An LED packaging structure and a preparation method of the LED packaging structure

Abstract

The embodiment of the present application provides an LED packaging structure and a preparation method of the LED packaging structure, wherein the LED packaging structure comprises: a substrate, the substrate is provided with a first pad and a second pad; a carrier, the bottom surface of the carrier is fixed on the substrate, and the carrier is provided with a third pad and a fourth pad, the third pad is configured to partially cover the top surface of the carrier and extend to each side surface, the fourth pad is configured to partially or totally cover the top surface of the carrier and extend to each side surface, the third pad is electrically connected with the first pad, and the fourth pad is electrically connected with the second pad; a plurality of LED chips, the plurality of LED chips are respectively fixed on each surface of the carrier except the bottom surface; and a protective glue body, the protective glue body covers the substrate, the carrier and the plurality of LED chips. By arranging the carrier and welding the LED chips on each surface of the carrier, the light emitting angle of one LED device reaches 180 degrees, and the light emitting angle and the light emitting brightness of each angle of the LED device are obviously improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of LED, more particularly, to an LED packaging structure and a preparation method of the same. BACKGROUND

[0002] Commonly used LED chips generally emit 90% of light from the front surface, and only about 10% of light from the side surface, so the light emitting angle of the LED chip is generally 120°. A common structure is to fix the LED chip in a support with a bowl cup, and to perform wire bonding, dispensing and other processes, so as to finally form an LED device. Figure 1 A common LED packaging structure includes an LED anode 10, an LED cathode 20, an LED chip 30, an LED support 40 and a protective glue 50. Since the chip angle is only about 120°, the light emitting angle of the LED device is generally 120°-130° after packaging due to the blocking of the bowl cup of the support and the refraction of the packaging glue. Even if a packaging glue with a very high refractive index is selected, the light emitting angle is difficult to exceed 140°. However, some special applications, such as mini TV backlight, lighting, infrared light supplement, ultraviolet sterilization and the like, have high requirements on the uniformity of light emission in all directions of the device, which requires that the light emitting angle of the LED device be as large as possible, and preferably close to 180°. SUMMARY

[0003] The technical problem to be solved by the present application is that the light emitting angle of the current LED device is small, and can only reach about 120°, and cannot reach 180°. In view of the above technical problem, the present application provides an LED packaging structure and a preparation method of the same.

[0004] To solve the above technical problem, the present application provides an LED packaging structure, which comprises:

[0005] a substrate, wherein the substrate is provided with a first pad and a second pad;

[0006] a carrier, wherein the bottom surface of the carrier is fixed on the substrate, and the carrier is provided with a third pad and a fourth pad, the third pad is configured to partially cover the top surface of the carrier and extend to each side surface, and the fourth pad is configured to partially or completely cover the top surface of the carrier and extend to each side surface, the third pad on the carrier is electrically connected to the first pad on the substrate, and the fourth pad on the carrier is electrically connected to the first pad on the substrate;

[0007] a plurality of LED chips, wherein the plurality of LED chips are respectively fixed on each surface of the carrier except the bottom surface, and the electrodes of the LED chips are respectively electrically connected to the third pad and the fourth pad on the surface.

[0008] a protective colloid covering the substrate, the carrier and the plurality of LED chips.

[0009] Optionally, the carrier is a straight prism structure.

[0010] Optionally, the third pads on the carrier are arranged in a circle along the edges of the top surface and extend to each side surface in a branch.

[0011] The fourth pads on the carrier cover the top surface and the side surface and are below the third pads, and an insulating layer is arranged between the third pads and the fourth pads.

[0012] Alternatively, the fourth pads on the carrier cover the top surface and the side surface and are not overlapped with the third pads, and a safe distance is maintained between the fourth pads and the third pads.

[0013] Optionally, the third pads on the carrier are arranged along the edges of three edges of the top surface and extend to each side surface in a branch.

[0014] The fourth pads on the carrier cover the top surface and the side surface and are below the third pads, and an insulating layer is arranged between the third pads and the fourth pads.

