CN201766098U - A zero thermal resistance structure of high-power LED and heat sink and LED lamp - Google Patents

Abstract

The utility model relates to a zero thermal resistance structure of a high-power LED (light-emitting diode) and a radiator, and an LED lamp based on the zero thermal resistance structure. The zero thermal resistance structure of the high-power LED and the radiator comprises at least one high-power LED, a printed circuit board, and the radiator; the single surface of the printed circuit board is coated by copper insulated base; the printed circuit board is provided with a through hole used for installing the light-emitting diode; an LED electrode lead pin is welded on a conductive wire of the printed circuit board; the outer plane of the LED heat sink is parallel to and higher than the non-conductive layer plane of the printed circuit board; the printed circuit board is installed on the radiator through a fixing device; the assembly glue excluding the solid particles is arranged between the heat sink and the radiator, and is zero in thickness. The advantages are as follows: the thermal resistance from the LED heat sink to the radiator is near to zero; the heat conduction efficiency is high; the LED junction temperature is low; larger working current is used for reducing cost; the lighting efficiency is high; the service life is long; the process is simple; and the cost is low. The zero thermal resistance structure can be used for manufacturing various LED lighting devices.

Description

A zero thermal resistance structure of high-power LED and heat sink and LED lamp

technical field

The utility model relates to a structure of an LED and a radiator and an LED lamp, more specifically, relates to a zero thermal resistance structure of a high-power LED and a radiator, and an LED lamp based on the structure. the

Background technique

All the high-power LEDs in the prior art need to be equipped with appropriate heat sinks and good heat dissipation conditions in order to work normally. Due to the high power of the LED lighting device, the heat dissipation management of the system is one of the important links in the design of the lighting device. the

The heat dissipation system of the LED, from the chip to the heat sink of the LED, to the heat sink, and finally to the surrounding medium, such as air and water. Among them, the thermal connection from the heat sink of the LED to the heat sink is an important part. the

There are many structures of high-power LEDs in the prior art, such as those with high thermal conductivity alloys as heat sink bases, those with ceramic substrates as bases, those with chips mounted on metal-based circuit boards, those with lead pins, There are surface-mounted, single-chip, multi-chip, round bases, and rectangular bases, such as 3528, 5050, 9070, and so on. the

High-power LEDs all have a heat sink for thermal connection with the radiator. The thermal connection between the LED heat sink and the radiator in the prior art is usually to first connect the LED to a metal base circuit board (MPCB) with thermally conductive glue or solder. ), and then connected to the radiator with thermal adhesive or thermal film. In this way, from the heat sink of the LED to the heat sink, it needs to go through the first heat-conducting glue or flux, the dielectric layer of the aluminum-based or copper-based metal circuit board, the metal substrate and the second layer of heat-conducting glue, before reaching the heat sink. If the contact thermal resistance of each contact interface is ignored, the thermal resistance (Rtt) of the LED heat sink to the heat sink is the thermal resistance of the first thermal conductive adhesive and solder layer (Rt1), the thermal resistance of the metal-based circuit board dielectric layer (Rt2), The sum of the thermal resistance (Rt3) of the metal substrate and the thermal resistance (Rt4) of the second thermally conductive adhesive layer. The dielectric layer on the metal circuit board is usually an insulating layer such as epoxy or low-melting glass, and its thermal conductivity is very small, that is, the thermal resistance Rt2 is very large; the second thermally conductive adhesive layer between the metal substrate and the radiator, due to its large area, The thickness of the thermally conductive adhesive layer is often difficult to achieve very small, and there are often some air bubble layers that are basically insulated; if a thermally conductive film is used, not only the thermal conductivity of the thermally conductive film itself is much lower than that of metal, but also the two sides of the thermally conductive film and the heat sink There is often an air layer between the radiator and the heat sink, that is, the contact thermal resistance on the two sides cannot be ignored, which increases Rt4; at the same time, the flatness of the aluminum substrate is generally not good, which also increases the thermal resistance Rt4. In addition, in some current LED lighting devices, and even some brand-name products, in order to reduce costs, the above-mentioned metal-based circuit boards are replaced by ordinary epoxy circuit boards, and epoxy boards are insulating boards with very low thermal conductivity. The thermal conductivity is only about 1 W/mK, which is much lower than the 121-238 W/mK of aluminum and aluminum alloys, which greatly increases the thermal resistance Rtt between the heat sink and the radiator. In short, the prior art method for installing the LED to the heat sink has a large total thermal resistance Rtt, complicated process, high cost and poor consistency. the

