JP2000298435A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To connect a hybrid integrated circuit substrate and a panel surely and electrically through FPC by forming a terminal group of FPC connected to a panel side and a terminal group of FPC connected to a hybrid integrated circuit substrate side with fine pitch and constituting terminal groups connecting FPCs with rough pitch. SOLUTION: A second FPC 30 and a third FPC 31 are prepared between a panel 1 and a hybrid integrated circuit substrate 3. The second FPC 30 is provided with a eighth terminal group 35 having the same pitch size as a second terminal group 5... of the panel 1 side, and they are stuck together. Also, a third FPC 31 is previously stuck to the hybrid integrated circuit substrate 3, after that a first FPC 7 is stuck together. Then pitch size of a fourth terminal group 36 of the second FPC 30 and a fifth terminal group 37 of the third FPC 31 is formed with rough pitch. Therefore, electrical contact can be performed even if the third FPC 31 is shifted to the left and the second FPC 30 is shifted to the right in sticking of the first FPC 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly to a display device using a flexible sheet.

[0002]

2. Description of the Related Art Recently, in the field of display devices, for example, a TFT employing poly-Si or a-Si, and a display employing EL recently have been focused on low power consumption, thin and lightweight, high-definition images and the like. The device is being actively studied. These display devices are provided between a panel and a printed circuit board on which a drive circuit is mounted (a ceramic substrate, an insulated metal substrate, and the like are also conceivable, and are hereinafter collectively referred to as a hybrid integrated circuit substrate). A flexible sheet (hereinafter, referred to as an FPC) provided with wiring is employed and mounted on a portable terminal, for example, a digital still camera, a mobile phone, a video camera, or the like.

FIG. 4 shows an example of the above. Reference numeral 1 denotes a panel having a display area 2 at the center, 3 denotes a hybrid integrated circuit board on which a drive circuit for displaying an image is mounted on the display area, and 4 denotes a hybrid integrated circuit board. A first terminal group provided on the vertical side of the display area 2 is a second terminal group provided on the horizontal side of the display area 2, and a first terminal group 6 is provided on the vertical side of the hybrid integrated circuit board 3. It is a third terminal group provided. In addition, in order to make it clear which terminal is mounted on the FPC, the panel, or the hybrid integrated circuit board, (F), (PA), and (base) are added to the end of the name in the figure.

The first terminal group 4 and the third terminal group are connected by a first FPC 7, and the second terminal group 5 and the hybrid integrated circuit board 3 are connected by a second FPC 8. I have. On the opposite side of the second FPC 8, a fourth terminal group 9 on the panel side and a fifth terminal group 10 on the hybrid integrated circuit board 3 side.
... are provided. And the fifth terminal group 10 ...
It is electrically connected to the driving IC 11 located in the vicinity via a thin metal wire, and the signal of the IC 11 is transmitted to the second
Are input to the display area via the terminal group 5.

On the other hand, the first FPC 7 is provided with a sixth terminal group 12 on the first terminal group 4 side and a seventh terminal group 13 on the third terminal group 6 side. It is stuck on the panel 1 side and the hybrid integrated circuit board 3 side. Also the third
A drive IC 14 is provided in the vicinity of the group of terminals 6..., And signals are also input to the display area 2 via the thin metal wires, the first FPC 7, the first group of terminals 4.

[0006] In these FPCs, the terminal groups are matched with each other, and electrical connection and mechanical fixation are realized by, for example, solder, anisotropic conductive resin, or the like.

With the recent high resolution of panels, the terminal groups are formed at a fine pitch. For example, the size of the terminals connected to each other is 0.15 mm × 0.1
5 mm and the pitch is 0.3 mm.

[0008]

For example, the first FPC
7 are bonded to the first terminal group 4 of the panel and the third terminal group 6 on the hybrid integrated circuit board 3 side, if they are slightly obliquely bonded due to bonding accuracy, the displacement is the second. Affects FPC8. That is, if the second FPC 8 is accurately bonded in advance to the hybrid integrated circuit board 3 side, the second terminal group 5 on the panel side and the fourth terminal group 9 on the second FPC 8 side will be displaced. This causes a problem of poor connection.

The second terminal group 5 on the panel 1 side and the second
Prepare the FPC8 of which is accurately attached,
The bonding accuracy between the terminal group 10 and the hybrid integrated circuit board 3 may be roughened. However, the IC bonding pads are formed on the flexible sheet side and have a pitch of 140 μm. Because of this pitch, the terminal group on the hybrid integrated circuit board 3 side has a size of 0.15 mm ×
It is specified to be about 0.15 mm and the pitch is about 0.3 mm.

