Crimping type IGBT simulation modeling method and system considering temperature effect

Abstract

The invention discloses a crimping type IGBT simulation modeling method considering a temperature effect, and the method comprises the steps: building a finite element model of an IGBT device according to the geometric shape and material attributes of each assembly in the IGBT device; setting a coupling relationship between physical fields, and establishing a corresponding physical field equation for each physical field; setting boundary conditions for the finite element model according to simulation requirements; carrying out coupling calculation based on the finite element model and the physical field equation, and carrying out simulation analysis according to a calculation result; according to the method, the influence of the temperature on the attributes of the packaging material in the crimping type IGBT device is considered, and the accuracy and reliability of stress simulation analysis of the finite element model of the crimping type IGBT device can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power semiconductor modules, and in particular to a compression-type IGBT simulation modeling method and system considering temperature effects. Background Art

[0002] The existing multi-physics field modeling and simulation of press-fit IGBT (Insulate-Gate Bipolar Transistor) devices mainly conducts single stress field modeling or considers the coupling relationship between multiple physical fields, such as separate modeling and simulation of electric field, thermal field, and mechanical field, electric field-thermal field coupling, thermal field-mechanical field coupling, or electric field-thermal field-mechanical field coupling simulation. However, the above simulation models all ignore the influence of temperature on the properties of packaging materials in press-fit IGBT devices. Materials science research shows that when the temperature of metal materials changes, the electrical conductivity and thermal conductivity of the materials will change. The resistivity of the IGBT chip is positively correlated with the temperature under a large on-voltage. However, in the multi-physics field simulation of press-fit IGBT devices, most of them ignore the changes of material parameters with temperature, which affects the accuracy of the finite element model simulation stress analysis of the press-fit IGBT device and the reliability of the press-fit IGBT device. Summary of the invention

[0003] The embodiment of the present invention provides a simulation modeling method for a crimped IGBT taking temperature effects into consideration, which can improve the accuracy of stress analysis of a finite element model of a crimped IGBT device and the reliability of the crimped IGBT device.

[0004] In a first aspect, an embodiment of the present invention provides a simulation modeling method for a press-fit IGBT considering temperature effects, comprising:

[0005] Establishing a finite element model of the IGBT device according to the geometric shape and material properties of each component in the IGBT device;

[0006] Setting coupling relationships between physical fields and establishing corresponding physical field equations for each of the physical fields;

[0007] According to simulation requirements, boundary conditions are set for the finite element model;

[0008] A coupling calculation is performed based on the finite element model and the physical field equation, and a simulation analysis is performed according to the calculation results.

[0009] Furthermore, the physical field includes an electric field, a thermal field and a mechanical field, and the coupling relationship includes:

[0010] At least one of a first coupling relationship between the electric field and the thermal field through power loss and material conductivity temperature effect, a second coupling relationship between the thermal field and the mechanical field through contact thermal resistance, a third coupling relationship between the electric field and the mechanical field through the contact resistance, a fourth coupling relationship between the thermal field and the mechanical field through thermal expansion and contact thermal resistance, a fifth coupling relationship between the electric field and material conductivity, and a sixth coupling relationship between the thermal field and the thermal conductivity of the material.

[0011] Furthermore, establishing a corresponding physical field equation for each of the physical fields includes:

[0012] Establishing an electric field equation for the electric field; wherein the electric field equation includes a displacement current equation, an Ohm's law equation, and an electric field distribution equation;

[0013] Establishing a thermal field equation for the thermal field; wherein the thermal field equation includes a loss calculation equation, a heat transfer equation and a boundary heat dissipation equation;

[0014] A mechanical field equation is established for the mechanical field; wherein the mechanical field equation includes a material force deformation displacement equation.

[0015] Furthermore, the boundary conditions include at least one of fixture pressure, on-current, ambient temperature, cycle period, duty cycle and water cooling heat dissipation coefficient.

[0016] Furthermore, the coupling calculation based on the finite element model and the physical field equation includes:

[0017] Performing coupled calculation based on the finite element model and the physical field equation; wherein the coupled calculation includes calculating at least one of contact thermal resistance, contact resistance, power loss, material deformation and material temperature effect equation;

[0018] The calculation formulas of the contact thermal resistance and the contact resistance are as follows:

[0019]

[0020] Among them, h c is the contact thermal conductivity, k s is the harmonic mean of the thermal conductivity of the contact interface, m is the relative slope of the surface, σ r is the relative surface roughness, P is the contact pressure, H c is the microhardness of the material, h e is the contact conductivity, q s is the harmonic mean of the conductivity of the contact interface.

