JPH1022334A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device which can prevent junction failure with good high frequency characteristics. SOLUTION: Bump electrodes 26 of a semiconductor chip 25 is eutectically bonded to a connection electrode 23 of a film substrate 22, and the semiconductor chip 25 is bonded to the film substrate 22 with resin 24 disposed therebetween. Accordingly, the electrical resistance of a junction part between the bump and connection electrodes 26 and 23 can be lowered and high frequency characteristics can be improved. Further, residual stress takes place in the interior of the film substrate 22 due to heat. Even when the residual stress causes the film substrate 22 to return to its original state, the resin 24 can prevent it and also prevent peeling off of a junction part between the bump and connection electrodes 26 and 23, that is, a junction failure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a semiconductor device.

[0002]

2. Description of the Related Art Some semiconductor devices have a semiconductor chip such as an IC chip or an LSI chip mounted on a film substrate. FIG. 6 shows an example of such a semiconductor device. In this case, the connection electrode 2 of the film substrate 1 includes a connection electrode body 2a and a tin plating layer 2b formed on the surface of the connection electrode body 2a. The bump electrodes 4 of the semiconductor chip 3 are eutectic-bonded to the connection electrodes 2 of the film substrate 1 by positioning and placing the connection electrodes 2 on the connection electrodes 2 and pressing them while heating.

In such a conventional semiconductor device, when the bump electrode 4 of the semiconductor chip 3 is connected to the connection electrode 2 of the film substrate 1 by eutectic bonding using a gold-tin alloy,
Since the semiconductor chip 3 and the film substrate 1 are also heated, when the semiconductor chip 3 and the film substrate 1 return to room temperature, residual stress is generated inside the film substrate 1 due to a difference in coefficient of thermal expansion between the semiconductor chip 3 and the film substrate 1. Occurs. Then, due to springback, that is, a phenomenon in which the film substrate 1 tries to return to the original state due to residual stress, as shown in FIG. 7, the joint between the bump electrode 4 and the connection electrode 2 is peeled off,
There has been a problem that poor joining may occur. Therefore, in order to solve such a problem, a bonding method that does not heat a semiconductor chip or a film substrate has been proposed.
FIG. 8 shows an example of a semiconductor device to which such a bonding method is applied. In this case, the bump electrode 14 of the semiconductor chip 11 is positioned and placed on the connection electrode 15 of the film substrate 12 in a state where the photocurable resin 13 is interposed between the semiconductor chip 11 and the film substrate 12. By irradiating ultraviolet rays while applying pressure, the bump electrodes 1
The photocurable resin 13 is cured in a state where 4 is pressed against the connection electrode 15, and the semiconductor chip 11 and the film substrate 12 are bonded by the cured photocurable resin 13.

[0004]

However, in such a conventional semiconductor device, the bump electrode 14 of the semiconductor chip 11 and the connection electrode 15 of the film substrate 12 are simply pressed against each other. In comparison with the above, there is a problem that the electrical resistance at the junction between the bump electrode 14 and the connection electrode 15 is increased, and the high-frequency characteristics are poor. SUMMARY OF THE INVENTION An object of the present invention is to prevent a bonding defect from occurring in a state in which high-frequency characteristics are good.

[0005]

According to the present invention, a bump electrode of a semiconductor chip and a connection electrode of a circuit board are eutectic-bonded, and the semiconductor chip and the circuit board are formed by a resin interposed therebetween. It is the one that is glued.

According to this invention, since the bump electrode of the semiconductor chip and the connection electrode of the circuit board are eutectic bonded, the electrical resistance at the junction between the bump electrode and the connection electrode can be reduced, and the high frequency The characteristics can be improved. In addition, since the semiconductor chip and the circuit board are bonded by the resin interposed therebetween, residual stress due to heating is generated inside the circuit board, and even if the circuit board attempts to return to the original state due to the residual stress. Prevent it,
It is possible to prevent the joint between the bump electrode and the connection electrode from peeling off, and to prevent a joint failure from occurring.

[0007]

1 and 2 show a manufacturing process of a semiconductor device according to an embodiment of the present invention. Therefore, referring to these figures in order,
The structure of the semiconductor device according to this embodiment will be described together with its manufacturing method.

First, as shown in FIG. 1, a film substrate 2 is placed on the upper surface of a stage 21 in a thermocompression bonding apparatus (not shown).
2 is positioned and positioned. In this case, a plurality of connection electrodes 23 are provided on the upper surface of the film substrate 22. The connection electrode 23 is a connection electrode body 2 made of copper or the like.
3a and a plating layer 23b formed on the surface of the connection electrode body 23a. The plating layer 23b is made of tin,
It is made of solder, gold, or the like, and has a thickness of about 1 μm. Next, a polyimide resin is provided at a predetermined position on the upper surface of the film substrate 22 where the connection electrode 23 is not formed.
A resin 24 made of a thermoplastic resin such as a silicone resin is applied by a printing method, a needle dispensing method, a transfer method, or the like. Next, the semiconductor chip 25 is arranged above the film substrate 22 in a state of being positioned so as to face the resin 24. In this case, a bump electrode 26 made of gold, solder, or the like has a height of 15 to
The thickness is set to about 30 μm.

