Silicon adapter plate structure with liquid metal wiring and preparation method thereof

Abstract

The invention discloses a silicon adapter plate structure with liquid metal wiring and a preparation method thereof, and belongs to the technical field of advanced packaging integrated chips, and the method comprises the steps: preparing a PI layer, and preparing a copper wiring external electrical interconnection structure; preparing a flowing chamber bottom groove structure, preparing a flowing chamber top covering structure, forming a liquid metal wiring chamber, injecting magnetic liquid metal, enabling the magnetic liquid metal to flow to a preset position by a magnetic liquid metal flowing control magnetic bar through magnetic guidance, solidifying the magnetic liquid metal, and completing metal wiring. And forming the silicon adapter plate structure with the liquid metal wiring. According to the invention, the preparation and control of the liquid metal wiring in the local area on the silicon adapter plate are realized, so that after the silicon adapter plate is prepared or the core particles and the silicon adapter plate are integrated, through the change of the liquid metal wiring structure, the change of the interconnection structure between key interfaces is realized, the interconnection circuit network in the core particle integration is changed, and the integration of the core particles and the silicon adapter plate is realized. And the function switching of the integrated chip can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of advanced packaged integrated chips, and in particular relates to a silicon adapter plate structure with liquid metal wiring and a preparation method thereof. Background Art

[0002] For the existing silicon adapter board used for advanced packaging integration, the multi-layer wiring layers on both sides are realized during the manufacturing process of the adapter substrate. After the silicon adapter board is manufactured, especially after the core particle is integrated with the silicon adapter board, the interconnection circuit therein is difficult to change. Therefore, the wiring on the adapter substrate needs to be customized according to the type and number of integrated chips and the function of the integrated chip, which is not conducive to fast and low-end manufacturing. Variable interconnection circuits can be realized based on liquid metal, but liquid metal is currently mostly used for the preparation of flexible wires for circuit boards or circuit systems, such as CN113095262A discloses a three-dimensional voxel gesture posture estimation method based on multi-task information complementarity, CN110391044A discloses a flexible wire based on composite liquid metal, or for the preparation of liquid metal wiring on a flexible substrate, such as CN114758844A discloses a flexible wire based on liquid metal and its manufacturing method. As an improvement, there are currently a few methods of realizing metal wiring by wiring liquid metal on a silicon adapter board, such as CN117121196A discloses a package substrate Z decomposition with liquid metal interconnection, and the core patch through hole includes a liquid metal plug. Some through holes can be surrounded by magnetic plugs and coaxially aligned with the magnetic plug to provide improved power signal transmission. However, the liquid metal wiring currently used cannot efficiently change the interconnection circuit structure in the integrated chip, and further optimization of the function switching of the integrated chip composed of multiple core particles is needed. Summary of the invention

[0003] The present invention provides a silicon adapter plate structure with liquid metal wiring and a preparation method thereof, aiming to solve the problem that the currently used liquid metal wiring cannot efficiently change the interconnection circuit structure in the integrated chip, and the function switching of the integrated chip composed of multiple core particles needs to be further optimized.

[0004] In order to achieve the above object, the present invention adopts the following technical scheme: A method for preparing a silicon adapter plate structure with liquid metal wiring comprises the following steps: S1. Prepare a PI layer on the first surface of the silicon adapter board, and expose a copper wiring interconnection area in the PI layer; prepare a copper wiring external electrical interconnection structure in the copper wiring interconnection area, and the copper wiring external electrical interconnection structure includes an under bump metallization layer and a plurality of interconnection interfaces; S2, preparing a flow chamber bottom groove structure in the area where a plurality of interconnection interfaces are formed on the PI layer, and preparing a liquid metal barrier layer on the surface of each interconnection interface; S3, preparing a flow chamber top covering structure on the flow chamber bottom groove structure to form a liquid metal wiring chamber, and forming a metal wiring groove in the liquid metal wiring chamber; S4, opening a liquid metal injection hole and an exhaust hole in the liquid metal wiring chamber corresponding to the metal wiring groove; S5, injecting the magnetic liquid metal into the liquid metal wiring chamber through the injection hole, and sealing the liquid metal wiring chamber under an inert gas environment to form a first structure as a whole; S6. Prepare a liquid metal flow control magnetic rod, place the first structure in an environment with a preset temperature, make the magnetic liquid metal liquid, and use the magnetic liquid metal flow control magnetic rod to guide the magnetic liquid metal to flow to a preset position, lower the ambient temperature, solidify the magnetic liquid metal, complete the metal wiring, and form a silicon adapter plate structure with liquid metal wiring.

