CN201502898U - A high-power LED light source using room temperature liquid metal to conduct heat - Google Patents

Abstract

The utility model discloses a high-power LED light source which utilizes liquid metal at room temperature to conduct heat. It includes LED chips, concave packaging substrates, room temperature liquid metal layers, sealing layers, heat sinks, and fluorescent adhesive layers; LED chips are installed on concave packaging substrates. There is a fluorescent adhesive layer, and the concave packaging substrate is installed on the radiator. There is a gap between the concave packaging substrate and the radiator, which is sealed by a sealing layer, and the gap is filled with a room temperature liquid metal layer. This method uses the high thermal conductivity of liquid metal at room temperature to effectively solve the problem of contact thermal resistance between the high-power LED package substrate and the heat sink, achieve better heat conduction effect, transmit the heat generated by the LED chip, and ensure the junction temperature of the LED chip kept at a low level, thereby increasing the operational reliability and lifetime of high-power LEDs.

Description

A high-power LED light source using room temperature liquid metal to conduct heat

technical field

The utility model relates to an illumination light source, in particular to a high-power LED light source utilizing room temperature liquid metal to conduct heat.

Background technique

LED light source is a new generation of green lighting source. Its power consumption is only one tenth of that of ordinary incandescent lamps, but its life is more than ten times longer. In addition, LED light sources also have the advantages of small size, durability, and rich colors. In order to meet the requirements of higher light intensity, the LED light source is realized by increasing the output power of a single chip or using an LED array. Under ideal conditions, matching optical materials and appropriate packaging structures can give full play to the efficient light-emitting performance of LEDs and convert most of the electrical energy into light. However, due to the very small area of the LED chip, a large amount of heat cannot be dissipated in time, thus causing the temperature of the LED to be too high during operation. Excessive temperature has a great impact on the output light intensity and color temperature performance of high-power LED light sources, especially the PN junction of the LED chip works at high temperature for a long time, and its optical performance will quickly decay, seriously affecting the service life of the LED. This is a key issue that needs to be addressed in LED packaging.

From the analysis of the heating characteristics of the LED light source, it can be known that the contact thermal resistance between the LED package substrate and the radiator seriously affects the heat dissipation performance of the LED, especially when the surface between the package substrate and the radiator is uneven, the method to solve this problem is to use Thermally conductive silicone or other thermally conductive material is used to fill between the two surfaces. However, these materials have very small thermal conductivity and are prone to aging, which affects the heat dissipation and long-term stability of the device. How to adopt a better cooling method on the premise of low cost, so that the LED light source can work at a lower temperature, so as to obtain higher luminous efficiency, longer life, and higher reliability are the key points of this utility model. key issues to be resolved.

Liquid metal is a metal that is liquid at normal temperature (such as below 100 degrees Celsius). This material has a large thermal conductivity, has fluidity at normal temperature, and can penetrate into very fine spaces. It can be used to reduce the size of two The thermal contact resistance between different materials. 200510108394.3 discloses a method of using liquid metal to cool an integrated chip. This method is mainly aimed at heat dissipation of the integrated chip, and the thermal resistance is reduced by adding liquid metal between two thermal interfaces. The heat dissipation problem of the LED chip to be solved by the utility model is different from that of the integrated chip in that the LED chip must be installed on a package substrate with a specific structure, and the package substrate is provided with lead wires of the LED chip, optical reflection devices and fluorescent adhesive layers. The contact thermal resistance between the mounting device, the package substrate and the heat sink is the main problem to be solved. The utility model makes full use of the characteristics of the LED packaging substrate, changes the form of the contact surface between the packaging substrate and the radiator, and makes the two contact surfaces form a concave-convex surface that engages with each other, greatly increasing the contact area between the two, and at the same time using the liquid The permeability and fluidity of the metal fill the gap between the two contact surfaces with liquid metal, and use the high thermal conductivity of liquid metal to improve the heat dissipation between the package substrate and the heat sink. This method can fundamentally solve the problem of packaging substrate and heat sink. The problem of excessive contact thermal resistance.

