Cob light source

Abstract

The utility model discloses a COB light source, including metal baseplate, light emitting unit, heat conduction solder pad, dam and light -transmitting layer, the metal baseplate has opposite first surface and second surface, the dam is set up on the first surface of metal baseplate, and the light emitting region is defined on the first surface, and the light emitting unit is in the light emitting region, the light -transmitting layer is set up in the light emitting region and covers on the light emitting unit, the light emitting unit includes several interval distribution's semiconductor light emitting chip, and the semiconductor light emitting chip with the first surface of metal baseplate between the fit connection has the heat conduction solder pad, in the COB light source of the utility model, and semiconductor light emitting chip is directly connected with metal baseplate heat conduction through heat conduction solder pad, can promptly conduct the heat generated when high -power operation to metal baseplate, promotes the maximum workable power of semiconductor light emitting chip, and the reliability is high.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor light source technology, and in particular to a COB light source. Background Technology

[0002] With the improvement of luminous efficiency and the decrease in manufacturing cost, semiconductor light sources have been widely used in backlighting, display and lighting fields. Semiconductor light sources include various types such as LEDs, COBs, modules, light boards, and light strips.

[0003] A typical COB (Chip-on-Board) light source structure includes a substrate, a semiconductor light-emitting chip, and first and second pads for conductive connection to the outside world. When the semiconductor light-emitting chip is directly soldered to the circuit board, the first and second pads of the chip are conductively connected to corresponding first and second pads on the circuit board. Under high-power operating conditions, commonly used FR4-based circuit boards cannot meet the heat dissipation requirements, so metal-based circuit boards, such as copper-clad laminates, are typically used. To insulate the first and second pads on the copper substrate from the copper substrate, an insulating layer must be added between them. This insulating layer is usually made of resin, which has very poor thermal conductivity. However, the heat generated when the chip emits light can only be conducted to the copper substrate through the pads, solder pads, and insulating layer. Due to the poor thermal conductivity of the insulating layer, the heat generated by the semiconductor light-emitting chip during high-power operation cannot be conducted to the copper substrate, limiting the maximum operating power of the chip. Utility Model Content

[0004] The technical problem to be solved by this invention is to provide an improved COB light source.

[0005] The technical solution adopted by this utility model to solve its technical problem is: to provide a COB light source, including a metal substrate, a light-emitting unit, a thermally conductive pad, a dam, and a light-transmitting layer;

[0006] The metal substrate has a first surface and a second surface opposite to each other; the dam is disposed on the first surface of the metal substrate, defining a light-emitting area on the first surface, and the light-emitting unit is located in the light-emitting area; the light-transmitting layer is disposed in the light-emitting area and covers the light-emitting unit.

[0007] The light-emitting unit includes a plurality of spaced semiconductor light-emitting chips, and each semiconductor light-emitting chip is bonded to the first surface of the metal substrate with the thermally conductive pad.

[0008] Preferably, the first surface of the metal substrate is provided with a plurality of thermally conductive protrusions, and each of the semiconductor light-emitting chips is connected to the thermally conductive protrusions through the thermally conductive pads.

[0009] Preferably, a groove is formed on the outer side of the heat-conducting protrusion relative to the heat-conducting protrusion, and a portion of the semiconductor light-emitting chip is suspended in the groove.

[0010] Preferably, the light-transmitting layer covers the surface and sides of each of the semiconductor light-emitting chips.

[0011] Preferably, the light-transmitting layer is a transparent layer or a fluorescent layer; or, the light-transmitting layer comprises a transparent layer and a fluorescent layer stacked together.

[0012] Preferably, a light-absorbing layer or a reflective layer is provided at part or all of the interface between the light-transmitting layer and the metal substrate.

[0013] Preferably, the COB light source further includes a conductive circuit and an insulating layer; the conductive circuit is disposed on the first surface of the metal substrate and is conductively connected to the conductive pads of the semiconductor light-emitting chip, and the insulating layer is disposed between the first surface of the metal substrate and the conductive circuit.

[0014] Preferably, the insulating layer is on the metal substrate and surrounds the semiconductor light-emitting chip.

