A structure and arrangement optimization method of a new energy vehicle IGBT module radiator fin

Abstract

The application discloses a new energy automobile IGBT module radiator fin needle structure, including: a rectangular structure of a radiator substrate, the bottom of the rectangular structure of the radiator substrate is provided with an upstream heat dissipation area, a midstream heat dissipation area, a downstream heat dissipation area and a high-temperature heat dissipation area, the upstream heat dissipation area, the midstream heat dissipation area and the downstream heat dissipation area are arranged along the direction of the cooling water flow, the high-temperature heat dissipation area is located directly below the corresponding IGBT chip of the radiator substrate, the bottom of the upstream heat dissipation area, the midstream heat dissipation area, the downstream heat dissipation area and the high-temperature heat dissipation area is integrally provided with an upstream fin needle group, a midstream fin needle group, a downstream fin needle group and a high-temperature heat dissipation fin needle group; through the variable-pitch fork arrangement and the gradient fin needle structure, the flow resistance and the heat exchange efficiency are synergistically optimized, the cooling liquid circulation energy consumption is reduced, the operation energy efficiency of the heat dissipation system is improved, meanwhile, the forming process is simplified, and the structural stability and the batch manufacturing feasibility are ensured.

Description

Technical Field

[0001] This invention relates to the field of heat sink technology for IGBT modules in new energy vehicles, specifically a method for optimizing the structure and arrangement of the fins in a heat sink for IGBT modules in new energy vehicles. Background Technology

[0002] Currently, direct liquid cooling has become the mainstream heat dissipation method for automotive-grade IGBT power modules. Among them, the single-sided direct water cooling structure adds a pin-fin heat dissipation structure on the back of the substrate, which does not require thermal grease and can be directly inserted into the heat dissipation water jacket, which can significantly reduce the module's thermal resistance by about 30%.

[0003] Existing pin-fin heat sink substrates mainly employ a uniform structure and regular arrangement design, meaning the pins have the same geometric dimensions (diameter and height) and are arranged in a straight or staggered pattern with equal spacing. Research shows that IGBT power modules contain multiple chips (such as IGBT chips and FRD diode chips), and the heat generation in different areas of the module is different and unevenly distributed, resulting in a non-uniform heat distribution on the substrate surface. However, existing technologies have not fully considered this non-uniform heat distribution.

[0004] Existing technological defects 1. Low heat dissipation area utilization: There is a structural contradiction between the excessive heat dissipation capacity of the fins in the low-temperature area and the insufficient heat dissipation capacity in the high-temperature area. 2. High flow resistance: The uniform high-density fin layout results in high coolant flow resistance, requiring higher pump power and reducing the system's energy efficiency coefficient. 3. Poor temperature gradient control: The temperature gradually increases along the direction of coolant flow, which worsens the heat dissipation conditions of downstream chips and exacerbates temperature imbalance. Summary of the Invention

[0005] The purpose of this invention is to provide a structure for the heat sink pins of an IGBT module in a new energy vehicle, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A structure of a heat sink fin for an IGBT module in a new energy vehicle includes: A rectangular heat sink substrate has an upstream heat dissipation area, a midstream heat dissipation area, a downstream heat dissipation area, and a high-temperature heat dissipation area at its bottom. The upstream, midstream, and downstream heat dissipation areas are arranged along the cooling water flow direction. The high-temperature heat dissipation area is located directly below the corresponding IGBT chip on the heat sink substrate. The bottom of each of the upstream, midstream, downstream, and high-temperature heat dissipation areas is integrally formed with an upstream fin group, a midstream fin group, a downstream fin group, and a high-temperature heat dissipation fin group. The heat dissipation pool is sealed and fixedly installed on the bottom outer wall of the radiator base plate. The heat dissipation pool is circulated with coolant. The input end and output end of the heat dissipation pool are respectively connected to the water inlet pipe and the water outlet pipe. The upstream fin group, the midstream fin group, the downstream fin group and the high-temperature heat dissipation fin group are inserted into the heat dissipation pool and come into contact with the coolant for heat exchange.

[0007] In a preferred embodiment of the present invention, the top of the radiator substrate is provided with an mounting groove for mounting a new energy vehicle IGBT module, the bottom perimeter of the radiator substrate is provided with a first sealing groove, the top perimeter of the heat sink is provided with a second sealing groove, the inner walls of the first sealing groove and the second sealing groove are fitted together to install a sealing ring, and the top and bottom of the sealing ring are respectively fitted together with the first sealing groove and the second sealing groove to seal and fill.

[0008] In a preferred embodiment of the present invention, the heat sink substrate has a length of 100 mm, a width of 80 mm, and a thickness of 10 mm. The heat sink substrate is made of oxygen-free copper material C11000 with a purity greater than 99.95%. The heat sink substrate has a thermal conductivity greater than 380 W / (m·K). The entire surface of the heat sink substrate is polished and treated with anti-corrosion. The flatness tolerance of the upper surface of the heat sink substrate is less than 0.02 mm, and the perpendicularity tolerance of the pins of each pin group on the lower surface of the heat sink substrate is less than 0.05 mm.

