JP2000323510A - Semiconductor wafer with columnar electrode, method of manufacturing the same, and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor wafer with a columnar electrode, which effectively reduces thermal stress by a columnar electrode and improves the bonding reliability of a bonding portion with a mounting substrate. SOLUTION: An electrode terminal forming surface of a semiconductor wafer 10 is
Wiring pattern 16 having one end connected to each electrode terminal 12
Is formed via an insulating layer 14, a columnar electrode 18 is formed on the other end side of the wiring pattern 16 by copper plating, and a protective plating film 18a is formed on a top end surface of the columnar electrode 18. Wherein a heat treatment for reducing the hardness of the columnar electrode 18 made of metal formed by the copper plating is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer with columnar electrodes used for manufacturing a chip size package, a method for manufacturing the same, and a semiconductor device manufactured using the semiconductor wafer with columnar electrodes.

[0002]

2. Description of the Related Art As a method of manufacturing a semiconductor device, a wiring pattern is formed on an electrode terminal forming surface of a semiconductor wafer, or an electrode for bonding an external connection terminal is formed, so as to reduce thermal stress during or after mounting. A method of obtaining a chip-sized semiconductor device by covering the electrode terminal forming surface of a semiconductor wafer with a buffer layer has been studied. FIG. 6 shows a configuration example of a semiconductor wafer for manufacturing a chip-sized semiconductor device. The semiconductor wafer 10 has a wiring pattern 16 connected to the electrode terminal 12 at one end via an insulating layer 14 on a passivation film for protecting the surface of the semiconductor wafer. Is established. The columnar electrode 18 is for joining the external connection terminal 20 via a protective plating film formed on the top end surface, and has a diameter of about 300 μm and a height of about 100 μm according to the size of the external connection terminal 20 such as a solder ball. Is formed.

[0003]

As shown in FIG. 6, the semiconductor wafer 10 provided with the columnar electrodes 18 is sealed with a resin 22 by exposing the top end surfaces of the columnar electrodes 18, as shown in FIG.
The external connection terminal 20 is joined to the top end surface of the columnar electrode 18 via a protective plating film. The reason why the electrode terminal forming surface of the semiconductor wafer 10 is covered with the resin 22 is that the semiconductor device is mounted by using the resin 22 to cover and protect the wiring pattern 16 and the like and to use the buffering action of the resin 22. This is to reduce thermal stress generated between the mounting substrate and the semiconductor chip during or after mounting. The formation of the columnar electrode 18 in a columnar shape also has the meaning of buffering thermal stress from the joint of the external connection terminal.

However, the columnar electrode 18 is actually formed to be quite flat, and the external connection terminal 2
The thermal stress generated at the joint portion of the wiring pattern 16
Therefore, even if the electrode terminal forming surface is sealed with the resin 22, the buffering effect cannot be expected so much. The present invention relates to a semiconductor wafer on which such columnar electrodes are formed, to solve the problem of relieving the thermal stress generated at the junction of the external connection terminals at the time of mounting or after mounting, and at the time of mounting or after mounting. It is an object of the present invention to provide a semiconductor wafer with columnar electrodes, which can effectively reduce the thermal stress between the mounting substrate and the semiconductor chip, and a suitable manufacturing method thereof, and a semiconductor device manufactured using the semiconductor wafer with columnar electrodes. I do.

[0005]

To achieve the above object, the present invention comprises the following arrangement. That is, a wiring pattern having one end connected to each electrode terminal is formed via an insulating layer on the electrode terminal formation surface of the semiconductor wafer, and a columnar electrode is formed by copper plating on the other end side of the wiring pattern. The semiconductor wafer with a columnar electrode having a protective plating film formed on the top end surface of the electrode is subjected to a heat treatment for reducing the hardness of the columnar electrode made of the metal formed by the copper plating. Further, the columnar electrode is formed in a tapered shape in which the base side connected to the wiring pattern is larger in diameter than the top side, and has an advantage that durability against thermal stress acting on the columnar electrode is improved. . Further, since the surface of the wiring pattern and the side surfaces of the columnar electrodes are covered with the oxide film of copper, an electrical short circuit during or after mounting can be suitably avoided. Further, since the electrode terminal formation surface and the side surface of the columnar electrode are covered with an electrically insulating resin film, an electrical short circuit can be avoided more reliably. In addition, the electrode terminal formation surface and the side surfaces of the columnar electrodes are sealed with a resin having substantially the same thickness as the columnar electrodes by exposing the protective plating film, so that thermal stress during or after mounting can be suitably reduced. Can be planned. Further, it is preferable that nickel plating and gold plating are applied in order from the top end surface side of the columnar electrode as the protective plating film.

