JPH04280036A - Flat type display - Google Patents

Abstract

PURPOSE:To prevent a flexible wiring plate and a substrate from being separated from each other by enhancing adhesive strength of the end portion of the flexible wiring plate in a flat type display where a drive signal is applied to electrodes on the substrate via the flexible wiring plate. CONSTITUTION:In a flat type display 1 where a substrate 11 with a plurality of electrode terminals 50, 51 arranged in one direction is secured to a flexible wiring plate 60 having a plurality of connecting terminals 70 paired with the electrode terminals 50, 51, respectively via an adhesive material 90, a projecting member 71 for enlarging a adhering area of the adhesive material 90 is provided outside of a terminal row consisted of the connecting terminals 70 on the inner surface of the flexible wiring plate 60.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat display device configured to apply drive signals to electrodes on a substrate via a flexible wiring board.

[0002] Flexible wiring boards (flexible printed wiring boards) have a large space advantage and can be used as a wiring means for flat-type display devices, which are characterized by a thin depth, because wiring for a large number of terminals can be done at once. It is widely used as

In particular, in high-definition display devices in which the arrangement pitch of electrode terminals is small, thermosetting resin (containing conductive particles) is used as a method for electrically connecting a display substrate and a flexible wiring board. The mainstream is a thermocompression bonding method using an anisotropic conductive material (anisotropic conductive material) as an adhesive.

0004

[Prior Art] A matrix display type plasma display panel (PDP) that displays characters and figures by a combination of dots (pixels) that emit light has a pair of glass substrates on the display side and the back side facing each other with a discharge space provided. The discharge cells defined at or near the intersections of the band-shaped electrodes arranged in a grid are selectively discharged.

FIG. 3 is an exploded perspective view showing the appearance of a general PDP 1. As shown in FIG.

The PDP 1 includes a pair of glass substrates 11 and 12 on the display surface H side and the back side, and each glass substrate 11 and 12.
It is composed of a flexible printed circuit board (FPC) 60 fixed to both ends of each. The periphery of the opposing gap between the glass substrates 11 and 12 is sealed, and a discharge space is formed inside. In the discharge space, discharge cells corresponding to dots are defined at each intersection of electrodes (not shown) arranged in a grid pattern.

Electrode terminals 50 and 51 are provided on the inner surfaces of the glass substrates 11 and 12 along their edges. A connection terminal (wiring board side terminal) 70 that pairs with each electrode terminal 50, 51 is provided on the inner surface of the FPC 60, and such an FPC 60 electrically connects the PDP 1 and an external drive circuit (not shown). connected to.

Note that the electrode terminal 50 is connected to a display electrode led out from the display area, but the electrode terminal 51 (
The terminals at both ends of the glass substrate side terminal row) are so-called dummy terminals that are not involved in display, and are provided to prevent the electrode terminals 50 from peeling off due to shrinkage of the FPC 60, and to reduce the bonding area with the glass substrates 11 and 12. It is formed wider in the column direction of the terminals than the electrode terminals 50 so as to be large.

[0009]FPC60 also has a metal film (thickness is about 30 μm) on a base plate made of polyimide or the like.
The connection terminals 70 are formed by patterning, and are fixed to the glass substrates 11 and 12 by thermocompression bonding using a thermosetting resin as an anisotropic conductive material as an adhesive.

FIG. 4 is a plan view showing the main parts of a conventional PDP 1j, and FIG. 5 is a sectional view taken along the line V--V in FIG.

In the PDP 1j, an FPC 60j having a strip-shaped connection terminal 70 is fixed to the glass substrate 11 by thermocompression bonding.

[0012] When fixing the FPC 60j, first, for example, on the inner surface of the FPC 60j, in a continuous manner including the top of the connection terminals 70 along the arrangement direction of the connection terminals 70 (hereinafter referred to as the "lateral direction" for convenience), The above-mentioned thermosetting resin is applied in a band shape of a constant width. At this time, the coating width and amount of the thermosetting resin are optimized in consideration of the degree of spreading due to the viscosity of the resin, cost, etc.

