JPH09325323A - Mounting method for display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the display panel from being broken owing to an external shock, etc., by improving the method for mounting the display panel on a frame member. SOLUTION: The display panel 1 consists of a driving substrate 11 and an opposite substrate 12 which are rectangular and different in the length of one side from one another, and liquid crystal which is sandwiched between them. The display panel 1 is divided into a thick screen part 13 where both the substrates 11 and 12 are put one over the other and a thin terminal part 14 where the driving substrate 11 is left without overlapping with the opposite substrate 12. The frame member 2 has an opening surrounded with a flank 21 and this opening part has size corresponding to the external shape of the display panel 1. After the display panel 1 is fallen in the opening of the frame member 2, the display panel 1 is adhered and fixed to the frame member 2 at only four places of the outer periphery along the thick screen part 13 except the thin terminal part 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting method for incorporating a relatively small display panel into a frame member. More specifically, the present invention relates to a technique for improving a method of adhering a display panel to a frame member to prevent the display panel from being damaged by an external impact.

[0002]

2. Description of the Related Art In recent years, active matrix type liquid crystal display panels capable of displaying moving images have been actively developed. This display panel has a structure in which two substrates made of a glass plate or the like are bonded to each other and liquid crystal is held in a gap between them. There are various types of active matrix liquid crystal display panels, from a small size of 1 inch or less to a large size of about 20 inches. The small-sized display panel is incorporated in, for example, a viewfinder of a camera. In this case, the display panel is mounted on the main body side after being mounted by a frame member surrounding the periphery. The frame member plays a role of preventing damage to a substrate made of a glass plate or the like and absorbing an external impact.

[0003]

The display panel is mounted by adhesively fixing it to a frame member that surrounds the outer periphery of the display panel. By the way, a display panel is generally composed of a pair of substrates each having a rectangular shape and one side having mutually different lengths, and an electro-optical substance made of liquid crystal or the like held between the substrates. The display panel is divided into a thick screen portion in which both substrates overlap with each other and a thin terminal portion in which one substrate is left without overlapping with the other substrate. The thin terminal portion has weaker mechanical strength than the thick screen portion. In the conventional mounting method, the display panel is adhered to the frame member at a plurality of positions on the outer periphery over both the thin terminal portion and the thick screen portion. Therefore, when an external shock or the like is applied, the thin-walled terminal portion, which has weaker mechanical strength than the thick-walled screen portion, may be damaged. This terminal portion is a portion used for electrical connection to the outside, and if this terminal portion is damaged, there is a problem that normal display driving is impaired and a fatal defect occurs.

[0004]

The following means have been taken in order to solve the above-mentioned problems of the prior art. That is, according to the present invention, the display panel is mounted by the following steps. First,
Prepare the display panel to be mounted. This display panel is composed of a pair of rectangular substrates each having a side length different from each other and an electro-optical material held between them, and a thick screen portion in which both substrates overlap each other and one substrate in the other. It is divided into a thin terminal part that does not overlap the board. Next, a frame member having an opening corresponding to the outer shape of the display panel is prepared. Then, after dropping the display panel into the opening, the display panel is bonded and fixed to the frame member only at a plurality of locations on the outer periphery along the thick screen portion other than the thin terminal portion. Preferably, the adhering step includes two positions on the outer periphery of the screen part, which are located at both left and right ends in the vicinity of the terminal part, and at two positions on the outer periphery of the screen part, which are located at the rear end opposite to the terminal part. Bond at a total of four places. In this case, for example, an ultraviolet curable resin is used for adhesive fixing. After the adhering step, a step of filling the gap left between the display panel and the frame member with a cushioning elastic resin is performed. Before the bonding step, a step of crimping a flexible connector for electrical connection to the terminal portion of the display panel is performed. By these steps, the mounting of the display panel is completed.

The display panel is divided into a thick screen portion having a relatively high mechanical strength and a thin terminal portion having a relatively low mechanical strength. According to the present invention, the display panel is bonded and fixed to the frame member only at a plurality of locations along the outer circumference of the thick screen portion. Therefore, when a shock is applied from the outside in a state after being assembled, the force is transmitted only to the screen portion having high mechanical strength, and is not transmitted to the terminal portion having weak mechanical strength. Therefore, it is possible to effectively prevent the terminal portion from being damaged.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic view showing a display panel mounting method according to the present invention. As shown in (A), the display panel 1 is mounted integrally with the frame member 2 and the flexible connector 3. In the present embodiment, the display panel 1 is an active matrix type and has a structure in which a drive substrate 11 and a counter substrate 12 are bonded to each other. In this case, the display panel 1 is composed of a pair of drive substrates 11 and a counter substrate 12 each having a rectangular shape and different lengths on one side, and an electro-optical material made of liquid crystal or the like held between them. The display panel 1 is divided into a thick screen portion 13 in which both substrates 11 and 12 are overlapped with each other, and one driving substrate 11 is divided into a thin terminal portion 14 left without overlapping with the other counter substrate 12. There is. A polarizing plate 15 is attached to the central display area of the screen portion 13. On the other hand, a terminal electrode 16 for external connection is patterned on the surface of the terminal portion 14.
On the other hand, the frame member 2 is made of, for example, a plastic molded product, and has a side surface 21 and a bottom surface 22. The opening surrounded by the side surface 21 has a size corresponding to the outer shape of the display panel 1. Further, the bottom surface 22 is provided with a window 23 aligned with the display area of the screen portion 13. The flexible connector 3 is composed of a flexible circuit board, and a wiring electrode 31 corresponding to the terminal electrode 16 on the display panel 1 side is patterned on the surface thereof.

