LED chip array, packaging unit, preparation method and application thereof

Abstract

The invention discloses an LED chip array, a packaging unit, a preparation method and application thereof. The LED packaging unit comprises a substrate, a first LED chip, a second LED chip and a third LED chip; the first electrode of the first LED chip or the second LED chip is arranged on one side, and the other two first electrodes are arranged on the other side; a first circuit on the substrate is sequentially connected in series with the first electrodes and extends outwards; the second circuit conducts the second electrodes of the first LED chip, the second LED chip and the third LED chip respectively and extends outwards, and spacing distances exist between the first circuit and the edge of the substrate and between the second circuit and the edge of the substrate. According to the technical scheme provided by the invention, by optimizing the structural design, a certain LED chip is twisted, so that a circuit can avoid the edge for wiring, the edge wiring problem which the existing MIP packaging unit has to face is optimized, and the problem of low luminous efficiency of a part of LED chips of the existing MIP packaging unit is further avoided.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic semiconductor technology, and in particular to an LED chip array, a packaging unit, a preparation method and application thereof. Background Art

[0002] Micro-LED is a new generation of display technology and is generally considered the ultimate display technology by the display industry. Compared with existing liquid crystal displays, it has higher photoelectric efficiency, higher brightness, higher contrast, and lower power consumption, and can also be combined with flexible panels to achieve flexible display.

[0003] The Micro-LED display panel includes several pixel areas, each of which includes red LED, blue LED, and green LED chips. In the display manufacturing process, the red, green, and blue LED chips need to be transferred from their respective growth substrates (wafers) to the display backplane to form an LED display array. The specific process is as follows: Figure 1 shown.

[0004] The above-mentioned Micro-LED display technology is called Micro-LED glass-based direct display. However, in view of the yield and cost issues of the current mass transfer and mass repair technologies, large-scale productization is still not possible. Therefore, in order to accelerate the industrialization process of Micro-LED display, the industry has proposed the MIP (Micro-LED in Package) technical solution for Micro-LED display, which is to pre-package the Micro-LED chip in a small light-emitting unit in advance, and then use relatively mature technology to transfer the MIP display unit of the pre-packaged Micro-LED chip to the corresponding PCB and glass-based display circuit. This technical solution has the feasibility of high technical maturity and low expected cost. Its structure is as follows: Figure 2 shown.

[0005] However, the inventors have found that the MIP technical solution of the above-mentioned Micro-LED display mainly involves that the luminous efficiency of the red light chip is low and an unavoidable problem in the arrangement of the existing light-emitting units is that the metal circuit has to be routed at the edge of the packaging unit. Figure 2 The part marked by the red dashed line is shown in FIG.

[0006] Since the metal circuit is too close to the edge of the packaging unit, the line width of the metal circuit has to be reduced, which will result in a thinner metal circuit, a significant resistance effect when current passes through it, and a significant heating effect of the packaging unit, further affecting the life and power consumption of the display device; and if the existing arrangement does not adopt the side routing method, leading out the metal circuit through other positions will increase the process difficulty and increase the production cost of the packaging unit. Summary of the invention

[0007] In view of the deficiencies in the prior art, an object of the present invention is to provide an LED chip array, a packaging unit, a preparation method and applications thereof.

[0008] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0009] In a first aspect, the present invention provides an LED packaging unit, comprising a substrate and a first LED chip, a second LED chip, and a third LED chip sequentially arranged on a surface of the substrate along an arrangement line;

[0010] The first LED chip, the second LED chip, and the third LED chip have first electrodes and second electrodes disposed at two ends; the first electrode of the first LED chip or the second LED chip is disposed on the first side of the arrangement line, and the first electrodes of the other two LED chips are disposed on the second side of the arrangement line;

[0011] The substrate is provided with a first circuit and a second circuit;

[0012] The first circuit sequentially connects the first electrodes of the first LED chip, the second LED chip and the third LED chip in series and then extends away from the center of the LED packaging unit; the second circuit is provided with a plurality of second circuits, which respectively extend from the second electrodes of the first LED chip, the second LED chip and the third LED chip toward the center of the LED packaging unit, and the first circuit and the second circuit are spaced apart from the edge of the substrate.