[0015] Preferably, the bottom surface of the dam is located on the conductive circuit and / or the insulating layer.

[0016] Preferably, the COB light source further includes a first connection layer and a second connection layer; the first connection layer is connected between the conductive pad of the semiconductor light-emitting chip and the conductive circuit, and the second connection layer is connected between the thermally conductive pad and the first surface of the metal substrate.

[0017] The beneficial effects of this utility model are: the semiconductor light-emitting chip is directly thermally connected to the metal substrate through the thermally conductive pad, which can promptly conduct the heat generated during high-power operation to the metal substrate, thereby increasing the maximum working power of the semiconductor light-emitting chip and improving its reliability; the structure is simple, which can simplify the manufacturing process and reduce costs. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0019] Figure 1 This is a schematic diagram of the structure of a COB light source according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the structure of a COB light source according to another embodiment of the present invention. Detailed Implementation

[0021] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0022] like Figure 1 As shown, a COB light source according to an embodiment of the present invention includes a metal substrate 10, a light-emitting unit, a thermally conductive pad 30, a dam 40, and a light-transmitting layer 50. The metal substrate 10 has opposing first and second surfaces, and the light-emitting unit, the thermally conductive pad 30, the dam 40, and the light-transmitting layer 50 are all disposed on the first surface of the metal substrate 10.

[0023] A dam 40 is disposed on the first surface of the metal substrate 10 to define a light-emitting area, and the light-emitting unit is located within the light-emitting area; a light-transmitting layer 50 is disposed within the light-emitting area and covers the light-emitting unit. The light-emitting unit includes a plurality of spaced semiconductor light-emitting chips 20, where "a plurality of" refers to two or more. Each semiconductor light-emitting chip 20 is bonded to the first surface of the metal substrate 10 with a thermally conductive pad 30, so that the heat generated by the semiconductor light-emitting chip 20 during operation is directly conducted to the metal substrate 10 through the thermally conductive pad 30.

[0024] The metal substrate 10 is preferably a copper-clad substrate. A conductive circuit 60 is provided on the first surface of the metal substrate 10, which is conductively connected to the semiconductor light-emitting chip 20. In order to prevent the conductive circuit 60 from conducting with the metal substrate 10, an insulating layer 70 is also provided on the first surface of the metal substrate 10. The insulating layer 70 is located between the first surface of the metal substrate 10 and the conductive circuit 60, isolating the metal substrate 10 and the conductive circuit 60.

[0025] Each semiconductor light-emitting chip 20 has conductive pads that are conductively connected to the conductive circuit 60. The conductive pads typically include a positive conductive pad 21 and a negative conductive pad 22, which are conductively connected to corresponding pads on the conductive circuit 60, respectively. The positive conductive pad 21 and the negative conductive pad 22 are insulated from each other and can be used as... Figure 1 The two sides shown are located on the thermally conductive pad 30.

[0026] In order to enable the semiconductor light-emitting chip 20 to be stably or horizontally disposed on the metal substrate 10, a plurality of heat-conducting protrusions 11 are provided on the first surface of the metal substrate 10. The number and distribution of the heat-conducting protrusions 11 correspond to the number and distribution of the semiconductor light-emitting chips 20, so that each semiconductor light-emitting chip 20 is disposed on a heat-conducting protrusion 11, and each heat-conducting pad 30 is attached between the surface of the semiconductor light-emitting chip 20 and the heat-conducting protrusion 11.

[0027] The conductive circuit 60 and the insulating layer 70 are arranged around the thermally conductive protrusion 11 on the first surface of the metal substrate 10, and thus also around the semiconductor light-emitting chip 20.

[0028] The thermally conductive protrusion 11 can be integrally formed on the first surface of the metal substrate 10. The thermally conductive protrusion 11 can be as follows: Figure 1 The trapezoid shown can also be a rectangle or other shapes. Preferably, the surface of the thermally conductive boss 11 is flush with the surface of the positive conductive pad 21 and the surface of the negative conductive pad 22.

