JP6788974B2 - Electronic components - Google Patents

Description

The present invention relates to an electronic component, and more particularly to an electronic component having a structure in which a conductor layer such as an electrode or a circuit including a metal sintered body layer is arranged on a base material.

One of the electronic components having an electrode containing a sintered film of metal fine particles on a base material is, for example, a conductive substrate as described in Patent Document 1.

In this conductive substrate, a coating liquid containing metal or metal oxide fine particles is printed on a base material to form a printed layer, and the printed layer is fired to form a metal fine particle sintered film. The substrate is characterized in that the crystallite diameter of the metal fine particle sintered film measured by X-ray diffraction is 25 nm to 100 nm, and the porosity of the cross section of the metal fine particle sintered film is 1% or less. ..

Further, Patent Document 1 discloses a conductive substrate in which the metal or metal oxide is at least one selected from copper, copper oxide, and copper whose surface is oxidized.

Further, Patent Document 1 discloses a structure having no dissimilar metal layer or metal oxide layer between the metal fine particle sintered film and the base material, and the material forming the base material is a polyimide resin. What is disclosed.

In addition to the polyimide resin, an inorganic material or an organic material having low heat resistance can be used as the base material.

Further, in Patent Document 1, the metal fine particle sintered film formed by firing treatment by microwave surface wave plasma is said to have a thickness of about 50 nm to 2 μm, preferably 100 to 1000 nm, and the volume of the wiring. The resistivity is exemplified in Example 1 as 6.5 × 10 ^-6 Ωcm.

According to the above-mentioned Patent Document 1, a metal fine particle sintered film such as copper wiring is formed on a base material such as polyimide, and the metal fine particle sintered film has high adhesion to the base material and has excellent conductivity. It is said that a conductive substrate having a possession can be obtained.

Japanese Patent No. 5387034

However, in the conductive substrate of Patent Document 1, the metal fine particle sintered film used as wiring has a thin thickness of, for example, 50 nm to 2 μm when fired by microwave surface wave plasma, so that it is suitable for forming low resistance wiring. There is a problem that it is not suitable.

On the other hand, if an attempt is made to thicken the metal fine particle sintered film, pores are likely to be generated when the solvent in the wiring material is vaporized, and the porosity of the metal fine particle sintered film is increased to form a wiring having a low volume resistance. It becomes difficult.

In addition, since the atmosphere penetrates from the surface of the sintered film, it is difficult to uniformly sinter the inside of the sintered film as the film thickness of the sintered film increases, and wiring having a low volume resistivity should be formed from this aspect as well. Is difficult.

Therefore, the metal fine particle sintered film obtained from the invention of Patent Document 1 is a metal such as a massive metal material that is not affected by the surface, that is, a so-called bulk metal material (for example, metal foil, plating film, rod-shaped metal, etc.). In reality, it is difficult to avoid having a higher volume resistance than that of a material.

In Example 1 of Patent Document 1, for example, one having a volume resistivity of 6.5 × 10 ^-6 Ωcm is shown (Example 1 of Table 1 of Patent Document 1), but it is in a so-called bulk form. In the case of the metal material film of No. 1, the volume resistivity is as low as 1.694 × 10 ^-6 Ωcm (Metal Data Book Revised 4th Edition, edited by Japan Institute of Metals, published by Maruzen Publishing Co., Ltd.).

Further, the conductive substrate of Patent Document 1 has a configuration for electrical connection on the surface of a base material (insulating base material), and has a configuration for electrical connection in the thickness direction of the base material and electricity between base material layers. No specific configuration is shown for the target connection, and no solution to problems such as improvement of reliability and reduction of resistance in the thickness direction of the base material and the electrical connection between the base materials is not shown.

The present invention solves the above-mentioned problems, and is a conductor layer provided with a base wiring layer containing a Cu sintered body on a base material, and has a lower volume resistivity than a conductor made of a metal sintered body. An object of the present invention is to provide an electronic component having a highly reliable conductor layer.

