Inverted LED COB lamp panel and preparation method thereof

Abstract

The invention discloses a flip LED COB lamp panel and a preparation method thereof. The flip LED COB lamp panel comprises an FPC (Flexible Printed Circuit) substrate, a flip MINI LED chip, a packaging adhesive layer and a light blocking layer; the plurality of flip MINI LED chips are arranged on the FPC substrate, and the plurality of flip MINI LED chips are arranged on the FPC substrate. The packaging glue layer is laid on the FPC substrate, and the flip MINI LED chip is surrounded in a sealed mode. The light blocking layer is arranged above the packaging adhesive layer; patterns are engraved on the light blocking layer through laser. According to the flip LED COB lamp panel and the preparation method thereof, the light blocking layer is engraved through the laser engraving technology, and therefore personalized patterns are flexibly displayed.

Description

Technical Field

[0001] The invention belongs to the technical field of LEDs, and in particular relates to an inverted LED COB lamp board and a preparation method thereof. Background Art

[0002] With the growing demand for personalized pattern customization and the continuous advancement of laser technology and material processing technology, the engraving effect of laser engraving machines has become more delicate and precise. This technology has gradually entered the home field from the professional field, providing more possibilities for the display of personalized patterns. However, at present, the application of light boards on the market is not flexible enough. Traditional light board design mainly focuses on improving the output efficiency of light. The present invention proposes a new idea, which uses laser engraving technology to engrave on the light barrier layer, so as to flexibly display personalized patterns. Summary of the invention

[0003] The object of the present invention is to provide a flip-chip LED COB lamp board and a preparation method thereof, and to perform engraving on a light-blocking layer through laser engraving technology, so as to flexibly display personalized patterns.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A flip-chip LED COB light board, comprising: an FPC substrate, a flip-chip MINI LED chip, a packaging adhesive layer, and a light blocking layer; A plurality of the flip-chip MINI LED chips are arranged on the FPC substrate; the encapsulation adhesive layer is laid on the FPC substrate to form a sealed enclosure around the flip-chip MINI LED chips; The light blocking layer is arranged above the packaging glue layer; The light blocking layer is engraved with a pattern by laser.

[0005] In one embodiment, the light blocking layer is an epoxy resin layer or a silicone layer.

[0006] In one embodiment, the thickness of the light blocking layer is 20-200 um.

[0007] In one embodiment, the light blocking layer includes any one or any combination of carbon black, titanium dioxide, zinc oxide, and zinc barium.

[0008] In one embodiment, the light blocking layer is one layer or more than two layers.

[0009] Another object of the present invention is to disclose a method for preparing a flip-chip LED COB light board, which is used to prepare the flip-chip LED COB light board, comprising: Installing the flip-chip MINI LED chip on the FPC substrate; The encapsulation adhesive layer is encapsulated on the FPC substrate, and the encapsulation adhesive layer forms a sealed enclosure around the flip-chip MINI LED chip; Disposing the light blocking layer on the packaging glue layer; The light blocking layer is laser engraved.

[0010] In one embodiment, the step of providing the light blocking layer on the packaging adhesive layer comprises: A light blocking layer is sprayed on the packaging adhesive layer by atomization.

[0011] In one embodiment, the step of providing the light blocking layer on the packaging adhesive layer comprises: Preparing light-blocking films in advance; The light blocking film is pasted on the packaging adhesive layer.

[0012] In one embodiment, the step of laser engraving the light blocking layer is performed by using a nanosecond laser or a picosecond laser for laser engraving.

[0013] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: The flip-chip LED COB light board of the present invention is provided with a light blocking layer on the packaging glue layer and the light blocking layer is laser engraved to engrave patterns of different depths; after laser engraving, the light blocking layer has different thicknesses, so that the flip-chip LED COB light board outputs a pattern with contrast and layering. The flip-chip LED COB light board of the present invention can be used in home creations, handicrafts, billboards, car atmosphere lights and other places. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 This is a schematic diagram of the structure of a flip-chip LED COB lamp board according to an embodiment of the present invention; Figure 2 This is a layout diagram of a flip-chip MINI LED chip according to an embodiment of the present invention; Figure 3 The present invention is a flowchart of a method for preparing a flip-chip LED COB lamp board according to an embodiment of the present invention. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0017] like Figure 1 As shown, a flip-chip LED COB light board 10 includes an FPC substrate 100 and a plurality of flip-chip MINI LED chips 200. The plurality of flip-chip MINI LED chips 200 are disposed on the FPC substrate 100. The flip-chip LED COB light board 10 may further include an encapsulation layer 300 and a light blocking layer 400. In this embodiment, the flip-chip MINI LED chip 200 may be a red, green, blue or purple MINI LED chip. Specifically, a single color chip or a combination of multiple color chips may be selected.

