CN104835794A - Intelligent power module and method for manufacturing same - Google Patents

Abstract

The invention discloses an intelligent power module and a manufacturing method thereof. The intelligent power module includes circuit wiring, power components and non-power components arranged at predetermined positions of the circuit wiring, and a paper radiator as a carrier. The radiator One side of the radiator is covered with an insulating layer as the front side, and the circuit wiring is arranged on the side of the insulating layer away from the heat sink; Wrinkles, the back of the radiator is provided with a partition. The invention improves the cooling effect, electrical performance and thermal stability of the intelligent power module, and reduces the cost.

Description

Intelligent power module and manufacturing method thereof

technical field

The invention relates to the technical field of intelligent power modules, in particular to an intelligent power module packaged in the form of a transfer mold for specific application occasions such as frequency conversion air conditioners and a manufacturing method thereof.

Background technique

Intelligent Power Module (IPM, Intelligent Power Module) is a power drive product that combines power electronics and integrated circuit technology. The intelligent power module integrates the power switching device and the high-voltage driving circuit, and has built-in fault detection circuits such as overvoltage, overcurrent and overheating. On the one hand, the intelligent power module receives the control signal from the MCU to drive the subsequent circuit to work, and on the other hand, it sends the system status detection signal back to the MCU. Intelligent power modules win more and more markets with their advantages of high integration and high reliability, and are especially suitable for frequency converters and various inverter power supplies for driving motors.

The structures of existing intelligent power modules are shown in Fig. 1(A), Fig. 1(B) and Fig. 1(C). Fig. 1(A) is a top view of an existing smart power module 100, Fig. 1(B) is a cross-sectional view taken along line XX' of Fig. 1(A), and Fig. 1(C) is after removing the resin in Fig. 1(A) schematic diagram.

As shown in Fig. 1(A), Fig. 1(B) and Fig. 1(C), the existing intelligent power module 100 has the following structure, which includes: a circuit substrate 106; an insulating layer 107 arranged on the surface of the circuit substrate 106 the circuit wiring 108 formed on the insulating layer 107; the solder resist layer 110 covering the specific position of the insulating layer 107 and the circuit wiring 108; the power element 109 and the non-power element 104 fixed on the circuit wiring 108 by the solder paste 112; Power elements 104, power elements 109, and metal wires 105 of circuit wiring 108; pins 101 connected to circuit wiring 108; at least one side of circuit substrate 106 is sealed by sealing resin 102, and the entire circuit substrate 106 is sealed in order to improve sealing performance. All surfaces are sealed.

Since the smart power module 100 generally works in a high-temperature environment, and the power element 109 emits a large amount of heat during operation, the junction temperature of the power element 109 is very high. , resulting in higher overall thermal resistance of the smart power module 100 . Moreover, due to the heat conduction of the circuit substrate 106, the heat of the power element 109 is transferred to other devices, causing non-negligible temperature drift in the electrical parameters of other devices.

Therefore, the existing intelligent power module works at high temperature for a long time, which will seriously reduce its service life and affect the stability of performance. In extreme cases, it will cause the intelligent power module to explode out of control due to overheating of internal components during operation. , causing casualties and property damage.

Contents of the invention

The main purpose of the present invention is to provide an intelligent power module with simple structure, good heat dissipation and high reliability and its manufacturing method.

In order to achieve the above object, the present invention proposes an intelligent power module, including circuit wiring, power components and non-power components arranged at predetermined positions of the circuit wiring, and a paper heat sink as a carrier, one side of the heat sink serves as The front side is covered with an insulating layer, and the circuit wiring is arranged on the side of the insulating layer away from the heat sink; the other side of the heat sink is used as the back side, and corrugations for heat dissipation are provided at positions corresponding to the power components , the back of the radiator is provided with a partition.

Preferably, there is a set interval between the power element and the non-power element, and the partition is arranged on the back of the radiator at a position corresponding to the interval, and the width of the partition is 1 mm to 5 mm .

Preferably, the intelligent power module further includes metal wires for connecting the circuit wiring, the power elements and the non-power elements to form corresponding circuits.

