JPH05206214A - Film carrier tape and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a highly precise film carrier tape excellent in matching with the electrode arrangement of a semiconductor chip, and manufacture a semiconductor device of high reliability at a low cost wherein bumps are unnecessary, by joining a metal protruding segment having a surface wherein both ends are cut by a metal mold to the tips of a lead. CONSTITUTION:Metal protruding segments 10a having surfaces wherein both ends are cut by a metal mold are joined to a film carrier tape having holes for conveyance and positioning and leads 4a. Since both ends of the metal protruding segment 10a are cut by a metal mold after thermo-compression bonding, matching with the electrode arrangement of a semiconductor chip is excellent and uniform. When the film carrier tape provided with the metal protruding segments 10a is used, bumps on a semiconductor chip become unnecessary, so that the cost of the semiconductor chip can be reduced. Since film carrier parts are used for both the side where the metal protruding segments 10 are formed and the side turning to the metal protruding segments 10a, automating of manufacture is easy and efficiency is high.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a film carrier tape for a film carrier semiconductor device.

[0002]

2. Description of the Related Art A conventional semiconductor device using a film carrier system will be described with reference to its manufacturing process.
A metal foil such as copper is adhered onto an insulating film (base film) such as polyimide having a sprocket hole 1 for transporting and positioning and a device hole 3 for opening the semiconductor chip 2 as shown in FIG. A film carrier tape having leads 4 (having pads 5 for electrical selection) formed in a desired shape by etching a foil and bumps 7 which are metal protrusions on electrode terminals in advance.
The semiconductor chip 2 provided with is prepared, and then the leads 4 of the film carrier tape and the bumps 7 of the semiconductor chip are subjected to inner lead bonding by a thermocompression bonding method, a eutectic method, or the like to perform electrical selection in the state of the film carrier tape. A bias test is performed and then the lead 4 is cut to the desired length. Then, as shown in FIG. 8, the semiconductor chip 2 is fixed on the printed board 8 by the adhesive material 9, and then the leads 4 are completed by outer lead bonding to the bonding pads on the printed board.

In such a semiconductor device using the film carrier method, bonding can be performed at one time regardless of the number of leads, and therefore the speed is fast. Also, since a film carrier tape is used, assembly and electrical selection work such as bonding can be automated. It has advantages such as excellent mass productivity.

[0004]

In the conventional film carrier semiconductor device described above, it is necessary to form bumps on the electrodes of the semiconductor chip, and the number of man-hours for forming bumps, which is mainly performed by electrolytic plating in a wafer state, is small. It has the disadvantage of being expensive and costly. Several bump forming methods have been introduced to solve this problem. As an example, “Solid State Technology” magazine (Sol
id State Technology) Japanese version, 1
Film carrier tape with bumps (hereinafter referred to as B-tape), "National Technical Report" introduced in the November 1978 issue, pages 33 to 35, etc.
Magazine (National Technical Repo)
rt) Vol. 31, No. 3, June, 1985, No. 116
Transfer bumps introduced on pages pp. 124-124, etc., a method of using metal balls as bumps in wire bonding disclosed in JP-A-54-2662 and JP-A-60-194543 (hereinafter referred to as ball bumps). There is a). Of these, the B-tape is one in which the lead tip of the film carrier tape is left and other lead portions are half-etched, and the lead tip remaining in a convex shape without being half-etched is used as a bump. It is necessary to pattern and etch both sides of the metal foil in order to perform half-attacking, and generally a single layer film carrier tape consisting of the metal foil is used. Therefore, the leads are electrically connected and have a drawback that it is difficult to perform electrical selection in a film carrier tape state. In order to solve this problem, it is possible to form bumps on the leads formed on the insulating film in the same manner as in the related art, but there is a disadvantage that the process is complicated and man-hours are required, which is conversely high in cost.

The transfer bump is a method in which bumps are formed on a substrate such as glass by electrolytic plating, leads of a film carrier tape are bonded, and the bumps are transferred from the substrate to the leads. Although there are many cost advantages over the bump formation method, there are drawbacks that need to be improved, such as formation of bumps by electrolytic plating and bonding for transfer to leads.

