KR20080018035A - Board for an electronic parts and lighting unit included the board - Google Patents

Abstract

A board for electronic parts and a lighting unit including the board and an electronic device including the lighting unit are provided to maximize heat dissipation efficiency by adding a new heat dissipation unit. A graphite sheet(18) diffuses heat. A printed circuit board(14) is stacked on the graphite sheet, and has a through-hole(20) at the position where electronic parts corresponding to heat sources are mounted. Thermal conductive materials(12) are located in the through-hole and transfer heat to the graphite sheet by contacting with the heat sources. An insulator(16) is formed between the thermal conductive members and the graphite sheet.

Description

Substrate for electronic components, a lighting unit including the same, and an electronic device including the lighting unit {BOARD FOR AN ELECTRONIC PARTS AND LIGHTING UNIT INCLUDED THE BOARD}

1 is an exemplary cross-sectional view of an LED substrate as an electronic component substrate and a lighting unit including the same according to an embodiment of the present invention.

2 is an exemplary cross-sectional view of an LED substrate as an electronic component substrate and a lighting unit including the same according to another embodiment of the present invention.

3 is an exemplary cross-sectional view of an LED substrate as an electronic component substrate and an illumination unit including the same according to another embodiment of the present invention.

4 is an exemplary cross-sectional view of an LED substrate as an electronic component substrate and an illumination unit including the same according to another embodiment of the present invention.

5 to 8 also illustrate a cross-sectional view of an LED substrate as an electronic component substrate and a lighting unit including the same according to another embodiment of the present invention.

9 to 16 are views for explaining the structural change of the substrate for an electronic component according to another embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate for an electronic component and a lighting unit including the same, and more particularly, to a technique for efficiently dissipating heat generated by an electronic component to dissipate heat.

The industry is designing parts, modules, and sets in consideration of high efficiency, high integration, high performance, and light and small size reduction. When designers in each field design to satisfy the above-mentioned technical trends, more heat is generated than heat generated in the conventional design technology. In particular, the heat generated from various panels in the display field and the BLU (Back Light Unit) of the LCD greatly affects the picture quality, and the phenomenon becomes more remarkable as the HD resolution and the size of the screen increase. In other words, the industry has taken this seriously. As a result, the industry continues to research to efficiently deal with thermal problems (ie heat dissipation, heat diffusion, heat dissipation, heat collection, heat transfer, etc.).

There is a method using a metal PCB as a way to solve the thermal problem. That is, by using a metal material on the substrate on which electronic components corresponding to the heat source are mounted, the heat of the heat source is effectively diffused and radiated. However, since metal PCB is more expensive than a general printed circuit board, there is a limit in lowering a unit cost of a product, and there is a problem that its application is limited due to hard physical characteristics. In addition, thermal conductivity (surface direction: 80-450W / mk, thickness direction: 3-7W / mk) is lower than that of graphite sheet, which is known as a heat diffusion material. Therefore, there is a limit in improving the heat diffusion efficiency.

The present invention is derived from the recognition of such a problem, the structure is simple and can be manufactured at low cost and at the same time add a new heat dissipation means to maximize the heat dissipation efficiency, the substrate for an electronic component and the lighting unit including the same and the electronics including the unit To provide the device,

Furthermore, another object of the present invention is to provide a substrate for an electronic component capable of absorbing and diffusing heat of a heat source more quickly by adopting a graphite sheet having quasi-isotropy excellent heat transfer characteristics in the surface direction as well as in the thickness direction. It provides a lighting unit including, and an electronic device including the lighting unit.

An electronic component substrate according to an embodiment of the present invention for achieving the above object,

A graphite sheet for diffusing heat;

A printed circuit board stacked on the graphite sheet and having a through hole formed at a position where electronic components corresponding to a heat source are mounted;

Thermally conductive members positioned in the through hole and having one end contacting a heat source to conduct heat to the graphite sheet;

And an insulator layer between the thermally conductive members and the graphite sheet.

According to the above-described structural features, since the graphite sheet, which is a heat diffusion sheet, is attached to the substrate for an electronic component itself, the heat dissipation efficiency can be improved more than a system employing a heat diffusion sheet outside the casing or a system using a metal PCB. There is

Since the rigid circuit board is adopted, there is an advantage that it can be manufactured at a lower cost than a substrate using a conductive thin film and a substrate using a metal PCB.