In order to solve the above problems, the electronic component of the present invention
An electronic component provided with a base material and a conductor layer disposed on the base material.
The conductor layer
A base wiring layer having a Cu sintered body having an average crystallite diameter of 60 nm or more and 150 nm or less, which is arranged on the base material,
An intermediate layer in which voids near the surface of the Cu sintered body constituting the base wiring layer are filled with Cu-plated metal, and
It is provided with a Cu plating film layer formed on the intermediate layer.
The periphery of the base wiring layer is covered with the intermediate layer, and the periphery of the intermediate layer is covered with the Cu plating film layer.
The Cu sintered body is characterized in that it is a sintered body in which Cu particles are sintered and connected to each other.

In the electronic component of the present invention, the base material has a via hole, a via electrode is arranged in the via hole, and the conductor layer is arranged so as to be electrically connected to the via electrode. It is preferable that the base wiring layer constituting the conductor layer and the via electrode are metal-bonded at the interface between the two.

By providing the via electrode, it is possible to obtain an electrical connection not only in the plane direction of the base material but also in the thickness direction of the base material via the via electrode.
Further, it becomes possible to provide a highly reliable electronic component in which the via electrode and the conductor layer are securely connected by metal bonding.

Further, it is preferable that the via electrode is formed of a material containing Cu or a Cu alloy.
By firing in a reducing firing atmosphere to reduce Cu oxide, or by reducing Cu oxide in the presence of a reducing solvent, the metal constituting the conductor layer and the metal constituting the via electrode It becomes possible to realize a strong bond in which metal bonds are directly formed with each other, and a highly reliable electronic component can be obtained.

Further, the electronic component of the present invention may have a configuration in which the conductor layer is disposed on both one main surface and the other main surface of the base material.
By disposing the conductor layer on both one main surface and the other main surface of the base material, it is possible to save space in the area for disposing the conductor layer.

Further, in the electronic component of the present invention, a plurality of the base materials are laminated to form a laminated body, and the conductor layer is disposed inside the laminated body and is arranged inside the laminated body. It is also possible that at least a part of the conductor layers facing each other via the base material is interconnected via the via electrode.
With the above configuration, it is possible to further save space in the arrangement region of the conductor layer in the plane direction.

Further, it is preferable that the base material is formed of either one of an organic material and an inorganic material, or a combination of both.
The electronic component of the present invention contains a Cu sintered body in which the conductor layer has an average crystallite diameter of 60 nm or more and 150 nm or less, and such a Cu sintered body can be formed by heat treatment at a low temperature. Therefore, it is possible to use an inorganic material having excellent heat resistance such as ceramic as a base material, and of course, an organic material having lower heat resistance than an inorganic material such as ceramic such as epoxy resin. It is also possible to use one consisting of.

In the electronic component of the present invention, the conductor layer formed on the base material has a base wiring layer having a Cu sintered body having an average crystallite diameter of 60 nm or more and 150 nm or less, and a surface of the Cu sintered body constituting the base wiring layer. An intermediate layer in which nearby voids are filled with Cu-plated metal and a Cu-plated film layer formed on the intermediate layer are provided, and the Cu-plated film layer and the intermediate layer constituting the conductor layer are dense. To provide an electronic component having a highly reliable conductor layer having a lower volume resistance than a conventional conductor made of a metal sintered body because it is high and has excellent adhesion to the underlying wiring layer. Becomes possible.

It is sectional drawing which shows the structure of the electronic component (wiring board) which concerns on Example 1 of this invention. It is a figure which shows the TEM image of the conductor layer of the electronic component (wiring board) which concerns on Example 1 of this invention. It is sectional drawing which shows the structure of the electronic component (wiring board) which concerns on Example 2 of this invention. It is a figure which shows the FE-SEM image of the bonding interface of the via electrode of the electronic component (wiring board) and the base wiring layer (Cu sintered body layer) which concerns on Example 2 of this invention. It is sectional drawing which shows the structure of the electronic component (wiring board) which concerns on Example 3 of this invention. It is sectional drawing which shows the structure of the electronic component (multilayer substrate) which concerns on Example 4 of this invention.

Hereinafter, embodiments for carrying out the present invention will be shown, and the features of the present invention will be described in more detail.

