JPH03250638A - Manufacture of semiconductor and device thereof - Google Patents

Abstract

PURPOSE:To spread Au-Sn alloy solder produced by eutectic in a wet and more enhanced manner and obtain stabilized bonding performance by forming a high temperature nitrogen gas atmosphere on a junction between a lead pattern formed on tape and plated with Sn and Au bump of a semiconductor chip. CONSTITUTION:Electricity is applied to a heater 10 while nitrogen gas is supplied to a gas intake passage 9 of a bonding tool 8, which is positioned on a Cu lead 2. A specified voltage is further applied to the bonding tool 8 where Sn plating 3 on the surface of the Cu lead 2 is reacted with an Au bump 5, thereby producing Au-Sn solder 6. At that time, the nitrogen gas heated with the heater 10 is arranged to be discharged from the gas intake passage 9, which turns a junction into a high temperature nitrogen gas atmosphere and thereby spreads the Au-Sn alloy generated in a wet and more enhanced manner and obtains more stabilized bonding performance.

Description

[Detailed Description of the Invention] Industrial Application Field] The present invention is directed to the TAB (Tape Automated
Semiconductor manufacturing technology using
This invention relates to a technique that is effective when used to bond Sn-plated inner leads of a tape to Au bumps on a semiconductor chip.

[Conventional technology]

One of the methods for electrically connecting the inner leads formed on the tape and the bumps on the chip is AU (silver)-3n.
(1) There is a eutectic alloy method. During bonding, the inner leads on the tape and the bumps on the chip are aligned, and the bonding tool is used to heat them (500~600℃).
The interconnection is achieved by supplying A, u-S n eutectic alloy (00 °C) and pressure.

Such a bonding technology using the Au-3n eutectic alloy method is described, for example, in "Latest Precision Bonding Technology Collection" published by Sogo Gijutsu Center Co., Ltd., pages 366 to 371.

By the way, the inventor of the present invention has investigated the problem of molten Au-5n alloy solder protruding around the joint and causing leaks between terminals or at the edge of a semiconductor chip.

The following are the techniques studied by the present inventor, and the outline thereof is as follows.

As shown in FIG. 2, a Cu lead 2 is attached to the polyimide tape 1, and the surface of the Cu lead 2 is S
N-plated. In addition, the semiconductor chip 4 includes
Au bumps 5 are provided. During bonding, the tip of the Cu lead 2 is positioned above the Au bump 5, and in this state, heat and pressure are applied using a bonding tool to establish the connection, as described above.

[Problem to be solved by the invention]

However, in the method described above (using Au-3n alloy solder for bonding), when the lead pitch becomes narrow,
It is difficult to control the amount of Au-3n alloy solder,
The inventor has discovered that if this protrudes from the joint, the protruding Au-3N solder 6 causes a problem between adjacent terminals or between the edges of the chip, as shown in FIG. It was done.

Therefore, an object of the present invention is to remove the Au-
The object of the present invention is to provide a technique that can prevent short-circuits between terminals and chips due to 5N alloy solder.

The above objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means to solve the problem]

A brief overview of typical inventions disclosed in this application is as follows.

That is, when bonding the lead pattern formed on the tape and plated with Sn to the Au bumps of the semiconductor chip, a high temperature nitrogen gas atmosphere is created at the bonded portion.

[Effect]

According to the above-mentioned means, when the Sn plating of the lead and the A'u bump of the semiconductor chip are bonded by eutectic, oxygen in the atmosphere that deteriorates the bonding property is removed from the bonding part, and the oxidizing atmosphere becomes a reducing atmosphere. Au-5n produced by eutectic
Wetting and spreading of the alloy solder becomes better, and stable bonding performance is obtained. Therefore, short circuits between terminals are eliminated, and yield can be improved.

〔Example〕

Hereinafter, a semiconductor manufacturing method according to the present invention will be explained.

As described above, the reason why the A u -'S n alloy solder protrudes from the joint is that the joint comes into contact with oxygen in the atmosphere. Therefore, in the present invention, in order to isolate the contact portion from the atmosphere, this is achieved by creating a nitrogen (N2) atmosphere in the joint portion (around the Au bump 5 shown in FIG. 2). As a result, the oxidizing atmosphere can be changed to a reducing atmosphere, and the wetting and spreading of the Au-3n alloy solder produced by the eutectic between the Sn plating of the leads and the Au bumps of the semiconductor chip is improved, and the bonding performance can be improved. Therefore, it is possible to prevent short-circuits between terminals and short-circuits at the edges of the semiconductor chip. Note that if this nitrogen atmosphere is at room temperature, the temperature of the Au-5n alloy solder will drop, so in order to stabilize the bonding temperature, the nitrogen atmosphere is kept at a high temperature.