A ball bump is a bump formed by connecting only metal balls formed during thermocompression wire bonding to electrodes of a semiconductor chip, but when forming bumps and bonding leads of a film carrier tape to the bumps. Since the electrodes of the semiconductor chip are subjected to thermal and mechanical stress twice, the electrodes are easily broken and the reliability is poor. Further, this method has a drawback that it takes time as the number of electrodes of the semiconductor chip increases.

[0007]

The film carrier tape of the present invention is a film carrier tape having at least holes for carrying and positioning and leads of a predetermined shape, and both ends of the leads are cut by a die. That is, metal projection pieces having a curved surface are joined together.

Further, the method for manufacturing a film carrier tape of the present invention comprises a step of preparing a film carrier tape-like component having at least holes for carrying and positioning and a lead-like first branch of a predetermined shape, and a predetermined step. Providing a metal part having a frame having a shape and a second branch projecting outward from the frame corresponding to the first branch;
A step of stacking and joining the tip end of the second branch of the metal component to the tip end of the first branch of the film carrier tape-like component, and cutting a lead at the tip having a metal projection piece at the joint. And a step of forming.

[0009]

The present invention will be described below with reference to the drawings.

FIG. 1 (a) is a plan view of an embodiment of the film carrier tape of the present invention, and FIG. 1 (b) is an X- line of FIG. 1 (a).
It is an X-ray sectional view.

In the film carrier tape of the present embodiment, metal projection pieces 10a having both ends cut by a mold are joined and formed at the tips of the leads 4a.

Since both ends of the metal projection piece 10a are cut with a mold, they are uniform for each lead. Therefore, a highly reliable film carrier semiconductor device can be implemented.

FIG. 2 is a sectional view showing a state in which the semiconductor chip 2a is connected to the film carrier tape of this embodiment.

Next, an embodiment of the method for producing the film carrier tape of the present invention will be described.

First, as shown in FIG. 3, a 35 .mu.m thick copper foil is adhered to a base film 3a made of, for example, a polyimide film, patterned, and then Au or Sn plated 3.
Layer film carrier tape like parts and, as shown in FIG.
At the same pitch as the tip of the lead-shaped first branch 4b of the film carrier tape-like component shown in FIG.
Another film carrier tape-like component having a second branch 4c extending in four directions from a is prepared. Figure 4
Film carrier tape-like parts are made of copper foil only 1
Either a two-layer tape or a two-layer tape or a three-layer tape may be used, but a single-layer tape is used because a selection pad is not necessary to reduce the cost. Further, the second branch 4c is gold-plated with a thickness of about 1 μm. Next, as shown in FIG. 5 (a), this single-layer tape is positioned using the sprocket hole 1b for positioning, and the cutting die 12a, 13a cuts the portion on the support frame 11a side from the main body. Support frame 1 at this time
1a is cut, leaving a second branch 4d of a desired length. Thus, the metal part having the shape shown in FIG. 5B is formed.

Next, the metal part cut as shown in FIG. 5 (c) is placed on the bonding stage 15 and the first branch 4b of the film carrier tape-like part and the second branch 4d of the metal part shown in FIG. Then, thermocompression bonding is performed with the bonding tool 14. The conditions of thermocompression bonding differ depending on the plating state of the first branch 4b of the film carrier tape-like component, but in the case of gold plating, for example, thermocompression bonding can be performed at 250 ° to 450 ° C.

This thermocompression bonding apparatus can be easily formed if an inner lead bonder for bonding a semiconductor chip and a film carrier tape is used, and batch bonding can be performed. The state of being joined in this way is shown in FIG. Next, as shown in FIG. 5E, the sprocket hole 1a is used again for positioning, the lead support frame 11b is cut by the cutting dies 11b and 12b, and the support frame 11a is removed.
The size of the cutting die at this time is determined so as to match the semiconductor chip electrode arrangement, unlike the cutting die of FIG.

Thus, as shown in FIGS. 5 (f) and 1, the film carrier tape having the metal projections 12a at the ends of the leads 4a having the surfaces cut by the mold at both ends is completed.

Even if some deformation occurs during thermocompression bonding, the position of the lead tip is determined by cutting after thermocompression bonding.
It is possible to form a metal projection piece that matches well with the electrode arrangement of the semiconductor chip.

