An LED bracket, an LED lamp bead and a manufacturing method thereof

Abstract

The present invention provides an LED bracket, an LED lamp bead and a manufacturing method thereof. The first substrate and the second substrate of the LED bracket are respectively provided with a plurality of continuous uneven portions near the edges of the isolation belt at the first welding area and the second welding area. Compared with the existing structure in which the positive electrode substrate and the negative electrode substrate are respectively close to the edges of the isolation belt and adopt straight edges, the surface area near the isolation belt of the first welding area and the second welding area can be increased. When the solder diffuses and overflows into the area of the continuous uneven portions, it will diffuse along the continuous uneven portions, thereby preventing the solder from quickly accumulating at the edge of the welding area and flowing into the isolation belt and possibly forming a short circuit due to solder bridging, and improving the reliability of the product.

Description

Technical Field

[0001] The present invention relates to the field of displays, and in particular, to an LED bracket, an LED lamp bead, and a manufacturing method thereof. Background Art

[0002] With the development of LED (Light Emitting Diode) display technology, LED display packaging products have gradually become a hot spot, and LED display products have gradually entered various fields of our lives.

[0003] Currently, a commonly used flip-chip LED chip packaging structure is shown in Figure 15 As shown, a functional area is provided at the bottom of the reflecting cup 101 of the LED bracket. The functional area includes a positive electrode substrate 102, a negative electrode substrate 103, and a separating strip 104 located between the two to isolate them. The positive electrode substrate 102, the negative electrode substrate 103, and the separating strip 104 are on the same plane. During packaging, a die bonder is used to dot solder paste or flux with relatively low viscosity at corresponding positions on the positive electrode substrate 102 and the negative electrode substrate 103 to form a dot solder layer 105. Then, the flip-chip LED chip is placed in the reflecting cup 101, and the positive and negative electrodes of the flip-chip LED chip are welded to the dot solder layer 105 through reflow soldering. This packaging structure has the following problems: during the reflow soldering process, the solder paste and / or flux of the dot solder layer 105 will spread around when heated and squeezed, and it is easy to overflow from the positive electrode substrate 102 and the negative electrode substrate 103 and flow to the separating strip 104 to form solder bridging and cause a short circuit.

[0004] Therefore, how to avoid the solder from spreading and overflowing to the separating strip to form solder bridging and cause a short circuit is an urgent problem to be solved. Summary of the Invention

[0005] In view of the deficiencies of the above-mentioned related technologies, the purpose of the present invention is to provide an LED bracket, an LED lamp bead, and a manufacturing method thereof, aiming to solve the problem of how to avoid the solder from spreading and overflowing to the separating strip to form solder bridging and cause a short circuit.

[0006] An LED bracket, characterized by comprising:

[0007] A first substrate and a second substrate forming a pair of leads, and a separating strip disposed between the first substrate and the second substrate to insulate and isolate them;

[0008] The area of the first substrate close to the separating strip is a first welding area corresponding to the first electrode of the flip-chip LED chip, and the area of the second substrate close to the separating strip is a second welding area corresponding to the second electrode of the flip-chip LED chip;

[0009] The first welding area and the second welding area are respectively provided with a plurality of continuous uneven portions near the edge of the isolation strip.

[0010] It should be noted that the insulating isolation strip in the present invention is disposed between the first substrate and the second substrate to insulate and isolate the two from each other, while preventing external water vapor from invading, ensuring the airtightness of the LED bracket. The first welding area and the second welding area on the first substrate and the second substrate (the first welding area and the second welding area are respectively located on the front sides of the first substrate and the second substrate) are respectively provided with a plurality of continuous uneven portions near the edge of the isolation strip. Compared with the existing structure where the positive electrode substrate and the negative electrode substrate are respectively straight edges near the edge of the isolation strip, the surface area near the isolation strip of the first welding area and the second welding area can be increased. When the solder diffuses and overflows into the area of the continuous uneven portions, it will diffuse along the continuous uneven portions, thereby preventing the solder from quickly accumulating at the edge of the welding area and directly flowing into the isolation strip and possibly forming a short circuit due to solder bridging, improving the reliability of the product. In addition, the plurality of continuous uneven portions are only provided near the edges of the first welding area and the second welding area respectively close to the isolation strip, and will not extend to the bottom surfaces of the first substrate and the second substrate (that is, the surfaces of the first substrate and the second substrate far from the first welding area and the second welding area). During the reflow soldering process, when solder balls are generated in the first welding area and the second welding area, the solder balls can flow into the concave portions of the continuous uneven portions to avoid the accumulation of solder balls; on the contrary, if the continuous uneven portions extend to the bottom surfaces of the first substrate and the second substrate, the generated solder balls are likely to flow to the bottom surfaces of the first substrate and the second substrate through the uneven portions and easily cause a short circuit.

[0011] In some embodiments, the top surface of the isolation strip is lower than the first welding area and the second welding area to form an isolation groove between the first welding area and the second welding area.

[0012] It should be noted that the top surface of the isolation strip is lower than the first welding area and the second welding area, thereby forming an isolation groove between the first welding area and the second welding area. Even if the solder on one of the first welding area or the second welding area diffuses and overflows into the isolation groove, the presence of the isolation groove will block this part of the solder from continuing to flow to the other welding area, further avoiding the occurrence of short circuits caused by solder bridging.

[0013] Based on the same inventive concept, the present invention also provides an LED lamp bead, which includes:

[0014] The above-mentioned LED bracket, further including a flip-chip LED chip, and the first electrode and the second electrode of the flip-chip LED chip are respectively electrically connected to the first welding area and the second welding area.

[0015] Since the LED lamp bead adopts the above-mentioned LED bracket with a plurality of continuous concave and convex portions provided on the edges of the first welding area and the second welding area close to the isolation belt respectively, when the first electrode and the second electrode of the flip-chip LED chip are electrically connected to the first welding area and the second welding area through solder respectively, if there is solder that diffuses towards the isolation belt, when this part of the solder flows to the continuous concave and convex portions, it will diffuse along the concave and convex portions, and as much as possible to avoid the situation that the solder directly flows to the isolation belt to form solder bridging and thus cause a short circuit. Therefore, the reliability of this LED lamp bead is better.