Contents of the invention

The purpose of the utility model is to overcome the deficiencies of the prior art and provide a high-power LED light source utilizing room temperature liquid metal to conduct heat.

A high-power LED light source that uses room temperature liquid metal to conduct heat includes an LED chip, a concave packaging substrate, a room temperature liquid metal layer, a sealing layer, a heat sink, and a fluorescent adhesive layer; the LED chip is installed on the concave packaging substrate, and the concave packaging substrate There is an optical reflective surface on the LED chip, and the LED chip is covered with a fluorescent glue layer. The concave packaging substrate is installed on the radiator. There is a gap between the concave packaging substrate and the radiator, which is sealed by a sealing layer. The gap is filled with room temperature liquid metal layer filled.

A high-power LED light source that uses room temperature liquid metal to conduct heat includes LED chips, plate-shaped packaging substrates, room-temperature liquid metal layers, sealing layers, heat sinks, and fluorescent adhesive layers; LED chips are installed on plate-shaped packaging substrates, covered with LED chips There is a fluorescent adhesive layer, and the plate-shaped package substrate is installed on the radiator. There is a gap between the plate-shaped package substrate and the radiator, which is sealed by a sealing layer. The gap is filled with a room temperature liquid metal layer. The gap between the plate-shaped package substrate and the radiator There is a concave-convex structure between them.

A high-power LED light source that utilizes room temperature liquid metal to conduct heat includes LED chips, bowl-shaped packaging substrates, room temperature liquid metal layers, sealing layers, heat sinks, and fluorescent adhesive layers; LED chips are installed on bowl-shaped packaging substrates, and bowl-shaped packaging substrates There is an optical reflective surface on the top, and the LED chip is covered with a fluorescent glue layer. The bowl-shaped packaging substrate is installed on the radiator. There is a gap between the bowl-shaped packaging substrate and the radiator, which is sealed by a sealing layer. The gap is filled with room temperature liquid metal. The layer is full, and a concave-convex structure is provided between the bowl-shaped package substrate and the heat sink.

The concave-convex structure is a strip-shaped or dot-shaped protrusion or a concave surface with a square, trapezoidal, triangular, or circular cross section.

The room temperature liquid metal layer is a metal or alloy that is liquid below 100 degrees Celsius, and includes at least one of the following elements: gallium, indium, zinc, tin, magnesium, copper or gold.

The radiator is a finned radiator or a heat pipe radiator.

The sealing layer is a thin layer made of silica gel or epoxy resin material.

The utility model makes full use of the characteristics of the LED packaging substrate, changes the form of the contact surface between the packaging substrate and the radiator, and makes the two contact surfaces form a concave-convex surface that engages with each other, greatly increasing the contact area between the two, and at the same time using the liquid The permeability and fluidity of the metal fill the gap between the two contact surfaces with liquid metal, and use the high thermal conductivity of liquid metal to improve the heat dissipation between the package substrate and the heat sink. This method can fundamentally solve the problem of packaging substrate and heat sink. The problem of excessive contact thermal resistance. The advantage of this method is that liquid metal at room temperature is a metal that is liquid below 100 degrees Celsius, such as gallium, etc. These metals have a very large thermal conductivity, which is dozens to hundreds of times that of ordinary silica gel. Filling this material between the packaging substrate and the heat sink will greatly reduce the thermal resistance drop of the heat generated by the LED chip through the packaging substrate to the heat sink. In addition, the liquid metal will also generate convection in the gap. heat, further enhancing the cooling effect. The effect of this method is equivalent to completely merging the package substrate and heat sink together. This fusion is different from soldering or silver glue bonding between the package substrate and the heat sink, and can effectively avoid stress and deformation problems caused by soldering and bonding between the two. In order to further increase the heat dissipation area between the package substrate and the heat sink, many concave-convex structures are arranged on the two surfaces where the package substrate and the heat sink meet. Excellent heat transfer effect, transmits a large amount of heat generated by the LED chip, and ensures that the junction temperature of the LED chip is kept at a low level, thereby improving the operational reliability and service life of the high-power LED.

