Insulation optimization method and device of power module and power module

Abstract

The invention relates to the technical field of power electronic devices, in particular to an insulation optimization method and device of a power module and the power module. The method comprises the following steps: acquiring first electric field simulation distribution of a to-be-optimized power module; the power module to be optimized comprises first upper-layer copper; according to the first electric field simulation distribution, a first potential corresponding to a first target area is determined, and the first target area is an area formed by a preset distance range from a three-phase point of the first upper layer copper; obtaining a target conductor, and arranging the target conductor in the first target area; calculating a voltage regulation range of the target conductor according to the first potential and a preset incremental voltage range; and in the voltage regulation range, the voltage of the target conductor is regulated until the field intensity peak value in the power module reaches the minimum value, so that the technical problems that the reliability of the power module becomes low and the power module is not suitable for the current process level in the existing optimization method are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronic devices, and in particular to an insulation optimization method and device for a power module and a power module. Background Art

[0002] A power module is a combination of power electronic devices (also known as power semiconductors) and a potted package, tailored to specific functions. With the rise and continued development of industries like renewable energy generation and electric vehicles, the requirements for power conversion and transmission in industrial applications are becoming increasingly stringent, leading to a growing demand for power semiconductors and power modules. Currently, the voltage levels of power modules used in industry are gradually increasing, and the internal electric field strength is also increasing. This increases the requirements for the internal insulation performance of power modules.

[0003] Currently, the main measure to optimize the internal insulation performance of power modules is to optimize the structure and materials of the internal copper-clad ceramic substrate (DBC). However, existing optimization methods have the problem of reducing the reliability of power modules and are not suitable for current process levels. Summary of the Invention

[0004] The present invention provides an insulation optimization method and device for a power module and a power module, which are used to solve the technical problems that the existing optimization method reduces the reliability of the power module and is not applicable to the current process level.

[0005] In one aspect, the present invention provides a method for optimizing insulation of a power module, comprising:

[0006] Obtaining a first electric field simulation distribution of a power module to be optimized; the power module to be optimized includes a first upper layer of copper;

[0007] determining a first electric potential corresponding to a first target area according to the first electric field simulation distribution, where the first target area is an area formed by a preset distance range from a triple point of the first upper copper layer;

[0008] Acquire a target conductor, and place the target conductor in the first target area;

[0009] calculating a voltage adjustment range of the target conductor based on the first potential and a preset incremental voltage range;

[0010] In the voltage regulation range, the voltage of the target conductor is regulated until the peak value of the field intensity in the power module reaches a minimum value.

[0011] Optionally, when the peak value of the field intensity of the power module that reaches the minimum value is greater than a preset expected peak value of the field intensity, the method further includes:

[0012] S1. According to the order in which the conductors are set, the last target conductor set in the current power module is used as the optimization object, and the electric field simulation distribution of the current power module is obtained;

[0013] S2. Determine a second electric potential corresponding to a second target region based on the electric field simulation distribution of the current power module, where the second target region is a region formed by a preset distance range from the triple point of the optimization object;

[0014] S3. Acquire and set a new target conductor in the second target area; and calculate a voltage adjustment range of the new target conductor based on the second potential and the incremental voltage range;

[0015] S4. For all target conductors provided in the power module, respectively adjust the voltage of each target conductor within the voltage adjustment range of each target conductor until the peak value of the field intensity of the power module reaches a minimum value;

[0016] S5. Determine whether the peak value of the field intensity of the power module is not greater than the preset expected peak value of the field intensity. If not, jump to execute S1 to S5. If so, stop the optimization.

[0017] Optionally, the power module includes a second upper copper layer for grounding; when the peak value of the field intensity of the power module that reaches the minimum value is not greater than a preset expected peak value of the field intensity, or after performing the stopping optimization, the method further includes:

[0018] determining an optimal voltage of the target conductor, wherein the optimal voltage is used to ensure that the peak value of the field intensity of the power module is no greater than the preset expected peak value of the field intensity;

[0019] Obtaining a first voltage between the first upper copper layer and the second upper copper layer;

[0020] Based on the series voltage division principle, the first voltage and the optimal voltage are used to configure each voltage-dividing resistor, and a connection relationship is established between each voltage-dividing resistor, the first upper copper layer, the second upper copper layer, and the target conductor; each voltage-dividing resistor is used to configure the voltage of the target conductor to the optimal voltage by dividing the first voltage.

[0021] Optionally, the preset distance range is 0.2 mm to 0.5 mm.

[0022] Optionally, the preset incremental voltage range is 500V-1500V.

[0023] The present invention also provides an insulation optimization device for a power module, comprising:

[0024] A first acquisition module is configured to acquire a first electric field simulation distribution of a power module to be optimized; the power module to be optimized includes a first upper layer of copper;

[0025] a first determining module, configured to determine a first electric potential corresponding to a first target area according to the first electric field simulation distribution, where the first target area is an area formed by a preset distance range from a triple point of the first upper copper layer;

[0026] a second acquisition module, configured to acquire a target conductor and place the target conductor in the first target area;

[0027] a first calculation module, configured to calculate a voltage adjustment range of the target conductor according to the first potential and a preset incremental voltage range;

[0028] The first regulating module is configured to regulate the voltage of the target conductor within the voltage regulating range until the peak value of the field intensity in the power module reaches a minimum value.

