JPS5910252A - Flexible tape of film carrier - Google Patents

Abstract

PURPOSE:To obtain a flexible tape of high yield at a low coat by providing a base layer of noble metal on inner leads. CONSTITUTION:Inner leads 2 are formed by photoetching after opening perforation through a polyimide tape 1 and laminating a copper foil. Au plated layer 3 is electrodeposited over the entire surface of patterns including the inner leads. The patterns Au plated except for the inner leads 2 are covered with resist by screen printing, and provided with an Sn plated layer 4. The tape of different kind of plating having the Au plated layer on the other patterns including outer leads 5 is completed by exfoliating the resist. Thus, the simplification of the manufacturing process is enabled, and accordingly a flexible tape of a film carrier of high yield at a low cost can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rose covering ffjK of an inner lead constituting a flexible tape of a film carrier.

For bonding to a semiconductor integrated circuit, a flexible tape (hereinafter simply referred to as "tape") is generally covered with a tin or solder layer (4+f+) over the entire pattern including the in-leads. However, if the outer lead is used in contact with an electronic component, as in the case of "V", if the coating layer is a tin or solder layer, the contact resistance will increase due to wear and the environment, resulting in failure. Therefore, it becomes necessary to use a tape with different multi-layered layers: the outer lead is a layer of precious metals such as Au, A17, PT, etc., and the inner lead is tin and a solder layer (hereinafter referred to as "heterogeneous layer tape"). ), conventional tapes of this type are
As shown in the manufacturing process shown in the figure, the manufacturing process is long (eight steps), which is laborious and expensive, and has the disadvantages of low yield. The present invention solves the conventional drawbacks by providing an underlayer of noble metal on the inner lead, and its purpose is to provide a flexible tape of a film carrier that is inexpensive and has a high yield. The present invention will be described in detail below based on Examples.

Example This example will be explained in the order of the manufacturing process shown in FIG. First, width 35
Tomiho, polyimide tape IVc 10m with a depth of 125μm
Drill a hole at the i+ corner (Fig. 3 - α), then make a hole with a thickness of 35 μm.
Copper foil is laminated to a width of about 7 cm by photo-etching the edges.
Form 12 inner leads 2 of 0 μm (Fig. 3-
b). Next, a gold plating layer 3 is electrodeposited to a thickness of about 05 .mu.m over the entire surface of the pattern including the inner leads (FIG. 3--). Next, the gold-plated patterns other than the inner leads 2 are covered with resin by screen printing (FIG. 3-d). Next, it is immersed in a tin plating solution for several minutes to form a tin plating layer 4 of about 0.5 tz m (FIG. 3-e). Finally, the resist is peeled off using an alkaline aqueous solution with a certain concentration (FIG. 3-f).

In this way, the inner lead has a gold plating layer as a base layer, the surface NK has a tin plating layer, and the other pattern Kl-j including the outer lead 5 is completed, as well as a dissimilar plating tape having a gold plating layer.

FIG. 1 is a schematic diagram of the inner lead of this embodiment, and FIG. 2 is a plan view thereof. Furthermore, the manufacturing process can be reduced by two steps compared to the conventional process (FIG. 5). Like this f
When the tape was bonded with a semiconductor integrated circuit, the bonding strength was 40g/1 inner lead.
Very high values were obtained, and the eutectic state was also good. As seen in the above examples, by destroying the noble metal layer as a base layer on the inner lead, it is possible to simplify the manufacturing process and provide a flexible tape of a film carrier that is inexpensive and has a high yield. Further, in this example, only a gold plating layer was used as the base layer, but if a copper plating layer is further provided, the adhesion of the surface tin plating layer is improved, and a highly reliable flexible tape of a film carrier can be obtained.

[Brief explanation of drawings]

FIG. 1 is a large-scale sectional view of the inner lead of the flexible tape of the film carrier of the present invention. Figure 2 is a sectional view. Figure 3 shows the order of manufacturing steps. FIG. 4 is an enlarged sectional view of the inner lead of the flexible tape of a conventional film carrier. FIG. 5 shows the order of manufacturing steps. 1 is polyimide tape 2 is inner lead 3 is gold plating layer 4 tin plating layer 51-T outer lead or above Applicant Suwa Seikosha Co., Ltd. - Figure P5

Claims (1)

[Claims] A flexible film carrier tape having different coating layers for the inner lead and other parts, characterized in that it has an inner lead coated with a negative metal layer as a base layer and a sparrow layer as the outermost layer. tape.