Alignment Module and Alignment Method for Magnetic Light-Emitting Diode Chip Transfer

Abstract

The present invention discloses an alignment module for magnetic light-emitting diode die transfer and an alignment method thereof. The alignment module includes a driving backplane having at least one recess, a magnetic light-emitting diode die, and a magnetic attraction device. The magnetic attraction device is located below the recess and is arranged corresponding to the recess. The magnetic light-emitting diode die includes a magnetic metal substrate and peripheral electrodes formed on the magnetic metal substrate. The peripheral electrodes are arranged around the magnetic metal substrate and are adjacent to the inner edge thereof. The depth of the recess is designed to be equal to the thickness of the magnetic metal substrate, so as to use the recess and the magnetic attraction device to attract the magnetic light-emitting diode die to be received and aligned and transferred into the driving backplane. Through the die alignment technology of the present invention, an accurate alignment effect can be achieved, and at the same time, it meets the requirements of the industry for rapid mass transfer technology.

Description

Technical Field

[0001] The present invention relates to a technology for transferring light-emitting diode chips, and particularly to an alignment module and an alignment method suitable for mass transfer of magnetic light-emitting diode chips having better soft magnetism and initial magnetic permeability. Background Art

[0002] Due to the advantages of long lifespan, energy saving, low failure rate, stable light, high luminous efficiency, and high compatibility with various lamps of light-emitting diode (LED) chips, the luminous lifespan is longer than that of traditional light sources, and it has become a mainstream product in the current market. The chip structure can be roughly divided into two types: horizontal structure and vertical structure. Among them, the vertical-structured light-emitting diode chips can provide better reliability in terms of structural strength, optoelectronic parameters, thermal characteristics, light decay, and cost, and thus are widely used in the industry.

[0003] With the progress of technology, these light-emitting diode chips are gradually mass transferred onto various electronic devices and their substrates. Several methods for transferring chips onto substrates are disclosed in the prior art, including: surface mount technology (SMT), wafer-to-wafer transfer technology, and electrostatic transfer technology, etc. Among them, in the surface mount technology, the chips need to be individually encapsulated into SMD (Surface Mount Device) components first, and then a surface mounter (SMT) uses a vacuum suction head to individually place the SMD components on the circuit board, and then they are fixed to the substrate through a reflow oven. However, using the surface mount technology can only transfer a single chip at a time, and when a large amount of mass transfer is required in the industry, it often encounters the problem of insufficient use.

[0004] The wafer-to-wafer transfer technology is to bond the original substrate of the chip to the target substrate, and then peel off the original substrate to transfer the chip to the target substrate. However, this method has relatively strict requirements for the sizes of both the original substrate and the target substrate. At the same time, the spacing of the chips set on the substrate must also be consistent. Due to these requirements and limitations, its application is greatly restricted. As for the electrostatic transfer technology, the chips must be picked up, transferred, and then placed on the target substrate by electrostatic means. However, using this electrostatic transfer method is likely to cause damage to the chip structure, and during the transfer, it is a contact between hardware, which is also likely to damage the substrate. In addition, it is also limited by the size of the electrostatic electrode.

[0005] Furthermore, when the die is transferred onto the target substrate, even with well-trained operators or precise transfer techniques, it is very difficult to achieve completely accurate die alignment. Inaccurate die alignment will further affect the difficulty and increase the complexity of subsequent die fixing operations, and may even increase the cost and working hours of rework. Summary of the Invention

[0006] To solve the problems existing in the prior art, an object of the present invention is to provide an alignment module for magnetic light-emitting diode die transfer, which can effectively avoid many deficiencies faced by traditional technologies in die transfer. Through the die transfer alignment technology disclosed by the present invention, the working hours and costs consumed during the transfer of existing dies can be significantly saved, and it can be widely applied to mass transfer, successfully meeting the rapid and large-scale transfer requirements of the industry.

[0007] Furthermore, another object of the present invention is to provide a method for aligning magnetic light-emitting diode die transfer. By designing a magnetic metal material with better soft magnetism and initial magnetic permeability as the substrate of the die, combined with a corresponding magnetic attraction device, the light-emitting diode die can be successfully attracted into the recess of the driving backplane through the magnetic effect, achieving an optimized result of automatic alignment.

[0008] In addition, through the alignment module and alignment method for magnetic light-emitting diode die transfer disclosed by the present invention, when the die is transferred to the driving backplane and subsequent back-end soldering and wire bonding processes are carried out, the distance between the electrode and the welding material can be further shortened, reducing the use of solder and consumables.

