CN215418170U

CN215418170U - Flip-chip LED lamp pearl, LED module and LED display screen

Info

Publication number: CN215418170U
Application number: CN202120617879.XU
Authority: CN
Inventors: 张汉春; 江忠永
Original assignee: Hangzhou Multi Color Optoelectronics Co ltd
Current assignee: Hangzhou Multi Color Optoelectronics Co ltd
Priority date: 2021-03-26
Filing date: 2021-03-26
Publication date: 2022-01-04
Anticipated expiration: 2031-03-26

Abstract

The application discloses an inverted LED lamp bead, an LED module and an LED display screen, wherein the inverted LED lamp bead comprises a support; the flip LED chip is arranged on the surface of the support and is electrically connected with the support; a reflective cup positioned on the support and surrounding the at least one flip-chip LED chip; the packaging adhesive layer is hermetically covered on the upper surface of the bracket, which is not covered by the inverted LED chip and the reflection cup, the step structure of the bracket, the reflection cup and the inverted LED chip; the juncture of the bracket and the side wall of the reflecting cup is wrapped by an encapsulation glue layer; the packaging adhesive layer comprises a convex part positioned above the inverted LED chip, and the convex part is a lens of the inverted LED lamp bead; the lens and the packaging adhesive layer are of an integrated structure. The encapsulation glue film covers the upper step face of this stair structure and support completely, improves the leakproofness of flip-chip LED lamp pearl.

Description

Flip-chip LED lamp pearl, LED module and LED display screen

Technical Field

The utility model relates to the technical field of LEDs, in particular to an inverted LED lamp bead, an LED module and an LED display screen.

Background

The LED display screen has the following advantages: high gray scale, wide viewing angle, rich color, and customizable screen shape. Therefore, the LED display screen is widely used in various fields such as industry, traffic, commercial advertisement, information distribution, sports competition, and the like.

The pixel element used in the LED display screen is an LED lamp bead. The pixel element is, for example, an LED lamp bead in a Surface Mounted Device (SMD) package manner. With the development of LED display technology, people have higher and higher requirements for quality of display screens, and firstly, the requirements for resolution are higher and higher, which makes the dot pitch of LED display screens smaller and smaller.

Currently, the outdoor LED display screen mainly includes a lamp (direct plug-in) series and an SMD (Surface Mounted Devices) outdoor series. Because the paster product can accomplish "trinity", 3 LED chips can encapsulate inside a reflection cup promptly, can reduce the point interval between the lamp pearl to make outdoor LED display screen's definition more and more high, the display effect is more and more good, obtains extensive use. The LED lamp bead applied to the existing outdoor display screen is of a glue-pouring type packaging patch structure, an LED chip is placed on a support with a reflecting cup, and then a packaging glue layer is used for filling and sealing. Because the pins adopt a bending process, the bending angle difference exists, so that the height difference exists between the pins of the LED lamp beads, and the left and right visual angles are different; in addition, the packaging adhesive layer adopts a dispensing process, and due to the fact that the metering type dispenser fluctuates and the size of a reflecting cup of the support fluctuates, the phenomenon of uneven dispensing exists, and the phenomenon of black spots and color cast exist when the side face is viewed at a large visual angle.

In addition, the reflecting cup is made of PPA (polyphthalamide) materials, the pins of the bracket are made of metal materials, and the PPA materials and the metal materials cannot be bonded, so that gaps exist between the pins of the bracket and the reflecting cup; the surface of the lamp bead has a combined interface of the reflecting cup and the packaging adhesive layer, and when the lamp bead is used for a long time, a tiny gap can be generated due to the mismatch of expansion coefficients of different materials; therefore, water vapor can permeate into the LED lamp beads along the gaps, so that the reliability of the LED lamp beads is reduced, and the service life is shortened. And the LED chip in the existing outdoor display screen adopts a front-mounted chip, 5-6 bonding wires exist in each LED lamp bead and need to be welded, the machine table efficiency is low, and the bonding wires are easy to lose effectiveness.

