JPH02297875A - Connection structure between electrode terminal rows - Google Patents

Abstract

PURPOSE:To have max. connective margin reasonably by incorporating such an arrangement that the sum of electrode widths of electrode terminal rows of a device terminal part and a cable terminal part and that the shortcircuiting mode due to dislocation between the two electrode terminals has the same dislocation margin as the open mode. CONSTITUTION:The sum w1+w2 of the electrode widths of the electrode terminals rows 1a-1d, 2a-2d of a device terminal part 1 and a cable terminal part 2 shall be greater than the electrode pitch (p), and the shortcircuiting mode due to dislocation delta of one electrode terminal center from the other has the same dislocation margin as the open mode. This setting of the electrode widths w1 and w2 so that the open and shortcircuiting mode margins are the same will enhance the total margin of electrode connections, which should enhance the quality and reliability of the electrical connections.

Description

[Detailed Description of the Invention] [Summary] Regarding the connection structure between electrode terminal rows, the purpose is to improve the stability, reliability, and yield of the connection by a conductive film between the electrode terminals and between the high-density terminal rows with a small electrode pitch. Then, a device terminal part having electrode terminal rows arranged in parallel and a cable terminal part having electrode terminal rows arranged in parallel at the same pitch as the electrode terminal rows of the terminal part are arranged so that both electrode terminal rows overlap. In a connection structure between rows of electrode terminals that are faced to each other and connected by pressing and heat bonding with a conductive film in between, the electrode widths of the respective electrode terminal rows of the device terminal section and the cable terminal section (w ++ sum of W ( w, +w,) is the electrode pitch (
The connection structure between the electrode terminal rows is configured so that the margin of positional deviation in the short mode and the open mode due to the positional deviation (δ) between the centers of both electrode terminals is larger than p) and equal to each other.

[Industrial application field]

The present invention relates to an improvement in the connection structure between a device-side electrode panel having a high-density electrode terminal row and a flat cable having a high-density electrode terminal row.

In recent years, the development of display devices has been remarkable, and in particular, flat displays have rapidly become popular due to their thinness and light weight. Among them, liquid crystal display devices have a low driving voltage and are inexpensive, so they are being actively introduced into the field of office automation equipment such as personal computers and word processors.

Liquid crystal display panels used for these applications are required to display characters and graphics, so they are inevitably moving toward larger screens, more pixels, and higher definition. There are over 100 cables, and the connection with the cable for connecting to the drive circuit is extremely delicate, and is becoming increasingly important in terms of quality and cost.

[Conventional technology]

Liquid crystal display devices generally have two glass panels with striped transparent electrodes (rTo: In, 0.-5nOz
), and the two electrode surfaces are made to face each other and pasted together at right angles with an interval of 10-odd μm.

Then, when liquid crystal is injected into the gap created by the two glass panels and a voltage is applied, the intersections of both striped electrodes form pixels due to the electro-optical effect of the liquid crystal, and a bright and dark display is performed.

FIG. 4 is a diagram showing a conventional example of a connection structure between electrode terminal rows.
Figure (a) is a plan view, and figure (b) is a sectional view taken along line A-A'. In the figure, 10 is a liquid crystal device electrode panel section, for example,
Size: 200 mm x 300 mm, thickness: 1.1 mm
The transparent glass plates 10a to 10g are striped transparent electrodes (ITO) with a width of 0.27 mm, a thickness of 1100 nm, and an interval between adjacent electrodes of 0.03 mm, that is, an interelectrode pitch (p) of 0.3 mm. It is formed. (2) is a device terminal portion formed at the end of the striped transparent electrode (ITO); in this example, the width is 0.15 mm at the same pitch as the striped transparent electrodes 10a to 10g;
It is constituted by device terminal electrode rows 1a to 1g spaced at equal intervals of lines/spaces of 0.15 mm.

20 is a so-called TAB cable (Tape Out
This is a type of printed wiring board in which a large number of conductor wirings are provided on a flexible thin resin plate using o-mated bonding. Reference numeral 2 denotes a cable terminal section, and cable terminal section electrode rows 28 to 28 are formed at the end of the TAB cable with the same width and the same spacing as the device terminal section electrode rows 1a-1g.
2g is provided. 100 is an I that drives the liquid crystal display panel with a driver IC mounted on the TAB cable.
It is C.

3 is a conductive film, which is made by mixing conductive particles, for example, Ni with a particle size of about 10 μm, into a resin that acts as an adhesive, such as a thermoplastic or semi-hardening resin, and forming a film with a thickness of 0.01 to 10 μm.
It is made into a 0.05 mm film, and when it is sandwiched between metal electrodes and heat-pressed, it becomes conductive in the film thickness direction, but
It is a so-called anisotropic conductive film that maintains insulation in the film surface direction.

