JPH0629351A - Manufacture of tab tape - Google Patents

Abstract

PURPOSE:To provide a manufacture of a TAB(tape automated bonding) tape in which a conductor pattern having a good precision of dimension is formed even if increasing an area of device hole. CONSTITUTION:Openings 14 for forming a top of a conductor pattern protruding in a device hole are opened with a part of a device hole forming part kept remaining as an auxiliary part 11 in the device hole forming part of a base film 10 in which the device hole is formed. Further, after forming a joint for joining the auxiliary part 11 to the base film body 10, a resist is applied on a metal foil 16 stuck on one side of the base film 10 in which the openings 14 are opened, and patterning and etching are performed, and the conductor pattern is formed. Then, the joint is cut and the auxiliary part 11 is removed and the device hole is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a TAB tape, and more specifically, the tip of a conductive pattern formed on an insulating base film is placed in a device hole formed in the base film. The present invention relates to a method of manufacturing a TAB tape which projects from an inner edge of the device hole so as to be bonded to a mounted semiconductor chip.

[0002]

2. Description of the Related Art TAB tape (Tape Automated Bonding)
Requires wire bonding because the electrodes of the semiconductor chip can be directly electrically connected to an external conductor circuit such as an external connection lead without wire bonding, and a fine conductor pattern can be formed. It is possible to connect more pins than the case. A plan view of such a TAB tape is shown in FIG. The TAB tape 100 shown in FIG.
Device hole 10 opened in a polyimide resin film (hereinafter sometimes referred to as a base film) 106
Conductor patterns 108, 108, ... Are formed so as to surround 2. One end portion (hereinafter, referred to as a tip end portion) of each of the conductor patterns 108 has a device hole 102.
Is a portion that protrudes from the inner edge of and is bonded to the electrode of the semiconductor chip. The other end of each of the conductor patterns 108 is formed so as to straddle the window holes 104 that are opened in all directions. A portion that straddles the window hole 104 is a portion that is connected to an external conductor circuit such as an external connection lead.

The TAB tape 100 shown in FIG.
It is manufactured by the method shown in FIG. First, the adhesive layer 1 on one side
The device hole 102, the window hole 104, and the like are opened in the base film 106 on which 01 is formed [FIG.
(a) (b)]. Next, the copper foil 107 is attached to one surface of the base film 106 having the device holes 102 and the like opened while heating and curing [FIG. 4 (c)]. Further, a resist is applied to the copper foil surface of the copper foil 107 and the film surface of the base film 106 with a roller or the like to form a resist layer 110,
After forming 112 [FIG. 4 (d)], the resist layer 110 formed on the copper foil 107 side is patterned to form the copper foil 107.
Are etched to form the conductor patterns 108 ... The resist layer 112 is a backing resist layer for preventing etching from the film surface side of the base film 106 by the etching solution.

[0004]

According to the method of manufacturing a TAB tape shown in FIG. 4, a TAB tape having a predetermined conductor pattern can be easily manufactured. By the way, recently, along with the increase in size of semiconductor chips due to the demand for thinner semiconductor devices and the like, it has become necessary to increase the area of the device hole of the TAB tape. However, it has been found that as the area of the device hole is increased, the dimensional accuracy of the finally obtained conductor pattern is likely to decrease. Then, the objective of this invention is proposing the manufacturing method of the TAB tape which can manufacture the TAB tape in which the conductor pattern of favorable dimensional accuracy was formed even if the area of a device hole was expanded.

[0005]

Means for Solving the Problems In order to achieve the above-mentioned object, the present inventor has observed in detail the manufacturing process of the TAB tape. As a result, it has been confirmed that heating and heating on a base film having a device hole with an enlarged area. When the copper foil 107 is cured and the copper foil 107 is attached, as shown in FIG.
It was found that the copper foil portion covering the opening of 02 was warped. When a resist is applied to the copper foil 107 in which warpage has occurred by a roller, thickness unevenness is likely to occur in the resist layer 110 as shown in FIG. 5B, so that the dimensional accuracy of the conductor pattern obtained by etching deteriorates. To do. Further, as the area of the device hole increases, the backing resist layer 112 formed on the film surface of the base film is lost during etching, and the etching of the tip of the conductor pattern is promoted, so that the tip of the conductor pattern is tapered. I also learned that is likely to occur. The present inventor, in order to improve the dimensional accuracy of the conductor pattern constituting the TAB tape finally obtained from these findings, prevents the copper foil from warping when the copper foil is attached onto the base film. The present invention has been achieved as a result of the study that it is important to prevent the backing resist layer from being lost.

