CN102983124A - Light emitting diode (LED) light source with cooling device - Google Patents

Abstract

The invention discloses an LED light source, which includes a heat dissipation device, an LED chip and an electrode layer. The heat dissipation device includes a substrate, a first transition layer and a diamond-like layer, and the first transition layer is attached between the substrate and the diamond-like layer. The adhesion between the first transition layer and the substrate and the diamond-like layer is greater than the adhesion between the substrate and the diamond-like layer, and the thermal expansion coefficient of the first transition layer is between the diamond-like layer and the substrate, and the LED chip Arranged on the diamond-like carbon layer, the LED chip is electrically connected to the electrode layer. Through the above method, the diamond-like carbon layer of the LED light source of the present invention is well bonded to the metal substrate, which can prolong the service life of the LED light source.

Description

LED light source with cooling device

technical field

The invention relates to a semiconductor device, in particular to an LED light source with a heat dissipation device.

Background technique

Because light-emitting diodes have the advantages of low power consumption, low heat generation, and long life; therefore, in the fields of electronic display and lighting, light-emitting diodes are gradually replacing traditional lighting fixtures with high energy consumption and short life.

When LED light sources perform their intended work, they typically generate a lot of heat; this heat needs to be dissipated. If the heat cannot be effectively dissipated, it will affect the normal operation of the LED light source.

DLC (Diamond-like carbon, diamond-like carbon) coating not only has good thermal conductivity, but also has the same thermal conductivity in all directions, so it is widely used in light-emitting diode light sources for heat dissipation.

A conventional light emitting diode light source includes a cooling device and a light emitting chip. The heat dissipation device includes a metal substrate and a diamond-like carbon layer arranged on one side of the metal substrate, and the light-emitting chip is arranged on the diamond-like carbon layer.

However, the thermal expansion coefficients of the metal substrate and the diamond-like layer differ by several times. When the heat generated by the light-emitting chip is dissipated through the heat-dissipating substrate, the diamond-like layer is easily peeled off from the metal substrate, which leads to the failure of the LED light source.

Contents of the invention

The main technical problem to be solved by the present invention is to provide an LED (light emitting diode, light emitting diode) light source with a stable combination of a diamond-like layer and a substrate.

In order to solve the above technical problems, a technical solution adopted by the present invention is to provide an LED light source, including a heat sink, an LED chip and an electrode layer, the heat sink includes a substrate, a first transition layer and a diamond-like layer, and the first transition layer adheres to between the substrate and the diamond-like layer, wherein the adhesion between the first transition layer and the substrate and the diamond-like layer is greater than the adhesion produced when the substrate and the diamond-like layer are attached to each other, and the coefficient of thermal expansion of the first transition layer Between the diamond-like carbon layer and the substrate, the LED chip is arranged on the diamond-like carbon layer, and the LED chip is electrically connected to the electrode layer.

Wherein, the surface of the substrate has a concave-convex structure, and the first transition layer and the diamond-like layer are arranged on the surface, and the shape matches the surface.

Wherein, the surface of the substrate includes a valley, a peak protruding outward relative to the valley, and a connecting portion obliquely connecting the valley and the peak, the LED chip is arranged on the area corresponding to the valley of the diamond-like layer, and the electrode layer provided on the region of the diamond-like carbon layer corresponding to the peak.

Wherein, the LED light source further includes a reflective film, and the reflective film is disposed on the area of the diamond-like carbon layer corresponding to the connecting portion.

Wherein, the LED light source further includes a second transition layer, the second transition layer is attached between the electrode layer and the diamond-like carbon layer, and the adhesion between the second transition layer and the electrode layer and the diamond-like carbon layer is greater than that between the electrode layer and the diamond-like carbon layer. The adhesive force generated when the layers are attached to each other, the thermal expansion coefficient of the second transition layer is between the diamond-like layer and the electrode layer.

Wherein, the LED light source further includes an epoxy resin layer, and the epoxy resin layer is attached between the electrode layer and the first transition layer.

Wherein, the electrode layer is formed on the diamond-like carbon layer by printing thick film silver paste.

Wherein, the substrate is metal, ceramic or high thermal conductivity plastic.

Wherein, the first transition layer is one of nickel, copper, chromium, titanium, silicon, titanium nitride, chromium tungsten, chromium nitride, and titanium carbide, or a composite layer composed of any two or more of them.

Wherein, the second transition layer includes a first nickel layer, a copper layer and a second nickel layer, and the copper layer is located between the first nickel layer and the second nickel layer.

