JPH11271793A - Tape carrier package and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the degradation of reliability as much as possible by providing notched lines in bent areas. SOLUTION: This device is provided with a base film 11 having bent areas 13a and 13b, first and second lead lines 12a and 12b formed on this base film, hole 18 provided at the base film so that one edge part of each first and second lead line can be exposed, IC chip 31 electrically connected with the ends of the first and second lead lines loaded and exposed in this hole, and notched lines 14a and 14b provided in the bent areas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a tape carrier package and a liquid crystal display device having the tape carrier package mounted thereon.

[0002]

2. Description of the Related Art Display devices, especially liquid crystal display devices, are used for personal computers, monitors, and the like. To drive the liquid crystal display device, an output electrode of a tape carrier package (hereinafter, also referred to as TCP) on which a driving IC chip is mounted is connected to an electrode formed on a glass substrate of a liquid crystal cell.
TAB (Tape Automated Bonding) mounting, which connects an electrode on the CP to an electrode on a printed circuit board, is usually used.

For a liquid crystal display device used for a display for a personal computer or the like, there is a strong demand for a so-called narrow frame in which a display area is enlarged and a peripheral "non-display area" is narrowed. To narrow the frame, it is easy to achieve this by bending and using TCP.

A conventional example of a liquid crystal display device having a narrow frame using a folded TCP will be described below with reference to FIGS.

FIG. 7 is a sectional view of a liquid crystal display device using a conventional TCP, and FIG. 8 is a plan view of the conventional TCP.
As shown in FIG. 8, in this conventional TCP 10, on a tape-shaped base film 11 made of polyimide,
For example, lead electrodes 12a made of tin-plated copper,
12b is formed. On the base film 11, a hole 33 for mounting the driving IC chip, slits 15a and 15b of the bent portions 13a and 13b, and a slit 16 for soldering are formed. Note that an insulating coating (not shown) is applied to the exposed lead wires 12a and 12b to prevent an electrical short circuit.
Is applied.

A solder resist 21 is applied to a region surrounded by a dashed line except for the slits 15a, 15b, 16 and a connection portion. The bumps 32 on the IC chip 31 and the lead electrodes 12a, 12 on the TCP 10
b performs the inner lead bonding,
The C chip 31 is mounted. Thereafter, the IC chip 31 is sealed with a resin 33.

The above steps are performed collectively on a tape carrier. Next, the TCP 10 is punched into a desired shape.

Next, as shown in FIG.
Liquid crystal cell 4 having liquid crystal layer 43 sandwiched between
The TC formed on one of the glass substrates 44 has a TC
The output-side lead electrode 12a of P10 is aligned, and is electrically connected via the anisotropic conductive film 36 by, for example, outer lead bonding by a thermocompression bonding method. T
The lead electrode 12b on the input side of the CP 10 is connected to an electrode on the printed circuit board 48 by the solder 38. Then, in this state, the printed circuit board 48 is bent inside the liquid crystal cell 40 by bending along the bending portions 13a and 13b, and the backlight 46 is incorporated as shown in FIG. The liquid crystal module is completed through the above steps. FIG. 9 is a plan view at the time when the connection between the liquid crystal cell 40 and the printed circuit board 48 via the TCP 10 is completed. Flat T is used for the side in the X direction using bent TCP, and the side in the Y direction is not bent.
This is an example in the case of using a CP.

[0009]

After the above-mentioned conventional liquid crystal module is subjected to a mechanical test such as a vibration and impact test, and a defective portion is examined, the T
Slits 15 at bent portions 13a and 13b of CP10
It was often found that the lead wires at the ends a and 15b were broken. In particular, TCP 10 where disconnection has occurred
It is located at both ends of the side in the direction, and it is often the case that some of the slits 15a, 15b of the bent portions 13a, 13b are cut at both ends or one end. In other words, the liquid crystal display device using the bent TCP has a problem that greening in a narrow frame is possible, but reliability of mechanical strength is poor.

