CN212570994U - LED display module and have its display screen cell board and display screen - Google Patents

Abstract

The utility model belongs to the technical field of LED display, specifically disclose a LED display module, including lead frame, R chip, G chip, B chip and dam structure, regard the fin as the carrier of RGB chip, the lead frame is preprocessed to hollow out construction, the solid part includes fin and pad, bear a set of RGB chip on the fin front, the heat that sends when the RGB chip switches on can be directly dissipated outside the LED display module through the fin back, effectively promote the product heat dissipation efficiency, solve the difficult problem of LED product high temperature inefficacy; the box dam structure realizes the functions of optical isolation and optical reflection of adjacent pixels, prevents light crosstalk and improves luminous intensity; the RGB chip is directly fixed on the lead frame without a substrate, the structure is simple, and the lightness and thinness are realized. The utility model also discloses a display screen cell board and display screen that have this LED display module assembly.

Description

LED display module and have its display screen cell board and display screen

Technical Field

The utility model belongs to the technical field of the LED shows, a LED display module assembly and have its display screen cell board and display screen is related to.

Background

With the breakthrough of the LED display technology and the maturity of products, the requirements of good heat dissipation, high reliability, lightness and thinness are provided for the LED display devices forming the pixels of the LED display device.

At present, a substrate or a foot-covering bracket formed by stamping a die is adopted as a chip carrier of most LED display modules, the heat dissipation of an LED and the improvement of the reliability of a product are limited due to the self heat conductivity, the mismatch of thermal expansion and the design limitation of a heat dissipation structure of a packaging material, and meanwhile, a packaging body is thick and cannot be thinned.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects existing in the prior art, the utility model aims to provide a LED display module assembly and have its display screen cell board and display screen has solved the problem that current LED display module assembly thermal diffusivity is not good, can't realize frivolousization.

The utility model discloses a realize through following technical scheme:

an LED display module comprises a lead frame, an R chip, a G chip, a B chip and a dam structure, wherein the lead frame comprises a solid part and a hollow part, the solid part comprises a radiating fin and a bonding pad, the bonding pad is positioned around the radiating fin, and the back surfaces of the radiating fin and the bonding pad are provided with welding feet; the bonding pad is positioned around the radiating fin;

arranging a dam structure on the front surfaces of the radiating fins and the bonding pads, and fixing an R chip, a G chip and a B chip on the front surface of the radiating fin part in the dam structure;

and plastic packaging materials for packaging the R chip, the G chip and the B chip are filled in the dam structure.

Further, the bonding pad comprises an R chip cathode bonding pad, a G chip cathode bonding pad, a B chip cathode bonding pad and an RGB chip common anode bonding pad; the R chip cathode bonding pad and the radiating fin are of an integral structure.

Furthermore, the anodes of the R chip, the G chip and the B chip are connected with the RGB chip common anode bonding pad through bonding wires, the cathode of the R chip is fixed on the R chip cathode bonding pad through conductive adhesive, the cathode of the G chip is connected with the G chip cathode bonding pad through the bonding wires, and the cathode of the B chip is connected with the B chip cathode bonding pad through the bonding wires.

Furthermore, the lead frame is made of copper strips and is manufactured by adopting an etching process.

Further, the solder tail is electrically connected to an external element.

Furthermore, the number of the radiating fins is 4, and the number of the welding feet is 14.

Furthermore, a groove is pre-formed in the outer edge surface corresponding to the back surface of the solid part to form a step surface.

Further, the LED display module comprises four pixel units.

The utility model also discloses a have the display screen cell board of LED display module assembly, the display screen cell board comprises on the PCB board a plurality of LED display module assembly subsides.

The utility model also discloses a have the LED display screen of display screen cell board, this display screen is formed by the concatenation of a plurality of display screen cell boards.

Compared with the prior art, the utility model discloses following profitable technological effect has:

the utility model discloses a LED display module, including the lead frame, R chip, G chip, B chip and dam structure, regard the carrier of fin as the RGB chip, the lead frame is preprocessed to hollow out construction, solid part includes fin and pad, bear a set of RGB chip at the fin front, because the hollow out construction of lead frame, and lead frame itself is lighter and thinner, the heat can be given off in time, the heat that sends when can switch on the RGB chip directly gives off to outside the LED display module through the fin back, effectively promote product heat and give off efficiency, solve the difficult problem that LED product high temperature became invalid; the box dam structure realizes the effect of adjacent pixel optoisolation and light reflection, prevents the crosstalk and promotes luminous intensity. The invention has no substrate, only fixes the RGB chip on the lead frame directly, has simple structure and realizes lightness and thinness.

