JP2022081161A - Electronic apparatus substrate - Google Patents

Abstract

To provide an electronic apparatus substrate that is provided with conductors having low electric resistance and a minute structure in a fine space in the electronic apparatus substrate without breaking wiring etc.SOLUTION: There is provided an electronic apparatus substrate which has a fine space, where a conductor is provided. The conductor has a structure having an intermetallic compound including Sn, Cu, Ni, and Ge in a host phase including Sn and Sn-Cu alloy, and the Sn-Cu alloy and the intermetallic compound have an endotaxial junction formed with at least a part.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electronic device substrate.

For example, in an electronic device or an electronic device substrate such as a micromachine, it may be necessary to form a fine conductor-filled structure, an insulating structure, or a functional structure having a high aspect ratio inside. In such a case, there is known a technique for realizing a conductor filling structure, an insulating structure, a functional structure, and the like by filling the micropores with a filler selected in advance. However, it is extremely difficult to sufficiently fill the bottom of the micropores with a high aspect ratio without causing voids or deformation after curing.

As prior arts capable of overcoming such technical difficulties, the fillers, filling methods and devices described in Patent Documents 1 and 2 are known.

The technique described in Patent Document 1 is a manufacturing method in which molten metal is filled and cured in micropores existing in a wafer, and a forced external force exceeding atmospheric pressure is applied to the molten metal in the micropores. Up to this point, the step of cooling and curing the molten metal is included. The forced external force is applied by at least one selected from press pressure, injection pressure or rolling compaction, and the molten metal is applied from the opening surface side where the micropores open with the other end side of the micropores closed. Is applied to. Patent Document 2 discloses an apparatus for carrying out the manufacturing method described in Patent Document 1.

According to the techniques described in Patent Documents 1 and 2 described above, the micropores can be filled with the filler without forming voids or voids, and the concave surface of the hardened metal cooled by the fine gaps can be avoided. It is possible to obtain excellent effects such as the fact that it can contribute to the simplification of the process and the improvement of the yield. However, these are pre-process micropore formation completed in the work process before the electronic equipment board wiring, and in the work process after the electronic equipment board wiring, the wiring is also diffused with molten metal. Since it melts, it is not suitable for post-process micropore molding and is expensive.

Japanese Patent No. 4278007 Japanese Patent No. 4505540

An object of the present invention is to provide an electronic device substrate in which a conductor having a low electric resistance and a dense structure is provided in a fine space without damaging wiring or the like.

The present invention is an electronic device substrate having a fine space, in which a conductor is provided in the fine space, and the conductor is Sn, Cu, Ni and Ge in a matrix containing a Sn and Sn—Cu alloy. It is a structure having an intermetallic compound containing, and the Sn—Cu alloy and the intermetallic compound provide an electronic device substrate in which an endotropic bond is formed between at least one part thereof.

According to the present invention, it is possible to provide an electronic device substrate in which a conductor having a low electric resistance and a dense structure is provided in a semi-fine space without damaging wiring or the like.

It is a STEM image of the cross section which thinly cut the metal particle of this invention with FIB (focused ion beam). It is a figure for demonstrating an example of the manufacturing apparatus suitable for manufacturing the metal particle of this invention. It is the element mapping analysis result by EDS of the metal particle cross section shown in FIG. It is a STEM image and a partial analysis result of the cross section of a metal particle obtained in Example 1. It is sectional drawing of the microspace for demonstrating one Embodiment of this invention. It is sectional drawing for demonstrating one Embodiment of the metal particle of this invention. It is a cross-sectional micrograph of a fine space obtained in Example 1. It is a TEM image showing the interface between the intermetallic compound crystal and the matrix in the cross section of the conductor obtained in Example 1, and the transmission type electron diffraction pattern of the matrix-intermetallic compound crystal interface. It is a cross-sectional micrograph of a fine space obtained in Comparative Example 1.

