Steady-state thermal simulation method of probe card
By setting convective heat transfer and thermal radiation coefficients in the probe card thermal simulation, and by simplifying and iteratively optimizing the model, the problem of inaccurate simulation results in the existing technology is solved, achieving more efficient calculation and more uniform temperature distribution, thus improving the R&D efficiency and quality of probe cards.
Patent Information
- Application Number
- CN202511090812.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-05
- Publication Date
- 2025-11-21
AI Technical Summary
Existing thermal simulation schemes for probe cards do not consider convective heat transfer and thermal radiation between metal and medium, resulting in large discrepancies between simulation results and actual temperatures, which prolongs the development cycle and increases costs.
In the thermal simulation of the probe card, the convective heat transfer coefficient and thermal radiation coefficient between the metal and the air are set, and the processing scheme of the probe model is reasonably planned, including mesh refinement and iterative optimization, to improve the simulation accuracy and efficiency.
It improves the accuracy of thermal simulation of probe cards, saves computing costs, shortens the R&D cycle, ensures uniform and reasonable temperature distribution, and improves the quality and design optimization direction of probe cards.
Smart Images
Figure CN120995770A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of probe card, in particular to a steady-state thermal simulation method of probe card. BACKGROUND
[0002] Wafer test is an indispensable link before chip packaging, which can greatly improve the yield of packaged chips. Probe card is a "bridge" for connecting test machine and wafer in wafer test, which can transmit electrical signals from test machine to wafer and transmit response signals back to test machine to determine whether the wafer is good. In order to reduce the test cost in the development process of probe card and improve the development efficiency of probe card, it is necessary to carry out numerical calculation and thermal simulation analysis of probe card before experimental test.
[0003] At present, there is no standard thermal simulation scheme for the working state of probe card. The existing scheme only considers the heat conduction between metal components in the probe card, and does not consider the convective heat transfer between metal and medium and the thermal radiation of the material, which will lead to a large difference between the simulation results and the actual component temperature, and a lot of time is needed to correct, which prolongs the product development cycle and increases the development cost.
[0004] In order to improve the simulation accuracy, the present application provides a thermal simulation scheme for the working state of probe card. In the present scheme, the convective heat transfer coefficient and thermal radiation coefficient of metal and air are set to improve the accuracy of simulation. And the processing scheme of the probe model is reasonably planned to save the calculation cost and improve the calculation efficiency. SUMMARY
[0005] In order to overcome the defects in the prior art, the present application provides a steady-state thermal simulation method of probe card. In the present scheme, the convective heat transfer coefficient and thermal radiation coefficient of metal and air are set to improve the accuracy of simulation. And the processing scheme of the probe model is reasonably planned to save the calculation cost and improve the calculation efficiency.
[0006] The present application discloses a steady-state thermal simulation method of probe card, comprising the following steps:
[0007] Step 1: establishing a three-dimensional model of probe card, and importing the three-dimensional model of probe card into finite element analysis software;
[0008] Step 2: discretizing the three-dimensional model of probe card in the finite element analysis software to establish a finite element model;
[0009] Step 3: setting boundary conditions for the finite element model, the boundary conditions including thermal conductivity coefficient, convective heat transfer coefficient and thermal radiation coefficient;
[0010] Step 4: submitting the solver calculation according to the relevant parameters to obtain a temperature calculation result, and obtaining a simulation cloud picture according to the temperature calculation result.
[0011] Specifically, step 1 comprises the following steps:
[0012] Step 1-1: defining multiple probes on a probe card for testing the same chip as a probe group, and simplifying a model for each probe group;
[0013] Step 1-2: participating in the assembly of the probe card with the simplified probe model to obtain a three-dimensional model of the probe card, and confirming that the assembly relationship of the three-dimensional model of the probe card is correct;
[0014] Step 1-3: importing the three-dimensional model of the probe card into finite element analysis software.
[0015] Specifically, in step 1-1, the method for simplifying the probe is to draw along the needle planting edge of the probe group to establish a three-dimensional simple model of the probe, and the height of the simple model is the same as the actual height of the probe.
[0016] Specifically, the simple model is a cuboid with the same height as the probe.
[0017] Specifically, in step 1-2, the contact properties of the surfaces in contact in the assembly relationship of the probe card are defined, wherein the threaded contact is defined as a binding contact, and the rest of the contacts are defined as frictional contacts.
[0018] Specifically, in step 2, when discretizing the three-dimensional model of the probe card, a mesh refinement area and a mesh coarsening area are set.
[0019] Specifically, the mesh refinement area includes an area on the probe card where the position accuracy is greatly affected by temperature; and the mesh coarsening area includes an area on the probe card where the position accuracy is not greatly affected by temperature.
