JP2011009509A - Electronic apparatus and electrical connection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve connection by reducing a connection failure occurring at a coupling portion which electrically connects two electrodes arranged on different two substrates and opposing each other.SOLUTION: This electronic apparatus includes: a first substrate 3 having a first electrode 50; a second substrate 4 formed on the surface with a second electrode 51 opposite to the first electrode 50; and a coupling member 2 pinched between the first electrode 50 and the second electrode 51 for connecting both the substrates. The coupling member 2 includes: an extended shell or flat extended shell resin core; and a conductive film coating the resin core, and the resin core has an air gap internally.

Description

  The present invention relates to an electronic device and an electrical connection method, and more particularly to an electronic device in which a substrate on which an electronic component is mounted and another substrate are connected using a connecting member and a connection method thereof.

  With the downsizing of electronic devices / devices, it is necessary to perform higher-density mounting in the scene where electronic components are mounted on a substrate in the electronic devices / devices. BGA (Ball Grid Array) has been proposed as an example of a high-density mounting form that meets such requirements.

  The mounting form of the BGA includes an interposer (package substrate) on which a semiconductor integrated circuit is previously mounted, an electrode disposed on the surface opposite to the mounting surface of the semiconductor integrated circuit, and a mounting provided facing the electrode. The electrode on the board (printed wiring board) is electrically and physically connected via solder balls. The realization of high-density mounting in BGA has made it possible to reduce the size of electronic devices / devices.

  However, the high-density mounting configuration as in the above example is an effective method in terms of high-density mounting of electronic components such as semiconductor integrated circuits on the mounting substrate, but the two substrates are connected via solder balls. It has the subject that the reliability of the connection part to fall falls.

  The decrease in the reliability of the connecting portion between both substrates is caused by the difference in thermal expansion coefficient between the interposer and the mounting substrate. The electronic device / device repeatedly causes a temperature rise and fall in the electronic device / device due to operation and stoppage. This temperature change causes a phenomenon of expansion (elongation) and contraction (shrinkage) of the interposer and the mounting substrate, and a load is applied to the connecting member that connects the two substrates, resulting in breakage of the connection portion and poor connection.

  For example, the thermal expansion coefficient of a ceramic interposer is approximately 7 ppm. The thermal expansion coefficient of the resin printed board is approximately 14 ppm. When a ceramic interposer is used for the package substrate and a resin printed circuit board is used for the mounting substrate, the thermal expansion coefficients of the two substrates are different from each other. A poor connection occurs.

  In recent years, many proposals have been made on a connecting member for connecting both substrates in a mounting form represented by BGA in order to eliminate the connection failure. For example, Non-Patent Document 1 proposes a resin core BGA using a solid resin core, and proposes that the temperature cycle life of the connection portion between the BGA package and the printed board can be improved. Patent Document 1 discloses a stress relaxation type electronic component mounting body in which a connecting member is formed by a stress relaxation mechanism body made of a conductive adhesive. Further, Patent Document 2 discloses a cylindrical holding body having a hollow portion opened to the outside, and a connection terminal having a conductive material disposed on the outer surface of the holding body.

Japanese Patent No. 3262532 JP 2001-118959 A

Werner Engelmaier; ”Achieving solder joint reliability in a lead-free world, part 2”, Global SMT & Packaging, August 2007, pp.44-46.

  However, the resin core BGA proposed in Non-Patent Document 1 and the one having a connecting member provided with a stress relaxation mechanism disclosed in Patent Document 1 are required because the rigidity of the connecting member is high. The standard temperature cycle life at the connected part cannot be obtained. Moreover, the connection terminal which is disclosed in Patent Document 2 and includes a holding body having a hollow portion opened to the outside and a conductive material disposed on the outer surface of the holding body is a shape of the holding body. However, the effect on the load from a certain direction (the open surface direction of the hollow portion opened to the outside) is small. As a result, it has not been possible to improve the connection failure occurring at the connecting portion connecting the two electrodes.

  The present invention has been made in view of the above problems, and the object thereof is a connection that occurs at a connecting portion that electrically connects two electrodes disposed on two different substrates. It is to improve defects.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a first substrate having a first electrode formed on one surface and a second electrode facing the first electrode on the surface. And a connecting member that is sandwiched between the first electrode and the second electrode to connect the two substrates, and the connecting member has a gap formed therein. In addition, it includes a spherical or flat spherical resin core and a conductive film covering the resin core.

