Electroplating apparatus and electroplating device

Abstract

The present application provides an electroplating apparatus and an electroplating device for electroplating a substrate. The electroplating apparatus is used for plating metal inside a plurality of through-hole vias, wherein the electroplating apparatus comprises: a tank body, which defines a chamber; a substrate holder, configured for maintaining a substrate in a vertical orientation within the chamber during electroplating and dividing the chamber into a first plating chamber and a second plating chamber, the first plating chamber and the second plating chamber being configured for accommodating an electroplating solution; during the process of electroplating inside the plurality of through-hole vias to form a metal bridge, the first plating chamber and the second plating chamber are configured to accommodate the electroplating solution at different liquid levels, so that the electroplating solution flows from a plating chamber with a higher liquid level to a plating chamber with a lower liquid level through the through-hole vias.

Description

Electroplating apparatus and electroplating equipment

[0001] This application claims priority to Chinese Patent Application No. 202510125703.5, filed on January 26, 2025, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] This application belongs to the field of semiconductor manufacturing equipment, and in particular relates to an electroplating apparatus and electroplating equipment for a substrate. Background Technology

[0003] 3D packaging is currently the most mature integration category in the industry, primarily stacking bare chips or individually packaged chips together through packaging. Currently, 3D packaging encompasses many different technologies, most of which are extensions of single-chip packaging technologies into three dimensions. Interposers, also known as insertion layers or intermediate layers, are a new type of electronic substrate that enables interconnection between fine-pitch I / O at the top die level and larger, wider-pitch I / O at the bottom package level. With the development of AI technology, the application of panel-level glass interposers is increasing. Glass interposers offer good insulation and isolation, effectively reducing insertion loss and crosstalk at high frequencies; simultaneously, the adjustable coefficient of thermal expansion of glass can reduce thermal mismatch with different materials. Glass interposers incorporate numerous through-glass vias (TGVs), extending interconnects through the substrate. This allows for vertical integration while shortening interconnect length, thereby reducing size, weight, and power consumption. TGVs are the foundation and core of current 2.5D and 3D electronic architectures and high-density MEMS (Micro-electromechanical Systems) devices.

[0004] TGV technology first requires forming through-holes on a glass substrate, followed by metallization of the hole walls. Typically, a conductive seed layer (e.g., a copper seed layer) is formed on the hole walls using processes such as PVD. Then, the holes are filled by electroplating to form a complete conductive path. The main challenge in filling deep holes via electroplating is achieving rapid filling.

[0005] Therefore, in view of the problems existing in the prior art, the inventor of this application, based on his many years of experience in this industry, actively researched and improved the technology, and thus the electroplating apparatus and electroplating equipment of this application came into being. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this application is to provide an electroplating apparatus and electroplating equipment to solve the problems of slow and uneven copper filling efficiency in the prior art.

[0007] To achieve the above and other related objectives, this application provides an electroplating apparatus for an electroplating substrate, the substrate including a first surface, a second surface opposite to the first surface, and a plurality of through holes extending from the first surface to the second surface, the electroplating apparatus being used to plate metal within the plurality of through holes, the electroplating apparatus comprising:

[0008] The tank body forms a cavity;

[0009] A substrate holder is used to hold the substrate in a vertical position within the chamber during electroplating and to divide the chamber into a first plating chamber and a second plating chamber, the first plating chamber and the second plating chamber being used to contain the electroplating solution;

[0010] During the electroplating process of forming metal bridges in the plurality of through holes, the first plating chamber and the second plating chamber are configured to contain electroplating solutions with different liquid levels so that the electroplating solution flows from the plating chamber with the higher liquid level through the through holes to the plating chamber with the lower liquid level.

[0011] Optionally, the first plating chamber and the second plating chamber are configured such that, during the process of forming a metal bridge by electroplating in the plurality of through holes, the height relationship of the electroplating solution in the first plating chamber relative to the second plating chamber is changed at least once to change the flow direction of the electroplating solution in the through holes.

[0012] Optionally, the liquid level relationship between the first plating chamber and the second plating chamber alternates, and the alternation interval is the same.

[0013] Optionally, the first plating chamber is provided with at least one first liquid outlet, and the second plating chamber is provided with at least one second liquid outlet, wherein at least one first liquid outlet is higher than at least one second liquid outlet, and at least one second liquid outlet is higher than at least one first liquid outlet.

[0014] Optionally, at least one plating chamber is provided with multiple liquid outlet pipes of different heights, with each liquid outlet located on each liquid outlet pipe.

[0015] Optionally, the first liquid outlet and the second liquid outlet are openings at different heights on the side wall of the tank.

[0016] Optionally, the first plating chamber is provided with a first liquid outlet, the second plating chamber is provided with a second liquid outlet, each plating chamber is provided with a liftable liquid outlet pipe, and each liquid outlet is provided on each liquid outlet pipe. The liquid outlet pipe of the first plating chamber can be raised and lowered until the first liquid outlet is higher than the second liquid outlet, and the liquid outlet pipe of the second plating chamber can be raised and lowered until the second liquid outlet is higher than the first liquid outlet.

[0017] Optionally, each plating chamber further includes a liquid supply assembly, which includes an inlet and an outlet. The inlet and outlet of each plating chamber are located on both sides of the substrate. The inlets of the first plating chamber and the second plating chamber are symmetrically arranged in the two plating chambers with respect to the substrate, so that the electroplating solution in the two plating chambers flows in the same direction relative to the substrate.

