Method for predicting and improving height uniformity of electroplated conductive post
By constructing a three-dimensional simulation model and optimizing the control equations and boundary conditions of the electroplating process, and adopting designs such as auxiliary conductive pillars and baffles, the problem of high cost and low efficiency in improving the height uniformity of electroplating conductive pillars was solved, achieving faster product launch and cost savings.
Patent Information
- Application Number
- CN202410344016.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-25
- Publication Date
- 2025-09-26
AI Technical Summary
The existing technology for improving the height uniformity of electroplated conductive pillars has the problems of long development time, high cost, low efficiency and unpredictable results.
By constructing a three-dimensional simulation model of the electroplating process and using simulation software to optimize the control equations and boundary conditions, the height uniformity of the electroplated conductive pillars is predicted and improved. Design modifications such as auxiliary conductive pillars and baffles are adopted to optimize the current distribution to improve uniformity.
It effectively saves the cost of electroplating solutions and test boards, improves the efficiency of design modification for uniformity of electroplated conductive posts, shortens time costs, and increases product launch speed and revenue.
Smart Images
Figure CN120706133A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of semiconductor packaging, and in particular relates to a method for predicting and improving the height uniformity of electroplated conductive columns. Background Art
[0002] With the advent of the intelligent era, more and more electronic products are developing in the direction of miniaturization, lightweighting, and multifunctionality. The growing functional demands of these high-end electronic products have also placed higher requirements on packaging technology. Advanced packaging technology has emerged as a response to this. To achieve higher packaging density, traditional C4 has become difficult to meet the requirements. At this time, copper pillar bump technology, which can achieve finer pitch interconnections, has demonstrated its strong vitality and become the mainstay of chiplets, achieving stable interconnections of various pitch sizes. To achieve interconnection on the same horizontal plane as the chip, different copper pillar sizes must be electroplated simultaneously. There is a solution that uses two sizes of copper pillars for step-by-step electroplating, but this solution is complex and step-by-step electroplating also greatly reduces the accuracy of exposure and alignment.
[0003] The traditional method to improve the height uniformity of electroplated copper pillars is to replace the electroplating solution system. However, the development of electroplating solution systems takes a long time, is costly, and the effect is unpredictable. Another method to improve the height uniformity of copper pillars is to modify the design of the anode plate. During the electroplating process of copper pillars, unbalanced distribution of power lines is an important reason for the poor height uniformity of copper pillars. In order to improve the height uniformity of electroplated copper pillars, modifying the anode plate into the same shape as the test plate is also one of the improvement methods. However, the cost of the anode plate itself is relatively high, and different anode plates need to be replaced for different models of test plates, which is obviously not suitable for industrial production.
[0004] It should be noted that the above introduction to the technical background is merely intended to provide a clear and complete description of the technical solutions of this application and facilitate understanding by those skilled in the art. Simply because these solutions are described in the background technology section of this application, it should not be assumed that the above technical solutions are well known to those skilled in the art. Summary of the Invention
[0005] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a method for predicting and improving the height uniformity of electroplated conductive columns, which is used to solve the problems in the prior art of using an electroplating process to form conductive columns on a packaging substrate, such as long development time, high cost, low efficiency, and unpredictable effects.
[0006] To achieve the above and other related objectives, the present invention provides a method for predicting and improving the height uniformity of electroplated conductive pillars, the method comprising:
[0007] S1. Provide a target product of electroplated conductive pillars, determine the electroplating conditions of the target product, and obtain a true result of electroplating height uniformity of the target product according to the electroplating conditions;
[0008] S2. Designing and constructing a three-dimensional simulation model of the electroplating process of the target product based on the actual size of the target product;
[0009] S3, importing the three-dimensional simulation model into simulation software, determining the control equations and boundary conditions of the three-dimensional simulation model to construct an initial electroplating model;
[0010] S4. Determine whether the initial electroplating model is valid. If the initial electroplating model is valid, use the initial electroplating model as a prediction model for the electroplating height uniformity of the target product. If the initial electroplating model is invalid, optimize the control equations and / or the boundary conditions of the three-dimensional simulation model until the prediction model for the electroplating height uniformity of the target product is obtained.
