Light-emitting device package device and display device

Abstract

This technical solution includes a plurality of LED chips spaced apart from one another, each having a first surface as a light-emitting surface, a second surface facing opposite to the first surface, and a side surface between the first and second surfaces; a circuit layer formed below the second surface of the LED chips, the circuit layer having an upper surface connected to an electrode of the LED chip, a lower surface facing opposite to the upper surface, and a side surface between the upper and lower surfaces; a first package layer covering the side surface and second surface of the LED chip; and a second package layer covering the side surface of the circuit layer and filling any gaps within the circuit layer, wherein the thickness of the LED chips is T A and the thickness of the first package layer is T B and the thickness of the circuit layer is T C Then, T B / T A A light-emitting diode package device characterized by satisfying the relational expression ≧1 is proposed.

Description

[Technical Field]

[0001] This application claims priority to Chinese Utility Model Application No. 201921553490.2, entitled "Light Emitting Diode Package Device and Display Apparatus," filed on September 18, 2019, and Chinese Utility Model Application No. 201921192783.2, entitled "Light Emitting Diode Package Device," filed on July 26, 2019, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a light emitting device packaging device and a light emitting device utilizing the light emitting device packaging device. [Background technology]

[0003] Light-emitting diodes (LEDs) are one of the most popular light source technologies today, and can be used not only as a light source for lighting devices but also as a light source for various electronic devices, such as display devices in televisions, mobile phones, desktop and laptop computers, and personal digital assistants. By reducing the size of LED devices, the resolution of display devices can be increased, which further expands the application fields of LED displays to include mobile phones, automobile instrument panels, televisions, computers, video conferencing, and more.

[0004] While miniature RGB LEDs are increasingly dominating the display market, they offer exceptional pixel experiences. However, they pose significant challenges to the production technology of miniature RGB LEDs. Their relatively thick construction limits the thickness of products and their application fields. Current technology primarily involves attaching RGB chips to substrates. Flat-type chip mounting requires wire bonding or solder paste, flip-chip mounting also requires solder paste, and vertical chip mounting also requires wire bonding. The thickness of such packages is determined by the thickness of the substrate, solder paste or wire bonding, and chip. This typically exceeds 500 μm, hindering the thinning and integration of packaged devices. At the same time, as miniaturization continues, the efficiency and yield of materials, such as solder paste, at the package end, and die bonding accuracy, are highly related to cost, creating technological challenges in all respects. Furthermore, the requirements for display quality and display effect are extremely high, but the surface treatment technology of the package is different and there are color differences between pixels, which leads to problems such as inconsistent light mixing and high difficulty in calibration, which affects the high-quality display effect. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION The present invention aims to provide a light emitting diode package device that can overcome at least one of the drawbacks of the prior art. [Means for solving the problem]

[0006] According to a first aspect of the present invention, a light-emitting diode package device includes: a plurality of LED chips spaced apart from one another, each having a first surface as a light-emitting surface, a second surface facing opposite to the first surface, and a side surface between the first surface and the second surface; a circuit layer formed below the second surface of the LED chips, the circuit layer having an upper surface connected to an electrode of the LED chip, a lower surface opposite to the upper surface, and a side surface between the upper surface and the lower surface; a first package layer covering the side surface and the second surface of the LED chip; and a second package layer covering the side surface of the circuit layer and filling a gap inside the circuit layer, wherein the thickness of the LED chips is T A and the thickness of the first package layer is T B and the thickness of the circuit layer is T C Then, T B / T A ≧1 is satisfied.

[0007] The thickness T of the LED chip A is in the range of 40 to 100 μm, and the thickness T B is 120 to 200 μm, the thickness T of the circuit layer C It is preferable that the thickness is in the range of 20 to 200 μm.

[0008] Said T A and T B and T C Regarding (T B +T C ) / T A It is preferable that the relational expression ≦10 holds.

[0009] Said T A and T B and T C Regarding (T B +T C ) / T A It is preferable that the relational expression ≧1.4 holds.

[0010] The thickness T of the LED chip A is in the range of 5 to 10 μm, and the thickness TB is in the range of 80 to 100 μm, and the thickness T C It is preferable that the thickness is in the range of 20 to 200 μm.

[0011] Said T A and T B and T C Regarding (T B +T C ) / T A It is preferable that the relational expression ≧10 holds.

[0012] Said T A and T B and T C Regarding (T B +T C ) / T A It is preferable that the relational expression ≦60 holds true.

[0013] Preferably, the first package layer further includes a third package layer.

[0014] Preferably, the second package layer further includes a fourth package layer.

[0015] The first and second packaging layers are preferably made of the same material.

[0016] The LED chip is preferably a mini LED chip or a micro LED chip.

[0017] The plurality of LED chips preferably include LED chips with different wavelengths.

[0018] It is preferable that a pair of electrodes is provided on the second surface of the LED chip.