[0005] In some embodiments, in S1, a second surface opposite to the first surface of the silicon interposer has a multi-layer wiring layer and an external interconnection structure, wherein: The multi-layer wiring layer includes copper wiring, and the external interconnection structure includes pads, solder balls and metal bumps.

[0006] Further, in S1, the thickness of the PI layer is controlled to be 20-50 μm, and the PI layer is prepared by exposure, development, and curing UV photolithography processes, and the position where the copper wiring is electrically interconnected to the outside is not covered with the PI layer; The height of each interconnect interface surface is 10-15 μm lower than the height of the PI layer surface.

[0007] In some embodiments, in S2, a photolithography process of exposure, development, and curing is used to prepare a bottom groove structure of the flow chamber, wherein: The bottom groove structure of the flow chamber includes a bottom ring groove and a storage cavity, a wiring groove, an interface groove, a connecting groove, a flow groove and a supporting structure located in the bottom ring groove; The storage cavity is used to store liquid metal for subsequent wiring, the wiring groove is used for the liquid metal to flow and eventually form wiring, the interface groove is used to connect the liquid metal with the interconnection interface, the connecting groove is used for the connection between the various parts in the liquid metal wiring chamber, the flow groove is used for the liquid metal to flow from the storage cavity to the wiring groove, and the support structure can support the top covering glue layer.

[0008] Furthermore, in S2, before preparing the liquid metal barrier layer on the surface of each interconnection interface, the bottom groove structure of the flow chamber is subjected to hydrophilic and hydrophobic treatment, wherein: Plasma etching technology is used to change the surface roughness of the bottom and side walls of the connecting groove and the flow groove; The side walls and bottom of the storage cavity, wiring groove and interface groove are treated hydrophilically by coating photoresist and photolithography process.

[0009] In some embodiments, in S2, the material of the liquid metal barrier layer includes a conductive organic material, and the liquid metal barrier layer is prepared by inkjet printing technology and micro titration technology.

[0010] In some embodiments, in S3, preparing a flow chamber top cover structure on the flow chamber bottom groove structure includes: The photosensitive PI dry film is pasted to the top of the bottom groove structure of the flow chamber in a non-vacuum environment using dry film adhesive pasting technology, and then the excess film is removed by exposure, development and curing to form a covering structure on the top of the flow chamber.

[0011] In some embodiments, in S5, the magnetic liquid metal is gallium-based liquid metal. After the gallium-based liquid metal is injected into the liquid metal wiring chamber, the injection hole and the exhaust hole are sealed with high-temperature resistant PI glue or PI glue film to form a sealing structure.

[0012] In some embodiments, in S6, the material of the liquid metal flow control magnetic rod is NdFeB magnet, the end of the liquid metal flow control magnetic rod has a magnetic shielding plate, and the design of the liquid metal flow control magnetic rod is determined according to wiring requirements.

[0013] The present invention also provides a silicon adapter plate structure with liquid metal wiring, which is prepared based on the preparation method of the silicon adapter plate structure with liquid metal wiring, and the silicon adapter plate structure includes a silicon adapter plate and a liquid metal wiring chamber located on the first surface of the silicon adapter plate, wherein: The liquid metal wiring chamber includes a flow chamber bottom groove structure and a flow chamber top covering structure sealed, and the liquid metal wiring chamber includes a PI layer, an external electrical interconnection structure, and a liquid metal barrier layer from bottom to top; A metal wiring groove is formed in the liquid metal wiring chamber, and metal wiring can be formed in the metal wiring groove; It also includes a liquid metal flow control magnetic rod, which can magnetically guide the magnetic liquid metal to move in the metal wiring groove, thereby forming metal wiring.