In addition, since the heat conductive member directly absorbs the heat of the heat source and conducts the heat diffusion sheet, excellent heat dissipation efficiency can be obtained.

Meanwhile, the lighting unit according to another embodiment of the present invention,

Casing;

A graphite sheet for diffusing heat in contact with the inner surface of the casing, a printed circuit board stacked on the graphite sheet, a pattern for supplying an electrical signal to each LED, and a through hole formed at a position where each LED is mounted; A thermally conductive member positioned in the through hole and having one end thereof in contact with the LED heat sink disposed on the printed circuit board to conduct heat to the graphite sheet; and an insulator layer between the thermally conductive members and the graphite sheet. A plurality of LED substrates;

And a plurality of LEDs which receive electric signals from the printed circuit board and emit light.

Since the lighting unit also attaches a graphite sheet, which is a heat diffusion sheet, to the LED substrate itself, there is an effect of improving heat dissipation efficiency than a lighting unit employing a heat diffusion sheet outside the casing.

In addition, since the heat conductive member directly absorbs the heat of the heat source and conducts the heat diffusion sheet, excellent heat dissipation efficiency can be obtained.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, for convenience of description, the LED substrate used for the BLU will be replaced with an electronic component substrate.

1 is a cross-sectional view illustrating an LED substrate and a lighting unit including the LED substrate according to the first embodiment of the present invention. More specifically, (a) illustrates a state in which the LED substrate is cross-sectional processed. , (b) shows a cross section of the LED substrate coupled to the casing (C).

As shown in FIG. 1, an LED substrate according to an embodiment of the present invention is laminated on a graphite sheet 18 for diffusing heat and the graphite sheet 18 to supply an electrical signal to each LED 10. And a printed circuit board 14 having a through hole 20 formed at a position where each LED 10 is mounted, and one end of the printed circuit board 14 located in the through hole 20. Thermally conductive members 12 that are in contact with the LED heat sink 22 positioned to conduct heat to the graphite sheet 18 and between the thermally conductive members 12 and the graphite sheet 18. An insulator layer 16 for disconnecting the connection.

For reference, the graphite sheet (also referred to as 18: GPS) is formed in a sheet state by rolling graphite with a force of flake structure. Such graphite sheet 18 is usually made so that the thermal anisotropy coefficient is 20 to 30, and has the characteristics of a high anisotropic graphite sheet. The thermal properties of the highly anisotropic graphite sheet have high thermal conductivity in the plane direction but low thermal conductivity in the thickness direction (heat source and horizontal direction) as close as 20: 1 to 50: 1. For this reason, when the highly anisotropic graphite sheet is applied to a large-area display device, there is a limit in effectively dissipating and removing heat generated from the center of the display. Therefore, by increasing the heat conductivity in the heat source and the horizontal direction, that is, the heat direction in the thickness direction, the heat generated from the heat source can be rapidly absorbed and diffused, thereby reducing the difference in heat diffusion between the center of the display and the outer portion. As described above, in order to increase the thermal conductivity in the thickness direction, a graphite sheet having quasi anisotropy of 3 to 20 may be used.

For reference, the semi-anisotropic graphite sheet having a thermal anisotropy coefficient of 3 to 20 is preferably 30-150 mesh, preferably 30-100 mesh natural graphite, for example, a mixed solution of high concentration nitric acid and sulfuric acid (90% sulfuric acid by volume ratio). Dilute 10% nitric acid solution) with distilled water so that the normal concentration of sulfuric acid (first solution) is 0.3-1.5, low concentration intercalate solution, and advantageously about 5 parts per 100 parts by weight of natural graphite. Intercalate by dispersing at 300 parts by weight.

After draining and rinsing the excess solution from the intercalated natural graphite, the washed natural side edges are exposed to increased temperature (above 700 ° C-1000 ° C), and the intercalated graphite particles are in the original volume in the c-direction. It expands 20-80 times to form worm-shaped low-expansion graphite particles. Compression rolling molding the expanded graphite in this manner produces a semi-anisotropic graphite sheet having a thermal anisotropy coefficient of 3 to 20.

On the other hand, the printed circuit board 14 having a pattern for supplying an electrical signal to the LED 10 is more preferably using a rigid printed circuit board for low cost implementation of the product. As is known, the bottom of the printed circuit board 14 is insulated.