[0013] In a second aspect, the present invention further provides a micro LED display array, which includes a first pixel, a second pixel and a third pixel, wherein the first pixel, the second pixel and the third pixel include a first light emitting unit, a second light emitting unit and a third light emitting unit respectively;

[0014] The first light-emitting unit and the second light-emitting unit are respectively formed by covering the first LED chip and the second LED chip in the LED packaging unit with a quantum dot light conversion layer, and the third light-emitting unit maintains the light color of the third LED chip in the LED packaging unit.

[0015] In a third aspect, the present invention further provides a method for preparing the above-mentioned LED packaging unit, comprising:

[0016] Providing a substrate and an LED chip array, wherein the LED chip array comprises a plurality of LED chips arranged in an array;

[0017] Transferring the LED chips from the LED chip array to the substrate surface;

[0018] And, the step of forming a first circuit and a second circuit on the surface of the substrate.

[0019] In a fourth aspect, the present invention further provides an LED chip array for the above application, which is used to provide LED chips for the above preparation method, comprising a plurality of LED chips arranged in an array and divided into a first group and a second group, wherein the electrodes of the first group are arranged along a first direction, and the electrodes of the second group are arranged along a second direction;

[0020] The electrode direction is an extension direction from the first electrode to the second electrode of the LED chip, and the first direction is opposite to the second direction.

[0021] Based on the above technical solution, compared with the prior art, the beneficial effects of the present invention at least include:

[0022] The technical solution provided by the present invention optimizes the structural design of the LED packaging unit so that the electrode direction of a non-central LED chip therein is twisted, so that the circuit corresponding to the twisted LED chip can avoid the edge of the packaging unit for routing. Through the special design of the packaging structure, the edge routing problem that the existing MIP packaging unit has to face is optimized, thereby avoiding the problem of low luminous efficiency of some LED chips in the existing MIP packaging unit.

[0023] The above description is only an overview of the technical solution of the present invention. In order to enable those skilled in the art to more clearly understand the technical means of the present application and implement them according to the contents of the specification, the following is a description of the preferred embodiments of the present invention in conjunction with detailed drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the preparation process of the LED display array provided by the background technology of the present invention;

[0025] Figure 2 It is a structural schematic diagram of a MIP encapsulation unit provided by the background technology of the present invention;

[0026] Figure 3 It is a schematic structural diagram of a repeating unit of an LED chip array provided in a typical implementation case of the present invention;

[0027] Figure 4 This is a physical photo of a repeating unit of an LED chip array provided in a typical embodiment of the present invention;

[0028] Figure 5 Schematic diagram of the transfer order of the repeating units of the LED chip array provided by a typical embodiment of the present invention;

[0029] Figure 6It is a structural schematic diagram of a temporary substrate provided by a typical implementation case of the present invention;

[0030] Figure 7 It is a structural schematic diagram of an LED packaging unit provided by a typical implementation case of the present invention;

[0031] Figure 8 It is a structural schematic diagram of an LED packaging unit provided by another typical implementation case of the present invention. DETAILED DESCRIPTION

[0032] In view of the deficiencies in the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principle will be further explained as follows.

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0034] Moreover, relational terms such as “first” and “second” are merely used to distinguish one component or method step from another with the same name, but do not necessarily require or imply any such actual relationship or order between these components or method steps.