[0014] Compared with the prior art, the silicon adapter plate structure with liquid metal wiring and the preparation method thereof of the present invention have the following beneficial effects: The present invention provides a method for preparing a silicon adapter plate structure with liquid metal wiring. By locally wiring liquid metal on the silicon adapter plate, the interconnection circuit structure in the integrated chip can be changed, and the interconnection relationship between different integrated core particles can be changed, which is further conducive to changing the function of the integrated chip composed of multiple core particles without changing the type, number and most of the interconnection circuit structure of the integrated core particles, and realizing function switching. The present invention is conducive to realizing 2.5D, 3D integrated chips and microelectronic systems with different function switching. At the same time, the convenient variable interconnection is conducive to realizing the rapid manufacturing of integrated chips, and has certain application prospects in the field of advanced electronic packaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings in the specification are used to provide further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0016] Figure 1 A schematic flow chart of a preparation method in an embodiment of a method for preparing a silicon transfer plate structure with liquid metal wiring according to the present invention; Figure 2 It is a schematic diagram of the structure after preparing through silicon vias and front and back wiring on a silicon substrate in a method for preparing a silicon adapter plate structure with liquid metal wiring of the present invention; Figure 3 It is a schematic diagram of the structure after preparing a photosensitive PI layer and photolithography in a method for preparing a silicon adapter plate structure with liquid metal wiring according to the present invention; Figure 4 It is a schematic diagram of the result after preparing the copper wiring external electrical interconnection structure in a method for preparing a silicon adapter plate structure with liquid metal wiring of the present invention; Figure 5 It is a schematic diagram of a local area of ​​a top view and a cross-section of a structure of an external electrical interconnection of a copper wiring in a method for preparing a silicon adapter plate structure with liquid metal wiring according to the present invention; Figure 6 It is a structural schematic diagram of a method for preparing a silicon adapter plate structure with liquid metal wiring according to the present invention after preparing a groove structure at the bottom of a flow chamber; Figure 7 It is a schematic structural diagram of a method for preparing a silicon adapter plate structure with liquid metal wiring according to the present invention after preparing a liquid metal barrier layer; Figure 8 It is a structural schematic diagram of a method for preparing a silicon adapter plate structure with liquid metal wiring according to the present invention after preparing a flow chamber top covering structure; Fig. 9It is a schematic structural diagram of a method for preparing a silicon adapter plate structure with liquid metal wiring according to the present invention after preparing liquid metal injection holes and exhaust holes; Fig.10 A schematic diagram of a state of injecting magnetic liquid metal in a method for preparing a silicon adapter plate structure with liquid metal wiring according to the present invention; Fig.11 It is a structural schematic diagram of a liquid metal flow control magnetic rod in a silicon adapter plate structure with liquid metal wiring according to the present invention; Fig.12 It is a schematic diagram of liquid metal wiring implemented in a chamber in a method for preparing a silicon adapter plate structure with liquid metal wiring according to the present invention; Fig.13 It is a structural schematic diagram of a silicon adapter plate structure with liquid metal wiring according to the present invention; Fig.14 It is a schematic structural diagram of a silicon transfer board structure with liquid metal wiring in the present invention, wherein the packaging welding structure is interconnected to the packaging carrier in application; Fig.15 It is a schematic structural diagram of electrical interconnection of different core particle interfaces in an application of a silicon adapter plate structure with liquid metal wiring according to the present invention; Fig.16 The present invention is a schematic structural diagram of a silicon adapter plate structure with liquid metal wiring, in which the liquid metal wiring solidifies during application, thereby changing the interconnection state of the interface.

