JPH0831295B2 - Electronic component manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing an electronic component having a portion for sealing a flexible substrate with an adhesive, such as a membrane switch and a film liquid crystal. Is.

(Prior Art) A conventional method of manufacturing an electronic component will be described with reference to FIGS. 2 and 3 by taking a membrane switch as an example.

FIGS. 2A to 2D are cross-sectional views showing a manufacturing process of a conventional membrane switch. Figure 2 (d) shows
In the cross-sectional view of the completed membrane switch, the membrane switch has electrode patterns 1 and 2 facing each other.
The lower insulating substrate 3 and the upper flexible substrate 4 on which are formed are sealed with a thermosetting adhesive layer 5.

A method of manufacturing a membrane switch having such a structure will be described with reference to FIGS.

First, as shown in FIG. 2A, a predetermined electrode pattern 1 is formed on the surface of the lower insulating substrate 3. Next, as shown in FIG. 2 (b), a liquid thermosetting adhesive layer 5a is applied on the lower insulating substrate 3 to a predetermined thickness by a method such as printing. Next, as shown in FIG. 2 (c), the lower insulating substrate 3
Electrode pattern 2 so as to face the electrode pattern 1 of
After the upper flexible substrate 4 having the above-mentioned structure is bonded and then the thermosetting adhesive 5a is thermally cured in a high temperature furnace, the membrane switch shown in FIG. 2 (d) is obtained.

(Problems to be Solved by the Invention) However, in the conventional method for manufacturing an electronic component, not only the thermosetting adhesive layer 5a is liquid but also the upper flexible substrate 4 has flexibility, so FIG. 3 shows the condition that the viscosity of the thermosetting adhesive layer 5a decreases in the thermosetting process in the furnace and the condition that the gap between the upper flexible substrate 4 and the lower insulating substrate 3 decreases due to the bending of the upper flexible substrate 4 is shown in FIG. So that the upper flexible substrate 4
There is a problem that the substance 6 having a particularly low molecular weight contained in the thermosetting adhesive layer 5a flows out due to a capillary phenomenon due to a minute gap between the lower insulating substrate 3 and the lower insulating substrate 3.

As a countermeasure against this, a method of applying a tensile force so that the upper flexible substrate 4 does not bend can be considered, but it is difficult to realize because a complicated process of fixing using various jigs is required. Further, by adding a filler or the like to the thermosetting adhesive to increase the viscosity, it is possible to prevent the outflow to some extent, but it is not possible to prevent it completely, and the adhesive properties are adversely affected, which is not a good measure.

The present invention solves the above problems and provides a method of manufacturing an electronic component in which a thermosetting adhesive does not flow out of a sealing portion.

(Means for Solving the Problems) In order to solve the above problems, the present invention applies the first thermosetting adhesive layer so as to surround the sealing portion of the lower insulating substrate and then cures it. And a step of applying a second thermosetting adhesive layer to the sealing portion, adhering the upper flexible substrate thereto, and then thermosetting the second thermosetting adhesive layer. It constitutes a manufacturing process of an electronic component.

(Operation) Since the barrier of the cured first thermosetting adhesive layer is formed along the periphery of the sealing portion of the lower insulating substrate by the above process, the second thermosetting adhesive applied to the sealing portion is formed. When the upper flexible substrate is bonded to the agent layer and thermally cured in a high temperature furnace, even if the upper flexible substrate bends to some extent, there is no reduction in the gap that causes a capillary phenomenon. Therefore, it is possible to manufacture an electronic component with a high yield and an excellent finished appearance.

(Embodiment) An embodiment of the present invention will be described with reference to FIGS. 1 (a) to 1 (f), taking a membrane switch as an example.

FIG. 1 (f) is a cross-sectional view of a membrane switch manufactured by the method for manufacturing an electronic component according to the present invention. The difference from the membrane switch manufactured by the conventional manufacturing method shown in FIG. 2 (d) is that the sealing is performed. A barrier is formed by the first thermosetting adhesive layer 7 surrounding the inner periphery of the portion, and the upper flexible substrate 4 is provided with an adhesive on the second thermosetting adhesive layer 8 of the sealing portion outside the barrier. That is what is being done.

A method of manufacturing an electronic component according to the present invention for obtaining a membrane switch having such a configuration will be described. First, the first
As shown in FIG. 3A, a predetermined electrode pattern 1 is formed on the surface of the lower insulating substrate 3. Then, as shown in FIG. 1 (b), a liquid first thermosetting adhesive layer 7a is applied to a position corresponding to the inner circumference of the sealing portion by a method such as screen printing, and then a high temperature furnace is used. When thermally cured inside, a barrier of the first thermosetting adhesive layer 7 is formed along the inner circumference of the sealing portion as shown in FIG. 1 (c). Next, as shown in FIG. 1 (a), a liquid second thermosetting adhesive layer 8a is applied by a method such as screen printing. Subsequently, as shown in FIG. 1 (e), after the upper flexible substrate 4 is bonded onto the second thermosetting adhesive layer 8a, it is heat-cured in a high temperature furnace. The membrane switch shown in FIG. 6 (f) is obtained.

In this way, the first thermosetting adhesive layer 7a is heat-cured to form a barrier on the inner surface of the sealing portion. Therefore, when the upper flexible substrate 4 is bonded at the sealing portion, the upper flexible substrate Since the capillary phenomenon does not occur even if 4 is slightly bent, the adhesive does not flow out of the sealing portion. Therefore, the manufacturing method can obtain a membrane switch having a high yield and a beautiful finished appearance.

In addition, although the membrane switch is described in the present embodiment, it is needless to say that the same effect can be obtained for an electronic component having a film liquid crystal or other flexible substrate.

Although the first thermosetting adhesive layer 7 is provided on the inner circumference of the adhesive shown in FIG. 1 (f), it may be provided on the outer side or both sides of the adhesive depending on the structure of the electronic component.

(Effects of the Invention) As described above, according to the present invention, the first thermosetting adhesive layer is first heat-cured and the barrier is formed so as to surround the sealing portion, so that When the second thermosetting adhesive layer is applied, and the upper flexible substrate is adhered to it and then heat cured, a gap phenomenon that causes a capillary phenomenon does not occur even if the upper flexible substrate bends to some extent, Since the adhesive does not flow out of the sealing portion, it is possible to obtain an electronic component with a high yield and a beautiful finished appearance.

[Brief description of drawings]

1 (a) to (f) are process cross-sectional views showing a method for manufacturing a membrane switch according to the present invention, and FIGS. 2 (a) to (d) are process cross-sectional views showing a conventional method for manufacturing a membrane switch, FIG. 3 is a sectional view of a membrane switch showing an example of an accident that is likely to occur in the conventional manufacturing method. 1,2 ... Electrode pattern, 3 ... Lower insulating substrate, 4 ... Upper flexible substrate, 5 ... Thermosetting adhesive layer, 5a ... Liquid thermosetting adhesive layer, 6 ... Low Molecular weight substance, 7 ... First thermosetting adhesive layer, 7a ... Liquid first thermosetting adhesive, 8 ...
Second thermosetting adhesive layer, 8a Liquid second thermosetting adhesive layer.

Claims (1)

[Claims] 1. A first thermosetting adhesive layer is applied so as to surround a sealing portion of a lower insulating substrate when sealing a lower insulating substrate and an upper flexible substrate each having a predetermined pattern formed thereon. After that, a step of thermosetting, and a second thermosetting adhesive layer is applied to the side surface of the first thermosetting adhesive layer of the sealing portion, and the upper flexible substrate is adhered thereto, and then thermosetting. A method of manufacturing an electronic component, which includes a step.