[0010] Further, even if a bonding pad of this size is formed on the hybrid integrated circuit board 3 side and the second FPC 8 side is roughened, it is 140 μm on the hybrid integrated circuit board side.
The high-definition pattern of the pitch was very difficult. Since the hybrid integrated circuit board 3 is formed over a wide range from a rough pitch to a high-definition pitch and a wide pattern from a thick pattern to a thin pattern, the high-definition pattern is over-etched and the pattern is lost. It is because. Even if it is realized, there is a problem that the cost increases because it is necessary to take measures against these problems.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a structure in which a panel and a hybrid integrated circuit board are provided.
Two FPCs are provided, a second FPC is attached to the panel side, and a third FPC having a fine pitch is attached to the hybrid integrated circuit board side, so that a rough pitch is formed between the second FPC and the third FPC. This is the solution.

[0012] Even if the first FPC is stuck diagonally,
The rough pitch electrode pattern can absorb the contact failure due to the deviation.

Second, the image display IC is mounted on the hybrid integrated circuit board adjacent to the third terminal group and the sixth terminal group. .

The fourth terminal group and the fifth terminal group are connected via solder. In particular, a through hole exposing the fifth terminal is provided at the center of the fourth terminal. The problem is solved by being electrically connected via the solder formed in the hole.

Particularly, since the fourth and fifth terminal groups have a rough pitch, they can be connected by soldering. Conventionally, if the pitch is fine, an anisotropic conductive resin must be used.
This problem has been solved although the contact resistance has increased.

[0016]

Embodiments of the present invention will be described below with reference to FIG.

First, there are a panel 1 and a hybrid integrated circuit board 3, between which three FPCs 7, 30 and 31 are laminated.

First, the panel 1 is made of, for example, poly-Si or a-S
This is a display panel employing TFT or EL employing i.

For example, in the case of a liquid crystal panel, a TFT substrate has gate lines composed of a plurality of wirings (Cr) on the left and right, and a plurality of wirings extending vertically are formed as drain lines. An intersection is formed in a matrix by these two types of lines.
A display region composed of a TO display electrode and a TFT electrically connected to the display electrode constitutes a pair. Opposing electrodes are formed on the opposing transparent substrates. A display device called a simple matrix is also conceivable.
These are already known and will not be described in detail.

If a liquid crystal is formed between these two sheets, it becomes a liquid crystal display element, and if an EL material is provided, it becomes an EL display element.

The first side 32 of the panel 1 has a first side 32
Are provided, and the second side group 33 is provided with a second terminal group 5. Also, it may be provided on the remaining side.

The hybrid integrated circuit board 3 may be a printed board, a ceramic board, an insulating metal board, or the like. Here, a printed board is used. A third terminal group 6 is provided on the third side of the hybrid integrated circuit board 3, and a terminal group is provided on the fourth side 34 if necessary. The terminal group realizes connection with a wiring extending on the FPC, connection with an IC chip, and connection with a hybrid integrated circuit board provided in a lower layer as necessary.

The first terminal group 4 on the panel 1 side and the third terminal group on the hybrid integrated circuit board 3 side are the first FPC 7
The sixth terminal group 12 and the seventh terminal group 13 provided in
Connected by Here, the sixth terminal 12 and the seventh terminal 13 are connected by wiring, but are omitted in the drawing. The shape of the two terminal groups shown here is, for example, 0.
15 mm x 0.15 mm, pitch is 0.3 mm.

The same applies to the second terminal group 5 on the panel 1 side and the sixth terminal group 40 on the hybrid integrated circuit board side. Here, as will be described later, the sixth terminal groups 40 are electrically connected to terminals formed on the hybrid integrated circuit board 3 at a fine pitch and are bonded with high precision in advance.

On the other hand, between the panel 1 and the hybrid integrated circuit board 3, a second FPC 30 and a third FPC 31 are provided. The second FPC 30 is provided with an eighth terminal group 35 having the same pitch size as the second terminal group 5 on the panel side and bonded together.

On the hybrid integrated circuit board 3 side, a third FPC 31 is prepared in a state of being bonded in advance, and then the first FPC 7 is bonded as described above.

The point of the present invention is the pitch size of the fourth terminal group 36 of the second FPC 30 and the fifth terminal group 37 of the third FPC 31. That is, the aforementioned pitch size, 0.15 mm × 0.15 mm, pitch: 0.3
It is formed at a rougher pitch than mm. For example, 0.5m
mx 0.5 mm, 1 mm pitch. Therefore, even if the first FPC 7 is misaligned, the third FPC 31 is shifted to the left by a maximum of 0.15 mm, and the second FPC 30 is shifted to the right by a maximum of 0.15 mm, the electrode size is 0.5 × 0.5.
mm, at least 0.2 mm remains and can be contacted.

