An electric field-induced three-dimensional core particle assembly method and three-dimensional core particle assembly structure

Abstract

The present application provides an electric field-induced three-dimensional core particle assembly method and a three-dimensional core particle assembly structure, which relate to the field of semiconductor technology. The method 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; applying a voltage to the assembly electrode 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 of the first layer of core particles are aligned one-to-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; applying a voltage to the assembly electrode 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-to-one with the alignment electrodes on the second surface of the first layer of core particles; and 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.

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, existing coreparticle assembly techniques are typically used to assemble single-layer coreparticles in two-dimensional circuits and are not fully applicable to three-dimensional coreparticle integration. Therefore, it is necessary to provide an electric field-induced three-dimensional coreparticle assembly method and a three-dimensional coreparticle assembly structure to achieve accurate and efficient three-dimensional coreparticle 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:

[0006] Placing a first layer of core particles on a substrate in a fluid environment 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 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;

[0007] Applying a voltage to the assembly electrodes of the substrate to guide the movement of the first layer of core particles 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;

[0008] 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 provided on the first surface and the second surface of the second layer of core particles;

[0009] Applying a voltage to the assembly electrodes of the substrate to guide the movement of the second-layer core particles by utilizing the generated electric field force, so that the alignment electrodes on the first surfaces of the second-layer core particles are aligned one-to-one with the alignment electrodes on the second surfaces of the first-layer core particles;

[0010] 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.

[0011] In a possible embodiment, a coating layer is provided on the second surface of each layer of core particles; after the alignment electrodes on the first surface of the core particles in the nth layer are aligned one-to-one with the alignment electrodes on the second surface of the core particles in the (n-1)th layer, the method further includes:

[0012] The coating layer on the second surface of the n-th layer of core particles is removed by wet etching or dry etching.

[0013] 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.

[0014] 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 traces or through holes.

[0015] In a possible implementation, the fluid environment is prepared by using any one of the following fluid materials: deionized water, ethanol, acetone, and developer.

[0016] In a possible implementation, the material of the coating layer is any one of the following: silicon oxide, parylene, photoresist, and silicon.

[0017] 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.

[0018] In a possible implementation manner, the electrode shape of the alignment electrodes on the first surface of each layer of core particles is different from the electrode shape of the alignment electrodes on the second surface.

[0019] In a possible embodiment, 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.

[0020] 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 the core particles in adjacent layers are aligned through the assembly electrodes on their respective surfaces.

[0021] 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.

[0022] The fourth aspect of the embodiment of the present application further provides a computer-readable storage medium having a computer program / instruction stored thereon, which, when executed by a processor, implements the steps of the electric field-induced three-dimensional core particle assembly method described in the first aspect of the embodiment of the present application.

[0023] The fifth aspect of the embodiments of the present application further provides a computer program product, which, when run on an electronic device, enables a processor to implement the steps of the electric field-induced three-dimensional core particle assembly method as described in the first aspect of the embodiments of the present application.

[0024] An embodiment of the present application proposes an electric field-induced three-dimensional core particle assembly method, the method comprising: 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 provided on the first and second surfaces of the first layer of core particles, and one or more assembly electrodes are provided on the upper surface of the substrate; applying a 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-to-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 provided on the first and second surfaces of the second layer of core particles; applying a voltage to the assembly electrodes of the substrate to use the generated electric field force to guide the movement of the second layer of core particles, so that the alignment electrodes on the first surface of the second layer of core particles are aligned one-to-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, multiple levels of core particles are assembled by repeating the above steps to obtain a three-dimensional core particle assembly structure.

[0025] 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, thereby realizing the assembly of multi-level core particles. The embodiment of the present application uses the dielectrophoretic force to move the core particles to the position required for assembly, thereby realizing the stacking and interconnection of multiple core particles in the vertical direction to achieve higher integration and better performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments of the present application. 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 any creative work.