[0021] Furthermore, the calculation formula of the material deformation is as follows:

[0022]

[0023] l2=l1·[1+α·(T1-T0)];

[0024] Among them, l0 is the initial length, l1 is the compression length, E is the elastic modulus, A is the material area, l2 is the thermal expansion length, α is the thermal expansion coefficient, T0 is the initial temperature, and T1 is the final temperature.

[0025] Furthermore, the calculation formula of the power loss is as follows:

[0026]

[0027] Among them, W is the power loss, U is the conduction voltage across the material, S is the area through which the current flows, ρ is the resistivity, and L is the length of the material through which the current flows.

[0028] In a second aspect, an embodiment of the present invention provides a compression-type IGBT simulation modeling system considering temperature effects, comprising:

[0029] A finite element model building module, used to build a finite element model of the IGBT device according to the geometric shape and material properties of each component in the IGBT device;

[0030] A coupling relationship setting module, used to set the coupling relationship between physical fields and establish a corresponding physical field equation for each of the physical fields;

[0031] A boundary condition setting module, used to set boundary conditions for the finite element model according to simulation requirements;

[0032] A coupling calculation module is used to perform coupling calculation based on the finite element model and the physical field equation, and perform simulation analysis according to the calculation results.

[0033] Furthermore, the physical field includes an electric field, a thermal field and a mechanical field, and the coupling relationship includes:

[0034] At least one of a first coupling relationship between the electric field and the thermal field through power loss and material conductivity temperature effect, a second coupling relationship between the thermal field and the mechanical field through contact thermal resistance, a third coupling relationship between the electric field and the mechanical field through the contact resistance, a fourth coupling relationship between the thermal field and the mechanical field through thermal expansion and contact thermal resistance, a fifth coupling relationship between the electric field and material conductivity, and a sixth coupling relationship between the thermal field and the thermal conductivity of the material.

[0035] Furthermore, the coupling relationship setting module includes:

[0036] An electric field equation establishing unit, used to establish an electric field equation for the electric field; wherein the electric field equation includes a displacement current equation, an Ohm's law equation and an electric field distribution equation;

[0037] A thermal field equation establishing unit, used to establish a thermal field equation for the thermal field; wherein the thermal field equation includes a loss calculation equation, a heat transfer equation and a boundary heat dissipation equation;

[0038] The mechanical field equation establishing unit is used to establish the mechanical field equation for the mechanical field; wherein the mechanical field equation includes the material force deformation displacement equation.

[0039] Compared with the prior art, the embodiment of the present invention provides a crimped IGBT simulation modeling method that takes temperature effects into consideration, and its beneficial effects are: by establishing a finite element model of the IGBT device according to the geometric shape and material properties of each component in the IGBT device; setting a coupling relationship between physical fields, and establishing corresponding physical field equations for each of the physical fields; setting boundary conditions for the finite element model according to simulation requirements; performing coupling calculations based on the finite element model and the physical field equations, and performing simulation analysis based on the calculation results; considering the influence of temperature on the properties of the packaging material in the crimped IGBT device, the accuracy and reliability of the simulation stress analysis of the finite element model of the crimped IGBT device can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical features of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 It is a flow chart of a simulation modeling method of a crimp-type IGBT considering temperature effect provided by an embodiment of the present invention;

[0042] Figure 2 It is a schematic diagram of the relationship between thermal conductivity and temperature of a compression-type IGBT simulation modeling method considering temperature effect provided by an embodiment of the present invention;

[0043] Figure 3 It is a schematic diagram of the relationship between resistivity and temperature of a compression-type IGBT simulation modeling method considering temperature effect provided by an embodiment of the present invention;

[0044] Figure 4 A simulation modeling method for a crimp-type IGBT considering temperature effect is provided in an embodiment of the present invention;

[0045] Figure 5is a schematic diagram of a finite element model of a simulation modeling method for a crimp-type IGBT taking temperature effect into consideration provided by an embodiment of the present invention;

[0046] Figure 6 It is a schematic diagram of a first comparison result of a simulation modeling method of a crimp-type IGBT considering temperature effect provided by an embodiment of the present invention;

