High-reliability chip sinking type lamp bead and manufacturing method

Abstract

The invention relates to the technical field of LED light emitting, in particular to a high-reliability chip sinking type lamp bead. The high-reliability chip sinking type lamp bead specifically comprises a substrate, a chip, a first bonding pad, a second bonding pad, a fluorescent sheet fixing layer, a light conversion layer, a transparent layer, a heat dissipation layer and a white glue layer. The substrate is provided with a groove, the chip, the light conversion layer and the transparent layer are located in the groove, the first bonding pad extends into the groove to be connected with the chip, the light conversion layer is located on the upper surface of the chip, the fluorescent sheet fixing layer is located between the chip and the light conversion layer, the transparent layer is located on the upper surface of the light conversion layer, the heat dissipation layer surrounds the chip, and the white glue layer surrounds the light conversion layer and the transparent layer. The second bonding pad is located at the bottom of the substrate and located under the chip. The method has the advantages that direct contact between the white glue and a heat source is avoided, and cracking of the white glue is fundamentally improved.

Description

Technical Field

[0001] The present invention relates to the field of LED lighting technology, and in particular to a high-reliability chip-sinking lamp bead and a manufacturing method thereof. Background Art

[0002] Existing high-power ceramic LED products have the problem of poor reliability, especially the cracking problem of white glue which needs to be solved.

[0003] There are two mainstream solutions at present: First, using softer white glue can achieve a certain effect in improving the problem of white glue cracking, but the soft glue solution has the problem of insufficient LED structural strength, which makes the white glue break during the use of SMD and other terminals;

[0004] Secondly, although molding EMC / SMC and other materials with higher hardness can solve the problem of LED structural strength compared to the above solutions, this solution requires too much initial investment in equipment, and the raw materials are more expensive than general white glue products.

[0005] At the same time, the above two solutions also have the disadvantage that the heat dissipation path of the chip is long.

[0006] Therefore, in view of the shortcomings of the prior art, a high-reliability chip-sinking lamp bead is provided. Summary of the invention

[0007] In order to overcome the deficiencies of the prior art, the present invention provides a high-reliability chip-sinking lamp bead, which aims to solve the problem of white glue cracking caused by direct contact with a heat source.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A high-reliability chip-sinking lamp bead comprises: a substrate, a chip, a first solder pad, a second solder pad, a solid fluorescent sheet layer, a light conversion layer, a transparent layer, a heat dissipation layer and a white glue layer;

[0010] The substrate is provided with a groove, the chip, the light conversion layer and the transparent layer are located in the groove, the first solder pad extends into the groove and is connected to the chip, the light conversion layer is located on the upper surface of the chip, the solid fluorescent sheet layer is located between the chip and the light conversion layer, the transparent layer is located on the upper surface of the light conversion layer, the heat dissipation layer is arranged around the chip, the white glue layer surrounds the light conversion layer and the transparent layer, the second solder pad is located at the bottom of the substrate, and the second solder pad is located directly below the chip.

[0011] As a further improvement of the technical solution of the present invention, the two first pads extend upward from the bottom of the substrate to the top of the substrate, extend along the inner wall of the groove to the bottom of the groove, and are respectively connected to the positive and negative electrodes of the chip;

[0012] The first pad is in a "X" shape.

[0013] As a further improvement of the technical solution of the present invention, the two first pads extend upward directly from the bottom of the substrate to the bottom of the groove and are respectively connected to the positive and negative electrodes of the chip;

[0014] The first pad is in a zigzag shape.

[0015] As a further improvement of the technical solution of the present invention, the width of the second pad is 70%-95% of the width of the chip.

[0016] As a further improvement of the technical solution of the present invention, the distance between the second pad and the chip is 50 μm-200 μm.

[0017] As a further improvement of the technical solution of the present invention, the heat dissipation layer is made of a high thermal conductivity insulating material, and the height of the heat dissipation layer is greater than the thickness of the chip;

[0018] The chip has a thickness of 50 μm-150 μm.

[0019] As a further improvement of the technical solution of the present invention, the height of the white glue layer is not higher than the upper surface of the transparent layer;

[0020] The thickness of the light conversion layer is 80 μm-150 μm.

[0021] As a further improvement of the technical solution of the present invention, the depth of the groove is 150 μm-300 μm.

[0022] As a further improvement of the technical solution of the present invention, the substrate is a ceramic substrate.

