Radiator capable of locally enhancing heat exchange capability and power module comprising same

Abstract

The utility model provides a radiator with locally enhanced heat exchange capability and a power module comprising the radiator. According to the radiator, the internal space of a shell is divided into a main cavity with an opening in the top end, and a cooling liquid inflow channel and a cooling liquid outflow channel which are communicated with the main cavity; the heat dissipation plate covers the opening end of the main chamber to form a heat dissipation chamber; the heat dissipation plate is used for bearing the substrate, and the substrate is used for bearing the power chip; a first area matched with the opening end of the main cavity is arranged on the lower surface of the heat dissipation plate, heat dissipation bosses are arranged at the positions, vertically opposite to the power chips, of the first area, and a plurality of first heat dissipation pin fins are arranged on the lower surface of each heat dissipation boss; a plurality of second heat dissipation pin fins are arranged on the part, except the heat dissipation boss, of the first area; a filling body is arranged at each position, vertically opposite to the heat dissipation boss, on the upper surface of the bottom plate of the shell, and the filling bodies are low-hardness bodies and used for filling gaps between the first heat dissipation pin fins and the bottom plate. The power module comprises the radiator. According to the utility model, the local heat exchange capability of the radiator can be improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of power module heat dissipation, more particularly, a local heat exchange capacity enhanced radiator and the power module containing it. BACKGROUND

[0002] In recent years, with the continuous improvement of application end demand, power module gradually develops towards high voltage and large current. However, the working condition of high voltage and large current can cause the heat generation of power module to increase, and with the rise of the temperature of power module, the performance of power module will correspondingly decrease, especially when the temperature of power module exceeds the set upper limit value, it is easy to cause the damage of power module, which affects its service life. Therefore, optimizing the heat exchange capacity of power module plays a vital role in ensuring the overall performance and service life of power module.

[0003] In the related art, a kind of power module generally uses needle fin type radiator, its schematic structure is as shown in Figure 1 As shown in Figure 1 , the radiator includes a radiator main body and a radiator shell, the radiator main body includes a heat dissipation plate and a plurality of heat dissipation needle fins arranged on the lower surface of the heat dissipation plate. The internal space of the radiator shell is divided into a main cavity with a top opening, and a cooling liquid inflow channel and a cooling liquid outflow channel in communication with the main cavity, and the heat dissipation plate is arranged on the top plate of the radiator shell and covers the opening end of the main cavity to form a heat dissipation cavity. The heat dissipation plate is used to carry a predetermined number of copper-clad ceramic substrates, and the copper-clad ceramic substrates are used to carry a predetermined number of power chips, and a package body cover is arranged on the upper surface of the heat dissipation plate to cover the copper-clad ceramic substrates and power chips therein.

[0004] For the above schematic structure, a series of heat dissipation needle fins arranged on the surface of the heat dissipation plate in contact with the cooling liquid are intended to improve the degree of turbulence of the cooling liquid and increase the contact area between the radiator main body and the cooling liquid, thereby enhancing the heat dissipation capacity of the radiator. However, due to the machining error of the heat dissipation needle fins, in order to facilitate the assembly of the radiator main body and the radiator shell, a gap of 0.2-0.5mm is reserved between the heat dissipation needle fins and the upper surface of the bottom plate of the radiator shell, and part of the cooling liquid will flow out of the heat dissipation cavity directly through the gap and does not participate in heat exchange, thereby affecting the heat exchange capacity of the radiator, and indirectly causing the temperature of the power chip to rise.

[0005] In addition, heat generated by the power chip during operation will generate heat diffusion phenomenon in the process of being transferred to the heat sink through the copper clad ceramic substrate, but due to the influence of thermal resistance, the heat generated by the power chip can only be diffused to a certain range of the heat sink, that is, most of the heat generated by the power chip is exchanged into the cooling liquid through the main heat dissipation part of the heat sink which is opposite to the power chip and the peripheral area of the main heat dissipation part defined by the heat diffusion angle. However, the heat sink adopted by the above-mentioned power module does not increase the contact area between the corresponding position of the heat sink and the cooling liquid based on the position of the power chip and the heat diffusion angle of the chip heat, which leads to the relatively insufficient effective heat transfer area of the heat sink and the weak heat exchange capacity with the cooling liquid, thereby causing the temperature of the power chip to be relatively high. Content of the utility model

[0006] Therefore, the utility model provides a heat sink with locally enhanced heat exchange capacity and a power module comprising the same.