[0016] In some embodiments, the LED bracket includes a base provided on the first substrate and the second substrate and formed with a reflective cup, and the first welding area and the second welding area are located at the bottom of the reflective cup; the LED lamp bead further includes a reflective glue layer located around the flip-chip LED chip and covering the bottom of the reflective cup, and the maximum thickness of the reflective glue layer on the side close to the flip-chip LED chip is less than or equal to the thickness of the flip-chip LED chip.

[0017] It should be noted that the maximum thickness of the reflective glue layer on the side close to the flip-chip LED chip is less than or equal to the thickness of the flip-chip LED chip, so as to ensure that the side of the reflective glue layer close to the flip-chip LED chip does not exceed the light-emitting surface of the flip-chip LED chip, thereby avoiding affecting the light emission of the flip-chip LED chip; at the same time, the reflective glue layer can also reflect the light emitted by the flip-chip LED chip to it, which can improve the light-emitting efficiency of the LED lamp bead and enrich the light-emitting angle of the LED lamp bead.

[0018] In some embodiments, the top surface of the reflective glue layer is a flat surface or a concave surface that is concave towards the bottom of the reflective cup.

[0019] It should be noted that when the top surface of the reflective glue layer is a flat surface, the light can be reflected evenly, so that its light emission is relatively uniform. When the light-emitting glue layer is a concave surface that is concave towards the bottom of the reflective cup, the reflectivity and reflection angle of the light can be increased to improve its light-emitting area and brightness, and improve its display effect.

[0020] In some embodiments, the LED lamp bead further includes a packaging layer provided in the reflective cup and covering the flip-chip LED chip and the reflective glue layer.

[0021] The setting of the packaging layer makes water vapor unable to invade the LED chip, avoiding the failure of the LED chip caused by the invasion of water vapor, thereby improving the quality and competitiveness of the product. At the same time, the packaging layer can also play a role in improving the diffusion effect of light, achieving a better display effect, and improving the user's satisfaction.

[0022] Based on the same inventive concept, the present invention also provides a manufacturing method of an LED lamp bead as described above, including:

[0023] Providing the first substrate and the second substrate, wherein the first welding area and the second welding area are respectively formed with a plurality of continuous concave and convex parts on edges close to the isolation zone;

[0024] forming an isolation zone between the first substrate and the second substrate to insulate and isolate the two;

[0025] The flip-chip LED chip is bonded on the first bonding area and the second bonding area.

[0026] It can be seen that the LED lamp bead produced by the LED lamp bead production method provided in this embodiment has a plurality of continuous concave and convex parts that can prevent the solder on the first welding area and the second welding area from overflowing to the isolation zone as much as possible, and the produced LED lamp bead has good reliability. In addition, the entire production process is simple and efficient, has no special requirements for the production process, has good versatility and low cost.

[0027] In some embodiments, completing the die bonding of the flip-chip LED chip on the first welding area and the second welding area includes:

[0028] According to the sizes of the first electrode and the second electrode of the flip-chip LED chip, tin is applied to the corresponding areas on the first welding area and the second welding area by a tinning machine, so as to form a first solder layer and a second solder layer on the first welding area and the second welding area respectively, which are adapted to the sizes of the first electrode and the second electrode and have uniform thickness;

[0029] The first electrode and the second electrode of the flip-chip LED chip are respectively aligned and welded to the first welding area and the second welding area to complete die bonding.

[0030] It should be noted that, by using a tinning machine to draw tin on the first welding area and the second welding area respectively, a first solder layer and a second solder layer with uniform thickness that are adapted to the electrode size of the flip-chip LED chip are formed. Compared with the existing method of forming a point solder layer by applying solder paste or flux to the corresponding position on the substrate through a crystal bonding machine, the area covered by the solder layer and the projected shape on the welding area are better adapted to the area and shape of the electrode of the flip-chip LED chip projected to the welding area, and the distribution of the solder is more uniform, which can further avoid the occurrence of cold solder joints or voids between the electrode and the welding area, and can also reduce the degree of outward diffusion of the solder after being heated and pressed to a certain extent, which can further improve the quality and reliability of the LED lamp beads. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of a top view of an LED bracket provided in Embodiment 1 of the present invention Figure 1 ;

[0032] Figure 2-1 forFigure 1 Schematic diagram of the C-C cross-sectional structure;

[0033] Figure 2-2 Enlarged schematic diagram of the three-dimensional structure of the concave-convex part provided in the first embodiment of the present invention; Figure 1 ;

[0034] Figure 2-3 is Figure 2-2 the top view of;

[0035] Figure 2-4 Enlarged schematic diagram of the three-dimensional structure of the concave-convex part provided in the first embodiment of the present invention II;

[0036] Figure 2-5 is Figure 2-4 the top view of;

[0037] Figure 3-1 Top view structure schematic diagram II of an LED bracket provided in the first embodiment of the present invention;

[0038] Figure 3-2 Top view structure schematic diagram III of an LED bracket provided in the first embodiment of the present invention;

[0039] Figure 3-3 is Figure 3-2 the C-C cross-sectional structure schematic diagram in;

[0040] Figure 4 Enlarged schematic diagram of the planar structure of the concave-convex part provided in the first embodiment of the present invention;

[0041] Figure 5 Top view structure schematic diagram of another LED bracket provided with a solder layer in the first embodiment of the present invention;

[0042] Figure 6 Cross-sectional structure schematic diagram of an LED lamp bead provided in the second embodiment of the present invention; Figure 1 ;

[0043] Figure 7 is Figure 6 the enlarged schematic diagram of the structure of part A in;

[0044] Figure 8 Cross-sectional structure schematic diagram II of an LED lamp bead provided in the second embodiment of the present invention;

[0045] Figure 9 Cross-sectional structure schematic diagram III of an LED lamp bead provided in the second embodiment of the present invention;

[0046] Figure 10 Cross-sectional structure schematic diagram of an LED lamp bead provided in the second embodiment of the present invention; Figure 4 ;

[0047] Figure 11Schematic diagram of the position of the positioning mark points provided in the third embodiment of the present invention;

[0048] Figure 12 Schematic diagram of the process flow of a method for manufacturing an LED lamp bead provided in the third embodiment of the present invention;

[0049] Figure 13 Schematic diagram of the tin painting process provided in the third embodiment of the present invention Figure 1 ;

[0050] Figure 14 Second schematic diagram of the tin painting process provided in the third embodiment of the present invention;

[0051] Figure 15 Schematic diagram of the top view structure of an existing LED lamp bead. Detailed implementation manners

[0052] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0054] In the prior art, the flip-chip LED chip packaging structure is prone to problems such as solder diffusion and overflow to the isolation belt to form tin bridging and cause short circuits. Based on this, the present invention hopes to provide a solution that can solve the above technical problems, and its detailed content will be elaborated in the subsequent embodiments.