[0027] Figure 1 This 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;

[0028] Figure 2 This is a schematic structural diagram of a core particle proposed in one embodiment of the present application;

[0029] Figure 3 This is a schematic diagram of an assembly structure of a first layer of core particles and a substrate proposed in one embodiment of the present application;

[0030] Figure 4 This is a schematic diagram of the assembly structure of a second-layer core particle and a first-layer core particle proposed in one embodiment of the present application;

[0031] Figure 5 This is a schematic diagram of a three-dimensional core particle assembly structure proposed in one embodiment of the present application;

[0032] Figure 6 This is a schematic structural diagram of an electronic device proposed in one embodiment of the present application;

[0033] 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

[0034] 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 accompanying drawings show exemplary embodiments of the present application, 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 to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0035] 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 address the challenges brought about by the slowdown of Moore's Law. As semiconductor process technology continues to approach physical limits, the method of simply reducing transistor size to improve performance is becoming increasingly difficult and expensive.

[0036] Common technologies used for 3D chip interconnection include: 1) Through-Silicon Via (TSV): A TSV is a conductive hole that runs vertically through the chip, allowing electrical connections between chips at different levels. TSV technology offers high integration density and versatility, but the complex process steps can lead to low packaging yields and high costs. 2) 2.5D packaging technology: 2.5D packaging technology uses an interposer (such as a silicon interposer or an organic interposer) to interconnect chips. The interposer is equipped with microbumps or solder joints to connect the different chips, providing high interconnect density and electrical performance. 3) 3D packaging technology: 3D packaging technology further reduces bump density, achieving connections directly through silicon vias on the wafer. This technology enables thinner chip stacking, reduces signal parasitics, and improves system performance. 4) Inductive coupling technology: Inductive coupling technology uses the principle of electromagnetic induction to achieve contactless communication between chips. This technology avoids the use of TSVs, reduces process complexity and cost, and is suitable for short-distance, high-speed communication.

[0037] Chiplet technology, an innovative breakthrough in the semiconductor industry, is rapidly becoming a key technology for addressing the challenges of the slowdown in Moore's Law. Against the backdrop of diminishing economic returns from Moore's Law, traditional system-on-chip (SoC) designs face sharply rising design and manufacturing costs. Chiplet technology, by independently manufacturing small chips with different functions and then integrating them, effectively reduces costs while also improving chip yield and performance. The significance of chiplet technology lies in its ability to not only enhance the performance and flexibility of semiconductor products but also bring new innovation momentum to the entire industry, driving rapid technology iteration and customization to adapt to evolving market demands. Chiplet technology, in particular, demonstrates tremendous potential for application in cutting-edge fields such as high-performance computing, artificial intelligence, and 5G.

[0038] Three-dimensional chiplet integration technology, a cutting-edge field in the semiconductor industry, is rapidly developing to address the limitations of traditional two-dimensional integration. It allows multiple chips, or chiplets, to be stacked and interconnected vertically, forming complex integrated circuits. This allows for higher levels of integration and improved performance, and is crucial for driving technological advancements in areas such as high-performance computing, artificial intelligence, and mobile devices. By enabling closer interconnections between chips and shortening signal transmission paths, this technology improves overall system performance, playing a crucial role in enhancing chip performance, increasing integration, reducing power consumption, and reducing size.

[0039] However, existing core particle assembly technology is usually used to realize the assembly of single-layer core particles in two-dimensional circuits and is not fully applicable to three-dimensional core particle integration.

[0040] 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.

[0041] In view of the above problems, the present invention proposes 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. The following, in conjunction with the accompanying drawings, describes in detail the electric field-induced three-dimensional core particle assembly method and the three-dimensional core particle assembly structure provided by the present invention through several embodiments and their application scenarios.

[0042] In a first aspect of the present application, an electric field-induced three-dimensional core particle assembly method is proposed. Figure 1 A flow chart of the steps of a three-dimensional core particle assembly method induced by an 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 The present invention provides a method for assembling three-dimensional core particles induced by electric field. Figure 1 As shown, the method includes the following steps:

[0043] 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.

[0044] Specifically, the present application utilizes dielectrophoretic force to move the core particles to the target location required for assembly (e.g., the location of the assembly electrode on the substrate). Dielectrophoresis (DEP) is a physical phenomenon that refers to the force caused by a non-uniform electric field in which a substance is subjected to a force due to differences in its dielectric properties from the surrounding medium. This force is called the dielectrophoretic force. The magnitude and direction of the dielectrophoretic force depend on the difference in dielectric properties (such as dielectric constant and conductivity) between the substance 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 occurs within the object, forming a dipole. If the dielectric properties of the object differ from those of the surrounding medium, this dipole will be subjected to a force that causes it to move toward areas of higher or lower electric field strength, depending on the relative dielectric properties of the object and the medium. In the embodiments of the present application, the dielectrophoretic force is only a potential dominant force, and other forces such as electrofluidic forces and electrophoresis can also achieve similar functions.

