JP2000200848A - Electronic component mounting circuit board and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable mounting structure which effectively relaxes a thermal stress induced when an electronic component such as a semiconductor device or the like is mounted on a mounting board. SOLUTION: An electronic component mounting circuit board is interposed between the surface of a surface-mounting electronic component where connecting terminals are formed and the surface of a mounting board where connecting electrodes are formed so as to electrically connect the connecting terminals of the electronic component to the electrodes of the mounting board, where pads 12a where connection terminals are joined are provided to the one surface of an insulating board 10 corresponding to the two-dimensional arrangement of the electrodes, and pads 12b where connection electrodes are joined, are arranged corresponding to the two-dimensional arrangement of the electrodes. Through holes 14 are bored in the insulation board 10 and provided between the pads 12a formed on its one side and the pads 12b formed on its other side, connecting wires 16 are each connected inside the through-holes 14 between the pads 12a formed on the one surface of the board 10 and the pads 12b formed on the other surface of the board 10, so that the pads 12a and 12b each provided to both the sides of the board 10 are electrically connected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting board for mounting a surface mount type electronic component such as a semiconductor element or a chip size package, and a semiconductor device using the same.

[0002]

2. Description of the Related Art A problem in mounting a surface-mount type electronic component such as a flip-chip type semiconductor device or a chip size package on a mounting board is a problem due to a difference in thermal expansion coefficient between the mounting board and the semiconductor element. There is a stress problem. That is, when a semiconductor element is mounted on a mounting substrate, cracks may occur in the semiconductor element due to thermal stress generated between the semiconductor element and the mounting substrate, or a joint between the mounting substrate and the semiconductor element may peel off. There's a problem.

As a method for solving the problem of thermal stress generated when electronic components such as semiconductor elements are mounted, a buffer portion for relaxing thermal stress is provided on a package side on which the semiconductor element is mounted, so that the semiconductor element becomes excessively large. A method for preventing the thermal stress from acting, after mounting the semiconductor element, filling the joint between the semiconductor element and the mounting board with an underfill material and fixing the semiconductor element does not cause separation at the joint. There is a method to do so. Further, as a method of providing a buffer portion for relaxing thermal stress on a package side on which a semiconductor element is mounted, a method of mounting a semiconductor element on a substrate via a buffer layer formed of a buffer material such as an elastomer, a method of forming an electrode on a semiconductor element, There is a method in which a connection terminal to be connected is formed by a wire, and elasticity is given to the connection terminal so that the connection terminal can be deformed.

[0004]

However, providing a buffer structure for relaxing thermal stress during mounting on a surface-mount type semiconductor device such as a semiconductor element or a chip size package requires a complicated manufacturing process. There's a problem. Further, when a flip-chip type semiconductor element is mounted, there is a problem that an effective buffer structure cannot be provided due to its structure.

The present invention has been made to solve these problems, and effectively alleviates the thermal stress generated when mounting a surface-mounted electronic component such as a flip-chip type semiconductor device or a chip size package. It is an object of the present invention to provide a circuit board for mounting electronic components and a semiconductor device using the same, which enable a highly reliable mounting structure.

[0006]

To achieve the above object, the present invention comprises the following arrangement. That is, the connection terminals of the electronic component and the electrodes of the mounting board are interposed between the surface of the surface-mounted electronic component on which the connection terminals are formed and the surface of the mounting board on which the connecting electrodes are formed. In the electronic component mounting circuit board to be electrically connected, a pad to which a connection terminal is joined corresponding to the planar arrangement of the connection terminal is provided on one surface of an electrically insulating substrate, and the other surface of the substrate is provided. A pad to which an electrode is bonded corresponding to the plane arrangement of the electrodes is provided on a surface, and between each pad provided on the one surface and each pad provided on the other surface, between both surfaces of the substrate. A connecting wire is connected between a pad provided on one surface of the substrate and a pad provided on the other surface in the through hole, and provided on both surfaces of the substrate. The pads are electrically connected. .
The fact that the connection wire is formed in a deformable shape such as an S-shape is effective in obtaining an effective buffering action at the joint between the pad and the connection terminal. Further, the through hole is filled with a buffer material made of an insulating material or a conductive material. Further, the cushioning material is
Young's modulus 10 MPa to 10 GPa, preferably 10 MP
By being made of a low elastic material of a to 1 GPa, a joint portion with a connection terminal or the like can exhibit a suitable buffering action.