[0015] Alternatively, the fourth pads on the carrier cover the top surface and the side surface and are not overlapped with the third pads, and a safe distance is maintained between the fourth pads and the third pads.

[0016] Optionally, the fourth pads further extend to the bottom surface of the carrier, the fourth pads on the bottom surface of the carrier are fixed on the second pads of the substrate, and the third pads on the top surface of the carrier are electrically connected to the first pads of the substrate through wires.

[0017] Optionally, the LED chips are vertical structure chips, the bottom electrodes of the LED chips are welded on the fourth pads on the surfaces where the LED chips are located, and the top electrodes are electrically connected to the third pads on the surfaces where the LED chips are located through wires.

[0018] Optionally, the plurality of LED chips are single-color LED chips, or different color LED chips, or different color temperature LED chips.

[0019] Optionally, the protective colloid is an epoxy resin colloid or a fluorescent colloid.

[0020] Further, the application also provides a preparation method of the LED packaging structure, and the preparation method comprises:

[0021] S01: providing a substrate and a carrier, the substrate is provided with a first pad and a second pad, the carrier is provided with a third pad and a fourth pad, the third pad is configured to partially cover the top surface of the carrier and extend to each side surface, the fourth pad is configured to partially or completely cover the top surface of the carrier and extend to each side surface and the bottom surface;

[0022] S02: fixing the carrier on the substrate, the fourth pad on the bottom surface of the carrier is welded with the second pad of the substrate;

[0023] S03: welding and fixing LED chips on each surface of the carrier except the bottom surface, the LED chips are vertical structure chips, the bottom electrode of the LED chip is welded and fixed on the fourth pad of the surface where the LED chip is located;

[0024] S04: electrically connecting the top electrode of the LED chip with the third pad on the surface where the LED chip is located through a wire, and electrically connecting the third pad on the carrier with the first pad on the substrate through a wire;

[0025] S05: covering the substrate, the carrier and the plurality of LED chips with a protective glue to form a protective glue body.

[0026] Optionally, the S01 further comprises:

[0027] coating the fourth pad on each surface of the carrier so that the surface of the carrier is completely covered by the fourth pad;

[0028] coating an insulating layer on the top surface of the carrier above the fourth pad, the insulating layer is configured to form a ring along the edge of the top surface of the carrier and extend a branch to each side surface;

[0029] coating the third pad along the path of the insulating layer.

[0030] The embodiment of the present application provides a LED packaging structure and a preparation method of the LED packaging structure, wherein the LED packaging structure comprises: a substrate, the substrate is provided with a first pad and a second pad; a carrier, the bottom surface of the carrier is fixed on the substrate, and the carrier is provided with a third pad and a fourth pad, the third pad is configured to partially cover the top surface of the carrier and extend to each side surface, the fourth pad is configured to partially or totally cover the top surface of the carrier and extend to each side surface, the third pad on the carrier is electrically connected with the first pad on the substrate, and the fourth pad on the carrier is electrically connected with the second pad on the substrate; a plurality of LED chips, the plurality of LED chips are respectively fixed on each surface of the carrier except the bottom surface; and a protective glue body, the protective glue body covers the substrate, the carrier and the plurality of LED chips. By fixing the carrier on the substrate and welding the LED chips on each surface of the carrier, the plurality of LED chips simultaneously emit light in multiple directions, so that the light emitting angle of the LED device reaches 180 degrees, and the light emitting angle and the light emitting brightness of each angle of the LED device are obviously improved. BRIEF DESCRIPTION OF DRAWINGS

[0031] The present application will be further described below in combination with the drawings and embodiments, wherein:

[0032] Figure 1 It is a structural schematic diagram of the prior LED packaging device;

[0033] Figure 2 It is a schematic diagram of the LED packaging structure provided by the first embodiment of the present application;

[0034] Figure 3 It is a top view of the LED packaging structure provided by the first embodiment of the present application;