[0035] See also Figure 7 As shown, an embodiment of the present invention first provides an LED packaging unit, which includes a substrate and a first LED chip, a second LED chip, and a third LED chip arranged in sequence on the surface of the substrate along an arrangement line; the first LED chip, the second LED chip, and the third LED chip have a first electrode and a second electrode arranged at both ends; the first electrode of the first LED chip or the second LED chip is arranged on the first side of the arrangement line, and the first electrodes of the other two LED chips are arranged on the second side of the arrangement line; the substrate is provided with a first circuit and a second circuit; the first circuit sequentially connects the first electrodes of the first LED chip, the second LED chip, and the third LED chip in series and then extends away from the center direction of the LED packaging unit; the second circuit is provided with a plurality of second circuits, which respectively extend from the second electrodes of the first LED chip, the second LED chip, and the third LED chip to the center direction away from the LED packaging unit, and the first circuit and the second circuit are both spaced apart from the edge of the substrate.

[0036] The specific value of the spacing distance can be appropriately adjusted based on the withstand voltage requirements of the device, the process requirements of the device, etc. In the present invention, one of the key technical means is to twist one of the three arranged LED chips, and to avoid edge routing with the corresponding circuit. There are two ways of twisting, the first is to twist the outer LED chip among the three, and the other is to twist the middle LED chip.

[0037] In some embodiments, the LED packaging unit is a polygon with at least 4 sides, and corner electrodes are respectively provided at the four corners; the first circuit extends to a corresponding one of the corner electrodes and is conducted with the corner electrode, and multiple second circuits extend to corresponding multiple corner electrodes and are conducted with the corner electrodes respectively.

[0038] As a specific typical example, the LED packaging unit is a rectangle, and the specific arrangement method can be, for example: when a coordinate system is established on the surface of the substrate (the coordinate axes are parallel to the four sides of the rectangle, and the origin is established at the center of the rectangle as much as possible), the four corners of the substrate are arranged in sequence as the first corner electrode, the second corner electrode, the third corner electrode and the fourth corner electrode in quadrant order, and the arrangement line extends in the X-axis direction of the coordinate system.

[0039] Through multiple second circuits, the first corner electrode is electrically connected to the second electrode of the third LED chip, the second corner electrode is electrically connected to the second electrode of the second LED chip, and the third corner electrode is electrically connected to the second electrode of the first LED chip, or the first corner electrode is electrically connected to the second electrode of the third LED chip, the second corner electrode is electrically connected to the second electrode of the first LED chip, and the third corner electrode is electrically connected to the second electrode of the second LED chip; and in the above two possibilities, the fourth corner electrode is connected to the first circuit.

[0040] Or, the LED packaging units are arranged in an axisymmetric mirror image according to the arrangement method. Specifically, for example, the Y axis is used as the axis of symmetry, and the left and right mirror images are arranged, or other equivalent forms. Of course, the coordinate system and arrangement distribution described in the present invention are not absolutely limited to horizontal and vertical straight lines and absolutely perpendicular to each other. For example, those skilled in the art move, tilt, and use non-square substrates for some LED chips, which also utilize the core inventive concept of the present invention and should fall within the scope of protection of the present invention.

[0041] In some embodiments, the first LED chip and the second LED chip include a backlight layer and a quantum dot light conversion layer that are stacked.

[0042] In some embodiments, the first LED chip is a red LED, and the second LED chip is a green LED.

[0043] The above preferred embodiment substantially provides a micro-LED display array, which includes a first pixel, a second pixel and a third pixel, wherein the first pixel, the second pixel and the third pixel respectively include a first light-emitting unit, a second light-emitting unit and a third light-emitting unit; the first light-emitting unit and the second light-emitting unit are respectively formed by covering a quantum dot light conversion layer with a first LED chip and a second LED chip in an LED packaging unit provided by any of the above embodiments, and the third light-emitting unit maintains the light color of the third LED chip in the LED packaging unit;

[0044] Furthermore, the light emitting color of the first light emitting unit may be, for example, red light, and the light emitting color of the second light emitting unit may be, for example, green light;

[0045] Furthermore, the light color of the third light emitting unit can be maintained as the color of the blue backlight, for example. Of course, in the industry, a filter layer can also be coated on its surface to optimize the light color, but the color it presents still mainly comes from the color of the backlight.

