Thermal analysis system and thermal analysis method

Abstract

To further improve heat analysis simulation.SOLUTION: A thermal analysis system (1) comprises: a simulation model (2); and a thermal simulation program (3) configured to calculate at least one of temperature, thermal resistance (θJA) and thermal characteristic parameters (ψJP1 and ψJP2) from a heat transfer rate that is set in the simulation model (2). The simulation model (2) includes a semiconductor model (5) including a semiconductor being a heat source (Ph) and environment models (6a and 6b) in which environments that are positioned on any heat radiation paths (L1 and L2) from the semiconductor model (5) are modeled. The heat transfer rate is set on a boundary surface on a semiconductor model (5) side of the environment models (6a and 6b) for a direction along the heat radiation paths (L1 and L2) (first configuration).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The invention disclosed herein relates to a thermal analysis system and a thermal analysis method. [Background technology]

[0002] Conventionally, there is a thermal analysis system that performs a thermal analysis simulation using a three-dimensional model created on a computer.

[0003] As an example of the related prior art, Patent Document 1 can be mentioned. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-227293

[0005] [overview] The thermal analysis system disclosed in Patent Document 1 leaves room for further consideration regarding the flexibility of analysis conditions.

[0006] The thermal analysis system disclosed herein includes a simulation model and a thermal simulation program. The thermal simulation program is configured to calculate at least one of the temperature, thermal resistance, and thermal characteristic parameters of the simulation model from a heat transfer coefficient set in the simulation model. The simulation model includes a semiconductor model including a semiconductor that serves as a heat source, and an environment model that models an environment located on an arbitrary heat dissipation path from the semiconductor model. The heat transfer coefficient is set on the boundary surface of the environment model on the semiconductor model side in the direction along the heat dissipation path.

[0007] The thermal analysis method disclosed herein includes a first step and a second step. In the first step, a simulation model and a thermal simulation program are prepared. In the second step, at least one of the temperature, thermal resistance, and thermal characteristic parameters of the simulation model is calculated using the simulation program. The simulation model includes a semiconductor model including a semiconductor that serves as a heat source, and an environment model that models an environment located on an arbitrary heat dissipation path from the semiconductor model. The thermal simulation program is configured to be able to calculate at least one of the temperature, thermal resistance, and thermal characteristic parameters from the heat transfer coefficient set in the simulation model. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing the configuration of a thermal analysis system 1. As shown in FIG. [Figure 2] FIG. 2 is a plan view showing the simulation model 2 from the side. [Figure 3] FIG. 3 is a graph showing an example of the first analysis result. [Figure 4] FIG. 4 is a graph showing an example of the second analysis result. [Figure 5] FIG. 5 is a plan view showing a simulation model 2 according to the second embodiment. [Figure 6] FIG. 6 is a plan view showing a simulation model 2 according to the third embodiment.

[0009] [Detailed explanation] <Considerations on analysis conditions> Conventionally, thermal analysis simulations have been performed using three-dimensional (3D) models created on a computer. The three-dimensional models are created using software such as CAD (Computer Aided Design) for devices including a semiconductor device, a circuit board on which the semiconductor device is mounted, and other components. Such thermal analysis simulations can calculate the thermal resistance, thermal characteristic parameters, temperature, and other parameters of any location on the three-dimensional model using CAE (Computer Aided Engineering) analysis, including the finite element method.

[0010] By the way, when calculating thermal resistance, thermal characteristic parameters, temperature, etc. using such thermal analysis simulation, environmental information of the model to be analyzed is required. This environmental information includes design information of the board (board shape, board material, board physical properties, etc.), the device usage environment, design information of each component of the device (component shape, component material, component physical properties, etc.), and heat sink information (presence or absence of a heat sink, heat sink performance, etc.).

[0011] However, when performing a thermal analysis simulation, there are cases where only part of the environmental information (for example, temperature measurement points, environmental temperature, etc.) is available. When the environmental information is insufficient, it is difficult to perform a thermal analysis.

