CN112951968B - Outdoor full-color display screen SMD LED device - Google Patents

Abstract

In order to overcome the inability to encapsulate the sealant around the lamp bead in the prior art, the water vapor easily penetrates into the interior of the lamp bead from the edge of the lamp bead, resulting in chip electrode metal migration failure, leakage failure, silver glue delamination failure, gold wire fracture failure and The technical problem of the layering of the colloid and the substrate is provided, and an outdoor full-color display SMD LED device is provided, which includes a base, and the base includes a mounting seat and a supporting seat. The end of the mounting seat away from the supporting seat is provided with an LED chip, and the supporting seat is far away from the mounting seat. One end of the seat is provided with pins, and the mounting seat and the supporting seat cooperate to form a sealing portion. The cross-sectional area of the mounting seat is smaller than that of the supporting seat. The outer periphery of the lamp bead is filled with encapsulating colloid, and the encapsulating colloid covers the sealing portion. The application can improve the air tightness of the CHIP type SMD LED, and can encapsulate the sealant around the lamp bead, thereby increasing the reliability of the lamp bead in a humid environment and reducing the repair rate of the LED display.

Description

An outdoor full-color display SMD LED device

technical field

The invention relates to the technical field of light emitting diodes, in particular to an outdoor full-color display screen SMD LED device.

Background technique

Outdoor Light Emitting Diode (LED) display is a new type of information display media that developed rapidly in the world in the late 1980s. It is a display screen composed of dot matrix modules or pixel units composed of LEDs. Its appearance makes up for the defects of the previous information release media such as magnetic flaps and neon lights, and has been widely used in railways, highways, squares and large shopping malls. Based on the requirements of waterproof and dustproof lamps, the lamp beads need to be packaged to improve their environmental adaptability. The traditional full-color LED device packaged in the form of Chip has a small height. Since the height of the sealant in the industry is at least 0.6mm, the sealant cannot be potted around the lamp bead of the above device, and water vapor can easily penetrate from the edge of the lamp bead to the lamp bead. Internally, it leads to problems such as chip electrode metal migration failure, leakage failure, silver glue delamination failure, gold wire breakage failure, and colloid and substrate delamination.

The Chinese patent with the application number CN201010247956.3 discloses a SMD type LED packaging method, which includes the following steps: 1) Electroplating: the functional area on the surface of the bracket on the SMD tape is partially silver-plated, and the functional area is used on the bracket for 2) Slicing: Cut the electroplated bracket to a standard length with a mold; 3) Die bonding: After dispensing glue at the bottom of the bracket, use a die bonding machine to fix the corresponding SMD LED chip on the effective surface of the bracket ;4), short bake: put the bracket with the SMD type LED chip fixed after dispensing into a 150 ℃ oven for 90 minutes to cure; 5), welding wire: put the fixed bracket of the SMD type LED chip into the bonding machine , Use 99.99% φ23 gold wire to connect the positive and negative electrodes of the SMD LED chip and the bracket; 6) Pressure injection: The bracket of the welded SMD LED chip is discharged into the injection mold, and the epoxy resin is used for injection and rapid encapsulation. The time is within 3 minutes; 7) Residual removal: put the bracket after injection molding into the mold to automatically process the burrs; 8), aging baking: put the bracket 1 after injection molding after processing the burr into a 120 ℃ oven to bake Bake for 8 hours for epoxy long-bake curing; 9), tin plating: the bracket after injection molding and encapsulating the SMD type LED chip is subjected to surface tin plating treatment; 10), bending: the surface treatment tin plated bracket is cut with a precision mold Electrodes, bent to form.

The above-mentioned patent can realize the effective packaging of SMD LED, and the tin-plating process ensures the anti-oxidation and anti-rust of the product, and improves the solderability of product application processing; the problem is that the above-mentioned packaging method cannot solve the technical problem of poor air tightness of SMD LED. When used in an outdoor environment, water vapor easily penetrates into the interior of the lamp bead and causes it to be damaged, and the reliability of the lamp bead in a humid environment is poor.

SUMMARY OF THE INVENTION

In order to overcome the inability to encapsulate the sealant around the lamp bead in the prior art, the water vapor easily penetrates into the interior of the lamp bead from the edge of the lamp bead, resulting in chip electrode metal migration failure, leakage failure, silver glue delamination failure, gold wire fracture failure and The technical problem of delamination of colloid and substrate, provides an outdoor full-color display SMD LED device, which can improve the air tightness of CHIP type SMD LED, and can encapsulate sealant around the lamp bead to increase the lamp bead in a humid environment. reliability and reduce the repair rate of the LED display.

In order to achieve the above objects, the present invention adopts the following technical solutions.