The electronic component of the present invention is, for example, an electronic component having a base material (board) 1 and a conductor layer 2 arranged on the base material 1, as shown in FIG. 1 which is also used in the description of Example 1 described later. Wiring board) A.

The conductor layer 2 includes a base wiring layer 21 having an average crystallite diameter of 60 nm or more and 150 nm or less as a main component, which is arranged on the base material 1, and near the surface of the base wiring layer 21. The gap (gap formed by sintering the base wiring layer 21) is filled with the Cu-plated metal 22a to form the intermediate layer 22 and the Cu-plated film layer 23 formed on the intermediate layer 22. I have.

Here, X-ray diffraction measurement was performed on the base wiring layer 21, and three peaks <111>, <200>, and <311> were obtained. Then, the crystallite diameter was calculated by the Rietveld method using the obtained three peaks, and the average value was taken as the average crystallite diameter.

In the electronic component (wiring substrate) A having such a configuration, the surface of the base wiring layer 21 having the Cu sintered body 21a to be subjected to Cu plating has irregularities and voids, so that Cu baking is performed. The adhesion between the base wiring layer 21 and the Cu plating film layer 23 is improved by the anchor effect of the intermediate layer 22 formed by the Cu plating metal 22a entering the voids of the body 21a.

Further, since the electronic component (wiring substrate) A of the present invention includes a high-density Cu plating film layer (so-called bulk metal layer) 23 and an intermediate layer 22 located below the high-density Cu plating film layer (so-called bulk metal layer) 23, it is a Cu sintered body. An electronic component A having a conductor layer (wiring) having a lower resistance and excellent conductivity than a wiring made of only a Cu sintered body can be realized when the thickness is the same as that of a wiring layer formed only of copper. ..

Further, in the electronic component A of the present invention, for example, as shown in FIG. 3 used in Example 2 described later, the base material 1 has a via hole 3, and the via electrode 4 is arranged in the via hole 3. can do.

The electronic component A of the present invention is configured such that the via electrode 4 and the Cu sintered body constituting the base wiring layer 21 are metal-bonded at the interface between the via electrode 4 and the base wiring layer 21.

By providing the above configuration, it is possible to perform electrical connection not only in the plane direction of the base material 1 but also in the thickness direction of the base material 1 via the via electrode 4.

The present invention can also be applied to a multilayer substrate or the like. By making it possible to make electrical connections also in the thickness direction of the base material 1, it is possible to reduce the area of the electronic component (wiring board) A and realize the miniaturization of the electronic component A.

Further, since the via electrode 4 and the Cu sintered body layer (base wiring layer) 21 are metal-bonded, it is possible to provide a highly reliable electronic component A in which the via electrode and the conductor layer are securely connected. become.

[Example 1]
FIG. 1 is a cross-sectional view showing a configuration of a wiring board which is an electronic component according to a first embodiment of the present invention.

The electronic component (wiring board) A (A1) includes a conductor layer 2 formed on a base material (board) 1 made of an epoxy resin. And the conductor layer 2
(A) The base wiring layer 21 containing the Cu sintered body 21a as a main component, and
(B) An intermediate layer 22 formed on the base wiring layer 21 in which voids near the surface of the Cu sintered body 21a constituting the base wiring layer 21 are filled with Cu-plated metal 22a.
(C) A Cu plating film layer 23 formed on the intermediate layer 22 is provided.

As the base material 1, an inorganic material such as ceramic or an organic material (resin-based material) such as a polyimide resin such as an epoxy resin having a lower heat resistance than the ceramic can be used. It is also possible to use a material that is a combination of an organic material and an inorganic material.

An organic material having low heat resistance can be used for the base material 1 as a wiring material (for example, a conductive paste) containing Cu particles having an average crystallite diameter of 60 nm or more and 150 nm or less after sintering as a conductor component. By applying this to a base material and baking it, Cu particles can be sintered at a relatively low temperature to form a Cu sintered body layer (underlayer wiring layer).