[0018] Optionally, each plating chamber includes two sets of liquid supply components. The inlets of the two sets of liquid supply components in each plating chamber are respectively located on both sides of the substrate. The two sets of liquid supply components are configured to switch from one set of liquid supply components to another set of liquid supply components to change the flow direction of the electroplating solution on the substrate surface.

[0019] Optionally, the two sets of liquid supply components are symmetrically arranged in the two plating chambers with respect to the substrate, and are configured to supply liquid simultaneously during the electroplating process of forming metal bridges in the plurality of through holes, so that the flow direction of the electroplating liquid in the two plating chambers is the same relative to the substrate.

[0020] Optionally, during the process of electroplating to form metal bridges in the plurality of through holes, each plating chamber is configured such that the electroplating solution enters the corresponding plating chamber from an inlet located on the same side of the substrate and exits the plating chamber from an outlet located on the same side of the substrate, so that the flow direction of the electroplating solution in the two plating chambers relative to the substrate is the same.

[0021] Optionally, during the process of electroplating to form metal bridges in the plurality of through holes, each plating chamber is configured such that the electroplating solution enters the corresponding plating chamber from an inlet located on the same side of the substrate and exits the plating chamber from an outlet located on the same side of the substrate, so that the flow direction of the electroplating solution in the two plating chambers relative to the substrate is the same.

[0022] Optionally, during the electroplating process of forming metal bridges within the plurality of through holes, the flow velocity within the through holes satisfies:

[0023] v is the flow velocity inside the through hole, r is the maximum radius of the through hole, ΔP is the pressure difference across the through hole, μ is the dynamic viscosity of the electroplating solution, and L is the length of the through hole.

[0024] Optionally, the electroplating apparatus is configured such that the flow rate of the electroplating solution entering each plating chamber increases.

[0025] Optionally, the electroplating apparatus is configured such that the flow rate of the electroplating solution entering each plating chamber increases.

[0026] Optionally, the electroplating apparatus is configured to increase the flow rate of the electroplating solution in the through hole by changing the difference in liquid level height between the two plating chambers.

[0027] Optionally, the substrate holder includes a first carrier plate and a second carrier plate for clamping the substrate respectively. Both the first carrier plate and the second carrier plate include openings for exposing a first surface and a second surface of the substrate to the electroplating solution. The openings are provided with cross structures for supporting the two surfaces of the substrate respectively.

[0028] Optionally, a strain gauge for detecting substrate warping during electroplating is further provided between the cross structure and the substrate surface.

[0029] Optionally, a strain gauge for detecting substrate warping during electroplating is further provided between the cross structure and the substrate surface.

[0030] Optionally, the outer periphery of the substrate holder is at least partially surrounded by a sealing ring to isolate the two plating cavities.

[0031] Optionally, the electroplating apparatus is configured to form metal bridges within the plurality of through holes and continue electroplating until the through holes are completely filled.

[0032] To achieve the above and other related objectives, this application also provides an electroplating apparatus for electroplating a substrate, the substrate including a first surface, a second surface opposite to the first surface, and a plurality of through holes penetrating the first surface and the second surface, the electroplating apparatus being used to plate metal in the plurality of through holes, the electroplating apparatus including a first electroplating apparatus and a second electroplating apparatus, the first electroplating apparatus being used to plate metal in the plurality of through holes to form metal bridges, the second electroplating apparatus being used to transfer the substrate from the first electroplating apparatus to the second electroplating apparatus after the metal bridges are formed to continue electroplating until the through holes are completely filled, the first electroplating apparatus being any of the electroplating apparatuses described above.

[0033] Optionally, during the process of electroplating the substrate in the second electroplating apparatus to completely fill the through-hole, the second electroplating apparatus is configured to alternately change the flow direction of the electroplating solution on the substrate surface.

[0034] To achieve the above and other related objectives, this application also provides an electroplating apparatus for an electroplating substrate, the substrate including a first surface, a second surface opposite to the first surface, and a plurality of through holes penetrating the first surface and the second surface, the electroplating apparatus being used to plate metal within the plurality of through holes, the electroplating apparatus comprising:

[0035] A first electroplating apparatus is used to vertically electroplat the substrate to form metal bridges within the plurality of through holes;

[0036] The second electroplating apparatus is used to completely fill the plurality of through holes by horizontal electroplating after the first electroplating apparatus electroplats the substrate to form metal bridges in the plurality of through holes.

[0037] Optionally, the first electroplating apparatus is configured to stop vertical electroplating when the time for electroplating the substrate reaches a threshold.

[0038] To achieve the above and other related objectives, this application also provides an electroplating apparatus for electroplating a substrate, the substrate including a first surface, a second surface opposite to the first surface, and a plurality of through holes penetrating the first surface and the second surface, the electroplating apparatus electroplating the substrate to plate metal in the plurality of through holes, the electroplating apparatus including a first electroplating apparatus and a second electroplating apparatus, the first electroplating apparatus being used to vertically electroplat the substrate to form metal bridges in the plurality of through holes, the second electroplating apparatus being used to transfer the substrate from the first electroplating apparatus to the second electroplating apparatus after the metal bridges are formed to continue electroplating until the through holes are completely filled, the first electroplating apparatus being any of the electroplating apparatuses described above, and the second electroplating apparatus being configured to continue electroplating the substrate by horizontal electroplating.

[0039] As described above, in the electroplating apparatus provided in this application, the electroplating solution flows from the plating chamber with a high liquid level to the plating chamber with a low liquid level through the through hole, allowing more metal ions to pass through the through hole to form metal bridges in the through hole more quickly. By changing the liquid level relationship between the two plating chambers, the flow direction of the electroplating solution in the through hole is changed, making the metal bridges formed in the through hole more uniform.

