CN107256921A - COB LED encapsulation methods, display device and lighting device - Google Patents

Abstract

The invention discloses a kind of COB LED encapsulation methods, display device and lighting device, wherein, the COB LED encapsulation methods include：LED lamp panel is provided, LED lamp panel includes the multiple pixels of circuit board and array in the side plate face of the circuit board, wherein, each pixel includes an at least LED chip；A mould is provided, the mould has opens up spaced multiple nibs in a plane, the plane；Encapsulating material is filled in multiple nibs；The plate face of LED lamp panel is fitted with the plane of mould, and each pixel in LED lamp panel is poured into the encapsulating material in a nib, so that the encapsulating material in a nib coats a pixel.COB LED encapsulation methods of the present invention simplify the encapsulation of dot spacing LED display modules, reduce encapsulation difficulty, improve packaging efficiency, save packaging cost, and without carrying out dispensing or injection on circuit boards.

Description

COB-LED packaging method, display device and lighting device

technical field

The invention relates to the technical field of LEDs, in particular to a COB-LED packaging method, a display device and a lighting device.

Background technique

LED display modules are divided into types with and without cups according to whether they have a cup or not, and are divided into large-pitch type and small-pitch type according to the size of the pixel pitch. Among them, the LED display module with bowl and cup type and large dot pitch can be packaged by dispensing glue point by point, and its glue amount and light pattern are easy to control; the cup with bowl and cup type and small dot pitch LED display module Layers are made with high precision and difficult to control, so it is not easy to realize. Therefore, it is necessary to use COB (Chip on Board, chip on board) packaging method to realize the manufacture of LED display modules with smaller dot pitches, and then make them suitable for indoor close-up viewing of LED displays such as large-size TVs and commercial displays. Screen.

Further, the LED display module made by COB packaging can be divided into the type with cup and the type without cup, wherein, the LED display module without cup is realized by dispensing or injection molding Protection for LED chips and gold wires on the circuit board. Thixotropic glue must be used in the dispensing packaging method to ensure that the light pattern of the light-emitting point is consistent, but due to the fluidity of the glue on the circuit board, the shape of the glue will deviate, and the requirements for the light color adjustment of the LED display are higher; The injection molding packaging method requires the use of high-precision molds and injection molding machinery, which has a high cost.

Contents of the invention

The main purpose of the present invention is to provide a COB-LED packaging method, which aims at simplifying the packaging of LED display modules with small dot pitches, reducing the difficulty of packaging, improving packaging efficiency, saving packaging costs, and eliminating the need for dispensing or injection molding on the circuit board .

In order to achieve the above object, the present invention provides a COB-LED packaging method, including the following steps:

An LED lamp board is provided, the LED lamp board includes a circuit board and a plurality of pixel points arrayed on one side of the circuit board, wherein each of the pixel points includes at least one LED chip;

A mold is provided, the mold has a plane, and a plurality of die holes at intervals are provided on the plane;

filling the plurality of mold holes with encapsulation material;

Lay the board surface of the LED light board to the plane of the mould, and insert each pixel on the LED light board upside down into the encapsulating material in a mold hole , so that the encapsulation material in a mold hole covers a pixel.

Preferably, in the step of filling the packaging material in the plurality of mold holes, it specifically includes:

Place a mask plate on the plane of the mold, the mask plate is provided with a plurality of hollowed out parts at intervals, each of the hollowed out parts corresponds to one of the mold holes;

The encapsulation material is printed on the mask plate, so that the encapsulation material fills the plurality of mold holes through the plurality of hollow parts.

Preferably, the encapsulation material is printed by scraping the encapsulation material on the surface of the mask plate with a strip-shaped scraper.

Preferably, in the step of filling the packaging material in the plurality of mold holes, it specifically includes:

Provide glue dispenser;

The glue dispenser dispenses glue one by one in the plurality of die holes of the mold to fill the packaging material.