Furthermore, the lead frame adopts a copper strip, so that the thickness of the product is effectively reduced, and the lightness and thinness are realized.

Furthermore, a groove is pre-formed in the outer edge surface corresponding to the back surface of the solid part to form a step surface, the step surface enables the plastic package material to be connected with the lead frame in a hanging mode, and the semi-etching area can be encapsulated in the plastic package material after being packaged, so that the lead frame is prevented from being separated from the plastic package material.

The utility model also discloses have LED display module's display screen cell board and display screen, heat dispersion is more excellent, and overall structure weight is lighter.

Drawings

Fig. 1 is a schematic structural diagram of an LED display module according to the present invention;

FIG. 2 is a front view of a lead frame;

FIG. 3 is a schematic diagram of a reverse structure of a lead frame;

FIG. 4 is a cross-sectional view A-A of FIG. 3;

FIG. 5 is a schematic view of a reverse fillet arrangement of the lead frame;

fig. 6 is a schematic view of the entire structure of the lead frame before the division.

Wherein, 1 is a lead frame; 2 is an R chip; 3 is a G chip; 4 is a chip B; 5 is a box dam structure; 6 is a bonding wire; 7 is a heat sink; 8 is a welding leg; 9 is the cathode bonding pad of the B chip; 10 is the chip cathode bonding pad G; 11 is a common anode bonding pad of the RGB chip; 12 is the R chip cathode pad; and 13 is a step surface.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings:

as shown in fig. 1, the utility model discloses a LED display module, including lead frame 1, R chip 2, G chip 3, B chip 4 and box dam structure 5, lead frame 1 includes solid portion and fretwork part, and solid portion includes fin 7 and pad, and the back of fin 7 and pad is leg 8; the pad is positioned around the heat sink 7; a dam structure 5 is arranged on the front surfaces of the heat sink 7 and the bonding pad, and the R chip 2, the G chip 3 and the B chip 4 are fixed on the front surface of the heat sink 7 part positioned in the dam structure 5.

As shown in fig. 2, the bonding pads include an R chip cathode bonding pad 12, a G chip cathode bonding pad 10, a B chip cathode bonding pad 9, and an RGB chip common anode bonding pad 11, and the RGB chip common anode bonding pad 11, the G chip cathode bonding pad 10, and the B chip cathode bonding pad 9 are located around the heat sink 7.

The R chip cathode pad 12 and the heat sink 7 are integrated, and a part of the region of the heat sink 7 extending from the R chip cathode pad 12 is used as the R chip cathode pad. The cathode of the R chip 2 is fixedly connected with the R chip cathode bonding pad 12 through conductive adhesive.

As shown in fig. 1, the anodes of the R chip 2, the G chip 3 and the B chip 4 are connected to the RGB chip common anode pad 11 through bonding wires 6, and the cathodes of the G chip 3 and the B chip 4 are connected to the corresponding chip cathode pads through bonding wires 6.

As shown in fig. 1, the solid portion is divided into four pixel units, forming 4 full-color pixels, and arranged in an XY-direction array. Specifically, each pixel unit includes one heat sink 7 and a set of RGB chips 4, and 2 pixel units in the X direction share 1 common anode pad.

A dam structure 5 is arranged at each pixel unit, and the R chip 2, the G chip 3 and the B chip 4 are fixed on the front surface of a radiating fin 7 part positioned in the dam structure 5; the R chip 2, the G chip 3 and the B chip 4 are connected with the RGB chip common anode bonding pad 11, the G chip 3 is connected with the G chip cathode bonding pad 10, and the B chip 4 is connected with the B chip cathode bonding pad 9.

And the dam structure 5 is filled with a plastic packaging material for packaging the R chip 2, the G chip 3 and the B chip 4. The dam structure 5 is formed by injection molding of a plastic package material on the lead frame 1 through a plastic package process, so that the effects of optical isolation and light reflection of adjacent pixels are realized, light crosstalk is prevented, and the luminous intensity is improved.

The plastic package material is made of materials with good light transmission such as epoxy resin and silicon resin, and effectively transmits light of the RGB chip to the outside of the product to form pixel points.

The lead frame 1 is made of a single-layer metal material, a hollow structure is formed through processes such as etching and the like, the internal circuit connection function of the display module is achieved, and a copper strip is generally adopted.