The beneficial effects of the present invention are: different from the situation of the prior art, the LED light source cooling device of the present invention uses the first transition layer to connect the substrate and the diamond-like layer; and the adhesion generated between the first transition layer and the substrate and the diamond-like layer Greater than the adhesion produced when the substrate and the diamond-like layer are attached to each other, the thermal expansion coefficient of the first transition layer is between the diamond-like layer and the substrate, which not only improves the adhesion between the substrate and the diamond-like layer; and the thermal expansion of the three The coefficients increase or decrease in turn, which can effectively improve the thermal mismatch problem between the substrate and the diamond-like carbon due to the large difference in thermal expansion coefficient; therefore, the diamond-like carbon layer and the metal substrate are well combined, which can prolong the service life of the LED light source.

Description of drawings

Fig. 1 is the schematic diagram of the first embodiment of the LED light source of the present invention;

2 is a schematic diagram of a second embodiment of the LED light source of the present invention;

3 is a schematic diagram of a third embodiment of the LED light source of the present invention;

4 is a schematic diagram of a fourth embodiment of the LED light source of the present invention;

5 is a schematic diagram of a fifth embodiment of the LED light source of the present invention;

6 is a schematic diagram of a sixth embodiment of the LED light source of the present invention;

Fig. 7 is a schematic diagram of a seventh embodiment of the LED light source of the present invention.

Detailed ways

Referring to FIG. 1 , an LED light source 100 according to the first embodiment of the present invention includes a heat sink 10 , an LED chip 11 , an electrode layer 12 and a transition layer 13 . The heat sink 10 includes a substrate 101 , a transition layer 102 and a diamond-like carbon (DLC, Diamond-like carbon) layer 103 . The LED chip is disposed on the diamond-like carbon layer 103 , and the electrode layer 12 is also disposed on the diamond-like carbon layer 103 ; and the LED chip 11 is electrically connected to the electrode layer 12 through wires (not shown). In this embodiment, the LED chips 11 are LED chips with a horizontal structure.

The substrate 101 is substantially plate-shaped. The substrate 101 can be selected from materials with better thermal conductivity, such as metal, ceramics, or plastics with high thermal conductivity. The transition layer 102 is attached between the substrate 101 and the diamond-like carbon layer 103, and the adhesion force produced between the transition layer 102 and the substrate 101 and the adhesion force produced between the transition layer 102 and the diamond-like carbon layer 103 are greater than the substrate 101 and the diamond-like carbon layer. 103 Adhesion produced when directly attached to each other. The thermal expansion coefficient of the transition layer 102 is between that of the diamond-like carbon layer 103 and the substrate 101 .

The transition layer 102 attached between the substrate 101 and the diamond-like carbon layer 103 may be one or more layers of coating. When the transition layer 102 is a plating layer, one of nickel copper, chromium, titanium, silicon, titanium nitride, chromium tungsten, chromium nitride and titanium carbide can be selected. When the transition layer 102 is a multi-layer coating, the aforementioned two or more materials can be selected for layer-by-layer plating.

For example, the transition layer 102 includes a layer-by-layer plating of nickel and copper layers, or includes a layer-by-layer plating of chromium and copper layers, or includes a layer-by-layer plating of nickel, chromium, and copper layers, or includes layer-by-layer plating Plated layers of nickel, titanium and copper, or including layers of chromium, titanium and copper applied layer by layer, or layers of nickel, chromium and silicon applied layer by layer, or layer by layer The nickel layer and silicon layer, or including layer-by-layer plating, etc. Experiments have proved that when the transition layer 102 is a first copper layer, a nickel layer and a second copper layer plated layer by layer, the adhesion between the transition layer 102 and the substrate 101 and the diamond-like carbon layer 103 is excellent.

The transition layer 13 is attached between the electrode layer 12 and the diamond-like carbon layer 103, and the adhesion force produced between the transition layer 13 and the electrode layer 12, and the adhesion force produced between the transition layer 13 and the diamond-like carbon layer 103 are all greater than the electrode 12 and the diamond-like carbon layer. Adhesion occurs when the diamond layers 103 are directly attached to each other. The thermal expansion coefficient of the transition layer 13 is between the diamond-like carbon layer 103 and the electrode layer 12 .

The transition layer 13 attached between the electrode layer 12 and the diamond-like carbon layer 103 may be one or more layers of plating. When the transition layer 13 is a plating layer, one of nickel copper, chromium, titanium, silicon, titanium nitride, chromium tungsten, chromium nitride and titanium carbide can be selected. When the transition layer 13 is a multi-layer coating, the aforementioned two or more materials can be selected for layer-by-layer plating.

For example, the transition layer 13 includes a chromium layer and a chromium nitride layer that are plated layer by layer, or a chromium layer and a chromium-tungsten layer that are plated layer by layer, or a titanium layer and a titanium nitride layer that are plated layer by layer, or include Layer-by-layer plating of nickel and copper layers, or layer-by-layer plating of silicon, chromium, chromium-tungsten, etc.

