JPH0416469Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an improvement in a light emitting display constructed using a light emitting element that emits point light, such as an LED chip or an LED lamp.

Conventional technology Conventionally, a dot matrix light-emitting display, which is a typical example of this type of light-emitting display, has light-emitting elements such as LED chips arranged and wired in a matrix on the top surface of a display substrate to form a lighting display circuit. Then, the entire upper surface of the display substrate was covered with a thermosetting resin sealing film. However, the light-emitting display body having such a structure has a problem in that the light emitted from each light-emitting element leaks to the surroundings, so that the outline of the display pattern becomes considerably blurred and the visibility is poor.

In order to solve this problem, the present applicant has bonded a neoprene rubber mask plate with through holes corresponding to each light emitting element to a display substrate on which a plurality of light emitting elements are disposed, so that each light emitting element can be A light-emitting display body has already been developed in which a light-emitting element is sealed by storing a light-emitting element in each through-hole and filling each through-hole with a translucent resin such as an epoxy resin. Such a structure has the advantage that the apparent light emitting area is increased and the light emitted from the light emitting element does not leak into the adjacent light emitting section, so that visibility is greatly improved. However, there was still room for improvement as described below.

Problems that the invention aims to solve: Namely, the neoprene rubber mask plate described above has poor weather resistance and deteriorates in a relatively short period of time, resulting in a short service life of the light emitting display. . Therefore, we decided to use a weather-resistant silicone rubber mask plate instead, but such silicone rubber mask plates have extremely poor adhesion (wettability) with other synthetic resins, etc. Therefore, when a transparent resin for sealing is filled into a transparent hole, air is trapped between the inner circumferential surface of the transparent hole and the transparent resin, resulting in a jagged, uneven surface at the interface, which causes the adhesive to form. The color of the inner circumferential surface of the through hole (usually white or silver with good light reflection) appears relatively clearly in the part where air is trapped, while the color of the inner circumferential surface of the hole is reflected diffusely in the part where air is trapped. New problems have arisen in that the colors appear blurry and blurred, resulting in poor appearance and low commercial value. Furthermore, as mentioned above, if the adhesion between the inner peripheral surface of the through hole in the mask plate and the transparent sealing resin becomes poor, the sealing will be insufficient and moisture will enter, causing deterioration of the light emitting element. A serious problem has also arisen in accelerating the process.

Means for Solving the Problems The light-emitting display of the present invention was created with the aim of solving the above-mentioned problems, and includes a display substrate on which a plurality of light-emitting elements are arranged, and a through-hole corresponding to each light-emitting element. A mask plate made of silicone rubber with The gist is that the light-emitting element is sealed in two layers.

Effect of the invention With this structure, when filling the liquid translucent silicone rubber into the through-hole, it has good leakage with the mask plate made of the same material, so there is no air entrapment, and the liquid is filled on the inner circumferential surface of the through-hole after curing. Due to the double sealing between this translucent silicone rubber and the lower translucent resin,
Intrusion of moisture etc. from the outside is reliably prevented. In addition, although there is a non-adhesive part between the transparent resin at the bottom of the hole and the inner circumferential surface of the hole, the transparent silicone rubber that occupies most of the hole is in close contact with the inner circumferential surface of the hole. Since the color of the surrounding surface appears clearly, deterioration in appearance can be kept to a minimum.

Examples Hereinafter, the light emitting display of the present invention will be described in detail with reference to Examples.

FIG. 1 is a perspective view showing an embodiment of the light emitting display of the present invention, and FIG. 2 is a schematic enlarged sectional view taken along the line - in FIG. Although the dot matrix light-emitting display A is shown having a total of 64 light-emitting parts (light-emitting dots) 1, the arrangement state and number of light-emitting parts 1 are not limited to this.

The display substrate 2 of the light-emitting display A is formed by etching a copper-clad laminate made of glass epoxy resin, paper phenol, etc. on its surface, and has eight vertical conductive patterns 3, ( For example, the conductive patterns 3 on the back side (for example, the anode side) are connected to each other through the through holes 31. Each light emitting part 1 is led out to the surface of the display substrate 2, and an LED chip 44 as a light emitting element is fixed thereon with a conductive paste (for example, silver paste etc.).
The LED chip 4 is connected via the bonding wire 5.
is connected to the other conductive pattern 3' (for example, on the cathode side) on the substrate surface. In this way,
An 8×8 XY matrix lighting display circuit is configured.

