LED packaging structure

Abstract

The utility model relates to the technical field of LED packaging, and discloses an LED packaging structure, which comprises a substrate, a bracket and a normal chip which are arranged on the substrate, and packaging glue filled in the bracket, the normal chip comprises a first chip, a second chip and a third chip which are stacked in the vertical direction, the first chip, the second chip and the third chip are distributed in a step shape after being stacked, the light-emitting centers of the first chip, the second chip and the third chip are overlapped, and a first table top, a second table top and a third table top are exposed; a first electrode and a second electrode are arranged on the first table top, a third electrode and a fourth electrode are arranged on the second table top, and a fifth electrode and a sixth electrode are arranged on the third table top; the substrate and the first chip, the first chip and the second chip, and the second chip and the third chip are connected through bonding layers. By implementing the LED packaging structure, the display effect and the display precision of the LED packaging structure can be improved, and the reliability and the stability are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of LED especially relates to a LED packaging structure. BACKGROUND

[0002] In the current display technical field, the conventional display LED as a widely used light emitting element, its basic structure mainly includes support, red light chip (R), green light chip (G), blue light chip (B), wire and encapsulation glue etc. Specifically, R, G, B three chips usually distribute on the same horizontal plane of the support bottom, this is the conventional layout mode of the LED product at present.

[0003] However, this traditional LED structure exposes significant defects in practical application, especially in the increasingly stringent display precision, its problem highlights increasingly. In this kind of conventional LED packaging structure, the light emitting center of R, G, B three chips respectively cannot coincide in vertical direction, this leads to the serious image offset phenomenon when displaying image, makes display precision greatly discount, is not applicable to high-definition image display. In the display screen module of direct display, it is by numerous LED matrix form arrangement combination, and each LED includes the R, G, B three color chips that can be independently driven. But when needing to accurately present tricolor alternate straight line on the display screen, due to the light emitting center of each chip in the conventional LED is not at the center position of LED, the straight line finally presented is not the coherent straight line in ideal state, but obvious misplacement occurs, as shown in Figure 1 This misplacement not only seriously influences the visual effect of image, reduces display quality, also limits the further application and development of this kind of conventional LED in high-definition display screen field. INVENTION CONTENTS

[0004] The utility model wants to solve the technical problem in, provide a kind of LED packaging structure, can improve the display effect and display precision of LED packaging structure, and improve the reliability and stability of LED packaging structure.

[0005] To solve the above technical problem, the utility model provides a kind of LED packaging structure, including: substrate, the support and the positive chip of setting on substrate, and fill in the encapsulation glue of the support inside;

[0006] The positive chip includes the first chip, the second chip and the third chip of vertical direction stack setting, first chip, second chip and third chip are stacked and present stepped distribution, the light emitting center of first chip, second chip and third chip is overlapped, and expose first mesa, second mesa and third mesa;

[0007] The first mesa is provided with a first electrode and a second electrode, the second mesa is provided with a third electrode and a fourth electrode, and the third mesa is provided with a fifth electrode and a sixth electrode.

[0008] The substrate and the first chip, the first chip and the second chip, and the second chip and the third chip are connected through an adhesive layer.

[0009] As an improvement of the above scheme, the light emitted by the first chip passes through the second chip and the third chip and is emitted, and the light emitted by the second chip passes through the third chip and is emitted.

[0010] As an improvement of the above scheme, the adhesive layer comprises a first transparent adhesive layer, a second transparent adhesive layer and a third transparent adhesive layer arranged in order from near to far from the substrate, and the refractive indexes of the first transparent adhesive layer, the second transparent adhesive layer and the third transparent adhesive layer match the light-emitting wavelength of the face-up chip located thereabove.

[0011] As an improvement of the above scheme, the face-up chip comprises a red light chip, a green light chip and a blue light chip arranged in order in the vertical direction.

[0012] The refractive index of the first transparent adhesive layer is less than that of the second transparent adhesive layer, and the refractive index of the second transparent adhesive layer is less than that of the third transparent adhesive layer.

[0013] As an improvement of the above scheme, the height ratio of the red light chip, the green light chip and the blue light chip is 1:(0.85-1):(0.75-1).

[0014] As an improvement of the above scheme, the thickness ratio of the first transparent adhesive layer and the red light chip is (0.15-0.25):1.

[0015] The thickness ratio of the second transparent adhesive layer and the green light chip is (0.12-0.18):1.

[0016] The thickness ratio of the third transparent adhesive layer and the blue light chip is (0.09-0.13):1.