[0046] The micro LED display array further includes an extraction circuit, which is used to supply power to the first light-emitting unit, the second light-emitting unit, and the third light-emitting unit. The form of the extraction circuit is not limited to a PCB, a glass backplane with a patterned circuit, etc. Of course, although the setting of the extraction circuit is necessary, it does not involve the specific structure of the core, so it will not be discussed too much here.

[0047] As some typical implementation cases of the above technical solutions, Figure 7 As shown, compared to Figure 2 In the prior art MIP packaging unit shown in the figure, in the packaging unit provided by the present invention, the arrangement of the red LED chip is twisted by 180°. In the original arrangement, the electrode directions of the red, green and blue LED chips (for example, the direction from the N electrode to the P electrode) are all consistent, which is also the key to the edge routing problem that the red LED chip must face in the prior routing method. The present invention twists the electrode direction of the red LED chip so that its P electrode faces the other side, and cooperates with the unique setting of the first circuit with a common N electrode and the second circuit led out of the P electrode, thereby avoiding the edge routing problem of the second circuit, thereby optimizing and solving a series of edge routing problems such as the luminous efficiency problem of the red LED.

[0048] Of course, the specific arrangement method is not limited to the form of this example. The P electrode and the N electrode can be swapped, the above arrangement structure can be mirrored left and right, the positions of the red LED chip and the green LED chip can be swapped (the green LED chip is naturally twisted at this time). Even in some extreme conditions, the color of the LED chip may not be limited to the three primary colors of red, blue and green. As long as it conforms to the above arrangement rules and produces the technical effect of avoiding edge routing, other color combinations also fall within the scope of implementation of the present invention.

[0049] In some embodiments, see Figure 7 The first circuit is preferably arranged in such a manner that it passes through the first electrode of the first LED chip, the spacing area between the first LED chip and the second LED chip, and the first electrode of the second LED chip in sequence.

[0050] In a possible mode in which the middle LED chip is twisted, the first circuit continues to sequentially pass through the spacing area between the second LED chip and the third LED chip and the first electrode of the third LED chip and then extends to the corresponding corner electrode. In this way, the lead wire of the first electrode serving as the common electrode is formed as follows: Figure 8 The V-shaped symmetry shown is conducive to balancing the internal stress of the metal wiring, thereby improving the structural stability of the package unit. Of course, in addition to the above V-shaped symmetry (the first electrode in the spacing area is a straight line), other symmetry forms are also possible, such as continuous fold lines arranged horizontally and vertically.

[0051] See also Figure 3-Figure 6 Corresponding to the structure of the above-mentioned LED packaging unit, the embodiment of the present invention further provides a method for preparing the LED packaging unit provided by any of the above-mentioned embodiments, which comprises the following main steps:

[0052] Providing a substrate and an LED chip array, wherein the LED chip array comprises a plurality of LED chips arranged in an array;

[0053] Transferring the LED chips from the LED chip array to the substrate surface;

[0054] And, the step of forming a first circuit and a second circuit on the surface of the substrate.

[0055] In the specific implementation, the following specific scheme can be most preferably adopted, first transferring the LED chip to the surface of the substrate, and then constructing multiple conductive circuits and electrodes and other structures. Of course, the implementation order can also be changed, first constructing the relevant circuit structure, and then transferring the LED chip. Of course, the implementation order and process of the electrodes and circuits can also be appropriately adjusted. The above non-sequential steps can be included to achieve the transfer of the LED chip and form the above LED packaging structure, which all belong to the protection scope of the present invention. In short, no matter what implementation order is adopted, the above-mentioned LED packaging structure that can avoid edge routing problems is finally formed based on the transfer of the LED chip array, which utilizes the inventive concept contributed by the present invention.

[0056] Specifically, in some embodiments, the LED chip in the LED chip array is a backlight chip; and the preparation method further comprises:

[0057] A quantum dot light conversion layer is selectively coated on the surface of a portion of the backlight chip, so that the backlight chip respectively constitutes a first LED chip, a second LED chip and a third LED chip with different luminous colors.

