JPH047559B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for manufacturing an electroluminescent lamp, and more particularly, an electroluminescent lamp element having a current collecting band along one side edge is attached to a folded resin outer film. The present invention relates to a method of manufacturing an electroluminescent lamp which is heat-sealed and is suitable for a backlight of a liquid crystal display device or the like.

2. Description of the Related Art Since liquid crystal display devices are non-emissive, a backlight is used. Organic electroluminescent lamps (hereinafter abbreviated as EL) are preferred as backlights because of their book shape, uniform brightness, and light weight. For example, this kind of EL is
As disclosed in Japanese Patent No.-8479, there is a device in which an EL element is sandwiched between two resin outer films and sealed by thermocompression, but this has the drawback of poor moisture resistance. Therefore, as disclosed in Japanese Patent Publication No. 40-8575, an EL element with improved moisture resistance was developed in which moisture-absorbing films were placed above and below the EL element, which was then sandwiched between two resin outer films and sealed by thermocompression. Proposed.

Figure 14 shows a plan view of the above EL, and Figure 15 shows the top view of the above EL.
The figure shows a sectional view taken along the line XV-XV in FIG. 14.
In the figure, numeral 1 is an EL element, with moisture absorbing films 2 and 3 arranged above and below, resin outer film 4,
The resin outer films 4 and 5 protruding from the periphery of the EL element 1 are sandwiched between the two and sealed together by thermocompression. As is clear from FIG. 15, the EL element 1 has a high dielectric constant and white material such as barium titanate contained in a high dielectric constant organic material such as cyanoethyl cellulose on a back electrode 6 made of aluminum foil or the like. reflective insulating layer 7 in which insulating material powder is dispersed;
A light-emitting layer 8 in which phosphor powder such as ZnS:Cu is dispersed in an organic substance similar to the above, and a resin film 10 made of polyester or the like with a transparent electrode 9 made of In ₂ O ₃ or the like formed on the lower surface are laminated. A current collecting band 11 coated with silver paste or the like is formed on the transparent electrode 6, and leads 12 and 13 made of phosphor bronze board or the like are connected to this current collecting band 11 and the back electrode 6. ing. The moisture-absorbing films 2 and 3 are made of a polyamide condensate known under the trade name Nylon-12 on one side of resin films 14 and 15 made of, for example, a polyamide condensate known under the trade name Nylon-6. Adhesive layers 16 and 17 made of a material or the like are formed. Furthermore, the resin outer films 4, 5 are made by forming adhesives 20, 21 made of polyethylene or the like on one side of resin films 18, 19 made of trifluorochloroethylene or the like.

If the resin outer films 4 and 5 have a structure in which the adhesive layers 20 and 21 are sealed together by thermocompression, as in the above EL, the sealing dimension A of the resin outer films 4 and 5 is required to be 2 mm or more. . Note that when the resin outer films 18 and 19 are directly sealed by thermocompression, the sealing dimension A may be 1 mm or more, but there is a drawback that the thermocompression sealing temperature becomes high and the light emitting layer 8 is likely to deteriorate.

Problems to be Solved by the Invention By the way, if the sealing dimension A is set to be the same on each of the four sides of the EL, this sealing dimension A will naturally become a non-light-emitting part, but the part of the current collecting band 11 will also be a current collecting band. As a result of the light emission being blocked by 11, it becomes a non-light emitting portion in fact. Therefore, the dimension B of the non-light-emitting portion at the side end where the current collecting band 11 is formed is the sealing dimension A.
becomes larger than Therefore, in the above EL,
There were problems in that the external dimensions of the EL were large in proportion to the light emitting area, and the dimensions of the non-light emitting part were different between the side ends with and without the current collecting band 11, and the light emitting part was not in the center of the EL.

Means for Solving the Problems The present invention provides an EL device having a current collecting band along one side edge.
The element is sandwiched between two folded resin outer films so that one end of the element is in close contact with the inner surface of the two-fold part, and the area near the two-fold part and the current collecting band forming part of the EL element are heated. After being temporarily fixed by applying pressure, this temporarily fixed body is passed through a thermocompression roller to thermocompress and seal the resin outer films together.

Effect According to the present invention, the resin outer film is folded in half at the side edge where the current collecting band is formed, and the dimension from the edge of the EL element to the edge of the EL element is the same as the thickness of the resin outer film. Because the thickness is small, the dimensions of the non-light-emitting part formed by the current collector band and the dimensions of the non-light-emitting part on the opposite side are close to each other, making it possible to obtain an EL device with a small outer dimension compared to the light-emitting area. The light emitting part of can be positioned in the center of the EL.

