A configuration method for improving the lifespan of IGBT power modules

Abstract

The present invention discloses a configuration method for improving the lifespan of an IGBT power module, which includes increasing the substrate thickness to H, simulating the amplitude of the junction temperature fluctuation, the maximum value of the junction temperature fluctuation, and the minimum value of the junction temperature fluctuation of the IGBT power module, obtaining the module cycle period according to the IGBT power module lifespan prediction strategy, and then obtaining the lifespan of the IGBT power module through the IGBT power module lifespan prediction strategy; this configuration method for improving the lifespan of the IGBT power module configures the substrate thickness of the IGBT power module, combines the strategy of increasing the substrate thickness of the power module with the lifespan configuration strategy to perform the optimal lifespan configuration for the IGBT power module, improves the specific heat capacity of the IGBT power module, and extends the service life of the IGBT power module.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics heat dissipation, and particularly to a configuration method for improving the service life of an IGBT power module. Background Art

[0002] In electrical industrial products, for the purposes of reducing product size and increasing power density, the operating frequency of products is continuously increased. As the frequency increases, the influence of the junction temperature fluctuation of the IGBT module on its service life becomes more obvious. In the power conversion field, the service life of the IGBT module directly affects the service life of the product. Therefore, improving the service life of the IGBT module is a factor that must be considered to improve product reliability.

[0003] There are some relatively complex models for judging the service life of power modules in the prior art to judge the remaining service life, such as the particle filter of the fusion type aging characteristic parameters. However, such judgment models only play a judgment function and cannot perform the optimal configuration of the service life of the power module while judging. The configuration of the substrate and the substrate of the IGBT power module are the two main factors affecting its service life. The prior art lacks the integration of these two factors and the use of a service life configuration strategy to perform the optimal service life configuration of the power module. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to propose a configuration method for improving the service life of an IGBT power module. The configuration method for improving the service life of the IGBT power module configures the substrate thickness of the IGBT power module, integrates the increase in the substrate thickness of the power module with the service life configuration strategy to perform the optimal service life configuration of the IGBT power module, improves the specific heat capacity of the IGBT power module, and extends the service life of the IGBT power module.

[0005] To solve the above technical problem, the present invention provides a configuration method for improving the service life of an IGBT power module. The IGBT power module includes a semiconductor, a substrate, and a substrate; the substrate is disposed between the semiconductor and the substrate, and the semiconductor and the substrate are connected together through the substrate; the method includes the following steps:

[0006] Step 1: Increase the substrate thickness to H, and simulate to obtain the junction temperature fluctuation amplitude ΔT of the IGBT power module vj , the equivalent junction temperature T of the module vj_eq , obtain the module conduction time t through the operating frequency of the IGBT power module on , look up the table according to the substrate thickness H to obtain the module thickness factor k corresponding to the IGBT power module thickness , and obtain the module cycle period N according to the above obtained data according to the IGBT power module life prediction strategy n-1 ;

[0007] Step 2: Let the new substrate thickness H be the original substrate thickness H in Step 1 plus h, and substitute the new substrate thickness H into Step 1 to obtain the life N of the IGBT power module. n ;

[0008] Step 3: Judge whether N n is greater than or equal to N n-1 ; if not, it is determined that when the substrate is increased to the thickness corresponding to N n , the life N n of the IGBT power module is the longest life; if so, execute Step 4;

[0009] Step 4: Let the new substrate thickness H be the original substrate thickness H in Step 2 plus h, let N n-1 = N n to obtain the new life N n-1 , and substitute the new substrate thickness H into Step 1 to obtain the new life N of the IGBT power module n ;

[0010] Step 5: Substitute the new life N n and N n-1 obtained in Step 4 into Step 3 for execution until the longest life of the IGBT power module is obtained.

[0011] Preferably, the substrate is a DCB substrate.

[0012] Preferably, the substrate is composed of copper or aluminum carbide silicon.

[0013] Preferably, the DCB substrate includes a ceramic layer, an upper copper layer attached to the upper surface of the ceramic layer, and a lower copper layer attached to the lower surface of the ceramic layer.

[0014] Preferably, increasing the substrate thickness includes increasing the ceramic layer thickness or increasing the upper copper layer thickness or both.