[0058] In the above technical scheme, in order to facilitate the implementation of the transfer process of the above-mentioned LED chip, an embodiment of the present invention also provides an LED chip array, which is used to provide LED chips for the preparation method provided by any of the above-mentioned embodiments, and includes a plurality of LED chips arranged in an array and divided into a first group and a second group, the electrode direction of the first group is set along a first direction, and the electrode direction of the second group is set along a second direction; the electrode direction is the extension direction from the first electrode to the second electrode of the LED chip, and the first direction is opposite to the second direction.

[0059] Correspondingly, in some embodiments, the LED chips are blue backlight chips, and the ratio of the number of LED chips in the first group to the number of LED chips in the second group is preferably 2:1.

[0060] The first group of LED chips is used to form a green LED and a blue LED, and the second group of LED chips is used to form a red LED.

[0061] In some embodiments, the LED chip array specifically includes a plurality of array-arranged repeating units, and the repeating unit includes a plurality of array-arranged LED chips.

[0062] In some embodiments, the repeating unit includes a first column of LED chips from the first group and a second column of LED chips from the second group.

[0063] In some embodiments, the LED chips in the repeating unit are arranged into n vertical columns, wherein the first column to the (ni)th column are the first group, and the (n-i+1)th column to the nth column are the second group, n and i are both integers and n is a multiple of 3 and greater than or equal to 6, 2≤i<n; more preferably, i=n / 3; more preferably, the LED chips in the repeating unit are arranged into n horizontal rows to form a square repeating unit. The purpose of this arrangement is, Figure 5 As shown, the first group is the first 4 columns, and the second group is the last 2 columns. When transferring, the interval is a preset number (in Figure 5 In the specific case shown, two LED chips of the first group and one LED chip of the second group are taken out in sequence, forming a group of chips and transferring them to the substrate together (i.e., the LED chips of the 1st, 3rd and 5th columns are transferred for odd times, and the LED chips of the 2nd, 4th and 6th columns are transferred for even times), which is conducive to reducing the complexity of the process. Of course, it can also be expanded to a combination of 6 columns + 3 columns, so that the number of intervals is adjusted to 2, that is, the 1st, 4th and 7th columns are a group, the 2nd, 5th and 8th columns are a group, the 3rd, 6th and 9th columns are a group, and so on, and it can still be expanded to a larger number. The best way is still to use the above-mentioned 4 columns + 2 columns, because the natural spacing distance of the 3 LED chips in the LED chips group extracted in this way is in line with the minimum spacing between LED chips in the field, usually 9-10μm, and can be directly transferred to the surface of the substrate in groups without adjusting their spacing, which is conducive to improving efficiency and reducing the size of the packaging unit.

[0064] Of course, the arrangement of the above-mentioned LED chip array is an implementation method for achieving the better technical effect of the present invention, but all possible implementation methods are not limited to this. By adopting other arrangements, it can be ensured that the number of forward LED chips and the number of reverse LED chips are maintained at about 2:1, and the above-mentioned packaging structure can also be produced through targeted transfer; multiple LED chip arrays can also be provided, in which the LED chips in one part are all forward and the LED chips in the other part are all reverse, and they can be transferred to the same substrate through multiple wafers; more likely, all the LED chip arrays provided are consistent, but in the process of transfer, for example, by using a robot or other various forms to make some LED chips turn 180° during the transfer process, it is also possible to successfully construct the above-mentioned packaging structure.

[0065] The technical solution of the present invention is further described in detail below through several embodiments and in conjunction with the accompanying drawings. However, the selected embodiments are only used to illustrate the present invention, and do not limit the scope of the present invention.

[0066] Example 1

[0067] This embodiment illustrates the manufacturing process and application of an LED packaging unit, which are specifically as follows:

[0068] By changing the conventional equal array processing technology and micro LED layout design in the micro LED chip manufacturing process, and using 400*400um as a repeating unit of an array, it is possible to produce such arrays on the wafer of the blue light micro LED native substrate. Figure 3 and Figure 4 The all-blue micro LED chip array shown.