  According to the first aspect of the present invention, it is possible to improve a connection failure that occurs in a connecting portion that electrically connects two electrodes facing each other.

  According to a second aspect of the present invention, in the first aspect of the invention, the connecting member includes a spherical or flat spherical shell-shaped hollow resin core and a conductive film that covers the resin core. It is characterized by.

  According to the second aspect of the present invention, it is possible to more reliably improve a connection failure that occurs at a connecting portion that electrically connects two electrodes disposed on two different substrates and that are opposed to each other. Can do.

  According to a third aspect of the invention, in the first or second aspect of the invention, the first substrate and the second substrate are made of materials having different coefficients of thermal expansion. The invention described in any one of claims 1 to 3 is characterized in that one of the first substrate and the second substrate is a ceramic substrate and the other is a resin substrate. And

  According to invention of Claim 3 and 4, even when the board | substrate which consists of a material with a different thermal expansion coefficient is used for said 1st board | substrate and said 2nd board | substrate, respectively on two different board | substrates. It is possible to prevent a connection failure that occurs at the connecting portion that electrically connects the two electrodes disposed opposite to each other.

  The invention according to claim 5 is the invention according to any one of claims 2 to 4, wherein the thickness of the shell of the resin core is set to 1/5 or less of the outer diameter of the resin core.

  According to the fifth aspect of the present invention, it is possible to more reliably improve the connection failure that occurs in the connecting portion that electrically connects the two electrodes disposed on two different substrates and that face each other. Can do.

  According to a sixth aspect of the present invention, in any of the second to fifth aspects of the present invention, the thickness of the conductive film is smaller than the thickness of the shell of the resin core.

  According to the sixth aspect of the present invention, it is possible to more reliably improve the connection failure that occurs in the connecting portion that electrically connects the two electrodes disposed on the two different substrates. Can do.

  According to a seventh aspect of the invention, in the first to sixth aspects of the invention, the conductive film includes at least one layer, and an outermost surface layer of the at least one layer is made of a brazing material. And

  According to the seventh aspect of the present invention, the outermost surface layer of the conductive film is made of a brazing material, so that the two electrodes disposed on the two different substrates are connected to each other by the connecting member. Can be easily connected.

  The invention according to claim 8 is the invention according to claims 2 to 7, wherein the connecting member is provided with three or more through holes.

  According to the eighth aspect of the present invention, it is possible to more reliably improve a connection failure that occurs in a connecting portion that electrically connects two electrodes disposed on two different substrates and that are opposed to each other. Can do.

  The invention according to claim 9 is a first substrate in which a first electrode is formed on one surface, and a second substrate in which a second electrode facing the first electrode is formed, Is electrically connected via a connecting member that is sandwiched between the first electrode and the second electrode and connects both substrates, and the connecting member is a sphere having a gap inside. The electrical connection method is characterized by using a member including a shell-shaped or flat spherical shell-shaped resin core and a conductive film covering the resin core.

  According to the ninth aspect of the present invention, the electrical connection that can improve the connection failure that occurs in the connecting portion that electrically connects the two electrodes disposed on the two different substrates and that faces each other. Can provide a method.

  As described above, according to the present invention, a connection member including a spherical shell-shaped resin core having a gap in the connection between the substrates and a conductive film covering the resin core is provided. It is possible to improve the connection failure occurring in the portion.

It is a partial cut appearance perspective view of an electronic device concerning an embodiment of the invention. It is a schematic cross section which showed the mounting state of the electronic device which concerns on embodiment of this invention, and is equivalent to the cross section of II-II of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is a disassembled perspective view which shows roughly the mounting part of the electronic device which concerns on embodiment of this invention. It is sectional drawing of the connection member which concerns on embodiment of this invention. It is a fragmentary sectional view which expands and shows VI enclosed by the broken-line part of FIG. It is the elements on larger scale which show the external appearance of the connection part which concerns on an example of embodiment of this invention. It is the elements on larger scale which show the external appearance of the connection part which concerns on another example of embodiment of this invention. It is a theoretical figure showing the relationship between the thickness of a resin core ball, and the shear rigidity of a connection member.

  Hereinafter, an embodiment of the present invention will be described in detail based on FIG. 1, FIG. 2, FIG. 3, and FIG.

