A type of display flip-chip RGB 4in1 LED bead

Abstract

The application discloses a display flip RGB 4in1 LED lamp bead, which comprises a square substrate, the front surface of the substrate is provided with a solder pad for connecting a light emitting component, the back surface of the substrate is provided with a pin for connecting an external circuit, a through hole is formed in the substrate, the pin is connected with the solder pad through a patterned circuit via the through hole, the number of the light emitting components is four, the light emitting components are respectively located at four corners of the front surface of the substrate, each light emitting component comprises one red chip, one blue chip and one green chip arranged in a flip mode, the number of the pin is eight, including two red positive pins, two blue positive pins, two green positive pins and two negative pins, each pin is shared by two light emitting components, and the two light emitting components sharing the negative pin do not share the positive pin at the same time. Through the product structure design of the flip chip and the IMD, the PCB wiring is optimized, the signal interference is effectively reduced, and the product is endowed with higher brightness and reliability.

Description

Technical Field

[0001] This invention relates to the field of surface mount LED device technology, and in particular to a flip-chip RGB 4in1 LED chip for display. Background Technology

[0002] With the increasingly widespread application of display technology and the continuous development of displays towards high-definition, full high-definition, and even ultra-high-definition, the market's requirements for display technology are constantly increasing, thus imposing stricter standards on LED displays in terms of impact resistance, brightness, viewing angle, and reliability. Against this backdrop, the components of LED displays are becoming increasingly crucial; among them, LED chips, as one of the core components, directly determine the main performance of the LED display. Therefore, the technical requirements for LED chips themselves, especially in key performance indicators such as light emission angle, brightness, airtightness, and impact resistance, have also significantly increased. Currently, technological advancements in LED chips urgently need to focus on breakthroughs in these areas.

[0003] Existing small-pitch LED devices typically use a flat BT substrate as a support. The substrate structure includes front and back wiring, as well as a substrate material: the front wiring is used to bond the light-emitting chips and achieve electrical interconnection; the back wiring is used for soldering to the LED display module PCB board; the wiring on both sides is electrically connected through vias. On the front side of the substrate, the wiring is divided into a die-bonding functional area, a wire-bonding functional area, and an insulating isolation area. During packaging, silver paste is used to fix the red light chip to the red die-bonding functional area, while the blue and green light chips are fixed to the blue and green die-bonding functional areas respectively using insulating glue or silver paste. Subsequently, through molding and cutting processes, individual LED beads capable of emitting RGB three primary colors of light are formed. However, as the size of the LED beads continues to shrink, the traditional single-lamp combination method leads to a sharp increase in the wiring density on the LED display PCB board, which can easily cause problems such as electrical signal interference, and the thrust of the LED beads also weakens accordingly. Utility Model Content

[0004] In view of the shortcomings of the prior art, the purpose of this utility model is to propose a flip-chip RGB 4in1 LED bead for display. Through the product structure design of flip-chip and IMD, the PCB board wiring is optimized, effectively reducing signal interference and giving the product higher brightness and reliability.

[0005] To solve the above-mentioned technical problems, this utility model provides a display flip-chip RGB 4in1 LED lamp bead, including a square substrate. The front side of the substrate is provided with pads for connecting light-emitting components; the back side of the substrate is provided with pins for connecting external circuits; the substrate has through holes, and the pins are connected to the pads through the through holes via patterned lines. The number of light-emitting components is 4, and the light-emitting components are located at the four corners of the front side of the substrate. Each light-emitting component includes one red chip, one blue chip and one green chip arranged in a flip-chip manner. The number of pins is 8, including 2 red positive pins, 2 blue positive pins, 2 green positive pins and 2 negative pins; each pin is shared by 2 light-emitting components, and the 2 light-emitting components sharing the negative pin do not share the positive pin at the same time.

[0006] Furthermore, the pins are located on the four sides of the back of the substrate, with two pins on each side.

[0007] Furthermore, the front side of the substrate is covered with an encapsulating colloid, and the encapsulating colloid has grooves that separate the four light-emitting components to form independent light-emitting areas.

[0008] Furthermore, the thickness of the encapsulating colloid is 0.2~0.3mm.

[0009] Furthermore, the groove is in the shape of a "well" with two grooves in the horizontal direction and two in the vertical direction.

[0010] Furthermore, the groove has a depth of 0.05~0.15mm, a width of 0.1~0.2mm, and a distance of 0.5~0.7mm between two adjacent grooves.

[0011] Furthermore, the substrate is characterized in that its front side is coated with matte black ink.

[0012] Furthermore, the matte black ink covers the patterned lines.

[0013] Furthermore, the surface of the pads is plated with nickel-gold using an electroplating process, with a gold plating thickness of 1.0~2.5 μm.

[0014] This utility model has the following beneficial effects: 1. By designing the light-emitting components to share positive and negative pins in pairs, and ensuring that the light-emitting components sharing the negative pin do not share the positive pin at the same time, the electrical connection that would have been achieved with traditionally 12 pins (4 independent RGB groups) can be completed with only 8 pins, greatly reducing the number of pins, while ensuring that each RGB chip does not share the same conduction circuit.