[0069] On the wafer of the above-mentioned blue light micro LED native substrate, each array is arranged with 6×6 blue light micro LED chips. The electrodes of the blue light micro LED chips in the first 4 columns are P at the top and N at the bottom, and the electrodes of the blue light micro LED chips in the last 2 columns are N at the top and P at the bottom. The 400*400um array block is used as a repeating unit to fill the 4-inch LED chip array of blue light micro LED chips. The above design continues the manufacturing process of conventional LEDs, but changes the processing positions of the MESA (step), P electrode, and N electrode of the last 2 columns of chips, which is fully adapted to the current production process.

[0070] The blue light micro LED chip wafer prepared based on the above design is transferred in the following order: Figure 5 The process is performed in the numerical order shown. For example, the first transfer transfers the LED chip labeled 1, the second transfer transfers the LED chip labeled 2, and so on until the LED chip labeled 12 is transferred. Finally, one original array unit of the blue light micro LED chip can be transferred 12 times.

[0071] After transferring through the above scheme, we get the following Figure 6 The temporary substrate shown in the arrangement is composed of 400um*400um array units. With this transfer method, one blue light micro LED chip can be transferred into a temporary substrate with 12 400um*400um array units.

[0072] The above-arranged 400um*400um blue light micro LED chip unit then uses the quantum dot conversion technology solution to convert two of the blue light LED chips into red light quantum dot chips and green light quantum dot chips by covering them with quantum dot light conversion layers, thereby achieving photoinduced production of red and green light, and then combined with the original blue light chip. Therefore, the three primary color display pixels of red, green and blue (from left to right) are realized on the 400um*400um array unit.

[0073] Then, through the semiconductor packaging process, the corner electrodes of different micro LED chips are brought out to obtain the following Figure 7The 400um*400um quantum dot conversion three-color micro LED packaging unit (QDMP) shown in the figure is assembled in an array and uses various existing technical means to lay out the lead-out circuit for supplying power to each corner electrode, thereby constructing a display array.

[0074] At this point, the MIP packaging unit for quantum dot color conversion has been completed based on the specially designed and processed blue light micro LED chip. This technology solves the light efficiency problem of previous red light micro LED chips and the edge routing problem after packaging.

[0075] In addition, in this embodiment and similar implementations, the one-time transfer of the full blue LED chip avoids the alignment problem of the original MIP package chip R\G\B three-color chip transfer, thereby improving the transfer accuracy.

[0076] By testing the display array prepared in this embodiment, it was found that its red light conversion efficiency was 40-50%. In comparison, using the existing MIP process provided by the above-mentioned background technology, its red light conversion efficiency was 10-15%. Moreover, during the maximum power continuous light emission process, the temperature of the display array prepared in this embodiment was significantly lower than that of the existing light-emitting array.

[0077] Example 2

[0078] The manufacturing process and application of an LED packaging unit in this embodiment are substantially the same as those in the embodiment, with the main differences being:

[0079] The arrangement of the formed LED packaging unit is a left-right mirror image of that in Example 1. Correspondingly, the arrangement of the repeating units in the prepared LED chip array is also a left-right mirror image of that in Example 1.

[0080] Finally, the manufactured LED display array has exactly the same red light conversion efficiency and heat generation as those of Example 1, the only difference being that the red light LED is on the right side of the packaging unit.

[0081] Example 3

[0082] This embodiment also provides a manufacturing process and application of an LED packaging unit, which is substantially the same as that of the first embodiment, except that:

[0083] Through quantum dot coating technology, patterned regional LED conversion is directly performed on the LED chip array to form blue light (third), green light (second) and red light (first) LED chips, and then the formed LED chips are transferred to the substrate to form corresponding packaging units.

