JPH0449633A - Film carrier tape, semiconductor device, and packaging of semiconductor device - Google Patents

Abstract

PURPOSE:To enable production yield to be enhanced in the packaging process and reliability to be improved without causing outer leads to stop to be parallel each other by providing a cut-out part at a region which is close to the in side of a region to be bonded by using a metal brazing material when performing packaging. CONSTITUTION:A plastic film such as polyimide, epoxy resin with glass, BT resin, and polyester material is formed by using a punching press, etc. A copper film 2, etc., is thermocompressed to a plastic film 1 by using an adhesive. A photoresist film is formed and an etching mask 5 is formed by using the photolithography method. A copper film is dissolved and eliminated from a region which is not covered with the etching mask 5, thus forming the metal film 2. Then, a cut-out 23 is formed in a region of the metal film 2 where an outer lead is cut late by using the forming press, etc., or the photolithograthy method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in film carrier tapes, improvements in semiconductor devices, and improvements in methods for mounting semiconductor devices.

In particular, improvements are being made to film carrier tapes used in mounting methods using the TAB method (tape automated bonding method) for semiconductor devices with a large number of pins, and improvements to semiconductor devices to which the above film carrier tapes are attached. The present invention relates to an improvement and an improvement in a method for mounting the improved semiconductor device on a printed circuit board or the like.

[Prior Art] As semiconductor devices become more highly integrated, the number of bins has increased in recent years, and multi-pin semiconductor devices having pins of 200 bins or more are also in practical use. In such multi-pin semiconductor devices, it is no longer always easy to use the wire bonding method that has been widely used in the prior art.

Therefore, a semiconductor device mounting method (TAB method) was developed based on the bonding concept using pads or a combination of pads and bumps.

The member used in this TAB type semiconductor device mounting method is a film carrier tape, and this film carrier tape has conventionally been roughly classified into one-layer tape, two-layer tape, and three-layer tape.

Single-layer tape is made of a copper plate, etc., with roughly the same shape as the conventionally used lead frame (however, it generally lacks a chip holder), and is manufactured using an etching process. .

The two-layer tape is made of polyimide, glass epoxy resin,
It is a laminate of a plastic film such as BT resin or polyester material and a copper film, and the view seen from the copper film side is as shown in Figure 9A, and the BB cross-sectional view is as shown in Figure 9B. In Figure 0, numeral 1 is a plastic film, and as is clear from the figure, a rectangular opening 12 is formed in the center, and a second strip-shaped opening 14 is formed around this opening 12. has been
The plastic film 1 in the area sandwiched between these two openings 12 and 14 is supported by the external plastic film 1 by connecting bands 13 provided at the four corners of the rectangle. Although the plastic film l has a width (width in a plan view) of several tens of meters, the length is generally about 20 m long, so the sprocket holes, etc. shown with 1] in the figure are provided and are fed sequentially using sprockets or the like. 2 is a needle-like member such as a copper film, and a portion 21 protrudes into the opening 12.
becomes an inner lead, and the portion 22 of the second opening 14 becomes an outer lead (pin).

In order to manufacture a film carrier tape according to the prior art having a shape as shown in 2, taking a three-layer tape as an example, (a) first, a plastic film 1 having the above shape is formed using a punching press or the like. (C) The molded plastic film 1 (previously coated with adhesive) and the copper film with the excess area cut off are bonded together by thermocompression, and (C) a photoresist film (not shown in the figure) is applied on both sides. 2) is exposed using a photomask having the same shape as shown at 2 in FIG. 9A, and then developed to produce an etching mask. Leave the copper film only in the area with the same shape as shown in , dissolve and remove the copper film from other areas, (d) dissolve and remove the used photoresist, and (e) remove the copper film on the remaining copper film 2. After applying nickel plating as a base, it is completed by plating with gold, tin, etc.

The two-layer tape has almost the same shape as the three-layer tape, but the difference is that the plastic film and copper film are directly attached without using an adhesive.