[0055] Embodiment 1:

[0056] This embodiment provides an LED bracket. For example, as Figure 1 and Figure 2-1 show an LED bracket, where Figure 1 shows the top view schematic diagram of the LED bracket, Figure 2-1 shows Figure 1Schematic cross-sectional structure diagram of an LED bracket along the C-C section. The LED bracket 100 of this embodiment includes a first substrate 1 and a second substrate 2 forming a pair of leads, and an isolation strip 3 disposed between the first substrate 1 and the second substrate 2 to insulate and isolate the two. The area of the first substrate 1 close to the isolation strip 3 is a first welding area 4 corresponding to the first electrode of the LED chip, and the area of the second substrate 2 close to the isolation strip 3 is a second welding area 5 corresponding to the second electrode of the LED chip. A plurality of continuous uneven portions 6 are provided on the edge of the first welding area 4 close to the isolation strip 3 (it should be noted that Figure 2-1 The part shown by the reference numeral 6 in the figure is a schematic diagram of a cross-section taken from the concave portion of the uneven portion 6.). A plurality of continuous uneven portions 6 are also provided on the edge of the second welding area 5 close to the isolation strip 3. In this embodiment, relative to Figure 15 In the existing positive electrode substrate 102 and negative electrode substrate 103 shown in the figure, the edges close to the isolation strip 104 adopt a straight-edge structure, which can increase the surface area of the first welding area 4 and the second welding area 5 close to the isolation strip 3. When the solder diffuses and overflows into the area of the continuous uneven portion 6, it will diffuse along the continuous uneven portion 6, which can prevent the solder from quickly accumulating at the edge of the welding area and then directly flowing into the isolation strip 3 and possibly forming a short circuit due to solder bridging, thus improving the reliability of the product.

[0057] For ease of understanding, the following will be described in conjunction with Figures 2-2 to 2-4 The following shows an example of the uneven portion structure for illustration. One example is shown in Figures 2-2 to 2-3 As shown, Figure 2-2 The figure shows a three-dimensional structure diagram of the uneven portion provided on the edge of the first welding area 4 on the first substrate 1, Figure 2-3 As shown in Figure 2-2 The figure shows a top view of the uneven portion shown in Figure 2-3 In this example, the uneven portion is composed of a plurality of concave portions 61 and convex portions 62 arranged alternately on the edge of the first welding area 4, and as shown in Figures 2-4 to 2-5 As shown, Figure 2-4 The figure shows a three-dimensional structure diagram of the uneven portion provided on the edge of the second welding area 5 on the second substrate 2, Figure 2-5 As shown in Figure 2-4 The figure shows a top view of the uneven portion shown in Figures 2-2 to 2-3In the illustrated example, in this example, the concave portion 61 and the convex portion 62 are respectively located on the front surface of the second substrate and the side surface adjacent to the front surface. In the above two examples, the formation of the concave and convex portions can be directly achieved by removing a part of the material from the edges of the first welding area 4 and the second welding area 5 to form the concave portion 61, and the portion where the material is not removed forms the convex portion 62 corresponding to the concave portion. The manufacturing method is simple, efficient and low-cost. And it should be understood that the shapes of the concave and convex portions provided at the edges of the first welding area 4 and the second welding area 5 can be the same or different, with good flexibility and wide applicable scenarios. In addition, in the above example, multiple consecutive concave and convex portions are only provided on the edges of the first welding area 4 and the second welding area 5, and will not extend to the bottom surfaces of the first substrate 1 and the second substrate 2. During the reflow soldering process, when solder balls are generated in the first welding area 4 and the second welding area 5, the solder balls can flow into the concave portion 61 of the consecutive concave and convex portions to avoid the accumulation of solder balls; on the contrary, if the consecutive concave and convex portions extend to the bottom surfaces of the first substrate 1 and the second substrate 2, the generated solder balls are likely to flow to the bottom surfaces of the first substrate 1 and the second substrate 2 through the concave and convex portions and easily cause a short circuit.

[0058] It should be understood that in some application scenarios, multiple consecutive concave and convex portions 6 can also be provided only on the edge of one of the first welding area 4 and the second welding area 5 close to the isolation strip 3. For example, see Figure 3-1 As shown, multiple consecutive concave and convex portions 6 can be provided only on the edge of the first welding area 4 close to the isolation strip 3, and no consecutive concave and convex portions 6 are provided on the edge of the second welding area 5 close to the isolation strip 3. This can also avoid the solder on the first welding area 4 from overflowing to the isolation strip 3 as much as possible, and thus can also avoid the situation of solder diffusion overflowing to the isolation strip to form bridging and causing a short circuit to a certain extent. Similarly, it can also be selected to provide multiple consecutive concave and convex portions 6 only on the edge of the second welding area 5 close to the isolation strip 3, and no consecutive concave and convex portions 6 are provided on the edge of the first welding area 4 close to the isolation strip 3.

[0059] It should be understood that in some application scenarios, multiple consecutive concave and convex portions 6 can be provided on the entire edge of the first welding area 4 and the second welding area 5 close to the isolation strip 3, or multiple consecutive concave and convex portions 6 can also be provided only on a part of the edge, as long as it can increase the surface area of the first welding area 4 and the second welding area 5 close to the isolation strip 3. For example, see Figure 3-2 As shown, multiple consecutive concave and convex portions 6 can be provided in the middle area (which can also be replaced with other areas according to requirements) on the edges of the first welding area 4 and the second welding area 5 close to the isolation strip 3, and this middle area corresponds to the area on the first welding area 4 and the second welding area 5 where the solder layer will be provided subsequently. This can also avoid the solder on the first welding area 4 and the second welding area 5 from overflowing to the isolation strip 3 as much as possible.