[0040] Overview of the attached figures

[0041] The features and performance of this application are further described by the following embodiments and accompanying drawings.

[0042] Figure 1 is a partial structural schematic diagram of the substrate in this application.

[0043] Figure 2 is a schematic diagram of the structure in this application where through holes on the substrate are bridged to form a metal bridge.

[0044] Figure 3 is a top-view structural diagram of the electroplating equipment in the first embodiment of this application.

[0045] Figure 4 is a top-view structural diagram of the electroplating equipment in the second embodiment of this application.

[0046] Figure 5A is a cross-sectional schematic diagram of an electroplating apparatus in one embodiment of this application.

[0047] Figure 5B is a cross-sectional schematic diagram of the electroplating apparatus in another embodiment of this application.

[0048] Figure 6 is a schematic diagram showing the height relationship between the inlet pipe and the outlet pipe in the two plating chambers in one embodiment of this application.

[0049] Figure 7 is a schematic diagram of the structure of a substrate holder in one embodiment of this application.

[0050] Preferred embodiments of the present invention

[0051] The terms "front", "back", "front", "rear", "upper", "lower", "left", and "right" are used in this specification for ease of explanation and to indicate the position and orientation of the illustrated figures on the paper. The actual configuration of the device during use may differ.

[0052] As shown in Figure 1, the substrate in this application includes a first surface S1, a second surface S2 opposite to the first surface S1, and a plurality of through holes V extending from the first surface S1 to the second surface S2. The TGV technology used in this application for electroplating and filling the through holes is shown in Figure 2. First, metal is plated into the through hole V from both sides to form metal bridges B, which bridge the through hole V. The metal bridges B divide the through hole into two blind holes V1 and V2. Then, metal plating continues to completely fill the two blind holes V1 and V2. As shown in Figure 1, in order to form the metal bridges B more quickly within the through holes V, the size of the through holes V gradually decreases from the first surface S1 and the second surface S2 towards the interior of the substrate until the narrowest part V3. This allows metal ions to enter the through hole from the first opening on the first surface S1 and the second opening on the second surface S2, and to more easily concentrate in the narrowest part V3, thus making it easier to form the metal bridges B shown in Figure 2 in the narrowest part V3.

[0053] In this application, the process of plating metal within a through-hole to form a metal bridge and divide the through-hole into two blind holes (the bridging process) and the process of plating metal to completely fill the two blind holes (the blind hole filling process) are completed in one or two electroplating apparatuses. In some embodiments, when bridging and blind hole filling are completed in one electroplating apparatus, metal is plated within a general-purpose hole to form a metal bridge. In other embodiments, bridging and blind hole filling are completed in two electroplating apparatuses, and different chemical additives are added to the electroplating solutions in different electroplating apparatuses according to the different requirements of bridging and blind hole filling.

[0054] The following will focus on the electroplating equipment provided in this application, where bridging and blind via filling are performed in two separate electroplating units. Figure 3 is a schematic diagram of a first embodiment of the electroplating equipment. As shown in Figure 3, the electroplating equipment includes substrate boxes LP1-LP2 for loading substrates, a front-end robot 101, a front-end cavity 102, a process robot 103, a loading cavity 104, and multiple process cavities PM11-PM14. The multiple process cavities PM11-PM14 include a first electroplating cavity PM11 and a second electroplating cavity PM12 for electroplating the substrate, a cleaning cavity PM13 for cleaning the substrate after electroplating, and a pre-wetting cavity PM14 for wetting the substrate before electroplating. The front-end robot 101 removes the substrate from the substrate boxes LP1-LP2 and transfers it to the loading chamber 104. Next, the process robot 103 removes the substrate from the loading chamber 104 and transfers it to the pre-wetting chamber PM14 to wet the substrate. It then transfers it to the first electroplating chamber PM11 for electroplating, depositing metal in the through-holes to form metal bridges, which divide the through-holes into two blind holes (described in detail below). Next, it transfers it to the cleaning chamber PM13 to clean the substrate, and then to the second electroplating chamber PM12 for vertical electroplating to fill the two blind holes (described in detail below). It should be understood that the substrate needs to be wetted before electroplating and cleaned after electroplating. This embodiment does not describe in detail the substrate wettation process before electroplating in the second electroplating chamber PM12 or the substrate cleaning process after electroplating, but these two substrate processing steps are not omitted before or after electroplating. In this embodiment, during the electroplating of the substrate, the substrate is held in a vertical position within the first electroplating chamber PM11 and the second electroplating chamber PM12.