Preferably, the intelligent power module further includes input and output pins disposed on the edge of the power module, connected to the circuit wiring, and extending in a direction opposite to the wrinkle.

Preferably, the intelligent power module further includes a thermosetting resin frame along the edge of the insulating layer, the circuit wiring, the power components and non-power components, metal wires, and the connection part between the pin and the circuit wiring Encapsulated by a thermoplastic resin filling the thermosetting resin frame.

Preferably, the thermosetting resin frame is provided with a through hole for installing the intelligent power module, and the through hole passes through the thermosetting resin frame, the insulating layer and the paper radiator.

Preferably, the circuit wiring forms one or more welding pads on at least one edge of the insulating layer; the plurality of welding pads are aligned and arranged along the edge of the insulating layer; the pins pass through the welding pads fixed and connected with the circuit wiring.

Preferably, both the heat sink and the folds are wet-type carbon composite functional paper; the heat sink and the folds are bonded or made integrally; the thickness of the heat sink is 1.5 mm to 2.5 mm ; The thickness of the heat sink is greater than the thickness of the corrugation.

Preferably, the circuit composed of the power element, the non-power element, the circuit wiring, and the metal wire has the functions of bridge stack, compressor inverter and power factor correction, or has bridge stack, compressor inverter , power factor correction and fan inverter function.

The embodiment of the present invention also proposes a method for manufacturing an intelligent power module, including the following steps:

Forming a paper heat sink, covering the front of the heat sink with an insulating layer, and forming circuit wiring and welding pads on the surface of the insulating layer;

assembling power components and non-power components on the surface of the circuit wiring, and assembling prefabricated pins on the surface of the pad;

Connecting the power elements, non-power elements and the circuit wiring through metal wires to form corresponding circuits;

Assembling a prefabricated thermosetting resin frame on the insulating layer and potting thermoplastic resin;

A partition is formed on the back of the heat sink, and the prefabricated heat dissipation folds are fixed on the back of the heat sink corresponding to the position of the power element.

Preferably, before the step of connecting the power element, the non-power element and the circuit wiring through metal wires to form a corresponding circuit, the step further includes:

Place the radiator with the elements assembled in the washing machine for cleaning.

Preferably, before the steps of assembling power components and non-power components on the surface of the circuit wiring, and assembling prefabricated pins on the surface of the solder pads, it also includes: making independent pins with plating; specifically The method includes: selecting a copper base material, and forming independent pins on the copper base material by stamping or etching; forming a nickel layer and a nickel-tin alloy layer on the surface of the pins in order to obtain a plated pin.

Preferably, after the step of manufacturing the independent plated pin, it further includes: manufacturing an independent thermosetting resin frame; specifically: molding the independent thermosetting resin frame by way of transfer molding.

Preferably, the step of assembling a prefabricated thermosetting resin frame on the insulating layer and potting thermoplastic resin includes:

forming a through hole for installing the intelligent power module on the thermosetting resin frame;

assembling the thermosetting resin frame with through holes on the insulating layer;

The insulating layer and the paper heat sink are pierced at the through holes of the thermosetting resin, so that the through holes penetrate the insulating layer and the paper heat sink.

Preferably, after the step of forming a partition on the back of the heat sink and fixing the prefabricated heat dissipation folds on the back of the heat sink corresponding to the position of the power element, the step further includes:

Carry out module function test.

Preferably, the step of forming a paper heat sink, covering the front of the heat sink with an insulating layer, and forming circuit wiring and welding pads on the surface of the insulating layer includes:

According to the set circuit layout, a wet carbon composite material with a predetermined size is selected to form a paper radiator;

On the front side of the radiator, insulating material and copper are used, and the insulating material is formed on the surface of the radiator as the insulating layer by hot pressing, and the copper is formed on the surface of the insulating layer as the copper foil layer;

Corroding a specific position of the copper foil layer, and forming circuit wiring and welding pads in the remaining part;

The step of forming a partition on the back of the heat sink and fixing the prefabricated heat dissipation folds on the back of the heat sink at a position corresponding to the power element includes:

By cutting, tearing, corroding, etc., the material at a specific position on the back of the paper heat sink is removed to form a partition.