[0011] S5. Redesigning a design modification scheme to improve the height uniformity of the electroplated conductive pillars using the electroplating height uniformity prediction model;
[0012] S6. Compare the deviation between the electroplating height uniformity simulation result of the design modification scheme and the actual electroplating height uniformity result of the design modification scheme to determine whether the design modification scheme can be used as a height uniformity improvement model for electroplated conductive pillars; if the deviation is within a preset range, use the design modification scheme as a height uniformity improvement model for electroplated conductive pillars; if the deviation is outside the preset range, optimize the control equations and / or the boundary conditions of the three-dimensional simulation model and repeat steps S4 to S6 until the height uniformity improvement model for electroplated conductive pillars is obtained;
[0013] S7. Improve the target product according to the height uniformity improvement model of the electroplated conductive pillars.
[0014] Optionally, the electroplated conductive pillars in step S1 are copper pillars.
[0015] Optionally, the basis for judging whether the initial electroplating model is valid in step S4 includes comparing the deviation between the simulation result of the electroplating height uniformity of the electroplating conditions and the actual result of the electroplating height uniformity of the electroplating conditions; if the deviation is within a preset value, the initial electroplating model is deemed valid; if the deviation value is outside the preset value, the initial electroplating model is deemed invalid.
[0016] Furthermore, the calculation formula of the electroplating height uniformity simulation result of the electroplating condition and the electroplating height uniformity actual result of the electroplating condition is (H max -H min ) / 2Hmean , where H max is the maximum height of the conductive column, H min is the minimum height of the conductive column, H mean is the average value of the height of the conductive column; the calculation formula for the deviation between the simulation result of the electroplating height uniformity of the electroplating conditions and the actual result of the electroplating height uniformity of the electroplating conditions is (AB) / A, wherein A is the actual result of the electroplating height uniformity of the electroplating conditions, and B is the simulation result of the electroplating height uniformity of the electroplating conditions.
[0017] Furthermore, the preset value is ±10%.
[0018] Optionally, the design modification scheme for improving the height uniformity of the electroplated conductive pillars in step S5 includes adding auxiliary conductive pillars next to the conductive pillars in the target product and / or adding a perforated baffle between the cathode and anode of the electroplating tank of the target product to change the current distribution.
[0019] Optionally, the simulation software includes COMSOL finite element software.
[0020] Optionally, the calculation formula for the electroplating height uniformity simulation result of the design modification scheme in step S6 and the actual result of the electroplating height uniformity of the design modification scheme is (L max -L min ) / 2L mean , where L max is the maximum height of the conductive column, L min is the minimum height of the conductive column, L mean is the average value of the height of the conductive column; the calculation formula for the deviation between the simulation result of the electroplating height uniformity of the design modification scheme and the actual result of the electroplating height uniformity of the design modification scheme is (CD) / C, wherein C is the actual result of the electroplating height uniformity of the design modification scheme, and D is the simulation result of the electroplating height uniformity of the design modification scheme; the preset range of the deviation between the simulation result of the electroplating height uniformity of the design modification scheme and the actual result of the electroplating height uniformity of the design modification scheme is -20% to 20%.
[0021] Optionally, the actual size of the target product in step S2 includes the graphic arrangement of the electroplated conductive columns on the target product, the thickness of the target product, the size of the electroplating tank, and the spatial distribution of the anode and cathode of the electroplating tank; the control equation includes the current distribution and the solute exchange coefficient; and the boundary conditions include temperature, solute charge number, and current density.
[0022] Optionally, the actual result of the electroplating height uniformity of the target product in step S1 is obtained by actually electroplating a product sheet or a non-product sheet; the actual result of the electroplating height uniformity of the design modification scheme in step S6 is obtained by actually electroplating a product sheet or a non-product sheet.