Further, the intermediate layer 22 in which the voids near the surface of the base wiring layer 21 are filled with the Cu-plated metal 22a, and the Cu-plated film layer 23 on the intermediate layer 22 are the base wiring layer 21 made of the Cu sintered body 21a. Can be formed by subjecting to Cu plating as a seed layer.

Next, an example of a method for manufacturing the electronic component (wiring board) A1 shown in FIG. 1 will be described.
First, an epoxy resin (SMC-850-4H manufactured by Shin-Etsu Chemical Co., Ltd.) was heated at, for example, 150 ° C. for 1 hour and then heated at 200 ° C. for 4 hours to be cured to prepare a substrate (substrate) 1. Then, the produced base material 1 was polished to smooth the surface.

Next, the base wiring layer 21 was formed on the surface of the base material 1. In Example 1, a material containing Cu particles and a solvent was used as the wiring material to be the Cu sintered body constituting the base wiring layer 21. As the Cu particles, particles having a particle size distribution with a particle size peak in the range of 0.1 μm or more and 5.0 μm or less and an average crystallite diameter before sintering in the range of 10 nm or more and 100 nm or less were used. Triethanolamine was used as the solvent.
Then, Cu particles and triethanolamine were blended in a weight ratio of 87:13 and kneaded to prepare a wiring material for the base wiring layer 21.

Then, the wiring material produced as described above is printed in a rectangular shape on the base material 1, and then heat-treated at 180 ° C. for 10 minutes in a formic acid atmosphere to sinter the Cu particles in the wiring material. The base wiring layer (Cu sintered body layer) was formed. The print size was 2 mm × 6 mm.

As a method for surely adhering the resin (insulator) constituting the base material 1 and the base wiring layer 21, a method of roughening the resin surface which is the surface of the base material 1 to obtain an anchor effect, and a primer on the resin surface. It is possible to apply a method of performing treatment, a method of applying a resin or a coupling agent that adheres to both the Cu sintered body and the resin to a material composed of Cu particles and a solvent, and exhibiting adhesion during heat treatment. is there.
In the first embodiment, the surface of the substrate made of epoxy resin is roughened, the wiring material is printed, and then the conditions are 180 ° C. for 10 minutes in an atmosphere of 97 vol% nitrogen (N ₂ ) and 3 vol% formic acid. It was sintered to form a base wiring layer (Cu sintered body layer) 21.

Then, using the base wiring layer (Cu sintered body layer) 21 as a feeding film, electrolytic plating of Cu is performed, and the Cu plating metal 22a is deposited in the voids near the surface of the Cu crystal constituting the base wiring layer 21. The intermediate layer 22 was formed and the Cu plating film layer 23 was formed on the intermediate layer 22. As a result, the conductor layer 2 including the base wiring layer 21, the intermediate layer 22, and the Cu plating film layer 23 is formed.

Next, the structure (wiring structure) of the formed conductor layer 2 was examined. FIG. 2 shows a TEM (transmission electron microscope) image of the conductor layer 2 provided with the base wiring layer 21, the intermediate layer 22, and the Cu plating film layer 23.

Since the brightness of the TEM image is recognized by the difference in crystal orientation, the Cu sintered body 21a constituting the base wiring layer (Cu sintered body layer) 21 is a Cu plating film based on the brightness of the TEM image. It can be seen that the crystallite diameter is smaller than that of the Cu particles constituting the layer. When observed with a TEM image, the brightness changes depending on the crystal orientation, and the region of the same brightness = one crystal grain. The size of these crystal grains is the crystallite diameter, and the overall average crystallite diameter measured by using X-ray diffraction can be measured.
Further, it was confirmed that the intermediate layer 22 was formed by filling the voids of the Cu sintered body 21a constituting the base wiring layer 21 with the Cu plated metal 22a.

Since the area of the same lightness is large in the plating layer 22, it can be seen that the crystallite diameter is large in the plating layer 22. On the other hand, since the region of the same brightness is small in the base wiring layer 21, it can be seen that the crystallite diameter is small in the base wiring layer 21. Further, in the intermediate layer 22, the region of the same brightness is small and there are no voids, so that it can be confirmed that the voids in the base wiring layer 21 are filled with the plated metal.

