiments, and many modifications are possible within the technical concept of the present invention. Furthermore, the effects described in the embodiments are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments.

[0118] In the above-described embodiment, the electronic device is described as a digital camera, but the present invention is not limited thereto. For example, the electronic device may be a mobile communication device. For example, the electronic device may be an information device such as a smartphone or a personal computer, or a communication device such as a modem or a router. Alternatively, the electronic device may be office equipment such as a printer or a copier, medical equipment such as a radiographic device, a magnetic imaging device, an ultrasound imaging device, or an endoscope, industrial equipment such as a robot or a semiconductor manufacturing device, or transportation equipment such as a vehicle, an airplane, or a ship. When wiring is required in the limited space within the housing of an electronic device, using the intermediate connection member 300 enables the electronic device to be miniaturized and highly dense. The electronic module of the present invention is applicable to any electronic device. [Explanation of symbols]

[0119] 211... wiring board (first wiring board), 221... wiring board (second wiring board), 300... intermediate connection member, 309... metal layer, 310... insulating substrate (insulator), 3301... wiring (first wiring), 3302... wiring (second wiring)

Claims

1. A first wiring board; a second wiring board arranged at a distance from the first wiring board in a first direction; an intermediate connection member disposed between the first wiring board and the second wiring board; The intermediate connection member is An insulator; a plurality of first wirings supported by the insulator and arranged at intervals in a second direction intersecting the first direction; a plurality of second wirings supported by the insulator and arranged at intervals in the second direction; a metal layer supported by the insulator and disposed between the first wirings and the second wirings so as to face the first wirings and the second wirings in a third direction intersecting the first direction and the second direction; a portion of the metal layer sandwiched between the insulators is joined to one of the first wiring board or the second wiring board by a first conductive joining member; 1. An electronic module comprising:

2. the plurality of first wirings and the plurality of second wirings include signal wiring that is joined to the one of the first wiring board or the second wiring board by a conductive second joining member and is used for transmitting signals; When viewed in the third direction, the second bonding member overlaps the metal layer.

2. The electronic module of claim 1.

3. The plurality of first wirings and the plurality of second wirings include signal wiring that is joined to the one of the first wiring board or the second wiring board with a conductive second joining member and is used for transmitting a signal; a distance between the signal wiring and the metal layer is equal to or less than a distance between two nearest wirings among the plurality of first wirings and the plurality of second wirings; 2. The electronic module of claim 1.

4. a distance between the signal wiring and the metal layer is equal to or less than a distance between two adjacent first wirings among the plurality of first wirings; 4. Electronic module according to claim 2 or 3.

5. the first wiring board has a first ground including a first ground pad; the metal layer is bonded to the first ground pad so as to be electrically connected to the first ground; 5. An electronic module according to any one of the preceding claims.

6. the plurality of first wirings includes a first ground wiring joined to the first ground pad; 6. Electronic module according to claim 5.

7. the plurality of second wirings includes a second ground wiring joined to the first ground pad; 7. Electronic module according to claim 5 or 6.

8. the second wiring board has a second ground including a second ground pad; the metal layer is bonded to the second ground pad so as to be electrically connected to the second ground; 8. Electronic module according to any one of the preceding claims.

9. the plurality of first wirings includes a third ground wiring joined to the second ground pad; 9. Electronic module according to claim 8.

10. the plurality of second wirings includes a fourth ground wiring joined to the second ground pad; 10. Electronic module according to claim 8 or 9.

11. the insulator includes a first insulating substrate and a second insulating substrate; the metal layer is disposed between the first insulating substrate and the second insulating substrate in the third direction, the first insulating substrate is disposed between the first wiring and the metal layer; the second insulating substrate is disposed between the second wiring and the metal layer; 11. Electronic module according to any one of the preceding claims.

12. the insulator includes a first insulating substrate and a second insulating substrate; the metal layer is disposed between the first insulating substrate and the second insulating substrate in the third direction, the first wirings are disposed between the first insulating substrate and the metal layer; the plurality of second wirings are disposed between the second insulating substrate and the metal layer; 11. Electronic module according to any one of the preceding claims.

13. a first semiconductor element mounted on the first wiring board; A second semiconductor element mounted on the second wiring board.

13. Electronic module according to any one of the preceding claims.

14. the first semiconductor element is mounted on a surface of the first wiring board facing the second wiring board; 14. Electronic module according to claim 13.

15. the second semiconductor element is mounted on a surface of the second wiring board that is opposite to a surface of the second wiring board that faces the first wiring board; 15. Electronic module according to claim 13 or 14.

16. The second semiconductor element is an image sensor. Electronic module according to any one of claims 13 to 15.

17. The first semiconductor device is a memory.

17. Electronic module according to any one of claims 13 to 16.

18. A first wiring board; a second wiring board arranged at a distance from the first wiring board in a first direction; an intermediate connection member disposed between the first wiring board and the second wiring board; The intermediate connection member is An insulator; a plurality of first wirings supported by the insulator and arranged at intervals in a second direction intersecting the first direction; a plurality of second wirings supported by the insulator and arranged at intervals in the second direction; a metal layer supported by the insulator and disposed between the first wirings and the second wirings so as to face the first wirings and the second wirings in a third direction intersecting the first direction and the second direction; the plurality of first wirings and the plurality of second wirings include signal wirings used for transmitting signals, a distance between the signal wiring and the metal layer is equal to or less than a distance between two nearest wirings among the plurality of first wirings and the plurality of second wirings; 1. An electronic module comprising:

19. an intermediate connection member disposed between a first wiring board and a second wiring board so as to space the first wiring board from the second wiring board in a first direction, An insulator; a plurality of first wirings supported by the insulator and arranged at intervals in a second direction intersecting the first direction; a plurality of second wirings supported by the insulator and arranged at intervals in the second direction; a metal layer supported by the insulator and disposed between the first wirings and the second wirings so as to face the first wirings and the second wirings in a third direction intersecting the first direction and the second direction; the metal layer has an end surface exposed from the insulator on a surface of the intermediate connection member that faces one of the first wiring board or the second wiring board; An intermediate connecting member characterized by:

20. A housing and and an electronic module according to any one of claims 1 to 18 disposed inside the housing.

1. An electronic device comprising:

Images