[0035] Figure 4 It is a schematic diagram of the LED packaging structure provided by the first embodiment of the present application when the LED chips are removed;

[0036] Figure 5 It is a schematic diagram of another LED packaging structure provided by the first embodiment of the present application when the LED chips are removed;

[0037] Figure 6 It is a schematic diagram of another LED packaging structure provided by the first embodiment of the present application;

[0038] Figure 7 It is a flow schematic diagram of the preparation method of the LED packaging structure provided by the second embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to make the objects, technical solutions and advantages of the present application clearer, further understand the embodiments of the present application, the following will be combined with the specific embodiments and the drawings to make a further detailed description. It should be understood that the specific embodiments described here are only used to explain the present application, and are not used to limit the present application.

[0040] Embodiment one:

[0041] For LED devices, the light emitting angle is a very important parameter, the larger the light emitting angle means the wider the illumination area of a LED device, the more the area that can be illuminated, and the light emitting angle of a LED lamp can only reach about 120° at most, and it is almost impossible to reach 180°, therefore, in view of the above problems, the present application provides a LED packaging structure, which can make the light emitting angle of a LED lamp reach 180°, and can also ensure that the brightness of each angle is close.

[0042] The embodiment provides a LED packaging structure, which comprises a substrate, a first pad and a second pad are arranged on the substrate; a carrier, the bottom surface of the carrier is fixed on the substrate, and a third pad and a fourth pad are arranged on the carrier, the third pad is configured to partially cover the top surface of the carrier and extend to each side surface, and the fourth pad is configured to partially or entirely cover the top surface of the carrier and extend to each side surface, the third pad on the carrier is electrically connected with the first pad on the substrate, and the fourth pad on the carrier is electrically connected with the second pad on the substrate; a plurality of LED chips, the plurality of LED chips are respectively fixed on each surface of the carrier except the bottom surface, and the electrodes of the LED chips are respectively electrically connected with the third pad and the fourth pad on the surface; and a protective glue body, the protective glue body covers the substrate, the carrier and the plurality of LED chips.

[0043] Referring to Figure 2 , Figure 2A schematic diagram of an LED packaging structure is provided in the embodiment. The LED packaging structure 100 comprises a substrate 110, the substrate 110 being provided with a first pad 111 and a second pad 112; a carrier 120, the bottom surface of the carrier 120 being fixed on the substrate 110, and the carrier 120 being provided with a third pad 121 and a fourth pad 122, the third pad 121 being configured to partially cover the top surface of the carrier 120 and extend to each side surface, and the fourth pad 122 being configured to partially or entirely cover the top surface of the carrier 120 and extend to each side surface; a plurality of LED chips 131 and 132, the plurality of LED chips 131 and 132 being respectively fixed on each surface of the carrier 120 except the bottom surface, and the electrodes of the LED chips 131 and 132 being respectively electrically connected with the third pad 121 and the fourth pad 122 on the surface; and a protective glue body 140, the protective glue body 140 covering the substrate 110, the carrier 120 and the plurality of LED chips 131 and 132.

[0044] The LED packaging structure provided in the embodiment of the present application includes but is not limited to Figure 2 The LED packaging structure further includes but is not limited to the structure that the carrier is arranged in the gap between the anode pad and the cathode pad of the substrate, and the carrier is connected with the anode pad and the cathode pad of the substrate through wires; the structure that the carrier is arranged on the anode pad; the structure that the pads of the substrate are located on the other side of the fixed carrier, and the pads on the back surface of the substrate are connected with the carrier through wires; and the like. Figure 2 In the embodiment, when the first pad 111 is the anode pad, the second pad 112 is the cathode pad, and when the first pad 111 is the cathode pad, the second pad 112 is the anode pad; the polarity of the third pad 121 is the same as that of the first pad 111, and the polarity of the fourth pad 122 is the same as that of the second pad 112.