Further, it can be seen that the Cu plating film layer 23, which is a layer made of plated metal Cu, is formed on the intermediate layer 22.

As described above, the wiring board (electronic component) A1 of the first embodiment has irregularities on the surface of the Cu sintered body 21a constituting the base wiring layer 21, that is, the surface to which Cu plating is applied. Therefore, the adhesion between the base wiring layer 21 and the Cu plating film layer 23 can be improved by the anchor effect of the intermediate layer 22 formed by the plating metal entering the voids of the Cu sintered body 21a.

Further, since the electronic component (wiring board) A1 of the present invention includes a high-density Cu plating film layer (so-called bulk metal layer) 23 and an intermediate layer 22 located below the high-density Cu plating film layer (so-called bulk metal layer) 23, it is a Cu sintered body. When the thickness is the same as that of the wiring layer formed only of copper, it is possible to realize an electronic component having a wiring having a lower resistance and excellent conductivity than a wiring made of only a Cu sintered body.

In Table 1, the conductor layer composed of only the Cu sintered body layer, the above-mentioned base wiring layer (Cu sintered body layer) 21, the intermediate layer 22, and the conductor layer 2 provided with the Cu plating film layer 23 are shown. Table 1 shows the conductor layer thickness, surface resistivity, and volume resistivity examined.

The conductor layer thickness in Table 1 is a thickness measured by the method described below.
<Measuring method of conductor layer thickness>
Using a laser displacement meter LT-9500V (manufactured by Keyence), the height of the substrate surface and the height of the surface of the conductor layer were measured on the lines in the longitudinal direction of the conductor layer 2 (see FIG. 1), and both were measured. The average value of the differences was taken as the conductor layer thickness. The measurement pitch of the conductor layer thickness on the line was 50 μm.

<Measurement method of surface resistivity and volume resistivity>
The surface resistivity was measured by a 4-probe method using a surface resistivity meter Loresta GP (manufactured by Mitsubishi Chemical Analytical).
Further, the volume resistivity was calculated by multiplying the surface resistivity by the thickness (film thickness) of the conductor layer.

As shown in Table 1, in the case of the conductor layer composed of only the Cu sintered body, either the case of Comparative Example 1 in which the conductor layer thickness is as thin as 10.5 μm and the case of Comparative Example 2 in which the conductor layer thickness is as thick as 52.3 μm. However, the surface resistivity and volume resistivity are higher than those of the conductor layer according to the embodiment of the present invention, and according to the present invention, a surface surface that cannot be obtained with a conventional conductor layer consisting only of a Cu sintered body. It was confirmed that a conductor layer having low resistivity and volume resistivity can be formed.

[Example 2]
FIG. 3 is a cross-sectional view showing the configuration of the wiring board which is the electronic component A2 according to the second embodiment of the present invention.
The electronic component A2 includes a base material (board) 1 made of an epoxy resin and a conductor layer 2 formed on the base material (board) 1.
A via hole 3 is formed in the base material (substrate) 1, and a columnar via electrode (Cu electrode) 4 formed by plating is arranged in the via hole 3.

Similar to the case of the first embodiment, the conductor layer 2 has a base wiring layer 21 containing the Cu sintered body 21a as a main component and voids of the Cu sintered body 21a formed on the base wiring layer 21. , An intermediate layer 22 filled with a Cu-plated metal 22a, and a Cu-plated film layer 23 formed on the intermediate layer 22 are provided.

As the via electrode 4, a columnar Cu electrode is used in the second embodiment, but the material constituting the via electrode 4 is not limited to Cu, and Au, Ag, Cu, Ni or these 1 It is possible to use alloys containing more than one type, and there are no particular restrictions on the specific type or composition. However, it is usually preferable to use Cu and Cu alloys which have good sintering bondability with the underlying wiring layer (Cu sintered body layer) 21 constituting the conductor layer 2 and are also excellent in economy.

Further, the via electrode 4 can be formed by a method of plating a metal for an electrode, a method of embedding a columnar electrode material, a method of filling and baking a conductive paste containing electrode material particles, or the like.
Further, the via electrode 4 may be a massive metal material that is not affected by the surface, that is, a so-called bulk metal, or may be a metal sintered body. Further, it is also possible to use a conductor in which the conductive material is dispersed in the insulating material such as resin or glass for the via electrode 4.

