Light emitting device
By combining back-to-back light-emitting chips and phosphors, the color halo problem between blue and green light is solved, achieving high color rendering index (CRI) light-emitting components that can emit green, blue, and red light to produce white light.
Patent Information
- Application Number
- CN202511038579.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2025-03-10
- Filing Date
- 2025-07-28
- Publication Date
- 2025-11-04
AI Technical Summary
In existing technologies, the color halo problem between blue and green light has not been effectively solved, resulting in poor color performance of the light-emitting components.
The first and second light-emitting chips are arranged back-to-back. The first chip is connected to the substrate by flip-chip and the second chip is connected to the substrate by upright mounting. They are electrically connected through a co-metal layer and a die-bonding layer to avoid direct contact. The combination of phosphor and light-emitting material produces red light to improve the color halo phenomenon.
It effectively improves the color halo phenomenon between different colors of light, enhances the color performance of the light-emitting components, and can emit green, blue and red light simultaneously to produce white light.
Smart Images
Figure CN120897598A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to a light emitting device. BACKGROUND
[0002] Currently, there is a great demand for high color rendering light emitting devices in various applications. Therefore, the method of using a blue light emitting component combined with red and green phosphor to generate blue, red and green light is not sufficient, and the method of using a blue light emitting component and a green light emitting component combined with red phosphor to generate blue, red and green light is needed. One important problem to be solved is how to improve the color mura problem between different colors of light, such as blue and green light, in the light emitting component. SUMMARY
[0003] The present application provides a light emitting device to improve the color mura problem between different colors of light in the light emitting component.
[0004] A light emitting device of the present application comprises: a substrate; a first light emitting chip for emitting a first color light, the first light emitting chip is disposed on the substrate, the first light emitting chip comprises a first substrate and a first light emitting layer, the first substrate comprises a first surface and a second surface opposite to the first surface, and the first light emitting layer is located on the first surface; a second light emitting chip for emitting a second color light different from the first color light, the second light emitting chip is disposed on the first light emitting chip, the second light emitting chip comprises a second substrate and a second light emitting layer, the second substrate comprises a third surface and a fourth surface opposite to the third surface, and the second light emitting layer is located on the third surface; wherein the second surface and the fourth surface are opposite.
[0005] In an embodiment of the above-mentioned light emitting device of the present application, the fourth surface is located within the second surface in the vertical direction.
[0006] In an embodiment of the above-mentioned light emitting device of the present application, the area of the second surface is greater than the area of the fourth surface.
[0007] In an embodiment of the above-mentioned light emitting device of the present application, the area of the fourth surface is 25% to 80% of the area of the second surface.
[0008] In an embodiment of the above-mentioned light emitting device of the present application, the first color light is green light, and the second color light is blue light.
[0009] In an embodiment of the above-mentioned light emitting device of the present application, the first color light is blue light, and the second color light is green light.
[0010] In one embodiment of the above light emitting device, the first light emitting chip and the second light emitting chip have the same cathode.
[0011] In one embodiment of the above light emitting device, further comprising:
[0012] a common gold layer between the substrate and the first light emitting chip; and
[0013] a first anode on the substrate; and
[0014] a cathode on the substrate,
[0015] wherein the first light emitting chip is electrically connected to the first anode and the cathode through the common gold layer, respectively.
[0016] In one embodiment of the above light emitting device, further comprising:
[0017] a plurality of pads, wherein the plurality of pads are on the substrate; and
[0018] a second anode on the substrate,
[0019] wherein the second light emitting layer is electrically connected to the second anode through a first pad of the plurality of pads with a first wire of the plurality of wires,
[0020] wherein the second light emitting layer is electrically connected to the cathode through a second pad of the plurality of pads with a second wire of the plurality of wires.
[0021] In one embodiment of the above light emitting device, further comprising:
[0022] a die bonding layer between the first light emitting chip and the second light emitting chip,
[0023] wherein the die bonding layer is transparent and electrically insulating.
[0024] In one embodiment of the above light emitting device, the first light emitting chip is electrically connected to the substrate in flip chip manner, and the second light emitting chip is electrically connected to the substrate in face-up manner.
[0025] In one embodiment of the above light emitting device, the first substrate is transparent to the first color light, and the second substrate is transparent to the first color light.
[0026] In one embodiment of the above light emitting device, the first color light has a wavelength range of 430-480 nm, and the second color light has a wavelength range of 500-560 nm.
