CN107816665B - A high color gamut blue-green LED backlight module and its manufacturing method - Google Patents

Abstract

The invention discloses a high-color gamut blue-green LED backlight module and a manufacturing method thereof. The backlight module comprises blue-red LED lamp beads, green LED lamp beads, a PCB board, a metal backplane, a reflective paper, a lower light guide plate, an upper Light guide plate, diaphragm, OPEN CELL; the PCB board is a rectangular strip circuit board, on which two rows of LED lamp beads are welded; the blue and red LED lamp beads and the green LED lamp beads are located in the upper and lower rows respectively ; One side of the PCB board is provided with four strip-shaped PCB solder joints perpendicular to the short side; the back of the PCB board is attached to the inner side of the short side of the L-shaped metal backplane, and the inner layer of the long side of the metal backplane is placed with reflective paper, A lower light guide plate, an upper light guide plate, a diaphragm, and an OPEN CELL are placed in sequence above the reflective paper. While improving the color gamut value, the present invention solves the technical problem of uneven light mixing between the blue light chip and the red light chip. In addition, an upper condenser lens and a lower condenser lens with upper and lower reflective layers can be added, so that the red, blue, green, and blue light can be increased. Before the light enters the lower light guide plate and the upper light guide plate, there is no light mixing and interference.

Description

A high color gamut blue-green LED backlight module and its manufacturing method

technical field

The invention relates to the field of LED backlight, in particular to a high color gamut blue-green LED backlight module and a manufacturing method thereof.

Background technique

As an emerging solid-state lighting source, LED has the characteristics of small size, long life, good reliability, energy saving and environmental protection, and has been widely used in lighting and display fields. With the rapid development of LED backlight technology, consumers have high expectations for LED TVs The demand for color gamut and other aspects is increasing day by day, which requires richer colors, better layering, and higher color reproduction. The current mainstream method is to use blue light chips to excite red and green phosphors, and the color gamut can only reach 90%-93%. Green light chips have narrower half-wave widths and shorter wavelengths than existing green phosphors. In addition, the excitation efficiency of phosphors is low. In order to obtain white light with high color gamut, the concentration of phosphors must be increased, which will undoubtedly increase the cost of the packaging industry and increase the defect rate. Another mainstream technology to achieve high color gamut of LED TVs is The use of blue LED light source with quantum tube and quantum film, but the quantum dot material itself has fatal defects such as poor thermal stability, toxicity, high cost, and the quantum dot tube is easy to break during use.

Whether it is the traditional method of mixing red, green, or yellow phosphors with encapsulant, and then applying them to blue light chips to form white LEDs through light-color recombination, or mixing red, green, and blue chips to form white light, or Quantum dot films and quantum dot tubes have the following defects: First, most of the current commercial phosphors are YAG powder or silicate, nitride phosphor, KSF phosphor, β-SiAlON, and the color gamut can only reach 72%- 93%; the excitation efficiency of phosphors is low, and the improvement of the color gamut can only be achieved by increasing the dosage, which is far from meeting the requirements of today's society for lower energy consumption, higher energy efficiency and higher color gamut; red, green and blue three colors LED chips are difficult to mix light, and there are also problems with heat dissipation. At the same time, the drive control system is more complicated; the current commercial quantum dot materials are easily affected by temperature and humidity and cause failure. At the same time, due to the complex preparation process of quantum dots, the yield is low and the stability is poor. , the price is higher, not fully popularized.

Application Publication No. CN 201710537225.4 discloses a high-color gamut LED lamp bead with blue-green dual chips and red phosphors and a backlight source thereof, wherein a blue-green dual-color LED lamp bead is produced, and the LED lamp bead is distributed inside the LED bracket The blue light chip and the green light chip, the blue light chip and the green light chip are packaged inside the LED bracket through the mutual mixing between the red phosphor and the encapsulant, and then baked and cured to form LED lamp beads, and the bodies of the plurality of lamp beads are uniform. It is distributed on the edge-type PCB board, and then made into an edge-type backlight module. The short-wavelength and narrow half-wavewidth green light chips are used to make up for the inability of green phosphors to achieve high color gamut effects.

The introduction of short-wavelength and narrow half-wavewidth green light chips in the above-mentioned existing solutions can effectively improve the color gamut of backlight display, but because of the slenderness of the edge-lit LED lamp beads, the blue light emitted by the blue light chip, and the blue light emitted by the blue light excited red phosphors. The green light emitted by the red light and green light chips is mixed for the first time in the LED lamp bead, and the second light is mixed in the edge-type light guide plate, but still cannot be mixed evenly, resulting in obvious flowers appearing on the light guide plate near the light source of the backlight module. Speckle (ie, bands of polychromatic light that are produced without uniform mixing of red and green light). In order to overcome the deficiencies of the prior art, a solution is now provided.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies of the prior art, and to provide a high color gamut blue-green LED backlight module and a manufacturing method thereof, which can improve the color gamut value and solve the problem of uneven light mixing between the blue light chip and the red light chip. technical problem.

