JP2000058599A - Manufacture of tab tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correspond to the high density and compactness in size and width of a lead and improve the yield of products by forming a lead pattern in a manner to connect leads mutually in a lead tip part, and cutting the connecting part of the lead tip part to separate every lead individually before connecting them to a semiconductor device. SOLUTION: An adhesives 2 is applied to an insulation film having a device hole, and a copper foil 3 is adhered thereto and a resist layer is provided on its surface. Then a mask is brought closely into contact with the resist layer, and it is exposed and developed. Further, the exposed copper foil part is etched to form a wiring pattern, and the remaining resist layer is removed. The lead tip parts 4 of the wiring pattern are entirely connected mutually, and when connecting them to semiconductor elements, the connection parts of the lead tip part 4 are cut into individual leads. Therefore, no wiring for plating conduction is provided to the periphery part at every lead, so that the density of broken wire can be reduced and a wiring of smaller laying length can be designed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a TAB tape having a small lead deformation and a high lead position accuracy.

[0002]

2. Description of the Related Art A TAB tape is one of the components mounted on a semiconductor device. A conventional TAB tape is obtained by using a copper polyimide film in which a Cu foil having a thickness of 15 to 35 μm is bonded to a polyimide film having a device hole and having a thickness of 50 to 125 μm, and forming a wiring pattern by photo-etching the Cu foil. .

The leading end of each lead portion of this wiring pattern protrudes in a cantilever manner into the device hole. In use, the leading end of each lead is connected to the electrode portion of the semiconductor element at a time or in units of one lead.

[0004] In recent years, there has been a demand for a higher density of a semiconductor element, with a lead width of 20 µm and a lead pitch of 40 µm.
Therefore, such a TAB tape has been actually manufactured. However, in such a TAB tape, the mechanical strength of the lead is remarkably reduced, and damage in the manufacturing process and deformation due to handling and the like are large, resulting in a reduction in product yield.

[0005] In addition, as the wiring pattern becomes higher in density and narrower, "disconnection" and "short" in a peripheral pattern including a lead.
The occurrence rate of so-called "etching failure" such as "residual etching", "missing wiring", and "pinhole" also increases, which also causes a reduction in product yield.

In addition, with the increase in the number of pins and the narrow pitch,
When a TAB tape for high-density mounting manufactured with a conventional lead pitch accuracy of the level of 0 to 15 μm is used, there is a shift between the leads and the electrodes of the semiconductor element, and there is no connection. For this reason, the required pitch accuracy is 5 μm or less. This point also causes a decrease in product yield.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method of manufacturing a TAB tape which can cope with high density and narrow leads and has a high product yield. I do.

[0008]

In order to achieve the above object, the present invention provides a method for manufacturing a TAB tape by photolithography using an insulating film provided with a conductive layer. Is a pattern in which the leads are connected to each other, and the connecting portion at the leading end of the lead is cut off before connecting to the semiconductor element to make each lead independent.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a manufacturing method according to the present invention, when a TAB tape is manufactured by a photolithographic method using an insulating film provided with a conductive layer, a lead pattern of a wiring portion is formed so that a leading end portion of a lead is connected to each other. When connecting to a semiconductor element, the connecting portion at the leading end of the lead is cut to make each lead independent.
This is to secure the strength of the entire lead portion by connecting the individual leads until the final step of manufacturing the TAB tape, and to prevent the leads from being deformed in each step.

In the present invention, a conventional process can be used as it is, except that the mask used is a mask having the shape required by the present invention, and the leads are cut off at the final step to make each lead independent. Specifically, for example, a copper foil is attached to an insulating film having a device hole, a resist layer is provided on the surface thereof, a mask satisfying the requirements of the present invention is brought into close contact with the resist layer, exposed, and developed. Then, the exposed copper foil portion is etched to form a wiring pattern, and the remaining resist layer is removed to obtain a wiring portion.

Thereafter, an insulating film etching resist is applied to the entire surface, exposed using a desired mask, developed, and the exposed insulating film portion is etched to form a via hole. The parts are plated, solder-resisted, and the ends of the leads are cut using a mold or laser light.

