Substrate for light emitting diodes
A substrate has a pair of metal bases, and a first heat insulation layer disposed between the metal bases. A second heat insulation layer is securely mounted on the metal bases, and a pair of circuit patterns are securely mounted on the second heat insulation layer for mounting an LED.
This application is a continuation of Ser. No. 10/823,594 filed Apr. 21, 2004, which is a continuation of Ser. No. 10/411,134, filed Apr. 11, 2003, now U.S. Pat. No. 6,740,903.
BACKGROUND OF THE INVENTIONThe present invention relates to a substrate for a light emitting diode (LED) used in an electronic instrument such as a portable telephone.
In recent years, it is required that the substrate for the LED has a high heat radiation property, heat-resistant property and high mechanical strength in accordance with the tendencies of a high performance, multifunction, small size of the electronic instrument.
The metal base 51 has a high heat radiation property.
In the substrate of
An object of the present invention is to provide a substrate having a high heat radiation property.
According to the present invention, there is provided a substrate comprising a pair of metal bases, a first heat insulation layer disposed between the metal bases, a second heat insulation layer securely mounted on the metal bases, and mounting means for mounting an LED on the substrate.
The mounting means comprises a pair of circuit patterns securely mounted on the second heat insulation layer, the LED is securely mounted on both the circuit patterns.
In another aspect, the mounting means comprises a hole formed in the second heat insulation layer to expose surfaces of metal bases, the LED is securely mounted on both the metal bases.
The substrate further comprises upper and lower electrodes provided on an upper surface of the circuit patterns and on undersides of the metal bases.
One of the metal bases is different from the other metal base in size of a sectional shape.
These and other objects and features of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
The substrate comprises a pair of metal bases 1a and 1b made of copper, each having a cubic shape, a first electrical insulation layer 2 of prepreg between the metal bases 1a and 1b, a second electrical insulation layer 3 of prepreg adhered to the metal bases 1a and 1b, a pair of circuit patterns 4a and 4b made of copper foil provided on the second insulation layer 3. On the circuit patterns 4a and 4b, electrodes 6a are formed by gold plating, and terminal electrodes 6b are formed on the underside of metal bases. An LED 40 is securely mounted on both the circuit patterns 4a and 4b.
The LED 40 on the circuit patterns 4a and 4b is connected to the terminal electrodes 6a and 6b by through holes 5 passing through the metal bases 1a and 1b.
Dimensions of the substrate, for example, are as shown in
Since the metal base is made of copper having a high heat conductivity, and there is not provided a heat insulation layer on the underside of the metal base, the substrate is excellent in heat radiation property. Therefore, an LED device using the substrate is properly used in the LED requiring a high current.
Referring to
Referring to
Next, as shown in
As shown in
Finally, as shown in
The substrate comprises a pair of metal bases 11a and 11b made of copper, a first electrical insulation layer 12 of prepreg between the metal bases 11a and 11b, a second electrical insulation layer 13 of prepreg adhered to the metal bases 11a and 11b. The insulation layer 13 has a central hole 13a. An LED 20 is mounted on both the metal bases 11a and 11b in the central hole 13a.
Since the LED 20 is directly mounted on the metal bases 11a and 11b, the heat radiation property is high.
The manufacturing method is the same as the steps of
Referring to
Next, as shown in
As shown in
The substrate comprises a pair of metal bases 30a and 30b made of copper, a first electrical insulation layer 31 of prepreg between the metal bases 30a and 30b, a second electrical insulation layer 32 of prepreg adhered to the metal bases 30a and 30b, a pair of circuit patterns 33a and 33b made of copper foil provided on the second insulation layer 32. An LED 35 is mounted on both the circuit patterns 33a and 33b.
The LED 35 on the circuit patterns 33a and 33b is connected to the metal bases 30a and 30b by through holes 36.
In the substrate of the third embodiment, the sizes of the metal bases 30a and 30b are different in sectional shape, thereby deflecting the position of the first electrical insulation layer from the center line.
The coefficient of the thermal expansion of the first electrical insulation layer 31 in the thickness direction is high, so that the positions of the metal bases 30a and 30b are deflected, which may generate stress in the LED 35.
However, since the thermal expansion coefficient of the second electrical insulation layer 32 in the plane direction is small, the metal bases are prevented from deflecting, thereby preventing the generation of the stress in the LED.
Furthermore, since the first heat insulation layer 31 is eccentric, the influence of thermal expansion of the first electrical insulation layer is reduced.
In accordance with the present invention, a substrate is excellent in heat radiation performance, heat insulation performance and rely can by obtained.
While the invention has been described in conjunction with preferred specific embodiment thereof, it will be understood that this description is intended to illustrate and not limit the scope of the invention, which is defined by the following claims.
Claims
1. A substrate comprising:
- a pair of metal bases;
- a first electrical insulation layer disposed between the metal bases;
- a second electrical insulation layer securely mounted on the metal bases; and
- mounting means for mounting an LED on the substrate.
2. The substrate according to claim 1 wherein the mounting means comprises a pair of circuit patterns securely mounted on the second electrical insulation layer, the LED is securely mounted on both the circuit patterns.
3. The substrate according to claim 1 wherein the mounting means comprises a hole formed in the second electrical insulation layer to expose surfaces of metal bases, the LED is securely mounted on the metal bases.
4. The substrate according to claim 2 further comprising upper and lower electrodes provided on an upper surface of the circuit patterns and on undersides of the metal bases.
5. The substrate according to claim 2 wherein one of the metal bases is different from the other metal base in size of sectional shape.
Type: Application
Filed: Sep 26, 2005
Publication Date: Feb 16, 2006
Inventor: Hiroto Isoda (Yamanashi-ken)
Application Number: 11/234,201
International Classification: H01L 33/00 (20060101);