JPH02189943A - Base material for tab tape carrier - Google Patents

Abstract

PURPOSE:To improve migration resistance to copper under high-temperature conditions, and to reduce the deterioration of a copper layer by forming a specific foundation layer between a resin board and a copper or copper alloy layer lead layer. CONSTITUTION:A base material is composed of a polyimide group resin board such as a polyimide film 13, foundation layers 12 shaped onto one surface or both surfaces of the resin board and copper or copper alloy layers 11 formed onto the foundation layers 12. A barrier layer having at least one selected from a group consisting of nickel, chromium and titanium is used as the foundation layer 12. Accordingly, the foundation layers 12 are formed, thus acquiring a multiple-pin TAB(Tape Automated Bonding) tape carrier in which copper and a polyimide are not reacted, even under a high-temperature state, the migration of copper is not generated and the pitches of inner leads are narrowed by employing the base material for the TAB tape carrier and an area TAB tape carrier.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a base material for a TAB tape carrier, and particularly to a base material in which copper foil serving as a lead portion does not deteriorate even under high temperature conditions.

<Prior art and its problems> Automation is being attempted in semiconductor element mounting technology to mass-produce products with performance above a certain level at high speed.

One of the semiconductor element mounting techniques developed for the purpose of this automation is to incorporate semiconductor elements into a long tape carrier by wireless bonding.
There is a (Tape Automated Bonding) method.

In this TAB, as shown in FIG. 5, a device hole 7 is made in the approximate center of the tape carrier, a semiconductor element 9 is installed in this device hole 7, a bump electrode 10 is provided, and a tape corresponding to this bump is provided. After heat-compression bonding with the inner reel 6 of the carrier using a honding tool,
The sealing area 8 is sealed with insulating fluid resin.
The process of forming a surface and then applying a surface protective coating is carried out continuously.

In recent years, however, a new TAB shape has been proposed, known as the so-called area TAB package.

The area TAB package, for example, has the structure of an area TAB package 20, which is not shown in cross section in FIG. Also, FIG. 4 shows the area TA for this area TAB.
An example of a B tape carrier 1 is shown in a plan view.

As shown in FIGS. 3 and 4, in the area TAB, the element 9 is electrically connected to the inner REIT 6 provided on the film 2 in a face-down state via the electric wire 10. A square hole 4 is made in the film 2 directly below the mounting part of the element f9. This square hole is not a space for mounting the element 9 like the device hole 7 of the conventional TAB package 21 shown in FIG.
This is provided for the purpose of alleviating the stress generated by temperature cycles due to the difference in thermal expansion coefficient between the package and the package, and also for dissipating heat from the bottom of the package.

This structure consists of ■ pasting copper foil on the device hole in advance;
There is no need to open your mouth before using it.

■Since there is no positional change or deformation of the inner REIT, there are advantages such as easy formation of multiple bins.

For this reason, the structure of the conventional TAB package 21 shown in FIG.
On the other hand, in the area TAB shown in Fig. 4, the pitch limit of the inner lead 6 is 0.050 mm.
It is believed that B tape carriers can be easily formed.

However, this area TAB has the following major problems. A cross-sectional view of the conventional film 2 is shown in FIG.
When pasting on polyimide film 13, adhesive 1
4 is required, and this adhesive 14 usually contains many impurities, and in the case of multi-bin TAB packages, especially at high temperatures (
Under conditions (100°C or higher), there is a risk that this impurity will cause copper migration and cause a short circuit between the inner leads.

■There is a manufacturing limit to the thickness of the copper or copper alloy layer 11, so 0.
020mm is the limit. Therefore, the pitch between the inner leads is considered to be at the limit of 0,060 mm.

In order to solve these problems, so-called adhesive-free TAB tape carrier materials have been developed in which steel is directly coated on a film by electroless plating or vacuum deposition.

However, under high temperature conditions, for example at temperatures above 100° C., the polyimide of the film resin reacts with the copper to form a chelate compound, which causes the problem that the copper is eroded and deteriorated.

<Problems to be Solved by the Invention> An object of the present invention is to provide a TABAB tape carrier material that does not cause migration of copper constituting an inner lead even in a high-temperature environment, and does not cause short circuits between inner leads or other quality deterioration. It is in.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides a polyimide resin substrate, and at least one material selected from the group consisting of nickel, chromium, and titanium provided on one or both sides of the resin substrate. A TA characterized in that it has a base layer having one layer and a copper or copper alloy layer provided on the base layer.
Provides BAB tape carrier material.

Here, the thickness of the base layer is 0.001 to 3.0 μm, and the thickness of the steel or copper alloy layer is 0.0 μm.
．． The preferred thickness is 5 to 10 μm.The present invention will be described in detail below.

As shown in a cross-sectional view of a preferred embodiment in FIG. 1, the base material for a tape carrier of the present invention comprises a polyimide resin substrate such as a polyimide film 13, and a base layer 12 provided on one or both sides of the resin substrate. , a copper or copper alloy layer 11 provided on the base layer 12.

The polyimide resin substrate is a resin substrate mainly made of polyimide resin, and preferably a polyimide film 13 or the like is used, but is not particularly limited.

A base layer 12 is provided on the resin substrate.

The base layer 12 is a barrier layer containing at least one selected from the group consisting of nickel, chromium, and titanium. Nickel, chromium, and titanium may be used alone, or may be used as an alloy layer of these materials, or may contain a small amount of other components as long as the object of the present invention is not impaired.