[0017] In the figure, 101, silicon substrate, 102, silicon through via, 103, multi-layer wiring layer, 104, copper wiring, 106, supporting substrate, 201, PI layer, 301, UBM, 302, interconnection interface, 401, bottom ring groove, 402, storage cavity, 403, wiring groove, 404, interface groove, 405, connecting groove, 406, flow groove, 407, supporting structure, 501, barrier layer, 601, chamber top covering structure, 701, injection hole, 702, exhaust hole, 801, magnetic liquid metal, 802, blocking structure, 901, magnetic rod, 902, magnetic shielding plate, 903, slit, 1001, metal wiring, 1101, core particle, 1102, welding structure. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0021] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention 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 invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0022] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0023] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Based on this, the present invention provides a method for preparing a silicon adapter plate structure with liquid metal wiring, comprising the following steps: S1. Prepare a PI layer on the first surface of the silicon adapter board, and expose a copper wiring interconnection area in the PI layer; prepare a copper wiring external electrical interconnection structure in the copper wiring interconnection area, and the copper wiring external electrical interconnection structure includes an under bump metallization layer and a plurality of interconnection interfaces; S2, preparing a flow chamber bottom groove structure in the area where a plurality of interconnection interfaces are formed on the PI layer, and preparing a liquid metal barrier layer on the surface of each interconnection interface; S3, preparing a flow chamber top covering structure on the flow chamber bottom groove structure to form a liquid metal wiring chamber, and forming a metal wiring groove in the liquid metal wiring chamber; S4, opening a liquid metal injection hole and an exhaust hole in the liquid metal wiring chamber corresponding to the metal wiring groove; S5, injecting the magnetic liquid metal into the liquid metal wiring chamber through the injection hole, and sealing the liquid metal wiring chamber under an inert gas environment to form a first structure as a whole; S6. Prepare a liquid metal flow control magnetic rod, place the first structure in an environment with a preset temperature, make the magnetic liquid metal liquid, and use the magnetic liquid metal flow control magnetic rod to guide the magnetic liquid metal to flow to a preset position, lower the ambient temperature, solidify the magnetic liquid metal, complete the metal wiring, and form a silicon adapter plate structure with liquid metal wiring.

[0025] The method for preparing a silicon adapter plate structure with liquid metal wiring of the present invention realizes the preparation and flow control of liquid metal wiring in a local area on the silicon adapter plate, so that after the silicon adapter plate is prepared, or after the core particle is integrated with the silicon adapter plate, the interconnection structure between key interfaces is changed by changing the liquid metal wiring structure, thereby changing the interconnection circuit network in the core particle integration, which is conducive to realizing the switching of the integrated chip function.

[0026] The silicon adapter plate structure with liquid metal wiring and the preparation method thereof of the present invention are further described in detail below through specific embodiments.

[0027] like Figure 1-12As shown, step 1: preparation of silicon through vias and front and back wiring on silicon substrate. The surface of silicon substrate 101 is cleaned, and the cleaning can be but not limited to chemical reagents and deionized water cleaning. A deep silicon etching process is used to prepare silicon through vias 102. An insulating layer is prepared on the inner wall of silicon substrate 101 and silicon through via 102 by one or more mixed processes such as thermal oxidation, atomic deposition, chemical vapor deposition, etc. The material of the insulating layer can be but not limited to SiO2, Si3N4, polyimide (Polyimide, PI), etc. Physical vapor deposition, low-pressure chemical vapor deposition, electroplating and other processes are used to prepare conductive materials filled in silicon through vias 102. The conductive materials can be copper, tungsten, polysilicon, etc. The surface is then polished by chemical mechanical polishing, and a multi-layer wiring layer 103 (containing copper wiring 104) and an external interconnection structure 105 (including pads, solder balls, metal bumps and other structures) are prepared. The multilayer wiring layer 103 can be an organic wiring layer prepared by PI photolithography and Cu electroplating, or an inorganic wiring layer prepared by Damascus wiring. The multilayer wiring layer 103 and one side of the external interconnection structure 105 have been temporarily bonded to the supporting substrate 106. The back side of the silicon substrate 101 is mechanically thinned, plasma silicon etched, and chemically mechanically polished in sequence, so that the back side exposes the conductive material filled in the silicon through hole 102 and has a flat surface. Finally, the multilayer wiring layer 103 on the back side is prepared. The preparation result is shown in FIG. Figure 2 shown.

[0028] Step 2: Preparation and photolithography of photosensitive PI layer. Figure 3 As shown, a photosensitive PI glue with a thickness of 20-50 μm is coated on the surface of the multilayer wiring layer 103 on the back, and the PI layer 201 is prepared through ultraviolet photolithography processes such as exposure, development, and curing, wherein the position of the copper wiring 104 for external electrical interconnection is not covered with PI glue.