Next, the FPC 6 is placed so that the electrode terminals 50 and 51 and the connection terminal 70 face the glass substrate 11.
After 0j is placed, a bonding tool heated to about 200° C. is pressed against the FPC 60j with a predetermined pressure from the FPC 60j side. As a result, the thermosetting resin spreads in the extending direction of the connecting terminal 70 (hereinafter referred to as "vertical direction" for convenience) and hardens.
Adhesive material 90 for bonding the FPC 60j and the glass substrate 11
becomes j.

Although not shown in the figure, the electrode terminals 50,
51 and the connecting terminal 70 are opposed to each other via a thin film-like adhesive 90j (containing conductive micropieces as described above), and are electrically conductive and bonded to each other. On the other hand, between each connection terminal 70, that is, between each electrode terminal 50, the conductive minute pieces are dispersed in the adhesive 90j (low density state). Insulated.

[0015]

[Problem to be solved by the invention] Conventionally, FP
At both ends of the C60j in the lateral direction, the adhesive 90j does not spread in the vertical direction, and the bonding area between the FPC 60j and the glass substrate 11 is small. In particular, the corner 60C of the FPC 60j is
As clearly shown in FIG. 5, the FPC 60j is in a floating state from the glass substrate 11, which causes the problem that the FPC 60j is easily peeled off from the glass substrate 11.

[0016] In order to solve such problems, FPC6
Regarding both ends of 0j, the thermosetting resin that will become the adhesive 90j is compared to the area facing the electrode terminal 50 (as described above, the resin application conditions should be selected in consideration of the spread during pressure bonding). It is conceivable to apply it in large numbers. However, in that case, the amount of resin applied is more likely to vary than when the application conditions are uniform, and there is a risk that the adhesion conditions will differ for each pressure bond. It is also disadvantageous in terms of productivity in the resin coating process.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention aims to prevent peeling between a flexible wiring board and a substrate by increasing the adhesive strength at the ends of the flexible wiring board.

[0018]

[Means for solving the problems] A PDP according to the present invention includes:
In order to solve the above-mentioned problem, as shown in FIG. 1, a substrate 11 on which a plurality of electrode terminals 50, 51 are arranged in one direction;
A flexible wiring board 60 having a plurality of connection terminals 70 paired with each of the electrode terminals 50 and 51 is bonded to an adhesive 9.
In the flat type display device 1 fixed by 0,
A protruding member 71 for enlarging the bonding area by the adhesive 90 is provided on the outside of the terminal row made up of the connection terminals 70 on the inner surface of the flexible wiring board 60.

[0019]

[Operation] Flexible wiring board 6 is attached to substrate 11 via adhesive 90.
0 is pressed, the adhesive 9 by the volume of the protruding member 71 is applied in the gap between the substrate 11 and the flexible wiring board 60.
0 expands as if being pushed out, and the bonding area between the substrate 11 and the flexible wiring board 60 increases.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view showing the main parts of a PDP 1 according to the present invention, and FIG. 2 is a sectional view taken along the line II--II in FIG. In these figures, components having the same functions as those in FIGS. 4 and 5 are denoted by the same reference numerals, and their explanations will be omitted or simplified.

[0021] In the PDP 1, electrode terminals 50 are arranged along the edge.
, 51, and an electrode terminal 50,
FPC having connection terminals 70 paired with each of 51
60 are fixed by thermocompression bonding using adhesive 90 which is an anisotropic conductive material.

The electrode terminals 50 and 51 are, for example, a three-layer thin film of chromium-copper-chromium (thickness 0.5 to 1
It is formed by patterning (on the order of μm).

The width of the electrode terminals 50 is, for example, about 0.3 mm, and the interval between the electrode terminals 50 is also about 0.3 mm. On the other hand, the electrode terminal 51 is a dummy terminal, and the width in the horizontal direction is, for example, about 4 mm, and the FPC 6
It is arranged so as to protrude outward with respect to 0.

On the other hand, the connecting terminal 70 has a slightly smaller width than the electrode terminal 50, and is connected to the electrode terminals 50 and 51 via a thin film-like adhesive 90, as in the conventional case. The gap between the FPC 60 and the glass substrate 11 is filled with an adhesive 90.

