JP2001176909A - Semiconductor device and mounting body thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the semiconductor device of structure where stress due to the difference of a thermal expansion coefficient between a semiconductor element and a circuit board and the mechanical deformation of the circuit board can securely be relieved and connection reliability between the semiconductor device and the circuit board is superior. SOLUTION: A semiconductor substrate 5 where the semiconductor element is formed, a pad electrode 8 which is formed on the main face of the semiconductor substrate, a protection resin layer 4 formed on the main face of the semiconductor substrate, a metallic body 6 passing through the protection resin layer, metallic wiring 7 connecting the metallic body and the pad electrode, and a connection electrode 2 which is installed on the surface of the protection resin layer by connecting it to the metallic body and is used for connection with the circuit board, are disposed. The connection electrode has structure including a part constituted of conductive resin 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a semiconductor device for collectively forming a package at a wafer level, and a package using the semiconductor device.

[0002]

2. Description of the Related Art In recent years, electronic devices and systems have become smaller and smaller.
In order to realize weight reduction and high performance, high-density mounting of semiconductor integrated circuits is required. Accordingly, miniaturization of semiconductor packages is also required, and as a semiconductor package corresponding to this demand, for example, a semiconductor chip is mounted on a carrier substrate by flip chip connection or wire bonding connection, and the semiconductor chip and the carrier substrate are mounted. A chip size package (CSP) in which an insulating resin is filled between the two has been developed and put into practical use.

Further, in recent years, a so-called wafer level packaging technique has been proposed in which a plurality of semiconductor chips are packaged at a wafer level in a lump. As a semiconductor package that can be formed at a wafer level, for example, a semiconductor package having a structure as shown in FIG. 4 is proposed in Japanese Patent Application Laid-Open No. Hei 10-79362 and "Nikkei Micro Devices", April 1998, pp. 164-167. Have been.

In FIG. 4, reference numeral 21 denotes a silicon substrate, on which elements are formed to constitute a semiconductor device. As shown in FIG. 4B, a metal wiring 22 is formed on the main surface, and a metal body 19 made of a copper metal pillar is formed on one end of the metal wiring 22. The other end of the metal wiring 22 is connected to the pad electrode 23.
On the upper surface of the metal body 19, a connection electrode with a circuit board made of solder balls 18 and the like is formed. An insulating protective resin layer 20 is formed between the plurality of metal bodies 19. The mounting on the circuit board is performed by forming a solder paste on the circuit board by printing or the like, then positioning the semiconductor device at a predetermined position on the circuit board with a chip mounter, and performing reflow.

In this conventional example, the metal wiring 22 and the metal body 19 use copper or the like formed by plating.

[0006] The above-described semiconductor device can be formed at a wafer level collectively as compared with the conventional CSP, and thus has advantages such as simplification of inspection in each manufacturing process and no need for a carrier substrate. The cost can be reduced in both production and material.

[0007]

The connection between the semiconductor device and the circuit board has a thermal stress caused by a difference in thermal expansion between the semiconductor device and the circuit board and a stress caused by a mechanical deformation of the circuit board. Join. In the semiconductor device as shown in FIG. 4, since the connection portions (the metal wiring 22 and the metal body 19) are made of a rigid metal, the resistance to the stress is poor. Therefore, there is a possibility that the connection portion may be damaged due to a difference in thermal expansion between the semiconductor device and the circuit board and a stress caused by mechanical deformation of the circuit board, and an electrical connection between the pad electrode 23 of the semiconductor element and the electrode of the circuit board may be caused. It was difficult to ensure the connection. In addition, Japanese Patent Application Laid-Open
No. 79362 discloses that the metal body 19 is provided with, for example, a high melting point solder interposed therebetween, but it cannot be said that a sufficient effect is obtained.

An object of the present invention is to provide a semiconductor device having an excellent connection portion between a connection electrode of the semiconductor device and a circuit board.

[0009]

In order to solve the above problems, a first semiconductor device according to the present invention comprises a semiconductor substrate on which a semiconductor element is formed, and a plurality of pads formed on a main surface of the semiconductor substrate. An electrode, a protective resin layer formed on the main surface of the semiconductor substrate to cover the pad electrode, a plurality of metal bodies penetrating the protective resin layer, and a metal body and the pad electrode formed below the protective resin layer. A metal wiring to be connected and connection electrodes provided on the surface of the protective resin layer so as to be connected to the respective metal bodies. The connection electrode has a structure including a portion made of a conductive resin.