SUMMERY OF THE UTILITY MODEL

In view of the above problems, the present invention provides a flip LED lamp bead, an LED module and an LED display screen, which improve the sealing performance and weather resistance of the flip LED lamp bead, improve the reliability and service life of the flip LED lamp bead, and reduce the processing difficulty and cost of the flip LED lamp bead.

According to one aspect of the utility model, a flip-chip LED lamp bead is provided, comprising: a bracket including a step structure at an edge of the bracket; the flip LED chip is arranged on the surface of the support and is electrically connected with the support; a reflective cup positioned on the support and surrounding the at least one flip-chip LED chip; the packaging adhesive layer is hermetically covered on the upper surface of the support, which is not covered by the flip LED chip and the reflection cup, the step structure of the support, the reflection cup and the flip LED chip; the juncture of the bracket and the side wall of the reflecting cup is wrapped by the packaging adhesive layer; the packaging adhesive layer comprises a protruding part positioned above the flip LED chip, and the protruding part is a lens of the flip LED lamp bead; the lens and the packaging adhesive layer are of an integral structure.

Preferably, the height of the first surface of the lens is gradually decreased from the center to the periphery.

Preferably, the cross-sectional shape of the first surface of the lens is: any one of a section of arc line, a section of arc splicing curve, a section of straight line and a splicing curve of the arc.

Preferably, the lens has a circular or elliptical shape in plan view.

Preferably, the second surface of the encapsulation adhesive layer is conformal with the surface of the bracket, the surface of the step structure, the surface of the reflection cup and the surface of the flip-chip LED chip respectively.

Preferably, the flip LED chip includes at least one of a first LED element, a second LED element, and a third LED element.

Preferably, the flip LED chip includes three of the first LED element, the second LED element, and the third LED element.

Preferably, the first LED element, the second LED element, and the third LED element emit at least one of red light, green light, and blue light, respectively.

Preferably, the light emitting side of each of the first LED element, the second LED element, and the third LED element is a side covered by the encapsulant layer.

Preferably, the reflective cup is bonded to the support and surrounds the at least one flip-chip LED chip.

Preferably, the cup mouth shape of the reflecting cup comprises any one of an arc splicing pattern, a rounded rectangle, a rectangle and a circle.

Preferably, the shape of the inner wall of the reflector cup includes any one of a rectangular, an inverted trapezoid or an arc structure.

Preferably, the color of the reflective cup is black or white.

Preferably, the color of the reflection cup is black, and the reflection cup further comprises a highly reflective material on the inner wall surface of the reflection cup.

Preferably, the color of the reflection cup is white, and the reflection cup further comprises black paint on the upper surface of the reflection cup.

Preferably, the material of the reflecting cup is resin or plastic.

Preferably, the support is double-deck circuit board, the support includes the PCB base plate and is located a plurality of pins and a plurality of outside pad on the PCB base plate, a plurality of pins are located the first surface of PCB base plate, a plurality of outside pad are located the second surface of PCB base plate, a plurality of pins respectively through electrically conductive hole between first surface and the second surface with a plurality of outside pad realize the electricity and are connected.

Preferably, the PCB substrate is an epoxy glass cloth laminate or a resin substrate.

Preferably, the encapsulation adhesive layer comprises at least one of a transparent adhesive layer and a fluorescent adhesive layer.

Preferably, the flip-chip LED chip is electrically connected to the support through a conductive adhesive layer.

Preferably, the surface of the flip LED chip facing the support is provided with a metal electrode, and the metal electrode is disposed on the support and electrically connected to the support.

Preferably, the width of the bottom of the step structure of the bracket is greater than or equal to 0.1 mm.

Preferably, the thickness of the bracket is 0.4 mm-1.0 mm.

Preferably, the height of the step structure of the bracket is one third to two thirds of the thickness of the bracket.

According to a second aspect of the present invention, there is provided an LED module comprising a printed circuit board; the flip LED lamp beads are arrayed on the printed circuit board; the waterproof layer is filled on the printed circuit board and covers each of the joints of the support and the packaging adhesive layer of the inverted LED lamp beads.

