LED device with high environment contrast and high luminous efficiency

Abstract

The invention discloses an LED device with high environment contrast and high luminous efficiency. Comprising a substrate, a carrier plate, an LED chip, a lead and packaging glue. A step-shaped through hole is formed in the middle of the base plate; a plurality of electrodes are arranged inside or on the surface of the substrate; the electrodes comprise a first electrode, a second electrode and a third electrode; the upper surface of the carrier plate is fixed with the lower surface of the substrate through a first binder; the LED chip is provided with an electrode surface, a light-emitting surface and a plurality of side surfaces, the electrode surface is electrically connected with the third electrode through the lead, and the light-emitting surface of the LED chip is fixed with the carrier plate through a second binder; and the packaging adhesive is filled in the step-shaped through hole. According to the invention, a novel packaging structure design is adopted, so that the light absorption of the packaging adhesive to the LED chip is avoided, and the LED device has the advantages of high environmental contrast and high light emitting efficiency at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of LEDs, and in particular to an LED device with high environmental contrast and high light extraction efficiency. Background Art

[0002] LED, or light-emitting diode, is a semiconductor device that can directly convert electrical energy into light energy. Due to its long life, fast response, high luminous efficiency, rich colors and high purity, LED devices are widely used in the display field.

[0003] In the display field, there are many indicators used to characterize the performance of display screens, among which ambient contrast and light output efficiency are two of the more critical indicators. Ambient contrast refers to the brightness ratio between the brightest and darkest parts of the display screen under ambient light; light output efficiency refers to the efficiency of the display screen in converting electrical energy into light energy.

[0004] In the existing technology, some LED devices are coated with a semi-transparent coating to reduce the surface reflectivity, thereby improving the ambient contrast, but this will reduce the light output efficiency of the display. Some LED devices are partially coated with black ink. Although it reduces the impact on the light output efficiency of the device, the process is relatively complicated, and the surface will still partially reflect ambient light.

[0005] Therefore, there is an urgent need to develop a new type of LED device structure and packaging method so as to improve the light extraction efficiency while improving the environmental contrast of the LED device. Summary of the invention

[0006] The object of the present invention is to overcome the problems of low ambient contrast and light extraction efficiency of LED devices in the above-mentioned prior art, and to provide an LED device with high ambient contrast and high light extraction efficiency.

[0007] The present invention is achieved through the following technical solutions: An LED device with high environmental contrast and high light extraction efficiency comprises a carrier board 100 and a substrate 300 located on the carrier board 100; a through hole 304 is opened in the middle of the substrate 300; The substrate 300 is provided with a first electrode 301, a second electrode 302 and a third electrode 303; The first electrode 301 is used for surface mounting, and the second electrode 302 is used to connect the first electrode 301 and the third electrode 303; An LED chip 500 is disposed on the carrier board 100 at the bottom of the through hole 304; The LED chip 500 includes a light emitting surface 502 and an electrode surface 501 ; the electrode surface 501 is electrically connected to the third electrode 303 .

[0008] The cross-sectional shape of the through hole 304 is a right-angle step-like step; The first electrode 301, the second electrode 302 and the third electrode 303 are sequentially connected from top to bottom and laid on the surface of the right-angled stepped steps; The electrode surface 501 of the LED chip 500 is connected to the third electrode 303 via a wire 600 .

[0009] The cross-sectional shape of the through hole 304 is a stepped ladder.

[0010] The second electrode 302 is embedded in the body of the substrate 300 and is electrically connected to the first electrode 301 and the third electrode 303 through via holes.

[0011] The electrode surface 501 of the LED chip 500 is electrically connected to the third electrode 303 directly through an adhesive.

[0012] The inner surface of the carrier 100 is fixed to the corresponding surface of the substrate 300 via the first adhesive 200; the outer surface of the carrier 100 is a smooth surface or a surface having a microstructure array.

[0013] The through hole 304 is filled with packaging glue 700 .

[0014] The packaging glue 700 is filled into the through hole 304 twice. The first filling is doped with carbon powder, and the filling height is flush with the LED device to form a light absorbing layer 701; the second filling is doped with reflective scattering particles, and the filling height is flush with the mouth of the through hole 304 to form a reflective layer 702.

[0015] The LED chip 500 is fixed to the upper surface of the carrier 100 via the second adhesive 400 .

[0016] The material of the carrier board 100 is glass, plastic, epoxy resin or silicone resin.

[0017] Compared with the prior art, the present invention has the following advantages and effects: By designing the structure of LED devices, the area ratio of black area is greatly increased, thereby reducing the surface reflectivity and improving the environmental contrast; The light emitted by the LED chip can be emitted directly, reducing losses, and the multi-layer packaging structure design can greatly improve the light output efficiency of the LED device; BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the carrier structure of Example 1.

