JP3274839B2 - LED display device and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED (Lihgt Emi
The present invention relates to a display device (light emitting diode) and a method for manufacturing the same.

[0002]

2. Description of the Related Art An LED display device employed as a component of various display devices is generally a flat plate-shaped LE.
It comprises an LED display unit in which a cured epoxy resin or the like is interposed on the surface of the D mounting board, and a terminal unit integrated with or connected to the LED display unit. Where LE
The D mounting board has a plurality of LED elements mounted on a printed board. Each LED element is connected to a cathode electrode and an anode electrode of a printed circuit board by a bonding wire or the like. The transparent resin protects the surface of the wiring on the printed circuit board and protects the surface of each LED element protruding from the printed circuit board. Usually,
An insulating resin may be interposed also on the back surface of the LED display unit. In addition, the terminal section includes a connector or a cable and a connector connected to the wiring of the printed circuit board.

In general, such an LED display device has a plurality of LED elements mounted on a flat printed board to form a flat LED mounting board, and an uncured transparent resin is interposed on the surface of the LED mounting board by coating or the like. After that, the uncured transparent resin is completely cured, and further obtained by interposing an insulating resin on the back surface. L thus obtained
In the ED display device, an LED display unit is assembled to the display device as a component of various display devices, and a connector of a terminal unit is connected to a driver of the display device. And this LED display device,
When driven by the driver, the LED display unit performs various displays using the respective LED elements.

[0004]

However, the above-mentioned general LED display device employs a flat LED mounting board, and the uncured transparent resin interposed on the surface thereof is completely cured as it is. It is in a non-flexible state with a flat shape. For this reason, in this LED display device,
The LED display section is also flat, and it is sometimes difficult for a person who looks at the LED display section from a position other than the front side to visually recognize the display. In addition, this LED display device
Although the LED display unit can be assembled flush with the display device having a flat portion, the LED display unit must be assembled with a step in the display device having a curved surface portion, and the visibility is impaired by the step. There is a disadvantage that the design of the display device is also impaired.

In this respect, as described in Japanese Patent Application Laid-Open No. 10-116039, a flexible (flexible) printed circuit board is employed, and the LED is also formed by a transparent resin.
It is also conceivable to ensure the flexibility of the display device. However, in such an LED display device, when assembling to a display device or the like, the LED display portion is likely to bend unnecessarily, thereby easily disconnecting the wiring of the printed circuit board, and particularly the bonding wire, and thus ensuring stable quality. There are difficulties.

On the other hand, it is conceivable to adopt a curved printed circuit board to provide a curved LED display device.
In this case, special equipment is required to obtain a curved LED mounting board, which causes a great increase in manufacturing cost and is not practical. The present invention has been made in view of the above-mentioned conventional situation, and realizes relatively inexpensive manufacturing costs and secures stable quality, and allows a person who looks at the LED display unit from other than the front to display the display. LEDs that are easy to see and do not impair the design of the display device that has a curved surface
It is an object to provide a display device and a method for manufacturing the display device.

[0007]

Means for Solving the Problems The inventors have conducted intensive studies to solve the above-mentioned problems, and first completed the method for manufacturing an LED display device of the present invention. That is, in the method of manufacturing an LED display device of the present invention, a plurality of LED elements are mounted on a printed circuit board, and a flexible flat plate-shaped LE is provided.
A first step of forming a first intermediate product by interposing an uncured transparent resin on the surface of the D mounting substrate; and, while incompletely curing the uncured transparent resin of the first intermediate product, removing the first intermediate product. The method includes a second step of forming a second intermediate product by curving, and a third step of completely curing the uncured transparent resin of the second intermediate product.

In the manufacturing method of the present invention, first, in a first step, an uncured transparent resin is interposed on the surface of the LED mounting board by coating or the like to obtain a first intermediate product. The LED mounting substrate is a generally flexible flat plate. As the uncured transparent resin, a thermopolymerized curable resin, a photopolymerized curable resin, or an electron beam polymerized curable resin can be employed. Note that L
The ED mounting board is one in which a plurality of LED elements are mounted on a printed board in which wiring is provided on a base material. The base is made of glass cloth epoxy resin, paper phenol, or the like, and the wiring is made of a copper foil pattern or the like printed on the base via a resist. Here, it is preferable that the resist has a color that clarifies various displays by each LED element. For example, if each LED element emits red or green, the resist is made of black or white insulating ink.

