Electric field induced three-dimensional core particle assembly method and three-dimensional core particle assembly structure

Abstract

The invention provides an electric field induced three-dimensional core particle assembly method and a three-dimensional core particle assembly structure, and relates to the technical field of semiconductors, and the method comprises the steps: placing a first layer of core particles on a substrate in a fluid environment, and enabling the first surfaces of the first layer of core particles to be in contact with the upper surface of the substrate; applying voltage to the assembly electrodes of the substrate to guide the first layer of core particles to move by using the generated electric field force, so that the alignment electrodes of the first layer of core particles are aligned with the assembly electrodes of the substrate one by one; placing the second layer of core particles on the first layer of core particles so that the second surfaces of the first layer of core particles are in contact with the first surfaces of the second layer of core particles; applying voltage to the assembly electrodes of the substrate so as to guide the second-layer core particles to move by utilizing generated electric field force, so that the alignment electrodes on the first surfaces of the second-layer core particles are aligned with the alignment electrodes on the second surfaces of the first-layer core particles one by one; and repeating the steps on the second surface of the second layer of core particles, and assembling the multi-layer core particles to obtain the three-dimensional core particle assembly structure.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of semiconductor technology, and in particular to an electric field-induced three-dimensional core particle assembly method and a three-dimensional core particle assembly structure. Background Art

[0002] As a cutting-edge field in the semiconductor industry, three-dimensional chiplet integration technology allows multiple high-performance chips or chiplets to be stacked and interconnected in the vertical direction to form complex integrated circuits, making the interconnections between chips or chiplets closer, shortening the signal transmission path, and achieving higher integration and better performance. It breaks through the limitations of traditional two-dimensional integration technology and is of great significance to promoting technological progress in fields such as high-performance computing, artificial intelligence and mobile devices.

[0003] However, the existing core particle assembly technology is usually used to realize the assembly of single-layer core particles in two-dimensional circuits, and is not completely applicable to three-dimensional core particle integration. Therefore, it is necessary to provide an electric field-induced three-dimensional core particle assembly method and a three-dimensional core particle assembly structure to achieve accurate and efficient three-dimensional core particle assembly. Summary of the invention

[0004] The embodiments of the present application provide an electric field-induced three-dimensional core particle assembly method and a three-dimensional core particle assembly structure, aiming to solve the problem of how to achieve accurate and efficient three-dimensional core particle assembly.

[0005] A first aspect of an embodiment of the present application provides an electric field induced three-dimensional core particle assembly method, the method comprising: In a fluid environment, placing a first layer of core particles on a substrate so that a first surface of the first layer of core particles contacts an upper surface of the substrate; wherein one or more alignment electrodes are respectively disposed on the first surface and the second surface of the first layer of core particles, and one or more assembly electrodes are disposed on the upper surface of the substrate; Applying voltage to the assembly electrodes of the substrate to guide the movement of the first layer of core particles by using the generated electric field force, so that the alignment electrodes on the first surface of the first layer of core particles are aligned one by one with the assembly electrodes of the substrate; Placing a second layer of core particles on the first layer of core particles so that the second surface of the first layer of core particles contacts the first surface of the second layer of core particles; wherein one or more alignment electrodes are respectively disposed on the first surface and the second surface of the second layer of core particles; Applying voltage to the assembly electrodes of the substrate to guide the movement of the second layer core particles by using the generated electric field force, so that the alignment electrodes on the first surface of the second layer core particles are aligned one by one with the alignment electrodes on the second surface of the first layer core particles; On the second surface of the second layer of core particles, multiple levels of core particles are assembled by repeating the above steps to obtain a three-dimensional core particle assembly structure.

[0006] In a possible implementation, a coating layer is disposed on the second surface of each layer of core particles; after the alignment electrodes on the first surface of the n-th layer of core particles are aligned one by one with the alignment electrodes on the second surface of the n-1-th layer of core particles, the method further includes: The coating layer on the second surface of the n-th layer of core particles is removed by wet etching or dry etching.

[0007] In a possible implementation manner, the alignment electrodes on the first surface or the second surface of each layer of core particles are not connected to each other.

[0008] In a possible implementation, the alignment electrodes on the first surface of each layer of core particles correspond one to one with the alignment electrodes on the second surface, and are connected through sidewall wiring or through holes.

[0009] In a possible implementation, the fluid environment is prepared by any one of the following fluid materials: deionized water, ethanol, acetone, and developer.

[0010] In a possible implementation manner, the material of the coating layer is any one of the following: silicon oxide, polyparaxylene, photoresist, and silicon.

[0011] In a possible implementation manner, the voltage applied to the assembly electrode of the substrate is alternating current, and the AC signal amplitude of the alternating current is within 60 Vpp and the frequency is within 1 k-1 MHz.

[0012] In a possible implementation manner, the electrode shape of the alignment electrode on the first surface of each layer of core particles is different from the electrode shape of the alignment electrode on the second surface.

