Multi-AMB spliced novel power module and manufacturing method thereof

Abstract

The invention relates to a multi-AMB splicing type novel power module and a manufacturing method, and belongs to the technical field of semiconductor instruments and manufacturing, a plurality of AMB copper layers are arranged on one insulating ceramic substrate, the plurality of AMB copper layers are carried through one insulating ceramic substrate, the distance between the insulating ceramic substrates with the AMB copper layers is 0 mm, the AMB copper layers are arranged on the insulating ceramic substrates, and the AMB copper layers are arranged on the AMB copper layers. The size of the AMB insulating ceramic substrate is greatly reduced, so that the size of the power module is reduced, and compared with a heat dissipation bottom plate of an existing module, the heat dissipation bottom plate is grooved in the surface of the heat dissipation bottom plate, and the AMB insulating ceramic substrate is arranged in the accommodating groove, so that the effect of reducing the weight and the size of the module is achieved; and the AMB insulating ceramic substrate is closer to the radiating fins of the radiating bottom plate, so that the radiating efficiency of the AMB insulating ceramic substrate is improved to the maximum extent under the condition that the size is reduced and the AMB insulating ceramic substrate is closer to the radiating fins.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor devices and preparation, and in particular relates to a multi-AMB splicing type novel power module and a preparation method thereof. Background Art

[0002] At present, the full-bridge power modules on the market are large in size, heavy in weight, and occupy a lot of space in the motor controller; secondly, the longitudinal distance between the heat dissipation base of the power module and the SIC chip is far, the actual working heat dissipation is slow, and the working junction temperature of the module cannot be reduced; and the bonding method of the source of the power module chip brings about adverse effects (such as stray inductance caused by current interference, module failure caused by material stress), etc. As a result, the existing full-bridge power module cannot be miniaturized, and the SIC chip cannot play its greatest advantage. In view of this, this solution was created. Summary of the invention

[0003] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a new type of multi-AMB splicing power module and a manufacturing method thereof, which can produce a smaller module with better heat dissipation effect.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a new type of multi-AMB splicing power module, including a heat dissipation base plate, an insulating ceramic substrate and multiple AMB copper layers, the heat dissipation base plate is provided with a receiving groove, the insulating ceramic substrate is adapted to the receiving groove and is located in the receiving groove, the AMB copper layer includes an upper copper layer and a lower copper layer, the upper copper layer and the lower copper layer are respectively located on the upper surface and the lower surface of the insulating ceramic substrate, and the multiple AMB copper layers are arranged at equal intervals.

[0005] Furthermore, the novel power module further comprises a plastic encapsulation layer, and the plastic encapsulation layer is used to prevent the insulating ceramic substrate and the plurality of AMB copper layers from being connected to the outside.

[0006] Furthermore, a chip, an FPC flexible circuit board and Pin needles are arranged on the surface of the upper copper layer.

[0007] Furthermore, a lead frame is provided on the surface of the upper copper layer, and the lead frame is used to be connected to an external component.

[0008] Furthermore, a frame is formed on the lower surface of the heat dissipation bottom plate, and a plurality of heat dissipation fins are arranged at intervals in the frame. The distance between the bottom surface of the frame and the bottom surface of the accommodating groove is 1 mm.

[0009] A method for manufacturing a novel multi-AMB splicing power module comprises the following steps:

[0010] S1, processing a plurality of AMB copper layers onto an insulating ceramic substrate to form an AMB insulating ceramic substrate;

[0011] S2, printing silver paste in the receiving groove of the heat dissipation base plate, and then drying it;

[0012] S3, the AMB insulating ceramic substrate is placed in the receiving tank for sintering;

[0013] S4, printing silver paste on the surface of the AMB insulating ceramic substrate, and then drying it;

[0014] S5, placing the chip on the surface of the printed and dried silver paste, applying a certain pressure to form a pre-sintered combination between the chip and the silver paste;

[0015] S6. Sinter the chip on the surface of the AMB at a pressure of 20MPa-30MPa and a temperature of 230°C-250°C, so that the chip and the silver paste on the surface of the AMB insulating ceramic substrate form a dense sintered body;

[0016] S7, sintering the FPC flexible circuit board onto the AMB insulating ceramic substrate according to the same sintering steps of steps S5 and S6;

[0017] S8, rubbing the AMB insulating ceramic substrate and the metal wire at high speed to form a eutectic bond;

[0018] S9, welding the terminals, plastic sealing and insulation, and obtaining the finished product.

[0019] Furthermore, the silver paste printing in step S2 and step S4 is performed by applying a certain scraper pressure on the surface of the steel mesh to effectively print the silver paste on the peripheral surface of the receiving groove or the surface of the AMB insulating ceramic substrate. The drying temperature in step S2 and step S4 is 100°C-120°C, and the drying time is 30min-40min.

[0020] Furthermore, in step S5, a thermal bonding machine is used to thermally bond the chip to the surface of the silver paste to form a pre-sintered combination. The bonding pressure of the thermal bonding machine is 3.5-4.5 kg, the duration is 3-5 s, the fixture temperature is 100°C-120°C, and the nozzle temperature is 75-85°C.

[0021] Furthermore, in step S8, the AMB insulating ceramic substrate and the metal wire are subjected to high-speed friction bonding to form a eutectic bond through a bonding machine, the bonding force of the bonding machine is 1000CN-5000CN, the wire arc height parameter is 200um-6000um, and the wire pulling parameter is 500um-3000um.

[0022] Furthermore, the metal wire is made of copper wire or aluminum wire.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. In the prior art, an AMB insulating ceramic substrate (that is, an insulating ceramic substrate with an AMB copper layer attached to the surface) has an AMB copper layer arranged on one insulating ceramic substrate. When a power module is installed, multiple AMB insulating ceramic substrates are required, and the multiple AMB insulating ceramic substrates need to be arranged at intervals of 2.5-3mm. If they are not spaced, adjacent AMB insulating ceramic substrates will have stacked contact during welding, resulting in abnormal welding. The present invention provides a new multi-AMB splicing power module, in which multiple AMB copper layers are arranged on one insulating ceramic substrate, and multiple AMB copper layers are carried on one insulating ceramic substrate. The distance between each insulating ceramic substrate having an AMB copper layer is 0mm, which is maximized. The size of the AMB insulating ceramic substrate is reduced, thereby reducing the size of the power module. Moreover, compared with the heat dissipation base plate of the existing module, the heat dissipation base plate in the present invention is grooved (accommodating groove) on its surface, and the AMB insulating ceramic substrate is built into the accommodating groove, thereby achieving the effect of reducing the weight and volume of the module; and in the method for manufacturing the multi-AMB splicing type new power module of the present invention, the bonding process of the module (that is, step S8) adopts FPC flexible circuit board to replace the traditional Cilp frame or copper frame, etc. Compared with the Cilp frame or copper frame on the existing module, the performance failure risk caused by the stress of the Cilp frame or copper frame is reduced to the greatest extent in the present invention, and compared with the bonding wire on the existing module, the stray inductance of the module is reduced.

[0025] 2. Dig a groove (accommodation groove) on the surface of the heat dissipation base plate, and embed the AMB insulating ceramic substrate in the accommodation groove, so as to reduce the weight and volume of the whole module, shorten the distance between the AMB insulating ceramic substrate and the heat sink under the heat dissipation base plate, reduce the junction temperature of the module, and have better heat dissipation performance.

[0026] 3. The overall size of the module produced by the present invention is 146*59*11mm, while the overall size of the existing module is 152*92*14mm. Under the condition of consistent actual functions, the multi-AMB splicing new power module mentioned in the present invention has a smaller size and better heat dissipation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a three-dimensional structural schematic diagram of a novel multi-AMB splicing power module of the present invention;

[0028] Figure 2 This is a schematic diagram of the top view of the structure of the present invention after the plastic sealing layer is hidden;

[0029] Figure 3 It is a schematic diagram of a three-dimensional structure of another aspect of the present invention;

[0030] Figure 4It is a schematic diagram of the three-dimensional structure of the insulating ceramic substrate and the AMB copper layer in the present invention;

[0031] Figure 5 It is a schematic diagram of the three-dimensional structure of the heat dissipation base plate in the present invention;

[0032] Figure 6 It is a partial enlarged side view of the insulating ceramic substrate and the AMB copper layer in the present invention.

[0033] Markings in the figure: 1. Heat dissipation base plate; 11. Receiving groove; 12. Frame; 121. Heat sink; 2. Insulating ceramic substrate; 3. AMB copper layer; 31. Upper copper layer; 32. Lower copper layer; 4. Pin needle; 5. FPC flexible circuit board; 6. Chip; 7. Lead frame; 8. Plastic packaging layer. DETAILED DESCRIPTION

[0034] In order to make the above features and advantages of the present invention more obvious and easy to understand, embodiments are given below with reference to the accompanying drawings for detailed description as follows.

[0035] like Figure 1-Figure 6 As shown, this embodiment provides a new type of multi-AMB splicing power module, including a heat dissipation base plate 1, an insulating ceramic substrate 2, a plurality of AMB copper layers 3 and a plastic packaging layer 8.

[0036] The AMB copper layer 3 includes an upper copper layer 31 and a lower copper layer 32, and the upper copper layer 31 and the lower copper layer 32 are respectively located on the upper surface and the lower surface of the insulating ceramic substrate 2, and the insulating ceramic substrate 2 is made of silicon nitride or aluminum nitride, etc. In this embodiment, the insulating ceramic substrate 2 made of silicon nitride is selected. A plurality of AMB copper layers 3 are arranged at equal intervals, and the insulating ceramic substrate 2 attached with the AMB copper layers 3 is an AMB insulating ceramic substrate. The number of AMB insulating ceramic substrates is distinguished by the number of AMB copper layers 3. In this embodiment, the number of AMB copper layers 3 is 3, that is, the number of AMB insulating ceramic substrates is three.

[0037] The surface of the upper copper layer 31 is provided with a chip 6, an FPC flexible circuit board 5 and a pin 4. The chip 6 is a Sic-MOS chip 6, specifically a third-generation wide bandgap semiconductor chip 6. The pin 4 is used to lead out the electrical signal of the module. The FPC flexible circuit board 5 has the characteristic of stress self-adaptation. The surface of the upper copper layer 31 is also provided with a lead frame 7, which is used to connect to an external part. Specifically, the lead frame 7 is made of full copper or full copper plated with gold. In this embodiment, a lead frame 7 made of full copper is selected. The lead frame 7 is used as an electrical terminal to lead out the electrical performance of the module and is connected to an external part.

[0038] Compared with the Cilp frame or copper frame on the existing module, the present invention reduces the performance failure risk caused by the stress of the Cilp frame or copper frame to the greatest extent, and compared with the bonding wire on the existing module, reduces the stray inductance of the module.

[0039] The upper surface of the heat dissipation base plate 1 has a receiving groove 11, and the lower surface of the heat dissipation bottom is provided with a frame 12, and a plurality of heat dissipation fins 121 arranged at intervals are arranged in the frame 12. Specifically, the heat dissipation fins 121 are wavy, and the heat dissipation fins 121 are made of metal with good heat dissipation performance, such as copper. The distance between the bottom surface of the frame 12 and the bottom surface of the receiving groove 11 is 1 mm, and the insulating ceramic substrate 2 and the plurality of AMB copper layers 3 are installed in the receiving groove 11.

[0040] The distance between the AMB insulating ceramic substrate in the existing module and the heat dissipation component on its heat dissipation base plate 1 (such as the heat sink 121 in this solution) is generally 3 mm. In this solution, since the three-jointed AMB copper layers 3 are on the same insulating ceramic substrate 2, the size of the AMB insulating ceramic substrate is greatly reduced, making the heat dissipation more concentrated, and a receiving groove 11 is opened on the heat dissipation base plate 1 to reduce the distance between the AMB insulating ceramic substrate and the heat sink 121, thereby greatly improving the heat dissipation performance of the entire module.

[0041] The plastic encapsulation layer 8 is used to prevent the insulating ceramic substrate 2 and the plurality of AMB copper layers 3 from being connected to the outside. Specifically, the plastic encapsulation layer 8 is made of epoxy resin.

[0042] The overall size of the module produced by the present invention is 146*59*11mm, while the overall size of the existing module is 152*92*14mm. Under the condition of the same actual functions, the multi-AMB splicing type new power module mentioned in the present invention has a smaller size and better heat dissipation performance.

