CN110690336B - Energy-saving LED lighting device and manufacturing method thereof - Google Patents

Abstract

The present invention provides an energy-saving LED lighting device and a manufacturing method thereof. The energy-saving LED lighting device of the present invention adopts a heat shrinkable material to prevent the disconnection of the bonding wire and the peeling of the LED chip, the fluorescent resin and the heat-dissipating substrate, and can achieve good packaging. The efficiency is improved, and the light extraction rate can be improved; the manufacturing method of the present invention is extremely simple, and the manufacturing cost is low.

Description

An energy-saving LED lighting device and its manufacturing method

technical field

The invention relates to the field of LED lighting packaging, in particular to an energy-saving LED lighting device and a manufacturing method thereof.

Background technique

Existing LED packaging structures are mostly COB structures, ie chip-on-board structures, which usually need to consider heat dissipation. Referring to FIG. 6( a ), the LED chip 21 is fixed on the heat dissipation substrate 20 through the adhesive layer 22 , and the LED chip 21 is electrically connected to the circuit layer of the heat dissipation substrate 20 through the bonding wire 23 to realize power supply, and finally uses fluorescent Resin 24 seals and adjusts color temperature. However, due to the problem of unbalanced thermal matching, the LED chip 21 and the fluorescent resin 24 are easily peeled off from the heat dissipation substrate 20 , resulting in the invasion of water vapor. In addition, most of the fluorescent resin 24 are relatively inexpensive materials such as epoxy resin and silicone resin, which are thermal expansion materials. When heated, they have a force F that stretches outward. The existence of F will lead to disconnection of the connection between the bonding wire 23 and the LED chip 21 , resulting in package failure.

SUMMARY OF THE INVENTION

Based on solving the above problems, the present invention provides an energy-saving LED lighting device, which includes:

a substrate, the substrate has a circuit layer;

The LED chip has electrodes, and the back of the LED chip is attached to the circuit layer through an adhesive layer;

a bonding wire, the bonding wire electrically connects the electrode and the circuit layer;

a heat shrinkable material that completely seals the bonding wire and the electrode, and at least seals a portion of the side surface of the LED chip;

A fluorescent resin covering at least a part of the heat shrinkable material and the light emitting surface of the LED chip.

Wherein, the heat shrinkable material seals a part of two opposite sides of the LED chip.

In one embodiment, the heat shrinkable material seals a portion of two opposite sides of the LED chip.

In one embodiment, the fluorescent resin completely encapsulates the heat shrinkable material.

In one embodiment, the heat shrinkable material completely seals the light emitting surface of the LED chip.

In one embodiment, the heat shrinkable material has two convex mirror structures symmetrical along the center of the LED chip.

In one embodiment, the fluorescent resin completely covers the heat shrinkable material.

In one embodiment, the top surface of the fluorescent resin has a convex structure.

In one embodiment, the substrate has a groove around the LED chip, and the heat shrink material fills at least a portion of the groove.

In one embodiment, the fluorescent resin fills another portion of the trench.

In one embodiment, the present invention provides a method for manufacturing an energy-saving LED lighting device, comprising:

(1) Fixing the LED chip on the substrate with an adhesive layer;

(2) electrically connecting the electrode of the LED chip and the circuit layer of the substrate with a bonding wire;

(3) dispensing and curing to form a heat shrinkable material, the heat shrinkable material completely seals the bonding wire and the electrode, and at least seals a part of the side surface of the LED chip;

(4) The fluorescent resin is formed by injection molding, and the fluorescent resin covers at least a part of the heat shrinkable material and the light emitting surface of the LED chip.

The advantages of the present invention are as follows:

The energy-saving LED lighting device of the present invention adopts the heat shrinkable material to prevent the disconnection of the bonding wire and the peeling of the LED chip, the fluorescent resin and the heat-dissipating substrate, which can improve the packaging yield and can improve the light output rate; the manufacturing method of the present invention is extremely Simple and low cost to manufacture.

Description of drawings

1 is (a) a cross-sectional view and (b) a top view of the energy-saving LED lighting device of the first embodiment;

2 is (a) a cross-sectional view and (b) a top view of the energy-saving LED lighting device of the second embodiment;

3 is (a) a cross-sectional view and (b) a top view of the energy-saving LED lighting device of the third embodiment;

4 is (a) a cross-sectional view and (b) a top view of the energy-saving LED lighting device of the fourth embodiment;

5 is (a) a cross-sectional view and (b) a top view of the energy-saving LED lighting device of the fifth embodiment;

FIG. 6 is a schematic diagram of a prior art LED lighting device.