On the surface of the LED display section of the LED mounting board, a partition member for partitioning various displays by the respective LED elements can be provided. Various display outlines may be formed by this partitioning material, and this partitioning material may be provided between individual LED elements when each LED element is mounted in a matrix or the like. In the former case, outlines of various displays by a plurality of LED elements become clear, and in the latter case, leakage of light from individual LED elements can be prevented and various displays can be partitioned. As the partitioning material, a black resin or a metal-colored resin that is polymerized and cured by heat or the like in the same manner as the uncured transparent resin can be used. When the partitioning material is provided by such a black resin or the like, the black resin or the like is interposed by coating or the like before the uncured transparent resin is interposed on the surface of the LED mounting board.

Then, in the second step, the first intermediate product is curved while the uncured transparent resin of the first intermediate product is incompletely cured to form a second intermediate product. The curing of the uncured transparent resin is made to such an extent that its shape can be maintained to some extent even when it is curved.
The degree of curvature is matched to the curved surface of the display device on which the LED display unit is assembled. Thereafter, in a third step, the uncured transparent resin of the second intermediate product is completely cured. As a fourth step, a flexible terminal portion can be connected to the third intermediate product after the third step. Note that an insulating resin may be interposed on the back surface of the LED display unit by coating or the like.

[0011] Thus, the LED of the present invention having an LED display portion made of a transparent resin or the like obtained by curing an uncured transparent resin for protecting the printed circuit board, each LED element and the surface, and a terminal portion connected to the LED display portion. A display device is obtained. In this LED display device, since the LED display unit is curved so as to match the curved surface portion of the display device,
The LED display unit can be assembled to the display device without any step, and a person who looks at the LED display unit from a position other than the front can easily see the display. In addition, this LED display device does not impair the design of the display device.

Also, in this LED display device, LE
Since the D display section is curved in a non-flexible state, the LED display section exhibits rigidity at the time of assembling to a display device or the like, and the wiring of the printed circuit board is hardly disconnected. In particular, LE
If each LED element of the D display unit employs an LED mounting board connected to the cathode electrode or the anode electrode by substantially parallel bonding wires, the LED display unit can be curved while maintaining each bonding wire substantially parallel. In this case, no stress acts on each bonding wire, and it is difficult for each bonding wire to break. Therefore, this L
An ED display device can exhibit stable quality.

Further, when manufacturing this LED display device, a curved flexible printed circuit board is not used, and a general flexible flat LED mounting board is used.
No special equipment is required other than the device for bending and holding the first intermediate product, and the device can be manufactured relatively inexpensively. Therefore, according to the LED display device and the method of manufacturing the same of the present invention, while realizing relatively inexpensive manufacturing cost and securing stable quality, a person or the like who views the LED display unit from other than the front can visually recognize the display. In addition, the design of a display device having a curved surface portion is not impaired.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments 1 and 2 embodying the present invention will be described below with reference to the drawings. Embodiment 1 First Step First, an LED mounting board 1 shown in FIGS. 1 and 2 is prepared. The LED mounting board 1 is one in which a plurality of red or green LED elements 1b are mounted on a printed board 1a, and is a generally flexible flat plate. As shown in FIG. 6, the printed circuit board 1a is made of a copper foil pattern printed on the front and back surfaces (only the front surface in the figure) of a base material 2 made of glass cloth epoxy resin via a black resist 4a. In which the wiring composed of the cathode electrode 3a or the anode electrode 3b is provided.
Each LED element 1b composed of an n-type layer, a p-type layer and the like is connected to the cathode electrode 3a and the anode electrode 3b on the printed circuit board 1a by bonding wires 5a and 5b which are substantially parallel to each other. Here, each LED element 1b is
Instead of being mounted in a circular shape as shown in FIGS. 1 and 2, it may be mounted in a rectangular shape. In FIG. 1, reference numeral 1c denotes a mounting hole for a display device described later.

