JPH03156818A - Touch panel - Google Patents

Abstract

PURPOSE:To prevent production of cracks at an electrode and peeling of the electrode from a substrate by interposing a layer of conductive synthetic resin thin film which is softer than a layer of binding agent between the electrode on the film substrate and the layer of conductive binding agent. CONSTITUTION:A layer 11 of conductive synthetic resin thin film is interposed almost over the whole surface of a boundary surface between an electrode 3 on a film substrate 1 and a layer 9 of conductive binding agent. As for the layer 11, material can be as desired as far as it is softer than the layer 9 and has resiliency. For example, paste of urethane binding agent including fillers can be used to be applied on the surface of the electrode 3 on the substrate 1 to form a thin film. The electrode 3 on the substrate is connected with a relay electrode 8 on a glass substrate 2 to be continuous through the layer 11.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is arranged on the surface of a display such as a CRT or LCD, and by pressing with a finger a position corresponding to a character, figure, etc. displayed on the display. Related to touch panels for inputting and giving instructions.

[Conventional technology]

For example, as shown in FIG. 8, this type of touch panel has transparent electrodes 3 and 4 made of ITO, SnO, etc., arranged in stripes or other shapes on the opposing surfaces of a synthetic resin film substrate 1 and a glass substrate 2. The substrates 1 and 2 are arranged in a pattern with a predetermined distance between them using a spacer 5 and a seal member 6.

The electrodes 3 and 4 on each substrate 1 and 2 are connected to a control circuit board, etc. (not shown in the figure), for example, via a flexible connection member such as a heat seal or a flexible printed circuit with connection wiring provided on the surface. do.

In this case, the glass substrate 2 and the electrodes 4 on the substrate are inorganic and have good adhesion, but the film substrate 1 and the electrodes 3 on the substrate are organic and inorganic, so the adhesion is somewhat insufficient. I don't like to do that.

Therefore, when the flexible connecting member 7 is directly connected to the electrode 3 on the film substrate 1 with a conductive adhesive or the like, for example, if the flexible connecting member is pulled carelessly, the electrode 3 and the film substrate 1 There is a risk of peeling off.

Conventionally, a relay electrode 8 for external extraction is formed on the glass substrate 2 as shown in FIG.
The flexible connecting member 7 is electrically connected to the other end of the relay electrode 8 through a conductive adhesive layer 10.

[Problem to be solved by the invention] However, due to differences in coefficient of thermal expansion and swelling due to moisture between film substrates and glass substrates, the film substrate shrinks due to heat during the heat-pressing process during production and assembly, resulting in the above-mentioned problem. Problems such as unreasonable stress acting between the relay electrode and the electrode on the film substrate 1 may cause the electrode 3 on the film substrate 1 to crack, or the electrode 3 may peel off from the film substrate 1. there were.

The present invention aims to solve the above problems with a simple configuration.

[Means for Solving the Problems] In order to achieve the above object, the present invention has the following configuration.

That is, electrodes 3 and 4 are provided on opposing surfaces of a synthetic resin film substrate 1 and a glass substrate 2, and the electrodes 3 and 4 on the film substrate 1 are
In the touch panel, the electrodes 3 on the film substrate 1 and the conductive adhesive layer are electrically connected to the relay electric scraper 8 for external drawer provided on the glass substrate 2 via the conductive adhesive layer 9. A conductive synthetic resin thin film layer 11 that is softer than the conductive adhesive N9 is interposed between the conductive adhesive N9 and the conductive adhesive N9.

[For production]

As described above, by interposing the conductive synthetic resin thin film layer 11, which is softer than the conductive adhesive layer 9, between the electrode 3 on the film substrate 1 side and the conductive adhesive layer 9, the film substrate When a misalignment occurs between the electrode 3 on the film substrate side and the relay electrode 8 due to a difference in thermal expansion between the film substrate 1 and the glass substrate 2, the elasticity of the soft conductive synthetic resin thin film layer 11 prevents the misalignment. It is possible to prevent cracks from occurring in the electrode 3 on the film substrate due to absorption, or from peeling off the electrode 3 from the film substrate 1.

〔Example〕

Hereinafter, the present invention will be specifically explained based on embodiments shown in the drawings.

FIG. 1 is a vertical cross-sectional view of a touch panel showing an embodiment of the present invention, FIG. 2 is an enlarged vertical cross-sectional view of the main parts thereof, and FIG. The same members as those in the figures are given the same reference numerals and repeated explanations will be omitted.

In this example, a conductive synthetic resin thin film layer 11 is interposed on substantially the entire boundary surface between the electrode 3 and the conductive adhesive layer 9 of the film substrate l.

As the conductive adhesive layer 9, for example, a silver filler artificial poxo adhesive mixed with a metal such as copper having a predetermined diameter is used.

The conductive synthetic resin thin film layer 11 may be made of any suitable material as long as it is softer, more elastic, and more conductive than the conductive adhesive layer 9, such as paste-like silver. A filler is applied to the surface of the electrode 3 of the film substrate 1 using a urethane adhesive or the like to a thickness of, for example, 20 mm to 20 mm.
It is formed into a thin film of about 30 μm. After forming the conductive synthetic resin thin film layer 11, the electrode 3 on the film base +ffl and the glass substrate 2 are connected via the thin film N11.
The upper relay electrode 8 is electrically connected to the upper relay electrode 8 through a conductive adhesive layer 9.