[0009] In a preferred embodiment of the present invention, the upstream fin needle group is composed of multiple circular cross-section columnar fin needles evenly arranged, and the diameter of the fin needles in the upstream fin needle group is 2.2 mm and the height H1 of the circular cross-section columnar fin needles is 3.25 mm. The midstream wing needle group is composed of multiple columnar wing needles with elliptical cross-sections. The ratio of the major axis to the minor axis of the elliptical cross-section of the columnar wing needles in the midstream wing needle group is 5:3, the equivalent diameter is 1.8 mm, and the height H2 of the columnar wing needles with elliptical cross-sections is 3.75 mm. The downstream fin group is composed of multiple rectangular cross-section columnar fins arranged in a row. The equivalent diameter of the rectangular cross-section columnar fins in the downstream fin group is 1.2 mm, and the height H3 of the rectangular cross-section columnar fins is 4.25 mm. The high-temperature zone fin group is located in the downstream middle section, directly below the chip. It consists of multiple teardrop-shaped columnar fins densely arranged. The equivalent diameter of the teardrop-shaped columnar fins is 1.0 mm, and the height is 9.0 mm. The fin height of the teardrop-shaped columnar fins is 0.5 mm to 1 mm higher than that of the fins in the same flow direction area. The fin height of each fin group forms a continuous gradient change, and the fin diameter decreases step by step. This ensures that the heat exchange capacity of the coolant gradually increases during the flow process, offsetting the decrease in heat exchange capacity caused by the increase in coolant temperature.

[0010] In a preferred embodiment of the present invention, the porosity of the upstream heat dissipation area where the upstream fin group is located is controlled between 0.75 and 0.85, the porosity of the midstream heat dissipation area where the midstream fin group is located is controlled between 0.72 and 0.80, the porosity of the downstream heat dissipation area where the downstream fin group is located is controlled between 0.70 and 0.78, and the porosity of the high-temperature heat dissipation area directly below the chip where the high-temperature fin group is located is controlled between 0.65 and 0.70. The high-temperature heat dissipation area completely covers the heat-generating core of the IGBT chip, does not cover the diode area, and is located in the downstream middle section. The porosity of the high-temperature heat dissipation area is significantly lower than that of the other heat exchange areas, resulting in a higher fin arrangement density, a larger heat exchange area, a faster local flow velocity, and a stronger turbulence intensity in the high-temperature area. This significantly improves the convective heat transfer efficiency of the high-temperature heat dissipation area, effectively reduces the local temperature directly below the chip, and suppresses the formation of hot spots.

[0011] A method for optimizing the arrangement of heat sink pins in IGBT modules for new energy vehicles includes the following steps: S1: Regional division. Based on the heat transfer law of coolant flowing from low temperature end to high temperature end, and the non-uniform heating characteristics of IGBT chip and FRD diode chip inside IGBT module, the heat sink substrate is divided into three continuous heat exchange areas along the coolant flow direction: upstream heat exchange area, midstream heat exchange area and downstream heat exchange area. In the middle section of the downstream heat exchange area, a high temperature heat exchange area is independently defined for each IGBT chip vertical projection position. The high temperature heat exchange area accurately covers the heat-generating core of IGBT chip and does not extend to the area below FRD diode, forming a zoned collaborative heat dissipation layout. S2: Gradient fin molding, the fin structure is made in one piece in each corresponding area on the lower surface of the heat sink substrate. Along the coolant flow direction, the fin diameter decreases step by step and the fin height increases step by step. Within the high-temperature heat dissipation zone, the diameter of the pins is further reduced, the height of the pins is increased, the density of the pin arrangement is increased, and the porosity of the area is reduced to form a structure with high local heat transfer capacity, which precisely matches the high heat flux density heat dissipation requirements of the IGBT chip. S3: Variable pitch forked arrangement, using an asymmetrical forked arrangement of fins with independent and gradual changes in longitudinal and transverse pitches. Both longitudinal and transverse pitches gradually decrease from the upstream heat dissipation area to the downstream heat dissipation area. The minimum longitudinal pitch and minimum transverse pitch are adopted in the high-temperature heat dissipation zone, and the fin arrangement density is the highest, which effectively enhances the flow disturbance of coolant and the intensity of local turbulence, and significantly improves the convective heat transfer efficiency of the high-temperature heat dissipation zone. S4: Irregular cross-section matching, based on the differences in coolant flow rate, temperature and heat exchange requirements in each heat exchange zone, the cross-sectional shape of the fins is matched in zones; The upstream heat dissipation area uses circular cross-section fins, the midstream heat dissipation area uses elliptical cross-section fins, the downstream heat dissipation area uses rectangular or long rhomboid cross-section fins, and the high-temperature heat dissipation area uses teardrop-shaped cross-section fins, taking into account both overall flow resistance control and local heat transfer enhancement effect. S5: Assembly and cooling matching. The upper surface of the heat sink substrate, which has completed the pin forming and layout optimization, is flatly and attached to the bottom of the IGBT power module. No additional heat conduction medium is required between the heat sink substrate and the module. The pins are placed inside the sealed coolant channel, and ethylene glycol aqueous solution coolant with a preset temperature and preset flow rate is introduced into the channel to complete the assembly of the heat sink pin structure and the matching of the heat dissipation system.