In any case of the above-mentioned one-layer film, two-layer film, or three-layer film, in order to attach a semiconductor device chip to the film carrier tape, a pad 31 is provided on the front or back surface as shown in the cross-sectional view in FIG. A bump 32 is formed on each pad 31 of the semiconductor device chip 3 (or a bump 32 is formed on the tip of the inner lead 21), and the semiconductor device chip 3 is attached to the film carrier tape via the bump 32. Thereafter, as shown in FIG. 1, the semiconductor device is sealed using, for example, a plastic package 33, and a packaged semiconductor device is manufactured.

Next, in order to mount the packaged semiconductor device manufactured as described above on a printed circuit board, etc., (a) 12th
As shown in the figure, after separating the outer lead (pin) 22 from the outer circumferential portion, (b) a metal brazing material 42 such as solder
Using a welder, the tips of the outer leads 22 are welded to the printed wiring 41 formed on the surface of the printed circuit board 4, resulting in the state shown in FIG. 13.

[Problem to be solved by the invention]

TAB made using the above film carrier tape
In this method of mounting semiconductor devices, the outer leads that are parallel to each other may no longer be parallel to each other during mounting, and may sometimes come into contact with each other and cause a short circuit, reducing the manufacturing yield of semiconductor devices and reducing reliability. It was difficult to avoid the disadvantage that it would lead to a decline in sexual performance.

An object of the present invention is to eliminate this drawback, and in a TAB type semiconductor device mounting method using a film carrier tape, the outer leads do not become parallel during mounting, and as a result, the semiconductor It is an object of the present invention to provide a film carrier tape, a semiconductor device, and a method for mounting a semiconductor device, which have the advantages of improved device manufacturing yield and improved reliability.

[1III! Among the above objects, the first object (film carrier tape) is to provide an opening in the area where the semiconductor device chip (3) is disposed, as shown in FIGS. 1a and 1b. A plurality of metal wires (2) are attached to one side of the plastic film (1) on which (12) is formed, and one end (21) of the metal wires (2) is connected to the opening (12). a notch (23) protruding towards the interior of the metal wire (2) and the plastic film (1) in an area spaced a certain distance outwardly from the opening (12); is provided, said metal wire (2) and said plastic film (1) being achieved by a film carrier tape which is adapted to be cut along said notch (23). Ru.

In addition, the above-mentioned first object (film carrier tape) is based on the above-mentioned configuration as shown in Fig. 1c, but in addition to this, the above-mentioned opening (12) is rectangular, Each of the plurality of metal wires (2) is connected to the opening (
A second opening (14) extending in a direction perpendicular to the side of the plastic film (12) extends from the area of the cut (23) toward the opening (12). ) is also achieved by a film carrier tape provided with a

Among the above objectives, the second objective (semiconductor device) is the fifth objective.
As shown in the figure, a pad (31) of a semiconductor device chip (3) is attached to the one end (21) of the metal wire (2) of the film carrier tape according to claim [1] or [21]. ) is achieved by the connected semiconductor device.

Further, the second object (semiconductor device) is, as shown in FIG. The pad (21) of the semiconductor device chip (3) is connected to one end (21) of the
31) is connected, the metal wire (2) can be cut along the notch (13), and the semiconductor device chip (3) is connected to the package (33). ) can also be achieved by a semiconductor device encapsulated in a.

Among the above objects, the third object (method for manufacturing a semiconductor device) is to produce the film carrier tape according to claim [1] or [2], as shown in FIGS. 7 and 8. The pad (31) of the semiconductor device chip (3) is connected to the one end (21) of the metal wire (2), the semiconductor device chip (3) is enclosed in a package (33), and the metal wire ( Area (22) near the inner end of the notch (23) in 2)
This is achieved by connecting the printed wiring (41) of the printed circuit board to and cutting the metal wire (2) along the notch (23).

[Effect]

The problem that the present invention aims to solve arises because the outer lead 22, which is made of an extremely thin metal needle, does not have a fixed support. However, in the film carrier tape according to the present invention, the outer leads 22 are integrated with the plastic film until the semiconductor device is mounted on the printed circuit board etc. 4 and the outer leads 22 are fixed to the printed wiring etc. 41 of the printed circuit board etc. 4. Since the semiconductor device is mounted on the printed circuit board etc. 4 and the outer leads 22 are fixed to the printed wiring etc. 41 of the printed circuit board etc. 4, the outer leads 22 are accurately parallel to each other. They are held in place, and there is no risk of them coming into contact with each other and causing a short circuit. Furthermore, a notch 23 is provided on the outside of the area to be soldered, making it extremely easy to solder after soldering is completed. Since it can be cut out, the above-mentioned drawbacks are eliminated without any disadvantages.

