JPH096259A - Led display - Google Patents

Abstract

PURPOSE: To provide an LED display having a high display grade. CONSTITUTION: The LED display is equipped with a board 1 on the surface of which a large number of LED electrode parts are arranged, light emitting diode elements 7 which are arranged on electrodes of the electrode parts and are wired via metal fine wires, a white first insulation layer 12a arranged in an area on the electrode parts excluding the arranged area of the light emitting diode elements 7 and the metal fine wires, a black second insulation layer 13 arranged so as to fill the space among the electrode parts, and light transmissible resin 11 which is arranged over the electrode parts so as to cover the light emitting diode elements 7 and the first insulation layer 12a. Thereby, the height of molding resin is heightened by the insulation layers 12a, 13, and also the light generated from the light emitting diode elements 7 is effectively reflected by the white insulation layer 12a so that color mixing performance can be excellent in the case of different luminescent colors. Contours of LED parts can be clear by the black insulation layer 13 so that a display grade can be heightened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED display in which a large number of LED parts are directly formed on a substrate.

[0002]

2. Description of the Related Art When LEDs are used for displaying characters or patterns, conventionally, ready-made LEDs are used and they are arranged in a matrix on a substrate to form a display device (Japanese Patent Laid-Open No. 1-1999).
-194479, etc.). However, ready-made LE
Since D is used, the assembling workability is poor, and the light emitting directions are likely to be uneven and stable display cannot be performed. Therefore, recently, a display device has been developed in which the LED section is directly formed on the substrate to solve the above-mentioned problems.

[0003]

When the LED section is directly formed on the substrate as described above, there are the following problems to be solved. First, since a large number of LED electrode portions, each of which is composed of an electrode group having a predetermined shape for arranging and connecting the light emitting diode elements, are formed on the surface of the substrate, and wiring for connecting these is also formed on the surface of the substrate. The periphery of the electrode portion is likely to be uneven due to the presence of the wiring. Although this unevenness is as small as several tens of μm, it is considerably larger than the size (about 300 μm square) of the light emitting diode element arranged on the electrode, so the light of the light emitting diode element escapes along this unevenness. It is easy to disperse, insufficient light amount for display, and defective contour are likely to occur. In particular, when the reflective frame around the LED electrode portion is omitted, when the resin covering the light emitting diode element is molded on the LED electrode portion, the resin flows out along the irregularities to stabilize the shape of the resin. However, unevenness is likely to occur in the light emitting direction. Further, even when a reflective frame is provided on the surface of the substrate, the adjacent LED parts communicate with each other at the back side of the reflective frame via the irregularities, and the light of the adjacent LED part may leak out through this connecting part. . Also, when the resin is dropped and molded so as to cover the gold-plated electrode portion, the surface tension of the electrode portion is relatively small, so the height of the resin cannot be increased and the emission color When a plurality of different light emitting diode elements are provided, if the lower surface of the transparent resin is a gold-plated electrode, color mixing is poor. Further, a circuit board for driving and the like is arranged on the back side of the board, but measures for shielding unnecessary radio waves generated from these circuits are not sufficiently implemented.

[0004]

The present invention has been made in consideration of the above points, and is an LED including a group of electrodes having a predetermined shape.
A substrate for LED display in which a large number of electrode parts are arranged on the surface, a light emitting diode element arranged on the electrode of the LED electrode part and wired through a thin metal wire, and surrounding the light emitting diode element and the thin metal wire. A white-based first insulating layer disposed on the LED electrode portion, a black-based second insulating layer disposed so as to fill a space between the LED electrode portions, the light-emitting diode element and the first insulating layer. The L to cover the layer
And a translucent resin disposed on the electrode portion for ED.

Further, according to the present invention, on the surface, a large number of LED electrode portions each consisting of an electrode group of a predetermined shape are insulated from each other and the LED electrode portions are insulated from each other so as to fill the space between the plurality of LED electrode portions. A substrate having a common electrode portion arranged, which is constituted by a conductive layer having substantially the same thickness, a light emitting diode element arranged on the electrode of the LED electrode portion and wired through a thin metal wire, A white-based first insulating layer disposed in a region on the LED electrode portion excluding the light emitting diode element and the metal thin wire disposition region and a region covering substantially the entire surface of the common electrode portion; and the first insulating layer on the common electrode portion. A second black insulating layer laminated on one insulating layer; and a translucent resin arranged on the LED electrode portion so as to cover the light emitting diode element and the first insulating layer. It is a thing.