FIG. 1 is a sectional view showing an embodiment of a semiconductor manufacturing apparatus according to the present invention.

The semiconductor chip 4 is placed on the bonding stage 7,
The Cu leads 2 are positioned with respect to the semiconductor chip 4 as shown in FIG. Then, the bonding tool 8 is pressed down so as to cover the Cu1J-dead 2 facing the Au bump 5.

The bonding tool 8 includes N2 for discharging to the bonding part.
A gas introduction path 9 for introducing gas is provided at the center, and its tip is open to the tip surface of the bonding tool 8. Furthermore, a heater 10 for heating the bonded portion is disposed around the gas introduction path 9 at the tip thereof.

In the above configuration, to perform bonding, the heater 10 is energized and nitrogen gas is supplied to the gas introduction path 9 of the bonding tool 8 heated to a sufficient temperature (500 to 600°C) as shown in FIG. position on the Cu lead 2. Furthermore, by applying a predetermined pressure to the bonding tool 8, the Sn plating 3 on the surface of the Cu lead 2 and the Au bumps 5 react, and the Au-Sn alloy solder 6
is generated. At this time, the nitrogen gas heated by the heater 10 is released from the gas introduction path 9, thereby creating a high-temperature nitrogen gas atmosphere at the joint, which improves the wetting and spreading of the produced Au-Sn alloy solder 6 and stabilizes it. A high bonding property can be obtained. Therefore, it is possible to prevent the occurrence of short circuits between terminals as in the conventional case. In addition, it is also possible to prevent dust from adhering during cleaning.

Although the invention made by the present invention has been specifically explained based on Examples, the present invention is not limited to the above-mentioned Examples (it goes without saying that various changes can be made without departing from the gist of the invention). stomach.

For example, instead of providing the gas introduction path 9 at the center of the bonding tool 8, nitrogen gas may be supplied around the bonding tool 80 using a separate heat-resistant hose.

Furthermore, instead of the bonding tool 8, it may be supplied from the bonding stage 7 side, or it may be supplied through the tape guide member.

Furthermore, in the above description, the invention made by the present inventor was mainly applied to the field of application of the invention, which is the bonding between a chip having an Au bump and a lead plated with Cu, but the present invention is not limited to this. It is applicable to all types of bonding using an Au-Sn eutectic alloy.

〔Effect of the invention〕

Among the inventions disclosed in this application, the effects obtained by typical ones are as follows.

In other words, when bonding the lead pattern formed on the tape and plated with Sn to the AU bump of the semiconductor chip, a high temperature nitrogen gas atmosphere is created at the bonded portion, so that the eutectic Au-Sn
The wetting and spreading of the alloy solder improves, stable bonding is obtained, various short circuits are eliminated, and yields can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a semiconductor manufacturing apparatus according to the present invention, and FIG. 2 is a sectional view illustrating protrusion of Au-Sn alloy solder. 1... Polyimide tape, 2... Cu lead, 3... Sn plating, 4... Semiconductor chip, 5...
...Au bump, 6...Au-Sn alloy solder, 7...
- Bonding stage, 8... Bonding tool, 9... Gas introduction path, 10... Heater. Figure 5: Au bump

Claims (1)

[Claims] 1. When bonding the lead pattern formed on the tape and plated with Sn to the Au bump of the semiconductor chip, a high temperature nitrogen gas atmosphere is formed in the bonded portion. A semiconductor manufacturing method. 2. A semiconductor manufacturing device for bonding a Sn-plated lead pattern formed on a tape and an Au bump on a semiconductor chip, in which the bonding temperature is lowered from the tip of a bonding tool for heating and pressurizing the bonded portion. 1. A semiconductor manufacturing apparatus comprising a gas supply means for blowing out heated nitrogen gas. 3. The semiconductor manufacturing apparatus according to claim 1, wherein the gas supply means includes a gas introduction path that passes near a heater in the bonding tool and opens at the tip of the tool.