JPH02311826A - Manufacture of liquid crystal electrooptic device - Google Patents

Abstract

PURPOSE:To inspect electric components, one by one, after they are mounted on an electric circuit by forming one wiring group for each individual electric component, forming an insulating film at a necessary part, and connecting one wiring group for one electric component mutually and thus forming a common wiring group lastly. CONSTITUTION:A 1st wiring group 2 is formed of a conductive material on a substrate 1 which has an insulating surface. At this time, the 1st wiring group 2 is one wiring group for one electric component 3 and not connected to a wiring group 2' to which an adjacent electric component is connected. Then the inter-layer insulating film 4 is formed covering part of the 1st wiring group, a 2nd wiring group 5 is formed beyond on the insulating film 4, and the 1st wiring groups 2 and 2' are connected mutually to complete the common wiring group. Consequently, the electric components mounted on the circuit can be inspected before the device is completed, so the yield of the product is improved.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a wiring board on which electrical parts, etc. are mounted, and in particular, to a liquid crystal electro-optical device, in which it is possible to individually test a plurality of electrical parts, etc. after mounting them on the board. The present invention relates to a method of manufacturing a novel wiring board.

"Conventional Technology" Conventionally, electrical components and the like are mounted on a board on which electrical circuits are drawn, and it is used as a wiring board with circuits for driving liquid crystal display devices, image sensors, thermal print heads, and other electronic components. P-boards were generally used.

This P-board consists of copper wiring formed on an epoxy or glass epoxy resin substrate by etching, etc., and holes drilled on the copper wiring for inserting the feet of electrical components. Insert it, solder it, etc., and connect it to the electrical circuit.

In the electric circuit installed on this P board, the common wiring part has been completed before the electric parts are installed, and after the electric parts are installed, the individual electric parts are tested and the connections with the individual electric parts are completed. It was not possible to test the section.

In addition, when setting up an electrical circuit on the P-board, it is necessary to connect the P-board and electronic components when driving a specific electronic component, which increases the number of connections and creates new problems such as poor connections. It has arisen.

On the other hand, an electric circuit for mounting electric parts, etc. is drawn directly on a part of the board that constitutes the electronic parts such as the image sensor-1 liquid crystal display device and the thermal head.
Techniques for attaching electrical components are also known. This method is superior in that the number of parts can be reduced compared to the case where a P board is used, and there is no need for a connection part with the electronic parts to be driven.

However, even in this method, common wiring is used for multiple electrical components, so after the electrical components are attached to the electrical circuit on the board, as in the case of the P board, each electrical component is It was not possible to test for defects and to check whether the connections were good or bad when installing electrical parts. Furthermore, in order to connect a plurality of electrical components to a common wiring, multilayer wiring is required, complicating the manufacturing process.

FIG. 2 schematically shows a method for manufacturing the multilayer wiring portion of this conventional device.

As shown in FIG. 2A, common wiring lines θ are formed on the substrate (1) using a conductive material (for example, copper, ITO, etc.) by wet etching or the like.

Next, an insulating film is formed in the pattern shown in FIG. Here, 06) is the common wiring jlfA05) and the technique-divided wiring 07
) is a contact hole for connection. Next, as shown in the same figure (C), branch wiring θ'7) is formed, and electrical components are attached to this branch wiring surface.

Branch wiring (+7) in such a multilayer wiring part
In order to connect to the common wiring a5) through the contact hole 0ω, it is necessary to limit the dimensions of the contact hole 00. However, when the number of terminals of the electrical components to be installed increases, or when the number of electrical components increases, the size of the contact hole 0ω must be made smaller, and contact failure occurs, especially when using the printing method. When forming an insulating layer, there is an advantage that the cost can be reduced, but there is a technical problem that a contact hole cannot be formed.

``Structure of the Invention'' The present invention relates to a novel structure for a method of manufacturing a liquid crystal electro-optical device having a wiring board as described above, and particularly relates to a method for manufacturing a liquid crystal electro-optical device having a wiring board as described above. This is an improved item.

In other words, a plurality of common wirings are provided on an insulating substrate, and the configuration is such that electrical parts can be mounted on the wiring divided from the common wiring and the wiring divided into technical parts. It is possible to carry out inspections.