According to a third aspect of the present invention, there is provided an LED display screen comprising: a plurality of the LED module.

The flip LED lamp bead comprises a support with a step structure, at least one flip LED chip, a reflecting cup and an encapsulating adhesive layer, wherein the flip LED chip is positioned on the support, the reflecting cup is positioned on the support and surrounds the at least one flip LED chip, and the encapsulating adhesive layer covers the upper surface of the support, which is not covered by the flip LED chip and the reflecting cup, the step structure of the support, the reflecting cup and the flip LED chip. This stair structure has reduced the height of support and encapsulation glue film in the junction of side, makes the faying face of support and encapsulation glue film can be by the waterproof glue complete coating, and the support with the juncture of reflection cup lateral wall quilt the encapsulation glue film parcel has prolonged the distance between flip-chip LED chip and the external world on the contact surface of support and encapsulation glue film, has prolonged the distance that steam invaded flip-chip LED chip, has improved the waterproof performance of flip-chip LED lamp pearl.

Furthermore, the flip LED chip is adopted, so that the material and equipment of a bonding wire are saved, the process complexity and the cost are reduced, and the flip LED chip is good in reliability, large in light emitting area and high in brightness.

Further, through carrying out the lens design on the mould to mould plastics through the mould pressing and make the encapsulation glue film form the shape that has certain curvature radius's lens on the product surface, the encapsulation glue film multiplexing after the solidification is lens, is located flip-chip LED chip's top, both can guarantee the wide viewing angle, also can obtain higher axial light intensity luminance simultaneously, reduction consumption and cost.

Furthermore, the lens can realize light distribution forms such as floodlight, projection and condensation of the LED after refraction or reflection, effectively improve light spots, guarantee uniformity of light emission, realize light type consistency at a large visual angle, and effectively improve the color cast problem at the large visual angle.

Furthermore, the reflection cup is designed independently, the reflection cup and the support are connected in a pressing mode through a pressing technology, light extraction efficiency is improved, and brightness is improved.

Furthermore, a PCB substrate which is similar to the packaging adhesive layer material is adopted, the PCB substrate and the packaging adhesive layer form good adhesion, or a reflection cup which is the same as or similar to the packaging adhesive layer material is formed on the PCB substrate, and the PCB substrate and the packaging adhesive layer form good adhesion through the reflection cup, so that the sealing property and the weather resistance of the outdoor flip LED lamp bead are improved, the service life of a screen is prolonged, and the cost is reduced.

Furthermore, the packaging adhesive layer is formed by adopting an injection molding process, so that a plurality of chips can be simultaneously operated, and the operation efficiency is high compared with an SMD common dispensing mode.

Furthermore, because the quantity of the lamp beads on the same area of the substrate type support is more than that of the SMD lead frames, the substrate type support can correspondingly improve the output in unit time, batch production can be realized, and the efficiency is improved.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings.

FIG. 1 shows a cross-sectional view of a prior art LED lamp bead for an outdoor display screen;

FIG. 2 shows a schematic structural diagram of a flip-chip LED lamp bead according to an embodiment of the utility model;

3a-3c show top views of flip-chip LED lamp beads according to embodiments of the present invention;

FIG. 4 is a schematic diagram of a prior art LED module;

fig. 5 is a schematic structural diagram of an LED module according to an embodiment of the utility model.

Detailed Description

Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by the same or similar reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale.

The present invention may be embodied in various forms, some examples of which are described below.

Fig. 1 shows a cross-sectional view of an LED lamp bead for an outdoor display screen in the prior art. As shown in fig. 1, the LED lamp bead 100 of the prior art includes a support 110, an LED chip 120, a packaging adhesive layer 130, and a reflective cup 140.

The LED chips 120 are uniformly disposed on the upper surface of the support 110, and the LED chips 120 are normally mounted LED chips. The bonding wires 121 electrically connect the LED chip 120 with the leads of the support 110.

The reflective cup 140 is located on the upper surface of the support 110 and is disposed around the LED chip 120.

