JPH0754813B2 - Film carrier board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a film carrier substrate used for mounting chip components using a TAB (Tape Automated Bonding) method, for example, an IC card or a card. It is used for manufacturing calculators and the like.

(Prior Art) An electrical component manufactured by using a film carrier substrate will be described by taking an IC card as an example. An IC card is a pocket-sized plastic card substrate, and an IC chip that constitutes a CPU and a memory. (Chip part) is embedded, and a plurality of external terminals for transmitting / receiving data to / from an external device such as a reader / writer and for inputting a power source are provided on the surface of the card substrate.

According to the ISO (International Organization for Standardization) standards, the thickness of the card substrate is specified to be 0.76 mm.

The IC card is thinly mounted because it is necessary to embed the IC chip in such a thin card base material. As this mounting method, for example, there is a TAB mounting method using a film carrier substrate.

FIG. 3 shows a conventional film carrier substrate used in such a TAB mounting method.

On the film carrier substrate 11, finger leads 2 made of copper foil are patterned on a polyimide film into a required shape, and a chip mounting hole 3 corresponding to the size and shape of the chip component is provided at a mounting portion of a chip component such as an IC chip. Has been drilled.

A bump such as gold is formed on the power supply pad of the chip component or on the tip of the finger lead 2 in order to avoid contact between the finger lead and the edge portion of the chip component and to increase the reliability of bonding.

Further, perforation holes 4 similar to those of the photographic film are formed on both sides of the polyimide film. The perforation holes 4 are used for feeding the film carrier substrate 11 and required alignment.

Then, a sprocket gear (not shown) meshes with the perforation hole 4, the long film carrier substrate 11 wound on the reel is drawn out, and the electrode pads of the chip component are aligned with the finger leads 2 and then the plurality of the electrode pads are aligned. The connection parts of are simultaneously bonded at once.

In this bonding step, the film carrier substrate 11 on which the chip parts 12 are mounted is wound around the film carrier reel 14 as shown in FIG.

In this way, the chip component 12 is transferred to the film carrier substrate 11.
After being bonded, the film carrier substrate 11 is punched at a predetermined punching line portion around the bonding portion by press punching, and the rear end side of the finger lead 2 is a wiring pattern of another wiring substrate. Then, they are bonded at once by a conductive adhesive or reflow soldering.

In this way, a plurality of chip parts 12 are mounted on one wiring board via the film carrier board 11 to form a required circuit.

Bonding of the chip component 12 to the film carrier substrate 11 is called ILB (Inner Lead Bonding), and connection of the film carrier substrate with chip component to another wiring substrate after punching is called OLB (Outer Lead Bonding).

The TAB mounting method is suitable for automation and is suitable for mass production because the long film carrier substrate 11 is pulled out from the reel as described above and the chip components 12 such as the IC chip are simultaneously bonded to it at one time. .

By the way, the film carrier substrate 11 is flexible because it is made of a plastic material such as a polyimide film. Therefore, when the film carrier substrate 11 on which the chip parts 12 are mounted is wound around the film carrier reel 14, only the film carrier substrate 11 is bent so as to conform to the circumferential winding surface of the film carrier reel 14. A tensile force is applied to the finger leads 2.

(Problems to be Solved by the Invention) Conventionally, as shown in FIG. 4, when a film carrier substrate 11 on which a chip component 12 is mounted is wound around a reel 14 for film carrier, etc. Since the carrier substrate 11 bends so as to conform to the circumferential winding surface of the film carrier reel 14, a tensile force may be applied to the finger leads 2 and the bonded chip components 12 may come off, resulting in reduced yield. There was a problem of inviting.
In particular, this problem was remarkable when the film carrier substrate 11 had a predetermined circuit function composed of a plurality of chip parts per frame.

A film carrier substrate which has been made based on the above circumstances of the present invention and which can prevent detachment of chip components by avoiding application of tensile force to finger leads to which chip components are bonded and which can improve yield The purpose is to do.

[Structure of the Invention] (Means for Solving Problems) In order to solve the above problems, the present invention includes finger leads, and electrode pads of chip parts are bonded to the finger leads to mount the chip parts. A film carrier substrate, in which a plurality of chip components form a predetermined circuit function, and a border portion between the plurality of chip components; and a portion between the plurality of chip components in the one frame. The gist is that a slit for imparting flexibility is provided in a direction orthogonal to the depth direction.

(Operation) When the film carrier substrate on which the chip parts are mounted is wound around a reel for film carrier or the like, it is largely bent at a portion provided with a slit which is separated from a portion on which the chip parts are mounted, The curvature of the portion where the chip component is mounted becomes small. Therefore, the tensile force applied to the finger leads is remarkably reduced, and the chip component is prevented from coming off.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing an embodiment of the present invention and is a plan view of a film carrier substrate. FIG. 2 is a block diagram of a bonding apparatus applied to the film carrier substrate bonding step of the present invention.