Furthermore, since JIA edge layered products can be inspected after the substrates are bonded together, it is possible to prevent foreign matter such as particles several micrometers in size from entering between the substrates when forming the insulation layer or inspecting the parts. Therefore, it greatly increases the yield in the manufacturing process of liquid crystal electro-optical devices.

The present invention will be explained below using drawings showing an example.

FIG. 1 shows an example of a method for manufacturing a novel wiring board for the liquid crystal electro-optical device of the present invention.

A first wiring group (2) is placed on a substrate (1) having an insulating surface.
) is made of conductive material. (Same figure (A)) At this time, the first
The wiring group (2) is a single wiring group for one electrical component (3) (for example, an IC chip), and is the first wiring group (2'') to which the adjacent electrical component is connected. is not connected.

At this stage, a process of bonding the two substrates is performed. This process is a process in which an adhesive is applied to one substrate using a method such as screen printing, and the substrates are bonded together with the electrode surface facing inside. However, it goes without saying that a step of dispersing spacers is performed before bonding.

In this way, electrical components can be mounted on the first wiring group (2) while preventing foreign matter such as particles from entering the board, and each electrical component can be inspected. If it is defective, it is possible to remove the defective electrical component at this stage, attach a new electrical component, and inspect it again.

Moreover, since the inspection is performed after the substrates are bonded together, it is possible to prevent dust from getting onto the substrates during the inspection.

Next, a glabellar insulating film (4) is formed to cover at least a portion of this first wiring group (FIG. 3(B)). Next, a second wiring group (5) is formed over this insulating film (4) with the same pitch and width as the first wiring group, and the first wiring group (2) and (
2") to complete a common wiring group. In this way, a wiring board having a common wiring group and wiring groups branched from the common wiring group can be configured.
Generally speaking, printing cannot be used to form the eyebrow insulating film (4) and the second wiring group (5) because the substrates have already been bonded together, so there is a level difference at the boundary between the upper and lower substrates. When a dispensing method is used or when forming an insulating film between the eyebrows, it is sufficient to simply apply a commercially available insulating material such as a sticker.

Here, the dispensing method means dropping or applying a liquid substance from above.

The present invention does not form a common wiring group, that is, a wiring group to which electrical components are connected, which is formed by interconnecting a plurality of wiring groups, from the beginning. A common wiring group is provided by forming one wiring group, then forming an insulating film on the necessary parts, and finally interconnecting one wiring group for one electric component. By using this method, it is possible to inspect each electrical component installed in an electrical circuit one by one.Furthermore, since the component inspection process is performed after the boards are bonded together, there is a This prevents foreign matter from entering.

EXAMPLES The present invention will be explained in detail with reference to Examples below.

(Example 1) FIG. 3 schematically shows a method for manufacturing a liquid crystal electro-optical device of this example.

In this example, soda lime glass was used as the substrate (1). Since this glass substrate also serves as a cell of a liquid crystal display device as will be described later, highly flat glass was used.

I was deposited on this glass substrate by a known sputtering method, vapor deposition method, etc.
A TO (indium oxide, tin) conductive film is formed, and the ITO film is used to form a liquid crystal display area that occupies most of the substrate (1). Electrodes (6) are patterned to form a matrix configuration, and the edges of the remaining substrate are patterned. At the same time, a first wiring group (7) constituting a liquid crystal display drive circuit was formed at the same time.

In this example, the electrode (6) and the first wiring group (7) were formed by wet etching.

Figure 3 (A) shows a schematic diagram of the vicinity of the end of the board (1) in this state, and although only two first wiring groups (7) are drawn, many more wiring groups are shown. is provided.

At this time, the first wiring group (7) is not yet connected to any other wiring portion and is in an independent state.

Here, a thin film for orienting the liquid crystal is formed on this substrate. This process involves N-methyl-2 of polyamic acid.
- A polyimide thin film was obtained by applying a pyrrolidone solution onto a substrate using an offset printing method and heating it at 280°C for 150 minutes.

Then, a rubbing process is performed using cotton cloth, and the substrate is bonded to another substrate on which spacers have been sprayed.