[0012] In a preferred embodiment of the present invention, in step S1, the heat sink substrate is divided into an upstream heat dissipation area, a midstream heat dissipation area, and a downstream heat dissipation area along the flow direction. The upstream heat dissipation area has a length of 0-33.3 mm, the midstream heat dissipation area has a length of 33.3-66.6 mm, and the downstream heat dissipation area has a length of 66.6-100 mm. The high-temperature heat dissipation area is located in the middle of the downstream section, with a length of 70-90 mm, corresponding to the area directly below the IGBT chip, and has a size of 18 mm × 14 mm, avoiding the diode area, with a spacing of 8-12 mm.

[0013] In a preferred embodiment of the present invention, in step S3, the longitudinal pitch of the upstream heat dissipation zone is 2 mm, the longitudinal pitch of the midstream heat dissipation zone is 1.5 mm, the longitudinal pitch of the downstream heat dissipation zone is 1 mm, and the longitudinal pitch of the high-temperature heat dissipation zone is 0.75 mm.

[0014] In a preferred embodiment of the present invention, in step S3, the lateral pitch of the upstream heat dissipation zone is 2mm, the lateral pitch of the midstream heat dissipation zone is 1.5mm, the lateral pitch of the downstream heat dissipation zone is 1mm, and the lateral pitch of the high-temperature heat dissipation zone is 0.5mm. A small-angle forked arrangement of 30°-45° is adopted to enhance heat exchange.

[0015] In a preferred embodiment of the present invention, in step S5, the coolant is a 50% ethylene glycol aqueous solution with an inlet temperature of 60℃±2℃ and a flow rate of 3-5L / min, and is in a turbulent state.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

[0017] 1. By using a heat sink substrate, partitioned fin groups, and irregularly shaped cross-section fins, the heat exchange capacity and heat source distribution are precisely matched, effectively suppressing local hot spots, improving module temperature uniformity, reducing thermal stress damage, and extending the service life of IGBT modules. 2. By using variable pitch fork arrangement and gradient fin structure, the flow resistance and heat exchange efficiency are synergistically optimized, reducing coolant circulation energy consumption, improving the operating energy efficiency of the heat dissipation system, and simplifying the molding process to ensure structural stability and the feasibility of mass production. Attached Figure Description

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the main structure of the heat sink pins of an IGBT module for a new energy vehicle. Figure 2 A schematic diagram of the heat dissipation component structure in the heat sink fin structure of an IGBT module heat sink for a new energy vehicle. Figure 3 This is a schematic diagram of the upstream pin structure in the structure of the IGBT module heat sink pin of a new energy vehicle. Figure 4 This is a schematic diagram of the midstream fin structure of a heat sink fin for an IGBT module in a new energy vehicle. Figure 5 This is a schematic diagram of the downstream fin structure of a heat sink fin for an IGBT module in a new energy vehicle. Figure 6 This is a schematic diagram of the fin structure directly below the high-temperature chip in the heat sink of an IGBT module for a new energy vehicle. Figure 7 A schematic diagram of the cooling pool installation structure in the finned structure of an IGBT module radiator for a new energy vehicle. Figure 8 This is a top view schematic diagram of the cooling pool structure in the finned structure of an IGBT module heat sink for a new energy vehicle.

[0019] In the figure: radiator base plate 100, mounting groove 110, first sealing groove 120, sealing ring 130, upstream heat dissipation area 140, circular cross-section columnar fins 141, midstream heat dissipation area 150, elliptical cross-section columnar fins 151, downstream heat dissipation area 160, rectangular cross-section columnar fins 161, high temperature heat dissipation area 170, teardrop-shaped cross-section columnar fins 171, heat dissipation pool 200, second sealing groove 210, water inlet pipe 220, water outlet pipe 230. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0021] Example 1: As Figures 1-8 ,include: A rectangular heat sink substrate 100 has an upstream heat dissipation area 140, a midstream heat dissipation area 150, a downstream heat dissipation area 160, and a high-temperature heat dissipation area 170 at its bottom. The upstream heat dissipation area 140, the midstream heat dissipation area 150, and the downstream heat dissipation area 160 are arranged along the cooling water flow direction. The high-temperature heat dissipation area 170 is located directly below the corresponding IGBT chip on the heat sink substrate 100. The bottom of the upstream heat dissipation area 140, the midstream heat dissipation area 150, the downstream heat dissipation area 160, and the high-temperature heat dissipation area 170 are all integrally formed with an upstream fin group, a midstream fin group, a downstream fin group, and a high-temperature heat dissipation fin group. The heat dissipation pool 200 is sealed and fixedly installed on the bottom outer wall of the radiator base plate 100. The coolant is circulated inside the heat dissipation pool 200. The input end and output end of the heat dissipation pool 200 are respectively connected to the water inlet pipe 220 and the water outlet pipe 230. The upstream fin assembly, the midstream fin assembly, the downstream fin assembly and the high-temperature heat dissipation fin assembly are inserted into the heat dissipation pool 200 and come into contact with the coolant for heat exchange.