Please refer to FIG. 2 , an LED light source 200 according to the second embodiment of the present invention includes a heat sink 20 , an LED chip 21 , an electrode layer 22 and a transition layer 23 . The heat sink 20 includes a substrate 201 , a transition layer 202 and a diamond-like carbon layer 203 .

Compared with the LED light source 100 of the first embodiment, the surface 204 of the substrate 201 of the LED light source 200 of the present embodiment has a concave-convex structure, the transition layer 202 and the diamond-like layer 203 are arranged on the surface 104, and the transition layer 202 and the diamond-like layer 203 The shape matches the surface 204 . The cross-sectional shape of the surface 204 is, for example, wavy, zigzag, square, etc. The concave-convex structure of the diamond-like carbon layer 203 increases the surface area of the diamond-like carbon layer 203 in a limited area occupied by the light source, which is beneficial for the diamond-like carbon layer 203 to quickly transfer heat from the LED chip.

In this embodiment, the surface 204 of the substrate 201 includes a valley portion 205 , a peak portion 206 protruding outward from the substrate 201 relative to the valley portion 205 , and a connecting portion 207 obliquely connecting the valley portion 205 and the peak portion 206 . The LED chip 21 is disposed on the area of the diamond-like carbon layer 203 corresponding to the valley 205 , so that the distance between the LED chip and the bottom of the substrate 201 is shorter, which is beneficial to reduce the conduction thermal resistance from the diamond-like carbon layer 203 to the substrate 201 .

Please refer to FIG. 3 together. The LED light source 300 according to the third embodiment of the present invention includes a heat sink 30 , an LED chip 31 , an electrode layer 32 and a transition layer 33 . The heat sink 30 includes a substrate 301 , a transition layer 302 and a diamond-like carbon (DLC, Diamond-like carbon) layer 303 .

Compared with the second embodiment, the LED light source 300 of this embodiment further includes a reflective film 34 . The reflective film 34 is arranged on the region of the diamond-like carbon layer 303 corresponding to the connecting portion 307, the LED chip 31 is arranged on the region of the diamond-like carbon layer 303 corresponding to the valley portion 305, and the electrode layer 32 is arranged on the region of the diamond-like carbon layer 303 corresponding to the In the region of peak 306 .

The reflective film 34 can be a high-emission film made of materials such as aluminum or silver, which can make the emission direction of the side light of the LED chip and the large-angle light on the upper surface tend to be perpendicular to the upper surface of the LED chip, thereby improving the LED chip. Light efficiency.

Please refer to Fig. 4 and Fig. 5, the fourth and fifth embodiments of the present invention shown in Fig. 4 and Fig. 5 correspond to the second and third embodiments shown in Fig. 2 and Fig. 3 respectively.

The LED chips 21 and 31 in the LED light sources 200 and 300 of the second and third embodiments are all LED chips with a horizontal structure, and two electrodes (not shown) of the same LED chip are arranged on the top of the chip. Compared with the second and third embodiments, the LED chips 41 and 51 in the LED light sources 400 and 500 of the fourth and fifth embodiments are all vertical structure LED chips, and the two electrodes (not shown) of the same LED chip are One is at the top of the chip and the other is at the bottom of the chip.

The electrodes of the LED chips 41 and 51 are generally made of superconducting materials such as gold, silver or copper, which are the same or similar to the materials of the electrode layers 42 and 52, and the direct adhesion to the diamond-like layers 403 and 503 is poor. Therefore, in the fourth and fifth embodiments, the LED power sources 400 and 500 further include transition layers 45, 55 attached between the LED chips 41, 51 and the DLC layers 403, 503, respectively.

The material and purpose of the transition layers 45 and 55 are the same as those of the transition layers 43 and 53 , and will not be repeated here.

Please refer to FIG. 6 . Compared with the LED light source 500 of the fifth embodiment shown in FIG. 5 , the electrode layer 62 of the LED light source 600 of this embodiment is formed on the diamond-like carbon layer 603 by thick-film silver paste printing. The bottom electrode of the LED chip 61 and the diamond-like carbon layer 603 are also connected by thick-film silver paste printing.

The electrode layer 603 can be directly formed by thick-film silver paste printing, and the bottom electrode of the LED chip 61 can be firmly connected to the diamond-like carbon layer 603 , effectively improving the problem of poor adhesion between the electrode material and the diamond-like carbon layer 603 .

Please refer to FIG. 7 together. Compared with the LED light source 100 of the first embodiment, the LED light source 700 of the seventh embodiment of the present invention further includes an epoxy resin layer 76 . An epoxy layer 76 is attached between the electrode layer 72 and the transition layer 702 .

