JPH0426097A - Manufacture of electroluminescent element - Google Patents

Abstract

PURPOSE:To facilitate sticking of a surface electrode in its post processing by making heating/pressing process after application of a luminescent layer. CONSTITUTION:A luminescent layer with its irregular surface is obtained through a process 106 of applying a reflective insulation layer for forming a reflective insulation layer on a base material and a process 108 of applying a luminescent layer for forming a luminescent layer thereon. Then, the luminescent layer with its irregular surface is formed in a luminescent layer with its smooth surface through heating/pressing processes 100 applied on the luminescent layer. Then, an electroluminescent element is obtained by a laminate process 109 for surface electrode in which a surface electrode made of a transparent conductive film is stuck on the luminescent layer by a thermal roll. Accordingly, the post processing for surface electrode sticking becomes easy.

Description

[Detailed Description of the Invention] The present invention relates to a method for manufacturing an electroluminescent device, and in detail,
This relates to a pretreatment process for forming transparent electrodes.

As shown in FIG. 6, the speed-following 4U rainbow electroluminescent lamp includes a back electrode 6, a reflective insulating layer 7, a light emitting layer 8, a transparent conductive ITO thin film 9 on a plastic film 10 serving as a transparent substrate. A light emitting element 1 having a structure in which a laminate consisting of a transparent conductive film and a hygroscopic film 11 and 12 are sandwiched is connected to a back electrode, a transparent electrode can to a glue 2 such as a phosphor bronze plate, etc.
3 is drawn out and hermetically sealed with moisture-proof outer skin films 4 and 5 made of fluorine-based resin.

To form the electroluminescent device 1, aluminum foil is used for the back electrode 6, a reflective insulating layer 7 is formed by dispersing a derivative such as barium titanate in a thermoplastic organic binder, and a phosphor is formed in the same binder. The light-emitting layer 8 in which particles 8a were dispersed was sequentially coated in layers by a doctor blade method or the like to obtain an aluminum-coated sheet whose cross section is shown in FIG. Then, the ITO 9 of the transparent conductive films 9 and 10 is applied to the light emitting layer 8 and the seventh layer.
As shown in the figure, the elements are bonded together using a hot roll to form the element shown in FIG. In addition, a moisture-absorbing film 11.12 made of nylon (trademark of DuPont) coated on one side with a hot melt adhesive such as polyethylene is formed on the front and back sides using a hot roll at the same time as the above lamination or by laminating in a separate process. was.

, EI 5 ″ 1 However, in the method of forming an electroluminescent device by bonding as shown above, as shown in FIG. When bonded to a certain ITO9, voids tended to remain, resulting in rough-textured light emission.Also, it was necessary to apply sufficient heat and pressure during bonding, making it impossible to increase the bonding process speed, resulting in production delays. The object of this invention is to provide a manufacturing method that smooths the surface of the light emitting layer, increases the adhesion to the surface electrode, and maintains the adhesion even when the packing density of the phosphor particles is increased. shall be.

In addition, in the case of a manufacturing method in which a transparent electrode is formed by printing, if the surface of the light emitting layer is uneven, the printing thickness must be increased, and there is also the problem that it is difficult to obtain bright light emission.

- In order to solve the above-mentioned problem, this invention is characterized by providing a step of pressing the surface of the light emitting layer with a hot roll after forming the light emitting layer 8 and before forming the transparent electrode.

1. The above-mentioned pressing step using a hot roll smoothes out the unevenness of the phosphor particles formed during the formation of the coating film of the light emitting layer 8, thereby facilitating the formation of the surface electrode, resulting in fine-grained light emission.

misfortune This invention will be explained with reference to the drawings.

FIG. 1 is a manufacturing flow diagram showing the main points of a manufacturing method according to an embodiment of the present invention.

A reflective insulating layer 7 is formed using an aluminum foil 6 as a base material, which serves as a back electrode.
The steps up to the reflective insulating layer coating step 106 for forming a reflective insulating layer and the light emitting layer coating step 108 for forming a light emitting layer thereon are the same as the conventional method and will not be described here. A light-emitting layer 8 having a roughened surface is obtained.

Next, heating and pressing treatment 100 of the light emitting layer, which is a feature of the present invention, is performed.