Hereinafter, the present invention will be described in more detail.
First, the terminology used herein is as follows, even if not specifically explained.
(1) When referring to a metal, it may include not only a simple substance of a metal element but also an alloy containing a plurality of metal elements and an intermetallic compound.
(2) When referring to a single metal element, it does not mean only a substance completely composed of the metal element, but also means a case containing a slight other substance. That is, it does not mean to exclude those containing a trace amount of impurities that have almost no effect on the properties of the metal element. Of course, for example, in the case of a matrix, some of the atoms in the Sn crystal are other elements ( For example, it does not mean to exclude those that have been replaced with Cu). For example, the other substance or other element such as Al, Co, Fe, Mn, Mo, and Cr may be contained in the metal particles in an amount of 0 to 1% by mass.
(3) Endotactic bonding means that an intermetal compound precipitates in a substance that becomes a metal / alloy (a matrix containing Sn and Sn—Cu alloy in the present invention), and during this precipitation, the Sn—Cu alloy and the Sn—Cu alloy are deposited. It means that the metal-to-metal compound is bonded at the crystal lattice level to form crystal grains. The term endotactic is well known and is described, for example, in Nature Chemisry 3 (2): 160-6, 2011, page 160, left column, final paragraph.

In the present invention, the conductor in the fine space (hereinafter, may be referred to as the conductor of the present invention) may be formed by using the following metal particles (hereinafter, may be referred to as the metal particles of the present invention). can.

FIG. 1 is an STEM image of a cross section obtained by thinly cutting the metal particles of the present invention with a FIB (focused ion beam). The particle size of the metal particles shown in FIG. 1 is about 5 μm, but the particle size of the metal particles of the present invention can be adjusted to the size of the fine space, and is preferably 1 μm to 50 μm, for example. It is a range. Referring to the metal particles of FIG. 1, the metal particles have an intermetal compound 120 containing Sn, Cu, Ni and Ge in a matrix 140 containing a Sn and Sn—Cu alloy.

The metal particles of the present invention have, for example, Cu of 0.7 to 15% by mass, Ni of 0.1 to 5% by mass, Ge of 0.001 to 0.1% by mass, and the balance of Sn, preferably Cu. Is 1 to 15% by mass, Ni is 0.1 to 3% by mass, Ge is 0.001 to 0.01% by mass, and the balance is Sn.

The metal particles of the present invention can be produced from, for example, a raw material having a composition of 8% by mass Cu, 1% by mass Ni, 0.001% by mass Ge and the balance Sn. For example, it is obtained by melting the raw material, supplying it onto a dish-shaped disk rotating at high speed in a nitrogen gas atmosphere, scattering the molten metal as small droplets by centrifugal force, and cooling and solidifying under reduced pressure.

An example of a manufacturing apparatus suitable for manufacturing the metal particles of the present invention will be described with reference to FIG. The granulation chamber 1 has a cylindrical upper portion and a cone-shaped lower portion, and has a lid 2 at the upper portion. A nozzle 3 is vertically inserted into the center of the lid 2, and a dish-shaped rotating disk 4 is provided directly below the nozzle 3. Reference numeral 5 is a mechanism for supporting the dish-shaped rotating disk 4 so as to be movable up and down. Further, a discharge pipe 6 for the generated particles is connected to the lower end of the cone portion of the granulation chamber 1. The upper part of the nozzle 3 is connected to an electric furnace (high frequency furnace) 7 for melting the metal to be granulated. Atmospheric gas adjusted to a predetermined component in the mixed gas tank 8 is supplied to the inside of the granulation chamber 1 and the upper part of the electric furnace 7 by the pipes 9 and 10, respectively. The pressure in the granulation chamber 1 is controlled by the valve 11 and the exhaust device 12, and the pressure in the electric furnace 7 is controlled by the valve 13 and the exhaust device 14, respectively. The molten metal supplied from the nozzle 3 onto the dish-shaped rotating disk 4 is scattered in the form of fine droplets by the centrifugal force of the dish-shaped rotating disk 4, and is cooled under reduced pressure to become solid particles. The generated solid particles are supplied from the discharge pipe 6 to the automatic filter 15 and separated. Reference numeral 16 is a particle recovery device.