[0043] The present invention also provides a method for manufacturing a multi-AMB splicing type novel power module, which is used to manufacture a multi-AMB splicing type novel power module; the method comprises the following steps:

[0044] S1, processing a plurality of AMB copper layers 3 onto an insulating ceramic substrate 2 to form an AMB insulating ceramic substrate;

[0045] S2, printing silver paste in the receiving groove 11 of the heat dissipation base plate 1, and then drying; the specific steps are as follows: using a printing machine for printing, applying a certain scraper pressure on the surface of the steel mesh, and effectively printing the silver paste on the surrounding surface of the receiving groove 11 or the surface of the AMB insulating ceramic substrate, specifically, the scraper pressure is 3kg, the printing speed is 25mm / s; the drying temperature is 100℃-120℃, and the drying time is 30min-40min. Preferably, the drying temperature is 110℃, and the drying time is 30min; the drying method is to use an oven for drying to volatilize the organic components of the silver paste into solid silver.

[0046] S3, the AMB insulating ceramic substrate is placed in the receiving tank 11 for sintering; the specific steps are as follows: a sintering machine is used for sintering, the sintering pressure is 20-30MPa, the sintering temperature is 250-270℃, and the duration is 4-6min. Preferably, the sintering pressure is 25MPa, the sintering temperature is 260℃, and the duration is 5min, and the sintering effect is best.

[0047] S4, printing silver paste on the surface of AMB insulating ceramic substrate, and then drying; the specific steps are as follows: using a printing machine for printing, applying a certain scraper pressure on the surface of the steel mesh, and effectively printing the silver paste on the surrounding surface of the receiving groove 11 or the surface of the AMB insulating ceramic substrate, specifically, the scraper pressure is 3kg, the printing speed is 25mm / s; the drying temperature is 100℃-120℃, and the drying time is 30min-40min. Preferably, the drying temperature is 110℃, and the drying time is 30min; the drying method is to use an oven for drying to volatilize the organic components of the silver paste into solid silver.

[0048] S5. Place chip 6 on the surface of the printed and dried silver paste, apply a certain pressure, and form a pre-sintered combination between chip 6 and the silver paste; the specific steps are as follows: a thermal bonding machine is used to thermally bond chip 6 to the surface of the silver paste to form a pre-sintered combination. The bonding pressure of the thermal bonding machine is 3.5-4.5kg, the duration is 3-5s, the fixture temperature is 100℃-120℃, and the nozzle temperature is 75-85℃. Preferably, the bonding pressure is 4kg, the duration is 4s, the fixture temperature is 110℃, the nozzle temperature is 80℃, and the thermal bonding effect is best.

[0049] S6. Under the conditions of pressure of 20MPa-30MPa and temperature of 230℃-250℃, the chip 6 is sintered on the surface of AMB. The chip 6 and the silver paste on the surface of the AMB insulating ceramic substrate form a dense sintered body. The specific steps are as follows: sintering is performed using a sintering machine with a pressure of 25MPa, a temperature of 235℃, and a time of 4min. The sintering effect is best.

[0050] S7, sintering the FPC flexible circuit board 5 onto the AMB insulating ceramic substrate according to the same sintering steps as steps S5 and S6; specifically, the FPC flexible circuit board 5 is first thermally bonded onto the AMB insulating ceramic substrate and then sintered.

[0051] S8. Friction the AMB insulating ceramic substrate and the metal wire at high speed to form a eutectic bond (between the metal wire and the AMB insulating ceramic substrate); the specific steps are as follows: the metal wire can be copper wire or aluminum wire, and copper wire is used in this embodiment. The AMB insulating ceramic substrate and the metal wire are frictionally bonded at high speed by a bonding machine to form a eutectic bond. The bonding force of the bonding machine is 1000CN-5000CN, the wire arc height parameter is 200um-6000um, and the Tail-length in the wire pulling parameter is 500um-3000um. Tail-length means "tail length", which is the length of the wire tail of a single solder joint.

[0052] S9, welding terminals, plastic sealing and insulation, and obtaining the finished product. The specific steps are as follows: using a terminal welding machine for welding, through high-speed friction between metals, a eutectic bond is formed (between the pin 4 and the AMB insulating ceramic substrate, between the terminal frame and the AMB insulating ceramic substrate), Sink (the sinking or flow distance of the solder during welding): 200-350um, Amplitude: 55%-90%, Force: 200N-500N; the chip 6, copper wire, FPC flexible circuit board 5, AMB insulating ceramic substrate and other materials are plastic sealed and electrically insulated by a plastic sealing machine, and finally a finished module is obtained.