The encapsulation adhesive layer 130 covers the upper surface of the support 110 and fills the reflective cup 140 to isolate the LED chip 120 from the outside.

In the prior art, the bending process of the pins of the support 110 causes the junction surface between the support 110 and the reflector cup 140 to be uneven. In addition, the bonding surface between the encapsulation adhesive layer 130 and the support 110 is on the upper surface of the support and inside the reflective cup 140, so that the bonding surface between the support 110 and the reflective cup 140 is not covered by the encapsulation adhesive layer 130.

Fig. 2 shows a schematic structural diagram of a flip-chip LED lamp bead provided by an embodiment of the present invention. The inverted LED lamp bead provided by the embodiment of the utility model is used for an outdoor display screen, the dot spacing is larger than P2, and the size of the inverted LED lamp bead is more than 1mm x 1 mm. As shown in fig. 2, the flip LED lamp bead 200 according to the embodiment of the present invention includes a support 210, at least one flip LED chip 220, a packaging adhesive layer 230, and a reflective cup 240, and the flip LED lamp bead is provided with a step structure 201 in an edge region of the support 210. The flip-chip LED chip 220 is located on the upper step surface (carrying surface), the packaging adhesive layer 230 covers the step structure 201 and completely covers the reflective cup 240, and the boundary between the support 210 and the sidewall of the reflective cup 240 is covered by the packaging adhesive layer 230. The position of the joint 202 of the packaging adhesive layer 230 and the support 210 is lower than the upper step surface of the support 210, so that the bearing surface of the flip LED chip 220 on the support 210 is completely sealed, the path of water vapor invading the flip LED chip is prolonged, and the sealing performance of the flip LED lamp bead is improved.

Wherein, the bottom width W1 of stair structure 201 is preferred more than or equal to 0.1 millimeter, makes things convenient for the cutting processing in the manufacturing process, and the marginal portion of the encapsulation glue film of the flip-chip LED lamp pearl after the guarantee cutting extends downwards conscientiously, has prolonged the route that steam invades the flip-chip LED chip, ensures the leakproofness of flip-chip LED lamp pearl.

The thickness of the bracket 210 is 0.4 mm-1.0 mm, and the height of the step structure 201 of the bracket 210 is one third to two thirds of the thickness of the bracket 210, so as to ensure the mechanical strength of the bracket after the groove is manufactured.

The flip-chip LED chip 220 is electrically connected to the support 210 through a conductive adhesive layer. Specifically, a conductive adhesive layer is disposed on the support 210, and the flip LED chip 220 is disposed on the conductive adhesive layer. The electrode of flip-chip LED chip 220 sets up at the back of the plain noodles, promptly the electrode orientation of flip-chip LED chip 220 the support 210 sets up, consequently, through set up on the support 210 the conducting resin layer, will flip-chip LED chip 220 sets up on the conducting resin layer, can make electrode on the flip-chip LED chip 220 with support 210 electric connection. Further, the conductive paste is, for example, but not limited to, one of silver paste or solder paste (solder).

In another implementation of the present embodiment, the flip-chip LED chip 220 is electrically connected to the support 210 through a eutectic soldering process. The eutectic bonding wire process does not need to adopt other conductive structures, and only needs to directly weld the electrode of the flip-chip LED chip 220 and the electrode of the bracket 210 together, so that the material and equipment of the bonding wire are saved, and the process complexity and the cost are reduced.

In the present embodiment, the packaging adhesive layer 230 includes a protruding portion located above the flip-chip LED chip 220, and the protruding portion is a lens 260 of the flip-chip LED chip 220.

The flip-chip LED chip 220 includes at least one of a first LED element, a second LED element, and a third LED element. The first LED element, the second LED element, and the third LED element emit at least one of red light, green light, and blue light, respectively. When the flip-chip LED chip 220 includes two or more LED elements, the arrangement order of the LED elements is not limited. Specifically, the flip LED chip 220 may be a single color, a double color, or a three-color combination of three types of flip LED chips, i.e., red, green, and blue, designed according to the functional requirements of the actual product, which is not limited herein. Therefore, the flip LED lamp bead provided by the utility model can cover various display screens (full-color, double-color and single-color screens) for flip LED lamp bead design.

