JP3258805B2 - Display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device in which a driving element is connected to a display substrate.

[0002]

2. Description of the Related Art Conventionally, a display device having a substrate having a transparent electrode, such as a liquid crystal display, has been disclosed in Japanese Patent Application Laid-Open No. 4-158.
As disclosed in Japanese Patent No. 338, a terminal portion of a driving element is connected to a terminal portion including terminals forming a row of a display using a connecting agent made of an anisotropic conductive material. This is done by using an adhesive made by kneading conductive particles such as small metal particles and solder particles as an anisotropic conductive material, with the terminal of the display and the terminal of the drive element facing each other, and between both terminal rows. An anisotropic conductive material is disposed on the substrate, and the material is connected by heating and pressing.

[0003]

However, the terminal portions forming the rows of the display are provided in large numbers and densely as the display capacity increases and the display density increases, so that the exposed terminal portions are liable to be damaged. When the terminal is a transparent electrode, it is relatively soft, so it is easy to be scratched during display device manufacturing work, and it is difficult to distinguish the scratches. Many. In such a case, when the terminals are connected with the anisotropic conductive material described above, the connection area is insufficient due to the short length of the terminal on the damaged display surface side, or the connection is made only at the terminal side of the damaged portion and the display surface side In some cases, connection was not established, and connection failures occurred frequently. When examining such poor connection, it is also found that the probability that the conductive particles are crowded at the damaged terminal part is low because the conductive particles of the connecting agent are randomly kneaded. Was.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has been made in view of the above, and is provided with a substrate for a display having a terminal portion including a row of terminals formed of transparent electrodes exposed on the surface. And a driving element having a terminal portion connected to the terminal portion of the substrate, and a connecting agent interposed between the terminal portion of the display device substrate and the terminal portion of the driving element to connect both terminals. And a row of solder particles forming an oblique row to the row of terminals as the connecting agent.

[0005]

This structure is made by paying attention to the fact that adjacent particles are connected to each other when the solder particles are connected to the terminal. To secure and connect the terminal as an effective connection surface.

[0006]

FIG. 1 shows a plan view a of a main part of a display device according to an embodiment of the present invention and a plan view b of a main part of a connecting agent 4 used therein. In the drawing, reference numeral 1 denotes a substrate such as a liquid crystal display, which is provided on a surface of a base 11 such as a glass plate and is exposed, and is made of a transparent electrode, and includes a terminal portion (region) including terminals 12 in a row.
2 Reference numeral 3 denotes a driving element for driving a display such as a liquid crystal display, which has an integrated circuit element 32 on a film-like support 31 and which constitutes a row of tongue-shaped metal foil aggregates such as copper foil. It has a unit electrode 33. Reference numeral 4 denotes a connection agent generally called an anisotropic conductive material, which is kneaded with an adhesive resin agent so that rows of solder particles are arranged obliquely, and is electrically connected in the thickness direction by applying pressure in the thickness direction. Electrical continuity is obtained, but no electrical continuity is achieved in the width direction, that is, the plane direction intersecting the thickness direction. Thereby, the terminal portion 2 is connected to the terminal portion electrode 33 of the drive element via the connection agent 4.

More specifically, the terminal 1 of the substrate 1
No. 2 has a width of 60 to 120 μm, has 48 to 2,000 lines arranged at a pitch of 75 to 170 μm, and the length of the exposed portion is 2.2 to 20 mm. The width (length of the terminal) of the effective connection terminal row as the terminal portion 2 is, for example, 2 mm, and the width of the terminal 12, that is, the electrode width is 90 μm.
In this case, the area of the connection portion of each terminal 12 is 0.09 × 2 m
m. On the other hand, the terminal electrode 33 of the driving element 3 has a width of 50 to
The alignment pitch is set to be equal to that of the terminal portion 2 at 120 μm.

[0008] Such terminal portions 2 are, for example, 1980
About 5 to 60% of the display devices (panels) have scratches 13 on a lot of 1000 substrates having terminal portions in a row.
Disconnection has occurred. For these lots, thickness 2
When a connection is made with a connection agent 4 having an epoxy resin-based adhesive of 0 to 30 μm as a base material, a connection failure display device of 5 to 40% occurs when the diameter of conductive particles as kneaded metal is 5 μm. , Based on the scratch 13 of the terminal 12
It accounts for about 90% of that.

On the other hand, in the present invention, the connecting agent 4
Has a row of solder particles 41 forming a row oblique to the row of terminals 12 in a base material 40 made of an adhesive. The rows of the solder particles 41 are, for example, rows in which high-density rows of particles having a diameter of 5 μm are provided at a pitch of 30 to 150 μm and a pitch of 60 to 200 μm. The terminals 13 are provided in a direction perpendicular to the edge of the substrate 1. 45
It is provided in a direction forming an angle θ of up to 85 degrees.