Next, a chip (9) of an integrated circuit for driving a liquid crystal display device is directly face-down bonded to the electrical component connecting portion (8) of the first wiring group (7). At this time, the chip (9) and the substrate (1) were bonded together using an ultraviolet curing type adhesive at a temperature of 150'C with a press pressure of approximately 3 kg and irradiated with ultraviolet rays with a wavelength of 365n* for 3 minutes to cure. . This state is shown in FIG. 3(B). In this state, the first wiring group (7) is independently provided for one chip (9).

At this time, the independent first wiring group (7) is used as an extraction terminal for testing, and the integrated circuit chip (9) for driving the liquid crystal display device and the face-down bonding connection portion are tested. If it is a good product or the connection part is good, it is fine, but if it is a defective product or the connection part is defective, the chip that has been bonded once (9
), reinstall the chip on the side, and perform the inspection again.

By doing this, the board bonding process is performed before the insulating layer fabrication process and the electrical component inspection process, which reduces the number of dust that gets between the substrates and improves the manufacturing yield of liquid crystal display devices. was able to improve.

Next, an inter-glabellar insulating film 0IID for the multilayer wiring portion was formed in the necessary portions by a dispensing method. The material was made of epoxy resin to a thickness of 50-100 .mu.m in the shape shown in FIG. 3(C), and was formed by heating at 180.degree. C. for 30 minutes.

By adopting the shape of the glabellar insulating film of the multilayer wiring part as in this embodiment, there is no contact hole, so it is possible to have a large margin during printing.

In addition, the pattern of this glabellar insulating film is shown in Fig. 4 (A) ~
A shape as shown in (C) is also possible.

In other words, it is sufficient that the interlayer insulating film is provided in the minimum required portion.

Further, after completing this interlayer insulating film formation process, a substrate bonding process is performed, and then an integrated circuit chip (9) is formed.
You may also perform a process of mounting and a process of inspecting.

Next, a second wiring group (11) connected to the independent first wiring group (7) is formed across this interlayer insulating film, and the second wiring group (11) is connected to the first independent wiring group (7).
The wiring group (7) is connected to each other to form a common wiring. This situation is shown in FIG. 3(D).

This second wiring group 00 was also formed by applying copper paste according to the pattern by a dispensing method, and then baking at 180° C. for 20 minutes.

Furthermore, a protective film was formed on the entire surface near the edges of these substrates.

Then, by injecting liquid crystal between the bonded substrates using a well-known vacuum injection method, a liquid crystal cell with an electric circuit and electrical components mounted on the glass substrate can be completed. Ta. (A pair of substrates bonded together and with liquid crystal present between them is called a "cell.") In this example, the electrodes (6
) may be done by a conventionally known etching method, but the method described in Japanese Patent Application No. 186202/1986 filed by the present applicant
Buttering may be performed using an excimer laser as described in the above.

In this case, since no wet process is used, the process cost and material cost can be reduced.

(Effects) By having the configuration of the present invention, it is possible to inspect the electrical components installed in the electrical circuit, which was impossible in the past, before the manufacturing of the liquid crystal electro-optical device is completed, and determine whether the device is good or bad. We were able to significantly improve product yield.

Further, since the contact hole connecting the common wiring and the branch wiring can be completely eliminated or its size can be increased, there is a margin in the accuracy of positioning in the manufacturing process.

Furthermore, since the electrical components can be inspected after the boards are bonded together, there is no possibility of dust getting between the boards during the inspection, and product yields can be significantly improved.

[Brief explanation of drawings]

FIGS. 1 and 3 schematically show the manufacturing process of the present invention. Figure 2 shows the multilayer wiring section of a conventional wiring board. FIG. 4 shows an example of the pattern of the glabellar insulating film of the present invention. 1... Board 2.7...First wiring group 5.11...Second wiring group 10... Interlayer insulation film 9...IC chip

Claims (2)

[Claims] 1. a step of forming a plurality of first wirings for providing input signals to a plurality of electrical components on a substrate having an insulating surface; a step of forming an insulating layer covering at least a portion of the first wirings; and a step of forming an insulating layer over at least a portion of the first wirings; forming a common wiring by forming a plurality of second wirings on and extending from the layer and electrically connecting them to the first wiring; A method for manufacturing a liquid crystal electro-optical device, the method being carried out after the step of bonding substrates together. 2. Manufacturing a liquid crystal electro-optical device according to claim 1, wherein the first wiring is formed by a method using photolithography, and the insulating layer is formed by dispensing or pasting an insulating material. Method.