JP2003188424A - Surface-mounted light-emitting diode - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-mounted light-emitting diode which raises the radiation of heat and has a structure which can prevent a position misalignment during mounting in the case of being used as a side-surface light-emitting diode. <P>SOLUTION: A surface-mounted light-emitting diode comprises a substrate having a pair of electrodes on the surface, and a light-emitting diode element which is mounted on the substrate and electrically connected to each electrode. The substrate is composed of an insulating layer, and a metal layer for a radiation of heat which is buried in the insulating layer and exposed to an end plane of the substrate. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount type light emitting diode, and more particularly to a surface mount type light emitting diode used for a backlight of a liquid crystal display such as a portable information terminal and various indicators.

[0002]

2. Description of the Related Art Conventional surface mount light emitting diode 101
Has a structure as shown in FIGS. 10 and 11, for example. Printed circuit board 1 made of glass epoxy
02 is a pair of terminal electrode portions 107a and 107b formed from the front surface to the back surface thereof, and the terminal electrode portions 10
Metal pad portions 108a and 108b extending from 7a and 107b to the center of the surface of the printed circuit board 102 are provided.

The light emitting diode element 104 is mounted on the metal pad portion 108a via a conductive paste 109, and is electrically connected to the metal pad portion 108b by a gold wire 110. The light emitting diode element 104 and the gold wire 110 are covered with a substantially rectangular parallelepiped resin sealing portion 111 made of a translucent resin.

In the actual manufacturing, the conventional surface mount type light emitting diode 101 has a structure in which the substrates 102 are connected in a row on the manufacturing substrate 13 as shown in FIG.
Built into 1. A plurality of light emitting diode elements (not shown) on each metal pad portion 108a on the manufacturing substrate 131.
After mounting each of them, wire-bonding a plurality of gold wires (not shown) respectively, and forming a long and narrow ridge-shaped resin sealing portion 111 so as to cover each light-emitting diode element and each gold wire, and then individually by the dicer 100. The surface mount type light emitting diode 101 is cut.

The conventional light emitting diode element 201 shown in FIGS. 4 and 5 has a structure similar to that of the conventional surface mounting type light emitting diode 101 described above, but the thickness T4 of the substrate 202 is the surface mounting type light emitting diode 101. It is thicker than the thickness T3 of the substrate 102 (see FIG. 10). This is because the board 202 is mounted such that the end surface 202a (that is, the cut surface) of the board 202 faces the surface 261a of the mounting board 261, so that the board 202 is used as a side surface light emitting surface mount light emitting diode 201.

[0006]

Among the light emitting diode devices, the blue light emitting diode device newly developed in recent years has a forward voltage higher than that of the conventional light emitting diode device.
It is higher than V. Also, in order to increase the brightness,
An applied current that is several tens of times that of the conventional case may be applied.

Under such circumstances, the amount of heat generated by the light emitting diode element tends to increase, and deterioration of the element due to heat generation becomes a problem. Therefore, it is important to design the surface-mounted light emitting diode in consideration of heat dissipation.

In particular, when it is used as a side-emission type light emitting diode (see FIG. 5), the area of the metal portion which comes into contact with the surface of the mounting substrate becomes small, so that it becomes even more severe thermally. In addition, since the area of the metal portion that is in contact with the mounting board is reduced, the possibility of misalignment during mounting increases.

The present invention has been made in consideration of the above circumstances, and has a surface mount type light emitting device having a structure capable of improving heat dissipation and preventing displacement during mounting even when used as a side surface light emitting type device. It provides a diode.

[0010]

The present invention comprises a substrate having a pair of electrodes on its surface, and a light emitting diode element mounted on the substrate and electrically connected to each electrode. Provided is a surface-mounted light emitting diode which is composed of a heat-dissipating metal layer embedded in an insulating layer and exposed at an end face of a substrate.