[0047] Figure 7 is a schematic diagram of a second comparison result of a simulation modeling method for a crimp-type IGBT considering temperature effect provided by an embodiment of the present invention;

[0048] Figure 8 is a schematic diagram of a third comparison result of a simulation modeling method for a crimp-type IGBT taking temperature effect into consideration provided by an embodiment of the present invention;

[0049] Fig. 9 It is a first distribution schematic diagram of a simulation modeling method of a crimp-type IGBT considering temperature effect provided by an embodiment of the present invention;

[0050] Fig.10 is a second distribution schematic diagram of a compression-type IGBT simulation modeling method considering temperature effect provided by an embodiment of the present invention;

[0051] Fig.11 It is a structural schematic diagram of a crimp-type IGBT simulation modeling system taking temperature effects into consideration provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] In the first aspect, the embodiment of the present invention provides a simulation modeling method of a crimped IGBT considering the temperature effect, see Figure 1 , which is a flow chart of an embodiment of a compression-type IGBT simulation modeling method considering temperature effect provided by the present invention.

[0054] like Figure 1 As shown, the method comprises the following steps:

[0055] S1: establishing a finite element model of the IGBT device according to the geometric shape and material properties of each component in the IGBT device;

[0056] S2: setting the coupling relationship between the physical fields and establishing a corresponding physical field equation for each of the physical fields;

[0057] S3: setting boundary conditions for the finite element model according to simulation requirements;

[0058] S4: performing coupling calculation based on the finite element model and the physical field equation, and performing simulation analysis according to the calculation results.

[0059] Materials science research shows that when the temperature of metal materials changes, the electrical conductivity and thermal conductivity of the material will change. For example, see Figure 2 , is the relationship between the thermal conductivity of each layer of the IGBT device and the temperature, Figure 2 It can be seen that the thermal conductivity of the packaging material decreases with the increase of temperature. Taking silicon as an example, its thermal conductivity is 100W / (m℃) at 100m℃, which is 0.7 times the thermal conductivity of silicon at 0m℃. Therefore, in the process of increasing the junction temperature of the press-fit IGBT device, the thermal conductivity of each layer of material decreases with the increase of temperature. The relationship between the thermal conductivity of the material and the temperature can be expressed by the following equation:

[0060] k=k0+β·(TT ref );

[0061] Where k is the thermal conductivity of the device at the operating temperature, k0 is the thermal conductivity of the device at the reference temperature, β is the calculation coefficient, T is the operating temperature, and T ref is the reference temperature.

[0062] For example, see Table 1 below, which shows the thermal conductivity and calculation coefficient of various packaging materials such as copper, molybdenum, silver, aluminum, and silicon at a reference temperature of 25 m°C:

[0063] Table 1 Thermal conductivity and calculation coefficient of packaging materials at 25m℃

[0064] Material k(W / (m·℃)) b(1 / ℃) <![CDATA[T ref (℃)]]> molybdenum 138 -0.0395 25 copper 400 -0.0573 25 aluminum 238 -0.0397 25 silicon 130 -0.4129 25

[0065] For example, see Figure 3 , is the relationship between the resistivity of each layer of the IGBT device and the temperature, Figure 3 It can be seen that as the temperature rises, the resistivity of metal materials increases. Taking molybdenum as an example, its resistivity at 100m℃ is 1.5 times that at 0m℃. Therefore, during operation, when the temperature of the press-fit IGBT device rises, the resistivity of the packaging material inside the press-fit IGBT device increases, and the on-state voltage of the press-fit IGBT device also increases. The relationship between the resistivity of metal materials and temperature can be expressed by the following equation:

[0066] ρ=ρ0·[1+β1·(TT ref )];

[0067] Where ρ is the conductivity of the device at the operating temperature, ρ0 is the conductivity of the device at the reference temperature, β1 is the calculation coefficient, T is the operating temperature, and T ref is the reference temperature.