In FIG. 1 and FIG. 2, the same or equivalent members or parts as those in FIG. 3 and FIG.

First, the structure will be described. In FIG. 1, 10 is a film carrier substrate, and the film carrier substrate 10 is a chip component.
Twelve mounting parts, that is, a portion other than the portion of the chip component mounting hole 3, a boundary portion for each frame and a portion between a plurality of chip components in the frame are orthogonal to the length direction. Slits 5, 5a, 5b for imparting bendability are provided in the direction of movement.

In FIG. 2 showing the bonding apparatus, 6 is a reel for winding the film carrier substrate 10 in advance, 7 is a stage, and 8 is a bonding tool.

Next, mounting and operation of the chip component on the film carrier substrate 10 will be described.

The long film carrier substrate 10 wound on the reel 6
It is driven and drawn out by a sprocket gear or the like (not shown) that meshes with the perforation hole 4. The film carrier substrate 10 that has been pulled out is the portion of the stage 7 that first has its finger leads (not shown) and the chip parts 12
Is aligned with the electrode pad 13. At this time, the film carrier substrate 10 is bent at the slit 5 as shown in FIG. 2 and the flatness of one frame is kept good, so that the alignment can be performed easily and accurately.

After the alignment, the bonding tool 8 simultaneously bonds a plurality of connection parts at once.

The film carrier substrate 10 is pulled out from the reel 6, the alignment and the collective bonding are automatically carried out successively, and the film carrier substrate 10 on which the chip parts 12 are mounted is sequentially wound on the film carrier reel 14. .

Even when the film carrier reel 14 is wound up, the film carrier substrate 10 keeps the chip component 12
The slits 5, 5a, 5b, which are separated from the mounted portion, are largely bent, and the curvature of the mounted portion of the chip component 12 is reduced. Therefore, as compared with the conventional film carrier substrate 11, the tensile force applied to the finger leads 2 is remarkably reduced and the chip component 12 is prevented from coming off the bonding portion.

By mounting the chip component 12, 1 of the film carrier substrate 10
Since the function for one circuit is configured in the frame,
It is also possible to cut out the diced pieces and stack the diced pieces as they are as a single module on electrical components such as an IC card.

On the other hand, when the OLB process is required, the film carrier substrate 10 is punched out by one press, and the punched wiring pattern on the film carrier substrate 10 becomes the wiring pattern of another wiring substrate. , Bonded by conductive adhesive or reflow soldering.

In this way, a plurality of chip parts 12 are mounted on one wiring board via the film carrier board 10 to form a required circuit.

Even in the above-mentioned press punching process, since the flatness of one frame of the film carrier substrate 10 is maintained by the bending action of the slit 5, a good punching property can be obtained.

[Effects of the Invention] As described above, according to the configuration of the present invention, since the film carrier substrate is largely bent at the slit portion other than the mounting portion of the chip component, the film carrier reel is mounted on the reel for film carrier after mounting the chip component. When you get rolled up,
The curvature of the portion where the chip component is mounted is reduced, the tensile force applied to the finger leads is reduced, and the chip component can be prevented from coming off. As an additional effect of the structure of the present invention, since the bonding between the finger lead and the electrode pad of the chip component is performed on a frame-by-frame basis, the film carrier substrate of the present invention is provided with a slit at the boundary of each frame. Therefore, the flatness of one frame portion is kept good, and the alignment is easily and accurately performed. Further, even in the step of removing the press, the flatness of one frame portion can be kept good because it is performed in units of one frame unit of the film carrier substrate.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a film carrier substrate according to the present invention, FIG. 2 is a configuration diagram of a bonding apparatus applied to a bonding step of the embodiment according to the present invention, and FIG. 3 is a conventional film carrier. Plan view showing the substrate, fourth
The figure is a diagram showing a winding portion on a reel for a film carrier for explaining the problems of the conventional example. 10, 11: Film carrier substrate, 2: Finger lead, 3: Chip mounting hole, 5, 5a, 5b: Slit, 12: Chip part, 13: Electrode pad.

Claims (1)

[Claims] 1. A film carrier substrate having finger leads, wherein electrode pads of chip parts are bonded to the finger leads to mount the chip parts, wherein a predetermined circuit function is constituted by a plurality of chip parts. A slit for facilitating bending of the film carrier in a direction orthogonal to the length direction of the film carrier is provided at a boundary part of each frame and a part between a plurality of chip parts in the frame. A film carrier substrate.