MINI RGB LED lamp bead with built-in resistor and preparation method of MINI RGB LED lamp bead

Abstract

The invention discloses a MINI RGB LED lamp bead with a built-in resistor and a preparation method of the MINI RGB LED lamp bead, and relates to the technical field of LEDs, the MINI RGB LED lamp bead with the built-in resistor comprises a substrate, a first chip, a second chip, a third chip and a chip resistor; the front surface of the substrate is provided with a front circuit, the back surface of the substrate is provided with a back circuit, and the front circuit and the back circuit are connected through a through hole; the front circuit comprises a die bonding area, a bonding wire area, an insulating area and a groove area; the die bonding area comprises a first die bonding area, a second die bonding area and a third die bonding area which are separated from one another, the first chip is arranged in the first die bonding area, the second chip is arranged in the second die bonding area, and the third chip is arranged in the third die bonding area; a groove is formed in the groove area, and the chip resistor is arranged in the groove and connected with the first chip in series. According to the invention, burning of the lamp beads and caterpillars on the display screen due to water vapor permeation can be reduced, so that the process yield and the display effect are improved.

Description

Technical Field

[0001] The present invention relates to the field of LED technology, and in particular to a MINI RGB LED lamp bead with a built-in resistor and a preparation method thereof. Background Art

[0002] With the advancement of technology and the reduction of costs, Mini RGB LED technology is increasingly being used in the display field. Thanks to its excellent display effect and color performance, high-end TVs, outdoor advertising displays, stage rental screens, and professional display equipment have all adopted this technology.

[0003] The core principle of Mini RGB LED is to use miniature RGB (red, green, blue) three-primary color LED lamp beads as pixel points or backlight sources. These LED lamp beads are usually small in size and can significantly improve the brightness and contrast of the screen. By independently adjusting the brightness of each RGB lamp bead, Mini RGB LED technology can achieve more sophisticated local dimming and wide dynamic range display, thereby providing better picture quality and color accuracy.

[0004] like Figure 1 As shown, the existing Mini RGB LED device uses a flat BT substrate as a bracket. The substrate is a single-layer board with a front circuit and a back circuit. The front circuit and the back circuit are connected and conducted through a through hole. Among them, the back circuit is used for welding with the LED display module PCB; the front circuit is used to bind the light-emitting chip and realize electrical interconnection. The front circuit is divided into a solid crystal functional area, a welding wire functional area and an insulating isolation area. During the manufacturing process of the lamp beads, silver glue is used to fix the red light chip on the red light solid crystal functional area, and insulating glue or silver glue is used to fix the blue light and green light chips on the corresponding solid crystal functional areas. However, in the actual operation process, due to the instability of the solid crystal machine, the amount of glue fluctuates, and the solid crystal area is not isolated as a whole, the solid crystal is easy to affect the adjacent chips, resulting in a low process yield; secondly, when water vapor penetrates into the blue light chip or the red light, it is also easy to cause water vapor to easily penetrate into other chips directly along the solid crystal area, and the display screen is prone to caterpillar phenomenon (see Figure 2 ), affecting the display effect of the display screen;

[0005] In addition, in the existing display manufacturing process, the Mini RGB LED device needs to be mounted on the PCB board by a mounting machine, and the LED display using common anode technology usually provides a unified power supply with a voltage higher than 3.8V for the red LED chip, green LED chip, and blue LED chip, resulting in large power loss; however, the voltage requirement of the red LED chip is generally around 2.8V, and the unified voltage of 3.8V will cause the red LED chip to burn out easily and increase the heat of the lamp beads (see Figure 3 ). Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a MINI RGB LED lamp bead with a built-in resistor and a preparation method thereof, which can improve the process yield and display effect.

[0007] In order to solve the above technical problems, the present invention provides a MINI RGB LED lamp bead with built-in resistors, including a substrate, a first chip, a second chip, a third chip and a chip resistor; a front circuit is provided on the front side of the substrate, a back circuit is provided on the back side of the substrate, and the front circuit and the back circuit are connected through a through hole; the front circuit includes a solid crystal area, a welding wire area, an insulating area and a groove area; the solid crystal area includes a first solid crystal area, a second solid crystal area and a third solid crystal area separated from each other, the first chip is arranged in the first solid crystal area, the second chip is arranged in the second solid crystal area, and the third chip is arranged in the third solid crystal area; a groove is provided in the groove area, and the chip resistor is arranged in the groove and is connected in series with the first chip.