The large thermal resistance Rtt from the LED heat sink to the radiator directly hinders the smooth conduction of a large amount of heat generated by the LED chip to the radiator when it is dissipated, resulting in an increase in the junction temperature of the chip, a decrease in the LED luminous efficiency, and a shortened service life. Poor performance and failure rate, luminous color shift, etc. Especially when using a chip and wanting to use a larger operating current to increase its power and reduce its cost, or to use more chips in the same package, reduce the thermal resistance from the LED heat sink to the heat sink Rtt is especially important. the

Contents of the invention

The purpose of this utility model is to solve the above problems, to provide a structure in which the thermal resistance Rtt of the high-power LED heat sink to the radiator is close to zero, and an LED lamp with this structure. the

The technical scheme of the utility model is as follows:

A zero thermal resistance structure of high-power LED and heat sink, including LED, PCB, and heat sink. The PCB is a single-sided copper-clad insulating base PCB. The PCB has through holes for installing LEDs, and the LED electrode leads are welded on the On the conductive line of the PCB, the outer plane of the heat sink of the LED is parallel to the non-conductive layer of the PCB and higher than the non-conductive layer of the PCB. The PCB is installed on the radiator through a fixing device, and the heat sink is located between the radiator and the PCB. between.

As a preference, glue is dripped on the heat sink. the

Preferably, the adhesive does not contain solid particles. the

As a preference, the adhesive glue can be silica gel, epoxy resin glue or plastic glue. the

Preferably, the fixing means are screw holes and screws. the

Preferably, the height difference between the outer plane of the heat sink and the non-conductive layer of the PCB is 0.05-5 mm. the

Preferably, the single-sided copper-clad insulation-based PCB is an epoxy-based or paper-based or glass fiber-based PCB. the

An LED lamp with a zero thermal resistance structure based on the above-mentioned high-power LED and radiator, including LED, PCB, and radiator. The PCB is a single-sided copper-clad insulating base PCB, and the PCB has through holes for installing LEDs. The lead-out pins of the LED electrodes are welded on the conductive wires of the PCB. The outer plane of the heat sink of the LED is parallel to the non-conductive layer of the PCB and higher than the non-conductive layer of the PCB. The PCB is installed on the radiator through a fixing device, and the heat sink The sink is located between the radiator and the PCB; it also includes a light-transmitting bulb, an electrical connector, and a driver for the LED, and the driver is placed in the central cavity and the electrical connector of the radiator; The connectors are connected to external power supply; the output of the driver is connected to the electrodes of the LED through the leads. the

Preferably, adhesive glue is dripped on the heat sink, and the adhesive glue does not contain solid particles, and can be silica gel, epoxy resin glue or plastic glue; the fixing device is a screw hole and a screw. the

Preferably, the height difference between the outer plane of the heat sink and the non-conductive layer of the PCB is 0.05-5 mm. the

The beneficial effects of the utility model are as follows:

Compared with the prior art, the utility model has the advantages that the thermal resistance from the LED heat sink to the radiator is close to zero, the heat conduction efficiency is high, the LED junction temperature is low, a larger working current can be used to reduce costs, the luminous efficiency is high, the service life is long, and the process is simple , low cost and other advantages, can be used to manufacture various LED lighting devices.