Further, the electrode terminal forming surface of the semiconductor wafer is
A wiring pattern having one end connected to each electrode terminal was formed via an insulating layer, a columnar electrode was formed by copper plating on the other end of the wiring pattern, and a protective plating film was formed on the top end surface of the columnar electrode. In the method of manufacturing a semiconductor wafer with columnar electrodes, a resist pattern is formed on the other end side of the wiring pattern where a columnar electrode is formed to cover an electrode terminal forming surface of the semiconductor wafer, and the exposed wiring pattern is formed. The other end of the columnar electrode to form a columnar electrode, apply protective plating to the top end surface of the columnar electrode to form a protective plating film, and then remove the resist pattern, and in air or in a nitrogen gas atmosphere. Then, a heat treatment for reducing the hardness of the columnar electrode is performed. Further, after performing the heat treatment, the surface of the protective plating film is coated with a releasable resin material, and after covering the electrode terminal forming surface of the semiconductor wafer and the side surface of the columnar electrode with a resin film having electrical insulation properties, The peelable resin material is peeled off to expose the protective plating film.
Further, by using a resin material that can be peeled off by heating as the releasable resin material, the resin material can be easily removed from the protective plating film to expose the end face of the protective plating film.

[0007] Further, on the electrode terminal forming surface of the semiconductor wafer,
A wiring pattern having one end connected to each electrode terminal is formed via an insulating layer, a columnar electrode is formed by copper plating on the other end of the wiring pattern, and a protective plating film is formed on a top end surface of the columnar electrode. A semiconductor device obtained by separating the semiconductor wafer with columnar electrodes into individual pieces, wherein a heat treatment for reducing the hardness of the columnar electrodes made of the metal formed by the copper plating is performed. Also,
It is preferable that the columnar electrode is formed in a tapered shape having a larger diameter on the base side connected to the wiring pattern than on the top side. Further, it is preferable that the surface of the wiring pattern and the side surfaces of the columnar electrodes are covered with a copper oxide film. Further, it is preferable that the electrode terminal formation surface and the side surface of the columnar electrode are covered with a resin film having electrical insulation. Further, it is preferable that the electrode terminal formation surface and the side surface of the columnar electrode are sealed with a resin having substantially the same thickness as the columnar electrode while exposing the protective plating film. Further, it is preferable that nickel plating and gold plating are applied in order from the top end surface side of the columnar electrode as the protective plating film.

[0008]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing a configuration of an embodiment of a semiconductor wafer with columnar electrodes according to the present invention. The configuration of each part such as the columnar electrode 18 of the semiconductor wafer with columnar electrodes of the present embodiment is the same as that of the above-described conventional semiconductor wafer with columnar electrodes. The electrode terminal forming surface of the semiconductor wafer 10 has an insulating layer 1 made of a resin such as polyimide.
The electrode terminals 12 and the columnar electrodes 18 are electrically connected to each other via a wiring pattern 16 formed on the surface of the insulating layer 14 and covered with the insulating layer 4. The columnar electrode 18 is formed by copper plating, and the top end surface of the columnar electrode 18 is covered with a protective plating film 18a.

The method of forming the columnar electrodes 18 on the electrode terminal forming surface of the semiconductor wafer 10 can be based on the manufacturing process shown in FIG. FIG. 2A shows a state where the electrode terminal forming surface of the semiconductor wafer 10 is covered with the insulating layer 14 and the electrode terminals 12 are exposed. From this state, chromium and copper are applied to the entire surface of the insulating layer 14 by sputtering to form the plating power supply layer 1.
Next, a resist pattern 15 is formed on the surface of the plating power supply layer 13, and electrolytic copper plating is performed to form a wiring pattern 16 (FIG. 2C). The resist pattern 15 is formed so that the plating power supply layer 13 is exposed at a portion where the wiring pattern 16 is formed. Plating power supply layer 1
3 is formed as thin as 0.5 μm to 1 μm, whereas the wiring pattern 15 is formed thick (about several μm).