[0019] In the LED package device, the LED chip is fixed by a first package layer, circuit connections are formed, and then a second package layer is filled to form the package body. This method does not require welding lines, improving reliability and contrast. Furthermore, since solder paste is not required for the LED chip, problems of soldering failure and reflow backflow that occur when using solder paste are avoided, and a smaller and thinner package size can be realized, achieving higher integration density.

[0020] According to a second aspect of the present invention, a light-emitting diode package device includes a plurality of LED chips spaced apart from one another, each having a first surface, a second surface facing opposite to the first surface, and a side surface between the first surface and the second surface, wherein the first surfaces of the plurality of LED chips are on the same side and serve as light exit surfaces, and a pair of electrodes are provided on the second surface; a circuit layer located on the second surface side of the LED chip, the circuit layer having a first surface connected to an electrode of the LED chip, a second surface facing opposite to the first surface, and a side surface between the first surface and the second surface; a package layer that covers side surfaces of the LED chips and a side surface of the circuit layer, fills gaps between the side surfaces of the LED chips and the side surfaces of the circuit layer, and has a first surface and a second surface facing opposite to the first surface, the first surface being located on the same side as the first surfaces of the LED chips, and the second surface being located on the same side as the second surface of the circuit layer; At least two of the plurality of LED chips have different light emission bands, the difference in horizontal height between the first surfaces of the at least two LED chips is greater than 0 micrometers and less than 10 micrometers, and a light transmitting layer is coated on the first surface of the package layer and the first surface side of the LED chip.

[0021] The packaging layer preferably contains a light-absorbing component.

[0022] It is preferable that there are at least two package layers, and at least one of the package layers between the side surfaces of the plurality of chips contains a light absorbing component.

[0023] It is preferable that there are at least two package layers, and that the package layer between the side surfaces of at least a plurality of chips has a light transmittance lower than that of the other layers.

[0024] The package layer may include a plurality of layers, and the package layer covering the circuit layer preferably has a higher light transmittance than the package layer covering the chip.

[0025] It is preferable that the circuit layer does not include a welding layer, or that there is no welding layer between the circuit layer and the LED chip.

[0026] Each of the LED chips has a transparent substrate having a first surface side and a second surface side facing opposite to the first surface side, the first surface side of the transparent substrate being the light emission surface of the LED chip, and the second surface side of the transparent substrate having a light emitting semiconductor stack including a first semiconductor layer, a light emitting layer, and a second semiconductor layer, and preferably further having two electrodes located on the same side of the light emitting semiconductor stack.

[0027] Preferably, the difference in horizontal height between the first surfaces of the at least two LED chips is greater than 0 micrometers and less than 5 micrometers.

[0028] It is preferable that the multiple chips are three RGB chips, and it is more preferable that, based on the second surface of the packaging layer, the height of the light emission surface of the blue light chip is lower than the height of the light emission surfaces of the other chips, and it is even more preferable that, based on the second surface of the packaging layer, the height of the light emission surface of the red light chip is lower than the height of the light emission surfaces of the other chips.

[0029] The light-transmitting layer preferably comprises a light-scattering material.

[0030] The light transmittance of the light transmitting layer is preferably within a range of 40% to 80%.

[0031] The light transmission rate of the light transmission layer is preferably 80% or more.

[0032] The thickness of the entire package device is preferably within the range of 100 to 500 micrometers.

[0033] The thickness of the light transmitting layer is preferably within the range of 5 to 20 micrometers.

[0034] It is preferably located on the same side as the second surface of the package layer and the second surface of the circuit layer.

[0035] It is preferable that the package further comprises two welding pads formed on the surface of the second package layer and connected to the second surface of the circuit layer. [Effects of the Invention]

[0036] The above light emitting diode package device has at least the following advantages:

[0037] (1) This package does not use a substrate, so there is no need to use solder paste to secure the LED chip. This avoids the problems of poor chip soldering and secondary reflow that occur when welding using solder paste. It also allows for a smaller and thinner package, achieving a higher integration density.

[0038] (2) The LED chips with different emission bands among the plurality of LED chips are arranged so that the heights of their light-emitting surfaces are different, and a thin light-transmitting layer on the light-emitting surface partially absorbs the light brightness of the chips with different emission bands, thereby achieving fine-tuning of the brightness, and ultimately realizing the requirements for the light-emitting ratio of LEDs with different emission bands and satisfying the color consistency in RGB display applications.