That is, in the surface mount type light emitting diode according to the present invention, since the substrate is composed of the insulating layer and the heat radiating metal layer which is embedded in the insulating layer and is exposed at the end face of the substrate, the area of the metal portion exposed to the outside is small. As a result, the heat dissipation of the light emitting diode element can be improved. Further, in the case of mounting as a side surface light emitting type on the mounting board, the area of the metal portion that comes into contact with the surface of the mounting board becomes large, so that it is possible to prevent positional deviation during mounting.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the surface mount type light emitting diode according to the present invention, a known light emitting diode element can be used as the light emitting diode element, and although not particularly limited, for example, gallium arsenide is used as a material. Infrared light emitting device, red light emitting device made of gallium / aluminum arsenide, orange or yellow light emitting device made of gallium arsenide phosphorus, yellow green light emitting device made of gallium phosphorus doped with nitrogen, and gallium nitride compound The blue or blue-violet light emitting element described above can be used.

Further, in the surface mount type light emitting diode according to the present invention, the optimum thickness of the metal layer for heat dissipation varies depending on the size of the product and is not particularly limited, but for example, about 100 to 400 μm. You can

Also, in the surface mount type light emitting diode according to the present invention, the substrate sandwiches the metal thin plate for forming the heat dissipation metal layer between the two insulating sheets for forming the insulation layer, and press-bonds these when they are hot. It may be formed by In this specification, the term “compression bonding under heat” means that compression bonding is performed while heating.

Here, both of the insulating sheets may be made of a fibrous sheet impregnated with a thermosetting resin, or one of them may be a fibrous sheet impregnated with a thermosetting resin and the other may be made of a thermosetting resin. It may be made of a resin sheet obtained by curing a curable resin.

That is, the substrate of the surface mount type light emitting diode according to the present invention has the metal layer for heat radiation embedded in the insulating layer as described above, so that the heat insulating metal layer serves as the metal layer for heat radiation. If a substrate is manufactured by sandwiching a thin metal plate and press-bonding it under heat, the insulating sheet needs to be cured following the shape of the substrate. Therefore, as the insulating sheet for sandwiching the metal thin plate, a fiber sheet impregnated with a thermosetting resin is used for at least one of them, and if the fiber sheet is pressed under heat, the fiber sheet is cured in a state of following the shape of the metal thin plate. As a result, it is possible to manufacture a substrate in which a thin metal plate is embedded in an insulating layer. When the thickness of the thin metal plate is relatively large, it is preferable to use two fibrous sheets impregnated with a thermosetting resin as the insulating sheets from the viewpoint of easily following the shape of the thin metal plate.

The fibrous sheet impregnated with the thermosetting resin is, for example, a known thermosetting resin used as a material for a printed circuit board in a woven sheet made of carbon fiber, aramid fiber, glass fiber or other fiber. , For example,
A material impregnated with a polyimide resin, a phenol resin, an unsaturated polyester, an epoxy resin, or the like can be used.

As the resin sheet obtained by curing the thermosetting resin, for example, a known insulating base material used for a printed circuit board can be used, and it is not particularly limited. An epoxy-based insulating base material can be used.

The thin metal plate is not particularly limited, but, for example, a plate made of a metal having good thermal conductivity such as aluminum or copper can be used. Further, the means for performing the hot press bonding is not particularly limited, but for example, a press device capable of heating can be used.

In the board-mounted light emitting diode according to the present invention, the insulating layer may contain a light reflective material. According to this structure, the surface of the substrate can be provided with light reflectivity, and of the light emitted from the light emitting diode element, the light emitted to the substrate side can be reflected and efficiently extracted to the outside. Note that, as a specific light-reflecting material, for example, titanium foil or the like can be used.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings. The present invention is not limited to the embodiments. Further, members common to a plurality of embodiments described below will be described using the same reference numerals.