The present invention has been made in view of the above circumstances, and has as its object to provide a highly reliable tape carrier package and a liquid crystal display device having the tape carrier package mounted thereon.

[0011]

A tape carrier package according to the present invention comprises a base film having a bent region, first and second lead wires formed on the base film, and the first and second lead films. A hole provided in the base film such that one end of each of the lead wires is exposed, and an IC chip mounted in the hole and electrically connected to the exposed ends of the first and second lead wires. And a cutting line provided in the bending area;
It is characterized by having.

According to the tape carrier package of the present invention having the above-described configuration, since the cut area is provided in the bending area, it is easier to bend as compared with the conventional case, and the load on the lead wire is reduced. Becomes possible. As a result, the lead wire is less likely to be cut than in the conventional case, and the reliability is improved. Also, the mechanical strength is higher than in the conventional case.

It is preferable that a plurality of the cut lines are formed in the bent area.

Further, the liquid crystal display device according to the present invention comprises two substrates each having an electrode formed thereon, a liquid crystal layer sandwiched between the two substrates, and one of the two substrates. A printed circuit board provided on a back surface side, on which a drive circuit for driving the liquid crystal layer is formed, wherein the first lead wire is electrically connected to the one substrate, and the second lead wire is connected to the printed circuit board; And the tape carrier package described above, which is electrically connected to the tape carrier package and is attached so as to be bent in the bent region.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of a first embodiment of a tape carrier package according to the present invention will be described with reference to FIGS. FIG. 2 is a plan view showing a configuration of the tape carrier package of the present embodiment, and FIG. 1 is a cross-sectional view of a liquid crystal display device on which the tape carrier package of the present embodiment is mounted.

The tape carrier package 5 according to the present embodiment has a base film 11 made of polyimide. The procedure for forming the tape carrier package 5 will be described below. First, as shown in FIG. 2, a hole 1 for mounting the driving IC chip 31 on the base film 11 is formed.
8a and a slit 16 for soldering connection with the printed circuit board 48, and the bent portion 13
a, 13b are previously cut straight lines 14a, 1
4b are formed in advance. The pitch of the straight cut lines 14a, 14b of the bent portions 13a, 13b is, for example, 0.3 mm, and the number of steps is, for example, six. The base film 11 has a thickness of, for example, 75 μm.
The lead wires 12a and 12b made of copper having a thickness of, for example, 35 μm are formed thereon, and a desired wiring pattern is drawn. The surfaces of the lead wires 12a and 12b are plated with, for example, tin with a thickness of about 4 μm. In addition,
The lead wires 12 a and 12 b are formed such that one end of each of them enters the hole 18.

IC chip 31 formed in slit 16
The solder resist 21 is applied to the lead wire area surrounded by the dashed line except for the lead wire area on the input side of FIG. It has been applied (see FIG. 2).

The IC chip 31 includes the bumps 32 of the IC chip 31 and the lead wires 12a, 1
2b is mounted on the tape carrier package 5 by inner lead bonding with each end, and is sealed with a resin 33. Next, before punching out the tape carrier package 5, the anisotropic conductive film 36 is collectively temporarily pressed on a series of lead electrodes to be subjected to outer lead bonding on the tape carrier package 5. The condition of the temporary crimping is, for example, 80 ° C. for 3 seconds. Next, it is die-cut into a desired shape with a mold. The shape of the tape carrier package 5 after punching is shown in FIG.

Next, a case where a liquid crystal display device is assembled using the tape carrier package of the present embodiment will be described.
First, as shown in FIG. 1, an electrode formed on one glass substrate 44 of a liquid crystal cell 40 having a liquid crystal layer 43 sandwiched between two glass substrates 42 and 44 each having an electrode formed thereon is anisotropically. The conductive conductive film 36 is aligned with the output-side lead wire 12a to which the temporary conductive film 36 has been temporarily pressed, and the carrier tape package 5 is temporarily mounted on the glass substrate 44.