[0055] In the second embodiment, as shown in FIG4, during the plating of the substrate in the first plating chamber PM11, the substrate is held in a vertical position within the chamber, and during the plating of the substrate in the second plating chamber PM12, the substrate is held in a horizontal position within the chamber. In the second embodiment, the substrate transfer logic and device structure are largely the same as in the first embodiment, but the transfer logic and device structure differ slightly due to the switching of the substrate's position. In the second embodiment, to facilitate substrate flipping, the plating equipment includes a flipping mechanism 105 for flipping the substrate to switch between a horizontal and a vertical position. The process robot 103 includes a first process robot 1031 for transferring substrates held in a vertical position between multiple process chambers and a second process robot 1032 for transferring substrates held in a horizontal position between multiple process chambers. The front-end robot 101 removes the substrate from the substrate boxes LP1-LP2 and transfers it to the loading cavity 104. Next, the first process robot 1031 removes the substrate from the loading cavity 104 and transfers it to the first pre-wetting cavity PM214 to wet the substrate. It then transfers it to the first electroplating cavity PM11 for electroplating, depositing metal in the through-holes of the substrate to form metal bridges that bridge the through-holes. The metal bridges divide the through-holes into two blind holes (described in detail below). When the electroplating time in the first electroplating cavity PM11 reaches a threshold, the bridging is considered complete, and vertical electroplating stops. The bridged substrate is then transferred to the first cleaning cavity PM213 for cleaning, and finally returned to the loading cavity 104. The front-end robot 101 transfers the cleaned substrate from the loading chamber 104 to the flipping mechanism 105 to change the substrate from a vertical to a horizontal position. Then, the second process robot 1032 removes the horizontally positioned substrate from the flipping mechanism 105 and transfers it to the second pre-wetting chamber PM224 to wet the substrate. It then transfers it to the second electroplating chamber PM12 for horizontal electroplating to deposit metal and fill two blind vias. Next, it transfers it to the second cleaning chamber PM223 to clean the substrate. It then transfers it back to the flipping mechanism 105 to change the substrate from a horizontal to a vertical position. Finally, the front-end robot 101 retrieves the substrate from the flipping mechanism 105 and places it in wafer cassettes LP1-LP2. In this embodiment, because the substrate is held horizontally within the chambers during processing in the second cleaning chamber PM223 and the second pre-wetting chamber PM224, this increases the horizontal space of the process chambers. Therefore, to save horizontal space, the second cleaning chamber PM223 and the second pre-humidification chamber PM224 can be stacked vertically. Furthermore, at least one of the second cleaning chamber PM223 and the second pre-humidification chamber PM224 can be stacked in the same vertical direction, and the stacking arrangement of the second cleaning chamber PM223 and the second pre-humidification chamber PM224 can be designed according to actual application needs.It should be noted that during the horizontal electroplating process of filling blind vias, the electroplating solution is stirred and flows through the blind vias at high speed, increasing the current density within the blind vias and accelerating the metal plating efficiency, thereby improving the filling rate of the blind vias. Furthermore, during the horizontal electroplating process, the substrate is rotated horizontally, resulting in better plating uniformity. Therefore, after the via V-bridge is completed, horizontal electroplating is superior to vertical electroplating for filling blind vias, not only saving significant processing time but also ensuring plating uniformity. It should be understood that in this application, "horizontal electroplating" refers to the substrate being held horizontally within the electroplating apparatus during plating, and "vertical electroplating" refers to the substrate being held vertically within the electroplating apparatus during plating.

[0056] This application also provides an electroplating apparatus 100 for bridging through-holes V in a glass substrate. In the first embodiment, the first electroplating chamber PM11 within the electroplating apparatus includes at least one electroplating apparatus 100. In the second embodiment, the first electroplating chamber PM11 within the electroplating apparatus can be the electroplating apparatus 100 provided in this application, or it can be an existing vertical electroplating apparatus. Figure 5A is a cross-sectional schematic diagram of an electroplating apparatus in one embodiment, which is a horizontal (parallel to the plane of the paper) cross-section of the electroplating apparatus 100 shown in Figure 4. The electroplating apparatus includes a tank 1 and a substrate holder 2. The tank 1 forms a chamber, and the substrate holder 2 holds the substrate W within the chamber to divide the sealed chamber into a first plating chamber 10 and a second plating chamber 20, and the substrate holder 2 holds the substrate W in a vertical position within the chamber. The first plating chamber 10 includes a first anode chamber 51, and the second plating chamber 20 includes a second anode chamber 52. In some embodiments, the first plating cavity 10 and the second plating cavity 20 have the same design structure. The structure inside the first plating cavity 10 will be described in detail below.

[0057] The first anode chamber 51 of the first plating chamber 10 is used to contain the anodic plating solution and the first anode 41. The first anode 41 is immersed in the anodic plating solution to provide the anodic plating solution with metal ions to be plated, such as copper ions. A first ion membrane 61 is provided between the first anode chamber 51 and the first surface S1 of the substrate. The first ion membrane 61 only allows metal ions of the metal to be plated in the anodic plating solution to pass through. During electroplating, the first anode 41 is electrically connected to the positive terminal of an external power source (not shown), and the substrate W is electrically connected to the negative terminal of the external power source. When the external power source supplies voltage between the first anode 41 and the substrate W, the current flows along the path from the external power source through the first anode 41, the plating solution, the substrate W, and back to the external power source. Thus, metal ions in the plating solution flow from the first anode 41 to the first surface S1 of the substrate, so that the metal ions of the metal to be plated pass through the first ion membrane, flow with the current to the first surface S1 of the substrate, and fill the through holes.

[0058] To allow metal ions of the metal to be plated to pass through the vias under the attraction of the electric field, the first ion membrane 61 and the first surface S1 also need to be filled with cathodic plating solution. Therefore, a first liquid flow space 81 for filling with cathodic plating solution is provided between the first ion membrane 61 and the first surface S1, and the first surface S1 is immersed in the cathodic plating solution in the first liquid flow space 81. Thus, the first ion membrane 61 isolates the anodic plating solution from the cathodic plating solution in the plating solution, and only allows metal ions of the metal to be plated in the anodic plating solution to pass through the first ion membrane 61. A first ion electric field control element 71 is also provided within the first liquid flow space 81. The first electric field control element 71 has a plate-like structure and is provided with multiple pores to change the density of the current flowing through the first ion electric field control element 71 and towards the first surface S1. In some embodiments, the pore size and density can be reasonably set according to the electric field distribution requirements of different regions of the substrate.