Further, in the electronic component (wiring board) A2 of the second embodiment, the via electrode 4 and the base wiring layer (Cu sintered body layer) 21 constituting the conductor layer 2 are metal-bonded at the interface between them. .. In the electronic component A2 of the second embodiment, when the base wiring layer (Cu sintered body layer) 21 is sintered, the Cu sintered body layer 21 is also applied to the via electrode (metal Cu) 4 included in the base material 1. The Cu sintered body layer 21 and the via electrode 4 were metal-bonded so that the Cu particles constituting the above were sintered.

Next, an example of a method for manufacturing the electronic component (wiring board) A2 shown in FIG. 3 will be described. In manufacturing the electronic component (wiring board) A2 of Example 2, the epoxy resin (SMC-850-4H manufactured by Shin-Etsu Chemical Co., Ltd.) is first heated at 150 ° C. for 1 hour and then at 200 ° C. for 4 hours. The substrate was heated and cured to prepare a substrate. Then, the produced base material 1 was polished to smooth the surface.

Next, a hole was machined to form a via hole 3, and the via hole 3 was filled with a Cu-plated metal by a filled via plating method to form a via electrode 4. Then, Cu (metal Cu formed by plating) raised on the surface of the base material (substrate) 1 was scraped off to obtain a base material having a flat surface.

Further, also in Example 2, a material containing Cu particles and a solvent was used as the wiring material to be the Cu sintered body constituting the base wiring layer 21. As the Cu particles, particles having a particle size distribution with a particle size peak in the range of 0.1 μm or more and 5.0 μm or less and an average crystallite diameter before sintering in the range of 10 nm or more and 100 nm or less were used. Triethanolamine was used as the solvent.
Then, Cu particles and triethanolamine were blended in a weight ratio of 87:13 and kneaded to prepare a wiring material for the base wiring layer 21.

Then, the wiring material produced as described above was printed in a rectangular shape on the base material 1. At this time, printing was performed so that the wiring material covered the via electrode 4. Then, a heat treatment was performed at 180 ° C. for 10 minutes in a formic acid atmosphere to sinter the Cu particles in the wiring material to form a base wiring layer (Cu sintered body layer).
At this time, the Cu particles constituting the base wiring layer (Cu sintered body layer) 21 are also sintered on the via electrode 4, and the base wiring layer (Cu sintered body layer) 21 and the via electrode 4 are made of metal. Combined.

Since formic acid can reduce Cu oxide, even when the via electrode 4 is, for example, Cu or a Cu alloy whose surface is easily oxidized, the Cu oxide on the surface of the via electrode 4 is reduced. It becomes possible to directly bond metals to each other, and a strong bond can be obtained.

In addition to the firing atmosphere, the wiring material may contain a reducing agent that reduces Cu oxide, so that the Cu oxide can be reduced without using a reducing atmosphere.

After that, by the same method as in the case of Example 1, the base wiring layer (Cu sintered body layer) 21 is used as a feeding film, and Cu is electroplated, and the voids of the Cu sintered body 21a constituting the base wiring layer 21 are performed. By forming the intermediate layer 22 filled with the Cu-plated metal 22a and forming the Cu-plated film layer 23 on the intermediate layer 22, the underlying wiring layer 21, the intermediate layer 22, and the Cu-plated film layer 23 are formed. The provided conductor layer 2 was formed.
As a result, an electronic component (wiring board) A2 having a structure as shown in FIG. 3 can be obtained.

FIG. 4 shows an FE-SEM (field emission scanning electron microscope) image of the bonding interface between the via electrode 4 of the electronic component and the base wiring layer (Cu sintered body layer) 21 according to the second embodiment.
From FIG. 4, it was confirmed that the base wiring layer (Cu sintered body layer) 21 was sintered on the via electrode (Cu metal) and metal-bonded.