The temporary attachment is performed by pressing a metal block at room temperature. Next, the main bonding outer lead bonding of the anisotropic conductive film 36 is performed using a thermocompression bonding apparatus. The thermocompression bonding apparatus is provided with a heater head.
As a heating method, a pulse heating method was used.
The conditions for the final pressure bonding are, for example, 170 ° C. and a pressure of 3 kg / c.
m ² , 20 seconds. After the outer lead bonding process, the lead wires 12b on the input side and the electrodes on the printed circuit board 48 are connected by solder 38. Soldering was performed by another pulse heating type soldering apparatus. Thus, as shown in FIG. 4, the connection between one glass substrate 44 of the liquid crystal cell and the printed circuit board 48 is completed. The liquid crystal cell 40 is a 12.1 ″ SVGA (Super Video Graphic Ar
Ray) TFT (Thin Film Transistor) driven color liquid crystal display device was used as an example. The number of pixels is 800 × 60
0. A folded tape carrier package was used for the sides of the display screen of the liquid crystal cell in the horizontal direction (X direction), and a flat tape carrier package that was not bent for the vertical direction (Y direction) of the surface screen of the liquid crystal cell. On the side in the X direction, a tape carrier package with 300 output-side leads is used.
And the number of output-side leads is 1 on the side in the Y direction.
Four 50 tape carrier packages were used. The pitch of the outer lead bonding performed through the anisotropic conductive film 36 is 64 μm in the X direction and 90 μm in the Y direction.
μm.

Next, as shown in FIG.
The printed circuit board 48 is bent inside the liquid crystal cell by bending along the cut lines 14a and 14b of a and 13b, and the backlight 46 is incorporated. The fixing of the backlight 46 and the printed circuit board was performed by fixing a printed circuit board 48 and a bezel (not shown) on which the backlight 46 was previously mounted with screws. The backlight 46 used was of a light guide type.

In the above embodiment, each of the plurality of cut lines 14a and 14b provided in the bent portions 13a and 13b is an enlarged view of a part 50 of the cut line shown in FIG. The cut line may be a continuous cut line as shown in FIG. 3, a cut line composed of short lines as shown in FIG. 3 (b), or a cut line composed of dots as shown in FIG. 3 (c). Lines or cut lines composed of a combination of these lines are provided in multiple stages, and TCP
May be bent.

Also, the cut line is the base film 1
1 or may extend to the end and cross. In addition, between the bent portions 13a and 13b, cut lines formed of straight lines, short lines, dots or a combination thereof may be provided in multiple stages, and the lines between the bent portions 13a and 13b are integrated by the above-mentioned lines. It may be connected.

The IC chip 31 and the printed circuit board 4
There is a distance between the electrode 8 and the connection slit 16, and a slit for action or a cut line formed of a straight line, a short line, a dot, or a combination thereof may be provided in multiple stages.

The lead wires 12a and 12b of the bent portions 13a and 13b may be coated with another insulating film other than the solder resist, or may not be coated with an insulating film.

A reliability test was performed on the liquid crystal display device formed as described above. As a mechanical reliability test, an impact test (acceleration 70 × 9.8 m / s ² , time 11 msec,
X, Y, Z directions), vibration test (acceleration 1.5 × 9.
8 m / s ² , frequency 100 to 500 Hz, time 15 minutes /
Cycle, three directions of X, Y, and Z). Each test was performed using five liquid crystal display devices, but no disconnection such as a lead wire occurred. Thermal reliability tests such as a high-temperature high-humidity test, a temperature-humidity cycle test, and a heat shock test were performed using five liquid crystal display devices, respectively.

As described above, according to the present embodiment, the following effects can be obtained.

Since the lead wire of the bent portion is fixed to the base film with a backing, the structure is such that even if stress is applied from the outside, the lead wire is not directly applied to the lead wire. Therefore, the lead wire of the bent portion did not break in the reliability test or in the market, and the reliability of the mechanical strength was improved.

Further, since the solder resist is applied to the lead wire of the bent portion, the reliability of the mechanical strength is improved, and the electrical short-circuit due to the contact between the leads or the adhesion of conductive dust from the outside is caused. It is also effective in preventing occurrence.