Preferably, the COB-LED packaging method further includes the following steps:

Put the bonded LED light board and the mold into an oven for baking;

After baking until the encapsulation material is solidified, take out and separate the mold and the LED light board.

Preferably, the COB-LED packaging method further includes the following steps:

cleaning the plurality of die holes of the mold prior to filling the encapsulating material;

Spraying or coating a release agent in the plurality of mold holes after cleaning.

Preferably, each of the mold holes has an asymmetric shape, and the encapsulation material in each of the mold holes covers a pixel-molded encapsulation lens that is asymmetrically arranged with respect to a reference plane, wherein the The reference plane is a normal plane of only one LED chip in the pixel point or a common normal plane of a plurality of LED chips.

Preferably, the distance between two adjacent pixel points is 0.6mm-2mm.

In addition, in order to achieve the above object, the present invention also provides a display device, including a mounting structure and an LED packaging structure mounted on the mounting structure, and the LED packaging structure is manufactured by the above-mentioned COB-LED packaging method.

In addition, in order to achieve the above object, the present invention also provides a lighting device, including a fixing structure and an LED packaging structure mounted on the fixing structure, and the LED packaging structure is manufactured by the above-mentioned COB-LED packaging method.

The technical solution of the present invention is to first fill the multiple die holes of the mold with encapsulation material, then fit the surface of the LED light board to the plane of the mold, and insert the multiple pixel points on the LED light board upside down into the multiple die holes Among the packaging materials in the package, the packaging material in each die hole is used to cover and package one pixel point; the packaging process of the present invention does not require glue dispensing or injection molding on the circuit board, which simplifies the packaging of LED display modules with small dot pitches, and reduces the Difficulty in encapsulation improves encapsulation efficiency and saves encapsulation cost; and the encapsulation process of the present invention can realize encapsulation with a minimum pixel pitch of 0.6 mm, which can fully meet the requirements of LED display screens with small dot pitches.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to the structures shown in these drawings without creative effort.

1 is a schematic diagram of the principle of the first embodiment of the COB-LED packaging method of the present invention;

Fig. 2 is a block flow diagram of the COB-LED packaging method in Fig. 1;

3 is a schematic diagram of the principle of the third embodiment of the COB-LED packaging method of the present invention;

Fig. 4 is a partially enlarged view of area A in Fig. 3;

FIG. 5 is a schematic diagram of a normal plane of the LED chip in FIG. 3 .

The realization of the purpose, function and advantages of the present invention will be further described in conjunction with the embodiments and with reference to the accompanying drawings.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relationship between the components in a certain posture (as shown in the accompanying drawings). Relative positional relationship, movement conditions, etc., if the specific posture changes, the directional indication will also change accordingly.

In addition, in the present invention, descriptions such as "first", "second" and so on are used for description purposes only, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In addition, the technical solutions of the various embodiments can be combined with each other, but it must be based on the realization of those skilled in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist , nor within the scope of protection required by the present invention.

The present invention provides a COB-LED packaging method, please refer to Figure 1 and Figure 2, in the first embodiment, the COB-LED packaging method includes the following steps:

S1. Provide an LED lamp board 1, the LED lamp board 1 includes a circuit board 10 and a plurality of pixel points 11 arrayed on one side of the circuit board 10, wherein each pixel point 11 includes at least one LED chip;

S2. A mold 12 is provided, the mold 12 has a plane 13, and a plurality of die holes 14 at intervals are provided on the plane 13;

S3, filling the packaging material 15 in a plurality of mold holes 14;

S4. Attach the surface of the LED lamp board 1 to the plane 13 of the mold 12, and insert each pixel point 11 on the LED lamp board 1 upside down into the packaging material 15 in a mold hole 14, so that a mold hole The packaging material 15 in 14 covers a pixel 11 .