[0045] In the embodiment, the shape of the carrier includes but is not limited to Figure 2 the straight prism structure shown in the figure, and further includes but is not limited to a triangular pyramid and a rhombic body, and the like.

[0046] In the embodiment, the pad structure on the substrate and the pad structure on the carrier include but are not limited to Figure 2 the structure shown in the figure, and in actual application, the structure of the pad is related to the design requirement and the circuit function, and the embodiment is not limited, for example, the pad structures of the series circuit and the parallel circuit are obviously different, and for example, in order to achieve better heat dissipation effect, the substrate below the carrier is hollowed out and filled with ceramic, which will cause obvious change of the structure of the pad.

[0047] In the embodiment, Figure 2The LED chip 131 shown represents an LED chip located on the top surface of the carrier 120, and the LED chip 132 represents an LED chip located on the side surface of the carrier 120, and the LED chip 131 and the LED chip 132 together constitute a plurality of LED chips mounted on the carrier 120. Figure 2 The 150 shown is a wire, and the wire 150 is used to electrically connect the chip and the pad, and electrically connect the pad on the carrier and the pad on the substrate, and the wire 150 can be selected from, but not limited to, gold wire and silver wire.

[0048] In another embodiment, the carrier is a straight prism structure.

[0049] Referring to Figure 2 and Figure 3 , Figure 3 is a top view of an LED packaging structure provided by the present embodiment, and the carrier 120 is a hexahedral straight prism structure, Figure 2 and Figure 3 The bottom surface and the top surface of the carrier 120 are square, and the side surface is rectangular, and the carrier 120 is hexahedral, so that after the LED chips are respectively soldered on the top surface and the side surface of the carrier 120, the full-angle coverage of the light-emitting surface can be achieved, and the light-emitting angle of the LED device reaches 180°.

[0050] In another embodiment, the third pad on the carrier forms a circle along the edge of the top surface, and extends a branch to each side surface; the fourth pad on the carrier covers the top surface and the side surface and is located below the third pad, and an insulating layer is further arranged between the third pad and the fourth pad; or, the fourth pad on the carrier covers the area on the top surface and the side surface which does not overlap with the third pad, and a safe distance is maintained between the third pad and the fourth pad.

[0051] Referring to Figure 3 and Figure 4 , Figure 4 is a schematic diagram of an LED packaging structure provided by the present embodiment without LED chips. The third pad 121 on the carrier 120 forms a circle along the edge of the top surface, and extends a branch of the third pad 121 to each side surface of the carrier 120, and the fourth pad 122 on the carrier covers the top surface and the side surface of the carrier 120 and is located below the third pad 121, and an insulating layer 160 is further arranged between the third pad 121 and the fourth pad 122, and the insulating layer 160 plays a role of insulating and isolating the positive and negative electrodes. In another arrangement, the fourth pad on the carrier covers the area on the top surface and the side surface which does not overlap with the third pad, and a safe distance is maintained between the third pad and the fourth pad. The requirement of maintaining a safe distance between the third pad and the fourth pad is to avoid short circuit between the third pad and the fourth pad, and at this time, the schematic diagram of the circuit structure is the same as Figure 3 and Figure 4Similarly, the difference is that 160 is no longer an insulating layer but an isolation gap between the third and fourth pads. It can be understood that, Figure 3 and Figure 4 is a pad structure that can be implemented provided by the present embodiment for the convenience of understanding and description, and the pad structure on the carrier and the insulating layer arrangement manner are not limited to Figure 3 and Figure 4 the structure shown in the figure, the pad structure on the carrier also includes but is not limited to, the third and fourth pads on each face of the carrier each occupy half, the third and fourth pads on the carrier and Figure 3 and Figure 4 are inversed, etc., and the insulating layer arrangement manner includes but is not limited to Figure 5 the structure shown in the figure, Figure 5 in which most of the fourth pad 122 is wrapped by the insulating layer 160, and only a small area is provided with a window of the fourth pad 122.