[0027] In one embodiment of the light emitting device of the present application, the first color light has a wavelength range of 500-560 nm, and the second color light has a wavelength range of 430-480 nm.
[0028] In one embodiment of the light emitting device of the present application, the light emitting device further comprises an encapsulant covering the substrate, the first light emitting chip, and the second light emitting chip, wherein the encapsulant comprises phosphor which emits third color light different from the first color light and the second color light when irradiated by the first color light and the second color light.
[0029] In one embodiment of the light emitting device of the present application, the third color light is red light.
[0030] Based on the above, the first light emitting chip is connected to the substrate in a flip chip manner, and the second light emitting chip on the first light emitting chip is connected to the substrate in a face-up manner, so that the color halo phenomenon between different color lights can be effectively improved. BRIEF DESCRIPTION OF DRAWINGS
[0031] Figure 1 is a schematic diagram of a light emitting device according to an embodiment of the present application.
[0032] Figure 2 is a circuit schematic diagram of a first light emitting chip and a second light emitting chip according to an embodiment of the present application.
[0033] Figure 3 is a schematic diagram of a light emitting device according to an embodiment of the present application.
[0034] Figures 4 to 9 is a flowchart of manufacturing a light emitting device according to an embodiment of the present application.
[0035] In the drawings:
[0036] 100: light emitting device
[0037] 110: substrate
[0038] 110A, 110B: surface
[0039] 120: first light emitting chip
[0040] 122: first substrate
[0041] 122A: first surface
[0042] 122B: second surface
[0043] 124: first light emitting layer
[0044] 126: Au layer
[0045] 130: second light emitting chip
[0046] 132: second substrate
[0047] 132A: third surface
[0048] 132B: fourth surface
[0049] 134: second light emitting layer
[0050] 136: electrode
[0051] 138: wire
[0052] 140: die-bonding layer
[0053] 150: solder pad
[0054] 160A: first anode
[0055] 160B: cathode
[0056] 160C: second anode
[0057] 170: encapsulant
[0058] L1: first color light
[0059] L2: second color light
[0060] L3: third color light DETAILED DESCRIPTION
[0061] Figure 1 is a schematic diagram of a light emitting device according to an embodiment of the present disclosure. Please refer to FIG. 1 Figure 1 . The light emitting device 100 includes a substrate 110, a common metal layer 126, a first light emitting chip 120, a second light emitting chip 130, a die-bonding layer 140, a solder pad 150, and an electrode 160.
[0062] The substrate 110 is used to provide support for the light emitting device 100. The substrate 110 has a surface 110A and a surface 110B opposite to each other. A plurality of solder pads 150 are located on the surface 110A of the substrate 110. A plurality of electrodes are disposed on the surface 110B, such as a first anode 160A, a cathode 160B, and a second anode 160C. Some of the plurality of solder pads 150 are electrically connected to some of the plurality of electrodes through the substrate 110. In some embodiments, the substrate 110 can be a printed circuit board (PCB), or other components with similar functions, and the present disclosure is not limited thereto.
[0063] As shown in FIG. 1 Figure 1As shown, the first light emitting chip 120 is electrically connected to the substrate 110 in a flip chip manner. The second light emitting chip 130 is electrically connected to the substrate 110 in a face-up manner.
[0064] Specifically, the first light emitting chip 120 is disposed on the substrate 110 to emit a first color light L1. The first light emitting chip 120 includes a first substrate 122 and a first light emitting layer 124.
[0065] The first substrate 122 includes a first surface 122A and a second surface 122B opposite to the first surface 122A. In some embodiments, the material of the first substrate 122 can be aluminum oxide, i.e. sapphire, or other materials with similar properties, without being limited thereto. In some embodiments, the first substrate 122 is transparent to the first color light L1 to avoid absorbing the first color light L1.
[0066] The first light emitting layer 124 is disposed on the first surface 122A to emit the first color light L1. Specifically, the first light emitting layer 124 of the first light emitting chip 120 is disposed between the first substrate 122 and the substrate 110. In some embodiments, the first light emitting layer 124 includes a plurality of light emitting components, such as light emitting diodes, laser diodes, quantum dots, or other components with similar properties, without being limited thereto. In some embodiments, the first light emitting layer 124 is formed on the first surface 122A of the first substrate 122 in an epitaxy manner. Thus, the first light emitting layer 124 is prone to be peeled off from the first surface 122A of the first substrate 122 when being rubbed by external force.