The encapsulation adhesive layer 230 allows light generated by the flip-chip LED chip 220 to pass through, and the material of the encapsulation adhesive layer 230 is, for example, one of epoxy resin, silicon gel, and silicone resin.

In a preferred embodiment, the lens 260 is integrated with the packaging adhesive layer 230, for example, the lens 260 may be formed on a first surface of the packaging adhesive layer 230 away from the support 210.

In this embodiment, a lens design is performed on a mold, the shape of the lens 260 with a certain curvature radius is formed on the surface of the product by the packaging adhesive layer 230 through mold pressing and injection molding, the packaging adhesive layer 230 is reused as a lens after being molded, and is located above the flip-chip LED chip 220, and the height of the first surface of the formed lens 260 gradually and smoothly decreases from the center to the periphery.

In a preferred embodiment, the cross-sectional shape of the first surface of the lens 260 is optionally any one of: one section of arc line, a plurality of sections of arc splicing curves and a plurality of sections of straight lines and arc splicing curves. The first surface of the encapsulation adhesive layer 230 (or the lens 260) includes a curved surface located at the upper region of the flip-chip LED chip 220 and a flat surface located at the edge of the curved surface, and is disposed as a curved surface with a curvature similar to that of the curved surface at the junction of the curved surface and the flat surface to reduce the optical loss at the junction and the influence on the optical effect caused by dust accumulation, and the second surface of the lens is conformal with the surface of the support 210, the surface of the step structure 201, the surface of the reflective cup 240 and the surface of the flip-chip LED chip 220, respectively. So, the multiplexing of encapsulation glue film 230 does lens 260 makes the light that sends change flip-chip LED lamp pearl's grading form after refraction or reflection, thereby can play the spotlight effect and promote flip-chip LED lamp pearl luminance, reduce consumption and cost.

Referring to fig. 3a-3c, the top view shape of the lens 260 (or the curved surface formed) is circular or elliptical.

Further, the encapsulant layer 230 (or the lens 260) is formed of a high molecular polymer of a transparent material. For example, at least one selected from the group consisting of PC (polycarbonate), PPA (polyphthalamide), PCT (Poly1, 4-cyclohexene dimethyl terephthalate), silicone resin, silica gel and epoxy resin.

Further, the encapsulation adhesive layer 230 (or the lens 260) includes at least one of a transparent adhesive layer and a fluorescent adhesive layer. The flip-chip LED chip 220 is sealed on the support 210 by the packaging adhesive layer 230 (or the lens 260), and the packaging adhesive layer 230 (or the lens 260) can also prevent the flip-chip LED chip 220 from being oxidized due to water or moisture when the flip-chip LED lamp bead 200 meets with water or is affected by moisture while playing a light distribution role. Furthermore, for example, a phosphor layer is coated on the flip-chip LED chip 220, so that the phosphor layer can generate light with different colors under the excitation of different lights.

In practical applications, the encapsulant layers 230 may be selected to have different effects according to the color of the light source.

In an implementation manner of the present embodiment, the encapsulation adhesive layer 230 is, for example, a transparent adhesive layer, and the transparent adhesive layer is formed by curing a transparent adhesive. The material of the transparent glue can be, but is not limited to, one of epoxy resin, silica gel, and silicone resin. Thus, the color of the light emitted by the flip LED chip 220 does not change after passing through the transparent adhesive layer, and the flip LED lamp bead 200 can finally obtain the light with the same color as the light emitted by the flip LED chip 220.

