JPH11298048A - Led mounting board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preferred light-emitting diode(LED) mounting board which functions as a surface light source without increase in the size. SOLUTION: A plurality of LEDs 11 arrayed in 2-dimension for parallel connection and a light-transmitting sealing member 12 for sealing each LED 11 are provided with a plurality of recessed parts 130 provided on the upper side, and a mounting board 13 comprising a metal plate 131 which is a bottom surface of the recessed parts 130, a resin substrate 132 where a plurality of through-holes TH corresponding to the side walls of the plurality of recessed parts 130 are formed, and a connection member 133 formed on the upper surface of the resin substrate 132 is provided. One end o each LED 11 is electrically connected to the metal plate 131, and the other end of it to the connection member 133 which a wire W through wire-bonding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED mounting substrate which can be used for, for example, a semiconductor device, a display device, a light emitting device, and the like.

[0002]

2. Description of the Related Art Conventionally, LEDs (light-emitting diodes) have been used exclusively as display elements, but in recent years, they have come to be used for lighting applications due to the increased light emission luminance.

[0003] For example, an LED mounting board in which a plurality of high-brightness LEDs are two-dimensionally arranged and used as planar illumination (surface light source) is known. In this configuration, the LED
Has a longer life than fluorescent lamps or white light bulbs, so replacement or maintenance is not needed semi-permanently, especially for lighting devices or lighting devices at high places such as traffic lights where replacement or maintenance is difficult. The use of an LED mounting board has a great advantage. In addition, high-brightness LEDs having higher energy efficiency than light bulbs are being obtained, and expectations for energy saving are increasing.

FIG. 6A is an exploded perspective view showing such a conventional LED mounting board, and FIG. 6B is a partial cross-sectional view of FIG. 6A. Referring to FIG. Further explanation will be given.

This LED mounting board is made of aluminum (A)
1) a metal plate 931 provided above the metal plate 931, a sealing frame 932 provided with a plurality of two-dimensionally arranged holes 932a, and a metal plate between the metal plate 931 and the sealing frame 932. The wirings P1 and P2 made of copper foil and the like formed on the upper surface of the insulating layer 933 and the insulating layer 933 between the insulating layer 933 and the sealing frame 932 are housed in the plurality of holes 932a. A plurality of LEDs 11 having one end electrically connected to the wiring P1 and the other end electrically connected to the wiring P2 via a wire W by wire bonding, and a sealing member 1 for sealing each LED 11
2.

[0006] The sealing member 12 is provided for the purpose of mechanical protection and improvement of moisture resistance, and is formed of a transparent and liquid resin (epoxy resin or the like). The reason that this resin is in a liquid state, unlike the resin for ordinary semiconductors, is that a filler (silica or the like) is not added in order to secure light transmission. For this reason, each L mounted on the mounting board composed of the metal plate 931, the insulating layer 933, and the wirings P1 and P2.
A sealing frame 932 is separately used so that the ED 11 can be sealed with a liquid resin. That is, a liquid resin is poured into each of the holes 932a and heat-cured,
Thereby, each LED 11 is sealed by the sealing member 12.

[0007]

In the structure of FIG. 6, however, it is necessary to secure a space for wire bonding with respect to the wiring P2 on the bottom surface of the recess formed in each hole 932a. Is LE
There is a problem (optically disadvantageous) that the light from the LED 11 becomes asymmetric with respect to D11 and the reflection direction of the light from the LED 11 in the concave portion is biased, thereby causing the LED mounting board to become a surface light source having partially uneven illuminance. is there.

If the shape of the concave portion with respect to the LED 11 is made symmetrical to solve this problem, the inner diameter of the hole 932a becomes large, and the LED mounting substrate becomes extremely large because there are a plurality of holes 932a. Also, holes 932a
Increases, the number of mountable LEDs 11 per unit area decreases, and a desired surface light source cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an LED mounting board which functions as a preferable surface light source without increasing its shape.

[0010]

An LED mounting board according to the present invention for solving the above-mentioned problem has a metal plate, and a plurality of element storage chambers are provided on one surface side of the metal plate. A mounting board in which each bottom surface of the storage chamber is formed by the metal plate, a plurality of LEDs housed in the plurality of element storage chambers, and one end of which is electrically connected to the metal plate; A light-transmissive sealing member for sealing, the element storage chamber has a symmetrical shape with respect to the LED stored in the element storage chamber, and the mounting substrate has It has a connection member electrically connected to each other end of the plurality of LEDs.