Wet carbon composite material is used to form folds, which are bonded to the back of the heat sink corresponding to the position of the power element by high temperature resistant glue.

Preferably, the steps of assembling power components and non-power components on the surface of the circuit wiring, and assembling prefabricated pins on the surface of the pads include:

The power components, non-power components and pins are fixed by solder paste or silver glue.

The invention proposes an intelligent power module and its manufacturing method. A paper heat sink as a carrier is introduced into the intelligent power module, and a partition part is set on the back of the paper heat sink. The back of the heat sink is set corresponding to the position of the power element. Heat dissipation folds, the heat dissipation area is greatly increased, and the insulation layer can meet the heat dissipation requirements of power components without using high thermal conductivity materials; moreover, most of the heat of power components is quickly dissipated without being conducted to non-power components, so that non-power components always work In a low-temperature environment, the temperature drift of non-power components is greatly reduced, and the existence of the partition part of the power component group with different functions greatly reduces thermal crosstalk, and the heat generation of each heat-generating part is different but very little conduction between each other and dissipate through the wrinkles, which improves the electrical performance and thermal stability of the intelligent power module; the invention adopts a lighter paper heat sink, which reduces the overall weight of the intelligent power module and reduces the load used in processing. Low tool requirements, easy positioning, reduced manufacturing costs, improved process pass rate; saves the process of mounting power components to the internal heat sink, reducing equipment investment costs.

Description of drawings

FIG. 1(A) is a top view of an existing intelligent power module;

Fig. 1 (B) is the X-X ' line sectional view of Fig. 1 (A);

Fig. 1 (C) is the schematic diagram after Fig. 1 (A) removes resin;

Fig. 2 (A) is the rear view of the preferred embodiment of the intelligent power module of the present invention;

FIG. 2(B) is a front view of a preferred embodiment of the intelligent power module of the present invention;

Fig. 2 (C) is the sectional view of Fig. 2 (A) or Fig. 2 (B) X-X ' line;

Fig. 2(D) is a top view of the smart power module according to the embodiment of the present invention after removing the sealing resin;

Fig. 3 (A) is the front view of the paper radiator in the first process of the embodiment of the present invention;

Fig. 3 (B) is the sectional view of the X-X ' line of Fig. 3 (A);

Fig. 3 (C) is the schematic diagram that forms insulation layer and copper foil layer on the front of paper radiator;

Fig. 3 (D) is the schematic diagram that forms circuit wiring on the copper foil layer shown in Fig. 3 (C);

Fig. 3 (E) is the sectional view of the X-X ' line of Fig. 3 (D);

FIG. 3(F) is a schematic diagram of forming heat dissipation wrinkles;

Figure 3 (G) is a schematic diagram of a single pin;

Figure 3(H) is a schematic diagram of a single pin with a radian;

Fig. 4(A) is a side view of an intelligent power module assembled with power components, non-power components and pins in the second process of the embodiment of the present invention;

Fig. 4 (B) is the top view of Fig. 4 (A);

Fig. 5(A) is a side view of connecting power elements, non-power elements, heat sinks and circuit wiring through metal wires in the fourth process of the embodiment of the present invention;

Fig. 5 (B) is the top view of Fig. 5 (A);

Fig. 6 (A) is a side view of assembling a prefabricated thermosetting resin frame on the insulating layer in the fifth process of the embodiment of the present invention;

Fig. 6 (B) is the top view of Fig. 6 (A);

Fig. 6 (C) is a side view of the thermoplastic resin potting in the thermosetting resin frame in the fifth process of the embodiment of the present invention;

Fig. 7(A) is a top view of the through hole for installing the intelligent power module formed on the thermosetting resin frame in the sixth process of the embodiment of the present invention;

Fig. 7(B) is a bottom view of forming partitions on the back of the radiator and pasting heat dissipation folds on the corresponding positions of the power components in the sixth process of the embodiment of the present invention;

Fig. 7 (C) is the sectional view of the X-X ' line of Fig. 7 (B);

Fig. 8 is a flowchart of a manufacturing method of an intelligent power module according to an embodiment of the present invention.