[0022] The specific application scenario of this embodiment is as follows: A new energy vehicle IGBT module is mounted on the top of a rectangular heat sink substrate 100. The bottom of the substrate is divided into an upstream heat dissipation area 140, a midstream heat dissipation area 150, and a downstream heat dissipation area 160 along the cooling water flow direction. A high-temperature heat dissipation area 170 is arranged directly below the corresponding IGBT chip on the substrate. The bottom of the four areas are respectively integrally formed with an upstream fin group, a midstream fin group, a downstream fin group, and a high-temperature heat dissipation fin group. A heat dissipation pool 200 is sealed and assembled on the bottom of the heat sink substrate 100. Coolant flows into the heat dissipation pool 200 through the inlet pipe 220 and fully contacts the four sets of fins extending into the flow channel to complete heat exchange, absorbing the heat from the IGBT module conducted by the heat sink substrate 100. After the heat exchange is completed, the coolant finally flows out from the outlet pipe 230 to form a coolant circulation and continuously dissipate heat from the IGBT module.

[0023] Example 2: Figure 1 and Figure 2 The upstream fin needle group is composed of multiple circular cross-section columnar fin needles 141 evenly arranged. The diameter of the fin needles in the upstream fin needle group is 2.2 mm, and the height H1 of the circular cross-section columnar fin needles 141 is 3.25 mm. The midstream wing needle group is composed of multiple elliptical cross-section columnar wing needles 151 arranged together. The ratio of the major axis to the minor axis of the elliptical cross-section of the columnar wing needle 151 in the midstream wing needle group is 5:3, the equivalent diameter is 1.8mm, and the height H2 of the elliptical cross-section columnar wing needle 151 is 3.75mm. The downstream fin group is composed of multiple rectangular cross-section columnar fins 161 arranged together. The equivalent diameter of the rectangular cross-section columnar fins 161 in the downstream fin group is 1.2 mm, and the height H3 of the rectangular cross-section columnar fins 161 is 4.25 mm. The high-temperature zone fin group is located in the downstream middle section, directly below the chip. It consists of multiple teardrop-shaped columnar fins 171 densely arranged. The equivalent diameter of the teardrop-shaped columnar fin 171 is 1.0 mm, and the height of the teardrop-shaped columnar fin 171 is 9.0 mm. The fin height of the teardrop-shaped columnar fin 171 is 0.5 mm to 1 mm higher than that of the fins in the same flow direction area. The fin height of each fin group forms a continuous gradient change, and the fin diameter decreases step by step to ensure that the heat exchange capacity of the coolant gradually increases during the flow process, offsetting the heat exchange capacity reduction caused by the increase in coolant temperature.

[0024] The specific application scenario of this embodiment is as follows: The IGBT module is positioned and installed in the mounting groove 110 on the top of the heat sink substrate 100. The first sealing groove 120 around the bottom of the heat sink substrate 100 is connected to the second sealing groove 210 around the top of the heat sink 200. A sealing ring 130 is embedded inside to achieve a sealed connection between the two, preventing the coolant in the heat sink 200 from leaking. The heat sink substrate 100 is made of high thermal conductivity oxygen-free copper material, which can quickly conduct the heat generated by the IGBT module. The fins in each area of ​​the bottom of the substrate adopt a gradient structure design. The upstream heat dissipation area 140 is equipped with an upstream fin group composed of circular cross-section columnar fins 141, the midstream heat dissipation area 150 is equipped with a midstream fin group composed of elliptical cross-section columnar fins 151, and the downstream heat dissipation area 160 is equipped with a downstream fin group composed of rectangular cross-section columnar fins 161, thus achieving high-temperature heat dissipation. Zone 170 is equipped with a high-temperature heat dissipation fin group composed of teardrop-shaped cross-section columnar fins 171. The diameter of the fins gradually decreases and the height gradually increases along the direction of coolant flow. At the same time, different porosities are set in each zone: 0.75-0.85 porosity in the upstream heat dissipation zone, 0.72-0.80 porosity in the midstream heat dissipation zone, and 0.70-0.78 porosity in the downstream heat dissipation zone. The high-temperature heat dissipation zone 170 has the lowest porosity of 0.65-0.70 and the highest fin density. As the coolant flows in the channel, the temperature gradually increases. The gradient fin structure can simultaneously improve the heat transfer capacity and offset the heat transfer attenuation caused by the increase in coolant temperature. The high-temperature heat dissipation zone 170 precisely covers the heat-generating core of the IGBT chip and avoids the FRD diode area. By relying on the high-density fins to increase the heat transfer area and enhance the fluid turbulence intensity, it effectively reduces the local temperature of the chip and suppresses the generation of hot spots.