Also, the connection terminals of the electronic component and the electrodes of the mounting substrate are interposed between the surface of the surface-mount type electronic component on which the connection terminals are formed and the surface of the mounting substrate on which the connection electrodes are formed. And an electronic component mounting circuit board for electrically connecting the connection terminals to one surface of the substrate having electrical insulation, the pad being provided with connection terminals corresponding to the planar arrangement of the connection terminals. A pad to which an electrode is joined corresponding to the planar arrangement of the electrodes is provided on the other surface of the substrate, and a substrate is provided between each pad provided on the one surface and each pad provided on the other surface. A through-hole penetrating between the two surfaces of the substrate is formed, and a conductive material is filled in the through-hole, and pads provided on both surfaces of the substrate are electrically connected. Further, the invention is characterized in that the conductor is made of a conductive material having a buffering property. Further, the substrate has a Young's modulus of 10 MPa to 10 GPa, preferably 10 MPa to 1 GPa.
By using a low elastic material of GPa, it is possible to obtain a circuit board for mounting electronic components having excellent buffering properties.

Further, as a semiconductor device, the electronic component mounting circuit board is interposed between a surface on which connection terminals of an electronic component to be mounted is formed and a surface of the mounting substrate on which electrodes are formed, The connection terminal is bonded to a pad provided on one surface of the substrate, and the electrode is bonded to a pad provided on the other surface of the substrate.

[0009]

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 an embodiment of a circuit board for mounting electronic components according to the present invention. The circuit board for mounting electronic components according to the present embodiment has a structure in which connection terminals of a mounting target such as a semiconductor element and electrodes provided on a mounting board are provided on both surfaces of an electrically insulating board 10 formed of a low elastic material. Pad 12 in an arrangement corresponding to the arrangement
a, 12b are provided, and the through-holes 1 are provided through the substrate 10 in the thickness direction in alignment with the pads 12a, 12b.
In 4, the inner surfaces of the pads 12a and 12b provided on both surfaces of the substrate 10 are connected by connecting wires 16, and the through holes 14 are filled with a buffer material 18.

[0010] The circuit board for mounting electronic components is interposed between a mounted product such as a semiconductor element and the mounting substrate, and electrically connects the mounted product and the mounting substrate. Therefore,
The pads 12a and 12b formed on both surfaces of the substrate 10 need to be arranged so as to coincide with the plane arrangement of the connection terminals of the mounted product and the plane arrangement of the electrodes provided on the mounting board. The circuit board for mounting electronic components of the embodiment shown in FIG. 1 is an example in the case where the plane arrangement of connection terminals of a mounting object such as a semiconductor element and the plane arrangement of electrodes provided on the mounting board are exactly the same. Pads 12a arranged on both sides of the substrate 10,
It is possible that the plane arrangements of 12b are slightly displaced from each other.

The reason why the substrate 10 is formed of a low-elastic material is to appropriately reduce the thermal stress generated when electronic components are mounted. For this reason, a material having a sufficient buffering property to alleviate the thermal stress during mounting, for example, a material having an excellent buffering property such as a silicone resin or a silicone rubber can be suitably used for the substrate 10. As the substrate 10 having a buffering property, a material having a Young's modulus of about 10 MPa to 10 GPa can be suitably used.
A material of about MPa to 1 GPa can be used.

Although the substrate 10 is made of a low-elastic material, the thermal stress during mounting can be effectively reduced. However, in the circuit board for electronic components of the present embodiment,
A through-hole 14 is provided to penetrate the substrate 10 in the thickness direction, and the pads 12a, 12
b, the pads 12a and 12b to which the connection terminals of the component to be mounted and the electrodes of the mounting board are joined.
A buffering action is also exerted on the part. Therefore, even when the substrate 10 is not formed of a low elastic material, a certain buffering effect can be obtained.

The pads 12a, 1 provided on both sides of the substrate 10
2b is electrically connected by connecting the inner surfaces of the pad 12a and the pad 12b in the through hole 14 by the connection wire 16. The connection wire 16 can be provided by using a wire bonding method generally used in a semiconductor device manufacturing process. As shown, connecting wire 1
If 6 is provided in a shape that can be flexibly bent, such as an S-shape or a spiral shape, even if the substrate 10 or the like is deformed due to thermal stress during mounting, it can be effectively followed. of course,
Even if the connection wires 16 are provided in a linear shape, an arc shape, or the like, the required action can be obtained.