[0007] According to the first aspect of the utility model, a heat sink with locally enhanced heat exchange capacity is provided, which comprises a heat sink and a shell.

[0008] The internal space of the shell is divided into a top-end-opened main cavity and a cooling liquid inflow channel and a cooling liquid outflow channel which are in communication with the main cavity, and the cooling liquid inflow channel and the cooling liquid outflow channel are oppositely arranged in the first direction.

[0009] The heat sink is arranged on the top plate of the shell and covers the open end of the main cavity, so as to form a heat dissipation cavity.

[0010] The heat sink is applied to a power module, the heat sink is used for carrying a predetermined number of substrates, and the substrates are used for carrying a predetermined number of power chips.

[0011] The lower surface of the heat sink has a first area which matches the open end of the main cavity, a heat dissipation boss is arranged at each position on the first area which is opposite to the power chip in the up-down direction, a plurality of first heat dissipation needle fins are arranged on the lower surface of each heat dissipation boss, and a plurality of second heat dissipation needle fins are arranged on the part of the first area other than the heat dissipation boss.

[0012] A filling body is arranged at each position on the upper surface of the bottom plate of the shell which is opposite to the heat dissipation boss in the up-down direction, the filling body is a low-hardness body relative to the first heat dissipation needle fins and the shell, and is used for filling the gap between the first heat dissipation needle fins and the bottom plate.

[0013] The second heat dissipation needle fins have a gap with the bottom plate.

[0014] Optionally, a separate heat dissipation boss is arranged below each power chip.

[0015] Alternatively, for all the power chips contained in the power module, if several power chips form a linear array along a second direction, a long strip-shaped heat dissipation boss is arranged below the linear array.

[0016] The second direction is perpendicular to the first direction.

[0017] Optionally, a separate filling body is arranged below each power chip.

[0018] Alternatively, for all the power chips contained in the power module, if several power chips form a linear array along a second direction, a long strip-shaped filling body is arranged below the linear array.

[0019] The second direction is perpendicular to the first direction.

[0020] Optionally, the cross section of the filling body is isosceles trapezoid, the upper base of the isosceles trapezoid is 1.5-2 times the length of the power chip in the first direction, the included angle between the lower base and the waist of the isosceles trapezoid is 30-60 degrees, and the height of the isosceles trapezoid is equal to the gap between the first heat dissipation pin fin and the bottom plate of the shell.

[0021] The lower base of the isosceles trapezoid is connected to the bottom plate of the shell.

[0022] Optionally, the cross section of the heat dissipation boss is a minor arc shape.

[0023] The vertical projection point of the centroid of the corresponding power chip of the heat dissipation boss on the plane of the cross section of the heat dissipation boss coincides with the center of the minor arc shape.

[0024] The chord length expression of the minor arc shape is:

[0025] L1=a+h*tanα

[0026] In the above formula, L1 is the chord length of the minor arc shape, a is the length of the power chip in the first direction, h is the sum of the thickness of the substrate and the heat dissipation plate, and α is the thermal diffusion angle of heat transfer below the power chip.

[0027] The chord of the minor arc shape is connected to the heat dissipation plate.

[0028] Optionally, the filling body has a cross section in the shape of an isosceles trapezoid with an outwardly expanding arc waist, the upper base of the isosceles trapezoid is 1.5-2 times the length of the power chip in the first direction, the lower base of the isosceles trapezoid is 2-2.5 times the length of the power chip in the first direction, and the height of the isosceles trapezoid is equal to the gap between the first radiating pin fin and the bottom plate of the shell.