According to this configuration, since the conductive resin is a flexible material that follows the deformation, the conductive resin contained in the connection electrode causes a difference in thermal expansion between the semiconductor and the circuit board and a mechanical expansion of the circuit board. It exerts the effect of relieving stress due to mechanical deformation.

The surface of the connection electrode is preferably made of a solderable material such as gold or copper. The reason is that when a semiconductor device is formed in a package form at a level like a wafer, and then divided into individual pieces and mounted at a predetermined position on a circuit board, for example, a CS
This is because most packages such as P or BGA are connected by solder, and therefore, a configuration that can be soldered is suitable for practical use.

According to another aspect of the present invention, there is provided a semiconductor device including: a semiconductor substrate having a semiconductor element formed thereon; a plurality of pad electrodes formed on a main surface of the semiconductor substrate; A protective resin layer formed over the main surface of the pad electrode to cover the pad electrode, a plurality of metal bodies penetrating the protective resin layer, and a metal wiring formed under the protective resin layer and connecting the metal body and the pad electrode. An insulating adhesive resin layer formed on the surface of the protective resin layer, and connection electrodes made of a conductive resin formed at positions corresponding to the metal body on the surface of the adhesive resin layer. The metal body has a structure electrically insulated from the connection electrode.

In the semiconductor device having such a structure, the conductive resin is also a flexible material that follows the deformation, so that the conductive resin has a thermal expansion difference between the semiconductor and the circuit board and a mechanical deformation of the circuit board. Exerts the effect of alleviating the stress caused by According to this configuration, since the pad electrode and the connection electrode are not electrically connected, electrostatic breakdown of the semiconductor device is suppressed in a semiconductor device manufacturing process, a storage and transport process, and a mounting process on a circuit board. can do. The semiconductor device of the present invention has not only a stress relaxation effect but also an effect of protecting the semiconductor device from electrical breakdown.

In the above structure, it is desirable that the connection electrode is buried in the adhesive resin layer by pressurization when mounted on a predetermined position of the circuit board, so that an electrical connection with the metal body can be formed. .

The metal body has a structure protruding from the protective resin layer, a sharp shape, or a metal body having a surface roughness Ra.
It is desirably 0.1 or more and 30 or less, preferably Ra1 or more and 10 or less. The reason is that the semiconductor device of the present invention achieves an electrical connection between the metal body and the connection electrode when the semiconductor device is mounted at a predetermined position on the circuit board by applying pressure, so that the connection at that time is well expressed. It is because it is suitable for making it.

The present invention can be applied in the form of a semiconductor wafer formed with a plurality of semiconductor devices having any one of the above structures.

Further, the semiconductor device having any one of the above structures is mounted at a predetermined position on a circuit board to form a semiconductor device package in which connection electrodes and electrodes of the circuit board are electrically connected.

Further, in the semiconductor device package having the above structure, an adhesive resin layer may be provided between the semiconductor device and the circuit board. Thereby, the mechanical connection between the semiconductor device and the circuit board is ensured by the adhesive resin, so that the semiconductor device is firmly connected to the circuit board. At this time, it is preferable that the conductive resin of the connection electrode is thermoplastic because it is excellent in stress relaxation action. The adhesive resin layer is
Since the semiconductor device and the connection portion between the semiconductor device and the circuit board are also protected from an external environment such as humidity, a highly reliable package is obtained.

[0019]

(Embodiment 1) FIG. 1 shows an example of a structure of a semiconductor device according to Embodiment 1 of the present invention. 1A is a plan view showing a semiconductor device at a wafer stage, FIG. 1B is a cross-sectional view showing a semiconductor device divided from a wafer, and FIG. 1C shows a structure of a connection portion. It is an expanded sectional view of an important section.