[0029] The present invention further provides a power module, applied to any of the above methods, comprising: a ceramic substrate;

[0030] A first upper layer of copper, a second upper layer of copper, a target conductor and a plurality of voltage-dividing resistors are provided on one side of the ceramic substrate;

[0031] The first upper copper layer, the target conductor, and the second upper copper layer are sequentially connected to each other through the voltage divider resistor.

[0032] Optionally, the number of the target conductor includes at least one;

[0033] The target conductors are connected to each other via the voltage dividing resistors.

[0034] Optionally, a lower layer of copper is provided on the other side of the ceramic substrate.

[0035] Optionally, it further comprises: a plurality of resistor supports;

[0036] The voltage-dividing resistors are mounted one by one on the resistor bracket, and are respectively connected to the first upper copper layer, the second upper copper layer and the target conductor through the resistor bracket.

[0037] It can be seen from the above technical solutions that the present invention has the following advantages:

[0038] The present invention provides an insulation optimization method for a power module, which obtains a first electric field simulation distribution of the power module to be optimized to determine the electric potential inside the power module; and determines, based on the first electric field simulation distribution, a first electric potential corresponding to a first target area formed by a preset distance range from the triple point of the first upper copper layer, thereby achieving determination of the peak area; obtains a target conductor, and sets the target conductor in the first target area, dispersing the dense equipotential lines at the triple point inside the power module, thereby reducing the electric field strength of the power module; and calculates the voltage adjustment range of the target conductor based on the first electric potential and a preset incremental voltage range; within the voltage adjustment range, adjusts the voltage of the target conductor until the peak field strength in the power module reaches a minimum value, thereby improving the insulation performance of the power module.

[0039] Therefore, the present invention sets a target conductor inside the power module and adjusts the charged voltage of the target conductor to disperse the potential lines at the three-phase point, so as to reduce the peak field strength inside the power module and make the peak field strength inside the power module reach a minimum value, thereby improving the insulation performance of the power module. The method is simple as a whole, easy to implement, and has high packaging reliability. It can meet the current manufacturing process requirements and solves the technical problems that the existing optimization methods reduce the reliability of the power module and are not suitable for the current process level. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 A flowchart of the steps of a method for optimizing insulation of a power module provided by an embodiment of the present invention;

[0042] Figure 2 A schematic longitudinal section of the structure at the triple-phase point of a power module provided by an embodiment of the present invention;

[0043] Figure 3 A schematic diagram of an electric field simulation of a power module before optimization provided by an embodiment of the present invention;

[0044] Figure 4 A schematic diagram of a longitudinal section of the structure at a triple point of a power module provided with a target conductor according to an embodiment of the present invention;

[0045] Figure 5 Schematic diagram of equipotential line distribution when the voltage of the upper copper layer provided by an embodiment of the present invention is 10kV;

[0046] Figure 6 This is a diagram of the electric field simulation results of the power module before optimization provided by the example of the present invention;

[0047] Figure 7 This is a diagram of the electric field simulation results after the power module is optimized according to the example of the present invention;

[0048] Figure 8 A flowchart of another step of a method for optimizing insulation of a power module provided by an embodiment of the present invention;

[0049] Figure 9 A flowchart of another step of a method for optimizing insulation of a power module provided by an embodiment of the present invention;

[0050] Figure 10 A schematic diagram of the configuration of a voltage divider resistor provided in an embodiment of the present invention;

[0051] Figure 11 Another configuration principle diagram of the voltage divider resistor provided in an embodiment of the present invention;

[0052] Figure 12 A schematic diagram of the structure of a power module provided in an embodiment of the present invention;

[0053] Figure 13 The electric field simulation result diagram of a power module without a target conductor provided in the simulation application example of the present invention;

[0054] Figure 14 The electric field simulation result diagram of a power module with a target conductor provided in the simulation application example of the present invention;

[0055] Figure 15 This is a structural block diagram of an insulation optimization device for a power module provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0056] Among existing optimization methods, aluminum nitride and aluminum oxide are the most commonly used materials for copper-clad ceramic substrates (DBCs). They have excellent insulation, heat dissipation, and thermal expansion coefficients, but they still cannot meet the requirements for better insulation performance. Insulation materials that are higher quality than aluminum nitride and aluminum oxide are weaker than aluminum nitride and aluminum oxide in terms of heat dissipation and stress. If higher quality insulation materials are directly used, the reliability of power module packaging and operation will be reduced. In addition, some high-quality insulation materials are often expensive and have high production costs. In terms of optimizing the structure of copper-clad ceramic substrates (DBCs), existing technologies have proposed optimized structures such as double-layer DBCs and boss structures. However, due to the current level of process manufacturing, these optimizations are difficult to implement and it is difficult to achieve the effect of optimizing insulation performance. Therefore, the means of optimizing the structure are difficult to adapt to the existing manufacturing process level, resulting in low reliability of the power module after structural optimization and difficulty in improving insulation performance.

[0057] It can be seen from this that the existing method for optimizing the insulation performance of a power module has the technical problem of reducing the reliability of the power module and being unsuitable for the current process level.