[0017] As an improvement of the above scheme, the first mesa is a red light mesa, the second mesa is a green light mesa, and the third mesa is a blue light mesa.

[0018] The first electrode and the second electrode are symmetrically arranged on the red light mesa, the length of the red light chip in the horizontal direction is L1, the distance between the first electrode or the second electrode and the side wall of the green light mesa is L2, and L 2＝ (0.03-0.07)L1.

[0019] The distance between the first electrode or the second electrode and the edge of the red light platform is L3, satisfying L 3＝ (0.02~0.05)L1.

[0020] As an improvement to the above scheme, the third electrode and the fourth electrode are symmetrically arranged on the green light platform, the length of the green light chip in the horizontal direction is L4, and the distance between the third electrode or the fourth electrode and the sidewall of the blue light platform is L5, satisfying L5 = (0.05~0.09)L4.

[0021] The distance between the third or fourth electrode and the edge of the green light platform is L6, satisfying L6 = (0.03~0.06)L4.

[0022] As an improvement to the above scheme, the fifth and sixth electrodes are symmetrically arranged on the blue light platform, the length of the blue light chip in the horizontal direction is L7, and the distance between the fifth or sixth electrode and the edge of the blue light platform is L8, satisfying L8 = (0.03~0.07)L7.

[0023] The distance between the fifth electrode and the sixth electrode is L9, which satisfies L9 = (0.5 ~ 0.55)L7.

[0024] As an improvement to the above solution, the substrate is further provided with pads, which are electrically connected to the first electrode, the second electrode, the third electrode, the fourth electrode, the fifth electrode, and the sixth electrode via bonding wires.

[0025] Implementing this utility model has the following beneficial effects:

[0026] In this invention, a standard-mounted chip, consisting of a first chip, a second chip, and a third chip stacked vertically, is used as the light-emitting chip in the LED packaging structure. The light-emitting centers of the first chip, the second chip, and the third chip overlap, which can accurately display alternating three-color straight lines. This avoids image misalignment caused by non-coincidence of light-emitting centers and can accurately display alternating three-color straight lines. When used in a display screen, it has a good display effect, high display accuracy, and can meet the miniaturization requirements of display devices.

[0027] Furthermore, the substrate is connected to the first chip, the first chip to the second chip, and the second chip to the third chip through adhesive layers. This not only ensures that the chips will not shift during use, guaranteeing the stability and reliability of the chip stacking structure, but also optimizes the propagation path of light at the interface, reduces reflection and refraction losses caused by differences in refractive index, and allows more photons to be emitted from the chip to the outside, thereby improving the light extraction efficiency and brightness of the LED packaging structure. Attached Figure Description

[0028] Figure 1 : A schematic diagram of the arrangement of LED chips in a display screen in the prior art;

[0029] Figure 2 : A schematic diagram of the LED packaging structure in this utility model;

[0030] Figure 3 : A schematic diagram of the stacked structure of the upright chip in this utility model;

[0031] Figure 4 : A schematic diagram of the arrangement of LED chips in the display screen in this utility model.

[0032] Reference numerals: 1-Substrate; 2-Support; 3-First chip; 31-First mesa; 32-First electrode; 33-Second electrode; 4-Second chip; 41-Second mesa; 42-Third electrode; 43-Fourth electrode; 5-Third chip; 51-Third mesa; 52-Fifth electrode; 53-Sixth electrode; 6-Encapsulating adhesive; 7-Adhesive layer; 71-First transparent adhesive layer; 72-Second transparent adhesive layer; 73-Third transparent adhesive layer; 8-Bonding wire. Detailed Implementation

[0033] To make the objectives, technical solutions and advantages of this utility model clearer, specific embodiments will be described in further detail below.

[0034] To address the above problems, this utility model provides an LED packaging structure, such as... Figure 2 As shown, it includes: a substrate 1, a support 2 disposed on the substrate 1, a mounting chip, and an encapsulating adhesive 6 filling the support 2; the support 2 is disposed around the mounting chip, serving to support and protect the mounting chip. It is understood that the substrate 1 can be a metal substrate, such as a copper plate; the encapsulating adhesive 6 can be transparent silicone; and the raw materials for preparing the support 2 can be polyphthalamide (PPA), poly(1,4-cyclohexanedimethyl terephthalate) (PCT), epoxy molding compound (EMC), etc., but are not limited to these.