[0029] The lower base of the isosceles trapezoid is in contact with the bottom plate of the shell.

[0030] Optionally, the radiating boss has a cross section in the shape of an isosceles trapezoid with an outwardly expanding arc waist, and the length of the lower base of the isosceles trapezoid is expressed as:

[0031] L2 = a + h*tanα

[0032] In the above formula, L2 is the length of the lower base of the isosceles trapezoid, a is the length of the power chip in the first direction, h is the sum of the thicknesses of the substrate and the radiating plate, and α is the thermal diffusion angle of heat transfer below the power chip.

[0033] The length of the upper base of the isosceles trapezoid is 0.7-0.8L2.

[0034] The lower base of the isosceles trapezoid is in contact with the radiating plate.

[0035] Optionally, the length of the cooling liquid inflow passage in the second direction is equal to the length of the cooling liquid outflow passage in the second direction.

[0036] The length of the cooling liquid inflow passage in the second direction is less than the length of the radiating chamber in the second direction.

[0037] The second direction is perpendicular to the first direction.

[0038] Optionally, the portion of the upper surface of the bottom plate of the shell corresponding to the first area forms a boss.

[0039] The height of the cooling liquid inflow passage is equal to the height of the cooling liquid outflow passage.

[0040] The height of the cooling liquid inflow passage is greater than the height of the radiating chamber.

[0041] According to a second aspect of the present application, a power module is provided, which comprises any one of the radiators with locally enhanced heat exchange capacity.

[0042] The power module further comprises:

[0043] A predetermined number of substrates are arranged on the upper surface of the heat dissipation plate, and a predetermined number of power chips are arranged on the substrates;

[0044] A package is arranged on the upper surface of the heat dissipation plate to cover the substrates and the power chips.

[0045] The heat dissipation device has the advantages that:

[0046] The heat dissipation device has the advantages that: on one hand, the lower surface of the heat dissipation plate has a first area matched with the opening end of the main cavity, and a heat dissipation boss is arranged at each position on the first area corresponding to the upper and lower positions of the power chip, so that the effective heat transfer area between the heat dissipation plate below the power chip and the cooling liquid is effectively increased, and the heat exchange capacity of the heat dissipation device is improved; on the other hand, a filling body is arranged at each position on the upper surface of the bottom plate of the shell corresponding to the upper and lower positions of the heat dissipation boss, so as to fill the gap between the first heat dissipation needle fin and the bottom plate, thereby avoiding the cooling liquid below the power chip from flowing out of the heat dissipation cavity through the gap between the first heat dissipation needle fin and the bottom plate, improving the convective heat transfer coefficient between the first heat dissipation needle fin below the power chip and the cooling liquid, and improving the heat exchange capacity of the heat dissipation device; at the same time, the filling body is a low-hardness body relative to the first heat dissipation needle fin and the shell, and since the hardness of the filling body is lower than that of the first heat dissipation needle fin and the shell, the assembly of the heat dissipation device is not affected; on the other hand, due to the joint action of the heat dissipation boss and the filling body, the longitudinal section of part of the heat dissipation cavity below the power chip is narrowed, so that the flow rate of the cooling liquid at this position is increased, and the convective heat transfer coefficient between the heat dissipation plate and the first heat dissipation needle fin of the corresponding part and the cooling liquid is further improved, thereby improving the heat exchange capacity of the heat dissipation device.

[0047] The power module comprises the heat dissipation device, and has the same advantages as the heat dissipation device.

[0048] Other features and advantages of the present application will be described in detail in the following specific embodiment part. BRIEF DESCRIPTION OF DRAWINGS

[0049] The present application can be better understood by referring to the following description made in conjunction with the accompanying drawings, in which like or similar numerals designate the same or similar parts throughout all the drawings.

[0050] Figure 1 A structure schematic view of a power module in the related art according to the background technology of the present application is shown;

[0051] Figure 2A structure schematic diagram of a local heat exchange capacity enhanced radiator is shown according to an embodiment of the present application.

