JPH03273638A - Bump-connection type semiconductor device - Google Patents

Abstract

PURPOSE:To cope with the production of a small amount of many kinds of products readily in a simple step by using an ordinary wire bonding device and to increase the connecting strength with leads and the like by forming a bump electrode on a semiconductor chip by thermal contact bonding of the ball of wire which is supplied into the wire bonding device. CONSTITUTION:A wire 12 comprising Au-2Si alloy is inserted through a capillary 13 of a wire bonding device. Then, a discharge voltage of 30-80V, preferably 50V, is applied across a discharge electrode and the tip of the above described thin wire, and the discharge is generated. The tip of the gold thin wire is heated and fused, and a ball 11 is formed. Then, the ball 11 undergoes thermal contact bonding to a bonding pad 22 on the SiO2 surface of a semiconductor substrate 21 comprising Si. Thereafter, the gold thin wire is lifted up, and the gold thin wire is cut from the ball 11, Thus a bump 24 is formed. A semiconductor chip 35 having the bump undergoes thermal contact bonding on an inner lead 33 of a chip carrier 31 comprising ceramics. As the wire 12, an ordinary wire used in a wire bonding method can be employed, but gold based alloy and lead-based alloy are preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device, and particularly to a bump-connected semiconductor device in which a semiconductor chip is electrically connected to leads via bump electrodes.

[Prior Art] Bump-connected semiconductor devices in which a semiconductor chip is electrically connected to leads of a chip carrier via bump electrodes formed on bonding bats have been conventionally known, along with semiconductor devices formed by wire bonding.

In such a bump-connected semiconductor device, as shown in FIG. 3, a semiconductor chip 35 is placed on a chip carrier 31 having external leads 32 and internal leads 33 via bump electrodes 34. Furthermore, it has a structure in which a lid 36 is provided.

The conventional bump electrode formed on the bonding butt has the structure shown in Figure 's4, and is formed in the next step.

(1) Surface image ff11 on surface 1' of 5i02 of substrate 1
(2) Step of forming Ti-W@4 and Au1i5 by vapor deposition; (3) Next, a photolithography method. (4) forming an Au bump electrode 6 on the bump plating forming area from which the photoresist has been removed by electroplating; (5) further applying photoresist. (6) Finally, a step of relaxing and softening the residual stress of the heat-treated and plated Au bump electrode 6, [Invention However, as mentioned above, such bump electrodes require many complicated processes and are not necessarily satisfactory in terms of shape, dimensional stability, adhesive strength, etc. However, there is a need for a bump electrode with even higher reliability.

Therefore, as a result of studying the above-mentioned problems, the present inventors found that the shape and dimensions, which are the problems, are stable, and the adhesive strength is excellent.
Furthermore, it is an object of the present invention to provide a bump-connected semiconductor device that can accommodate high-mix low-volume production.

[Means for Solving the Problems] The object of the present invention is to provide a bump-connected semiconductor device in which a semiconductor chip is electrically connected to leads via bump electrodes, in which the bump electrodes on the semiconductor chip are wire-bonded. This is achieved by a bump-connected semiconductor device characterized by thermocompression bonding a ball at the tip of a wire that is formed by supplying a wire to the device.

Next, the present invention will be explained in more detail.

The present invention is characterized in that bump electrodes on a semiconductor chip are formed by thermocompression bonding a ball at the tip of a wire that is formed by supplying a wire to a wire bonding device, thereby achieving stability in shape, size, and adhesion. It has excellent strength, etc., and has the effect of easily making bump connections.

The wires used in the present invention include wires commonly used in wire bonding methods made of gold, silver, copper, aluminum, lead, brazing metal, or alloys thereof, but preferably full alloys, lead wires, etc. type alloy is better.

All-based alloys include alloys such as ^u-5L, ^u-Ge, and ^u-5n, and lead-based alloys include Pb-Ag,
Examples include alloys such as PPb-5n-A. Among these, it is preferable to use a full alloy in consideration of reliability and the like.

The wire bonding device used in the present invention includes:
Equipment equipped with capillaries commonly used in ball bonding methods can be used.