[0029] Step 3: Preparation of copper wiring for external electrical interconnection structure. Figure 4As shown, the copper wiring on the PI layer 201 includes UBM (Under-Bump Metallurgy) 301 and interconnection interface 302 for external electrical interconnection structure. UBM 301 is used to connect the copper wiring 104 to the external interconnection chip. Interconnection interface 302 is used to interconnect the copper wiring 104 with the liquid metal wiring. First, 100-400nm Ti and Cu layers are sequentially deposited on the PI layer 201 by physical vapor deposition technology, and the area where the UBM 301 and the interconnection interface 302 need to be prepared is exposed by coating photoresist and performing photolithography. Then, a thicker Cu metal layer is prepared on the exposed area by electroplating Cu process. Finally, the photoresist is removed by a degumming liquid, and the excess Ti and Cu metals are removed by reagents such as hydrogen peroxide, phosphoric acid, and hydrofluoric acid. This process needs to adjust the thickness of the Cu metal layer according to the thickness of the PI layer 201 to ensure that the height of the surface of the interconnection interface 302 should be 10-15μm lower than the height of the surface of the PI layer 201. Optionally, in order to reduce oxidation of Cu metal in subsequent processes, a Ni or Au metal layer may be prepared on the Cu surface using chemical plating technology.

[0030] Step 4: Preparation of the bottom groove structure of the flow chamber. A liquid metal flow chamber is prepared in a local area with an interconnection interface 302 on the PI layer 201. The top view and cross-sectional view of the local area are shown in FIG. Figure 5 As shown. The figure shows an example of a top view and a cross-sectional view of the interconnection interface 302 of eight liquid metal wirings, and the interconnection interface 302 forms an electrical interconnection with the bottom copper wiring 104. A photoresist layer is prepared on the PI layer 201, and a bottom ring groove 401 is prepared by photolithography processes such as exposure, development, and curing. Among them, the photoresist layer should be thicker than 20μm after coating, and materials with high aspect ratio structures can be prepared after photolithography, including but not limited to PI glue and SU-8 glue, which can be liquid glue or dry film glue. As shown Figure 6 As shown, the bottom ring groove 401 should include a storage cavity 402, a wiring groove 403, an interface groove 404, a connecting groove 405, a flow groove 406, and optionally also includes a support structure 407, but is not limited to Figure 6 Structure shown. Storage cavity 402 is used for storing liquid metal after it is injected into the chamber, and for storing the remaining liquid metal after the wiring is completed. Wiring groove 403 is used for the liquid metal to flow and eventually form wiring. Interface groove 404 is used to connect the liquid metal to the interconnection interface 302. Communication groove 405 is used for communication between various structures in the chamber to avoid gas accumulation when the liquid metal flows, thereby affecting the flow of liquid metal. Flow groove 406 is used for liquid metal to flow from storage cavity 402 to wiring groove 403. Support structure 407 is used to support the top layer covering glue layer to prevent it from collapsing when the storage cavity 402 is large in size.

[0031] Step 5: Hydrophilic and hydrophobic treatment of the bottom groove structure. This process is an optional process, and the hydrophilic and hydrophobic treatment is beneficial to the flow and wiring of the liquid metal. The wafer is coated with photoresist, and the bottom and side walls of the connecting groove 405 and the flow groove 406 are exposed by exposure, development and other processes, and the bottom and side walls of the storage cavity 402, the wiring groove 403, and the interface groove 404 are covered. Using plasma etching technology, the surface roughness of the bottom and side walls of the connecting groove 405 and the flow groove 406 is changed, so that the surface has a hydrophobic effect on the liquid metal, which is beneficial to reduce the residual material when the liquid metal flows in the connecting groove 405 and the flow groove 406. Optionally, the side walls and bottom of the storage cavity 402, the wiring groove 403, and the interface groove 404 are hydrophilic by coating photoresist and photolithography technology, so that the material adheres to the surface when the liquid metal flows to form metal wiring.

[0032] Step 6: Preparation of liquid metal barrier layer. Since liquid metal has an erosive effect on Cu metal, in order to avoid corrosion of the interconnection interface 302, a barrier layer 501 needs to be prepared on its surface, such as Figure 7 As shown. The material of the barrier layer 501 is a conductive organic material, such as a polythiophene conductive polymer solution. In order to realize the preparation of the barrier layer 501 in the local area around the interconnection interface 302, inkjet printing technology, micro titration technology, etc. are used to accurately control the spraying amount of the solution material such as the polythiophene conductive polymer according to the volume of the countersunk hole above the interconnection interface 302 to avoid overflowing into the flow tank 406.