Embodiment 1 A surface mount type light emitting diode according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is a perspective view showing a surface mount type light emitting diode according to a first embodiment, FIG. 2 is a plan view of the surface mount type light emitting diode shown in FIG. 1, and FIG.
4 is a perspective view showing a metal plate used as a material for a substrate for manufacturing a surface-mount light emitting diode according to Example 1; FIG. 4 is a perspective view showing a metal plate for a metal layer obtained by processing the metal plate shown in FIG. 3; 5 is a process diagram showing a manufacturing process of a substrate for manufacturing a surface-mount light emitting diode according to Example 1, and FIG. 6 is a perspective view of the manufacturing substrate manufactured by the manufacturing process shown in FIG.

As shown in FIGS. 1 and 2, the surface mount type light emitting diode 1 according to the first embodiment of the present invention has a substrate 2 having a pair of electrodes 3a and 3b on its surface, and a substrate 2 mounted on the substrate 2. The substrate 2 includes insulating layers 5a and 5b, each of which includes a light emitting diode element 4 electrically connected to the electrodes 3a and 3b.
And a heat-dissipating metal layer 6 embedded in the insulating layers 5a and 5b and exposed at the end surface of the substrate 2.

As shown in FIG. 2, the electrode 3a is a terminal electrode portion 7a formed from the front surface to the back surface of the substrate 2.
And a circular metal pad portion 8a extending from the terminal electrode portion 7a to the center of the surface of the substrate 2. On the other hand, electrode 3
b is composed of a terminal electrode portion 7b formed from the front surface to the back surface of the substrate 2 and a substantially L-shaped metal pad portion 8b extending from the terminal electrode portion 7b to the center of the surface of the substrate 2.

The light emitting diode element 4 has a metal pad portion 8
It is mounted on a through a conductive paste 9 and is electrically connected to the metal pad portion 8b by a gold wire 10.
As shown in FIG. 1, the light emitting diode element 4 and the gold wire 1
Reference numeral 0 denotes a substantially rectangular parallelepiped resin sealing portion 1 made of a transparent resin.
Covered by 1.

That is, in the surface mount type light emitting diode 1 according to the first embodiment of the present invention, the structure other than the substrate 2 is the same as the conventional surface mount type light emitting diode 101 (see FIG. 10).
And FIG. 11). Also, in the actual manufacturing, it is different from the conventional one in that after being manufactured into a manufacturing substrate in which a plurality of substrates 2 are connected, each surface mounting type light emitting diode 1 is finally cut by a dicer (see FIG. 12). Is the same.

As described above, in the surface mount light emitting diode 1 according to the first embodiment, since the heat dissipation metal layer 6 is exposed on the end surface 2a of the substrate 2, the surface mount light emitting diode 101 is exposed to the outside more than the conventional surface mount light emitting diode 101. The area of the exposed metal part is increasing. Therefore, the heat generated from the light emitting diode element 4 is easily dissipated to the outside, and the heat dissipation property is improved as compared with the conventional surface mount type light emitting diode 101.

A method of manufacturing the substrate for manufacturing the surface mount light emitting diode according to the first embodiment will be described below with reference to FIGS.

First, a thin metal plate 23 as shown in FIG.
Is prepared, and the thin metal plate 23 is processed into a shape as shown in FIG. 4 by a method such as etching or punching with a press to produce a thin metal plate 23a for a metal layer.

Next, as shown in FIG. 5 (a), the back surface copper foil 21b, the thermosetting resin-impregnated fiber sheet 22, the metal layer metal thin plate 23a, and the thermosetting resin adhesive sheet 24,
The glass epoxy insulating base material (resin sheet) 25 on which the front surface copper foil 21a is formed is superposed in this order.

Next, as shown in FIG. 5 (b), the stacked laminates are hot-pressed using a press device 26 capable of heating. After that, steps such as metal plating and etching necessary for completing the printed board are performed in the same manner as in the conventional case, and the manufacturing board 31 shown in FIG. 5C is completed.