[0013] In a possible implementation, the distance between any two alignment electrodes on the first surface or the second surface of each layer of core particles is 5-50 microns.

[0014] The second aspect of the embodiments of the present application provides a three-dimensional core particle assembly structure, which is prepared by the electric field induced three-dimensional core particle assembly method described in the first aspect of the embodiments of the present application; the three-dimensional core particle assembly structure includes multiple layers of stacked core particles, and each pair of core particles in adjacent layers are aligned by assembly electrodes on their respective surfaces.

[0015] The third aspect of the embodiments of the present application also provides an electronic device, including a memory, a processor and a computer program stored on the memory, wherein the processor executes the computer program to implement the steps in the electric field induced three-dimensional core particle assembly method described in the first aspect of the embodiments of the present application.

[0016] The fourth aspect of the embodiments of the present application further provides a computer-readable storage medium on which a computer program / instruction is stored. When the computer program / instruction is executed by a processor, the steps in the electric field induced three-dimensional core particle assembly method described in the first aspect of the embodiments of the present application are implemented.

[0017] The fifth aspect of the embodiments of the present application also provides a computer program product. When the computer program product is run on an electronic device, the processor is enabled to implement the steps in the electric field induced three-dimensional core particle assembly method as described in the first aspect of the embodiments of the present application.

[0018] An electric field-induced three-dimensional core particle assembly method proposed in an embodiment of the present application comprises: placing a first layer of core particles on a substrate in a fluid environment so that the first surface of the first layer of core particles contacts the upper surface of the substrate; wherein one or more alignment electrodes are respectively arranged on the first surface and the second surface of the first layer of core particles, and one or more assembly electrodes are arranged on the upper surface of the substrate; applying voltage to the assembly electrodes of the substrate to guide the movement of the first layer of core particles by utilizing the generated electric field force, so that the alignment electrodes on the first surface of the first layer of core particles are aligned one by one with the assembly electrodes of the substrate; placing a second layer of core particles on the first layer of core particles so that the second surface of the first layer of core particles contacts the first surface of the second layer of core particles; wherein one or more alignment electrodes are respectively arranged on the first surface and the second surface of the second layer of core particles; applying voltage to the assembly electrodes of the substrate to guide the movement of the second layer of core particles by utilizing the generated electric field force, so that the alignment electrodes on the first surface of the second layer of core particles are aligned one by one with the alignment electrodes on the second surface of the first layer of core particles; on the second surface of the second layer of core particles, by repeating the above steps, multi-level core particles are assembled to obtain a three-dimensional core particle assembly structure.

[0019] The specific beneficial effects are as follows: the embodiment of the present application sets assembly electrodes on the substrate, and sets alignment electrodes on the upper and lower surfaces of the core particles. By applying voltage to the assembly electrodes of the substrate, an electric field is generated, and the dielectrophoretic force is used to move the first layer of core particles placed on the substrate to an area with higher or lower electric field strength, thereby moving to the target position (the position corresponding to the assembly electrode of the substrate), so that the assembly electrode contacts the alignment electrode, and the assembly of the first layer of core particles is completed. Then, according to the same steps, the dielectrophoretic force is used to move the core particles, so that the core particles of adjacent layers are aligned with each other through the alignment electrodes, and the assembly of multi-level core particles is realized. The embodiment of the present application uses the dielectrophoretic force to move the core particles to the position required for assembly, and realizes the stacking and interconnection of multiple core particles in the vertical direction to achieve higher integration and better performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0021] Figure 1 It is a flowchart of the steps of an electric field induced three-dimensional core particle assembly method proposed in one embodiment of the present application; Figure 2 It is a schematic diagram of the structure of a core particle proposed in one embodiment of the present application; Figure 3 This is a schematic diagram of an assembly structure of a first layer of core particles and a substrate proposed in an embodiment of the present application; Figure 4 It is a schematic diagram of an assembly structure of a second layer core particle and a first layer core particle proposed in an embodiment of the present application; Figure 5 is a schematic diagram of a three-dimensional core particle assembly structure proposed in one embodiment of the present application; Figure 6 It is a structural schematic diagram of an electronic device proposed in one embodiment of the present application; Description of reference numerals: 100, first layer core particles; 101, alignment electrode; 102, through hole; 200, substrate; 201, assembly electrode; 300, second layer core particles. DETAILED DESCRIPTION

[0022] The exemplary embodiments of the present application will be described in more detail below in conjunction with the accompanying drawings in the embodiments of the present application. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present application and to enable the scope of the present application to be fully communicated to those skilled in the art.

[0023] Chiplet technology is an innovative technology that has emerged in the semiconductor industry in recent years. It allows multiple small chips with specific functions to be integrated into a larger system through advanced packaging technology, thereby achieving higher performance, lower costs and faster development cycles. The emergence of this technology is mainly to meet the challenges brought about by the slowdown of Moore's Law, that is, as semiconductor process technology continues to approach physical limits, the method of simply relying on reducing the size of transistors to improve performance has become increasingly difficult and expensive.