The process of cooling and solidifying the molten metal from high temperature melting is important for forming the metal particles of the present invention.
For example, the following conditions can be mentioned.
The melting temperature of the metal in the melting furnace 7 is set to 600 ° C. to 800 ° C., and the molten metal is supplied from the nozzle 3 onto the dish-shaped rotating disk 4 while maintaining the temperature.
As the dish-shaped rotating disk 4, a dish-shaped disk having an inner diameter of 60 mm and a depth of 3 mm is used, and the rotation speed is 80,000 to 100,000 rotations per minute.
As the granulation chamber 1, a vacuum chamber having the ability to reduce the pressure to about 9 × 10 ⁻² Pa is used to reduce the pressure, and then exhaust is performed simultaneously while supplying nitrogen gas at 15 to 50 ° C. to the granulation chamber. The atmospheric pressure in 1 is 1 × 10 ^-1 Pa or less.

Further, the composition of the intermetallic compound in the metal particles of the present invention is, for example, Sn40 to 60, Cu30 to 50, Ni4 to 9, Ge0.001 to 0.01 as the ratio of the number of atoms of Sn, Cu, Ni and Ge. be.

Further, the ratio of the intermetallic compound in the metal particles of the present invention is, for example, 20 to 60% by mass, preferably 30 to 40% by mass, based on the entire metal particles.
The composition and proportion of the intermetallic compound can be satisfied according to the production conditions of the metal particles.

The metal particles of the present invention preferably have at least one portion of the Sn—Cu alloy and the intermetallic compound endutically bonded. As described above, in the end-tactical bonding, an intermetal compound is deposited in a substance that becomes a metal / alloy (a matrix phase containing Sn and a Sn—Cu alloy in the present invention), and Sn—Cu is deposited during this precipitation. The alloy and the metal-to-metal compound are joined at the crystal lattice level to form crystal grains. By forming the endotropic junction, the problem of brittleness of the intermetallic compound can be solved, and the decrease in mechanical strength due to the change in the crystal structure of Sn described below can be suppressed, and the material has higher heat resistance and mechanical strength. Can provide conductors. The present inventors have confirmed that the conductor of the present invention formed by using the metal particles of the present invention maintains the endaxial bonding of the metal particles.
The endotropic bonding of the metal particles of the present invention can be formed according to the conditions for forming the metal particles of the present invention, in which the molten metal is cooled and solidified from high temperature melting.

The crystal structure of Sn is tetragonal (note that Sn having a tetragonal crystal structure is referred to as β-Sn) in the temperature region of about 13 ° C to about 160 ° C, and cubic (cubic) in the lower temperature region. Sn having a tetragonal crystal structure is referred to as α-Sn), and the crystal structure changes. Further, the crystal structure of β-Sn changes to an orthorhombic crystal of a high-temperature phase crystal in a temperature region exceeding about 160 ° C. (Note that Sn having an orthorhombic crystal structure is referred to as γ-Sn). It is generally known that a large volume change occurs, especially during the phase transition between the tetragonal β-Sn and the cubic α-Sn.
The metal particles of the present invention contain high temperature phase crystals even at about 160 ° C. or lower (for example, at room temperature). For example, when the metal particles are heated, the metal material is in a semi-melted state in which the metal material is not completely melted, and if the metal particles include an endotic bond between the metal-metal compound and the matrix, the temperature is 160 ° C. or lower after cooling. Maintains a state containing high temperature phase crystals even in the temperature range. Even if the temperature of the high-temperature phase crystal is lowered to a certain extent, the phase transition of the square crystal to the low-temperature phase crystal β-Sn is unlikely to occur, and for Sn that does not undergo the phase transition to the square β-Sn, α No phase transition to -Sn occurs, and no large volume change occurs due to the phase transition to α-Sn due to a decrease in temperature. Therefore, a conductor containing Sn having a high temperature phase crystal even in a temperature region of 160 ° C. or lower (for example, even at room temperature) intentionally has a high temperature crystal phase in another conductor containing Sn in the composition (that is, even in a temperature region of 160 ° C. or lower). The volume change due to temperature change is reduced as compared with the one not included in).
Therefore, the metal particles of the present invention contain a high temperature phase crystal phase in a wide temperature range (for example, even at room temperature), and by avoiding the generation of a square low temperature phase β-Sn as much as possible, the metal particles are square due to temperature change. It is useful as a material for forming conductors because it has the property of being less likely to cause a large volume change associated with the phase transition from β-Sn of crystals to α-Sn of cubic crystals.