[0015] 2. The reduction in the number of pins directly leads to a reduction in the PCB wiring connected to them. This not only simplifies the design and manufacturing of the PCB, but also reduces the risk of parasitic capacitance, inductance and signal crosstalk caused by excessively dense lines, thereby improving the stability of the display driver and the picture quality.

[0016] 3. The light-emitting components are located at the four corners of the front side of the substrate. The patterned circuits are connected to the pads and the pins on the back side through through holes, so that there are no through holes and circuits around the front side of the substrate, and the airtightness of the lamp beads is effectively improved. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the front circuitry of the flip-chip RGB 4in1 LED bead substrate of this utility model.

[0018] Figure 2 for Figure 1 The image shows a schematic diagram of the front of a finished flip-chip RGB 4in1 LED chip.

[0019] Figure 3 for Figure 1 The diagram shows the back circuitry of a flip-chip RGB 4in1 LED chip substrate.

[0020] Figure 4 for Figure 1 The diagram shows the electrical schematic of a flip-chip RGB 4-in-1 LED chip.

[0021] Figure 5 for Figure 1 The image shows a cross-sectional view of the finished flip-chip RGB 4in1 LED chip.

[0022] Figure 6 for Figure 1 The diagram shows the ink on the substrate of a flip-chip RGB 4in1 LED bead.

[0023] In the figure: substrate 1, pad 2, first light-emitting component 31, second light-emitting component 32, third light-emitting component 33, fourth light-emitting component 34, red chip 311, blue chip 312, green chip 313, second blue positive electrode pin 41, second red positive electrode pin 42, first green positive electrode pin 43, first negative electrode pin 44, second negative electrode pin 45, first red positive electrode pin 46, first blue positive electrode pin 47, second green positive electrode pin 48, through hole 5, encapsulating colloid 6, groove 7. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings. This utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0025] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] like Figures 1 to 3 As shown, a flip-chip RGB 4in1 LED lamp bead includes a square substrate 1. The front side of the substrate 1 is provided with pads 2 for connecting light-emitting components 31-34. The back side of the substrate 1 is provided with pins 41-48 for connecting external circuits. The substrate 1 is provided with through holes 5, and the pins 41-48 are connected to the pads 2 via the through holes 5 through patterned lines. There are four light-emitting components 31-34, which are located at the four corners of the front side of the substrate 1. Each light-emitting component 31-34 includes a red chip 311, a blue chip 312 and a green chip 313 arranged in a flip-chip configuration. The pads 2 are the positive and negative terminals of the four flip-chip RGB chips, and are fixed to the substrate 1 by solder paste to form an electrical connection.

[0028] The number of pins 41 to 48 is 8, including 2 red positive pins 42 and 46, 2 blue positive pins 41 and 47, 2 green positive pins 43 and 48, and 2 negative pins 44 and 45; each pin 41 to 48 is shared by 2 light-emitting components 31 to 34, and the 2 light-emitting components sharing the negative pins 44 and 45 do not share the positive pins 41 to 43, 46 to 48 at the same time.

[0029] Specifically, please refer to, for example Figure 4The electrical principle shown is as follows: the first light-emitting component 31 includes RGB chips R1, G1, and B1; the second light-emitting component 32 includes RGB chips R2, G2, and B2; the third light-emitting component 33 includes RGB chips R3, G3, and B3; and the fourth light-emitting component 34 includes RGB chips R4, G4, and B4. The RGB chips of the first and second light-emitting components 31 and 32 are connected to the first negative terminal pin 44, and the RGB chips of the third and fourth light-emitting components 33 and 34 are connected to the second negative terminal pin 45. The RGB chips of the first and third light-emitting components 31 and 33 are each connected to the first red positive terminal pin 46, the first green positive terminal pin 43, and the first blue positive terminal pin 47, respectively. The RGB chips of the second and fourth light-emitting components 32 and 34 are each connected to the second red positive terminal pin 42, the second green positive terminal pin 48, and the second blue positive terminal pin 41, respectively.

[0030] In use, by controlling the current of the positive and negative pin circuits connected to each RGB chip individually, all RGB chips on the LED can be controlled to emit light. Furthermore, because the two light-emitting components sharing a negative pin do not simultaneously share a positive pin, all RGB chips avoid sharing a common conduction circuit. Combined with dynamic scanning, the color and brightness of each light-emitting component can be independently controlled. Simultaneously, since there are no through holes or circuits on the front perimeter of the substrate, the airtightness of the LED is effectively improved.

[0031] In this embodiment, the common electrode line between pad 2 and negative electrode pins 44 and 45 is thicker than the single electrode line between pad 2 and positive electrode pins 41-43 and 46-48. The purpose of this is to improve the current carrying capacity and increase the heat dissipation capacity.

[0032] Furthermore, pins 41-48 are located on the four sides of the back of substrate 1, with two pins on each side. The pins are evenly distributed along the four sides of the substrate, which avoids excessively dense local circuitry when the LED bead is connected to external circuits, improves the convenience and stability of connecting to external circuits, enhances the mechanical strength of the LED bead, optimizes space utilization, makes the LED bead structure more compact, facilitates high-density mounting on the PCB, reduces the thickness of the display screen, and improves heat dissipation performance.