[0024] Common technologies used for three-dimensional chip interconnection are: 1) Through Silicon Via (TSV): Through Silicon Via is a conductive hole that runs vertically through the chip, which allows electrical connections between chips at different levels. TSV technology can provide higher integration density and versatility, but the process steps are complex, which may lead to low packaging yield and high cost. 2) 2.5D packaging technology: 2.5D packaging technology uses an interposer (such as a silicon interposer or an organic interposer) to achieve interconnection between chips. Microbumps or solder joints are arranged on the interposer to connect different chips, providing higher interconnection density and electrical performance. 3) 3D packaging technology: 3D packaging technology further compresses the bump density and directly connects through silicon vias on the wafer. This technology can achieve thinner chip stacking, reduce signal parasitic effects, and improve system performance. 4) Inductive coupling technology: Inductive coupling technology uses the induction principle of electromagnetic fields to achieve contactless communication between chips. This technology can avoid the use of TSV, reduce process complexity and cost, and is suitable for short-distance high-speed communication.

[0025] As an innovative breakthrough in the semiconductor industry, chiplet technology is rapidly becoming a key technology to meet the challenges of the slowdown of Moore's Law. Against the backdrop of the diminishing economic benefits of Moore's Law, traditional system-on-chip (SoC) faces a sharp rise in design and manufacturing costs. Chiplet technology can effectively reduce costs and improve chip yield and performance by independently manufacturing small chips with different functions and then integrating them. The significance of chiplet technology lies in that it not only improves the performance and flexibility of semiconductor products, but also brings new innovation momentum to the entire industry, promotes the rapid iteration and customized development of technology to adapt to the ever-changing market needs, especially in cutting-edge fields such as high-performance computing, artificial intelligence, and 5G, showing great application potential.

[0026] As a cutting-edge field in the semiconductor industry, 3D chiplet integration technology is developing rapidly to cope with the limitations of traditional 2D integration technology. It allows multiple chips or chips to be stacked and interconnected in the vertical direction to form complex integrated circuits, achieve higher integration and better performance, and is of great significance to promoting technological progress in high-performance computing, artificial intelligence, and mobile devices. 3D chiplet integration technology can make the interconnection between chips closer, shorten the signal transmission path, and thus improve the performance of the overall system. It is of great significance to improve chip performance, increase integration, reduce power consumption, and reduce size.

[0027] However, existing chiplet assembly technology is usually used to realize the assembly of single-layer chiplets in two-dimensional circuits and is not fully applicable to three-dimensional chiplet integration.

[0028] Therefore, it is necessary to provide an electric field-induced three-dimensional core particle assembly method and a three-dimensional core particle assembly structure to achieve accurate and efficient three-dimensional core particle assembly.

[0029] In view of the above problems, the embodiments of the present application propose an electric field induced three-dimensional core particle assembly method and a three-dimensional core particle assembly structure to achieve accurate and efficient three-dimensional core particle assembly. In combination with the accompanying drawings, the electric field induced three-dimensional core particle assembly method and a three-dimensional core particle assembly structure provided by the embodiments of the present application are described in detail through some embodiments and their application scenarios.

[0030] In a first aspect, an electric field-induced three-dimensional core particle assembly method is proposed. Figure 1 A flow chart of the steps of a method for assembling three-dimensional core particles induced by electric field is shown. In order to enable those skilled in the art to better understand the preparation method of the present application, the following is combined with Figure 1 A three-dimensional core particle assembly method induced by electric field provided in this application is described in detail. Figure 1 As shown, the method comprises the following steps: Step S101, in a fluid environment, placing a first layer of core particles on a substrate so that the first surface of the first layer of core particles contacts the upper surface of the substrate; wherein one or more alignment electrodes are respectively provided on the first surface and the second surface of the first layer of core particles, and one or more assembly electrodes are provided on the upper surface of the substrate.

[0031] Specifically, the present application uses dielectrophoresis force to move the core particles to the target position required for assembly (such as the position of the assembly electrode of the substrate). Among them, dielectrophoresis (DEP for short) is a physical phenomenon, which refers to the force caused by a non-uniform electric field caused by the difference between the dielectric properties of the substance and the surrounding medium in a non-uniform electric field. This force is called dielectrophoretic force. The magnitude and direction of the dielectrophoretic force depend on the difference between the dielectric properties of the substance (such as dielectric constant and conductivity) and the surrounding medium, as well as the frequency of the electric field. When an object is placed in a non-uniform alternating current (AC) electric field, polarization will occur inside the object to form a dipole. If the dielectric properties of the object are different from those of the surrounding medium, the dipole will be subjected to a force to move it to an area with higher or lower electric field strength, depending on the relative dielectric properties of the object and the medium. In the embodiment of the present application, the dielectrophoretic force is only a potential dominant role, and it is not ruled out that other forces such as electrofluid forces and electrophoresis can also achieve similar functions.