  FIG. 1 is a partially cutaway perspective view of an electronic apparatus 1 according to the present embodiment. The electronic device 1 includes a semiconductor package 70 mounted on a mounting substrate (second substrate) 4 inside the device, and includes a housing 11 that forms an outer shell.

  FIG. 2 is a schematic cross-sectional view corresponding to the cross-sectional view taken along the line II-II of FIG. FIG. 2 shows a state in which the interposer (first substrate) 3 and the mounting substrate 4 facing each other are electrically connected via the connecting member 2. In addition, FIG. 2 schematically shows a state in which the semiconductor integrated circuit 5 is connected to the upper surface of the interposer 3 via the solder balls 6. The heat dissipating material 7 is disposed in close contact with the upper surface of the semiconductor integrated circuit 5, and heat generated from the inside of the semiconductor package 70 during operation of the electronic device / apparatus is conducted to the metal housing 8 to be outside the semiconductor package 70. Has the role of heat dissipation.

  FIG. 3 is a view showing an arrangement example of a plurality of connecting members connected to the interposer 3, and corresponds to a cross-sectional view taken along the line III-III in FIG. In the present embodiment, an interposer 3 in which a plurality of electrodes 50 are regularly arranged is used.

  FIG. 4 is an exploded perspective view schematically showing a mounting portion of the electronic apparatus 1 according to the present embodiment. In FIG. 3, the plurality of electrodes 50 shown in FIG. The same number of electrodes 51 are disposed on the mounting substrate 4 so as to face the plurality of electrodes 50 provided in the interposer 3.

  The electronic device in the present invention refers to various electronic modules, various electronic devices, or the like.

  The electronic device 1 of the present invention in this embodiment is an optical transmission device. Two semiconductor packages 70 are mounted on the electronic device 1 in FIG. One of the semiconductor packages 70 is a receiving IC package, and the other is a transmitting IC package. An optical signal transmitted from the outside via the optical fiber cable 12 is transmitted to the receiving IC via the coaxial cable 10 in the electronic device 1. The receiving IC has a role of converting the transmitted optical signal into an electric signal and transmitting it to another electronic device or the like. The transmission IC has a function of converting an electrical signal transmitted from another electronic device into an optical signal, passing through the coaxial cable 10, and then transmitting the signal to the outside through the optical fiber cable 12.

  In the electronic device 1 of the present embodiment, when a 40 Gbit / s high-frequency electrical signal is transmitted from the electronic device 1, the signal transmitted from the semiconductor integrated circuit 5 in FIG. 1 is transmitted through a coaxial cable 10 shown in FIG. 1 from a coaxial connector (not shown) installed in the metal housing 8. In order to mount the metal housing 8 having the coaxial connector and the semiconductor integrated circuit 5 for 40 Gbit / s described above, the size of the interposer 3 should be larger than about 20 mm × 20 mm × thickness 5 mm. Is needed.

  In the present embodiment, a ceramic substrate is used as the interposer 3. In addition, a substrate having a size of 20 mm × 20 mm × thickness 5 mm is used. As the first substrate in the present invention, in addition to the ceramic substrate used in the present embodiment, a resin substrate, for example, a substrate such as a polyimide base material or a glass epoxy base material can be appropriately used depending on the intended use. It is. Also, the size of the substrate can be changed as appropriate.

  In the present embodiment, a resin substrate is used as the mounting substrate 4. Specifically, a printed wiring board made of glass epoxy is used. The size of the substrate can be appropriately changed and used depending on the outer shape of the electronic device 1. The second substrate in the present invention is not limited to the printed circuit board made of glass epoxy used in the present embodiment, but other resin substrates such as a bakelite substrate, a glass composite substrate, a PTFE substrate, a composite substrate, a paper epoxy substrate, A ceramic substrate can be appropriately used according to the intended use.

  When the first and second substrates are used in combination with substrates made of materials with different coefficients of thermal expansion, the difference in the coefficient of thermal expansion between the two substrates increases, and the resulting shear stress causes A poor connection occurs. Also in this embodiment, substrates made of materials having different coefficients of thermal expansion, such as a ceramic substrate and a resin substrate, are used.

  Even in the above case, by providing the connecting member 2 of the present invention in the connecting portion, it is possible to improve the connection failure generated in the connecting portion.

  FIG. 5 is a cross-sectional view of the connecting member 2 of the present embodiment. FIG. 6 is a partial cross-sectional view showing the configuration of the connecting member 2 further enlarging the VI surrounded by the broken line in FIG.