[0009] In view of the above, according to the alignment module for magnetic light-emitting diode die transfer disclosed by the present invention, it includes: a driving backplane having at least one recess, at least one magnetic light-emitting diode die, and a magnetic attraction device. The magnetic attraction device is located below the recess and is arranged corresponding to the recess. The magnetic light-emitting diode die includes a magnetic metal substrate and peripheral electrodes formed on the magnetic metal substrate. The peripheral electrodes are arranged around the magnetic metal substrate and are adjacent to the inner edge of the magnetic metal substrate to provide electrical conduction with at least one pad on the driving backplane. According to an embodiment of the present invention, the depth of the recess is designed to be equal to the thickness of the magnetic metal substrate, so as to use the magnetic attraction of the recess and the magnetic attraction device below it to attract the magnetic light-emitting diode die to be accommodated and aligned and transferred into the driving backplane.

[0010] According to an embodiment of the present invention, the magnetic attraction device can be buried in a bottom layer of the driving backplane corresponding to the recess.

[0011] According to another embodiment of the present invention, the magnetic attraction device can also be selectively disposed outside the driving backplane.

[0012] According to an embodiment of the present invention, the depth of the recess and the thickness of the magnetic metal substrate are between 30 microns and 50 microns. The recess further has a two-dimensional plane length and a two-dimensional plane width, and the two-dimensional plane length of the recess is equal to the two-dimensional plane width, and the two-dimensional plane length and the two-dimensional plane width are between 30 microns and 100 microns.

[0013] The magnetic metal substrate also has a two-dimensional plane length and a two-dimensional plane width, and the two-dimensional plane length of the magnetic metal substrate is also designed to be equal to the two-dimensional plane width. In an embodiment of the present invention, the two-dimensional plane length and the two-dimensional plane width of the recess can be equal to the two-dimensional plane length and the two-dimensional plane width of the magnetic metal substrate, so that the magnetic metal substrate can be exactly received in the recess.

[0014] In another embodiment of the present invention, the two-dimensional plane length and the two-dimensional plane width of the recess can also be selectively greater than the two-dimensional plane length and the two-dimensional plane width of the magnetic metal substrate. In this case, when the magnetic metal substrate is transferred to the driving backplane, there will be a gap between it and the recess. This gap can be filled with a welding material during postprocess welding. Or, according to still another embodiment of the present invention, this gap can also be selectively filled with an insulating material.

[0015] The magnetic light-emitting diode die disclosed in the present invention further includes an epitaxial layer and a transparent insulating layer. The epitaxial layer is disposed on the top surface of the magnetic metal substrate, and the transparent insulating layer covers the epitaxial layer, so that the peripheral electrodes are disposed on the transparent insulating layer and penetrate through the transparent insulating layer to be electrically coupled to the epitaxial layer at the bottom of the transparent insulating layer. Therefore, when the magnetic light-emitting diode die forms a vertical light-emitting diode die through wire bonding and encapsulation, and the vertical light-emitting diode die has an initial magnetic permeability, the magnetic metal substrate can conduct a micro current to its epitaxial layer through the initial magnetic permeability.

[0016] On the other hand, at least one pad on the driving backplane includes a first semiconductor type pad and a second semiconductor type pad. The first semiconductor type pad and the second semiconductor type pad provide different conductive states and are respectively disposed on different sides of the recess. The first semiconductor type pad and the second semiconductor type pad can be electrically connected to the peripheral electrodes and the magnetic metal substrate through a welding material respectively. According to a preferred embodiment of the present invention, the distance ΔX between an outer contact on the first semiconductor type pad or the second semiconductor type pad and the peripheral electrode of the welding material is preferably controlled to be less than 10 microns.

[0017] Furthermore, according to an embodiment of the present invention, the magnetic metal substrate at least includes an Invar layer, and may optionally include a Copper layer on the Invar layer. The Invar layer and the Copper layer can also be combined by means of cutting, vacuum heating, and grinding and polishing, so that the magnetic metal substrate disclosed in the present invention can simultaneously have a high thermal conductivity, a low thermal expansion coefficient, and an initial magnetic permeability.