[0039] (3) The first light-exiting surfaces of the chips are controlled to be less than 10 micrometers, and the uniformity of the light-exiting surfaces is achieved in conjunction with the package layer, thereby reducing the effects of optical crosstalk between the sides. Other features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description, claims and drawings. [Brief explanation of the drawings]

[0040] In order to describe the embodiments of the technical means of the present invention more clearly, the following briefly describes the accompanying drawings used in the embodiments of the present invention. [Figure 1] FIG. 1 is a perspective view illustrating the structure of an LED package device according to some embodiments. [Figure 2] FIG. 2 is a perspective view illustrating the structure of an LED package device according to some embodiments. [Figure 3] FIG. 3 is a side cross-sectional view illustrating the structure of an LED package device according to some embodiments. [Figure 4] FIG. 4 is a side cross-sectional view illustrating a conventional flip-chip LED chip in an LED package device according to some embodiments. [Figure 5] FIG. 5 is a perspective view illustrating one modified LED package device of the present invention. [Figure 6] FIG. 6 is a partial cross-sectional side view showing the configuration of FIG. [Figure 7] FIG. 7 is a top view of a display panel according to some embodiments. [Figure 8] FIG. 8 is a partial cross-sectional side view illustrating one procedure for fabricating an LED package device according to some embodiments. [Figure 9] FIG. 9 is a partial cross-sectional side view illustrating one procedure for fabricating an LED package device according to some embodiments. [Figure 10]FIG. 10 is a partial top view illustrating one procedure for fabricating an LED package device according to some embodiments. [Figure 11] FIG. 11 is a partial cross-sectional side view illustrating one procedure for fabricating an LED package device according to some embodiments. [Figure 12] FIG. 12 is a partial top view illustrating one procedure for fabricating an LED package device according to some embodiments. [Figure 13] FIG. 13 is a diagram illustrating one procedure for fabricating an LED package device according to some embodiments. [Figure 14] FIG. 14 is a side cross-sectional view illustrating the structure of an LED package device according to some embodiments. [Figure 15] FIG. 15 is a side cross-sectional view illustrating an LED package device structure according to some embodiments. [Figure 16] FIG. 16 is a side cross-sectional view illustrating an LED package device structure according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0041] In the following embodiments, a substrate-less LED package device is disclosed, in which a plurality of spaced apart LED chips of the package device are fixed and packaged by a package layer, and a circuit layer is formed within the package layer.

[0042] In some embodiments, the package device is well suited for use in display panels, as it can minimize the size of the package device, which is important for improving the resolution of the display panel, and can significantly reduce the ratio of the LED to the light-emitting area, which is beneficial for improving the contrast ratio of the display panel. The ratio of the LED to the light-emitting area can be preferably 30% or less, or 15% or less, or even 5% or less, for example, 8.5%, or 2.8%, or 1.125%, or even lower.

[0043] 1-3 are perspective and cross-sectional views, respectively, of an example light-emitting diode (LED) package device 100 according to some embodiments. The LED package device 100 includes a plurality of spaced-apart LED chips 111, a package layer 120, a circuit layer 130, and weld pads 140, with each LED chip 111 having a pair of electrodes 112 located on the same side, as shown in FIG.

[0044] 3 , the circuit layer 130 has a first surface, a second surface, and a side surface, the first surface of the circuit layer being connected to the electrodes 112 of each LED chip 111, and the package layer 120 fixing the LED chips 111 and covering the side surfaces of the LED chips and the circuit layer 130, filling gaps on the side surfaces between the LED chips 111 and between the side surfaces of the circuit layer 130, while exposing at least a portion of the second surface of the circuit layer 130. The welding pads 140 are connected to the circuit layer 130. The role of the circuit layer 130 is to connect the electrodes of the LED chips 111 in series or parallel within the package layer, while exposing at least a portion of the second surface to the package layer 120 to provide electrical connection to the outside, or to form welding pads on the second surface of the circuit layer 130 for electrical connection to the outside.

[0045] The package layer 120 has a first surface S11 and a second surface S12 facing opposite to each other, and as shown in FIG. 1, the first surface S11 of the package layer 120 is located on the same side as the first surface S21 of the plurality of LED chips, and the second surface S12 of the package layer 120 is flush with the second surface of the circuit layer 130.

[0046] Specifically, the LED package device 100 may have three LED chips, for example, the first LED chip is a blue chip B, the second LED chip is a green chip G, and the third LED chip is a red chip R. For ease of explanation, the LED package device 100 shown in Figures 1 and 2 has three LED chips R, G, and B, which can emit light of different emission bands, for example, red light, green light, and blue light, respectively. To minimize the size of the package device, the distance between each LED chip is preferably 100 micrometers or less, for example, 100 to 50 micrometers, or preferably 50 micrometers or less. In some display panel applications, the distance between LED chips is preferably 50 micrometers or less, for example, 50-40 micrometers, or 40-30 micrometers, or 30-20 micrometers, or 20-10 micrometers. A smaller distance is advantageous for reducing the size of the packaged device, thereby increasing the resolution of the display panel. In some lighting applications, reducing the distance between chips can increase the area ratio of the chip to the packaged device.

