JP2929882B2 - Carrier tape for semiconductor device and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrier tape for a semiconductor device and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, carrier tapes used in this type of tape carrier package (TCP) can be roughly classified into three types, namely, a carrier tape, a two-layer carrier tape and a three-layer carrier tape, depending on the structure thereof.

A single-layer carrier tape has a sectional structure as shown in FIG. 4, and is manufactured by forming a wiring pattern 4 by etching a copper foil on both sides. The general manufacturing process excluding the plating process is very simple as shown in FIG. 6A, and a carrier tape can be manufactured at a low cost. On the other hand, all the patterns are connected to maintain the pattern. The semiconductor device must be assembled as it is, and there is a fatal disadvantage that an electrical characteristic test cannot be performed during the process.

The two-layer carrier tape has a sectional structure similar to that shown in FIG. 1, and two types of manufacturing methods shown in FIGS. 7A and 7B are well known. FIG. 7A shows 3M in the United States.
A thin copper layer is formed by sputtering on the surface of polyimide (mainly Kapton manufactured by DuPont) of about 100 μm as a base film, and a photosensitive resist is applied to both sides of the film. After the exposure and the phenomenon, first, a pattern is formed on the thin copper layer by electrolytic copper plating using the thin copper layer provided by sputtering as a current path. Further, the polyimide of the base film on the back side is etched using an alkaline etching material such as hydrazine or potassium hydroxide to form device holes, outer lead bonding (OLB) holes, and the like. Thereafter, the resist is removed, and the thin copper layer used as a current path is removed by etching.

FIG. 7B is also used by 3M Company in the United States and is known as a method for manufacturing not only a carrier tape but also a flexible substrate. In this method, a polyimide varnish, which is a polyimide precursor, is applied to the entire surface of a copper foil and heated to form a polyimide base film layer. Thereafter, as in the method of FIG. After applying a photosensitive resist and exposing and developing a phenomenon, pattern formation by copper foil etching and formation of device holes and OLB holes by polyimide etching are performed. Further, it is obtained by removing the resist.

[0006] Unlike the three-layer tape described below, such a two-layer carrier tape has no adhesive layer between the copper wiring pattern and the polyimide base film. Such as high insulation resistance in a high temperature environment or excellent bending resistance. On the other hand, since the photolithography process of exposure, phenomena, and etching using a photosensitive resist is performed on both sides of the film, there is a problem that the manufacturing process is complicated and the fabrication cost is increased.

As shown in FIG. 3, the cross-sectional structure of the three-layer carrier tape is such that the base film layer 9 and the wiring pattern 1 are bonded by an adhesive layer 8. As shown in FIG. 6 (b), a method of manufacturing such a three-layer carrier tape is such that device holes, OLB holes, sprocket holes, and the like are formed on a base film coated with a thermosetting adhesive. It is formed by punching with a mold. Thereafter, the copper foil is superimposed on the base film and bonded by applying pressure and heat to laminate. Thereafter, a photosensitive resist was applied to the copper foil surface, and a resist was applied to openings such as device holes on the base film surface, and the photosensitive resist on the copper foil surface was exposed and developed to form a copper foil wiring pattern. Thereafter, the resist is obtained by removing the resist.

The three-layer carrier tape has a high degree of freedom in the base film material because an opening is formed in the base film by mechanical processing, and the manufacturing process is simplified because the photolithography process is performed only on the copper foil side. Therefore, there is an advantage that the manufacturing cost can be kept low.

[0009]

Among these carrier tapes, the generally widely used two-layer and three-layer carrier tapes are obtained by chemically and mechanically processing the base film, so that the base film material itself is not processed. There is a loss,
Further, there is a limit to the processing accuracy due to the processing method.

Therefore, in a two-layer / three-layer carrier tape,
There is a problem that the degree of freedom in designing the opening of the base film that functions as the insulating support of the wiring pattern in the carrier tape is low.

[0011]

A carrier tape for a semiconductor device according to the present invention has a wiring pattern of a copper foil and a base film layer formed by a screen printing method for holding the wiring pattern.

Further, the present invention relates to a method for manufacturing a carrier tape used in a semiconductor device, wherein a copper foil is first screened.
Base film layer with required pattern
Then, the photolithography process to the copper foil
It is characterized in that a wiring pattern is formed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 shows a cross-sectional structure of a carrier tape according to a first embodiment of the present invention, which has the same structure as a two-layer carrier tape. 1 is a wiring pattern of copper foil, 3 is a base film layer formed by a screen printing method, 2 is an inner lead, 4 is a sprocket hole, 5 is a device hole,
6 is an OLB hole and 7 is an outer lead. Such a structure can be obtained through a manufacturing process as shown in FIG. First, a polyimide varnish (for example, SPI-200N of Nippon Steel Chemical Co., Ltd.) is printed on a copper foil in a required pattern by screen printing. Heat for more than 10 minutes and 40
Heat to about 0 ° C. and cure for 1 to several hours. Note that these heating steps are desirably performed in an inert atmosphere to prevent oxidation of the copper foil. After that, a photosensitive resist is applied to the surface of the copper foil and a resist is applied to the part without the polyimide pattern on the back surface in the same manner as in the manufacturing process of the three-layer carrier tape. It is obtained by doing.

In this case, the ratio of the thickness of the copper foil serving as the wiring layer to the thickness of the polyimide serving as the base film layer of the carrier tape after completion of the curing is about 2: 1 to 1: 1. Good results were obtained in the yield. The processing limit of the base film at this time is 50
It turned out that about 100 μm can be obtained for a base film thickness of μm.

FIG. 2 is a sectional structural view of a carrier tape according to a second embodiment of the present invention. In the present invention, a polyimide pattern 3 'is formed by screen printing on the surface of the device hole 5 on which the semiconductor element is mounted,
The other base film layer 9 and the wiring pattern 1 have a three-layer carrier tape structure bonded by an adhesive layer 8. This is similar to what 3M manufactures with a two-layer carrier tape structure and calls it an area tape.
Such a structure is obtained by a manufacturing process as shown in FIG.

[0016]

As described above, according to the present invention, since the patterning of the base film is formed by the screen printing method, the processing limit of the pattern formation is almost governed by the accuracy of the screen printing mask. This has the effect that the degree of freedom in pattern design of the base film is significantly higher than in the manufacturing method.

[Brief description of the drawings]

FIG. 1 is a sectional view of a carrier tape according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a carrier tape according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a conventional three-layer carrier tape.

FIG. 4 is a sectional view of a conventional one-layer carrier tape.

FIGS. 5A and 5B are first and second views of the present invention, respectively.
It is a figure which shows the manufacturing process of Example of this.

FIG. 6A is a diagram illustrating a manufacturing process of a single-layer carrier tape, and FIG. 6B is a diagram illustrating a manufacturing process of a three-layer carrier tape.

FIGS. 7A and 7B are diagrams illustrating a manufacturing process of a two-layer carrier tape.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Wiring pattern 2 Inner lead 3,3 'Base film layer formed by screen printing method 4 Sprocket hole 5 Device hole 6 OLB hole 7 Outer lead 8 Adhesive layer 9 Base film layer

Claims (2)

(57) [Claims] 1. A required pattern is formed on a copper foil by a screen printing method.
To form a base film layer, followed by photolithography.
A method of manufacturing a carrier tape for a semiconductor device , comprising forming a wiring pattern on the copper foil by a luffing process . 2. A wiring pattern of a copper foil and a required pattern entirely formed by a screen printing method to hold the wiring pattern.
The semiconductor device carrier tape, characterized in that it comprises a base film layer over emissions.