JPH0493040A - Film carrier tape - Google Patents

Abstract

PURPOSE:To accurately bond a pad on a printed-circuit board or the like to a lead of a semiconductor chip by a method wherein a base film constituting a film carrier tape has a structure in which an insulating film and a metal foil are included. CONSTITUTION:A base film 10 constituting a film carrier tape has a structure in which a metal foil 3 of, e.g. copper or the like is included in its central part and in which polyimide layers 1 are bonded to its upper part and its lower part by using an adhesive 2A of, e.g. an epoxy resin. A metal foil 4 which forms a lead part is bonded to the base film 10 via an adhesive 2 by a treatment such as a lamination treatment or the like. Thereby, the film carrier tape is constituted. When the metal foil 4 of Cu or the like is formed in the central part and an IL bonding operation is executed, the heating shrinkage amount of the film carrier tape by heat is only the influence by the adhesives 2, 2A and its heating shrinkage can be reduced to about 0.01 % or lower.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a film carrier tape, and in particular to the structure of a base film.

[Conventional technology]

As shown in the plan view of FIG. 4 and the cross-sectional view of FIG. 5, the conventional film carrier tape is made of a polyimide layer having sprocket holes 5 for conveyance and positioning and device holes 6 that are openings for semiconductor chips. A first grade insulating film is used as a base film, and a metal foil 4 made of copper or the like is adhered to the base film using an adhesive 2. The metal foil is etched to form inner leads 4A, outer leads 4B and electrically selected shapes into desired shapes. A pad 8 is formed for this purpose. Then, these leads and bumps, which are metal protrusions provided in advance on the electrode terminals of the semiconductor chip, are bonded to inner leads (hereinafter referred to as IL) using a thermocompression bonding method or a eutectic method.
The film carrier tape is then subjected to an electrical selection bias test, and the reed is then cut to the desired length. In this case, in the case of multiple pins with a large number of pins, in order to prevent the outer lead (hereinafter referred to as OL) of the lead from coming apart, attach an insulating film such as polyimide that makes up the film carrier tape to the outer lead. A method of leaving it at the outer edge of 4B is often adopted. For example, OL bonding is performed on bond pads 1 to 1 on a printed circuit board or lead frame.

With the above-mentioned film carrier tape, each bonding can be done once regardless of the number of leads, so the speed of each bonding is fast, and the assembly of bonding and electrical sorting can be automated. It has advantages such as excellent mass productivity of semiconductor devices.

[Problem to be solved by the invention]

When using the above-mentioned conventional film carrier and bonding the inner 1 to 2 humps of the film carrier and the hump of the semiconductor chip 2, heat of 400 to 500° C. is required. When this heated IL porting is performed, the heat is transmitted to the insulating film of the film carrier through the leat, causing heat shrinkage of the insulating film. For example, in the case of polyimide film, this amount is approximately 0.3 at 250°C for 30 minutes.
%. In the case of a fill carrier, the time of I L bonding ink is several seconds, but the heat shrinkage of about 0.3% occurs in the same way as when the heat is 400 to 50 o'C.For example, when the length of one side of the device hole is 10 mm, A shrinkage of approximately 30 μm will occur. Here, the number is 200 to 300 or more and the pitch is 1.50 to Aratali-1 to 4B glue-1.
When below Jim, the end lead part is 22.5 to 33.8μ
Because of the shrinkage, there is a drawback that when using OL bonding, the lead may short-circuit with the OL bonding pad adjacent to the printed circuit board 1 or the like.

[Means to solve the problem]

The film carrier tape of the present invention includes a base film and a metal foil adhered to the base film, wherein the base film is composed of an insulating film and a metal foil.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view of a first embodiment of the invention.

Base film 10 constituting the film carrier tape
has a metal foil 3 made of, for example, copper at its center, and the polyurethane molds 1 to Jr4 are bonded above and below it with an adhesive 2A such as epoxy resin. A film carrier tape is constructed by adhering a metal foil 4 forming a lead portion onto this base film 1o via an adhesive 2 through a process such as lamination.

This base film 10 includes a metal foil 3 in the center, and the film carrier tape can be manufactured in the same manner as the conventional so-called three-layer tape.

In this way, conventionally, only an insulating film such as polyimide was used as a base film, but by providing a metal foil 3 such as Cu in the center, it is possible to use a film carrier tape by heat when performing IL bonding. The amount of heat shrinkage is only affected by the adhesive 2.2A, and the heat shrinkage can be suppressed to about 0.01% or less.

This effect has the advantage that no short circuit occurs between the OL bonding pad on the printed circuit board and the bonding portion of the outer lead of the semiconductor chip.

FIGS. 2 and 3 are a sectional view and a plan view of a second embodiment of the present invention.

In the embodiment of Section 2, the base film constituting the film carrier tape] OA is composed of a polyimide layer 1 adhered to a metal foil 3 with an adhesive 2A. And the film carrier tape is this base film]
, a metal foil 4 forming a reed or the like is provided on the OA via an adhesive 2, and a ring composed of a polyimide layer 1, two adhesives, and a metal foil 3 is provided near the device hole 6 via an adhesive 2. It has a structure in which a frame 7 corresponding to a shaped base film is provided. This frame 7 is bonded and fixed using the conventional three-layer tape manufacturing method after etching the pattern or plating the leads with gold or soot.

With the film carrier tape having such a structure, I
Heat when L bonding is performed is efficiently dissipated due to the presence of the metal foil 3 of the base film IOA and the metal foil 3 of the frame, and the dimensions due to the heat of the adhesive 2, 2A and the polyimide layer 1. The amount of change, that is, the amount of heat shrinkage, can be suppressed to about 0.01% or less. This effect makes it possible to perform OL punch ink work with multiple pins and narrow pitches more efficiently.

〔Effect of the invention〕

As explained above, the present invention has a structure in which the heat film constituting the film carrier tape includes an insulating film and a metal foil, thereby reducing heat shrinkage of the film carrier tape due to heat during IL bonding. Since the amount can be reduced, there is an effect that the mounting of the pads on the substrate and the leads of the semiconductor chip to the print 1 can be performed accurately.

In particular, the present invention can be applied to film carrier tapes that require high-density packaging, such as products that require 250 or more leats, a lead pitch of 140 μm or less, and dimensional accuracy of the leat portion and alignment accuracy during assembly. The effect will be significant.

3 and 3 are a sectional view and a plan view of a second embodiment of the present invention, and FIGS. 4 and 5 are a plan view and a sectional view of a conventional example.

1...Bottle 451 ~ layer, 2,2A...adhesive, 34 metal foil, 4A...inner lead, 4B...interleave 1
~, 5... Sprocket hole, 6... Device pole, 7... Frame, 8... Para 1 ~, ], 0.10A-- Heath film.

Claims (1)

[Claims] A film carrier tape comprising a base film and a metal foil adhered to the base film, wherein the base film is composed of an insulating film and a metal foil.