[0015] Preferably, the material used for the ceramic layer is aluminum nitride or silicon nitride.

[0016] Preferably, the IGBT power module life prediction strategy is:

[0017]

[0018] Or where N n-1 or N n is the life of the IGBT power module, A0 is the gain coefficient, α is the coffin-manson fatigue life curve constant, E a is the activation energy for module power calculation, k Bis the Boltzmann activation energy operation constant, C is the time coefficient, γ is the time exponent, and T vj_eq is the module equivalent junction temperature, and the module equivalent junction temperature is the arithmetic mean of the maximum value T vj_max of the module junction temperature fluctuation and the minimum value T vj_min of the module junction temperature fluctuation.

[0019] After adopting the above method, a configuration method for improving the life of an IGBT power module. The IGBT power module includes a semiconductor, a substrate, and a substrate; the substrate is disposed between the semiconductor and the substrate, and the semiconductor and the substrate are connected together through the substrate; the method includes the following steps: Step 1: Increase the substrate thickness to H, and simulate to obtain the junction temperature fluctuation amplitude ΔT vj of the IGBT power module, the module equivalent junction temperature T vj_eq , obtain the module conduction time t on through the operating frequency of the IGBT power module, look up the corresponding module thickness factor k thickness of the IGBT power module according to the substrate thickness H, and obtain the module cycle period N n-1 based on the above obtained data according to the IGBT power module life prediction strategy; Step 2: Let the new substrate thickness H be the original substrate thickness H in Step 1 plus h, and substitute the new substrate thickness H into Step 1 to obtain the life N n of the IGBT power module; Step 3: Determine whether N n is greater than or equal to N n-1 ; if not, it is determined that when the substrate is increased to the thickness corresponding to N n , the life N n of the IGBT power module is the longest life; if so, execute Step 4; Step 4: Let the new substrate thickness H be the original substrate thickness H in Step 2 plus h, let N n-1 =N n to obtain the new life N n-1 , substitute the new substrate thickness H into Step 1 to obtain the new life N n of the IGBT power module; Step 5: Substitute the new life N n and N n-1 obtained in Step 4 into Step 3 for execution until the longest life of the IGBT power module is obtained; the configuration method for improving the life of the IGBT power module configures the substrate thickness of the IGBT power module, integrates the life configuration strategy of increasing the substrate thickness of the power module to perform the optimal life configuration on the IGBT power module, improves the specific heat capacity of the IGBT power module, and extends the service life of the IGBT power module. Description of the Drawings

[0020] Figure 1The overall structure of the IGBT power module for a configuration method to improve the lifespan of the IGBT power module according to the present invention Figure 1 ;

[0021] Figure 2 The overall structure of the IGBT power module for a configuration method to improve the lifespan of the IGBT power module according to the present invention Figure 2 ;

[0022] Figure 3 A comparative graph of the changes in the module equivalent junction temperature Tvj_eq and the module junction temperature fluctuation ΔTvj of the IGBT power module for a configuration method to improve the lifespan of the IGBT power module according to the present invention;

[0023] Figure 4 A corresponding curve graph of the lifespan and the module junction temperature fluctuation ΔTvj of the IGBT power module for a configuration method to improve the lifespan of the IGBT power module according to the present invention. Specific embodiments

[0024] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] Embodiment 1

[0026] Please refer to Figure 1 and Figure 3 , Figure 1 which is the overall structure diagram of the IGBT power module for a configuration method to improve the lifespan of the IGBT power module in Embodiment 1 of the present invention;

[0027] This embodiment discloses a configuration method to improve the lifespan of the IGBT power module. The IGBT power module 10 includes a semiconductor 13, a substrate 12 and a substrate 11; the substrate 12 is arranged between the semiconductor 13 and the substrate 11, and the semiconductor 13 and the substrate 11 are connected together through the substrate 12; the method includes the following steps:

[0028] Step 1: Increase the thickness of the substrate 12 to H, simulate to obtain the junction temperature fluctuation amplitude ΔT of the IGBT power module 10 vj , the module equivalent junction temperature T vj_eq , obtain the module conduction time t through the operating frequency of the IGBT power module 10 on , look up the corresponding module thickness factor k of the IGBT power module according to the substrate thickness H thickness , and obtain the module cycle period N according to the above obtained data according to the IGBT power module lifespan prediction strategy n-1 ;

