JPH10144717A - Semiconductor element connection structure and method of connection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor element connection structure, wherein distortion due to the difference between thermal expansion coefficients or the like is not generated at the junction even in the high-temperature environment and the highly reliable connection state of the element with the substrate can be obtained, and a method of connecting the element with the substrate. SOLUTION: The metallic materials for a bump electrode 4, which is formed on a semiconductor element 2, a connecton electrode 7 on a substrate 1 and a wire 5 are all formed of the same metallic material, such as an Au material. Thereby, the state of a bonding of the element 2 to the substrate 1 due to the same metallic materials is obtained, distortion due to the difference between thermal expansion coefficients or the like is not generated at the junction even in the high-temperature environment unlike the state of a bonding of the element 2 to the substrate 1 between dissimilar metallic materials and the highly reliable connection state of the element with the substrate is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for wire-bonding a semiconductor device to a component such as a substrate or another semiconductor device, and a method for connecting the same.

[0002]

2. Description of the Related Art Conventionally, as a connection structure of an element using a wire bond and a connection method thereof, "V
LSI Packaging Technology (2) " 17 to 30, a metal wire such as A is provided between an Al electrode on a chip such as a semiconductor element mounted on a package or a substrate and a lead electrode of the package or a wiring electrode on the substrate.
A method of connecting with a thin wire made of a u material is disclosed.

FIG. 3 is a schematic sectional view of a connection portion of such a conventional semiconductor device. A connection electrode 106 is formed on a substrate 101, and a semiconductor element 102 is formed on the connection electrode 106.
Is installed. The electrode 103 of the semiconductor element 102
The ball portion 105 of the wire 104 is bonded to the connection electrode 10 of the substrate 101.
6 is bonded.

According to the prior art disclosed in the above document,
A molten ball is formed at the tip of the Au wire with an electric torch or the like, and is crimped on the Al electrode with a tool called a capillary, the Au wire is guided on the lead electrode, and the Au wire is crimped on the edge of the capillary, and the Au wire is crimped. There is a method called nail head bonding that completes the connection by clamping and cutting.

[0005] The Au wire applied here is firstly difficult to be broken because of its large ductility, secondly, it is hard to corrode, and thirdly, because it is easy to form a true sphere without being oxidized in the atmosphere, it is a nail. Used for head bonding.

[0006]

By the way, wire connection is a solid phase diffusion bonding between an electrode and a wire. In the conventional connection method as described above, the metal material of the electrode and the wire is different, and for example, the Al portion is connected to the bonding portion. -When an Au intermetallic compound is formed, the growth of the intermetallic compound is promoted in a high-temperature environment, so that a boundary surface is distorted due to a difference in a coefficient of thermal expansion between the metals and the like, leading to electrical opening. There was a need for a reliable connection method.

Further, as shown in FIG. 4, when a wire 104 is to be launched from a connection electrode 106 to an electrode 103 on the surface of a semiconductor element 102 having a conventional structure,
The loop height H2 of No. 4 can be suppressed as low as the thickness of the electrode 103;
There was a problem that there was.

In view of the above circumstances, the present invention provides a connection of a semiconductor element capable of obtaining a highly reliable connection state in which distortion due to a difference in thermal expansion coefficient or the like does not occur at a joint interface even in a high temperature environment. It is intended to provide a structure and a connection method.

[0009]

In order to achieve the above object, the present invention provides: (1) In a semiconductor element connection structure, a base material on which connection electrodes are formed, and a semiconductor element mounted on the base material. A protruding electrode formed on the input portion and the output portion of the electric signal, and a wire connecting the protruding electrode and the connection electrode, wherein the protruding electrode, the connection electrode, and the same metal material are used for the wire. Things.

(2) In the method of connecting a semiconductor element,
(A) A base material on which a connection electrode is formed is prepared, (b) a semiconductor element is mounted on the base material, and (c) an electric signal input part and an output part of the semiconductor element are equivalent to the connection electrode. A protruding electrode made of a metal material is formed, and (d) the protruding electrode and the connection electrode are connected by a wire made of a metal material equivalent to these electrodes.

(3) In the method for connecting a semiconductor element according to the above (2), in the step (d), a spherical portion of a wire formed by heat melting is pressure-bonded to the connection electrode, and the other wire end is connected. Is pressed against the protruding electrode.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic sectional view of a connection portion of a semiconductor device according to a first embodiment of the present invention. In this figure, for example, an IC chip is shown as the semiconductor element 2, and the substrate 1 on which the connection electrode 7 is provided as a base material on which the semiconductor element 2 is mounted is shown.

An electrode 3 serving as an input / output terminal is formed of, for example, Al on the semiconductor element 2, and a barrier electrode layer (not shown) for making an ohmic connection to the electrode 3 is provided.
The protruding electrode 4 protruding therethrough is formed of, for example, an Au material. The connection electrode 7 of the substrate 1 is obtained by plating a base electrode (not shown) made of, for example, Cu or the like with an Au material.
Each connection electrode 7 is formed at a position corresponding to the position where the bump electrode 4 is provided.