[0059] In some embodiments, the structure of the second plating chamber 20 is generally the same as that of the first plating chamber 10, but the layout of the structures may differ slightly, such as the positional relationship between the structures, which can be designed as needed. The second plating chamber 20 includes a second anode chamber 52, a second anode 42, a second ion membrane 62, a second electric field control element 72, and a second liquid flow space 82, and the second surface S2 is immersed in the cathodic electroplating solution in the second liquid flow space 82. During electroplating, the second anode 42 is electrically connected to the positive terminal of an external power source (not shown), and the substrate is electrically connected to the negative terminal of the external power source. When the external power source supplies voltage between the second anode 42 and the substrate W, the current flows along the path from the external power source through the second anode 42, the electroplating solution, the substrate W, and back to the external power source. Thus, metal ions in the electroplating solution flow from the second anode 42 to the second surface S2 of the substrate and fill the through holes. The function of the structures in the second plating chamber 20 and the interrelationship between the structures are the same as those in the first plating chamber 10, and will not be described in detail here.

[0060] To allow more metal ions to enter the through-hole V, a pressure difference can be created by controlling the difference in the liquid level of the electroplating solution between the first plating chamber 10 and the second plating chamber 20. This causes the electroplating solution to flow from the plating chamber with the higher liquid level through the through-hole V to the plating chamber with the lower liquid level, thereby allowing more metal ions to flow through the through-hole and form metal bridges within it, thus accelerating the formation of metal bridges. However, the process of forming metal bridges within the through-hole V requires ensuring that the metal bridges are located as close as possible to the narrowest point of the through-hole V, and that the bottom morphologies of the two blind holes V1 and V2 formed are as similar as possible to ensure uniform filling of the through-hole. During the formation of metal bridges within the through-hole, if the flow direction of the electroplating solution remains constant, the copper electroplated within the through-hole V may tilt along the flow direction of the electroplating solution, affecting the electroplating morphology. Therefore, the flow direction of the electroplating solution through the through-hole can be changed by altering the liquid level relationship between the two plating chambers at least once. To ensure the uniformity of the metal bridge, the liquid levels in the two plating chambers alternate during the entire bridging process, with the alternation intervals being the same.

[0061] The first plating chamber is provided with a first inlet for introducing the electroplating solution (cathode plating solution) and a first outlet for discharging the electroplating solution (cathode plating solution). The second plating chamber is provided with a second inlet for introducing the electroplating solution (cathode plating solution) and a second outlet for discharging the electroplating solution (cathode plating solution). To allow the electroplating solution to flow from the second plating chamber to the first plating chamber through the through-hole, the liquid level in the second plating chamber needs to be higher than the liquid level in the first plating chamber. To change the flow direction of the electroplating solution in the through-hole during the process, the liquid level in the first plating chamber also needs to be adjustable to be higher than the liquid level in the second plating chamber, thus altering the height relationship between the electroplating solution levels in the first and second plating chambers. Therefore, in one specific embodiment, multiple outlets are provided to change the liquid level in different plating chambers. In different examples, such as the embodiment shown in Figure 5A, there can be multiple first liquid outlets 21, multiple second liquid outlets 22, or multiple first liquid outlets 21 and multiple second liquid outlets 22. In the embodiment shown in Figure 6, to illustrate the height of the liquid outlets in the two plating chambers, only the first liquid outlet 21 in the first plating chamber 10 and the second liquid outlet 22 in the second plating chamber 20 are shown. The first liquid outlet 21 is located at the end of each liquid outlet pipe 210, and the number of first liquid outlets 21 is one. The second liquid outlet 22 in the second plating chamber 20 is located at the end of each liquid outlet pipe 220, and the number of second liquid outlets 22 is two. The height of the first liquid outlet 21 in the first plating chamber 10 is between the heights of the two second liquid outlets 22 in the second plating chamber 20; that is, the height of the first liquid outlet 21 is higher than one of the second liquid outlets 22, and the height of the other second liquid outlet 22 is higher than the first liquid outlet 21. In this application, the electroplating apparatus also includes a control unit that controls the on / off state and flow direction of the electroplating solution. The on / off state of the electroplating solution includes controlling the flow into and out of the pipes in each plating chamber. Each outlet is connected to a pipe to discharge the electroplating solution from the electroplating apparatus. During the process, the control unit is configured to control the on / off state of valves on the pipes connected to each outlet to select different outlets from which the electroplating solution overflows. By switching between two second outlets 22 at different heights and allowing the electroplating solution to overflow from the second plating chamber at these different heights, the liquid level of the electroplating solution in the second plating chamber changes. This changes the height relationship between the first plating chamber and the second plating chamber, thus altering the flow direction of the electroplating solution within the through-hole.

[0062] The number of outlets in each plating chamber can be set as needed. The number of outlets in Figure 6 is only the number in an example embodiment; other numbers of outlets can be designed in other embodiments. In some embodiments, as shown in Figure 5A, the first plating chamber 10 is marked with three first outlets 21, and the second plating chamber 20 is marked with three second outlets 22. The heights of the first and second outlets need to meet the following requirements: the height of at least one second outlet is designed to be higher than at least one first outlet, and the height of at least one first outlet is designed to be higher than at least one second outlet. Furthermore, the control unit controls the opening and closing of the outlets to select an outlet of appropriate height from which the plating solution overflows, thereby configuring a suitable liquid level in each plating chamber.

[0063] The outlets at different heights can be openings 21 and 22 on the outlet pipes 210 and 220 at different heights as shown in the embodiment of Figure 6, or they can be openings at different heights on the side wall of the tank, or they can be a combination of openings at different heights on the outlet pipe and the side wall of the tank.