Further, unlike the conventional case, it is not necessary to provide a slit in the bent portion and thereafter apply an insulating film to the lead wire. Therefore, it is possible to shorten the TCP manufacturing process and reduce the material cost. Therefore, the cost of TCP can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 5 is a plan view of the tape carrier package 6 according to the second embodiment, and FIG.
1 is a sectional view of a liquid crystal display device when the tape carrier package 6 shown in FIG.

The tape carrier package 6 of the second embodiment is different from the tape carrier package 5 of the first embodiment shown in FIG.
An IC chip 31 is mounted between a and 13b. The IC chip 31 is mounted on the opposite side (outside) of the liquid crystal cell 40 as can be seen from FIG.

The liquid crystal display device on which the tape carrier package 6 of the second embodiment is mounted has a narrower frame than that of the liquid crystal display device on which the tape carrier package 5 of the first embodiment is mounted. The tape carrier package 6 is mounted so that the portion 13a is sharply bent sharply. The tape carrier package 6 according to the second embodiment is shorter than the tape carrier package 5 according to the first embodiment. Therefore, in the second embodiment, as shown in FIG.
b is formed so as to reach the end of the base film 11. Here, the cut lines 14a and 14b of the bent portions 13a and 13b are continuous straight lines, each having a pitch of 0.3 mm, and the number of the cut lines 14a and 14b is, for example, 10 and 8, respectively.

A liquid crystal display device having the tape carrier package of the second embodiment mounted thereon was subjected to a reliability test in the same manner as in the case of the first embodiment. Did not occur.

It goes without saying that the second embodiment also has the same effect as the first embodiment.

[0036]

As described above, the reliability can be improved as compared with the conventional case.

[Brief description of the drawings]

FIG. 1 shows a first tape carrier package according to the present invention.
Sectional drawing which shows the structure of the liquid crystal display device which mounted embodiment of FIG.

FIG. 2 is a plan view showing the configuration of the tape carrier package according to the first embodiment.

FIG. 3 is an explanatory diagram illustrating types of cut lines.

FIG. 4 is a top view of the liquid crystal display device on which the tape carrier package according to the first embodiment is mounted.

FIG. 5 shows a second tape carrier package according to the present invention.
FIG. 2 is a plan view showing the configuration of the embodiment.

FIG. 6 is a cross-sectional view illustrating a configuration of a liquid crystal display device on which the tape carrier package according to the second embodiment is mounted.

FIG. 7 is a cross-sectional view illustrating a configuration of a conventional liquid crystal display device.

FIG. 8 is a plan view of a conventional tape carrier package.

FIG. 9 is a plan view of a conventional liquid crystal display device.

[Explanation of symbols]

 Reference Signs List 5 tape carrier package 6 tape carrier package 11 base film 12a, 12b lead wire 13a, 13b bent portion (bending area) 14a, 14b cut line 16 slit 18 hole 21 solder resist 31 driving IC chip 32 bump 33 resin 36 anisotropy Conductive film 38 Solder 40 Liquid crystal cell 42,44 Glass substrate 43 Liquid crystal layer 46 Backlight 48 Printed circuit board

Claims (3)

[Claims] 1. A base film having a bent region,
First and second leads formed on the base film, holes provided in the base film such that one end of each of the first and second leads is exposed, and mounting in the holes. A tape carrier package comprising: an IC chip electrically connected to end portions of the exposed first and second lead wires; and a cut line provided in the bending area. 2. The tape carrier package according to claim 1, wherein a plurality of said cut lines are formed in each bending area. 3. A liquid crystal display device comprising: two substrates each having electrodes formed thereon; a liquid crystal layer sandwiched between the two substrates; and a liquid crystal layer disposed on the back side of one of the two substrates. A printed circuit board on which a driving circuit for driving a layer is formed, wherein the first lead wire is electrically connected to the one substrate;
3. The tape carrier package according to claim 1, wherein the lead wire is electrically connected to the printed circuit board, and is attached so as to be bent in the bent area. 4. Liquid crystal display.