As shown in FIGS. 3 and 4, a black resin (manufactured by Cemedine Co., Ltd.) 6 is applied to the surface of the LED mounting board 1 by printing in order to form various display contours. Thereafter, a photopolymerized and cured resin (manufactured by Toray Dow Corning Co., Ltd.) 7 is applied to the surface of the LED mounting board 1 including the black resin 6 with a thickness of 2 mm to form a first intermediate product 8. "Second step" Then, as shown in FIG.
Is irradiated for 10 seconds to cure the uncured transparent resin 7 of the first intermediate product 8 by about 30%. In this state, the first intermediate product 8 is curved to a degree that matches the curved surface portion of the display device,
It is referred to as a second intermediate product 9. At this time, as shown in FIG. 6, the bonding wires 5a and 5b are maintained substantially parallel. "Third step" Thereafter, the second intermediate product 9 is further irradiated with ultraviolet rays for 3 more times.
Irradiation for 0 second completely cures the uncured transparent resin 7 of the second intermediate product 9 to obtain a third intermediate product 10. "Fourth Step" As shown in FIG. 7, on the back surface of the third intermediate product 10, the flexible terminal portion 11 composed of the flat cable 11a and the connector 11b is connected to the wiring pad of the printed board 1a. Then, a connection portion between the pad and the flat cable 11a is fixed with silicone rubber or the like, and a known insulating resin is applied to the entire back surface of the printed board 1a.

In this manner, the LED display section 12 composed of the printed board 1a, each LED element 1b, the partition member 6 in which the black resin 6 is cured, the transparent resin 7 in which the uncured transparent resin 7 is cured, and the like.
And the terminal unit 1 connected to the LED display unit 12.
1 is obtained. This LE
As shown in FIGS. 8 and 9, the D display device is, for example, a component part of a cylindrical guide display device 13 of an escalator. At this time, the LED display unit 12 is
And the connector 11b of the terminal unit 11 is connected to the drive board 13a of the display device 13. Note that the drive substrate 13a is a photoelectric device 13
b, 13c and terminal block 13 connected to switch 13d
e, and the terminal block 13e is connected to a control device of an escalator body (not shown) by a cable 13f. This LED display device is connected to the drive board 13a.
LED display unit 12 is driven by
Various displays are performed by the ED element 1b. For example, the LED display unit 12 displays “up” by green color shown in FIG. 10A, “down” by green color shown in FIG. 10B, and “red” shown in FIG. 10C by red color. "Stop" is displayed.

At this time, in such an LED display device,
Since the LED display unit 12 is curved so as to be aligned with the cylindrical surface of the display device 13, the LED display unit 12 can be assembled without any step on the display device 13, and LE
A person who looks at the D display unit 12 from a place other than the front can easily visually recognize the display. Further, this LED display device does not impair the design of the display device 13.

In this LED display device, LE
Since the D display unit 12 is curved in a non-flexible state, the LED display unit 12
Exerts rigidity, and the wiring of the printed circuit board 1a, in particular, the bonding wires 5a and 5b hardly break. Therefore, this LED display device can exhibit stable quality.

Further, when manufacturing this LED display device, the first intermediate product 8 is not used because a curved printed circuit board is employed and the general flexible flat LED mounting board 1 is used. There is no need for special equipment other than the device for holding in a curved state, and the device can be manufactured relatively inexpensively.
Therefore, according to the LED display device and the method of manufacturing the same, a person or the like who looks at the LED display unit 12 from a position other than the front can visually recognize the display while realizing relatively low manufacturing cost and securing stable quality. It is easy and the design of the columnar display device 13 is not impaired. (Embodiment 2) In Embodiment 2, the printed circuit board 1d shown in FIG. 11 is employed. This printed circuit board 1d has a white resist 4b on the front and back surfaces of the base material 2 (only the front surface in the figure).
Through which a wiring such as a copper foil pattern printed by printing is applied. Each LED element 1b has a cathode electrode 3 made of a copper foil pattern on the printed board 1d.
a, and connected to the anode electrode 3b by bonding wires 5c substantially parallel to each other on the printed board 1d. Other configurations are the same as in the first embodiment.