After the diffusion step is completed, the main surface of the semiconductor wafer 1 having the elements formed on the silicon substrate 5 is placed on the main surface of FIG.
As shown in FIG. 7, a metal wiring 7 is formed on the surface of a passivation layer (not shown) from the pad electrode 8 as a rewiring electrode. On the other end of the pad electrode 8 in the metal wiring 7,
A metal body 6 made of a copper metal column is formed. Around the metal body 6, a protective resin layer 4 is filled and formed.

The formation of the metal wiring 7, the metal body 6, the protective resin layer 4 and the like on the main surface of the wafer as described above can be performed, for example, by the method disclosed in Japanese Patent Application Laid-Open No. 10-79362. . In addition, metal wiring 7, metal body 6,
And the material, shape and dimensions of the protective resin layer 4 and the like,
For example, the content disclosed in JP-A-10-79362 can be applied.

In this embodiment, the connection electrode 2 is further formed on the surface of the metal body 6. The connection electrode 2 is a conductive resin layer 2
a and a gold / nickel plating layer 2b formed thereon.

The conductive resin layer 2a is formed, for example, in a circular pattern. As a material of the conductive resin layer 2a, a thermosetting conductive adhesive in which a metal filler is dispersed in a thermosetting binder is used. In an example based on this embodiment, a thermosetting conductive adhesive in which an epoxy resin is used as a binder and a silver filler is dispersed is used. When the conductive resin layer 2a is formed, a paste-like conductive adhesive is pattern-formed by, for example, screen printing of a metal mask.
Is placed in a hot air circulating furnace at 150 ° C. for 30 minutes, for example,
The patterned conductive adhesive is cured. In the embodiment, the conductive resin layer 2a has a columnar shape and a height of 20.
0 μm, diameter 500 μm, and pitch between adjacent 80
It was set to 0 μm.

Next, a gold / nickel plating layer 2b is formed on the surface of the conductive resin layer 2a by, for example, electroless plating nickel and gold sequentially. This nickel, gold,
As shown in FIG. 1 (c), it is preferably formed on the surface of the conductive resin layer 2a, but not formed on the side surface. When nickel or gold is also formed on the side surface, when soldering to a circuit board with solder, the solder is also bonded to the side surface of the conductive resin 2a, and the stress relaxation effect of the conductive resin 2a is hardly exhibited. is there. In the example, the thickness of nickel was 1.0 μm, and the thickness of gold was 0.05 μm.

As described above, the semiconductor device at the wafer stage shown in FIG. 1 is completed. Thereafter, the semiconductor wafer 1 is divided into chip-size packages of the individual pieces 3. The semiconductor wafer 1 is placed at a predetermined position on the circuit board on which the solder paste is printed, and is mounted by soldering in a solder reflow furnace.

In the semiconductor device of the present embodiment, since the conductive resin layer 2a constituting a part of the connection electrode 2 is a flexible material that follows deformation, the conductive resin layer 2a is It exerts an effect of alleviating a difference in thermal expansion from the circuit board and a stress due to mechanical deformation of the circuit board. Therefore, connection reliability is greatly improved.

In the above embodiment, the conductive adhesive is made of an epoxy resin binder in which a silver filler is dispersed, but another resin binder may be used as the thermosetting binder. As metal filler,
Copper, nickel, and silver coated copper can also be used. In addition, a thermoplastic resin can be used as the resin binder. For example, a resin such as polyimide, acrylic, or silicone can be used. Further, a mixture of both a thermosetting resin and a thermoplastic resin may be used.

(Embodiment 2) FIGS. 2 and 3 show an example of the structure of a semiconductor device according to Embodiment 2 of the present invention. FIG. 2A is a cross-sectional view of a semiconductor device at an individual level divided from a semiconductor wafer, and FIG. 2B is an enlarged cross-sectional view of a main part of a connection portion of the semiconductor device of FIG. FIG. 3 is FIG.
FIG. 4 is an enlarged view of a connection portion of a mounting body on which the semiconductor device of FIG.

In FIG. 2A, on the main surface of the silicon substrate 12 of the semiconductor wafer, a metal wiring 14 is formed on the surface of the passivation layer from the pad electrode 15 as a rewiring electrode. On the other end of the pad electrode 15 in the metal wiring 14, a metal body 13 formed of a copper metal column is formed. The protective resin layer 11 is filled and formed around the metal body 13.