[0018] On the other hand, the present invention also provides an alignment method for transferring magnetic light-emitting diode chips, including: providing a driving backplane having at least one recess; arranging a magnetic attraction device below the recess, and the magnetic attraction device is arranged corresponding to the recess. Then, providing at least one magnetic light-emitting diode chip including a magnetic metal substrate and a peripheral electrode formed on the magnetic metal substrate, wherein the peripheral electrode is arranged around the magnetic metal substrate; and using the magnetic attraction of the magnetic attraction device to attract the magnetic light-emitting diode chip, so that the magnetic light-emitting diode chip is received and aligned and transferred into the recess. According to an embodiment of the present invention, the depth of the recess is designed to be equal to the thickness of the magnetic metal substrate, and the peripheral electrode is arranged adjacent to the inner edge of the magnetic metal substrate to provide electrical conduction with at least one pad on the driving backplane.

[0019] According to an embodiment of the present invention, the driving backplane can be, for example, a transparent substrate or an insulating substrate, and M such recesses are provided thereon, and the number of magnetic light-emitting diode chips provided for transfer is N, where N≥M.

[0020] In addition, the magnetic attraction device disclosed in the present invention can be selectively buried in a bottom layer of the driving backplane corresponding to the recess. Or, the magnetic attraction device can be directly arranged outside the driving backplane.

[0021] According to the specific embodiments provided by the present invention, the following technical effects are disclosed: The present invention provides an alignment module for transferring magnetic light-emitting diode chips, which can effectively avoid many deficiencies faced by traditional technologies in transferring chips. Through the alignment technology for transferring chips disclosed in the present invention, the working hours and costs consumed during the transfer of existing chips can be greatly saved, and it can be widely applied to mass transfer, successfully meeting the requirements of the industry for rapid and large-scale transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1A Schematic diagram of the alignment module for magnetic light-emitting diode die transfer according to a first embodiment of the present invention;

[0024] Figure 1B Schematic diagram of the alignment module for magnetic light-emitting diode die transfer according to a second embodiment of the present invention;

[0025] Figure 2 Schematic diagram of the step flow of the alignment method for magnetic light-emitting diode die transfer according to an embodiment of the present invention;

[0026] Figure 3 Top view of the driving backplane disclosed according to an embodiment of the present invention;

[0027] Figure 4 Top view of the magnetic light-emitting diode die disclosed according to an embodiment of the present invention;

[0028] Figure 5A For Figure 1A Cross-sectional schematic diagram of the alignment module after die transfer is completed;

[0029] Figure 5B For Figure 1B Cross-sectional schematic diagram of the alignment module after die transfer is completed;

[0030] Figure 5C Top view of the alignment module after die transfer is completed as disclosed according to an embodiment of the present invention;

[0031] Figure 6A For Figure 1A Schematic diagram of the alignment module after die transfer is completed and the back-end wire bonding process is performed;

[0032] Figure 6B For Figure 1B Schematic diagram of the alignment module after die transfer is completed and the back-end wire bonding process is performed;

[0033] Figure 7 Schematic diagram of the alignment module for magnetic light-emitting diode die transfer according to another embodiment of the present invention;

[0034] Figure 8 For Figure 7 Top view of the driving backplane disclosed according to the embodiment;

[0035] Figure 9 is the top view of the magnetic light-emitting diode die disclosed according to Figure 7 the embodiment;

[0036] Figure 10A is the schematic cross-sectional view after the die transfer is completed by the alignment module according to Figure 7 ;

[0037] Figure 10B is the top view after the die transfer is completed by the alignment module according to Figure 7 ;

[0038] Figure 11 is the schematic diagram of the alignment module completing the die transfer and performing the back-end wire bonding process according to Figure 7 ;

[0039] Symbol description:

[0040] Steps S202, S204, S206, S208..., two-dimensional plane lengths L1, L1', L2, L2'..., two-dimensional plane widths W1, W1', W2, W2'..., depth D1, thickness T1, driving backplane 10, driving backplane 10A, recess 12, recess 12A, magnetic attraction device 14, magnetic light-emitting diode die 20, magnetic light-emitting diode die 20A, magnetic metal substrate 101, magnetic metal substrate 101A, epitaxial layer 102, peripheral electrode 103, transparent insulating layer 104, first semiconductor type pad 31, second semiconductor type pad 32, transparent conductive wire 33, welding material 60, electrical insulating layer 62, gap 70, outer contact P1, distance ΔX. Detailed implementation manners

[0041] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0042] The above description of the content of the present invention, together with the following embodiments, is used to demonstrate and explain the spirit and principle of the present invention, and to provide a further explanation of the patent application scope of the present invention. The features, implementations and effects of the present invention will be described in detail in the following preferred embodiments in conjunction with the drawings.

[0043] In view of the various deficiencies elucidated in the aforementioned prior art, the present invention aims to provide an improved die transfer technology. Through the die transfer technology disclosed in the present invention, an accurate die alignment effect can be achieved, while meeting the requirements of the industry for rapid mass transfer.