[0012] To address this issue, the thermal analysis system 1 of the present disclosure is capable of performing a thermal analysis simulation using part of the environmental information. The thermal analysis system 1 according to each embodiment of the present disclosure will be described below.

[0013] <Thermal analysis system according to the first embodiment> 1 is a diagram showing the configuration of a thermal analysis system 1. As shown in FIG. 1, the thermal analysis system 1 includes a simulation model 2, a thermal simulation program 3, and a calculation device 4.

[0014] The simulation model 2 is a three-dimensional model generated by software such as a three-dimensional CAD. The thermal simulation program 3 is an analysis program configured to be executable on a computing device 4. The computing device 4 is a computer such as a PC (Personal Computer).

[0015] The thermal simulation program 3 is capable of performing a thermal analysis simulation on the simulation model 2 using a heat transfer coefficient, which will be described later. This thermal analysis simulation calculates at least one of the temperature, thermal resistance, and thermal characteristic parameters of the simulation model 2 as an analysis result. The thermal analysis system 1 will be described in more detail below.

[0016] Fig. 2 is a plan view showing the side of the simulation model 2. As shown in Fig. 2, the simulation model 2 includes a semiconductor model 5, an environment model 6a, and a contact body model 7. The simulation model 2 also has a heat dissipation path L1, a first temperature measurement point P1, and a second temperature measurement point P2 set therein.

[0017] The semiconductor model 5 is a model of a packaged large-scale integrated circuit. The semiconductor model 5 includes a main body 8 and a package 9. The main body 8 includes a semiconductor IC (Integrated Circuit) chip (more specifically, a semiconductor element, not shown) that serves as a heat source Ph, a die pad, wires, resin, etc.

[0018] The package 9 is a semiconductor package that houses the main body 8. The package 9 is formed as a polyhedron that includes an upper surface 10, a lower surface 11, a first side surface 12, and a second side surface 13.

[0019] The upper surface 10 and the lower surface 11 are planes parallel to each other. The lower surface 11 is located downstream of the upper surface 10 and the main body 8 in the mounting direction (the direction from the top to the bottom of the paper in FIG. 1 ) of the semiconductor model 5 to a substrate model 17 (details of which will be described later).

[0020] The first side surface 12 and the second side surface 13 are parallel to each other. The first side surface 12 and the second side surface 13 are perpendicular to the upper surface 10 and the lower surface 11, respectively. The first side surface 12 and the second side surface 13 are aligned in a horizontal direction (the left-right direction on the paper in FIG. 2 ) perpendicular to the mounting direction.

[0021] The heat dissipation path L1 is a path that starts at the heat source Ph and extends toward the outside of the package 9. The heat dissipation path L1 is set arbitrarily. Here, the heat dissipation path L1 is set parallel to the mounting direction so as to extend from the heat source Ph to the outside of the package 9, passing through the lower surface 11.

[0022] The first temperature measurement point P1 and the second temperature measurement point P2 are each set at an arbitrary position on the simulation model 2. The first temperature measurement point P1 is set on the upper surface 10. The second temperature measurement point P2 is set near the second side surface 13. Specifically, this is as follows.

[0023] The first temperature measurement point P1 is located at the center of the top surface 10 in a plan view. That is, the first temperature measurement point P1 is located at the center of the top surface 10 in the horizontal direction and at the center of the top surface 10 in the direction perpendicular to the paper surface of FIG. 2 (the horizontal direction and the direction perpendicular to the mounting direction) (not shown).

[0024] The second temperature measurement point P2 is located on the second side surface 13 side of the simulation model 2 (here, the package 9). Specifically, the second temperature measurement point P2 is located at a predetermined distance (preferably a distance shorter than the distance between the upper surface 10 and the lower surface 11, and more preferably a distance shorter than 2 / 3 times the distance between the upper surface 10 and the lower surface 11) perpendicular to the boundary surface 14. Note that while the second temperature measurement point P2 is shown in FIG. 2 as being located on the second side surface 13, more specifically, it can be understood as being located on the die pad of the semiconductor integrated circuit that forms the basis of the semiconductor model 5.