The formation of the metal wiring 14, the metal body 13, the protective resin layer 11 and the like on the main surface of the silicon substrate 12 as described above uses, for example, a method disclosed in Japanese Patent Application Laid-Open No. 10-79362. Can be. Also, metal wiring 1
4, the materials, shapes, and dimensions of the metal body 13, the protective resin layer 11, and the like can be the same as those disclosed in, for example, JP-A-10-79362.

In this embodiment, an insulating adhesive resin layer 10 is further formed on the protective resin layer 11. As the adhesive resin layer 10, for example, a thermocompression bonding type film or a liquid resin material can be used. In an example based on this embodiment, a thermocompression-bonded film having a thickness of 20 μm was used.

Further, on the surface of the adhesive resin layer 10 and immediately above the metal body 13, a connection electrode 9 made of a conductive resin is provided.
Are formed, for example, in a circular pattern. In the example, a thermoplastic conductive adhesive in which an acrylic resin was used as a binder and a silver filler was dispersed was used as a material of the conductive resin forming the connection electrode 9. In forming the connection electrode 9, for example, a paste-like conductive adhesive is patterned by screen printing of a metal mask, and then the semiconductor wafer on which the pattern is formed is placed in, for example, a 120 ° C. hot air circulation furnace for 60 minutes. Then, the patterned conductive adhesive is cured. In the example, the shape of the connection electrode 9 was cylindrical, the height was 200 μm, the diameter was 500 μm, and the pitch between adjacent electrodes was 800 μm.

As described above, the semiconductor device at the wafer stage is completed. Thereafter, the wafer is divided into individual chip size packages as shown in FIG.

In this state, the metal body 13 and the connection electrode 9 are not electrically connected due to the interposition of the adhesive resin layer 10. The purpose of this structure is to suppress the electrostatic breakdown of the semiconductor device in the manufacturing process of the semiconductor device, the storage and transport process, the mounting process on the circuit board, and the like.
Semiconductor devices are sensitive to noise such as static electricity.
When the connection electrode 9 of the semiconductor device is electrically connected to the pad electrode 15, noise enters the transistor circuit portion of the semiconductor device from the connection electrode through the pad electrode, and the like.
The circuit may be destroyed. The semiconductor device of the present embodiment also has the function of protecting the semiconductor device from such electrical destruction.

FIG. 3 shows a state in which the semiconductor device singulated as described above is mounted on a circuit board. As shown in FIG. 3, the chip of the semiconductor device is mounted on a predetermined position of the circuit board 16 by a chip mounter having a heating head mounted thereon, thereby forming a semiconductor device mounted body. At this time, the connection electrode 9 is connected to the substrate electrode 17 on the circuit board 16. In addition, the connection electrode 9 is buried in the adhesive resin layer 10 and connected to the metal body 13 by heating and pressing of the chip mounter. Thereby, an electrical connection between the semiconductor device and the circuit board 16 is formed. Further, the semiconductor device is firmly fixed to the circuit board 17 by the adhesive resin layer 10. In one embodiment, the mounting condition is such that the set temperature of the heating head is 200.
° C, the mounting load of the chip mounter was 5 kgf, and the mounting time was 10 seconds.

It is desirable that the metal body 13 has a structure protruding from the protective resin layer 11 or a sharp shape. Alternatively, the surface roughness of the surface of the metal body 13 is Ra 0.1 or more and 30 or less, preferably Ra 1 or more and 10 or less. The reason for this is that when the package is mounted by pressurization as described above, it is suitable for favorably developing an electrical connection between the metal body 13 and the connection electrode 9.

Also in the semiconductor device of the present embodiment, since the conductive resin forming the connection electrode 9 is a flexible material that follows the deformation, the connection electrode 9 is formed by a thermal expansion difference between the semiconductor device and the circuit board. , And an effect of alleviating stress due to mechanical deformation of the circuit board. Therefore, connection reliability is greatly improved.

In the above embodiment, an acrylic resin binder in which a silver filler is dispersed as a metal filler is used as the conductive adhesive. However, another resin binder may be used as the thermosetting binder. Thermoplastic materials are preferred in terms of stress relaxation, but are not limited thereto. Copper, nickel, and silver-coated copper can also be used as the metal filler.