[0023] A method for manufacturing a high-reliability chip-sinking lamp bead, which is applicable to the above-mentioned high-reliability chip-sinking lamp bead, comprises the following steps:

[0024] S1: fix the chip in the groove of the substrate by eutectic welding or thermocompression welding, fill the heat dissipation layer around the chip, and electrically connect the positive and negative electrodes of the chip to the two first pads in the groove by eutectic welding or thermocompression welding respectively;

[0025] S2: Fixing the light conversion layer on the upper surface of the chip through a solid fluorescent sheet layer;

[0026] S3: Fill the white glue layer around the light conversion layer and the transparent layer by dispensing.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] In the high-reliability chip-sinking lamp bead of the present invention, the chip, the light conversion layer and the transparent layer are stacked in sequence in the groove, the first pad extends into the groove to connect with the chip, and the heat dissipation layer is filled around the chip to prevent the white glue layer from directly contacting the chip. At the same time, the first pad and the second pad are used to ensure the heat dissipation of the chip, and white glue is injected around the transparent layer to achieve the effect of single-sided light emission of the lamp bead. The high-reliability chip-sinking lamp bead has the characteristics of avoiding direct contact between the white glue and the heat source, and fundamentally improving the cracking of the white glue. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The technology of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0030] Figure 1 It is a schematic diagram of the structure of the chip-sinking lamp bead with high reliability of the present invention;

[0031] Figure 2 It is a structural schematic diagram of the high-reliability chip-sinking lamp bead of the present invention.

[0032] In the figure:

[0033] 1. Substrate; 11. Groove; 2. Chip; 3. First pad; 4. Solid fluorescent sheet layer; 5. Light conversion layer; 6. Transparent layer; 7. Heat dissipation layer; 8. White glue layer; 9. Second pad. DETAILED DESCRIPTION

[0034] The following will be combined with the embodiments and drawings to clearly and completely describe the concept, specific structure and technical effects of the present invention, so as to fully understand the purpose, scheme and effect of the present invention. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other without conflict. The same reference numerals used throughout the drawings indicate the same or similar parts.

[0035] It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature, or it may be indirectly fixed or connected to the other feature. In addition, the descriptions of up, down, left, right, etc. used in the present invention are only relative to the relative positional relationship of the components of the present invention in the drawings.

[0036] Reference Figure 1 to Figure 2 , a high-reliability chip-sinking lamp bead, comprising: a substrate 1, a chip 2, a first solder pad 3, a second solder pad 9, a solid fluorescent sheet layer 4, a light conversion layer 5, a transparent layer 6, a heat dissipation layer 7 and a white glue layer 8;

[0037] The substrate 1 is provided with a groove 11, the chip 2, the light conversion layer 5 and the transparent layer 6 are located in the groove 11, the first solder pad 3 extends into the groove 11 and is connected to the chip 2, the light conversion layer 5 is located on the upper surface of the chip 2, the solid fluorescent sheet layer 4 is located between the chip 2 and the light conversion layer 5, the transparent layer 6 is located on the upper surface of the light conversion layer 5, the heat dissipation layer 7 is arranged around the chip 2, and the white glue layer 8 surrounds the light conversion layer 5 and the transparent layer 6.

[0038] Among them, the chip 2, the light conversion layer 5 and the transparent layer 6 are stacked in the groove 11 in sequence, the first pad 3 extends into the groove 11 and connects with the chip 2, and the heat dissipation layer 7 is filled around the chip 2 to prevent the white glue layer 8 from directly contacting the chip 2. At the same time, the first pad 3 and the second pad 9 are used to ensure the heat dissipation of the chip 2, and white glue is injected around the transparent layer 6 to achieve the effect of single-sided light emission of the lamp bead. This high-reliability chip 2 sinking lamp bead has the characteristics of avoiding direct contact between the white glue and the heat source, and fundamentally improving the cracking of the white glue.

[0039] In one embodiment, the two first pads 3 extend upward from the bottom of the substrate 1 to the top of the substrate 1, extend along the inner wall of the groove 11 to the bottom of the groove 11, and are respectively connected to the positive and negative electrodes of the chip 2; the first pads 3 are in a "X" shape. The structure of the first pads 3 is also conducive to enhancing the strength of the substrate 1.

[0040] In one embodiment, the two first pads 3 extend upward from the bottom of the substrate 1 directly to the bottom of the groove 11 and are respectively connected to the positive and negative electrodes of the chip 2; the first pads 3 are in a Z shape. The structure of the first pads 3 effectively shortens the heat dissipation path of the chip 2, which can improve the overall heat dissipation performance of the lamp bead and improve reliability.

[0041] In one embodiment, the second pad 9 is located at the bottom of the substrate 1, the second pad 9 is located directly below the chip 2, and the width of the second pad 9 is 70%-95% of the width of the chip 2 to enhance the heat dissipation effect of the chip 2. The distance between the second pad 9 and the chip 2 is 50μm-200μm. Preferably, the width of the second pad 9 can be changed according to the heat dissipation of the chip 2, and the larger the width of the second pad 9, the better the heat dissipation.

[0042] In one embodiment, the heat dissipation layer 7 is made of a highly thermally conductive insulating material, and the height of the heat dissipation layer 7 is greater than the thickness of the chip 2; the thickness of the chip 2 is 50 μm-150 μm. Preferably, the chip 2 is a flip chip.