[0068] For example, see Table 2 below, which shows the resistivity and calculation coefficient of various packaging materials such as copper, molybdenum, and aluminum at a reference temperature of 25 m°C:

[0069] Table 2 Resistivity and calculation coefficient of packaging materials at 25m℃

[0070] Material r(W·m) <![CDATA[b1(1 / ℃)]]> <![CDATA[T ref (℃)]]> molybdenum <![CDATA[5.29×10 -8 ]]> <![CDATA[4.5×10 -3 ]]> 25 copper <![CDATA[1.62×10 -8 ]]> <![CDATA[4.3×10 -3 ]]> 25 aluminum <![CDATA[2.68×10 -8 ]]> <![CDATA[3.8×10 -3 ]]> 25

[0071] The chip of the press-fit IGBT device is made of silicon. The IGBT device has a negative temperature effect at a small on-voltage. The resistance of the IGBT chip decreases as the temperature rises. The resistivity of the IGBT chip has a positive temperature effect at a large on-voltage. The resistance of the IGBT chip increases as the temperature rises. The equivalent structure of the IGBT chip cell includes a PN junction and an equivalent MOSFET. The potential calculation of the IGBT includes the potential between the PN junction and the equivalent MOSFET on-voltage. The calculation formula of the IGBT potential is as follows:

[0072] V IGBT =V P-N +V MOSFET ;

[0073] Among them, V IGBT is the potential of the IGBT, V P-N is the potential between PN junctions, V MOSFET is the equivalent MOSFET on-state potential.

[0074] Specifically, the calculation formulas for the PN junction potential and the equivalent MOSFET potential are as follows:

[0075]

[0076] Where k is the Boltzmann constant, T is the device temperature, and J c is the collector current density, W N is half the width of the N-type drift region, q is the amount of electron charge, D a is the bipolar diffusion coefficient, n i is the intrinsic carrier density, F is the rectification function, L a is the bipolar diffusion length, L CH is the channel length, W CELL is the cell width, μ i is the inversion layer mobility, C OX is the gate characteristic capacitance, V G is the gate voltage, VTH is the threshold voltage.

[0077] Among them, the threshold voltage of the equivalent MOSFET is also affected by temperature and is calculated as follows:

[0078]

[0079] Among them, N A is the doping concentration of the P-type base region, ε S is the semiconductor dielectric constant, and at a small on-state voltage V P-N Plays a major role, under large conduction voltage V MOSFET Plays a major role. During operation, the on-state voltage of the crimped IGBT device is greater than 1V. Under the large on-state voltage, therefore, the IGBT chip only considers the equivalent V MOSFET From the above formula, we can know that the equivalent MOSFET voltage on the IGBT chip is affected by the temperature T and the current density J c Double influence, therefore, when analyzing the relationship between the resistivity and temperature of the IGBT chip during normal operation of the press-fit IGBT device, the following formula can be used to express it:

[0080]

[0081] Among them, ρ2 is the resistivity of the IGBT chip, α1 is the relative calculation coefficient, and β2 is the calculation index.

[0082] Therefore, the relationship between the resistivity and temperature of the press-fit IGBT device can be obtained as follows:

[0083] ρ IGBT(I,T) =ρ1(I,T)+ρ2(T);

[0084] ρ2(T)=α2·[1+β3·(TT ref )];

[0085] Wherein, ρ2 is the equivalent resistivity of other packaging materials in the crimped IGBT device, only the influence of temperature is considered, α2 is the calculation coefficient, and β3 is the calculation index. The values ​​of α1, α2, β2, and β3 need to be measured experimentally. The values ​​obtained by testing the crimped IGBT device used in the present invention are α1=0.186304V·m, α2=0.01152W·m, β2=0.01421 / ℃, and β3=0.0034041 / ℃.

[0086] In summary, the present invention establishes a finite element model of the IGBT device according to the geometric shape and material properties of each component in the IGBT device; sets a coupling relationship between physical fields, and establishes a corresponding physical field equation for each physical field; sets boundary conditions for the finite element model according to simulation requirements; performs coupling calculations based on the finite element model and the physical field equations, and performs simulation analysis based on the calculation results; and considers the influence of temperature on the properties of the packaging material in the crimped IGBT device, which can improve the accuracy and reliability of the simulation stress analysis of the finite element model of the crimped IGBT device.

[0087] In an optional implementation, the physical field includes an electric field, a thermal field and a mechanical field, and the coupling relationship includes:

[0088] At least one of a first coupling relationship between the electric field and the thermal field through power loss and material conductivity temperature effect, a second coupling relationship between the thermal field and the mechanical field through contact thermal resistance, a third coupling relationship between the electric field and the mechanical field through the contact resistance, a fourth coupling relationship between the thermal field and the mechanical field through thermal expansion and contact thermal resistance, a fifth coupling relationship between the electric field and material conductivity, and a sixth coupling relationship between the thermal field and the thermal conductivity of the material.