[0064] In other embodiments, to change the liquid level of the electroplating solution in each plating chamber, each plating chamber includes only one outlet pipe. Each outlet pipe is movable, and each outlet is located on a separate outlet pipe; that is, the outlet in the first plating chamber is the first outlet, and the outlet in the second plating chamber is the second outlet. Furthermore, to ensure that the flow direction of the electroplating solution within the through-hole can be switched when each plating chamber includes only one outlet pipe, the movable height of the outlet pipes in the first and second plating chambers must at least satisfy the following: the outlet pipe in the first plating chamber can be moved up to the point where the first outlet is higher than the second outlet, allowing the electroplating solution to flow from the first plating chamber through the through-hole to the second plating chamber; and the outlet pipe in the second plating chamber can be moved up to the point where the second outlet is higher than the first outlet, allowing the electroplating solution to flow from the second plating chamber through the through-hole to the first plating chamber. In some embodiments, each outlet pipe is mounted on a lifting mechanism, which is coupled to and controlled by a control unit. The controller is configured to control the lifting mechanism to raise and lower the outlet pipe of the first plating chamber until the first outlet is higher than the second outlet, so that the electroplating solution flows from the first plating chamber through the through hole to the second plating chamber; and to control the lifting mechanism to raise and lower the outlet pipe of the second plating chamber until the second outlet is higher than the first outlet, so that the electroplating solution flows from the second plating chamber through the through hole to the first plating chamber. As an example, the lifting mechanism is a motor or a cylinder.

[0065] To allow electroplating solution to flow into each plating chamber, each plating chamber also includes an inlet for the electroplating solution. As shown in the embodiment of FIG5A, a first inlet 11 is provided in the first plating chamber 10, and a second inlet 12 is provided in the second plating chamber 20. In some embodiments, the inlet of each plating chamber can be an opening on a pipe, as shown in FIG6, where the inlets are openings 11 and 12 on inlet pipes 110 and 120. In other embodiments, the inlet of each plating chamber can also be an opening on the side wall or bottom of the tank. To ensure that the electroplating solution flows from one side of the substrate to the other within the same plating chamber, the inlet and outlet are respectively located on opposite sides of the substrate. Furthermore, to better ensure that the electroplating solution flows from one plating chamber through the through-hole to another without flow interference, the inlets of the two plating chambers are symmetrically arranged within the two plating chambers with respect to the substrate, ensuring that the electroplating solution flows in the same direction within the two plating chambers. As shown in Figure 5A, the first liquid inlet 11 and the second liquid inlet 12 are symmetrically arranged in the first plating cavity 10 and the second plating cavity 20 with the substrate as the substrate, and the first liquid outlet 21 and the second liquid outlet 22 are symmetrically arranged in the first plating cavity 10 and the second plating cavity 20 with the substrate as the substrate.

[0066] If the plating solution always flows from one side of the substrate to the other within the same plating chamber, the copper plating inside the via V may tilt along the flow direction of the plating solution within the same plating chamber, thus affecting the plating morphology. Therefore, the plating morphology can be changed by alternating the flow direction of the plating solution relative to the substrate surface within the same plating chamber using a control unit. The control unit is further configured to control the opening and closing of valves on pipes connected to each inlet to select different inlets within the same plating chamber to introduce plating solution into the plating chamber, thereby alternating the flow direction of the plating solution relative to the substrate surface within the same plating chamber, wherein the two inlets within the same plating chamber are located on opposite sides of the substrate. As shown in the embodiment of Figure 5B, each plating chamber includes two sets of liquid supply components. Each liquid supply component includes inlets 11 and 12 and outlets 21 and 22. The inlets 11 and 12 of the two sets of liquid supply components in each plating chamber are located on the upper and lower sides of the substrate W, respectively. That is, in the first plating chamber 10, the inlets 11 of the two sets of liquid supply components are located on the upper and lower sides of the substrate W, respectively, and in the second plating chamber 20, the inlets 12 of the two sets of liquid supply components are located on the upper and lower sides of the substrate W, respectively. The inlets are used to introduce plating solution into the corresponding plating chamber, and the outlets are used to discharge the plating solution from the corresponding plating chamber. The two sets of liquid supply components are configured such that after supplying liquid from one set of liquid supply components to make the plating solution flow from one side of the substrate to the other side, the other set of liquid supply components is switched to supply liquid to make the plating solution flow from the other side of the substrate to one side, thereby changing the flow direction of the plating solution on the substrate surface. In order to ensure that as much plating solution as possible flows over the substrate surface in the plating chamber, the height of multiple outlets is higher than the height of the substrate. In some embodiments, the liquid supply assembly is coupled to and controlled by the control unit. The controller is configured to control one set of liquid supply assemblies to supply liquid (while the other set of liquid supply assemblies does not supply liquid) so that the electroplating solution flows from one side of the substrate to the other side of the substrate, and then switch to another set of liquid supply assemblies to supply liquid (while the aforementioned set of liquid supply assemblies does not supply liquid) so that the electroplating solution flows from the other side of the substrate to one side of the substrate, thereby changing the flow direction of the electroplating solution on the substrate surface.

[0067] In some embodiments, two sets of liquid supply components are symmetrically arranged in two plating cavities 10 and 20 with respect to the substrate, and are configured to supply liquid simultaneously during the electroplating process of forming metal bridges in multiple through holes, so that the flow direction of the plating solution in the two plating cavities 10 and 20 relative to the substrate W is the same. As an example, the control unit is configured to control the simultaneous supply of liquid by the two sets of liquid supply components during the aforementioned process.