An outdoor full-color display SMD LED device includes a base, the base includes a mounting seat and a support seat, an LED chip is arranged at one end of the mounting seat away from the support seat, and a pin is arranged at one end of the support seat away from the mounting seat, and the mounting seat A sealing portion is formed in cooperation with the support seat, the cross-sectional area of the mounting seat is smaller than that of the support seat, and the outer periphery of the lamp bead is filled with encapsulating colloid, and the encapsulating colloid covers the sealing portion. Traditional LED devices have poor sealing performance. The present application provides a full-color display SMD LED device, which can be used outdoors. Specifically, the mounting seat and the supporting seat cooperate to form a stepped structure. Compared with the traditional structure, the dispersion path of water vapor in the present application is elongated when the water vapor penetrates, and the dispersion path of the water vapor is twisted from the original straight path to a folded line path. The path includes a horizontal path constructed by the end face of the support base and a vertical path constructed by the side of the mounting base. During the dispersion process, the water vapor needs to diffuse to the bottom of the horizontal path before climbing up along the vertical path. During the working process, heat energy is released to the surroundings, and the water vapor that climbs up along the vertical path will hedge against the heat energy released by the LED device, further reducing the dispersion rate of water vapor; The colloid covers the sealing part, which effectively increases the airtightness of the display screen, and the display screen can be used outdoors.

Preferably, the LED chip includes a first chip, a second chip and a third chip, a first pole part and a second pole part are respectively provided on both sides of the LED chip, and the LED chip and the first pole part and the second pole part pass through wires connected. In this application, the LED chips are selected as RGB three-primary color chips, and the first chip, the second chip and the third chip are separated and connected by wires.

Preferably, the height of the sealing portion is h, the height of the base is H, H≧0.6 mm, and 0.2 mm≦h<0.6 mm. The above technical solution limits the size of the base, the overall height of the base is more than 0.6mm, the height of the sealing portion formed by the mounting seat and the support seat is 0.2mm-0.6mm, and the width is not limited.

Preferably, the support base is in the shape of a cube, and the number of pins is four, which are respectively close to the corners of the support base. The pins are gold-plated, gold-plated or tin-plated.

Preferably, the encapsulant is formed by compression molding.

Preferably, the encapsulating colloid includes a colloid body and a circumferential colloid, the colloid body is located on a side of the support seat close to the mounting seat, and the circumferential colloid is arranged along the circumference of the support seat.

Preferably, the height of the circumferential colloid is greater than the height of the support seat.

Preferably, the color of the base is black, gray or white, and the base is made of BT material or FR-4.

Preferably, the chip adopts a front-loading process or a flip-chip process. When the front-loading process is used, the electrical circuit is conducted through the wire welding, and when the flip-chip process is adopted, the electrical circuit is conducted through solder paste welding.

Preferably, encapsulated colloid treasure house solid or liquid epoxy resin, silicone resin or epoxy modified material, etc. In this application, the encapsulation method is molding (plastic encapsulation) or vacuum brushing.

To sum up, the present invention has the following beneficial effects: (1) In the present application, a sealing portion is added on the base, so that the water vapor in the external environment cannot easily penetrate into the interior of the lamp bead from the edge of the lamp bead, thereby increasing the reliability of the lamp bead in a humid environment (2) The sealing part is covered by the encapsulating colloid, which effectively increases the airtightness of the display screen, and the display screen can be used outdoors; (3) In this application, the water vapor infiltrates The dispersion path is elongated, and the dispersion path of water vapor is twisted from the original straight path to a polyline path, which further reduces the dispersion rate of water vapor to the interior of the lamp bead.

Description of drawings

Figure 1 is a schematic diagram of a base in the present invention.

Figure 2 is a front view of the SMD LED of the present invention.

FIG. 3 is a cross-sectional view of FIG. 1 .

FIG. 4 is a cross-sectional view of FIG. 2 .

Figure 5 is a schematic view of the present invention as a whole.

In the picture:

Mounting base 1, support base 2, LED chip 3, first chip 301, second chip 302, third chip 303, lead 4, sealing part 5, encapsulation glue 6, glue body 601, circumferential glue 602, first Pole part 7, second pole part 8, wire 9.

Fig. 1(a) is a top view of the base, Fig. 1(b) is a bottom view of the base, and Fig. 1(c) is a side view of the base.

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, only used to explain the present invention, and should not be construed as a limitation of the present invention.

In the description of the present invention, it should be understood that the terms "portrait", "horizontal", "upper", "lower", "front", "rear", "left", "right", "vertical", The orientations or positional relationships indicated by "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than An indication or implication that the referred device or element must have a particular orientation, be constructed and operate in a particular orientation, is not to be construed as a limitation of the invention.