[0045] The embodiments of the present application provide a fluid environment. By placing the core particles to be assembled in the fluid environment and applying an electric field to the electrodes on the substrate, a series of electro-microfluidic effects are generated (including but not limited to 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 dielectrophoretic force.

[0046] In a possible implementation, the fluid environment is prepared by using any one of the following fluid materials: deionized water, ethanol, acetone, and developer.

[0047] In the embodiment 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.

[0048] 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 are 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 2As shown, one or more alignment electrodes 101 are provided 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 provided on the upper surface of the substrate. The position of the assembly electrode can be set according to actual needs and is not limited in the embodiment of the present application. The core particles of each layer (including the first layer of core particles 100) are made of silicon or SU-8 material as the main body, and the substrate is made of silicon or silicon dioxide. One or more assembly electrodes with micron to nanometer feature scales are prepared on the substrate to be assembled with the core particles by micromachining. The assembly electrode and the alignment electrode are both metal pattern electrodes, which enable the electrodes to generate a local AC electric field after connecting to an AC signal source. In the embodiment of the present application, the patterns of the assembly electrodes and the alignment electrodes are not limited. For example, they can be rectangular, circular, square or other pattern electrodes.

[0049] Step S102 , applying voltage to the assembly electrodes of the substrate to utilize 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-to-one with the assembly electrodes of the substrate.

[0050] Specifically, the first layer of core particles is placed in a fluid environment. An electric field is then applied to the assembled electrodes on the substrate, thereby generating a series of electro-microfluidic effects (including but not limited to dielectrophoretic forces, electroosmotic flows, and electrothermal flows on the core particles). In one possible embodiment, the voltage applied to the assembled electrodes on the substrate is an alternating current (AC), with an AC signal amplitude within 60 Vpp and a frequency within 1 kJ to 1 MHz.

[0051] 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 the alignment is completed to complete the assembly of the core particles. In this embodiment, the alignment electrodes correspond to the assembly electrodes one by one. Alignment between the two means that the surfaces of the two electrodes overlap a certain area, which can achieve electrical conduction.

[0052] In one possible embodiment, the alignment electrodes on the first surface or the second surface of each layer of core particles are not connected to each other. Figure 2As shown, the alignment electrodes for each core particle are arranged in an island pattern, meaning that the alignment electrodes on the same surface are not electrically connected to each other, to prevent short circuits in the substrate assembly circuit caused by contact between the alignment electrodes and 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 become electrically connected. If two alignment electrodes are electrically connected to each other, this would cause a short circuit in the substrate assembly circuit. In one possible embodiment, the distance between the alignment electrodes on the first or second surface of each layer of core particles is 5-50 microns.

[0053] In one possible embodiment, 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 routing or through holes. For non-top layer core particles (i.e., the core particles in 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 through-hole technology (TSV, Through Silicon Via) to achieve two-to-two interconnection. Figure 2 As shown, the alignment electrodes on the first surface correspond to the alignment electrodes on the second surface one-to-one, which means that for each alignment electrode A on the first surface, there is a corresponding alignment electrode a on the second surface, and the alignment electrodes A and a are electrically connected through the through hole 102.

[0054] 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 provided on the first surface and the second surface of the second layer core particle.

[0055] The second layer of core particles are placed on the second surface of 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. Specifically, the second layer of core particles can be core particles that are required to be assembled with the first layer of core particles in actual assembly requirements. In the actual design, they are located in the second layer. Their specific structure or type is not limited in the embodiments of this application. In this step, the second layer of core particles are randomly placed at any position on the first layer of core particles, and can be placed as close as possible to the area near the alignment electrode on the second surface of the first layer of core particles.

[0056] like Figure 2As shown, one or more alignment electrodes are provided on the first and second surfaces of the second-layer core particles, respectively. 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. The position of the assembly electrodes can be set according to actual needs and is not limited in the embodiments of the present application. The structure of the alignment electrodes in the second-layer core particles is the same as that of the first-layer core particles, and will not be repeated here.