[0052] Figure 3 A local structure schematic diagram of a local heat exchange capacity enhanced radiator is shown according to an embodiment of the present application.

[0053] Figure 4 A local structure schematic diagram of another local heat exchange capacity enhanced radiator is shown according to an embodiment of the present application.

[0054] Figure 5 A local structure schematic diagram of still another local heat exchange capacity enhanced radiator is shown according to an embodiment of the present application.

[0055] Figure 6 A distribution schematic diagram of a filling body is shown according to an embodiment of the present application.

[0056] Figure 7 Another distribution schematic diagram of a filling body is shown according to an embodiment of the present application.

[0057] Figure 8 A structure schematic diagram of a power module is shown according to an embodiment of the present application. DETAILED DESCRIPTION

[0058] In order to enable a person skilled in the art to more fully understand the technical solutions of the present application, in the following, exemplary embodiments of the present application will be described more fully and in detail with reference to the accompanying drawings. Obviously, the embodiments of the present application described below are only one or more of the specific manners of implementing the technical solutions of the present application, and are not exhaustive. It should be understood that the technical solutions of the present application can be implemented in other manners belonging to the general inventive concept without creative labor, and should not be limited by the exemplary described embodiments. Based on one or more embodiments of the present application, all other embodiments obtained by a person skilled in the art without creative labor should belong to the scope of protection of the present application.

[0059] Embodiment: Figure 2 A structure schematic diagram of a local heat exchange capacity enhanced radiator is shown according to an embodiment of the present application. Referring to Figure 2 , the local heat exchange capacity enhanced radiator of the embodiment of the present application comprises a heat dissipation plate 110 and a shell 200;

[0060] The internal space of the shell 200 is divided into a top-end-opened main chamber 210, and a cooling liquid inflow channel 220 and a cooling liquid outflow channel 230 communicated with the main chamber 210, the cooling liquid inflow channel 220 and the cooling liquid outflow channel 230 are oppositely arranged in a first direction;

[0061] The heat dissipation plate 110 is arranged on the top plate of the shell 200 and covers the open end of the main chamber 210, so that the main chamber 210 forms a heat dissipation chamber;

[0062] The heat dissipation plate 110 is arranged on the top plate of the shell 200 and covers the open end of the main chamber 210, so that the main chamber 210 forms a heat dissipation chamber;

[0063] The lower surface of the heat dissipation plate 110 has a first area matched with the open end of the main chamber 210, a heat dissipation boss 120 is arranged at each position opposite to the power chip in the first area, a plurality of first heat dissipation needle fins 130 are arranged on the lower surface of each heat dissipation boss 120, and a plurality of second heat dissipation needle fins 140 are arranged on the part of the first area except the heat dissipation boss 120;

[0064] A filling body 300 is arranged at each position opposite to the heat dissipation boss 120 on the upper surface of the bottom plate of the shell 200, the filling body 300 is a low-hardness body relative to the first heat dissipation needle fin 130 and the shell 200, and is used for filling the gap between the first heat dissipation needle fin 130 and the bottom plate of the shell 200;

[0065] The second heat dissipation needle fin 140 has a gap with the bottom plate of the shell 200.

[0066] Specifically, in the embodiment of the utility model, the filling body 300 is made of soft alloy or rubber or other corrosion-resistant materials.

[0067] Further, Figure 3 A partial structure schematic diagram of the heat dissipation device with locally enhanced heat exchange capacity is shown, wherein, 400 is a substrate, and 500 is a power chip. Figure 3 In the embodiment of the utility model, the cross section of the filling body 300 is isosceles trapezoid A, the upper base of the isosceles trapezoid A is 1.5-2 times the length of the power chip in the first direction, the included angle between the lower base and the waist of the isosceles trapezoid A is 30-60 degrees, the height of the isosceles trapezoid A is equal to the gap between the first heat dissipation needle fin 130 and the bottom plate of the shell 200, and the lower base of the isosceles trapezoid A is connected with the bottom plate of the shell 200.

