JPH0816114A - Light emitting display - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a light emitting display device which is thin, has high display quality and reliability, and is inexpensive. [Structure] A plurality of chip type LED elements 1 are mounted on one surface of a single substrate 2 having a plurality of conductor layers, and drive circuit parts of the chip type LED elements are mounted on the other surface. . A plurality of chip-type LEs are provided on one surface of a laminated substrate 2 in which a plurality of substrates having conductor layers are integrally laminated.
D-element 1 is mounted, and chip-type LED element 1 is on the other side
Drive circuit component 3 is mounted, and the laminated substrate 2 has at least an LED mounting substrate 11 on which the chip-type LED element 1 is mounted, a drive circuit component mounting substrate 14 on which the drive circuit component 3 is mounted, and an LED mounting. And a circuit connection substrate that is interposed between the drive substrate 11 and the drive circuit component mounting substrate 14 to electrically connect the chip-type LED element 1 and the drive circuit component 3 to each other. To do. Further, the light emitting display device having the above structure is characterized in that the chassis 6 having the female screw portion 7 for external attachment is attached to the drive circuit component mounting side of the laminated substrate 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dot matrix type LED display device.

[0002]

2. Description of the Related Art In a conventional dot matrix type LED display device, a substrate on which a lamp type LED element is mounted or a substrate on which an LED chip is mounted by direct bonding is used as a display section substrate and a circuit component for lighting drive is provided. It was configured to be mounted on separate boards and to connect two boards with connection pins.

LED mounted with a lamp type LED in FIG.
FIG. 8 shows a structural diagram of the display device, and FIG. 8 shows a structural diagram of a display device of a type in which an LED chip is bonded.

Further, FIG. 9 shows a block diagram of a lighting drive circuit of these display devices.

FIG. 10 (a) shows an outline of the flow of manufacturing steps in the case of manufacturing a conventional lamp type LED display device.

First, as shown in FIG. 7, the LED mounting board 7
2, a plurality of lamp-type LED elements 71 are automatically inserted, lead cutting is performed in order to make the lengths of the inserted leads uniform, and then a lamp-type LED element 71 ′ having a connecting pin 73 is inserted on the outer periphery, We are doing a solder dip.
After that, the LED board is inspected and corrected to prepare an LED mounting board.

On the other hand, a circuit component 74 is mounted on the drive circuit board 75.
After automatic mounting, solder reflow, inspection and correction are performed, the input / output connector 77 and the power supply connector 78 are mounted, a drive circuit mounting board is created, and the spacer 76 is mounted.

After that, the LED mounting board and the drive circuit mounting board with a spacer are connected by soldering using the connecting pins 73, and then the LED lamp case 70 is fitted.

Further, a final inspection is carried out to complete the lamp type LED display device.

Next, FIG. 10B shows an outline of a manufacturing process flow of a conventional LED chip bonding type display device.

First, the LED chip 81 is mounted on the LED mounting substrate 83 as shown in the enlarged view (e) of the portion A of FIG.
After die-bonding and wire-bonding, the reflection plate 80 is attached, the LED substrate is inspected and corrected, and the LED mounting substrate is prepared.

On the other hand, the circuit component 8 is mounted on the drive circuit board 86.
After automatic mounting of No. 5, solder reflow is performed for inspection and correction, an input / output connector 89 and a power supply connector 90 are mounted, a drive circuit mounting board is prepared, and a chassis 87 having mounting screw holes 88 is mounted. After that, the LED mounting board and the drive circuit mounting board with chassis are connected by soldering using the connection pin connector 84, and then a final inspection is performed to complete the chip bonding type LED display device.

[0013]

The above-mentioned conventional LED display device has the following problems.

(1) In both the lamp type element type and the chip bonding type, it is impossible to mount drive circuit components on the back surface of the substrate, so that a two-substrate structure is inevitable, resulting in a thin display device. Cannot be achieved.

This is because, in the lamp type, it is difficult to mount the drive circuit component on the back surface because the leads of the LED element penetrate the substrate and require a soldering portion.
In particular, it cannot be mounted on a small-sized display device in which the lead interval is narrow.

Further, in the bonding type, if high heat is applied after bonding the chip and the wire, the reliability is lowered, so that the circuit component cannot be mounted on the back surface.

In the case of the reverse procedure, it is difficult to perform chip bonding and wire bonding work.