[0020] Specifically, in step 3, the thermal conductivity coefficient, the convective heat transfer coefficient and the thermal radiation coefficient are reversely calculated according to the temperature of the probe card under the actual working condition measured by experiment.
[0021] Specifically, after step 4, step 5 of judging the rationality of the internal temperature distribution of the probe card according to the obtained temperature calculation result is further included.
[0022] Specifically, in step 5, further comprising multiple iteration optimizations of the finite element model based on the judgment result of the rationality of the internal temperature distribution of the probe card, and the iteration optimization steps comprise: repeating steps 1-5, adjusting the structure parameters and contact relationship of the probe card, and performing multiple iteration simulations until the internal temperature of the probe card in the simulation cloud picture is uniformly distributed.
[0023] The present application has at least the following advantages:
[0024] 1. The convection heat transfer coefficient and thermal radiation coefficient of the metal and air in the probe card are set in the scheme, the simulation precision is improved, and the simplification processing scheme of the probe model is reasonably planned, the calculation cost is saved, and the calculation efficiency is improved.
[0025] 2. The working temperature distribution and heat conduction process of each component in the probe card are accurately analyzed, so that the components of the probe card that cannot be tested at the working temperature are thermodynamically benchmarked.
[0026] 3. The scheme can greatly reduce the research and development test cycle of the probe card, provide an optimization direction for improving the probe card design, ensure that the internal temperature distribution of the probe card is uniform and reasonable, and is beneficial to improving the quality of the probe card.
[0027] 4. The method can calculate the thermodynamic parameters of the probe card with different structures and different numbers of probes, and has wide versatility.
[0028] In order to make the above and other objects, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS
[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.
[0030] Figure 1 is a flow chart of the steady-state thermal simulation method of the probe card in the embodiment of the present application;
[0031] Figure 2 is a structural schematic diagram of the 2.5D probe card in the embodiment of the present application;
[0032] Figure 3 is a sectional view of the 2.5D probe card in the embodiment of the present application;
[0033] Figure 4 is a finite element model of the 2.5D probe card in the embodiment of the present application;
[0034] Figure 5 is a boundary condition and parameter setting interface (only the thermal radiation coefficient parameter setting interface is shown) in the embodiment of the present application;
[0035] Figure 6 is a boundary condition and parameter setting interface (only the heat source temperature parameter setting interface is shown) in the embodiment of the present application;
[0036] Figure 7 is a post-processing result figure of the steady-state thermal simulation of the 2.5D probe card in the embodiment of the application under the working condition of 150℃.
[0037] Reference numerals of the above drawings: 1, ceramic substrate; 2, PCB; 3, probe; 4, support ring; 5, fixing ring; 6, reinforcing piece; 7, connecting head. DETAILED DESCRIPTION
[0038] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative effort belong to the protection scope of the application.
[0039] In the description of the application, it should be noted that, unless specifically defined and limited, the terms “mounting”, “connection”, “fixing”, “connection” should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.
[0040] In the application, unless specifically defined and limited, the first feature “above” or “below” the second feature can include that the first feature and the second feature are in direct contact, or that the first feature and the second feature are not in direct contact but are in contact through another feature between them. Moreover, the first feature “above”, “below” and “on” the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. The first feature “below”, “under” and “under” the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the horizontal height of the first feature is less than that of the second feature.
[0041] In the description of the embodiments, it should be understood that the terms “center”, “longitudinal”, “transverse”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the protection scope of the application.
[0042] In addition, the terms "first", "second" and the like are used only to distinguish the description and have no special meaning.
[0043] The embodiment will take the simulation of a 2.5D probe card as an example to explain the steady-state thermal simulation method of the probe card in detail. As shown in Figure 2 and Figure 3 The 2.5D probe card includes a ceramic substrate 1 (MLC), a plurality of probes 3 (PROBE), a PCB 2 (printed circuit board), a reinforcing member 6, a support ring 4, a fixing ring 5 and a connecting head 7. The plurality of probes 3 are arranged on the ceramic substrate 1. The reinforcing member 6 is used to enhance the structural strength. The support ring 4 is used to connect the ceramic substrate 1 and the PCB 2. The fixing ring 5 is used to connect the PCB 2 and the reinforcing member 6. The connecting head 7 is used to connect the reinforcing member 6 and the tester. Among them, the probe 3 is used to transmit electrical signals between the ceramic substrate 1 and the wafer. Adjacent two components are in contact with each other, and the contact mode is friction contact with a certain friction coefficient. The main structure is connected by different types of bolts.
[0044] As shown in Figure 1 The steady-state thermal simulation method of the probe card of the embodiment includes the following steps:
[0045] Step 1: Establish a three-dimensional model of the probe card, and import the three-dimensional model of the probe card into a finite element analysis software.