[0052] In another embodiment, the third pad of the carrier is arranged along the edges of the three edges of the top surface and extends a branch to each side surface; the fourth pad on the carrier covers the top surface and the side surface and is located below the third pad, and an insulating layer is further arranged between the third and fourth pads; or, the fourth pad on the carrier covers the top surface and the side surface and the area where the fourth pad does not overlap with the third pad, and a safe distance is maintained between the fourth and third pads.

[0053] Referring to FIG. 6, Figure 6 is a schematic diagram of another LED packaging structure provided by the present embodiment, the third pad of the carrier 120 is arranged along the edges of the three edges of the top surface and extends a branch of the third pad 121 to each side surface of the carrier 120, and the fourth pad 122 on the carrier covers the top surface and the side surface of the carrier 120 and is located below the third pad 121, and an insulating layer 160 is further arranged between the fourth pad 122 and the third pad 121, which plays an insulating isolation role. In another arrangement, the fourth pad on the carrier covers the top surface and the side surface and the area where the fourth pad does not overlap with the third pad, and a safe distance is maintained between the fourth and third pads, which requires that a safe distance be maintained between the fourth and third pads to avoid short circuit between the third and fourth pads. At this time, the schematic diagram of the circuit structure is similar to Figure 6 Similarly, the difference is that 160 is no longer an insulating layer but an isolation gap between the third and fourth pads. It can be understood that, Figure 6 is a pad structure that can be implemented provided by the present embodiment for the convenience of understanding and description, and the pad structure on the carrier and the insulating layer arrangement manner are not limited to Figure 6The structure shown, the pad structure on the carrier also includes but is not limited to, the third pad and the fourth pad each occupying half on each face of the carrier, the third pad and the fourth pad on the carrier are electrically connected to the first pad and the second pad on the substrate through the wire Figure 6 The structure shown, the pad structure on the carrier also includes but is not limited to, the third pad and the fourth pad each occupying half on each face of the carrier, the third pad and the fourth pad on the carrier are electrically connected to the first pad and the second pad on the substrate through the wire Figure 5 The structure shown, Figure 5 The structure shown,

[0054] In another embodiment, the fourth pad also extends to the bottom face of the carrier, the fourth pad on the bottom face of the carrier is fixed on the second pad on the substrate, and the third pad on the top face of the carrier is electrically connected to the first pad on the substrate through the wire.

[0055] The structure shown, Figures 2 to 6 , Figures 2 to 6 For the case that the bottom face of the carrier 120 is fixed on the second pad 112 on the substrate 110, the area of the second pad 112 on the substrate 110 is obviously larger than that of the first pad 111, and the bottom face of the carrier 120 is fixed on the second pad 112 on the substrate 110, so that the heat generated by the LED chip carried on the carrier 120 can be quickly conducted to the second pad 112 on the substrate 110 and then transmitted out, thereby improving the heat dissipation effect. At this time, covering the entire bottom face of the carrier 120 with the fourth pad 122 can allow the fourth pad 122 of the carrier to be directly soldered to the second pad 112 of the substrate to achieve electrical connection. Since the pad is usually made of copper or other metal, the heat conduction efficiency of the metal is higher, and the entire negative pad on the bottom face of the carrier can quickly transmit the heat. It can be understood that the bottom face of the carrier 120 can also be fixed on the first pad 111 on the substrate 110, and the schematic diagram thereof is similar to Figures 2 to 6 .

[0056] In another embodiment, the LED chip is a vertical structure chip, the bottom electrode of the LED chip is soldered to the fourth pad on the face where the LED chip is located, and the top electrode is electrically connected to the third pad on the face where the LED chip is located through the wire.

[0057] The structure shown, Figures 2 to 6 The negative electrode of the LED chip is on the bottom face of the LED chip, the positive electrode of the LED chip is on the top face, and the top face of the LED chip is the light emitting face. Such a structure of the LED chip can directly solder the negative electrode on the bottom face of the LED chip to the negative pad 122 of the carrier 120, and the positive electrode on the top face of the LED chip is connected to the third pad 121 through the wire 150. Since the area of the fourth pad 122 of the carrier 120 is larger than that of the third pad 121, the LED chip can be more quickly transmitted to the fourth pad 122 when soldered to the fourth pad 122.