Further, it is preferable to bond them as shown in FIG. That is, a hybrid integrated circuit board 3 on which the third FPC 31 is bonded with high precision and a panel 1 on which the second FPC 30 is bonded with high precision are prepared, and the first integrated circuit board 3 is provided between the panel 1 and the hybrid integrated circuit board 3. Attach FPC7. FIG. 2 shows this state. Finally, the fourth terminal group 36 and the fifth terminal group 37 are bonded together, and at the same time, electrical connection is performed.

Here, all the terminal groups may be contacted with an anisotropic conductive resin, but the fourth terminal group 36.
May be joined by solder.

A ninth terminal group 38... Serving as a bonding pad is provided at the tip of the third FPC 31. The ninth terminal group 38 is electrically connected to a driving IC mounted on the hybrid integrated circuit board 3 via a thin metal wire. Have been. Also the first FPC
7, a tenth terminal group 39 serving as a bonding pad is provided separately, and is electrically connected to a driving IC mounted on the hybrid integrated circuit board 3 via a thin metal wire.

Subsequently, the second FPC 30 and the third FPC
The solder connection 31 will be described with reference to FIG.

At the bottom is the hybrid integrated circuit board 3, on which the third FPC 31 is bonded via an adhesive 52. Naturally, the sixth terminal group 40... And the terminal group on the side of the hybrid integrated circuit board 3 are bonded together with high precision and are electrically connected to the circuit on the hybrid integrated circuit board 3. Here, a state is shown in which a copper foil is bonded to a flexible sheet, but it may be realized by multilayer wiring. Further, a second FPC 30 bonded to the panel 1 is disposed at the upper right. Here, it is a double-sided wiring.
Electrodes serving as the fourth terminal groups 36 are formed on both surfaces of the flexible sheet 53 serving as a core, and a flexible sheet 54 is further attached to the surface for insulation treatment.
Reference numeral 50 denotes a through hole. The through hole 50 and its periphery are exposed from the flexible sheet to form a fourth terminal group 36, and the portion exposed from the through hole becomes a fifth terminal group 37. Therefore, the terminals here are
Since they are formed at a pitch of about 0.5 × 0.5 mm and 1 mm, solder connection is possible and, unlike anisotropic conductive resin, contact resistance can be reduced.
In addition, 51 is solder.

[0033]

As is clear from the above description, two FPCs are prepared between the panel and the hybrid integrated circuit board, and the terminal group of the FPC connected to the panel side and the hybrid integrated circuit board are provided. The terminal group of the FPC connected to the FPC is formed at a fine pitch, and the terminal group connecting the FPCs is formed at a rough pitch. Can be reliably electrically connected via the FPC. Further, since the fourth terminal group and the fifth terminal group are formed at a rough pitch, they can be connected via solder, and the contact resistance of the display device can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a display device of the present invention.

FIG. 2 is a diagram illustrating a method of assembling a display device.

FIG. 3 is a diagram illustrating a solder connection.

FIG. 4 is a diagram of a conventional display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Panel 3 Hybrid integrated circuit board 7 1st FPC 30 2nd FPC 31 3rd FPC

Claims (4)

[Claims] 1. An image display area, and a first part which is located around the image display area and forms a corner.
A panel having a first terminal group and a second terminal group respectively on the side and the second side of the panel, and a circuit for supplying a signal to the image display area are mounted. A third integrated circuit board having a third side provided near the third terminal group connected to the third side, and a fourth side forming a corner with the third side; A first FPC electrically connecting the third terminal group to the first terminal group; a second terminal group and one side connected to each other; and a rougher pitch on the opposite side than the second terminal group. A second FPC having the fourth terminal group described above, and a fifth terminal group electrically fixed at substantially the same pitch as the fourth terminal group are provided on one side, and on the opposite side, A third FPC provided with a sixth terminal group having a finer pitch than the fifth terminal group. Display device. 2. The display device according to claim 1, wherein the image display IC is mounted on the hybrid integrated circuit board adjacent to the third terminal group and the sixth terminal group. 3. The display device, wherein the fourth terminal group and the fifth terminal group are connected via solder. 4. The device according to claim 3, wherein a through hole exposing the fifth terminal is provided at a center of the fourth terminal, and the fourth terminal is electrically connected via solder formed in the through hole. The display device according to the above.