[0032] The embodiments of the present application provide a fluid environment, in which the core particles to be assembled are placed in the fluid environment and an electric field is applied to the electrodes on the substrate, thereby generating a series of electro-microfluidic effects (including but not limited to the effects of dielectrophoretic force, electroosmotic flow, electrothermal flow, etc. on the core particles), so as to achieve assembly by moving the core particles to the target position using the dielectrophoretic force.

[0033] In a possible implementation, the fluid environment is prepared by any one of the following fluid materials: deionized water, ethanol, acetone, and developer.

[0034] In the embodiments of the present application, the fluid material in the provided fluid environment can be selected from conventional micro-nano processing fluids such as deionized water, ethanol, acetone, and developer. The fluid material must satisfy the requirement that its own electrical conductivity or dielectric constant is less than the material of the core particle's alignment electrode, and is greater than or equal to the core particle's main material, so as to generate a repulsive force on the core particle's main material and an attractive force on the core particle's alignment electrode.

[0035] In a fluid environment, the first layer of core particles is placed on the substrate so that the first surface of the first layer of core particles contacts the upper surface of the substrate. Specifically, the first layer of core particles can be core particles that need to be assembled with the substrate in actual assembly requirements, and their specific structure or type is not limited in the embodiments of the present application. In this step, the first layer of core particles is randomly placed at any position on the substrate, and can be placed as close to the assembly electrode of the substrate as possible. Figure 2 , Figure 2 A schematic diagram of the structure of a core particle is shown, Figure 2 As shown, one or more alignment electrodes 101 are respectively arranged on the first surface and the second surface of each layer of core particles (including the first layer of core particles 100). The first surface is the lower surface of the core particle, and the second surface is the upper surface of the core particle. One or more assembly electrodes are arranged on the upper surface of the substrate, and the position of the assembly electrode can be set according to actual needs, which is not limited in the embodiment of the present application. Among them, each layer of core particles (including the first layer of core particles 100) uses silicon or SU-8 material as the main body, and the substrate uses silicon or silicon dioxide substrate. One or more assembly electrodes with micron to nanometer feature scales are prepared by micromachining on the substrate to be assembled with the core particles. The assembly electrode and the alignment electrode are both metal graphic electrodes, so that the electrode can generate a local AC electric field after the AC signal source is connected. In the embodiment of the present application, the graphics of the assembly electrode and the alignment electrode are not limited. For example, they can be rectangular, circular, square and other graphic electrodes.

[0036] Step S102 , applying voltage to the assembly electrodes of the substrate to use the generated electric field force to guide the movement of the first layer of core particles, so that the alignment electrodes on the first surface of the first layer of core particles are aligned one by one with the assembly electrodes of the substrate.

[0037] Specifically, the first layer of core particles is first placed in a fluid environment, and an electric field is applied to the assembly electrodes on the substrate, thereby generating a series of electro-microfluidic effects (including but not limited to dielectrophoretic force, electroosmotic flow, electrothermal flow, etc. on the core particles). In a possible implementation, the voltage applied to the assembly electrodes of the substrate is alternating current, and the amplitude of the alternating current signal is within 60Vpp and the frequency is within 1k-1MHz.

[0038] Under the direct or indirect action of the electric field force (the force exerted by the electric field on the core particles is mainly generated by the positive and negative dielectrophoretic forces), the core particles distributed near the assembly electrode can be directed to move to the electrode surface (i.e., the location of the assembly electrode on the upper surface of the substrate). Figure 3 , Figure 3 A schematic diagram of the assembly structure of the first layer of core particles and the substrate is shown, Figure 3 As shown, the alignment electrodes 101 on the first layer of core particles 100 are in contact or close to the assembly electrodes 201 on the substrate 200, and are aligned one by one to complete the assembly of the core particles. In this embodiment, the alignment electrodes correspond to the assembly electrodes one by one, and the alignment of the two means that the surfaces of the two electrodes cover a certain area with each other, and can achieve conduction.

[0039] In a possible implementation, the alignment electrodes on the first surface or the second surface of each layer of core particles are not connected to each other. Figure 2 As shown, the alignment electrodes for each core particle are all isolated island patterns, that is, the alignment electrodes on the same surface are not connected to each other, so as to avoid short circuit of the substrate assembly circuit after the alignment electrodes contact the assembly electrodes. This is because after the alignment electrodes of the first layer of core particles are aligned with the assembly electrodes of the substrate, the two are connected. If there are two alignment electrodes that are connected to each other, it will cause a short circuit of the substrate assembly circuit. In a possible embodiment, the distance between the alignment electrodes on the first surface or the second surface of each layer of core particles is 5-50 microns.