When such a connecting agent 4 is used, 95 to 100% of the connection failure display devices disappear when pressurized and heated with the connecting agent 4 even if the terminal 12 having the scratch 13 is present.

In such a connection, the connection agent 4 has a thickness of 1.5 in both the prior art and the embodiment of the present invention.
The solder particles having a diameter of 5 μm agglomerate at the portions touching the terminal portions 2 and 33, and the size in contact with the terminals 12 and the like is reduced to approximately 30 to 60 μm. And the close contact with the upper and lower terminals is improved.

As a result of observing the state of this connection, as shown in FIG. 2A, if the solder particles 43 were randomly dispersed and kneaded in a truly uniform manner as shown in FIG. It may have been done, but in reality it was found that the density was uneven and the number of defects was increasing. On the other hand, in the present invention, as shown in FIG. 2B, the solder particles 41 are concentrated around the intersection of the row of the solder particles and the terminals, so that the amount of solder sufficient for the connection is obtained and
There was also solder that straddled No. 3. It was also found that electrical connection failure would occur unless 10 to 15 or more solder particles per terminal normally contributed to the connection.

In order to secure the connection at the intersection, the pitch of the row of the solder particles 41 should be set at the terminal 1.
The pitch of the second row is approximately equal to or shorter than the pitch, and the inclination angle θ
It was particularly preferable to shift about 10 degrees by about 10 degrees in accordance with the pitch of the row of the solder particles 41 around 60 degrees. This is because if the crossing angle is large, the crossing portion tends to be square and the area is easily limited, while if the crossing angle is small, the connection area is easily limited by the pitch rubbing. It is not necessary that the solder particles are aligned inside the row 42 of the solder particles 41, and that the solder particles must not be located outside the row. For example, other than the rows, the arrangement may be such that a density of 0 to 5 terminals / 1 terminal is provided, and a portion having a high density of 10 to 50 terminals / 1 terminal and solder particles is provided in a band shape. A row of solder particles may be clearly formed by laminating a bonding agent material sheet and a bonding agent material sheet in which solder particles are randomly kneaded, and cutting and shaping to a predetermined thickness. In the row 42 of the main connection portion, care should be taken so that the anisotropic conductivity is not broken over a relatively long length. Therefore, the density of the solder particles 41 in the row 42 is preferably 15 to 30 terminals / 1 terminal. preferable. Also base material 4
As for No. 0, besides the above-mentioned epoxy resin type, ultraviolet curable acrylic resin, alkyd resin, ester type resin and the like could be used. As long as the base material 40 has adhesiveness, the problem of whether or not it can be peeled off without repairing the terminal surface when repairing is greater, and the affinity with the solder particles is not a problem with these four types of adhesives. Was.

In addition to the solder particles other than the solder particles, for example, in the case of indium or gold particles having a diameter of 3 to 10 μm, the particles may not only come into contact with the terminals but also be crushed and rubbed at the terminal portions. In this case, the electrical conduction becomes good. Therefore, in practicing the present invention, these metal particles and solder particles may be used in combination. In this case, it is considered that the anisotropy conductivity of the connection agent 4 is locally impaired by the solder, and the connection is made more reliable, rather than the adhesion of the connection conductive particles is increased. In addition to the method according to the present invention,
It was also considered to increase the kneading conductive particles of the anisotropic conductive material and to increase the kneading density. (FIG. 1a,
Electric conduction occurs in a direction parallel to the paper surface of b, for example, in the longitudinal direction of the connection agent 4), and especially when the terminal pitch is small, short-circuiting between terminals frequently occurs, which is not preferable.

[0015]

As described above, according to the present invention, the substrate 1 and the driving element 3 can be reliably connected without causing a short circuit between adjacent terminals even in a dense terminal section. Since the probability of connection is high even when a flaw is found during connection, the effect is extremely large especially in a display device having a large number of terminals and a high terminal density.

[Brief description of the drawings]

FIG. 1 is a plan view a of a main part of a display device according to an embodiment of the present invention and a plan view b of a main part of a connecting agent 4 used for the same.

FIG. 2 is a state diagram a in the related art and a state diagram b in the present invention on the surface of the connecting agent after connection.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 12 Terminal 2 Terminal part 3 Drive element 33 Terminal part electrode 4 Connecting agent

Continuation of the front page (72) Inventor Masayoshi Isobe 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture Tottori Sanyo Electric Co., Ltd. (56) References (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G02F 1/1345 G09F 9/00

Claims (1)

(57) [Claims] 1. A display device substrate having a terminal portion including a row of terminals made of transparent electrodes provided on a surface thereof, a driving element having a terminal portion connected to the terminal portion of the substrate,
A connecting agent interposed between the terminal portion of the substrate and the terminal portion of the driving element to connect the two terminals, wherein the connecting agent forms a row of solder particles forming a row oblique to the row of the terminals. A display device, comprising: