High-power-density hollow heat dissipation power module and packaging method thereof

Abstract

The invention relates to a high-power-density hollow heat dissipation power module and a packaging method thereof, the power module comprises a hollow ceramic plate, a first chip, a second chip, a first metal clamp, a second metal clamp and a plastic package body, and the side surface of the hollow ceramic plate is provided with heat dissipation holes. The hollow ceramic plate is adopted, heat generated during operation of the first chip and the second chip can be directly transmitted to the hollow ceramic plate, the heat dissipation holes are formed in the side face of the hollow ceramic plate and exposed out of the plastic package body, the heat dissipation holes can rapidly dissipate the heat, the heat transfer path is greatly shortened, temperature rise of the center of the power module is rapidly reduced, and the service life of the power module is prolonged. If air is blown towards the heat dissipation holes or a cooling medium is led in, the heat dissipation performance is better, the reliability is higher, and the service life is longer; the first chip and the second chip are directly welded on the hollow ceramic plate, and electrode connection is realized by using the metal clamp, so that the over-current capability is strong, the power density is larger, and the performance is better; and meanwhile, the assembling process is simple and efficient, the size is smaller, fewer materials are used, and the cost is better.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor packaging, and in particular to a high-power-density hollow heat-dissipating power module and a packaging method thereof. Background Art

[0002] IGBT / MOSFET power modules are widely used in various energy fields, especially new energy vehicles. When the power modules are running at high power and high current, the chips inside the power modules will generate a lot of heat, which must be dissipated in time. Otherwise, the chip temperature will rise too high, resulting in unstable chip performance and even direct damage and failure of the chip.

[0003] In the existing technology, high-thermal-conductivity double-sided copper-clad ceramic plates are generally used to connect chips. Double-sided copper-clad ceramic plates not only have stable and reliable circuit functions, but can also carry large currents, while also having high heat dissipation performance and rapid heat conduction and heat dissipation. For example, the Chinese invention patent application with publication number CN114242699A, entitled "A High-Power-Density Ultra-Heat-Dissipating Chip Symmetrical Stacking Package Structure and Its Packaging Method," has multiple chips stacked one above the other in the power module, located in the middle of the double-sided copper-clad ceramic plate. The heat source is concentrated in the center, requiring gradual heat transfer outward. The heat transfer path is long, and there is still room for improvement in heat dissipation efficiency. In addition, the use of a large number of metal pads makes the assembly process slightly complicated, making it difficult to meet the high reliability and high stability requirements of downstream products, which needs to be improved. Summary of the Invention

[0004] The present invention provides a high-power density hollow heat dissipation power module and a packaging method thereof, which has the advantages of better heat dissipation, higher reliability, and longer service life. At the same time, the assembly process is simpler and more efficient, the power module is smaller in size, uses less material, and has better cost.

[0005] The technical solution provided by the present invention is: a high power density hollow heat dissipation power module, comprising a hollow ceramic plate, a first chip, a second chip, a first metal clip, a second metal clip and a plastic package, wherein the side of the hollow ceramic plate is provided with heat dissipation holes;

[0006] The first chip and the second chip each include a first electrode and a second electrode located on the front side, and a third electrode located on the back side;

[0007] The front of the hollow ceramic board is provided with a first front copper-clad circuit, a second front copper-clad circuit and a third front copper-clad circuit, the first front copper-clad circuit extends a first pin outward or is welded with a first pin, the second front copper-clad circuit extends a second pin outward or is welded with a second pin, and the third front copper-clad circuit extends a third pin outward or is welded with a third pin; the back of the hollow ceramic board is provided with a first back copper-clad circuit, a second back copper-clad circuit and a third back copper-clad circuit, and the side of the hollow ceramic board is provided with a first side copper-clad circuit, a second side copper-clad circuit and a third side copper-clad circuit; the first back copper-clad circuit is connected to the first front copper-clad circuit through the first side copper-clad circuit; the second back copper-clad circuit is connected to the second front copper-clad circuit through the second side copper-clad circuit, and the third back copper-clad circuit is connected to the third front copper-clad circuit through the third side copper-clad circuit;

[0008] The first chip is flip-chip mounted on the front surface of the hollow ceramic board, the first electrode of the first chip is electrically connected to the first front copper-clad circuit, the second electrode of the first chip is electrically connected to the second front copper-clad circuit, and the third electrode of the first chip is electrically connected to the third front copper-clad circuit via a first metal clip;

[0009] The second chip is flip-chip mounted on the back of the hollow ceramic board, the first electrode of the second chip is electrically connected to the first back copper-clad circuit, the second electrode of the second chip is electrically connected to the second back copper-clad circuit, and the third electrode of the second chip is electrically connected to the third back copper-clad circuit via a second metal clip;

[0010] The plastic package is used to wrap the hollow ceramic plate, the first chip, the second chip, the first metal clip and the second metal clip, and expose the heat dissipation holes.

[0011] Among them, the first chip and the second chip are both field effect transistors, the first pole is the D pole, the second pole is the G pole, and the third pole is the S pole; or the first chip and the second chip are both IGBTs, the first pole is the E pole, the second pole is the G pole, and the third pole is the C pole.

[0012] The power module includes multiple groups of first chips and second chips, which are arranged horizontally in parallel, and multiple first chips and second chips are arranged in parallel.

[0013] The first chip and the second chip are symmetrically arranged with respect to the hollow ceramic plate, and the first metal clip and the second metal clip are also symmetrically arranged with respect to the hollow ceramic plate.

[0014] The side of the hollow ceramic plate is provided with a plurality of through heat dissipation holes, which are arranged in an array. The cross-section of the heat dissipation holes is circular, elliptical or rectangular.

[0015] The hollow ceramic plate is made of high thermal conductivity AIN ceramic.

[0016] The thickness of the hollow ceramic plate is greater than or equal to 3 mm, the distance between the edge of the heat dissipation hole and the upper and lower surfaces of the hollow ceramic plate is greater than 200 μm, and the height of the heat dissipation hole is between one third and two thirds of the thickness of the hollow ceramic plate.

[0017] Among them, the outer surface of the first metal clip is also provided with a first insulating heat dissipation plate, and the outer surface of the second metal clip is also provided with a second insulating heat dissipation plate, the outer surfaces of the first insulating heat dissipation plate and the second insulating heat dissipation plate are exposed to the plastic package body, and the first insulating heat dissipation plate and the second insulating heat dissipation plate are arranged symmetrically above and below relative to the hollow ceramic plate.

[0018] This application also provides another technical solution: a packaging method for the high power density hollow heat dissipation power module described above, comprising the following steps:

[0019] S1, providing a hollow ceramic board, and manufacturing a first front copper clad circuit, a second front copper clad circuit, a third front copper clad circuit, a first pin, a second pin, a third pin, a first back copper clad circuit, a second back copper clad circuit, a third back copper clad circuit, a first side copper clad circuit, a second side copper clad circuit, and a third side copper clad circuit on the hollow ceramic board;

[0020] S2, using a blocking object to block both ends of the heat dissipation hole on the hollow ceramic plate;

[0021] S3, mounting the first chip on the front surface of the hollow ceramic plate, and then performing sintering or reflow soldering;

[0022] S4, attaching a first metal clip to the back surface of the first chip and the front surface of the hollow ceramic plate, and then performing sintering or reflow soldering;

[0023] S5, mounting the second chip on the back of the hollow ceramic plate, and then performing sintering or reflow soldering;

[0024] S6, attaching a second metal clip to the back side of the second chip and the back side of the hollow ceramic plate, and then performing sintering or reflow soldering;

[0025] S7, performing plastic sealing to expose the first pin, the second pin, and the third pin;

[0026] S8, grinding the side of the plastic package body to expose the heat dissipation holes of the hollow ceramic plate;

[0027] S9, remove the blocking objects at both ends of the heat dissipation hole to open both ends of the heat dissipation hole.

[0028] Optionally, step S3 and step S4 are replaced by step S3.5, wherein the first chip is mounted on the front surface of the hollow ceramic plate, and the first metal clip is mounted on the back surface of the first chip and the front surface of the hollow ceramic plate, and then sintering or reflow soldering is performed;

[0029] Replace step S5 and step S6 with step S5.5, attach the second chip to the back of the hollow ceramic board, attach the second metal clip to the back of the second chip and the back of the hollow ceramic board, and then perform sintering or reflow soldering.

[0030] Optionally, the following steps are further included between steps S4 and S5:

[0031] S4.1, attaching a first insulating heat dissipation plate to the outer surface of the first metal clip, and then performing sintering or reflow soldering;

[0032] The following steps are also included between steps S6 and S7:

[0033] S6.1, attaching a second insulating heat dissipation plate to the outer surface of the second metal clip, and then performing sintering or reflow soldering;

[0034] Step S8 also includes a step of grinding the upper and lower surfaces of the plastic package body to expose the outer surfaces of the first insulating heat dissipation plate and the second insulating heat dissipation plate.

[0035] The present application includes at least one of the following beneficial effects: 1. The present application adopts a hollow ceramic plate. The heat generated by the first chip and the second chip during operation can be directly transferred to the hollow ceramic plate. The hollow ceramic plate is provided with heat dissipation holes on the side and exposed from the plastic package. The heat dissipation holes can quickly dissipate the heat, greatly shorten the heat transfer path, and quickly reduce the temperature rise in the center of the power module. If air is blown towards the heat dissipation holes or a cooling medium is introduced, the heat dissipation is better, the reliability is higher, and the service life is longer; 2. The first chip and the second chip are directly welded on the hollow ceramic plate, and a metal clip is used to realize the electrode connection to realize a complete circuit connection, shorten the line transmission path, greatly reduce the parasitic inductance and line power consumption of the power module, have strong overcurrent capability, greater power density, and better performance; 3. The present invention covers the side The copper circuit is used to connect the front copper-clad circuit and the back copper-clad circuit, so that each pole of the chip can be directly welded to the hollow copper-clad carrier board, thereby replacing metal welding wire and metal pads, reducing the welding of the dielectric layer, simplifying the packaging process, reducing the use of plastic packaging materials, reducing the use of packaging equipment and packaging materials, and having better costs. At the same time, it reduces the problem of welding tilt, improves the module yield, and makes the assembly process simpler and more efficient; 4. The present application reduces a layer of double-sided copper-clad board, the thickness of the product becomes smaller, the space for setting metal pads is eliminated, the width size is further reduced, and the overall product becomes thinner and smaller, thereby greatly improving the power density of the power module, and more chips and components can be integrated and transplanted into the power module, providing conditions for higher integration of the power module without increasing or even reducing the size, thereby improving the space utilization of the power module. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a three-dimensional diagram of a first embodiment of the power module of the present invention;

[0037] Figure 2 is a three-dimensional diagram of the power module embodiment 1 of the present invention from another angle;

[0038] Figure 3 is a top view of the first embodiment of the power module of the present invention;

[0039] Figure 4 yes Figure 3 Middle AA section view;

[0040] Figure 5 is a three-dimensional diagram of the hollow ceramic plate in the first embodiment of the power module of the present invention;

[0041] Figure 6 This is a front perspective view of a copper-clad circuit disposed on a hollow ceramic plate in the first embodiment of the power module of the present invention;

[0042] Figure 7 This is a back perspective view of a hollow ceramic plate with a copper-clad circuit disposed thereon in the first embodiment of the power module according to the present invention;

[0043] Figure 8 This is a rear perspective view from another angle showing a copper-clad circuit disposed on a hollow ceramic plate in the first embodiment of the power module according to the present invention;

[0044] Figure 9 Schematic diagram of a packaging method according to the present invention, wherein a sealing material is inserted into a heat dissipation hole on a hollow ceramic plate;

[0045] Figure 10 1 is a schematic diagram of applying solder to the front surface of a hollow ceramic plate in Example 1 of the packaging method of the present invention;

[0046] Figure 11 1 is a schematic diagram of mounting a first chip on a hollow ceramic board in accordance with an embodiment of the packaging method of the present invention;

[0047] Figure 12 is a schematic diagram of applying solder to the hollow ceramic plate and the first chip in Example 1 of the packaging method of the present invention;

[0048] Figure 13 is a schematic diagram of attaching a first metal clip to a first chip and a hollow ceramic board in a first embodiment of the packaging method of the present invention;

[0049] Figure 14 1 is a schematic diagram of applying solder to the back of a hollow ceramic plate in Example 1 of the packaging method of the present invention;

[0050] Figure 15 2. It is a schematic diagram of mounting a second chip on a hollow ceramic board in Embodiment 1 of the packaging method of the present invention;

[0051] Figure 16 2. It is a schematic diagram of coating solder on the hollow ceramic plate and the second chip in Example 1 of the packaging method of the present invention;

[0052] Figure 17 is a schematic diagram of attaching a second metal clip to a second chip and a hollow ceramic board in embodiment 1 of the packaging method of the present invention;

[0053] Figure 18 This is a schematic diagram of the packaging method according to the present invention after plastic packaging;

[0054] Figure 19 This is a schematic diagram of a first embodiment of the packaging method of the present invention, wherein the side of the plastic package body is ground to expose the hollow ceramic plate;

[0055] Figure 20 is a three-dimensional diagram of a second embodiment of the power module of the present invention;

[0056] Figure 21 is a cross-sectional view of a second embodiment of the power module of the present invention;

[0057] Figure 22 Schematic diagram of the second embodiment of the packaging method of the present invention, wherein solder is applied to the first metal clip;

[0058] Figure 23 This is a schematic diagram of a second embodiment of the packaging method of the present invention, wherein the first insulating heat dissipation plate is attached to the first metal clip;

[0059] Figure 24 Schematic diagram of the second embodiment of the packaging method of the present invention, wherein solder is applied to the second metal clip;

[0060] Figure 25 This is a schematic diagram of a second embodiment of the packaging method of the present invention, in which the second insulating heat dissipation plate is attached to the second metal clip;

[0061] Figure 26 This is a schematic diagram of the second embodiment of the packaging method of the present invention after plastic packaging;

[0062] Figure 27 Schematic diagram of the second embodiment of the packaging method of the present invention, wherein the plastic package body is ground to expose the hollow ceramic plate, the first insulating heat dissipation plate, and the second insulating heat dissipation plate;

[0063] Figure 28 is a cross-sectional view of another embodiment of the hollow ceramic plate of the present invention;

[0064] Figure 29 It is a three-dimensional diagram of the first chip of the present invention.

[0065] Among them, 1. Hollow ceramic board; 101. Heat dissipation hole; 102. First front copper-clad circuit; 103. Second front copper-clad circuit; 104. Third front copper-clad circuit; 105. First pin; 106. Second pin; 107. Third pin; 108. First back copper-clad circuit; 109. Second back copper-clad circuit; 110. Third back copper-clad circuit; 111. First side copper-clad circuit; 112. Second side copper-clad circuit; 113. Third side copper-clad circuit; 2. First chip; 21. First pole; 22. Second pole; 23. Third pole; 3. Second chip; 4. First metal clip; 5. Second metal clip; 6. Plastic package; 7. First insulating heat dissipation plate; 8. Second insulating heat dissipation plate; 9. Solder; 10. Sealing material. DETAILED DESCRIPTION

[0066] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0067] As the embodiment 1 of the high power density hollow heat dissipation power module of the present invention, refer to Figures 1 to 8 , comprising a hollow ceramic plate 1, a first chip 2, a second chip 3, a first metal clip 4, a second metal clip 5 and a plastic package 6, wherein the hollow ceramic plate 1 is provided with heat dissipation holes 101 on its side. The heat dissipation holes 101 are preferably through holes that pass through from front to back and are arranged in an array. The cross-sectional shape of the heat dissipation holes 101 can be circular or elliptical. The cross-sectional area of ​​the heat dissipation holes 101 is slightly smaller, but the strength of the hollow ceramic plate 1 is good, or it can be as follows Figure 28 The rectangular shape (with rounded corners) shown has a large cross-sectional area of ​​heat dissipation holes 101, resulting in better heat dissipation performance but slightly lower strength. The hollow ceramic plate 1 can be made of insulating thermally conductive ceramics such as Al2O3, AlN, and AlSiC, with AlN ceramics having high thermal conductivity being preferred. The plastic package 6 is used to enclose the hollow ceramic plate 1, the first chip 2, the second chip 3, the first metal clip 4, and the second metal clip 5, exposing the heat dissipation holes 101 to accelerate heat dissipation.

[0068] In this embodiment, the thickness of the hollow ceramic plate 1 is greater than or equal to 3 mm, which is convenient for manufacturing and ensures sufficient strength. The distance between the edge of the heat dissipation hole 101 and the upper and lower surfaces of the hollow ceramic plate 1 is greater than 200 μm to ensure the insulation performance of the hollow ceramic plate 1. The height of the heat dissipation hole 101 is between one-third and two-thirds of the thickness of the hollow ceramic plate 1. While ensuring strength, the cross-sectional proportion of the heat dissipation hole 101 should be moderately increased to ensure heat dissipation performance.

[0069] Reference Figure 29 The first chip 2 includes a first electrode 21 and a second electrode 22 on the front side, and a third electrode 23 on the back side. The second chip 3 has the same structure as the first chip 2. The first chip 2 is a field effect transistor, the first electrode 21 is a D electrode, the second electrode 22 is a G electrode, and the third electrode 23 is an S electrode; or the first chip 2 is an IGBT, the first electrode 21 is an E electrode, the second electrode 22 is a G electrode, and the third electrode 23 is a C electrode. The first chip 2 and the second chip 3 can be GaN chips or SiC chips. GaN chips or SiC chips are power chips with high heat dissipation requirements. The electrical performance and heat dissipation advantages of the packaging structure described in the present invention are more obvious.

[0070] Reference Figures 4 to 8The front of the hollow ceramic board 1 is provided with a first front copper clad circuit 102, a second front copper clad circuit 103 and a third front copper clad circuit 104. The first front copper clad circuit 102 extends outwardly to form a first pin 105 (the first pin 105 can also be welded), the second front copper clad circuit 103 extends outwardly to form a second pin 106 (the second pin 106 can also be welded), and the third front copper clad circuit 104 extends outwardly to form a third pin 107 (the third pin 107 can also be welded). The one-piece formed pins can eliminate the separate pin re-welding process of previous products, reduce the welding quality risk, and improve product reliability; the hollow ceramic board 1 The back of the ceramic board 1 is provided with a first back copper-clad circuit 108, a second back copper-clad circuit 109, and a third back copper-clad circuit 110. The side of the hollow ceramic board 1 is provided with a first side copper-clad circuit 111, a second side copper-clad circuit 112, and a third side copper-clad circuit 113. The first back copper-clad circuit 108 is connected to the first front copper-clad circuit 102 via the first side copper-clad circuit 111; the second back copper-clad circuit 109 is connected to the second front copper-clad circuit 103 via the second side copper-clad circuit 112; and the third back copper-clad circuit 110 is connected to the third front copper-clad circuit 104 via the third side copper-clad circuit 113. The first chip 2 is flip-chip mounted on the front of the hollow ceramic board 1. The first electrode 21 of the first chip 2 is electrically connected to the first front copper-clad circuit 102, the second electrode 22 of the first chip 2 is electrically connected to the second front copper-clad circuit 103, and the third electrode 23 of the first chip 2 is electrically connected to the third front copper-clad circuit 104 via the first metal clip 4. The second chip 3 is flip-chip mounted on the back of the hollow ceramic board 1, the first pole of the second chip 3 is electrically connected to the first back copper-clad circuit 108, the second pole of the second chip 3 is electrically connected to the second back copper-clad circuit 109, and the third pole of the second chip 3 is electrically connected to the third back copper-clad circuit 110 through the second metal clip 5.

[0071] The copper cladding on the front, back, and sides has excellent thermal conductivity, quickly transferring heat generated by the chip to the hollow ceramic plate 1 and dissipating it through the heat dissipation holes 101. The width of the copper cladding on the sides should be adjusted according to the different chips and electrodes connected. To ensure high current operation and rapid heat dissipation, the width of the copper cladding on the sides is generally greater than 2mm. The size of each pin should be designed to match the current it is expected to carry.

[0072] In this embodiment, referring to Figure 4 The power module includes multiple groups of first chips 2 and second chips 3, specifically two groups, which are arranged horizontally in parallel. Multiple first chips 2 and second chips 3 are arranged in parallel. All chips can basically be understood as a parallel relationship. By increasing the number of chips, the current capacity is improved.

[0073] In this embodiment, the first chip 2 and the second chip 3 are arranged symmetrically with respect to the hollow ceramic plate 1, and the first metal clip 4 and the second metal clip 5 are also arranged symmetrically with respect to the hollow ceramic plate 1. The symmetrical heat dissipation structure ensures symmetrical heat dissipation from the chips, resulting in better heat dissipation, more stable chip performance, and improved power module reliability.

[0074] The packaging method of the high power density hollow heat dissipation power module described in this embodiment includes the following steps:

[0075] S1, providing a hollow ceramic board 1, and manufacturing a first front copper clad circuit 102, a second front copper clad circuit 103, a third front copper clad circuit 104, a first pin 105, a second pin 106, a third pin 107, a first back copper clad circuit 108, a second back copper clad circuit 109, a third back copper clad circuit 110, a first side copper clad circuit 111, a second side copper clad circuit 112, and a third side copper clad circuit 113 on the hollow ceramic board 1;

[0076] S2, reference Figure 9 , using the blocking material 10 to block both ends of the heat dissipation hole 101 on the hollow ceramic plate 1; after this step, plasma cleaning is generally performed to prevent the blocking material 10 from adhering to the surface of the hollow ceramic plate 1;

[0077] S3, refer to Figure 10 and Figure 11 , mounting the first chip 2 on the front surface of the hollow ceramic board 1, and then performing reflow soldering;

[0078] S4, ref. Figure 12 and Figure 13 , attaching the first metal clip 4 to the back surface of the first chip 2 and the front surface of the hollow ceramic board 1, and then performing reflow soldering;

[0079] S5, refer to Figure 14 and Figure 15 , mount the second chip 3 on the back of the hollow ceramic board 1, and then perform reflow soldering;

[0080] S6, ref. Figure 16 and Figure 17 , attach the second metal clip 5 to the back side of the second chip 3 and the back side of the hollow ceramic board 1, and then perform reflow soldering;

[0081] S7, cf. Figure 18 , perform plastic sealing to expose the first pin 105, the second pin 106 and the third pin 107;

[0082] S8, refer to Figure 19 , grinding the side surface of the plastic package body 6 to expose the heat dissipation holes 101 of the hollow ceramic plate 1;

[0083] S9, remove the blocking objects 10 at both ends of the heat dissipation hole 101, so that both ends of the heat dissipation hole 101 are open, and the heat dissipation hole 101 is obtained. Figure 1 The power module shown.

[0084] In this embodiment, if the solder 9 is replaced with a conductive adhesive, a sintering process is used instead of reflow soldering.

[0085] The mounting order of the first chip 2, the second chip 3, the first metal clip 4 and the second metal clip 5 in this embodiment can be changed according to actual conditions and does not need to be strictly followed. The solder 9 of this application is preferably a nano-sintered material with high electrical and thermal conductivity.

[0086] Alternatively, as a simplified version of the packaging method described in this embodiment, the following optimization can be performed: Steps S3 and S4 can be replaced with Step S3.5, where the first chip is mounted on the front of the hollow ceramic plate, the first metal clip is attached to the back of the first chip and the front of the hollow ceramic plate, and then sintering or reflow soldering is performed. Steps S5 and S6 can be replaced with Step S5.5, where the second chip is mounted on the back of the hollow ceramic plate, the second metal clip is attached to the back of the second chip and the back of the hollow ceramic plate, and then sintering or reflow soldering is performed. This can reduce the need for secondary sintering or reflow soldering, further simplifying the process.

[0087] This application adopts a hollow ceramic plate 1. The heat generated by the first chip 2 and the second chip 3 during operation can be directly transferred to the hollow ceramic plate 1. The side of the hollow ceramic plate 1 is provided with a heat dissipation hole 101, and it is exposed from the plastic package 6. The heat dissipation hole 101 can quickly dissipate the heat, and the heat transfer path is greatly shortened, which quickly reduces the temperature rise in the center of the power module. If air is blown towards the heat dissipation hole 101 or a cooling medium is introduced, the heat dissipation is better, the reliability is higher, and the service life is longer.

[0088] The first chip 2 and the second chip 3 are directly welded on the hollow ceramic plate 1, and the electrodes are connected using metal clips to achieve complete circuit connection, shorten the line transmission path, greatly reduce the parasitic inductance and line power consumption of the power module, have strong overcurrent capability, greater power density, and better performance.

[0089] The present invention connects the front and back copper-clad circuits via side copper-clad circuits, allowing each chip pole to be directly welded to the hollow copper-clad carrier board. This replaces metal welding wires and metal pads, reduces dielectric layer welding, and uses sintering welding throughout. This standardizes the process, simplifies the packaging process, reduces the amount of plastic encapsulation compound used, and reduces the use of packaging equipment and packaging materials, resulting in better cost. It also reduces the problem of welding tilt, improves reliability, improves module yield, and makes the assembly process simpler and more efficient. The chip circuit path in the power module is shortened, reducing power loss in the circuit path during operation and achieving faster signal response.

[0090] This application reduces a layer of double-sided copper clad laminate, the product thickness becomes smaller, the space for setting metal pads is eliminated, the width dimension is further reduced, and the overall product becomes thinner and smaller, thereby greatly improving the power density of the power module. More chips and components can be integrated and transplanted into the power module, providing conditions for higher integration of the power module without increasing or even reducing the size, thereby improving the space utilization of the power module.

[0091] As the second embodiment of the high power density hollow heat dissipation power module of the present invention, Figure 20 and Figure 21 As shown, the difference from Example 1 is that the outer surface of the first metal clip 4 is further provided with a first insulating heat dissipation plate 7, and the outer surface of the second metal clip 5 is further provided with a second insulating heat dissipation plate 8, the outer surfaces of the first insulating heat dissipation plate 7 and the second insulating heat dissipation plate 8 are exposed to the plastic package 6, and the first insulating heat dissipation plate 7 and the second insulating heat dissipation plate 8 are arranged symmetrically above and below relative to the hollow ceramic plate 1.

[0092] The packaging method of this embodiment differs from the packaging method of the first embodiment mainly in that the step of mounting the first insulating heat dissipation plate 7 and the second insulating heat dissipation plate 8 is added. The specific changes are as follows:

[0093] The following steps are also included between steps S4 and S5:

[0094] S4.1, refer to Figure 22 and Figure 23 , attach the first insulating heat dissipation plate 7 to the outer surface of the first metal clip 4, and then perform reflow soldering (if the solder 9 is replaced with conductive glue, then a sintering process should be used instead of reflow soldering);

[0095] The following steps are also included between steps S6 and S7:

[0096] S6.1, refer to Figure 24 and Figure 25 , attach the second insulating heat dissipation plate 8 to the outer surface of the second metal clip 5, and then perform reflow soldering (if the solder 9 is replaced with conductive glue, then a sintering process should be used instead of reflow soldering);

[0097] In step S8, refer to Figure 27 , also includes the step of grinding the upper and lower surfaces of the plastic package body 6 to expose the outer surfaces of the first insulating heat dissipation plate 7 and the second insulating heat dissipation plate 8.

[0098] The power module described in this embodiment has a double-sided heat dissipation structure and a side heat dissipation structure, forming a three-dimensional heat dissipation structure, which has the advantages of more stable performance, better heat dissipation, lower power consumption, higher reliability and longer service life.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high power density hollow heat dissipation power module, characterized in that: It includes a hollow ceramic plate, a first chip, a second chip, a first metal clip, a second metal clip and a plastic package, wherein the side of the hollow ceramic plate is provided with heat dissipation holes; The first chip and the second chip each include a first electrode and a second electrode located on the front side, and a third electrode located on the back side; The front of the hollow ceramic board is provided with a first front copper-clad circuit, a second front copper-clad circuit and a third front copper-clad circuit, the first front copper-clad circuit extends a first pin outward or is welded with a first pin, the second front copper-clad circuit extends a second pin outward or is welded with a second pin, and the third front copper-clad circuit extends a third pin outward or is welded with a third pin; the back of the hollow ceramic board is provided with a first back copper-clad circuit, a second back copper-clad circuit and a third back copper-clad circuit, and the side of the hollow ceramic board is provided with a first side copper-clad circuit, a second side copper-clad circuit and a third side copper-clad circuit; the first back copper-clad circuit is connected to the first front copper-clad circuit through the first side copper-clad circuit; the second back copper-clad circuit is connected to the second front copper-clad circuit through the second side copper-clad circuit, and the third back copper-clad circuit is connected to the third front copper-clad circuit through the third side copper-clad circuit; The first chip is flip-chip mounted on the front surface of the hollow ceramic board, the first electrode of the first chip is electrically connected to the first front copper-clad circuit, the second electrode of the first chip is electrically connected to the second front copper-clad circuit, and the third electrode of the first chip is electrically connected to the third front copper-clad circuit via a first metal clip; The second chip is flip-chip mounted on the back of the hollow ceramic board, the first electrode of the second chip is electrically connected to the first back copper-clad circuit, the second electrode of the second chip is electrically connected to the second back copper-clad circuit, and the third electrode of the second chip is electrically connected to the third back copper-clad circuit via a second metal clip; The plastic package is used to wrap the hollow ceramic plate, the first chip, the second chip, the first metal clip and the second metal clip, and expose the heat dissipation holes.

2. The high power density hollow heat dissipation power module according to claim 1, characterized in that: The first chip and the second chip are both field effect tubes, with the first pole being the D pole, the second pole being the G pole, and the third pole being the S pole; or the first chip and the second chip are both IGBTs, with the first pole being the E pole, the second pole being the G pole, and the third pole being the C pole.

3. The high power density hollow heat dissipation power module according to claim 1, characterized in that: The power module includes multiple groups of first chips and second chips, which are arranged horizontally in parallel, and multiple first chips and second chips are arranged in parallel.

4. The high power density hollow heat dissipation power module according to claim 1, characterized in that: The first chip and the second chip are symmetrically arranged with respect to the hollow ceramic plate, and the first metal clip and the second metal clip are also symmetrically arranged with respect to the hollow ceramic plate.

5. The high power density hollow heat dissipation power module according to claim 1, characterized in that: The side of the hollow ceramic plate is provided with a plurality of through heat dissipation holes arranged in an array, and the cross-section of the heat dissipation holes is circular, elliptical or rectangular; the material of the hollow ceramic plate is high thermal conductivity AIN ceramic.

6. The high power density hollow heat dissipation power module according to claim 1, characterized in that: The thickness of the hollow ceramic plate is greater than or equal to 3 mm, the distance between the edge of the heat dissipation hole and the upper and lower surfaces of the hollow ceramic plate is greater than 200 μm, and the height of the heat dissipation hole is between one third and two thirds of the thickness of the hollow ceramic plate.

7. The high power density hollow heat dissipation power module according to claim 1, characterized in that: A first insulating heat dissipation plate is also provided on the outer surface of the first metal clip, and a second insulating heat dissipation plate is also provided on the outer surface of the second metal clip. The outer surfaces of the first insulating heat dissipation plate and the second insulating heat dissipation plate are exposed to the plastic package body, and the first insulating heat dissipation plate and the second insulating heat dissipation plate are arranged symmetrically above and below relative to the hollow ceramic plate.

8. A packaging method for the high power density hollow heat dissipation power module according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, providing a hollow ceramic board, and manufacturing a first front copper clad circuit, a second front copper clad circuit, a third front copper clad circuit, a first pin, a second pin, a third pin, a first back copper clad circuit, a second back copper clad circuit, a third back copper clad circuit, a first side copper clad circuit, a second side copper clad circuit, and a third side copper clad circuit on the hollow ceramic board; S2, using a blocking object to block both ends of the heat dissipation hole on the hollow ceramic plate; S3, mounting the first chip on the front surface of the hollow ceramic plate, and then performing sintering or reflow soldering; S4, attaching a first metal clip to the back surface of the first chip and the front surface of the hollow ceramic plate, and then performing sintering or reflow soldering; S5, mounting the second chip on the back of the hollow ceramic plate, and then performing sintering or reflow soldering; S6, attaching a second metal clip to the back side of the second chip and the back side of the hollow ceramic plate, and then performing sintering or reflow soldering; S7, performing plastic sealing to expose the first pin, the second pin, and the third pin; S8, grinding the side of the plastic package body to expose the heat dissipation holes of the hollow ceramic plate; S9, remove the blocking objects at both ends of the heat dissipation hole to open both ends of the heat dissipation hole.

9. The packaging method of the high power density hollow heat dissipation power module according to claim 8, characterized in that: Replace step S3 and step S4 with step S3.5, attaching the first chip to the front surface of the hollow ceramic plate, attaching the first metal clip to the back surface of the first chip and the front surface of the hollow ceramic plate, and then performing sintering or reflow soldering; Replace step S5 and step S6 with step S5.5, attach the second chip to the back of the hollow ceramic board, attach the second metal clip to the back of the second chip and the back of the hollow ceramic board, and then perform sintering or reflow soldering.

10. The packaging method of the high power density hollow heat dissipation power module according to claim 8, characterized in that: The following steps are also included between steps S4 and S5: S4.1, attaching a first insulating heat dissipation plate to the outer surface of the first metal clip, and then performing sintering or reflow soldering; The following steps are also included between steps S6 and S7: S6.1, attaching a second insulating heat dissipation plate to the outer surface of the second metal clip, and then performing sintering or reflow soldering; Step S8 also includes a step of grinding the upper and lower surfaces of the plastic package body to expose the outer surfaces of the first insulating heat dissipation plate and the second insulating heat dissipation plate.

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