The effect of suppressing the change in the crystal structure of Sn is satisfactorily achieved by the end-tactical bonding in the metal particles.

Further, in the metal particles of the present invention, the endotactic junction is preferably 30% or more, more preferably 60% or more, when the entire bonding surface between the matrix and the intermetallic compound is 100%. The ratio of the end-tactical joint can be calculated, for example, as follows.
The cross section of the metal particles as shown in FIG. 1 below is photographed by an electron microscope, and the joint surface between the intermetallic compound and the Sn—Cu alloy is arbitrarily sampled at 50 locations. Subsequently, the joint surface is image-analyzed to investigate how much the end-tactical joint as shown in FIG. 4 below exists with respect to the sampled joint surface.

As described above, the conductor of the present invention can be formed by using the metal particles of the present invention. It has been confirmed by the present inventors that the conductor of the present invention formed by using the metal particles has a crystal structure similar to the crystal structure of the metal particles.

That is, the composition of the conductor of the present invention contains, for example, 0.7 to 40% by mass of Cu, 0.1 to 5% by mass of Ni, and 0.001 to 0.01% by mass of Ge, preferably 1 by mass of Cu. It contains about 15% by mass, 1 to 3% by mass of Ni, and 0.001 to 0.01% by mass of Ge.
Further, the composition of the intermetallic compound in the conductor of the present invention is, for example, Sn40 to 60, Cu30 to 50, Ni4 to 9, Ge0.01 to 0.06 as the ratio of the number of atoms of Sn, Cu, Ni and Ge. be.
The intermetallic compound contains 60 to 95% by mass of Sn, 4 to 40% by mass of Cu, 0.1 to 5% by mass of Ni, and 0.01 to 0.06% by mass of Ge.
The proportion of the intermetallic compound in the conductor of the present invention is, for example, 50 to 90% by mass, preferably 60 to 80% by mass, based on the conductor.

The conductor of the present invention preferably has at least one portion of the Sn—Cu alloy and the intermetallic compound endutically bonded. The endotropic bonding is preferably 30% or more, more preferably 60% or more, when the entire bonding surface between the Sn—Cu alloy and the intermetallic compound is 100%.

Next, a specific example of the conductor forming method of the present invention will be described.
For the conductor of the present invention, the step (1) of preparing the metal particles of the present invention having a size capable of filling a fine space and dispersing them in a liquid dispersion medium to obtain a dispersion liquid, and the dispersion liquid under vacuum. Can be formed by a method having a step (2) of filling the fine space into the fine space and a step (3) of applying a centrifugal force to the fine space after passing through the step (2) to pressurize the fine space.

In the step (1), examples of the liquid dispersion medium include flux, organic acids such as malonic acid, alcohols such as ethanol, and mixtures thereof, and the inclusion of the metal particles of the present invention in the liquid dispersion medium. The amount is preferably, for example, 70 to 90% by mass, more preferably 87 to 82% by mass.