4 and 5 show other embodiments of the present invention, in which the conductive synthetic resin thin film layer 11 of the electrode 3 on the film substrate side is shown.
forming an electrode opening 3a by cutting off a part of the contact surface with the electrode;
A portion 11a of the conductive synthetic resin thin film layer 11 is brought into direct contact with the film substrate 1 through the opening 3a.

In particular, the figure shows an example in which the electrode opening 3a is formed in the shape of a slit in the longitudinal direction of the electrode 3.

As mentioned above, there is an opening 3a in a part of the film substrate side electrode 3.
, so that a part of the conductive synthetic resin thin film layer 11 is in direct contact with the film substrate 1, the conductive synthetic resin thin film layer 11 is generally in closer contact with the film substrate 1 than the electrode 3 made of ITO or the like. Because of its good properties, peeling of the electrode 3 can be more effectively prevented.

The electrode openings 3a can be formed at the same time, for example, when electrodes are provided on the entire surface of the film substrate and then patterned by etching or the like.

Furthermore, when the film substrate is formed by etching as described above, the surface of the film substrate at the opening 3a is activated compared to the untreated surface of the film substrate, thereby increasing the adhesion strength of the conductive synthetic resin thin film layer 11 to the film substrate 1. It can be further increased.

Note that, if necessary, an opening in the same slit shape or any other shape as described above may be formed on the contact surface of the relay electrode 8 on the glass substrate 2 side with the conductive adhesive layer, so that the conductive adhesive layer It is also possible to make a part of the glass substrate 2 come into close contact with the glass substrate 2 directly. By doing so, as in the case where the conductive adhesive layer and the glass substrate are the film substrates described above, it is possible to improve adhesion and improve reliability.

Furthermore, if necessary, a conductive synthetic resin thin film layer similar to the above may be interposed on the interface between the relay electrode 8 and the conductive adhesive layer of the two glass substrates.

FIGS. 6 and 7 show still other embodiments of the present invention. In this example, the end of the electrode 3 on the film substrate side is formed short, and a conductive synthetic resin thin film layer 11 is formed on the surface of the film substrate as an extension.
is directly provided, and a portion 11b of the conductive synthetic resin thin film layer 11 covers the end portion 3b of the electrode 3. The other configurations are the same as in the previous example.

When the electrode 3 is formed short as described above and the conductive synthetic resin thin film layer 11 is directly formed on the surface of the film substrate on the extension thereof to cover the end portion 3b of the electrode 3, the thin film layer 11 and the film substrate 1 are bonded well. It is possible to maintain close contact and further effectively prevent peeling of the electrode 3.

In particular, when the electrodes on the film substrate 1 to which the thin film layer 11 is in close contact are removed by etching, the adhesion between the resin layer and the film substrate is strong, and the electrodes 3 on the film substrate 1 and the adhesive 9 are As shown in Figure 7, if the electrodes do not overlap on the plane, the expansion and contraction of the substrate will cause the electrodes to overlap.
It is possible to reduce as much as possible the unreasonable stress that is applied to the
Cracking and peeling of the electrode 3 can be further reduced.

〔Effect of the invention〕

As explained above, the present invention provides an electrode 3 of one example of a film substrate.
By providing the paste-like conductive synthetic resin thin film layer 11 between the conductive adhesive layer and the conductive adhesive layer, the electrode 3 on the film substrate side and the relay electrode 8 can be connected to each other due to, for example, the difference in thermal expansion between the film substrate and the glass substrate. If a misalignment occurs between them, the elasticity of the paste-like conductive synthetic resin thin film layer 11 will absorb the misalignment, causing cracks in the electrode 3 on the film substrate, or the electrode 3 may become stuck to the film substrate 1. It is possible to prevent the touch panel from peeling off from the surface, and has the effect of providing a highly durable touch panel.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a touch panel showing an embodiment of the present invention, Fig. 2 is an enlarged longitudinal cross-sectional view of its main parts, Fig. 3 is a plan view taken along the line ■-■ in Fig. 2, and Fig. 4 is a main FIG. 5 is a vertical sectional view of the main part of a touch panel showing another embodiment of the invention, FIG. 5 is a plan view taken along the line v-v in FIG. FIG. 7 is a plan view taken along the line ■--■ in FIG. 6, and FIG. 8 is a vertical cross-sectional view of a conventional touch panel. l is a film substrate, 2 is a glass substrate, 3 and 4 are electrodes, 5
is a spacer, 6 is a sealing member, 7 is a flexible connecting member, 8
1 is a relay electrode, 9 and 10 are conductive adhesive layers, and 11 is a conductive synthetic resin thin film layer.

Claims (1)

[Claims] (1) Electrodes are provided on opposing surfaces of a synthetic resin film substrate and a glass substrate, and the electrodes on the film substrate are electrically connected to the external lead-out relay electrode provided on the glass substrate via a conductive adhesive layer. The touch panel is characterized in that a conductive synthetic resin thin film layer that is softer than the conductive adhesive layer is interposed between the electrode on the film substrate and the conductive adhesive layer. touch panel.