[0023] As described above, the method for predicting and improving the height uniformity of electroplated conductive columns of the present invention is to first build a three-dimensional simulation model of the electroplating process of the target product according to the actual size of the target product and import it into the simulation software to determine the control equations and boundary conditions; then, the control equations and / or boundary conditions of the three-dimensional simulation model are optimized to obtain the electroplating height uniformity prediction model of the target product, and based on the electroplating height uniformity prediction model, the performance of the height uniformity of the electroplated conductive columns under different conditions is simulated to obtain a design modification scheme for improving the height uniformity of the electroplated conductive columns; then, the electroplating height uniformity simulation results of the design modification scheme are compared with the actual results to determine whether the design modification scheme can be used as a height uniformity improvement model for the electroplated conductive columns, and the above process is repeated after optimizing the control equations and / or boundary conditions of the three-dimensional simulation model to finally obtain the height uniformity improvement model for the electroplated conductive columns, and the target product is improved according to the height uniformity improvement model for the electroplated conductive columns. This method constructs a three-dimensional model and obtains a target product's electroplating height uniformity prediction model and an electroplating conductive column height uniformity improvement model through software simulation, which can avoid a large number of actual electroplating processes, thereby effectively saving the cost of electroplating solutions, test boards and other materials, and reducing manufacturing costs; in addition, it can also improve the efficiency of electroplating conductive column uniformity design modification and save time costs; furthermore, it can enable electroplating conductive column products to flow to the market faster and increase profits. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 Shown is a schematic top view of the structure of the target product in the method for predicting and improving the height uniformity of electroplated conductive pillars of the present invention.
[0025] Figure 2 A schematic top view of an example of a design modification solution in the method for predicting and improving the height uniformity of electroplated conductive pillars according to the present invention is shown.
[0026] Figure 3 A schematic top view of another example of a design modification scheme in the method for predicting and improving the height uniformity of electroplated conductive pillars of the present invention is shown.
[0027] Figure 4 Displayed as Figure 3 Schematic diagram of the cross-sectional structure of the design modification placed in the electroplating tank.
[0028] Figure 5Shown is a flow chart of the steps of the method for predicting and improving the height uniformity of electroplated conductive pillars of the present invention.
[0029] Component number description
[0030] 10 Target Products
[0031] 100 electroplated conductive posts
[0032] 11 Design Modification Plan
[0033] 110 auxiliary conductive column
[0034] 12 Baffle
[0035] 120 diversion holes
[0036] 13 electroplating tank
[0037] 130 Anode
[0038] 131 parts to be plated DETAILED DESCRIPTION
[0039] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.
[0040] See also Figures 1 to 5 It should be noted that the diagrams provided in this embodiment are merely schematic illustrations of the basic concept of the present invention. Therefore, the diagrams only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.
[0041] This embodiment provides a method for predicting and improving the height uniformity of electroplated conductive pillars, the method comprising:
[0042] S1. Provide a target product of electroplated conductive pillars, determine the electroplating conditions of the target product, and obtain a true result of electroplating height uniformity of the target product according to the electroplating conditions;
[0043] S2. Designing and constructing a three-dimensional simulation model of the electroplating process of the target product based on the actual size of the target product;
[0044] S3, importing the three-dimensional simulation model into simulation software, determining the control equations and boundary conditions of the three-dimensional simulation model to construct an initial electroplating model;
[0045] S4. Determine whether the initial electroplating model is valid. If the initial electroplating model is valid, use the initial electroplating model as a prediction model for the electroplating height uniformity of the target product. If the initial electroplating model is invalid, optimize the control equations and / or the boundary conditions of the three-dimensional simulation model until the prediction model for the electroplating height uniformity of the target product is obtained.
