JPS62216337A - Film carrier for semiconductor device - Google Patents

Abstract

PURPOSE:To shorten a procedure, to reduce a cost and to prevent a film carrier from shortcircuiting in a semiconductor device by forming a contact metal of projecting section in contact with wirings through a film at opposite side of the wirings, press-bonding the metal to an electrode by thermal press-bonding to connect the electrode with the wirings. CONSTITUTION:Wirings 12 are formed on the projection 11a of a film 11, and the wirings are formed, for example, by a printing technique on the film having approx. 10mum of thickness, several mum thick. The contact 21 at the end of the wirings 12 has a structure in Figure b along the line A-A in Figure a, the projection 22a of a contact 22 of projecting section is engaged within the film 11, and a press-bonded portion 22b at opposite side of the projection 22a so mounts the metal 22 on the film 11 as to project externally from the film 11. In mounting, the contact 21 of the wirings 11 is brought to aluminum electrode 14 of a chip. Then, the projection 22a of the metal 22 is contacted with the electrode 14, the portion 22b is press-bonded, for example, by thermal press- bonding on the electrode 14 to connect the wirings 12 with the electrode 14.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to a structure of a film carrier for a semiconductor device that has performance equivalent to that of a bump, and achieves reductions in turn and cost.

[Industrial application field]

The present invention relates to a film carrier for semiconductor devices, and more specifically, to the structure of a film carrier on which wiring is formed for connection to the electrodes of a semiconductor chip housed in an IC card.

[Conventional technology]

In place of conventional cards with magnetic stripes, IC cards containing semiconductor chips (hereinafter simply referred to as chips) have been developed.

An IC card is generally a few millimeters thick, and the chip enclosed inside it is formed to a thickness of 2 to 3 mm, and a film is formed with wiring to connect to the electrodes of the chip. The carrier is of special construction.

3(a), (b) and (C1 are a plan view, a partially enlarged plan view, and a side view of the film carrier described above, in which 10 is a film carrier, 11 is an insulating film, and 12 is a side view of the film carrier. is, for example, tin-plated copper wiring.

On the other hand, the structure of the chip is shown in the cross-sectional views of FIGS. 4 and 5, in which 13 is the chip, 14 is the aluminum (A7 electrode) formed on the chip 13, and 15 is the aluminum electrode formed on the surface of the chip 13. This cover film 15 has an electrode 1 on it.
The bonding window 15a for No. 4 is opened.

To connect the electrode 14 of the chip 13 and the wiring 12, a bump 17 made of, for example, gold (Au) is formed on the electrode 14 via the barrier metal 11g116, and the contact portion 12a of the wiring 12 is connected to the bump 17. The connections are made by thermocompression bonding as shown in FIG. The barrier metal film 16 is provided to prevent the eutectic reaction between i and Au, and the bump 17
is grown by plating to a thickness of about 20 μm.

[Problems to be Solved by the Invention] The problem with the above method is that a barrier metal film 16 must be provided to prevent the sieve from diffusing into A2 due to the eutectic reaction between Au and 8β. , growing Au by plating requires more than 10 steps, increasing costs, and plating itself takes several hours. Further, since the contact portion 12a of the wiring 12 is in a floating state before being crimped as shown in FIG. 5, there is a risk of a short circuit due to bending.

The present invention was created in view of these points, and an object of the present invention is to provide a film carrier having wiring that is effective in reducing manual short circuits and cost reduction, and without the risk of short circuits during contact (connection) formation. do.

[Means for solving problems]

FIGS. 1 fal and (b) are a plan view and a cross-sectional view of an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the embodiment of the present invention showing connection with a chip electrode using the wiring shown in FIG. 1.

In the film carrier 10 according to the present invention, the protrusion 11a of the insulating film 11 of the film carrier 10
In the contact portion 21 of the wiring 12 formed in the above, on the opposite side of the wiring 12, there is a convex cross section that penetrates the film 11 and contacts the wiring 11, that is, a convex portion 22a and a crimp portion 22b.
A contact metal 22 having a diameter is provided, and the contact metal 22 is bonded to the electrode work 4 of Aj2 by thermocompression bonding to connect the electrode work 4 and the wiring 12.

[Effect]

The contact metal 22 mentioned above is in contact with the wiring 12 at the negative end, and the other end is connected to the electrode 14 by thermocompression bonding, so the conventional bump 17 is no longer necessary, and the contact metal If a material that does not cause a eutectic reaction with i is used, the conventional barrier metal 16 becomes unnecessary.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

In the conventional example, the contact portion of the wiring 12 protruded from the surface of the film 11 as shown in FIG. 3, and this protruding portion of the wiring I2 remained floating, but in the present invention,
The wiring 12 is formed on the protrusion 11a of the film 11. The wiring is formed on a film with a thickness of about 10 μm by, for example, a printing technique, and has a thickness of several μm.