[0040] In one possible implementation, the alignment electrodes on the first surface of each layer of core particles correspond one-to-one to the alignment electrodes on the second surface, and are connected through sidewall routing or through holes. For non-top layer core particles (i.e., the core particles on the top layer of the final three-dimensional core particle assembly structure), their alignment electrodes should be distributed on different planes (i.e., the first surface and the second surface). For example: for cylindrical core particles, the upper and lower surfaces of the cylinder are respectively designed with alignment electrodes belonging to an island pattern, and the alignment electrodes on the upper and lower surfaces need to be connected. The connection method can be achieved through sidewall routing design, or through-hole technology (TSV, Through Silicon Via) to achieve two-to-two interconnections. Figure 2As shown, the alignment electrodes on the first surface correspond to the alignment electrodes on the second surface one by one, which means that for an alignment electrode A on the first surface, there is a corresponding alignment electrode a on the second surface, and the alignment electrode A is connected to the alignment electrode a through the through hole 102.

[0041] Step S103, placing the second layer core particle on the first layer core particle so that the second surface of the first layer core particle contacts the first surface of the second layer core particle; wherein one or more alignment electrodes are respectively disposed on the first surface and the second surface of the second layer core particle.

[0042] The second layer core particles are placed on the second surface of the first layer core particles, so that the second surface of the first layer core particles contacts the first surface of the second layer core particles. Specifically, the second layer core particles can be core particles that are required to be assembled with the first layer core particles in actual assembly requirements, and are located in the second layer in actual design. Their specific structure or type is not limited in the embodiments of the present application. In this step, the second layer core particles are randomly placed at any position on the first layer core particles, and can be placed as close to the alignment electrode on the second surface of the first layer core particles as possible.

[0043] like Figure 2 As shown, one or more alignment electrodes are respectively provided on the first surface and the second surface of the second layer core particle. The first surface is the lower surface of the core particle, and the second surface is the upper surface of the core particle. One or more assembly electrodes are provided on the upper surface of the substrate, and the position of the assembly electrode can be set according to actual needs, which is not limited in the embodiment of the present application. The structure of the alignment electrode in the second layer core particle is the same as the structure of the alignment electrode in the first layer core particle, and it will not be repeated here.

[0044] Step S104, applying voltage to the assembly electrodes of the substrate to use the generated electric field force to guide the movement of the second layer core particles so that the alignment electrodes on the first surface of the second layer core particles are aligned one by one with the alignment electrodes on the second surface of the first layer core particles.

[0045] Specifically, in a fluid environment, a voltage is applied to the assembly electrode of the substrate to generate an electric field force to guide the first layer of core particles to move and assemble to the substrate. After the first layer of core particles and the substrate are assembled, the assembly electrode of the substrate is aligned with the bottom electrode of the core particle (the alignment electrode on the first surface) and is turned on, and the electric field is guided from the surface of the substrate to the alignment electrode on the upper surface (second surface) of the first layer of core particles. At this time, the alignment electrode on the top surface (second surface) of the first layer of core particles has a similar function to the assembly electrode of the substrate, so that the alignment electrode of the second layer of core particles can be assembled to the top surface of the first layer of core particles under the action of the electric field (aligned one by one with the alignment electrode on the second surface of the first layer of core particles). Step S104 can also be performed in a fluid environment. The fluid environment required for this step is the same as that required for step S101, and it will not be repeated in this embodiment.

[0046] Under the direct or indirect action of the electric field force (the force exerted by the electric field on the core particles is mainly generated by the positive and negative dielectrophoretic forces), the second layer of core particles distributed near the alignment electrode can be directed to move to the electrode surface (i.e., the position of the alignment electrode on the upper surface of the first layer of core particles). Figure 4 , Figure 4 A schematic diagram of the assembly structure of the second layer core particles and the first layer core particles is shown, Figure 4 As shown, the alignment electrodes on the second layer core particle 300 are in contact or close to the alignment electrodes on the first layer core particle 100, and are aligned one by one to complete the assembly of the second layer core particle and the first layer core particle. In this embodiment, the alignment electrodes on the first surface of the second layer core particle correspond one by one to the alignment electrodes on the second surface of the first layer core particle. For the alignment electrode A on the first surface of the second layer core particle, there is a corresponding alignment electrode a on the second surface of the first layer core particle. Alignment of the two means that the surfaces of the two electrodes cover a certain area with each other, and conduction can be achieved.

[0047] In a possible implementation, a coating layer is disposed on the second surface of each layer of core particles; after the alignment electrodes on the first surface of the n-th layer of core particles are aligned one by one with the alignment electrodes on the second surface of the n-1-th layer of core particles, the method further includes: The coating layer on the second surface of the n-th layer of core particles is removed by wet etching or dry etching.