[0025] Example 3: Figures 2-6 A method for optimizing the arrangement of fins in an IGBT module heat sink for new energy vehicles includes the following steps: S1: Regional division. Based on the heat transfer law of coolant flowing from low temperature end to high temperature end, and the non-uniform heat generation characteristics of IGBT chip and FRD diode chip inside IGBT module, the heat sink substrate is divided into three continuous heat exchange areas along the coolant flow direction: upstream heat exchange area 140, midstream heat exchange area 150, and downstream heat exchange area 160. Within the middle section of downstream heat exchange area 160, a high temperature heat exchange area 170 is independently defined for each IGBT chip's vertical projection position. The high temperature heat exchange area 170 precisely covers the heat generation core of the IGBT chip and does not extend to the area below the FRD diode, forming a zoned collaborative heat dissipation layout. S2: Gradient fin molding, the fin structure is made in one piece in each corresponding area on the lower surface of the heat sink substrate. Along the coolant flow direction, the fin diameter decreases step by step and the fin height increases step by step. Within the high-temperature heat dissipation zone 170, the diameter of the pins is further reduced, the height of the pins is increased, the density of the pin arrangement is increased, and the porosity of the area is reduced to form a structure with high local heat transfer capacity, which precisely matches the high heat flux density heat dissipation requirements of the IGBT chip. S3: Variable pitch forked arrangement, using an asymmetrical forked arrangement of fins with independent and gradual changes in longitudinal and transverse pitches. Both longitudinal and transverse pitches gradually decrease from the upstream heat dissipation area to the downstream heat dissipation area. Within the high-temperature heat dissipation zone 170, the minimum longitudinal pitch and minimum transverse pitch are adopted throughout the entire area, and the fin arrangement density is the highest, which effectively enhances the flow disturbance of coolant and the intensity of local turbulence, and significantly improves the convective heat transfer efficiency of the high-temperature heat dissipation zone. S4: Irregular cross-section matching, based on the differences in coolant flow rate, temperature and heat exchange requirements in each heat exchange zone, the cross-sectional shape of the fins is matched in zones; The upstream heat dissipation zone 140 uses circular cross-section fins, the midstream heat dissipation zone 150 uses elliptical cross-section fins, the downstream heat dissipation zone 160 uses rectangular or long rhomboid cross-section fins, and the high-temperature heat dissipation zone 170 uses teardrop-shaped cross-section fins, taking into account both overall flow resistance control and local heat exchange enhancement effect. S5: Assembly and cooling matching. The upper surface of the heat sink substrate, which has completed the pin forming and layout optimization, is flatly and attached to the bottom of the IGBT power module. No additional heat conduction medium is required between the heat sink substrate and the module. The pins are placed inside the sealed coolant channel, and ethylene glycol aqueous solution coolant with a preset temperature and preset flow rate is introduced into the channel to complete the assembly of the heat sink pin structure and the matching of the heat dissipation system.

[0026] The specific application scenario of this embodiment is as follows: The heat sink is fabricated and assembled using four optimization steps: partitioned design, gradient molding, variable pitch staggered arrangement, and irregular cross-section matching. First, combining the cooling fluid heating law with the non-uniform heating characteristics of the IGBT chip and FRD diode, the heat sink substrate 100 is divided into three heat exchange zones along the flow direction: upstream, midstream, and downstream. A separate high-temperature heat dissipation zone 170 is designated at the IGBT chip projection position in the downstream midstream section, matching different heat dissipation requirements. Second, each set of fins is integrally formed at the bottom of the substrate, with the fin diameter decreasing and the height increasing along the cooling fluid flow direction. In the high-temperature heat dissipation zone, the fins are further densified and the porosity reduced to adapt to the high heat flux density conditions of the IGBT chip. Finally, the fins are arranged in an asymmetrical staggered arrangement, with the longitudinal and transverse pitches from upstream to downstream. The flow pattern gradually shrinks, with the high-temperature heat dissipation zone 170 employing the smallest pitch across the entire area to enhance coolant disturbance and turbulence. Simultaneously, different cross-section fins are selected according to the regional flow characteristics: circular fins upstream, elliptical fins midstream, rectangular fins downstream, and teardrop fins in the high-temperature zone. This balances overall flow resistance control with localized heat transfer enhancement. Finally, the IGBT module is directly bonded to the upper surface of the radiator substrate 100 without additional heat transfer medium. Each set of fins is placed within the sealed flow channel of the heat dissipation pool 200, and coolant is introduced to form a circulation. Heat from the IGBT module is directly transferred to the radiator substrate and each set of fins. The coolant undergoes thorough heat exchange with the irregularly shaped, variable-pitch, and gradient-structured fins within the flow channel, achieving differentiated heat dissipation based on the heat load of different areas and completing the synergistic optimization of heat dissipation efficiency and flow resistance.

[0027] Example 4: Figures 2-8 In step S1, the heat sink substrate is divided into an upstream heat sink area 140, a midstream heat sink area 150 and a downstream heat sink area 160 along the flow direction. The upstream heat sink area 140 has a length of 0-33.3mm, the midstream heat sink area 150 has a length of 33.3-66.6mm, and the downstream heat sink area 160 has a length of 66.6-100mm. The high-temperature heat sink area 170 is located in the middle of the downstream section, with a length of 70-90mm, corresponding to the bottom of the IGBT chip, with a size of 18mm×14mm, avoiding the diode area, and a spacing of 8-12mm. In step S3, the longitudinal pitch of the upstream heat dissipation zone 140 is 2mm, the longitudinal pitch of the midstream heat dissipation zone 150 is 1.5mm, the longitudinal pitch of the downstream heat dissipation zone 160 is 1mm, and the longitudinal pitch of the high-temperature heat dissipation zone 170 is 0.75mm. In step S3, the lateral pitch of the upstream heat dissipation zone 140 is 2mm, the lateral pitch of the midstream heat dissipation zone 150 is 1.5mm, the lateral pitch of the downstream heat dissipation zone 160 is 1mm, and the lateral pitch of the high-temperature heat dissipation zone 170 is 0.5mm. A small-angle fork arrangement of 30°-45° is adopted to enhance heat exchange. In step S5, the coolant is a 50% ethylene glycol aqueous solution with an inlet temperature of 60℃±2℃ and a flow rate of 3-5L / min, and is in a turbulent state.