[0035] The mounted chip comprises a first chip 3, a second chip 4, and a third chip 5 stacked vertically. The first chip 3, second chip 4, and third chip 5 are selected from red, green, and blue light chips, and each emits a different color. The first chip 3, second chip 4, and third chip 5 are stacked sequentially in a stepped arrangement, causing their light-emitting centers to overlap. This avoids image misalignment caused by misaligned light-emitting centers and allows for accurate display of alternating three-color straight lines. When used in a display screen, the resulting LED package structure can more accurately display straight lines, curves, or complex graphics, improving display precision. It is ideal for high-definition display scenarios with high resolution requirements. Furthermore, since the light-emitting centers of the first chip 3, second chip 4, and third chip 5 are at the same point, the light emitted from the same point can achieve uniform mixing over a shorter distance, presenting purer and more natural colors. The light emitted from the first chip 3 passes through the second chip 4 and the third chip 5 before exiting. The light emitted from the second chip 4 passes through the third chip 5 before exiting. During this process, light mixing occurs within the chips, and this internal light interaction makes the color mixing more uniform and natural, improving color accuracy and consistency. It is understood that the first chip 3, the second chip 4, and the third chip 5 are made of transparent materials.

[0036] Preferably, the substrate 1 is connected to the first chip 3, the first chip 3 to the second chip 4, and the second chip 4 to the third chip 5 via an adhesive layer 7. This layer secures the stacked chips, ensuring they do not shift during use, improving the stability and reliability of the chip stack structure, and insulating adjacent chips from each other to prevent short circuits caused by direct contact. It is understood that the adhesive in the adhesive layer 7 is made of a transparent material, specifically a highly transparent and thermally conductive insulating layer, insulating film, or insulating heat-dissipating adhesive, but is not limited to these. Specifically, the adhesive layer 7 includes a first transparent adhesive layer 71, a second transparent adhesive layer 72, and a third transparent adhesive layer 73 arranged sequentially from near to far from the substrate 1. The refractive indices of the first transparent adhesive layer 71, the second transparent adhesive layer 72, and the third transparent adhesive layer 73 are matched with the emission wavelength of the upright chip located above them, so that the propagation of different colors of light at the interface between the chip, the adhesive layer 7, and the encapsulation material is smoother, reducing reflection and refraction losses caused by the difference in refractive index, and enabling more photons to be emitted from the chip to the outside, thereby improving the light extraction efficiency and brightness of the LED encapsulation structure.

[0037] Furthermore, the first chip 3, the second chip 4, and the third chip 5 are stacked sequentially, exposing a first mesa 31, a second mesa 41, and a third mesa 51. The first mesa 31 is provided with a first electrode 32 and a second electrode 33 for driving the first chip 3; the second mesa 41 is provided with a third electrode 42 and a fourth electrode 43 for driving the second chip 4; and the third mesa 51 is provided with a fifth electrode 52 and a sixth electrode 53 for driving the third chip 5. This allows for individual control of the first chip 3, the second chip 4, and the third chip 5. Moreover, the electrodes are located on the exposed mesa, simplifying the circuit design. It is understood that the first electrode 32 and the second electrode 33 are the positive and negative electrodes of the first chip 3, the third electrode 42 and the fourth electrode 43 are the positive and negative electrodes of the second chip 4, and the fifth electrode 52 and the sixth electrode 53 are the positive and negative electrodes of the third chip 5. The substrate 1 is also provided with pads, the number of which corresponds to the number of electrodes. The pads are electrically connected to the first electrode 32, the second electrode 33, the third electrode 42, the fourth electrode 43, the fifth electrode 52 and the sixth electrode 53 via bonding wires 8.

[0038] The following description uses a standard chip assembly comprising red, green, and blue light chips stacked vertically in sequence as an example. Specifically, the first chip 3 is a red light chip, the second chip 4 is a green light chip, and the third chip 5 is a blue light chip. Please refer to [link / reference needed]. Figure 3 .

[0039] Specifically, a first transparent adhesive layer 71 is disposed between the substrate 1 and the red light chip, a second transparent adhesive layer 72 is disposed between the red light chip and the green light chip, and a third transparent adhesive layer 73 is disposed between the green light chip and the blue light chip. Light emitted from the red light chip passes sequentially through the second transparent adhesive layer 72, the green light chip, the third transparent adhesive layer 73, and the blue light chip before exiting. Light emitted from the green light chip passes through the third transparent adhesive layer 73 and the blue light chip before exiting. Therefore, controlling the refractive index of the first transparent adhesive layer 71 to be less than the refractive index of the second transparent adhesive layer 72 can reduce interface reflection between the red light chip and the substrate 1, allowing red light to be transmitted more effectively from the red light chip to the outside. Controlling the refractive index of the second transparent adhesive layer 72 to be less than the refractive index of the third transparent adhesive layer 73 can reduce reflection and refraction losses at the interface due to excessive refractive index differences, thereby improving light transmission efficiency.