[0047] 4, the LED chip 111 may be a typical flip-chip structure LED chip, having a first surface S21, a second surface S22, and a side surface S24 facing opposite to each other. The first surface S21 is a light-emitting surface, and a pair of electrodes 112 are disposed on the second surface S22. The electrode 112 has a first semiconductor layer 1111 electrically connected to the first electrode 1121 and a second semiconductor layer 1113 electrically connected to the second electrode 1122. The LED chip 111 has a semiconductor light-emitting stack including a first semiconductor layer 1111, a source layer 1112, and a second semiconductor layer 1113. The first semiconductor layer 1111 and the second semiconductor layer 1113 may be p-type and n-type semiconductor layers, respectively. For example, the first and second semiconductor layers of the blue and green LED chips may be Al x In y Ga (1-x-y) The red light LED chip may be formed of a nitride semiconductor that can be represented by a chemical formula of AlN (where 0≦x≦1, 0≦y≦1, 0≦x+y≦1), and the first and second semiconductor layers of the red light LED chip may be formed of Al z In w Ga (1-x-y) The source layer 1112 of the blue LED chip and the green LED chip can be formed of a phosphide semiconductor that can be expressed by a chemical formula of 0≦z≦1, 0≦w≦1, 0≦z+w≦1. The source layer 1112 of the blue LED chip and the green LED chip can have a multiple quantum well (MQW) structure in which quantum well layers and quantum potential barrier layers are alternately stacked. For example, the source layer 1112 can have a nitride-based MQW, such as, but not limited to, InGaN / GaN or InGaN / AlGaN. By adjusting the relative content of In, Al, or Ga in the source layer, the emission bands of the blue and green chips can be effectively adjusted. The red source layer can be formed of, for example, an InGaP / GaP, GaP / AlGaP, or AlGaInP / AlGaInP multiple quantum well structure, and by adjusting the relative content of Al, Ga, or In, the emission band can be adjusted.

[0048] Furthermore, by disposing a transparent rough surface on the light exit surface S21 of the LED chip, it is possible to form diffuse reflection and reduce glare. This rough surface can be made of an anti-glare material.

[0049] In some embodiments, the LED chip 111 may further include a transparent substrate 1110 located on the light-emitting surface, which is located on the first surface S21 side of the LED chip 111 and is used for emitting light, and may further include a pattern or adhesive layer at the interface between the transparent substrate 1110 and the semiconductor light-emitting stack.

[0050] As shown in FIG. 3, the circuit layer 130 connects to the electrodes 112 of the LED chips. The circuit layer 130 can connect three LED chips in series or parallel as needed, and can also route the electrodes 112 of the LED chip 111 to areas other than the LED chips, making wiring more convenient. A preferred circuit layer 130 can have multiple circuit layers, and each circuit layer can be separated by a package layer. In some preferred embodiments, the circuit layer 130 has at least two circuit layers, which can be formed by electroplating or chemical plating, allowing wiring inside the package layer. According to the design of the present invention, the material of the circuit layer 130 can be Cu, Cu x The circuit layer 130 can be made of W or other metal materials, and is obtained by electroplating or chemical plating. By forming a direct electrical connection with the LED chip, the use of solder paste is avoided, and eutectic welding or reflow welding is not required. Therefore, there is no weld layer between the circuit layer and a pair of electrodes of the LED chip. The weld layer here includes a weld layer formed by eutectic welding or reflow welding between the flip chip and the weld pad of the package substrate, specifically, a eutectic layer of AuSn or a reflow weld layer. The material for the circuit layer preferably has a melting point of 400°C or higher, which is advantageous for increasing the reliability of the circuit layer.

[0051] 2-3 , the weld pads 140 are formed on the lower surface S12 of the package layer 120 to connect with the circuit layer 130. By providing large-sized weld pads 140 outside the package device, downstream attachment can be achieved. It should be noted, however, that the weld pads 140 are not required. In some embodiments, the circuit layer 130 may have multiple layers, one of which can be directly used as a weld pad for the package device 100 to connect to a circuit board, thereby eliminating the need for additional weld pads 140 on the package layer 120. The number of weld pads is not limited, and can be determined based on the series-parallel relationship between the LED chips. For example, in this embodiment, a parallel connection is designed for three chips, so the number of weld pads is at least four.

[0052] In some embodiments, the packaging layer 120 preferably has no or low light transmittance, for example, light transmittance of 30% or less, such as 2-20% or less.

[0053] In some embodiments, the packaging device can use a commonly used packaging resin, such as epoxy resin or silicone, as the packaging layer 120 depending on the application needs of the display panel. The packaging layer 120 can be made of a material that is opaque or has a low light transmittance, specifically a light-absorbing component (not shown). The light-absorbing component is located at least around the side of the LED chip or between adjacent LED chips, or at least around the LED semiconductor light-emitting stack or adjacent semiconductor light-emitting stack. The light-absorbing component can be a light-absorbing powder, such as black powder or carbon powder, dispersed in the epoxy resin or silicone used in the packaging layer, or a black resin. The light-absorbing component in the packaging layer can be located at least around the side of the LED chip to prevent light from emitting from the side of the LED chip. This allows light emitted from the LED chip to be mainly or entirely emitted from the light-emitting surface, preventing light crosstalk or mixing between different LED chips in the lateral direction and improving the contrast ratio of the packaged device.