[0008] As an improvement of the above solution, the groove is opened below the first bonding area and the second bonding area, one end of the chip resistor is located below the first bonding area, and the other end of the chip resistor is located below the second bonding area.

[0009] As an improvement of the above-mentioned scheme, the groove is opened below the first bonding area, the second bonding area and the third bonding area, one end of the chip resistor is located below the first bonding area, the other end of the chip resistor is located below the third bonding area, and the middle insulating area of ​​the chip resistor is located below the second bonding area.

[0010] As an improvement of the above solution, the first crystal-bonding region, the second crystal-bonding region and the third crystal-bonding region are arranged in sequence along the same direction.

[0011] As an improvement of the above solution, the wire bonding area is arranged at the periphery of the die bonding area.

[0012] As an improvement of the above solution, the back circuit includes a pin area, the welding wire area, the through hole and the pin area correspond one to one, and the welding wire area is connected to the corresponding pin area through the corresponding through hole.

[0013] As an improvement of the above solution, the through hole is arranged at a corner of the substrate.

[0014] As an improvement of the above solution, the operating voltage of the first chip is lower than the operating voltage of the second chip and the operating voltage of the third chip.

[0015] As an improvement of the above solution, the first chip is a red light chip, the second chip is a green light chip, and the third chip is a blue light chip.

[0016] Correspondingly, the present invention also provides a method for preparing a MINI RGB LED lamp bead with a built-in resistor, comprising: setting a solid crystal area, a welding wire area, an insulating area and a groove area on the front side of the substrate, and setting a pin area on the back side of the substrate; fixing the chip resistor in the groove; fixing the first chip in the first solid crystal area, fixing the second chip in the second solid crystal area, and fixing the third chip in the third solid crystal area; setting bonding wires through a welding wire process to electrically interconnect the solid crystal area and the welding wire area; packaging the first chip, the second chip, the third chip and the chip resistor; and cutting them through a cutting process to form a MINI RGB LED lamp bead.

[0017] The implementation of the present invention has the following beneficial effects:

[0018] The present invention changes the die-bonding area from an integral form to a split form to form a first die-bonding area, a second die-bonding area and a third die-bonding area separated from each other, thereby avoiding mutual influence between the first die-bonding area, the second die-bonding area and the third die-bonding area, reducing the risk of lamp beads burning due to water vapor infiltration and the appearance of caterpillars on the display screen, thereby improving the process yield and display effect;

[0019] At the same time, the present invention introduces a chip resistor, and by connecting the chip resistor in series with the first chip, the operating voltage of the first chip can be effectively reduced, and the heat generated by the first chip can be effectively reduced to adapt to different chip characteristics;

[0020] In addition, the present invention also introduces a groove. Through the groove design, the chip resistor can be embedded in the groove, so as to facilitate the layout of the first chip, the second chip and the third chip in the same plane without affecting the layout of the first chip, the second chip and the third chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of the existing MINI RGB LED lamp beads;

[0022] Figure 2 This is a short circuit diagram of the existing MINI RGB LED lamp beads;

[0023] Figure 3 This is a heat diagram of the existing MINI RGB LED lamp beads;

[0024] Figure 4 This is a front view of the MINI RGB LED lamp bead with built-in resistor of the present invention;

[0025] Figure 5 This is a front view of the MINI RGB LED lamp bead with built-in resistors of the present invention when the chip and the chip resistor are not installed;

[0026] Figure 6 This is a front view of the MINI RGB LED lamp bead with built-in resistor without the chip installed;

[0027] Figure 7 It is a rear view of the MINI RGB LED lamp bead with built-in resistor of the present invention;

[0028] Figure 8 It is a cross-sectional view of a first embodiment of a MINI RGB LED lamp bead with a built-in resistor according to the present invention;

[0029] Fig. 9 It is a cross-sectional view of a second embodiment of a MINI RGB LED lamp bead with a built-in resistor according to the present invention;

[0030] Fig.10 It is a schematic diagram of the structure of the chip resistor in the MINI RGB LED lamp bead with built-in resistor of the present invention;

[0031] Fig.11 It is a flow chart of an embodiment of a method for preparing a MINI RGB LED lamp bead with a built-in resistor according to the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. It is hereby stated that the directional terms such as up, down, left, right, front, back, inside, outside, etc. that appear or will appear in the text of the present invention are only based on the accompanying drawings of the present invention, and are not specific limitations of the present invention.