In another implementation manner of this embodiment, the encapsulating adhesive layer 230 is, for example, a fluorescent adhesive layer, and the fluorescent adhesive layer is formed by mixing and curing fluorescent powder particles and transparent glue. The material of the transparent glue can be, but is not limited to, one of epoxy resin, silica gel, and silicone resin. Specifically, the phosphor particles may be yellow phosphor particles, red phosphor particles, green phosphor particles, or a mixture thereof. For example, the yellow phosphor particles may be composed of silicate, YAG, nitride, etc., the green phosphor may be composed of SiAlON, etc., and the red phosphor particles may be composed of nitride, silicate, KSF, KGF, etc.

Further, when the bracket 210 is soldered on a printed circuit board to be electrically conductive, or directly electrically conductive, the flip LED chip 220 can emit light. Therefore, after being refracted or reflected by the packaging adhesive layer 230 (or the lens 260), the light distribution forms of floodlight, projection, condensation and the like of the LED are realized, light spots can be effectively improved, the uniformity of light emission is ensured, and meanwhile, the visual angle of a formed light path is maximized.

The bracket 210 is a double-layer circuit board manufactured by a PCB process, and includes a PCB substrate 211, a plurality of external pads 212, and a plurality of pins 213. The plurality of pins 213 are located on the same side of the PCB substrate 211 and are respectively opposite to the plurality of external pads 212 located on the other side of the PCB substrate 211, and the plurality of pins 213 are respectively electrically connected to the corresponding plurality of external pads 212 through conductive holes in the PCB substrate 211.

The PCB substrate 211 is made of an epoxy glass fabric laminated board (FR-4) or a resin substrate (BT), and preferably has a color of white, black or gray, and the PCB substrate 211 can be better bonded with the encapsulation adhesive layer 230, so that a gap is avoided. And the outer bonding pad 212 is arranged on the back of the bracket 210, so that the waterproof glue pouring height can be reduced, and the weight of the module and the glue cost are reduced. Both sides of the PCB substrate 211 may be solder-mask coated with white oil.

The packaging adhesive layer 230 is made of an outdoor glue material such as epoxy resin and silicone resin. The glue materials and the PCB substrate material of the support can form good bonding strength, and the sealing performance of the LED lamp bead is improved.

In this embodiment, the reflective cup 240 is adhered to the support 210 by an adhesive and surrounds the at least one flip LED chip 220. The reflective cup 240 is formed by injection molding, and the material of the reflective cup 240 is an insulating material resistant to reflow soldering, such as PPA, PCT, epoxy resin.

Referring to fig. 3a-3c, the cup rim shape of the reflective cup 240 is selected from, but not limited to, any one of a rounded rectangle (as shown in fig. 3 a), a rectangle, a circle (as shown in fig. 3 b), and an arc stitching pattern (as shown in fig. 3 c). The shape of the inner wall of the reflective cup 240 is selected from any one of, but not limited to, a rectangular, an inverted trapezoid, or an arc structure.

The color of the reflective cup 240 is black or white. When the color of the reflecting cup 240 is black, the reflecting cup 240 further includes a highly reflective material on the inner wall surface of the reflecting cup, so as to achieve light condensing and reflecting effects. When the color of the reflecting cup 240 is white, the reflecting cup 240 further comprises black paint on the upper surface of the reflecting cup, so that the contrast of the product is ensured.

Fig. 4 shows a schematic structural diagram of an LED module according to the prior art. As shown in fig. 4, the LED module of the prior art includes a PCB (Printed Circuit Board) 01, a plurality of LED beads 100 disposed on the PCB 01 in an array, and a waterproof layer 02.

Waterproof layer 02 can select waterproof silica gel, fills around each LED lamp pearl 100, with the common isolated bottom component of LED lamp pearl 100 of PCB board 01, also isolated steam and the contact of PCB board 01. However, in order to ensure the light emitting effect of the LED module, the waterproof layer 02 cannot shield the side surface of the LED chip, so as to ensure the light emitting effect of the side surface, that is, the thickness of the waterproof layer 02 cannot be higher than the height of the surface of the LED chip carried by the bracket, so that the joint of the reflection cup of the LED lamp bead 100 and the packaging adhesive layer cannot be covered by the waterproof layer 02, which results in poor waterproof effect of the LED lamp bead 100.