In order to obtain a semiconductor device using such a TAB tape, the electrodes of the semiconductor element and the ends of the leads are connected and sealed with a resin, as in the prior art. Such a connection between the semiconductor device and the printed wiring board is made via a solder ball or the like provided in a via hole.

FIGS. 1 and 2 show examples of wiring patterns used in the present invention.
It was shown to. FIG. 1 shows an example in which all the lead ends are connected, and FIG. 2 shows an example in which the lead ends are connected for each side. In any case, since the leading ends of the leads are connected, it is not necessary to arrange the wiring for plating conduction in the periphery for each lead, so that the wiring density can be reduced and the wiring length can be reduced. Design can be shortened.

(Study Example) The present invention will be described below using a study example.

The polyimide film 1 used has a thickness of 125
μm Ube Industries UPIREX S (trade name)
The adhesive 2 used was an X type having a thickness of 12 μm manufactured by Tomagawa Paper Mill, and the copper foil 3 used was a U-SLP manufactured by Nihon Denki having a thickness of 18 μm. A device hole was provided in a polyimide film to which an adhesive was attached, and then this was laminated with a copper foil to produce a copper polyimide substrate. A photosensitive resist is applied to the copper foil surface of this copper polyimide substrate, and the number of leads is 800
A mask pattern designed with a pin-to-lead pitch of 40 μm and a lead width of 20 μm was brought into close contact with the surface of the photosensitive resist layer, exposed and developed. Next, the exposed copper foil portion was removed by etching, and the remaining resist layer was removed to form a wiring portion. At this time, the lead length of the portion that cantilevered into the device hole was set to about 0.5 mm. When the photomask was prepared, as shown in FIG. 2, the tip 4 of the lead was connected to the tip of the lead for each side, and the wiring 5 for plating conduction was arranged for each side. .

Next, a resist for polyimide etching is applied to the entire surface of the substrate, a mask for via holes is closely contacted, exposed, developed, and etched to remove the exposed polyimide portions. The part was plated and subjected to a solder resist treatment. Thereafter, a part of 200 to 300 μm from the innermost part of the lead tip was cut using a mold to obtain a TAB tape a according to the method of the present invention.

Next, as a comparison, a conventional method was used in the same manner as described above, except that a mask pattern designed with a lead number of 800 pins, a lead pitch of 40 μm, and a lead width of 20 μm was used. A TAB tape b according to the above was obtained.

When the product yields of the TAB tape a and TAB tape b were compared, the defect rate of lead deformation was TA
The result of the B tape a was 1/3 or less of the TAB tape b, and the result of the poor etching was 1/4 or less.
Regarding the positional accuracy between the leads, n = 800 for TAB tape b, 1 μm on average, 3 μm for standard deviation,
TAB tape a has an average of 0.2 μm when n = 800,
The standard deviation was 0.7 μm, and it was found that good results could be obtained according to the method of the present invention.

In the present invention, the end-shaped connection pattern is infinite, but the pattern width for connecting the lead end portion is basically about 50 to 200 μm, and finally the cut-off portion for forming the lead is formed. Is preferably 200 to 300 μm from the innermost side of the tip of the lead.

[0020]

According to the present invention, a wiring portion is formed using a pattern in which lead ends are connected, and the connection portion is cut at the end or immediately before mounting a semiconductor chip. The rate of defects such as defects can be reduced, and as a result, the yield can be greatly improved.

Further, the accuracy of the pitch between leads can be ensured,
The yield in assembly can be improved. And
The present invention is extremely effective because it can exert the above effects regardless of the number of lead pins, the pitch between leads, and the lead width.

[Brief description of the drawings]

FIG. 1 is an example of a wiring pattern used in the present invention, which is an example in which all lead ends are connected.

FIG. 2 is an example of a wiring pattern used in the present invention, in which lead end portions are connected for each side.

[Explanation of symbols]

 1 ---- Polyimide film 2--Adhesive 3--Copper foil 4--Lead tip 5--Plating wiring

Claims (1)

[Claims] When a TAB tape is manufactured by a photolithographic method using an insulating film provided with a conductive layer, a lead pattern is a pattern in which a lead end portion is connected to a lead, and a final step or a semiconductor element is formed. A method for manufacturing a TAB tape, comprising cutting a connecting portion of a lead tip portion before mounting to make each lead independent.