The thermally conductive member 12 that absorbs heat from the heat sink 22 of each LED 10 and transfers it to the graphite sheet 18 may be made of all conductive pastes and powders such as gold paste, silver paste, lead paste, and the like. It may also be made of metals such as gold, silver, copper, aluminum and copper. In some cases, it may be made of a conductive tape or a copper foil film. Since these thermally conductive members 12 are mostly electrically conductive, direct contact with the graphite sheet 18 causes a short circuit of adjacent LEDs 10 in series connection relationship. In order to prevent such a phenomenon, the non-conductive layer 16 should be positioned between the thermally conductive members 12 and the graphite sheet 18.

The non-conductive layer 16 is located between one end of the thermally conductive member 12 and the graphite sheet 18, and may be coated on one end of the thermally conductive member 12, or a thermally conductive member. The coating may be formed only on a portion of the graphite sheet 18 in contact with (12).

The form in which the LED substrate having the above-described configuration is attached to the gap casing C of the display device (or the lighting unit) is shown in FIG. 1B. Referring to FIG. 1B, a graphite sheet 18 is adhered to the inner surface of the casing C, and a printed circuit board 14 is laminated on the graphite sheet 18. The thermally conductive member 12 is located in the through hole 20 formed in the printed circuit board 14 stacked on the graphite sheet 18. One end or the skin layer of the thermally conductive member 12 is Since it is coated with an insulator layer, it is possible to prevent the adjacent LEDs 10 from being electrically shorted by the graphite sheet 18.

Therefore, the heat generated from the heat sink 22 of the LED 10 as a heat source is transferred to the graphite sheet 18 directly through the thermal conductive member 12, so that the heat diffusion can obtain an excellent heat dissipation effect, furthermore, the present invention It is possible to obtain even more excellent heat dissipation effect by using the graphite sheet having quasi-anisotropy property that thermal diffusion is performed not only in the surface direction but also in the thickness direction.

In addition, since a rigid printed circuit board is used instead of a conductive thin film such as FPCB, a low-cost LED substrate can be provided.

Meanwhile, FIG. 2 illustrates a cross-sectional view of an LED substrate and a lighting unit including the same according to another embodiment of the present invention. Compared with FIG. 1, thermally conductive members 26 are extended to be inserted into the graphite sheet 18. Except for that, it has the same structure and material properties as those mentioned in FIG. 1. For reference, in FIG. 2, the insulator layer 16 is coated on the skin of the thermally conductive member 26. Since the LED substrate having such a structure is a structure in which the thermally conductive member 26 is inserted into the graphite sheet 18, the heat dissipation effect will be excellent due to the increase in contact surface than the structure shown in FIG. 1.

3 illustrates a cross-sectional view of an LED substrate and a lighting unit including the same according to another embodiment of the present invention. Compared to FIG. 1, the thermally conductive members 28 penetrate the graphite sheet 18 to the outside. It extends to be drawn out, but has the same structure and material properties as those of FIG. 1 except that a thread is formed at the end thereof. In some cases, the thermally conductive member 28 extends to be pulled out of the casing C as well as the graphite sheet 18 for attaching the casing of the LED substrate, but has a threaded thermal conductive member for screwing at the end thereof. 28) may be considered. Of course, the skin of each thermally conductive member 28 must be coated with a non-conductive layer to prevent electrical shorts of adjacent LEDs.

3, the heat generated from the heat sink 22 of the LED 10 is transferred to the graphite sheet 18 directly through the thermally conductive member 28 and thermally diffused. It is possible to obtain excellent heat dissipation effect, and furthermore, it is possible to obtain even more excellent heat dissipation effect by using the graphite sheet having quasi anisotropy property in which heat diffusion is well performed not only in the surface direction but also in the thickness direction.

4 illustrates a cross-sectional view of an LED substrate and a lighting unit including the same according to another embodiment of the present invention, and has the same structure as that of FIG. 1 except for the thermally conductive member 32 when compared with FIG. 1.

The thermally conductive member 32 shown in FIG. 4 is a flat plate, on which a plurality of protrusions 34 penetrating the graphite sheet 18 and the printed circuit board 14 to contact each LED heat sink 22. Formed. The outer surface of the thermally conductive member 32 is also coated with an insulator layer to insulate the graphite sheet 18. The contact surface of the thermally conductive member 32 and the graphite sheet 18 shown in FIG. 4 is relatively wider than the LED substrate shown in FIG. Therefore, it can be said that the shape of the thermally conductive member 32 shown in FIG. 4 is for obtaining an excellent heat dissipation effect. For reference, the thermally conductive member 32 may be a metal material.