That is, as shown in FIG.
Connect the cable terminal portion 2 of the cable 20 to each electrode row 1.
A to 1g and 2a to 2g are overlapped so that they match, and heated at, for example, 150'C.

When heated and pressed at 20 kg/cm', the device terminal section 1 and the cable terminal section 2 are electrically connected via the metal particles 30 and also mechanically adhesively fixed.

[Problem to be solved by the invention]

However, the electrode width of each electrode terminal row is very narrow at 0.15 mm (furthermore, due to future demands for higher definition displays,
Due to the demand for color, the electrode width is becoming smaller. Therefore, it is difficult to ideally connect the two electrode terminal rows as shown in the cross-sectional view of FIG. 4(b), resulting in misalignment of the connection.

Figure 3 shows how a connection failure occurs due to misalignment of electrode terminal rows. Figure (a) shows the open mode where a connection failure causes an open circuit, and figure (b) shows a short mode where a connection failure causes a short circuit. FIG. For example, if the cable terminal portion 2 is displaced to the right in FIG. This is the case between lb and 2b, and between 1d and 2d, and there is poor continuity in each electrode bear.
.

■ occurs. In the case of the short mode shown in FIG. 3(b), the positional deviation between both electrode terminal rows becomes larger, and the electrodes 2b and 20 of the electrode terminal row of the cable terminal section 2 are connected to the metal particle 30 and the electrode terminal of the device terminal section l. A short-circuit failure occurs through the column electrode 1b.

In the case of display devices, there is a serious problem in that even one defective point can lead to a defect in the entire display panel, and it is necessary to solve this problem.

[Means to solve the problem]

The above problems are solved by the device terminal section 1 having electrode terminal rows arranged in parallel, and the cable terminal section 2 having electrode terminal rows arranged in parallel at the same pitch as the electrode terminal rows of the terminal section l.
and facing each other so that both electrode terminal rows overlap, and the conductive film 3
In the connection structure between the electrode terminal rows, which are connected by sandwiching and pressing and heat bonding, the device terminal part l and the cable terminal part 2
The electrode width of each electrode terminal row (W+, Wt)
The sum (wt +w= ) is larger than the electrode pitch (p), and the positional deviation margins in the short mode and open mode due to the positional deviation (δ) between the centers of both electrode terminals are made equal. This problem can be solved by a connection structure between the electrode terminal rows.

[Effect]

Since the connection between the two electrode terminal rows by the anisotropic conductive film 3 is made via the metal particles 30 in the anisotropic conductive film 3, it depends on the particle size of the metal particles, but is usually about 10 μm. Conductive films made of materials are often used due to their connection resistance characteristics. Therefore, the relationship between the degree of overlap between the upper and lower electrodes and the size of the metal particles will affect the connection characteristics.

FIG. 1 is a diagram explaining the present invention in detail, where ■ is the device terminal section, 2 is the cable terminal section, 1a-1d is the device terminal section electrode array, 2a-2d is the cable terminal section electrode array, and w is the device terminal section. The electrode width of the terminal part electrode row, W8 is the electrode width of the cable terminal part electrode row, p is the electrode terminal pitch of both electrode rows, δ is the positional deviation between the electrode width centers of both electrode rows, and X is the overlap of both upper and lower electrodes. , y is the distance between adjacent electrodes facing each other in both the upper and lower electrode rows.

Calculating the area where open mode and short mode do not occur from the above conditions is as follows.

(a) Open mode, x=w+/2 +wz/2−δ ・−・−・−・・
−・・−・・−・−(1) If the minimum amount of overlap that results in open mode is set to is given by the following equation.

6m <1/2 (wt +wz) xo・・・・・・
−・・・・・・・・・・・−・・−(2)(b) Short mode y=p−δ−W +/2 + W t/2−・・・−
・・・・・・・・−・−・(3) Minimum electrode gap y for short mode.

Then, since the condition for not causing a short-circuit is y>'jo, the region in which a short-circuit does not occur, that is, the short mode ma, −gin Δ, is given by the following equation.

Δb <1/2 (W+ +w, z) + p-y, ...
・・・－・・・－(4) Figure 2 is a diagram explaining the connection margin of the present invention, and the vertical axis represents the positional deviation (δ) of the upper and lower electrode terminal rows.
, the horizontal axis is the sum of the electrode widths of the upper and lower electrode terminal rows (wt + wz
). In the figure, the straight line of the open mode is when X = X o in equation (1), and the upper left part across the straight line is the open occurrence area, and the lower right part is the good connection area, that is, the automatic mode. It represents the margin Δ-.