[0068] Further, Figure 3 In the embodiment of the utility model, the cross section of the heat dissipation boss 120 is inferior arc shape;

[0069] The vertical projection point of the centroid of the power chip corresponding to the heat dissipation boss 120 on the plane where the cross section of the heat dissipation boss 120 is located coincides with the center of the arc of inferiority;

[0070] The chord length expression of the arc of inferiority is:

[0071] L1=a+h*tan alpha

[0072] In the above formula, L1 is the chord length of the arc of inferiority;

[0073] a is the length of the power chip in the first direction, ranging from 4 to 10 mm;

[0074] h is the sum of the thicknesses of the substrate 400 and the heat dissipation plate 110, ranging from 4 to 5 mm;

[0075] alpha is the thermal diffusion angle of heat transfer below the power chip, ranging from 30 to 60 degrees;

[0076] The chord of the arc of inferiority is connected with the heat dissipation plate 110.

[0077] Further, Figure 4 A partial structure schematic view of another heat dissipation device with locally enhanced heat exchange capacity is shown. Figure 4 As an optional implementation, in the embodiment of the present application, the cross section of the filling body 300 is a similar isosceles trapezoid B with an outwardly expanding arc waist, the upper base of the similar isosceles trapezoid B is 1.5-2 times the length of the power chip in the first direction, the lower base of the similar isosceles trapezoid B is 2-2.5 times the length of the power chip in the first direction, and the height of the similar isosceles trapezoid B is equal to the gap between the first heat dissipation pin fin 130 and the bottom plate of the shell 200.

[0078] The lower base of the similar isosceles trapezoid B is connected with the bottom plate of the shell 200.

[0079] Further, Figure 5 A partial structure schematic view of another heat dissipation device with locally enhanced heat exchange capacity is shown. Figure 5 As an optional implementation, in the embodiment of the present application,

[0080] The cross section of the heat dissipation boss 120 is a similar isosceles trapezoid C with an outwardly expanding arc waist, and the length expression of the lower base of the similar isosceles trapezoid C is:

[0081] L2=a+h*tan alpha

[0082] In the above formula, L2 is the length of the lower base of the similar isosceles trapezoid C;

[0083] a is the length of the power chip in the first direction, ranging from 4 to 10 mm;

[0084] h is the sum of the thickness of the substrate 400 and the heat sink 110, ranging from 4 to 5 mm;

[0085] α is the heat diffusion angle of heat transfer below the power chip, ranging from 30 to 60 degrees;

[0086] The length of the upper base of the isosceles trapezoid C is 0.7-0.8L2;

[0087] The lower base of the isosceles trapezoid C is in contact with the heat sink 110.

[0088] Further, in the embodiment of the utility model, the power module comprises a plurality of power chips, and the plurality of power chips form a rectangular array;

[0089] An independent heat dissipation boss 120 is correspondingly arranged below each power chip, and the plurality of heat dissipation bosses 120 form a corresponding rectangular array.

[0090] Further, as an optional implementation, in the embodiment of the utility model, the power module comprises a plurality of power chips, and the plurality of power chips form a rectangular array, wherein the rectangular array comprises a plurality of columns of power chips arranged along a second direction, and the second direction is perpendicular to the first direction;

[0091] A long strip-shaped heat dissipation boss 120 is correspondingly arranged below each column of power chips.

[0092] Further, Figure 6 A distribution diagram of the filling body in the embodiment of the utility model is shown. Figure 6 In the embodiment of the utility model, the power module comprises a plurality of power chips, and the plurality of power chips form a rectangular array;

[0093] An independent filling body 300 is correspondingly arranged below each power chip, and the plurality of filling bodies 300 form a corresponding rectangular array.

[0094] Further, Figure 7 Another distribution diagram of the filling body in the embodiment of the utility model is shown. Figure 7 As an optional implementation, in the embodiment of the utility model, the power module comprises a plurality of power chips, and the plurality of power chips form a rectangular array, wherein the rectangular array comprises a plurality of columns of power chips arranged along a second direction, and the second direction is perpendicular to the first direction;

[0095] A long strip-shaped filling body 300 is correspondingly arranged below each column of power chips.

