JPH0410756B2 - - Google Patents

Description

[Detailed Description of the Invention] "Field of Application of the Invention" This invention is applicable to glass substrates, printed circuit boards or
Multiple electrodes are provided on one substrate such as FRP (flexible printed circuit board), and the opposing electrodes are electrically connected to each other, and the respective substrates are brought into close contact with each other at the connecting part. .

"Prior Art" Conventionally, a large number of electrodes are provided on each of a glass substrate and an FRP, and attempts have been made to make these electrodes face each other and interconnect the electrodes. For this purpose, a method is known in which a rubber having a needle-shaped conductor embedded vertically between the pair of electrodes is used, and the rubber is pressed between the substrates to connect them.

In this method, there are a large number of electrodes on the two substrates, but if there are needle-like conductors at a higher density, the desired electrodes can be connected to each other without having to align them with great precision.

"Problems to be Solved by the Invention" However, in such a case, pressure must be constantly applied between the two substrates. And, once removed, it has disadvantages such as the need for fitting work to reconnect them.

"Means for Solving the Problem" Therefore, a method is required in which the boards are brought into close contact with each other at this connection part and integrated.

For this purpose, the present invention uses a magnetic acicular conductor and mixes it with a liquid organic resin. Then, since it is in a liquid state, the needle-like state can be arranged in the same direction by external magnetism.

That is, in the present invention, a plurality of electrodes on two substrates are opposed to each other, and a liquid organic resin mixed with an acicular magnetic conductor is applied between them. Thereafter, by bringing these substrates close to each other and applying an external magnetic field in the vertical direction, the acicular magnetic conductors are rearranged in a direction perpendicular to the electrodes. Furthermore, the electrodes are brought closer to each other,
After the electrodes are electrically connected to each other using the acicular magnetic conductor, the liquid organic resin is solidified to integrate the connecting portions.

"Action" Two connected to each other made by the method of the present invention
Since the two substrates are bonded to each other with organic resin, high electrical reliability, especially against product vibrations and collisions, can be maintained.

Furthermore, if the needle-like magnetic conductor is made of fiber-like material, its diameter can be as thin as 10μ. Therefore, the density of the liquid organic resin in the acicular magnetic conductor is high, and even if they are randomly arranged, they are rearranged in the direction perpendicular to the substrate when the substrates are fixed to each other. Therefore, in the organic resin solution, the acicular magnetic conductors only need to be dispersed, and there is no need to provide them with directionality, so it is expected that the price of this mixed solution will be reduced.

The present invention will be described below with reference to Examples.

Example 1 FIG. 1 shows a longitudinal sectional view for carrying out the method of the present invention.

In FIG. 1, an electrode 2 of copper plated with gold is formed to a thickness of 30 μm on a lower substrate, such as a glass substrate. Further, on the lower side of the FRP 1' (in the direction in which the electrodes face each other), an electrode 2' which is similar to copper plated with gold is formed.

Furthermore, carbon fiber to which cobalt was added was used as the acicular magnetic conductor used in the present invention. It has an electrical conductivity on the order of 10 ³ Sm ^-1 and responds relatively effectively to magnetism. This carbon fiber had a diameter of about 10μ and a length of 300μ. Furthermore, the organic resin solution used was a thermosetting material with little volumetric shrinkage. For example, a polyimide-based or epoxy-based material was used, and in order to improve the decomposition of the fibers in this solution, the surface of the fibers was coated with a resin on the surface of the carbon fibers cut into 300 μm pieces. An organic resin solution mixed with such a needle-shaped magnetic conductor was applied in advance onto the lower hard substrate. If necessary, it was also applied to the upper side to improve adhesion to the substrate.

Furthermore, as shown in FIG. 1A, an FRP 2' was pasted on the upper surface of this substrate 1. Furthermore, as shown in FIG. 1B, an electric magnet was placed on the lower side to apply magnetism to this needle-shaped magnetic conductor. The acicular magnetic conductors are then aligned perpendicularly to the substrate within this solution. After this,
This upper substrate was pressed so that the counter electrode terminals were electrically connected to each other. This was heated with a heater. Then, the thermosetting resin was cured to connect the electrodes of the two substrates so that they corresponded to each other.

Example 2 The electrodes of the two substrates were made of a magnetically sensitive material, such as iron, and their upper surfaces were further coated with silver or gold.

Furthermore, a paramagnetic material, such as needle-shaped iron, was used as the needle-shaped magnetic conductor. This iron used had a diameter of 30μ and a length of 400μ. A solution containing this needle-shaped magnetic conductor was applied to the lower substrate. A magnet was also placed on the bottom. Then, the iron acicular magnetic conductors 4 are relatively concentrated in the electrode portion, making it possible to reduce the number of acicular magnetic conductors 4'. It is then oriented in the magnetic direction, ie perpendicular to the substrate. In addition, an electromagnet 5 was placed on the upper side where the heater was built (however, if the lower side was the N pole, the upper side was the S pole), and the electrodes were pressed closer to each other and connected electrically. . Furthermore, the heater 5 was turned on to heat and harden the thermosetting resin 3.

Thus, even if this heater and magnet are turned off,
The two substrates could be brought into close contact with each other and integrated. In addition, each electrode could be connected to each other by a needle-like magnetic conductor.

"Effects" As described above, in the method of the present invention, the electrodes of two substrates can be connected and fixed to each other without using a method such as soldering.

Furthermore, the two substrates were fixed together using an organic resin to prevent pressure from being applied to the electrical connections. As a result, electrical reliability could be greatly improved.

Furthermore, the length of this acicular magnetic conductor may be increased if the distance between adjacent electrodes on one substrate is long. However, in consideration of adhesion, the thickness is preferably 1 mm or less, preferably 100 to 500 μm.

[Brief explanation of drawings]

FIG. 1 shows a longitudinal cross-sectional view of a substrate etc. on which the present invention is implemented.

Claims (1)

[Claims] 1. A first substrate provided with a plurality of electrodes and a second substrate provided with a plurality of electrodes, the first substrate being provided with a plurality of electrodes.
and a step of making the electrodes of a second substrate face each other, and applying a magnetic field in a direction perpendicular to the substrate with a liquid organic resin containing the acicular magnetic conductor interposed therebetween, so that the acicular magnetic conductor is directed in a direction perpendicular to the substrate. a step of electrically connecting the opposing electrodes to each other by the acicular magnetic conductor by reducing the distance between the opposing electrodes; and a step of solidifying the liquid organic resin. A method for connecting electrodes characterized by: 2. The method for connecting electrodes according to claim 1, wherein the acicular magnetic conductor is made of a paramagnetic material. 3. The method for connecting electrodes according to claim 1, wherein the acicular magnetic conductor is made of carbon fiber or iron to which iron, nickel, or cobalt is added.