[0058] Different from existing optimization methods such as double-layer DBC and boss DBC, the insulation optimization method, device, and power module proposed in the present invention fully consider the causes of electric field distortion within the power module and the distribution pattern of electric field lines within the power module. By adding charged equipotential regions, the dense equipotential lines at the triple point of the power module are dispersed, thereby effectively reducing the peak field intensity within the power module, weakening the peak electric field within the power module, and improving the insulation performance of the power module. The insulation performance of the power module is improved, and the implementation method is simple and has high process and packaging reliability. The present invention comprehensively solves the technical problems of existing optimization methods that reduce the reliability of power modules and are not applicable to current process levels.

[0059] In order to make the purpose, features, and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below 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 making creative work are within the scope of protection of the present invention.

[0060] See also Figure 1 , an embodiment of the present invention provides a method for optimizing insulation of a power module, comprising:

[0061] 101. Obtain a first electric field simulation distribution of a power module to be optimized; the power module to be optimized includes a first upper copper layer.

[0062] It should be noted that the power module to be optimized refers to a power module whose insulation performance needs to be optimized.

[0063] like Figure 2 As shown, the power module includes an upper copper layer A101, a lower copper layer A103, and potting compound A104. The upper copper layer A101 includes a first upper copper layer and a second upper copper layer. The second upper copper layer is the grounding layer, used for grounding. In actual applications, the first upper copper layer is connected to the positive terminal of the DC power supply via a terminal, while the lower copper layer A103 is grounded via the baseplate.

[0064] Specifically, in the power module, the location where the electric field distribution is dense is mainly at the junction of the ceramic substrate, copper layer, and potting compound, that is, the triple point. Figure 2 The structure shown includes two triple points: A105 triple point P1 and A106 triple point P2.

[0065] according to Figure 2 As can be seen from the structure shown, the structures on both sides of the ceramic substrate A102 are symmetrical, and the electric field strengths of the three-phase points on both sides are similar. Therefore, the present invention takes the electric field simulation of the upper half structure as an example. Among them, the electric field line distribution in the upper half structure area is as follows Figure 3 As shown, based on the electric field distribution, it can be seen that due to the right-angle structure of the copper layer, the equipotential lines at the right-angle corners are densely distributed, so that the triple point (i.e. Figure 3 The electric field strength is higher at the bottom right corner of the blank rectangle in the upper left corner of the figure. Therefore, increasing the spacing between the equipotential lines at the triple point can reduce the peak field strength at that point. It should be understood that the peak field strength refers to the maximum field strength value within the power module.

[0066] This step obtains the first electric field simulation distribution of the power module to be optimized, and can determine the position corresponding to the highest electric field intensity based on the first electric field simulation distribution, thereby positioning the area to be optimized in the power module and providing a technical basis for the placement of the target conductor.

[0067] 102. Determine a first electric potential corresponding to a first target area according to the first electric field simulation distribution, where the first target area is an area formed by a preset distance range from a triple point of the first upper copper layer.

[0068] It should be noted that, in this embodiment, the triple point of the first upper copper layer is Figure 2 The triple point P1 of A105 in the circuit.

[0069] Starting from the triple point of the first upper copper layer, horizontal measurements are performed, with the area within a preset distance from the triple point of the first upper copper layer serving as the first target area. This first target area is used to place charged target conductors to disperse the equipotential lines at the triple point.

[0070] In combination with step 101, it can be seen that after obtaining the first electric field simulation distribution, the triple point of the first upper copper layer is determined based on the density of the equipotential lines displayed in the first electric field simulation distribution, the first target area is determined based on the position of the triple point and the preset distance range, and then the corresponding first potential is determined based on the equipotential lines involved in the first target area.

[0071] It is understandable that based on Figure 2 It can be seen that before the target conductor is placed, the triple point P1 of the upper copper layer and the triple point P2 of the lower copper layer are symmetrical along the horizontal center line of the ceramic substrate, so the electric field strength distribution around these two points is the same. After the target conductor is set in the first target area, the electric field of the triple point P1 and the triple point P2 is asymmetrically distributed, so that the electric field strength at the triple point P2 of the lower copper layer also changes. Therefore, this embodiment optimizes the electric field strength of the overall electric field in the power module by setting the target conductor in the first target area and adjusting the voltage of the target conductor.

[0072] In one embodiment, the preset distance range is 0.2 mm to 0.5 mm.

[0073] It should be noted that the closer to the upper copper layer, the denser the equipotential lines. Evacuating the equipotential lines in this area can more effectively reduce the electric field strength. However, since the target conductor will be installed in subsequent steps, if it is too close to the upper copper layer, a stronger electric field may be generated between the two conductors. Therefore, after experimental determination, the preset distance range is preferably 0.2mm to 0.5mm. Placing the target conductor within this range can effectively reduce the peak electric field strength while avoiding the generation of a stronger electric field between the target conductor and the upper copper layer.

[0074] 103. Acquire a target conductor, and place the target conductor in a first target area.

[0075] It should be noted that the target conductor is used to increase the spacing between equipotential lines at the triple point, thereby reducing the peak field intensity at the triple point. The target conductor can be set at any position in the first target area.

[0076] In one example, the target conductor is positioned such that Figure 4 shown.

[0077] It is understandable that the structure, shape, size and material of the target conductor can be set according to the actual design requirements of the power module. For example, in a two-dimensional plane, the shape of the target conductor is generally rectangular and the material can be copper. Figure 11 and Figure 12 As shown, the first upper copper layer is approximately semi-elliptical, so the target conductor can also be approximately semi-elliptical.

