JPH0229685A - Terminal electrode - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to terminal electrodes in liquid crystal panels and the like, particularly to a large number of high-density terminal electrodes.

Conventional technology Advances in microfabrication technology, liquid crystal materials, packaging technology, etc. have made it possible to obtain television screens with a small screen size of 2 to 6 inches, but with no practical problems with liquid crystal panels, at a commercial pace. It has become.

By forming an RGH colored layer on one of the two glass plates that make up the liquid crystal panel, color display can be easily realized, and in so-called active type liquid crystal panels that have a built-in switching element in each pixel, An image without crosstalk and with a high contrast ratio is ensured.

Such a liquid crystal panel has 120 to 240 scanning lines.
A matrix arrangement of approximately 240 to 720 signal lines is standard, and several hundred electrode lines are required.

Mounting is a means for connecting several hundred wires to terminal electrodes of a liquid crystal panel having an image display function, and is formed on one glass plate 2 constituting a liquid crystal panel 1, for example, as shown in FIG. A connection film 6 based on a polyimide resin thin film and having a connection portion 5 of gold-plated copper foil is pressed onto the terminal electrodes 3 and 4 of the scanning line and signal line, and is cured with an adhesive. . A more advanced form is C0G (chip on glass), in which a semiconductor integrated circuit chip 7 that supplies drive signals to terminal electrodes 3' and 4' is directly pressed and fixed with adhesive, as shown in Figure 4. There is a method to reduce the cost of the mounting process without using the connection film 6 (see Fig. 3). Alternatively, it is planned to be introduced for the purpose of promoting higher density implementation. In FIGS. 3 and 4, reference numeral 8 denotes another glass plate constituting the liquid crystal panel 1, which has one colored layer and is called a color filter. Reference numerals 9 and 1o denote wiring paths that connect the image display section located at the center of the liquid crystal panel 1 and the terminal electrodes 3 and 4 or 3' and 4' of the scanning lines and signal lines, and are not necessarily connected. Although it is not necessary that the terminal electrodes 3.4 or 3', 4' be made of the same conductive material, in a simple matrix type liquid crystal panel used on a boat, the terminal electrodes 3, 4 or 3' are made of a transparent conductive material such as ITO. , 4' and wiring paths 9 and 10 are formed simultaneously.

Problems to be Solved by the Invention There are two well-known types of adhesive printing presses that play an important role in mounting technology: a thermosetting type and an ultraviolet curing type. In the case of thermosetting adhesives, there are no special restrictions regarding the conductive material of the terminal electrodes, but rather the heat resistance of the liquid crystal panel becomes a problem. A colored layer made of an organic thin film containing either a dye or a pigment, or both, together with liquid crystal, cannot withstand heating exceeding 160° C., and the optical properties of the liquid crystal panel are impaired. Therefore, it is necessary to take measures such as heat treatment below 100℃ or shortening the treatment time if the temperature is high, but the degree of curing of the adhesive will not increase and there will be difficulties in ensuring moisture resistance. .

On the other hand, in the case of UV-curable adhesives, the light resistance of the color filter is poor and unless selective irradiation with UV rays is required, they are easier to use and have excellent properties from the viewpoint of productivity. have. However, in the case of the ultraviolet curing type, as shown in FIG.
It is an essential requirement that the ultraviolet curing resin 12 be irradiated with
The terminal electrode 3 and the like must also be made of a transparent conductive thin film such as ITO. As mentioned earlier, this is not a problem with simple matrix type liquid crystal panels, but in the case of active type, it is not necessarily a good idea to configure the terminal electrodes of the scanning line and the terminal electrode of the signal line with the same ITO. 1 reference (H, Tanaka at al, S
I Dl 987 Digest pp, 14o
~120), in order to streamline the process, if a terminal electrode group arrangement in which the scanning line side is made of metal such as chromium and the signal line side is made of ITO is adopted, ultraviolet rays will be removed as shown in Figure 6. The cured resin 12 cannot be cured around the metal terminal electrodes 13. By making the irradiation direction of the ultraviolet rays 11 not only perpendicular to the glass substrate 2 but also adding a component in a random direction, lengthening the ultraviolet irradiation time, or increasing the irradiation power, the terminal electrode of the ultraviolet rays 11 can be Although it is possible to increase the wrapping around the periphery of the terminal electrode 3 (see Figure 5), it is essentially impossible to obtain the same degree of curing and productivity as when the terminal electrode 3 (see Fig. 5) is made of a transparent conductive thin film such as ITO. However, there is a problem in that it is necessary to take measures to prevent deterioration of the color filter. In FIGS. 5 and 6, reference numeral 14 denotes a member for pressing the connection film 6 and the semiconductor chip against the glass substrate 2, and the pressing mechanism will be omitted. 15
is an insulating layer such as 5i02 or Si3N4, and is not necessarily located directly under the terminal electrodes 3, 13, and there are devices in which the terminal electrodes 3, 13 are exposed through openings.