[0084] The implementation method illustrated in this embodiment is slightly different from the implementation method represented by Example 1 in terms of execution order, but the device structure finally obtained is the same, and can also achieve the same level of technical effect of avoiding edge routing to improve the light conversion efficiency of the first LED chip.

[0085] Example 4

[0086] This embodiment also provides a manufacturing process and application of an LED packaging unit, which is substantially the same as that of the first embodiment, except that:

[0087] All N and P structures in the LED packaging unit are swapped and replaced. Specifically, the lower right corner is adjusted to a common P electrode, and the remaining triangles are three independent N electrodes. The direction of the NP electrodes of the chip is also swapped.

[0088] The implementation method illustrated in this embodiment is completely opposite to the implementation method represented by Example 1 in terms of the arrangement direction of the PN junction, but the device structure finally obtained is similar and can also achieve the same level of technical effect of avoiding edge routing to improve the light conversion efficiency of the first LED chip.

[0089] Example 5

[0090] This embodiment also provides a manufacturing process and application of an LED packaging unit, which is substantially the same as that of the first embodiment, except that:

[0091] like Figure 8 As shown, the sub-pixel in the packaging unit uses the middle pixel (green LED chip) whose P / N electrode direction is opposite to the direction of the electrodes on both sides, and the common N electrode lead is led out in a V-shaped symmetrical manner. The three P electrodes are connected to the corresponding corner electrodes in the same manner as the embodiment. This implementation method is conducive to balancing the internal stress of the metal routing, thereby improving the structural stability of the QDMP packaging unit.

[0092] Example 6

[0093] This embodiment also provides a manufacturing process and application of an LED packaging unit, which is substantially the same as that of the first embodiment, except that:

[0094] The conventional blue light microLED chip growth wafer is used completely. The first and second blue light micro LED chips are transferred onto a temporary substrate for the target packaging unit. Then the microLED chip growth wafer is turned 180 degrees and the third blue light chip is transferred. This method uses conventional blue light microLED chip growth wafer and can still prepare packaging units in which the P / N electrodes are no longer on the same side, and can also achieve the above-mentioned technical effects.

[0095] Based on the above embodiments, it can be clearly seen that the technical solution provided by the embodiments of the present invention optimizes the structural design of the LED packaging unit so that the electrode direction of the LED chip therein is twisted, so that the circuits corresponding to the twisted LED chips can avoid the edge of the packaging unit for routing. Through the special design of the packaging structure, the edge routing problem that the existing MIP packaging unit has to face is improved, thereby avoiding the problem of low luminous efficiency of some LED chips in the existing MIP packaging unit.

[0096] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. An LED packaging unit, characterized in that: It includes a substrate and a first LED chip, a second LED chip, and a third LED chip which are sequentially arranged on the surface of the substrate along an arrangement line; The first LED chip, the second LED chip, and the third LED chip have first electrodes and second electrodes disposed at two ends; the first electrode of the first LED chip or the second LED chip is disposed on the first side of the arrangement line, and the first electrodes of the other two LED chips are disposed on the second side of the arrangement line; The substrate is provided with a first circuit and a second circuit; The first circuit sequentially connects the first electrodes of the first LED chip, the second LED chip and the third LED chip in series and then extends away from the center of the LED packaging unit; the second circuit is provided with a plurality of second circuits, which respectively extend from the second electrodes of the first LED chip, the second LED chip and the third LED chip toward the center of the LED packaging unit, and the first circuit and the second circuit are spaced apart from the edge of the substrate.

2. The LED packaging unit according to claim 1, characterized in that: The LED packaging unit is a polygon, the number of sides of the polygon is at least 4, and corner electrodes are respectively arranged at the four corners; The first circuit extends to a corresponding one of the corner electrodes and is conducted with the corner electrode, and the plurality of second circuits extend to the corresponding plurality of corner electrodes and are conducted with the corner electrodes respectively.