[0046] Step 2: Discretize the three-dimensional model of the probe card in the finite element analysis software to establish a finite element model (FEM).
[0047] Step 3: Apply boundary conditions to the finite element model, including thermal conductivity coefficient, convective heat transfer coefficient and thermal radiation coefficient.
[0048] Step 4: According to the set related parameters (heat source temperature, thermal conductivity coefficient, convective heat transfer coefficient and thermal radiation coefficient), submit the solver to calculate the temperature calculation result, and obtain the simulation cloud picture according to the temperature calculation result.
[0049] Specifically, in step 1, the method for establishing the three-dimensional model of the probe card includes the following steps:
[0050] Step 1-1: Define multiple probes 3 on the probe card used for testing the same chip as a probe group, and simplify the model of each probe group. More specifically, the wafer to be tested contains multiple dies to be diced (referring to unpackaged bare chips cut from the wafer). Define multiple probes 3 used for testing the same die as a probe group, and trace along the pin edges of the probe group to create a simplified 3D model of the probe 3. This simplified 3D model is a cuboid with the same height as the probe 3. This simplification of the model can significantly reduce the complexity of the probe card's 3D model and significantly improve computational efficiency. Furthermore, features smaller than 1 mm in key areas of interest (e.g., ceramic substrate 1) and features smaller than 5 mm in non-key areas of interest (e.g., reinforcement 6) can be removed.
[0051] Steps 1-2: Incorporate the simplified probe model (i.e., the simplified probe 3 model) into the probe card assembly to obtain the probe card's 3D model. It should be noted that during assembly, the assembly relationships of the probe card's 3D model must be verified to ensure they are correct, guaranteeing that contacting components within the probe card's 3D model are tightly connected (e.g., ...). Figure 3 (As shown). Further, after the probe cards are assembled, the contact properties of the contacting surfaces in the probe card assembly relationship are defined. Threaded contact is defined as binding contact, and the remaining contacts are defined as frictional contact.
[0052] Steps 1-3: Import the probe card 3D model into the finite element analysis software.
[0053] In step 2, as Figure 4 As shown, when discretizing the 3D model of the probe card, mesh refinement and coarsening regions are set. Specifically, the mesh refinement region includes areas on the probe card where the positional accuracy is significantly affected by temperature. These areas require close attention during probe card development. The ceramic substrate 1 (MLC) and probe 3 (PROBE) have large coefficients of thermal expansion. The coefficient of thermal expansion is defined as the amount of displacement caused by a unit change in temperature. Therefore, their deformation is very sensitive to temperature changes. Furthermore, the thermal expansion of MLC directly affects the measurement accuracy of the probe card, requiring close attention; hence, a fine mesh is needed. The mesh coarsening region includes areas on the probe card where the positional accuracy is less affected by temperature. These areas do not require close attention during probe card development. Areas requiring close attention, such as MLC and PROBE, are close to the heat source, have a large coefficient of thermal expansion, and require high accuracy in thermal expansion measurement. Areas not requiring close attention, such as reinforcement 6, are structural reinforcement areas, far from the testing areas like MLC, and have lower accuracy requirements. In other words, when discretizing the 3D model of the probe card, refining the mesh in the areas of focus can improve computational accuracy, while coarsening the mesh in the areas of non-focus can improve computational efficiency.
[0054] In step 3, according to the measured temperature of the probe card under actual working conditions, the thermal conductivity coefficient, the convection heat transfer coefficient and the thermal radiation coefficient are reversely calculated (as shown in FIG. 6). Then, the heat source temperature is set according to the actual working temperature of the probe card (as shown in FIG. 7). In step 4, the above-mentioned thermal parameters are submitted to the solver for calculation to obtain the temperature calculation result, and the simulation cloud chart is obtained according to the temperature calculation result (as shown in FIG. 8). Figure 5 Figure 6 Figure 7
[0055] The setting of the thermal radiation surface is as follows: all surfaces between the PCB2 and the heat source are set as the thermal radiation surface, the thermal radiation coefficient is 0.55 (calculated according to the measured value), the radiation mode is set as "surface to surface", the environment temperature is set as the air temperature during the test, and the shell coefficient is set as 1, as shown in FIG. 5. Figure 5
[0056] The setting of the convection heat transfer surface is as follows: in theory, all surfaces of the probe card are in contact with the air, so the convection heat transfer coefficient is set for all surfaces of the probe card, the convection heat transfer coefficient of the metal surface is set as 1x10-6 W / (m2℃), such as the reinforcing member 6, the support ring 4 and the fixing ring 5, and the convection heat transfer coefficient of the non-metal surface is set as 0.6x10-6 W / (m2℃), such as the MLC.