[0054] 5-6, the package layer 120 has multiple layers, specifically at least two layers, and the first package layer 121 has a light-absorbing component, specifically a black powder such as carbon powder dispersed in silicone or epoxy resin, which covers the periphery of the LED chip and is used to seal the LED chip, and is located at least around the semiconductor light-emitting stack. The second package layer 122 covers the periphery or gaps of the circuit layer 130, or mainly covers the periphery or gaps of the circuit layer and is used to seal the circuit layer 130. The second layer packaging layer 122 is made of the same material as the first layer packaging layer 121 or is different from the first layer packaging layer 121, and the second layer packaging layer 122 preferably does not contain any light-absorbing components such as carbon powder, and is preferably a light-transmitting layer such as silicone or epoxy resin, thereby ensuring the reliability of the coating of the second layer packaging layer 122 on the circuit layer, and therefore the light transmittance of the second layer packaging layer 122 is higher than that of the first layer packaging layer 121.

[0055] The LED package device 100 integrates the circuit layer 130 within the package layer 120, thereby effectively improving the area ratio between the LED chip and the package device without the need for wire bonding or flip-chip bonding. Meanwhile, the circuit layer can minimize the number of welding pads on the package device 100. At the same time, the welding pads can be extended to areas other than the LED chip on the package device, increasing the size of each welding pad and reducing the circuit design required in downstream processes, which is advantageous for bonding in downstream processes and effectively reducing the size of the package device.

[0056] In order to guarantee the light emission efficiency and amount of light from the chip light emitting surface, the light is emitted from the light emission surface S21 of the LED chip as much as possible, so as to prevent the proportional decrease in light emission, and the light emitted from the side of the chip is absorbed by the black resin as much as possible to improve the contrast ratio, so the smaller the difference in altitude between the light emission surfaces S21 of the three RGB LED chips, the better.

[0057] As shown in FIG. 3, in one embodiment, the surface of the package layer 120 further includes a light-transmitting layer 401, which seals the first surfaces S21 of the three LED chips. The light-transmitting layer 401 can be made of a light-transmitting material such as resin or silicone, with a light transmittance of at least 40%, or between 40% and 80%, or the light transmittance of the light-transmitting layer 401 is 80% or more. The light-transmitting layer 400 seals the first surfaces S21 of the three LED chips, thereby protecting the light-emitting surfaces of the LED chips and acting as a light-scattering lens to generate a light-scattering effect, which ultimately effectively reduces glare when the RGB package device is used in a display panel. Furthermore, the light-scattering layer 401 can contain a light-scattering material, such as scattering powder.

[0058] In accordance with the requirements for display applications, in this embodiment, the LED chips are chips with different emission bands, specifically chips with three different emission bands (RGB). Furthermore, to meet the different color temperature requirements for display applications, the three chips must have an appropriate light emission ratio. Since the RGB tricolor chips typically cannot meet the absolute light emission ratios based on chip technology, the present invention adjusts the first light-emitting surfaces S21 of the three RGB tricolor chips to different horizontal planes, i.e., to have a certain horizontal height difference. Furthermore, a light-transmitting layer is combined with the surface to act as an optical lens to absorb or scatter part of the light, thereby adjusting the light emission ratios of the chips with different emission bands and thereby meeting the color temperature requirements for RGB display applications. The height difference is preferably less than 10 micrometers and greater than 0 micrometers. A too high height difference will cause side light crosstalk between adjacent chips. Preferably, the height of the light-emitting surface of the blue chip in the three RGB chips is lower than that of the green chip, and the height of the surface of the green chip is lower than that of the red chip, based on the second surface S21 of the package layer 120. In one embodiment, based on the height of the light-emitting surface of the blue chip, the difference in height between the light-emitting surface of the red chip and the light-emitting surface of the blue chip is about 5 micrometers, and the difference in height between the light-emitting surface of the green chip and the light-emitting surface of the blue chip is about 1 micrometer. The thickness of the light-transmitting layer 401 should be greater than the difference in height between the light-emitting surfaces of the three chips, and the light-transmitting layer 401 completely covers the light-emitting surfaces of the three chips. Therefore, in this embodiment, the thickness of the light-transmitting layer 401 is preferably 10 micrometers, and the surface of the blue chip is flush with the first surface of the package layer.

[0059] In FIG. 7, a simplified top view of a display panel 10 including an LED package device 100 according to an example embodiment is shown.

[0060] The display panel 10 may include a circuit board 200 and a plurality of LED package devices 100 disposed on the circuit board, each of which selectively emits red, green, or blue light. Any one of the plurality of LED package devices 100 may constitute a single pixel of the display panel, and the plurality of LED package devices 100 may be arranged on the circuit board 200 in rows and columns.