  In this embodiment, a hollow shell-shaped resin core ball 30 is used as a resin core constituting the connecting member 2. The resin core ball 30 has one spherical hollow portion 32 therein, and has a uniform shell thickness. The connecting member 2 includes a conductive film that covers the resin core ball 30. In the present embodiment, the metal film 31 is used for the conductive film.

  A major feature of the connecting member 2 is that the difference in physical elongation (shrinkage) between the two substrates due to the difference in thermal expansion coefficient is borne by the deformation (strain) of the resin core ball 30.

  As shown in FIG. 3, the resin core ball 30 has a circular cross section when viewed from the normal direction 90 on the mounting substrate 4 side. By having the cross-sectional shape, the connecting member 2 can distort itself by following the deformation direction against shear deformation in a direction perpendicular to the normal direction 90 on the mounting substrate 4 side. Due to the distortion of the shape of the connecting member 2, it is possible to effectively bear the shear deformation generated by the difference in thermal expansion.

  With respect to the structure of the resin core constituting the connecting member in the present invention, it is preferable that the center of the resin core and the center of the spherical hollow portion coincide. That is, a structure in which one spherical hollow portion is formed so that the thickness of the resin core shell is uniform is preferable in that the connecting member is uniformly distorted.

  The resin core ball 30 can reduce the rigidity of the connecting portion even when a spherical or flat spherical porous resin core in which a large number of minute voids are formed inside the resin is used. . Decreasing the rigidity of the connecting portion means that the poor connection occurring in the connecting portion is effectively improved.

  Further, the Young's modulus of the resin core ball 30 constituting the connecting member 2 is lower than the Young's modulus of the metal film 31. By providing the connecting core 2 with the resin core ball 30, the rigidity of the connecting member 2 is reduced, and it is possible to cope with shear deformation. Specifically, the material of the resin core used in the present invention is divinylbenzene polymer, benzoguanamine, polystyrene, divinylbenzene-styrene copolymer, divinylbenzene-acrylate copolymer, diallyl phthalate polymer, polymethacrylate. It is possible to make timely selections from methyl acid, polyacrylonitrile, polyimide, polyethylene terephthalate, polycarbonate, and the like.

  The outer shape of the resin core ball 30 and the connecting member 2 can be a flat spherical shell shape or a substantially spherical shell shape in addition to the spherical shell shape. In other words, the outer shape of the resin core used in the present invention is effective as long as it is not a true sphere but a spherical outer shape.

  The outer diameter D of the resin core ball 30 in the present embodiment is preferably used at 100 to 1000 μm for the original purpose of mounting electronic components with higher density. More preferably, it is 100-700 micrometers. A metal film 31 is provided on the outer surface of the resin core ball 30. As shown in FIG. 6, the metal film 31 has a three-layer structure including a copper plating layer 40, a nickel plating layer 41, and a brazing material (tin plating layer) 42 in order from the resin core ball 30 side.

  As an example of this embodiment, the resin core ball outer diameter D is 600 μm, and as shown in FIG. 5, the thickness of the shell portion of the resin core ball 30 is uniformly 100 μm (1/6 of the outer diameter D, hereinafter referred to as D / 6). To do). As an example of the three-layer structure constituting the metal film 31, a copper plating layer 40 (10 μm), a nickel plating layer 41 (30 μm), a brazing material (tin plating) layer 42 (30 μm) are formed with respective thicknesses. ing.

  The thickness of the metal film 31 of this embodiment is 70 μm. By making the thickness of the metal film 31 smaller than the thickness of the resin core ball 30, the Young's modulus of the connecting member 2 can be kept low, and the rigidity of the connecting member 2 can be effectively reduced.

  Although the metal film 31 used in this embodiment has a three-layer structure, in the present invention, a single-layer structure, a two-layer structure, or a multilayer structure including three or more layers can also be implemented.

  The copper plating layer 40 is formed in close contact with the resin core ball 30. The copper plating layer 40 plays a role as a base layer for forming a conductive metal film on the surface of the resin core ball 30. As long as the surface of the resin core ball 30 is in close contact with the surface of the resin core ball 30, a composition other than copper plating can serve as a base layer. Depending on the composition for forming the underlayer, the underlayer can also function as a brazing material layer. In this case, the metal film 31 is formed with a single layer structure.