In this structure, the element storage chamber is symmetrical with respect to the LED housed in the element storage chamber.
The direction of reflection of light from the ED in the element storage chamber is not biased, and the LED mounting board functions as a preferable surface light source. Also, the metal plate connected to one end of each LED serves as the bottom surface of the element storage chamber, while the connection member connected to the other end of each LED is located on the upper surface side of the mounting board. Even when the ends are electrically connected by wires by wire bonding, it is not necessary to separately provide a space for the wire bonding in the element storage chamber. There is no asymmetry, which makes it possible to form the element storage chamber symmetrically with respect to the LED without making it large.

The element storage chamber is a recess, and the mounting board has a resin board in which a plurality of through holes corresponding to side walls of the plurality of recesses are formed. The structure attached to one surface of the plate may be used. In this structure, a concave portion is formed by the metal plate and the through hole. Also in this case, similarly to the above, it is possible to obtain an LED mounting board that functions as a preferable surface light source without increasing the shape.

Further, a plurality of grooves may be formed on the other surface of the metal plate. According to this structure, the LE functions as a preferable surface light source without increasing its shape.
In addition to being able to obtain a D mounting board, a higher heat dissipation effect can be obtained.

[0014]

FIG. 1 is a partial cross-sectional view of an LED mounting board according to a first embodiment of the present invention. The first embodiment will be described below with reference to FIG.

The LED mounting board 10 is similar to FIG.
A plurality of two-dimensionally arranged LEDs 11 connected in parallel (only one LED 11 is shown in FIG. 1) and each of these LEDs 11
6 and a light-transmitting sealing member 12 for sealing
And a mounting substrate 13 having a structure different from that of FIG.
Numeral 11 emits light to perform illumination as a surface light source.

The mounting substrate 13 is made of a metal plate 1 made of Al.
A plurality of recesses 130 are provided on the upper surface (one surface) side of the metal plate 131 (only one is shown in FIG. 1). It is formed by the upper surface. And these recesses 13
A plurality of LEDs 11 are stored in 0, respectively.
One end (lower surface) of each LED 11 is electrically connected to the upper surface of the metal plate 131 which is the bottom surface of the recess 130. As a result, one ends of the plurality of LEDs 11 are electrically connected to each other via the metal plate 131, and a large current flows through the plurality of LEDs 11 during illumination as a surface light source. Although this occurs, the generated heat is appropriately radiated to the outside from the metal plate 131, and both the metal plate 131, which is one of the current paths, and each of the LEDs 11 are cooled.

The mounting substrate 13 has a plurality of recesses 130.
A plurality of through holes TH respectively corresponding to the side walls of the resin substrate 132.
Is mounted on the upper surface of the metal plate 131 and is set to a thickness corresponding to the height of the LED 11. The thickness of each LE
If the height of D11 is, for example, about 0.3 mm, 0.3
It is set to about 0.5 mm.

As described above, in the first embodiment, each recess 1
30 is formed in a tapered shape by the through hole TH and the upper surface of the metal plate 131, and is formed symmetrically with respect to the LED 11 housed in the concave portion 130. This makes it possible to use a liquid resin having low viscosity and poor shape stability for the sealing member 12,
Since the direction of reflection of the light from the concave portion 130 is not biased, a surface light source with uniform illuminance can be obtained. In addition, each recess 13
0 is not limited to the tapered shape, but may be a mortar shape, or may be various shapes determined in consideration of a light reflection function, that is, by calculating light reflection. Thus, the recess 130
The optical characteristics can be controlled by changing the shape of.

The mounting substrate 13 has a connecting member 133 as a wiring made of copper foil formed on the upper surface of the resin substrate 132. The connecting member 133 is formed by a plurality of wires W such as copper by wire bonding. It is electrically connected to each other end (upper surface) of the LED 11. In this manner, both electrodes are collectively connected to the plurality of LEDs 11 by the metal plate 131 and the connection member 133, respectively. Thus, when power is supplied from an external power supply to the metal plate 131 and the connection member 133, each LED 11 emits light. The upper surface of the metal plate 131 connected to one end of each LED 11 becomes the bottom surface of the concave portion 130, while the LE
The connection member 133 connected to the other end of D11
Is located on the upper surface side of the LED 1 so that the connection member 133 is
1 is electrically connected to the other end of the LED 1 by a wire W by wire bonding, since there is no need to separately provide a space for the wire bonding in the concave portion 130, the LED 11 is provided by the space for the wire bonding.
The shape of the concave portion 130 does not become asymmetric with respect to
Thus, the LED can be used without increasing the size of the recess 130.
11 can be easily formed in a symmetrical shape.