In the present embodiment, the buffer material 18 is filled in the through hole 14 so that the thermal stress can be reduced even in the through hole 14. The buffer material 18 may be the same material as the base material 10 or a different material. If the cushioning material 18 and the base material 10 are the same material and a paste-like material can be used as the cushioning material 18, the paste-like cushioning material 18 may be filled in the through hole 14. This is because the buffering effect of the paste-like or jelly-like buffering material 18 is large. Further, the cushioning member 18 is not limited to a material having electrical insulation. Even if the cushioning material 18 has conductivity, a required cushioning effect can be obtained by using a low elasticity material. The buffer material 18 has a Young's modulus of 10 MPa to 10
A material having about GPa is suitably used, and a material having a Young's modulus of about 10 MPa to 1 GPa is more preferably used.

As described above, the parts for electrically connecting electronic parts such as semiconductor elements and the mounting substrate and the substrate 10 supporting them are configured to effectively reduce the thermal stress, so that the semiconductor element It is possible to effectively reduce the thermal stress when electronic components such as are mounted. FIG. 2 shows a state in which the semiconductor element 20 is mounted on a mounting substrate 30 using the circuit board for mounting electronic components of the above embodiment. The connection terminal 22 formed on the connection terminal formation surface of the semiconductor element 20 and the pad 12a formed on one surface of the substrate 10 are solder 2
4, each electrode 32 formed on the surface of the mounting substrate 30 and the pad 1 formed on the other surface of the substrate 10.
2b are joined by solder 34.

The circuit board for mounting electronic parts is a semiconductor element 20.
The connection terminal 22 of the semiconductor element 20 and the electrode 32 of the mounting substrate 30 are electrically connected to each other between the semiconductor device 20 and the mounting substrate 30. Since the circuit board for mounting electronic components has a sufficient buffering property due to the action of the board 10, the connecting wires 16, and the buffer material 18, the thermal expansion coefficients of the mounting board 30 and the semiconductor element 20 are different, and thermal stress is generated between them. Even if it occurs, it is possible to effectively prevent thermal stress from acting on the semiconductor element 20 or acting on a joint between the mounting board and the semiconductor element 20 due to the buffering action of the electronic component mounting circuit board. Becomes possible. This makes it possible to provide a highly reliable mounting structure.

FIG. 3 shows a method of manufacturing the circuit board for mounting electronic components according to the above-described embodiment. FIG. 3A shows a copper foil 42 on a substrate 40 formed of an elastic material such as silicone resin in a sheet shape.
Is a material to which is adhered. The substrate 40 is to be the substrate 10 of the electronic component mounting circuit board, and is formed of a material having a predetermined elasticity. The copper foil 42 serves as a pad for electrical connection.

FIG. 3B shows a state in which the substrate 40 is irradiated with laser light to form the through-holes 14. The through-holes 14 are formed in accordance with the planar arrangement of connection terminals of electronic components mounted on a mounting substrate such as a semiconductor element. As described above, the through hole 1
Numeral 4 is provided to connect the pads 12a and 12b provided on both surfaces of the substrate 10 by the connection wires 16, and is formed to have a diameter dimension that allows the connection wires 16 to be formed. When the through hole 14 is provided by laser light irradiation, the laser light is blocked by the copper foil 42, and the through hole 14 exposing the copper foil 42 can be easily formed.

FIG. 3C shows a copper foil 42 in each through hole 14.
The base end of the connecting wire 16 is bonded to the inner surface of the connecting wire 16 and pulled out so as to be curved in an S-shape.
Is a state where it is cut at a position protruding outward from the opening surface of. Next, as shown in FIG. 3D, the buffer material 18 is filled in the through hole 14. When filling the cushioning material 18, the base material 4
The filling is performed up to the upper end surface of the through-hole 14 so that the surface of the through hole 14 is flush with the surface of the cushioning material 18.

Next, the upper surface of the substrate 40 is subjected to electroless copper plating and electrolytic copper plating, and the surface of the substrate 40 is covered with a copper layer 44. FIG. 3E shows a state in which the exposed surface of the base material 40 and the exposed surface of the cushioning material 18 are covered with the copper layer 44. Since the tip of the connection wire 16 protrudes from the opening surface of the through hole 14, the connection wire 16 and the copper layer 44 are electrically connected.

FIG. 3F shows a state in which the copper foil 42 on the lower surface of the substrate 40 and the copper layer 44 on the upper surface of the substrate 40 are finally etched to form the pads 12a and 12b. Pad 12
A and 12b may be formed in a predetermined shape according to the dimensions of the connection terminals of the electronic component to be mounted and the dimensions of the electrodes of the mounting board. Thus, the electronic component mounting circuit board shown in FIG. 1 is obtained. Pad 12 of this electronic component mounting circuit board
The plane arrangement of a and 12b is such that pads 12a and 12b are arranged in an area array in accordance with the plane arrangement of the connection terminals of the electronic component and the electrodes of the mounting board.