That is, according to the present invention, the tip of the conductor pattern formed on the insulating base film is bonded to the semiconductor chip mounted in the device hole opened in the base film. When manufacturing a TAB tape protruding from the inner edge of the device hole, the device hole forming part of the base film in which the device hole is formed is left as a part of the device hole forming part as an auxiliary part. One side of the base film in which the opening is opened after forming an opening for forming the tip of the conductive pattern protruding inward and forming a connecting portion connecting the auxiliary portion and the base film main body. On the metal foil attached to
A method of manufacturing a TAB tape is characterized in that a resist is applied, patterning is performed, etching is performed to form a conductor pattern, and then the connecting portion is cut to remove the auxiliary portion to form a device hole.

[0007]

In some cases, the coefficient of thermal expansion of metal foil such as copper foil is higher than that of base film such as polyimide resin film. In this case, when the base film having the device hole opened and the metal foil attached on the base film are heated at the same time, the metal foil is attached more stretched than the base film. At this time, the device hole metal foil covering the device hole can be freely stretched without being restricted by the base film. The expansion of the device hole metal foil becomes large as the area of the device hole increases, and becomes apparent as a warp of the device hole metal foil.
Incidentally, depending on the type of the base film, there is one that shrinks due to heating, and even when such a type of base film is used, the coefficient of thermal expansion of the metal foil described above is larger than the coefficient of thermal expansion of the base film. Similarly, the warp of the device-hole metal foil appears. Further, when the area of the device hole is enlarged, the backing resist is missing during the etching because the holding force of the base film against the backing resist is reduced. In this respect, in the present invention, in the device hole forming portion of the base film,
An opening having a small area is opened while leaving an auxiliary portion in a portion where a tip portion of the conductor pattern protruding into the device hole is formed, and then a metal foil is attached. Therefore, when the metal foil is attached, the opening area of the opening formed in the base film can be made as small as possible, and the opening of the opening covering the opening can be freely heated by heating the metal foil. Since the elongation can be reduced and the holding power of the base film with respect to the backing resist can be improved, it is possible to prevent warping of the metal foil in the opening and lack of the backing resist that occurs during etching.

[0008]

The present invention will be further described with reference to the drawings. Figure 1
FIG. 1A is a process diagram showing an embodiment of the present invention, in which a device hole forming portion of a polyimide resin film (base film) 10 having an adhesive layer 12 formed on one surface thereof has an opening 1
A plurality of openings 4 are formed [Fig. 1 (a) (b)]. The plurality of openings 14 are smaller in area than the area of the device hole in which the total area is formed, and are the openings in which the tips of the conductor patterns protruding into the device hole are formed.
The remaining portion surrounded by the plurality of openings 14 is an auxiliary portion 11 which will be described later, and is connected to the base film body 10 by the connecting portion. Next, a copper foil 16 is laminated on the adhesive layer 12 of the base film 10 and heat-bonded [Fig.
(C)]. At the time of this heating and pasting, since the area of the opening 14 that allows the free extension of the copper foil 16 is small, the free extension of the copper foil covering the opening 14 can be suppressed, and It is possible to prevent the warp of the copper foil from becoming apparent.

Further, a resist layer 18 for forming a conductor pattern is formed on the upper surface of the adhered copper foil 16, and a backing resist layer 20 is formed on the lower surfaces of the base film body 10 and the auxiliary portion 11 [FIG. )]. The conductor pattern forming resist layer 18 and the backing resist layer 20 are
The resist layer can be formed by roller coating, and the copper foil or the like in the opening is not warped and a resist layer having a uniform thickness can be formed. After that, the conductor pattern forming resist layer 18 is patterned, and the copper foil 16 is etched to form a predetermined conductor pattern. In this embodiment, the holding power of the base film with respect to the backing resist layer 20 is higher than the holding power of the base film with the predetermined device holes opened in advance with respect to the backing resist layer 20. Therefore, at the time of etching, it is possible to prevent the tapering phenomenon of the tip portion of the conductor pattern due to the improvement of the circulation property of the etching solution caused by the lack of the backing resist layer 20. Moreover, the conductor pattern forming resist layer 18 can be formed to have a uniform thickness, and the dimensional accuracy of the conductor pattern can be significantly improved in combination with the prevention of the tapering phenomenon.