[0019] Figure 2 It is a schematic diagram of the structure after the carrier plate and the substrate of Example 1 are bonded together.

[0020] Figure 3 It is a schematic diagram of the structure after crystal bonding of Example 1.

[0021] Figure 4 It is a schematic diagram of the structure after the lead wire of Example 1.

[0022] Figure 5 Schematic diagram of the structure of the LED device of Example 1.

[0023] Figure 6 It is a schematic structural diagram of the LED device of Example 2.

[0024] Figure 7 It is a schematic structural diagram of the LED device of Example 3.

[0025] Figure 8 It is a schematic structural diagram of the LED device of Example 4. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with specific embodiments.

[0027] Example 1 like Figure 1-5 The present invention discloses an LED device with high environmental contrast and high light extraction efficiency, comprising a carrier 100 and a substrate 300 located on the carrier 100; a through hole 304 is opened in the middle of the substrate 300; The substrate 300 is provided with a first electrode 301, a second electrode 302 and a third electrode 303; The first electrode 301 is used for surface mounting PCBA, and the second electrode 302 is used for connecting the first electrode 301 and the third electrode 303; An LED chip 500 is disposed on the carrier board 100 at the bottom of the through hole 304; The LED chip 500 includes a light emitting surface 502 and an electrode surface 501 ; the electrode surface 501 is electrically connected to the third electrode 303 .

[0028] The through hole 304 is filled with packaging glue 700 .

[0029] The LED chip 500 is fixed to the upper surface of the carrier 100 via the second adhesive 400 .

[0030] The through hole 304 may be in a circular, square or other shapes.

[0031] The cross-section of the through hole 304 is in the shape of a right-angled step.

[0032] The first electrode 301, the second electrode 302 and the third electrode 303 are sequentially connected from top to bottom and laid on the surface of the right-angled stepped steps.

[0033] The electrode surface 501 of the LED chip 500 is connected to the third electrode 303 via a wire 600 .

[0034] The number of the through hole 304 is one or more, and the number of the corresponding LED chips 500 is one or more.

[0035] The packaging glue 700 is filled in the stepped through hole 304 to protect the LED chip 500 and the lead 600 .

[0036] The substrate 300 is double-layered or multi-layered. The substrate 300 is made of ceramic material, glass material or glass fiber / resin composite material, preferably BT resin material. The material of the substrate 300 is dark or has a dark coating on the surface. In this example, the substrate 300 is a black BT resin plate with a double-layer structure; the electrode is prepared by nickel-gold or nickel-palladium-gold process, which is convenient for wire bonding; the second electrode 302 is located on the inner surface of the substrate 300.

[0037] The material of the carrier 100 is glass, plastic, epoxy resin or silicone resin. In this example, the material of the carrier 100 is epoxy resin, more specifically, Japanese IK0010 epoxy resin, because IK0010 epoxy resin has the advantages of high temperature resistance, high light transmittance, high refraction, high hardness, etc. The carrier 100 can be cut and separated after the device is packaged or before packaging.

[0038] The carrier 100 contains no filler or contains fillers with functions of mechanical reinforcement, light conversion, light reflection, light absorption or light enhancement, such as glass fiber, quantum dots or phosphors. In this example, the carrier 100 contains no filler.

[0039] The material of the lead wire 600 is one or more of gold, silver, copper or aluminum and alloys thereof. In this example, the material of the lead wire 600 is gold, because gold wire has excellent thermal conductivity, electrical conductivity, and stable performance.

[0040] The second adhesive 400 is a transparent insulating adhesive with good light transmittance to the wavelength of the LED chip 500, or a translucent insulating adhesive doped with functional particles, and the material of the first adhesive 200 is the same as or different from that of the second adhesive 400. In this example, the second adhesive 400 and the first adhesive 200 are both made of Shin-Etsu KER-3000-M2 glue, because Shin-Etsu KER-3000-M2 glue has the advantages of high transparency, high heat resistance, high bonding strength, etc.

[0041] The material of the packaging glue 700 is one or more of silicone resin, epoxy resin or polyimide resin. The packaging glue 700 is pure resin or doped with functional particles. The functional particles have reflection, absorption or conversion functions. The materials of the functional particles include but are not limited to graphite, carbon powder, carbon nanotubes, silicon dioxide, boron nitride, zirconium dioxide, hafnium dioxide, aluminum oxide, zinc oxide, titanium dioxide, quantum dots and perovskite. In this example, the packaging glue 700 is an epoxy resin of IK0010 type with nano carbon black added.

[0042] Example 2 like Figure 6 The main difference between this embodiment and the first embodiment is that the cross-sectional shape of the through hole 304 is a ladder-shaped step. From the cross-sectional view, it is sloped, which is used for buffering and is more convenient for metal plating and wire bonding.

