JP3505265B2 - Film carrier and liquid crystal display device using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film carrier having an IC mounted on a flexible substrate and a liquid crystal display device using the film carrier.

[0002]

2. Description of the Related Art A liquid crystal display device includes a liquid crystal panel in which a liquid crystal layer is held between a pair of electrode substrates, and a drive circuit substrate for driving the liquid crystal panel. Since it is necessary to electrically connect each electrode of the liquid crystal panel to the drive circuit board in a large number and at a fine pitch, they are connected through a plurality of film carriers in which a drive IC is mounted on a flexible substrate such as polyimide.

The film carrier supplies a video signal voltage to each signal line of the liquid crystal panel based on a drive voltage, image data and a control signal input from a drive circuit board.
Alternatively, it functions to supply a scan pulse to each scan line of the liquid crystal panel based on a drive voltage and a control signal input from the drive circuit board.

For example, the number of leads on the input side of the film carrier is about several tens, and the leads are arranged sufficiently overlapped on one main surface of the drive circuit board on which no component is mounted, and the lead or solder is connected to the drive circuit board. It is electrically connected by the anisotropic conductive film.

The output side lead of the film carrier is 20
Since the number of lines is 0 to 300 and the pitch is fine, the drive circuit board is electrically connected to the anisotropic conductive film.

[0006]

By the way, each of the leads of the film carrier described above is formed by etching a copper foil attached to a flexible substrate into a predetermined shape, and is restricted by the number and pitch of the leads. The width is about several hundred μm, and the lead thickness is set sufficiently smaller than the lead width.

Under these circumstances, although the input side leads of the film carrier are smaller in number than the output side leads, they are easily subjected to stress concentration due to heat or impact, and lead breakage is likely to occur. Especially in the liquid crystal display device,
In order to repair the breakage of the lead, it is necessary to peel off the film carrier firmly connected by the anisotropic conductive film or the like, and there is a problem that the connection pad is damaged, so that the repair is difficult.

The present invention has been made in view of the above technical problems, and an object of the present invention is to provide a film carrier in which lead breakage is unlikely to occur and a liquid crystal display device which can obtain high connection reliability.

[0009]

The invention according to claim 1 is
The drive IC is mounted on the flexible substrate, and the drive I
A plurality of input side leads are arranged with one end side being an input side with respect to C, and a plurality of output side leads are arranged with the other one end side being an output side with respect to the drive IC. The input side lead at the outer end of the input side is wider than the lead width of the other input side leads, and the lead width is wider than the side where the drive IC side of the input lead at the outer end is opposite. It is a featured film carrier.

The invention according to claim 2 is the film carrier according to claim 1, characterized in that the outer dimension of the input side is 0.9 times or less the outer dimension of the output side.
The invention according to claim 3 is characterized in that the lead width on the drive IC side of the input lead on the outer end is set to be twice or more the lead width on the opposite side. In career.

According to a fourth aspect of the invention, a liquid crystal panel in which a liquid crystal layer is held between a pair of electrode substrates, and a drive circuit board for supplying a drive signal required to drive the liquid crystal panel,
In a liquid crystal display device including a plurality of film carriers for electrically connecting the liquid crystal panel and the drive circuit board, the film carrier has a drive IC mounted on a flexible substrate and one end side with respect to the drive IC. A plurality of input leads are arranged with the input side being
A plurality of output side leads are arranged with the other end side being the output side with respect to C, and the input side lead at the outer end of the input side is wider than the lead width of the other input side lead, and The liquid crystal display device is characterized in that the lead width is wider than the side of the outer end of the input side lead opposite to the drive IC side.

According to a fifth aspect of the present invention, the film carrier is arranged in parallel with the drive circuit board, and the drive circuit is provided on the drive circuit board corresponding to the gap between the input sides of the adjacent film carriers. The liquid crystal display device according to claim 4, wherein components are mounted.

[0013]

As a result of sincerity research conducted by the present inventor, it has been found that the input side lead of the film carrier is likely to be broken along the outer end side, and further, the lead IC is likely to be broken at the driving IC side of the input side lead.

Therefore, according to the present invention, the area where lead breakage is likely to occur is reinforced positively without increasing the outer dimensions, that is, the input side lead at the input side outer end of the film carrier is different from the other input side leads. Since the lead width is wider than the lead width and the drive IC side of the input lead at the outer end is wider than the opposite side, the structure is resistant to heat or impact.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An active matrix type liquid crystal display device according to an embodiment of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, the active matrix type liquid crystal display device (1) is a normally white mode light transmissive type having a display pixel region (5) and is opposed to the display device array substrate (100). Although not shown, a light transmission type liquid crystal panel (3) having a liquid crystal composition held via an alignment film is included between the substrates (200).