[0046] S5. Redesigning a design modification scheme to improve the height uniformity of the electroplated conductive pillars using the electroplating height uniformity prediction model;
[0047] S6. Compare the deviation between the electroplating height uniformity simulation result of the design modification scheme and the actual electroplating height uniformity result of the design modification scheme to determine whether the design modification scheme can be used as a height uniformity improvement model for electroplated conductive pillars; if the deviation is within a preset range, use the design modification scheme as a height uniformity improvement model for electroplated conductive pillars; if the deviation is outside the preset range, optimize the control equations and / or the boundary conditions of the three-dimensional simulation model and repeat steps S4 to S6 until the height uniformity improvement model for electroplated conductive pillars is obtained;
[0048] S7. Improve the target product according to the height uniformity improvement model of the electroplated conductive pillars.
[0049] The method of predicting and improving the height uniformity of electroplated conductive pillars in this embodiment is as follows: first, a three-dimensional simulation model of the electroplating process of the target product is constructed according to the actual size of the target product and imported into the simulation software to determine the control equations and boundary conditions; then, the control equations and / or boundary conditions of the three-dimensional simulation model are optimized to obtain a prediction model of the electroplating height uniformity of the target product (i.e., an effective three-dimensional simulation model of the electroplating process of the target product); and based on the electroplating height uniformity prediction model, the performance of the height uniformity of the electroplated conductive pillars under different conditions is simulated to obtain a design modification scheme for improving the height uniformity of the electroplated conductive pillars; then, the electroplating height uniformity simulation results of the design modification scheme are compared with the actual results to determine whether the design modification scheme can be used as a model for improving the height uniformity of the electroplated conductive pillars; and the above process is repeated after optimizing the control equations and / or boundary conditions of the three-dimensional simulation model to finally obtain a model for improving the height uniformity of the electroplated conductive pillars, and the target product is improved according to the model for improving the height uniformity of the electroplated conductive pillars. This method constructs a three-dimensional model and obtains a target product's electroplating height uniformity prediction model and an electroplating conductive column height uniformity improvement model through software simulation, which can avoid a large number of actual electroplating processes, thereby effectively saving the cost of electroplating solutions, test boards and other materials, and reducing manufacturing costs; in addition, it can also improve the efficiency of electroplating conductive column uniformity design modification and save time costs; furthermore, it can enable electroplating conductive column products to flow to the market faster and increase profits.
[0050] The method for predicting and improving the height uniformity of electroplated conductive pillars according to this embodiment is described in detail below with reference to specific drawings.
[0051] like Figure 1 and Figure 5 As described above, step S1 is first performed to provide a target product 10 for electroplating a conductive column 100, determine the electroplating conditions of the target product 10, and obtain a true result of the electroplating height uniformity of the target product 10 according to the electroplating conditions.
[0052] The specific structure of the target product 10 of the electroplated conductive column 100 is not limited, as long as the target product 10 has the electroplated conductive column 100 that needs to be formed by the electroplating process, such as a packaging substrate in the field of chip packaging. The packaging substrate generally includes a core board located in the inner layer and a build-up layer on the core board. The build-up layer can be formed on the upper and lower surfaces or one of the sides of the core board according to actual conditions, and the electroplated conductive column 100 is formed on the build-up layer to achieve circuit conduction between the packaging substrate and the chip and / or circuit board. Depending on the specific structure of the target product 10, the parameters of the electroplated conductive column 100, such as the height, diameter, distribution method, etc. of the electroplated conductive column are also different, and are set according to actual needs.
[0053] The electroplating conditions of the target product 10 are generally determined according to the electroplating equipment used and based on certain electroplating rules, including parameters such as electroplating current density, jet flow, and electroplating time.
[0054] The actual result of the electroplating height uniformity of the target product 10 is obtained by measuring the actual heights of all the electroplated conductive pillars 100 on the target product 10 obtained by electroplating under the described electroplating conditions. Generally, the actual height uniformity of all the electroplated conductive pillars 100 on the target product 10 obtained by electroplating under the described electroplating conditions will be poor and fail to meet the process requirements. Therefore, it is necessary to improve the initial electroplating conditions so that the actual height uniformity of all the electroplated conductive pillars 100 on the target product 10 meets the process requirements. In addition, the actual result of the electroplating height uniformity of the target product 10 can be obtained by actually electroplating a product sheet or a non-product sheet.