[0089] Specifically, during the operation of the press-fit IGBT device, there are three physical fields: electric field, thermal field, and mechanical field, and the fields directly interact with each other. The present invention considers the temperature effect of the resistivity and thermal conductivity of the packaging material in the press-fit IGBT device, and establishes a finite element model. The coupling principle diagram is shown in FIG. Figure 4 As shown, compared with the existing crimped IGBT device that only considers the electric field-thermal field-mechanical field coupling finite element model, the coupling relationship of the finite element model proposed in the present invention is more complex, including: a first coupling relationship between the electric field and the thermal field through power loss and material conductivity temperature effect, a second coupling relationship between the thermal field and the mechanical field through contact thermal resistance, a third coupling relationship between the electric field and the mechanical field through the contact resistance, a fourth coupling relationship between the thermal field and the mechanical field through thermal expansion and contact thermal resistance, a fifth coupling relationship between the electric field and material conductivity, and a sixth coupling relationship between the thermal field and the thermal conductivity of the material.

[0090] In an optional implementation, establishing a corresponding physical field equation for each physical field includes:

[0091] Establishing an electric field equation for the electric field; wherein the electric field equation includes a displacement current equation, an Ohm's law equation, and an electric field distribution equation;

[0092] Establishing a thermal field equation for the thermal field; wherein the thermal field equation includes a loss calculation equation, a heat transfer equation and a boundary heat dissipation equation;

[0093] A mechanical field equation is established for the mechanical field; wherein the mechanical field equation includes a material force deformation displacement equation.

[0094] Specifically, the electric field calculation mainly involves three equations, namely the displacement current equation, Ohm's law equation and the electric field distribution equation. The formulas are as follows:

[0095]

[0096] J=σ e ·E+j·ω·D+J e ;

[0097]

[0098] in, is the Laplace operator, J is the current density vector, Q j is the current source, σ e is the conductivity, E is the electric field vector, j·ω·D is the displacement current, J e is the externally generated current density and V is the electric potential.

[0099] There are three main equations involved in thermal field calculation, namely loss calculation equation, heat transfer equation and boundary heat dissipation equation. The formulas are as follows:

[0100]

[0101]

[0102] -n·q conv =h·(T ext -T);

[0103] Where m is the density, C p is the specific heat capacity, T is the temperature, t is the time, and u is the displacement speed of the node in the model. In this simulation, the press-fit IGBT device is in a fixed state, u = 0m / s, q cond is the heat flux of heat conduction in the model, k is the thermal conductivity, n is the heat dissipation direction vector, q conv is the heat flux of convective heat dissipation under boundary conditions, h is the heat transfer coefficient, T ext is the external temperature and Q is the total heat source.

[0104] The mechanical field calculation mainly involves the material force, deformation and displacement equations. The formulas are as follows:

[0105]

[0106] Where S is the total deformation of the solid, F s is the stress, and ν is the deformation displacement velocity.

[0107] In an optional embodiment, the boundary condition includes at least one of a fixture pressure, a conduction current, an ambient temperature, a cycle period, a duty cycle, and a water cooling heat dissipation coefficient.

[0108] In an optional implementation, the performing coupled calculation based on the finite element model and the physical field equation includes:

[0109] Performing coupled calculation based on the finite element model and the physical field equation; wherein the coupled calculation includes calculating at least one of contact thermal resistance, contact resistance, power loss, material deformation and material temperature effect equation;

[0110] The calculation formulas of the contact thermal resistance and the contact resistance are as follows:

[0111]

[0112]

[0113] Among them, h c is the contact thermal conductivity, k s is the harmonic mean of the thermal conductivity of the contact interface, m is the relative slope of the surface, σ r is the relative surface roughness, P is the contact pressure, H c is the microhardness of the material, h e is the contact conductivity, q s is the harmonic mean of the conductivity of the contact interface.