5 also illustrates a cross-sectional view of an LED substrate and a lighting unit including the same according to another embodiment of the present invention. Except for the thermally conductive member 36, the LED substrate illustrated in FIG. 5 has the same configuration and material properties as those of the above-described embodiments.

In FIG. 5, the thermally conductive members 36 extend to be inserted into the graphite sheet 18, and a screw groove that can be screwed from the outside is formed therein. This facilitates the attachment between the LED casing and the gap casing C of the display device, as well as directly transferring the heat of the heat source to the graphite sheet 18. The skin of this thermally conductive member 36 should also be coated with a non-conductive layer.

6 also illustrates a cross-sectional view of an LED substrate and a lighting unit including the same according to another embodiment of the present invention.

Referring to FIG. 6, an LED substrate according to another embodiment of the present invention is laminated on a graphite sheet 18 for diffusing heat and the graphite sheet 18, and supplies an electrical signal to each LED 10. And a printed circuit board 14 having a through hole 20 formed at a position where each LED 10 is mounted, and inserted into the through hole 20 of the printed circuit board 14. And a heat conductive member 40 having a protrusion 42 contacting the heat sink 22 and a plurality of heat radiation fins 44. These thermally conductive members 40 conduct heat to the adjacent graphite sheet 18 as a heat sink. Of course, the contact surface between the thermally conductive member 40 and the graphite sheet 18 is coated with an insulator layer.

The form in which the LED substrate having the configuration as described above is attached to the gap casing C of the display device is shown in FIG. Referring to FIG. 6B, the casing structure C of the display apparatus may have a casing structure in which a plurality of holes are formed so that the heat dissipation fin 44 of the thermal conductive member 40 is exposed to the atmosphere. . This is to obtain an excellent heat dissipation effect. That is, the heat generated from the heat dissipation plate 22 of the LED 10, which is a heat source, is directly transmitted to the graphite sheet 18 through the protrusion 42 and the body of the heat conductive member 40, and through the heat dissipation fin 44. Since it is diffused into the atmosphere, it is possible to expect better heat dissipation effect than any of the embodiments.

The LED substrate shown in FIG. 7 is also a variant of the thermally conductive member 40 shown in FIG. That is, the LED substrate shown in FIG. 7 also has a graphite sheet 18 for diffusing heat and a pattern for supplying an electrical signal to each LED 10 and stacked on the graphite sheet 18 and each LED 10. Is a printed circuit board 14 having through holes 20 formed thereon, and a protrusion 48 penetrating the printed circuit board 14 and the graphite sheet 18 to contact the LED heat sink 22. And thermally conductive members 46 on which a plurality of heat dissipation fins 50 are formed. This thermally conductive member 46 also serves to conduct heat to the adjacent graphite sheet 18 as a heat sink. Heat transmitted from the heat source is excellent in heat dissipation effect because it is transferred to the graphite sheet 18 through the protrusion 48 of the heat conductive member 46 as well as through the heat dissipation fin 50.

8 also illustrates a cross-sectional view of an LED substrate and a lighting unit including the same according to another embodiment of the present invention.

The LED substrate shown in FIG. 8 also has a graphite sheet 18 for diffusing heat, and a pattern for supplying an electrical signal to each LED 10 and mounted on the graphite sheet 18 and each LED 10 is mounted. The printed circuit board 14 having the through holes 20 formed thereon and stacked on the graphite sheet 18 is inserted into the through holes 20 of the printed circuit board 14 by pressing. A sliced copper foil film 52 is included. The fragmentary copper foil film 52 is in contact with the heat sink 22 of the LED 10 mounted on the printed circuit board 10 and serves to conduct heat to the graphite sheet 18. Of course, the skin of the sliced copper foil film 52 should also be coated with an insulator layer to prevent shorting of the LEDs 10.

The LED substrate having the above-described structure is not a structure for manufacturing a separate thermally conductive member and inserting the same into the printed circuit board 14, but simply placing the sliced copper foil film 52 on the graphite sheet 18 and printing the printed circuit thereon. Since the heat dissipation plate 22 of the LED can be brought into contact with the thermally conductive member only by applying a predetermined pressure after the substrate 14 is laminated, there will be advantages in that the substrate manufacturing process can be simplified.