The COB-LED packaging method of this embodiment first fills the packaging material 15 in the multiple mold holes 14 of the mold 12, and then attaches the surface of the LED lamp board 1 to the plane 13 of the mold 12, and the LED lamp board 1 A plurality of pixels 11 are inserted upside down into the packaging material 15 in the plurality of mold holes 14, so that the packaging material 15 in each mold hole 14 covers and encapsulates one pixel 11; the packaging process of the present invention does not require glue dispensing on the circuit board 10 Or injection molding, which simplifies the packaging of small-pitch LED display modules, reduces the difficulty of packaging, improves packaging efficiency, and saves packaging costs; and the COB-LED packaging method of this embodiment can achieve packaging with a minimum pixel pitch of 0.6mm , It can fully meet the needs of LED display screens with small dot pitches.

It should be noted that, in the present invention, the LED chip is positioned on the circuit board 10 through die bonding. When the LED chip is a positive chip, it needs to be bonded to connect its positive and negative electrodes to the circuit board 10 respectively. When the LED chip is a flip chip, the electrical connection between its positive and negative electrodes and the pads on the circuit board 10 can be completed through die bonding, without the need for wire bonding. As for the number of LED chips in a single pixel point 11, it can be set according to actual needs. For example, a single pixel point 11 can use only one white light (W) chip; it can also use three LED chips, which are respectively red light (R) chips , green (G) chip and blue (B) chip; four LED chips can also be used, namely red (R) chip, green (G) chip, blue (B) chip and white (W) chip, Five LED chips can also be used. The encapsulation material 15 can fill the mold hole 14 of the mold 12 by printing, pinhole injection or dispensing.

In this embodiment, further, the COB-LED packaging method further includes the following steps:

S5, putting the bonded LED light board 1 and the mold 12 into an oven for baking;

S6. After baking until the encapsulation material 15 is cured, take out and separate the mold 12 and the LED light board 1 .

By baking the packaging material 15, the curing of the packaging material 15 is accelerated, the curing time is reduced, and the time required for the manufacturing process is shortened.

In this embodiment, further, the COB-LED packaging method further includes the following steps:

S2.1, before filling the packaging material 15, cleaning a plurality of die holes 14 of the mold 12;

S2.2. Spray or coat a release agent in the multiple mold holes 14 after cleaning.

The impact of impurities on the surface of the mold 12 on the packaging material 15 can be avoided by cleaning, and the release agent is beneficial to the separation of the cured packaging material 15 and the mold 12 .

In this embodiment, further, step S1 specifically includes:

S10, performing crystal bonding on the circuit board 10, wherein the red (R) chip, the green (G) chip and the blue (B) chip form a pixel point 11 as a group;

S11, welding wires, electrically connect the electrodes of the LED chip to the pads on the circuit board 10 through aluminum wires or gold wires.

Since a single pixel point 11 is composed of a red light (R) chip, a green light (G) chip and a blue light (B) chip, full-color light emission is realized, and it can be used as a full-color LED display screen.

In this embodiment, further, step S3 specifically includes:

S30, placing the mask plate 16 on the plane 13 of the mold 12, the mask plate 16 is provided with a plurality of hollowed out parts 17 at intervals, and each hollowed out part 17 corresponds to a mold hole 14;

S31 , printing the encapsulation material 15 on the mask plate 16 , so that the encapsulation material 15 fills the plurality of mold holes 14 through the plurality of hollow parts 17 .

The packaging material 15 is filled into the mold hole 14 by printing, which simplifies the injection of the packaging material 15 into the mold hole 14 and improves production efficiency; at the same time, the mask plate 16 is used for printing, which can realize multiple printings and avoid The encapsulation material 15 adheres to the surface of the mold 12 during printing, so that the circuit board 10 is not easily separated from the mold 12 .

In this embodiment, further, the encapsulation material 15 is printed by scraping the encapsulation material 15 on the surface of the mask plate 16 by a strip-shaped scraper.