In the description of the present invention, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, unless otherwise expressly specified and limited, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Example:

As shown in Figures 1 to 5, an outdoor full-color display SMD LED device includes a base, the base includes a mounting seat 1 and a support seat 2, and the end of the mounting seat away from the support seat is provided with an LED chip 3, and the support seat The end away from the mounting seat is provided with a pin 4. The mounting seat and the support seat cooperate to form a sealing portion 5. The cross-sectional area of the mounting seat is smaller than that of the support seat. The sealing part; the LED chip includes a first chip 301, a second chip 302 and a third chip 303, the two sides of the LED chip are respectively provided with a first pole part 7 and a second pole part 8, and the LED chip is connected with the first pole part, the first pole part, the second pole part 8 respectively. The diode parts are connected by wires 9; the height of the sealing part is h, the height of the base is H, H≥0.6mm, 0.2mm≤h<0.6mm; the support seat is in the shape of a cube, and the number of pins is four and respectively Close to the corner of the support seat; the encapsulation colloid is formed by molding; the encapsulation colloid includes a colloid body 601 and a circumferential colloid 602, the colloid body is located on the side of the support seat close to the mounting seat, and the circumferential colloid is arranged along the circumferential direction of the support seat; the circumferential direction The height of the colloid is greater than the height of the support seat; the color of the base is black, gray or white, and the base is made of BT material or FR-4; The electrical circuit is turned on, and the electrical circuit is turned on by solder paste welding when the flip-chip process is used; the solid or liquid epoxy resin, silicone resin or epoxy modified material of the colloid treasure house is encapsulated.

As shown in Figure 1(c), the base includes a mounting seat and a supporting seat from top to bottom. Combining with Figure 1(a), it can be seen that the mounting seat and the supporting seat are both cube-shaped, and the cross-sectional area of the mounting seat is smaller than that of the supporting seat. There are LED chips on the upper end surface of the mounting seat, the left and right sides of the LED chips are respectively provided with a first pole part and a second pole part, and the lower end surface of the support seat is provided with pins, and the number of pins is four and are respectively close to the four corners of the support base. The color of the PCB board of the base is black, gray or white, and the material is BT material or FR-4; the pins and pads are gold-plated or silver-plated or gold or tin, and the overall height of the base is more than 0.6mm, The length and width are not limited, the height of the sealing part is 0.2mm-0.6mm, and the width is not limited.

As shown in Figure 2, the number of LED chips is three, and the three LED chips are arranged at intervals from top to bottom. The LED chips include a first chip, a second chip and a third chip from top to bottom, which are R(red) , G (green) and B (blue) chips, when the chip adopts the formal installation process, the LED chip is connected with the first and second poles on the left and right sides by wires, and the wires are gold wires, alloy wires or copper wires. The electrical circuit is turned on by soldering, and when the chip adopts the flip-chip process, the electrical circuit is turned on by soldering with solder paste.

As shown in Figures 3 and 4, the mounting seat and the support seat cooperate to form a sealing portion, and a colloidal body is potted on the sealing portion. It can be seen from Figure 5 that the circumferential direction of the supporting seat is provided with a circumferential colloid, and the height of the circumferential colloid is greater than that of the supporting seat. The height of the colloid body and the circumferential colloid cooperate to form an encapsulation colloid. The encapsulation method is molding or vacuum brushing, and the encapsulation colloid includes solid or liquid epoxy resin, silicone resin, epoxy modified materials and other traditional materials.

Claims (8)

1. an outdoor full-color display SMD LED device, comprising a base, it is characterized in that, the base comprises a mounting seat and a support seat, the end of the mounting seat away from the support seat is provided with an LED chip, and the end of the support seat away from the mounting seat is provided with an LED chip. There are pins, the mounting seat and the supporting seat cooperate to form a sealing part, the outer periphery of the lamp bead is filled with packaging colloid, the cross-sectional area of the mounting seat is smaller than that of the supporting seat, and the packaging colloid covers the sealing part; the packaging colloid includes the colloid body and The circumferential colloid is arranged along the circumferential direction of the support seat, and the colloid body is located on the side of the support seat close to the mounting seat. 2. The outdoor full-color display SMD LED device according to claim 1, wherein the LED chip comprises a first chip, a second chip and a third chip, and the two sides of the LED chip are respectively provided with first pole parts and the second pole part, the LED chip is connected with the first pole part and the second pole part through wires. 3 . The outdoor full-color display SMD LED device according to claim 1 , wherein the height of the sealing portion is h, and the height of the base is H , where H≧0.6mm, and 0.2mm≦h<0.6mm. 4 . 4 . The outdoor full-color display SMD LED device according to claim 1 , wherein the support base is in the shape of a cube, and the pins are four in number and are respectively close to the corners of the support base. 5 . 5 . The outdoor full-color display SMD LED device according to claim 1 , wherein the height of the circumferential colloid is greater than the height of the support base. 6 . 6. a kind of outdoor full-color display SMD LED device according to claim 1 or 2 or 3 or 4, is characterized in that, the color of the base is black, gray or white, and the base selects BT material or FR-4 to prepare . 7. The outdoor full-color display SMD LED device according to claim 2, wherein the chip adopts a front-loading process or a flip-chip process, and when the front-loading process is adopted, the electrical circuit is made conductive through the wire welding, and the flip-chip is adopted. During the process, the electrical circuit is turned on by soldering with solder paste. 8. An outdoor full-color display SMD LED device according to claim 1 or 2 or 3 or 4, characterized in that the package is a colloidal treasure house of solid or liquid epoxy resin, silicone resin or epoxy modified material and the like.

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