[0068] In some embodiments, during the electroplating process of forming metal bridges within multiple through-holes, each plating chamber 10, 20 is configured such that the electroplating solution enters the corresponding plating chamber 10, 20 from an inlet located on the same side of the substrate W, and then exits the plating chamber from an outlet located on the same side of the substrate W, so that the flow direction of the electroplating solution within the plating chambers 10, 20 relative to the substrate is the same. This process can be achieved by controlling the opening and closing of valves on the pipelines connected to each inlet using the aforementioned control unit.

[0069] Because glass substrates have limited stress tolerance, excessive electroplating solution flow rate may cause warping and breakage of the glass substrate. Therefore, the flow rate within the vias needs to be controlled throughout the bridging process. In this application, the flow rate within the vias is controlled according to the Hagen-Poiseuille law, namely:

[0070] Where v is the flow velocity inside the through hole, r is the maximum radius of the through hole, ΔP is the pressure difference across the through hole, μ is the dynamic viscosity of the electroplating solution, and L is the length of the through hole.

[0071] During the through-hole bridging process, as the metal bridge gradually forms, the narrowest part V3 of the through-hole V becomes increasingly filled with copper material, resulting in a smaller and smaller size of the narrowest part V3. To allow more plating solution to pass through the narrowest part V3, the flow rate v within the through-hole V is controlled to increase during the bridging process. Furthermore, as the metal bridge gradually forms within the through-hole during electroplating, the concentration of metal ions in the plating solution decreases. To replenish the consumed metal ions, the flow rate within the through-hole needs to be increased. One method is to control the flow rate entering each plating chamber to increase. Another method is to adjust the liquid level difference between the two plating chambers using a liftable outlet pipe, further controlling the change in the plating solution flow rate during the bridging process.

[0072] In some embodiments, as shown in FIG. 5, the substrate holder 2 is at least partially surrounded by a sealing ring to seal the gap between the substrate holder 2 and the inner wall of the tank 1, completely isolating the first plating cavity 10 and the second plating cavity 20. This allows more plating solution to enter the second plating cavity from one plating cavity through the through hole V, thereby plating metal in the through hole more quickly to form a metal bridge. In other embodiments, a gap may also be left between the substrate holder 2 and the inner wall of the tank 1 to allow the plating solution to flow between the first plating cavity 10 and the second plating cavity 20.

[0073] To prevent warping of the substrate during the via filling process, as shown in Figure 7, the substrate holder 2 includes a first carrier plate 21 and a second carrier plate 22 for clamping the substrate. Both the first carrier plate 21 and the second carrier plate 22 include openings 23 for exposing the first and second surfaces of the substrate to the electroplating solution. Cross structures 24 are provided within the openings 23 for supporting the two surfaces of the substrate respectively. A strain gauge (not shown) is also provided between the cross structure 24 and the substrate surface for detecting substrate warping during electroplating.

[0074] The electroplating apparatus provided in this application allows more metal ions to flow from a plating chamber with a high liquid level to a plating chamber with a low liquid level through through-holes, thus forming metal bridges within the through-holes more quickly. The electroplating apparatus also allows for changes in the flow direction of the electroplating solution within the same plating chamber. Depending on process requirements, during through-hole bridging or the entire blind via filling process, the flow direction of the electroplating solution on the substrate surface in each plating chamber can be alternately changed to achieve a better electroplating morphology.

[0075] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. An electroplating apparatus for an electroplating substrate, the substrate comprising a first surface, a second surface opposite to the first surface, and a plurality of through holes extending from the first surface to the second surface, the electroplating apparatus being used to plate metal within the plurality of through holes, characterized in that, The electroplating apparatus includes: The tank body forms a cavity; A substrate holder is used to hold the substrate in a vertical position within the chamber during electroplating and to divide the chamber into a first plating chamber and a second plating chamber, the first plating chamber and the second plating chamber being used to contain the electroplating solution; During the electroplating process of forming metal bridges in the plurality of through holes, the first plating chamber and the second plating chamber are configured to contain electroplating solutions with different liquid levels so that the electroplating solution flows from the plating chamber with the higher liquid level through the through holes to the plating chamber with the lower liquid level.

2. The electroplating apparatus according to claim 1, characterized in that, The first plating chamber and the second plating chamber are configured such that, during the process of electroplating to form a metal bridge in the plurality of through holes, the height relationship of the electroplating solution in the first plating chamber relative to the second plating chamber is changed at least once to change the flow direction of the electroplating solution in the through holes.

3. The electroplating apparatus according to claim 2, characterized in that, The liquid levels in the first and second plating chambers alternate, with the same time interval between the alternations.

4. The electroplating apparatus according to claim 2, characterized in that, The first plating chamber is provided with at least one first liquid outlet, and the second plating chamber is provided with at least one second liquid outlet. The at least one first liquid outlet is higher than the at least one second liquid outlet, and the at least one second liquid outlet is higher than the at least one first liquid outlet.

5. The electroplating apparatus according to claim 4, characterized in that, At least one plating chamber is provided with multiple liquid outlet pipes at different heights, and each liquid outlet is provided on each liquid outlet pipe.

6. The electroplating apparatus according to claim 4, characterized in that, The first liquid outlet and the second liquid outlet are openings at different heights on the side wall of the tank.

7. The electroplating apparatus according to claim 2, characterized in that, The first plating chamber is provided with a first liquid outlet, the second plating chamber is provided with a second liquid outlet, and each plating chamber is provided with a liftable liquid outlet pipe. Each liquid outlet is provided on each liquid outlet pipe. The liquid outlet pipe of the first plating chamber can be raised and lowered until the first liquid outlet is higher than the second liquid outlet, and the liquid outlet pipe of the second plating chamber can be raised and lowered until the second liquid outlet is higher than the first liquid outlet.