In the case of the electronic component A2 of the second embodiment as well, the surface of the Cu sintered body 21a constituting the base wiring layer 21, that is, Cu plating is applied, as in the case of the electronic component A1 of the first embodiment described above. Since the surface has irregularities, the adhesion between the base wiring layer 21 and the Cu plating film layer 23 is improved by the anchor effect of the intermediate layer 22 formed by the plating metal entering the voids of the Cu sintered body 21a. Can be made to.

Further, since the electronic component (wiring board) A2 also has a high-density Cu plating film layer (so-called bulk metal layer) 23 and an intermediate layer 22 located below the high-density Cu plating film layer (so-called bulk metal layer) 23, it is formed only from the Cu sintered body. When the thickness is the same as that of the resulting wiring layer, it is possible to realize an electronic component having a wiring having a lower resistance and excellent reliability than a wiring made of only a Cu sintered body.

Further, according to the configuration of the second embodiment, a more useful electronic component (which can be electrically connected not only in the plane direction of the base material 1 but also in the thickness direction of the base material 1 via the via electrode 4) ( Wiring board) can be provided.
Further, since the via electrode 4 and the Cu sintered body layer 21 are metal-bonded, wiring with high bonding reliability can be formed.

[Example 3]
FIG. 5 is a cross-sectional view showing the configuration of the wiring board which is the electronic component A3 according to the third embodiment of the present invention.

The electronic component A3 is formed on a base material (board) 1 made of an epoxy resin, a conductor layer 2 (2a) formed on the upper surface of the base material (board) 1, and a lower surface of the base material (board) 1. It includes a conductor layer 2 (2b).

The conductor layers 2 (2a) and 2 (2b) are the base wiring layer 21 containing the Cu sintered body 21a as a main component and the base wiring layer, as in the case of the conductor layers 2 of Examples 1 and 2. An intermediate layer 22 in which the voids of the Cu sintered body 21a formed on the 21 are filled with the Cu-plated metal 22a, and a Cu-plated film layer 23 formed on the intermediate layer 22 are provided.

The conductor layers 2 (2a) and 2 (2b) are electrically connected to each other via the via electrodes 4 arranged in the via holes 3.

Further, the base wiring layer (Cu sintered body layer) 21 constituting the conductor layers 2 (2a) and 2 (2b) is bonded to the via electrode 4 by a metal bond.
Other configurations are the same as in the case of the electronic component (wiring board) A2 of the second embodiment.

Further, the electronic component (wiring board) A3 of this embodiment is a base wiring layer constituting the conductor layer 2 (2a) on the upper surface side of the base material (board) 1 by a method similar to the case of the above-mentioned second embodiment. After forming the (Cu sintered body layer) 21, a base wiring layer (Cu sintered body layer) 21 constituting the conductor layer 2 (2b) is further formed on the lower surface side of the base material (board) 1. After that, it can be produced by performing Cu plating to form the intermediate layer 22 and the Cu plating film layer 23.

By forming the conductor layers 2 (2a) and 2 (2b) on both the upper surface side and the lower surface side of the base material (board) 1 as in the electronic component (wiring board) A3 of the third embodiment, the surface direction It is possible to save space in the wiring area of.
In addition, the same effects as those of the electronic components (wiring boards) A1 and A2 of Examples 1 and 2 can be obtained in other respects as well.

[Example 4]
FIG. 6 is a cross-sectional view showing the configuration of the multilayer substrate which is the electronic component A4 according to the fourth embodiment of the present invention.
The electronic component A4 is provided with conductor layers 2 inside and on the upper surface of a laminate 11 having a structure in which a plurality of base material layers (base materials) 1a are laminated, and conductor layers 2 of different layers are arranged in via holes 3. It is a multilayer substrate having a structure electrically connected by the via electrode 4.

Each conductor layer 2 included in the electronic component (multilayer substrate) has the same configuration as the conductor layer 2 in the electronic components A1, A2, and A3 of Examples 1 to 3. Further, the via electrode 4 also has the same configuration as the via electrode 4 in the electronic components A2 and A3 of the second and third embodiments.