[0040] Preferably, the thickness of the chip affects the propagation and absorption of light within the chip. In this application, the height ratio of the red, green, and blue light chips is controlled to be 1:(0.85~1):(0.75~1), ensuring smooth emission of photons within the red, green, and blue light chips. Furthermore, the emission angles of the red, green, and blue light chips can be adjusted to match their respective emission angles and intensities, resulting in a more uniform color mixing effect. On the other hand, adjusting the chip thickness helps reduce the operating voltage during chip operation and improves its thermal stability.

[0041] Furthermore, the thickness ratio of the first transparent adhesive layer 71 to the red light chip is (0.15~0.25):1, the thickness ratio of the second transparent adhesive layer 72 to the green light chip is (0.12~0.18):1, and the thickness ratio of the third transparent adhesive layer 73 to the blue light chip is (0.09~0.13):1. The transparent adhesive layers, combined with chips of specific thicknesses, not only achieve good fixation of the red, green, and blue light chips, but also effectively reduce the air gap between the chips, reducing light loss at the interface, thereby improving light propagation efficiency and light extraction efficiency. An excessively thick adhesive layer 7 will hinder heat conduction from the chip to the external heat dissipation structure, while an excessively thin adhesive layer 7 will have poor bonding and fixation effects, and the difference in thermal expansion coefficients between the chip and the heat dissipation structure will cause the chip to be subjected to greater thermal stress, affecting the reliability and stability of the chip.

[0042] Specifically, the first platform 31 is a red light platform, the second platform 41 is a green light platform, and the third platform 51 is a blue light platform. The first electrode 32 and the second electrode 33 are symmetrically arranged on the red light platform, the third electrode 42 and the fourth electrode 43 are symmetrically arranged on the green light platform, and the fifth electrode 52 and the sixth electrode 53 are symmetrically arranged on the blue light platform. The red light platform, the green light platform, and the blue light platform can be annular in shape.

[0043] In some specific and preferred embodiments, the length of the red light chip in the horizontal direction is L1, and the distance between the first electrode 32 or the second electrode 33 and the sidewall of the green light mesa is L2, satisfying L... 2＝ The distance (0.03~0.07)L1 facilitates the placement of the green light chip and reduces the light obstruction by the first electrode 32 and the second electrode 33, providing more favorable conditions for light propagation and extraction. More importantly, it ensures that the green light chip receives a uniform electric field and carrier injection in different areas, guaranteeing the uniformity of luminous intensity and color in different areas of the green light chip. The distance between the first electrode 32 or the second electrode 33 and the edge of the red light platform is L3, satisfying L... 3＝The distance between the first electrode 32 and the second electrode 33 and the sidewall of the blue light mesa is L1, which is (0.02~0.05)L1. This avoids the first electrode 32 and the second electrode 33 directly blocking part of the light emitted from inside the chip, optimizes the emission angle and optical path difference of the red light, and effectively avoids edge effects. This makes the electric field distribution inside the red light chip more uniform, improves the uniformity and efficiency of carrier injection, and thus improves the overall electrical performance and light emission quality of the chip. Similarly, the length of the green light chip in the horizontal direction is L4, the distance between the third electrode 42 or the fourth electrode 43 and the sidewall of the blue light mesa is L5, which satisfies L5=(0.05~0.09)L4; the distance between the third electrode 42 or the fourth electrode 43 and the edge of the green light mesa is L6, which satisfies L6=(0.03~0.06)L4. The length of the blue light chip in the horizontal direction is L7, and the distance between the fifth electrode 52 or the sixth electrode 53 and the edge of the blue light platform is L8, satisfying L8 = (0.03~0.07)L7; the distance between the fifth electrode 52 and the sixth electrode 53 is L9, satisfying L9 = (0.5~0.55)L7.

[0044] Furthermore, the substrate 1 is also provided with pads, which include paired positive and negative pads corresponding to the electrodes. Specifically, these include a first pad, a second pad, a third pad, a fourth pad, a fifth pad, and a sixth pad, which are electrically connected to the first electrode 32, the second electrode 33, the third electrode 42, the fourth electrode 43, the fifth electrode 52, and the sixth electrode 53 respectively via bonding wires 8, thereby enabling individual driving of the red, green, and blue light chips. It is understood that the pads extend from one side of the substrate 1 to the other for easy soldering and assembly.