The strip-shaped scraper can realize uniform scraping of the encapsulation material 15 on the mask plate 16, improving printing efficiency and uniformity of glue filling.

In this embodiment, further, each die hole 14 has a symmetrical shape and is in the shape of a hemisphere. In other embodiments, the die hole 14 may also be in the shape of a ball cone, a cylinder, a cone, an ellipsoid, or a cube.

In this embodiment, further, the distance between two adjacent pixel points 11 is 0.6mm˜2mm.

Since the pixel pitch is 0.6 mm to 2 mm, it can meet the application requirements of LED display screens with small pixel pitches. Preferably, the distance between two adjacent pixel points 11 is 0.8mm˜1.2mm. Most preferably, the distance between two adjacent pixel points 11 is 0.8 mm. In other embodiments, the distance between two adjacent pixel points 11 may be 0.9mm, 1.0mm, 1.1mm or 1.2mm.

The present invention also provides a second embodiment of the COB-LED packaging method. The difference between this second embodiment and the above-mentioned first embodiment is:

Step S3 specifically includes:

S30', providing a glue dispenser;

S31', the dispensing machine dispenses glue one by one in the plurality of die holes 14 of the mold 12 to fill the packaging material 15.

Compared with printing the encapsulation material 15 in the plurality of die holes 14 of the mold 12 , a glue dispenser is used to directly dispense glue in the die holes 14 of the mold 12 without using printing tools, which further simplifies the filling process of the encapsulation material 15 .

Please refer to Figure 3 to Figure 5, Figure 3 is a schematic diagram of the principle of the third embodiment of the COB-LED packaging method of the present invention; Figure 4 is a partial enlarged view of area A in Figure 3; Figure 5 is the normal plane of the LED chip in Figure 3 schematic diagram. The difference between this third embodiment and the above-mentioned first embodiment or second embodiment is:

Each mold hole 14 has an asymmetric shape, and the encapsulation lens formed by covering a pixel point 11 with the packaging material 15 in each mold hole 14 is arranged asymmetrically with respect to a reference plane S, wherein the reference plane S is a pixel point 11 A normal plane P1 ( P2 ) of only one LED chip 110 or a common normal plane P1 ( P2 ) of multiple LED chips 110 . As shown in FIG. 5 , the normal plane P1 (P2) is a plane passing through the normal line L of the LED chip 110 and perpendicular to the upper surface of the LED chip 110. In other words, an LED chip 110 has two normal planes P1 (P2) , one of which is parallel to one side, and the other is parallel to the other adjacent side.

Since the mold hole 14 is asymmetrically arranged, and the encapsulation lens formed by it is asymmetrically arranged with respect to the normal plane P1 (P2), and then the light emission of the LED chip is concentrated toward one side after being processed by the encapsulation lens, which can meet the requirements of the light emitting side. Orientation needs.

In this embodiment, further, another normal plane perpendicular to the reference plane S cuts the package lens to form a section, the section has a first curve segment 150 and a second curve segment 151, wherein the first curve segment 150 and the second curve segment 151 The intersection point I of the second curve segment 151 is located on one side of the reference plane S. Preferably, the intersection point I is located on the left side of the reference plane S, so that the light emitted by the packaging lens is concentrated toward the right side to realize right-inclined light emission. In other embodiments, the intersection point I can be located on the right side of the reference plane S, and then the light emitted by the packaging lens can be concentrated toward the left side to achieve left-inclined light emission; the intersection point I can also be located on the upper side of the reference plane S, and then the packaging lens The emitted light is concentrated toward the lower side, realizing down-tilt light emission.

The present invention also provides a display device. Please refer to FIG. 1 and FIG. 3. In one embodiment, the display device includes a mounting structure and an LED packaging structure installed in the mounting structure. The LED packaging structure adopts the COB of all the above embodiments. - Manufactured by LED encapsulation method. Since the LED packaging structure of this embodiment adopts all the technical solutions of all the above-mentioned embodiments, it also has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, and will not be repeated here. It should be noted that the display device includes but is not limited to LED display modules, LED display screens, LED splicing screens and LED floor tile screens. Taking the LED display module as an example, the installation structure is a casing, and the LED packaging structure is installed in the casing.