[0044] First, please refer to the present invention Figure 1A and Figure 1B as shown, which is a schematic diagram of an alignment module for magnetic light-emitting diode die transfer according to a first embodiment and a second embodiment of the present invention. Figure 2 It is a schematic flow chart of the steps of an alignment method for transferring magnetic light-emitting diode dies disclosed in the present invention. Among them, the alignment method disclosed in the present invention includes step S202, step S204, step S206, and step S208. The following relevant descriptions of the alignment module and its alignment method for die transfer disclosed in the present invention are also referred to Figures 1A to 1B the shown structure and its component symbols, and in conjunction with Figure 2 the disclosed steps S202 - S208, the present invention provides a detailed description as follows.

[0045] As shown in step S202, the present invention provides a driving backplane 10, and the driving backplane 10 can be, for example, a transparent substrate or an insulating substrate. Figure 3 It is a top view of the driving backplane 10 disclosed according to an embodiment of the present invention. As Figures 1A to 1B and Figure 3 shown, at least one pad is provided on the driving backplane 10, including a first semiconductor-type pad 31 and a second semiconductor-type pad 32. At least one cavity 12 is provided in the driving backplane 10.

[0046] After that, as shown in step S204, the present invention then provides a magnetic attraction device 14 below the cavity 12, and this magnetic attraction device 14 is provided corresponding to the position of the cavity 12. According to the first embodiment of the present invention, as Figure 1A shown, then this magnetic attraction device 14 can be, for example, buried in a bottom layer of the driving backplane 10 corresponding to the cavity 12. Or, according to the second embodiment of the present invention, as Figure 1B shown, the magnetic attraction device 14 can also be provided outside the driving backplane 10, so that an external mechanism can provide an adsorption ability of a remote force through the magnetic attraction device 14 established outside.

[0047] Among them, according to the embodiment of the present invention, the magnetic attraction device 14 can include, for example, at least one set of electromagnetic coils wound around a magnetic ring (Ferrite Core) and its circuit formed together. By Figure 3As can be seen from the top view, the recessed portion 12 has a two-dimensional plane length L1 and a two-dimensional plane width W1. Among them, the two-dimensional plane length L1 and the two-dimensional plane width W1 are of equal length, and both the two-dimensional plane length L1 and the two-dimensional plane width W1 are between 30 micrometers (μm) and 100 micrometers.

[0048] The first semiconductor type pad 31 and the second semiconductor type pad 32 are respectively disposed on different sides of the recessed portion 12 and provide different conduction states. In an embodiment of the present invention, the first semiconductor type pad 31 may be, for example, an N-type semiconductor pad (N-type pad), and the second semiconductor type pad 32 may be, for example, a P-type semiconductor pad (P-type pad). The first semiconductor type pad 31 and the second semiconductor type pad 32 are respectively connected to a plurality of transparent conductive wires 33, and the material thereof may be, for example, indium tin oxide (Indium Tin Oxide, ITO) or silver nanowire (Silver Nanowire), to provide signal input and output.

[0049] Next, please refer to Figure 2 As shown in step S206 of Figure 1A and Figure 1B As shown, such a magnetic light-emitting diode die 20 includes a magnetic metal substrate 101 and a peripheral electrode 103 formed on the magnetic metal substrate 101. Among them, the magnetic metal substrate 101 used in the present invention is an innovative substrate material, which at least includes a nickel-iron alloy layer, so that the magnetic metal substrate 101 can have better soft magnetic properties and initial magnetic permeability compared with traditional substrates. Secondly, the magnetic metal substrate 101 may also selectively include a copper layer on the nickel-iron alloy layer for subsequent signal measurement. Based on the nickel-iron alloy layer and the copper layer disclosed in the present invention, they can be combined by cutting, vacuum heating and grinding and polishing, so that the formed magnetic metal substrate 101 not only has an initial magnetic permeability, but also has a high thermal conductivity coefficient and a low thermal expansion coefficient. In the subsequent wire bonding packaging process, it can provide a better production yield. Compared with other known metal substrates, such a magnetic metal substrate 101 has a lower cost and is thin enough, and can provide a new substrate option with excellent low thermal expansion coefficient, high thermal conductivity coefficient, low cost, high yield and easy bonding without additional thinning process.

