JPH04188741A - Method of producing semiconductor device and carrier tape for use therein - Google Patents

Abstract

PURPOSE:To prevent a deformation of a lead tip by a method wherein, in such a condition that an end of each wire lead is supported by an insulating film, a part of the wire lead is connected to a projecting electrode of a semiconductor chip through an opening. CONSTITUTION:A copper foil is formed on a flexible insulating film such as a polyimide film 1a by a partial etching as a wire pattern to make a plurality of leads 2. A window hole 9 is so opened as to expose a part of the lead 2. making a condition that both ends of the lead 2 are supported by the polyimide film 1a. Then, a semiconductor chip 3 is positioned under a tape 1a so that an electrode 4 of the chip may be connected to the lead 2 through a device hole 9 of the tape, and each lead 2 and the corresponding electrode 4 are concurrently thermo-compressed by using a bonding tool so as to connect to each other. Thus, a deformation at a lead tip may be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an automatic tape carrier bonding technique using a carrier tape in the manufacture of semiconductor devices.

[Conventional technology]

TAB (Tape Out) uses a carrier tape with lead wiring formed on a long flexible insulating film (tape) to continuously manufacture semiconductor devices on the tape.
Regarding bonding) technology, see Nikkei Micro Devices, April 1987 issue, pages 99-1.
It is described on page 06.

In this TAB technique, referring to FIG. 11, an opening (device hole) 14 is made in advance in the flexible film 1a, and a part 5 of the tip of the wiring lead 2 is made to protrude from the entrance part 14. At the same time, as shown in the cross-sectional view in FIG. It connects semiconductor chips electrically and mechanically completes mounting.

Such a flexible film allows continuous and automated packaging of a plurality of semiconductor devices by using a long tape. This TAB technology enables devices to be made smaller, thinner, and lighter, such as thin calculators,
It is especially widely used in liquid crystal display devices and the like.

[Problem to be solved by the invention]

Compared to the conventional method of assembling semiconductor devices using wire bonding, which has been commonly used, the TAB technology described above can significantly reduce the pitch of the external electrode lead-out portions (bonding pads) on the semiconductor pellet (chip). This makes it possible to cope with the recent increase in the number of pins in semiconductor pancakes.

In other words, when the pa/nod pitch is determined by wire bonding, the field is approximately 130 μm, whereas the TA
For B, 50-60 μm is also possible. As a result, even in a multi-bin semiconductor device having more than 200 pins, it is possible to avoid increasing the size due to the band.

By the way, in the conventional carrier tape technology for TAB, as mentioned above, a carrier tape is used in which a part of the tip of the wiring lead protrudes from the device hole (opening) of the tape, but when making it compatible with a multi-pin semiconductor device, Cu (copper) aB! Since the width of the wiring lead made of J is extremely narrow, the protruding tip of the lead is easily deformed by even the slightest wind pressure, and it may come into contact with the electrode of the semiconductor chip in an unstable state, resulting in a connection failure. there were.

The present invention has been made to solve the above-mentioned problems, and its purpose is to prevent deformation of the lead tips when connecting wiring leads and chip electrodes using a carrier tape.

Another object of the present invention is to provide a carrier tape structure that is also effective when using a solder hump as a protruding electrode of a TAB.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a plurality of wiring leads arranged on a flexible insulating film, an opening in the insulating film, and an end of each wiring lead supported by the insulating film. The present invention relates to a method of manufacturing a semiconductor device, characterized in that a part of the wiring lead is connected to a protruding electrode of a semiconductor chip through the opening in this state.

The present invention also provides a method for manufacturing a semiconductor device as described above, by using a pattern in which the inner ends of the wiring leads are connected to each other on an insulating film in advance, so that when forming an electroplated film on the surface of the leads, the wiring leads are not conductive. After plating, the inner ends of the leads are separated by punching.

The present invention also provides the method for manufacturing a semiconductor device described above, in which after electroplating, the inner ends of the leads are separated by punching at the same time as a part of the insulating film.

The present invention further provides a plurality of sets of wiring leads arranged opposite to each other along a long flexible insulating film, and each set of the plurality of wiring leads has an insulated inner end and an outer end. The present invention relates to a carrier tape for a semiconductor device, which is supported by a film and has a window hole opened in the insulating film in the middle part of the lead corresponding to the protruding electrode position of the semiconductor chip.

The present invention further provides a structure in which, in the carrier tape for a semiconductor device, a frame (crosspiece) is formed from a wiring lead material on both sides of the long tape and perpendicularly thereto to separate the plurality of wiring leads of each set from each other. It is something.

[Effect]

Deformation of the lead can be prevented by supporting the minute lead tip protruding into the device hole with the insulating film (center part) left inside the device hole.

By creating a pattern that connects the inner ends of the leads to each other on the insulating film, it becomes a conductive path when plating the leads.
After plating, the inner ends of the leads can be punched and separated at the same time as the film, simplifying the assembly process.