Description of drawings

Figure 1 is a schematic diagram of a type I structure of a high-power LED light source that uses room temperature liquid metal to conduct heat;

Figure 2 is a schematic diagram of the type II structure of a high-power LED light source that uses room temperature liquid metal to conduct heat;

Figure 3 is a schematic diagram of a type III structure of a high-power LED light source using room temperature liquid metal for heat conduction;

Fig. 4 is a schematic structural diagram of a high-power LED light source of a multi-chip array.

Fig. 5 is a schematic diagram of a package substrate with a frustum-shaped protrusion;

In the figure: LED chip 1, concave packaging substrate 2, room temperature liquid metal layer 3, sealing layer 4, heat sink 5, fluorescent adhesive layer 6, concave-convex structure 7, optical reflective surface 8, plate-shaped packaging substrate 9, bowl-shaped packaging The substrate 10 , the first LED chip 11 , the second LED chip 12 , the third LED chip 13 , the fourth LED chip 14 , and the frustum-shaped protrusion 15 .

Detailed ways

The specific embodiment of the utility model will be described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1, a high-power LED light source utilizing room temperature liquid metal heat conduction includes an LED chip 1, a concave packaging substrate 2, a room temperature liquid metal layer 3, a sealing layer 4, a heat sink 5, and a fluorescent adhesive layer 6; the LED chip 1 is installed On the concave packaging substrate 2, the concave packaging substrate 2 is provided with an optical reflective surface 8, the LED chip 1 is covered with a fluorescent adhesive layer 6, the concave packaging substrate 2 is installed on the radiator 5, and the concave packaging substrate 2 and There are gaps between the radiators 5, which are sealed by the sealing layer 4, and the gaps are filled with the liquid metal layer 3 at room temperature. The room temperature liquid metal layer 3 is a metal or alloy that is liquid below 100 degrees Celsius, and includes at least one of the following elements: gallium, indium, zinc, tin, magnesium, copper or gold. The radiator 5 is a finned radiator or a heat pipe radiator. The sealing layer 4 is a thin layer made of silicone or epoxy resin material.

The light generated by the LED chip 1 is emitted through the fluorescent adhesive layer 6 , and most of the heat generated by the LED chip 1 is conducted to the radiator 5 through the concave packaging substrate 2 . The concave packaging substrate 2 and the heat sink 5 are generally made of metal with high thermal conductivity. However, the concave package substrate 2 and the radiator 5 rely on contact heat transfer, and due to machining accuracy, it is difficult to achieve good contact between the two surfaces, so the contact between the concave package substrate 2 and the radiator 5 The thermal resistance is very large. In order to reduce thermal contact resistance, a liquid metal layer 3 is added between the concave package substrate 2 and the heat sink 5 . The liquid metal is a metal or alloy that is liquid below 100 degrees Celsius and includes at least one of the following elements: gallium, indium, zinc, tin, magnesium, copper or gold. For example, metal gallium is a metal that can become liquid at 30 degrees Celsius. This liquid metal has a large thermal conductivity, good fluidity and wettability, and can completely penetrate into the concave package substrate 2 and the heat sink 5 in the gap between. In this way, the heat conducted from the concave package substrate 2 is conducted to the radiator 5 through the liquid metal layer 3 . This liquid metal has a very large thermal conductivity, which is dozens to hundreds of times that of ordinary silica gel. When this material is filled between the concave package substrate 2 and the heat sink 5, the heat generated by the LED chip 1 passes through the concave The thermal resistance drop conducted from the shape package substrate 2 to the heat sink 5 is greatly reduced. In addition, the liquid metal will also generate convective heat transfer in the gap, which further enhances the heat dissipation effect. The effect of this method is equivalent to completely merging the concave package substrate 2 and the heat sink 5 together. This fusion is different from soldering or silver glue bonding between the concave package substrate 2 and the heat sink 5 , and can effectively avoid stress and deformation problems caused by soldering and bonding between the two. Finally, in order to prevent the oxidation and loss of the liquid metal, a sealing layer 4 made of silica gel or epoxy resin material is provided around the liquid metal layer.