Description of drawings

Fig. 1 is a structural schematic diagram of a high-power LED and a heat sink in the prior art. the

Fig. 2 is a structural schematic diagram of an embodiment of a zero thermal resistance structure of a high-power LED and a radiator. the

Fig. 3 is a structural schematic diagram of an embodiment of an LED lamp based on a zero thermal resistance structure of a high-power LED and a radiator. the

In the figure: 1. LED; 2. Chip; 3. Silicon substrate; 4. Flux; 5. Heat sink; 6. Lens; 7. Electrode leads; 8. MPCB (metal-based circuit board); 9. Metal substrate; 10. Dielectric layer; 11. Conductive layer; 11a. Conductive layer for fixing LED; 12. Radiator; 13. Thermally conductive adhesive; 14. Solder; 15. Thermally conductive adhesive; 16. PCB; 17. Insulating substrate; 18. Conductive layer ;19, the through hole for placing LED on the PCB; 20, the screw hole; 21, the outer plane of the heat sink; 22, the non-conductive layer of the PCB; 23, the adhesive; 24, the mounting surface of the radiator; 25, the screw; 26. Adhesive glue layer between heat sink and radiator; 27. LED lamp; 28. Light-transmitting bulb; 30. Electrical connector; 31. Driver; 32. Central cavity of the driver; 33. Lead wire; 34. Lead wire; D, height difference. the

Detailed ways

Below in conjunction with accompanying drawing the embodiment of the present utility model is described in further detail:

The prior art high-power LED and heat sink installation structure shown in Figure 1, LED1 in Figure 1 is one of the existing high-power LEDs in various packaging forms, such as Luxeon emitter LED, its LED chip 2 is Flip-chip on a piece of silicon substrate 3, and then use solder 4 to install the silicon substrate 3 on a heat sink 5 made of an alloy with high thermal conductivity, and the lens 6 of the LED1 is covered on the LED chip 2. LED 1 is fixed on the conductive layer 11a of the fixed LED of MPCB8 with thermally conductive glue or solder 13, and the lead pin 7 of LED1 is welded on the conductive layer 11 of MPCB 8 with solder 14; MPCB 8 is used thermally conductive glue or thermally conductive film 15 fixed on the radiator 12.

It can be seen from Figure 1 that the thermal resistance (Rtt) from the heat sink 5 of LED1 to the heat sink 12 is the thermal resistance (Rt1) of the first thermal conductive glue and solder layer 13, the thermal resistance (Rt2) of the dielectric layer 10 of MPCB8, the metal The sum of the thermal resistance (Rt3) of the substrate 9 and the thermal resistance (Rt4) of the second thermally conductive adhesive layer 15. The dielectric layer 10 on the MPCB8 is usually an insulating layer such as epoxy or low-melting glass, and its thermal conductivity is very small, that is, the thermal resistance Rt2 is very large; Large, the thickness of the thermally conductive adhesive layer 15 is often difficult to be very small, and there are often some basically heat-insulating air bubble layers; There is often an air layer between the surface and the heat sink 5 and the radiator 12, that is, the contact thermal resistance of the two surfaces cannot be ignored, which increases Rt4; meanwhile, the area of the metal substrate 9 is large and the flatness of its plane is large. Generally not good, which also increases the thermal resistance Rt4. the

In addition, in some current LED lighting devices, in order to reduce costs, the above-mentioned MPCB8 is replaced by a common epoxy circuit board, and the epoxy board is an insulating board with a very low thermal conductivity, and its thermal conductivity is only about 1 W/mK. It is much lower than 121-238 W/mK of aluminum and aluminum alloy, which greatly increases the thermal resistance Rtt between the heat sink 5 and the radiator 12. the

The utility model is like this:

A zero thermal resistance structure of a high-power LED and a heat sink, comprising at least one high-power LED1, a PCB16, and a heat sink 12, characterized in that the PCB16 is a single-sided copper-clad insulating base PCB, and the PCB16 is used to install the LED1 The through hole 19, the LED1 electrode pin 7 is welded on the conductive wire 18 of the PCB16, the outer plane 21 of the heat sink 5 of the LED1 is parallel to the non-conductive layer 22 of the PCB16, and is higher than the non-conductive layer 22 of the PCB16, the PCB16 It is installed on the heat sink 12 through the fixing device, and there is adhesive glue (23) between the heat sink (5) and the heat sink (12), and its thickness is close to zero.