Next, in order to mount the semiconductor device, in which the semiconductor device chip is attached to the above-mentioned improved film carrier tape, on a printed circuit board, etc., it is done in exactly the same manner as above, so that the outer leads 22 are mounted on the printed circuit board, etc. 4. Until the outer lead 22 is fixed to the printed wiring etc. 41, the outer lead 22 is fixed integrally with the plastic film.
Similarly to the above, there is no risk of the outer leads 2 coming into contact with each other and causing a short circuit. Moreover, since the notch 23 is provided on the outside slightly in the area where the soldering is to be performed, the soldering After completion of the process, it can be cut away very easily and the above-mentioned drawbacks are eliminated without any disadvantages.

〔Example〕

Hereinafter, with reference to the drawings, a film carrier tape according to an embodiment of the present invention, a semiconductor device having this film carrier tape, and a method of mounting a semiconductor device using this film carrier tape on a printed circuit board will be described. explain.

In order to simplify the explanation, the explanation will be based on a three-shoulder tape, but the other cases are also substantially four-shoulder tapes.

2. Using a punching press or the like, a plastic film made of polyimide, glass-containing epoxy resin, BT resin, polyvarnish material, etc. is molded into the shape shown in the figure. The reason these resins are used is that they have good thermal and mechanical properties.In Figure 0, 1 is a plastic film with a thickness of 75 to 125 nm, 1] is a sprocket hole, 12 is a square opening, 14 is a second opening provided slightly apart from the square opening 12, and the plastic film 1 in the area sandwiched between the openings 12 and 14 is in the square opening It is supported by connecting bands 13 provided at the four corners.

A copper film or the like having a thickness of 15 to 50 nm is thermocompression bonded to the plastic film 1 using an adhesive.

The thickness of the adhesive remaining after bonding is 15 to 25 nm.

In the case of a two-layer tape, the copper film is directly attached to a plastic film having a thickness of 15 to 75 nm.

Referring to FIG. 3, a photoresist film is formed and removed using photolithography from areas other than the area indicated by 2 in FIG. 1C to form an etching mask 5.

Referring to FIG. 4, the copper film is dissolved and removed from the area not covered by the etching mask 5 using a weak acid or the like to form the metal film 2 shown in the figure. In addition, the photoresist 5 is shown in the figure.
is removed.

Next, using a molding press or the like, or again using photolithography, a cut 23 is formed in the area of the metal film 2 where the outer lead will be cut away in the future.

Refer to FIG. 1C Through the above steps, the film carrier tape according to the illustrated embodiment of the present invention (corresponding to claim 2) is completed.

Referring to FIG. 5, a bump 32 is formed on each pad 31 of the semiconductor device chip 3 on which the pad 31 is grown on the front or back surface (or a bump 32 is formed on the tip of the inner lead 21), and a bump 32 is formed on the tip of the inner lead 21. Then, the semiconductor device chip 3 is attached to the film carrier tape.

Refer to FIG. 6. For example, a plastic package 33 is used to seal and manufacture a packaged semiconductor device.

Through the above steps, a semiconductor device according to an embodiment of the present invention (corresponding to claim 4) is completed.

Referring to FIG. 7, the notch 23 of the outer lead 22 of the semiconductor device manufactured by the above process is placed on the printed circuit board 4 on which the printed wiring 41 is formed.
The semiconductor device is fixed to the printed circuit board 4 by using a soldering tool or the like to fix the innermost area of the semiconductor device.

Referring to FIG. 8, the film carrier tape is then cut out at the notch 23 to complete the semiconductor device mounting process. In order to facilitate cutting of the film carrier tape, the four corners of the film carrier tape may be cut off from the beginning.