[0006]

According to the present invention, as described above, the first white-colored portion is formed on the LED electrode portion so as to surround the light emitting diode element and the thin metal wire.
Since the insulating layer is arranged, the height of the resin can be increased by the surface tension of the first insulating layer when the mold resin is arranged on the LED electrode portion, and at the same time the outer peripheral surface of the lower surface of the translucent resin is covered. The white-based first insulating layer is positioned to effectively reflect the light generated from the light emitting diode device.
When arranging a plurality of light emitting diode elements having different emission colors, the white color first insulating layer can improve the color mixing property. Further, by arranging the black second insulating layer so as to fill the space between the LED electrode portions, the LE
It is possible to improve the display quality by making the contour of the D portion clear.

Further, according to the present invention, as described above, the adjacent L
Since the common electrode portion is arranged so as to fill the space between the ED electrode portions, the periphery of the LED electrode portion is flattened and surrounded by a certain height, so that undesired light leakage is prevented and the LED It enables stable molding of the resin when the molding resin is arranged and molded. Moreover, the common electrode portion effectively functions as a shield layer that absorbs unnecessary radio waves. Furthermore, by configuring the LED electrode portion and the common electrode portion with conductive layers having substantially the same thickness, and covering the substantially entire surface of the common electrode portion with the first and second insulating layers, the periphery of the LED electrode portion is It is surrounded by the common electrode part and the insulating layer at a predetermined height to prevent undesired light leakage, and prevents the resin from flowing out when the mold resin is arranged on the LED electrode part by the common electrode part and the insulating layer. Can be suppressed.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. The substrate 1 is composed of an insulating base material 2 such as glass epoxy resin colored in black, and a plurality of LED electrode portions 3 are formed on the surface of the insulating base material 2 independently from each other as shown in FIG. 2 (a). 3 (24 rows and 24 columns), and on the back surface thereof, as shown in the perspective view of FIG.
The wiring pattern 4 made of copper foil that constitutes the wiring portion for performing the electrical connection wiring is provided. The connection between each LED electrode portion 3 and the wiring pattern 4 is performed inside the base material 2 through a through hole 5 penetrating the base material 2 as shown in FIG. 1, and the wiring pattern 4 on the back surface is black. Covered by an insulating layer.

Each of the LED electrode portions 3 has an electrode group made of a conductive metal foil of a predetermined shape, that is, as shown in FIG. 2 (b), has a circular shape as a whole, and the surface thereof is gold-plated if necessary. It is composed of the three lead electrodes 3a, 3b, 3c made of copper foil. Each of the lead electrodes 3a, 3b, 3c has a base material 2
Through holes 5 are formed so as to penetrate through the through holes 5, and as shown in FIG. 1, wiring is performed to the wiring pattern 4 on the back surface via the wiring copper foil provided in the through holes 5. Each of the LED electrode portions 3 is electrically connected by the wiring copper foil penetrating the base material 2 and the wiring pattern 4 on the back surface of the base material 2 as described above, and is not connected on the front surface side of the base material 2. Since there is no,
They are independent of each other on the surface side of the base material 2. And FIG.
When constructing the LED section 6 shown in FIG.
As shown by a dotted line, one to a plurality of light emitting diode elements 7 are attached to a predetermined lead electrode via a conductive adhesive, and the light emitting diode element 7 is attached to another lead electrode by gold, aluminum, or the like. They are electrically connected by wire-bonding wiring using the thin metal wires 8 of.

The surface of the substrate 1 is shown in FIG.
As shown in, the common electrode portion 9 is formed so as to fill the space between the adjacent LED electrode portions 3. The common electrode portion 9 is used as the lead electrodes 3a, 3 which constitute the LED electrode portion 3.
Since the copper foil made of the same material as b and 3c is formed by etching, it has substantially the same thickness as the LED electrode portion 3.
Between the common electrode portion 9 and each LED electrode portion 3, an annular insulating region 10 for maintaining electrical insulation is provided by etching a copper foil. In this way, the periphery of the LED electrode portion 3 can be a flat surface without irregularities because the common electrode portion 9 having a single thickness is annularly surrounded, and the edges of the common electrode portion 9 are annular and have the same height. Therefore, when the LED is formed, the transparent resin 11 can be molded more uniformly when the transparent resin 11 is poured into the LED electrode portion 3 and molded. Further, since the common electrode portion 9 is formed over a wide area on the substrate 1 so as to fill the space between the LED electrode portions 3, a shield that absorbs unnecessary radio waves generated from the substrate 1 or a drive substrate separately attached to the substrate 1. It can effectively function as a layer.