[0025] The environmental model 6a is a model of the environment located on the heat dissipation path L1 around the semiconductor model 5. Models of structures, fluids (liquid or gas), etc. located around the semiconductor model 5 can be set as the environmental model 6a. The environmental model 6a here is a model of a structure (more specifically, a heat sink, a cold plate, or a cooling member equivalent thereto).

[0026] The environment model 6a has a boundary surface 14 at its boundary on the semiconductor model 5 side in the direction along the heat dissipation path L1 (here, the direction parallel to the mounting direction). The heat transfer coefficient of the environment model 6a is set at the boundary surface 14.

[0027] The contact body model 7 is disposed between the semiconductor model 5 and the environment model 6a in the mounting direction. The contact body model 7 is in contact with both the semiconductor model 5 and the environment model 6a. The contact body model 7 includes an object model 15 and a bonded body model 16.

[0028] The object model 15 is a model consisting of at least one (here, two) material layer. The surface of the object model 15 on the downstream side in the mounting direction (in other words, the surface on the environment model 6a side) is in contact with the boundary surface 14 of the environment model 6a. The details of the object model 15 are as follows.

[0029] The object model 15 includes a board model 17 and a grease model 18. The board model 17 is a model of a board on which the semiconductor model 5 is mounted. The board model 17 is formed as a plate-like body with a uniform thickness. The grease model 18 is a model of grease for heat dissipation. In the simulation model 2, the grease model 18 is modeled as a plate-like polyhedron with a uniform thickness.

[0030] The grease model 18 is sandwiched between the board model 17 and the environment model 6a in the mounting direction. The grease model 18 is in contact with the surface of the board model 17 on the downstream side in the mounting direction. The grease model 18 is also in contact with the boundary surface 14 of the environment model 6a.

[0031] The bonded body model 16 is in contact with the bottom surface 11 of the semiconductor model 5. The bonded body model 16 is also in contact with the surface of the substrate model 17 on the upstream side in the mounting direction (in other words, the surface opposite to the surface in contact with the grease model 18). The bonded body model 16 fixes the semiconductor model 5 to the substrate model 17. The bonded body model 16 here is a model of solder.

[0032] The thermal simulation program 3 is a program that runs on a computer and is configured to be able to calculate at least one of the temperature, thermal resistance, and thermal characteristic parameters of a model generated by a three-dimensional CAD or the like.

[0033] <Thermal analysis method> Next, a description will be given of a thermal analysis method using the above-described simulation model 2 and thermal simulation program 3. This thermal analysis method includes a first step and a second step.

[0034] The first step is a step of preparing a simulation model 2 and a thermal simulation program 3. Specifically, the first step includes a model setting step, a heat dissipation path setting step, and a temperature measurement point setting step. In the model setting step, a three-dimensional model of the simulation model 2 is created using three-dimensional CAD software. Alternatively, data of an existing three-dimensional model is prepared.

[0035] In the heat radiation path setting step, the heat radiation path L1 described above is set for the simulation model 2 created or prepared in the model setting step. By setting the heat radiation path L1, the boundary surface 14 is defined and the heat transfer coefficient is determined. In the temperature measurement point setting step, temperature measurement points (first temperature measurement point P1 and second temperature measurement point P2 in the first embodiment) are set.

[0036] The second step is a step of calculating at least one of the temperature, thermal resistance, and thermal characteristic parameters of the simulation model 2 using the thermal simulation program 3. Specifically, the second step includes an analysis setting step and a calculation step. The analysis setting step is a step of defining the analysis conditions and analysis target of the thermal simulation program 3. The analysis conditions include at least a portion of the above-mentioned environmental information. The analysis target is selected from at least one of the temperature, thermal resistance, and thermal characteristic parameters. The calculation step is a step of the thermal simulation program 3 performing analysis using a predetermined analysis method (e.g., the finite element method) based on the analysis conditions. Through the calculation step, analysis results are obtained for the temperature, thermal resistance, or thermal characteristic parameters defined as the analysis target.