In addition, by temporarily fixing the folded resin outer film and the current collecting band forming part of the EL element, when the temporarily fixed body is passed through a thermocompression roller and the resin outer films are thermocompressed and sealed together. In this case, only the resin outer film is sandwiched between the thermocompression rollers, so that the relative position between the resin outer film and the EL element does not shift, and the light emitting area of the EL element where the current collecting band is not formed is not temporarily fixed. Therefore, the EL of the present invention does not change color due to changes in the resistance value of the transparent electrode or deterioration of the resin outer film due to excessive heating and pressure.
can be manufactured efficiently and with high dimensional accuracy.

Embodiment FIG. 2 shows a plan view of the EL of the present invention, and FIG. 3 shows an enlarged sectional view taken along the line - in FIG. The figure is the same as FIGS. 14 and 15 except for the following points, so the same parts are given the same reference numerals. The difference from FIGS. 14 and 15 is that the resin outer film 22 is
It is folded in two at the side end where the current collecting band 11 is formed, and the resin outer films 22 are sealed together by thermocompression at three side ends excluding this side end. This resin outer film 22 is made of, for example, ethylene trifluoride chloride.
Adhesive layer 2 made of polyethylene etc. on the inner surface of 3
4 is formed, and more specifically, these adhesive layers 24 are sealed together by thermocompression. In this way, when the resin outer film 22 is folded in half at the side end where the current collecting band 11 is formed and sealed by thermocompression, the non-light-emitting portion of the resin outer film 22 on the current collecting band 11 side The dimension C becomes extremely small depending on the thickness of the resin outer film 22, and even if there is a non-light emitting part due to the current collecting band 11, the dimension C of the total non-light emitting part is the same as the heat between the resin outer films 22 on the opposite side. This is approximately the same as the dimension B of the non-light-emitting portion formed by pressure sealing. For this reason, not only can the external dimensions of the EL be reduced in relation to the light emitting area, but also the light emitting part can be reduced.
It can be located in the center of the EL.

By the way, when the above-mentioned EL is manufactured using a flat plate type heat press machine, air bubbles may be packed depending on the flatness of the heat press machine, and the work of setting, thermocompression sealing, and removing the EL is difficult. The problem is that it is troublesome and time-consuming, making it unsuitable for mass production. Therefore, it is conceivable to perform continuous thermocompression sealing using a thermocompression roller. However,
If such a method is adopted, the following new problems will be encountered.

4 and 5 show cross-sectional views at different stages of the method described above. In the figure, 25 and 26 are thermocompression rollers, which fix hard rubber 29 and 30 to the outer peripheries of pipes 27 and 28 made of stainless steel, etc., and alumina,
Insulating powder 31, 32 such as magnesia and heater 3
3 and 34, and is rotated in the direction of the arrow shown in the figure. Then, the laminate of the EL element 1 and the moisture-absorbing films 2 and 3 is supplied to the inner surface of the folded part of the resin outer film 22 in the direction of the arrow shown in the figure, and the laminate is bonded to the thermocompression rollers 25 and 26.
The resin outer film 22 is sealed together by thermocompression by passing through the gap. However, as shown in FIG. 5, when the two-folded portion of the resin outer film 22 is wedged between the thermocompression rollers 25 and 26, only this resin outer film 22 is inserted between the thermocompression rollers 25 and 26.
It is likely that the EL element 1 will be pulled between the thermocompression rollers 25 and 26 with a slight delay.

If the resin outer film 22 and
If slippage occurs between the EL element 1 and the EL element 1, the desired EL cannot be obtained. The 6th is such an undesired EL
FIG. 7 shows an enlarged sectional view taken along the line - in FIG. 6. In other words, if slippage occurs between the resin outer film 22 and the EL element 1, the EL
The dimension D of the non-light-emitting part on the collector band 11 side of the element 1 increases, and the sealing dimension E on the opposite side decreases, so not only is the light-emitting part no longer located in the center of EL, but the sealing dimension also decreases. Moisture resistance decreases as E decreases. In addition, the resin outer film 22 and the EL element 1
In order to obtain a sufficient sealing dimension on the side opposite to the current collecting band 11 even if slipping occurs between the current collecting band 11 and the current collecting band 11, if a large-sized resin outer film 22 is used in advance, the usage amount of the resin outer film 22 may be reduced. increases, causing an increase in costs.

FIGS. 8 to 10, FIG. 1, and FIGS. 11 to 13 show different steps for explaining the manufacturing method of the present invention that solves the above problems.
A plan view or a cross-sectional view of an EL element 1 or EL is shown.