[0055] The material of the electroplated conductive pillar 100 satisfies any metal material suitable for preparation by electroplating process. For example, in the packaging substrate, the electroplated conductive pillar 100 is generally selected to be a copper pillar.
[0056] like Figure 5 As shown, step S2 is then performed to design and construct a three-dimensional simulation model of the electroplating process of the target product 10 based on the actual size of the target product 10.
[0057] As an example, the actual size of the target product 10 generally includes the parameters required to construct a three-dimensional simulation model of the electroplating process, such as the graphic arrangement of the electroplated conductive columns on the target product, the thickness of the target product, the size of the electroplating tank, the spatial distribution of the anode and cathode of the electroplating tank, etc.
[0058] like Figure 5 As shown, step S3 is then performed to import the three-dimensional simulation model established in the above step S2 into the simulation software, determine the control equations and boundary conditions of the three-dimensional simulation model, and construct an initial electroplating model.
[0059] As an example, the control equations are equations required in simulating the electroplating process, such as current distribution, solute exchange coefficient, etc.; the boundary conditions are boundary conditions required in simulating the electroplating process, such as temperature, solute charge number, current density, etc.
[0060] The simulation software can be any simulation software suitable for simulating electroplating process, such as COMSOL finite element software.
[0061] like Figure 5As shown, step S4 is then performed to determine whether the initial electroplating model is valid. If the initial electroplating model is valid, the initial electroplating model is used as the electroplating height uniformity prediction model of the target product; if the initial electroplating model is invalid, the control equation and / or the boundary conditions of the three-dimensional simulation model are optimized until the electroplating height uniformity prediction model of the target product is obtained.
[0062] The purpose of this step is to obtain a plating height uniformity prediction model for the target product, so as to lay the foundation for the subsequent redesign of the electroplating conductive column height uniformity using this model. If the initial plating model is valid, it can be directly used as the plating height uniformity prediction model for the target product; if the initial plating model is invalid, it means that the initial plating model is unreliable and it is necessary to continuously optimize the initial plating model by optimizing the control equations and / or boundary conditions of the three-dimensional simulation model once or even multiple times to make it gradually approach the plating height uniformity prediction model of the target product and finally obtain the plating height uniformity prediction model of the target product.
[0063] As an example, the basis for judging whether the initial electroplating model is valid in this step includes: comparing the deviation between the simulation result of the electroplating height uniformity of the electroplating conditions (i.e., the electroplating conditions in step S1) and the actual result of the electroplating height uniformity of the electroplating conditions (i.e., the electroplating conditions in step S1); if the deviation is within the preset value, the initial electroplating model is deemed valid; if the deviation value is outside the preset value, the initial electroplating model is deemed invalid.
[0064] The electroplating height uniformity simulation result of the electroplating conditions is the result obtained by inputting the electroplating conditions in step S1 into the initial electroplating model constructed in step S3 and performing simulation calculation. The actual electroplating height uniformity result of the electroplating conditions is the actual electroplating height uniformity result of the target product obtained in step S1.
[0065] As a specific example, the calculation formula of the electroplating height uniformity simulation result of the electroplating condition and the actual result of the electroplating height uniformity of the electroplating condition is unified as follows: (H max -H min ) / 2H mean , where H max is the maximum height of the conductive column, H min is the minimum height of the conductive column, H meanis the average height of the conductive pillars. It should be noted that the conductive pillars here are the conductive pillars under the corresponding circumstances. For example, when calculating the simulation results of the electroplating height uniformity of the electroplating conditions, the conductive pillars are the conductive pillars obtained under the simulated electroplating process; when calculating the actual results of the electroplating height uniformity of the electroplating conditions, the conductive pillars are the conductive pillars obtained under the actual electroplating process. In addition, the calculation formula for the deviation between the simulation results of the electroplating height uniformity of the electroplating conditions and the actual results of the electroplating height uniformity of the electroplating conditions is: (AB) / A, where A is the actual result of the electroplating height uniformity of the electroplating conditions, and B is the simulation result of the electroplating height uniformity of the electroplating conditions. Since the purpose of this step is to obtain a prediction model for the electroplating height uniformity of the target product, the smaller the deviation range, the closer the prediction model is. For example, a deviation within the range of ±10% is selected. That is, when the range of (AB) / A is within -10% to 10%, including the endpoint value, the initial electroplating model is considered valid. When the range of (AB) / A is outside the range of -10% to 10%, the initial electroplating model is considered invalid.