Detailed ways

The energy-saving LED lighting device of the present invention can prevent the mismatch of thermal stress between the LED chip, the fluorescent resin and the heat dissipation substrate, and can ensure the reliability of the bonding wire connection and improve the efficiency of light extraction. The heat-expandable material referred to in the present invention refers to a material whose volume expands when heated, and a heat-shrinkable material refers to a material whose volume shrinks when heated.

first embodiment

Referring to FIG. 1( a ), it includes an LED chip 2 fixed on a substrate 1 through an adhesive layer 3 , the LED chip is a gallium nitride-based LED chip, or a mini-LED chip; the substrate 1 is for heat dissipation Substrates, such as LTCC substrates, DBC substrates, etc., have circuit layers thereon. The adhesive layer 3 has permanent adhesiveness, and can be selected from a high polymer adhesive material, which can be an adhesive material commonly used in the art, and details are not described herein again.

The back of the LED chip 2 is attached to the circuit layer through the adhesive layer 3; the light-emitting surface of the LED chip 2 faces upward, and the edge of the light-emitting surface has electrodes (not shown), and the electrodes are soldered Lines 4 are electrically connected to the wiring layer. The bonding wires 4 are copper wires, gold wires, silver wires and the like. The bonding wire 4 is wire-bonded by a wire bonding tool, which may be a wedge-shaped bonding head, and the bonding wire 4 has an upwardly protruding arc shape.

In the prior art, the welding wire 4 is easily broken due to the tensile force of the fluorescent resin; in order to solve this problem, the present invention uses a dispensing technology to form a heat shrinkable material 5 around the welding wire 4, and the heat shrinkable material 5 wraps The bonding wire 4 and the electrode (not shown) are covered. Referring to FIG. 1( b ), in this embodiment, the heat shrinkable material 5 is only disposed on a part of two sides of the LED chip 2 , and the heat shrinkable material 5 connects the light emitting surface and the substrate 1 top surface. Of course, the position of the heat shrinkable material 5 may also be different according to the position of the bonding wire. The heat-shrinkable material 4 has a heat-shrinking property with an inwardly shrinking stress F2.

The heat shrinkable material 5 is covered with a fluorescent resin 6 , which covers the heat shrinkable material 5 and the light-emitting surface of the LED chip 2 . The fluorescent resin 6 is a resin material such as epoxy resin and silicone resin doped with fluorescent powder, which has a positive thermal expansion coefficient, which generates an outward stretching stress F1. The heat shrinkable material 4 can be selected from polyvinylidene chloride, polyvinyl chloride, PET, polyester resin material, etc. In this embodiment, it can be a transparent or translucent material.

The stress F1 should be less than the stress F2, so that the welding wire 4 will eventually generate a downward force. Due to the arc shape of the protrusion of the welding wire 4, this force will not cause the disconnection of the welding wire 4 to ensure the welding. reliability of the wire connection. In addition, since F1 is smaller than F2, the overall performance of the structure on the substrate is shrinkage stress, that is, the stress shrinking toward the center, which can offset the tensile force of the substrate 1 (the substrate is generally a ceramic material, such as LTCC, DBC, etc., which has tensile force force), thereby preventing the LED chip 2 and the fluorescent resin 6 from peeling off the substrate 1 .

Second Embodiment

In the first embodiment, since the structure on the substrate generally exhibits shrinkage stress, the heat shrinkable material 5 presses down the LED chip 2 and adheres to the substrate 1. If the heat shrinkable material 5 and the substrate If the bonding force is too small, peeling is also likely to occur. To this end, in this embodiment, referring to FIG. 2( a ), on the substrate 1 , grooves 7 are formed around the LED chip 2 , and the grooves 7 may be two or four discrete, etc., or It is a ring-shaped structure surrounding the LED chip 2 . Referring to FIG. 2( b ), the heat shrinkable material 5 fills a part of the groove 7 , and the fluorescent resin 6 fills other parts of the groove 7 , so that the fluorescent resin and the heat shrinkable material can be combined with each other. The bonding force of the substrate improves the reliability of the heat shrinkable material 5 pressing the LED chip 2 .