[0018] In this embodiment, the FPC substrate 100 can be made of RF4, BT or FPC material; the thickness of the FPC substrate 100 is 0.07-1.0 mm. The size of the die-bonding pad of the FPC substrate 100 is designed according to the electrode specifications of the flip-chip LED chip 200.

[0019] In this embodiment, the FPC substrate 100 is provided with pads and circuits for connecting the flip-chip MINI LED chip 200. Figure 2 As shown, the circuit adopts a row and column lighting circuit design. By mounting row and column loop resistors, the lighting / extinguishing of each row or column of LED lights can be controlled. The resistors configured in each row / column are placed at the edge of the circuit board without sealing. The dot pitch between the flip-chip MINI LED chips 200 is 0.3~0.5mm. In this embodiment, 5# powder or 6# powder solder paste is used to connect the flip-chip MINI LED chips 200.

[0020] In actual application, the flip-chip LED COB light board 10 can be designed with a circuit for lighting up rows and columns. Each row and each column of the flip-chip LED COB light board 10 is connected to a resistor or a jumper, and the flip-chip MINI LED chip 200 is controlled to turn on and off by the resistor or jumper. When using flip-chip MINI LED chips 200 of multiple colors, the control circuit of each color is separated, and can be lit independently or simultaneously, and mixed light through an external controller.

[0021] The encapsulation glue layer 300 is laid on the FPC substrate 100 to form a sealed enclosure for the flip-chip MINI LED chip 200. Specifically, the encapsulation glue layer 300 is set above the flip-chip MINI LED chip 200. The encapsulation glue layer 300 can be selected from epoxy resin or silicone. In specific applications, diffusion powder or phosphor is added to the epoxy resin or silicone, and stirred evenly by a vacuum centrifugal mixer. It should be noted that when the flip-chip LED COB light board 10 needs to emit white light or light of other color temperatures, a blue flip-chip MINI LED chip 200 or a purple flip-chip MINI LED chip 200 can be used in combination with a phosphor solution; when red light, green light or blue light is required, only the color corresponding to the flip-chip MINI LED chip 200 itself is required, and no phosphor is required.

[0022] When encapsulating the encapsulation glue layer 300, control the appropriate amount of encapsulation glue, and pour the glue on the FPC substrate 100 according to the set dispensing path; apply dam glue around the light board and solidify it; after the glue is solidified, a surface light source with uniform light output is obtained. Preferably, the thickness of the encapsulation glue layer 300 is controlled to be 0.2~1.0mm.

[0023] The light blocking layer 400 is disposed above the encapsulation glue layer 300; the light blocking layer 400 is patterned by laser engraving. In this embodiment, the light blocking layer 400 is an epoxy resin layer or a silicone layer. The thickness of the light blocking layer 400 is preferably 20-200 um. The light blocking layer 400 includes any one or any combination of carbon black, titanium dioxide, zinc oxide, and zinc barium. The light blocking layer 400 is one layer or more than two layers.

[0024] It should be noted that, in this embodiment, the resistors arranged in each row / column are placed at the edge of the circuit board without being sealed with glue.

[0025] The flip-chip LED COB light board 10 of the present invention is provided with a light blocking layer 400 on the packaging glue layer 300, and then a pattern is laser engraved on the light blocking layer 400. By controlling the thickness of the engraved pattern, the flip-chip LED COB light board 10 outputs a pattern with contrast and layering. The flip-chip LED COB light board 10 of the present invention can be used in home creations, handicrafts, billboards, car atmosphere lights, and the like.