Next, the resist pattern 15 is removed, the portion for forming the columnar electrode 18 is covered with the resist pattern 17 in which the exposed hole is formed, and the electrode terminal forming surface is formed by electrolytic copper plating to form the columnar electrode 18. I do. The exposed hole is formed in a circular hole on the bottom surface where the wiring pattern 16 is exposed, and copper plating is raised in the exposed hole. After the columnar electrode 18 is formed, protection plating is performed, and the top end surface of the columnar electrode 18 is covered with a protective plating film 18a (FIG. 2D). As the protective plating, there is used one in which the inner layer is nickel-plated and the outer layer is gold-plated, or one in which the inner layer is nickel-plated and the outer layer is palladium-plated. After forming the columnar electrode 18 and performing protection plating, the resist pattern 17 is removed, and the plating power supply layer 13 exposed on the surface is removed by etching.
As a result, a semiconductor wafer having the columnar electrode 18 whose top end surface is covered with the a is obtained.

The semiconductor wafer with columnar electrodes according to the present embodiment has a purpose of reducing the hardness of the metal portion of the columnar electrode 18 formed by copper plating after forming the columnar electrode 18 and performing protective plating. The heat treatment is performed on the entire semiconductor wafer. As a heat treatment method, 200 ° C., about 1
A method of keeping time may be used. According to an experiment, by performing such a heat treatment, the hardness of the columnar electrode 18 before the treatment is about 120 Vickers hardness.
Hv, but after treatment the Vickers hardness is 90
It was confirmed that it decreased to １００100 Hv. The ductility of solid copper is usually 15 to 20%, but after the treatment, the ductility has increased to 30% or more.
Changes in these characteristics are caused by the heat treatment.
This shows that the buffering action of increases. When the semiconductor wafer is heat-treated, when the heat treatment is performed in the air, the outer surface of the columnar electrode 18 and the outer surface of the wiring pattern 16 formed by copper plating are covered with a copper oxide film, and the heat treatment is performed in a nitrogen gas. In this case, there is a difference that the outer surface of the columnar electrode 18 and the outer surface of the wiring pattern 16 are hardly covered with the copper oxide film.

When a chip size package (semiconductor device having a size substantially equal to a semiconductor chip) is formed using a semiconductor wafer with columnar electrodes, the difference in the thermal expansion coefficient between the mounting substrate and the semiconductor chip during or after mounting. As a result, thermal stress generated between the mounting substrate and the semiconductor chip directly acts on the columnar electrode 18 from the joint portion of the external connection terminal. Therefore, reducing the hardness of the columnar electrode 18 and increasing the buffering action is not possible with the columnar electrode 18. This is extremely effective as an action to relieve thermal stress in a part. The effect of lowering the hardness of the columnar electrode 18 by the above-described heat treatment is that the columnar electrode 18 is formed by electrolytic copper plating, so that the heat treatment causes the copper crystals to be rearranged, and the copper particles become larger by oxidation. It is thought that it is due to becoming.

After the semiconductor wafer on which the columnar electrodes 18 are formed is subjected to heat treatment as described above, the semiconductor wafer 1 is heated.
2 is sealed with a resin 22 (FIG. 2).
(f)). The semiconductor wafer with columnar electrodes thus obtained is
By performing the above-described heat treatment, the hardness of the columnar electrode 18 is reduced, and a semiconductor wafer with the columnar electrode 18 having the columnar electrode 18 with improved buffering properties as compared with a conventional semiconductor wafer with a columnar electrode is obtained.

As shown in FIG. 2 (f), the electrode terminal forming surface of the semiconductor wafer 10 is not sealed with the resin 22, but the columnar electrode 18 is formed as shown in FIG. After that, a semiconductor wafer product with columnar electrodes can be obtained in a state where the heat treatment is performed. According to the heat treatment in the air, the side surface of the columnar electrode 18 and the surface of the wiring pattern 16 are covered with a copper oxide film, and the surface of the columnar electrode 18 and the wiring pattern 16 are protected by the oxide film. 18 has good wettability with solder or the like on the top end surface of the columnar electrode 18 due to the protective plating provided on the top end surface of the column electrode 18, whereas the oxide film has low solder wettability. This is because the problem can be avoided, and the buffering property of the resin 22 is not so expected, so that the necessity of performing the step of sealing with the resin 22 is not high.