The step (2) is a step of filling the fine space with the dispersion liquid under vacuum.
This step (2) can be performed by a known technique such as a vacuum screen printing method. As the vacuum screen printing method, for example, a known vacuum screen printing machine is used, specifically, an object is placed in the vacuum chamber of the vacuum screen printing machine, and the degree of vacuum in the vacuum chamber is 10 ² to 10 ⁴ . Set to about Pa, add the dispersion liquid (paste) prepared in step (1) to the surface of the object in the vacuum chamber, perform squeegee operation, start printing embedding, and imprinting operation, and then move the inside of the vacuum chamber. It can be done through the steps of returning to atmospheric pressure and taking out the object.

The step (3) is a step of applying a centrifugal force to the fine space to pressurize the fine space after passing through the step (2).
In this step (3), for example, an object is placed in a centrifuge, the atmosphere inside the centrifuge is replaced with an inert gas such as nitrogen, and then the fine space is, for example, about 55 to 1000 × g. Examples thereof include a step of applying centrifugal force to pressurize. Further, the metal particles of the present invention are preferably heated at 220 ° C. to 250 ° C. for the formation of endotactic junctions.

Further, after performing this step (3), as the step (4), it is preferable to apply an atmospheric pressure of about 0.11 MPa to 0.3 MPa to the object in the pressurizing chamber. The atmospheric pressure may be controlled according to a conventional method, and the pressurizing time is, for example, about 1 to 60 minutes. Further, in the step (4), it is preferable to raise the atmospheric temperature to 50 to 250 ° C.

When the atmospheric temperature is raised as described above in the step (4), the liquid dispersion medium in the fine space such as a solvent can be evaporated. As a result, the conductor in the fine space has a more dense structure.

According to the steps (2) and (3) of the present invention, since the dispersion liquid (functional material) is filled in the fine space by combining the above-mentioned specific methods, the fine powder which is originally difficult to fill can be functionally charged. By utilizing the fluidity of the sex material, it is possible to reliably fill the fine space with, for example, a solvent. After passing through the step (3) or the step (4) of the present invention, it is preferable to perform a cooling step. The cooling temperature may be appropriately set in consideration of the melting point of the metal particles of the present invention to be used.

The metal particles in the fine space are obtained by the parent phase acting as an anchor for suppressing molten metal condensation, and the metal-to-metal compound acting as a metal diffusion bonding and acting as a conduction hole wiring and a heat dissipation material in the fine space. The conductor has low electrical resistance and excellent mechanical strength.

In the present specification, the dispersion liquid means a suspension or a paste in which fine metal particles are dispersed in a liquid dispersion medium, and is a monodisperse system in which particles having the same particle size are arranged, and the particle size changes irregularly. Includes both polydisperse systems. Further, it includes not only a coarse-grained dispersion system but also a colloidal dispersion system.

Hereinafter, the present invention will be further described with reference to the drawings.
FIG. 5 is a cross-sectional view of a fine space for explaining an embodiment of the present invention.
First, an object 100 having a fine space 103 is prepared (FIG. 5A). The object 100 includes a wide range of electronic device boards having a fine space such as wafers, circuit boards, laminated boards, semiconductor chips, and MEMS (Micro-Electro-Mechanical Systems). The fine space 103 includes through holes represented by TSVs (Through Silicon Vias), non-through holes (blind holes), and the like. The inner wall surface of the fine space 103 is composed of an insulating film or an insulating layer.

The microspace 103 provided in the object 100 is a through hole or a non-through hole, and has a hole diameter D1 and a depth H1 of the opening. The pore diameter D1 is, for example, 1 μm to 300 μm, preferably 10 μm to 100 μm, and the depth H1 is a value such that the aspect ratio with the pore diameter D1 is 1 or more and 10 or less, preferably 5 or more and 10 or less. When the object 1 is, for example, a wafer, a large number of the above-mentioned fine spaces 103 are provided in the wafer surface.