Although not shown, the array substrate (100) for a display device which constitutes the liquid crystal panel (3) has a plurality of signal lines and a plurality of scanning lines arranged in a matrix on a glass substrate. A thin film transistor (hereinafter abbreviated as TFT) is arranged as a switch element near the intersection, and this TF is used.
A pixel electrode made of ITO is provided via T.
Further, on this glass substrate, an auxiliary capacitance line that is substantially parallel to the scanning line is arranged, and the auxiliary capacitance line and the pixel electrode are arranged so that an auxiliary capacitance (Cs) is formed between the auxiliary capacitance line and the pixel electrode. An insulating film is interposed between them. The counter substrate (200) is
A matrix-shaped light-shielding film for light-shielding the TFT and the periphery of the pixel electrode is arranged on the glass substrate, and a counter electrode made of ITO is arranged on the matrix light-shielding film.

In the active matrix type liquid crystal display device (1) of this embodiment, in order to reduce the external dimensions of the device, the signal lines are arranged along one long side (1) of the display device array substrate (100).
The scanning lines are led out only to the 01a) side, and the scanning lines are led out only to the one short side (101b) side of the array substrate (100) for a display device.

Then, on the long side (101a) side of the array substrate (100) for the display device, eight X-side film carriers (300-1), which supply video signals (Vs) to the respective signal lines ,. , (300-8) are arranged in parallel, and four Y-side film carriers (400-1) for supplying the scanning signal (Vg) to the scanning line are provided on the short side (101b) side of the array substrate (100). ), ..., (400-4) are arranged in parallel.

The X side film carrier (300-1) will be described as an example. Figure 2 shows the X side film carrier (300-1).
As shown in (a) and (b), a rectangular drive IC (32) is mounted on a flexible substrate (311) made of polyimide resin.
1) is mounted, and is divided into an input side and an output side by this drive IC (321). The outer dimension (Lo) on the output side of the X side film carrier (300-1) is 20.
mm, the external dimension (Li) of the input side is 16.3 mm, and is formed in a trapezoidal shape. In addition, the drive IC (321) is
The rectangular shape is smaller than the outer dimension (Lo) on the output side, but larger than the outer dimension on the input side so that the diagonal wiring area of the lead derived from 1) can be set small.

On the output side of the X side film carrier (300-1), a group of 240 output side leads (331) made of copper foil connected to the drive IC (321) is arranged, and on the input side, a drive group is formed. I
46 input side lead groups (341) made of copper foil connected to C (321) are arranged.

The input side lead group (341) is arranged with a lead length of 1.2 mm, a lead width of 0.175 mm and a lead pitch of 0.35 mm in the region that contributes to the connection, and the outermost end. The pair of input leads (341a), (341b) has a wider lead width (LA) of 0.53 mm on the front end side and a lead width (LB) of 1.2 mm on the rear end side, which substantially contributes to the connection, and is wider than the others. It has a trapezoidal shape.

The X-side film carriers (300-1), (300-8) thus constructed are arranged in parallel with each other as shown in FIG. 1, and each X-side film carrier (300-). 1),
, (300-8) output side lead group (331) is, as shown in FIG. 3, an array substrate (100) for a display device via an anisotropic conductive film.
Is electrically and mechanically connected to the signal line connection pad (121). Also, each X-side film carrier (300-1) ...,
The input side lead group (341) of (300-8) is an X circuit board that supplies desired image data, control signals and drive voltage to each X side film carrier (300-1), ..., (300-8). It is electrically and mechanically connected to the connection pad (521) of (500).

Each Y-side film carrier (400-1), ..., (400-
4) is substantially the same as the X side film carrier (300-1), ..., (300-8), and each Y side film carrier (400-1) ,.
The output side lead of 4) is electrically and mechanically connected to the scanning line connection pad of the display device array substrate (100) through the anisotropic conductive film, and each Y side film carrier (400-1), …, (40
The input side lead 0-4) is electrically and mechanically connected to the connection pad of the Y circuit board (600) which supplies a desired control signal and drive voltage to the Y side film carrier.

Liquid crystal display device configured as described above
According to (1), the X side film carrier (300-1), ..., (300-
The pair of outermost input leads (341a), (341b) of the input side lead group (341) of 8) has a lead width three times or more that of the others, and especially lead breakage. Input lead (341a), (341b) rear end side lead width (LB)
Is set wider than twice the lead width (LA) on the tip side.