[0058] In another embodiment, the several LED chips are all single-color LED chips, or are LED chips of different colors, or are LED chips of different color temperatures.

[0059] The LED packaging structure provided in the embodiment contains several LED chips, so there are more choices when selecting LED chips. The LED chips can be all single-color LED chips, or LED chips of different colors, or LED chips of different color temperatures. The LED chips can include, but are not limited to, visible light such as blue light, green light, and red light, and invisible light such as ultraviolet light and infrared light according to wavelength, can be horizontal structure (both positive and negative electrodes are on the chip), can be vertical structure (positive electrode on top and negative electrode on bottom or positive electrode on bottom and negative electrode on top), or can be flip chip. It can be understood that LED chips of different structures need to be matched with different design of positive and negative electrode pad circuits.

[0060] In another embodiment, the protective glue is epoxy resin glue or fluorescent glue.

[0061] In addition to protecting the carrier 120 and the LED chips on the carrier in the LED packaging structure, the protective glue 140 can be added with fluorescent substances to become fluorescent glue. The fluorescent glue will generate light of different wavelengths under the excitation of the LED chips.

[0062] The LED packaging structure provided in the embodiment includes a substrate, the substrate is provided with a first pad and a second pad; a carrier, the bottom surface of the carrier is fixed on the substrate, and the carrier is provided with a third pad and a fourth pad, the third pad is configured to partially cover the top surface of the carrier and extend to each side surface, and the fourth pad is configured to partially or completely cover the top surface of the carrier and extend to each side surface, the third pad on the carrier is electrically connected to the first pad on the substrate, and the fourth pad on the carrier is electrically connected to the second pad on the substrate; several LED chips, the several LED chips are respectively fixed on each surface of the carrier except the bottom surface; and a protective glue, the protective glue covers the substrate, the carrier, and the several LED chips. By fixing the carrier on the substrate and welding the LED chips on each surface of the carrier, the several LED chips emit light in multiple directions at the same time, so that the light emitting angle of one LED device reaches 180°, and the light emitting angle and the light emitting brightness of each angle of the LED device are obviously improved.

[0063] Embodiment two:

[0064] The embodiment also provides a preparation method of the LED packaging structure, the preparation method of the LED packaging structure includes:

[0065] S01: A substrate and a carrier are provided, a first pad and a second pad are disposed on the substrate, and a third pad and a fourth pad are disposed on the carrier. The third pad is configured to partially cover the top surface of the carrier and extend to each side surface, and the fourth pad is configured to partially or completely cover the top surface of the carrier and extend to each side surface and the bottom surface.

[0066] S02: Fix the carrier on the substrate, and solder the fourth pad on the bottom surface of the carrier to the second pad on the substrate.

[0067] S03: LED chips are welded and fixed on each surface of the carrier except the bottom surface. The LED chips are vertical structure chips, and the bottom electrode of the LED chip is attached to the fourth pad on its surface.

[0068] S04: Connect the top electrode of the LED chip to the third pad on its surface via a wire, and connect the third pad on the carrier to the first pad on the substrate via a wire.

[0069] S05: A protective colloid is formed by covering the substrate, carrier, and several LED chips with protective adhesive.

[0070] like Figure 7 As shown, Figure 7 This is a schematic flowchart illustrating a method for fabricating an LED packaging structure provided in this embodiment. The steps of the method for fabricating the LED packaging structure include:

[0071] S01. A substrate and a carrier are provided, wherein a first pad and a second pad are disposed on the substrate, and a third pad and a fourth pad are disposed on the carrier, wherein the third pad is configured to partially cover the top surface of the carrier and extend to each side surface, and the fourth pad is configured to partially or completely cover the top surface of the carrier and extend to each side surface and the bottom surface.