As shown in (B), the display panel 1 is dropped into the opening surrounded by the side surface 21 of the frame member 2. Then, the display panel 1 is adhesively fixed (temporarily fixed) to the frame member 2 only at a plurality of locations on the outer periphery along the thick screen portion other than the thin terminal portion 14. In this embodiment, the ultraviolet curable resin 4
Adhesive fixing is done in. Specifically, there are two places, left and right side ends 17 and 18 located near the terminal portion 14 on the outer periphery of the screen portion, and two places on the rear end 19 which is also located on the outer periphery of the screen portion opposite to the terminal portion 14. Adhere at 4 points in total.
After this bonding step, the gap 5 left between the display panel 1 and the frame member 2 is filled with a cushioning elastic resin (not shown), and the mounting of the display panel 1 is completed. Before the bonding step, a step of crimping the flexible connector 3 for electrical connection to the terminal portion 14 of the display panel 1 is performed. As a result, the terminal electrode 16 on the terminal portion 14 side and the wiring electrode 31 on the flexible connector 3 side are electrically connected to each other.

[0008] (C) shows a bonding portion at the right end located near the terminal portion 14 on the outer periphery of the screen portion 13. As shown in the figure, the display panel 1 includes a counter substrate 12 and a driving substrate 11.
A thick screen portion 13 overlapping each other and a thin terminal portion 14 in which the drive substrate 11 is left without overlapping the counter substrate 12 are provided. The flexible connector 3 is crimped to the terminal portion 14. The resin 4 for adhesion is a thin-walled terminal portion 1
It is supplied to the end face of the thick screen portion 13 without hitting 4. Therefore, the display panel 1 is mechanically supported only by the thick screen portion 13 with respect to the frame member, and the thin terminal portion 14 is in a floating state in the frame member. Therefore, when an external impact is applied to the frame member, the impact force is transmitted only to the screen portion 13 having high mechanical strength, and is not transmitted to the terminal portion 14 having weak mechanical strength. Therefore, the terminal portion 14 is less likely to be damaged.

FIG. 2 is a flowchart showing steps of the display panel mounting method according to the present invention. First, the display panel 1 is prepared in step S1. The frame member 2 is prepared in step S2. Next, in step S3, the polarizing plate 15 is attached to the central display area of the screen portion 13 of the display panel 1. The polarizing plate 15 is attached to both upper and lower surfaces of the screen unit 13. Next, in step S4, a defoaming process (autoclave) is performed. The polarizing plate 15 is glued on the surfaces of the substrates 11 and 12, but in this case bubbles may remain. Then, pressure is applied from above the attached polarizing plate 15 in a heated state to defoam. In step S5, the display panel 1 is driven to perform the final image quality inspection. In step S6, the flexible connector 3 is attached to the terminal portion 14 of the display panel 1.
It is thermo-compression bonded (heat seal). In step S7, an ultraviolet curable resin is applied to the tip of the thermocompression-bonded flexible connector 3 and the resin is hardened to reinforce the thermocompression bonding portion. Proceeding to step S8, the display panel 1 is dropped into the opening of the frame member 2, and the display panel 1 is bonded and fixed to the side surface of the frame member 2 only at four positions on the outer periphery along the screen portion 13 other than the rear terminal portion 14 (temporary). Stop). Proceeding to step S9, the gap 5 left between the display panel 1 and the frame member 2 is filled (molded) with a cushioning elastic resin (for example, silicone resin). This improves impact resistance and moisture resistance.
After advancing to step S10 and marking the product number and the like, appearance inspection is performed in step S11. Finally, in step S12, an electrical check is performed to check the flexible connector 3 and the display panel 1.
Check the electrical continuity of the.

FIG. 3 is a schematic view showing a reference example of a mounting method of a display panel. 3A corresponds to FIG. 1B, and FIG. 3B corresponds to FIG. 1C.
To facilitate understanding, corresponding parts in FIGS. 1 and 3 are designated by corresponding reference numerals. In this reference example, in the step of adhering (temporarily fixing) the display panel 1 and the frame member 2 to which the flexible connector 3 has been thermocompression-bonded in advance, the ultraviolet curable resin 4 is used for adhering at four points. Two of the four places are located on the end face of the terminal portion 14 where the flexible connector 3 and the display panel 1 are thermocompression-bonded to each other. For this reason, when an external impact is applied to the frame member 2 or the like after the bonding step, an external force is applied to the terminal portion 14 of the display panel 1, and the terminal portion 14 is damaged. On the other hand, in the present invention, all the adhesion portions for temporary fixing are changed to the outer periphery of the thick screen portion, and the ultraviolet curable resin is applied and cured.