The protruding electrode 4 of the semiconductor element 2 and the connection electrode 7 on the substrate 1 are pressed by a wire 5 made of Au material.
Electrical connections are made. In FIG. 1, 6
Is a ball portion of the wire 5. As described above, in the first embodiment, the metal materials of the projecting electrode 4 formed on the semiconductor element 2, the connecting electrode 7 of the substrate 1, and the wire 5 are all A
Since it is formed of a u material, a joining state using the same metal material is obtained, and unlike a joining state between dissimilar metals, distortion due to a difference in thermal expansion coefficient or the like does not occur at the joint interface even in a high temperature environment. Thus, a highly reliable connection state can be obtained.

Next, a second embodiment of the present invention will be described. FIG. 2 is a schematic sectional view of a connection portion of a semiconductor device according to a second embodiment of the present invention. The same portions as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
In the conventional nail head bonding described above,
Due to the heat effect when the tip of the wire is melted to form a ball, the wire portion immediately above the ball is recrystallized, so in order to obtain a wire state without disconnection, form a wire loop in a part where recrystallization does not occur Must.
For this reason, in order to reduce the loop height H3 of the wire (see FIG. 3), it has been essential to develop a wire material having a short length of the recombination portion.

In FIG. 2, when connecting the protruding electrode 11 and the connection electrode 12, the ball portion 14 formed at the tip of the connection wire 13 is first crimped to the connection electrode 12, and the wire 13 is protruded. The wire 13 is lifted to a height that can be pressed against the electrode 11, and then the wire 13 is pressed onto the protruding electrode 11. Therefore, as shown in FIG. 2, the loop height H1 of the wire can be suppressed to approximately the thickness of the electrode 3 + the height of the protruding electrode 11. Moreover, the length of the wire 13 immediately above the ball portion 14 is at least the thickness of the semiconductor element 2 +
Since about 0.5 mm is secured, a low-loop wire connection can be obtained with a conventional wire.

When the wire 104 is launched from the connection electrode 106 to the electrode 103 on the surface of the semiconductor element 102 having the conventional structure, the loop height H2 of the wire is as low as the thickness of the electrode 103, as shown in FIG. Although it can be suppressed, a crack 107 may be formed at an end of the semiconductor element 102 on the connection electrode 106 side due to an impact at the time of pressure bonding.

However, in the second embodiment, as shown in FIG. 2, since the protruding electrode 11 is provided on the electrode 3,
The impact at the time of pressure bonding can be absorbed by the protruding electrode 11 and the impact on the semiconductor element 2 can be reduced, so that the occurrence of cracks can be eliminated. In addition, as for the method of crimping a wire, since there is no restriction condition at the time of crimping, load, heat,
All methods using ultrasonic waves can be applied.

Therefore, according to the present invention, since the metal materials of the projecting electrodes, the connection electrodes of the base material, and the wires formed on the semiconductor element are all made of Au material, the bonding state by the same metal material can be maintained. Therefore, a highly reliable connection state is obtained. In this embodiment, since the wire of the connection wire is further pressure-bonded to the protruding electrode of the semiconductor element after the connection wire ball is pressure-bonded to the connection electrode, a good wire connection with a reduced wire loop height is possible.

It should be noted that the present invention is not limited to the above embodiment, but various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0021]

As described above, according to the present invention, the following effects can be obtained. (1) According to the first aspect of the invention, since the protruding electrodes formed on the semiconductor element, the connecting electrodes of the base material, and the metal materials of the wires are all formed of the same metal material, for example, Au material, Since a bonding state using the same metal material can be obtained, a highly reliable semiconductor element connection structure can be obtained.

(2) According to the second aspect of the present invention, since the joining state is obtained by the same metal material, unlike the joining state between dissimilar metals, the thermal expansion coefficient and the like at the joint interface even in a high-temperature environment. And a highly reliable connection state free from distortion due to the difference between the two. (3) According to the third aspect of the present invention, after the wire ball is pressure-bonded to the connection electrode, the wire is pressure-bonded to the protruding electrode of the semiconductor element, so that the height of the wire loop is reduced. Good wire connection becomes possible.

Further, it is possible to prevent the semiconductor element from being cracked.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a connection portion of a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view of a connection portion of a semiconductor device according to a second embodiment of the present invention.

FIG. 3 is a schematic sectional view of a connection portion of a conventional semiconductor element.

FIG. 4 is a schematic sectional view of a connection portion of another conventional semiconductor element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Semiconductor element 3 Electrode of semiconductor element 4,11 Projection electrode 5,13 Wire 6,14 Ball part of wire 7,12 Connection electrode

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor ▲ Taka ▼ Wataru Washi 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (3)

[Claims] (A) a substrate on which connection electrodes are formed;
(B) a protruding electrode formed on an input portion and an output portion of an electric signal of a semiconductor element mounted on the base material, and (c) a wire connecting the protruding electrode and the connection electrode,
(D) A connection structure of a semiconductor element, wherein equivalent metal materials are used for the protruding electrodes, connection electrodes, and wires. 2. A semiconductor device comprising: (a) a base material on which connection electrodes are formed; (b) a semiconductor element mounted on the base material; and (c) an electric signal input and output part of the semiconductor element. Form a protruding electrode made of a metal material equivalent to the connection electrode,
(D) A method of connecting a semiconductor element, wherein the protruding electrode and the connection electrode are connected by a wire made of a metal material equivalent to these electrodes. 3. The method of connecting a semiconductor device according to claim 2, wherein in the step (d), a spherical portion of a wire formed by heat melting is pressure-bonded to the connection electrode, and another end of the wire is connected to the connection electrode. A method for connecting a semiconductor element, comprising crimping to a protruding electrode.