The object of the present invention can be realized through the following technical solutions:

A high-color gamut blue-green LED backlight module, comprising blue-red LED lamp beads, green LED lamp beads, a PCB board, a metal backplane, a reflective paper, a lower light guide plate, an upper light guide plate, a diaphragm, and an OPEN CELL;

The PCB board is a rectangular strip circuit board on which two rows of LED lamp beads are welded; the blue and red LED lamp beads and the green LED lamp beads are located in the upper and lower rows respectively; Four strip-shaped PCB solder joints on the short side; the back of the PCB board is attached to the inner side of the short side of the L-shaped metal backplane, the inner layer of the long side of the metal backplane is placed with reflective paper, and the lower light guide plate is placed on the top of the reflective paper. , Upper light guide plate, diaphragm, OPEN CELL;

The LED lamp beads include brackets, LED chips, gold wires, packaging glue, white strips, small pads, and large pads; the bracket is a rectangular slot with an inclined inner sidewall; a white strip is inlaid in the middle of the bottom of the bracket, and two sides of the white strip are respectively provided with through-holes. Small pads and large pads at the bottom of the bracket; small pads and large pads protrude from both sides of the bottom of the bracket respectively; the inner side of the bottom of the bracket is fixed with an LED chip, the top of the LED chip is provided with P electrodes and N electrodes on the left and right, the P electrodes and The N electrodes are respectively connected to the small pads and large pads at the bottom through gold wires; the bracket groove is filled with packaging glue;

The PCB board is provided with two upper and lower rows of series circuits, the upper row is a series circuit of blue and red LED lamp beads, the two ends of the series circuit of blue and red LED lamp beads are connected to two of the PCB solder joints, and the lower row is a green LED lamp. Bead series circuit, both ends of the green LED lamp bead series circuit are connected to the other two PCB solder joints; the PCB solder joints of the two rows of series circuits are respectively connected with two control power supplies by wires;

The lower light guide plate and the left side of the upper light guide plate are respectively added with an upper condenser lens and a lower condenser lens corresponding to the blue and red LED lamp beads and the green LED lamp beads; Upper condenser lens reflection layer, lower condenser lens reflection layer;

The blue-red LED lamp beads and the green light LED lamp beads are replaced with flip-chip LED lamp beads, that is, the LED flip-chip is matched with a flip-chip bracket;

In the blue-red LED lamp beads, the excitation wavelength of the blue light chip is 440nm-470nm, the excitation wavelength of the red phosphor is 620nm-650nm, and in the green LED lamp bead, the wavelength of the green light chip is 500nm-545nm, the red fluorescent The powder material is one or more of nitride phosphor, fluoride phosphor, KSF phosphor or silicate phosphor;

The material in the bracket is composed of one or more of ceramics, PCT, EMC, and SMC, and the size specification of the bracket is one of 4010, 4014, 7020, and 7016;

One or more LED chips are arranged in the blue-red LED lamp bead and the green LED lamp bead;

A manufacturing method of a high color gamut blue-green LED backlight module:

Step 1. Preparation of LED lamp beads: the blue light chip is solidified to the bottom of the bracket, the blue light chip is connected to the P electrode, the N electrode, the small pad and the large pad respectively through gold wires, and a package of mixed red phosphor powder is added into the bracket groove. Glue, bake and solidify the encapsulation glue to form blue and red LED lamp beads; the green light chip is solidified to the bottom of the bracket, and the green light chip is connected to the P electrode, the N electrode, the small pad and the large pad respectively through the gold wire, and the green light chip is connected to the bracket. Add packaging glue into the groove, bake and cure the packaging glue to form green LED lamp beads;

Step 2: Preparation of dual-circuit circuit board: the blue and red LED lamp beads and the green LED lamp beads are respectively soldered on the PCB board through solder paste on the lower and lower rows of the PCB board; four wires on the four PCB solder joints , and connect two control power sources;

Step 3: Assembling the backlight module: the back of the PCB board is pasted on the inside of the L-shaped short board of the metal backboard through the adhesive, and the L-shaped long board of the metal backboard is placed in sequence with the lower light guide plate, the upper light guide plate, the diaphragm, the OPEN Cell.