FIG. 4 shows another embodiment of a circuit board for mounting electronic components. The electronic component mounting circuit board of the present embodiment includes:
The conductors 50 are filled in the through holes 14 to electrically connect the pads 12a and 12b provided on both surfaces of the substrate 10. Conductive resin as the conductor 50,
A paste body such as a silver paste can be used. As in the above-described embodiment, it is effective that the conductor 50 is also a material having a buffering property for the purpose of relieving thermal stress. The substrate 10
The configuration of the pads 12a and 12b is the same as in the above embodiment. In the case of manufacturing the electronic component mounting circuit board of the present embodiment, the conductor 50 may be filled after forming the through hole 14 by the manufacturing method of the above embodiment.
Other manufacturing steps are the same as in the above embodiment.

FIG. 5 shows still another embodiment of the circuit board for mounting electronic components. In the electronic component mounting circuit board of the present embodiment, the pads 12a and 12b on both surfaces of the board 10 are electrically connected by providing metal pillars 52 as conductors in the through holes. In the case of manufacturing an electronic component mounting circuit board having the metal columns 52, for example, the through-holes 14 are formed in the base material 40 and then the copper foil 42 is plated and supplied by the above-described method for manufacturing an electronic component mounting circuit board. The metal pillar 52 is formed by raising copper in the through hole 14 by electrolytic copper plating as a layer. The method of forming the pads 12a and 12b is the same as in the above embodiment.

FIG. 6 shows an example of a manufacturing method for forming a circuit board for mounting electronic components in multiple layers. FIG. 6 (a) shows pads 12a on both surfaces of a base material 40 by the same method as the manufacturing method described above.
This is a state in which a first-layer circuit board provided with 12b is formed. When the circuit board for mounting electronic components is formed in multiple layers, a substrate 40a made of an elastic material having the same electrical insulation property as the substrate 40 is laminated on the surface of the substrate 40 of the first layer, and The base material 40a is irradiated with laser light in the same manner as the form,
A through-hole 14 is formed in accordance with the connection position with the pad 12a provided on the first-layer circuit board (FIG. 6B). Substrate 40
a can be formed by a method of bonding a sheet-like material or a method of applying an elastic material to a uniform thickness.

Next, a connection wire 16 is inserted into each through hole 14.
And connecting wire 16 is drawn out in the same manner as in the above-described embodiment by bending into an S-shape,
6 at a position protruding outside the opening surface of FIG.
(c)). Next, the buffer material 18 is filled in the through holes 14 and the base material 4
The copper layer 44 is formed by performing electroless copper plating and electrolytic copper plating on the surface of No. 0 (FIG. 6D). Finally, the pad 12c is formed on the surface of the second-layer base material 40a by etching the copper layer 44 (FIG. 6E).

In this way, a multilayer circuit board for mounting electronic components, in which the first-layer pads 12a and 12b and the second-layer pads 12c are electrically connected via the connection wires 16, is obtained. In the case of a multilayer electronic component mounting circuit board, it is considered that the substrate 10 is configured by combining the base material 40 and the base material 40a, and thus connection terminals of electronic components such as semiconductor elements and electrodes of the mounting substrate are provided on both surfaces of the substrate 10. Is provided as a circuit board for mounting electronic components provided with pads 12c and 12b in accordance with the arrangement.

In the electronic component mounting circuit board formed in multiple layers, similarly to the above-described electronic component mounting circuit board, the portion for electrically connecting the substrate and the pad such as the connection wire 16 has a sufficient buffering property. Since the semiconductor device and the mounting substrate are interposed between the semiconductor device and the mounting substrate and used as a circuit board for electrically connecting the connection terminals of the semiconductor device and the electrodes of the mounting substrate, the heat of the semiconductor device and the mounting substrate can be reduced. The thermal stress generated due to the difference in the expansion coefficient can be effectively reduced, and a highly reliable mounting structure can be provided.

When the circuit board for mounting electronic components is formed in multiple layers as in this embodiment, the pads 12a provided between the layers can be used as wiring patterns for electrical connection. That is, since the pad 12a is formed by etching a conductor layer such as a copper layer, the conductor layer can be etched to form a wiring pattern in an arbitrary pattern. Can be connected. In the case where the connection terminals of the semiconductor element are arranged at a very high density and the electrodes of the mounting board cannot be arranged in the same plane arrangement as the connection terminals of the semiconductor element, the circuit board for mounting electronic components is formed in multiple layers. It is possible to widen the arrangement interval of the electrodes. In such a case, it is effective to form the electronic component mounting circuit board in multiple layers.