Next, as already apparent, the procedure for assembling the LED mounting board 10 will be described. First, a resin substrate 132 is attached to the upper surface of the metal plate 131 with an adhesive or the like. Thereby, the mounting substrate 13 is obtained.

Next, the chips of the plurality of LEDs 11 are respectively mounted on the centers of the bottom surfaces of the plurality of recesses 130 by a die bonding process. At this time, one end of each LED 11 is electrically connected to the metal plate 131. The metal plate 1
It should be noted that since 31 is formed by Al, it oxidizes to alumite. That is, each LED
It is necessary to avoid a heat treatment that inhibits electrical conduction before die-bonding 11 and to prevent the Al surface from becoming an electrically non-conductive material.

Next, by a wire bonding process,
The other end of each of the plurality of LEDs 11 is connected to the connection member 133 with a wire W
To make electrical connection.

Next, a liquid resin as a raw material of the sealing member 12 is poured into each concave portion 130, and the resin is cured by heating. Thereby, each LED 11 is sealed by the sealing member 12.

In this manner, a plurality of L
The LED mounting board 10 on which the EDs 11 are two-dimensionally arranged and mounted is obtained.

As described above, according to the first embodiment, it is possible to obtain an LED mounting board which functions as a preferable surface light source without increasing its shape.

In addition to being easy to assemble, the electrodes can be connected collectively to a plurality of LEDs 11.
A suitable heat radiation effect can be obtained.

When forming the through holes TH in the resin substrate 132, either before or after attaching the resin substrate 132 to the metal plate 131, the through holes TH may be formed before the attachment.
It is desirable because it is easy to form.

The connection member 1 on the upper surface of the resin substrate 132
33 may be formed (for example, by etching a conductor) or before or after attaching the resin substrate 132 to the metal plate 131, but before attaching the resin substrate 132, the adverse effect on the metal plate 131 when the connecting member 133 is formed is reduced. It is desirable because it can be eliminated.

Further, the metal plate 131 is not limited to Al but may be made of, for example, copper or the like. In this case, it is not necessary to consider the alumite conversion of Al. FIG. 2 is a partial cross-sectional view of the LED mounting board according to the second embodiment of the present invention. Hereinafter, the second embodiment will be described with reference to this drawing. In addition to the plurality of LEDs 11 and the sealing member 12, a mounting substrate 23 having a structure different from that of the first embodiment is provided.

The mounting board 23 includes a resin substrate 132 and the connecting member 1 formed on the upper surface thereof, as in the first embodiment.
33, a metal plate 231 having a different structure from the metal plate 131 of the first embodiment. This metal plate 231
Is made of Al, and a plurality of grooves 231a are formed on the lower surface side. Thereby, since the surface area of the metal plate 231 is larger than that of the metal plate 131, a higher heat radiation effect than in the first embodiment can be obtained.

As described above, according to the second embodiment, in addition to the effects of the first embodiment, it is possible to obtain a higher heat radiation effect than the first embodiment, and the power consumption of the plurality of LEDs 11 is reduced to the level of the incandescent lamp. Even when it reaches several tens of watts.

In the second embodiment, a plurality of grooves 231a are formed on the lower surface of the metal plate 231 as a means for improving the heat radiation effect.
Is formed, but the present invention is not limited to this groove structure, and may have a structure of a radiation fin / block.

FIG. 3A is a partial sectional view of an LED mounting board according to a third embodiment of the present invention, and FIG. 3B is a perspective view showing the resin board in FIG. 3A and a connecting member provided on the upper surface thereof. Hereinafter, a third embodiment will be described with reference to FIG. 3. The LED mounting board 30 includes a plurality of LEDs 11 and a sealing member 12 as in the first embodiment. Has a different mounting board 33.

The mounting substrate 33 has a metal plate 131 and a resin substrate 132 as in the first embodiment, and has a connecting member 333 different from that of the first embodiment on the upper surface of the resin substrate 132. The connecting member 333 is provided with a plurality of recesses 1.
The connection to the other ends of the plurality of LEDs 11 housed in the respective LEDs 30 is performed at a stretch, and therefore, TAB (Tape A) of a lead frame or a flexible circuit board is used.
utomated Bonding) substrates are used.