[0033] Step 7: Preparation of the flow chamber top covering structure. Use photosensitive PI dry film adhesive with high support strength, and use dry film adhesive film sticking technology to stick it to the top of the bottom ring groove 401 in a non-vacuum environment. Then remove the excess adhesive film through exposure, development, and curing to form the chamber top covering structure 601, as shown in FIG. Figure 8 The chamber top covering structure 601 and the bottom annular groove 401 together form an airtight liquid metal wiring chamber to prevent the liquid metal from leaking out.

[0034] Step 8: Preparation of liquid metal injection hole and exhaust hole. In order to inject the liquid metal into the airtight liquid metal wiring chamber, it is necessary to prepare an injection hole 701 and an exhaust hole 702 above the storage cavity 402, such as Fig. 9 As shown. The former is used for the injection of the solution metal, and the latter is used for the exhaust of the gas inside the chamber during the injection. Optionally, the injection hole 701 and the exhaust hole 702 can be directly prepared on the dry film glue by using the photolithography process in step 7, or they can be prepared by laser drilling technology after step 7. Laser drilling can effectively realize the processing of micro-sized hole structures, and can also process only the chamber top cover structure 601 through the laser focusing position to avoid damage to the bottom ring groove 401.

[0035] Step 9: Preparation of magnetic gallium-based liquid metal. This process can also be completed before steps 1 to 8. The present invention uses gallium-based liquid metal and adds magnetic materials such as Fe and Ni to form a magnetic gallium-based liquid metal alloy. In addition, the Fe and Ni elements can increase the melting point of the alloy, increase the density of the alloy, and make the alloy have better tensile resistance. At the same time, Ag material is added to increase the melting point of the liquid metal alloy while improving its conductivity. By adjusting the doping concentration of the above materials, the liquid metal can be made magnetic for subsequent control of its flow. And the melting point is increased to 100°C, which is used to control the melting and solidification of the liquid metal.

[0036] Step 10: Injection of magnetic liquid metal. Use a micro-injection device with heating function to heat the magnetic liquid metal 801 to above the melting point, and inject an appropriate amount of 801 magnetic liquid metal according to the volume of the wiring cavity, such as Fig.10 As shown. Too little magnetic liquid metal 801 is not enough to form a wiring of sufficient length, and too much magnetic liquid metal 801 will cause it to accumulate in the wiring groove. After the magnetic liquid metal 801 is injected, the injection hole 701 and the exhaust hole 702 are sealed with high temperature resistant PI glue or PI glue film to form a sealing structure 802 to ensure the airtightness of the wiring cavity. The whole process should be carried out in a nitrogen environment to reduce the oxidation of the magnetic liquid metal 801.

[0037] Step 11: Preparation of magnetic rod for controlling the flow of liquid metal. The flow of magnetic liquid metal 801 is controlled by a magnetic rod 901, the end of which is as follows: Fig.11 As shown. In order to ensure that it has sufficient magnetic force on the magnetic liquid metal 801 to realize the movement of the magnetic liquid metal 801 in the wiring cavity, the magnetic bar should be a NdFeB magnet. In order to control the magnetic force to act only on a local area in the wiring cavity, there should be a magnetic shielding plate 902 at the end of the magnetic bar 901, and materials with good magnetic shielding effect such as Permalloy should be used. There is a slit 903 on the magnetic shielding plate 902, so that the magnetic field acts on the magnetic liquid metal 801 only through the slit 903. The width of the slit 903 should be consistent with the width of a single groove of the wiring groove 403 to avoid the magnetic field from acting on adjacent grooves. The shape of the slit 903 is determined according to the wiring requirements, including "I" shape, "X" shape, "M" shape, etc.