[0026] like Figure 3 As shown, the present invention also discloses a method for preparing a flip-chip LED COB light board, which is used to prepare a flip-chip LED COB light board 10, comprising: Step S11, mounting the flip-chip MINI LED chip on the FPC substrate; Step S12, encapsulating the FPC substrate with a sealing adhesive layer, wherein the sealing adhesive layer forms a sealed enclosure around the flip-chip MINI LED chip; Step S13, providing a light blocking layer on the packaging adhesive layer; Step S14, laser engraving the light blocking layer.

[0027] In this embodiment, after the step of mounting the flip-chip MINI LED chip on the FPC substrate and before the step of encapsulating the FPC substrate with an encapsulation adhesive layer, the following steps are also included: According to the VCC supply voltage and the maximum current of the flip-chip MINI LED chip, the resistance and power of the corresponding resistor are calculated; Print 5# solder paste on flip-chip LED COB lamp board and pass SPI inspection; Perform die bonding on the flip-chip LED COB light board. Use a die bonding machine to transfer the blue flip-chip MINI LED chip from the blue film to the corresponding pad of the flip-chip LED COB light board and pass AOI inspection. Perform resistor patching on flip-chip LED COB light board; Put the flip-chip LED COB lamp board after die bonding into a nitrogen-filled reflow oven for tin melting and soldering; After soldering, the PCBA is surface cleaned using a plasma cleaning machine.

[0028] The specific steps of encapsulating the encapsulation glue layer of the FPC substrate are as follows: the flip-chip LED COB light board is placed on the flat molding machine mold, and a suitable amount of liquid fluorescent glue is injected onto the flip-chip LED COB light board through a matching glue injection machine.

[0029] In this embodiment, the specific method of encapsulating the FPC substrate with the encapsulation glue layer is to place the FPC substrate after the glue is poured on a flat platform or a heating platform to allow the glue to flow naturally and solidify gradually.

[0030] In other embodiments, the specific method of encapsulating the FPC substrate with the encapsulation glue layer is to place the FPC substrate after the glue is filled in a mold of a molding device, form a plane through molding and heating, and initially solidify it.

[0031] In other embodiments, a specific method of encapsulating the FPC substrate with the encapsulation adhesive layer is to position the FPC substrate and the prefabricated semi-cured fluorescent adhesive film up and down and encapsulate them by vacuum hot pressing.

[0032] Before the step of setting a light-blocking layer on the encapsulation adhesive layer, the following steps are also included: according to the designed fluorescent adhesive ratio, the fluorescent powder, diffusion powder and silicone resin glue are prepared by a precision adhesive dispenser, and degassing and mixing them evenly by a planetary vacuum centrifugal mixer.

[0033] In this embodiment, the step of providing the light blocking layer on the encapsulation adhesive layer is: spraying the light blocking layer on the encapsulation adhesive layer by atomization. After the light blocking layer is cured, 100% light blocking is achieved.

[0034] In other embodiments, the step of disposing a light blocking layer on the packaging adhesive layer includes: Preparing light-blocking films in advance; A light blocking film is pasted on the encapsulation adhesive layer.

[0035] The glue material of the light blocking layer needs to be selected according to the material of the encapsulation glue layer to ensure the bonding strength of the two.

[0036] Specifically, the light-blocking film can be prepared in advance on a substrate such as PET, and protected with a release film to form a roll or film shape. When in use, the light-blocking film is pasted on the encapsulation adhesive layer. In the present embodiment, the prefabricated light-blocking film is removed from one of the surface protective films and placed on the liquid encapsulation adhesive layer. The light-blocking film can be prefabricated according to the luminous brightness of the flip-chip LED COB light board. Under the current highest brightness state of the light board, the light blocking rate reaches 100%, and zero transmittance can be achieved. The liquid encapsulation adhesive layer is flattened by a molding machine under vacuum, and the encapsulation adhesive layer is cured by heating. After the encapsulation adhesive layer is cured, it adheres to the flip-chip LED COB light board and the light-blocking film. The flip-chip LED COB light board that has been initially cured after molding is placed on a carrier and flattened with a magnetic cover.

[0037] Put the flip-chip LED COB light board with the flattened carrier into a long oven to thoroughly cure the encapsulation adhesive layer. Peel off the light-blocking film of the cured flip-chip LED COB light board from its other release protective film, leaving the light-blocking film (also known as the light-blocking layer). Remove the process edge through the cutting process. Stick a protective film on the coating of the flip-chip LED COB light board to complete a flip-chip LED COB light board that is completely opaque when powered on.

