JPH01201988A - Printed-wiring board - Google Patents

Abstract

PURPOSE:To enable electrical parts fitted to an electrical circuit to be inspected completely before they are produced and to improve yield of the products by providing a plurality of common wirings on an insulation substrate, by providing wiring branched from the common wiring, and by enabling electrical parts to be fitted to this branched wiring. CONSTITUTION:A wiring group 2 is formed on a board 1 with insulation surface using a conductive material. At this time, the wiring group 2 is a lump of wiring group for one electrical parts 3 and is not connected to a wiring group 2' where the neighboring electrical parts are connected to. When electrical parts are fitted to the wiring group 2 in this status, each electrical parts are inspected and improper electrical parts are removed, new ones are mounted, and inspection is performed again if they are not appropriate. Then, an inner-layer insulation film 4 is formed by covering one part of this wiring group, a wiring group 5 is formed in the same pitch and width as the wiring group over this insulation film 4 and the wiring groups 2 and 2' are connected mutually to complete a common wiring group.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a wiring board on which electrical components, etc. are mounted, and particularly relates to a structure of a wiring board that allows testing of a plurality of electrical components, etc., individually after mounting them. .

"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. This involved inserting the wire, soldering it, etc., and connecting 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, in this method as well, as in the case of P-boards, after the electrical components are mounted on the electrical circuit on the board, each electrical component is tested to see if it is good or bad, and the connections are tested to see if the connections are good or bad when the electrical components are mounted. Couldn't do the test. 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, IT◯, etc.) by wet etching or the like.

Next, an insulating film is formed in the pattern shown in FIG. Here, 00 is a contact hole that connects the common wiring (151) with the branch wiring q.
), a branched wiring 0'l) is formed, and electrical components are attached to this branched wiring 07).

In order to connect the branch wiring θ force to the common wiring q5) through the contact hole 06) in such a multilayer wiring part, it is necessary to limit the dimensions of the contact hole 06). However, when the number of terminals of the electrical components to be installed increases, or when the number of electrical components increases, the dimensions of the contact hole 06) must be made smaller, resulting in poor contact, especially in printing methods. Forming an insulating layer using the same method has the advantage of reducing costs, but there is a technical problem in that contact holes cannot be formed.

"Structure of the Invention" The present invention relates to a novel structure of a wiring board as described above, and in particular, it is a wiring board having some multilayer wiring components, which improves the problems described above.

In other words, a plurality of common wirings are provided on an insulating board, and the configuration is such that wiring branches from the common wiring and electrical components can be attached to these branched wirings, and each individual component can be inspected after the electrical components are mounted. It is something that can be done.

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

FIG. 1 shows an example of the method for manufacturing the novel wiring board 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. If electrical components are attached to the first wiring group (2) in this state, 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. Next, an interlayer 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 the insulating film (4) with the same pitch and width as the first wiring group,
The first wiring group (2) and (2'') are interconnected 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 is constructed. Can be done.

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. In particular, this feature allows inspection of electrical components installed in an electrical circuit one by one.

The present invention will be explained in detail by way of examples below.

[Example 1] This example shows an example in which the present invention is applied to a liquid crystal display device.

FIG. 3 shows an outline of the method for manufacturing the substrate 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 T○ (indium oxide, tin) conductive film is formed, and the IT○ film is used to pattern the electrodes (6) in a matrix configuration for the liquid crystal display area that occupies most of the substrate (1). At the same time, a first electrode group (7) constituting a liquid crystal display drive circuit was formed at the end of the electrode.

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

Figure 3 (A) shows a rough view of the vicinity of the end of the substrate (1) in this state, and although only two portions of the first electrode group (7) are drawn, there are many more bones. 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.

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 adhesive between the chip (9) and the substrate (1) was cured using an ultraviolet curing type adhesive at a temperature of 150° C. by applying a press pressure of about 3 kg and irradiating ultraviolet rays with a wavelength of 365 nm for 3 minutes. This state is shown in FIG. 3(B). In this state, one chip (
9), a first electrode group (7) is provided independently.

At this time, the independent first electrode group (7) is used as an extraction terminal for inspection, and the integrated circuit chip (9) for driving the liquid crystal display device and the face-down bonding connection portion are inspected. 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
), attach another chip, and test again.