  The copper plating layer 40 in the present embodiment is formed using an electroless plating (chemical plating) method, but other suitable methods may be used. For example, when a conductive resin is used for the resin core ball 30, the metal film 31 can be formed on the resin surface by electroplating.

  A nickel plating layer 41 is provided on the intermediate layer of the metal film 31 in the present embodiment. In addition, a brazing material (tin plating) layer 42 is provided on the outermost surface layer. In the present embodiment, it is difficult to directly provide the brazing material (tin plating) layer 42 on the surface of the copper plating layer 40. Therefore, a nickel plating layer 41 is provided as an intermediate layer that serves to connect the brazing material (tin plating) layer 42 and the copper plating layer 40 as a binder.

  FIG. 7 is a partial enlarged view showing a connection state in which the interposer 3 and the mounting substrate 4 in this embodiment are connected via the connecting member 2 using the solders 52 and 53. FIG. 8 shows another example of the present embodiment in which the interposer 3 and the mounting substrate 4 are connected to each other through a flat spherical shell-shaped connecting member 20 using solders 52 and 53. As in FIG. It is the elements on larger scale which took out and showed. The connecting member 20 is provided so that the uniaxial direction is perpendicular to the substrate. The connecting members 2 and 20 are provided between a pair of electrodes 50 and 51 disposed on the surfaces of both substrates. The gap between the two substrates in FIG. 7 is substantially the same as the outer diameter of the connecting member 2.

  The electrical connection method of this embodiment is demonstrated using FIG. A first step in which the semiconductor integrated circuit 5 is mounted on the interposer 3 via the solder balls 6, a heat dissipation material 7 is disposed on the upper surface of the semiconductor integrated circuit 5, and the metal housing 8 is connected to the semiconductor integrated circuit 5 and the heat dissipation material. The connecting member 2 is soldered to each of a plurality of electrodes 50 regularly arranged on the lower surface of the interposer 3 and the second step of mounting on the upper surface of the interposer 3 so as to enclose 7. The semiconductor package 70 is obtained through the third step. Next, the semiconductor package 70 is mounted on the mounting substrate 4 by a reflow method. A fourth step in which solder 53 is printed and applied to each of the plurality of electrodes 51 disposed on the mounting substrate 4, and after the semiconductor package 70 is aligned with a predetermined position on the mounting substrate 4, the solder 53 is heated and heated. And the fifth step in which the connecting member 2 is connected constitutes the electrical connection method of the present embodiment.

  FIG. 9 is a theoretical diagram showing the relationship between the thickness of the resin core ball and the shear rigidity of the connecting member when a hollow spherical shell resin core ball is used as the resin core in the present invention. The vertical axis represents the ratio of the shear rigidity to the measured value when a solid resin core ball is used, and the horizontal axis represents the thickness of the shell of the resin core ball. The shear rigidity of the connecting portion of the electronic device 1 having the resin core ball 30 (D / 6) in the connecting member 2 is about 1/20 as compared with the case where a solid resin core ball having no voids is used. FIG. 9 shows that it was able to be lowered.

  Next, a temperature cycle test of −40 / 85 ° C. was performed. The result of a temperature cycle test of an electronic device using a solid resin core ball having no voids inside the resin core was that the connection part was broken in about 100 temperature cycles. On the other hand, in the temperature cycle test using the electronic apparatus 1 of the present embodiment, a result that the connection portion was not broken even when the temperature cycle was performed 500 times was obtained.

  The above-described results indicate that the fracture life of the connection portion of the electronic device 1 of the present embodiment is 5 times longer than that of the conventional one. Regarding the electronic device 1 of the present embodiment, when the state of the solder connection part after the temperature cycle test was observed, there was almost no cracking in the solder of the connection part. This means that the electronic device 1 of the present embodiment is improved in connection failure that occurs in the connecting portion.

  In the embodiment of the present invention, the case where the brazing material (tin plating) layer 42 is formed in the outermost layer of FIG. 6 is shown. However, the brazing material (tin plating) layer 42 is composed of the solder 52, 53 has the function of ensuring wettability with 53. As an alternative to the brazing material (tin plating) layer 42, for example, a gold plating layer does not impede the function of the present invention. When the gold plating is used, the thickness of the gold plating layer is about 50 μm, which is an appropriate thickness from an economic viewpoint.