[0028] The specific application scenario of this embodiment is as follows: This structure is divided into regions according to standard dimensions. The upstream heat dissipation area 140 has a length of 0-33.3mm, the midstream heat dissipation area 150 has a length of 33.3-66.6mm, the downstream heat dissipation area 160 has a length of 66.6-100mm, and the high-temperature heat dissipation area 170 is located in the downstream mid-section of 70-90mm. The unit size is 18mm×14mm, precisely corresponding to the IGBT chip and avoiding the diode area. The pins are arranged in a small-angle staggered manner of 30°-45°. The pitch gradually decreases along the flow direction. The longitudinal pitch is 2mm upstream, 1.5mm midstream, 1mm downstream, and 0.75mm for the high-temperature heat dissipation area 170. The transverse pitch is 2mm upstream. The minimum pitch is 1.5mm in the middle section, 1mm in the downstream section, and 0.5mm in the high-temperature heat dissipation zone 170. The combination of the minimum pitch and the small-angle forked arrangement can significantly improve the fin arrangement density and fluid turbulence intensity in the high-temperature heat dissipation zone. The heat dissipation system is supplied with a 50% ethylene glycol aqueous solution as coolant, and the inlet temperature is controlled at 60℃±2℃ and the flow rate is 3-5L / min to keep the coolant in a stable turbulent state in the flow channel. The coolant enters the heat dissipation pool 200 through the inlet pipe 220, flows through the four major heat dissipation zones in sequence, and completes heat exchange with the fins of different specifications and arrangements before flowing out from the outlet pipe 230. The entire structure relies on precise dimensions, arrangement and cooling parameters to ensure that the IGBT module works within a reasonable temperature range for a long time.

[0029] The working principle of this invention is as follows: When used by those skilled in the art, the IGBT module of the new energy vehicle is directly assembled in the mounting groove 110 at the top of the radiator substrate 100. The substrate is made of high thermal conductivity oxygen-free copper material, which can quickly conduct the heat generated by the module. The bottom of the radiator substrate 100 is sealed with the heat sink 200 through the first sealing groove 120, the second sealing groove 210 and the sealing ring 130, which prevents coolant leakage. Combining the characteristics of the coolant gradually heating up along the flow direction and the non-uniform heating of the IGBT chip and the FRD diode, the bottom of the radiator substrate is divided into an upstream heat dissipation area 140, a midstream heat dissipation area 150 and a downstream heat dissipation area 160 along the cooling water flow direction. A high-temperature heat dissipation area 170 is set separately below the IGBT chip in the downstream middle section. The four areas are respectively integrally formed as an upstream fin group, a midstream fin group, a downstream fin group and a high-temperature heat dissipation fin group. Each group of fins adopts three major optimization designs: gradient structure, irregular cross section and variable pitch forked arrangement. The diameter of the fins gradually decreases and the height gradually increases along the coolant flow direction, and the porosity of the area gradually decreases. The upstream section uses circular cross-section columnar fins 141, the midstream section uses elliptical cross-section columnar fins 151, the downstream section uses rectangular cross-section columnar fins 161, and the high-temperature zone uses teardrop-shaped cross-section columnar fins 171. The longitudinal and transverse pitches of the fins continuously decrease from upstream to downstream. The high-temperature heat dissipation zone 170 adopts the smallest pitch across the entire area and a staggered arrangement with small angles of 30°-45°. A 50% ethylene glycol aqueous solution, used as the heat exchange medium, flows into the heat dissipation pool 200 through the inlet pipe 220, maintaining turbulent flow within the closed channel and sequentially contacting each group of fins for heat exchange. The gradient structure can offset the decrease in heat exchange capacity caused by the increase in coolant temperature. Differentiated cross-sections The pitch arrangement balances overall flow resistance and local heat exchange efficiency. The high-temperature heat dissipation zone 170 utilizes high-density, large-area teardrop-shaped pins to specifically enhance heat dissipation in high-heat-flux areas of the IGBT chip, suppressing local hot spots. The coolant after heat exchange flows out from the outlet pipe 230 and circulates repeatedly, continuously removing heat from the IGBT module. The entire structure achieves a precise match between heat source distribution, fluid characteristics, and pin structure, reducing coolant circulation energy consumption while improving the overall energy efficiency of the heat dissipation system, reducing module thermal stress, and extending service life. The one-piece molding structure has a simple process, strong stability, and can meet the requirements of mass production.