[0060] It should be understood that there is no strict limitation on the shape of the continuous concave-convex portions 6 in this embodiment, and at least one of the shapes and sizes of the concave portions in the continuous concave-convex portions 6 in this embodiment can be the same or different, and at least one of the shapes and sizes of the convex portions in the continuous concave-convex portions 6 can also be the same or different. For example, in one example, referring to Figures 1 to 3-2 as shown, the continuous concave-convex portions 6 can include continuous serrated portions. In Figures 1 to 3-2 , the shape of the protrusions forming each serrated portion is a pointed tooth shape similar to a triangle, and the concave portion between adjacent serrated portions forms a groove shape similar to a triangle. Moreover, the shapes and sizes of each serrated portion and the shapes and sizes of the concave portions between adjacent serrated portions can be set to be the same, which is convenient for processing the first substrate and the second substrate and can ensure the consistency of the manufactured concave-convex portions, thereby improving the product quality. Also, for example, in another example, referring to Figure 4 as shown, compared with the serrated portion shown in Figure 3-3 ( Figure 3-3 is Figure 3-2 the cross-sectional structure schematic diagram of the LED bracket along the D-D section in Figure 4 , the shape of the protrusions forming each serrated portion in the serrated portion in Figure 4 is an arc-shaped protrusion, and the concave portion between adjacent serrated portions is an arc-shaped concave portion. Of course, the shape, size, and set position of the concave-convex portions in this embodiment can also be flexibly deformed and replaced according to requirements, which will not be elaborated one by one here.

[0061] In some examples of this embodiment, in order to further avoid the occurrence of short circuits caused by the solder in the welding area forming continuous solder. Referring to Figure 2-1 as shown, the top surface 7 of the isolation strip 3 can also be set lower than the first welding area 4 and the second welding area 5, so as to form an isolation groove between the first welding area 4 and the second welding area 5 (at this time, the top surface 7 of the isolation strip 3 forms the bottom of the isolation groove). In this way, even if the solder on the first welding area 4 or the second welding area 5 diffuses and overflows into this isolation groove, the presence in the isolation groove will also block this part of the solder from continuing to flow to the other welding area, which can further avoid the occurrence of short circuits caused by continuous solder.

[0062] It should be understood that in this embodiment, the height difference between the top surface 7 of the isolation strip 3 and the first welding area 4 and the second welding area 5 (i.e., the depth of the isolation groove) can be flexibly set, as long as it can block the solder flowing into the isolation groove from continuing to flow to the other welding area. For example, in one example, referring to Figure 2 as shown, the top surface 7 of the isolation strip 3 can be lower than the side of the continuous concave-convex portions 6 close to the isolation strip 3. Of course, it can also be set that the top surface 7 of the isolation strip 3 can be slightly higher than the side of the continuous concave-convex portions 6 close to the isolation strip 3.

[0063] It should be understood that the top surface 7 of the isolation strip 3 in this embodiment can be set as a flat surface, or can be set as a curved surface or a concave-convex surface with a concave-convex structure. When set as a flat surface, it is simple to manufacture. When set as a curved surface or a concave-convex surface, the effect of blocking solder can be improved. For example, one example is shown in Figure 2-1 As shown, the top surface 7 of the isolation strip 3 is set as a flat surface and is basically a horizontal plane. Another example is shown in Figure 3-3 As shown, the top surface 7 of the isolation strip 3 is set as an inclined surface. Relative to Figure 2-1 the horizontal plane shown, the capacity of the isolation groove can be increased on the premise of ensuring the strength of the isolation strip, and the effect of blocking solder can be improved.

[0064] In this embodiment, the first substrate 1 and the second substrate 2 forming the lead pair can include but are not limited to conductive metal sheets, conductive carbon sheets, and can also be a PCB board with wires arranged inside and well-connected, etc. Those skilled in the art can select the materials of the first substrate 1 and the second substrate 2 according to the actual situation and requirements, as long as the function of conducting electricity can be achieved, and this embodiment does not limit it.

[0065] In some embodiments, as shown in Figure 1 and Figure 5 shown, the LED bracket further includes a base 13 provided on the first substrate 1 and the second substrate 2 and having a reflecting cup 131 formed thereon. The first welding area 4 and the second welding area 5 are located at the bottom of the reflecting cup 131, as Figure 5 shown. In some embodiments, the LED bracket 100 further includes a protection circuit area 14 provided on the first substrate 1 and the second substrate 2. The protection circuit area 14 is used to set a protection circuit to protect the LED chip. It should be noted that there is a protrusion between the protection circuit area 14 and the first welding area 4 and the second welding area 5 to prevent the excess solder in the welding area from spreading and overflowing to the protection circuit area 14, and at the same time can play the role of a reinforcing rib to improve the overall strength of the LED bracket. The protection circuit in this embodiment can include but is not limited to using a voltage stabilizing tube, a fuse, etc., as long as it can play the role of protecting the LED chip. Those skilled in the art can select how to set the protection circuit according to the actual situation and requirements, and the present invention does not limit it. Preferably, in this embodiment, a voltage stabilizing tube is used to protect the LED chip to avoid damage to the LED chip and even more serious safety accidents when a short circuit or an open circuit occurs in the circuit, thereby improving its safety and user satisfaction. It should be understood that the material of the base 13 in this embodiment can be flexibly set, for example, it can be but not limited to plastic, ceramic, etc. The isolation strip 3 and the base 13 can be an integrally formed structure or a non-integrally formed structure, and details will not be elaborated here.

[0066] Embodiment Two

[0067] This embodiment provides an LED lamp bead. For example, as Figure 6 shown is a schematic cross-sectional structure diagram of an LED lamp bead (without a reflective adhesive layer and a packaging layer. Figure 6 The schematic cross-sectional diagram of the LED bracket in Figure 1 is obtained by a C-C cross-section of the LED bracket shown). The LED lamp bead includes a flip-chip LED chip 16. The first electrode 17 and the second electrode 18 of the flip-chip LED chip 16 are electrically connected to the first welding area 4 and the second welding area 5 respectively. Since the LED lamp bead adopts the above-mentioned LED bracket in which a plurality of continuous uneven portions 6 are provided on the edges of the first welding area 4 and the second welding area 5 respectively close to the isolation strip 3, when the first electrode 17 and the second electrode 18 of the flip-chip LED chip 16 are electrically connected to the first welding area 4 and the second welding area 5 through solder respectively, if there is solder that diffuses towards the isolation strip 3, when this part of the solder flows to the continuous uneven portions 6, it will diffuse along the uneven portions 6, as much as possible to avoid the situation that the solder directly flows to the isolation strip 3 to form solder bridging and cause a short circuit, and the reliability of the LED lamp bead is better.