[0037] <Example of thermal analysis simulation results> Next, a thermal analysis simulation will be described while showing a first example of an analysis result and a second example of an analysis result as examples of thermal analysis by the thermal analysis system 1.

[0038] <Example of the first analysis result> 3 is a graph showing a first example of the analysis results. The first example of the analysis results is obtained by analyzing the relationship between the heat transfer coefficient and the thermal characteristic parameters ψJP1 and ψJP2 at the first temperature measurement point P1 and the second temperature measurement point P2. As described above, the heat transfer coefficient here is set at the boundary surface 14.

[0039] 3 is a thermal characteristic parameter from the junction (not shown) of the semiconductor model 5 to the first temperature measurement point P1. The thermal characteristic parameter ψJP2 in Fig. 3 is a thermal characteristic parameter from the junction of the semiconductor model 5 to the second temperature measurement point P2.

[0040] As shown in Fig. 3, the thermal characteristic parameter ψJP1 decreases as the heat transfer coefficient increases. On the other hand, the thermal characteristic parameter ψJP2 remains approximately constant regardless of changes in the heat transfer coefficient. In other words, the thermal characteristic parameter ψJP2 remains approximately constant regardless of the ambient environment of the simulation model 2. Therefore, the thermal design of a device including the simulation model 2 can be performed based on the thermal characteristic parameter ψJP2 calculated here.

[0041] <Example of second analysis result> Figure 4 is a graph showing a second example of analysis results. The second example of analysis results is an analysis of the relationship between the thermal characteristic parameter ψJP1 and thermal resistance θJA at the first temperature measurement point P1 and the heat transfer coefficient. The thermal resistance θJA in Figure 4 is the thermal resistance from the junction of the semiconductor model 5 to the ambient temperature measurement position in accordance with the JEDEC standard (JESD51-2A). Note that the semiconductor model 5 in the second example of analysis results has been modified from the semiconductor model 5 in the first example of analysis results by changing the values included in the environmental information.

[0042] As shown in FIG. 4, the thermal characteristic parameter ψJP1 decreases slightly as the heat transfer coefficient increases, but remains approximately constant. Furthermore, the thermal resistance θJA decreases as the heat transfer coefficient increases. More specifically, when the heat transfer coefficient is between predetermined values n1 and n2, the thermal resistance θJA decreases rapidly as the heat transfer coefficient increases. However, once the heat transfer coefficient exceeds the predetermined value n2, the thermal resistance θJA remains approximately constant regardless of changes in the heat transfer coefficient. In other words, at the predetermined value n2, the thermal resistance θJA is saturated. Therefore, the thermal design of a device including simulation model 2 can be performed based on the thermal resistance θJA calculated here.

[0043] <Thermal analysis system 1 according to the second embodiment> Next, a thermal analysis system 1 according to a second embodiment will be described. In the following, differences from the first embodiment will be described, and the same components as those in the first embodiment will be assigned the same reference numerals and will not be described again.

[0044] Fig. 5 is a plan view showing a simulation model 2 according to the second embodiment. As shown in Fig. 5, the object model 15 of the thermal analysis system 1 according to this embodiment is a model of one material layer. Specifically, the object model 15 is an insulating sheet body. The object model 15 is made of a material with a relatively high thermal conductivity.

[0045] <Thermal analysis system 1 according to the third embodiment> Next, a thermal analysis system 1 according to a third embodiment will be described. As with the second embodiment, only differences from the other embodiments will be described, and similar components will be assigned the same reference numerals and descriptions thereof will be omitted.