The specific implementation method is that, firstly, the epoxy resin is used to screen-print and cure the electrode pattern on the transition layer 702 , so as to form the epoxy resin layer 76 on the transition layer 702 . The diamond-like carbon layer 703 is then plated on the entire transition layer 702 using vacuum ion coating technology. The diamond-like layer 703 is formed on the non-insulating area, that is, the diamond-like layer 703 is formed on the area of the transition layer 702 not covered by the epoxy resin layer 76 . Finally, the surface of the diamond-like carbon layer 703 is put into the electroplating solution to cover the circuit by means of magnetron sputtering. Since the adhesion between the diamond-like carbon and the circuit layer material is very poor, and the epoxy resin and the circuit layer material Therefore, in the process of thickening the electroplating solution to the diamond-like layer 703 and the epoxy resin layer 76, the electroplated layer on the diamond-like layer 703 falls off naturally, while the electroplated layer on the epoxy resin layer 76 Layers form the circuit layer 72 ; thereby forming a firmly bonded circuit layer 72 over the transition layer 702 through the epoxy layer 76 .

Different from the prior art, the LED light source cooling devices 100, 200, 300, 400, 500, 600, 700 of the present invention adopt transition layers 102, 202, 302, 402, 502, 602, 702 to connect the substrates 101, 201, 301, 401 , 501, 601, 701 and diamond-like carbon layer 103, 203, 303, 403, 503, 603, 703; The adhesive force is greater than the adhesive force produced when the substrate and the diamond-like layer are attached to each other, and the thermal expansion coefficients of the transition layers 102, 202, 302, 402, 502, 602, and 702 are between the diamond-like layer and the substrate, which not only improves the substrate and the like. The adhesion between the diamond layers; and the thermal expansion coefficients of the three are sequentially increased or decreased, which can effectively improve the thermal mismatch problem between the substrate and the diamond-like carbon due to the large difference in thermal expansion coefficient; therefore, the diamond-like carbon layer and the metal substrate The combination of good, can prolong the service life of LED light source. .

The above is only the embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process conversion made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technologies fields, all of which are equally included in the scope of patent protection of the present invention.

Claims (10)

1. led light source, it is characterized in that, described led light source comprises heat abstractor, led chip and electrode layer, described heat abstractor comprises substrate, First Transition layer and diamond like carbon layer, described First Transition layer is attached between described substrate and the described diamond like carbon layer, wherein, the adhesive force that the adhesive force that produces between described First Transition layer and described substrate and the described diamond like carbon layer produces when all mutually adhering to greater than described substrate and described diamond like carbon layer, and the thermal coefficient of expansion of described First Transition layer is between described diamond like carbon layer and described substrate, described led chip is arranged on the described diamond like carbon layer, and described led chip is electrically connected to described electrode layer.

2. led light source according to claim 1 is characterized in that, the surface of described substrate has concaveconvex structure, and described First Transition layer and described diamond like carbon layer are arranged on the described surface, and shape and described surface are complementary.

3. led light source according to claim 2 is characterized in that, the surface of described substrate comprises paddy section, with respect to the peak section outstanding to the described substrate outside of described paddy section and tilt to connect described paddy section and the connecting portion of described peak section.

4. led light source according to claim 3 is characterized in that, described led chip is arranged on the zone corresponding to described paddy section of described diamond like carbon layer, and described electrode layer is arranged on the zone corresponding to described peak section of described diamond like carbon layer; Described led light source further comprises reflective membrane, and described reflective membrane is arranged on the zone corresponding to described connecting portion of described diamond like carbon layer.

5. led light source according to claim 1, it is characterized in that, described led light source further comprises the second transition zone, described the second transition zone is attached between described electrode layer and the described diamond like carbon layer, the adhesive force that the adhesive force that produces between described the second transition zone and described electrode layer and the described diamond like carbon layer produces when all mutually adhering to greater than described electrode layer and described diamond like carbon layer, the thermal coefficient of expansion of described the second transition zone is between described diamond like carbon layer and described electrode layer.

6. led light source according to claim 1 is characterized in that, described led light source further comprises epoxy resin layer, and described epoxy resin layer is attached between described electrode layer and the described First Transition layer.

7. led light source according to claim 1 is characterized in that, described electrode layer adopts thick film silver slurry mode of printing to be formed on the described diamond like carbon layer.

8. led light source according to claim 1 is characterized in that, described substrate is metal, pottery or high heat-conducting plastic.

9. led light source according to claim 8 is characterized in that, described First Transition layer is a kind of or any two or more composite beds that form in nickel, copper, chromium, titanium, silicon, titanium nitride, chromium tungsten, chromium nitride, the titanium carbide.

10. led light source according to claim 9 is characterized in that, described the second transition zone comprises the first nickel dam, copper layer and the second nickel dam, and described copper layer is between described the first nickel dam and described the second nickel dam.

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