Means for Solving the Problems The present invention provides a means for providing a sufficient amount of light to an ultraviolet curing resin even when the terminal electrode is opaque to ultraviolet light. This is achieved by forming the terminal electrode into a pattern having a large number of openings instead of forming it solidly.

Ultraviolet rays penetrate around the opening formed in the working terminal electrode and harden the UV curable resin in the vicinity, so by increasing the number of openings and giving them an optimal size, the UV curable resin can be cured almost entirely.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 shows the pattern shape of the terminal electrode 16 in this embodiment, and FIG. 2 shows a cross-sectional view of the manufacturing process when the same pattern shape is irradiated with ultraviolet rays.

According to this embodiment, the opening 1 formed in the terminal electrode 16
The diffracted light of the ultraviolet rays around the rays 7 irradiates the ultraviolet curing resin 18 in the area that is in the shadow with respect to the vertically incident light. Therefore, in order to narrow the shadow area, opening 1
The area of the terminal electrode 16 may be increased.
The area of the opening 17 is determined based on the contact resistance data because the contact area with the connecting portion 5 of the connecting film 6 and the pande electrode of the semiconductor chip (not shown) decreases, and the contact resistance increases. It's good to do that. In order to increase the amount of light that wraps around the shadow area, it is necessary to increase the pitch of the apertures 17, that is, to increase the resolution of the phosphorography for forming the apertures 17, and as mentioned earlier, the ultraviolet 1
It is important to add the oblique component 11' to the incident component 1.

In addition, when a metal thin film is used for the terminal electrode, it is extremely easy to reduce the contact resistance to less than 100% compared to transparent conductive ITO. Excellent effects such as being made possible can be obtained. Another notable effect is that it has become possible to develop new technologies such as mounting multiple semiconductor chips on transparent insulating substrates such as glass or quartz to create high-density chip boards without using packages. .

Note that metal thin films used for terminal electrodes, such as Muβ and Or, which tend to form a passivity state on the surface, often lack reliability in mounting, so please be careful with ultra-LSI people! - Take measures for passivation like the two-layer interconnection of the metal β, directly use materials such as platinum or gold, or use suitable metals and noble metals such as platinum or gold, or silicides containing molybdenum, tungsten, etc. It should be noted that there may be cases where lamination formation is required.

Effects of the Invention As stated above, since the terminal electrode made of a thin metal film formed on a transparent insulating substrate such as glass has an opening, mounting can be realized using an ultraviolet curing adhesive. has been proven. As a result, for example, in an active liquid crystal panel, the restriction that the terminal groups on the scanning line side and the signal line side are made of transparent conductive material is removed, and process rationalization and flexibility are guaranteed.

[Brief explanation of the drawing]

Figure 1 shows a terminal electrode pattern having an opening in an embodiment of the present invention, Figure 2 is a sectional view of the main part of the mounting process during ultraviolet irradiation using the same pattern, and Figure 3 shows a liquid crystal panel in a conventional example. FIG. 4 is a perspective view showing the mounting process for the opaque terminal electrodes in the conventional example of liquid crystal display in another conventional example. be. 2...Transparent insulating substrate, 6...Connection part, 6...Connection film, 11.11...
・Ultraviolet light, 12...Ultraviolet curing resin, 16...
...Terminal electrode, 17...Opening. Name of agent: Patent attorney Shigetaka Awano and one other person

Claims (1)

[Claims] A terminal electrode formed on a transparent insulating substrate and fixed to a gold-plated connection part of a connection film or a pande electrode of a semiconductor chip by pressure contact via an ultraviolet curing resin, characterized by being made of metal having an opening. terminal electrode.