[0046] 6 is a plan view showing a simulation model 2 according to the third embodiment. The heat dissipation path L2 of the thermal analysis system 1 according to this embodiment is set to extend from the heat source Ph in the direction opposite to the mounting direction, passing through the top surface 10, to the outside of the package 9. The environmental model 6b is a model of the air in contact with the top surface 10, first side surface 12, and second side surface 13 of the semiconductor model 5. The boundary surface 14 here is set at the contact surface of the environmental model 6b with the top surface 10.

[0047] Although the contact body model 7 is omitted in FIG. 6, the simulation model 2 may include the contact body model 7, as in the first embodiment.

[0048] As described above, the thermal analysis system 1 according to each of the above embodiments can use the heat transfer coefficient to perform thermal analysis of the simulation model 2, and ultimately thermal analysis of an actual product corresponding to the simulation model 2. Even if sufficient environmental information cannot be prepared, by setting the heat dissipation path L1 in the simulation model 2, it is possible to calculate the relationship between the heat transfer coefficient and at least one of the temperature, the thermal resistance, and the thermal characteristic parameters.

[0049] As described above, the thermal analysis system 1 according to the first embodiment can perform thermal analysis on a device including a heat dissipation member such as a semiconductor, solder, a substrate, grease, or a heat sink.

[0050] Furthermore, as described above, the thermal analysis system 1 according to the second embodiment can perform thermal analysis between a semiconductor and its surrounding environment (air).

[0051] <Modification> The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the present invention. For example, the environment model 6a is a model of a solid structure (specifically, a cooling member such as a heat sink), and the environment model 6b is a model of air, but the environment models 6a and 6b are not limited to solids or gases, and may be a model of a fluid (for example, a liquid such as pure water or cooling oil, or a viscous material such as grease).

[0052] Furthermore, although the simulation model 2 is described as being a three-dimensional model generated by software such as a three-dimensional CAD, the present invention is not limited to this. For example, the simulation model 2 may be a two-dimensional model, a numerical / mathematical model, or other abstract model that can be analyzed by the thermal simulation program 3.

[0053] <Additional Notes> The thermal analysis system (1) disclosed in the specification comprises a simulation model (2) and a thermal simulation program (3) configured to be able to calculate at least one of the temperature, thermal resistance (θJA), and thermal characteristic parameters (ψJP1, ψJP2) (ψJP1, ψJP2) of the simulation model (2) from the heat transfer coefficient set in the simulation model (2), and the simulation model (2) includes a semiconductor model (5) including a semiconductor that serves as a heat source (Ph), and environmental models (6a, 6b) that model an environment located on any heat dissipation path (L1, L2) from the semiconductor model (5), and the heat transfer coefficient is set on the boundary surface of the environmental models (6a, 6b) on the semiconductor model (5) side in the direction along the heat dissipation path (L1, L2) (first configuration).

[0054] In the thermal analysis system (1) according to the first configuration, the simulation model (2) is arranged between the semiconductor model (5) and the environmental models (6a, 6b), and includes a contact body model (7) that is in contact with each of the semiconductor model (5) and the environmental models (6a, 6b), and the boundary surface is preferably configured to be a surface of the environmental models (6a, 6b) that is in contact with the contact body model (7) (second configuration).

[0055] In the thermal analysis system (1) according to the second configuration, the contact body model (7) may be configured to include an object model (15) that contacts the environment model (6a, 6b), and a bonded body model (16) that contacts the semiconductor model (5) and the object model (15) and bonds the semiconductor model (5) and the object model (15) together (third configuration).

[0056] In the thermal analysis system (1) according to the third configuration, the object model (15) is in contact with the bonded body model (16) and includes a substrate model (17) that models a substrate on which the semiconductor model (5) is mounted via the bonded body model (16), and the bonded body model (16) is preferably configured to model solder (fourth configuration).

[0057] In the thermal analysis system (1) according to the second configuration, the contact body model (7) may be configured as a sheet body sandwiched between the semiconductor model (5) and the environmental models (6a, 6b) (fifth configuration).