[0067] As shown, the first light emitting chip 120 is electrically connected to the substrate 110 in a flip chip manner. The second light emitting chip 130 is electrically connected to the substrate 110 in a face-up manner. Figure 1 The common gold layer 126 is disposed between the substrate 110 and the first light emitting chip 120. Thus, the first light emitting chip 120 can be electrically connected to the first anode 160A and the cathode 160B of the substrate 110 through the common gold layer 126. Thus, the light emitting state of the first light emitting layer 124 of the first light emitting chip 120 can be controlled by the first anode 160A and the cathode 160B.
[0068] In some embodiments, the material of the common gold layer 126 includes indium (In), tin (Sn), copper (Cu), silver (Ag), bismuth (Bi), or alloys thereof, or other suitable materials, without being limited thereto.
[0069] The second light emitting chip 130 is disposed on the first light emitting chip 120 to emit a second color light L2 different from the first color light L1. The second light emitting chip 130 includes a second substrate 132 and a second light emitting layer 134.
[0070] In some embodiments, the first color light L1 is green light and the second color light L2 is blue light. In other embodiments, the first color light L1 is blue light and the second color light L2 is green light. In some embodiments, the wavelength range of blue light is 430–480 nm and the wavelength range of green light is 500–560 nm.
[0071] The second substrate 132 includes a third surface 132A and a fourth surface 132B opposite to the third surface 132A. In some embodiments, the material of the second substrate 132 may be aluminum oxide, i.e., sapphire, or something with similar properties, and this disclosure is not limited thereto. In some embodiments, the second substrate 132 is transparent to the first color light L1 to avoid absorbing the first color light L1.
[0072] In some embodiments, the orthographic projection of the fourth surface 132B in the vertical direction lies within the second surface 122B. That is, the second substrate 132 is completely located within the first substrate 122.
[0073] In some embodiments, the area of the second surface 122B is larger than that of the fourth surface 132B. The area of the fourth surface 132B is 25% to 80% of the area of the second surface 122B. That is, the second substrate 132 is completely located within the first substrate 122.
[0074] The second light-emitting layer 134 is located on the third surface 132A and is used to emit a second color light L2. Specifically, the second light-emitting layer 134 of the second light-emitting chip 130 is located on the third surface 132A of the second substrate 132 away from the substrate 110. In some embodiments, the second light-emitting layer 134 includes multiple light-emitting components, such as light-emitting diodes, laser diodes, quantum dots, or other components with similar properties, and this disclosure is not limited thereto. In some embodiments, the second light-emitting layer 134 is formed on the third surface 132A of the second substrate 132 by epitaxy. Therefore, the second light-emitting layer 134 is easily peeled off from the third surface 132A of the second substrate 132 when subjected to external friction.
[0075] like Figure 1 As shown, the second light-emitting chip 130 further includes electrodes 136 located on the second light-emitting layer 134. Therefore, the second light-emitting layer 134 can be electrically connected to the second anode 160C via one electrode 136, one wire 138, one pad 150, and through the substrate 110, and electrically connected to the cathode 160B via the other electrode 136, the other wire 138, the other pad 150, and through the substrate 110. Therefore, the light-emitting state of the second light-emitting layer 134 of the second light-emitting device 130 can be controlled by the second anode 160C and the cathode 160B.
[0076] In this embodiment, the first light emitting chip 120 and the second light emitting chip 130 have the same cathode 160B. Please refer to Figure 2 . Figure 2 is a circuit schematic diagram of a first light emitting chip and a second light emitting chip according to an embodiment of the present disclosure. As mentioned in the foregoing description, the light emitting device 100 can control the light emitting state of the first light emitting layer 124 of the first light emitting device 120 by the first anode 160A and the cathode 160B, and control the light emitting state of the second light emitting layer 134 of the second light emitting device 130 by the second anode 160C and the cathode 160B. Since the first light emitting device 120 and the second light emitting device 130 share the cathode, the number of electrodes required for operating the first light emitting device 120 and the second light emitting device 130 can be reduced.
[0077] Please refer back to Figure 1 . As shown in Figure 1 , the second surface 122B of the first substrate 122 is opposite to the fourth surface 132B of the second substrate 132. Therefore, the first light emitting chip 120 and the second light emitting chip 130 are in a back-to-back configuration, the first light emitting layer 124 of the first light emitting chip 120 does not contact the second substrate 132 of the second light emitting chip 130, and the second light emitting layer 134 of the second light emitting chip 130 does not contact the first substrate 122 of the first light emitting chip 120. By this back-to-back configuration, the damage of the first light emitting layer 124 and the second light emitting layer 134 caused by directly contacting the second substrate 132 and the first substrate 122, such as peeling off from the first substrate 122 or the second substrate 132, can be avoided.