[0078] In one embodiment, in order to further reduce the peak value of the field intensity, after the target conductor is placed on the power module, a potting compound is placed between the target conductor and the upper copper layer, wherein the sum of the longitudinal section lengths of the target conductor, the first upper copper layer, and the first potting compound is equal to the longitudinal section length of the lower copper layer, such as Figure 4 As shown, the gray block between the upper copper layer and the target conductor represents the potting compound.

[0079] It can be understood that if a plurality of target conductors are provided, potting glue is provided at intervals between the plurality of target conductors, and the sum of the longitudinal section lengths of the upper copper layer and the plurality of target conductors with the potting glue provided therewith is still equal to the sum of the longitudinal section lengths of the lower copper layer.

[0080] 104. Calculate a voltage adjustment range of the target conductor based on the first potential and a preset incremental voltage range.

[0081] It should be noted that, in the first potential, the original potential corresponding to the position where the target conductor is set (that is, the potential used to set the position of the target conductor before the target conductor is set) is determined, and the original potential is added to the two endpoint values ​​of the preset incremental voltage range respectively to obtain the voltage adjustment range of the target conductor.

[0082] In one embodiment, the preset incremental voltage range is 500V-1500V.

[0083] It should be noted that if the voltage of the target conductor exceeds the original potential by too small a amount, the insulation optimization effect is not obvious. If it is too high, an excessively high electric field is easily generated between the target conductor and the first upper copper layer, resulting in an insignificant optimization effect. Therefore, after experimental testing, the incremental voltage range of this embodiment is preferably 500V-1500V. Within this incremental voltage range, the target conductor can achieve the goal of reducing the peak field strength of the power module while avoiding the generation of a higher electric field between the target conductor and the first upper copper layer, thereby further improving the insulation performance of the power module.

[0084] 105. Within the voltage regulation range, adjust the voltage of the target conductor until the peak value of the field intensity in the power module reaches a minimum value.

[0085] It should be noted that after the target conductor is set in the first target area within the power module, an electric field simulation is performed on the power module in which the target conductor is set to update the first electric field simulation distribution, and combined with the field strength peak value fed back by the updated first electric field simulation distribution, a voltage value is selected as the voltage of the target conductor within the voltage adjustment range. After that, the electric field simulation of the power module is updated again, and the field strength peak value fed back by the updated electric field simulation is recorded. Similarly, the voltage of the target conductor is cyclically adjusted until the final field strength peak value of the power module is determined to be the minimum value, thereby completing the optimization of the internal insulation performance of the power module.

[0086] In one example, the adjustment step for adjusting the field intensity peak of the power module to the minimum value may be that, when all voltage values ​​within the adjustment range have been set to the voltage of the target conductor, the field intensity peak values ​​displayed by the first electric field simulation distribution corresponding to the voltage of the target conductor at each adjustment number are compared to determine the minimum field intensity peak value.

[0087] Alternatively, the adjustment step may be that after each adjustment of the voltage of the target conductor, the electric field simulation distribution of the power module corresponding to the voltage is obtained, and the field strength peak value displayed by the electric field simulation distribution is compared with the field strength peak value displayed by the electric field simulation distribution saved last time; if the field strength peak value displayed by the current electric field simulation distribution is smaller than the field strength peak value displayed by the electric field simulation distribution saved last time, the field strength peak value displayed by the electric field simulation distribution saved last time is updated to the field strength peak value displayed by the current electric field simulation distribution, which is used as a judgment basis for the field strength peak value obtained by the next adjustment; if the field strength peak value displayed by the current electric field simulation distribution is larger than the field strength peak value displayed by the electric field simulation distribution saved last time, the field strength peak value displayed by the electric field simulation distribution saved last time is retained as a judgment basis for the next field strength peak value, and the adjustment is cyclically performed until the final field strength peak value is the minimum value, or, when the difference between the obtained field strength peak value and the field strength peak value obtained by the last adjustment is within a preset error range, the field strength peak value is taken as the minimum value and the adjustment is stopped. It is understandable that, when adjusting for the first time, the field intensity peak value displayed by the electric field simulation distribution obtained by the first adjustment can be compared with the field intensity peak value when no target conductor is provided.

[0088] In one embodiment, the above-mentioned adjustment means can be implemented by performing parameter scanning on the voltage of the target conductor using mathematical modeling software and multi-physics field simulation software to find the minimum value of the peak value of the field intensity inside the power module.

[0089] In a simulation example, assume that the voltage of the upper copper layer is 10kV, such as Figure 5The left figure shows the distribution of equipotential lines under the original structure (i.e., the power module without adding the target conductor). The distribution is relatively dense, resulting in a higher electric field intensity at the triple point. Among them, the electric potential at a distance of 0.5mm from the 10kV high-voltage upper copper is about 8kV. If the target conductor is set at the position of the 8kV equipotential line, the voltage adjustment range of the target conductor is 8.5kV~9.5kV. The voltage of the target conductor is adjusted according to this voltage adjustment range until the peak value of the field intensity reaches the minimum value. Figure 5 As shown in the right figure, when the voltage of the target conductor is 9kV, the overall electric field lines disperse to the lower right, reducing the electric field intensity at the triple point compared to the left figure, thereby reducing the overall electric field peak of the power module.

[0090] In one example, the electric field simulation results before optimization (i.e., before adding the target conductor) and after optimization (i.e., after adding the target conductor) are shown as follows: Figure 6 and Figure 7 As shown by Figure 6 and Figure 7 It can be seen that by adding the target conductor, the electric field strength is reduced from 17.8 kV / mm to 16.9 kV / mm.