[0066] like Figure 5 As shown, step S5 is then performed to redesign a design modification scheme for improving the height uniformity of the electroplated conductive pillars using the electroplating height uniformity prediction model obtained in step S4.
[0067] The design modification scheme for improving the height uniformity of the electroplated conductive pillars can adopt any suitable design modification scheme, and the design modification scheme is input into the electroplating height uniformity prediction model for judgment. Figure 2 As shown in FIG. 1 , an exemplary design modification scheme 11 is provided, in which the thickness of the outer plated conductive pillars 100 is balanced by adding auxiliary conductive pillars 110 next to the required plated conductive pillars 100 so as to be as consistent as possible with the thickness of the inner plated conductive pillars 100, thereby achieving the effect of improving the height uniformity of the plated conductive pillars 100. It should be noted that the size, position, quantity and other parameters of the auxiliary conductive pillars 110 can be flexibly set according to actual conditions; Figure 3 and Figure 4 As shown in FIG. 1 , another exemplary design modification scheme 11 is provided with a baffle 12, as shown in FIG. Figure 4 As shown, by adding a baffle 12 between the anode 130 of the electroplating tank 13 and the workpiece 131 to change the current distribution in the electroplating tank 13 during the electroplating process, the current density on each electroplating conductive column is almost the same, thereby achieving the effect of improving uniformity, as shown in FIG. Figure 3 As shown, the baffle plate 12 is provided with a guide hole 120, which allows the plating solution to pass through. It should be noted here that the shape of the baffle plate 12 can be flexibly modified according to the graphics of the actual product, and the position between the anode 130 of the baffle plate 12 and the workpiece 131 to be plated can be freely adjusted as needed.
[0068] like Figure 5 As shown, step S6 is then performed to compare the deviation between the electroplating height uniformity simulation result of the design modification scheme and the actual result of the electroplating height uniformity of the design modification scheme, and determine whether the design modification scheme can be used as a height uniformity improvement model for the electroplated conductive column; if the deviation is within the preset range, the design modification scheme is used as a height uniformity improvement model for the electroplated conductive column; if the deviation is outside the preset range, the control equation and / or the boundary condition of the three-dimensional simulation model is optimized and steps S4 to S6 are repeated until the height uniformity improvement model for the electroplated conductive column is obtained.
[0069] Since there is bound to be a gap between numerical simulation and actual production process, it is necessary to compare the electroplating height uniformity simulation results of the design modification scheme with the actual electroplating height uniformity results of the design modification scheme to determine the deviation between the two. In most cases, the deviation will exceed the preset range. At this time, the control equations and / or boundary conditions of the three-dimensional simulation model can be optimized based on the simulation results to adjust the electroplating height uniformity prediction model of the target product. This optimization process may need to be performed N times, N ≥ 1, to obtain the height uniformity improvement model of the electroplated conductive column. Of course, it is also possible that this optimization process is not required and the height uniformity improvement model of the electroplated conductive column can be directly obtained.