3. The LED packaging unit according to claim 2, characterized in that: The arrangement of the LED packaging units is as follows: when a coordinate system is established on the surface of the substrate, the four corners of the substrate are sequentially arranged as a first corner electrode, a second corner electrode, a third corner electrode and a fourth corner electrode in quadrant order, and the arrangement line extends along the X-axis direction of the coordinate system; Through the second circuit, the first corner electrode is electrically connected to the second electrode of the third LED chip, the second corner electrode is electrically connected to the second electrode of the second LED chip, and the third corner electrode is electrically connected to the second electrode of the first LED chip, or the first corner electrode is electrically connected to the second electrode of the third LED chip, the second corner electrode is electrically connected to the second electrode of the first LED chip, and the third corner electrode is electrically connected to the second electrode of the second LED chip; The fourth corner electrode is connected to the first circuit; Alternatively, the LED packaging units are arranged in an axisymmetric mirror image manner.

4. The LED packaging unit according to claim 1, characterized in that: The first circuit sequentially passes through the first electrode of the first LED chip, the spacing area between the first LED chip and the second LED chip, and the first electrode of the second LED chip; Preferably, the first circuit continues to sequentially pass through the spacing area between the second LED chip and the third LED chip and the first electrode of the third LED chip and then extends to the corresponding corner electrode.

5. A micro LED display array, characterized in that: comprising a first pixel, a second pixel and a third pixel, wherein the first pixel, the second pixel and the third pixel respectively comprise a first light emitting unit, a second light emitting unit and a third light emitting unit; The first light-emitting unit and the second light-emitting unit are respectively formed by covering the first LED chip and the second LED chip in the LED packaging unit according to any one of claims 1 to 4 with a quantum dot light conversion layer, and the third light-emitting unit maintains the light color of the third LED chip in the LED packaging unit; Preferably, the light emitting color of the first light emitting unit is red light, and the light emitting color of the second light emitting unit is green light; Preferably, the light emitting color of the third light emitting unit is blue.

6. The micro LED display array according to claim 5, characterized in that: It also includes an extraction circuit, which is used to supply power to the first light-emitting unit, the second light-emitting unit and the third light-emitting unit.

7. The method for preparing an LED packaging unit according to any one of claims 1 to 5, characterized in that: include: Providing a substrate and an LED chip array, wherein the LED chip array comprises a plurality of LED chips arranged in an array; Transferring the LED chips from the LED chip array to the substrate surface; And, the step of forming a first circuit and a second circuit on the surface of the substrate.

8. The preparation method according to claim 7, characterized in that: The LED chips in the LED chip array are backlight chips; The preparation method further comprises: A quantum dot light conversion layer is selectively coated on the surface of a portion of the backlight chip, so that the backlight chip respectively forms a first light-emitting unit, a second light-emitting unit and a third light-emitting unit with different light-emitting colors.

9. An LED chip array, used to provide LED chips for the preparation method according to any one of claims 7-8, characterized in that: A plurality of LED chips are arranged in an array and divided into a first group and a second group, wherein electrodes of the first group are arranged along a first direction, and electrodes of the second group are arranged along a second direction; The electrode direction is an extension direction from the first electrode to the second electrode of the LED chip, and the first direction is opposite to the second direction.

10. The LED chip array according to claim 9, characterized in that: The LED chips are blue backlight chips, and the ratio of the number of LED chips in the first group to that in the second group is 2:1; Preferably, the first group of LED chips is used to form a green LED and a blue LED, and the second group of LED chips is used to form a red LED.

11. The LED chip array according to claim 9, characterized in that: Specifically comprising a plurality of repeating units arranged in an array, wherein the repeating unit comprises a plurality of LED chips arranged in an array; Preferably, the LED chips in the repeating unit are arranged in n vertical columns, wherein the first column to the (ni)th column are the first group, and the (n-i+1)th column to the nth column are the second group, n and i are both integers and n is a multiple of 3 and greater than or equal to 6, 2≤i<n; Preferably, i=n / 3; Preferably, the LED chips in the repeating unit are arranged in n horizontal rows.

Images