This base layer does not react with the polyimide resin even at high temperatures (approximately 400° C.) and serves as a barrier layer, so that the copper or copper alloy layer that is the lead portion provided thereon becomes stable.

The thickness of the base layer 12 is preferably 0.01 to 3.0 μm. If it is less than 0.01 μm, the barrier layer will not be effective, and if it exceeds 3.0 μm, the unit cost of the component will increase.

A copper or copper alloy layer 11 is provided on the base layer 12.

When these are mounted as a tape carrier, they are patterned by photolithography (photochemical etching) or the like to become lead portions.

The thickness of the copper or copper alloy layer 11 is preferably 0.5 to 10 μm. This is because within this range, it is easy to form a multi-pin lead portion.

The base layer 12 and the copper or copper alloy layer 11 may be provided on one side or both sides of the polyimide film 13.

Since the base material of the present invention has the base layer 12, when used in a TAB tape carrier or an area TAB tape carrier, copper and polyimide do not react even under high temperature conditions, and copper migration does not occur, so the inner lead pitch is narrow. A pin TAB tape carrier is obtained. Particularly when used in area TAB tape carriers, there is no positional variation or deformation of the inner leads, so the pitch limit is, for example, 0.
An area TAB tape carrier of 0.050 mm is obtained.

<Example> Hereinafter, the present invention will be specifically explained with reference to Examples.

(Example 1) On the surface of a polyimide film with a thickness of 75 μm and a width of 300 mm, 0.3 μm of chromium was applied as a base (barrier) layer by vacuum deposition, and 5.0 μm of copper was applied thereon by vacuum deposition. A base material for a TAB tape carrier was prepared.

This film was cut into 8 pieces of 35mm wide film, and then photolithography (photochemical etching) was performed to create a 200-pin TAB (area TAB) with a pitch of 0.050mm.
AB) was produced. Before photochemical etching, a square hole with a diameter of 5.0 mm was opened just below the element mounting part of the tape. This square hole is not meant to be a device hole as in conventional TAB packages, but is used to relieve stress caused by temperature cycles due to the difference in thermal expansion coefficient between the polyimide film and the element when an element is bonded directly above it in a face-down state. , provided for the purpose of heat radiation from the bottom.

(Example 2) In Example 1, vapor deposition was performed on both sides. The advantages of this case include that the film is less likely to warp due to the difference in thermal expansion coefficients between copper and polyimide because it is vapor-deposited on both sides, and that elements can be mounted on both sides.

Example 3 An area TAB tape carrier was fabricated using the same process as in Example 1, but with titanium applied to the barrier layer.

(Example 4) An area TAB tape carrier was manufactured using the same process as in Example 1, except that nickel was applied as a barrier layer.

(Comparative Example 1) An area TAB tape carrier was manufactured using the same process as in Example 1, but without providing a barrier layer.

(Comparative Example 2) 100 having an adhesive layer shown in FIG. 2 by a conventional method
We made a prototype of 200-bin TAB for μm bit. Example 1
Using the same polyimide film as used in the conventional method, the thickness of commercially available copper foil is at least 25 μm, so it is similar to this, and the polyimide side is treated with a 20 μm thick epoxy thermosetting adhesive to form a laminate. I used a different one.

Migration Test Figure 6 shows the results of a migration test in which the inter-pattern surface resistance was measured when a bias voltage was applied after a test in which the TAB tape carriers of Example 1 and Comparative Example 1.2 were held at 150°C for different high-temperature holding times. show. In the case of Comparative Example 12 without a barrier metal layer, copper is corroded at high temperatures and the surface resistance of the polyimide decreases, making migration more likely to occur.

Further, when a fine pattern was produced by photolithography using the same base material of the present invention as in Example 1, 0.03
It was possible to create a bit spacing of mm. On the other hand, when a similar pattern was created using the laminate material having an adhesive layer used in Comparative Example 2, the limit was 0.06 mm.

<Effects of the Invention> Since the TAB tape carrier base material of the present invention has a specific underlayer between the resin substrate and the copper or copper alloy layer, when a TAB tape carrier is created using this, A TAB package with improved reliability can be obtained because the migration resistance against the copper under the high-temperature strip 1 is high and there is little deterioration of the copper layer due to the reaction between copper and polyimide.

In particular, when using an area TAB tape carrier, the pitch between the edges can be made very small, which improves migration resistance against copper, making it possible to create a fine area TAB package.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the base material for a TAB tape carrier of the present invention. FIG. 2 is a sectional view showing a conventional base wing for a tape carrier. FIG. 3 is a cross-sectional view without showing the area TAB package. FIG. 4 is a plan view showing the area TAB tape carrier. FIG. 5 is a sectional view showing the TAB package. FIG. 6 is a graph showing the results of the migration resistance test. Explanation of symbols 1...Area TAB tape carrier, 2...Film, 3...Pilot hole, 4...Square hole, 6...Inner Lee I~, 8...
...Sealing area, 9...Element, 10...Electrode, 11...Copper or copper alloy layer, 12...Underlayer, 13...Polyimide film, 14...Adhesive, 20 ...Area TAB package, 21...TAB package

Claims (2)

[Claims] (1) A polyimide resin substrate, a base layer provided on one or both sides of the resin substrate and having at least one selected from the group consisting of nickel, chromium, and titanium, and a copper base layer provided on the base layer. Alternatively, a base material for a TAB tape carrier, characterized by having a copper alloy layer. (2) The base material for a TAB tape carrier according to claim 1, wherein the base layer has a thickness of 0.01 to 3.0 μm, and the copper or copper alloy layer has a thickness of 0.5 to 10 μm.