[0043] In one embodiment, the height of the white glue layer 8 is not higher than the upper surface of the transparent layer 6; the thickness of the light conversion layer 5 is 80 μm-150 μm. Preferably, the composition of the white glue layer 8 includes but is not limited to a fluid and high reflectivity material such as a TiO2 powder + silica gel mixture. The light conversion layer 5 includes but is not limited to a sheet-like light conversion material such as a fluorescent sheet / fluorescent film, and the thickness of the adhesive material solid crystal glue layer does not exceed 20 μm.

[0044] In one embodiment, the depth of the groove 11 is 150 μm-300 μm; the thickness of the solid fluorescent sheet layer 4 does not exceed 20 μm; the thickness of the transparent layer 6 is 80 μm-150 μm. Preferably, the cross section of the groove 11 is an isosceles trapezoid, which can be formed by laser cutting or dry / wet etching; and the side wall has a high-reflective coating, which can be a DBR or a silver mirror.

[0045] In one embodiment, the substrate 1 is a ceramic substrate. Preferably, the ceramic substrate has high insulation, corrosion resistance and dimensional stability, and is used as the basis of the chip 2 to help dissipate the heat generated by the chip 2, improve its performance and extend its service life.

[0046] A method for manufacturing a high-reliability chip-sinking lamp bead, which is applicable to the above-mentioned high-reliability chip-sinking lamp bead, comprises the following steps:

[0047] S1: fix the chip 2 in the groove 11 of the substrate 1 by eutectic welding or thermocompression welding, fill the heat dissipation layer 7 around the chip 2, and electrically connect the positive and negative electrodes of the chip 2 to the two first pads 3 in the groove 11 by eutectic welding or thermocompression welding respectively;

[0048] S2: Fixing the light conversion layer 5 on the upper surface of the chip 2 through the solid fluorescent sheet layer 4;

[0049] S3: Fill the white glue layer 8 around the light conversion layer 5 and the transparent layer 6 by dispensing method.

[0050] For other contents of the high-reliability chip-sinking lamp bead described in the present invention, please refer to the prior art and will not be repeated here.

[0051] The above are only preferred embodiments of the present invention and are not intended to limit the present invention in any form. Therefore, any modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention are still within the scope of the technical solution of the present invention.

[0052] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0053] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. A high reliability chip sinking lamp bead, characterized in that: include: Substrate, chip, first solder pad, second solder pad, solid fluorescent sheet layer, light conversion layer, transparent layer, heat dissipation layer and white glue layer; The substrate is provided with a groove, the chip, the light conversion layer and the transparent layer are located in the groove, the first solder pad extends into the groove and is connected to the chip, the light conversion layer is located on the upper surface of the chip, the solid fluorescent sheet layer is located between the chip and the light conversion layer, the transparent layer is located on the upper surface of the light conversion layer, the heat dissipation layer is arranged around the chip, the white glue layer surrounds the light conversion layer and the transparent layer, the second solder pad is located at the bottom of the substrate, and the second solder pad is located directly below the chip.

2. According to claim 1, a high reliability chip sinking lamp bead is characterized in that: The two first pads extend upward from the bottom of the substrate to the top of the substrate, extend along the inner wall of the groove to the bottom of the groove, and are respectively connected to the positive and negative electrodes of the chip; The first pad is in a "X" shape.

3. A high reliability chip sinking lamp bead according to claim 1, characterized in that: The two first pads extend upward directly from the bottom of the substrate to the bottom of the groove and are respectively connected to the positive and negative electrodes of the chip; The first pad is in a zigzag shape.

4. A high reliability chip sinking lamp bead according to claim 1, characterized in that: The width of the second pad is 70%-95% of the width of the chip.

5. A high reliability chip sinking lamp bead according to claim 4, characterized in that: The distance between the second pad and the chip is 50 μm-200 μm.

6. The high reliability chip sinking lamp bead according to claim 1, characterized in that: The heat dissipation layer is made of a highly thermally conductive insulating material, and the height of the heat dissipation layer is greater than the thickness of the chip; The chip has a thickness of 50 μm-150 μm.

7. The high reliability chip sinking lamp bead according to claim 1, characterized in that: The height of the white glue layer is not higher than the upper surface of the transparent layer; The thickness of the light conversion layer is 80 μm-150 μm.

8. The high reliability chip sinking lamp bead according to claim 1, characterized in that: The depth of the groove is 150 μm-300 μm.

9. The high reliability chip sinking lamp bead according to claim 1, characterized in that: The substrate is a ceramic substrate.

10. A method for manufacturing a high-reliability chip-sinking lamp bead, applicable to the high-reliability chip-sinking lamp bead described in any one of claims 1 to 9, characterized in that: The following steps are involved: S1: fix the chip in the groove of the substrate by eutectic welding or thermocompression welding, fill the heat dissipation layer around the chip, and electrically connect the positive and negative electrodes of the chip to the two first pads in the groove by eutectic welding or thermocompression welding respectively; S2: Fixing the light conversion layer on the upper surface of the chip through a solid fluorescent sheet layer; S3: Fill the white glue layer around the light conversion layer and the transparent layer by dispensing.

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