[0038] Step 12: Induction of liquid metal flow and solidification. Place the silicon adapter plate on the heating table and adjust the heating temperature to transform the magnetic liquid metal 801 into a liquid state. Place the magnetic bar 901 above the wiring cavity, and apply a magnetic field to the liquid magnetic liquid metal 801 by controlling the direction and position of the slit 903, so that it enters the wiring groove 403 from the storage cavity 402 through the flow groove 406. According to the interface position of the electrical interconnection as needed, the magnetic liquid metal 801 flows along the wiring groove 403, enters the interface groove 404 and interconnects with the barrier layer 501. After the connection is completed, the excess magnetic liquid metal 801 is induced to enter the storage cavity 402 through the flow groove 406. Finally, the temperature is lowered to solidify the magnetic liquid metal 801, and the electrical interconnection is finally completed. Fig.12 Schematic diagram of liquid metal wiring implemented in the chamber. Fig.13 Silicon interposer with liquid metal wiring.

[0039] The present invention provides a silicon transfer board structure with liquid metal wiring and a preparation method thereof. The prepared silicon transfer board with liquid metal wiring can realize a variable interconnection network in core particle integration. First, the steps 1 to 7 of the preparation process of liquid metal wiring 11 are completed on the silicon transfer board. Then, multiple core particles 1101 are interconnected to the silicon transfer board through a welding structure 1102 (solder balls or micro bumps), and the silicon transfer board is then interconnected to a packaging carrier 1103 through the welding structure 1102. Fig.14 As shown. Continue to complete the remaining process steps of liquid metal wiring preparation. By controlling the flow of liquid metal through the magnetic rod, the electrical interconnection of different core particle interfaces can be achieved. Through the flow and solidification of liquid metal, the electrical interconnection between the left core particle IO-2 interface and the right core particle I / O-1, and the electrical interconnection between the side core particle IO-4 interface and the right core particle I / O-3 can be achieved, as shown. Fig.15 The temperature is further heated to above the melting point of the liquid metal to liquefy it, and then the flow of the liquid metal is controlled by a magnetic rod, and then the temperature is lowered to solidify the liquid metal wiring, thereby changing the interconnection state of the interface, for example, the left core particle IO-2 interface becomes an electrical interconnection with the right core particle I / O-2, and the side core particle IO-4 interface becomes an electrical interconnection with the right core particle I / O-4, as shown. Fig.16 As shown. The present invention can realize the change of interconnection circuits in multi-chip 2.5D integration, thereby changing the function of the entire integrated chip after the core particles are integrated. With the help of standardized chip selection and interconnection circuit design, most of the interconnected integrated circuits are realized, and key interconnection interfaces are reserved. The local variable interconnection of liquid metal is used to realize the interconnection of different interfaces, thereby changing the function of the entire integrated chip and realizing different types of products. It is helpful to realize the rapid manufacturing and function switching of products with different functions, and reduce the production cycle and cost.

[0040] Finally, it should be noted that the above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as shown in the specification and described above, and any equivalent changes, modifications and evolutions made by using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a silicon transfer plate structure with liquid metal wiring, characterized in that: The steps include: S1. Prepare a PI layer on the first surface of the silicon adapter board, and expose a copper wiring interconnection area in the PI layer; prepare a copper wiring external electrical interconnection structure in the copper wiring interconnection area, and the copper wiring external electrical interconnection structure includes an under bump metallization layer and a plurality of interconnection interfaces; S2, preparing a flow chamber bottom groove structure in the area where a plurality of interconnection interfaces are formed on the PI layer, and preparing a liquid metal barrier layer on the surface of each interconnection interface; S3, preparing a flow chamber top covering structure on the flow chamber bottom groove structure to form a liquid metal wiring chamber, and forming a metal wiring groove in the liquid metal wiring chamber; S4, opening a liquid metal injection hole and an exhaust hole in the liquid metal wiring chamber corresponding to the metal wiring groove; S5, injecting the magnetic liquid metal into the liquid metal wiring chamber through the injection hole, and sealing the liquid metal wiring chamber under an inert gas environment to form a first structure as a whole; S6. Prepare a liquid metal flow control magnetic rod, place the first structure in an environment with a preset temperature, make the magnetic liquid metal liquid, and use the magnetic liquid metal flow control magnetic rod to guide the magnetic liquid metal to flow to a preset position, lower the ambient temperature, solidify the magnetic liquid metal, complete the metal wiring, and form a silicon adapter plate structure with liquid metal wiring.