[0039]

According to the semiconductor device of the present invention and the package of the semiconductor device of the present invention, the connection structure between the semiconductor element and the circuit board includes a portion made of a flexible conductive resin. In the semiconductor device composed of such metal wiring and metal body, the difference in the coefficient of thermal expansion between the semiconductor element and the circuit board, and the stress caused by the mechanical deformation of the circuit board, which were the issues, were reliably reduced, and the connection reliability was improved. Can be greatly improved.

[Brief description of the drawings]

1A and 1B show a semiconductor device according to a first embodiment of the present invention, wherein FIG. 1A is a plan view showing a surface configuration at a wafer stage, FIG. 1B is a cross-sectional view showing a semiconductor device singulated from a wafer, (C) is an enlarged sectional view of a main part showing the connection part structure.

2A and 2B show a semiconductor device according to a second embodiment of the present invention, wherein FIG. 2A is a cross-sectional view, and FIG. 2B is an enlarged cross-sectional view of a main part showing a connection structure thereof.

FIG. 3 is a sectional view showing a connection structure of a package using the semiconductor device of FIG. 2;

4A and 4B show a conventional semiconductor device, in which FIG. 4A is a cross-sectional view, and FIG. 4B is an enlarged cross-sectional view of a main part showing a connection structure thereof.

[Explanation of symbols]

 Reference Signs List 1 semiconductor wafer 2, 9 connection electrode 4, 11 protective resin layer 5, 12 silicon substrate 6, 13 metal body 7, 14 metal wiring 8, 15 pad electrode 10 adhesive resin layer 16 circuit substrate 17 substrate electrode

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) H01L 23/12 L (72) Inventor Yukihiro Ishimaru 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. ( 72) Inventor Koji Kitae 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Katsuhide Tsukamoto 1006 Kadoma Kadoma Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (10)

[Claims] A semiconductor substrate on which a semiconductor element is formed;
A plurality of pad electrodes formed on the main surface of the semiconductor substrate, a protective resin layer formed on the main surface of the semiconductor substrate so as to cover the pad electrodes, and a plurality of penetrating the protective resin layer; A metal body, a metal wiring formed under the protection resin layer and connecting the metal body and the pad electrode, and a connection electrode provided on the surface of the protection resin layer so as to be connected to the metal body. Wherein the connection electrode has a structure including a portion made of a conductive resin. 2. The semiconductor device according to claim 1, wherein the surface of the connection electrode is solderable. 3. A semiconductor substrate on which a semiconductor element is formed;
A plurality of pad electrodes formed on the main surface of the semiconductor substrate, a protective resin layer formed on the main surface of the semiconductor substrate so as to cover the pad electrodes, and a plurality of penetrating the protective resin layer; A metal body, a metal wiring formed under the protection resin layer and connecting the metal body and the pad electrode, and an insulating adhesive resin layer formed on a surface of the protection resin layer;
A connection electrode made of a conductive resin formed at a position corresponding to each of the metal members on the surface of the adhesive resin layer, wherein the metal member is electrically insulated from the connection electrode. apparatus. 4. A structure in which a connection electrode is buried in an adhesive resin layer by pressurization when mounted on a predetermined position of a circuit board, so that an electrical connection with a metal body can be formed. The semiconductor device according to claim 3. 5. The semiconductor device according to claim 3, wherein the conductive resin is thermoplastic. 6. A structure in which the metal body protrudes from the protective resin layer,
Or, the sharpness or the surface roughness of the metal body surface is R
4. The semiconductor device according to claim 3, wherein a is not less than 0.1 and not more than 30. 7. The metal body has a surface roughness of Ra1 or more,
7. The semiconductor device according to claim 6, wherein the value is 0 or less. 8. A semiconductor wafer on which a plurality of the semiconductor devices according to claim 1 are formed. 9. A package of a semiconductor device, wherein the semiconductor device according to claim 1 is mounted at a predetermined position on a circuit board, and wherein the connection electrode is electrically connected to an electrode of the circuit board. . 10. A semiconductor device according to claim 3, wherein
The semiconductor device package according to claim 9, wherein an adhesive resin layer exists between the semiconductor device and the circuit board.