[0091] This embodiment obtains a first electric field simulation distribution of the power module to be optimized to determine the electric potential inside the power module; and based on the first electric field simulation distribution, determines a first electric potential corresponding to a first target area formed by a preset distance range from the triple point of the first upper copper layer, thereby achieving determination of the peak area; obtains a target conductor and sets the target conductor in the first target area, dispersing the dense equipotential lines at the triple point inside the power module and reducing the electric field strength of the power module; and calculates the voltage adjustment range of the target conductor based on the first electric potential and a preset incremental voltage range; within the voltage adjustment range, adjusts the voltage of the target conductor until the peak field strength in the power module reaches a minimum value, thereby achieving optimization of insulation.

[0092] Therefore, this embodiment sets a target conductor inside the power module and adjusts the charged voltage of the target conductor to disperse the potential lines at the three-phase point, so as to reduce the peak field strength inside the power module and minimize the peak field strength inside the power module, thereby improving the insulation performance of the power module. The method is simple as a whole, easy to implement, and has high packaging reliability. It can meet the current manufacturing process requirements and solves the technical problem that the existing optimization method reduces the reliability of the power module and is not suitable for the current process level.

[0093] In one embodiment, if the internal space of the power module allows, the insulation performance of the power module can be further optimized by setting the expected field intensity peak value. The optimization steps are as follows: Figure 8When the peak value of the field intensity of the power module that has reached the minimum value is greater than the preset expected peak value of the field intensity, the method further includes:

[0094] S1. According to the order in which the conductors are set, the last target conductor set in the current power module is taken as the optimization object, and the electric field simulation distribution of the current power module is obtained.

[0095] It should be noted that the expected peak field intensity refers to the peak field intensity target that the optimized power module must meet, which can be determined based on the design requirements of the power module. When the peak field intensity of the optimized power module is no greater than the expected peak field intensity, it indicates that the optimized power module meets the design requirements.

[0096] The current power module refers to the power module at the time step S1 is executed. For example, if step S1 is executed after step 105, the current power module is the power module at which the peak field intensity reaches the minimum in step 105. If step S1 is executed after step S5, the current power module is the power module obtained after step S5 is executed.

[0097] It will be appreciated that in this embodiment, each target conductor is set in a certain order, and each time a target conductor is set, a target conductor is set. Therefore, according to the order in which each target conductor is set, the last target conductor set in the current power module can be used as the optimization target. The optimization goal is to reduce the peak field intensity at the triple point of the optimization target.

[0098] S2. Determine a second electric potential corresponding to a second target area according to the electric field simulation distribution of the current power module, where the second target area is an area formed by a preset distance range from the triple point of the optimization object.

[0099] S3. Acquire and set a new target conductor in the second target area; and calculate a voltage adjustment range of the new target conductor according to the second potential and the incremental voltage range.

[0100] It should be noted that the principles of steps S2-S3 are similar to those of steps 102-104, except that the measurement starting points for the first and second target regions are different. The measurement starting point for the second target region is the triple point of the optimization object. Therefore, the principles of steps S2-S3 can be found in the description of steps 102-103 and will not be repeated here.

[0101] S4. For all target conductors provided in the power module, voltage regulation is performed on each target conductor within a voltage regulation range of each target conductor until the peak value of the field intensity of the power module reaches a minimum value.

[0102] It should be noted that, prior to step S4, the voltage adjustment ranges for all target conductors disposed within the power module have been determined. During step S4, the voltage of each target conductor is adjusted based on its voltage adjustment range. After each adjustment, the electric field simulation distribution of the power module is updated to determine the peak field intensity corresponding to each adjustment. This determines whether the peak field intensity of the power module has reached a minimum value. When the peak field intensity of the power module has reached the minimum value, adjusting the voltage of the target conductor is stopped.

[0103] It is understandable that the adjustment principle of this step is similar to the adjustment principle of step 105. For details, please refer to the description of step 105 and will not be repeated here.

[0104] S5. Determine whether the peak value of the field intensity of the power module is not greater than the preset expected peak value of the field intensity. If not, jump to execute S1 to S5. If so, stop the optimization.

[0105] It should be noted that the power module in step S5 refers to the power module obtained after executing step S4. This step determines whether the field strength peak of the power module is not greater than the preset expected field strength peak. If so, it indicates that the field strength peak of the power module has met the optimization requirements and the optimization can be stopped. If not, it is necessary to re-execute steps S1 to S5 to determine the power module with the best insulation performance.

[0106] The method provided in this embodiment is applicable to situations where the internal space of the power module allows. By setting a lower voltage target conductor outside the target conductor, the electric field strength outside the original target conductor is reduced, thereby further reducing the peak electric field strength inside the power module. This cycle is repeated, and ultimately the peak field strength of the power module is lower than the preset expected field strength peak, so that the insulation performance of the further optimized power module is better.

[0107] In one embodiment, Figure 9 As shown, when the peak value of the field intensity of the power module that has reached the minimum value is not greater than the preset expected peak value of the field intensity, or after the optimization is stopped, the method further includes:

[0108] 201. Determine an optimal voltage of a target conductor, where the optimal voltage is used to ensure that a peak value of a field intensity of a power module is no greater than a preset expected peak value of a field intensity.