[0029] On the first surface of the metal substrate 10, a groove 12 is formed on the outer side of the heat-conducting protrusion 11 relative to the heat-conducting protrusion 11. A portion of the semiconductor light-emitting chip 20 extends outward relative to the heat-conducting protrusion 11 and is suspended on the groove 12. The conductive circuit 60 and the insulating layer 70 are located in the groove 12, or in other positions in the groove 12 and on the first surface of the metal substrate 10.

[0030] Preferably, the semiconductor light-emitting chip 20 is positioned on the groove 12 with the portion having conductive pads, so that both the positive conductive pad 21 and the negative conductive pad 22 are located on the groove 12 and are electrically connected to the conductive circuit 60 in the groove 12 respectively.

[0031] On the first surface of the metal substrate 10, an insulating layer 70 surrounds the thermally conductive protrusion 11 and the semiconductor light-emitting chip 20, and may cover part or all of the first surface of the metal substrate 10. The insulating layer 70 may be in contact with or spaced from the side of the thermally conductive protrusion 11. The insulating layer 70 includes one or more combinations of white glue, silicone, resin, glass glaze, liquid glass, ink, and coating.

[0032] A dam 40 is disposed on the first surface of the metal substrate 10, and the bottom surface of the dam 40 is located on the conductive circuit 60 and / or the insulating layer 70. The dam 40 is preferably made of an opaque material, such as a damming adhesive.

[0033] A light-transmitting layer 50 covers the light-emitting unit, enclosing the sides and the surface facing away from the metal substrate 10 of each semiconductor light-emitting chip 20; a dam 40 forms the boundary of the light-transmitting layer 50. The groove 12 can also be filled with the light-transmitting layer 50.

[0034] Alternatively, the light-transmitting layer 50 can be a transparent layer, primarily serving a light-transmitting and protective function. Alternatively, the light-transmitting layer 50 can be a fluorescent layer, capable of providing the desired light color. Or, the light-transmitting layer 50 may comprise a stacked transparent layer and a fluorescent layer.

[0035] Alternatively, the light-emitting area defined by the dam 40 can be divided into several sub-light-emitting areas by an isolation wall (not shown). The light-transmitting layer 50 corresponding to each sub-light-emitting area may be the same or different, and the semiconductor light-emitting chip 20 corresponding to each sub-light-emitting area may be the same or different.

[0036] In terms of materials, the light-transmitting layer 50 includes one or more of silicone, resin, glass sheet, and ceramic sheet. When glass or ceramic sheet is used, an adhesive is provided between the glass or ceramic sheet and the semiconductor light-emitting chip 20, and the metal substrate 10 and the glass or ceramic sheet are usually filled with transparent glue or adhesive.

[0037] Further, the light-transmitting layer 50 is colorless and transparent or doped with at least one of photoluminescent powder, light-diffusing powder, and coloring powder. The photoluminescent powder is a phosphor and / or quantum dots; wherein the phosphor includes one or more of YAG phosphor, oxide phosphor, nitride phosphor, fluoride phosphor, aluminate phosphor, silicate phosphor, and oxynitride phosphor; the quantum dots include one or more of silicon quantum dots, germanium quantum dots, cadmium sulfide quantum dots, cadmium selenide quantum dots, cadmium telluride quantum dots, zinc selenide quantum dots, lead sulfide quantum dots, lead selenide quantum dots, indium phosphide quantum dots, and indium arsenide quantum dots. The light-diffusing powder is one or more of glass powder, ceramic powder, oxide powder, and nitride powder with micron, submicron, or nano-sized particles. The coloring powder is one or more of carbon black, oxide powder, and salts with micron, submicron, or nano-sized particles.

[0038] like Figure 2 As shown, the COB light source of the second embodiment of this utility model includes a metal substrate 10, a light-emitting unit, a thermally conductive pad 30, a dam 40, and a light-transmitting layer 50. The metal substrate 10 has a first surface and a second surface facing each other, and the light-emitting unit, the thermally conductive pad 30, the dam 40, and the light-transmitting layer 50 are all disposed on the first surface of the metal substrate 10.