[0048] Specifically, considering that the front and back surfaces (i.e., the first surface and the second surface) of the core particle assembly may have different functions, the bottom surface of the core particle needs to be assembled on the top surface of the substrate or the secondary core particle, and the embodiment of the present application proposes to cover the upper surface of the core particle with a coating layer to improve the effect of the electric field force on the movement of the core particle, and the coating layer is used to increase the force difference of the alignment electrodes on the top and bottom surfaces of the core particle. Specifically, the alignment of the front and back surfaces of the core particle can be achieved based on the bidirectional force characteristics of the dielectrophoretic force. For example, a material (such as silicon dioxide, polyparaxylene, SU-8 photoresist) with a lower conductivity or dielectric constant than the fluid medium (such as deionized water, ethanol, acetone, developer) is used to pre-coat the top surface (i.e., the second surface) of the core particle to be assembled, so that it is subjected to a negative dielectrophoretic force; or a material (such as Si) with a lower conductivity or dielectric constant than the electrode material is used to make the top surface (second surface) of the core particle subject to a lower positive dielectrophoretic force than the bottom surface (first surface). Both of the above coating methods are to achieve the difference in force on the front and back surfaces of the core particle. Due to the difference in force between the top and bottom surfaces of the core particle, the bottom surface of the core particle is assembled to the upper surface of the substrate or the sub-level core particle. The material of the coating layer is an insulating material or a semiconductor material. In a possible embodiment, the material of the coating layer is any one of the following: silicon oxide, polyparaxylene, photoresist, silicon.

[0049] For each layer of core particles, for example, the core particles of the nth layer (where n is an integer greater than 1), after assembling them on the second surface of the n-1th layer of core particles in a fluid environment (i.e., aligning the alignment electrodes on the first surface of the nth layer of core particles with the alignment electrodes on the second surface of the n-1th layer of core particles one by one), the topmost coating layer can be removed by wet etching, dry etching, etc., so that the alignment electrodes on the top surface (the alignment electrodes on the second surface of the nth layer of core particles) are exposed again, effectively providing an electric field and avoiding the weakening of the electric field strength. If the coating layer is removed by dry etching, it is necessary to detach the assembled core particle structure from the fluid environment and then perform the dry etching step.

[0050] Exemplarily, before assembly, the upper surfaces of all core particles are coated with Parylene or SiO2 to provide insulation. After the first layer of core particles are assembled, the coating layer on the second surface of the first layer of core particles is removed by dry etching to expose the alignment electrodes on the top surface of the first layer of core particles. The electric field is enhanced at the alignment electrodes on the top surface, further attracting the alignment electrodes on the bottom surface of the second layer of core particles. After the second layer of core particles are assembled, the coating layer on the top surface of the second layer of core particles is further removed, and higher-level core particles can be assembled by analogy.

[0051] Step S105 , assembling multiple levels of core particles on the second surface of the second layer of core particles by repeating the above steps to obtain a three-dimensional core particle assembly structure.

[0052] Specifically, after the assembly of the second layer of core particles is completed, the assembly of the third layer of core particles on the second surface of the second layer of core particles is continued until the assembly of the last layer of core particles is completed. Specifically, during the assembly process, after the assembly of the n-1 layer of core particles and the n-1 layer of core particles is completed, the alignment electrode on the second surface of the n-1 layer of core particles is aligned with the alignment electrode on the first surface of the n-1 layer of core particles and is turned on, and the electric field is guided from the second surface of the n-1 layer of core particles to the alignment electrode on the second surface of the n-1 layer of core particles. At this time, the alignment electrode on the second surface of the n-1 layer of core particles has a similar function to the assembly electrode of the substrate, so that the alignment electrode of the n+1 layer of core particles can be assembled to the second surface of the n-1 layer of core particles under the action of the electric field. By analogy, the core particles assembled to the third layer or above are always matched with the alignment electrode on the upper surface of the core particles of the next level (that is, the n-1 layer of core particles matches the alignment electrode on the upper surface of the n-1 layer of core particles), and the stacking of three-dimensional multi-layer core particles is realized in sequence.

[0053] Reference Figure 5 , Figure 5 A schematic diagram of a three-dimensional core particle assembly structure is shown. Figure 5 As shown, the three-dimensional core particle assembly structure has four layers in total, consisting of a substrate 200 and three layers of core particles. Among them, the alignment electrodes on the first surface of the first layer of core particles are aligned one by one with the assembly electrodes on the upper surface of the substrate, the alignment electrodes on the second surface of the first layer of core particles are aligned one by one with the alignment electrodes on the first surface of the second layer of core particles, and the core particles of adjacent levels are aligned one by one through the alignment electrodes, and the alignment electrodes on the upper and lower surfaces of each layer of core particles are connected through through holes or through sidewall routing. For the last layer of core particles (i.e., the third layer of core particles), since there is no need to continue assembling the core particles, the alignment electrodes may not be set on the second surface.