The manufacturing substrate 3 manufactured as described above
FIG. 6 shows a perspective view of 1 viewed from above. FIG. 6 shows the electrode pattern 32 on the surface of the manufacturing substrate 31 and the metal thin plate 23 for the metal layer.
The positional relationship with a is shown. That is, the terminal electrode portions 7a and 7b are provided above the strip-shaped portions of the metal layer thin metal plate 23a.
The electrode pattern 32a for the terminal electrode portion, which becomes (see FIGS. 1 and 2), is located. In addition, from the electrode pattern 32a for each terminal electrode portion to the metal pad portions 8a and 8b (see FIG. 2).
The metal pad portion electrode pattern 32b to be formed extends, and the metal layer metal thin plate 23a does not exist below each metal pad portion electrode pattern 32b.

The glass epoxy insulating base material 25 may be impregnated with a light-reflecting material such as titanium foil. When impregnated with a light-reflecting material,
The surface of the substrate 2 can have light reflectivity, and the luminous intensity of the surface-mounted light emitting diode 1 can be improved.

Second Embodiment A second embodiment of the present invention will be described with reference to FIG.
Example 2 is an example for explaining a method of manufacturing a manufacturing substrate, and a manufacturing substrate is manufactured by a method different from the method of manufacturing a manufacturing substrate described in Example 1 above. Figure 7
[FIG. 8] is a process drawing showing a method of manufacturing a manufacturing substrate according to a second embodiment.

The manufacturing method of the manufacturing substrate according to the second embodiment is as follows.
The above-described first embodiment is that the metal thin plate 23a for the metal layer is sandwiched between the two thermosetting resin-impregnated fiber sheets 22a and 22b.
This is different from the method of manufacturing a manufacturing substrate according to.

More specifically, as shown in FIG.
Backside copper foil 21b, thermosetting resin-impregnated fiber sheet 22
b, the metal thin plate 23a for the metal layer, the thermosetting resin-impregnated fiber sheet 22a, and the surface copper foil 21a are stacked in this order. Next, as shown in FIG. 7 (b), the stacked laminates are hot-pressed using a press device 26 capable of heating,
The manufacturing substrate 41 shown in FIG. 7C is completed. The manufacturing method of the manufacturing substrate according to the second embodiment is as described above.
Since the metal layer metal thin plate 23a is sandwiched between the thermosetting resin-impregnated fibrous sheets 22a and 22b, the metal layer metal thin plate 23 is sandwiched.
This is a preferable method when the thickness of a is relatively large.

In order to improve the luminous intensity of the surface-mounted light emitting diode 1, the thermosetting resin-impregnated fiber sheet 22 is used.
For example, a may be impregnated with a light-reflecting material such as titanium foil.

Third Embodiment A surface mount type light emitting diode according to a third embodiment of the present invention will be described with reference to FIGS. 8 and 9. FIG. 8 is a perspective view of a surface mount light emitting diode according to the third embodiment, and FIG. 9 is a perspective view showing a state in which the surface mount light emitting diode according to the third embodiment is mounted on a mounting board.

As shown in FIG. 8, the surface mount type light emitting diode 51 according to the third embodiment has a substrate 52 having a thickness T2.
However, the surface mount type light emitting diode 1 according to the first embodiment (see FIG.
It is made thicker than the thickness T1 of the substrate 2 in (see). As shown in FIG. 9, the mounting substrate 61 is mounted so that the end face 52a of the substrate 52 faces the surface 61a of the mounting substrate 61 and is used as the side surface emitting type surface mounting light emitting diode 51. This is to improve stability.

Further, as shown in FIG. 9, when mounted on the mounting substrate 61 as a side surface light emitting type, the heat dissipation metal layer 56 exposed on the end face 52a of the substrate 52 is mounted on the mounting substrate 61.
Circuit 62 is soldered. Therefore, the conventional surface mount type light emitting diode 201 used as the side surface light emitting type.
(See FIG. 14) The contact area of the mounting substrate 61 with the circuit 62 is larger than that of the mounting substrate 61, and positional deviation during mounting is prevented.
Further, since the area in contact with the circuit 62 of the mounting board 61 is increased, the heat generated from the light emitting diode element 4 is transferred to the circuit 62 of the mounting board 61 via the metal layer 56 for heat dissipation.
It becomes easy to radiate heat to.

