JPH0447469B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lighting device that uses a light emitting element as a light source.

[Conventional technology]

In recent years, with the development of semiconductor technology, high-brightness light-emitting diodes have been developed and are now available at low prices, which has led to the development of light-emitting diodes for vehicles, especially taillights.
Consideration has been given to the use of light bulbs instead of light bulbs as light sources for brake lights and the like, and one example of this is known as shown in FIG. 11. That is, this is a so-called on-board type in which light-emitting elements 2 such as light-emitting diodes are arranged on a metal substrate 1, and the surface of the substrate 1 has a large number of element-accommodating recesses 3 each forming a reflective surface. An insulating layer 4 is formed corresponding to the light emitting element 2, and an insulating layer 4 is formed on the entire surface of the substrate including the recess 3 by printing, vapor deposition, etc. Further, a common electrode 5 is formed on the insulating layer 4, and a common electrode 5 is formed on each insulating layer 4. A conductive layer 6 is formed in each of the recesses 3, and the light emitting element 2 is disposed on the conductive layer 6. The light emitting elements 2 in each column (or row) are connected in series through the gold wire (lead wire) 7 and the conductive layer 6, and the light emitting elements 2 in each column (or row) are connected in parallel to the power supply. It is connected. Note that the light emitting elements 2a at the ends are electrically connected to the common conductive layer 5 by gold wires 7a.

FIG. 12 shows an electric circuit of a lighting device having a configuration as shown in FIG. 12, where R is a lighting resistor.

[Problem that the invention seeks to solve]

However, in such conventional lighting devices,
When forming the insulating layer 4 on the entire surface of the substrate 1 including the recess 3 by vapor deposition or the like, it is difficult to uniformly form the insulating layer 4 inside the recess 3;
There was a problem with the insulation between the conductive layer 6 and the conductive layer 6. Further, since the conductive layer 6 is formed within the recess 3, it is difficult to form it with a uniform thickness like the insulating layer 4, which increases the manufacturing cost.

Furthermore, since the substrate 1 is manufactured according to the size of the lighting device, there are many types, and manufacturing and management are troublesome.

[Means for solving problems]

The lighting device according to the present invention has been made to solve the above-mentioned problems at once, and is a high-conducting pair in which a large number of element housing recesses are formed on the surface and the surface other than the recesses is covered with an insulating layer. a plurality of light emitting elements disposed in each of the element storage recesses and electrically connected to the metal substrate; and a plurality of light emitting elements formed on the surface of the insulating layer and connected to each other through lead wires. A common conductive layer that is electrically connected constitutes a substrate unit, and a plurality of these substrate units are electrically connected.

[Effect]

In the present invention, the light emitting element is directly disposed within the element housing recess and brought into contact with the metal substrate, and the substrate itself is used as an electrical conductor, so there is no need to laminate an insulating layer and a conductive layer within the recess. , easy to manufacture. Furthermore, since it is sufficient to form a board unit and electrically connect a plurality of these board units as necessary, the number of types of boards can be reduced.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a sectional view showing the basic structure of a lighting device according to the present invention, and FIG. 2 is a perspective view of the main parts of a substrate unit. In the drawings, the same components as in FIGS. 11 and 12 are designated by the same reference numerals, and their explanations will be omitted. In these figures,
A plurality of element housing recesses 3 are formed at appropriate intervals in the longitudinal direction on the surface of a metal substrate 1 made of a good conductor such as Al, and the entire surface except for the recesses 3 is covered with an insulating layer 4. ing. A common conductive layer 5 is formed on the insulating layer 4 so as to extend in the longitudinal direction of the metal substrate 1, and a plurality of chip-shaped conductive layers 10 are formed on the insulating layer 4 in each of the element housing recesses 3. are formed accordingly.

The light emitting elements 2 are made of semiconductor chips, and are electrically connected to the metal substrate 1 by being directly arranged and fixed at the center of the bottom of each element storage recess 3, and are connected to the elements by gold wires 7 as lead wires. They are electrically connected in parallel to the conductive layer 10, respectively. Each conductive layer 10 is connected to the common conductive layer 5 via a lighting resistor R, respectively. The lighting resistor R is advantageous in that it can be formed with a small printed resistance, but a chip resistor may also be used.

The element storage recess 3 is formed in a substantially inverted trapezoidal shape, and its inner wall surface 3a forms a reflective surface by vapor deposition of aluminum, coating with a paint having excellent reflective properties, or the like. This reflective surface 3a is the metal substrate 1
It can also be formed by plating the entire part.
The element housing recess 3 is filled with a transparent resin 14 to mold the light emitting element 2. resin 1
Epoxy resin or the like is used for the lens 4, and its surface is bulged into a substantially hemispherical shape to form a convex lens. In addition, in Fig. 2, resin 1
4 is omitted.

The substrate 1 thus constructed constitutes a substrate unit 12 by being formed to a predetermined size. As shown in FIG. 3, this board unit 12 has a heat sink 3 according to the size of the lighting device.
A plurality of them are arranged in parallel on 0 and electrically connected by lead wires 32. FIG. 4 shows an example in which six board units 12 are electrically connected, in which four board units 12 are connected in series to the power supply 15, and two board units 12 are connected in parallel. The heat sink 30 is made of aluminum or the like, and the substrate unit 1 is disposed on its surface.
2 is disposed with an insulating layer 31 in between, and a plurality of grooves 34 are formed on the back surface to increase the heat dissipation effect.