[0109] It should be noted that, from the aforementioned embodiment, when the peak value of the field strength of the power module obtained in step 105 is not greater than the preset expected peak value of the field strength, the voltage of the target conductor at this time is the optimal voltage, and when the peak value of the field strength of the power module obtained after step S5 is not greater than the preset expected peak value of the field strength, the voltage of each target conductor at this time is the optimal voltage of each target conductor.

[0110] Therefore, in this step, when it is determined that the peak value of the field intensity of the power module is not greater than the preset expected peak value of the field intensity, the voltage of the target conductor at this time can be obtained as the optimal voltage.

[0111] 202. Obtain a first voltage between a first upper copper layer and a second upper copper layer.

[0112] It should be noted that the second upper copper layer is used for grounding, while the first upper copper layer is used for connecting to a power supply. The first voltage is the power supply voltage connected to the first upper copper layer.

[0113] 203. Based on the series voltage division principle, the first voltage and the optimal voltage are used to configure each voltage dividing resistor, and a connection relationship is established between each voltage dividing resistor, the first upper copper layer, the second upper copper layer, and the target conductor; each voltage dividing resistor is used to configure the voltage of the target conductor to the optimal voltage by dividing the first voltage.

[0114] It should be noted that, based on the series voltage division principle, the first upper copper layer, the target conductor, and the second grounded upper copper layer are connected via voltage division resistors to form a series voltage division circuit. Based on the series voltage division principle, the resistance value of each voltage division resistor is determined and set. Thus, in actual applications, the voltage division resistors are used to divide the first voltage to configure the corresponding optimal voltage for the target conductor.

[0115] The resistance value of each voltage-dividing resistor is configured based on the principle of adjusting the resistance value of each voltage-dividing resistor based on the relationship between the first voltage and the voltage of each target conductor, and the first voltage and the optimal voltage of each second conductor, with the goal of satisfying the voltage of the target conductor as the optimal voltage.

[0116] The following will illustrate the principle of configuring the resistance value of the voltage divider resistor by combining Example 1 and Example 2.

[0117] Example 1: Take the number of target conductors as 1 for example. Figure 10 As shown, U is the voltage between the first upper copper layer and the second upper copper layer, R1 is the first voltage dividing resistor, and R2 is the second voltage dividing resistor.

[0118] The voltage of the target conductor can be expressed as follows:

[0119]

[0120] Based on the relationship between the voltage of the target conductor and the first voltage, the resistance values ​​of the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 are determined, thereby completing the configuration of the first voltage-dividing resistor and the second voltage-dividing resistor.

[0121] It is understandable that the values ​​of the first voltage-dividing resistor and the second voltage-dividing resistor need to be as large as possible to reduce the current flowing through the resistors, thereby reducing the power loss of the voltage-dividing resistor component and the leakage current when the chip in the power module is turned off. In one example, the initial resistance values ​​of the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 can be set based on experience, and the initial resistance values ​​are substituted into the above relationship. The voltage of the target conductor is compared with the optimal voltage of the target conductor. The resistance values ​​of the first voltage-dividing resistor R1 and the second voltage-dividing resistor are adjusted based on the comparison result. After multiple adjustments, the resistance values ​​of the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 corresponding to the optimal voltage of the target conductor are obtained.

[0122] Example 2: As can be seen from the preceding, the number of target conductors can be multiple. This example uses two target conductors as an example to illustrate the resistance configuration of each voltage divider resistor. It should be understood that when the number of target conductors exceeds two, the resistance configuration of each voltage divider resistor can refer to Example 2.

[0123] like Figure 11 As shown in Figure 1, U is the voltage between the first upper copper layer and the second upper copper layer, R1 is the first voltage-dividing resistor, R2 is the second voltage-dividing resistor, and R3 is the third voltage-dividing resistor. The two target conductors are named Target Conductor 1 and Target Conductor 2.

[0124] Based on the principle of series voltage division, the voltage V1 of target conductor 1 and the voltage V2 of target conductor 2 are:

[0125]

[0126]

[0127] Based on the relationship between target conductor 1 and target conductor 2, the resistance values ​​of the first voltage-dividing resistor, the second voltage-dividing resistor, and the third voltage-dividing resistor are adjusted to determine the first voltage-dividing resistor value, the second voltage-dividing resistor value, and the third voltage-dividing resistor value that can make the voltage of target conductor 1 the optimal voltage of target conductor 1 and the voltage of target conductor 2 the optimal voltage of target conductor 2.

[0128] This embodiment optimizes the internal structure of the power module by configuring each voltage-dividing resistor in the power module and establishing connections between each voltage-dividing resistor and the first upper copper layer, the second upper copper layer, and each first conductor. Compared with the unoptimized power module, the optimized power module has an effectively reduced field intensity peak, thereby improving the insulation of the power module. The overall method is simple and easy to implement.

[0129] See Figure 12 , a power module provided by an embodiment of the present invention is applied to the method provided by any of the above embodiments, comprising: a ceramic substrate 1;

[0130] A first upper copper layer 2, a second upper copper layer 3, a target conductor 4 and a plurality of voltage-dividing resistors 5 are provided on one side of the ceramic substrate 1;

[0131] The first upper copper layer 2 , the target conductor 4 , and the second upper copper layer 3 are sequentially connected to each other via the voltage divider resistor 5 .