The present invention provides a high-color gamut blue-green LED backlight module and a manufacturing method thereof. While improving the color gamut value, the technical problem of uneven light mixing between the blue light chip and the red light chip is solved. In addition, an upper condenser lens is added. , Lower condenser lens, and set up reflective layers on the upper and lower lens surfaces, so that red, blue, green light does not interfere with light mixing before entering the lower light guide plate and the upper light guide plate, and avoid the obvious appearance of the light guide plate near the traditional blue-green high-color gamut backlight mode light source. dappled pattern.

Description of drawings

In order to facilitate the understanding of those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

1 is a schematic structural diagram of a high color gamut blue-green LED backlight module of the present invention;

2 is a schematic diagram of the structure of an LED lamp bead of a high color gamut blue-green LED backlight module according to the present invention;

3 is a schematic diagram of a light source structure of a high color gamut blue-green LED backlight module of the present invention;

4 is a schematic structural diagram of a backlight module with a high-color gamut blue-green LED backlight module added with a condenser lens according to the present invention;

FIG. 5 is a flow chart of a manufacturing method of a high color gamut blue-green LED backlight module according to the present invention.

Detailed ways

The object of the present invention can be realized through the following technical solutions:

A high color gamut blue-green LED backlight module, see Figure 1-4, including blue-red LED lamp beads 11, green LED lamp beads 12, PCB board 2, metal backplane 3, reflective paper 4, and lower light guide plate 5 , Upper light guide plate 6, diaphragm 7, OPEN CELL 8;

The PCB board 2 is a rectangular strip-shaped circuit board on which two rows of LED lamp beads are welded; the blue and red LED lamp beads 11 and the green LED lamp beads 12 are respectively located in the upper and lower rows; one side of the PCB board 2 Four strip-shaped PCB solder joints 21 perpendicular to the short sides are provided; the back of the PCB board 2 is attached to the inner side of the short side of the L-shaped metal backplane 3, and the inner layer of the long side of the metal backplane 3 is placed with a reflective paper 4, A lower light guide plate 5, an upper light guide plate 6, a diaphragm 7, and an OPEN CELL 8 are placed in sequence above the reflective paper 4;

The LED lamp beads include brackets 101, LED chips 102, gold wires 103, packaging glue 104, white strips 105, small pads 106, and large pads 107; the bracket 101 is a rectangular slot with an inclined inner sidewall; the bottom of the bracket 101 is inlaid in the middle A section of white strip 105, two sides of the white strip 105 are respectively provided with small pads 106 and large pads 107 that penetrate the bottom of the bracket; the small pads 106 and the large pads 107 respectively protrude from both sides of the bottom of the bracket 101; the inner side of the bottom of the bracket 101 is fixed with LEDs The chip 102, the LED chip 102 is provided with a P electrode and an N electrode on the left and right sides, and the P electrode and the N electrode are respectively connected to the small pad 106 and the large pad 107 at the bottom through the gold wire 103; the groove of the bracket 101 is filled with packaging glue 104;

The PCB board 2 is internally provided with two upper and lower rows of series circuits, the upper row is a series circuit of blue and red LED lamp beads 11, the two ends of the series circuit of the blue and red LED lamp beads 11 are connected to the two upper and lower PCB solder joints 21, and the lower row is a series circuit of blue and red LED lamp beads 11. The green LED lamp beads 12 are connected in series circuit, and both ends of the series circuit of green LED lamp beads 12 are connected to the other two PCB solder joints 21; the PCB solder joints 21 of the two PCB circuits are respectively connected with two control wires by wires power supply;

The blue-red LED lamp beads 11 series circuit and the green light LED lamp bead 12 series circuit can be reversed with each other to form an upper row of green light LED lamp beads 12 series circuit, and a lower row of blue and red LED lamp beads 11 series circuit;

On the left side of the lower light guide plate 5 and the upper light guide plate 6, the upper condensing lens 13 and the lower condensing lens 14 corresponding to the blue and red LED lamp beads 11 and the green LED lamp beads 12 can be respectively added; The upper and lower surfaces of the condenser lens 14 are respectively provided with an upper condenser lens reflection layer 131 and a lower condenser lens reflection layer 141; The blue-red light and green light emitted by the beads 12 are collected into the lower light guide plate 5 and the upper light guide plate 6, and the setting of the upper condensing lens reflective layer 131 and the lower condensing lens reflective layer 141 prevents the red, blue and green light from entering. The lower light guide plate 5 and the upper light guide plate 6 interfere with each other by mixing light;