It is also possible to maximize the heat dissipation effect by adding a separate thermal conductive member to each embodiment described above. For example, a thermally conductive member penetrating (or inserting) the printed circuit board 14 and the graphite sheet 18 between the LEDs 10 mounted on the printed circuit board 14 (column assembly position). Inserting, and forming a screw thread that can be coupled to the gap casing (C) of the display device at the end thereof can be obtained an efficient heat dissipation effect, as well as easy to fasten the LED substrate and the casing.

In the above embodiment, the structure of the LED substrate has been described to prevent adjacent LEDs from being electrically shorted through the insulator layer. Hereinafter will be described with respect to the LED substrate to prevent the electrical short circuit of adjacent LEDs by changing the structure of the graphite sheet.

9 and 10 are a plan view and a cross-sectional view for explaining the structure of the LED substrate according to another embodiment of the present invention, more specifically, adjacent LEDs through the mechanical deformation of the graphite sheet 62 Insulated.

9 and 10, the LED substrate according to the embodiment of the present invention is a printed circuit board having a through hole 64 is formed in a pattern for supplying an electrical signal to the LED and each LED is mounted ( 60) and thermally conductive members positioned in the through-holes 64 of the printed circuit board 60, the one end of which is in contact with the heat sink of the LED located on the printed circuit board 60 to conduct heat (reference number) 65) and a plurality of graphite fragments which are contacted to the other end of each of the thermally conductive members to diffuse heat, and are separated from each other and attached to the printed circuit board 60 to prevent electrical short circuits between adjacent LEDs. And (62).

That is, the LED substrate shown in FIGS. 9 and 10 is not a structure in which an insulator layer is formed between the graphite sheet and the thermally conductive member like the LED substrates shown in FIGS. 1 to 8, but the graphite fragments 62 are structurally formed. By spaced apart from each other to prevent electrical short circuit between adjacent LEDs. As such, when the graphite fragments 62 in contact with each of the LED heat sinks are spaced apart from each other, electrical short circuits between adjacent LEDs do not occur. 64 is to be transferred to the graphite fragments 62 to obtain a heat dissipation effect.

In the LED substrate having such a structure, the thermally conductive member 64 may be implemented in various forms as described with reference to FIGS. 1 to 8.

For example, the thermally conductive member 65 may be extended to be inserted into the graphite sheet 62 as shown in FIG. 11, and as shown in FIG. 12, the graphite sheet 62 and the printed circuit board may be formed. It may be a thermally conductive member having a protrusion formed to contact each of the LED heat sinks 22 through 60. Such a thermally conductive member may be a conductive paste, powder, metal, conductive tape, or copper foil films as described above. Either one may be used.

Furthermore, the thermally conductive member 65 may include a heat sink in which a protrusion 67 inserted into the through hole 64 of the printed circuit board 60 and a plurality of heat dissipation fins 68 are formed as shown in FIGS. 13A and 13B. The thermally conductive member 64 must be coated with a non-conductive layer on a part of the thermal conductive member 64 to prevent electrical short with the casing C contact surface of the display device.

Furthermore, the thermally conductive member 65 may be a fragmentary copper foil film laminated on the graphite sheet 62 and inserted into the through hole 64 of the printed circuit board 60 by pressing as shown in FIG. 14. It may be.

Meanwhile, in the LED substrates illustrated in FIGS. 9 to 14, since the graphite material, which is a heat diffusion sheet, is disposed on the printed circuit board 60 by processing the fragment 62, the graphite material is attached to the entire surface of the printed circuit board. The heat dissipation effect is inferior. In order to overcome this problem, an LED substrate having a structure as shown in FIG. 15 may be provided.