[0033] See also Figure 4 to Figure 7 , Figure 4 to Figure 7 The first embodiment of the MINI RGB LED lamp bead with built-in resistor of the present invention is shown, which includes a substrate, a first chip 1, a second chip 2, a third chip 3 and a chip resistor 4; a front circuit is provided on the front side of the substrate, and a back circuit is provided on the back side of the substrate, and the front circuit and the back circuit are connected through a through hole 5; the front circuit includes a solid crystal area, a welding wire area 7, an insulating area 8 and a groove area 9; wherein the solid crystal area includes a first solid crystal area 6a, a second solid crystal area 6b and a third solid crystal area 6c separated from each other, the first chip 1 is arranged in the first solid crystal area 6a, the second chip 2 is arranged in the second solid crystal area 6b, and the third chip 3 is arranged in the third solid crystal area 6c; a groove is provided in the groove area 9, and the chip resistor 4 is arranged in the groove and is connected in series with the first chip 1.

[0034] In the prior art, the die-bonding area is an integral structure without isolation, and the die-bonding easily affects the adjacent chips, resulting in a low process yield, and the display screen is prone to caterpillar phenomenon, which affects the display effect of the display screen. Different from the prior art, in the present invention, the die-bonding area includes a first die-bonding area 6a, a second die-bonding area 6b, and a third die-bonding area 6c that are separated from each other, that is, the first die-bonding area 6a, the second die-bonding area 6b, and the third die-bonding area 6c are separated from each other, which can avoid mutual influence between the first die-bonding area 6a, the second die-bonding area 6b, and the third die-bonding area 6c, thereby improving the process yield and display effect.

[0035] In addition, the present invention also introduces a chip resistor 4. By connecting the chip resistor 4 in series with the first chip 1, the operating voltage of the first chip 1 can be effectively reduced, and the heat generated by the first chip 1 can be effectively reduced to adapt to different chip characteristics. At the same time, the present invention also introduces a groove. Through the groove design, the chip resistor 4 can be embedded in the groove, so that the first chip 1, the second chip 2 and the third chip 3 are arranged in the same plane, and the layout of the first chip 1, the second chip 2 and the third chip 3 is not affected.

[0036] like Figure 8 and Fig.10 As shown, in this embodiment, the groove is opened below the first solid crystal area 6a and the second solid crystal area 6b, one end 41 of the chip resistor 4 is located below the first solid crystal area 6a, and the other end 42 of the chip resistor 4 is located below the second solid crystal area 6b.

[0037] It should be noted that, by recessing a groove below the first die-bonding region 6 a and the second die-bonding region 6 b , the series connection of the chip resistor 4 and the first chip 1 can be facilitated, and the area of ​​the groove can be effectively saved.

[0038] Generally, the resistance of the chip resistor 4 is about 200Ω, but it is not limited to this and can be set according to actual conditions. The height of the groove is preferably 0.1-0.15mm, the width is preferably 0.15-0.25mm, and the length is preferably 0.35-0.45mm, but it is not limited to this and can be adjusted according to the size of the chip resistor 4 as long as it can completely accommodate the chip resistor 4.

[0039] Furthermore, the first crystal-bonding region 6a, the second crystal-bonding region 6b and the third crystal-bonding region 6c are arranged in sequence along the same direction, which facilitates neat division of regions and facilitates processing.

[0040] At the same time, the welding wire area 7 is arranged on the periphery of the solid crystal area; the back circuit includes the pin area 10, the welding wire area 7, the through hole 5 and the pin area 10 correspond one to one, and the welding wire area 7 is connected to the corresponding pin area 10 through the corresponding through hole 5, thereby realizing mutual conduction between the front circuit and the back circuit.