As shown in Figure 2, the high-power LED light source using room temperature liquid metal heat conduction includes LED chip 1, plate-shaped package substrate 9, room temperature liquid metal layer 3, sealing layer 4, heat sink 5, fluorescent glue layer 6; LED chip 1 is installed On the plate-shaped packaging substrate 9, the LED chip 1 is covered with a fluorescent glue layer 6, and the plate-shaped packaging substrate 9 is installed on the heat sink 5. There is a gap between the plate-shaped packaging substrate 9 and the heat sink 5, and the sealing layer 4 Sealed, the room temperature liquid metal layer 3 fills the gap, and a concave-convex structure 7 is provided between the plate-shaped package substrate 9 and the heat sink 5 . The concave-convex structure 7 is a strip-shaped or dot-shaped protrusion or a concave surface with a square, trapezoidal, triangular, or circular cross section. The room temperature liquid metal layer 3 is a metal or alloy that is liquid below 100 degrees Celsius, and includes at least one of the following elements: gallium, indium, zinc, tin, magnesium, copper or gold. The radiator 5 is a finned radiator or a heat pipe radiator. The sealing layer 4 is a thin layer made of silicone or epoxy resin material.

The plate-shaped packaging substrate 9 adopted in this structure is not provided with an optical reflective surface 8 . Different from the previous design in which the protruding part of the concave packaging substrate 2 is embedded in the heat sink 5 , this design directly installs the plate-shaped packaging substrate 9 on the heat sink 5 . In order to further increase the heat conduction area between the plate-shaped package substrate 9 and the heat sink 5, the two surfaces where the plate-shaped package substrate 9 and the heat sink 5 meet are provided with concave-convex structures 7, and these structures are interlocked together so that the plate-shaped package substrate 9 and radiator 5 have larger heat conduction area. Set the same concave-convex structure 7 on the heat sink 5 to match the shape of the plate-shaped packaging substrate 9, and then fill the gaps between the concave-convex structures 7 through the liquid metal layer, and realize heat conduction through the liquid metal to achieve better heat conduction effect. A large amount of heat generated by the LED chip is transmitted to ensure that the junction temperature of the LED chip is kept at a low level, thereby improving the operation reliability and service life of the high-power LED.

As shown in Figure 3, the high-power LED light source using room temperature liquid metal heat conduction includes LED chip 1, bowl-shaped package substrate 10, room temperature liquid metal layer 3, sealing layer 4, heat sink 5, fluorescent glue layer 6; LED chip 1 is installed On the bowl-shaped packaging substrate 10, the bowl-shaped packaging substrate 2 is provided with an optical reflective surface 8, the LED chip 1 is covered with a fluorescent glue layer 6, the bowl-shaped packaging substrate 10 is installed on the radiator 5, and the bowl-shaped packaging substrate 10 is connected to There is a gap between the radiators 5 and is sealed by the sealing layer 4 , the gap is filled with the room temperature liquid metal layer 3 , and a concave-convex structure 7 is provided between the bowl-shaped package substrate 10 and the radiator 5 . The concave-convex structure 7 is a strip-shaped or dot-shaped protrusion or a concave surface with a square, trapezoidal, triangular, or circular cross section. The room temperature liquid metal layer 3 is a metal or alloy that is liquid below 100 degrees Celsius, and includes at least one of the following elements: gallium, indium, zinc, tin, magnesium, copper or gold. The radiator 5 is a finned radiator or a heat pipe radiator. The sealing layer 4 is a thin layer made of silicone or epoxy resin material.

Figure 4 shows a room temperature liquid metal heat conduction high-power LED light source composed of LED chip arrays. Since the power of a single LED chip is not high, to achieve a higher power LED light source, it is necessary to arrange multiple LED chips in an array to achieve lighting. This array consists of LED chips arranged at certain intervals in a triangle, square or circle. The concave packaging substrate 2 is provided with a chip mounting structure according to the arrangement of the LED chips, a convex array is formed on the back of the concave packaging substrate 2 , and a concave array interlocking with each other is provided on the radiator 5 . The entire contact surface between the concave package substrate 2 and the heat sink 5 is filled with the liquid metal layer 3 . The figure shows that the first LED chip 11, the second LED chip 12, the third LED chip 13, and the fourth LED chip 14 are installed on the same packaging substrate, and the liquid metal layer 3 is filled in the concave packaging substrate 2 and the radiator. between 5. Figure 4 shows the LED chip array high-power LED light source realized by the structure in Figure 1, and the LED chip array high-power LED light source with the same function can also be realized by using the structure in Figure 2 and Figure 3.