[0068] It should be understood that in this embodiment, the number of flip-chip LED chips 16 included in the LED lamp bead can be one or multiple. In order to more clearly express the structure of the LED lamp bead, a local area A is magnified. For example, as Figure 7 shown is a schematic enlarged view of a partial structure of an LED lamp bead. It should be noted that the structures of the two electrodes of the LED chip can be symmetrical or can be set as an asymmetrical structure. Figure 7Only the structure of the first electrode terminal among them is shown in the enlarged view shown. In this embodiment, the light-emitting color of the flip-chip LED chip 16 included in the LED lamp bead can be flexibly set, and for example, it can be an LED chip that emits red light, green light, blue light, or other colors. In some application scenarios, when the LED lamp bead includes two or more flip-chip LED chips 16, the light-emitting colors of these flip-chip LED chips 16 can be the same, all different, or some the same and some different, which can be specifically set flexibly according to requirements. For example, in one example, the LED lamp bead may include three flip-chip LED chips, which are a blue flip-chip LED chip, a red flip-chip LED chip, and a green flip-chip LED chip respectively. Among them, the blue LED chip and the green LED chip can be gallium nitride-based LED chips, while the red LED chip can be a gallium arsenide-based LED chip. In some other examples, all the flip-chip LED chips 16 in the LED lamp bead can also be blue LED chips. In order to make some of the flip-chip LED chips 16 emit green light and red light respectively, corresponding light conversion layers can be provided on the light-emitting surfaces of these flip-chip LED chips 16. The light conversion layer can include but is not limited to a phosphor layer, a quantum thin film layer, etc. It should be understood that only the case where an LED lamp bead can support emitting red, green, and blue light is introduced above. However, in some examples, in addition to emitting red, green, and blue light, the flip-chip LED chip 16 of the same LED lamp bead can also emit at least one of cyan, white, and yellow light. Therefore, in some examples of this embodiment, an LED lamp bead may include three flip-chip LED chips 16 or a larger number of flip-chip LED chips 16, which will not be elaborated one by one here.

[0069] In some embodiments, the LED lamp bead further includes a reflective glue layer located around the LED chip and covering the bottom of the reflector cup. It should be noted that the reflective glue layer can be disposed on the bottom of the reflector cup of the LED lamp bead by means including but not limited to spraying and dispensing. And the maximum thickness of the side of the reflective glue layer close to the flip-chip LED chip (that is, the side of the reflective glue layer away from the side wall of the reflector cup) should be less than or equal to the thickness of the flip-chip LED chip, so that the side of the reflective glue layer close to the flip-chip LED chip will not affect the light-emitting effect of the flip-chip LED chip due to excessive thickness. The reflective glue layer in this embodiment can include but not limited to white wall glue. By setting the reflective glue layer, the solder paste is not easily affected by external factors and melts and fails. At the same time, it can also improve the light diffusion effect and increase the light-emitting efficiency. It should be noted that the maximum thickness of the side of the reflective glue layer close to the side wall of the reflector cup (that is, the side of the reflective glue layer away from the flip-chip LED chip) can also be set to be less than or equal to the thickness of the flip-chip LED chip, or can be set to be greater than the thickness of the flip-chip LED chip according to requirements. This embodiment does not limit it. The top surface shape of the reflective glue layer in this embodiment can include but not limited to a flat surface or a concave surface that is concave towards the bottom of the reflector cup. For example, as Figure 8 shown is a schematic cross-sectional structure diagram of the reflective glue layer of an LED lamp bead, Figure 8 and the schematic cross-sectional diagram of the LED bracket in Figure 1 is obtained by a C-C cross-section of the LED bracket shown in the figure. In the example shown in this figure, the reflective glue layer 19 included in the LED lamp bead is located around the LED chip and covers the bottom of the reflector cup. The top surface of the reflective glue layer 19 is a flat surface 191, so that the light can be reflected more evenly and ensure its display effect. Another example can be seen in Figure 9 shown is a schematic cross-sectional structure diagram of the reflective glue layer of another LED lamp bead, Figure 9 and the schematic cross-sectional diagram of the LED bracket in Figure 1 is obtained by a C-C cross-section of the LED bracket shown in the figure. In the example shown in this figure, the top surface of the reflective glue layer 19 is a concave surface 192 that is concave towards the bottom of the reflector cup. The concave surface 192 can be formed by means including but not limited to adopting a centrifugal method, and can also be formed by a die pressing method. By forming an arc-shaped concave surface, its reflection efficiency and reflection angle are increased, the light-emitting area is increased, the light-emitting effect and the display effect are improved, and the user satisfaction is improved.

[0070] In some embodiments, as Figure 10 shown, the LED lamp bead further includes a packaging layer 20 disposed in the reflector cup 131 and covering the flip-chip LED chip 16 and the reflective glue layer 19, Figure 10 and the schematic cross-sectional diagram of the LED bracket in Figure 1Obtained from the C-C cross-section of the shown LED bracket. It should be noted that the encapsulation layer 20 can be, but is not limited to, an adhesive layer, which can be provided in the reflector cup 131 by, but is not limited to, injection molding, compression molding, hot pressing and other methods, and covers the surfaces of the flip-chip LED chip 16 and the reflective adhesive layer 19, so that the encapsulation layer 20 can protect the flip-chip LED chip 16 from moisture erosion, thus avoiding the failure problem of the flip-chip LED chip 16 caused by moisture. At the same time, in order to ensure the light transmittance of the encapsulation layer 20 and diffuse the light, the material of the encapsulation layer 20 can include, but is not limited to, at least one of a transparent adhesive layer, a fluorescent adhesive layer, a quantum dot adhesive layer, etc. Those skilled in the art can select the material of the encapsulation layer according to the actual situation and requirements, and the present invention does not make a limitation. By setting the encapsulation layer, the light emitted by the LED chip can be better diffused, ensuring the light output effect and display effect, and improving the user's satisfaction.