[0041] More preferably, the through hole 5 is arranged at the corner of the substrate to facilitate layout; the substrate is made of BT resin, which has excellent dielectric properties, low thermal expansion coefficient, and good mechanical characteristics.

[0042] Accordingly, in the present invention, the operating voltage of the first chip 1 is lower than the operating voltage of the second chip 2 and the operating voltage of the third chip 3. The first chip 1 is preferably a red chip, the second chip 2 is preferably a green chip, and the third chip 3 is preferably a blue chip.

[0043] In practical applications, the working voltages of the red light chip, the green light chip and the blue light chip are different, and the working voltage of the red light chip is generally 1V lower than that of the green light chip and the blue light chip. In the present invention, the red light chip is connected in series with the chip resistor 4. By connecting the chip resistor 4 in series, the working current of the red light chip can be effectively reduced, and the PN junction is prevented from being seriously heated due to excessive current, and the heating of the lamp beads is reduced, thereby protecting the LED chip from damage and extending its service life; at the same time, it can play a voltage stabilizing role, ensure the current stability in the circuit, thereby improving the stability of the entire circuit, and reducing faults caused by current fluctuations. In addition, the series resistor in the LED circuit can prevent excessive voltage from causing excessive current, and avoid the LED from burning out due to excessive working current. At the same time, it also helps to reduce light decay and maintain the brightness stability of the LED.

[0044] See also Fig. 9 , Fig. 9 The second embodiment of the MINI RGB LED lamp bead with built-in resistor of the present invention is shown. Figure 8 What is different from the first embodiment shown is that in this embodiment, the groove is opened below the first solid crystal area 6a, the second solid crystal area 6b and the third solid crystal area 6c, one end 41 of the chip resistor 4 is located below the first solid crystal area 6a, the other end 42 of the chip resistor 4 is located below the third solid crystal area 6c, and the middle insulating area 43 of the chip resistor 4 is located below the second solid crystal area 6b.

[0045] It should be noted that by recessing a groove below the first die-bonding region 6a, the second die-bonding region 6b and the third die-bonding region 6c, the series connection of the chip resistor 4 and the first chip 1 can be facilitated; at the same time, the insulating region 43 in the middle of the chip resistor 4 is located below the second die-bonding region 6b (see Fig.10 ), and can also effectively prevent the chip resistor 4 from being conductively connected to the second die-bonding area 6b, thereby providing high safety.

[0046] In summary, the present invention changes the solid crystal area from an integral form to a split form, which can reduce the burnout of lamp beads due to water vapor infiltration and the appearance of caterpillars on the display screen, thereby improving the process yield and display effect; at the same time, the present invention introduces the chip resistor 4, and by connecting the chip resistor 4 in series with the first chip 1, the operating voltage of the first chip 1 can be effectively reduced, and the heat generation of the first chip 1 can be effectively reduced to adapt to different chip characteristics; in addition, the present invention also introduces a groove, and through the groove design, the chip resistor 4 can be embedded in the groove, so as to facilitate the layout of the first chip 1, the second chip 2 and the third chip 3 in the same plane, without affecting the layout of the first chip 1, the second chip 2 and the third chip 3.

[0047] See also Fig.11 , Fig.11 The flowchart of an embodiment of the method for preparing a MINI RGB LED lamp bead with a built-in resistor of the present invention is shown, which includes:

[0048] S101, a die-bonding area, a wire bonding area, an insulating area, and a groove area are provided on the front side of the substrate, and a lead area is provided on the back side of the substrate (see Figure 5 );

[0049] S102, fix the chip resistor in the groove (see Figure 6 );

[0050] Specifically, the chip resistor can be buried in the groove by applying solder paste; wherein, the resistance of the chip resistor can be calculated according to the client driving voltage, which is highly targeted.