The adhesive 23 does not contain solid particles. the

The bonding glue 23 can be silica gel, epoxy resin glue or plastic glue. the

Described fixing device is screw hole 20 and screw 25. the

The height difference D between the outer plane 21 of the heat sink 5 and the non-conductive layer 22 of the PCB 16 is 0.05-5 mm. the

The single-sided copper-clad insulating base PCB 16 is epoxy-based or paper-based or glass fiber-based PCB. the

An LED lamp with zero thermal resistance structure based on the above-mentioned high-power LED and radiator, comprising at least one high-power LED1, PCB16, and radiator 12, the PCB16 is a single-sided copper-clad insulating base PCB, and the PCB16 is useful for installation The through hole 19 of the LED1, the lead pin 7 of the LED1 electrode is welded on the conductive wire 18 of the PCB16, the outer plane 21 of the heat sink 5 of the LED1 is parallel to the non-conductive layer 22 of the PCB16, and is higher than the non-conductive layer 22 of the PCB16. The PCB 16 is installed on the heat sink 12 through a fixing device, and there is an adhesive (23) between the heat sink (5) and the heat sink (12), and its thickness is close to zero; it also includes a light-transmitting bulb 28, an electrical connector 30. LED driver 31, said driver 31 is arranged in the central cavity 32 of radiator 12 and electrical connector 30; the input of driver 31 is connected with electrical connector 30 through lead wire 33, and is used for connecting external power supply; The output of the driver 31 is connected to the electrode of the LED1 via the lead wire 34 . the

Adhesive glue 23 is dripped on the heat sink 5, and the adhesive glue 23 does not contain solid particles, and can be silica gel or epoxy resin glue or plastic glue; the described fixing device is a screw hole 20 and a screw 25. the

The height difference D between the outer plane 21 of the heat sink 5 and the non-conductive layer 22 of the PCB 16 is 0.05-5 mm. the

Example 1

An embodiment of the zero thermal resistance structure of the high-power LED and radiator of the present invention shown in Fig. 2 is the example of Luxeon emitter LED, and the insulating substrate 17 of PCB16 can be epoxy substrate, paper substrate, glass fiber Substrate, etc., on the PCB 16 there are through holes 19 equal to the number of LED1 to arrange the LED1 and at least one screw hole 20 for fixing the PCB16, the LED 1 is arranged in the through hole 19, and the electrode lead-out pin 7 of the LED 1 is Soldered on the conductive layer 18 of the PCB 16, the outer plane 21 of the heat sink 5 of the LED 1 is parallel to the non-conductive layer side 22 of the PCB 16, but the outer plane 21 of the heat sink 5 is higher than the non-conductive layer 22 of the PCB, and the height difference is D It is 0.05-5mm.

During installation, put adhesive glue 23 on the outer surface 21 of the heat sink 5 of each LED1, and then put the glued side on the mounting surface 24 of the heat sink 12, and then use screws 25 to connect the PCB 16 to the heat sink. Device 12 is compressed and fixed. the

The adhesive 23 can be silica gel, epoxy resin glue, plastic glue, etc. They have good fluidity before curing, and the glue does not contain solid particles. If the outer surface 21 of the heat sink and the mounting surface 24 of the radiator 12 are If it is flat enough, under the pressure of the screw 25 and the PCB 16, the bonding glue 23 is automatically extruded from between the heat sink 5 and the radiator mounting surface 24, and the thickness of the bonding glue layer 26 therebetween is easily close to zero. We know that the thermal resistance is proportional to the thickness of the heat conducting layer, and the thickness of the adhesive layer 26 is close to zero, that is, its thermal resistance is close to zero, that is, the thermal resistance Rtt between the heat sink 5 and the heat sink 12 of the LED1 is close to Zero, the thickness is between 0 and 0.1mm. the

The heat sink 12 can be equipped with one or more LEDs 1, and the height difference D between the outer plane 21 of the heat sink 5 of each LED1 and the non-conductive layer 22 of the PCB is equal. For this reason, when installing and welding the LED1, use a At the heat sink 5 of the LED1, there is a groove template whose depth is consistent with the height difference D, so that the height difference D and its consistency can be guaranteed. the

Each high-power LED 1 can include one or more LED chips 2. the

The zero thermal resistance structure of the high-power LED of the utility model is suitable for various high-power LED lighting devices. the

Example 2

An embodiment of an LED lamp based on a high-power LED and a heat sink with a zero thermal resistance structure shown in FIG. A light-transmitting bulb 28, a radiator 12, an electrical connector 30, and a driver 31 of an LED; the driver 31 is placed in the central cavity 32 and the electrical connector 30 of the radiator 12; the input of the driver It is connected to the electrical connector 30 through the lead wire 33 and is used for connecting to an external power supply; the output of the driver is connected to the electrode of the LED1 through the lead wire 34 . Turn on the external power supply to light up LED1.