[0041]

According to the present invention, since the substrate is composed of the insulating layer and the heat-dissipating metal layer which is embedded in the insulating layer and exposed to the end surface of the substrate, the area of the metal portion exposed to the outside becomes large, resulting in As a result, the heat dissipation of the light emitting diode element can be improved. Further, in the case of mounting as a side surface light emitting type on the mounting board, the area of the metal portion that comes into contact with the surface of the mounting board becomes large, so that it is possible to prevent positional deviation during mounting.

[Brief description of drawings]

FIG. 1 is a perspective view showing a surface mount type light emitting diode according to a first embodiment of the present invention.

FIG. 2 is a plan view of the surface-mounted light emitting diode shown in FIG.

FIG. 3 is a perspective view showing a metal plate used as a material for a substrate for manufacturing a surface-mount light emitting diode according to Embodiment 1 of the present invention.

4 is a perspective view showing a metal plate for a metal layer obtained by processing the metal plate shown in FIG.

FIG. 5 is a process drawing showing a manufacturing process of a substrate for manufacturing a surface-mount light emitting diode according to Embodiment 1 of the present invention.

FIG. 6 is a perspective view of a manufacturing substrate manufactured by the manufacturing process shown in FIG. 5 when seen in a plan view.

FIG. 7 is a process chart showing a manufacturing process of a substrate for manufacturing a surface-mount light emitting diode according to a second embodiment of the present invention.

FIG. 8 is a perspective view showing a surface mount light emitting diode according to a third embodiment of the present invention.

9 is a perspective view showing a state in which the surface-mounted light emitting diode shown in FIG. 8 is mounted on a mounting substrate as a side surface light emitting type.

FIG. 10 is a perspective view showing a conventional surface mount light emitting diode.

11 is a plan view of the conventional surface mount light emitting diode shown in FIG.

FIG. 12 is a process of manufacturing the conventional surface mount type light emitting diode shown in FIG. 10, in which a plurality of surface mount type light emitting diodes formed on a manufacturing substrate are cut into individual surface mount type light emitting diodes by a dicer. It is a perspective view showing a process.

FIG. 13 is a perspective view showing a conventional surface mount light emitting diode.

FIG. 14 is a perspective view showing a state in which the conventional surface mount light emitting diode shown in FIG. 13 is mounted on a mounting board as a side surface light emitting type.

[Explanation of symbols]

1 ... Surface mount type light emitting diode 2 ... Substrate 2a ... end face 3a, 3b ... Electrodes 5a, 5b ... Insulating layer 6 ... Metal layer for heat dissipation 7a, 7b ... Terminal electrode part

Claims (6)

[Claims] 1. A substrate having a pair of electrodes on a surface thereof, and a light emitting diode element mounted on the substrate and electrically connected to each electrode, the substrate being an insulating layer and an end surface of the substrate embedded in the insulating layer. Surface-mount light-emitting diode consisting of a heat-dissipating metal layer exposed to the outside. 2. The heat dissipation metal layer has a thickness of 100 to 40.
The surface-mount light emitting diode according to claim 1, which has a thickness of 0 μm. 3. The substrate is formed by sandwiching a thin metal plate for forming a heat-dissipating metal layer between two insulating sheets for forming an insulating layer and press-bonding these sheets at the time of heat. Alternatively, the surface mount light emitting diode according to the item 2. 4. The surface mount light emitting diode according to claim 3, wherein the insulating sheet is a fiber sheet impregnated with a thermosetting resin. 5. The surface mount light emitting diode according to claim 3, wherein one of the insulating sheets is a fiber sheet impregnated with a thermosetting resin and the other is a resin sheet obtained by curing a thermosetting resin. 6. The surface-mount light emitting diode according to claim 1, wherein the insulating layer contains a light-reflecting material.