A drop test was conducted to confirm the effect of the present invention. 10 samples shown in FIG. 1 and 10 samples shown in FIG. 3 were prepared, respectively, and dropped from a height of about 90 cm to examine the damaged state of the terminal portion. In the sample according to the present invention, the terminal portion was not damaged at all, whereas in the reference example, the terminal portion was damaged in 4 out of 10 samples. or,
The adhesive strength of the display panel to the frame member was measured for the 19 samples shown in FIG. 1 and the 19 samples shown in FIG. The sample according to the present invention had an average adhesive strength of 5.73 [N], whereas the reference example had an average adhesive strength of 9.86 [N]. In this way, it is undeniable that if all the adhesion points are selected along the outer periphery of the screen portion according to the present invention, the adhesion strength will be lower than that of the reference example. However, no adverse effect on the quality due to the decrease in adhesive strength was confirmed.

Finally, FIG. 4 is a schematic perspective view showing a specific example of the structure of the active matrix type liquid crystal display panel. This display panel includes a drive substrate 101, a counter substrate 102, and a liquid crystal 103 held between the two. On the drive substrate 101, a pixel array unit 104 and a drive circuit unit are integrally formed. These are collectively referred to as a screen portion in this specification. Actually, the pixel array section 104 constitutes a display area. The drive circuit section is divided into a vertical drive circuit 105 and a horizontal drive circuit 106. Further, the terminal portion 10 for external connection is provided on the upper end of the peripheral portion of the driving substrate 101.
7 are formed. The terminal portion 107 is connected to a vertical drive circuit 105 and a horizontal drive circuit 106 via a wiring 108. On the other hand, a counter electrode (not shown) is formed entirely on the inner surface of the counter substrate 102. The pixel array section 104 includes a row-shaped gate wiring 109 and a column-shaped signal wiring 1.
10 are formed. The gate wiring 109 is connected to the vertical drive circuit 105, and the signal wiring 110 is connected to the horizontal drive circuit 10.
Connect to 6. A pixel electrode 111 and a thin film transistor 112 for driving the pixel electrode 111 are integrated and formed at the intersection of both wirings. In addition, the vertical drive circuit 105 and the horizontal drive circuit 106
Is also composed of thin film transistors.

[0013]

As described above, according to the present invention, after the display panel is dropped into the opening of the frame member, the display is made only at a plurality of positions on the outer periphery along the thick screen portion other than the thin terminal portion. The panel is adhesively fixed to the frame member. This makes it possible to protect the terminal portion, which has a relatively low strength, from damage due to external impact. Further, it becomes possible to withstand external stress after the bonding process, and the damage of the terminal portion due to handling or the like does not occur, leading to an improvement in yield.

[Brief description of drawings]

FIG. 1 is a schematic view showing a display panel mounting method according to the present invention.

FIG. 2 is a flowchart showing a display panel mounting method according to the present invention.

FIG. 3 is a schematic diagram showing a reference example of a display panel mounting method.

FIG. 4 is a schematic perspective view showing a specific configuration example of a display panel.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Display panel, 2 ... Frame member, 3 ... Flexible connector, 4 ... Resin, 11 ... Drive substrate, 12 ... Counter substrate, 13
... screen portion, 14 ... terminal portion, 21 ... side surface, 22 ... bottom surface, 2
3 ... window

Claims (5)

[Claims] 1. A thick screen portion in which a pair of rectangular substrates each having a side length different from each other and an electro-optical material held between these substrates are overlapped with each other, and one substrate is the other. Preparing a display panel divided into a thin terminal portion left without overlapping the substrate, a frame member having an opening corresponding to the outer shape of the display panel, and the display in the opening. A method for mounting a display panel, which comprises performing a bonding step of bonding the display panel to the frame member only at a plurality of locations on the outer periphery along the thick screen portion other than the thin terminal portion after the panel is dropped. 2. The adhering step includes two positions on the outer periphery of the screen portion, the left and right side ends being located near the terminal portion, and the rear end, which is also located on the outer periphery of the screen portion, opposite the terminal portion. The method for mounting a display panel according to claim 1, wherein the bonding is performed at two positions, that is, a total of four positions. 3. The method of mounting a display panel according to claim 1, wherein the adhering step is performed by adhering and fixing with an ultraviolet curable resin. 4. The method of mounting a display panel according to claim 1, further comprising a step of filling a gap left between the display panel and the frame member with a cushioning elastic resin after the adhering step. 5. The method of mounting a display panel according to claim 1, further comprising the step of crimping a flexible connector for electrical connection to a terminal portion of the display panel before the adhering step.