[0043] The inner surface of the carrier 100 is fixed to the corresponding surface of the substrate 300 by the first adhesive 200; the outer surface of the carrier 100 is a smooth surface or a surface with a microstructure array. Of course, the number of microstructures can be single. The shape of the microstructure is one or more of spherical, conical, trapezoidal or other shapes.

[0044] Example 3 like Figure 7 The main difference between this embodiment and the first embodiment is that the second electrode 302 is embedded in the body of the substrate 300 and is electrically connected to the first electrode 301 and the third electrode 303 through vias.

[0045] The packaging glue 700 is filled into the through hole 304 twice. During the first filling, it is doped with light-absorbing particles, such as carbon powder, metal nanoparticles, etc.; the filling height is flush with the LED device to form a light-absorbing layer 701; during the second filling, it is doped with reflective scattering particles (titanium dioxide, silicon dioxide, etc.) and the filling height is flush with the mouth of the through hole 304 to form a reflective layer 702. The inner surface of the carrier 100 is fixed to the corresponding surface of the substrate 300 by the first adhesive 200; the outer surface of the carrier 100 is a smooth surface or a surface with a microstructure array. Of course, the number of microstructures can be single. The shape of the microstructure is one or more of spherical, conical, trapezoidal or other shapes.

[0046] Example 4 like Figure 8 The main difference between this embodiment and the first embodiment is that the electrode surface 501 of the LED chip 500 is directly electrically connected to the third electrode 303 through an adhesive.

[0047] The inner surface of the carrier 100 (high-transmittance material) is fixed to the corresponding surface of the substrate 300 through the first adhesive 200; the outer surface of the carrier 100 is a smooth surface or a surface with a microstructure array. Of course, the number of microstructures can be single. The shape of the microstructure is one or more of spherical, conical, trapezoidal or other shapes.

[0048] As described above, the present invention can be implemented well.

[0049] The implementation methods of the present invention are not limited to the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be equivalent replacement methods and shall be included in the protection scope of the present invention.

Claims

1. An LED device with high ambient contrast and high light extraction efficiency, comprising a carrier (100) and a substrate (300) located on the carrier (100); characterized in that: A through hole (304) is provided in the middle of the substrate (300); The substrate (300) is provided with a first electrode (301), a second electrode (302) and a third electrode (303); The first electrode (301) is used for surface mounting, and the second electrode (302) is used to connect the first electrode (301) and the third electrode (303); An LED chip (500) is arranged on the carrier board (100) at the bottom of the through hole (304); The LED chip (500) comprises a light emitting surface (502) and an electrode surface (501); the electrode surface (501) is electrically connected to the third electrode (303).

2. The LED device with high ambient contrast and high light extraction efficiency according to claim 1, characterized in that: The cross-sectional shape of the through hole (304) is a right-angle step-like step; The first electrode (301), the second electrode (302) and the third electrode (303) are connected in sequence from top to bottom and laid on the surface of the right-angled stepped step; The electrode surface (501) of the LED chip (500) is connected to the third electrode (303) via a lead wire (600).

3. The LED device with high ambient contrast and high light extraction efficiency according to claim 1, characterized in that: The cross-sectional shape of the through hole (304) is a trapezoidal step.

4. The LED device with high ambient contrast and high light extraction efficiency according to claim 1, characterized in that: The second electrode (302) is buried inside the body of the substrate (300) and is electrically connected to the first electrode (301) and the third electrode (303) through a via hole.

5. The LED device with high ambient contrast and high light extraction efficiency according to claim 4, characterized in that: The electrode surface (501) of the LED chip (500) is electrically connected to the third electrode (303) directly through an adhesive.

6. The LED device with high ambient contrast and high light extraction efficiency according to any one of claims 1 to 5, characterized in that: The inner surface of the carrier plate (100) is fixed to the corresponding surface of the substrate (300) via a first adhesive (200); and the outer surface of the carrier plate (100) is a smooth surface or a surface having a microstructure array.

7. The LED device with high ambient contrast and high light extraction efficiency according to any one of claims 1 to 5, characterized in that: The through hole (304) is filled with packaging glue (700).

8. The LED device with high ambient contrast and high light extraction efficiency according to claim 7, characterized in that: The packaging glue (700) is filled into the through hole (304) twice. During the first filling, it is doped with carbon powder, and the filling height is flush with the LED device to form a light absorbing layer (701). During the second filling, it is doped with reflective scattering particles, and the filling height is flush with the mouth of the through hole (304) to form a light reflecting layer (702).

9. The LED device with high ambient contrast and high light extraction efficiency according to any one of claims 1 to 5, characterized in that: The LED chip (500) is fixed to the upper surface of the carrier board (100) via a second adhesive (400).

10. The LED device with high ambient contrast and high light extraction efficiency according to any one of claims 1 to 5, characterized in that: The material of the carrier plate (100) is glass, plastic, epoxy resin or silicone resin.

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