The LED display device thus obtained can also provide the same functions and effects as in the first embodiment.

[Brief description of the drawings]

FIG. 1 is a plan view of an LED mounting board according to a first embodiment.

FIG. 2 is a side view of the LED mounting board according to the first embodiment.

FIG. 3 is a plan view of a first intermediate product according to the first embodiment.

FIG. 4 is a side view of a first intermediate product according to the first embodiment.

FIG. 5 is a side view of a second intermediate product and the like according to the first embodiment.

FIG. 6 is an enlarged sectional view taken along the line VI-VI in FIG. 5 according to the first embodiment;

FIG. 7 is a rear view of the LED display device according to the first embodiment.

FIG. 8 is a cross-sectional view of the display device according to the first embodiment.

FIG. 9 is a perspective view of a display device and the like according to the first embodiment.

FIG. 10 is a block diagram illustrating an LED display device according to the first embodiment;
FIG. 4 is a plan view showing a display by an ED display unit.

FIG. 11 is an enlarged sectional view similar to FIG. 6, according to the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... LED mounting board 1a, 1d ... Printed board 1b ... LED element 12 ... LED display part 13a ... Drive board 11 ... Terminal part (11a ... Cable, 11b ... Connector) 7 ... Transparent resin, uncured transparent resin 5a, 5b, 5c Bonding wire 3a Cathode electrode 3b Anode electrode 4a, 4b Resist 6 Partitioning material, black resin 8 First intermediate product 9 Second intermediate product 10 Third intermediate product

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazuyuki Shibata 2-5-2-2 Otemachi, Chiyoda-ku, Tokyo Mitsubishi Electric Engineering Co., Ltd. (72) Inventor Makoto Toyoda 1-35-1 Mitsugi, Musashimurayama-shi, Tokyo No. Toyota Electronics Co., Ltd. (56) References JP-A-7-302931 (JP, A) JP-A-9-16107 (JP, A) JP-A-6-266298 (JP, A) JP-A-8-36368 (JP, A) JP-A-7-114347 (JP, A) JP-A-6-33181 (JP, U) JP-A 52-120567 (JP, U) JP-A 48-29833 (JP, Y1) ( 58) Field surveyed (Int.Cl. ⁷ , DB name) G09F 9/30-9/46 G09F 13/20

Claims (8)

(57) [Claims] An LED display having a plurality of LED elements mounted on a printed circuit board and capable of performing display by each of the LED elements, and a terminal connected to the LED display and connected to a driver. In the device, the LED display section is curved in an inflexible state by a cured transparent resin that protects a surface.
ED display device. 2. Each of the LED elements of the LED display section is connected to a cathode electrode or an anode electrode by substantially parallel bonding wires, and the LED display section is curved while maintaining the bonding wires substantially parallel. The LED display device according to claim 1, wherein: 3. The LED display device according to claim 1, wherein the terminal portion has flexibility. 4. The LED display device according to claim 1, wherein a partition member for partitioning various displays by each LED element is provided on a surface of the LED display section. 5. The LED display device according to claim 1, wherein the printed circuit board has a color in which a resist clarifies various indications by each LED element. 6. A first step in which a plurality of LED elements are mounted on a printed board, and a first intermediate product is obtained by interposing an uncured transparent resin on the surface of a flexible flat LED mounting board; A second step of bending the first intermediate product while incompletely curing the uncured transparent resin of the first intermediate product to form a second intermediate product, and the uncured transparent resin of the second intermediate product And a third step of completely curing the LED display device. 7. An LED mounting board in which each LED element is connected to a cathode electrode or an anode electrode by substantially parallel bonding wires on a printed circuit board, and in a second step, the bonding wires are substantially parallel to each other. The method for manufacturing an LED display device according to claim 6, wherein the first intermediate product is curved while maintaining the same. 8. The LED according to claim 6, further comprising a fourth step of connecting a flexible terminal portion to the third intermediate product after the third step, the third intermediate product being connected to a driver. A method for manufacturing a display device.