By doing so, it was possible to improve the manufacturing yield of the liquid crystal display device.

Next, an interlayer insulating film 00) for the multilayer wiring portion was formed on the necessary portions by screen printing. The material used was epoxy resin, which was printed to a thickness of 40 to 50 .mu.m in the shape shown in FIG. 3(C), and then incubated at 180 DEG C. for 30 minutes.

By using the shape of the interlayer insulating film of the multilayer interconnection 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 the formation process of the glabella insulating film is completed, the process of mounting the integrated circuit chip (9) and the process of inspecting it may be performed.

Next, a second wiring group O1) that connects to the independent first wiring group (7) is formed across this glabella insulating film, and the first wiring group (7) is connected to each other, and a common Configure the wiring.

This situation is shown in FIG. 3(D).

This second wiring group (11) is printed at 180°C after printing copper paste according to the pattern by screen printing method.
Bake for 20 minutes to form.

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

In this way, it was possible to complete a wiring board having an electrical circuit on a glass substrate and having electrical components mounted thereon.

Create another board using almost the same process as this board,
After applying the necessary processing for a liquid crystal display device to both substrates,
A liquid crystal cell was completed by stacking two substrates (1) and sealing the outer periphery with a spacer to maintain a constant gap between them, and a liquid crystal display device was completed by injecting a liquid crystal material into the space.

In this example, the electrode (
The patterning in 6) may be performed by a conventionally known etching method, but the method described in Japanese Patent Application No. 61-1862 filed by the present applicant
Patterning may be performed using an excimer laser as described in No. 02.

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

In addition, in this case, the first wiring group (7) is also connected to the second wiring group (7).
l1) It may also be formed by a printing method in the same way.

[Embodiment 2] In this embodiment, a case will be described in which the configuration of the present invention is applied to an image sensor.

A sensor in which a first conductive film 02) which is patterned in a predetermined manner on a substrate (1), a semiconductor layer 03) that performs photoelectric conversion, and a second conductive film 04) are formed using a conventionally known technique. An electric circuit for driving the sensor array is provided near the end of the array substrate (1). For this purpose, a pattern of the first wiring group is formed using copper paste by a screen printing method.

At this time, the first wiring group (7) and the first conductive film or the second conductive film of the sensor array are aligned and partially connected.

Next, this printed board is beta-baked and the copper paste is baked to form wiring. The temperature at this time is preferably 200° so that the material used in the sensor is not affected.
It is preferable to fire at C or lower.

Next, after forming a glabellar insulating film 00) covering at least a part of this first wiring group (7) in the same manner as in Example 1, I
Connect C(9) by face down bonding and connect I
The connection portion between C (9) and IC (9) and the first wiring group (7) was inspected.

At this time, the connection between the IC chip (9) and the board (1) is temporarily bonded, and the IC is inspected and if there are no defects, the connection is complete.

After complete adhesion, if any defects were found, some IC chips (9) were removed and reconnected to achieve complete adhesion.

By doing this, it is possible to eliminate the accident of accidentally removing the first wiring group at the same time when removing the IC chip in the case of a defect, and it is possible to further improve the manufacturing yield. Ta.

Thereafter, printing of a second wiring group, printing of a protective film, etc. were performed under the same conditions as in Example 1 to complete an image sensor.

It goes without saying that the present invention can be widely applied to other electrical and electronic components, but as shown in Example 1.2 above, IC When applied when a chip is directly mounted on a substrate, it has become possible to obtain a remarkable effect in reducing manufacturing costs and manufacturing steps.

〔effect〕

By having the configuration of the present invention, it is possible to inspect electrical components installed in an electrical circuit before the manufacturing is completed, which was impossible in the past, and determine whether the electrical components are good or defective.
We were able to significantly improve product yield.

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

In addition, since there is margin for wiring alignment accuracy, all wiring can be done by screen printing, significantly reducing manufacturing costs.

[Brief explanation of the drawing]

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 (1)

[Claims] 1. In a wiring board having a plurality of common wirings provided on an insulating substrate and a plurality of wirings for connecting electrical components separated from the common wirings, the plurality of common wirings and branched wirings are part of the common wiring. A wiring board characterized in that a first wiring that also serves as a branched wiring and a second wiring that constitutes only a part of a common wiring are electrically connected by applying insulation treatment to necessary parts. .