[0030] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A structure for the fins of a heat sink for an IGBT module in a new energy vehicle, characterized in that, include: A rectangular heat sink substrate (100) has an upstream heat sink area (140), a midstream heat sink area (150), a downstream heat sink area (160), and a high-temperature heat sink area (170) at its bottom. The upstream heat sink area (140), the midstream heat sink area (150), and the downstream heat sink area (160) are arranged along the direction of cooling water flow. The high-temperature heat sink area (170) is located directly below the IGBT chip on the heat sink substrate (100). The bottom of the upstream heat sink area (140), the midstream heat sink area (150), the downstream heat sink area (160), and the high-temperature heat sink area (170) are all integrally formed with an upstream fin group, a midstream fin group, a downstream fin group, and a high-temperature heat sink fin group. A heat dissipation pool (200) is sealed and fixedly installed on the bottom outer wall of the radiator base plate (100). Coolant is circulated inside the heat dissipation pool (200). The input end and output end of the heat dissipation pool (200) are respectively connected to the inlet pipe (220) and the outlet pipe (230). The upstream fin group, the midstream fin group, the downstream fin group and the high temperature heat dissipation fin group are inserted into the heat dissipation pool (200) and contact the coolant for heat exchange.

2. The structure of the heat sink fins for a new energy vehicle IGBT module according to claim 1, characterized in that, The top of the radiator substrate (100) is provided with an installation groove (110) for installing the IGBT module of the new energy vehicle. The bottom of the radiator substrate (100) is provided with a first sealing groove (120) on the outer wall around the perimeter. The top of the heat sink (200) is provided with a second sealing groove (210) on the outer wall around the perimeter. The inner walls of the first sealing groove (120) and the second sealing groove (210) are fitted together to install a sealing ring (130). The top and bottom of the sealing ring (130) are respectively fitted together with the first sealing groove (120) and the second sealing groove (210) to seal and fill.

3. The structure of the heat sink fins for a new energy vehicle IGBT module according to claim 2, characterized in that, The heat sink substrate (100) has a length of 100mm, a width of 80mm, and a thickness of 10mm. The heat sink substrate (100) is made of oxygen-free copper material C11000 with a purity greater than 99.95%. The thermal conductivity of the heat sink substrate (100) is greater than 380W / (m·K). The entire surface of the heat sink substrate (100) is polished and treated with anti-corrosion. The flatness tolerance of the upper surface of the heat sink substrate (100) is less than 0.02mm, and the verticality tolerance of each fin group on the lower surface of the heat sink substrate is less than 0.05mm.

4. The structure of the heat sink fins for a new energy vehicle IGBT module according to claim 3, characterized in that, The upstream fin needle group is composed of multiple circular cross-section columnar fin needles (141) evenly arranged. The diameter of the fin needles in the upstream fin needle group is 2.2 mm, and the height H1 of the circular cross-section columnar fin needles (141) is 3.25 mm. The midstream wing needle group is composed of multiple elliptical cross-section columnar wing needles (151) arranged together. The ratio of the major axis to the minor axis of the elliptical cross-section of the elliptical cross-section columnar wing needle (151) in the midstream wing needle group is 5:3, the equivalent diameter is 1.8 mm, and the height H2 of the elliptical cross-section columnar wing needle (151) is 3.75 mm. The downstream fin group is composed of multiple rectangular cross-section columnar fins (161) arranged together. The equivalent diameter of the rectangular cross-section columnar fins (161) in the downstream fin group is 1.2 mm, and the height H3 of the rectangular cross-section columnar fins (161) is 4.25 mm. The high-temperature zone fin group is located in the downstream middle section, directly below the chip. It consists of multiple teardrop-shaped columnar fins (171) arranged densely. The equivalent diameter of the teardrop-shaped columnar fins (171) is 1.0 mm, and the height of the teardrop-shaped columnar fins (171) is 9.0 mm. The fin height of the teardrop-shaped columnar fins (171) is 0.5 mm to 1 mm higher than that of the fins in the same flow direction area. The fin height of each fin group forms a continuous gradient change, and the fin diameter decreases step by step to ensure that the heat exchange capacity of the coolant gradually increases during the flow process, offsetting the heat exchange capacity reduction caused by the increase in coolant temperature.

5. The structure of the heat sink fins for a new energy vehicle IGBT module according to claim 4, characterized in that, The porosity of the upstream heat dissipation area where the upstream fin group is located is controlled between 0.75 and 0.85; the porosity of the midstream heat dissipation area where the midstream fin group is located is controlled between 0.72 and 0.80; the porosity of the downstream heat dissipation area where the downstream fin group is located is controlled between 0.70 and 0.78; and the porosity of the high-temperature heat dissipation area directly below the chip where the high-temperature fin group is located is controlled between 0.65 and 0.

70. The high-temperature heat dissipation area completely covers the heat-generating core of the IGBT chip, does not cover the diode area, and is located in the downstream middle section. The porosity of the high-temperature heat dissipation area is significantly lower than that of other heat exchange areas, resulting in a higher fin arrangement density, a larger heat exchange area, a faster local flow velocity, and stronger turbulence intensity in the high-temperature area. This significantly improves the convective heat transfer efficiency of the high-temperature heat dissipation area, effectively reduces the local temperature directly below the chip, and suppresses the formation of hot spots.