[0051] S103, fix the first chip in the first die-bonding region, fix the second chip in the second die-bonding region, and fix the third chip in the third die-bonding region (see Figure 4 );

[0052] S104, setting a bonding wire through a wire bonding process to electrically interconnect the die bonding area and the wire bonding area;

[0053] S105, packaging the first chip, the second chip, the third chip and the chip resistor;

[0054] Specifically, the internal chips (the first chip, the second chip, the third chip) and the chip resistors can be protected by sealing.

[0055] S106, performing cutting processing through a cutting process to form MINI RGB LED lamp beads.

[0056] Finally, by cutting and splitting the blanks, MINI RGB LED lamp beads with photoelectric parameters are formed.

[0057] Therefore, the present invention redesigns the functional area structure and adopts an embedded resistor method to improve the waterproof ability of the lamp beads; reduces the conversion of excessive voltage into heat energy on the display screen, reduces the temperature of the display screen, protects the LED lamp bead chip, and extends the service life of the lamp beads; at the same time, when a short circuit occurs in the chip, the series connection of the resistor can prevent abnormalities such as caterpillars on the display screen.

[0058] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A MINI RGB LED lamp bead with built-in resistor, characterized in that: It includes a substrate, a first chip, a second chip, a third chip and a chip resistor; A front circuit is provided on the front side of the substrate, and a back circuit is provided on the back side of the substrate, and the front circuit and the back circuit are connected via a through hole; The front circuit includes a die-bonding area, a wire bonding area, an insulation area and a groove area; The die-bonding region includes a first die-bonding region, a second die-bonding region, and a third die-bonding region separated from each other, the first chip is arranged in the first die-bonding region, the second chip is arranged in the second die-bonding region, and the third chip is arranged in the third die-bonding region; A groove is provided in the groove area, and the chip resistor is arranged in the groove and connected in series with the first chip.

2. The MINI RGB LED lamp bead with built-in resistor as claimed in claim 1, characterized in that: The groove is opened below the first die-bonding area and the second die-bonding area. One end of the chip resistor is located below the first die-bonding area, and the other end of the chip resistor is located below the second die-bonding area.

3. The MINI RGB LED lamp bead with built-in resistor as claimed in claim 1, characterized in that: The groove is opened below the first bonding area, the second bonding area and the third bonding area, one end of the chip resistor is located below the first bonding area, the other end of the chip resistor is located below the third bonding area, and the middle insulating area of ​​the chip resistor is located below the second bonding area.

4. The MINI RGB LED lamp bead with built-in resistor as claimed in claim 3, characterized in that: The first crystal-bonding region, the second crystal-bonding region and the third crystal-bonding region are sequentially arranged along the same direction.

5. The MINI RGB LED lamp bead with built-in resistor as claimed in claim 1, characterized in that: The wire bonding area is arranged at the periphery of the die bonding area.

6. The MINI RGB LED lamp bead with built-in resistor as claimed in claim 1, characterized in that: The back circuit includes a pin area, and the wire bonding area, the through hole and the pin area correspond to each other one by one, and the wire bonding area is connected to the corresponding pin area through the corresponding through hole.

7. The MINI RGB LED lamp bead with built-in resistor as claimed in claim 1 or 6, characterized in that: The through hole is arranged at a corner of the substrate.

8. The MINI RGB LED lamp bead with built-in resistor as claimed in claim 1, characterized in that: An operating voltage of the first chip is lower than an operating voltage of the second chip and an operating voltage of the third chip.

9. The MINI RGB LED lamp bead with built-in resistor as claimed in claim 1 or 8, characterized in that: The first chip is a red light chip, the second chip is a green light chip, and the third chip is a blue light chip.

10. A method for preparing a MINI RGB LED lamp bead with a built-in resistor as claimed in any one of claims 1 to 9, characterized in that: include: A die-bonding region, a wire bonding region, an insulating region and a groove region are arranged on the front side of the substrate, and a pin region is arranged on the back side of the substrate; Fixing the chip resistor in the groove; Fixing the first chip in the first die-bonding region, fixing the second chip in the second die-bonding region, and fixing the third chip in the third die-bonding region; Setting bonding wires by wire bonding process to electrically interconnect the die bonding area with the wire bonding area; Packaging the first chip, the second chip, the third chip and the chip resistor; The cutting process is used to form MINI RGB LED lamp beads.

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