[0096] Further, in the embodiment of the utility model, the length of the cooling liquid inflow channel 220 in the second direction is equal to the length of the cooling liquid outflow channel 230 in the second direction.

[0097] The length of the cooling liquid inflow passage 220 in the second direction is less than the length of the heat dissipation chamber in the second direction;

[0098] The second direction is perpendicular to the first direction;

[0099] The part of the upper surface of the bottom plate of the shell 200 corresponding to the first area forms a boss;

[0100] The height of the cooling liquid inflow passage 220 is equal to the height of the cooling liquid outflow passage 230;

[0101] The height of the cooling liquid inflow passage 220 is greater than the height of the heat dissipation chamber.

[0102] Correspondingly, on the basis of the heat sink for locally enhancing the heat exchange capacity of the embodiment of the utility model, the utility model embodiment still proposes a power module containing the heat sink.

[0103] Figure 8 The structure schematic diagram of the power module of the embodiment of the utility model is shown. Figure 8 In addition to comprising the heat sink for locally enhancing the heat exchange capacity as described above, the power module of the embodiment of the utility model still comprises:

[0104] A predetermined number of substrates 400 are arranged on the upper surface of the heat dissipation plate 110, and a predetermined number of power chips 500 are arranged on the substrate 400;

[0105] An encapsulant 600 is arranged on the upper surface of the heat dissipation plate 110 to cover the substrate 400 and the power chip 500 therein.

[0106] A silica gel layer 700 is formed in the idle part of the space enclosed by the encapsulant 600 and the heat dissipation plate 110 except the substrate 400 and the power chip 500.

[0107] Specifically, in the embodiment of the utility model, the substrate 400 is a copper-clad ceramic substrate and is fixedly arranged on the heat dissipation plate 110 through a sintering process; the power chip 500 is fixedly arranged on the substrate 400 through a sintering or welding process; the encapsulant 600 is used for protecting the internal components of the power module and plays an external insulation role, and the encapsulant 600 is fixedly connected with the heat dissipation plate 110 through a bolt; the silica gel layer 700 is used for protecting the internal components of the power module and plays an electrical insulation role; the filler 300 is pasted on the upper surface of the bottom plate of the shell 200 through waterproof glue; and the heat dissipation plate 110 is fixedly connected with the shell 200 through a bolt.

[0108] Although one or more embodiments of the present application have been described above with a certain degree of particularity, one skilled in the art could make numerous alterations to the details disclosed herein without departing from the spirit and scope of the present application. Accordingly, the protective scope of the present application should be defined only by the appended claims rather than by the above description.

Claims

1. A heat sink for locally enhancing heat exchange capacity, characterized in that, The heat sink comprises a heat dissipation plate and a shell; An inner space of the shell is divided into a top-open main cavity and a cooling liquid inflow channel and a cooling liquid outflow channel communicated with the main cavity, the cooling liquid inflow channel and the cooling liquid outflow channel are oppositely arranged in a first direction; The heat dissipation plate is arranged on a top plate of the shell and covers an open end of the main cavity to form a heat dissipation cavity; The heat sink is applied to a power module, the heat dissipation plate is used for carrying a predetermined number of substrates, and the substrates are used for carrying a predetermined number of power chips; A first area matching the open end of the main cavity is arranged on a lower surface of the heat dissipation plate, a heat dissipation boss is arranged at each position opposite to the power chip in a vertical direction, a first heat dissipation needle fin is arranged on a lower surface of each heat dissipation boss, and a plurality of second heat dissipation needle fins are arranged on a part of the first area except the heat dissipation boss; A filling body is arranged at each position opposite to the heat dissipation boss in the vertical direction on an upper surface of a bottom plate of the shell, the filling body is a low-hardness body relative to the first heat dissipation needle fin and the shell, and is used for filling a gap between the first heat dissipation needle fin and the bottom plate; The second heat dissipation needle fin has a gap relative to the bottom plate.