However, when the wiring pattern 16 is mounted with the wiring pattern 16 exposed even if it is covered with an oxide film, the wiring pattern of the mounting board and the wiring pattern 16 of the chip size package may be electrically short-circuited. Therefore, it is effective to cover the surface of the wiring pattern 16 and the side surface of the columnar electrode 18 with a resin film having electrical insulation. In this case, the resin that covers the wiring pattern 16 and the side surfaces of the columnar electrodes 18 is preferably formed to a thickness that does not impair the buffering action of the columnar electrodes 18.

FIG. 3 shows a manufacturing process for covering the side surfaces of the wiring pattern 16 and the columnar electrode 18 with resin. Fig. 3 (a)
A columnar electrode 18 is formed on the electrode terminal forming surface of the semiconductor wafer 10, and a top end surface of the columnar electrode 18 is coated with a protective plating film 18.
a. FIG. 3 (b) shows the peeling resin material 2 which is easily peeled off by heating so that the protective plating film 18a is not covered with the resin.
6 is applied to the surface of the protective plating film 18a. Next, as shown in FIG. 3 (c), a resin 28 having electrical insulation such as a polyimide resin or a silicone resin is applied to the electrode terminal forming surface of the semiconductor wafer 10, the columnar electrode 18, and the surface of the protective plating film 18a. Application is performed according to these external shapes, and the entire surface of the semiconductor wafer 10 is covered with a resin film of the resin 28. As a method of coating the resin 28, a method by spraying, a method by spin coating, or the like can be used.

After coating the resin 28, the resin material 26 is heated to release the release resin material 26 that has covered the protective plating film 18a.
Is removed, and at the same time, the resin 28 covering the protective plating film 18a is removed (FIG. 3D). Since the peeling resin material 26 covers the protective plating film 18a, the protective plating film 18a is exposed by removing the peeling resin material 26, and the side surface of the columnar electrode 18 and the surface of the wiring pattern 16 are covered with the resin film. A coated semiconductor wafer with columnar electrodes is obtained. The resulting semiconductor wafer with columnar electrodes is shown in FIG.
As shown in (d), since only the protective plating film 18a for bonding the external connection terminal 20 is obtained by being exposed, the wiring pattern 16 and the wiring pattern on the mounting board side are electrically short-circuited during or after mounting. Such a problem can be solved. Also, the resin 2 covering the side surface of the columnar electrode 18 may be used.
8 is several μm to several tens μm following the side surface of the columnar electrode 18
The electrode 18 is formed as thin as
The buffering property and the deformability are not impaired by the resin 28, and the thermal stress at the time of mounting or after mounting can be effectively dispersed.

An external connection terminal 20 is bonded to each of the columnar electrodes 18 of the semiconductor wafer with columnar electrodes, and the semiconductor wafer with columnar electrodes is cut at predetermined positions and separated into individual pieces, thereby obtaining a chip-sized semiconductor device. Can be In addition,
Release resin material 2 covering the surface of protective plating film 18a
Reference numeral 6 denotes a protective film 18a which is peeled and removed in a later step so as not to be covered with the resin 28. Therefore, a resist material that can be removed by heating or a resist material that can be removed by etching or the like can be used as the peeling resin material 26.

FIG. 4 shows another method of covering the protective plating film 18a on the top end face of the columnar electrode 18 with a resin material 26 for peeling. In other words, the columnar electrode 18 is formed in the step shown in FIG. 2D, the protective plating film 18a is formed on the top end surface of the columnar electrode 18, and the resist pattern 17 is formed on the surface of the protective plating film 18a. A resin material 26 is applied (FIG. 4A), and then a resist pattern 1 is formed.
7 is removed and the protective plating film 18a is
In a state covered by According to this method, in the state where the resist pattern 17 is formed, the release resin material 26 is formed.
Is advantageous in that the resin material 26 for peeling can be easily applied to the protective plating film 18a.
After the step shown in FIG. 4B, the steps after FIG. 3C may be performed.