[0058] In the thermal analysis system (1) according to any one of the first to fifth configurations, the environmental model (6a) may be configured to be a model of an individual structure (sixth configuration).

[0059] In the thermal analysis system (1) according to the first to fifth configurations, the environmental model (6b) may be configured to be a model of a fluid (seventh configuration).

[0060] The thermal analysis method disclosed in the specification includes a first step of preparing a simulation model (2) and a thermal simulation program (3), and a second step of calculating at least one of the temperature, thermal resistance (θJA), and thermal characteristic parameters (ψJP1, ψJP2) of the simulation model (2) using the thermal simulation program (3), wherein the simulation model (2) includes a semiconductor model (5) including a semiconductor that serves as a heat source (Ph), and environmental models (6a, 6b) that model the environment located on any heat dissipation path (L1, L2) from the semiconductor model (5), and the thermal simulation program (3) is configured to be able to calculate at least one of the temperature, thermal resistance (θJA), and thermal characteristic parameters (ψJP1, ψJP2) from the heat transfer coefficient set in the simulation model (2) (eighth configuration). [Explanation of symbols]

[0061] 1. Thermal analysis system 2 Simulation model 3. Thermal Simulation Program 4 Computing equipment 5 Semiconductor Model 6a, b Environmental Model 7 Contact body model 8 Main body 9 packages 10 Top side 11 Bottom side 12 First aspect 13 Second aspect 14 Boundary 15 Object Models 16 Zygote Model 17 PCB Model 18 Grease Model L1, L2 heat dissipation path P1 First temperature measurement point P2 2nd temperature measurement point Ph heat source n1 predetermined value n2 predetermined value θJA thermal resistance ψJP1 Thermal characteristic parameters ψJP2 thermal characteristic parameters

Claims

1. A simulation model, a thermal simulation program configured to be able to calculate at least one of the temperature, thermal resistance, and thermal characteristic parameters of the simulation model from the heat transfer coefficient set in the simulation model; and Equipped with The simulation model is A semiconductor model that includes a semiconductor that acts as a heat source. an environmental model that models an environment located on an arbitrary heat dissipation path from the semiconductor model; Including, A thermal analysis system in which the heat transfer coefficient is set on the boundary surface of the environmental model on the semiconductor model side in a direction along the heat dissipation path.

2. the simulation model includes a contact body model disposed between the semiconductor model and the environmental model and in contact with each of the semiconductor model and the environmental model; The thermal analysis system according to claim 1 , wherein the boundary surface is a surface of the environmental model that is in contact with the contact body model.

3. The contact body model is an object model that contacts the environment model; a bonded body model that comes into contact with the semiconductor model and the object model and bonds the semiconductor model to the object model; The thermal analysis system of claim 2 , comprising:

4. the object model includes a substrate model that is in contact with the bonded body model and that models a substrate on which the semiconductor model is mounted via the bonded body model, 4. The thermal analysis system according to claim 3, wherein the joint model is a model of solder.

5. The thermal analysis system according to claim 2 , wherein the contact body model is a sheet body sandwiched between the semiconductor model and the environment model.

6. The thermal analysis system according to claim 1 , wherein the environmental model is a model of an individual structure.

7. The thermal analysis system according to claim 1 , wherein the environmental model is a model of a fluid.

8. a first step of preparing a simulation model and a thermal simulation program; a second step of calculating at least one of a temperature, a thermal resistance, and a thermal characteristic parameter of the simulation model using the thermal simulation program; Including, The simulation model is A semiconductor model that includes a semiconductor that acts as a heat source. an environmental model that models an environment located on an arbitrary heat dissipation path from the semiconductor model; Including, A thermal analysis method in which the thermal simulation program is configured to be able to calculate at least one of the temperature, the thermal resistance, and the thermal characteristic parameters from a heat transfer coefficient set in the simulation model.

Images