[0071] The LED lamp bead of this embodiment is provided with a flip-chip LED chip on the above-mentioned LED bracket, then a reflective adhesive layer with a maximum thickness less than or equal to the thickness of the flip-chip LED chip is arranged around the flip-chip LED chip and covers the bottom of the reflector cup. At the same time, the top surface of the reflective adhesive layer is set to be a flat surface or a concave surface concave towards the bottom of the reflector cup. Finally, an encapsulation layer is covered on the flip-chip LED chip and the reflective adhesive layer. The LED lamp bead well protects the solder paste by arranging the reflective adhesive layer on the above-mentioned LED bracket, making it not easily affected by external factors such as melting and deterioration. At the same time, the reflective adhesive layer can also improve the diffusion of light, enhance the display effect and light output efficiency. By setting the top surface of the reflective adhesive layer with different shapes to adapt to the LED lamp beads in different application scenarios, the setting of the encapsulation layer makes the LED lamp bead not easily invaded by moisture, avoids the problem of LED chip failure caused by moisture invasion, and at the same time can also improve the diffusion effect of light, increase the display effect, and improve the quality of the product and the user experience satisfaction.

[0072] Embodiment Three

[0073] In order to solve the problems that solder diffusion and overflow cause short circuits due to solder bridging, and uneven solder distribution leads to large voids and high thermal resistance, which are urgent problems to be solved. This embodiment provides a manufacturing method of an LED lamp bead, see Figure 12 shown, which includes but is not limited to:

[0074] S1201: Provide a first substrate and a second substrate, and a plurality of continuous concavo-convex portions are formed on the first welding area and the second welding area respectively near the edge of the isolation belt.

[0075] It should be understood that, in this embodiment, the manner of forming a plurality of continuous uneven portions on the first welding area and the second welding area respectively close to the edge of the isolation belt can be flexibly adopted. For example, it can be formed by, but not limited to, etching, cutting, stamping and other methods. This embodiment does not limit it.

[0076] S1202: Form an isolation belt between the first substrate and the second substrate to insulate and isolate the two.

[0077] In some examples, when the LED bracket further includes the above-mentioned base, the isolation belt and the base can be manufactured simultaneously in step S1202. Of course, the isolation belt can also be manufactured first and then the base.

[0078] After manufacturing the LED bracket, when manufacturing the LED lamp beads, the following step S1203 can also be included.

[0079] S1203: Complete the die bonding of the flip-chip LED chip on the first welding area and the second welding area.

[0080] For example, in some examples, it can be adopted Figure 15 The shown method is used to dot liquid solder on the first welding area and the second welding area by a die bonder to form a dot-shaped solder layer, and then the first electrode and the second electrode of the flip-chip LED chip are aligned and welded with the corresponding solder layer to complete die bonding.

[0081] In other examples of this embodiment, in order to further improve the quality and reliability of the manufactured LED lamp beads, the process of completing the die bonding of the flip-chip LED chip on the first welding area and the second welding area can be referred to Figure 13 as shown, which includes but is not limited to:

[0082] S1301: According to the sizes of the first electrode and the second electrode of the flip-chip LED chip, draw solder on the corresponding areas of the first welding area and the second welding area respectively by a solder drawing machine, so as to form a first solder layer and a second solder layer on the first welding area and the second welding area respectively that are adapted to the sizes of the first electrode and the second electrode and have uniform thickness. Draw solder on the first welding area and the second welding area respectively by a solder drawing machine to form a first solder layer and a second solder layer that are adapted to the sizes of the electrodes of the flip-chip LED chip and have uniform thickness. For example, one example is referred to Figure 5As shown, solder is painted on corresponding areas of the first welding area 4 and the second welding area 5 by a solder painting machine to form a first solder layer 11 and a second solder layer 12. Compared with the existing method of using a die bonder to dot solder paste or flux on corresponding positions of a substrate to form a dot-shaped solder layer, the formed first solder layer 11 and second solder layer 12 have a uniform thickness. The areas covered by the formed first solder layer 11 and second solder layer 12 in the first welding area 4 and the second welding area 5 respectively, as well as the projection shapes, are adapted to the areas and shapes of the projections of the first electrode and the second electrode of the flip-chip LED chip onto the first welding area 4 and the second welding area 5. This can avoid the occurrence of poor soldering or voids between the first electrode and the second electrode and the first welding area 4 and the second welding area 5, and can also reduce to a certain extent the degree of outward diffusion of the solder after being heated and pressed, further improving the quality and reliability of the LED lamp beads.

[0083] It should be noted that the solder painting machine is a high-precision device. After manual programming, it can automatically perform the solder painting operation, or the solder painting operation can be carried out manually. At the same time, it also needs to be used in conjunction with a device that can accurately position. This device includes but is not limited to a positioning device containing a CCD vision system. It should be noted that the first solder layer 11 and the second solder layer 12 include at least one of solder paste and flux. It can be only solder paste, only flux, or of course a mixture of solder paste and flux at the same time. Those skilled in the art can choose according to the actual situation and requirements, and this embodiment does not limit it. In an application scenario, when using a high-precision solder painting machine, the nozzle of the solder painting machine uses a solder painting nozzle with a diameter of 0.1 mm. After manual programming, a CCD vision system is used at this time to accurately position the area where solder needs to be painted, and then the solder painting machine starts to work. It evenly applies solder with the composition of solder paste to the preset positions of the first welding area 4 and the second welding area 5 of the bracket, such as Figure 5 the positions where the first solder layer 11 and the second solder layer 12 are located in. After the solder painting is completed, it can also include but is not limited to using a 3D solder paste inspection machine to detect the amount of solder painted. The detection of the amount of solder painted includes but is not limited to area, volume, height, etc., to ensure the consistency of the solder paste.

[0084] To more clearly express the process of solder painting, the following takes Figure 14 an example of the process of solder painting by a solder painting machine shown in the figure for illustration.