[0057] Step S104 , applying voltage to the assembly electrodes of the substrate to utilize 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.

[0058] 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 functions similarly 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 (one-to-one alignment 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 will not be repeated in this embodiment.

[0059] 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 the two are aligned one-to-one, thereby completing the assembly of the second-layer core particles with the first-layer core particles. In this embodiment, the alignment electrodes on the first surface of the second-layer core particle correspond one-to-one with the alignment electrodes on the second surface of the first-layer core particle. For each 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 between the two electrodes means that the surfaces of the two electrodes overlap to a certain extent, enabling electrical conduction.

[0060] In a possible embodiment, a coating layer is provided on the second surface of each layer of core particles; after the alignment electrodes on the first surface of the core particles in the nth layer are aligned one-to-one with the alignment electrodes on the second surface of the core particles in the (n-1)th layer, the method further includes:

[0061] The coating layer on the second surface of the n-th layer of core particles is removed by wet etching or dry etching.

[0062] Specifically, considering that the front and back surfaces (i.e., the first and second surfaces) of the core particles in the core particle assembly may have different functions, it is necessary to assemble the core particle bottom surface toward the substrate or the top surface of the secondary core particle. In this embodiment of the application, a coating layer is applied to the top surface of the core particle to enhance the effect of the electric field force on the movement of the core particle. This coating layer is used to increase the force difference between 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, parylene, 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 a difference in force between 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 one possible embodiment, the material of the coating layer is any one of the following: silicon oxide, parylene, photoresist, and silicon.

[0063] For each layer of core particles, such as the nth layer of core particles (where n is an integer greater than 1), after being assembled onto the second surface of the n-1th layer of core particles in a fluid environment (i.e., after the alignment electrodes on the first surface of the nth layer of core particles are aligned one-to-one with the alignment electrodes on the second surface of the n-1th layer of core particles), the topmost coating layer can be removed by wet etching, dry etching, or the like, so that the alignment electrodes on the top surface (the alignment electrodes on the second surface of the nth layer of core particles) are re-exposed, effectively providing an electric field and avoiding a weakening of the electric field strength. If dry etching is used to remove the coating layer, the assembled core particle structure needs to be separated from the fluid environment before the dry etching step is performed.

[0064] Exemplarily, before assembly, the top surfaces of all core particles are coated with Parylene or SiO2 to provide insulation. After the first layer of core particles is assembled, the coating on the second surface of the first layer of core particles is removed by dry etching, exposing 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 is assembled, the coating on the top surface of the second layer of core particles is further removed, and higher-level core particles can be assembled in this way.

[0065] 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.

[0066] Specifically, after the assembly of the second layer of core particles is completed, the assembly of the third layer of core particles continues on the second surface of the second layer of core particles, until the assembly of the final layer of core particles is completed. Specifically, during the assembly process, after the assembly of the core particles in the n-1 layer and the n layer is completed, the alignment electrodes on the second surface of the core particles in the n-1 layer are aligned and conductive with the alignment electrodes on the first surface of the core particles in the n layer, and the electric field is guided from the second surface of the core particles in the n-1 layer to the alignment electrodes on the second surface of the core particles in the n layer. At this point, the alignment electrodes on the second surface of the core particles in the n layer function similarly to the assembly electrodes on the substrate, allowing the alignment electrodes of the core particles in the n+1 layer to be assembled to the second surface of the core particles in the n layer under the action of the electric field. Similarly, the core particles assembled in the third layer or above always align with the alignment electrodes on the top surface of the core particles in the next layer (i.e., the core particles in the n layer align with the alignment electrodes on the top surface of the core particles in the n-1 layer), thereby achieving a three-dimensional multi-layer stacking of core particles.

[0067] 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, consisting of a substrate 200 and three layers of core particles. The alignment electrodes on the first surface of the core particles in the first layer are aligned one-to-one with the assembly electrodes on the upper surface of the substrate. The alignment electrodes on the second surface of the core particles in the first layer are aligned one-to-one with the alignment electrodes on the first surface of the core particles in the second layer. Core particles in adjacent layers are aligned one-to-one via alignment electrodes. The alignment electrodes on the upper and lower surfaces of each layer of core particles are connected via through-holes or sidewall wiring. For the last layer of core particles (i.e., the third layer), since no further assembly of core particles is required, alignment electrodes can be omitted on the second surface.