[0114] Specifically, the surface roughness and microhardness of each packaging material of the press-fit IGBT device used in the present invention are measured experimentally, as shown in Table 3 below:

[0115] Table 3 Surface roughness and microhardness of each layer of materials of press-fit IGBT device

[0116] layer Roughness(μm) Microhardness(MPa) Collector copper 0.568 473 Collector Mo 0.108 1590 chip 0.069 300 Emitter Molybdenum 0.105 1590 Transmitter Copper 0.162 473

[0117] In an optional embodiment, the calculation formula of the material deformation is as follows:

[0118]

[0119] l2=l1·[1+α·(T1-T0)];

[0120] Among them, l0 is the initial length, l1 is the compression length, E is the elastic modulus, A is the material area, l2 is the thermal expansion length, α is the thermal expansion coefficient, T0 is the initial temperature, and T1 is the final temperature.

[0121] In an optional implementation, the power loss is calculated as follows:

[0122]

[0123] Among them, W is the power loss, U is the conduction voltage across the material, S is the area through which the current flows, ρ is the resistivity, and L is the length of the material through which the current flows.

[0124] For example, see Figure 5 As shown, it is a schematic diagram of the finite element model of the present invention. Since the dimensions of the gate PCB, gate ejector pins and insulating brackets are very small, meshing is difficult. The above structures are ignored in the current finite element modeling of the press-fit type IGBT device. The parameters of the material properties of each layer of the press-fit type IGBT in the present invention are shown in Table 4 below:

[0125] Table 4 Material properties of each layer of crimped IGBT

[0126]

[0127] The crimped IGBT device of the present invention is subjected to a power cycle simulation condition. The applied pressure of 1200N is selected as the simulation boundary condition. The pressure is applied on the collector side of the device. The emitter side of the device is set to be fixed. The on-current of 50A is set on the collector side. The emitter side is grounded. The current flows from the collector of the device to the emitter. The water cooling radiator is placed outside the collector and the emitter. The simulation simulates a 150s period power cycle with a duty cycle of 0.5, as shown in Table 5 below:

[0128] Table 5 Simulation boundary condition parameters of crimped IGBT devices

[0129]

[0130] The performance of the IGBT device electric field, thermal field, and mechanical field coupling model established by the present invention is compared with the existing coupling model. The comparison results are shown in Figure 6 , Figure 7 and Figure 8 As shown, according to Figure 6 , Figure 7 and Figure 8 It can be seen that the maximum junction temperature of the press-fit IGBT multi-physics field coupling finite element model taking into account the material temperature effect is about 2°C higher than that of the existing press-fit IGBT device multi-physics field coupling finite element model during the power cycle, the on-state voltage is almost the same, and the maximum contact pressure between the IGBT chip and the emitter molybdenum layer is about 2MPa higher.

[0131] Further extraction of the pressure, temperature, and potential distribution of the press-fit IGBT device when the junction temperature of the press-fit IGBT device reaches stability at the simulation time of 75s, such as Fig. 9 As shown, it is the pressure, temperature and potential distribution diagram of the press-fit IGBT device of the present invention. Fig.10 The pressure, temperature and potential distribution diagram of the press-fit IGBT device in the prior art shows that when the junction temperature of the press-fit IGBT device reaches stability, the pressure, temperature and potential distribution trends of the existing press-fit IGBT device multi-physics field coupling model and the press-fit IGBT device multi-physics field coupling model taking into account the material temperature effect of the present invention are almost the same. The contact part between the emitter of the IGBT chip and the emitter molybdenum layer in the press-fit IGBT device model of the present invention is subjected to a maximum pressure of about 126MPa, while the maximum pressure of the existing press-fit IGBT device model is about 124MPa. The maximum junction temperature of the press-fit IGBT device model of the present invention is about 120°C on the emitter side of the IGBT chip, while the existing press-fit IGBT device model is about 118°C. The on-voltage of the press-fit IGBT device of the present invention is about 3.5V, while the on-voltage of the existing press-fit IGBT device is also about 3.5V. Therefore, during the power cycle, the press-fit IGBT chip is subjected to the maximum pressure, junction temperature and on-voltage.

[0132] In a second aspect, an embodiment of the present invention provides a simulation modeling system for a crimped IGBT taking into account temperature effects, see Fig.11 , which is a schematic structural diagram of a compression-type IGBT simulation modeling system considering temperature effects provided by an embodiment of the present invention.