As shown in (b), the LED substrate shown in FIG. 15 includes a graphite sheet 70 for diffusing heat and a pattern for supplying an electrical signal to each LED, and stacked on the graphite sheet 70. Is mounted on the printed circuit board 78 and through holes 76 are formed in the mounting position, and one end of the through hole 76 is located in the through hole in contact with the LED heat sink 22 located on the printed circuit board 78 The thermally conductive members 80 that conduct heat and the corresponding thermally conductive members of the thermally conductive members 80 and the graphite sheet 70 are in contact with each other to transfer heat, the surface of which is electrically shorted between adjacent LEDs. In order to prevent this, a non-conductive layer is coated with a plurality of metal pieces 74. These metal fragments 74 may be inserted into the graphite sheet 70 as shown, and may have a structure in which only one portion thereof is inserted so that one surface thereof is exposed to the outside of the graphite sheet 70. If the metal pieces 74 are inserted into the graphite sheet 70, the corresponding thermally conductive member 80 is inserted into the graphite sheet 70 so as to be in contact with the metal pieces 74. A number of holes 72 will have to be formed.

As such, when the metal pieces 74 corresponding to each LED are inserted into the graphite sheet 70, the heat transferred through the thermally conductive member 80 is transferred to the graphite sheet 70 through the metal pieces 74. It has a heat dissipation effect, and since the skin of the metal pieces 74 is coated with a non-conductive layer, adjacent LEDs can be prevented from being electrically shorted.

For reference, FIG. 16 illustrates another form of cross section in which an insulated thermally conductive member 80 is inserted into the graphite sheet 70. As the graphite sheets of the LED substrates described in Figs. 9 to 16, quasi-anisotropic graphite sheets having a thermal anisotropy coefficient of 3 to 20 can also be used. In addition, as described above, the thermally conductive member may use any one of a conductive paste, a powder, a metal material, a conductive tape, and a copper foil film.

In such embodiments, the auxiliary heat conductive member penetrating through the printed circuit board and the graphite sheet may be further inserted into the heat collection position between the LEDs mounted on the printed circuit board, thereby maximizing the heat spreading effect.

Meanwhile, a lighting unit including an LED substrate according to the above-described embodiments may be proposed. That is, the lighting unit including the LED substrate according to the embodiment of the present invention is largely as shown in FIG.

Casing (C),

Graphite sheet 18 for diffusing heat in contact with the inner surface of the casing (C), and a pattern for supplying an electrical signal to each LED, and a through-hole in a position where each LED is mounted, stacked on the graphite sheet 18. 20 are formed on the printed circuit board 14 and the LED heat sink positioned in the through hole 20 and having one end thereof in contact with the heat sink of the graphite sheet 18. A plurality of LED substrates for illumination including thermally conductive members 12 for conducting light, a non-conductive layer positioned between the thermally conductive members 12 and the graphite sheet 18, and the printed circuit board 14. It may be configured to include a plurality of LEDs (10) for receiving an electric signal from the light emitting.

Of course, even in such a lighting unit, the thermally conductive members 12 may be formed to extend through the graphite sheet 18 and the casing C to be drawn out.

In some cases, the thermally conductive member 12 formed therein may be provided with a screw groove that can be coupled to a screw inserted through the casing C and the graphite sheet 18.

The important fact is that the lighting unit of the above configuration also attaches a graphite sheet, which is a heat diffusion sheet, to the LED substrate itself, so that the heat dissipation efficiency can be improved more than a system employing a heat diffusion sheet outside the casing. Therefore, it is possible to manufacture at a lower cost than a substrate using a conductive thin film, and by adopting a thermally conductive member, it is possible to directly absorb heat from a heat source and conduct it to the heat diffusion sheet, thereby obtaining excellent heat dissipation efficiency.

Of course, the electronic component substrate including the graphite fragments described in the embodiment of the present invention, or the electronic component substrate including the metal fragments may also be used as a circuit board of the lighting unit.

For reference, the LED consumption current and temperature when using each substrate having a conductive thin film (FPCB) laminated on a metal PCB, graphite, the experimental data for the LED consumption current and temperature in the substrate according to the embodiment of the present invention Are listed in the table below.

Referring to the following table, according to an embodiment of the present invention, the substrate inserted into the graphite sheet by fragmentation of the thermally conductive member or the substrate when the thermally conductive member is insulated is relatively metal PCB and the conductive thin film (FPCB). It can be seen that the temperature in the case is lower than in the case of using a substrate. This means that the present invention has a better heat diffusion effect than the prior art. Therefore, the present invention can be said that the invention can be manufactured at low cost and at the same time, it has superior performance to any product in terms of heat diffusion efficiency.

 sample  Applied voltage (V)  Current (mA)  Temperature  Effect ranking  Metal pcb  8  482  51.8  4  FPCB  8  463  50  3  Substrates with thermally conductive members   8   391   44.2   One Board with thermally conductive member insulated  8  415  46.5  2

As described above, since the present invention directly absorbs the heat of the heat source through the heat conductive member and transfers the heat to the heat diffusion sheet, the present invention has an advantage of obtaining excellent heat dissipation effect than heat diffusion using the metal PCB.