[0085] S1401: According to the sizes of the first electrode and the second electrode of the flip-chip LED chip, determine the solder painting areas on the first welding area and the second welding area respectively.

[0086] It should be understood that the tin - drawing area determined on the first welding area and the second welding area according to the sizes of the first electrode and the second electrode of the flip - chip LED chip in this example mainly refers to the size of the area where tin - drawing is required. In this step, the specific position of the tin - drawing area can also be determined according to the design of the specific die - bonding position of the flip - chip LED chip.

[0087] For example, in an application example scenario, the size and position of the specific tin - drawing area can be determined according to the electrode size of the flip - chip LED chip and the design of the die - bonding position. Taking a flip - chip LED chip with a size of 700um * 700um as an example, the size of a single electrode is 230um * 650um. Therefore, according to this size, the length of the tin - drawing area is determined to be 520um, and the width is 200um. Then, the inner diameter of the nozzle of the tin - drawing machine required is determined to be 0.1mm, and then the tin - drawing reference point is determined to edit the tin - drawing program.

[0088] S1402: Obtain the tin - drawing reference point and the tin - drawing center point.

[0089] For example, continuing with the above - mentioned application example scenario, the tin - drawing reference point can be selected as the bottom center point of the bracket reflector cup to make it more convenient and clear when editing the tin - drawing program. At the same time, the obtained tin - drawing center point is the initial point during tin - drawing. In this example, the mid - point of the isolation strip is used as the tin - drawing center point, and tin - drawing is performed along the length direction of the isolation strip.

[0090] S1403: Edit the tin - drawing program according to the tin - drawing reference point, and use the tin - drawing center point as the initial point to draw tin on the tin - drawing areas on the first welding area and the second welding area respectively to form the first solder layer and the second solder layer.

[0091] In some examples of this embodiment, after the first solder layer and the second solder layer are formed, the following detection steps may further be included:

[0092] S1404: Obtain the first specification size of the first solder layer and the second specification size of the second solder layer respectively.

[0093] S1405: According to the obtained first specification size and second specification size, detect whether they meet the preset specification size range.

[0094] In this embodiment, after tin - drawing is completed, a 3D solder paste inspection machine (SPI) including but not limited to it can be used to detect the specification sizes of the tin - drawing, including but not limited to area, volume, and height, to ensure the consistency of the tin - drawing, and determine whether the detected results meet the preset specification size range. For example, the preset specification size range shown in Table 1 below. It should be noted that this preset specification size range is set according to the electrode size of the LED chip, and those skilled in the art can set it according to the actual situation and requirements.

[0095] Table 1

[0096] Item Lower limit (um) Upper limit (um) Tin drawing length 480 560 Tin drawing width 180 230 Tin drawing height 80 120

[0097] S1302: Aligning and welding the first electrode and the second electrode of the flip-chip LED chip to the first welding area and the second welding area respectively to complete die bonding.

[0098] It should be understood that in some examples, the bonding process is not limited to using solder paste and / or flux, and conductive glue or other materials may be used as equivalent replacements as required, which will not be described in detail here.

[0099] In some examples of this embodiment, after the solid crystal is completed, a reflective adhesive layer should be covered around the LED chip, and a packaging layer, such as a packaging adhesive layer, should be provided on the reflective adhesive layer. The maximum thickness of the reflective adhesive layer provided in this embodiment on the side close to the flip-chip LED chip should be less than or equal to the thickness of the LED chip. At the same time, the top surface of the reflective adhesive layer can be a curved surface, or a flat surface or a concave-convex surface, etc., to increase the reflectivity of the light, and enhance the display brightness and display effect. In actual production, multiple LED brackets can be arranged to form a matrix to produce multiple LED lamp beads in batches. In order to ensure the consistency of welding, positioning mark points can be set on the edge of the LED bracket for positioning, such as Figure 11The following is a schematic diagram showing the position of a positioning mark point 15. The dispensing device automatically identifies the positioning mark point 15 and automatically calculates the offset distance between the die bonding position and the standard position according to the preset standard position and corrects it. The positioning mark point 15 may include, but is not limited to, a set hole, a groove, an identification, etc. In this embodiment, it is preferable to use a hole to set the positioning mark point, and its aperture may include, but is not limited to, a diameter of 1.5 mm, a diameter of 1 mm, etc. Those skilled in the art can set it according to the actual situation and requirements, and this embodiment does not limit it. It should be noted that the nozzle of the dispensing device is customized according to the sizes of the LED bracket and the LED chip, and at the same time, it is ensured that the center point of the nozzle is perpendicular to the center point of the target dispensing point, so that the center point of the nozzle coincides with the center point of the target dispensing point during dispensing. The spray valve may include, but is not limited to, a piezoelectric spray valve, and it can dispense glue at multiple points in one spray. It should be noted that during the operation of the dispensing device, the high-definition camera may include, but is not limited to, the way of pre-scanning or scanning while running. It can automatically scan and calculate the deviation during the operation, so as to correct the dispensing point in real time, ensure the consistency of dispensing, and improve the quality and consistency of the product. In this embodiment, a piezoelectric spray valve is used for dispensing, and when dispensing, it can dispense glue at multiple points in one spray or only at one point in one spray. Those skilled in the art can set it according to the actual situation and requirements, and this embodiment does not limit it. In this embodiment, during the die bonding process of aligning and welding the first electrode and the second electrode of the flip-chip LED chip to the first welding area and the second welding area respectively, when installing the flip-chip LED chip, the installation position can be accurately controlled. For example, a foolproof identification hole (which can also be replaced with other foolproof structures) is set to facilitate accurate positioning by software, and a high-definition camera is used to automatically calculate the deviation between its installation position and the standard installation position, and the installation position is corrected according to the calculated result.

[0100] In the method for manufacturing an LED lamp bead provided in this embodiment, after providing a first substrate and a second substrate, an isolation band is formed between the first welding area and the second welding area respectively, and continuous concave and convex parts are formed at the edges close to the isolation band respectively, so that the excess solder can be accommodated, avoiding the problem of short circuit caused by excessive solder resulting in solder bridging. At the same time, a tin drawing machine is used to draw tin on the first welding area and the second welding area to form a first solder layer and a second solder layer, making the first solder layer and the second solder layer more uniform, ensuring their consistency, and improving the quality of the product and the user's satisfaction.