[0050] Figure 4FIG. 0 is a top view of the magnetic light-emitting diode die 20 disclosed according to an embodiment of the present invention. It can be seen that the magnetic metal substrate 101 also has a two-dimensional plane length L2 and a two-dimensional plane width W2, wherein the two-dimensional plane length L2 is equal to the two-dimensional plane width W2. Please refer to Figures 1A to 1B and Figure 4 shown. It can be clearly seen that the peripheral electrode 103 provided on this magnetic light-emitting diode die 20 is disposed around the magnetic metal substrate 101 and is adjacent to the inner edge of the magnetic metal substrate 101. The peripheral electrode 103 is looped on the magnetic metal substrate 101 in a closed and symmetric pattern, and its electrode pattern can be, for example, a symmetric square or circle. The present invention discloses Figure 4 taking a square as an illustrative example, but the present invention is not limited thereto. An epitaxial layer 102 and a transparent insulating layer 104 are disposed between the magnetic metal substrate 101 and the peripheral electrode 103. The epitaxial layer 102 is formed on the top surface of the magnetic metal substrate 101, and the transparent insulating layer 104 covers the epitaxial layer 102. The peripheral electrode 103 is disposed on the transparent insulating layer 104 and penetrates through the transparent insulating layer 104 to be electrically coupled to the epitaxial layer 102 under the transparent insulating layer 104.

[0051] It should be noted that, please refer to Figures 1A to 1B shown. In the present invention, it is designed that a depth D1 of the recess 12 on the driving backplane 10 is equal to the thickness T1 of the magnetic metal substrate 101, such that D1 = T1, and both the depth D1 of the recess 12 and the thickness T1 of the magnetic metal substrate 101 are between 30 micrometers and 50 micrometers, which conforms to the current trend of miniaturization of light-emitting elements in the industry.

[0052] In this way, please refer to Figure 2 shown in step S208. The present invention can use the magnetic attraction of the magnetic attraction device 14 located below the recess 12 to attract the magnetic light-emitting diode die 20, so that the magnetic light-emitting diode die 20 is received and aligned and transferred to the corresponding recess 12. A schematic diagram after the transfer is completed, Figures 5A to 5C shown, wherein, Figure 5A and Figure 5B are respectively cross-sectional views of the alignment module disclosed in the present invention Figure 1A and Figure 1B after the die transfer is completed, Figure 5C and FIG. 28 is a top view thereof. It can be clearly seen from these figures that in the technical solution disclosed in the present invention, when the present invention designs D1 = T1, L1 = W1 = L2 = W2 through precise dimensional considerations, the size of the magnetic metal substrate 101 of the magnetic light-emitting diode die 20 can just fit tightly with its corresponding recess 12 after being transferred to the driving backplane 10.

[0053] Afterwards, as shown in Figure 6A and Figure 6B , the module after grain transfer completed by the alignment method disclosed in the first and second embodiments of the present invention can further perform the subsequent backend process of postbonding, so that the peripheral electrode 103 is electrically connected to the first and second semiconductor type pads 31 and 32 on the driving backplane 10.

[0054] Among them, the first semiconductor type pad 31 and the second semiconductor type pad 32 are each electrically connected to the peripheral electrode 103 of the magnetic light-emitting diode grain 20 and the magnetic metal substrate 101 through a welding material (solder) 60. At the same time, to avoid signal short-circuit, an electrically insulating layer 62 is disposed between the first semiconductor type pad 31, the welding material 60, the peripheral electrode 103 and the transparent insulating layer 104 at its bottom. According to an embodiment of the present invention, the welding material 60 may be, for example, solder paste or solder balls of solder, but the present invention is not limited thereto, and the selection of the welding material 60 can be adjusted according to the actual requirements of the subsequent backend process.

[0055] At this time, the magnetic light-emitting diode grain 20 forms a vertical light-emitting diode grain through wire bonding and encapsulation, so that the vertical light-emitting diode grain can have the initial magnetic permeability of the magnetic metal substrate 101, and the magnetic metal substrate 101 can conduct a micro current through its initial magnetic permeability to the previous epitaxial layer 102 to form a micro light-emitting diode (Micro LED). Afterwards, the manufactured micro light-emitting diodes can be further integrated into a high-density and small-size light-emitting diode array on the wafer, so that each pixel therein can be effectively addressed and individually driven to emit light. In addition, as shown in Figure 6B , after the vertical light-emitting diode grain structure formed by the present invention is assembled into a diode module, it can further achieve a new application of mass transfer by the adsorption ability of the long-range force of a magnetic attraction device 14 (such as an electromagnetic coil) of an external mechanism, so as to fully meet the mass transfer application requirements of the light-emitting diode module.