As described above, according to the third embodiment, the same effects as those of the first embodiment can be obtained.

FIG. 4 shows an LE according to a fourth embodiment of the present invention.
A fourth embodiment of the present invention will be described with reference to FIG.
Plural LEDs 11 and sealing member 1 as in the first embodiment
2 and a mounting substrate 43 having a structure different from that of the first embodiment.

The mounting board 43 has a metal plate 431 made of Al, and a plurality of recesses 430 are provided on the upper surface side of the metal plate 431. Each part of the recesses 430 is formed by the metal plate 431. . Each of the recesses 430 contains a plurality of LEDs 11, and one end of each LED 11 is electrically connected to a metal plate 431 that is the bottom surface of the recess 430. Each recess 43
0 is formed in a circular cross section.

The mounting board 43 is formed on the upper surface of the metal plate 431 except for the insulating layer 4 formed in a portion other than the concave portion 430.
32, and a connection member 133 formed on the upper surface of the insulating layer 432 in the same manner as in the first embodiment.

As described above, according to the fourth embodiment, the same effects as those of the first embodiment can be obtained.

FIG. 5 shows an LE according to a fifth embodiment of the present invention.
The fifth embodiment will be described below with reference to this drawing, which is a partial cross-sectional view of a D mounting board.
Plural LEDs 11 and sealing member 1 as in the first embodiment
2 and a mounting substrate 53 having a structure different from that of the first embodiment.

The mounting substrate 53 has a metal plate 531 made of Al, and a plurality of recesses 530 are provided on the upper surface side of the metal plate 531, and each part of these recesses 530 is formed by the metal plate 531. . Each of the recesses 530 houses a plurality of LEDs 11, and one end of each LED 11 is electrically connected to a metal plate 531 which is the bottom surface of the recess 530. Each recess 53
0 is formed in the same shape as the concave portion 130 of the first embodiment.

The mounting substrate 53 is formed on the upper surface of the metal plate 531 except for the insulating layer 5 formed in a portion other than the concave portion 530.
32, and a connection member 133 formed on the upper surface of the insulating layer 532 in the same manner as in the first embodiment.

As described above, according to the fifth embodiment, the same effects as those of the first embodiment can be obtained.

[0044]

As is clear from the above, according to the first and second aspects of the present invention, it is possible to obtain an LED mounting board which functions as a preferable surface light source without increasing its shape.

According to the third aspect of the present invention, it is possible to obtain an LED mounting board functioning as a preferable surface light source without increasing the shape, and to obtain a higher heat radiation effect.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of an LED mounting board according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of an LED mounting board according to a second embodiment of the present invention.

FIG. 3A is a partial sectional view of an LED mounting board according to a third embodiment of the present invention, and FIG. 3B is a perspective view showing a resin board in FIG. 3A and a connecting member provided on the upper surface thereof. .

FIG. 4 is a partial cross-sectional view of an LED mounting board according to a fourth embodiment of the present invention.

FIG. 5 is a partial cross-sectional view of an LED mounting board according to a fifth embodiment of the present invention.

6A is an exploded perspective view showing a conventional LED mounting board, and FIG. 6B is a partial cross-sectional view of FIG.

[Explanation of symbols]

 10, 20, 30, 40, 50 LED mounting substrate 11 LED 12 sealing member 13, 23, 33, 43, 53 mounting substrate 130 recess 131, 231, 431, 531 metal plate 132 resin substrate 432, 532 insulating layer 133, 333 connection member

Claims (3)

[Claims] A mounting board having a metal plate, a plurality of element storage chambers provided on one surface side of the metal plate, and a bottom surface of each of the element storage chambers formed by the metal plate; A plurality of LEDs respectively housed in the plurality of element storage chambers and one end of which is electrically connected to the metal plate; and a translucent sealing member for sealing the LEDs. The mounting substrate has a connection member electrically connected to each of the other ends of the plurality of LEDs on the upper surface side. An LED mounting board, characterized in that: 2. The element storage chamber is a recess, and the mounting board includes a resin substrate having a plurality of through holes corresponding to side walls of the plurality of recesses, respectively. The LED mounting board according to claim 1, wherein the LED mounting board is attached to one surface of the plate. 3. The L according to claim 1, wherein a plurality of grooves are formed on another surface of the metal plate.
ED mounting board.