(2) The main measure for heat dissipation of the LED display device is cooling by blowing air from the drive circuit surface side. Conventionally, since it has a two-substrate structure, it is not possible to directly blow air onto the substrate of the LED element part that generates a large amount of heat, and the air between the two substrates serves as a heat storage layer to efficiently cool the LED element. I can't.

(3) If the bonding type LED element has a defect, a failure, a work failure, or the like, it is difficult to correct it, and the yield is reduced.

Further, since the reflection efficiency of the reflection plate of the bonding type LED element is low, there is a large amount of light emission loss and sufficient brightness cannot be obtained.

Therefore, an object of the present invention is to realize a highly reliable light emitting display device which can be made thinner than conventional ones and which is excellent in heat dissipation and light emitting properties.

[0022]

In order to solve the above-mentioned object, the present invention has a plurality of chip-type LED elements mounted on one surface of a single substrate having a plurality of conductor layers, and the chip-type LED elements on the other surface. A plurality of chip-type LED elements are mounted on one surface of a laminated substrate on which a driving circuit component of an LED element is mounted or a plurality of substrates having conductor layers are integrally laminated, and the chip is mounted on the other surface. Drive circuit components for the LED device are mounted, and the laminated substrate is at least
An LED mounting substrate on which the chip-type LED element is mounted, a drive circuit component mounting substrate on which the drive circuit component is mounted, and the chip mounted on the LED mounting substrate and the drive circuit component mounting substrate. And a circuit connecting board for electrically connecting the drive circuit component to the LED element.

In the light emitting display device having the above structure,
A chassis having a female screw portion for external attachment is attached to the drive circuit component mounting side of the laminated substrate.

[0024]

Since the LED element and the drive circuit component are mounted on both sides of one substrate, a thin display device can be realized.

Further, by adopting a display device having a single-substrate structure, it is possible to enhance the heat dissipation efficiency when forcedly cooled from the drive circuit surface side. Furthermore, because the heat dissipation chassis with the mounting part is attached to the drive circuit side of the board, the heat generated by the display device can be dissipated to the main body side of the system through this chassis, and further heat dissipation effect can be achieved. Can be improved.

Further, since the chip type LED element for MID surface mounting is used instead of the bonding type LED element, it becomes easy to correct when a defect, failure, work failure or the like occurs, and the yield is improved. Can be achieved.

Moreover, since the MID chip type LED element has a reflecting wall formed inside the element by molding and the reflecting wall is plated with metal, a high reflection efficiency can be obtained, which is higher than the conventional one. Can realize a high-brightness display device.

[0028]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing the structure of a dot matrix type LED display device according to an embodiment of the present invention.
(A), (b), (c), (d) are top views,
It is a side view, a right side view, and a bottom view.

In this display device, a total of 512 chip type LED elements 1 (16 vertical × 32 horizontal) are arranged on one surface of a laminated substrate 2 at equal pitches, while lighting driving circuit components 3 are mounted on both surfaces. Is.

FIG. 2 is a view showing the internal structure of the laminated substrate, wherein (a), (b), (c) and (d) are respectively the first conductor layer which is the chip type LED element mounting surface. , The second conductor layer of the anode common line, the third conductor layer of the LED drive signal line, and the fourth conductor layer of the drive circuit component mounting surface.

The first conductor layer is composed of the cathode electrode pattern 20 and the anode electrode pattern 21 of the chip type LED element on the LED element mounting board 11, and the anode electrode 21 is the second conductor on the circuit connecting board 12. The anode common line 23 of the layer is connected to the through-hole conductor 22. Further, the third conductor layer is the LED drive signal line 25 on the circuit connection substrate 13, the drive circuit component soldering land 27 and the through hole 26 of the fourth conductor layer, and the cathode electrode 20 of the first conductor layer. The anode common line 23 of the second conductor layer is also interconnected with a through-hole (not shown) conductor.

The embodiment of the structure of a single substrate is not limited to the above-mentioned structure. For example, a method of forming a conductor layer on both surfaces of a double-sided through-hole wiring board with an insulating layer interposed therebetween, or double-sided through-hole wiring. There is also a method of stacking and integrating the substrates.

FIG. 3 is an enlarged schematic view of the A portion of the first conductor layer (a) shown in FIG. 2. In the figure, 31 and 34 are cathode electrodes of the green LED 38 and the red LED 39, respectively, and the cathode common line. Connected to 32 and 33, 35 and 36 are green LED and red LED, respectively.
, And is connected to the anode common electrode 37 by through-hole conductors 35 'and 36'.