Now, in the PDP 1 of this embodiment, the connection terminals 70 that are paired with the electrode terminals 51, that is, the connection terminals 70 at both ends of the terminal row made up of a plurality of connection terminals 70, are provided on the outside and parallel to the connection terminals 70. Two band-shaped protruding members 71 are provided. This protrusion member 71 is formed simultaneously with the formation of each connection terminal 70 in the FPC 60.

[0026] As a result, the FPC 60 and the glass substrate 11
As explained in the prior art section, prior to the thermocompression bonding, a film is applied to the inner surface of the FPC 60 in a predetermined width (for example, about 3 mm) in the lateral direction and a thickness of about 35 μm, for example. The thermosetting resin is pushed out and spread in the vertical direction as the FPC 60 and the glass substrate 11 are pressed against each other. Therefore, as clearly shown in FIG. 1, the bonding area with the glass substrate 11 at the end of the FPC 60 becomes large, and separation between the FPC 60 and the glass substrate 11 is suppressed.

In other words, when the temperature returns to room temperature after thermocompression bonding of the FPC 60, since the FPC 60 has a larger coefficient of thermal expansion than the glass substrate 11, the FPC 60 contracts more than the glass substrate 11, creating stress between them. . This stress is
Since the glass substrate 11 has high rigidity, it acts as a shear stress at the interface between the FPC 60 and the glass substrate 11, and also acts as a tensile stress particularly at both ends of the FPC 60.

However, as described above, in the PDP 1, a wide adhesive surface is formed on the outside of the connection terminal 70, so the bonding force against the above-mentioned stress is large, and the FP
The fixed state between C60 and the glass substrate 11 is maintained.

According to the above-described embodiment, the bonding strength between the FPC 60 and the glass substrate 11 can be increased compared to the prior art by simply arranging the projection member 71 when forming a conductor pattern on the FPC 60.

In the above embodiment, the thickness (height) of the protrusion member 71 is the same as the thickness of the connection terminal 70, but the thickness of the protrusion member 71 is smaller than the thickness of the connection terminal 70. It's okay. Further, when the electrode terminal 51 is arranged so that the protruding member 71 and the glass substrate 11 face each other, the thickness of the protruding member 71 is greater than the sum of the thickness of the connecting terminal 70 and the thickness of the electrode terminal 50. It may be larger than the thickness of the connection terminal 70 as long as it is small. Furthermore, the planar shape of the protrusion member 71 is not limited to a band shape, and the protrusion member 71 of any shape (for example, circular) can be arranged at an appropriate position.

In the above embodiment, the glass substrate 11
The electrode terminals 51 arranged at both ends of the terminal row on the side were made into dummy terminals having no function on the electric circuit.
It may also be used as a terminal for short-circuiting the display electrode array during aging to display or to turn on all display cells.

[0032]

According to the present invention, it is possible to increase the adhesion strength at the end portion of a flexible wiring board, and it is possible to prevent separation between the flexible wiring board and the substrate.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the main parts of a PDP according to the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG. 1;

FIG. 3 is an exploded perspective view showing the appearance of a typical PDP.

FIG. 4 is a plan view showing the main parts of a conventional PDP.

FIG. 5 is a sectional view taken along the line V-V in FIG. 4;

[Explanation of symbols]

1 PDP (flat display device) 11 Glass substrate (substrate) 50, 51 Electrode terminal 60 FPC (flexible wiring board) 70 Connection terminal 90 Adhesive (adhesive material) 71 Projection member

Claims (1)

[Claims] 1. A substrate (11) on which a plurality of electrode terminals (50) (51) are arranged in one direction, and each of the electrode terminals (50).
In the flat display device (1), a flexible wiring board (60) having a plurality of connection terminals (70) paired with each of the flexible wiring boards (60) is fixed with an adhesive (90). A protrusion member (71) is provided on the outside of the terminal row consisting of the connection terminals (70) on the inner surface of the plate (60) for expanding the bonding area by the adhesive (90). flat type display device.