As described above, the method of covering the electrode terminal forming surface of the semiconductor wafer 10 and the side surface of the columnar electrode 18 with the resin 28 is the same as the conventional method in which the electrode terminal forming surface of the semiconductor wafer is formed using a resin sealing device. The manufacturing is much easier than the method of sealing with the resin 22 having substantially the same thickness as the columnar electrode. When the electrode terminal forming surface is sealed with a resin using a resin sealing device, the semiconductor wafer may be warped due to the contraction force of the resin. If it is a method of forming, the generation of internal stress can be suppressed small,
Deformation such as warpage of the semiconductor wafer can be prevented.
This suppresses the deformation of a chip-sized semiconductor device obtained by separating the semiconductor wafer with columnar electrodes into individual pieces, and makes it possible to provide a highly reliable semiconductor device.

FIG. 5 shows another embodiment of a semiconductor wafer with columnar electrodes in which the electrode terminal forming surface and the side surfaces of the columnar electrodes 18 are covered with a resin 28. The semiconductor wafer with columnar electrodes according to the present embodiment is also subjected to a heat treatment to reduce the hardness of the columnar electrodes 18. The present embodiment is characterized in that the base of the columnar electrode 18 is formed in a tapered shape having a larger diameter than the top side of the columnar electrode 18. FIG.
By adjusting the etching conditions during the step of forming the resist pattern 17 shown in (d), an exposed hole having a large diameter on the bottom side can be formed, and the base portion can be formed more than the top side by performing electrolytic copper plating. Can form a tapered columnar electrode 18 having a large diameter. As previously mentioned,
When a semiconductor device obtained by separating a semiconductor wafer with columnar electrodes into individual pieces is mounted, thermal stress at the time of mounting or after mounting acts on the columnar electrodes 18 most directly. It is effective to support the wiring pattern 16 in order to increase the durability against thermal stress.

The semiconductor wafer with columnar electrodes of the present embodiment also has columnar electrodes 18 on the electrode terminal forming surface of the semiconductor wafer 10.
Is formed, and the top end surface of the columnar electrode 18 is covered with the protective plating film 1.
8a and then coated with an electrically insulating resin 2
8 is spin-coated or sprayed to cover the electrode terminal forming surface and the side surface of the columnar electrode 18 with a resin 28. Of course, the entire surface of the electrode terminal forming surface is
Even when the resin is sealed with the resin 22 to have substantially the same thickness as that of the column electrode 8, forming the base side portion of the columnar electrode 18 in a tapered shape is effective in increasing the durability of the columnar electrode 18 against thermal stress.

[0023]

According to the semiconductor wafer with columnar electrodes, the method of manufacturing the same, and the semiconductor device according to the present invention, as described above, the columnar electrodes are heat-treated to reduce the hardness of the columnar electrodes formed by copper plating. By doing so, the thermal stress generated when the semiconductor device is mounted or after mounting can be effectively reduced, and the bonding reliability of the bonding portion with the mounting substrate can be improved. When the electrode terminal formation surface and the side surface of the columnar electrode are covered with resin according to these external shapes, the electrical relaxation due to the wiring pattern at the time of mounting and after mounting is maintained without impairing the relaxation of thermal stress by the columnar electrode. It has a remarkable effect such as being able to be mounted while preventing a short circuit.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a semiconductor wafer with columnar electrodes according to the present invention.

FIG. 2 is an explanatory view illustrating a method of forming a columnar electrode on an electrode terminal formation surface.

FIG. 3 is an explanatory view showing a method for manufacturing a semiconductor wafer with columnar electrodes according to the present invention.

FIG. 4 is an explanatory view showing another method for manufacturing a semiconductor wafer with columnar electrodes according to the present invention.

FIG. 5 is a cross-sectional view showing another configuration of the semiconductor wafer with columnar electrodes.