The MID (Mol used in the present invention
ded Interconnected Device
e) A structural view of the chip-type LED element for surface mounting is shown in FIG.

The MID technique is a three-dimensional wiring technique in which a molded substrate is wired by metal plating. (A) in the figure
Is a top view of the molded substrate, (b) is a BB 'sectional view of (a), (c) is a CC' sectional view of (a), (d) is a bottom view, and ( (e) shows the EE 'sectional view of (a) after bonding the LED chip.

Chip type LE to which this MID technology is applied
The D element is three-dimensionally wired as shown in FIG.
The LED chip 42 is die-bonded to the recess of the molded substrate 41, and is then wire-bonded with a gold wire 43. Then, as shown in FIG. 3D, since the external connection electrode portions 45 to 48 are provided on the bottom surface of the molded board, it is possible to perform surface mounting on the printed board by solder reflow.

Here, 45 and 46 are anode electrodes and 4
Reference numerals 7 and 48 are cathode electrodes, which correspond to 35, 36 and 31, 34 in FIG.

If, during the process, a defective LED element, a failure, a work failure, or the like occurs, the MID chip type LED element can be easily corrected or replaced, and the yield is improved.

By molding, a light reflection wall (44 in the figure (e)) can be formed inside the element.
By applying metal plating to the reflection wall, the reflection efficiency is further increased, so that sufficient brightness can be obtained as a display device.

The circuit configuration of the lighting drive circuit is shown in FIG.
This is the same as the conventional example shown in.

FIG. 10 (c) shows a flow of manufacturing steps for manufacturing the LED display device of the present invention. First, after automatically mounting the surface mount type drive circuit component 3, the input / output connector 4 and the power connector 5 on one surface of the laminated substrate 2 shown in FIG.
Solder reflow, inspection and correction on both sides of the board. afterwards,
The chassis 6 with the female screw 7 for attachment is attached to the circuit component side of the substrate with an adhesive.

FIG. 5 is an external view of the chassis used in the present invention.
In the figure, (a), (b), (c), and (d) are a top view, a side view, a right side view, and a bottom view, respectively.

The structure of the mounting portion is as follows. The chassis is formed by molding weather-resistant plastic into the shape shown in FIG. 5 and embedding the female screw 51, and the adhesive surface 52 is attached to the circuit component surface side of the substrate with an adhesive.

There is also a method in which a metal piece 53, which also functions as a positioning member in combination with an adhesive, is projected from a molded product and soldered to a land on the substrate to increase the strength.

As the material of the chassis, metal such as aluminum die cast or zinc die cast can be used in addition to plastic such as glass fiber-containing thermoplastic resin.

Since metal has better thermal conductivity than plastic one, heat can be more efficiently released to the system body mounted through this chassis. According to the above configuration, it is not necessary to mount the LED display board and the drive circuit board on separate boards as in the conventional case,
Since the single-substrate structure can be used, the display device can be thinned.

For that reason, in the conventional case, as shown in FIG.
As shown in (a), because of the two-substrate structure, heat is generated from the LED element between the LED display substrate 72 and the drive circuit substrate 75 even if forced cooling is performed from the drive circuit surface side. Heat was collected and the heat dissipation efficiency was not good,
In the present invention, as shown in FIG. 11 (b), since it has a single substrate structure, the heat dissipation efficiency is remarkably improved by performing forced cooling by blowing air.

Further, unlike the prior art, it is not necessary to manually combine the LED element mounting board and the drive circuit component mounting board, the assembly process can be omitted, and the manufacturing cost can be reduced.

Furthermore, by using the display device having the above structure, a thin and lightweight display board system can be constructed.
The use of the system is expanded and the system can be constructed at low cost. In the display device of the above embodiment, a sufficient heat radiation effect can be expected by blowing air to the chassis opening on the side of the circuit component. There is.

FIG. 6 shows another embodiment. First, FIG.
As shown in (a), a rubber sheet (for example, silicone rubber) having high heat conductivity is sandwiched between the display device and the system main body so as to be in contact with both the substrate surface of the display device and the system main body. It is a method of attaching the display device. In this method, the heat generated in the display device is
It escapes to the system main body side 63 through the chassis 61 and the rubber sheet 62.