A region 12a located on the outer periphery of the upper surface of each LED electrode portion 3 so as to surround the light emitting diode element 7 and the thin metal wire 8 and a region 12b which covers substantially the entire surface of the common electrode portion 9.
5 has a white insulating layer 12 (12a, 12b) having electrical insulation as shown by the diagonal lines in FIG. 5, good light reflectivity, and a surface tension larger than that of the LED electrode portion 3.
Are formed by screen printing or the like, and are arranged so as to have a substantially uniform thickness (set to be about 2 to 3 times thicker than the thickness of the common electrode portion 9). In this way, each LED electrode portion 3
By arranging the white insulating layer 12a having good light reflectivity and having a surface tension larger than that of the LED electrode portion 3 so as to surround the light emitting diode element 7 and the thin metal wire 8 on the outer peripheral portion of the upper surface of When molding the light-sensitive resin 11, the white insulating layer 12a is formed on the skirt portion of the light-transmitting resin having a low viscosity.
Due to the surface tension of 1, the overall height of the translucent resin can be maintained high for molding. In addition, since the white insulating layer 12a is present on the lower surface of the translucent resin 11, the reflection efficiency of the light emitted from the light emitting diode element 7 can be improved and the light emitting diode elements having different emission colors can be formed. When used, the color mixing property can be improved. The insulating layer 12b that covers substantially the entire surface of the common electrode portion 9 is formed on the insulating layer 12a in order to simplify the manufacturing process.
Although it is formed of the same material as described above, it may be formed of another material, and may be formed simultaneously with the formation of the black insulating layer 13 described later.

In a region that covers substantially the entire surface of the common electrode portion 9, as shown by the cross hatched lines in FIG. 6, it has electrical insulation, good light absorption, and a larger surface than the LED electrode portion 3. The black insulating layer 13 having tension is formed by screen printing or the like, and is arranged so as to have a substantially uniform thickness (set to be about 2 to 3 times thicker than the thickness of the common electrode portion 9). By thus providing the black insulating layer 13, the LED
The area surrounding the working electrode portion 3 can be made flat, and the common electrode portion 9 and the white insulating layer 12 can be formed as shown in FIG.
b and the height of the edge of the black insulating layer 13, that is, LE
The height of a portion functioning as a wall 14 surrounding the D electrode portion 3 in an annular shape through the annular insulating region 10 is increased to effectively prevent the translucent resin 11 from flowing out, and at the same time, to prevent the light emitting diode element 7 from flowing out. The light leakage path can be blocked. Also,
By providing the black insulating layer 13 on the common electrode portion 9, it is possible to enhance the effect of absorbing unnecessary reflected light, and
When the part 6 is turned on, the color tone can be made clear. The insulating layer covering the common electrode portion 9 is the black insulating layer 1
Alternatively, the upper surface of the black insulating layer 13 may have the same height as the upper surface of the white insulating layer 12a.
It is preferable to form it so that it is higher than the white insulating layer 12a.

Then, the LED electrode portions 3 of the substrate 1 are provided.
After the light emitting diode element 7 is attached to the above with the conductive adhesive as described above, wiring is performed by bonding using the thin metal wire 8, and the translucent resin 11 is dripped from a nozzle so as to cover the bonding portion, for example. Molding is performed, or if necessary, a reflective frame (not shown) having circular windows provided in a matrix corresponding to, for example, that shown in FIG. 4 is arranged on the substrate 1 to cover the bonding portion. By pouring the translucent resin 11 into the resin mold and molding the resin to form the LED section 6 directly on the substrate 1, an LED display having the matrix-shaped LED section 6 can be constructed. When the reflection frame is arranged, the periphery of each LED electrode portion 3 is flattened by the presence of the black resin layer 13, so that the adhesion between the substrate 1 and the reflection frame is good and the light leakage path is not formed. Further, when the light-transmissive resin 11 is molded without the reflection frame, the light of the light-emitting diode element 7 can be output in a wide range through the light-transmissive resin 11, so that the visibility is improved. be able to.