[0068] 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 the 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 is not limited to the same electrode pattern, but under the action of the electric field, the interaction between the two electrodes can help alignment).

[0069] The electrode patterns on existing core particles cannot both ensure alignment and direct the electric field through the through-holes to the upper core particles. Common core particle alignment electrodes are shaped like rods or rings. Simple designs can cause short circuits when assembled to the base electrode pair. The solution proposed in this invention achieves both short circuit prevention and power supply to the upper layer.

[0070] Existing core particle assembly technology is generally used to realize the assembly of single-layer core particles in two-dimensional circuits, which is not feasible in three-dimensional integration. The related technology modifies the assembly site to form a droplet array, and captures the core particles through the droplets, combining liquid volatilization and capillary forces to bind the core particles to the substrate. However, this method is limited by the core particle geometry and assembly angle, and requires restrictions on the substrate material (hydrophilicity and hydrophobicity differences). 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 particle. 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, completing the assembly of the first layer of core particles. 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, thereby realizing the assembly of multi-level core particles. The embodiments of the present application utilize 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.

[0071] The second aspect of the embodiment 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 embodiment 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 through the assembly electrodes on their respective surfaces.

[0072] 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-to-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-to-one with the alignment electrodes on the first surface of the second layer of core particles. The core particles in adjacent layers are aligned one-to-one via the alignment electrodes. The alignment electrodes on the upper and lower surfaces of each layer of core particles are connected via through-holes or sidewall traces. For the last layer of core particles (i.e., the third layer), since no further assembly of core particles is required, alignment electrodes can be omitted on the second surface.

[0073] 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.

[0074] 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 traces or through holes.

[0075] In a possible implementation, the fluid environment is prepared by using any one of the following fluid materials: deionized water, ethanol, acetone, and developer.

[0076] In a possible implementation, the material of the coating layer is any one of the following: silicon oxide, parylene, photoresist, and silicon.

[0077] 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.

[0078] In a possible implementation manner, the electrode shape of the alignment electrodes on the first surface of each layer of core particles is different from the electrode shape of the alignment electrodes on the second surface.

[0079] In a possible embodiment, 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.

[0080] The present application also provides an electronic device, Figure 6 , Figure 6 Schematic diagram of the electronic device proposed in the embodiment of the present application. Figure 6As 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, and 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.

[0081] An 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.

[0082] The embodiments of the present application also provide a computer program product, which, when executed on an electronic device, enables a processor to implement the steps of the electric field-induced three-dimensional core particle assembly method disclosed in the embodiments of the present application.

[0083] 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 and similar parts between the various embodiments can be referenced to each other.

[0084] 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 accompanying drawings, which is only for the convenience of describing this 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 this application. In addition, relational terms such as "first" and "second" are merely 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", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device that includes a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, an element defined by the phrase "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or terminal device that includes the element.

[0085] 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 become aware of the basic creative concepts. 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.

[0086] The technical solutions provided by this application are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of this application. The description of the above embodiments is only intended to help understand this application, and the contents of this specification should not be construed as limiting this application. At the same time, for those skilled in the art, according to this application, there may be various changes in the specific implementation methods and application scopes. It is not necessary and impossible to list all implementation methods here, and obvious changes or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. A method for assembling three-dimensional core particles induced by electric field, characterized in that: The method comprises: Placing a first layer of core particles on a substrate in a fluid environment 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 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; Applying a voltage to the assembly electrodes of the substrate to guide the movement of the first layer of core particles 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 provided on the first surface and the second surface of the second layer of core particles; Applying a voltage to the assembly electrodes of the substrate to guide the movement of the second-layer core particles by utilizing the generated electric field force, so that the alignment electrodes on the first surfaces of the second-layer core particles are aligned one-to-one with the alignment electrodes on the second surfaces 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 provided 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-to-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 traces 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 using 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 AC signal amplitude of the alternating current is within 60 Vpp and the frequency is within 1 k-1 MHz.

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 any two alignment 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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