[0061] The three LED chips in the LED package device 100 correspond to subpixels of an RGB light source. The emission bands of the subpixels are not limited to RGB. In the multiple LED package devices 100, the packaging layer is preferably made of epoxy resin or silicone with black powder added, so that the entire LED package device 100 is black except for the light-emitting surface S21 of the LED chip. This contributes to improving the contrast ratio of the display panel, and the black packaging material separates the LED chips, reducing optical interference between them. When the LED package device 100 shown in FIG. 1 or FIG. 5 is used as a single pixel, the pixel pitch of the display panel can be 1 mm or less.

[0062] The following explains in detail the process of creating an LED package device in accordance with Figures 8 to 13.

[0063] As shown in FIG. 8, three LED chips RGB are prepared. The LED chip 100 has first and second surfaces facing opposite each other and a side surface between the first surface S11 and the second surface S12, with a pair of electrodes distributed on the second surface S12. The LED chips are arranged so that the electrodes 112 of all the LED chips are located on the same side as shown in FIG. 8. In the embodiment shown in FIG. 8, the electrodes 112 of the LED chips are arranged facing upward, and the LED chips are three RGB color chips. The light-emitting surfaces of the three different RGB chips are collectively fixed on a substrate 300, which has an adhesive layer 301 on the substrate 300. The first surfaces S11 of the chips face the adhesive layer 301, ensuring that the first surfaces S11 of the three LED chips are located on the same side.

[0064] By applying appropriate pressure, the three RGB chips generate different amounts of elastic deformation on the surface of adhesive layer 301. The thickness of adhesive layer 301 is preferably 10 micrometers or less, so that the height difference of the light exit surfaces of the three chips is controlled within the range of 0 to 10 micrometers. The material of adhesive layer 301 is preferably a thermally decomposable resin or a photodecomposable resin, and more preferably double-sided tape.

[0065] As shown in FIG. 9, a package layer 120 and a circuit layer 130 are formed on the sides of the three LED chips 111, and the package layer 120 fills the gaps between the sides of each LED chip and seals the circuit layer 130, thereby fixing and connecting the three LED chips 111 together, and exposing one surface of the circuit layer 130.

[0066] Furthermore, the package layer 120 covers the side surfaces of the three LED chips 111, and its upper surface S13 is flush with the upper surface S23 of the LED chip circuit layer. In some embodiments, the package layer 120 is first filled to a certain thickness by a thermo-compression molding method to cover the electrode surfaces of the three LED chips, and then the chip electrode surfaces and connection paths are exposed by a pattern opening technique to form the circuit layer 130. The circuit layer 130 is an electroplated metal layer or a chemically plated metal layer.

[0067] Furthermore, in this embodiment, the three RGB colors are connected in parallel, and the design of the circuit layer 130 is as shown in Figure 10, in which the circuit layer 130 has at least four portions 1311, 1312, 1313, and 1314. Among them, portion 1311 of the circuit layer connects one electrode of the three LED chips, and the remaining three portions connect the remaining electrodes of the three chips, respectively. In some preferred embodiments, the circuit layer 130 has a structure of two or more layers, each circuit layer has a different pattern, and the circuit layer 131 is composed of multiple sub-circuits, each sub-circuit connecting to at least one electrode of the LED chip 111 and extending to the surface of the first package layer 121 other than the electrodes of the LED chips.

[0068] 11 to 13, a welding pad 140 is fabricated on the surface S12 of the package layer 122, and the welding pad 140 forms an electrical connection with the circuit layer 130. This allows the package layer to seal the LED chip and integrate the circuit layer 130 inside the package layer 120. The welding pad 140 is fabricated on the surface of the package layer 120, and its size can be much larger than the size of the electrode 1120 of the LED chip 111.

[0069] After the welding pad 140 is manufactured, one side of the welding pad is transferred to another temporary substrate using a transfer technique, and the temporary substrate and adhesive layer on the light-emitting surface side are removed to expose the light-emitting surface of the LED chip whose horizontal height does not match.

[0070] The light-emitting surfaces of the three chips and the surface of the package layer can be further coated with a light-transmitting layer 401, such as epoxy resin or silicone, with a thickness of preferably 5 to 20 micrometers. The light-transmitting resin layer covers the first surface higher than the three LED chips. Alternatively, a black resin can be dropped onto the surface of at least one chip before the light-transmitting layer 401 to reduce the brightness of the chip and reduce the glare effect of light emission, thereby controlling the light emission ratio of the three RGB colors.