[0029]

According to the circuit board for mounting electronic components according to the present invention, as described above, the thermal stress when electronic components such as semiconductor elements are mounted on the mounting board can be effectively alleviated. The adverse effect of thermal stress on the electronic component and the adverse effect on the joint between the electronic component and the mounting board can be eliminated, thereby enabling highly reliable mounting of the electronic component.
Further, the use of the circuit board for mounting electronic components according to the present invention makes it possible to mount flip-chip type semiconductor elements by suitably reducing thermal stress. Further, according to the semiconductor device of the present invention, the thermal stress at the time of mounting, which acts on the junction between the electronic component to be mounted and the mounting board, is effectively reduced by the electronic component mounting circuit board,
The semiconductor device can be provided as a highly reliable semiconductor device.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an embodiment of a circuit board for mounting electronic components.

FIG. 2 is a cross-sectional view showing a state where a semiconductor element is mounted on a mounting board using an electronic component mounting circuit board.

FIG. 3 is an explanatory view illustrating a method of manufacturing a circuit board for mounting electronic components.

FIG. 4 is a sectional view showing another embodiment of a circuit board for mounting electronic components.

FIG. 5 is a sectional view showing still another embodiment of the circuit board for mounting electronic components.

FIG. 6 is a cross-sectional view showing a method of manufacturing a multilayer circuit board for mounting electronic components.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Substrate 12a, 12b, 12c Pad 14 Through hole 16 Connection wire 18 Buffer material 20 Semiconductor element 22 Connection terminal 24 Solder 30 Mounting substrate 32 Electrode 34 Solder 40, 40a Base material 42 Copper foil 50 Conductor 52 Metal column

Claims (8)

[Claims] 1. A connection terminal of an electronic component and an electrode of a mounting substrate interposed between a surface of the surface mounting type electronic component on which a connection terminal is formed and a surface of the mounting substrate on which a connection electrode is formed. An electronic component mounting circuit board for electrically connecting the connection terminals to one another on a surface of the substrate having electrical insulation, the pads being provided with connection terminals corresponding to the planar arrangement of the connection terminals. A pad to which an electrode is joined corresponding to the planar arrangement of the electrodes is provided on the other surface of the substrate, and a substrate is provided between each pad provided on the one surface and each pad provided on the other surface. A connection wire is connected between a pad provided on one surface of the substrate and a pad provided on the other surface in the through hole, and a connection wire is formed on both surfaces of the substrate. The provided pads are electrically connected Electronic component mounting circuit board. 2. The electronic component mounting circuit board according to claim 1, wherein the connection wire is formed in a deformable shape such as an S-shape. 3. The circuit board for mounting electronic components according to claim 1, wherein the through hole is filled with a buffer material made of an insulating material or a conductive material. 4. The cushioning material has a Young's modulus of 10 MPa to 1
The electronic component mounting circuit board according to claim 3, wherein the circuit board is made of a low elastic material of 0 GPa, preferably 10 MPa to 1 GPa. 5. A connection terminal of an electronic component and an electrode of a mounting substrate interposed between a surface of the surface mounting type electronic component on which a connection terminal is formed and a surface of the mounting substrate on which a connection electrode is formed. An electronic component mounting circuit board for electrically connecting the connection terminals to one another on a surface of the substrate having electrical insulation, the pads being provided with connection terminals corresponding to the planar arrangement of the connection terminals. A pad to which an electrode is joined corresponding to the planar arrangement of the electrodes is provided on the other surface of the substrate, and a substrate is provided between each pad provided on the one surface and each pad provided on the other surface. A through-hole penetrating between both surfaces of the substrate is formed, and a conductor is filled in the through-hole and pads provided on both surfaces of the substrate are electrically connected to each other. . 6. The electronic component mounting circuit board according to claim 5, wherein the conductor is made of a conductive material having a buffering property. 7. The method according to claim 1, wherein the substrate has a Young's modulus of 10 MPa to 10 MPa.
7. The electronic component mounting circuit board according to claim 1, wherein the circuit board is made of a low elastic material of GPa, preferably 10 MPa to 1 GPa. 8. The method of claim 1, 2, 3, 4, 5, 6, or 7.
The electronic component mounting circuit board described above is interposed between the surface on which the connection terminal of the electronic component to be mounted is formed and the surface of the mounting substrate on which the electrode is formed, and the connection terminal is provided on one side of the substrate. A semiconductor device, wherein the electrode is bonded to a pad provided on a surface of the substrate, and the electrode is bonded to a pad provided on the other surface of the substrate.