If the film carrier tape having this metal projection piece is used, bumps are not required on the semiconductor chip, and the cost of the semiconductor chip can be reduced, and the metal projection piece can be the side on which the metal projection piece is attached and the metal projection piece. Since film carrier tape-like parts are used on both sides, there is an effect that the transport system is simple, automation is easy, and metal projection pieces are attached all at once regardless of the number of leads, resulting in good efficiency.

FIG. 6 is a plan view of a film carrier tape-like component used in the second embodiment of the method for manufacturing a film carrier tape of the present invention.

The insulating base tape 6C is provided with a sprocket hole 1c, a branch 4e having a desired shape, and an electric selection pad 5b, and a support frame 11b is provided at the tip of the branch 4e. Support frame 11b using a cutting die having a predetermined size
Can be separated to form a structure similar to that shown in FIG. Further, by changing the cutting die, the same one as shown in FIG. 5B can be formed. Others are the same as the above-mentioned embodiment.

This embodiment has the advantage that only one type of film carrier tape-like component may be used, and the manufacturing process can be simplified accordingly.

[0024]

As described above, the film carrier tape of the present invention is highly accurate because the metal projection pieces having the surfaces cut by the mold at both ends are joined to the ends of the leads, and the film carrier tape of the semiconductor chip has high accuracy. Good matching with the electrode arrangement. Therefore, a highly reliable film carrier semiconductor device can be realized.

The method of manufacturing a film carrier tape according to the present invention is, so to speak, prepared by preparing an ordinary film carrier tape (film carrier tape-like component) having no protrusions at the ends of the leads and projecting it outward. A metal projection piece is provided on the tip of the lead by joining the branch of the frame with a branch and the tip of the lead, and then the frame is separated by mechanical means, which can be formed by diverting the inner bonder. Therefore, there is an effect that the metal carrier projection method can be formed at one time regardless of the number of leads and that the advantage of the film carrier tape method is excellent in mass productivity.

[Brief description of drawings]

FIG. 1 is a plan view (FIG. 1A) and a cross-sectional view (FIG. 1B) showing an embodiment of a film carrier tape of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a semiconductor chip is mounted on an embodiment of the film carrier tape of the present invention.

FIG. 3 is a plan view used for explaining one embodiment of the method for manufacturing the film carrier tape of the present invention.

FIG. 4 is a plan view used for explaining one embodiment of the method for manufacturing the film carrier tape of the present invention.

FIG. 5 is a cross-sectional view in order of the steps, which is illustrated in FIGS. 5A to 5F for explaining one embodiment of the method for manufacturing the film carrier tape of the present invention.

FIG. 6 is a plan view used for explaining a second embodiment of the method for manufacturing the film carrier tape of the present invention.

FIG. 7 is a plan view of a conventional film carrier tape.

FIG. 8 is a sectional view of a film carrier semiconductor device.

[Explanation of symbols]

 1, 1a, 1b, 1c Sprocket hole 2, 2a Semiconductor chip 3, 3a, 3b, 3c Device hole 4, 4a Lead 4b First branch 4c Second branch 4e Branch 5, 5a, 5b Select pad 6, 6a, 6b, 6c Base film 7 Bump 8 Printed circuit board 9 Adhesive 10a Metal projection piece 11a, 11b Support frame

Claims (3)

[Claims] 1. A film carrier tape having at least holes for transporting and positioning and leads having a predetermined shape, and metal projection pieces having a surface whose both ends are cut by a mold are joined to the tips of the leads. A film carrier tape characterized in that. 2. The film carrier tape according to claim 1, wherein the metal projection pieces are gold-plated. 3. A step of preparing a film carrier tape-like component having at least a transporting and positioning hole and a lead-shaped first branch of a predetermined shape, and corresponding to a frame of the predetermined shape and the first branch. And preparing a metal part having a second branch projecting outwardly from the frame, and at the tip of the first branch of the film carrier tome-like part, the second branch of the metal part is attached. A method of manufacturing a film carrier tape, comprising: a step of overlapping and joining the tip portions; and a step of cutting at the joining portion to form a lead having a metal projection piece at the tip.