First, a laminate in which moisture absorbing films 2 and 3 are placed above and below an EL element 1 is manufactured in the same manner as in the conventional method (FIGS. 8 and 9). Next, the resin outer film 22 is prepared in a two-folded state, and the resin outer film 2 is folded so that the side end where the current collecting band 11 of the EL element 1 is formed is brought into close contact with the inner surface of the two-folded part.
The EL element 1 is sandwiched between the two (FIGS. 10A and 10B). In this state, the resin outer film 2
From the outside of the EL element 1, the diagonal line 35 along the side edge where the current collecting band 11 is formed is heated and pressurized.
The laminate of the EL element 1 and the moisture-absorbing films 2 and 3 is temporarily fixed to the resin outer film 22 (see Fig. 1A).
and Figure 1B). Next, this temporarily fixed body is passed between the thermocompression rollers 25 and 26 from the temporarily fixed side end side, and the resin outer film 22 protruding from the EL element 1 is sealed by thermocompression (11th
figure). Then, the resin outer film 22 and the EL
Since the element 1 and the laminate of the moisture-absorbing films 2 and 3 are temporarily fixed, there is no slippage between the resin outer film 22 and the laminate, and the dimensions of the non-light-emitting portion of the current collecting band 11 of the EL element 1 are reduced. F becomes the minimum,
Accordingly, the sealing dimension G on the opposite side also becomes sufficiently large. Therefore, the external dimensions are small compared to the light emitting area, and the light emitting part is in the center of the EL.
Moreover, an EL with excellent moisture resistance can be obtained (FIGS. 12 and 13).

Further, the reason why the temporary fixing is performed in the diagonal line portion 35 along the side edge where the current collecting band 11 is formed is as follows.

In other words, when a part of the light-emitting region is temporarily fixed beyond the shaded area 35, this part is heated and pressurized twice in addition to the thermocompression bonding that is the final fixation of the outer skin film in the subsequent process, and the heat and pressure of this part becomes excessive. If the resistance value of the transparent electrode changes or the moisture absorbing film or outer film deteriorates, this part may appear discolored when the electroluminescent lamp is turned on, and the light emitted from other parts may change. This results in unevenness and significantly impairs marketability. Therefore, the optimum conditions for temporary fixing must be selected in consideration of the conditions for permanent fixing.

In addition, although the above embodiment describes the case where the moisture absorbing films 2 and 3 are used, the moisture absorbing films 2 and 3 are
The same is true even when not using.

Effects of the Invention According to the present invention, an EL can be obtained in which the light emitting portion is located in the central portion and the external dimensions are small compared to the area of the light emitting portion.

In addition, by using a thermocompression roller suitable for mass production, there is no slippage between the resin outer film and the EL element, and the light emitting part is located in the center.
ELs with small external dimensions relative to the area of the light-emitting part and excellent moisture resistance can be manufactured efficiently and with high precision.

[Brief explanation of drawings]

FIG. 1A is a plan view of an electroluminescent lamp showing the temporary fixing portion of the present invention, and FIG. 1B is a side view thereof. FIG. 2 is a plan view of an electroluminescent lamp according to an embodiment of the present invention, and FIG. 3 is an enlarged sectional view taken along the line - in FIG. 4 and 5 are cross-sectional views at different stages for explaining an efficient method of manufacturing the electroluminescent lamp of FIG. 2 and its problems. FIG. 6 is a plan view of an undesired electroluminescent lamp manufactured by the above method, and FIG. 7 is an enlarged sectional view taken along the line -- in FIG. 6. 8 to 13 show plan views and sectional views of an electroluminescent lamp element or an electroluminescent lamp at different stages for explaining the manufacturing method of the present invention, and FIG. 8 shows an electroluminescent lamp element and a moisture-absorbing film. 9 is an enlarged sectional view taken along the - line in FIG. 8, and FIG. 10A is a plan view of a laminate of an electroluminescent lamp element and a moisture-absorbing film sandwiched between folded resin outer films. 10B is a side view, and FIG. 11 is a cross-sectional view before the temporarily fixed body of the electroluminescent lamp element, the hygroscopic film laminate, and the resin outer film is passed between a pair of thermocompression rollers, and 12B is a side view. The figure is a plan view of the electroluminescent lamp after thermocompression sealing, and FIG. 13 is an enlarged sectional view taken along the line - in FIG. 12. FIG. 14 is a plan view of a conventional electroluminescent lamp, and FIG. 15 is an enlarged sectional view taken along line XV-XV in FIG. 14. DESCRIPTION OF SYMBOLS 1... Electroluminescent lamp element, 2, 3... Moisture absorption film, 6... Back electrode, 8... Light emitting layer, 9... Transparent electrode, 11... Current collecting band, 22... Resin outer film, 25, 26...Thermocompression bonding roller, 35...Temporary fixing part.

Claims (1)

[Scope of Claims] 1. A step of manufacturing an electroluminescent lamp device having a light emitting layer sandwiched between a pair of electrodes, at least one of which is transparent and having a current collecting band along one side edge; a step of sandwiching a lamp element between two folded resin outer films so that one end provided with a current collecting band is in close contact with the inner surface of the two folded parts; and an electric field in the vicinity of the two folded parts of the resin outer film. a step of temporarily fixing the current collection band forming portion of the light emitting lamp element by heating and pressing; passing the temporarily fixed body through a pair of thermocompression rollers;
A method for manufacturing an electroluminescent lamp, which includes a step of thermocompression-bonding sealing resin outer films protruding from the remaining side ends of an electroluminescent lamp element.