Further, since the white insulating layer 12a having a large surface tension is arranged on the outer peripheral portion of the upper surface of each LED electrode portion 3, when the translucent resin 11 is molded, the translucent resin having a low viscosity is transmitted. The skirt portion of the transparent resin can be raised by the surface tension effect of the white insulating layer 12a, and the entire height of the translucent resin can be maintained high for molding. And the resin is LE
Even if it flows out to the periphery of the D electrode portion 3, the periphery of each LED electrode portion 3 is, as shown in FIG.
0 and the common electrode part 9 and the insulating layer 12b, 13 are surrounded by the annular wall 14 constituted by the edges of the insulating layers 12b, 13, so that the annular insulating region 10 and the wall 14 prevent the resin from flowing out during the translucent resin molding. It functions as a groove and a weir,
The shape of the translucent resin 11 when it is cured can be made uniform, and the quality of the LED parts 6 can be made uniform.

[0015]

As described above, according to the present invention, since the white first insulating layer is arranged on the LED electrode portion so as to surround the light emitting diode element and the thin metal wire, the LED electrode portion is covered with the moth. When arranging the sealing resin, the height of the resin can be increased by the surface tension of the first insulating layer, and the white first insulating layer is located on the outer peripheral portion of the lower surface of the translucent resin. It is possible to effectively reflect the light generated from the. When arranging a plurality of light emitting diode elements having different emission colors, the white color first insulating layer can improve the color mixing property. Further, by arranging the black second insulating layer so as to fill the space between the LED electrode portions, the contour of the LED portion can be made clear and the display quality can be improved.

In addition, the present invention, as described above, uses adjacent L
Since the common electrode portion is arranged so as to fill the space between the ED electrode portions, the periphery of the LED electrode portion is flattened and surrounded by a certain height, so that undesired light leakage is prevented and the LED It enables stable molding of the resin when the molding resin is arranged and molded. Moreover, the common electrode portion effectively functions as a shield layer that absorbs unnecessary radio waves. Furthermore, by configuring the LED electrode portion and the common electrode portion with conductive layers having substantially the same thickness, and covering the substantially entire surface of the common electrode portion with the first and second insulating layers, the periphery of the LED electrode portion is It is surrounded by the common electrode part and the insulating layer at a predetermined height to prevent undesired light leakage, and prevents the resin from flowing out when the mold resin is arranged on the LED electrode part by the common electrode part and the insulating layer. Can be suppressed.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of a display device according to an embodiment of the present invention.

FIG. 2 is a substrate according to one embodiment of the present invention (without an insulating layer)
2A is a plan view of FIG. 3A, and FIG.

FIG. 3 is a transparent plan view of a wiring pattern formed on a back surface of a substrate according to an embodiment of the present invention.

FIG. 4 is a plan view of a display according to an exemplary embodiment of the present invention.

FIG. 5 is a partially enlarged plan view of a substrate according to an embodiment of the present invention in which a first insulating layer is applied.

FIG. 6 is a partially enlarged plan view of a substrate according to an embodiment of the present invention in which first and second insulating layers are applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Base material 3 LED electrode part 6 LED part 7 Light emitting diode element 8 Metal thin wire 9 Common electrode part 10 Annular insulating area 11 Translucent resin 12 White resin layer 13 Black resin layer

Continuation of the front page (72) Inventor Tatsuya Motoike 3 201 Minamiyoshikata, Tottori City, Tottori Prefecture Tottori Sanyo Electric Co., Ltd.

Claims (2)

[Claims] 1. An LED display substrate having a large number of LED electrode portions, each of which has an electrode group of a predetermined shape, arranged on the surface, and the LE.
A light emitting diode element arranged on the electrode of the D electrode section and wired through a metal thin wire, and a white-based element arranged in an area on the LED electrode section excluding the area where the light emitting diode element and the metal thin wire are arranged. A first insulating layer, a black second insulating layer arranged to fill the space between the LED electrode portions, and a light emitting diode element and the first insulating layer are arranged on the LED electrode portions. And a translucent resin as described above. 2. A large number of LED electrode portions each consisting of an electrode group having a predetermined shape and a common electrode arranged on the surface so as to insulate the LED electrode portions from each other and fill the spaces between the plurality of LED electrode portions. And a substrate formed of a conductive layer having substantially the same thickness, and a light emitting diode element arranged on the electrode of the LED electrode portion and wired through a thin metal wire,
A white-based first insulating layer arranged in a region on the LED electrode portion excluding a region where the light emitting diode element and the metal thin wire are arranged and a region covering substantially the entire surface of the common electrode portion; and the white insulating layer on the common electrode portion. A black-based second insulating layer laminated on the first insulating layer; and a translucent resin arranged on the LED electrode portion so as to cover the light emitting diode element and the first insulating layer. Characteristic LED display.