Therefore, the X side film carrier (300-1),
The breakage of the input side lead group (341) of (300-8) is effectively prevented. In addition, the X side film carrier (300-
By adopting 1), ..., (300-8), as shown in FIG. 3, the X circuit board corresponding to the gap between the input sides of the adjacent X side film carriers (300-1), (300-2). A driving circuit component (511) can be mounted on the (500).

For example, each X side film carrier (300-1),
, (300-8) are mounted at intervals of 0.14 mm, in this embodiment, a component mounting space of 6.6 mm 2 is obtained on the X circuit board (500) corresponding to the space between adjacent film carriers. You can This allows the X circuit board (5
00) component mounting efficiency can be improved, the substrate size can be further reduced, and the liquid crystal display device (1) can be formed in a smaller external dimension.

Particularly, by mounting a relatively tall component on the X circuit board (500) corresponding to the gap of the film carrier, the X circuit board (500) and the X side film carrier (3
00-1), ..., (300-8) can be housed within the thickness of the liquid crystal panel (3), and the device can be made thinner.

Each Y side film carrier (400-1), ...,
With the same configuration in (400-4), the outer size of the liquid crystal display device (1) can be further reduced in size. In this embodiment, each X-side film carrier (300-1), ..., (300-
8), each Y-side film carrier (400-1), ..., (400-4) is formed in a trapezoidal shape, but in addition to this, the side surface shape on the input side is set to the output lead side as shown in FIG. By configuring by curving in a convex shape, adjacent film carriers (300-1), (300-
A larger component mounting space can be obtained on the X circuit board (500) corresponding to the gap of 2), and the drive circuit component (51
Since 1) and (513) can be mounted, a liquid crystal display device
The external dimensions of (1) can be further reduced.

In this embodiment, the pair of input-side leads at the outermost end on the input side of the film carrier has a reinforcing structure different from the others, but the effect of the present invention can be obtained even if only one of the leads is likely to break. be able to.

The outermost input side lead may be used as a dummy electrode, or if it is several from the outermost end, it may be arranged inside. In this case, it is desirable that the outermost input lead be a dummy electrode or an electrode redundantly connected.

[0031]

According to the film carrier of the present invention, due to its peculiar structure, lead breakage can be effectively prevented even with stress concentration due to heat or impact. Moreover, since the outer dimensions of the film carrier are not increased, the outer dimensions are not increased even when used in a liquid crystal display device.

[Brief description of drawings]

FIG. 1 is a schematic front view of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a schematic front and back view of an X-side film carrier of the liquid crystal display device of FIG.

FIG. 3 is a partial schematic front view of the liquid crystal display device of FIG.

FIG. 4 is a partial schematic front view of a liquid crystal display device according to another embodiment.

[Explanation of symbols]

(1)… Liquid crystal display (3)… Liquid crystal panel (300-1), ..., (300-8) ... X side film carrier (400-1), ..., (400-4) ... Y side film carrier (500)… X side circuit board (600)… Y side circuit board

Claims (5)

(57) [Claims] 1. A drive IC is mounted on a flexible substrate, a plurality of input-side leads are arranged with one end side being an input side with respect to the drive IC, and another one end side being an output side with respect to the drive IC. As a film carrier in which a plurality of output side leads are arranged, the input side outer end input side lead is wider than the lead widths of other input side leads, and the outer end input side lead is A film carrier, wherein the drive IC side has a wider lead width than the opposite side. 2. The external dimension of the input side is 0.9 times or less the external dimension of the output side.
The described film carrier. 3. The drive IC of the input lead at the outer end
2. The film carrier according to claim 1, wherein the lead width on one side is set to be twice the lead width on the opposite side or more. 4. A liquid crystal panel in which a liquid crystal layer is held between a pair of electrode substrates, a drive circuit board for supplying a drive signal required to drive the liquid crystal panel, and the liquid crystal panel and the drive circuit board are electrically connected to each other. In a liquid crystal display device including a plurality of film carriers that are electrically connected, the film carrier is driven on a flexible substrate.
C is mounted, and a plurality of input-side leads are arranged with one end side being an input side with respect to the drive IC, and a plurality of output-side leads being arranged with another end side being an output side with respect to the drive IC. The input side lead at the outer end of the input side is wider than the lead width of the other input side lead, and the lead width is wider than the side where the drive IC side of the input lead at the outer end is opposite. A liquid crystal display device characterized in that 5. The film carrier is arranged in parallel with the drive circuit board, and drive circuit parts are mounted on the drive circuit board corresponding to a gap between input sides of adjacent film carriers. The liquid crystal display device according to claim 4, wherein