[0071] 14 is a cross-sectional view of a sidewall of a light-emitting diode (LED) package device according to some embodiments. Please refer to FIG. 14. The light-emitting diode package device includes: a plurality of LED chips 2101 spaced apart from one another, each having a first surface as a light-emitting surface, a second surface facing opposite to the first surface, and a side surface between the first and second surfaces; a circuit layer formed below the second surfaces of the LED chips and having an upper surface connected to an electrode of the LED chip, a lower surface facing opposite to the upper surface, and a side surface between the upper and lower surfaces; a first package layer 2201 covering the side surface and the second surface of the LED chip; and a second package layer 2202 covering the side surface of the circuit layer, filling gaps within the circuit layer, and exposing at least a portion of the underside of the circuit layer. The thickness of the LED chips 2101 is T. A and the thickness of the first package layer 2201 is T B and the thickness of the circuit layer is T C Then, T B / T A The relation: =1 holds true.

[0072] The LED chip 2101 can be a normal-sized LED chip (generally referring to a chip with a single side size exceeding 200 μm), a mini LED chip (generally referring to a chip with a size between 100 and 200 μm), or a micro LED chip (generally referring to a chip with a size less than 100 μm), and in this embodiment, a mini LED chip is preferred.

[0073] In this embodiment, the plurality of LED chips include LED chips with different wavelengths, for example, at least three LED chips emitting red light (R), green light (G), and blue light (B), respectively, or LED chips emitting white light (including a wavelength conversion layer), i.e., forming an RGBW combination, which can improve the brightness of the display screen and is very advantageous for outdoor displays.

[0074] In this embodiment, a pair of electrodes 2102 are provided on the second surface of the LED chip 2101, and the LED chip 101 may further include an electrode 2103 with increased thickness. The electrode with increased thickness is formed by electroplating, chemical plating, printing, or other methods, and may be made of Cu, CuW, or other conductive metals. The provision of the electrode with increased thickness increases the contact area between the side of the LED chip and the first package layer 2201, thereby increasing the adhesion between the LED chip and the package layer. Meanwhile, the electrode with increased thickness 2103 and the first package layer 2201 form a pile structure, thereby better securing the LED chip to the package layer 120.

[0075] In this embodiment, the circuit layer has a first sub-circuit layer 2301, a second sub-circuit layer 2302, and a welding pad 2303, the first sub-circuit layer 2301 is used for electrical connection with the multiple LED chips 2101 in series, parallel, or a combination of both, the second sub-circuit layer 2302 can be used to simplify the wiring structure, i.e., to reduce the number of connection terminals, and the welding pad 2303 is connected to the second sub-circuit layer 2302.

[0076] The first package layer 2121 and the second package layer 2122 may be made of the same material or different materials. If the same material is used, the two layers will be combined into one layer, making them difficult to distinguish. For example, in some embodiments where the LED package device is used in a display device, the first and second package layers may be made of epoxy resin or silicone with a colorant added, in which case the package layers can fix and seal the LED chips 2101 and reduce optical interference between the LED chips 2101.

[0077] In this embodiment, the thickness T of the LED chip A is between 40 and 100 μm, and the thickness T Bis between 120 and 200 μm, and the thickness T C It is preferable that the thickness T of the circuit layer is between 20 and 200 μm. C is more preferably between 40 and 180 μm, and A , T B , T C Regarding , 1.4 ≦ (T B +T C ) / T A The relational expression ≦10 holds. It should be noted here that the number of layers of the circuit layer may be at least two, or may be four, and the thickness of each layer is, for example, 30 μm.

[0078] In this embodiment, the first package layer is used to secure the LED chip, then form the circuit connection, and then fill in the second package layer to form the package body. This method eliminates the need for wire bonding, improving reliability and contrast ratio. Furthermore, since solder paste welding to the LED chip is not required, the problems of solder failure and reflow backflow that occur when using solder paste are avoided, and a smaller and thinner package size can be achieved, resulting in higher integration density.

[0079] FIG. 15 is a cross-sectional view of a sidewall of a light-emitting diode (LED) package device illustrating some embodiments. The difference from the LED package device shown in FIG. 14 is that the first package layer in this embodiment further includes a third package layer 2203, which covers the LED chip 2101 and the second package layer from above, thereby preventing the LED chip from being exposed. Selecting a transparent layer such as silicone or resin as the third package layer can reduce specular reflection and improve scattering, thereby contributing to improving the color unevenness of the surface of the package structure. In addition, in this embodiment, a micro LED chip is preferably used as the LED chip 2101, and the thickness T of the LED chip is 1 / 2 mm. A is between 5 and 10 μm, and the thickness T B is between 80 and 100 μm, and the thickness T Cis preferably between 20 and 200 μm, and further, the thickness T C is more preferably between 40 and 180 μm, and A , T B and T C Regarding , 10≦(T B +T C ) / T A By satisfying the relationship of ≦60, excessive stress and thermal resistance caused by circuit layers that are too thick can be avoided, ensuring the strength of the package structure while also reducing the thickness of the entire package structure, ultimately resulting in a thinner product.