[0132] It should be noted that the power module provided in this embodiment is the optimized power module in the above embodiment. The optimized power module sets the target conductor 4 and the voltage-dividing resistor 5 so that the voltage of the target conductor 4 is the optimal voltage, so as to disperse the equipotential line distribution between the first upper copper layer 2 and the first conductor, thereby reducing the peak value of the electric field strength inside the power module and improving the insulation performance of the power module. It has a simple structure, is easy to implement, and has high packaging reliability, which can meet the current manufacturing process requirements and solves the technical problem that the existing optimization method reduces the reliability of the power module and is not suitable for the current process level.

[0133] In a specific embodiment, a lower layer of copper 7 is disposed on the other side of the ceramic substrate 1 .

[0134] In a specific embodiment, it further includes a plurality of resistor supports 6;

[0135] Each voltage-dividing resistor 5 is mounted one by one on a resistor support 6 , and is respectively connected to the first upper copper layer 2 , the second upper copper layer 3 and the target conductor 4 through the resistor support 6 .

[0136] It should be noted that the resistor bracket in this embodiment is conductive.

[0137] In one embodiment, the number of voltage-dividing resistors connecting the first upper copper layer and the target conductor can be determined based on the desired resistance and the internal space of the power module, so that their total resistance meets the desired resistance. The same applies to the voltage-dividing resistors connecting the target conductors and the voltage-dividing resistors connecting the target conductors and the second upper copper layer.

[0138] For example: consider symmetry, such as Figure 12 As shown, the voltage divider resistors connecting the target conductor 4 and the second upper copper layer 3 can be set to two, which are symmetrically set at the left and right connections of the target conductor 4 and the second upper copper layer 3. Since the connection relationship between the two resistors is parallel, the total resistance of the parallel connection must be equal to Figure 10 The resistance of the resistor R2 in the target conductor 4 is equal to the resistance of the resistor R2. The voltage divider resistor connecting the target conductor 4 and the first upper copper 2 is one, which is set at the top of the arc of the target conductor 4. Its resistance must be equal to Figure 10 The resistance of resistor R1 in.

[0139] In a simulation application example, Figure 12The power module shown in FIG. 1 is simulated, wherein the simulation parameters include: setting the voltage of the first upper copper layer 2 to 10 kV, the original electric field strength at the location where the target conductor 4 is to be placed (i.e., the electric field strength without the target conductor 4) is between 3 kV and 3.5 kV, setting the target conductor 4, and setting the voltage of the target conductor 4 to 5 kV, the resistance between the first upper copper layer 2 and the target conductor 3 to 100 kΩ, and the resistance between the target conductor 4 and the second upper copper layer 3 to 200 kΩ.

[0140] The simulation results are as follows Figure 13 and Figure 14 As shown, Figure 13 This is the electric field simulation result of the power module without the target conductor. Figure 14 The electric field simulation result diagram of the power module with the target conductor is shown in Figure 2. Figure 13 、 Figure 14 It can be seen that the addition of the target conductor reduces the peak electric field intensity from the original 46.3 kV / mm to 42.4 kV / mm. Therefore, it can be seen that the optimization method provided by the present invention can effectively improve the insulation performance of the optimized power module.

[0141] In one embodiment, the number of target conductors includes at least one;

[0142] The target conductors are connected to each other via voltage divider resistors.

[0143] It should be noted that every two target conductors are connected via a voltage-dividing resistor.

[0144] It should be noted that, under the premise that there is sufficient space inside the power module, new target conductors can be obtained for appropriate expansion, that is, a target conductor with a lower voltage is set on the outside of the target conductor (that is, on the side away from the first upper copper layer) to achieve a reduction in the outer electric field strength of the originally set target conductor. Similarly, the external electric field strength of each target conductor is gradually reduced, thereby reducing the peak electric field strength inside the module. The setting process of multiple target conductors can refer to the description of the aforementioned method embodiment and will not be repeated here.

[0145] See Figure 15 , an embodiment of the present invention provides an insulation optimization device for a power module, comprising:

[0146] A first acquisition module 301 is configured to acquire a first electric field simulation distribution of a power module to be optimized; the power module to be optimized includes a first upper layer of copper;

[0147] A first determining module 302 is configured to determine a first electric potential corresponding to a first target area based on the first electric field simulation distribution, where the first target area is an area formed by a preset distance range from a triple point of the first upper copper layer;

[0148] A second acquisition module 303 is used to acquire a target conductor and place the target conductor in the first target area;

[0149] A first calculation module 304 is configured to calculate a voltage adjustment range of the target conductor based on the first potential and a preset incremental voltage range;

[0150] The first regulating module 305 is configured to regulate the voltage of the target conductor within a voltage regulating range until the peak value of the field intensity of the power module reaches a minimum value.

[0151] In one embodiment, it further includes:

[0152] A setting module is used to use the voltage of the target conductor corresponding to the minimum field intensity peak as the optimal voltage of the target conductor;

[0153] A third acquisition module is used to acquire a first voltage between the first upper copper layer and the second upper copper layer;

[0154] a configuration module, configured to configure a first voltage-dividing resistor component and a second voltage-dividing resistor component according to the first voltage and the optimal voltage;

[0155] The connection module is used to connect one end of the first voltage-dividing resistor component to the first upper copper layer, connect the second end of the first voltage-dividing resistor component to the target conductor and one end of the target conductor respectively; and connect the other end of the second voltage-dividing resistor component to the second upper copper layer.