[0029] Step 2: Let the new substrate thickness H be the original substrate thickness H in Step 1 plus h, and substitute the new substrate thickness H into Step 1 to obtain the lifespan N of the IGBT power module 10. n ;

[0030] Step 3: Determine whether N n is greater than or equal to N n-1 ; if not, it is determined that when the substrate is increased to the thickness corresponding to N n , the lifespan N n of the IGBT power module 10 is the longest lifespan; if so, execute Step 4;

[0031] Step 4: Let the new substrate thickness H be the original substrate thickness H in Step 2 plus h, let N n-1 = N n to obtain the new lifespan N n-1 , and substitute the new substrate thickness H into Step 1 to obtain the new lifespan N of the IGBT power module 10 n ;

[0032] Step 5: Substitute the new lifespan N n and N n-1 obtained in Step 4 into Step 3 for execution until the longest lifespan of the IGBT power module 10 is obtained.

[0033] Example 2

[0034] This example is based on Example 1. In this example, the substrate is a DCB substrate. In other examples, the substrate can also be other types of substrates.

[0035] Example 3

[0036] This example is based on Example 1. In this example, the substrate is composed of copper or aluminum carbide silicon. In other examples, the substrate can also be composed of other types of materials.

[0037] Example 4

[0038] This example is based on Example 2. In this example, the DCB substrate includes a ceramic layer 122, an upper copper layer 123 attached to the upper surface of the ceramic layer 122, and a lower copper layer 121 attached to the lower surface of the ceramic layer 122.

[0039] Increasing the thickness of the substrate 12 includes increasing the thickness of the ceramic layer 122, or increasing the thickness of the upper copper layer 123, or increasing both the thickness of the ceramic layer 122 and the upper copper layer 123.

[0040] In this example, preferably, the material used for the ceramic layer 122 is aluminum nitride or silicon nitride.

[0041] The configuration method for improving the lifespan of the IGBT power module increases the specific heat capacity of the module by increasing the thickness of the ceramic layer 122 of the IGBT power module, reduces the junction temperature fluctuation of the module, and ultimately improves the lifespan of the IGBT power module 10. The upper copper layer 121 of the DCB substrate 12 is directly connected to the semiconductor 11. Besides ensuring the transmission of current, the upper copper layer 121 also directly transfers the heat of the semiconductor 11. Increasing the thickness of the upper copper layer 121 in the DCB substrate 12 can achieve a similar effect to increasing the thickness of the ceramic layer 122.

[0042] Example Five

[0043] Please refer to Figure 4 , Figure 4 which is the corresponding curve graph of the lifespan of a configuration method for improving the lifespan of an IGBT power module of the present invention and the module junction temperature fluctuation ΔT vj .

[0044] This embodiment is based on Embodiment One. In this embodiment, the lifespan prediction strategy of the IGBT power module 10 is as follows:

[0045]

[0046] where N cycle is the cycle period of the module, A0 is the gain coefficient, α is the coffin-manson fatigue life curve constant, E a is the activation energy for module power calculation, k B is the Boltzmann activation energy operation constant, C is the time coefficient, γ is the time exponent, T vj_eq is the equivalent junction temperature of the module, and the equivalent junction temperature of the module is the arithmetic mean of the maximum value T vj_max of the module junction temperature fluctuation and the minimum value T vj_min of the module junction temperature fluctuation. The value of α ranges from -2.3 to -4.5, the value of E a ranges from 4.5 J to 6.5 J, the value of k B ranges from 1.38 1 / J to 2.65 1 / J, the value of k thickness ranges from 0.33 to 1, the value of γ ranges from -0.5 to -0.9, and the value of C ranges from 0.21 to 0.56.