The blue-red LED lamp beads 11 and the green light LED lamp beads 12 can be replaced with flip-chip LED lamp beads, that is, LED flip-chip with flip-chip bracket;

In the blue-red LED lamp beads, the excitation wavelength of the blue light chip is 440nm-470nm, the excitation wavelength of the red phosphor is 620nm-650nm, and in the green LED lamp bead, the wavelength of the green light chip is 500nm-545nm, the red fluorescent The powder material is one or more of nitride phosphor, fluoride phosphor, KSF phosphor or silicate phosphor;

The material in the bracket 101 is composed of one or more of ceramics, PCT, EMC, and SMC, and the size of the bracket 101 can be one of 4010, 4014, 7020, and 7016;

One or more LED chips 102 are arranged in the blue-red LED lamp bead 11 and the green light LED lamp bead 12;

As shown in Figure 5, a manufacturing method of a high color gamut blue-green LED backlight module:

Step 1. Preparation of LED lamp beads: the blue light chip is solidified to the bottom of the bracket 101, the blue light chip is connected to the P electrode, the N electrode, the small pad 106 and the large pad 107 through the gold wire 103, respectively, and red is added to the slot of the bracket 101. The encapsulation glue 104 mixed with phosphor powder is baked and cured to form the blue and red LED lamp beads 11; Small pads 106 and large pads 107, add packaging glue 104 into the groove of bracket 101, bake and solidify packaging glue 104, and form green LED lamp beads 12;

Step 2: Preparation of a dual-circuit circuit board: on the PCB board 2, the blue and red LED lamp beads 11 and the green light LED lamp beads 12 are respectively soldered on the upper and lower rows of the PCB board 2 through solder paste; four of the PCB solder joints 21 on the four wires, and connect two control power;

Step 3: Assembling the backlight module: the back of the PCB board 2 is pasted on the inside of the L-shaped short board of the metal backboard 3 through the adhesive, and the lower light guide plate 5, the upper light guide plate 6, and the L-shaped long version of the metal backboard 3 are placed in sequence. Diaphragm 7, OPEN CELL 8.

working principle:

The PCB board 2 independently controls the luminous intensity of the blue and red LED lamp beads 11 and the green LED lamp beads 12 through two control power supplies; the blue and red LED lamp beads 11 emit red and blue light, and the red and blue light enter the upper light guide plate 6, and the green light The light LED lamp beads 12 emit green light, and the green light enters the lower light guide plate 5; after the green light in the lower light guide plate 5 is refracted on the end face of the reflective paper, it passes through the upper surface of the lower light guide plate 5 and enters the upper light guide plate 6. ; After the red and blue light in the upper light guide plate 6 and the green light entering from the lower light guide plate 5 are mixed, they pass through the upper light guide plate 6; the mixed light is mixed again through the diaphragm 7, and finally the mixed light reaches the OPEN CELL 8.

The present invention provides a high color gamut blue-green LED backlight module and a manufacturing method thereof. While improving the color gamut value, the technical problem of uneven light mixing between the blue light chip and the red light chip is solved. Lenses, lower condenser lenses, and reflective layers are arranged on the upper and lower lens surfaces, so that red, blue, and green light does not interfere with light mixing before entering the lower light guide plate and the upper light guide plate, and avoids the appearance of the light guide plate near the traditional blue-green high-color gamut backlight mode light source. Conspicuous floral markings.

The above content is only an example and description of the structure of the present invention, and those skilled in the art can make various modifications or supplements to the specific embodiments described or replace them in similar ways, as long as they do not deviate from the structure of the invention or Anything beyond the scope defined by the claims shall belong to the protection scope of the present invention.

Claims (1)

1. The utility model provides a blue and green LED backlight unit, includes blue red LED lamp pearl (11), green glow LED lamp pearl (12), PCB board (2), metal backboard (3), reflection paper (4), lower light guide plate (5), goes up light guide plate (6), diaphragm (7), OPEN CELL (8), its characterized in that:

the PCB (2) is a rectangular strip-shaped circuit board, and two rows of LED lamp beads are welded on the PCB; the blue-red LED lamp beads (11) and the green LED lamp beads (12) are respectively positioned in an upper row and a lower row; one side of the PCB (2) is provided with four strip-shaped PCB welding spots (21) vertical to the short edge; the back of the PCB (2) is attached to the inner side of the short side of an L-shaped metal back plate (3), reflective paper (4) is placed on the inner layer of the long side of the metal back plate (3), and a lower light guide plate (5), an upper light guide plate (6), a diaphragm (7) and an OPEN CELL (8) are sequentially placed above the reflective paper (4);