By making the thickness of the insulating film equal to or slightly thinner than the protruding electrodes on the chip, when solder is used for the protruding electrodes on the chip, it is possible to maintain the distance between the leads and the chip when connecting the leads and the protruding electrodes, and Even when solder is used for the protruding electrodes, it is possible to prevent the solder from melting and protruding laterally.

〔Example〕

Hereinafter, the present invention will be explained along with some embodiments with reference to the drawings.

(Example 1) FIGS. 1 and 2 are a plan view and a sectional view taken along the line AA' of the TAB carrier tape according to the present invention.

On the carrier tape, a plurality of adhesive portions 2 are provided on a flexible insulating film, for example, a polyimide film la, and a wiring pattern is formed by partially etching a 35 μm thick copper foil.
A window hole 9 is made so that a part of the lead is exposed, and both ends of the lead are supported by the polyimide film 1a.

Note that the polyimide IjJ6 supporting the tip end 5 of the lead
and the polyimide film 1a supporting the outer end side of the lead 2 are formed as an integral pattern by an obliquely bulge-shaped portion 6a of the polyimide film.

Figures 3 and 4 are plan views and A-
It is an A' sectional view.

To assemble the semiconductor chip 3 on the carrier tape, as shown in FIG. Each lead and the corresponding electrode are connected by thermocompression bonding simultaneously using a bonding tool (not shown).

In this way, the lead tips 5 protruding inside the wiring leads are supported by the polyimide film, so even if the leads become finer and the pitch between the leads becomes smaller,
It can be connected to semiconductor chip electrodes without fear of deformation or contact and short circuit.

In this example, the height of the bump 4 was 25 μm, and the thickness of the polyimide film was 20 μm. If the polyimide film is thin like this, there is a risk that the film will stretch during handling and the dimensional accuracy will be lost.

Accordingly, as shown in FIG.
Leave 5 and then frame (or crosspiece) 7 across the film.
is made of copper foil and reinforced. Therefore, even if the polyimide film is thin, there is no concern that the dimensional accuracy of the tape will deteriorate due to film deformation.

(Example 2) FIG. 5 shows another embodiment of the present invention. Similarly to FIG. 4, FIG. 5 is a sectional view after the chip is assembled to the gear shaft. The designation symbols are the same as those used in FIGS. 1-4.

In the example shown in Fig. 4, the semiconductor chip 3 is connected to the polyimide film la side on the carrier tape through a window hole, whereas in Fig. 5, the semiconductor chip 3 is connected to the polyimide film la side on the carrier tape without passing through the window hole. It is something.

In the case of the example shown in Fig. 3, the height of the bump (protruding electrode) 4 is 25
5, the thickness of the polyimide film is quite thick, 125 μm, and the polyimide part 6 at the center surrounded by the device hole 9 gets in the way, and the pellet 3 is connected from the film 1a side. Can not. In this example 2, the mounting position of the chip 3 is opposite to the tape (on the upper side), but it has the same effect as example 1 in terms of preventing the desired deformation of the fine lead tip 5. is clear. Since the polyimide film 1a is sufficiently thick, there is no need to worry about deformation of the tape itself, and Example 1
It is not necessary to form a frame (7) like this.

Note that when the film 1a is thin and easily deformed when connecting the pellet to the lead side, it is effective to provide a frame similar to Example 1.

(Example 3) FIG. 6 is another example of the present invention. Bump (protruding electrode)
This is a case where solder (a low melting point metal that melts when connected) is used for the 4P. In the case of hump soldering, the TAB connection (
If pressure bonding is performed all at once using a heated tool, there are many problems such as the humps melting and flowing laterally, shorting out adjacent humps, and making it impossible to maintain a constant connection height. In such a case, if a carrier tape with the same thickness as the bump is used, the central film 6 left in the device hole 9 will act as a standoff, as shown in Figure 6, and the The bumps do not collapse during pressure, and problems such as short circuits as described above do not occur.

(Example 4) FIGS. 7 and 8 are other examples of the present invention, and are a plan view and a cross-sectional view of a carrier tape (when manufactured) similarly to the case of FIG. 1. The symbols used in this figure are the same as those used in FIG.

A carrier tape for TAB generally consists of a polyimide film covered with copper foil and partially etched to form patterns such as circuits and wiring leads.

These circuits and leads are insulated from each other on a polyimide film. The carrier tape is plated with metal such as gold (Au) on this steel to facilitate connection with semiconductor pellets and other devices and to prevent corrosion. Electroplating is desirable for this plating, but since the above wiring and leads are electrically isolated from each other on the insulating polyimide film, electroplating is impossible as is, and electroless plating is normally used. Immersion tin plating is carried out. However, tin plating is prone to the phenomenon of growing whiskers known as "tin whiskers," and there is a risk of short circuits between adjacent wires, especially when circuits become finer.