The lead frame 1 is made of a single-layer metal material, a hollow structure is formed through processes such as etching and the like, the internal circuit connection function of the display module is achieved, and a copper strip is generally adopted.

The back of the solid portion serves as an SMT pad 8, and the SMT pad 8 is electrically connected to an external component.

The LED display module comprises 4 full-color pixel points which are arranged in an XY direction array.

As shown in fig. 5, the number of the heat sinks 7 is 4, the number of the solder fillets 8 is 14, and the solder fillets 8 are circular portions corresponding to gray areas in the drawing.

As shown in fig. 4, the solid portion is pre-grooved on the corresponding outer edge surface of the back surface to form a step surface 13 as a half-etched region, i.e., a gray region as shown in fig. 3, i.e., the cross-sectional area of the back surface is smaller than that of the front surface. The step surface 13 enables the plastic package material to be hung with the lead frame 1, and the semi-etching area can be encapsulated in the plastic package material after being encapsulated, so that the lead frame 1 is prevented from being separated from the plastic package material.

The utility model discloses a preparation method of LED display module assembly specifically includes following step:

s1, forming the lead frame 1 shown in FIG. 6 by etching process, and forming a heat sink 7, an RGB chip common anode bonding pad 11, a G chip cathode bonding pad 10 and a G chip cathode bonding pad 10 on the front surface;

s2, forming solder fillets 8 on the back surface by half etching;

s3, forming a dam structure 5 at the pixel unit on the front surface of the lead frame 1 through a plastic package process, and fixing the R chip 2, the G chip 3 and the B chip 4 on the front surface of a radiating fin 7 in the dam structure 5 through die bonding glue;

s4, connecting the R chip 2, the G chip 3 and the B chip 4 with the RGB chip common anode bonding pad 11 and the corresponding chip cathode bonding pad through the bonding wires 6;

s5, filling liquid glue into the box dam structure 5 through a glue dispensing process, and ensuring that the R chip 2, the G chip 3, the B chip 4 and the bonding wire 6 are packaged in the box dam structure 5;

and S6, separating through a cutting process to form a plurality of LED display modules as shown in figure 1.

Claims (10)

1. The LED display module is characterized by comprising a lead frame (1), an R chip (2), a G chip (3), a B chip (4) and a dam structure (5), wherein the lead frame (1) comprises a solid part and a hollow part, the solid part comprises a radiating fin (7) and a bonding pad, the bonding pad is positioned around the radiating fin (7), and the back surfaces of the radiating fin (7) and the bonding pad are provided with welding feet (8); the pad is positioned around the heat sink (7);

arranging a dam structure (5) on the front surfaces of the radiating fins (7) and the bonding pads, and fixing an R chip (2), a G chip (3) and a B chip (4) on the front surface of the radiating fin (7) positioned in the dam structure (5);

and plastic packaging materials for packaging the R chip (2), the G chip (3) and the B chip (4) are filled in the dam structure (5).

2. The LED display module of claim 1, wherein the bonding pads comprise an R chip cathode bonding pad (12), a G chip cathode bonding pad (10), a B chip cathode bonding pad (9) and an RGB chip common anode bonding pad (11); the R chip cathode bonding pad (12) and the radiating fin (7) are of an integral structure.

3. The LED display module according to claim 2, wherein the anodes of the R chip (2), the G chip (3) and the B chip (4) are connected with the RGB chip common anode bonding pad (11) through the bonding wire (6), the cathode of the R chip (2) is fixed on the R chip cathode bonding pad (12) through a conductive adhesive, the cathode of the G chip (3) is connected with the G chip cathode bonding pad (10) through the bonding wire (6), and the cathode of the B chip (4) is connected with the B chip cathode bonding pad (9) through the bonding wire (6).

4. The LED display module according to claim 1, wherein the lead frame (1) is made of copper tape by etching process.

5. The LED display module of claim 1, wherein the solder tails (8) are electrically connected to external components.

6. The LED display module of claim 1, wherein there are 4 heat sinks (7) and 14 solder feet (8).

7. The LED display module according to claim 1, wherein the solid portion is pre-grooved with a step surface (13) on the outer edge surface corresponding to the back surface.

8. The LED display module of claim 1, wherein the LED display module comprises four pixel cells.

9. The display screen unit board with the LED display module of any one of claims 1-8, wherein the display screen unit board is formed by attaching a plurality of LED display modules on a PCB board.

10. An LED display panel having the panel of claim 9, wherein the panel is formed by splicing a plurality of panels.

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