Further, as shown in FIG. 6B, the chassis is made to have no opening, and a resin 62 '(for example, silicone type) having good thermal conductivity is filled between the chassis 61' and the substrate. There is also a way to do it. At this time, if the entire surface of the chassis is attached so as to be in contact with the system body 63, heat can be released to the system side.

It should be noted that according to this embodiment, the same effect as that of the embodiment of FIG. 1 can be obtained in addition to the heat dissipation.

[0054]

The effects of the present invention are listed below.

(1) By using the chip-type LED element for MID surface mounting and the laminated substrate, it becomes possible to mount the LED element and the driving circuit component on both sides of one substrate.
The display device can be thinned.

(2) The display device having a single substrate structure enhances the heat dissipation efficiency when the drive circuit surface side is forcibly cooled. In addition, by attaching a heat dissipation chassis with a mounting part to the drive circuit side of the board and letting the heat generated by the display device escape to the main body of the system via this chassis, the heat dissipation effect can be further enhanced, Device life,
Improves reliability.

(3) By using MID surface mounting chip type LED elements instead of bonding type LED elements, it becomes easy to correct when defects, failures, work failures, etc. occur, and the yield is improved. .

(4) Further, in the MID chip type LED element, the reflection wall can be formed inside the element by molding, and the reflection efficiency is further increased by applying metal plating to the reflection wall. Sufficient brightness can be obtained as a display device, and display quality is improved.

(5) In the display device of the present invention, the LED element substrate and the drive circuit are mounted in the same manner as in the prior art so that the LED element and the drive circuit component are mounted on both sides of a single board by an automatic mounting machine to complete the process. It is not necessary to manually combine the two component boards after creating them separately, and the assembly process can be omitted, and the manufacturing cost can be reduced.

(6) By using the display device of the present invention, it is possible to construct a thin and lightweight display board system, so that the application of the system such as a wall-mounted display board is widened and the system is inexpensively constructed. can do.

[Brief description of drawings]

1A to 1D are a top view, a side view, a right side view and a bottom view of a light emitting display device according to an embodiment of the present invention, respectively.

FIG. 2 is an exploded perspective view showing the internal structure of the laminated substrate of the present invention.

FIG. 3 is an enlarged view of part A of FIG.

4 (a) to 4 (e) are respectively a chip LED element to which the MID technology is applied, (a) is a top view of a molded substrate, and (b) is a cross-sectional view taken along the line BB 'of (a). , (C) is a sectional view taken along line CC ′ of (a), (d) is a bottom view, and (e) is a sectional view taken along line EE ′ of (a) after LED chips are bonded.

5A to 5D are respectively a top view, a side view, a right side view and a bottom view of a chassis according to an embodiment of the present invention.

6A and 6B are cross-sectional views according to another embodiment of the present invention.

7A to 7D are a top view, a side view, a right side view and a bottom view of a conventional lamp type LED display device, respectively.

8A to 8D are respectively a top view, a side view, a right side view and a bottom view of a conventional chip bonding type LED display device, and FIG. 8E is an enlarged view of part A of FIG. 8A. .

FIG. 9 is a block circuit diagram of a lighting drive circuit of the LED display device.

FIG. 10 is a manufacturing process flow chart according to the related art and the present invention.

11 (a) and 11 (b) are views showing a heat dissipation method of a conventional display device and a display device of the present invention, respectively.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 chip type LED element 2 laminated board 3 drive circuit component 6 chassis 7 female screw for mounting 11 LED element mounting substrate 12, 13 circuit connection substrate 14 drive circuit component mounting substrate

Claims (3)

[Claims] 1. A plurality of chip type LED elements are mounted on one surface of a single substrate having a plurality of conductor layers, and drive circuit parts for the chip type LED elements are mounted on the other surface. Light emitting display device. 2. A plurality of chip type LED elements are mounted on one surface of a laminated board integrally formed by laminating a plurality of boards having conductor layers, and drive circuit parts for the chip type LED elements are mounted on the other surface. The laminated substrate includes at least an LED mounting substrate on which the chip-type LED element is mounted, a drive circuit component mounting substrate on which the drive circuit component is mounted, the LED mounting substrate, and a drive circuit component mounting. A light-emitting display device comprising a circuit connection substrate which is interposed between the chip type LED element and the drive circuit component and which is interposed between the chip type LED device and the drive circuit component. 3. The light emitting display device according to claim 1, wherein a chassis having a female screw portion for external attachment is attached to a drive circuit component mounting side of the laminated substrate. .