[0070] As a specific example, the calculation formulas for the electroplating height uniformity simulation results of the design modification scheme and the actual results of the electroplating height uniformity of the design modification scheme are unified as follows: (L max -L min ) / 2L mean , where L max is the maximum height of the conductive column, L min is the minimum height of the conductive column, L meanis the average height of the conductive pillars. It should be noted that the conductive pillars here refer to the conductive pillars in the corresponding circumstances. For example, when calculating the electroplating height uniformity simulation results of the design modification, the conductive pillars are the conductive pillars obtained under the simulated electroplating process; when calculating the actual electroplating height uniformity results of the design modification, the conductive pillars are the conductive pillars obtained under the actual electroplating process. In addition, the calculation formula for the deviation between the electroplating height uniformity simulation results of the design modification and the actual electroplating height uniformity results of the design modification is: (CD) / C, where C is the actual electroplating height uniformity results of the design modification, and D is the electroplating height uniformity simulation results of the design modification. Generally, the preset range of the deviation between the electroplating height uniformity simulation results of the design modification and the actual electroplating height uniformity results of the design modification is selected to be -20% to 20%. Of course, the actual electroplating height uniformity results of the design modification can be obtained by actually electroplating on product pieces, or by actually electroplating on non-product pieces.
[0071] like Figure 5 As shown, step S7 is finally performed to improve the target product according to the height uniformity improvement model of the electroplated conductive pillars obtained in step S6.
[0072] In summary, the present invention provides a method for predicting and improving the height uniformity of electroplated conductive columns, by first building a three-dimensional simulation model of the electroplating process of the target product according to the actual size of the target product and importing it into the simulation software to determine the control equations and boundary conditions; then, by optimizing the control equations and / or boundary conditions of the three-dimensional simulation model, a plating height uniformity prediction model of the target product is obtained, and based on the electroplating height uniformity prediction model, the performance of the height uniformity of the electroplated conductive columns under different conditions is simulated to obtain a design modification scheme for improving the height uniformity of the electroplated conductive columns; then, the electroplating height uniformity simulation results of the design modification scheme are compared with the actual results to determine whether the design modification scheme can be used as a height uniformity improvement model for the electroplated conductive columns, and the above process is repeated after optimizing the control equations and / or boundary conditions of the three-dimensional simulation model to finally obtain a height uniformity improvement model for the electroplated conductive columns, and the target product is improved according to the height uniformity improvement model for the electroplated conductive columns. This method constructs a three-dimensional model and uses software simulation to obtain a prediction model for the electroplating height uniformity of the target product and a model for improving the height uniformity of the electroplated conductive pillars. This method can avoid a large number of actual electroplating processes, effectively saving the cost of electroplating solutions, test boards, and other materials, and reducing manufacturing costs. It can also improve the efficiency of designing and modifying the uniformity of the electroplated conductive pillars, saving time and costs. Furthermore, it can accelerate the market release of electroplated conductive pillar products and increase profits. Therefore, the present invention effectively overcomes the various shortcomings of the existing technology and has high industrial application value.
[0073] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.
Claims
1. A method for predicting and improving the height uniformity of electroplated conductive pillars, characterized in that: The method comprises: S1. Provide a target product of electroplated conductive pillars, determine the electroplating conditions of the target product, and obtain a true result of electroplating height uniformity of the target product according to the electroplating conditions; S2. Designing and constructing a three-dimensional simulation model of the electroplating process of the target product based on the actual size of the target product; S3, importing the three-dimensional simulation model into simulation software, determining the control equations and boundary conditions of the three-dimensional simulation model to construct an initial electroplating model; S4. Determine whether the initial electroplating model is valid. If the initial electroplating model is valid, use the initial electroplating model as a prediction model for the electroplating height uniformity of the target product. If the initial electroplating model is invalid, optimize the control equations and / or the boundary conditions of the three-dimensional simulation model until the prediction model for the electroplating height uniformity of the target product is obtained. S5. Redesigning a design modification scheme to improve the height uniformity of the electroplated conductive pillars using the electroplating height uniformity prediction model; S6. Compare the deviation between the electroplating height uniformity simulation result of the design modification scheme and the actual electroplating height uniformity result of the design modification scheme to determine whether the design modification scheme can be used as a height uniformity improvement model for electroplated conductive pillars; if the deviation is within a preset range, use the design modification scheme as a height uniformity improvement model for electroplated conductive pillars; if the deviation is outside the preset range, optimize the control equations and / or the boundary conditions of the three-dimensional simulation model and repeat steps S4 to S6 until the height uniformity improvement model for electroplated conductive pillars is obtained; S7. Improve the target product according to the height uniformity improvement model of the electroplated conductive pillars.