Fig. 5 shows a schematic structural diagram of an LED module according to an embodiment of the present invention. As shown in fig. 5, the LED module of the embodiment of the present invention includes a PCB 01, a waterproof layer 02, and a plurality of flip LED beads 200 distributed in an array, where a height of a joint 202 between a packaging adhesive layer of the flip LED bead 200 and a support is lower than a thickness of the waterproof layer 02, that is, the joint 202 between the packaging adhesive layer of the flip LED bead 200 and the support can be completely covered by the waterproof layer 02, and side light emission of the flip LED bead 200 is not affected, so that a waterproof effect of the flip LED bead 200 can be achieved while a light emission effect of the LED module is ensured.

The inverted LED lamp bead can achieve a better waterproof effect under the condition of maintaining the original assembly process of the LED module, and the LED module with high waterproof coefficient and suitable for the outdoors is achieved at lower cost.

The inverted LED lamp bead and the LED module can be used for an LED display screen, and the LED display screen can be an LED display screen applying the LED module, has a comprehensive waterproof effect, or only partially applies the LED module to partially prevent water according to requirements.

The flip LED lamp bead comprises a support with a step structure, at least one flip LED chip positioned on the support, a reflecting cup positioned on the support and surrounding the at least one flip LED chip, and an encapsulating adhesive layer covering the upper surface of the support, which is not covered by the flip LED chip and the reflecting cup, the step structure of the support, the reflecting cup and the flip LED chip. This stair structure has reduced the height of support and encapsulation glue film in the junction of side, makes the faying face of support and encapsulation glue film can be by the waterproof glue complete coating, and the support with the juncture of reflection cup lateral wall quilt the encapsulation glue film parcel has prolonged the distance between flip-chip LED chip and the external world on the contact surface of support and encapsulation glue film, has prolonged the distance that steam invaded flip-chip LED chip, has improved the waterproof performance of flip-chip LED lamp pearl.

The LED module comprises a PCB, a plurality of inverted LED lamp beads distributed on the PCB in an array mode and a waterproof layer filling intervals among the inverted LED lamp beads, wherein the inverted LED lamp beads are the inverted LED lamp beads provided by the utility model, the position of the edge joint of the packaging adhesive layer of the inverted LED lamp beads and the support is lower than the upper surface of the waterproof layer, namely the waterproof layer can cover the joint of the packaging adhesive layer of the inverted LED lamp beads and the side edge of the support, the waterproof performance of the inverted LED lamp beads can be improved, the waterproof performance of the LED module is further improved, and the LED module can be suitable for outdoor high-humidity use environments. The manufacturing process of the packaging glue layer of the flip LED lamp bead is die-pressing injection molding, and the cost is low.

In accordance with the embodiments of the present invention as set forth above, these embodiments are not exhaustive and do not limit the utility model to the precise embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the utility model and the practical application, to thereby enable others skilled in the art to best utilize the utility model and various embodiments with various modifications as are suited to the particular use contemplated. The utility model is limited only by the claims and their full scope and equivalents.

Claims

1. The utility model provides a flip-chip LED lamp pearl which characterized in that includes:

a bracket including a step structure at an edge of the bracket;

the flip LED chip is arranged on the surface of the support and is electrically connected with the support;

a reflective cup positioned on the support and surrounding the at least one flip-chip LED chip;

the packaging adhesive layer is hermetically covered on the upper surface of the support, which is not covered by the flip LED chip and the reflection cup, the step structure of the support, the reflection cup and the flip LED chip; the juncture of the bracket and the side wall of the reflecting cup is wrapped by the packaging adhesive layer;

the packaging adhesive layer comprises a protruding part positioned above the flip LED chip, and the protruding part is a lens of the flip LED lamp bead;

the lens and the packaging adhesive layer are of an integral structure.

2. The flip-chip LED lamp bead of claim 1, wherein the height of the first surface of the lens gradually decreases from the center to the periphery.

3. The flip-chip LED lamp bead of claim 1, wherein the cross-sectional shape of the first surface of the lens is: any one of a section of arc line, a section of arc splicing curve, a section of straight line and a splicing curve of the arc.