FIG. 6 is a sectional view showing a conventional configuration of a semiconductor wafer with columnar electrodes.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Semiconductor wafer 12 Electrode terminal 14 Insulating layer 16 Wiring pattern 18 Columnar electrode 18a Protective plating film 20 External connection terminal 22 Resin 26 Peeling resin material 28 Resin

Claims (15)

[Claims] 1. A wiring pattern having one end connected to each electrode terminal is formed on an electrode terminal formation surface of a semiconductor wafer via an insulating layer, and a columnar electrode is formed on the other end of the wiring pattern by copper plating. In a semiconductor wafer with a columnar electrode in which a protective plating film is formed on the top end surface of the columnar electrode, a heat treatment for reducing the hardness of the columnar electrode made of a metal formed by the copper plating is performed. Semiconductor wafer with columnar electrodes. 2. The semiconductor wafer with columnar electrodes according to claim 1, wherein the columnar electrodes are formed in a tapered shape such that the base side connected to the wiring pattern has a larger diameter than the top side. 3. The semiconductor wafer with columnar electrodes according to claim 1, wherein the surface of the wiring pattern and the side surfaces of the columnar electrodes are covered with a copper oxide film. 4. An electrode terminal forming surface and a side surface of a columnar electrode,
4. The semiconductor wafer with columnar electrodes according to claim 1, wherein the semiconductor wafer is covered with a resin film having electrical insulation. 5. An electrode terminal forming surface and a side surface of a columnar electrode,
4. The semiconductor wafer with columnar electrodes according to claim 1, wherein the protective plating film is exposed and sealed with a resin having substantially the same thickness as the columnar electrodes. 6. The semiconductor with columnar electrodes according to claim 1, wherein nickel and gold are plated in order from the top end surface of the columnar electrodes as the protective plating film. Wafer. 7. A wiring pattern having one end connected to each electrode terminal is formed on an electrode terminal formation surface of a semiconductor wafer via an insulating layer, and a columnar electrode is formed on the other end of the wiring pattern by copper plating. A method of manufacturing a semiconductor wafer with a columnar electrode in which a protective plating film is formed on the top end surface of the columnar electrode, wherein a portion for forming the columnar electrode at the other end of the wiring pattern is exposed to form an electrode terminal forming surface of the semiconductor wafer. After forming a resist pattern that covers the wiring pattern, electrolytic copper plating is performed on the other end side of the exposed wiring pattern to form a columnar electrode, and a protective plating film is formed by performing protective plating on the top end surface of the columnar electrode. Removing the resist pattern and performing a heat treatment for reducing the hardness of the columnar electrode in the air or in a nitrogen gas atmosphere; A method for manufacturing a semiconductor wafer. 8. After the heat treatment, the surface of the protective plating film is covered with a releasable resin material, and the electrode terminal forming surface of the semiconductor wafer and the side surfaces of the columnar electrodes are covered with a resin film having electrical insulation. 8. The method of manufacturing a semiconductor wafer with columnar electrodes according to claim 7, wherein the peelable resin material is peeled off to expose the protective plating film. 9. The method for manufacturing a semiconductor wafer with columnar electrodes according to claim 8, wherein a resin material that can be peeled off by heating is used as the peelable resin material. 10. A wiring pattern having one end connected to each electrode terminal is formed on an electrode terminal formation surface of a semiconductor wafer via an insulating layer, and a columnar electrode is formed by copper plating on the other end of the wiring pattern. In a semiconductor device obtained by separating a semiconductor wafer with a columnar electrode on which a protective plating film is formed on the top end surface of the columnar electrode into individual pieces, the hardness of the columnar electrode made of a metal formed by the copper plating is determined. A semiconductor device which has been subjected to a heat treatment for lowering it. 11. The semiconductor device according to claim 10, wherein the columnar electrode is formed in a tapered shape such that the base side connected to the wiring pattern has a larger diameter than the top side. 12. The semiconductor device according to claim 10, wherein the surface of the wiring pattern and the side surfaces of the columnar electrodes are covered with a copper oxide film. 13. The semiconductor device according to claim 10, wherein the electrode terminal forming surface and the side surface of the columnar electrode are covered with an electrically insulating resin film. 14. The electrode terminal formation surface and the side surfaces of the columnar electrodes are sealed with a resin having substantially the same thickness as the columnar electrodes by exposing the protective plating film.
13. The semiconductor device according to 1 or 12. 15. The semiconductor device according to claim 10, wherein nickel plating and gold plating are applied in order from the top end face side of the columnar electrode as the protective plating film.