[0078] As shown in Figure 1 , the light emitting device 100 further includes a die bonding layer 140 between the first light emitting chip 120 and the second light emitting chip 130. In some embodiments, the die bonding layer 140 is transparent material to avoid absorbing the first color light L1 emitted by the first light emitting device 120. In some embodiments, the die bonding layer 140 is electrically insulating material to avoid the first light emitting device 120 and the second light emitting device 130 being electrically connected by the die bonding layer 140. In some embodiments, the material of the die bonding layer 140 can be silicone-base glue or epoxy-base glue, or the like, and the present disclosure is not limited thereto.
[0079] Figure 3 is a schematic diagram of a light emitting device according to an embodiment of the present disclosure. Please refer to Figure 3 . Figure 3 The light emitting device 100 shown in Figure 1 is similar to the light emitting device 100 shown in , the difference is that inFigure 3 In some embodiments, the encapsulant 170 further includes phosphor. The phosphor emits a third color light L3 different from the first color light L1 and the second color light L2 when illuminated by the first color light L1 and the second color light L2. In some embodiments, the third color light L3 is red light having a wavelength range of 590 nm to 660 nm. In some embodiments, the phosphor is red phosphor A2BF6:Mn4+, where A can be K, Na, Ba, and B can be Si, Ti, Zr, Al, such as K2SiF6:Mn4+(KSF).
[0080] In some embodiments, if the light emitting device 100 is required to emit white light, the encapsulant 170 further includes phosphor. The phosphor emits a third color light L3 different from the first color light L1 and the second color light L2 when illuminated by the first color light L1 and the second color light L2. In some embodiments, the third color light L3 is red light having a wavelength range of 590 nm to 660 nm. In some embodiments, the phosphor is red phosphor A2BF6:Mn4+, where A can be K, Na, Ba, and B can be Si, Ti, Zr, Al, such as K2SiF6:Mn4+(KSF).
[0081] Thus, by means of the light emitting device 100 as shown in Figure 3 , the light emitting device can emit green light and blue light of the first color light and the second color light, and red light of the third color light at the same time, and emit white light.
[0082] Figures 4 to 9 A flow chart of a manufacturing process of a light emitting device according to an embodiment of the present disclosure.
[0083] Please refer to Figure 4 . A substrate 110 is provided. The substrate 110 has a surface 110A and a surface 110B opposite to each other.
[0084] Please refer to Figure 5 . The first light emitting chip 120 is electrically connected to the substrate 110 in a flip chip manner. The first light emitting chip 120 includes a first substrate 122 and a first light emitting layer 124. A common gold layer 126 is located between the substrate 110 and the first light emitting chip 120. Thus, the first light emitting chip 120 can be electrically connected to the substrate 110 through the common gold layer 126. Please refer to Figure 5 . A solder pad 150 is formed on the surface 110A of the substrate 110, and the solder pad 150 is electrically connected to the substrate 110.
[0085] Please refer to Figure 6 . A die attach layer 140 is formed on the second surface 122B of the first substrate 122 of the first light emitting chip 120. In some embodiments, the die attach layer 140 is an electrically insulating material, and the material of the die attach layer 140 can be a silicone-base adhesive or an epoxy-base adhesive, or the like, without being limited thereto.
[0086] Referring to Figure 7 The second light emitting chip 130 is configured on the die-bonding layer 140 in a face-up manner. The second light emitting chip 130 includes a second substrate 132 and a second light emitting layer 134. A fourth surface 132B of the second substrate 132 of the second light emitting chip 130 is in contact with the die-bonding layer 140. An electrode 136 is formed on the second light emitting layer 134 of the second light emitting chip 130.
[0087] Referring to Figure 8 The electrode 136 is electrically connected to the solder pad 150 by the wire 138 in a wire-bonding manner.
[0088] Referring to Figure 9 An encapsulant 170 is formed on the substrate 110 to cover the substrate 110, the first light emitting chip 120, and the second light emitting chip 130, and to protect the wire 138. In some embodiments, the encapsulant 170 is a transparent material including a molding compound, a polymer material such as a silicone-base adhesive or an epoxy-base adhesive, a combination thereof, or other suitable material.
