JPH0717161Y2 - Surface emitting element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a surface emitting device having a plurality of LEDs arranged in a common housing.

<Prior Art> This type of surface-emitting device has a substrate 101, as shown in FIG.
A plurality of pairs of, for example, a pair of red and green LEDs 102 mounted on the above is incorporated into the housing 103 and the surface of the substrate 101
The LED 102 is molded with a resin 104 such as an epoxy resin. The reason why this resin molding is performed is to mix the red and green light emission and to increase the surface emission brightness.

In this surface emitting element, in order to increase the brightness, the LED
Increasing the current of causes the Joule heat generated in the LED to increase. However, since there is a difference in the coefficient of thermal expansion between the substrate and the resin, or the LED chip and the resin, the heat generated by the LED may distort the element, which may lead to disconnection or cracking of the chip, resulting in non-lighting.

Therefore, as a measure against heat of the surface emitting element, the heat conductive rubber sheet 105 is provided on the back side of the substrate 101 as shown in the sectional structure of FIG.
The heat radiating plate 106 is disposed through the heat radiating plate 106, and the heat radiating plate 106 radiates heat to lower the temperature of the substrate 101.

<Problems to be Solved by the Invention> In the method of disposing the heat dissipation plate 106 on the back side of the substrate 101 described above,
There were the following problems.

That is, the heat dissipation plate 106 is often made of a metal having a good thermal conductivity, particularly an aluminum-based metal. However, since this aluminum-based metal has a good electrical conductivity, a large empty space is provided to insulate the portion where the electrode pin 107 penetrates. Need to be formed. However, in this case, when the area of the substrate 101 is small, the number of mounted LEDs is large, and the number of the electrode pins 107 is large, the effective area of the heat dissipation plate 106 is small and heat is not sufficiently dissipated.

Further, on the back side of the substrate 101, it is necessary to dispose a rubber sheet 105 having electrical insulation and good heat conductivity in order to perform electrical insulation and reduce contact thermal resistance. As a result, the number of parts is increased, and the number of assembling steps is increased accordingly, resulting in an increase in product cost.

<Means for Solving Problems> The surface emitting element of the present invention is a surface emitting element formed by resin-molding a plurality of LED chips on a substrate supported by a housing, and the cross-sectional shape is substantially triangular, And a grid-like member which is integrally formed with the housing and which is arranged at a position close to the LED chip and which is made of a heat conductive member for partitioning the substrate into a grid-like shape. The member is characterized by being resin-molded on the substrate together with the LED chip.

<Operation> In the surface emitting device according to the present invention, since the heat generated by the LED chip is transferred to the heat conductive member through the resin mold, the heat transfer path is shortened and further transferred from the heat conductive member to the housing, By radiating heat at, the temperature rise of the substrate can be suppressed low. The grid-like member surrounding each LED forms a slope, and the slope efficiently reflects light forward. Furthermore, as compared with the conventional example, the volume occupied by the lattice-like member and the amount of mold resin to be filled may be smaller.

<Example> FIG. 1 shows the external structure of the surface emitting device of this example.
The figure shows the cross-sectional structure. In the figure, 1 is a substrate, 2 is an LED chip, 3 is a housing, and 4 is a resin mold layer.

A plurality of LED chips 2 are arranged and mounted on a substrate 1 at predetermined positions. The LED chip 2 has a pair of LEDs that emit red and green lights, and a plurality of pairs of the LED chips are mounted at predetermined positions on the substrate 1. The housing 3 is
In the figure, the substrate 1 is fixedly supported on the lower inner peripheral portion 3a. The inner surface 3b of the housing 3 that surrounds the substrate 1 from all sides forms a reflective surface. The reflecting surface 3b is inclined, and the housing 3 extends in the emission direction of the light emitted from the LED 2 on the substrate 1.

On the lower part of the housing 3, a lattice-shaped member 3c is formed integrally with the housing 3. The grid-like member 3c partitions the substrate 1 supported by the housing 3 and is arranged close to the LED chips 2 on the substrate 1. The housing 3 including the lattice member 3c is formed of a metal having a good thermal conductivity, for example, an aluminum alloy. The cross-sectional shape of the lattice-like member 3c is substantially triangular.
The surface of is forming a reflective surface.

A resin mold layer 4 is formed on the surface of the substrate 1 supported by the housing 3. The resin mold layer 4 is formed over the entire surface of the substrate 1 and covers the LED chips 2 and the grid-like member 3c.

The light emitted from the LED 2 passes through the resin mold layer 4, and the surface of the resin mold layer 4, the surface of the grid-like member 3c, and the housing 3
While repeating reflection on the inner surface 3b of the, it becomes surface emitting and goes out.

The heat generated by energizing the LED 2 is transmitted from the LED chip 2 through the resin mold layer 4 to the lattice member 3c and further to the housing 3. Then, the housing 3 radiates heat from its surface. In this case, the grid-like member 3c is on the substrate 1.
Since it is on the same side as the LED chip 2 and close to the LED chip 2, the heat generated by the LED chip 2 is efficiently transmitted to the grid-like member 3c via the resin mold layer 4. As a result, the heat generated by the LED chip 2 is efficiently radiated from the housing 3, and therefore the temperature rise of the substrate 1 due to the heat generated by the LED chip 2 is reduced.

<Effects of the Invention> As described above, according to the surface emitting device of the present invention, the cross-sectional shape is a substantially triangular shape, is formed integrally with the housing, and is disposed at a position close to the LED chip on the substrate. In addition to the above, a grid-like member made of a heat-conductive member for partitioning the board into a grid is provided, and since the grid-like member is resin-molded on the board together with the LED chip, the heat generated by the LED does not occur. The heat is efficiently transmitted from the heat conductive member to the housing through the resin mold layer and radiates heat from the housing. Therefore, it is possible to reduce the temperature rise of the element and prevent disconnection and cracking due to strain of the element. Also, the amount of mold resin filled is small,
Therefore, there is no influence of the stress of the mold resin. Furthermore, the slope of the grid-like member improves the light reflection efficiency and increases the surface emission brightness.

In addition, the cost of the product can be reduced by eliminating the conventional independent heat dissipation plate and heat conductive rubber sheet, reducing the number of parts, and simplifying the assembly process.

Further, it is possible to solve the problem of the reduction of the effective area from the empty space of the heat dissipation plate due to the increase in the number of electrode pins as in the conventional case.

[Brief description of drawings]

 FIG. 1 is a view showing a perspective external structure of an embodiment of the present invention, FIG. 2 is a view showing a sectional structure of an embodiment of the present invention, FIG. 3 is a view showing a perspective external structure of a conventional example, and FIG. It is a figure which shows the cross-section of an example. 1 ... Substrate 2 ... LED chip 3 ... Housing 3c ... Lattice member 4 ... Resin mold layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-61-158606 (JP, A) JP-A-52-75127 (JP, A) Actually open 62-12183 (JP, U) Actual-open Sho 61- 123555 (JP, U) Actual opening Sho 58-185888 (JP, U) Actual opening Sho 62-92504 (JP, U) Actual opening Sho 62-92505 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A plurality of substrates on a substrate supported by a housing.
In a surface-emitting element obtained by resin-molding an LED chip, the cross-sectional shape is a substantially triangular shape, is formed integrally with the housing, and is arranged at a position close to the LED chip, and the grid is formed on the substrate. 1. A surface emitting device, comprising: a grid-shaped member made of a heat-conductive member for partitioning into a shape, and the grid-shaped member being resin-molded on the substrate together with the LED chips.