6. An optimized method for arranging the fins of a heat sink for an IGBT module in a new energy vehicle as described in any one of claims 1-5, characterized in that, Includes the following steps: S1: Regional division. Based on the heat transfer law of the coolant flowing from the low temperature end to the high temperature end, and the non-uniform heat generation characteristics of the IGBT chip and FRD diode chip inside the IGBT module, the heat sink substrate is divided into three continuous heat exchange areas along the coolant flow direction: upstream heat exchange area (140), midstream heat exchange area (150) and downstream heat exchange area (160). In the middle section of the downstream heat exchange area (160), a high temperature heat exchange area (170) is independently defined for each IGBT chip at its vertical projection position. The high temperature heat exchange area (170) precisely covers the heat generation core of the IGBT chip and does not extend to the area below the FRD diode, forming a zoned collaborative heat dissipation layout. S2: Gradient fin molding, the fin structure is made in one piece in each corresponding area on the lower surface of the heat sink substrate. Along the coolant flow direction, the fin diameter decreases step by step and the fin height increases step by step. Within the high-temperature heat dissipation zone (170), the diameter of the pins is further reduced, the height of the pins is increased, the density of the pin arrangement is increased, and the porosity of the area is reduced to form a structure with high local heat transfer capacity, which precisely matches the high heat flux density heat dissipation requirements of the IGBT chip. S3: Variable pitch forked arrangement, using an asymmetrical forked arrangement of fins with independent and gradual changes in longitudinal and transverse pitches. Both longitudinal and transverse pitches gradually decrease from the upstream heat dissipation area to the downstream heat dissipation area. Within the high-temperature heat dissipation zone (170), the minimum longitudinal pitch and minimum transverse pitch are used throughout the entire area, resulting in the highest density of fin arrangement. This effectively enhances the flow disturbance of the coolant and the intensity of local turbulence, significantly improving the convective heat transfer efficiency of the high-temperature heat dissipation zone. S4: Irregular cross-section matching, based on the differences in coolant flow rate, temperature and heat exchange requirements in each heat exchange zone, the cross-sectional shape of the fins is matched in zones; The upstream heat dissipation area (140) adopts circular cross-section fins, the midstream heat dissipation area (150) adopts elliptical cross-section fins, the downstream heat dissipation area (160) adopts rectangular or long rhomboid cross-section fins, and the high-temperature heat dissipation area (170) adopts teardrop-shaped cross-section fins, taking into account both overall flow resistance control and local heat exchange enhancement effect. S5: Assembly and cooling matching. The upper surface of the heat sink substrate, which has completed the pin forming and layout optimization, is flatly and attached to the bottom of the IGBT power module. No additional heat conduction medium is required between the heat sink substrate and the module. The pins are placed inside the sealed coolant channel, and ethylene glycol aqueous solution coolant with a preset temperature and preset flow rate is introduced into the channel to complete the assembly of the heat sink pin structure and the matching of the heat dissipation system.

7. The method for optimizing the arrangement of fins in a heat sink for an IGBT module in a new energy vehicle according to claim 6, characterized in that, In step S1, the heat sink substrate is divided into an upstream heat sink area (140), a midstream heat sink area (150) and a downstream heat sink area (160) along the flow direction. The upstream heat sink area (140) has a length of 0-33.3mm, the midstream heat sink area (150) has a length of 33.3-66.6mm, and the downstream heat sink area (160) has a length of 66.6-100mm. The high temperature heat sink area (170) is located in the middle of the downstream section, with a length of 70-90mm, corresponding to the bottom of the IGBT chip, with a size of 18mm×14mm, avoiding the diode area, and a spacing of 8-12mm.

8. The method for optimizing the arrangement of fins in a heat sink for an IGBT module in a new energy vehicle according to claim 7, characterized in that, In step S3, the longitudinal pitch of the upstream heat dissipation area (140) is 2mm, the longitudinal pitch of the midstream heat dissipation area (150) is 1.5mm, the longitudinal pitch of the downstream heat dissipation area (160) is 1mm, and the longitudinal pitch of the high-temperature heat dissipation area (170) is 0.75mm.

9. The method for optimizing the arrangement of fins in a heat sink for an IGBT module in a new energy vehicle according to claim 8, characterized in that, In step S3, the lateral pitch of the upstream heat dissipation area (140) is 2mm, the lateral pitch of the midstream heat dissipation area (150) is 1.5mm, the lateral pitch of the downstream heat dissipation area (160) is 1mm, and the lateral pitch of the high-temperature heat dissipation area (170) is 0.5mm. A small-angle fork arrangement of 30°-45° is adopted to enhance heat exchange.

10. The method for optimizing the arrangement of fins in a heat sink for an IGBT module in a new energy vehicle according to claim 9, characterized in that, In step S5, the coolant is a 50% ethylene glycol aqueous solution with an inlet temperature of 60℃±2℃ and a flow rate of 3-5L / min, and is in a turbulent state.

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