[0133] like Fig.11 As shown, the system comprises:

[0134] A finite element model building module 21, used to build a finite element model of the IGBT device according to the geometric shape and material properties of each component in the IGBT device;

[0135] A coupling relationship setting module 22, used to set the coupling relationship between physical fields and establish a corresponding physical field equation for each of the physical fields;

[0136] A boundary condition setting module 23, used to set boundary conditions for the finite element model according to simulation requirements;

[0137] The coupling calculation module 24 is used to perform coupling calculation based on the finite element model and the physical field equation, and perform simulation analysis according to the calculation results.

[0138] In an optional implementation, the physical field includes an electric field, a thermal field and a mechanical field, and the coupling relationship includes:

[0139] At least one of a first coupling relationship between the electric field and the thermal field through power loss and material conductivity temperature effect, a second coupling relationship between the thermal field and the mechanical field through contact thermal resistance, a third coupling relationship between the electric field and the mechanical field through the contact resistance, a fourth coupling relationship between the thermal field and the mechanical field through thermal expansion and contact thermal resistance, a fifth coupling relationship between the electric field and material conductivity, and a sixth coupling relationship between the thermal field and the thermal conductivity of the material.

[0140] In an optional implementation, the coupling relationship setting module 22 includes:

[0141] An electric field equation establishing unit, used to establish an electric field equation for the electric field; wherein the electric field equation includes a displacement current equation, an Ohm's law equation and an electric field distribution equation;

[0142] A thermal field equation establishing unit, used to establish a thermal field equation for the thermal field; wherein the thermal field equation includes a loss calculation equation, a heat transfer equation and a boundary heat dissipation equation;

[0143] The mechanical field equation establishing unit is used to establish the mechanical field equation for the mechanical field; wherein the mechanical field equation includes the material force deformation displacement equation.

[0144] In an optional embodiment, the boundary condition includes at least one of a fixture pressure, a conduction current, an ambient temperature, a cycle period, a duty cycle, and a water cooling heat dissipation coefficient.

[0145] In an optional implementation, the coupling calculation module 24 is further used for:

[0146] Performing coupled calculation based on the finite element model and the physical field equation; wherein the coupled calculation includes calculating at least one of contact thermal resistance, contact resistance, power loss, material deformation and material temperature effect equation;

[0147] The calculation formulas of the contact thermal resistance and the contact resistance are as follows:

[0148]

[0149] Among them, h c is the contact thermal conductivity, k s is the harmonic mean of the thermal conductivity of the contact interface, m is the relative slope of the surface, σ r is the relative surface roughness, P is the contact pressure, H c is the microhardness of the material, h e is the contact conductivity, q s is the harmonic mean of the conductivity of the contact interface.

[0150] In an optional embodiment, the calculation formula of the material deformation is as follows:

[0151]

[0152] l2=l1·[1+α·(T1-T0)];

[0153] Among them, l0 is the initial length, l1 is the compression length, E is the elastic modulus, A is the material area, l2 is the thermal expansion length, α is the thermal expansion coefficient, T0 is the initial temperature, and T1 is the final temperature.

[0154] In an optional implementation, the power loss is calculated as follows:

[0155]

[0156] Among them, W is the power loss, U is the conduction voltage across the material, S is the area through which the current flows, ρ is the resistivity, and L is the length of the material through which the current flows.

[0157] The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. It should be pointed out that for those skilled in the art, several equivalent obvious variations and / or equivalent substitutions can be made without departing from the technical principles of the present invention. These obvious variations and / or equivalent substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A simulation modeling method for a crimped IGBT considering temperature effects, characterized in that: include: Establishing a finite element model of the IGBT device according to the geometric shape and material properties of each component in the IGBT device; Setting coupling relationships between physical fields and establishing corresponding physical field equations for each of the physical fields; According to simulation requirements, boundary conditions are set for the finite element model; A coupling calculation is performed based on the finite element model and the physical field equation, and a simulation analysis is performed according to the calculation results.

2. The simulation modeling method of the crimped IGBT considering the temperature effect as claimed in claim 1, characterized in that: The physical field includes electric field, thermal field and mechanical field, then the coupling relationship includes: At least one of a first coupling relationship between the electric field and the thermal field through power loss and material conductivity temperature effect, a second coupling relationship between the thermal field and the mechanical field through contact thermal resistance, a third coupling relationship between the electric field and the mechanical field through the contact resistance, a fourth coupling relationship between the thermal field and the mechanical field through thermal expansion and contact thermal resistance, a fifth coupling relationship between the electric field and material conductivity, and a sixth coupling relationship between the thermal field and the thermal conductivity of the material.