[0053] In step S8, an FPC flexible circuit board 5 is used to replace the traditional Cilp frame or copper frame. Compared with the Cilp frame or copper frame on the existing module, the present invention minimizes the risk of performance failure caused by the stress of the Cilp frame or copper frame, and compared with the bonding wires on the existing module, reduces the stray inductance of the module.

[0054] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A new type of multi-AMB splicing power module, characterized by: It includes a heat dissipation base plate, an insulating ceramic substrate and multiple AMB copper layers. The heat dissipation base plate is provided with a receiving groove. The insulating ceramic substrate is adapted to the receiving groove and is located in the receiving groove. The AMB copper layer includes an upper copper layer and a lower copper layer. The upper copper layer and the lower copper layer are respectively located on the upper surface and the lower surface of the insulating ceramic substrate. The multiple AMB copper layers are arranged at equal intervals.

2. A multi-AMB splicing type novel power module according to claim 1, characterized in that: The novel power module further comprises a plastic encapsulation layer, which is used to prevent the insulating ceramic substrate and the plurality of AMB copper layers from being connected to the outside.

3. A multi-AMB splicing type novel power module according to claim 2, characterized in that: The surface of the upper copper layer is provided with a chip, an FPC flexible circuit board and Pin needles.

4. A multi-AMB splicing type novel power module according to claim 3, characterized in that: A lead frame is also provided on the surface of the upper copper layer, and the lead frame is used to be connected to an external component.

5. The multi-AMB splicing type novel power module according to claim 1 is characterized in that: A frame is formed on the lower surface of the heat dissipation bottom plate, and a plurality of heat dissipation fins arranged at intervals are arranged in the frame. The distance between the bottom surface of the frame and the bottom surface of the accommodating groove is 1 mm.

6. A method for manufacturing a novel multi-AMB splicing power module according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, processing a plurality of AMB copper layers onto an insulating ceramic substrate to form an AMB insulating ceramic substrate; S2, printing silver paste in the receiving groove of the heat dissipation base plate, and then drying it; S3, the AMB insulating ceramic substrate is placed in the receiving tank for sintering; S4, printing silver paste on the surface of the AMB insulating ceramic substrate, and then drying it; S5, placing the chip on the surface of the printed and dried silver paste, applying a certain pressure to form a pre-sintered combination between the chip and the silver paste; S6. Sinter the chip on the surface of the AMB at a pressure of 20MPa-30MPa and a temperature of 230°C-250°C, so that the chip and the silver paste on the surface of the AMB insulating ceramic substrate form a dense sintered body; S7, sintering the FPC flexible circuit board onto the AMB insulating ceramic substrate according to the same sintering steps of steps S5 and S6; S8, rubbing the AMB insulating ceramic substrate and the metal wire at high speed to form a eutectic bond; S9, welding the terminals, plastic sealing and insulation, and obtaining the finished product.

7. The method for manufacturing a multi-AMB splicing novel power module according to claim 6, characterized in that: The silver paste printing in step S2 and step S4 is performed by a printing machine, and a certain scraper pressure is applied to the surface of the steel mesh to effectively print the silver paste on the peripheral surface of the receiving groove or the surface of the AMB insulating ceramic substrate. The drying temperature is 100°C-120°C, and the drying time is 30min-40min.

8. The method for manufacturing a multi-AMB splicing novel power module according to claim 6, characterized in that: In step S5, a thermal bonding machine is used to thermally bond the chip to the surface of the silver paste to form a pre-sintered combination. The bonding pressure of the thermal bonding machine is 3.5-4.5 kg, the duration is 3-5 s, the fixture temperature is 100° C.-120° C., and the nozzle temperature is 75-85° C.

9. The method for manufacturing a multi-AMB splicing novel power module according to claim 6, characterized in that: In step S8, the AMB insulating ceramic substrate and the metal wire are subjected to high-speed friction bonding to form a eutectic bond through a bonding machine. The bonding force of the bonding machine is 1000CN-5000CN, the wire arc height parameter is 200um-6000um, and the wire pulling parameter is 500um-3000um.

10. The method for manufacturing a novel multi-AMB splicing power module according to claim 9, characterized in that: The metal wire is a copper wire or an aluminum wire.

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