The electronic component (multilayer substrate) A4 of the fourth embodiment is manufactured by, for example, the method described below.
(1) First, a wiring board (1) in which a via electrode 4 is arranged in a via hole 3 provided in a base material (board) 1 made of an epoxy resin and a conductor layer 2 is formed on an upper surface by the method described in the second embodiment. A base material layer) 1a provided with the conductor layer 2 is produced.

(2) Then, after applying the uncured epoxy resin on the base material layer 1a, the epoxy resin is cured by heating at 200 ° C. for 4 hours, for example, to form the second base material layer 1a. To do.

(3) After that, a hole is formed in the second base material layer 1a to form a via hole 3. Subsequently, as described in the second embodiment described above, the via hole 3 is filled with Cu-plated metal by filled via plating to form the via electrode 4.

(4) After that, Cu (metal Cu formed by plating) raised on the surface of the base material layer 1a is scraped off by polishing, and the surface of the base material layer 1a is in a flat state so that wiring can be formed. And.

(5) Next, on the base material layer 1a and the via electrode 4, a wiring material containing Cu particles and a solvent, which is the same as the wiring material used in Examples 1 to 3 above, is printed and baked to form a base wiring. The layer (Cu sintered body layer) 21 is formed.

(6) After that, the base wiring layer (Cu sintered body layer) 21 is subjected to Cu plating to form the intermediate layer 22 and the Cu plating film layer 23. As a result, the conductor layer 2 including the base wiring layer (Cu sintered body layer) 21, the intermediate layer 22, and the Cu plating film layer 23 is formed.

(7) Then, by repeating the steps (2) to (6) above, the base material layer 1a and the conductor layer 2 are sequentially laminated. As a result, the multilayer substrate A4 having the structure as shown in FIG. 6 can be obtained.

By stacking the base material layer and the conductor layer in the thickness direction as in the electronic component (multilayer substrate) A4 of the fourth embodiment, the space saving of the arrangement region of the conductor layer in the surface direction can be further promoted. This makes it possible to provide small, high-performance electronic components (multilayer boards).

The present invention is not limited to the above-described embodiments and examples, and the shape and dimensions of the base material, constituent materials, types of materials constituting the conductor layer and via electrode, specific patterns of the conductor layer, and the like. It is possible to add various applications and modifications within the scope of the invention regarding the arrangement mode of the via electrode.

1 Substrate (board)
1a Base material layer
2,2a, 2b Conductor layer 3 Via hole 4 Via electrode 11 Laminated body A (A1, A2, A3, A4) Electronic component 21 Base wiring layer (Cu sintered body layer)
21a Cu sintered body 22a Cu plated metal 22 Intermediate layer 23 Cu plated film layer

Claims (6)

An electronic component provided with a base material and a conductor layer disposed on the base material.
The conductor layer
A base wiring layer having a Cu sintered body having an average crystallite diameter of 60 nm or more and 150 nm or less, which is arranged on the base material,
An intermediate layer in which voids near the surface of the Cu sintered body constituting the base wiring layer are filled with Cu-plated metal, and
It is provided with a Cu plating film layer formed on the intermediate layer.
The periphery of the base wiring layer is covered with the intermediate layer, and the periphery of the intermediate layer is covered with the Cu plating film layer.
The Cu sintered body is an electronic component characterized in that Cu particles are sintered and connected to each other. The base material has a via hole, a via electrode is arranged in the via hole, the conductor layer is arranged so as to be electrically connected to the via electrode, and the base material constituting the conductor layer is formed. The electronic component according to claim 1, wherein the wiring layer and the via electrode are metal-bonded at the interface between the two. The electronic component according to claim 2, wherein the via electrode is formed of a material containing Cu or a Cu alloy. The electronic component according to any one of claims 1 to 3, wherein the conductor layer is disposed on both one main surface and the other main surface of the base material. A plurality of the base materials are laminated to form a laminated body, and the conductor layer is arranged inside the laminated body and is arranged inside the laminated body so as to face each other via the base material. The electronic component according to claim 2 or 3, wherein at least a part of the conductor layer is interconnected via the via electrode. The electronic component according to any one of claims 1 to 5, wherein the base material is formed of either one of an organic material and an inorganic material, or a combination of both.