JPS6185842A - Cross wiring - Google Patents

Abstract

PURPOSE:To obtain a highly reliable cross wiring substrate, which can be easily manufactured, by a method wherein both ends of the conductive layer are pressure welded by heat on the circuit patterns; whereto the small substrate for cross wiring in the sandwich structure, wherein the conductive layer is insulatingly coated, is to be connected; excluding the sites, becoming the contact points of the conductive layer and the other circuit patterns, being connected with the conductive layer, on the substrate. CONSTITUTION:A gold thin film is formed on a insulative flexible substrate 10 by an evaporation method, and after that, gold patterns 11, each having the desired size, are formed by a photolithographic etching method. An insulative epoxy resin is applied on the upper layer of each gold pattern by a printing method in such a way as to leave both ends of the gold pattern 11 and an insulating layer 12 is formed. The gold patterns are severed along dotted lines (a), whereby small substrates 8 for cross wiring in the sandwich structure are obtained. A pressure welding by heat is performed facing the insulating layer 12 downward in such a way that both ends of the gold patterns 11b of the small substrate 8 for cross wiring are made to conform to the end parts 6 and 7 of the second and third wiring patterns on a glass substrate 1. Thereby, the cross wiring substrate is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a cross-wiring method, and particularly to a cross-wiring method that requires fewer manufacturing steps and is highly reliable.

[Prior art]

Conventionally, when cross wiring is required on a printed wiring board, the following two methods have been mainly used.

One of them is, for example, as shown in FIG. 5, three wires are arranged vertically on the board 101! Insulating layer 1 on 102
A bonding method is used, such as a method of electrically connecting the first and second wiring layers 104 and 105 disposed on both sides of the wiring layer 03 with a jumper bonding wire 106. It is a thing,
The other method is to drill an insertion hole 108 for the jumper 1s 107 from the ends of the first and second wiring layers 104 and 105 so as to penetrate the board 101, as shown in FIG. This method uses soldering, such as a method in which both ends of the jumper wire are inserted from the back side of the board 1 and connected with solder 109.

[Problems to be solved by the invention]

However, the former method requires a step of forming an insulating layer and a bonding step, and the latter method requires a step of drilling a jumper wire insertion hole and a soldering step, and both methods have poor manufacturing workability. Furthermore, there were also problems with mechanical strength, such as bonding wires or jumper wires coming off due to external impact.

The present invention has been made in view of the above-mentioned actual situation, and an object of the present invention is to provide a cross wiring board that is easy to manufacture and has high reliability.

[Means for solving problems]

Therefore, in the present invention, when connecting circuit patterns formed on a substrate so as to intersect with each other, the conductor layer is covered with an insulating coating except for the portion that becomes the contact point between the conductor layer and the circuit pattern to be connected on the substrate. A small board for cross-wiring having a sandwich structure and having an insulating layer made of the above-mentioned insulating layer is placed on the circuit pattern to be connected.

[Effect]

In other words, the formation of an insulating layer on the substrate itself
There is no need to form a hole for inserting a jumper wire, and a small board for cross-wiring having a sandwich structure formed in advance can be attached immediately after the wiring pattern is formed.

In addition, to form small substrates for cross wiring, conductive layers and insulating layers are sequentially formed on an insulating substrate such as a flexible substrate by vapor deposition or printing, and then cut into individual small substrates. By dividing, work efficiency can be improved.

〔effect〕

As described above, according to the method of the present invention, the workability of manufacturing is good, and the formed cross-wiring board can be formed without exposing jumper wires or bonding wires for jumpers on the surface even in the cross-wiring portion. It is a small, flat insulating board, and is highly reliable as it is unaffected by external shocks.

Also, since it has a good appearance, an external case or the like is not necessarily required.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, in the thick film wiring pattern 2 formed on the insulating glass substrate 1, the second and third wiring patterns 3 on both sides of the three first wiring patterns 3 intersect with each other. When connecting the third wiring pattern 4.5, the sandwich structure cross wiring small board 8 is connected to the second and third wiring patterns 4.
The ends of the wiring pattern 4.5 are coated with hot pressure salt.

That is, first, a first wiring pattern 3 and second and third wiring patterns 4 and 5 are formed on an insulating glass substrate 1.
A thick film wiring pattern 2 containing the above is formed as shown in FIG. 2 by screen printing using gold paste as ink and baking.

Next, after forming a gold thin film by vapor deposition on the insulating flexible substrate 10 made of polyimide film,
A gold pattern 11 of a desired size is formed by photolithography as shown in FIG. 3(a).

Subsequently, an insulating epoxy resin is applied to this upper layer by a printing method, leaving both ends of the gold pattern 11, to form an insulating layer 12 as shown in FIG. 3(b).

By dividing the flexible substrate 10 having a large number of patterns thus formed along the dotted line a, a small substrate 8 for cross wiring having a sandwich structure as shown in FIG. Obtain (many items).

Furthermore, as shown in FIG. 4, a thin insulating layer is placed so that both ends of the gold pattern 11 of the small substrate 8 for nuclear cross wiring are aligned with the ends 6, 7 of the second and third wiring patterns on the glass plate. By thermocompression bonding with the substrate facing down, a cross wiring board as shown in FIG. 1 is completed.

According to this method, it is possible to extremely easily form a large number of small substrates 1 for cross wiring at the same time, and there is no need for an insulating layer formation process, a bonding process, or a drilling process for the wiring board itself. It is only necessary to bond the small substrate for cross wiring by thermocompression, and the manufacturing process is easy.

In addition, the formed cross wiring board is strong against external impact, has high reliability, and has a good appearance.

Note that the small board for cross wiring does not necessarily have to be a flexible board.

In addition, in the example, when forming a small board for cross-wiring, a vapor deposition method was used to form a conductor layer on a flexible board. Other methods may also be used, such as patterning into a desired shape.

Furthermore, when attaching the cross-wiring small substrate to the wiring board, it is also possible to use a method of attaching it using an adhesive in addition to the thermocompression bonding method.

[Brief explanation of drawings]

FIG. 1 is a partial schematic diagram of a cross wiring board formed by the method of the embodiment of the present invention, FIGS. 2 to 4 are diagrams showing the manufacturing process of the cross wiring board, and FIGS. 5 and 6 1 is a diagram showing a conventional cross-wiring board. 101... Substrate, 102... Wiring layer, 103...
Insulating layer, 104...first wiring layer, 105...second
wiring layer, 106... jumper bonding wire, 107... jumper wire, 108... insertion hole,
109...Solder, 1...Glass substrate, 2...Thick film wiring pattern, 3...First wiring pattern, 4...
Second wiring pattern, 5...Third wiring pattern, 6
, 7... End part (connection part), 8... Small board for cross wiring, 10... Flexible board, 11... Gold pattern,
12...Insulating layer. Figure 1 Figure 3 (C) Figure 4 Figure 5 Figure 6

Claims (2)

[Claims] (1) A method of connecting circuit patterns formed on a board so as to cross each other, the conductor layer being covered except for the contact points between the conductor layer and the circuit pattern to be connected on the board. 1. A cross-wiring method characterized in that a small board for cross-wiring having a sandwich structure on which an insulating layer is formed is placed on a circuit pattern to be connected. (2) The cross-wiring method according to claim (1), wherein the small board is made of a flexible board.