[0056] It should be noted that, according to a preferred embodiment of the present invention, as shown in Figures 6A to 6BAs shown, a distance ΔX exists between an outer contact point P1 on the first semiconductor type pad 31 where the welding material 60 is located and the peripheral electrode 103. Since the upper electrode in the prior art is usually disposed in the exact middle of the entire die structure, when subsequent welding is performed, the solder distance between its upper electrode and the connecting pad is too long. To solve this problem, the present invention designs the position of the peripheral electrode 103 such that it is symmetrically and circumferentially disposed on the magnetic metal substrate 101 and is adjacent to the inner edge of the magnetic metal substrate 101, effectively controlling and reducing the distance ΔX. Preferably, the distance ΔX can be made less than 10 micrometers. Through the design of the present invention, the use of solder can be effectively reduced and the solder distance can be shortened. Similarly, the inventive concept of shortening the distance ΔX can also be applied to one side of the second semiconductor type pad 32. Those of ordinary skill in the art can make modifications according to their actual implementation aspects under the inspiration of the technical solutions taught by the present invention, and all fall within the scope of the present invention.

[0057] Specifically, further, to meet the requirements of the industry for mass transfer, the alignment module and alignment method for magnetic light-emitting diode die transfer disclosed in the present invention can be further applied to a plurality of die to be transferred. In this case, M of the recesses 12 can be provided on the driving backplane 10, and N magnetic light-emitting diode die 20 to be transferred are provided, such that N≧M. Whether additionally through a vibration mechanism or directly combined with a vibrating magnetic platform, the present invention can magnetically attract and vibrate the N die to be transferred through the magnetic attraction of the magnetic attraction device, and successfully align and transfer them into the corresponding recesses of the driving backplane.

[0058] On the other hand, the present invention further provides another embodiment for the dimensional relationship between the magnetic metal substrate 101 and its corresponding recess 12, as shown in the present invention Figure 7 As shown, in this other embodiment, a magnetic light-emitting diode die 20A is aligned and transferred into a recess 12A of the driving backplane 10A. It can be seen that the size of the magnetic metal substrate 101A of this magnetic light-emitting diode die 20A can also be slightly smaller than the size of its corresponding recess 12A, but the depth D1 of the recess 12A still remains equal to the thickness T1 of the magnetic metal substrate 101A, such that D1=T1, and both are between 30 micrometers and 50 micrometers.

[0059] Among them, the installation position of the magnetic attraction device 14 is as in the foregoing Figure 1A embodiment of the present invention and Figure 1BAs shown in the embodiments, those skilled in the art with ordinary knowledge can choose to embed the magnetic attraction device 14 in a bottom layer of the driving backplane 10A or set the magnetic attraction device 14 outside the driving backplane 10A according to their own needs and specifications. Here, for the technical content of the embodiments of the relatively small-sized magnetic metal substrate 101A of the present invention, the following takes the example of embedding the magnetic attraction device 14 in the bottom layer of the driving backplane 10A for illustration, as Figure 7 shown, but this technical content can also be applied to the case where the magnetic attraction device 14 is set outside the driving backplane 10A, which will not be elaborated in the present invention.

[0060] Please refer to Figure 8 and Figure 9 , which are respectively the top views of the driving backplane 10A and the magnetic light-emitting diode die 20A according to the embodiments of the present invention. It can be clearly seen from these figures that in another embodiment here, the recess 12A also has its two-dimensional plane length L1' and two-dimensional plane width W1', where L1' = W1', and both are between 30 micrometers and 100 micrometers. The magnetic metal substrate 101A also has its two-dimensional plane length L2' and two-dimensional plane width W2', where L2' = W2'. Different from the foregoing Figure 1A and Figures 1B to 6A and Figure 6B embodiments, in this embodiment, the two-dimensional plane length L1' and two-dimensional plane width W1' of the recess 12A are greater than the two-dimensional plane length L2' and two-dimensional plane width W2' of the magnetic metal substrate 101A, so that L1' > L2' and W1' > W2'. Under this condition, after the magnetic light-emitting diode die 20A is transferred to the driving backplane 10A, there will be a gap 70 between its magnetic metal substrate 101A and the recess 12A, as Figure 10A and Figure 10B shown.