[0080] 16 is a side cross-sectional view of a light-emitting diode (LED) package device illustrating some embodiments. The difference from the LED package device shown in FIG. 15 is that the second package layer in this embodiment further includes a fourth package layer 2204, which is used to fill the gaps between the welding pads 2303. The material of the fourth package layer 2204 can be selected from an insulating layer, an epoxy resin, a solder resist ink, or a combination thereof. Since the fourth package layer is filled between the welding pads 2303, the welding pads can be considered as part of the circuit layer, i.e., the thickness T of the circuit layer. C includes the total thickness of the first sub-circuit layer 2301, the second sub-circuit layer 2302, and the weld pad 2303.

[0081] Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, but is intended to encompass all modifications and equivalent configurations as various configurations falling within the spirit and scope of the broadest interpretation.

Claims

1. a plurality of LED chips spaced apart from one another, each having a first surface, a second surface facing opposite to the first surface, and a side surface between the first surface and the second surface, wherein the first surfaces of the plurality of LED chips are on the same side and serve as light exit surfaces, and a pair of electrodes are provided on the second surface; a circuit layer located on the second surface side of the LED chip, the circuit layer having a first surface connected to an electrode of the LED chip, a second surface facing opposite to the first surface, and a side surface between the first surface and the second surface; a package layer that covers side surfaces of the LED chips and a side surface of the circuit layer and fills gaps between the side surfaces of the LED chips and the side surfaces of the circuit layer, and has a first surface and a second surface facing opposite to the first surface, the first surface being located on the same side as the first surfaces of the LED chips and the second surface being located on the same side as the second surface of the circuit layer; At least two of the plurality of LED chips have different light emission bands, a difference in horizontal height between first surfaces of the at least two LED chips is greater than 0 micrometers and less than 10 micrometers, and a light transmitting layer is coated on the first surface of the package layer and on the first surface side of the LED chips; a light-emitting diode package device comprising: the at least two LED chips being a red chip and a green chip, respectively; a light-emitting surface of the green chip being lower than that of the red chip; an upper surface of the light-transmitting layer facing the chips being flat; the light-transmitting layer containing resin or silicone; a thickness from the upper surface of the light-transmitting layer to the surface of the packaging layer being within a range of 5 to 20 micrometers, so that light from the light-emitting surfaces of the chips is emitted from the upper surface of the light-transmitting layer; a thickness of the light-transmitting layer being greater than the range of the height difference between the light-emitting surfaces of all of the LED chips, so that the light-transmitting layer completely covers the light-emitting surfaces of all of the LED chips; and the packaging layer containing a light-absorbing component.

2. 2. The light-emitting diode package device according to claim 1, wherein the package layer comprises at least two layers, and at least one of the package layers between the side surfaces of the plurality of LED chips comprises a light-absorbing component.

3. 2. The light-emitting diode package device according to claim 1, wherein the package layer has at least two layers, and the light transmittance of at least one package layer between the sides of the LED chips is lower than that of other layers.

4. 2. The LED package device according to claim 1, wherein the package layer comprises a plurality of layers, and the light transmittance of the package layer covering the circuit layer is higher than that of the package layer covering the chip.

5. 2. The light-emitting diode package device as claimed in claim 1, wherein the circuit layer does not include a welding layer, or there is no welding layer between the circuit layer and the LED chip.

6. 2. The light-emitting diode package device according to claim 1, wherein each of the LED chips has a transparent substrate having a first surface side and a second surface side facing opposite to the first surface side, the first surface side of the transparent substrate being a light-emitting surface of the LED chip, and the second surface side of the transparent substrate having a light-emitting semiconductor stack including a first semiconductor layer, a light-emitting layer, and a second semiconductor layer, and further having two electrodes located on the same side of the light-emitting semiconductor stack.

7. 2. The light-emitting diode package device as claimed in claim 1, wherein the difference in horizontal height between the first surfaces of the at least two LED chips is greater than 0 micrometers and less than 5 micrometers.

8. 2. The light emitting diode package device as claimed in claim 1, wherein the plurality of LED chips are three chips of RGB.

9. 9. The LED package device according to claim 8, wherein the height of the light exit surface of the blue chip is lower than the height of the light exit surfaces of the other chips relative to the second surface of the package layer.

10. 2. The light emitting diode package device according to claim 1, wherein the light transmittance of the light transmitting layer is in the range of 40% to 80%.

11. 2. The light-emitting diode package device according to claim 1, wherein the thickness of the entire package device is in the range of 100 to 500 micrometers.

12. 2. The light-emitting diode package device according to claim 1, further comprising two welding pads formed on the second surface of the package layer and connecting to the second surface of the circuit layer.

13. 2. The light-emitting diode package device according to claim 1, wherein the second surface of the package layer and the second surface of the circuit layer are flush with each other.

14. A display device based on a light emitting diode package device according to any one of claims 1 to 13.

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