The functional material 50 is filled in the fine space 103 of the object 100 described above. The functional material 50 is obtained by dispersing the metal particles 52 of the present invention in the liquid dispersion medium 51 (FIG. 5 (b)). The filling method is as described in the steps (2) and (3) of the present invention.

Next, by evaporating the liquid dispersion medium 51 and then cooling and solidifying it, a conductor having a dense structure inside the fine space 3, having low electrical resistance, and having excellent mechanical strength is formed (FIG. 5). (c)).

The metal particles of the present invention are preferably metal particles 500 coated with a resin film. This is because the resin-coated metal particles have antioxidant and antiaggregating effects. The conceptual diagram is shown in FIG. Referring to FIG. 6, the metal particles 501 are coated with the resin film 502. The resin film 502 functions as an antioxidant film and an anti-aggregation film. Such a technique is known, for example, in Japanese Patent Application Laid-Open No. 2006-22384.

According to the technique disclosed in Japanese Patent Application Laid-Open No. 2006-22384, in producing a resin-coated metal particle in which the surface of the metal particle is coated with a resin layer, the metal particle is surface-treated with a triazinethiol compound as the metal particle. And a metal having a polymerizable reactive group on the surface obtained by reacting an organic compound having a polymerizable reactive group and capable of reacting with a triazinethiol compound, and using the metal particles having a polymerizable reactive group on the surface. Resin coating is performed by polymerizing the particles and the polymerizable monomer.

The metal particles 500 coated with the resin film 502 as described above are dispersed in the liquid dispersion medium to form a functional material.

Hereinafter, the present invention will be further described with reference to Examples, but the present invention is not limited to the following examples.

(Example 1)
(Preparation of metal particles)
Using a raw material having a composition of 8% by mass Cu, 1% by mass Ni, 0.001% by mass Ge and Sn as the raw material, metal particles 1 having a diameter of about 3 to 40 μm were manufactured by the manufacturing apparatus shown in FIG. ..
At that time, the following conditions were adopted.
A melting pot was installed in the melting furnace 7, the raw material was put in the melting pot, the metal was melted at 650 ° C., and the molten metal was supplied from the nozzle 3 onto the dish-shaped rotating disk 4 while maintaining the temperature.
As the dish-shaped rotating disk 4, a dish-shaped disk having an inner diameter of 60 mm and a depth of 3 mm was used, and the rotation speed was 80,000 to 100,000 rpm.
As the granulation chamber 1, a vacuum chamber having the ability to reduce the pressure to about 9 × 10 ⁻² Pa is used to reduce the pressure, and then exhaust is performed simultaneously while supplying nitrogen gas at 15 to 50 ° C. to the granulation chamber. The air pressure in 1 was set to 1 × 10 ^-1 Pa or less.

The obtained metal particles 1 had a cross section as shown in FIG.
FIG. 3 is an element mapping analysis result by EDS of the cross section of the metal particle shown in FIG. From this analysis result, it was found that Cu was 10.24% by mass, Ni was 0.99% by mass, Ge was 0.001% by mass, and the balance was Sn.

The intermetallic compound in the metal particles 1 accounted for 30 to 35% by mass in the metal particles.

FIG. 4 shows a STEM image and a partial analysis result of the cross section of the metal particle obtained in Example 1 of the metal particle 1.
With reference to the upper part of FIG. 4, it can be seen that the intermetallic compound 120 composed of Sn, Cu, Ni and Ge is present in the matrix 140 containing the Sn and Sn—Cu alloy. In addition, the lattice constants (and crystal orientations) of the matrix 140 and the intermetallic compound 120 are uniform (0.3 nm in FIG. 4), and the respective crystals are continuously bonded at the crystal lattice level. Was confirmed. That is, according to the upper part of FIG. 4, since the lattice bonding is realized, it is confirmed that the bonding is an endpoint, and the transmission electron diffraction at the interface between the matrix 140 and the intermetallic compound 120 in the lower part of FIG. 4 is confirmed. According to the pattern, it was also confirmed that there was no buffer layer between the crystals.