[0039] A dam 40 is disposed on the first surface of the metal substrate 10 to define a light-emitting area, and the light-emitting unit is located within the light-emitting area; a light-transmitting layer 50 is disposed within the light-emitting area and covers the light-emitting unit. The light-emitting unit includes a plurality of spaced semiconductor light-emitting chips 20, where "a plurality of" refers to two or more. Each semiconductor light-emitting chip 20 is bonded to the first surface of the metal substrate 10 with a thermally conductive pad 30, so that the heat generated by the semiconductor light-emitting chip 20 during operation is directly conducted to the metal substrate 10 through the thermally conductive pad 30.

[0040] The metal substrate 10 is preferably a copper-clad substrate. A conductive circuit 60 is provided on the first surface of the metal substrate 10, which is conductively connected to the semiconductor light-emitting chip 20. In order to prevent the conductive circuit 60 from conducting with the metal substrate 10, an insulating layer 70 is also provided on the first surface of the metal substrate 10. The insulating layer 70 is located between the first surface of the metal substrate 10 and the conductive circuit 60, isolating the metal substrate 10 and the conductive circuit 60.

[0041] Each semiconductor light-emitting chip 20 has conductive pads that are conductively connected to the conductive circuit 60. The conductive pads typically include a positive conductive pad 21 and a negative conductive pad 22, which are conductively connected to corresponding pads on the conductive circuit 60, respectively. The positive conductive pad 21 and the negative conductive pad 22 are insulated from each other and can be used as... Figure 2 The two sides shown are located on the thermally conductive pad 30.

[0042] In order to enable the semiconductor light-emitting chip 20 to be stably or horizontally disposed on the metal substrate 10, a plurality of heat-conducting protrusions 11 are provided on the first surface of the metal substrate 10. The number and distribution of the heat-conducting protrusions 11 correspond to the number and distribution of the semiconductor light-emitting chips 20, so that each semiconductor light-emitting chip 20 is disposed on a heat-conducting protrusion 11, and each heat-conducting pad 30 is attached between the surface of the semiconductor light-emitting chip 20 and the heat-conducting protrusion 11.

[0043] The conductive circuit 60 and the insulating layer 70 are arranged around the thermally conductive protrusion 11 on the first surface of the metal substrate 10, and thus also around the semiconductor light-emitting chip 20.

[0044] The thermally conductive protrusion 11 can be integrally formed on the first surface of the metal substrate 10. The thermally conductive protrusion 11 can be as follows: Figure 1 The trapezoid shown can also be a rectangle or other shapes.

[0045] The COB light source in this embodiment also includes a first connection layer 23 and a second connection layer 31. The first connection layer 23 is connected between the conductive pad of the semiconductor light-emitting chip 20 and the conductive circuit 60, and the second connection layer 31 is connected between the thermally conductive pad 30 and the first surface of the metal substrate 10.

[0046] The first connecting layer 23 and the second connecting layer 31 can be an adhesive layer or a solder layer, respectively. Corresponding to the setting of the heat-conducting boss 11, the second connecting layer 31 is disposed on the heat-conducting boss 11.

[0047] On the first surface of the metal substrate 10, a groove 12 is formed on the outer side of the heat-conducting protrusion 11 relative to the heat-conducting protrusion 11. A portion of the semiconductor light-emitting chip 20 extends outward relative to the heat-conducting protrusion 11 and is suspended on the groove 12. The conductive circuit 60 and the insulating layer 70 are located in the groove 12, or in other positions in the groove 12 and on the first surface of the metal substrate 10.

[0048] Preferably, the semiconductor light-emitting chip 20 is positioned on the groove 12 with the portion having conductive pads, so that both the positive conductive pad 21 and the negative conductive pad 22 are located on the groove 12 and are electrically connected to the conductive circuit 60 in the groove 12 respectively.

[0049] On the first surface of the metal substrate 10, an insulating layer 70 surrounds the thermally conductive protrusion 11 and the semiconductor light-emitting chip 20, and may cover part or all of the first surface of the metal substrate 10. The insulating layer 70 may be in contact with or spaced from the side of the thermally conductive protrusion 11. The insulating layer 70 includes one or more combinations of white glue, silicone, resin, glass glaze, liquid glass, ink, and coating.