[0054] In one possible embodiment, the electrode shape of the alignment electrode on the first surface of each layer of core particles is different from the electrode shape of the alignment electrode on the second surface. Specifically, the core particles contain patterned metal electrodes on the upper and lower surfaces (i.e., the alignment electrodes on the first surface and the second surface), and the electrode patterns on the upper and lower surfaces are different, providing selectivity for the assembly of core particles in different layers. The electrode shape of the alignment electrode on the first surface of the core particle is different from the electrode shape of the alignment electrode on the second surface, thereby distinguishing the front and back sides of the core particle and avoiding assembly errors. In addition, different electrode patterns of alignment electrodes can be set for core particles of different levels to distinguish them, so as to avoid undesirable multi-layer repeated assembly. In order to align the top electrode of the first layer of core particles with the bottom electrode pattern of the second layer of core particles, the bottom surface of the second layer of core particles has an alignment relationship with the electrode pattern of the top surface of the first layer of core particles. The alignment here does not limit the electrode patterns to be the same, but under the action of the electric field, the interaction between the two electrodes can help alignment).

[0055] The electrode patterns on the prior art core particles cannot take into account both alignment and the electric field to be directed to the upper core particles through the through holes; the electrode shapes used for alignment in the commonly used core particles are rod-shaped or ring-shaped. A simple design may cause a short circuit after being assembled to the base electrode pair. The solution proposed by the present invention takes into account both no short circuit and the ability to feed power to the upper layer.

[0056] Existing core particle assembly technology is usually used to realize the assembly of single-layer core particles in two-dimensional circuits, which is not feasible in three-dimensional integration. The relevant technology modifies the assembly site to form a droplet array, and captures the core particles through the droplets, and combines the core particles with the substrate in combination with liquid volatilization and capillary force. However, the method is limited by the limitation of the core particle geometry and the assembly angle, and the substrate material must be restricted (hydrophobic difference). In the embodiment of the present application, an assembly electrode is set on the substrate, and an alignment electrode is set on the upper and lower surfaces of the core particles. By applying a voltage to the assembly electrode of the substrate, an electric field is generated, and the dielectrophoretic force is used to move the first layer of core particles placed on the substrate to an area with higher or lower electric field intensity, thereby moving to the target position (the position corresponding to the assembly electrode of the substrate), so that the assembly electrode contacts the alignment electrode, and the assembly of the first layer of core particles is completed. Then, according to the same steps, the dielectrophoretic force is used to move the core particles, so that the core particles of adjacent layers are aligned with each other through the alignment electrode, and the assembly of multi-level core particles is realized. The embodiment of the present application utilizes dielectrophoretic force to move the core particles to the position required for assembly, thereby achieving stacking and interconnecting multiple core particles in the vertical direction to achieve higher integration and better performance.

[0057] The second aspect of the embodiments of the present application also provides a three-dimensional core particle assembly structure, which is prepared by the electric field induced three-dimensional core particle assembly method described in the first aspect of the embodiments of the present application; the three-dimensional core particle assembly structure includes multiple layers of stacked core particles, and the core particles in adjacent layers are aligned by assembly electrodes on their respective surfaces.

[0058] In the embodiment of the present application, the three-dimensional core particle assembly structure is as follows Figure 5 As shown, the alignment electrodes on the first surface of the first layer of core particles are aligned one by one with the assembly electrodes on the upper surface of the substrate, the alignment electrodes on the second surface of the first layer of core particles are aligned one by one with the alignment electrodes on the first surface of the second layer of core particles, the core particles of adjacent levels are aligned one by one through the alignment electrodes, and the alignment electrodes on the upper and lower surfaces of each layer of core particles are connected through through holes or through sidewall routing. For the last layer of core particles (i.e., the third layer of core particles), since there is no need to continue assembling the core particles, the alignment electrodes may not be set on the second surface.

[0059] In a possible implementation manner, the alignment electrodes on the first surface or the second surface of each layer of core particles are not connected to each other.

[0060] In a possible implementation, the alignment electrodes on the first surface of each layer of core particles correspond one to one with the alignment electrodes on the second surface, and are connected through sidewall wiring or through holes.

[0061] In a possible implementation, the fluid environment is prepared by any one of the following fluid materials: deionized water, ethanol, acetone, and developer.

[0062] In a possible implementation manner, the material of the coating layer is any one of the following: silicon oxide, polyparaxylene, photoresist, and silicon.

[0063] In a possible implementation manner, the voltage applied to the assembly electrode of the substrate is alternating current, and the AC signal amplitude of the alternating current is within 60 Vpp and the frequency is within 1 k-1 MHz.

[0064] In a possible implementation manner, the electrode shape of the alignment electrode on the first surface of each layer of core particles is different from the electrode shape of the alignment electrode on the second surface.

[0065] In a possible implementation, the distance between any two alignment electrodes on the first surface or the second surface of each layer of core particles is 5-50 microns.