[0072] In this embodiment, the substrate may include, but is not limited to, a PCB substrate and a flexible PCB substrate. A first pad and a second pad are also provided on the substrate. The specific shape and structure of the first pad and the second pad can be adjusted according to the type of LED chip and the circuit structure; this embodiment does not impose any limitations. For example… Figure 2 The PCB shown connects the front pads and the back electrodes by drilling through holes.

[0073] In another embodiment, the step S01 further comprises: coating the fourth pads on each surface of the carrier so that the surfaces of the carrier are entirely covered by the fourth pads; coating an insulating layer on the top surface of the carrier above the fourth pads, the insulating layer being configured to form a ring along the edge of the top surface of the carrier and extend a branch to each side surface; and coating the third pads along the path of the insulating layer. The structure of the pads made by the step S01 can be seen from Figure 4 .

[0074] S02, fixing the carrier on the substrate, and welding the fourth pads on the bottom surface of the carrier with the second pads of the substrate.

[0075] In the embodiment, a carrier with a circuit structure is designed, and the carrier is fixed on the negative electrode of the PCB pad by conductive solder. The internal material of the carrier is a resin material with relatively high thermal conductivity, which can be PPA, PCT, EMC, SMC, BT, ceramic, etc. Different materials with different thermal conductivities can be selected according to the power of the device. The external material of the carrier is a metal with good electrical conductivity, which can be gold, silver, etc. The circuit structure of the positive and negative pads is designed in advance according to the shape and size of the chip. The circuit design can be parallel or series according to the needs. The structure diagram of the carrier can be seen from Figures 2-4 When the first pad 111 is a positive pad, the second pad 112 is a negative pad. When the first pad 111 is a negative pad, the second pad 112 is a positive pad. The polarity of the third pad 121 is the same as that of the first pad 111, and the polarity of the fourth pad 122 is the same as that of the second pad 112.

[0076] S03, welding and fixing LED chips on each surface of the carrier except the bottom surface, the LED chips being vertical structure chips, and the bottom electrodes of the LED chips being welded on the fourth pads on the surfaces.

[0077] The LED chips are bonded to the negative pads of the carrier by silver glue. One LED chip is placed on the front surface of the carrier, and four LED chips are placed on the side surfaces of the carrier. The LED chips can be visible light such as blue light, green light, red light, etc., or invisible light such as ultraviolet light, infrared light, etc. according to the wavelength. According to the chip structure, it can be horizontal structure (positive and negative electrodes are on the chip), vertical structure (positive electrode on the top and negative electrode on the bottom or positive electrode on the bottom and negative electrode on the top), or flip chip (positive and negative electrodes are on the bottom of the chip). The circuit of the positive and negative pads of the carrier needs to be designed in advance when using LED chips with different structures. As shown in Figures 2-4 The LED chip shown in the figure is a vertical structure chip (positive electrode on the top and negative electrode on the bottom).

[0078] S04, the top electrode of the LED chip is electrically connected with the third pad on the surface through a wire, and the third pad on the carrier is electrically connected with the first pad on the substrate through a wire.

[0079] The electrode of the chip is electrically connected with the pad of the corresponding electrode on the carrier through a conductor such as a gold wire, and the pad on the carrier is electrically connected with the pad of the corresponding electrode on the PCB, so that a loop is formed between the chip and the carrier, and between the carrier and the PCB.

[0080] S05, the substrate, the carrier and the plurality of LED chips are covered with a protective glue to form a protective glue body.

[0081] The packaging glue is uniformly made on the PCB by processes such as molding, coating, spraying and dispensing to form a protective layer. Different types of glue bodies can be made according to the needs of different LED chips. For example, visible light such as blue light, green light and red light can be made into transparent glue body, and fluorescent glue body, and invisible light such as ultraviolet and infrared is generally made into transparent glue body. The material of the glue body can also be selected according to the power size of the product. For example, epoxy glue is generally selected for small power (less than 0.5W), silicone glue is generally selected for medium power (0.5-2.5W), and silicone glue is generally selected for large power (more than 2.5W).