3. The simulation modeling method of the crimped IGBT considering the temperature effect as claimed in claim 1, characterized in that: The step of establishing a corresponding physical field equation for each physical field comprises: Establishing an electric field equation for the electric field; wherein the electric field equation includes a displacement current equation, an Ohm's law equation, and an electric field distribution equation; Establishing a thermal field equation for the thermal field; wherein the thermal field equation includes a loss calculation equation, a heat transfer equation and a boundary heat dissipation equation; A mechanical field equation is established for the mechanical field; wherein the mechanical field equation includes a material force deformation displacement equation.

4. The simulation modeling method of the crimped IGBT considering the temperature effect as claimed in claim 1, characterized in that: The boundary conditions include at least one of fixture pressure, on-current, ambient temperature, cycle period, duty cycle and water cooling heat dissipation coefficient.

5. The simulation modeling method of the crimped IGBT considering the temperature effect as claimed in claim 1, characterized in that: The coupling calculation based on the finite element model and the physical field equation comprises: Performing coupled calculation based on the finite element model and the physical field equation; wherein the coupled calculation includes calculating at least one of contact thermal resistance, contact resistance, power loss, material deformation and material temperature effect equation; The calculation formulas of the contact thermal resistance and the contact resistance are as follows: Among them, h c is the contact thermal conductivity, k s is the harmonic mean of the thermal conductivity of the contact interface, m is the relative slope of the surface, σ r is the relative surface roughness, P is the contact pressure, H c is the microhardness of the material, h e is the contact conductivity, q s is the harmonic mean of the conductivity of the contact interface.

6. The simulation modeling method of the crimped IGBT considering the temperature effect as claimed in claim 5, characterized in that: The calculation formula of the material deformation is as follows: l2=l1·[1+α·(T1-T0)]; Among them, l0 is the initial length, l1 is the compression length, E is the elastic modulus, A is the material area, l2 is the thermal expansion length, α is the thermal expansion coefficient, T0 is the initial temperature, and T1 is the final temperature.

7. The simulation modeling method of the crimped IGBT considering the temperature effect as claimed in claim 5, characterized in that: The power loss is calculated as follows: Among them, W is the power loss, U is the conduction voltage across the material, S is the area through which the current flows, ρ is the resistivity, and L is the length of the material through which the current flows.

8. A simulation modeling system for a crimped IGBT taking temperature effects into account, characterized in that: include: A finite element model building module, used to build a finite element model of the IGBT device according to the geometric shape and material properties of each component in the IGBT device; A coupling relationship setting module, used to set the coupling relationship between physical fields and establish a corresponding physical field equation for each of the physical fields; A boundary condition setting module, used to set boundary conditions for the finite element model according to simulation requirements; A coupling calculation module is used to perform coupling calculation based on the finite element model and the physical field equation, and perform simulation analysis according to the calculation results.

9. The compression-type IGBT simulation modeling system considering temperature effect as claimed in claim 8, characterized in that: The physical field includes electric field, thermal field and mechanical field, then the coupling relationship includes: At least one of a first coupling relationship between the electric field and the thermal field through power loss and material conductivity temperature effect, a second coupling relationship between the thermal field and the mechanical field through contact thermal resistance, a third coupling relationship between the electric field and the mechanical field through the contact resistance, a fourth coupling relationship between the thermal field and the mechanical field through thermal expansion and contact thermal resistance, a fifth coupling relationship between the electric field and material conductivity, and a sixth coupling relationship between the thermal field and the thermal conductivity of the material.

10. The simulation modeling method of the crimped IGBT considering the temperature effect as claimed in claim 8, characterized in that: The coupling relationship setting module includes: An electric field equation establishing unit, used to establish an electric field equation for the electric field; wherein the electric field equation includes a displacement current equation, an Ohm's law equation and an electric field distribution equation; A thermal field equation establishing unit, used to establish a thermal field equation for the thermal field; wherein the thermal field equation includes a loss calculation equation, a heat transfer equation and a boundary heat dissipation equation; The mechanical field equation establishing unit is used to establish the mechanical field equation for the mechanical field; wherein the mechanical field equation includes the material force deformation displacement equation.

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