In addition, since the present invention uses a general rigid printed circuit board instead of a metal PCB or a conductive thin film, there is an advantage of relatively lower manufacturing costs, and because it adopts a flexible graphite sheet, it can be widely used regardless of the application object. There is an advantage to this.

In addition, the present invention employs a graphite sheet having a semi-isotropic property excellent in heat transfer properties in the surface direction as well as the thickness direction instead of the graphite sheet having a high anisotropy property has the advantage of being able to quickly absorb and diffuse the heat of the heat source Have

Furthermore, since the present invention transmits heat by inserting an auxiliary thermal conductive member into a printed circuit board at a point where heat absorption is required, it is possible to minimize the difference in temperature distribution in the lighting unit, thereby preventing damage caused by stress. There are also benefits.

On the other hand, the present invention has been described with reference to the embodiments shown in the drawings, which are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. For example, the LED board and the lighting unit for lighting according to the embodiment of the present invention are not only a display device such as a backlight for a flat panel, but also a wide range of electronic / electrical devices such as a turn signal for a vehicle, a brake light, a traffic signal, a light, a billboard, and the like. It can be widely applied. Therefore, the true technical protection scope of the present invention should be defined only by the appended claims.

Claims (32)

A graphite sheet for diffusing heat; A printed circuit board stacked on the graphite sheet and having a through hole formed at a position where electronic components corresponding to a heat source are mounted; Thermally conductive members positioned in the through hole and having one end contacting a heat source to conduct heat to the graphite sheet; And an insulator layer between the thermally conductive members and the graphite sheet. The substrate of claim 1, wherein the thermally conductive members extend to be inserted into the graphite sheet. The electronic component substrate of claim 1, wherein the thermally conductive members extend through the graphite sheet to be drawn out to the outside, and are threaded at their ends. The electronic component substrate of claim 1, wherein the thermally conductive member is a flat plate, and a plurality of protrusions are formed on the plate to penetrate the graphite sheet and the printed circuit board and contact each LED heat sink. . The substrate of claim 1, wherein the thermally conductive members extend to be inserted into the graphite sheet, and a screw groove is formed therein, which may be screwed from the outside. The substrate of claim 1, wherein the heat conductive members are heat sinks, and protrusions and a plurality of heat dissipation fins are formed into the through holes. The electronic component substrate of claim 1, wherein the thermally conductive member is a fragmentary copper foil film laminated on the graphite sheet and inserted into a through hole of the printed circuit board by a press. The electronic component substrate according to any one of claims 1 to 7, wherein the insulator layer is coated on the skin of the thermally conductive member. The electronic component substrate of claim 1, further comprising auxiliary thermal conductive members penetrating the printed circuit board and the graphite sheet at a column assembly position between the electronic components mounted on the printed circuit board. The electronic component substrate of claim 1, further comprising one or more LEDs mounted on the printed circuit board. The electronic component substrate according to any one of claims 1 to 7, wherein the graphite sheet is a quasi anisotropic graphite sheet having a thermal anisotropy coefficient of 3 to 20. The substrate for electronic parts according to any one of claims 1 to 7, wherein the thermally conductive member uses any one of a conductive paste, a powder, a metal material, and a conductive tape. A printed circuit board having through-holes formed in a position for mounting an electronic component corresponding to a heat source and a pattern for supplying an electrical signal to each electronic component; Thermally conductive members positioned in the through hole and having one end thereof in contact with a heat source positioned on the printed circuit board to conduct heat; And a plurality of graphite fragments contacting the other end of each of the thermally conductive members to diffuse heat, spaced apart from each other, and attached to the printed circuit board to prevent electrical short circuits between adjacent electronic components. Board for electronic parts. The board of claim 13, wherein each of the thermally conductive members extends to be inserted into the graphite sheet. The electronic component of claim 13, wherein each of the thermally conductive members is formed with protrusions for penetrating the graphite sheet and the printed circuit board to contact each heat source, and are spaced apart from adjacent thermally conductive members. Board. The electronic component of claim 13, wherein each of the thermal conductive members is a heat sink, and a protrusion and a plurality of heat dissipation