  Further, in the above-described embodiment of the present invention, as a means for further improving the temperature cycle life of the connecting portion, there is a means for providing an opening in the connecting member 2 and further reducing the shear rigidity. In this case, it is preferable that the connecting member 2 has three or more openings and are distributed substantially evenly on the spherical surface of the sphere.

  Specifically, when the connecting member 2 is provided with three circular through holes (openings) having a diameter of about 15 μm evenly distributed on the spherical surface of the connecting member 2, the temperature cycle life of the connecting portion is further increased. A result of an improvement of more than 2 times was obtained.

  The total weight of the ceramic interposer 3 and the semiconductor integrated circuit 5 used in this embodiment is as large as about 10 g. Further, when the electronic apparatus of the present invention is used as a communication device, there is a test subject to an impact acceleration of 500G, and the force applied to the connecting member at this time is approximately 5 kg. When a hollow spherical shell is used for the resin core, it is necessary to set the thickness of the resin core shell that can withstand the severe conditions described above.

  For the purpose of appropriately securing the rigidity of the connecting portion, it is desirable that the thickness of the resin core shell is 1/10 or more of the outer diameter of the resin core.

  The thickness of the resin core shell in the present invention is preferably 1/2 to 1/10, more preferably 1/5 to 1/10, of the outer diameter of the resin core.

  The required size of the thickness of the resin core shell varies depending on the application of the electronic device of the present invention. Therefore, it is necessary to appropriately design the thickness of the resin core shell according to the application. That is, it is possible to satisfy the effects of the present invention in a range other than the thickness of the resin core shell, depending on the application.

  Although the BGA connection is used in this embodiment, the present invention is not limited to the BGA connection method. It can be widely used in the technical field of so-called CSP (chip size package).

  In addition, the sealing resin (underfill agent) is applied in the gap between the interposer and the mounting substrate in the conventional mounting method, and is used as a reinforcement for relaxing stress on the connecting member and preventing the semiconductor package 70 from falling off. However, there is no problem to use an underfill agent in combination.

  DESCRIPTION OF SYMBOLS 1 Electronic device, 2,20 Connecting member, 3 Interposer, 4 Mounting board, 5 Semiconductor integrated circuit, 6 Solder ball, 7 Heat dissipation material, 8 Metal housing, 10 Coaxial cable, 11 Case, 12 Optical fiber cable, 30 Resin core Ball, 31 Metal film, 32 Hollow part, 40 Copper plating layer, 41 Nickel plating layer, 42 Brazing material (tin plating) layer, 50, 51 Electrode, 52, 53 Solder, 70 Semiconductor package, 80 Thickness of resin core ball Characteristic curve showing the relationship of shear stiffness, 90 normal direction.

Claims (9)

A first substrate having a first electrode formed on one surface;
A second substrate having a second electrode facing the first electrode formed on the surface;
A connecting member that is sandwiched between the first electrode and the second electrode to connect the two substrates; and
The connecting member includes a spherical or flat spherical resin core having a void formed therein, and a conductive film covering the resin core.
An electronic device characterized by that. The connecting member is a spherical resin shell having a spherical shell shape or a flat spherical shell shape, and
Including a conductive film covering the resin core,
The electronic device according to claim 1. The first substrate and the second substrate are made of materials having different coefficients of thermal expansion.
The electronic device according to claim 1, wherein the electronic device is an electronic device. One of the first substrate and the second substrate is a ceramic substrate,
The other is a resin substrate,
The electronic apparatus according to claim 1, wherein the electronic apparatus is an electronic apparatus. The thickness of the resin core shell is 1/5 or less of the outer diameter of the resin core,
The electronic device according to claim 2, wherein the electronic device is an electronic device. The thickness of the conductive film is smaller than the thickness of the resin core shell,
The electronic device according to claim 2, wherein the electronic device is an electronic device. The conductive film includes at least one layer, and an outermost surface layer of the at least one layer is made of a brazing material.
The electronic device according to any one of claims 1 to 6, wherein The connecting member has three or more through holes,
The electronic device according to claim 2, wherein the electronic device is an electronic device. A first substrate having a first electrode formed on one surface;
A second substrate on which a second electrode facing the first electrode is formed,
In the electrical connection method in which the first electrode and the second electrode are sandwiched between the two electrodes and electrically connected via a connecting member that connects both substrates,
As the connecting member, a spherical shell-shaped or flat spherical shell-shaped resin core having a void inside, and
An electrical connection method using a member including a conductive film covering the resin nucleus.

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