the LED lamp bead comprises a support (101), an LED chip (102), a gold wire (103), packaging glue (104), a white strip (105), a small bonding pad (106) and a large bonding pad (107); wherein the bracket (101) is a rectangular groove with an inclined inner side wall; a section of white strip (105) is embedded in the middle of the bottom of the support (101), and small bonding pads (106) and large bonding pads (107) penetrating through the bottom of the support are respectively arranged on two sides of the white strip (105); the small bonding pad (106) and the large bonding pad (107) respectively extend out of two sides of the bottom of the bracket (101); an LED chip (102) is fixed on the inner side of the bottom of the support (101), a P electrode and an N electrode are arranged on the left and right of the top of the LED chip (102), and the P electrode and the N electrode are respectively connected to a small bonding pad (106) and a large bonding pad (107) on the bottom through gold wires (103); packaging glue (104) is filled in the groove of the bracket (101);

an upper row and a lower row of series circuits are arranged in the PCB (2), a blue-red LED lamp bead (11) series circuit is arranged on the upper row, two ends of the blue-red LED lamp bead (11) series circuit are connected to two PCB welding spots (21), a green LED lamp bead (12) series circuit is arranged on the lower row, and two ends of the green LED lamp bead (12) series circuit are connected to the other two PCB welding spots (21); the PCB welding spots (21) of the two rows of series circuits are respectively connected with two control power supplies by leads;

an upper condensing lens (13) and a lower condensing lens (14) which correspond to the blue-red LED lamp beads (11) and the green-light LED lamp beads (12) are respectively arranged on the left sides of the lower light guide plate (5) and the upper light guide plate (6), and an upper condensing lens reflecting layer (131) and a lower condensing lens reflecting layer (141) are respectively arranged on the upper surface and the lower surface of the upper condensing lens (13) and the lower condensing lens (14);

in the blue-red LED lamp bead, the excitation wavelength of a blue chip is 440nm-470nm, the excitation wavelength of red fluorescent powder is 620nm-650nm, in the green LED lamp bead, the wavelength of a green chip is 500nm-545nm, and the red fluorescent powder is made of one or more of nitride fluorescent powder, fluoride fluorescent powder, KSF fluorescent powder or silicate fluorescent powder;

the material in the bracket (101) is composed of one or more of ceramics, PCT, EMC and SMC, and the size specification of the bracket (101) is one of 4010, 4014, 7020 and 7016;

one or more LED chips (102) are arranged in the blue-red LED lamp beads (11) and the green LED lamp beads (12);

the PCB (2) independently controls the luminous intensity of the blue-red LED lamp beads (11) and the green LED lamp beads (12) through two control power supplies; the blue-red LED lamp beads (11) emit red blue light, the red blue light enters the upper light guide plate (6), the green light LED lamp beads (12) emit green light, and the green light enters the lower light guide plate (5); green light in the lower light guide plate (5) is refracted on the upper end face of the reflection paper surface, penetrates out of the upper surface of the lower light guide plate (5) and enters the upper light guide plate (6); the red and blue light in the upper light guide plate (6) and the green light entering from the lower light guide plate (5) are mixed and then penetrate out of the upper light guide plate (6); the mixed light is mixed again through a membrane (7), and finally the mixed light is irradiated on OPENCELL (8);

the blue-green LED backlight module is manufactured by the following steps:

step one, preparing an LED lamp bead: the blue light chip is fixedly crystallized at the bottom of the support (101), the blue light chip is respectively connected with the P electrode, the N electrode, the small bonding pad (106) and the large bonding pad (107) through gold wires (103), packaging glue (104) mixed with red fluorescent powder is added into a groove of the support (101), and the packaging glue (104) is baked and cured to form a blue-red LED lamp bead (11); the green chip is fixedly crystallized at the bottom of the support (101), the green chip is respectively connected with the P electrode, the N electrode, the small bonding pad (106) and the large bonding pad (107) through gold wires (103), packaging glue (104) is added into the groove of the support (101), and the packaging glue (104) is baked and cured to form a green LED lamp bead (12);

step two, preparing a double-circuit board: the blue-red LED lamp beads (11) and the green LED lamp beads (12) are fixedly welded on the PCB (2) in an upper row and a lower row respectively through solder paste on the PCB (2); four wires are arranged on the four PCB welding spots (21) and are connected with two control power supplies;

step three, assembling the backlight module: the back of the PCB (2) is pasted on the inner side of the L-shaped short plate of the metal back plate (3) through back glue, and the lower light guide plate (5), the upper light guide plate (6), the diaphragm (7) and the OPEN CELL (8) are sequentially placed on the L-shaped long plate of the metal back plate (3).

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