Example 4 is an application example of a TAB carrier tape that can be electroplated as a countermeasure to this problem. In order to perform electroplating, all wiring and leads must be connected to each other. As shown in Fig. 7, a part of lead 2 is
By connecting to the parts (copper foil current-carrying part) 12 of eight sprocket holes, and connecting the common lead connecting part 10 to the tips of all the leads on the center part 6 of the polyimide film, all the leads can be electrically connected. conducts to.

After completing any electroplating on such a carrier tape, the tape and the lead connection portion are simultaneously punched out using a punch or the like at a location 11 shown in FIG. 7.8. This creates a punch hole (12 in Figure 9.10) and electrically isolates all the leads, but even during this punching, the lead tips 5 are still supported by the remainder of the polyimide film b, so there is no deformation. There's no fear.

The protruding electrode (bump) 4 of the semiconductor chip 7 3 is connected through the device hole 9 of the polyimide film 1a to the carrier tape 1a which is electroplated and punched with holes 12 as shown in Figure 9.10, and the chip is mounted. The completed state is shown in a plan view and a cross-sectional view.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

By leaving an insulating film in the device hole and supporting the lead tips, deformation of the leads can be suppressed and a fine TAB type semiconductor device can be manufactured.

In the above manufacturing method, when using an insulating film that is thinner than the hump height, leave copper foil on the feed section (sprocket hole section) of the carrier tape and provide a frame of copper foil across the film to prevent film deformation. This enables stable production.

Furthermore, in an application example of the present invention, a portion where the lead tips are commonly connected is left on the center of the insulating film, and after electroplating, the connecting portion is punched out and separated, so that the electroplating on the leads of the carrier tape is performed. It is possible to easily prevent deformation of the lead tip and effectively prevent the deformation of the lead tip.

[Brief explanation of drawings]

FIG. 1 shows one embodiment of the present invention, and is a plan view of a TAB carrier tape in which a pellet is attached before being attached. FIG. 2 is a sectional view taken along the line AA' in FIG. FIG. 3 is a plan view of the TAB carrier tape after the bellet attachment. FIG. 4 is a sectional view taken along line AA' in FIG. FIGS. 5 and 6 are sectional views showing another embodiment of the present invention, with pellets attached. FIG. 7 shows another embodiment of the present invention, and is a plan view of the TAB carrier tape before the bellet attachment. FIG. 8 is a sectional view taken along line AA' in FIG. FIG. 9 is a plan view of the TAB carrier tape after the bellet attachment. FIG. 10 is a sectional view taken along line AA' in FIG. 9. FIG. 11 is a plan view of a TAB carrier tape (with a pellet attached to the front), which is an example of the prior art. FIG. 12 is a sectional view taken along the line AA' after attaching the carrier tape to the pellet in FIG. 11. Soil...TAB carrier tape, 1a...Polyimide film, 2...Lead, 3...Semiconductor chip (bellet), 4...Protruding electrode (bump), 5...Lead tip, 6 ... Polyimide film, 7... Crosspiece (
Lead material) 8... Hole for sprocket, 9... Window hole drilled in polyimide film, lO...
Lead connection part (center part of lead material) 11... punch hole,
12... Punch hole, 13... Current carrying part (lead material), 14... Window hole. 3, FIG. 1, FIG. 4, FIG. 5, FIG. 6, FIG. 7, 711, FIG. 13-■″Fl 蔀

Claims (1)

[Claims] 1. A plurality of wiring leads are arranged on a flexible insulating film, an opening is made in the insulating film, and the end of each wiring lead is supported by the insulating film. A method of manufacturing a semiconductor device, characterized in that a part of the wiring lead is connected to a protruding electrode of a semiconductor chip through the opening in this state. 2. In the method for manufacturing a semiconductor device according to claim 1,
An insulating film whose thickness is equal to or slightly thinner than the height of the protruding electrodes on the semiconductor chip is used, and the semiconductor chip is mounted on the side in contact with the film. 3. In the method for manufacturing a semiconductor device according to claim 2,
The electrodes of the semiconductor chip and the tips of the wiring leads are connected via a low melting point alloy mainly composed of tin and lead. 4. The method for manufacturing a semiconductor device according to claim 1,
Use wiring leads with a pattern in which the inner ends are connected to each other on the insulating film in advance to serve as a conduction path when forming an electroplated film on the lead surface, and after electroplating, to connect the inner ends of the leads to each other. are punched out and separated from each other. 5. In the method for manufacturing a semiconductor device according to claim 4,
After plating, a part of the insulating film and the inner ends of the leads are separated by punching. 6. A plurality of sets of wiring leads are arranged facing each other along a long flexible insulating film, and the inner and outer ends of each set of the plurality of wiring leads are supported by the insulating film. Also, a carrier tape for a semiconductor device, characterized in that a window hole is opened in the insulating film in the middle part of the lead corresponding to the protruding electrode position of the semiconductor chip. 7. In the carrier tape for a semiconductor device according to claim 3, both sides of the elongated tape and a frame perpendicular thereto which separates each set of a plurality of wiring leads from each other are formed of wiring lead material.