Next, as shown in FIG.
With the resin 24 interposed between the semiconductor chip 25 and the semiconductor chip 25, the bump electrodes 26 of the semiconductor chip 25 are positioned and mounted on the corresponding connection electrodes 23 of the film substrate 22. Next, when a thermocompression bonding head (not shown) is pressed from above the semiconductor chip 25 while being heated, the bump electrodes 26 of the semiconductor chip 25 and the connection electrodes 23 of the film substrate 22 are shared by an alloy of both constituent metals. Crystal bonding. In this case, the heating temperature is about 400 to 600 ° C., for example, since the softening temperature of the polyimide resin is about 230 ° C., the resin 24 interposed between the semiconductor chip 25 and the film substrate 22 is heated. The semiconductor chip 25 and the film substrate 22 are softened and then solidified by cooling, and the solidified resin 24 adheres the semiconductor chip 25 and the film substrate 22.

Here, as an example of a preferable combination of metal materials, a case where the bump electrode 26 is made of gold and the plating layer 23b is made of tin, and a case where the bump electrode 26 is made of gold and
There are a case where the plating layer 23b is made of solder, and a case where the bump electrode 26 is made of solder and the plating layer 23b is made of gold. In these cases, a eutectic alloy of gold and tin is formed between the bump electrode 26 and the plating layer 23b, and the eutectic alloy of gold and tin causes the bump electrode 26 and the connection electrode 23 to be eutectic. Joined.

As described above, since the bump electrodes 26 of the semiconductor chip 25 and the connection electrodes 23 of the film substrate 22 are eutectic-bonded, the electrical resistance at the junction between the bump electrodes 26 and the connection electrodes 23 can be reduced. And high frequency characteristics can be improved. Further, since the semiconductor chip 25 and the film substrate 22 are bonded by the resin 24 interposed therebetween, residual stress is generated inside the film substrate 22 by heating, and the residual stress causes the film substrate 22 to return to its original state. Even if it is attempted to return, the resin 24 does not do so, so that the joint between the bump electrode 26 and the connection electrode 23 can be prevented from peeling off, so that a joint failure does not occur. Further, since the resin 24 is made of a thermoplastic resin, it is softened again when heated. Therefore, the semiconductor chip 25 can be easily removed from the film substrate 22 by heating, and the semiconductor chip 25 can be easily repaired.

In the above embodiment, the film substrate 2
The resin 24 was applied to a predetermined location on the upper surface of the second 2,
Not limited to this, as in the modification of the application position shown in FIG.
Resin 24 is provided at a predetermined location on the lower surface of semiconductor chip 25.
May be applied. Further, in the above-described embodiment, the circuit board is a single-layer film board 22, but the circuit board is not limited to this, and may be a multilayer film board 22 as in a first modification of the circuit board shown in FIG. Further, in the above-described embodiment, the circuit board is a single-sided wiring film substrate 22, but is not limited to this, and may be a double-sided wiring film substrate 22 as in a second modification of the circuit board shown in FIG. In the above embodiment, a thermoplastic resin such as a polyimide resin or a silicone resin is described as the resin 24. However, the present invention is not limited to this, and a thermosetting resin such as an epoxy resin or a phenol resin may be used. It may be a mixture of a resin and a thermosetting resin. Further, in the above embodiment, the bump electrodes 26 are provided on the lower surface of the semiconductor chip 25. However, the present invention is not limited to this, and the bump electrodes 26 may be provided on the connection electrodes 23 of the film substrate 22. In this case, since the film substrate 22 is cheaper than the semiconductor chip 25, it is possible to reduce money loss when a defect occurs.

[0013]

As described above, according to the present invention, since the bump electrode of the semiconductor chip and the connection electrode of the circuit board are eutectic-bonded, the electrical resistance of the junction between the bump electrode and the connection electrode is increased. Can be reduced, and high-frequency characteristics can be improved. In addition, since the semiconductor chip and the circuit board are bonded by the resin interposed therebetween, residual stress due to heating is generated inside the circuit board, and even if the circuit board attempts to return to the original state due to the residual stress. However, it is possible to prevent the bonding portion between the bump electrode and the connection electrode from peeling off, and to prevent the occurrence of poor bonding.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a resin is applied to an upper surface of a film substrate and a semiconductor chip is arranged on the film substrate in manufacturing a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the semiconductor device.

FIG. 3 is a cross-sectional view showing a modification of the application position of the resin in the embodiment.

FIG. 4 is an exemplary sectional view showing a first modification of the circuit board according to the embodiment;

FIG. 5 is an exemplary sectional view showing a second modification of the circuit board according to the embodiment;

FIG. 6 is a cross-sectional view illustrating an example of a conventional semiconductor device.

FIG. 7 is a cross-sectional view for explaining a conventional problem.

FIG. 8 is a sectional view showing another example of a conventional semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 22 Film board 23 Connection electrode 23a Connection electrode main body 23b Plating layer 24 Resin 25 Semiconductor chip 26 Bump electrode

Claims (4)

[Claims] 1. The semiconductor device according to claim 1, wherein the bump electrodes of the semiconductor chip and the connection electrodes of the circuit board are eutectic bonded, and the semiconductor chip and the circuit board are bonded by a resin interposed therebetween. Semiconductor device. 2. The semiconductor device according to claim 1, wherein said circuit board comprises a film substrate. 3. The semiconductor device according to claim 1, wherein the bump electrode is made of gold, and the connection electrode is made of a connection electrode body and a tin plating layer formed on a surface of the connection electrode body. . 4. The semiconductor device according to claim 1, wherein said resin is made of a thermoplastic resin or a thermosetting resin.