Further, from FIG. 4, it was found that at least a part of Sn in the metal particles of this example contained high temperature phase crystals even at room temperature.

(Formation of conductor)
Through holes in TSVs (Through Silicon Vias) were prepared as objects with fine spaces.
The through hole had a hole diameter of 15 μm and an aspect ratio of 4.

Using malonic acid / ethanol as the liquid dispersion medium, the metal particles of the present invention were dispersed to prepare a dispersion (step (1)).

Using the obtained dispersion liquid, the following steps (2) and (3) were performed, and the dispersion liquid was filled in the fine space 3.

Step (2): An object is placed in a vacuum chamber, the degree of vacuum in the vacuum chamber is set to 10 ² Pa, a dispersion liquid is added to the surface of the object in this vacuum chamber, and squeegee operation, printing embedding start, and printing are performed. After performing vacuum screen printing to perform the crowding operation, the pressure was returned to atmospheric pressure and the object was taken out.
Step (3): The removed object was placed in a box inside the chamber of a centrifuge, the inside of the box inside the chamber was filled with an N ₂ atmosphere, and centrifugation was performed at atmospheric pressure, 500 rpm, and 1 minute.
Step (4): Subsequently, N ₂ gas was pressurized and introduced into the box in the chamber to reach 0.2 MPa, and while maintaining this pressurized atmosphere for 2 minutes, centrifugation was performed at 500 rpm, and after 2 minutes. The inside of the box in the chamber was maintained at 230 ° C. for 2 minutes at the same rotation speed, then decelerated centrifugation was performed, the mixture was cooled to 40 ° C., and the object was taken out.

FIG. 7 shows a cross-sectional micrograph (magnification: 1500 times) of the conductor formed in the fine space 3.
From the results of FIG. 7, it was found that the conductor 32 having a dense structure was formed in the fine space 3.

FIG. 8 is a TEM image showing the interface between the intermetallic compound crystal and the parent phase Sn—Cu alloy in the cross section of the conductor obtained in Example 1. The lower right portion is a transmission electron diffraction pattern at the Sn—Cu alloy-intermetallic compound crystal interface. From this TEM image and diffraction pattern, it was clarified that the intermetallic compound has a crystal structure endutically bonded to the Sn—Cu alloy.

(Comparative Example 1)
As a result of retesting the embodiment described in Patent Document 1 (Japanese Patent No. 4278007), in the method using molten metal in the subsequent step, as shown in FIG. 9, fine copper wiring is broken. There was found.

Although the contents of the present invention have been specifically described above with reference to preferred embodiments, those skilled in the art will have various modifications and other unexplained applications based on the basic technical ideas and teachings of the present invention. It is self-evident that you can think of the technical field.

1 Granulation chamber 2 Lid 3 Nozzle 4 Dish-shaped rotating disk 5 Rotating disk support mechanism 6 Particle discharge pipe 7 Electric furnace 8 Mixing gas tank 9 Piping 10 Piping 11 Valve 12 Exhaust device 13 Valve 14 Exhaust device 15 Automatic filter 16 Fine particle recovery device 120 Metallic compound 140 Mother phase 100 Object 103 Fine space 50 Functional material 51 Liquid dispersion medium 52 Metal particles 500 Metal particles 501 Metal core part 502 Resin film

Claims (2)

An electronic device board with a fine space,
A conductor is provided in the fine space.
The conductor has a structure having an intermetallic compound containing Sn, Cu, Ni and Ge in a matrix containing Sn and a Sn—Cu alloy.
The Sn—Cu alloy and the intermetallic compound are formed with an endaxial bond formed between at least one part thereof.
Electronic device board. The electronic device substrate according to claim 1, wherein the fine space has a pore diameter of 1 μm to 300 μm and an aspect ratio of 1 to 10.

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