[0045] In this invention, a standard-mounted chip, consisting of a first chip 3, a second chip 4, and a third chip 5 stacked vertically, is used as the light-emitting chip in the LED packaging structure. The light-emitting centers of the first chip 3, the second chip 4, and the third chip 5 overlap, accurately displaying alternating three-color lines. This avoids image misalignment caused by non-aligned light-emitting centers, ensuring accurate display of alternating three-color lines. When used in a display screen, it provides excellent display quality and high image precision. Figure 4 As shown.

[0046] The above-disclosed embodiment is merely a preferred embodiment of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the claims of the present utility model shall still fall within the scope of the present utility model.

Claims

1. An LED packaging structure, characterized in that, include: A substrate, a support and a mounted chip disposed on the substrate, and encapsulating adhesive filled within the support; The upright chip includes a first chip, a second chip, and a third chip stacked vertically. The first chip, the second chip, and the third chip are stacked in a stepped distribution. The light-emitting centers of the first chip, the second chip, and the third chip overlap and expose the first platform, the second platform, and the third platform. The first platform is provided with a first electrode and a second electrode, the second platform is provided with a third electrode and a fourth electrode, and the third platform is provided with a fifth electrode and a sixth electrode; The substrate is connected to the first chip, the first chip to the second chip, and the second chip to the third chip via an adhesive layer.

2. The LED packaging structure as described in claim 1, characterized in that, The light emitted by the first chip passes through the second and third chips and then exits, while the light emitted by the second chip passes through the third chip and then exits.

3. The LED packaging structure as described in claim 1, characterized in that, The adhesive layer includes a first transparent adhesive layer, a second transparent adhesive layer, and a third transparent adhesive layer disposed sequentially from near to far from the substrate. The refractive indices of the first transparent adhesive layer, the second transparent adhesive layer, and the third transparent adhesive layer are matched with the emission wavelength of the upright chip located above them.

4. The LED packaging structure as described in claim 3, characterized in that, The mounted chip includes red light chip, green light chip and blue light chip stacked sequentially in a vertical direction; The refractive index of the first transparent adhesive layer is less than that of the second transparent adhesive layer, and the refractive index of the second transparent adhesive layer is less than that of the third transparent adhesive layer.

5. The LED packaging structure as described in claim 4, characterized in that, The height ratio of the red light chip, green light chip and blue light chip is 1:(0.85~1):(0.75~1).

6. The LED packaging structure as described in claim 5, characterized in that, The thickness ratio of the first transparent adhesive layer to the red light chip is (0.15~0.25):1; The thickness ratio of the second transparent adhesive layer to the green light chip is (0.12~0.18):1; The thickness ratio of the third transparent adhesive layer to the blue light chip is (0.09~0.13):

1.

7. The LED packaging structure as described in claim 4, characterized in that, The first tabletop is a red light tabletop, the second tabletop is a green light tabletop, and the third tabletop is a blue light tabletop; The first and second electrodes are symmetrically disposed on the red light stage. The length of the red light chip in the horizontal direction is L1, and the distance between the first or second electrode and the sidewall of the green light stage is L2, satisfying L... 2＝ (0.03~0.07)L1; The distance between the first electrode or the second electrode and the edge of the red light platform is L3, satisfying L 3＝ (0.02~0.05)L1.

8. The LED packaging structure as described in claim 7, characterized in that, The third and fourth electrodes are symmetrically arranged on the green light platform. The length of the green light chip in the horizontal direction is L4. The distance between the third or fourth electrode and the sidewall of the blue light platform is L5, satisfying L5 = (0.05~0.09)L4. The distance between the third or fourth electrode and the edge of the green light platform is L6, satisfying L6 = (0.03~0.06)L4.

9. The LED packaging structure as described in claim 7 or 8, characterized in that, The fifth and sixth electrodes are symmetrically arranged on the blue light platform. The length of the blue light chip in the horizontal direction is L7. The distance between the fifth or sixth electrode and the edge of the blue light platform is L8, satisfying L8 = (0.03~0.07)L7. The distance between the fifth electrode and the sixth electrode is L9, which satisfies L9 = (0.5 ~ 0.55)L7.

10. The LED packaging structure as described in claim 1, characterized in that, The substrate is also provided with pads, which are electrically connected to the first electrode, the second electrode, the third electrode, the fourth electrode, the fifth electrode, and the sixth electrode via bonding wires.

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