FIG. 5 shows a package substrate with frustum-shaped protrusions. This packaging substrate is the concave packaging substrate 2 used in FIG. 4 , and there are many frustum-shaped protrusions 15 on the bottom of the concave packaging substrate 2 .

Claims (7)

1. a high-power LED light source that utilizes room temperature liquid metal heat conduction is characterized in that comprising led chip (1), spill base plate for packaging (2), room temperature liquid metal layer (3), sealant (4), radiator (5), fluorescence glue-line (6); Led chip (1) is installed on the spill base plate for packaging (2), spill base plate for packaging (2) is provided with optical reflection face (8), be coated with fluorescence glue-line (6) on the led chip (1), spill base plate for packaging (2) is installed on the radiator (5), has the space between spill base plate for packaging (2) and the radiator (5), and, be full of by room temperature liquid metal layer (3) in the space by sealant (4) sealing.

2. a high-power LED light source that utilizes room temperature liquid metal heat conduction is characterized in that comprising led chip (1), plate shape base plate for packaging (9), room temperature liquid metal layer (3), sealant (4), radiator (5), fluorescence glue-line (6); Led chip (1) is installed on the plate shape base plate for packaging (9), be coated with fluorescence glue-line (6) on the led chip (1), plate shape base plate for packaging (9) is installed on the radiator (5), has the space between plate shape base plate for packaging (9) and the radiator (5), and, be full of by room temperature liquid metal layer (3) in the space by sealant (4) sealing.

3. a kind of high-power LED light source that utilizes room temperature liquid metal heat conduction according to claim 2 is characterized in that being provided with concaveconvex structure (7) between described plate shape base plate for packaging (9) and the radiator (5).

4. a high-power LED light source that utilizes room temperature liquid metal heat conduction is characterized in that comprising led chip (1), bowl-type base plate for packaging (10), room temperature liquid metal layer (3), sealant (4), radiator (5), fluorescence glue-line (6); Led chip (1) is installed on the bowl-type base plate for packaging (10), bowl-type base plate for packaging (2) is provided with optical reflection face (8), be coated with fluorescence glue-line (6) on the led chip (1), bowl-type base plate for packaging (10) is installed on the radiator (5), has the space between bowl-type base plate for packaging (10) and the radiator (5), and, be full of by room temperature liquid metal layer (3) in the space by sealant (4) sealing.

5. a kind of high-power LED light source that utilizes room temperature liquid metal heat conduction according to claim 4 is characterized in that being provided with concaveconvex structure (7) between described bowl-type base plate for packaging (10) and the radiator (5).

4. according to claim 2 or 4 described a kind of high-power LED light sources that utilize room temperature liquid metal heat conduction, it is characterized in that described concaveconvex structure (7) is that the cross section is square, trapezoidal, triangle, circular strip or point-like protrusion or concave face.

5. according to claim 1,2 or 4 described a kind of high-power LED light sources that utilize room temperature liquid metal heat conduction, it is characterized in that described room temperature liquid metal layer (3) is a kind of liquid metal or alloy that just is rendered as, and comprises at least a of following element: gallium, indium, zinc, tin, magnesium, copper or gold below 100.

6. according to claim 1,2 or 4 described a kind of high-power LED light sources that utilize room temperature liquid metal heat conduction, it is characterized in that described radiator (5) is fin shape radiator or heat-pipe radiator.

7. according to claim 1,2 or 4 described a kind of high-power LED light sources that utilize room temperature liquid metal heat conduction, it is characterized in that described sealant (4) is the thin layer that is made of silica gel or epoxide resin material.

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