〔Effect of the invention〕

As explained above, the film carrier tape according to the present invention has a notch in the innermost area of the area that will be bonded using a metal brazing material etc. when the semiconductor device in which the film carrier tape is used is mounted in the future. Because of this, the mounting process can be carried out with the outer region of the outer lead that will be removed in the future attached, and the outer lead portion, which has many pins and is therefore in the form of extremely fine metal needles, is parallel to each other. Therefore, there is no fear that the outer lead portion will cause defects such as short circuits. Therefore, semiconductor devices using the film carrier tape according to the present invention have a high manufacturing yield and reliability in the mounting process. will improve.

[Brief explanation of the drawing]

FIG. 1a is a perspective view of the film carrier tape according to the invention from the metal wire (copper film) side. FIG. 1b shows A of the film carrier tape according to the invention.
-A sectional view. FIG. 1c is a diagram of a film carrier tape according to an embodiment of the present invention viewed from the metal wire (copper film) side. FIG. 2 is a diagram of a manufacturing process for a film carrier tape according to an embodiment of the present invention (a diagram of the completed process of forming slits in a plastic film). FIG. 3 is a manufacturing process diagram (after formation of a photoresist film for forming a mask for copper film etching) of a film carrier tape according to an embodiment of the present invention. FIG. 4 is a manufacturing process diagram (after completion of the copper film forming process) of a film carrier tape according to an embodiment of the present invention. FIG. 5 is a manufacturing process diagram of a semiconductor device according to an embodiment of the present invention (after bonding a semiconductor device chip to a film carrier tape). FIG. 6 is a manufacturing process diagram (after completion of packaging) of a semiconductor device according to an embodiment of the present invention. FIG. 7 is a process diagram of a mounting process of a semiconductor device according to an embodiment of the present invention (after completion of bonding with a printed circuit board). FIG. 8 shows step V! of the semiconductor device mounting process according to an embodiment of the present invention. J (completed drawing). FIG. 9A is a diagram of a film carrier tape according to the prior art seen from the metal wire (copper film) side. FIG. 9B is a BB sectional view of a film carrier tape according to the prior art. FIG. 10 shows a semiconductor mounted on a film carrier tape according to the prior art! It is a diagram showing bonding of chips. FIG. 1 is a diagram showing a state in which a semiconductor device chip is bonded to a film carrier tape according to the prior art and then encapsulated in a package. FIG. 12 is a diagram showing a conventional film carrier tape in which unnecessary outer leads of a packaged semiconductor device are further cut away. FIG. 13 is a diagram in which a semiconductor device having a film carrier tape according to the prior art is mounted on a printed circuit board. 22. . . . Plastic film, sprocket hole, opening in plastic film, connecting band in plastic film, second opening in plastic film, metal wire (copper film), one end of metal wire (copper film) (tip of inner lead) )
, the other end of the metal wire (W4 film) (the tip of the outer lead), 3... semiconductor device chip, 31... pad of semiconductor device chip, 32... bump, 33... package, 4... - Printed circuit board, 41...Tab of printed circuit board, 42...Metal brazing material such as solder, 5...Photoresist. Figure 1a

Claims (1)

[Claims] [1] A plastic film (1) in which an opening (12) is formed in a region where a semiconductor device chip (3) is disposed.
A film carrier tape comprising a plurality of metal wires (2) adhered to one surface of the film carrier tape, one end (21) of the metal wires (2) protruding toward the inside of the opening (12), The metal wire (2) and the plastic film (1) are provided with a notch (23) in a region spaced a certain distance outward from the opening (12), and the metal wire (2) ) and the plastic film (1) can be cut along the cut (23). [2] The opening (12) is rectangular, each of the plurality of metal wires (2) extends in a direction perpendicular to the sides of the opening (12), and the plastic film (1) includes:
The film carrier tape [3] according to claim [1], characterized in that a second opening (14) is provided from the region of the cut (23) toward the opening (12). A pad (31) of a semiconductor device chip (3) is connected to the one end (21) of the metal wire (2) of the film carrier tape according to item [1] or [2]. Semiconductor equipment. [4] A pad (31) of a semiconductor device chip (3) is connected to the one end (21) of the metal wire (2) of the film carrier tape according to claim [1] or [2], A semiconductor device characterized in that the semiconductor device chip (3) is enclosed in a package (33). [5] In the semiconductor device according to claim [3] or [4], printed wiring (
41), and cutting the metal wire (2) along the notch (23).