2. The locally enhanced heat transfer capability heat sink of claim 1, wherein, An independent heat dissipation boss is arranged below each power chip; Alternatively, for all the power chips included in the power module, if a plurality of power chips form a linear array in a second direction, a long strip-shaped heat dissipation boss is arranged below the linear array; The second direction is perpendicular to the first direction.

3. The locally enhanced heat transfer capability heat sink of claim 1, wherein, An independent filling body is arranged below each power chip; Alternatively, for all the power chips included in the power module, if a plurality of power chips form a linear array in a second direction, a long strip-shaped filling body is arranged below the linear array; The second direction is perpendicular to the first direction.

4. The locally enhanced heat transfer capability heat sink of claim 1, wherein, A cross section of the filling body is isosceles trapezoidal, an upper base of the isosceles trapezoid is 1.5-2 times a length of the power chip in the first direction, an included angle between a lower base and a leg of the isosceles trapezoid is 30-60 degrees, and a height of the isosceles trapezoid is equal to a gap between the first heat dissipation needle fin and the bottom plate of the shell; The lower base of the isosceles trapezoid is connected with the bottom plate of the shell.

5. The locally enhanced heat transfer capability heat sink of claim 1, wherein, A cross section of the heat dissipation boss is a poor arc shape; A vertical projection point of a centroid of the corresponding power chip on a plane where the cross section of the heat dissipation boss is located is coincident with a center of the poor arc shape; An expression of a chord length of the poor arc shape is: L1=a+h*tanα In the expression, L1 is the chord length of the poor arc shape, a is the length of the power chip in the first direction, h is a sum of thicknesses of the substrate and the heat dissipation plate, and α is a heat diffusion angle of heat transfer below the power chip; The chord of the poor arc shape is connected with the heat dissipation plate.

6. The locally enhanced heat transfer capability heat sink of claim 1, wherein, The cross section of the filling body is a trapezoid with an outwardly expanding arc waist, the upper base of the trapezoid is 1.5-2 times the length of the power chip in the first direction, the lower base of the trapezoid is 2-2.5 times the length of the power chip in the first direction, and the height of the trapezoid is equal to the gap between the first radiating pin fin and the bottom plate of the shell. The lower base of the trapezoid is in contact with the bottom plate of the shell.

7. The locally enhanced heat transfer capability heat sink of claim 1, wherein, The cross section of the radiating boss is a trapezoid with an outwardly expanding arc waist, and the length of the lower base of the trapezoid is expressed as: L2=a+h*tanα In the above formula, L2 is the length of the lower base of the trapezoid, a is the length of the power chip in the first direction, h is the sum of the thickness of the substrate and the radiating plate, and α is the heat diffusion angle of heat transfer below the power chip. The length of the upper base of the trapezoid is 0.7-0.8L2. The lower base of the trapezoid is in contact with the radiating plate.

8. The locally enhanced heat transfer capability heat sink of claim 1, wherein, The length of the cooling liquid inflow channel in the second direction is equal to the length of the cooling liquid outflow channel in the second direction. The length of the cooling liquid inflow channel in the second direction is less than the length of the radiating chamber in the second direction. The second direction is perpendicular to the first direction.

9. The locally enhanced heat transfer capability heat sink of claim 8, wherein, The portion of the upper surface of the bottom plate of the shell corresponding to the first area forms a boss; The height of the cooling liquid inflow channel is equal to the height of the cooling liquid outflow channel. The height of the cooling liquid inflow channel is greater than the height of the radiating chamber.

10. A power module, characterized by The heat sink with locally enhanced heat exchange capacity according to any one of claims 1-9; The power module further comprises: a predetermined number of substrates, the substrates being arranged on the upper surface of the radiating plate, and a predetermined number of power chips being arranged on the substrates; an encapsulating body covering the upper surface of the radiating plate to encapsulate the substrates and the power chips therein.

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