2. The method for predicting and improving the height uniformity of electroplated conductive pillars according to claim 1, wherein: The electroplated conductive pillars in step S1 are copper pillars.
3. The method for predicting and improving the height uniformity of electroplated conductive pillars according to claim 1, wherein: The basis for judging whether the initial electroplating model is valid in step S4 includes comparing the deviation between the simulation result of electroplating height uniformity of the electroplating condition and the actual result of electroplating height uniformity of the electroplating condition; If the deviation is within the preset value, the initial electroplating model is determined to be valid; if the deviation value is outside the preset value, the initial electroplating model is determined to be invalid.
4. The method for predicting and improving the height uniformity of electroplated conductive pillars according to claim 3, wherein: The calculation formula of the electroplating height uniformity simulation result of the electroplating condition and the actual result of the electroplating height uniformity of the electroplating condition is (H max -H min ) / 2H mean , where H max is the maximum height of the conductive column, H min is the minimum height of the conductive column, H mean is the average value of the height of the conductive column; the calculation formula for the deviation between the simulation result of the electroplating height uniformity of the electroplating conditions and the actual result of the electroplating height uniformity of the electroplating conditions is (AB) / A, wherein A is the actual result of the electroplating height uniformity of the electroplating conditions, and B is the simulation result of the electroplating height uniformity of the electroplating conditions.
5. The method for predicting and improving the height uniformity of electroplated conductive pillars according to claim 4, wherein: The preset value is ±10%.
6. The method for predicting and improving the height uniformity of electroplated conductive pillars according to claim 1, wherein: The design modification scheme for improving the height uniformity of the electroplated conductive pillars in step S5 includes adding auxiliary conductive pillars next to the conductive pillars in the target product and / or adding a perforated baffle between the cathode and anode of the electroplating tank of the target product to change the current distribution.
7. The method for predicting and improving the height uniformity of electroplated conductive pillars according to claim 1, wherein: The simulation software includes COMSOL finite element software.
8. The method for predicting and improving the height uniformity of electroplated conductive pillars according to claim 1, wherein: The calculation formula for the electroplating height uniformity simulation result of the design modification scheme in step S6 and the actual result of the electroplating height uniformity of the design modification scheme is (L max -L min ) / 2L mean , where L max is the maximum height of the conductive column, L min is the minimum height of the conductive column, L mean is the average value of the height of the conductive column; the calculation formula for the deviation between the simulation result of the electroplating height uniformity of the design modification scheme and the actual result of the electroplating height uniformity of the design modification scheme is (CD) / C, wherein C is the actual result of the electroplating height uniformity of the design modification scheme, and D is the simulation result of the electroplating height uniformity of the design modification scheme; the preset range of the deviation between the simulation result of the electroplating height uniformity of the design modification scheme and the actual result of the electroplating height uniformity of the design modification scheme is -20% to 20%.
9. The method for predicting and improving the height uniformity of electroplated conductive pillars according to claim 1, wherein: The actual size of the target product in step S2 includes the pattern arrangement of the electroplated conductive pillars on the target product, the thickness of the target product, the size of the electroplating tank, and the spatial distribution of the anode and cathode of the electroplating tank; the control equation includes the current distribution and the solute exchange coefficient; The boundary conditions include temperature, solute charge number, and current density.
10. The method for predicting and improving the height uniformity of electroplated conductive pillars according to claim 1, wherein: The actual result of the electroplating height uniformity of the target product in step S1 is obtained by actually electroplating the product sheet or the non-product sheet; the actual result of the electroplating height uniformity of the design modification scheme in step S6 is obtained by actually electroplating the product sheet or the non-product sheet.