[0082] It should be noted that in this text, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or device. Without more limitations, the element defined by the sentence "including a…" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0083] The above-mentioned serial numbers of the embodiments of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0084] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above-mentioned specific embodiments, and the above-mentioned specific embodiments are only illustrative, not restrictive. Those skilled in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, which are all within the protection of the present application.

Claims

1. An LED packaging structure, characterized in that, The LED packaging structure includes: A substrate having a first pad and a second pad, wherein the area of ​​the second pad is larger than the area of ​​the first pad; A carrier, the bottom surface of which is fixed on the second pad, and the carrier is provided with a third pad and a fourth pad. The third pad is configured to partially cover the top surface of the carrier and extend to each side. The fourth pad is configured to partially or completely cover the top surface of the carrier and extend to each side. The third pad on the carrier is electrically connected to the first pad on the substrate, and the fourth pad on the carrier is electrically connected to the second pad on the substrate. A plurality of LED chips are fixed on various surfaces of the carrier except the bottom surface, and the electrodes of the LED chips are electrically connected to the third and fourth pads on their respective surfaces. A protective colloid covers the substrate, the carrier, and the plurality of LED chips; The carrier has a right prism structure; The third pad on the carrier is configured to form a circle around the edge of the top surface or to be set along the edges of the three sides of the top surface, and to extend a branch to each side. The fourth pad on the carrier covers the top and side surfaces and is located below the third pad, while an insulating layer is provided between the fourth pad and the third pad. Alternatively, the fourth pad on the carrier covers the top and side surfaces of the area that does not overlap with the third pad, and a safe distance is maintained between the fourth pad and the third pad.

2. The LED packaging structure as described in claim 1, characterized in that, The fourth pad extends to the bottom surface of the carrier, and the fourth pad on the bottom surface of the carrier is fixed to the second pad on the substrate. The third pad on the top surface of the carrier is electrically connected to the first pad on the substrate via a wire.

3. The LED packaging structure as described in claim 1, characterized in that, The LED chip is a vertical structure chip. The bottom electrode of the LED chip is bonded to the fourth pad on its surface, and the top electrode is electrically connected to the third pad on its surface via a wire.

4. The LED packaging structure as described in claim 1, characterized in that, The LED chips are either monochrome LED chips, LED chips of different colors, or LED chips of different color temperatures.

5. The LED packaging structure as described in claim 1, characterized in that, The protective colloid is an epoxy resin colloid or a fluorescent colloid.

6. A method for preparing an LED packaging structure, characterized in that, The method for preparing the LED packaging structure includes: S01: A substrate and a carrier are provided, wherein a first pad and a second pad are disposed on the substrate, and a third pad and a fourth pad are disposed on the carrier, wherein the third pad is configured to partially cover the top surface of the carrier and extend to each side surface, and the fourth pad is configured to partially or completely cover the top surface of the carrier and extend to each side surface and the bottom surface. The fourth pad is coated on each side of the carrier so that the entire surface of the carrier is covered by the fourth pad; An insulating layer is coated on the top surface of the carrier above the fourth pad. The insulating layer is configured to form a ring around the edge of the top surface of the carrier and extend a branch to each side. The third pad is coated along the path of the insulating layer; S02: The carrier is fixed on the substrate, and the fourth pad on the bottom surface of the carrier is soldered to the second pad on the substrate; S03: LED chips are welded and fixed on each of the carrier surfaces except the bottom surface. The LED chips are vertical structure chips, and the bottom electrode of the LED chip is attached to the fourth pad on its surface. S04: Connect the top electrode of the LED chip to the third pad on its surface via a wire, and connect the third pad on the carrier to the first pad on the substrate via a wire. S05: A protective colloid is formed by covering the substrate, the carrier, and the plurality of LED chips with protective adhesive.

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