After the etching is completed, the conductor pattern forming resist layer 18 and the backing resist layer 20 are removed. An intermediate product obtained by removing the resist layer is shown in FIG. In FIG. 2, the rectangular auxiliary portion 11 remains in the central portion of the device hole forming portion forming the device hole. The auxiliary portion 11 is connected to the base film body 10 by the connecting portions 24 formed at the respective corners. Opening 1 along each piece of such auxiliary portion 11
4 are formed, and the tips of the conductor patterns 22 ... Formed by etching the copper foil 16 project into the openings 14. In addition, the intermediate product shown in FIG.
A window hole 21 ... Is opened to the outside of .. and the conductor patterns 22 ... A portion that straddles the window hole 20 is a portion that is connected to an external conductor circuit such as an external connection lead. In addition, wind hall 21
Does not increase the opening area due to an increase in size of a semiconductor chip or the like like a device hole, and even if the window hole 20 is opened when the metal foil 16 is attached,
The dimensional accuracy of the obtained conductor pattern 22 is not reduced. In such an intermediate product shown in FIG. 2, the auxiliary portion 11 can be removed and a device hole having a predetermined area can be opened by cutting the connecting portion 24 for connecting the auxiliary portion 11, and the TAB tape shown in FIG. Can be obtained.
In this embodiment, the connecting portion 2 that supports the auxiliary portion 11
4 are provided at the four corners of the auxiliary portion 11, but the auxiliary portion 11 may be supported by the connecting portions 24 provided at two locations.

Here, a TAB tape having a rectangular device hole with one side of 15 mm opened is manufactured by the method of this embodiment shown in FIG. 1, and the width of the tip of the conductor pattern 22 ... (3σ) was compared with the variation (3σ) in the conductor pattern width on the base film body 10. As a result, the variation (3σ) in the conductor pattern width on the base film body 10 is 100%.
(Index), the variation (3σ) in the tip end width of the conductor patterns 22 ...
It was 8 (index). As described above, according to the manufacturing method of this embodiment, the conductor pattern 2 protruding into the device hole is formed.
.. can be formed with the same precision as the dimensional precision of the conductor pattern on the base film body 10. On the other hand, FIG.
When a TAB tape in which a rectangular device hole of which one piece is 15 mm is opened is manufactured by the conventional method shown in, and the variation (3σ) of the conductor pattern width is similarly investigated, the variation of the conductor pattern width on the base film body ( When 3σ is 100 (index), the variation (3σ) in the width of the tip of the conductor pattern protruding into the device hole is 133.
(Index).

[0012]

According to the present invention, even if the area of the device hole is enlarged, the tip portion of the conductor pattern projecting into the device hole can be accurately manufactured, and the semiconductor chip can be made larger. TAB tape can be manufactured.

[Brief description of drawings]

FIG. 1 is a process diagram illustrating an example of the present invention.

FIG. 2 is a front view of an intermediate product obtained in the process shown in FIG.

FIG. 3 is a front view of a TAB tape finally obtained.

FIG. 4 is a process diagram illustrating a method of manufacturing a conventional TAB tape.

5 is an explanatory diagram illustrating a state of an intermediate product in the conventional method of manufacturing the TAB tape shown in FIG.

[Explanation of symbols]

 10 Base Film 12 Adhesive Layer 14 Opening 16 Copper Foil (Metal Foil) 18, 20 Resist Layer

Claims (1)

[Claims] 1. The device hole of a conductive pattern formed on an insulating base film is bonded to a semiconductor chip mounted in the device hole opened in the base film. When manufacturing a TAB tape projecting from the inner edge, projecting into the device hole while leaving a part of the device hole forming part as an auxiliary part in the device hole forming part of the base film in which the device hole is formed. After opening an opening for forming the tip of the conductor pattern and forming a connecting portion for connecting the auxiliary portion and the base film body, the opening was attached to one surface of the base film. Apply a resist on the metal foil, pattern it, and then etch it to form a conductor pattern. 2. A method of manufacturing a TAB tape, wherein the connecting portion is cut to remove the auxiliary portion to form a device hole.