FIG. 5 is a sectional view showing an example in which the lighting device shown in FIG. 3 is applied to a vehicular lamp. In the figure, 35 is a back cover, 36 is a front lens, 37 is an inner lens, and 38 is a heat radiation hole. A large number of fisheye condensing lenses 39 are formed on the surface of the inner lens 37, corresponding to each light emitting element (not shown).

Thus, according to the lighting device having such a configuration, the electrical properties of the metal substrate 1 as a good conductor are utilized as they are, and the light emitting element 2 and the substrate 1 are brought into conduction, so that a current is caused to flow through the substrate 1. Therefore, unlike the conventional device shown in FIG. 11, there is no need to laminate an insulating layer and a conductive layer in the element storage recess 3, and the lighting device can be manufactured easily and inexpensively. obtain. Moreover, since it is sufficient to bring the light emitting element 2 into direct contact with the metal substrate 1, the conduction between them is also reliable.

Furthermore, since the metal substrate 1 is formed to a predetermined size and the light emitting elements 2 are mounted in advance to constitute the substrate unit 12, the substrate unit 12 can be assembled into a number of electrical units according to the size of the lighting device. By connecting the metal substrates 1 to 1, it is possible to correspond to various lighting devices and reduce the number of types of metal substrates 1.
Therefore, storage and management of the substrate units 12 is easy, and if one or any number of light emitting elements 2 in a certain unit breaks down, only that unit needs to be replaced, so maintenance is also simple.

FIG. 6 is a plan view showing another embodiment of the substrate unit. This embodiment has four terminal parts 41, 4.
2, 43, and 44 are provided at each corner of the surface of the substrate unit 12, respectively. Left terminal section 4
1 and 42, the insulating layer 4 is removed to expose the metal substrate 1 to form a terminal portion. On the other hand, the terminal portions 43 and 44 on the right side are formed of conductive patterns formed on the insulating layer 4, and are respectively connected to the common conductive layer 5 of each column. Each terminal part 41, 42,
Screw attachment holes 46 penetrating the back surface of the metal substrate 1 are formed in the holes 43 and 44, respectively. FIG. 7 shows the electric circuit of the substrate unit 12 formed in this way, and FIG.
12H) are arranged side by side, four in the left-right direction (in series) and two in the front-to-back direction (in parallel), and these are electrically connected. As a means for electrical connection, a conductive plate 4 is used as shown in FIG.
1 and 43, 42 and 44, 41, 42, 43 and 44 are connected, respectively. The conductive plate 50 is attached to the substrate by a pair or four set screws 52 that are inserted into screw mounting holes 46 provided at each end 41 , 42 , 43 , 44 and screwed into the screw holes 51 of the radiator 30 . It is fixed on the unit 12. In this case, the conductive plate 50 that connects the terminal parts 41 and 43, and 42 and 44 is formed in a rectangular shape, and the conductive plate 50 that connects the terminal parts 41, 42, 43, and 44 is formed in a rectangular shape. The set screw 52 is made of an insulating material.

FIG. 10 shows a diagram of the electric circuit of the lighting device configured in this manner.

Although the present invention has been described as an embodiment in which the board units 12 are connected to each other by the lead wires 33 and the conductive plates 50, the present invention is not limited to this in any way. Any electrical connection means may be used.

〔Effect of the invention〕

As explained above, according to the lighting device according to the present invention, the electrical characteristics of the metal substrate itself are utilized as they are to establish electrical continuity between the metal substrate and the light emitting element, so that the electrical connection between the metal substrate and the light emitting element is ensured. Therefore, there is no need to laminate an insulating layer and a conductive foil in the element housing recess, and the device can be provided at low cost. Additionally, multiple light emitting elements are assembled onto a metal substrate to form a unit, and multiple board units are electrically connected to form a lighting device. It is only necessary to select the number of sheets to be used, and the types of metal substrates can be reduced. Therefore,
Parts management is easy, and in the event of a failure, it is only necessary to replace the board unit, so maintenance is also simple.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the main parts showing the basic structure of the lighting device according to the present invention, FIG. 2 is a perspective view of the main parts of the board unit, FIG. 3 is a perspective view of the main parts of the lighting device, and FIG. An electric circuit diagram of the device, FIG. 5 is a sectional view when the present invention is applied to a vehicle lamp, FIG. 6 is a plan view of a board unit showing another embodiment of the present invention, and FIG. 7 is a diagram of the same unit. Fig. 8 is a plan view when eight of the same units are electrically connected, Fig. 9 is a sectional view of the main parts, Fig. 10 is an electric circuit diagram, and Fig. 11 is a diagram of a conventional lighting device. Main part sectional view showing an example, 12th
The figure is an electrical circuit diagram. 1... Metal substrate, 2, 2a... Light emitting element, 3...
...Element housing recess, 4...Insulating layer, 5...Common conductive layer, 6...Conductive layer, 7...Gold wire (lead wire), 1
0... Conductive layer, 12... Substrate unit, 15...
Power supply, 41-44...terminal section, 50...conductive plate,
R...Resistor for lighting.

Claims (1)

[Claims] 1. A metal substrate made of a good conductor and having a plurality of element storage recesses formed on its surface and whose surface other than the recesses is covered with an insulating layer; A substrate unit is constituted by a plurality of conductive light emitting elements and a common conductive layer formed on the surface of the insulating layer and to which each of the light emitting elements is electrically connected via a lead wire. A lighting device characterized in that it is connected to