On the display substrate 2, an LED chip 4 is mounted.
8 mortar-shaped through holes 6 are formed vertically and horizontally corresponding to each of the
A mask plate 7 made of silicone rubber made of 8 pieces is joined together, and an LED chip 4 is placed inside each through hole 6.
are stored in each. This mask plate 7 is
This is to improve visibility by enlarging the apparent light-emitting part (light-emitting dot) 1 and preventing light from leaking to adjacent light-emitting parts, and preferably the surface of the mask plate is configured with a black or gray light-absorbing surface. The upwardly expanding tapered inner circumferential surface 61 of the through hole 6 is formed into a light reflecting surface of white or silver color.

The lower part of the through hole 6 of this mask plate 7 is filled with a thermosetting light-transmitting resin 8, such as epoxy resin, which has excellent adhesiveness to the display substrate 2, and a light-transmitting resin 8 is filled thereon. It is filled with silicone rubber 9, and the wiring portion of the LED chip 4 inside the through hole 6 is sealed in two layers by the light-transmitting resin 8 and the light-transmitting silicone rubber 9. In this case, the filling amount of the translucent resin 8 is set to approximately 1/3 or less of the internal volume of the through hole 6 and an amount that can cover the LED chip 4 and the bonding wire 5, so that most of the through hole is transparent. Transparent silicone rubber 9 that can be in close contact with the inner peripheral surface 61 of the hole
It is preferable to fill it with Furthermore, the filling form of the translucent resin 8 may be in the form of a layer with a uniform thickness as shown in FIG. 2, or in the form of a bulge as shown in FIG. Any form may be used as long as the wiring portion can be sealed. Note that the surface of the translucent silicone rubber 9 is desirably configured to have a concave surface as shown in FIGS. 2 and 3 in order to enlarge the viewing angle.

A plurality of the light-emitting display members A having the above structure are arranged side by side and attached to the mounting frame of a display device, and the lighting is dynamically controlled according to a program of a controller (consisting of a CPU, etc.), and desired characters, figures, and symbols are displayed. etc., but as mentioned above,
Since the mask plate 7 is made of silicone rubber with excellent weather resistance, deterioration of the mask plate 7 is unlikely to occur.
The service life will be significantly extended compared to the conventional mask plate made of neoprene rubber.

Moreover, since the transparent silicone rubber 9 filled in the transparent hole 6 is in close contact with the inner circumferential surface 61 of the transparent hole of the mask plate 7 made of the same material, there is no gap between the transparent silicone rubber 9 and the transparent silicone rubber 9 in the lower part. The two-layer sealing with the synthetic resin 8 can reliably prevent moisture from entering from the outside, and can therefore sufficiently prevent early deterioration of the LED chip 4 due to the invasion of moisture. becomes. Furthermore, although there is a non-adhesive portion between the transparent resin 8 at the bottom of the hole 6 and the inner circumferential surface 61 of the hole, the transparent silicone rubber 9 that occupies most of the above is the inner circumferential surface of the hole. 61, and the color of the inner peripheral surface appears clearly, so it is possible to minimize the deterioration in appearance.

Such an effect is achieved by reducing the filling amount of the translucent resin 8 to approximately 1/3 or less of the internal volume of the through hole 6 and reducing the amount of the LED chip 4 and the bonding wire 5 as described above.
This is particularly noticeable when the amount is enough to cover the area and the remaining part is filled with the transparent silicone rubber 9.

Although the present invention has been described above with reference to the embodiment of the dot matrix light emitting display A, the light emitting display of the present invention can of course also be applied to a segment type light emitting display in which a segment light emitting portion having a light emitting element is formed. It is.

Effects of the invention As is clear from the above explanation, according to the light emitting display of the present invention, the mask plate is made of silicone rubber with good weather resistance and is difficult to deteriorate, and the light emitting element is also made of a transparent resin and a transparent material. Due to the reliable two-layer sealing with photosensitive silicone rubber, it is not affected by moisture and other harmful effects, making it possible to significantly extend the service life of the light emitting display. Air is not trapped at the interface of the translucent silicone rubber, and the color of the inner circumferential surface of the through hole appears clearly, resulting in the effect that deterioration in appearance can be minimized.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a light-emitting display according to an embodiment of the present invention, FIG. 2 is a schematic enlarged sectional view taken along the line - in FIG. 1, and FIG. 3 is a partial sectional view of another embodiment of the present invention. It is. 2...Display substrate, 4...LED chip (light emitting element), 6...Through hole, 7...Mask plate, 8...Transparent resin, 9...Transparent silicone rubber.

Claims (1)

[Scope of utility model registration request] A silicone rubber mask plate with through holes corresponding to each light emitting element is bonded to a display substrate on which a plurality of light emitting elements are arranged, and each light emitting element is housed in each through hole. A light-emitting display body comprising a light-emitting element sealed in two layers by filling the lower part of the resin with a light-transmitting resin and filling the upper part with a light-transmitting silicone rubber.