[0089] The first anode 160A and the cathode 160B are electrically connected to the substrate 110 on the surface 110B of the substrate 110. The first light emitting chip 120 is electrically connected to the first anode 160A and the cathode 160B through the common metal layer 126 and the substrate 110, respectively. Thus, the light emitting state of the first light emitting layer 124 of the first light emitting chip 120 can be controlled by the first anode 160A and the cathode 160B. In addition, the second light emitting layer 134 is electrically connected to the second anode 160C through one of the electrodes 136 and one of the wires 138 through one of the solder pads 150 and the substrate 110, and is electrically connected to the cathode 160B through the other of the electrodes 136 and the other of the wires 138 through the other of the solder pads 150 and the substrate 110. Thus, the light emitting state of the second light emitting layer 134 of the second light emitting chip 130 can be controlled by the second anode 160C and the cathode 160B.
[0090] In summary, the color halo phenomenon between different color lights can be effectively improved by the first light emitting chip in contact with the substrate in a die-bonding manner and the second light emitting chip in contact with the substrate in a face-up manner.
Claims
1. A light-emitting device, characterized in that, include: One substrate; A first light-emitting chip is disposed on the substrate to emit a first color of light. The first light-emitting chip includes a first substrate and a first light-emitting layer. The first substrate includes a first surface and a second surface opposite to the first surface. The first light-emitting layer is located on the first surface. A second light-emitting chip is disposed on the first light-emitting chip to emit a second color light different from the first color light. The second light-emitting chip includes a second substrate and a second light-emitting layer. The second substrate includes a third surface and a fourth surface opposite to the third surface. The second light-emitting layer is located on the third surface. The second surface is opposite to the fourth surface.
2. The light-emitting device as described in claim 1, characterized in that, The orthographic projection of the fourth surface in the vertical direction lies within the second surface.
3. The light-emitting device as described in claim 1, characterized in that, The area of the second surface is larger than that of the fourth surface.
4. The light-emitting device as described in claim 1, characterized in that, The area of the fourth surface is 25% to 80% of the area of the second surface.
5. The light-emitting device as claimed in claim 1, characterized in that, The first color light is green light, and the second color light is blue light.
6. The light-emitting device as claimed in claim 1, characterized in that, The first color light is blue light, and the second color light is green light.
7. The light-emitting device as claimed in claim 1, characterized in that, The first light-emitting chip and the second light-emitting chip have the same cathode.
8. The light-emitting device as claimed in claim 1, characterized in that, Including: A co-gold layer is located between the substrate and the first light-emitting chip; as well as The first anode is located on the substrate; as well as The cathode is located on the substrate. The first light-emitting chip is electrically connected to the first anode and the cathode respectively via the co-gold layer.
9. The light-emitting device as described in claim 8, characterized in that, Including: Multiple solder pads, wherein the multiple solder pads are located on the substrate; as well as The second anode is located on the substrate. The second light-emitting layer is electrically connected to the second anode via a first wire of multiple wires and a first pad of the multiple pads. The second light-emitting layer is electrically connected to the cathode via the second wires of the plurality of wires and the second pads of the plurality of pads.
10. The light-emitting device as claimed in claim 1, characterized in that, Including: The die-bonding layer is located between the first light-emitting chip and the second light-emitting chip. The solid layer is transparent and electrically insulating.
11. The light-emitting device as claimed in claim 1, characterized in that, The first light-emitting chip is electrically connected to the substrate via a flip-chip method, and the second light-emitting chip is electrically connected to the substrate via a top-mount method.
12. The light-emitting device as claimed in claim 1, characterized in that, The first substrate is transparent to the first color light, and the second substrate is transparent to the first color light.
13. The light-emitting device as claimed in claim 1, characterized in that, The wavelength range of the first color light is 430–480 nm, and the wavelength range of the second color light is 500–560 nm.
14. The light-emitting device as claimed in claim 1, characterized in that, The wavelength range of the first color light is 500–560 nm, and the wavelength range of the second color light is 430–480 nm.
15. The light-emitting device as claimed in claim 1, characterized in that, It further includes: an encapsulation body for covering the substrate, the first light-emitting chip, and the second light-emitting chip, wherein the encapsulation body includes phosphor, and the phosphor emits a third color light different from the first color light and the second color light after being irradiated by the first color light and the second color light.
16. The light-emitting device as claimed in claim 15, characterized in that, The third color light is red light.