4. The flip-chip LED lamp bead of claim 1, wherein the lens has an elliptical or circular top view shape.

5. The flip-chip LED lamp bead of claim 1, wherein a second surface of the encapsulation adhesive layer is conformal with the surface of the support, the surface of the step structure, the surface of the reflective cup, and the surface of the flip-chip LED chip, respectively.

6. The flip-chip LED lamp bead of claim 1, wherein said flip-chip LED chip comprises at least one of a first LED element, a second LED element, and a third LED element.

7. The flip-chip LED lamp bead of claim 1, wherein said flip-chip LED chip comprises three of a first LED element, a second LED element, and a third LED element.

8. The flip-chip LED lamp bead of claim 6 or 7, wherein the first LED element, the second LED element and the third LED element emit at least one of red light, green light and blue light, respectively.

9. The flip-chip LED lamp bead of claim 6 or 7, wherein the light emitting side of each of the first LED element, the second LED element and the third LED element is the side covered by the encapsulant layer.

10. The flip-chip LED lamp bead of claim 1, wherein said reflective cup is bonded to said support and surrounds said at least one flip-chip LED chip.

11. The inverted LED lamp bead according to claim 1 or 10, wherein the cup mouth shape of the reflective cup comprises any one of an arc-shaped tiled pattern, a rounded rectangle, a rectangle, and a circle.

12. The flip-chip LED lamp bead of claim 1 or 10, wherein the shape of the inner wall of the reflector cup comprises any one of a rectangular, an inverted trapezoidal, or an arc-shaped structure.

13. The flip-chip LED lamp bead of claim 1 or 10, wherein said reflective cup is black or white in color.

14. The flip-chip LED lamp bead of claim 13, wherein said reflective cup is black in color, said reflective cup further comprising a highly reflective material on an inner wall surface of said reflective cup.

15. The flip-chip LED lamp bead of claim 13, wherein said reflective cup is white in color, said reflective cup further comprising a black paint on an upper surface of said reflective cup.

16. The flip-chip LED lamp bead of claim 1 or 10, wherein the material of said reflective cup is resin or plastic.

17. The flip-chip LED lamp bead of claim 1, wherein the support is a double-layer circuit board, the support includes a PCB substrate, and a plurality of pins and a plurality of external pads on the PCB substrate, the plurality of pins are located on a first surface of the PCB substrate, the plurality of external pads are located on a second surface of the PCB substrate, and the plurality of pins are electrically connected to the plurality of external pads through conductive vias between the first surface and the second surface, respectively.

18. The flip-chip LED lamp bead of claim 17, wherein the PCB substrate is an epoxy glass cloth laminate or a resin substrate.

19. The flip-chip LED lamp bead of claim 1, wherein the encapsulation adhesive layer comprises at least one of a layer of transparent adhesive and a layer of phosphor adhesive.

20. The flip-chip LED lamp bead of claim 1, wherein the flip-chip LED chip is electrically connected to the support through a conductive adhesive layer.

21. The flip-chip LED lamp bead of claim 1, wherein a surface of the flip-chip LED chip facing the support is provided with a metal electrode, and the metal electrode is disposed on the support and electrically connected to the support.

22. The flip-chip LED lamp bead of claim 1, wherein a bottom width of the step structure of the support is greater than or equal to 0.1 mm.

23. The flip-chip LED lamp bead of claim 1, wherein the support has a thickness of 0.4mm to 1.0 mm.

24. The flip-chip LED lamp bead of claim 1, wherein the height of the step structure of the support is one-third to two-thirds of the thickness of the support.

25. An LED module, comprising:

a printed circuit board;

a plurality of flip-chip LED lamp beads according to any one of claims 1-24, arrayed on the printed circuit board;

the waterproof layer is filled on the printed circuit board and covers each of the joints of the support and the packaging adhesive layer of the inverted LED lamp beads.

26. An LED display screen, comprising: a plurality of LED modules according to claim 25.