The present invention also provides a lighting device. Please refer to FIG. 1 and FIG. 3. In one embodiment, the lighting device includes a fixed structure and an LED package structure mounted on the fixed structure. The LED package structure adopts the COB of all the above embodiments. - Manufactured by LED encapsulation method. Since the LED packaging structure of this embodiment adopts all the technical solutions of all the above-mentioned embodiments, it also has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, and will not be repeated here. It should be noted that the lighting device includes but not limited to LED street lamps, LED ceiling lamps, LED spotlights and LED pendant lamps. Taking an LED ceiling lamp as an example, the fixed structure is a lamp housing, and the LED packaging structure is installed in the lamp housing.

The above is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Under the inventive concept of the present invention, the equivalent structural transformation made by using the description of the present invention and the contents of the accompanying drawings, or direct/indirect use All other relevant technical fields are included in the patent protection scope of the present invention.

Claims (10)

1. A COB-LED encapsulation method, characterized in that, comprises the steps as follows: An LED lamp board is provided, the LED lamp board includes a circuit board and a plurality of pixel points arrayed on one side of the circuit board, wherein each of the pixel points includes at least one LED chip; A mold is provided, the mold has a plane, and a plurality of die holes at intervals are provided on the plane; filling the plurality of mold holes with encapsulation material; Lay the board surface of the LED light board to the plane of the mould, and insert each pixel on the LED light board upside down into the encapsulating material in a mold hole , so that the encapsulation material in a mold hole covers a pixel. 2. The COB-LED packaging method according to claim 1, characterized in that, in the step of filling the packaging material in the plurality of mold holes, specifically comprising: Place a mask plate on the plane of the mold, the mask plate is provided with a plurality of hollowed out parts at intervals, each of the hollowed out parts corresponds to one of the mold holes; The encapsulation material is printed on the mask plate, so that the encapsulation material fills the plurality of mold holes through the plurality of hollow parts. 3. The COB-LED encapsulation method according to claim 2, wherein the encapsulation material is printed by scraping the encapsulation material on the surface of the mask with a strip scraper. 4. The COB-LED packaging method according to claim 1, characterized in that, in the step of filling the packaging material in the plurality of mold holes, specifically comprising: Provide glue dispenser; The glue dispenser dispenses glue one by one in the plurality of die holes of the mold to fill the packaging material. 5. The COB-LED packaging method according to claim 1, further comprising the following steps: Put the bonded LED light board and the mold into an oven for baking; After baking until the encapsulation material is solidified, take out and separate the mold and the LED light board. 6. The COB-LED packaging method according to claim 1, further comprising the following steps: cleaning the plurality of die holes of the mold prior to filling the encapsulating material; Spraying or coating a release agent in the plurality of mold holes after cleaning. 7. The COB-LED encapsulation method according to claim 1, wherein each of the die holes has an asymmetric shape, and the encapsulation material in each of the die holes covers one of the pixel points The molded encapsulation lens is arranged asymmetrically with respect to a reference plane, wherein the reference plane is a normal plane of only one LED chip in the pixel point or a normal plane shared by multiple LED chips. 8. The COB-LED packaging method according to any one of claims 1 to 7, wherein the distance between two adjacent pixels is 0.6mm-2mm. 9. A display device, comprising a mounting structure and an LED packaging structure mounted on the mounting structure, characterized in that, the LED packaging structure is manufactured by the COB-LED packaging method described in any one of claims 1 to 8 have to. 10. A lighting device, comprising a fixed structure and an LED packaging structure mounted on the fixed structure, characterized in that, the LED packaging structure is manufactured by the COB-LED packaging method described in any one of claims 1 to 8 have to.