[0066] The present application also provides an electronic device, referring to Figure 6 , Figure 6 Schematic diagram of an electronic device proposed in an embodiment of the present application. Figure 6 As shown, the electronic device 100 includes: a memory 110 and a processor 120. The memory 110 and the processor 120 are connected via a bus communication. A computer program is stored in the memory 110. The computer program can be run on the processor 120 to implement the steps in the electric field induced three-dimensional core particle assembly method disclosed in the embodiment of the present application.

[0067] The embodiment of the present application also provides a computer-readable storage medium having a computer program / instruction stored thereon, which, when executed by a processor, implements the steps in the electric field-induced three-dimensional core particle assembly method disclosed in the embodiment of the present application.

[0068] The embodiment of the present application also provides a computer program product. When the computer program product is run on an electronic device, the processor is enabled to implement the steps of the electric field induced three-dimensional core particle assembly method disclosed in the embodiment of the present application.

[0069] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0070] It should also be noted that, in this article, the orientation or position relationship indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations, nor can they be understood as indicating or implying relative importance. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. Without more restrictions, an element defined by the phrase "comprising a ..." does not exclude the existence of other identical elements in the process, method, article or terminal device comprising the element.

[0071] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0072] The technical solution provided by the present application is described in detail above. The principle and implementation method of the present application are described in this article using specific examples. The description of the above embodiments is only used to help understand the present application, and the content of this specification should not be understood as limiting the present application. At the same time, for those of ordinary skill in the art, according to the present application, there will be different forms of changes in the specific implementation methods and application scopes. It is not necessary and impossible to list all the implementation methods here, and the obvious changes or modifications derived therefrom are still within the scope of protection of the present application.

Claims

1. A method for assembling three-dimensional core particles induced by electric field, characterized in that: The method comprises: In a fluid environment, placing a first layer of core particles on a substrate so that a first surface of the first layer of core particles contacts an upper surface of the substrate; wherein one or more alignment electrodes are respectively disposed on the first surface and the second surface of the first layer of core particles, and one or more assembly electrodes are disposed on the upper surface of the substrate; Applying voltage to the assembly electrodes of the substrate to guide the movement of the first layer of core particles by using the generated electric field force, so that the alignment electrodes on the first surface of the first layer of core particles are aligned one by one with the assembly electrodes of the substrate; Placing a second layer of core particles on the first layer of core particles so that the second surface of the first layer of core particles contacts the first surface of the second layer of core particles; wherein one or more alignment electrodes are respectively disposed on the first surface and the second surface of the second layer of core particles; Applying voltage to the assembly electrodes of the substrate to guide the movement of the second layer core particles by using the generated electric field force, so that the alignment electrodes on the first surface of the second layer core particles are aligned one by one with the alignment electrodes on the second surface of the first layer core particles; On the second surface of the second layer of core particles, multiple levels of core particles are assembled by repeating the above steps to obtain a three-dimensional core particle assembly structure.

2. The electric field induced three-dimensional core particle assembly method according to claim 1, characterized in that: A coating layer is disposed on the second surface of each layer of core particles; after the alignment electrodes on the first surface of the n-th layer of core particles are aligned one by one with the alignment electrodes on the second surface of the n-1-th layer of core particles, the method further comprises: The coating layer on the second surface of the n-th layer of core particles is removed by wet etching or dry etching.

3. The electric field induced three-dimensional core particle assembly method according to claim 1, characterized in that: The alignment electrodes on the first surface or the second surface of each layer of core particles are not connected to each other.

4. The electric field induced three-dimensional core particle assembly method according to claim 1, characterized in that: The alignment electrodes on the first surface of each layer of core particles correspond one to one with the alignment electrodes on the second surface, and are connected through sidewall wiring or through holes.

5. The electric field induced three-dimensional core particle assembly method according to claim 1, characterized in that: The fluid environment is prepared by any one of the following fluid materials: deionized water, ethanol, acetone, and developer.

6. The electric field induced three-dimensional core particle assembly method according to claim 2, characterized in that: The material of the coating layer is any one of the following: silicon oxide, polyparaxylene, photoresist, and silicon.

7. The electric field induced three-dimensional core particle assembly method according to claim 1, characterized in that: The voltage applied to the assembly electrode of the substrate is alternating current, and the amplitude of the alternating current signal is within 60Vpp and the frequency is within 1k-1MHz.

8. The electric field induced three-dimensional core particle assembly method according to claim 1, characterized in that: The electrode shape of the alignment electrode on the first surface of each layer of core particles is different from the electrode shape of the alignment electrode on the second surface.

9. The electric field induced three-dimensional core particle assembly method according to any one of claims 1 to 8, characterized in that: The distance between the aligned electrodes on the first surface or the second surface of each layer of core particles is 5-50 microns.

10. A three-dimensional core particle assembly structure, characterized in that: The three-dimensional core particle assembly structure is prepared by the electric field induced three-dimensional core particle assembly method described in any one of claims 1 to 9; the three-dimensional core particle assembly structure includes multiple layers of stacked core particles, and the core particles in adjacent layers are aligned by assembly electrodes on their respective surfaces.

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