The contact portion 21 at the tip of the wiring 12 has a structure as shown in the interlayer diagram on line A-A in FIG. The crimping part 2 on the opposite side of the protruding part 22a
Reference numeral 2b attaches a contact metal 22 to the film 11 so as to protrude to the outside of the film 11. Except for the contact portion 21, the wiring is the same as that of the conventional example, and the cross-sectional view taken along the line B--B in FIG. 1 appears the same as the side view in FIG. 3(C).

In order to obtain such a configuration, holes are made in the film 11,
It is preferable to fit the protruding portion 22a into this hole. The contact metal is made of a material that does not cause a eutectic reaction, such as tungsten, and the height of the crimp portion 22b is as shown in Figure 1 (b).
Height 20.17 m) as shown in Figure 1).

During mounting, the contact portion 21 of the wiring 11 shown in FIG. 1('b) is connected to the Aj2 of the chip as shown in FIG.
It comes on top of the electrode 14. For chips, contact metal and Aj! Since there is no risk of eutectic reaction of
The conventional barrier metal 16 is not provided.

The crimp portion 22b of the contact metal 22 is brought into contact with the electrode 14, and the crimp portion 22b is crimp-bonded to the electrode 14 by, for example, thermocompression bonding, as shown in FIG. 2, thereby connecting the wiring 12 and the electrode 14.

The advantage of using the above-mentioned film carrier is that since the arrangement of the electrodes 14 of the chip 13 is determined at the wafer process stage, the film carrier can be manufactured in accordance with this electrode arrangement, and the wafer can be attached to the wafer after the wafer process. By proceeding immediately with the process of forming the contact shown in Figure 2, in other words, there is no need to form a barrier metal, and the plating process is omitted, so bumps can be grown by plating after the wafer process, and 5th time since the end of
Compared to the conventional technology in which the contact formation process shown in the figure is advanced, the manufacturing steps and time are significantly shortened, and costs are reduced.

In addition, as described above, in the conventional example, the contact part 12a of the wiring in a floating state and the bump 17 are bonded by thermocompression, and if the contact part 12a is bent, for example, correct contact cannot be obtained and there is a risk of short circuit. However, according to the present invention, since the crimp portion 22b, which is crimped and has a width larger than the width of the wiring 12, and the electrode 14 are thermocompression bonded, there is an advantage that risks such as short circuits can be avoided.

〔Effect of the invention〕

As described above, according to the present invention, when connecting wiring to electrodes of a chip formed as thin as 2 to 3 mm,
Effects such as shorter turnaround times, lower costs, and prevention of short circuits can be obtained.
This is effective in improving the manufacturing yield of IC cards, etc.

Note that the above description is based on an example in which the wiring is connected by thermocompression bonding in the case of an RC card, but the scope of the present invention is not limited to IC cards.
The present invention is not limited to the example using a card, and the wiring connection method is not limited to thermocompression bonding.

[Brief explanation of drawings]

Figures 1 fa) and fb) are a plan view and a sectional view of an embodiment of the present invention, Figure 2 is a sectional view of an embodiment of the present invention, and Figure 3 fa), fb), and (C) are a plan view of a conventional example. 1 is a partially enlarged front view and a side view, and FIGS. 4 and 5 are cross-sectional views of the conventional example. 1 to 5, 10 is a film carrier, 11 is a film, 11a is a protrusion, 12 is a wiring, 12a is a contact part of the wiring 12, 13 is a chip 14 is an electrode, 15 is a cover film, 15a is a bonding 16 is a barrier metal, 17 is a bump, 21 is a contact portion, 22 is a contact metal, 22a is a protruding portion, and 22b is a crimp portion. Agent Patent Attorney Hajime Kuki Agent Patent Attorney Yoshiyuki Osuga To Fukutomi (5f) -I

Claims (1)

[Claims] In a film carrier (10) in which a wiring (12) connected to an electrode (14) of a semiconductor chip (13) is formed on an insulating film (11), the film (11)
The wiring (12) is arranged on the protrusion (11a) of the wiring (12), and the wiring (12) is placed on the contact part (21) of the wiring (12).
A contact metal (22) is placed on the opposite side of 12) through the film (11), and the protruding part (22a) of the metal contacts the wiring (12) through the film (11), and the protruding part (22a) The lower crimp part (22b) of the film (11
1. A film carrier for a semiconductor device, characterized in that the crimping portion (22b) is provided so as to protrude from the surface of the semiconductor device, and the crimping portion (22b) is directly crimped to an electrode (14) of a chip.