[0101] The LED bracket, LED lamp beads and their manufacturing methods provided in the foregoing embodiments can be applied to various display fields. For example, they can be made into display modules for use in display fields (such as display modules of terminals like display screens), and can also be applied to the backlight modules of display products such as TVs and mobile phones. In addition, they can also be applied to the field of button backlighting, household lighting, medical lighting, decoration, vehicle lighting, transportation, etc. When applied to the field of button backlighting, it can be used as the button backlight source for devices with buttons such as mobile phones, calculators, and keyboards; when applied to the field of household lighting, it can be made into floor lamps, table lamps, lighting lamps, ceiling lamps, downlights, projection lamps, etc.; when applied to the field of medical lighting, it can be made into operating lamps, low-electromagnetic lighting lamps, etc.; when applied to the field of decoration, it can be made into various decorative lamps, such as various colored lights, landscape lighting lamps, and advertising lights; when applied to the field of vehicle lighting, it can be made into car headlights, etc.; when applied to the field of transportation, it can be made into various traffic lights or various street lamps. The above applications are only several examples shown in this embodiment. It should be understood that the applications of the LED lamp beads in this embodiment are not limited to the several fields exemplified above.

[0102] It should be noted that the number, shape, and size relationship of each element in the drawings do not represent the actual situation of the elements, but are only schematic diagrams for easy understanding. The embodiments of the present invention have been described above in conjunction with the drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are only illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the purpose of the present invention and the scope protected by the claims. All of these are within the protection scope of the present invention.

Claims

1. An LED bracket, characterized in that, Comprising: A first substrate and a second substrate forming a lead pair, and an isolation strip disposed between the first substrate and the second substrate to insulate and isolate the two; The area of the first substrate close to the isolation strip is a first welding area corresponding to the first electrode of the flip-chip LED chip, and the area of the second substrate close to the isolation strip is a second welding area corresponding to the second electrode of the flip-chip LED chip; A plurality of continuous uneven portions are respectively disposed at the edges of the first welding area and the second welding area close to the isolation strip. The uneven portions are composed of convex portions and concave portions. The concave portions form grooves on the top surfaces of the corresponding substrates of the first welding area and the second welding area, and the uneven portions do not extend to the bottom surfaces of the corresponding substrates. During the reflow soldering process, the continuous uneven portions can increase the surface area of the first welding area and the second welding area close to the isolation strip. When the solder diffuses and overflows into the area of the continuous uneven portions, it will diffuse along the continuous uneven portions, preventing the solder from accumulating too quickly at the edges of the welding areas.

2. The LED bracket according to claim 1, wherein The top surface of the isolation strip is lower than the first welding area and the second welding area to form an isolation groove between the first welding area and the second welding area.

3. The LED bracket according to claim 1 or 2, characterized in that, The LED bracket further includes a base disposed on the first substrate and the second substrate and formed with a reflecting cup, and the first welding area and the second welding area are located at the bottom of the reflecting cup.

4. An LED lamp bead, characterized in that, The LED lamp bead includes the LED bracket according to any one of claims 1-3, and further includes a flip-chip LED chip, and the first electrode and the second electrode of the flip-chip LED chip are respectively electrically connected to the first welding area and the second welding area.

5. The LED lamp bead according to claim 4, characterized in that, The LED bracket includes a base disposed on the first substrate and the second substrate and formed with a reflecting cup, and the first welding area and the second welding area are located at the bottom of the reflecting cup; The LED lamp bead further includes a reflective glue layer located around the flip-chip LED chip and covering the bottom of the reflecting cup, and the maximum thickness of the side of the reflective glue layer close to the flip-chip LED chip is less than or equal to the thickness of the flip-chip LED chip.

6. The LED lamp bead according to claim 5, wherein, The top surface of the reflective glue layer is a flat surface or a concave surface recessed towards the bottom of the reflecting cup.

7. The LED lamp bead according to claim 5 or 6, characterized in that, The LED lamp bead further includes a packaging layer disposed in the reflecting cup to cover the flip-chip LED chip and the reflective glue layer.

8. A manufacturing method of an LED lamp bead as described in any one of claims 4-7, characterized in that, Comprising: Providing the first substrate and the second substrate, and a plurality of continuous uneven portions are formed on the edges of the first welding area and the second welding area respectively close to the isolation strip. The uneven portions are composed of convex portions and concave portions. The concave portions form grooves on the top surfaces of the corresponding substrates of the first welding area and the second welding area, and the uneven portions do not extend to the bottom surfaces of the corresponding substrates. During the reflow soldering process, the continuous uneven portions can increase the surface area of the first welding area and the second welding area close to the isolation strip. When the solder diffuses and overflows into the area of the continuous uneven portions, it will diffuse along the continuous uneven portions, preventing the solder from accumulating too quickly at the edges of the welding areas; An isolation belt for insulating and isolating the first substrate and the second substrate is formed therebetween; Die bonding of the flip-chip LED chip is completed on the first bonding area and the second bonding area; 9. The manufacturing method of the LED lamp bead according to claim 8, characterized in that, The die bonding of the flip-chip LED chip on the first bonding area and the second bonding area includes: According to the sizes of the first electrode and the second electrode of the flip-chip LED chip, solder is drawn in corresponding areas on the first bonding area and the second bonding area respectively by a solder drawing machine, so as to form a first solder layer and a second solder layer which are adapted to the sizes of the first electrode and the second electrode and have uniform thicknesses on the first bonding area and the second bonding area respectively; The first electrode and the second electrode of the flip-chip LED chip are respectively butt-welded to the first bonding area and the second bonding area to complete die bonding.

10. The manufacturing method of the LED lamp bead according to claim 9, wherein, The drawing of solder in corresponding areas on the first bonding area and the second bonding area respectively by the solder drawing machine includes: According to the sizes of the first electrode and the second electrode of the flip-chip LED chip, the solder drawing areas are determined on the first bonding area and the second bonding area respectively; Obtain a solder drawing reference point and a solder drawing center point; Edit a solder drawing program according to the solder drawing reference point, and draw solder on the solder drawing areas on the first bonding area and the second bonding area respectively with the solder drawing center point as the starting point to form the first solder layer and the second solder layer.

Images