[0061] After that, Figure 11 is a schematic diagram of the module after die transfer completed according to this embodiment of the present invention, which further shows the back-end processes such as wire bonding through the welding material 60. Regarding the connection relationships of the peripheral electrodes, the magnetic metal substrate, and the pads on the driving backplane, these technical features are basically the same as those in the foregoing embodiments ( Figures 6A to 6B ), so they will not be repeated here. Different from the foregoing embodiments, in the embodiments of the present invention Figure 11 , at this time, the gap 70 formed between the magnetic metal substrate 101A and the recess 12A can be filled with the welding material 60; or alternatively, the gap 70 formed between the magnetic metal substrate 101A and the recess 12A can also be filled with an insulating material. At the same time, in Figure 11In the embodiments, the minimization of the distance ΔX can also be achieved by improving the position of the peripheral electrode 103, making ΔX preferably less than 10 microns, effectively reducing the use of solder and shortening the soldering distance.

[0062] Therefore, in summary, according to several embodiments disclosed in the present invention and the technical ideas taught thereby, those with ordinary knowledge in the art can change their designs on the actual implementation level by themselves, and all fall within the scope of the present invention. The several examples listed in the foregoing paragraphs of the present invention are for the purpose of properly explaining the main technical features of the present invention so that those skilled in the art can understand and implement them accordingly. However, the present invention should not be limited to these examples.

[0063] Therefore, in view of the above, it can be clearly seen that the present invention discloses an alignment module and an alignment method for magnetic light-emitting diode die transfer. By improving the substrate structure and material of the original die, it has better soft magnetism and initial magnetic permeability, so that the light-emitting diode die itself can be used as a magnetic conduction structure. When corresponding recesses and magnetic attraction devices are designed in the driving backplane to be transferred, the principle of magnetic adsorption can be used to effectively suck the light-emitting diode die with soft magnetism, achieving the effect of fast and accurate transfer. At the same time, under the condition of a large number of additional recesses, the mass transfer technology can be further implemented to meet the current requirements of micro light-emitting diodes for fast and massive die transfer, effectively enhancing the competitiveness of its industrial production.

[0064] Furthermore, another effect of the present invention also includes: the miniaturization of the soldering distance can be achieved by improving the position of its upper electrode (i.e., the peripheral electrode), making the soldering distance preferably less than 10 microns, effectively reducing the use of solder and shortening the soldering distance. It can be seen from this that the technical solution disclosed in the present invention indeed has excellent industrial applicability and competitiveness. At the same time, it is verified that the technical features, methods and achieved effects disclosed in the present invention are significantly different from the current solutions and are not easily completed by those familiar with this technology.

[0065] The above-described embodiments are only for explaining the technical ideas and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It should not be used to limit the patent scope of the present invention. That is, all equivalent changes or modifications made in accordance with the spirit disclosed in the present invention should still be covered within the patent scope of the present invention.

[0066] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0067] In this article, specific examples are used to elaborate on the principles and implementation modes of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. At the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation modes and application scopes. To sum up, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. An alignment module for magnetic light-emitting diode die transfer, characterized in that The alignment module for the magnetic light-emitting diode die transfer includes: A driving backplane having at least one recess; A magnetic attraction device located below the recess and disposed corresponding to the recess; and At least one magnetic light-emitting diode die, including a magnetic metal substrate and a peripheral electrode formed on the magnetic metal substrate. The peripheral electrode is disposed around the magnetic metal substrate and adjacent to the inner edge of the magnetic metal substrate to provide electrical conduction with at least one pad on the driving backplane. Wherein, a depth of the recess is equal to a thickness of the magnetic metal substrate, and the magnetic attraction device is embedded in a bottom layer of the driving backplane corresponding to the recess, or the magnetic attraction device is disposed outside the driving backplane to use the magnetism of the recess and the magnetic attraction device to attract the magnetic light-emitting diode die to be received and aligned and transferred into the driving backplane.

2. The alignment module for magnetic light-emitting diode die transfer according to claim 1, wherein The depth of the recess and the thickness of the magnetic metal substrate are between 30 microns and 50 microns.

3. The alignment module for magnetic light-emitting diode die transfer according to claim 1, wherein The magnetic light-emitting diode die further includes an epitaxial layer and a transparent insulating layer. The epitaxial layer is disposed on a top surface of the magnetic metal substrate, the transparent insulating layer covers the epitaxial layer, and the peripheral electrode is disposed on the transparent insulating layer and penetrates the transparent insulating layer to be electrically coupled to the epitaxial layer at the bottom of the transparent insulating layer. The magnetic light-emitting diode die is a vertical light-emitting diode die, so that the vertical light-emitting diode die has an initial magnetic permeability, and the magnetic metal substrate can conduct a micro current to the epitaxial layer through the initial magnetic permeability.