On the other hand, the short mode straight line is y=y in equation (3)
0, the upper right portion across the straight line represents the short-circuit occurrence region, and the lower left portion represents the good connection region, that is, the short mode margin Δb.

The intersection point ■ of both straight lines is the open mode margin Δ.

and short mode margin Δ are equal, that is, the total margin of electrode connection is maximized, and if Wo is the sum of the electrode widths that give the intersection ■ of both straight lines, then from equations (1) and (3), Wo=P+(Xo yo)・−−1−−・・・・
~ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ (5) This is the XO> YO, so the sum of the electrode width (W ++ WZ) is larger than the electrode pitch P.

In other words, the method of the present invention makes it possible to realize a connection structure that more rationally provides the maximum connection margin, compared to the conventional connection structure between rows of electrode terminals that have an equal electrode width of 1 and are arranged at equal intervals. .

〔Example〕

The size of the liquid crystal device electrode panel section 10 is 200 mm.
A transparent glass plate with a size of 300 mm and a thickness of 1.1 mm was used, and a striped transparent electrode (ITO) made of a mixed oxide of InzO=SnO□ was formed on it.

The electrode pitch of the device terminal electrode row formed at the end is 200 μm and 100 μm.
A total of six types of liquid crystal panel terminal samples were prepared, each having three different types of liquid crystal panel terminal parts (1) and three types of inter-electrode spaces (S, ).

On the other hand, TAB cable (Tape Automate)
d Bonding) 20 is similarly 200 μm and 10
It has two types of electrode pitch of 0 μm, and has a different electrode width (WZ) and inter-electrode space (3
A total of 6 types of TAB cable terminal samples were created, 3 types for each of 2).

The anisotropic conductive film 3 is made by mixing conductive particles, for example, Ni with a particle size of about 10 μm, into a semi-hardenable resin that acts as an adhesive and forming a film with a thickness of 15 μm. is sandwiched between the electrode terminal rows, and overlapped so that the respective electrode rows match, and
A pressure of 20 kg/Cm2 was applied with C, and the adhesive was bonded by heating and pressing for 20 seconds.

In this way, open, short, and connection resistance of the connected samples were measured.

Table 1 is a table showing samples and measurement data of Examples of the present invention.

l - death: m oven mode merge Δ, 50 65 65 25 33
33 short mode merge Δ, 80 65 65 35 33
33 SO comprehensive merge Δ 50 65 65 25 33 3
In the 3S table, sample numbers *1 and *4 have the same electrode line width and space, that is, data for the prior art.

On the other hand, sample number 2. *1 umbrella5. and *6 show data when the connection structure according to the method of the present invention is adopted. In other words, the sum of electrode widths (wl+wz)
are both larger than the electrode pitch p, and the open mode margin Δ and short mode margin Δ
The electrode widths W and W2 are set so that , are equal.

As a result, the total margin Δ was significantly improved by 30% in both cases compared to the conventional example.

Although this embodiment shows the case of electrical connection between the electrode terminal row of the terminal section of the liquid crystal display panel and the electrode terminal row of the TAB cable terminal section, the present invention is not limited to this.
Needless to say, the present invention can also be applied to connection structures of other products for the same purpose.

〔Effect of the invention〕

As explained above, according to the present invention, the electrode widths W and W2 are set so that the open mode margin Δ and the short mode margin Δ are equal, and the total margin of electrode connection is wide. For example, this greatly contributes to improving the quality and reliability of the electrical connection between the terminal section of the liquid crystal display panel and the TAB cable terminal section, and to improving the product yield.

[Brief explanation of the drawing]

Fig. 1 is a diagram for explaining the present invention in detail, Fig. 2 is a diagram for explaining the connection margin of the present invention, Fig. 3 is a diagram showing a situation where a connection failure occurs due to positional deviation of the electrode terminal row, and Fig. 4 is a diagram for explaining the connection margin of the present invention. It is a figure which shows the conventional example of the connection structure between electrode terminal rows. In the figure, 1 is a device terminal, 2 is a cable terminal, 3 is a conductive film, and 30 is a metal particle.

Claims (1)

[Claims] A device terminal section (1) having electrode terminal rows arranged in parallel;
A cable terminal part (2) having electrode terminal rows arranged in parallel at the same pitch as the electrode terminal rows of the terminal part (1) is made to face each other so that both electrode terminal rows overlap, and a conductive film (3
), the electrode widths (w_1, w_2) of the respective electrode terminal rows of the device terminal part (1) and the cable terminal part (2) are Japanese (w_
1+w_2) is larger than the electrode pitch (p), and the positional deviation margins in the short mode and open mode due to the positional deviation (δ) between the centers of both electrode terminals are equal. connection structure between.