JPH05251450A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To improve adhesive properties of a metal brazing material for fixing a pinlike electrode lead to a bump formed on a semiconductor integrated circuit chip in a semiconductor integrated circuit to be connected to an exterior of the chip via the lead. CONSTITUTION:A bump 2 is formed on a surface of a semiconductor integrated circuit formed with a semiconductor element, and a pinlike electrode lead 3 is fixed to the bump 2 via a metal brazing material 4 in a semiconductor device. A surface of the bump is formed with an uneven part. Thus, a contact area of the brazing material for fixing the lead with the bump is increased by forming the uneven part on the surface of the bump without increasing the area of the bump to improve its adhesive strength.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit device, and more particularly to a bump structure of a semiconductor integrated circuit device for connecting a chip to the outside by means of pin-shaped electrode leads.

[0002]

2. Description of the Related Art In recent years, as semiconductor integrated circuit devices have become highly integrated, pin-shaped electrode lead connections have begun to be used for external connection. (Application number 63-27978
9) FIG. 4 is a sectional view of the structure of a conventional bump for connecting a pin-shaped electrode lead. In FIG. 4A, bumps 2 are formed of, for example, gold on a semiconductor integrated circuit chip 1 on which a semiconductor element is formed, and I-shaped pin-shaped electrode leads 3 are erected on the bumps, for example, a metal brazing material 4 such as gold tin. The pin-shaped electrode lead 3 is fixed with. In FIG. 4B, the pin-shaped electrode lead shape is a nail head type.

[0003]

In this conventional bump structure, when the I-shaped pin-shaped electrode lead 3 is used as shown in FIG. 4 (a), the skirt spread of the metal brazing material is narrow, and the metal brazing material 4 and the bump 2 are formed. Since the contact area between the metal brazing material 4 and the bump 2 is small
Adhesive strength of is insufficient. If the pin-shaped electrode lead shape is a nail head type as shown in FIG.
Although the contact area becomes larger, the bonding strength between the metal brazing material 4 and the bump 2 can be increased, but the area of the bump 2 becomes large, which is disadvantageous for high integration.

An object of the present invention is to provide a semiconductor integrated circuit device capable of increasing the adhesion strength between a pin-shaped electrode and a bump without increasing the bump area.

[0005]

The semiconductor integrated circuit device of the present invention is a semiconductor device in which bumps are formed on the surface of a semiconductor chip on which semiconductor elements are formed and pin-shaped electrode leads are fixed on the bumps. Is characterized by being formed in an uneven shape.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of one embodiment of the present invention and top views of three examples of bumps thereof. As shown in FIG. 1 (a), bumps 2 are formed on 1000 angstrom titanium tungsten 6 and 1000 angstrom gold 7 which are gold-plated electrodes on a semiconductor integrated circuit chip 1 on which a semiconductor element is formed.
Is formed with a thickness of 3 μm and a size of 100 μm □, and selective etching is performed to form a recess on the bump 2. The contact area between the metal brazing material 4 and the bump 2 is compared between the bump in the present invention having an uneven surface (b) 2 in the present invention and the bump formed in the prior art with a flat surface in FIG. 4 (a). Since the side surface of the uneven portion can be viewed as the contact area, the same contact area can be obtained even if the bump area is small.

Then, a nail head type pin-shaped electrode lead 3 is erected on the bump, and the pin-shaped electrode lead 3 is fixed by a metal brazing material 4 such as gold tin. FIGS. 1B to 1D show an example of unevenness formed on the bump 2 in the top view of the bump 2 in FIG. 1A, but the present invention is not limited to this. Figure 1
(B) is a square-shaped recess arranged vertically and horizontally, as shown in FIG. 1 (c).
Is an array of slit-shaped recesses, and FIG. 1D shows a concentric recess. BB ₁ in FIG. 1 (b)
The cross section between CC ₁ in FIG. 1C and DD _{1 in} FIG. 1D can be represented by the bump cross section of FIG. 1A. In this embodiment, in order to obtain the same contact area between the metal brazing material 4 and the bump 2 as in FIG. 4A, both the nail head and the bump area can be reduced.

FIG. 2 shows a manufacturing process of another embodiment of the present invention. First, as shown in FIG. 2 (a), for example, titanium tungsten 6 of 1000 angstrom and gold 7 of 10 serving as a plating electrode are formed on the entire surface of the semiconductor integrated circuit chip 1.
Coating by 00 angstrom sputtering method, plating patterning 100μ by photolithography technology
Then, the bump 2 is formed by performing m □ and performing gold plating by 3 μm.
Further, as shown in FIG. 2B, the patterning of the plating is performed again by the photolithography technique, and then the gold plating is performed to form the bumps 3 having the uneven surface. Next, as shown in FIG. 2C, after removing the photoresist 5, the entire surface is etched by RIE or the like to etch titanium tungsten 6 and gold 7. Then Fig. 2
As shown in (d), the pin-shaped electrode lead 3 is fixed on the bump with the metal brazing material 4. FIG. 3 shows a third embodiment in which the semiconductor integrated circuit chip 1 is provided with a concave portion in advance and plating is performed on the concave portion to form irregularities on the bump 2. The previously provided recess may be a through hole.

[0009]

As described above, according to the present invention, the bump surface is formed in a concavo-convex shape without increasing the bump area, so that the contact area between the metal brazing material for fixing the pin-shaped electrode lead and the bump is increased to improve the adhesion strength. Has the effect of improving.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an embodiment of the present invention and top views of three examples corresponding to the cross-sectional view of a bump thereof.

FIG. 2 is a cross-sectional view of a semiconductor integrated circuit chip shown in the order of steps for explaining another embodiment of the present invention and a manufacturing method thereof.

FIG. 3 is a sectional view of a third embodiment of the present invention.

FIG. 4 is a cross-sectional view of two examples of conventional semiconductor integrated circuit chips.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor integrated circuit chip 2 Bumps 3 Pin-shaped electrode leads 4 Metal brazing material 5 Photoresist 6 Titanium tungsten 7 Gold

Claims (1)

[Claims] 1. A semiconductor integrated circuit device in which bumps are formed on the surface of a semiconductor chip on which a semiconductor element is formed, and pin-shaped electrode leads are fixed on the bumps, wherein the bump surface is uneven. Integrated circuit device.