[0038] In this embodiment, the light blocking layer is an epoxy resin layer or a silicone layer. The light blocking layer is a diffusion powder or a fluorescent powder. The thickness of the light blocking layer is 20-200um. The powder material of the light blocking layer is not limited to a single material. The powder material of the light blocking layer includes any one or any combination of carbon black, titanium dioxide, zinc oxide, and zinc barium. The light blocking layer is one layer or more than two layers.

[0039] In this embodiment, the step of laser engraving the light blocking layer is specifically to use a nanosecond laser or a picosecond laser to perform laser engraving.

[0040] In this embodiment, the process of laser engraving the light blocking layer is as follows: Place the flip-chip LED COB light board under the laser engraving platform, with the light blocking layer facing the laser emitter, and the platform contains a flattening fixture or a vacuum flattening fixture. In this embodiment, a 355nm ultraviolet laser engraving machine is selected.

[0041] Test the coating thickness and light transmittance curve data corresponding to the light barrier layer; Place the flip-chip LED COB light board with light-blocking layer on the working platform of the laser engraving machine and fix it with a carrier.

[0042] Import the graphic file to be engraved on the laser engraving machine.

[0043] Adjust the focal length of the laser engraving machine and start engraving. Specifically, the laser adjusts the focal length appropriately, and the thickness and light transmittance of the light blocking layer can be changed by engraving the depth of the coating. It should be noted that the light blocking layer is engraved with different thicknesses in each area of ​​the pattern, and the coating in each area forms different light transmittances.

[0044] After engraving, a pattern is formed on the light board. Each area of ​​the pattern is engraved at different depths, and the light barrier layer in each area forms different light transmittance. When the flip-chip LED COB light board is lit, the pattern can show different contrasts.

[0045] According to the maximum size of the pattern, remove the resistors of the rows and columns outside the pattern, and control the LEDs outside the maximum area of ​​the pattern in rows and columns to be off.

[0046] After the flip-chip LED COB light board is powered on, different areas of the pattern show different contrast effects.

[0047] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0048] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A flip-chip LED COB light board, characterized in that: include: FPC substrate, flip-chip MINI LED chip, encapsulation layer, light barrier layer; A plurality of the flip-chip MINI LED chips are arranged on the FPC substrate; the encapsulation adhesive layer is laid on the FPC substrate to form a sealed enclosure around the flip-chip MINI LED chips; The light blocking layer is arranged above the packaging glue layer; The light blocking layer is engraved with a pattern by laser.

2. The flip-chip LED COB light board according to claim 1, characterized in that: The light blocking layer is an epoxy resin layer or a silica gel layer.

3. The flip-chip LED COB lamp board according to claim 1, characterized in that: The thickness of the light blocking layer is 20-200 um.

4. The flip-chip LED COB light board according to claim 1, characterized in that: The light blocking layer includes any one or any combination of carbon black, titanium dioxide, zinc oxide, and zinc barium.

5. The flip-chip LED COB light board according to claim 1, characterized in that: The light blocking layer is one layer or two or more layers.

6. A method for preparing a flip-chip LED COB light board, used for preparing the flip-chip LED COB light board according to any one of claims 1 to 5, characterized in that: include: Installing the flip-chip MINI LED chip on the FPC substrate; The encapsulation adhesive layer is encapsulated on the FPC substrate, and the encapsulation adhesive layer forms a sealed enclosure around the flip-chip MINI LED chip; Disposing the light blocking layer on the packaging glue layer; The light blocking layer is laser engraved.

7. The method for preparing the flip-chip LED COB lamp board according to claim 6, characterized in that: The step of providing the light blocking layer on the packaging glue layer comprises: A light blocking layer is sprayed on the packaging adhesive layer by atomization.

8. The method for preparing the flip-chip LED COB lamp board according to claim 6, characterized in that: The step of providing the light blocking layer on the packaging glue layer comprises: Preparing light-blocking films in advance; The light blocking film is pasted on the packaging adhesive layer.

9. The method for preparing a flip-chip LED COB lamp board according to claim 6, characterized in that: The step of laser engraving the light blocking layer uses a nanosecond laser or a picosecond laser for laser engraving.

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