[0033] like Figure 2 and Figure 5 As shown, the front side of the substrate 1 is covered with an encapsulating colloid 6, and the encapsulating colloid 6 has grooves 7. The grooves 7 separate the four light-emitting components 31-34 to form independent light-emitting areas. The groove structure can prevent light crosstalk between the four light-emitting components, ensure the color purity and consistency of each RGB chip, and improve the display quality. In this embodiment, the encapsulating colloid is specifically epoxy resin.

[0034] Specifically, the encapsulating colloid 6 has a thickness of 0.2~0.3mm, preferably 0.25mm, which is thinner than the conventional 0.37mm. The thinner encapsulating colloid reduces light attenuation and significantly improves the brightness of the LED beads; at the same time, it reduces the overall thickness of the LED beads, making the LED display screen lighter and thinner, meeting the requirements of ultra-high-definition displays for thinness.

[0035] Furthermore, the groove 7 is in the shape of a "well" with two grooves in the horizontal direction and two in the vertical direction. Compared with the simple "+" shape with one groove in the horizontal direction and one in the vertical direction, the "well" shaped groove leaves a light-free area in the middle of each light-emitting component, which completely prevents light with a large angle with the substrate surface from passing directly through the groove to the adjacent light-emitting area. This significantly enhances the overall groove structure's ability to block cross-light and improves color contrast.

[0036] Specifically, the groove 7 has a depth of 0.05~0.15mm, a width of 0.1~0.2mm, and a distance of 0.5~0.7mm between two adjacent grooves. In this embodiment, the groove has a depth of 0.1mm, a width of 0.15mm, and a distance of 0.58mm between two adjacent grooves.

[0037] like Figure 6 As shown, the front side of the substrate 1 is coated with matte black ink. The matte black ink reduces the reflectivity of the metal surface, improves the ink color consistency of the LED beads, and makes the background of the display screen darker and the contrast higher in dark environments, thus solving the problem of difficulty in achieving both ink color consistency and brightness in the prior art.

[0038] In this embodiment, the matte black ink covers the entire area, including the patterned circuitry and excluding the solder pads, to avoid exposing the copper foil circuitry, minimize the exposed metal area, and further improve the overall ink color consistency of the LED.

[0039] Furthermore, the surface of the solder pad 2 is plated with nickel-gold using an electroplating process, with a gold plating thickness of 1.0~2.5 μm, to avoid excessive reaction between SnCu solder paste and gold to form a brittle AuSn4 alloy, which would result in poor solder paste graying.

[0040] The above embodiments describe the technical principles of this utility model. These descriptions are merely for explaining the principles of this utility model and should not be construed as limiting the scope of protection of this utility model in any way. Based on the explanation herein, those skilled in the art can conceive of other specific embodiments of this utility model without creative effort, and these embodiments will all fall within the scope of protection of this utility model.

Claims

1. A display flip-chip RGB 4-in-1 LED bead, characterized in that: The substrate includes a square substrate with pads on the front side for connecting light-emitting components; pins on the back side for connecting external circuits; and through-holes on the substrate, with the pins connected to the pads via patterned lines. The number of light-emitting components is 4, and the light-emitting components are located at the four corners of the front side of the substrate. Each light-emitting component includes one red chip, one blue chip and one green chip arranged in a flip-chip manner. The number of pins is 8, including 2 red positive pins, 2 blue positive pins, 2 green positive pins and 2 negative pins; each pin is shared by 2 light-emitting components, and the 2 light-emitting components sharing the negative pin do not share the positive pin at the same time.

2. The display flip-chip RGB 4-in-1 LED bead according to claim 1, characterized in that, The pins are located on the four sides of the back of the substrate, with two pins on each side.

3. The display flip-chip RGB 4-in-1 LED bead according to claim 1, characterized in that, The front side of the substrate is covered with an encapsulating colloid, and the encapsulating colloid has grooves that separate the four light-emitting components to form independent light-emitting areas.

4. The display flip-chip RGB 4in1 LED bead according to claim 3, characterized in that, The thickness of the encapsulating colloid is 0.2~0.3mm.

5. The display flip-chip RGB 4in1 LED bead according to claim 3, characterized in that, The groove is in the shape of a "well" with two grooves in the horizontal direction and two in the vertical direction.

6. The display flip-chip RGB 4-in-1 LED bead according to claim 5, characterized in that, The groove has a depth of 0.05~0.15mm, a width of 0.1~0.2mm, and a distance of 0.5~0.7mm between two adjacent grooves.

7. The display flip-chip RGB 4-in-1 LED bead according to claim 1, characterized in that, The front side of the substrate is coated with matte black ink.

8. The display flip-chip RGB 4-in-1 LED bead according to claim 7, characterized in that, The matte black ink covers the patterned lines.

9. The display flip-chip RGB 4-in-1 LED bead according to claim 1, characterized in that, The surface of the pads is plated with nickel-gold using an electroplating process, with a gold plating thickness of 1.0~2.5 μm.

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