2. The method for preparing a silicon transfer plate structure with liquid metal wiring according to claim 1, characterized in that: In S1, the second surface opposite to the first surface of the silicon transfer board has a multi-layer wiring layer and an external interconnection structure, wherein: The multi-layer wiring layer includes copper wiring, and the external interconnection structure includes pads, solder balls and metal bumps.

3. The method for preparing a silicon transfer plate structure with liquid metal wiring according to claim 2, characterized in that: In S1, the thickness of the PI layer is controlled to be 20-50 μm, and the PI layer is prepared by exposure, development, and curing ultraviolet photolithography processes, and the position where the copper wiring is electrically interconnected to the outside is not covered with the PI layer; The height of each interconnect interface surface is 10-15 μm lower than the height of the PI layer surface.

4. The method for preparing a silicon transfer plate structure with liquid metal wiring according to claim 1, characterized in that: In S2, a photolithography process of exposure, development and curing is used to prepare a groove structure at the bottom of the flow chamber, wherein: The bottom groove structure of the flow chamber includes a bottom ring groove and a storage cavity, a wiring groove, an interface groove, a connecting groove, a flow groove and a supporting structure located in the bottom ring groove; The storage cavity is used to store liquid metal for subsequent wiring, the wiring groove is used for the liquid metal to flow and eventually form wiring, the interface groove is used to connect the liquid metal with the interconnection interface, the connecting groove is used for the connection between the various parts in the liquid metal wiring chamber, the flow groove is used for the liquid metal to flow from the storage cavity to the wiring groove, and the support structure can support the top covering glue layer.

5. The method for preparing a silicon transfer plate structure with liquid metal wiring according to claim 4, characterized in that: In said S2, before preparing the liquid metal barrier layer on the surface of each interconnection interface, the bottom groove structure of the flow chamber is subjected to hydrophilic and hydrophobic treatment, wherein: Plasma etching technology is used to change the surface roughness of the bottom and side walls of the connecting groove and the flow groove; The side walls and bottom of the storage cavity, wiring groove and interface groove are treated hydrophilically by coating photoresist and photolithography process.

6. The method for preparing a silicon transfer plate structure with liquid metal wiring according to claim 1, characterized in that: In S2, the material of the liquid metal barrier layer includes a conductive organic material, and the liquid metal barrier layer is prepared by inkjet printing technology and micro titration technology.

7. The method for preparing a silicon transfer plate structure with liquid metal wiring according to claim 1, characterized in that: In the above S3, preparing the flow chamber top cover structure on the flow chamber bottom groove structure comprises: The photosensitive PI dry film is pasted to the top of the bottom groove structure of the flow chamber in a non-vacuum environment using dry film adhesive technology. The excess film is removed through exposure, development and curing to form a covering structure on the top of the flow chamber.

8. The method for preparing a silicon transfer plate structure with liquid metal wiring according to claim 1, characterized in that: In S5, the magnetic liquid metal is gallium-based liquid metal. After the gallium-based liquid metal is injected into the liquid metal wiring chamber, the injection hole and the exhaust hole are sealed with high temperature resistant PI glue or PI glue film to form a sealing structure.

9. The method for preparing a silicon transfer plate structure with liquid metal wiring according to claim 1, characterized in that: In the above S6, the material of the liquid metal flow control magnetic rod is NdFeB magnet, the end of the liquid metal flow control magnetic rod has a magnetic shielding plate, and the design of the liquid metal flow control magnetic rod is determined according to the wiring requirements.

10. A silicon transfer board structure with liquid metal wiring, characterized in that: The silicon adapter plate structure with liquid metal wiring is prepared based on the preparation method of the silicon adapter plate structure with liquid metal wiring according to any one of claims 1 to 9, and the silicon adapter plate structure includes a silicon adapter plate and a liquid metal wiring chamber located on the first surface of the silicon adapter plate, wherein: The liquid metal wiring chamber includes a flow chamber bottom groove structure and a flow chamber top covering structure sealed, and the liquid metal wiring chamber includes a PI layer, an external electrical interconnection structure, and a liquid metal barrier layer from bottom to top; A metal wiring groove is formed in the liquid metal wiring chamber, and metal wiring can be formed in the metal wiring groove; It also includes a liquid metal flow control magnetic rod, which can magnetically guide the magnetic liquid metal to move in the metal wiring groove, thereby forming metal wiring.

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