[0050] A dam 40 is disposed on a first surface of the metal substrate 10, and the bottom surface of the dam 40 is located on the conductive circuit 60 and / or the insulating layer 70. The dam 40 is preferably formed of an opaque material.

[0051] A light-transmitting layer 50 covers the light-emitting unit, enclosing the sides of each semiconductor light-emitting chip 20 and the surface facing away from the metal substrate 10; a dam 40 forms the boundary of the light-transmitting layer 50. Alternatively, the light-transmitting layer 50 can be a transparent layer, primarily serving a light-transmitting and protective function. Alternatively, the light-transmitting layer 50 can be a fluorescent layer, capable of providing the desired light color. Or, the light-transmitting layer 50 may comprise a stacked transparent layer and a fluorescent layer.

[0052] In the above Figures 1-2 In the COB light source of the illustrated embodiment, a light-absorbing layer or a reflective layer may also be provided at part or all of the interface between the light-transmitting layer 50 and the metal substrate 10. For example, in the light-emitting area of ​​the first surface of the metal substrate 10, the light-transmitting layer 50 also covers the exposed surface of the metal substrate 10 (the surface portion not covered by the insulating layer 70). In this case, a light-absorbing layer or a reflective layer is provided between the exposed surface of the metal substrate 10 and the light-transmitting layer 50 to reflect the light reaching that location, thereby improving luminous efficiency and reducing light loss.

[0053] Understandably, in other embodiments, semiconductor light-emitting chips or other components may also be disposed on the opposite second surface of the metal substrate to form a double-sided light-emitting device.

[0054] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A COB light source, characterized by, It includes a metal substrate, a light-emitting unit, a thermally conductive pad, a dam, and a light-transmitting layer; The metal substrate has a first surface and a second surface opposite to each other; the dam is disposed on the first surface of the metal substrate, defining a light-emitting area on the first surface, and the light-emitting unit is located in the light-emitting area; the light-transmitting layer is disposed in the light-emitting area and covers the light-emitting unit. The light-emitting unit includes a plurality of spaced semiconductor light-emitting chips, and each semiconductor light-emitting chip is bonded to the first surface of the metal substrate with the thermally conductive pad.

2. The COB light source according to claim 1, characterized in that, The first surface of the metal substrate is provided with a plurality of thermally conductive protrusions, and each of the semiconductor light-emitting chips is connected to the thermally conductive protrusions through the thermally conductive pads.

3. The COB light source according to claim 2, characterized in that, A groove is formed on the outer side of the heat-conducting protrusion relative to the heat-conducting protrusion, and part of the semiconductor light-emitting chip is suspended on the groove.

4. The COB light source according to claim 1, characterized in that, The light-transmitting layer covers the surface and sides of each of the semiconductor light-emitting chips.

5. The COB light source of claim 1, wherein, The light-transmitting layer is a transparent layer or a fluorescent layer; or, the light-transmitting layer includes a transparent layer and a fluorescent layer stacked together.

6. The COB light source according to claim 1, characterized in that, The interface between the light-transmitting layer and the metal substrate is provided with a light-absorbing layer or a reflective layer in part or all of its components.

7. The COB light source according to any one of claims 1-6, characterized in that, The COB light source further includes a conductive circuit and an insulating layer; the conductive circuit is disposed on the first surface of the metal substrate and is conductively connected to the conductive pads of the semiconductor light-emitting chip, and the insulating layer is disposed between the first surface of the metal substrate and the conductive circuit.

8. The COB light source according to claim 7, characterized in that, The insulating layer is on the metal substrate and surrounds the semiconductor light-emitting chip.

9. The COB light source of claim 7, wherein, The bottom surface of the dam is located on the conductive circuit and / or the insulating layer.

10. The COB light source of claim 7, wherein, The COB light source further includes a first connection layer and a second connection layer; the first connection layer is connected between the conductive pad of the semiconductor light-emitting chip and the conductive circuit, and the second connection layer is connected between the thermally conductive pad and the first surface of the metal substrate.

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