fins are formed in the through hole, and a non-conductive layer is formed on a portion thereof. Board. The board of claim 13, wherein each of the thermally conductive members is a piece-shaped copper foil film laminated on the graphite sheet and inserted into a through hole of the printed circuit board by a press. The electronic component substrate according to any one of claims 13 to 17, wherein the graphite sheet is a quasi anisotropic graphite sheet having a thermal anisotropy coefficient of 3 to 20. The electronic component board according to any one of claims 13 to 17, wherein the thermally conductive member uses any one of a conductive paste, a powder, a metal material, and a conductive tape. A graphite sheet for diffusing heat; A printed circuit board laminated on the graphite sheet, the through-holes being formed at a position where the electronic component corresponding to the heat source and the pattern for supplying an electrical signal to each electronic component are mounted; Thermally conductive members positioned in the through hole and having one end contacting a heat source positioned on the printed circuit board to conduct heat; A plurality of metal pieces having a non-conductive layer coated on the surface of the thermally conductive members to be in contact with a corresponding thermally conductive member and the graphite sheet to prevent electrical short circuit between adjacent electronic components; An electronic component substrate, characterized in that it comprises a. 21. The substrate of claim 20, wherein each of the metal pieces is inserted into the graphite sheet. 21. The substrate of claim 20, wherein one side of each of the metal pieces is exposed on the graphite sheet. The substrate for electronic parts according to any one of claims 20 to 22, wherein the graphite sheet is a quasi anisotropic graphite sheet having a thermal anisotropy coefficient of 3 to 20. 21. The electronic component substrate of claim 20, further comprising auxiliary thermal conductive members penetrating the printed circuit board and the graphite sheet at a column assembly position between the electronic components mounted on the printed circuit board. The substrate for electronic parts according to any one of claims 20 to 22 and 24, wherein the thermally conductive member uses any one of a conductive paste, a powder, a metal material, and a conductive tape. The board of claim 20, further comprising one or more LEDs mounted on the printed circuit board. Casing; A graphite sheet for diffusing heat in contact with the inner surface of the casing, a printed circuit board stacked on the graphite sheet, a pattern for supplying an electrical signal to each LED, and a through hole formed at a position where each LED is mounted; A thermally conductive member positioned in the through hole and having one end thereof in contact with the LED heat sink disposed on the printed circuit board to conduct heat to the graphite sheet, and an insulator layer between the thermally conductive members and the graphite sheet; A plurality of LED substrates including; And a plurality of LEDs which receive electric signals from the printed circuit board and emit light. 28. The lighting unit of claim 27, wherein the thermally conductive members extend through the graphite sheet and the casing to extend outwards, and are threaded at their ends. 28. The lighting unit of claim 27, wherein the thermally conductive members are provided with a screw groove that can be engaged with a screw inserted through the casing and the graphite sheet. Casing; A printed circuit board having a pattern for supplying an electrical signal to each LED in contact with an inner surface of the casing and through holes formed at a position where each LED is mounted, and one end of which is located in the through hole and is positioned on the printed circuit board Thermally conductive members that are in contact with the heat radiation of the LED and conduct heat, and are in contact with the other end of each of the thermally conductive members to diffuse heat, and are spaced apart from each other to prevent electrical short circuits between adjacent LEDs. A plurality of LED substrates comprising a plurality of graphite fragments attached; And a plurality of LEDs which receive electric signals from the printed circuit board and emit light. A lighting unit comprising a casing, a plurality of LED substrates attached to the inner surface of the casing, and LEDs mounted on the plurality of LED substrates, Each of the plurality of LED substrates, A graphite sheet for diffusing heat; A printed circuit board stacked on the graphite sheet, the printed circuit board having a through hole formed at a position where each LED is mounted and a pattern for supplying an electrical signal to each LED; Thermally conductive members positioned in the through hole and having one end contacting the LED heat sink disposed on the printed circuit board to conduct heat; A plurality of metal pieces having a non-conductive layer coated thereon to transfer heat in contact with the corresponding thermally conductive member of the thermally conductive member and the graphite sheet, the surface of which is to prevent electrical short between the adjacent LEDs; Lighting unit, characterized in that. An electronic device comprising the illuminating unit of any one of the illuminating units according to claim 27.

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