JPH06151477A - Semiconductor device - Google Patents

Abstract

PURPOSE:To make a defective chip or nondefective chip easily removable from a substrate at the time of removing the defective chip or replacing the nondefective chip with another chip. CONSTITUTION:A conductive bonding agent 14 containing solder particles is used and, at the time of bonding a semiconductor chip 3 to a substrate 1, the substrate 1 is heated to a temperature lower than the melting point of the solder. At the time of removing a defective chip or replacing a nondefective chip with another chip, the substrate 1 is heated to a temperature higher than the melting point of the solder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device in which a semiconductor chip is bonded to a substrate via a conductive adhesive.

[0002]

2. Description of the Related Art There is known a semiconductor device having a structure as shown in FIG. 3, in which at least a semiconductor chip is bonded on a common substrate with a conductive adhesive. In the figure, 1 is a substrate on which a plurality of conductors 2 are arranged, 3 is a semiconductor chip bonded on the conductor 2 by a conductive adhesive 4, and 5 is another conductor 2 by a conductive adhesive 4 in the same manner. Chips other than the semiconductor chips bonded on top, 6 is a semiconductor chip 3
Alternatively, it is a bonding wire connected between another chip 5 and the conductor 2 so as to form a desired circuit.

In the semiconductor device in which the semiconductor chip 3 or the other chip 5 is mounted on the common substrate 1 as described above, one of important problems is removal of defective chips and replacement of non-defective chips (referred to as repair). ). As described above, in order to remove or replace a defective chip or a non-defective chip once mounted on the base 1, it is necessary to disassemble the conductive adhesive 4 bonding each chip onto the conductor 2 on the base 1. There is. In order to decompose the conductive adhesive 4 in this way,
By heating the substrate 1 to a high temperature (for example, 300 ° C.),
The semiconductor chip 3 or another chip 5 is removed by applying a mechanical force. Alternatively, the conductive adhesive 4 is dissolved using a special chemical.

The removal of defective chips and the replacement of non-defective chips on the substrate 1 in this manner are necessary in order to effectively utilize expensive chips such as the semiconductor chip 3 or the substrate 1 to reduce costs. That's right.

[0005]

In the conventional semiconductor device, it is technically necessary to melt the conductive adhesive and remove the required chip from the substrate in order to remove defective chips and replace good chips. The problem is that it is difficult.

For example, when the substrate is heated to a high temperature to decompose the conductive adhesive as described above, it may damage other chips, and when a special chemical is used, the other chips may be damaged. Not only that, but the substrate may be chemically attacked. Therefore, as still another method, a method using a flip chip or a method using a solder for joining is also known, but an increase in cost is inevitable.

The present invention has been made to solve the above problems, and when the necessary chips are removed from the substrate by melting the conductive adhesive in order to remove defective chips and replace good chips. It is an object of the present invention to provide a semiconductor device having a structure in which this chip can be taken out easily.

[0008]

In order to achieve the above object, the present invention relates to a conductor arranged on a substrate, a semiconductor chip bonded on the conductor with a conductive adhesive containing solder particles, and It is characterized by comprising a bonding wire connected between a semiconductor chip and a conductor so as to form a desired circuit.

[0009]

When the semiconductor chip is bonded onto the conductor on the base, the base is heated to a temperature below the solder melting temperature to melt and cure the conductive adhesive. When removing defective chips and exchanging non-defective chips, the substrate is heated to a solder melting temperature or higher to melt the conductive adhesive and the chips are removed.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of a semiconductor device of the present invention, 1 is a conductor having a plurality of conductors 2 arranged on its surface, and 3 is bonded on the conductor 2 by a conductive adhesive 14 containing solder particles 13. Similarly, semiconductor chips 5 are conductive adhesives 1
Chips other than the semiconductor chip joined on the other conductor 2 by 4, 6 is a bonding wire connected between the semiconductor chip 3 or another chip 5 and the conductor 2 so as to form a desired circuit. is there.

Since the curing temperature of the conductive adhesive 14 containing the solder particles 13 is set lower than the melting temperature of the solder, at the curing temperature of the conductive adhesive 14 the solder particles 1
The sample No. 3 did not melt and remained in the state of particles.
On the other hand, when the solder particles 13 are heated to the melting temperature or higher, the solder particles 13 are melted, so that the entire conductive adhesive 14 is decomposed so as to be spread.

First, the semiconductor chip 3 is attached to the conductor 2 on the substrate 1.
In the case of bonding to the upper side, the conductive adhesive 14 is hardened by heating the substrate 1 to the solder melting temperature or lower to bond the semiconductor chip 3. Then, the semiconductor chip 3 and the conductor 2
The bonding wire 6 is bonded between the and. Similar processing is performed on the other chips 5.

Next, each chip bonded on the substrate 1 is inspected to select defective chips and non-defective chips. In order to remove these defective chips and replace good chips, the substrate 1 is heated to the solder melting temperature or higher. This melts the solder particles 13, so that the conductive adhesive 14
As shown in FIG. 2, the whole is expanded as it is disassembled.

As a result, the adhesive strength of the semiconductor chip 3 is reduced because the thickness of the conductive adhesive 14 is reduced, so that the semiconductor chip 3 can be easily removed from the conductor 2 by using tweezers or the like. .

As described above, according to this embodiment, when the semiconductor chip 3 is bonded using the conductive adhesive 14 containing the solder particles 13, the substrate 1 is heat-treated at a temperature not higher than the solder melting temperature, so that the semiconductor chip 3 is formed. Since the substrate 1 is heat-treated at a temperature equal to or higher than the solder melting temperature when it is removed, the chip can be easily removed when the defective chip is removed and the good chip is replaced.

That is, as compared with the conventional method of removing a semiconductor chip by applying a mechanical force to the semiconductor chip by applying a high temperature heat treatment, the semiconductor chip can be removed without damaging the chip and no special chemical is used. Therefore, the substrate and the like are not chemically attacked. As a result, an expensive semiconductor chip or base can be effectively used, and the cost can be reduced.

[0017]

As described above, according to the present invention, when a semiconductor chip is bonded using a conductive adhesive containing solder particles, the substrate is heat-treated at a solder melting temperature or lower to remove defective chips and obtain good products. When exchanging chips, the substrate was heated at a temperature above the solder melting temperature.
The semiconductor chip can be easily removed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a semiconductor device of the present invention.

FIG. 2 is a cross-sectional view illustrating a method of removing a semiconductor chip according to this embodiment.

FIG. 3 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 Base 2 Conductor 3 Semiconductor Chip 13 Solder Particles 14 Conductive Adhesive

Claims (1)

[Claims] 1. A conductor arranged on a substrate, a semiconductor chip bonded on the conductor with a conductive adhesive containing solder particles, and a desired circuit is formed between the semiconductor chip and the conductor. A semiconductor device comprising a bonding wire connected to the.