As shown in FIG. 3, the surface of the light-emitting layer 8 is pressed with a hot roll 18, 17 through a film 15 having high mold releasability, such as Teflon or polyester. This releasable film 15
is continuously unwound and wound in synchronization with the hot roll 16. The heating rolls 16 and 17 are set at a temperature above the softening point of the binder binder, for example in the range of 100 to 200°C, in relation to the feeding speed, and are made of metal or silicone rubber with high hardness. FIG. 4A shows a cross-sectional view of part A of the coated aluminum sheet before heat-pressing treatment, and FIG. 4B shows a cross-sectional view of part B after heat-pressing treatment.

As another example of the heat suppression method, a metal roll whose surface is coated with Teflon can be used as the heat roll without using the releasable film described in the previous section. This embodiment has the advantage that running costs can be reduced because no releasable film is used.

By performing the above heating and pressing treatment 100 on the light emitting layer, the light emitting layer 8 having an uneven surface becomes a light emitting layer 8b having a smooth surface as shown in FIG. 4B.

Next, a surface electrode laminating step 109 is performed in which a surface electrode made of a transparent conductive film is laminated to the light emitting layer 8a using a hot roll in the same manner as in the conventional method, thereby obtaining an electroluminescent device.

According to the above manufacturing method, since the surface of the light-emitting layer 8b is smooth, the bonding work is easy, and an electroluminescent lamp with fine-grained light emission can be obtained, and the adhesion strength is also increased, resulting in a highly reliable electroluminescent lamp.

Another embodiment will be described with reference to FIG. The steps up to the reflective insulating layer coating step 106, the light emitting layer coating step 108, and the light emitting layer heating and pressing treatment are the same as those in the previous embodiment, and therefore their explanations will be omitted.

The difference is that the surface electrodes are not formed by bonding transparent conductive films, but by printing 109a a transparent conductive paste made of ITO powder or the like. In this case as well, the fifth
As shown in the figure, since the surface of the light emitting layer 8b is smooth, ITO9
Even if the printing thickness of a is made thinner, it can be applied evenly,
Increases transmittance and provides bright and uniform light emission.

As described above, this invention eliminates unevenness on the surface of the luminescent layer made of phosphor particles and voids in the binder by applying a heat-pressing treatment using a hot roll after coating the luminescent layer, and eliminates the voids in the binder. Facilitates bonding of surface electrodes. That is, the surface of the light-emitting layer becomes smooth, the contact area with the surface electrode increases, and the process speed can be increased because bonding can be performed without applying sufficient heat or pressure. In addition, an electroluminescent device that emits light with a dense and fine texture can be obtained. Furthermore, in an electroluminescent element formed by printing a powdery transparent conductive paste (9a) of ITO as shown in FIG. 8 instead of ITO (9) for the surface electrode, the ITO printing thickness can be made uniform and thin. Increases transmittance and provides bright and uniform light emission.

[Brief explanation of the drawing]

1 and 2 are flowcharts showing the main points of the method for manufacturing an electroluminescent lamp according to the present invention. FIG. 3 is a drawing showing one method of the hot pressing treatment of the present invention, and FIG. 4 is a sectional view showing the state of the surface of the light emitting layer before and after the hot pressing treatment. FIG. 5 is a sectional view of an example of an electroluminescent device according to the present invention. Figure 6,
FIG. 8 is a sectional view of an electroluminescent lamp and an electroluminescent element, respectively. FIG. 7 is a diagram showing a method of forming surface electrodes by bonding. FIG. 9 is a sectional view showing the surface of a conventional light-emitting layer before bonding. 106... Reflective insulating layer coating step, 108... Luminescence coating step, 100... Luminescent layer heating and pressing treatment, 109... Surface electrode lamination step, 109 a...
・Surface electrode printing process. ] Figure Figure Figure Figure Figure Figure Figure Figure also t, 4] ]] 2 zuζ1 file l\ 13] 4 I anti, i&') Tates. Figure Figure

Claims (1)

[Claims] An electroluminescent device consists of a laminate in which a reflective insulating layer and a light-emitting layer are sequentially coated on a back electrode, and a transparent electrode is formed on top of that. Leads are led out from the back electrode and the transparent electrode and hermetically sealed with an outer cover material. A method for manufacturing an electroluminescent device, which comprises sequentially coating and forming a reflective insulating layer and a luminescent layer and then subjecting the luminescent layer to a heating and pressing treatment before forming a transparent electrode.