The structure of each LED1 and radiator 12 is all the same as that of embodiment 2, and PCB 16 is installed on radiator 12 with at least one screw 25. the

Heat sink 12 may have a series of fins. the

What is described above is only the preferred embodiment of the present utility model. It should be pointed out that for those of ordinary skill in the art, some improvements and modifications can be made without departing from the core technical features of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. the

Claims (9)

1. the zero thermal resistance structure of great power LED and radiator, comprise at least one great power LED (1), PCB(16), radiator (12), it is characterized in that, described PCB(16) covers the copper basic PCB that insulate for single face, PCB(16) be useful on LED(1 is installed) through hole (19), LED(1) electrode leading foot (7) is welded on PCB(16) conductor wire (18) on, the outerplanar (21) and the PCB(16 of LED(1) heat sink (5)) no conductor planes (22) parallel, and exceed PCB(16) no conductor planes (22), described PCB(16) is installed on the radiator (12) by fixture, between heat sink (5) and the radiator (12) adhesive glue (23) is arranged, its thickness is close to zero.

2. the zero thermal resistance structure of great power LED according to claim 1 and radiator is characterized in that described adhesive glue (23) does not contain solid particle.

3. the zero thermal resistance structure of great power LED according to claim 2 and radiator is characterized in that, described adhesive glue (23) can be silica gel or epoxide-resin glue or plastic cement.

4. the zero thermal resistance structure of great power LED according to claim 1 and radiator is characterized in that, described fixture is screw hole (20) and screw (25).

5. the zero thermal resistance structure of great power LED according to claim 1 and radiator is characterized in that, the difference in height (D) of outerplanar of described heat sink (5) (21) and no conductor planes (22) PCB(16) is 0.05-5mm.

6. the zero thermal resistance structure of great power LED according to claim 1 and radiator is characterized in that, described single face covers the copper basic PCB(16 that insulate) be epoxy radicals or papery base or glass base PCB.

7. LED lamp based on the zero thermal resistance structure of described great power LED of claim 1 and radiator, comprise at least one great power LED (1), PCB(16), radiator (12), it is characterized in that, described PCB(16) covers the copper basic PCB that insulate for single face, PCB(16) be useful on LED(1 is installed) through hole (19), LED(1) electrode leading foot (7) is welded on PCB(16) conductor wire (18) on, the outerplanar (21) and the PCB(16 of LED(1) heat sink (5)) no conductor planes (22) parallel, and exceed PCB(16) no conductor planes (22), described PCB(16) is installed on the radiator (12) by fixture, between heat sink (5) of LED and the radiator (12) adhesive glue (23) is arranged, its thickness is close to zero; The driver (31) that also comprises printing opacity cell-shell (28), electric connector (30), LED, described driver (31) are positioned in the cavity (32) and electric connector (30) of central authorities of radiator (12); The input of driver (31) links to each other with electric connector (30) through lead-in wire (33), is used to connect external power; The output of driver (31) through the lead-in wire (34) and LED(1) electrode be connected.

8. the LED lamp of the zero thermal resistance structure of great power LED according to claim 7 and radiator, it is characterized in that, described heat sink (5) are gone up to drip and are placed with adhesive glue (23), and described adhesive glue (23) does not contain solid particle, can be silica gel or epoxide-resin glue or plastic cement; Described fixture is screw hole (20) and screw (25).

9. the LED lamp of the zero thermal resistance structure of great power LED according to claim 8 and radiator is characterized in that, the difference in height (D) of outerplanar of described heat sink (5) (21) and no conductor planes (22) PCB(16) is 0.05-5mm.

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