[0047] This configuration method for improving the lifespan of the IGBT power module extends the practical lifespan of the power module by reducing the amplitude of the module junction temperature fluctuation ΔT vj . Please refer to Figure 3 . When the module is working normally, the junction temperature change curve is as shown by the solid line. The equivalent junction temperature of the module is T vj_eq1 , and the amplitude of the junction temperature fluctuation is ΔT vj1 . After appropriately increasing the ceramic thickness in the DCB substrate, although the thermal resistance is increased to a certain extent, resulting in the increase of the module equivalent junction temperature to Tvj_eq2 , but the specific heat capacity of the DCB substrate has increased, reducing the amplitude of the junction temperature fluctuation to ΔT vj2 . From the calculation formula of the module service life in the above formula, it can be seen that the amplitude of the junction temperature fluctuation ΔT vj is the base of the power exponent in the formula, and the equivalent junction temperature T vj_eq is inversely proportional to the numerator of the exponential function with e as the base in the formula. When ΔT vj fluctuates greatly, the influence of ΔT vj on the life is more obvious than that of T vj_eq .

[0048] The configuration method for improving the life of the IGBT power module configures the substrate thickness of the IGBT power module, combines the strategy of increasing the substrate thickness of the power module with the life configuration to perform the optimal life configuration for the IGBT power module, improves the specific heat capacity of the IGBT power module, and extends the service life of the IGBT power module.

[0049] It should be understood that the above are only the preferred embodiments of the present invention, and the patent scope of the present invention cannot be limited thereby. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A configuration method for improving the lifespan of an IGBT power module, characterized in that, The IGBT power module includes a semiconductor, a substrate, and a base plate; the substrate is disposed between the semiconductor and the base plate, and the semiconductor and the base plate are connected together through the substrate; the method includes the following steps: Step 1: Increase the substrate thickness to H, and simulate to obtain the amplitude of the IGBT power module junction temperature fluctuation ΔT vj , the equivalent junction temperature T of the module vj_eq , obtain the module conduction time t through the operating frequency of the IGBT power module on , look up the table according to the substrate thickness H to obtain the module thickness factor k corresponding to the IGBT power module thickness , obtain the module cycle period N based on the above obtained data according to the IGBT power module life prediction strategy n-1 ; Step 2: Let the new substrate thickness H be the original substrate thickness H in Step 1 plus h, and substitute the new substrate thickness H into Step 1 to obtain the life N of the IGBT power module n ; Step 3: Determine N n whether it is greater than or equal to N n-1 ; if not, it is determined that when the substrate is increased to the thickness corresponding to N n , the life N n of the IGBT power module is the longest life; if so, perform Step 4; Step 4: Let the new substrate thickness H be the original substrate thickness H in Step 2 plus h, and let N n-1 = N n to obtain the new lifetime N n-1 . Substitute the new substrate thickness H into Step 1 to obtain the new lifetime N of the IGBT power module n ; Step Five: Substitute the new lifespan N n and N n-1 obtained in Step Four into the execution of Step Three until the longest lifespan of the IGBT power module is obtained.

2. The configuration method for improving the lifespan of an IGBT power module according to claim 1, wherein The substrate is a DCB substrate.

3. The configuration method for improving the lifespan of an IGBT power module according to claim 1, wherein The base plate is made of copper or aluminum silicon carbide.

4. The configuration method for improving the lifespan of an IGBT power module according to claim 2, characterized in that, The DCB substrate includes a ceramic layer, an upper copper layer attached to the upper surface of the ceramic layer, and a lower copper layer attached to the lower surface of the ceramic layer.

5. The configuration method for improving the lifespan of an IGBT power module according to claim 4, characterized in that, Increasing the thickness of the substrate includes increasing the thickness of the ceramic layer, or increasing the thickness of the upper copper layer, or increasing both the thickness of the ceramic layer and the thickness of the upper copper layer.

6. The configuration method for improving the lifespan of an IGBT power module according to claim 4, characterized in that, The material used for the ceramic layer is aluminum nitride or silicon nitride.

7. The configuration method for improving the lifespan of an IGBT power module according to claim 1, characterized in that, The IGBT power module life prediction strategy is: Or where N n-1 or N n is the lifetime of the IGBT power module, A0 is the gain coefficient, α is the coffin-manson fatigue life curve constant, E a is the activation energy for module power calculation, k B is the Boltzmann activation energy operation constant, C is the time coefficient, γ is the time exponent, T vj_eq is the module equivalent junction temperature, and the module equivalent junction temperature is the arithmetic mean of the maximum module junction temperature fluctuation T vj_max and the minimum module junction temperature fluctuation T vj_min .

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