4. The alignment module for magnetic light-emitting diode die transfer according to claim 1, wherein The at least one pad on the driving backplane includes a first semiconductor-type pad and a second semiconductor-type pad. The first semiconductor-type pad and the second semiconductor-type pad provide different conduction types and are respectively disposed on different sides of the recess.

5. The alignment module for magnetic light-emitting diode die transfer according to claim 4, wherein The first semiconductor-type pad and the second semiconductor-type pad are respectively electrically connected to the peripheral electrode and the magnetic metal substrate through a welding material, and there is a distance between an outer contact on the first semiconductor-type pad or the second semiconductor-type pad and the peripheral electrode, and the distance is less than 10 microns. And an electrical insulating layer is disposed between the at least one pad, the welding material, the peripheral electrode and a transparent insulating layer at the bottom thereof.

6. The alignment module for magnetic light-emitting diode die transfer according to claim 1, wherein The recess and the magnetic metal substrate each have a two-dimensional plane length and a two-dimensional plane width. The two-dimensional plane length and the two-dimensional plane width of the recess are equal, the two-dimensional plane length and the two-dimensional plane width of the magnetic metal substrate are equal, and the two-dimensional plane length and the two-dimensional plane width of the recess are greater than the two-dimensional plane length and the two-dimensional plane width of the magnetic metal substrate, so that there is a gap between the magnetic metal substrate after transfer and the recess, and the gap is filled with a welding material or an insulating material.

7. The alignment module for magnetic light-emitting diode die transfer according to claim 1, wherein The driving backplane is a transparent substrate or an insulating substrate.

8. The alignment module for magnetic light-emitting diode die transfer according to claim 1, wherein There are M recesses on the driving backplane, and the number of magnetic light-emitting diode dies to be transferred is N, and N≧M.

9. The alignment module for magnetic light-emitting diode die transfer according to claim 1, wherein The magnetic metal substrate at least includes a nickel-iron alloy layer.

10. The alignment module for magnetic light-emitting diode die transfer according to claim 1, wherein The magnetic metal substrate includes a nickel-iron alloy layer and a copper layer located on the nickel-iron alloy layer.

11. An alignment method for magnetic light-emitting diode die transfer, characterized in that The alignment method for transferring the magnetic light-emitting diode die includes: providing a driving backplane having at least one recess; arranging a magnetic attraction device below the recess, the magnetic attraction device being buried in a bottom layer of the driving backplane corresponding to the recess, or the magnetic attraction device being arranged outside the driving backplane, and the magnetic attraction device being arranged corresponding to the recess; providing at least one magnetic light-emitting diode die, including a magnetic metal substrate and a peripheral electrode formed on the magnetic metal substrate, the peripheral electrode being arranged to surround the magnetic metal substrate; and using the magnetism of the magnetic attraction device to attract the at least one magnetic light-emitting diode die, so that one of the magnetic light-emitting diode dies is received and aligned and transferred into one of the recesses, wherein a depth of the recess is equal to a thickness of the magnetic metal substrate, and the peripheral electrode is disposed adjacent to an inner edge of the magnetic metal substrate to provide electrical conduction with at least one pad on the driving backplane.

12. The alignment method for magnetic light-emitting diode die transfer according to claim 11, wherein The depth of the recess and the thickness of the magnetic metal substrate are between 30 microns and 50 microns.

13. The alignment method for magnetic light-emitting diode die transfer according to claim 11, wherein The recess and the magnetic metal substrate each further have a two-dimensional plane length and a two-dimensional plane width, the two-dimensional plane length and the two-dimensional plane width of the recess are equal, the two-dimensional plane length and the two-dimensional plane width of the magnetic metal substrate are equal, and the two-dimensional plane length and the two-dimensional plane width of the recess are greater than the two-dimensional plane length and the two-dimensional plane width of the magnetic metal substrate, so that there is a gap between the magnetic metal substrate after transfer and the recess, and the gap is filled with a welding material or an insulating material.

14. The alignment method for magnetic light-emitting diode die transfer according to claim 11, wherein There are M such recesses on the driving backplane, and the number of magnetic light-emitting diode dies provided for transfer is N, and N≧M.

15. The alignment method for magnetic light-emitting diode die transfer according to claim 11, characterized in that, The magnetic metal substrate at least includes a nickel-iron alloy layer.

16. The alignment method for magnetic light-emitting diode die transfer according to claim 11, characterized in that, The magnetic metal substrate includes a nickel-iron alloy layer and a copper layer located on the nickel-iron alloy layer.

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