[0057] The simulation method of the embodiment further includes step 5, which specifically includes: judging the rationality of the internal temperature distribution of the probe card according to the temperature calculation result obtained in step 4. Step 5 further includes: performing multiple iterative optimizations on the finite element model based on the judgment result of the rationality of the internal temperature distribution of the probe card, and the iterative optimization step includes: repeating steps 1-5, adjusting the structure parameters and the contact relationship of the probe card, and performing multiple iterative simulations until the internal temperature of the probe card is uniformly distributed in the simulation cloud chart.
[0058] In summary, the steady-state thermal simulation method of the probe card of the embodiment has the following advantages:
[0059] 1. In the scheme, the convection heat transfer coefficient and the thermal radiation coefficient of the metal and the air in the probe card are set, the accuracy of the simulation is improved, and the simplification scheme of the probe model is reasonably planned, the calculation cost is saved, and the calculation efficiency is improved.
[0060] 2. The working temperature distribution and the heat conduction process of each component in the probe card are accurately analyzed, so that the components in the probe card which cannot be tested at the working temperature, such as the probe 3 and the ceramic substrate 1, are thermodynamically benchmarked at the working temperature of the formal test machine, the system is kept closed during the test process, the sensor cannot be connected, and the temperature cannot be tested, so the accuracy of the simulation is needed to provide data support for the design.
[0061] 3. The scheme can greatly reduce the research and development test cycle of the probe card, provide an optimization direction for improving the probe card design, ensure that the internal temperature distribution of the probe card is uniform and reasonable, and is beneficial to improving the quality of the probe card.
[0062] 4. The method can calculate thermodynamic parameters for probe cards with different structures and different numbers of probes, and has wide universality.
[0063] The principles and implementation manners of the present application are described by using specific examples in the present application, and the above example is only used to help understand the method and core idea of the present application; meanwhile, for those skilled in the art, the specific implementation manners and application ranges will be changed according to the idea of the present application, and the above description should not be understood as a limitation on the present application.
Claims
1. A steady-state thermal simulation method for a probe card, characterized in that, Includes the following steps: Step 1: Create a 3D model of the probe card and import the 3D model of the probe card into the finite element analysis software; Step 2: Discretize the three-dimensional model of the probe card in the finite element analysis software to establish a finite element model; Step 3: Set boundary conditions for the finite element model, including thermal conductivity coefficient, convective heat transfer coefficient and thermal radiation coefficient; Step 4: Submit the calculation to the solver based on the relevant parameters to obtain the temperature calculation results, and obtain the simulation cloud map based on the temperature calculation results.
2. The steady-state thermal simulation method for the probe card according to claim 1, characterized in that, Step 1 includes the following steps: Step 1-1: Define multiple probes on the probe card used to test the same chip as a probe group, and simplify the model for each probe group; Step 1-2: Incorporate the simplified probe model into the probe card assembly to obtain the probe card 3D model, and confirm that the assembly relationship of the probe card 3D model is correct; Steps 1-3: Import the three-dimensional model of the probe card into the finite element analysis software.
3. The steady-state thermal simulation method for the probe card according to claim 2, characterized in that, In step 1-1, the method for simplifying the probe is as follows: trace along the edge of the probe group to create a simplified three-dimensional model of the probe, the height of which is the same as the actual height of the probe.
4. The steady-state thermal simulation method for the probe card according to claim 3, characterized in that, The simplified model is a cuboid with the same height as the probe.
5. The steady-state thermal simulation method for the probe card according to claim 2, characterized in that, In steps 1-2, the contact properties of the surfaces in contact during the probe card assembly relationship are defined, where threaded contact is defined as binding contact and the other contacts are defined as frictional contact.
6. The steady-state thermal simulation method for the probe card according to claim 1, characterized in that, In step 2, when discretizing the 3D model of the probe card, a mesh refinement region and a mesh coarsening region are set.
7. The steady-state thermal simulation method for the probe card according to claim 1, characterized in that, In step 3, the thermal conductivity coefficient, convective heat transfer coefficient, and thermal radiation coefficient are calculated in reverse based on the temperature of the probe card under actual operating conditions measured in the experiment.
8. The steady-state thermal simulation method for the probe card according to claim 1, characterized in that, After step 4, there is also step 5: judging the rationality of the internal temperature distribution of the probe card based on the obtained temperature calculation results.
9. The steady-state thermal simulation method for the probe card according to claim 8, characterized in that, Step 5 also includes iterative optimization of the finite element model based on the judgment result of the reasonableness of the internal temperature distribution of the probe card. The iterative optimization steps include: repeating steps 1-5, adjusting the structural parameters and contact relationship of the probe card, and performing multiple iterative simulations until the internal temperature of the probe card is uniformly distributed in the simulation cloud map.