[0156] In one embodiment, it further includes:

[0157] A fourth acquisition module, configured to acquire a second electric field simulation distribution of the current power module;

[0158] a second determining module, configured to determine a second electric potential corresponding to a second target area according to a second electric field simulation distribution, where the second target area is formed by a preset distance range from a triple point of the target conductor;

[0159] a fifth acquisition module, configured to acquire a second conductor and place the second conductor in a second target area;

[0160] a second calculation module, configured to calculate a voltage adjustment range of the second conductor according to the second potential and a preset incremental voltage range;

[0161] The second regulating module is configured to regulate the voltage of the second conductor within a voltage regulating range of the second conductor until a peak value of a field intensity in the second electric field simulation distribution reaches a minimum value.

[0162] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0163] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0164] In addition, the functional units in various embodiments of the present invention may be integrated into a single processing unit, or each functional unit may exist as a separate physical unit, or two or more functional units may be integrated into a single processing unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0165] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the method of the present invention. The aforementioned storage medium includes various media that can store program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0166] The terms "first," "second," "third," "fourth," and the like (if any) in the specification of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or apparatus.

[0167] It should also be noted that, in the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0168] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for optimizing insulation of a power module, characterized in that: The method comprises: Obtaining a first electric field simulation distribution of a power module to be optimized; the power module to be optimized includes a first upper layer of copper; determining a first electric potential corresponding to a first target area according to the first electric field simulation distribution, where the first target area is an area formed by a preset distance range from a triple point of the first upper copper layer; Acquire a target conductor, and place the target conductor in the first target area; calculating a voltage adjustment range of the target conductor based on the first potential and a preset incremental voltage range; In the voltage regulation range, the voltage of the target conductor is regulated until the peak value of the field intensity in the power module reaches a minimum value.

2. The method according to claim 1, characterized in that When the peak value of the field intensity of the power module that reaches the minimum value is greater than a preset expected peak value of the field intensity, the method further includes: S1. According to the order in which the conductors are set, the last target conductor set in the current power module is used as the optimization object, and the electric field simulation distribution of the current power module is obtained; S2. Determine a second electric potential corresponding to a second target region based on the electric field simulation distribution of the current power module, where the second target region is a region formed by a preset distance range from the triple point of the optimization object; S3. Acquire and set a new target conductor in the second target area; and calculate a voltage adjustment range of the new target conductor based on the second potential and the incremental voltage range; S4. For all target conductors provided in the power module, respectively adjust the voltage of each target conductor within the voltage adjustment range of each target conductor until the peak value of the field intensity of the power module reaches a minimum value; S5. Determine whether the peak value of the field intensity of the power module is not greater than the preset expected peak value of the field intensity. If not, jump to execute S1 to S5. If so, stop the optimization.

3. The method according to claim 2, characterized in that The power module includes a second upper copper layer for grounding; when the peak value of the field intensity of the power module that reaches the minimum value is not greater than a preset expected peak value of the field intensity, or after performing the stopping optimization, the method further includes: determining an optimal voltage of the target conductor, wherein the optimal voltage is used to ensure that the peak value of the field intensity of the power module is no greater than the preset expected peak value of the field intensity; Obtaining a first voltage between the first upper copper layer and the second upper copper layer; Based on the series voltage division principle, the first voltage and the optimal voltage are used to configure each voltage-dividing resistor, and a connection relationship is established between each voltage-dividing resistor, the first upper copper layer, the second upper copper layer, and the target conductor; each voltage-dividing resistor is used to configure the voltage of the target conductor to the optimal voltage by dividing the first voltage.

4. The method according to claim 1, wherein The preset distance range is 0.2mm~0.5mm.

5. The method according to claim 1, characterized in that The preset incremental voltage range is 500V-1500V.

6. An insulation optimization device for a power module, characterized in that: include: A first acquisition module is configured to acquire a first electric field simulation distribution of a power module to be optimized; the power module to be optimized includes a first upper layer of copper; a first determining module, configured to determine a first electric potential corresponding to a first target area according to the first electric field simulation distribution, where the first target area is an area formed by a preset distance range from a triple point of the first upper copper layer; a second acquisition module, configured to acquire a target conductor and place the target conductor in the first target area; a first calculation module, configured to calculate a voltage adjustment range of the target conductor according to the first potential and a preset incremental voltage range; The first regulating module is configured to regulate the voltage of the target conductor within the voltage regulating range until the peak value of the field intensity of the power module reaches a minimum value.

7. A power module, characterized in that: The method as claimed in any one of claims 1 to 5, comprising: a ceramic substrate; A first upper layer of copper, a second upper layer of copper, a target conductor and a plurality of voltage-dividing resistors are provided on one side of the ceramic substrate; The first upper copper layer, the target conductor, and the second upper copper layer are sequentially connected to each other through the voltage divider resistor.

8. The power module according to claim 7, characterized in that: The number of the target conductors includes at least one; The target conductors are connected to each other via the voltage dividing resistors.

9. The power module according to claim 7, wherein: A lower layer of copper is disposed on the other side of the ceramic substrate.

10. The power module according to claim 7, wherein: Also includes: Multiple resistor brackets; The voltage-dividing resistors are mounted one by one on the resistor bracket, and are respectively connected to the first upper copper layer, the second upper copper layer and the target conductor through the resistor bracket.

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