8. The electroplating apparatus according to claim 1, characterized in that, Each plating chamber also includes a liquid supply assembly, which includes an inlet and an outlet. The inlet and outlet of each plating chamber are located on both sides of the substrate. The inlets of the first plating chamber and the second plating chamber are symmetrically arranged in the two plating chambers with respect to the substrate, so that the electroplating solution in the two plating chambers flows in the same direction relative to the substrate.

9. The electroplating apparatus according to claim 8, characterized in that, Each plating chamber includes two sets of liquid supply components. The inlets of the two sets of liquid supply components in each plating chamber are respectively located on both sides of the substrate. The two sets of liquid supply components are configured to switch from one set of liquid supply components to the other set of liquid supply components to change the flow direction of the electroplating solution on the substrate surface.

10. The electroplating apparatus according to claim 9, characterized in that, The two sets of liquid supply components are symmetrically arranged in the two plating chambers with respect to the substrate, and are configured to supply liquid simultaneously during the process of electroplating to form metal bridges in the plurality of through holes, so that the flow direction of the electroplating liquid in the two plating chambers is the same relative to the substrate.

11. The electroplating apparatus according to claim 10, characterized in that, During the process of electroplating to form metal bridges in the plurality of through holes, each plating chamber is configured such that the electroplating solution enters the corresponding plating chamber from the inlet located on the same side of the substrate and exits the plating chamber from the outlet located on the same side of the substrate, so that the flow direction of the electroplating solution in the two plating chambers relative to the substrate is the same.

12. The electroplating apparatus according to claim 8, characterized in that, During the electroplating process to form metal bridges within the plurality of through holes, the flow velocity within the through holes satisfies: v is the flow velocity inside the through hole, r is the maximum radius of the through hole, ΔP is the pressure difference across the through hole, μ is the dynamic viscosity of the electroplating solution, and L is the length of the through hole.

13. The electroplating apparatus according to claim 12, characterized in that, The electroplating apparatus is configured such that the flow rate of the electroplating solution entering each plating chamber increases progressively.

14. The electroplating apparatus according to claim 12, characterized in that, The electroplating apparatus is configured to increase the flow rate of the electroplating solution in the through hole by changing the difference in liquid level between the two plating chambers.

15. The electroplating apparatus according to claim 1, characterized in that, The substrate holder includes a first carrier plate and a second carrier plate for clamping the substrate respectively. Both the first carrier plate and the second carrier plate include openings for exposing a first surface and a second surface of the substrate to the electroplating solution. The openings are provided with cross structures for supporting the two surfaces of the substrate respectively.

16. The electroplating apparatus according to claim 15, characterized in that, A strain gauge for detecting substrate warping during electroplating is also provided between the cross structure and the substrate surface.

17. The electroplating apparatus according to claim 1, characterized in that, The substrate holder is at least partially surrounded by a sealing ring to isolate the two plating cavities.

18. The electroplating apparatus according to claim 1, characterized in that, The electroplating apparatus is configured to form metal bridges within the plurality of through holes and continue electroplating until the through holes are completely filled.

19. An electroplating apparatus for an electroplating substrate, the substrate comprising a first surface, a second surface opposite to the first surface, and a plurality of through holes penetrating the first surface and the second surface, the electroplating apparatus being used to plate metal within the plurality of through holes, characterized in that, The electroplating equipment includes a first electroplating device and a second electroplating device. The first electroplating device is used to plate metal in the plurality of through holes to form metal bridges. The second electroplating device is used to transfer the substrate from the first electroplating device to the second electroplating device after the metal bridges are formed so that electroplating continues until the through holes are completely filled. The first electroplating device is the electroplating device according to any one of claims 1-17.

20. The electroplating apparatus according to claim 19, wherein during the process of the second electroplating apparatus electroplating the substrate to completely fill the through-hole, the second electroplating apparatus is configured to alternately change the flow direction of the electroplating solution on the substrate surface.

21. An electroplating apparatus for an electroplating substrate, the substrate comprising a first surface, a second surface opposite to the first surface, and a plurality of through holes penetrating the first surface and the second surface, the electroplating apparatus being used to plate metal within the plurality of through holes, characterized in that, The electroplating equipment includes: A first electroplating apparatus is used to vertically electroplat the substrate to form metal bridges within the plurality of through holes; The second electroplating apparatus is used to completely fill the plurality of through holes by horizontal electroplating after the first electroplating apparatus electroplats the substrate to form metal bridges in the plurality of through holes.

22. The electroplating equipment according to claim 21, characterized in that, The first electroplating apparatus is configured to stop vertical electroplating when the time for electroplating the substrate reaches a threshold.

23. An electroplating apparatus for electroplating a substrate, the substrate comprising a first surface, a second surface opposite to the first surface, and a plurality of through holes penetrating the first surface and the second surface, the electroplating apparatus electroplating the substrate to plate metal within the plurality of through holes, characterized in that, The electroplating equipment includes a first electroplating device and a second electroplating device. The first electroplating device is used to vertically electroplat the substrate to form metal bridges in the plurality of through holes. The second electroplating device is used to transfer the substrate from the first electroplating device to the second electroplating device after the metal bridges are formed, and continue electroplating until the through holes are completely filled. The first electroplating device is the electroplating device according to any one of claims 1-17, and the second electroplating device is configured to continue electroplating the substrate by horizontal electroplating.

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