The means of melting the tip of the wire passed through the capillary of the wire bonding device to form a ball include the ball bonding method, which includes a method of discharging between the tip of the wire and a movable electrode, a method using oxyhydrogen flame, etc. The normal ball-making method is used.

The ball thus formed is thermocompression bonded to a desired position on a bonding pad or lead of a semiconductor device, hybrid integrated circuit, or the like.

In this case, if thermocompression bonding at a low temperature is required, it is preferable to use a thermosonic method in which ultrasonic waves are applied to the capillary.

The ball is formed using spark discharge, hydrogen torch, etc.

After the ball thus obtained is bonded by thermocompression, the wire can be cut by pulling up the wire.

Note that the shape, dimensions, etc. of the bump electrode can be changed as appropriate by controlling the diameter of the wire, the conditions for forming the ball, etc.

A semiconductor chip with bump electrodes formed as described above is
It is electrically connected to the leads of the chip carrier via bump electrodes by thermocompression bonding or the like.

[Example] Next, an example of the present invention will be described using FIG. 1, FIG. 2, and FIG. 3, but the present invention is not limited thereto.

FIG. 1 is a cross-sectional view of a ball formed at the tip of a wire passed through a capillary of a wire bonding device;
1 is a ball, 12 is a wire, and 13 is a capillary.

FIG. 2 is a cross-sectional view of the bump electrode installed on the bonding pad of the semiconductor chip, where 21 is the semiconductor substrate, 2
2 is a bonding pad, 23 is a surface protective film, and 24 is a bump electrode.

The wire 12 is made of u-2Si alloy with a diameter of 0.0
A thin gold wire of 11n+ is used, and this thin wire is passed through the capillary 13 of the wire bonding device.Then, between the discharge electrode (not shown) and the tip of the thin wire, a voltage of 30V to 80V (
A discharge voltage of preferably 50 V is applied to generate a discharge, thereby heating and melting the tip of the thin gold wire to form a ball 11. The ball 11 is attached to a semiconductor substrate 21 made of Si. of Si
n. Bonding with thermocompression to the bonding pad 22 on the surface. The bonding load at this time is 50 g to 100 g.

The bonding temperature is 150° C. to 250° C., and after the thermocompression bonding is completed, the thin gold wire is pulled up and separated from the ball 11 to form a bump electrode.

The semiconductor chip having the bump electrodes thus obtained is thermocompression bonded onto the internal leads 33 of the chip carrier 31 made of ceramic main ivy. Finally, it is sealed with a ceramic or metal 136 to form a ceramic package consisting of a bump-connected semiconductor device.

[Effects of the Invention] In the present invention, the bump electrodes on the semiconductor chip are formed by thermocompression bonding the balls of the wire supplied to the wire bonding device, so that the following highly reliable semiconductor devices can be manufactured. There are excellent effects that can be obtained.

(a) Bump electrodes can be formed in a simple process using an ordinary wire bonding device, and it can easily respond to low-volume, high-mix production.

(b) Since thermocompression bonding is used, the strength of the connection between the bump electrode and the bonding pad or lead can be increased.

(c) The shape, dimensions, etc. of the bump electrode can be freely controlled and can be formed stably.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a ball formed at the tip of a wire passed through a capillary of a wire bonding apparatus used in the present invention, and FIG. FIG. 3 is a cross-sectional view showing an electrode. FIG. 3 is a cross-sectional view showing a bump electrode formed on a bonding pad. FIG. 4 is a cross-sectional view showing a pants electrode formed on a conventional bonding pad. Explanation of symbols 1...Substrate 2.22...Bonding bat 3.23
...Surface protective film 4...ri-w film 5...^U film
6...Au bump electrode 11...Ball 12...Wire 13...Capillary 21...Semiconductor substrate 24.34
...Bump electrode 31...Chip carrier 32...External lead 33...
Internal lead 35... Semiconductor chip 36... Lid Figure 1 Figure 2 Figure 3 1

Claims (1)

[Claims] In a bump-connected semiconductor device in which a semiconductor chip is electrically connected to a lead via a bump electrode, the bump electrode on the semiconductor chip heats the ball at the tip of the wire that is formed by supplying the wire to a wire bonding device. A bump-connected semiconductor device characterized by being crimped.