Third Embodiment

Referring to FIG. 3( a ), in this embodiment, the heat shrinkable material 5 completely seals the side surface of the LED chip 2 , and its pressing force is greater. In addition, a part of the surface of the heat shrinkable material 5 and the groove of the light exit surface form a concave part, the fluorescent resin 6 fills the concave part, and forms a convex curved surface (ie, a convex surface structure) due to surface tension. The curved surface can increase the light extraction rate. Referring to FIG. 3( b ), at this time, the fluorescent resin 6 only covers a part of the heat shrinkable material. Of course, in this embodiment, for example, the groove 7 of the second embodiment may also be provided. At this time, the groove 7 is completely filled with the heat shrinkable material 5 .

Fourth Embodiment

Referring to FIG. 4( a ), in this embodiment, the heat shrinkable material 5 completely seals the side surface of the LED chip 2 and its light emitting surface, and its pressing force is greater. In addition, the heat shrinkable material 5 has two convex mirror structures 8 and 9 symmetrical along the center of the LED chip 2 . The convex mirror structures 8 and 9 can increase the light extraction rate and prevent the brightness difference between the central light and the edge light from being large. In this embodiment, the heat shrinkable material 5 is a transparent material. Referring to FIG. 4( b ), at this time, the fluorescent resin 6 covers the heat shrinkable material 5 . Of course, in this embodiment, for example, the groove 7 of the second embodiment may also be provided. At this time, the groove 7 is completely filled with the heat shrinkable material 5 .

Fifth Embodiment

Referring to FIG. 5( a ), in this embodiment, the structure of the heat shrinkable material 5 is the same as that of the first embodiment, which is not repeated here. However, the fluorescent resin 6 covers the heat shrinkable material 5 and the light emitting surface. The fluorescent resin 6 has a convex curved surface (ie, a convex structure), and the curved surface can increase the light extraction rate.

The present invention also provides a manufacturing method of an energy-saving LED lighting device, comprising:

(1) Fixing the LED chip on the substrate with an adhesive layer;

(2) electrically connecting the electrode of the LED chip and the circuit layer of the substrate with a bonding wire;

(3) dispensing and curing to form a heat shrinkable material, the heat shrinkable material completely seals the bonding wire and the electrode, and at least seals a part of the side surface of the LED chip;

(4) The fluorescent resin is formed by injection molding, and the fluorescent resin covers at least a part of the heat shrinkable material and the light emitting surface of the LED chip.

Of course, the above methods can be applied to the first to fifth embodiments, and the specific details and processes thereof may be different, which should be understood by those skilled in the art.

Finally, it should be noted that: obviously, the above-mentioned embodiments are only examples for clearly illustrating the present invention, and are not intended to limit the implementation manner. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. However, the obvious changes or changes derived from this are still within the protection scope of the present invention.

Claims (4)

1. An energy-saving LED lighting device, comprising: a substrate, the substrate has a circuit layer; The LED chip has electrodes, and the back of the LED chip is attached to the circuit layer through an adhesive layer; a bonding wire, the bonding wire electrically connects the electrode and the circuit layer; a heat-shrinkable material, which completely seals the bonding wire and the electrode, and the heat-shrinkable material completely seals the light-emitting surface of the LED chip; Fluorescent resin, completely encapsulating the heat shrinkable material; Wherein, the heat shrinkable material has two convex mirror structures symmetrical along the center of the LED chip; And the heat shrinkable material is selected from polyvinylidene chloride, polyvinyl chloride, PET or polyester resin material, which is a transparent material. 2 . The energy-saving LED lighting device according to claim 1 , wherein the substrate has a groove around the LED chip, and the heat shrinkable material fills at least a part of the groove. 3 . 3 . The energy-saving LED lighting device according to claim 2 , wherein the fluorescent resin fills another part of the groove. 4 . 4. A manufacturing method of an energy-saving LED lighting device, which is used for manufacturing the energy-saving LED lighting device according to any one of claims 1-3, comprising: (1) Fixing the LED chip on the substrate with an adhesive layer; (2) electrically connecting the electrode of the LED chip and the circuit layer of the substrate with a bonding wire; (3) dispensing and curing to form a heat shrinkable material, the heat shrinkable material completely seals the bonding wire and the electrode, and the heat shrinkable material completely seals the light emitting surface of the LED chip; (4) injection molding to form a fluorescent resin that completely seals the heat shrinkable material; Wherein, the heat shrinkable material has two convex mirror structures symmetrical along the center of the LED chip; And the heat shrinkable material is selected from polyvinylidene chloride, polyvinyl chloride, PET or polyester resin material, which is a transparent material.

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