In order to make the technical solution of the present invention clearer and clearer, it will be further described below in conjunction with the accompanying drawings.

Detailed ways

It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

As mentioned above, due to the poor heat dissipation effect of the existing intelligent power modules, working at high temperature for a long time will seriously reduce their service life and affect the stability of the intelligent module performance.

The present invention considers that in specific applications such as frequency conversion air conditioners, although the high thermal conductivity insulating layer and the addition of radiators can solve the heat dissipation problem of the intelligent power module, the cost of using the high thermal conductivity insulating layer for heat dissipation is very high on the one hand, and on the other hand Due to the use of a large amount of doping in the high thermal conductivity insulating layer, the smart power module is very hard, which increases the difficulty of manufacturing the smart power module; if a heat sink is added inside the smart power module, and the power components are mounted on the heat sink, On the one hand, it will increase the cost of raw materials, and on the other hand, it will also increase the difficulty of the process of the intelligent power module; if a heat sink is added outside the intelligent power module, the heat sink is mounted on the back of the intelligent power There are other heating elements on the board. If the same radiator is installed for all heating elements, the area of the radiator will be increased, thereby increasing the application cost. If radiators are installed separately for all heating elements, it will increase the difficulty of assembly. Therefore, the selection of high thermal conductivity insulating layer and the addition of heat sinks have created difficulties in the application and popularization of intelligent power modules, which is not conducive to the popularization of intelligent power modules in civilian applications such as frequency conversion air conditioners.

Based on the above considerations, the embodiment of the present invention introduces a paper heat sink, forms a partition on the back of the paper heat sink and arranges heat dissipation wrinkles at positions corresponding to power components, and forms an insulating layer and a circuit on the front of the paper heat sink Wiring, power components, non-power components and other elements, and complete orderly processing, because the paper heat sink is lighter in weight, has low requirements for the carrier used in processing, and is easy to locate, which can reduce manufacturing costs and improve process pass rate; save Eliminate the process of mounting power components to the internal heat sink, reducing equipment investment costs; in addition, due to the heat dissipation folds on the back of the paper heat sink, the heat dissipation area is greatly increased, and the power components with different functions are due to The existence of the partition greatly reduces thermal crosstalk. Although the heat generation of each heating part is different from each other, it is seldom conducted between each other and dissipated through the folds. Under the premise of using a common insulating layer, the intelligent power module and its The heat-generating parts of the application platform have a good heat dissipation effect, and there is little thermal interference between the heat-generating sources, which makes the performance of the intelligent power module stable, thereby improving the reliability of the intelligent power module; in addition, the paper heat sink is also convenient for transportation .

Specifically, referring to FIG. 2(A), FIG. 2(B), FIG. 2(C) and FIG. 2(D), an intelligent power module 10 proposed by an embodiment of the present invention, this embodiment has a bridge stack , compressor inverter, power factor correction, and fan inverter function of the intelligent power module 10 as an example to illustrate, for applications that do not need the fan inverter function, just remove the fan inverter part, and the other parts are identical.

The intelligent power module 10 of this embodiment includes a paper radiator 17 as a carrier, a circuit wiring 18, a power element 19 and a non-power element 14 arranged at a predetermined position of the circuit wiring 18; wherein:

One side of the radiator 17 is used as the front side, and the other side is used as the back side.

The front surface of the radiator 17 is covered with an insulating layer 21 , and the circuit wiring 18 is arranged on a side of the insulating layer 21 away from the radiator 17 .

Corrugations 17A for heat dissipation are provided on the back of the heat sink 17 at positions corresponding to the power elements 19 .

Wherein, both the radiator 17 and the crease 17A can use wet carbon composite material functional paper.

A partition 22 is provided on the back of the radiator 17. The partition 22 is formed by removing the heat dissipation material at a specific position on the back of the radiator. It can be partially removed or completely removed to expose the insulating layer 21. In order to obtain a better heat dissipation effect in this embodiment , adopt the way of all removal.

Here, the corrugation 17A must be provided below the power element 19 , and the power element 19 is not provided above the partition portion 22 .

The heat sink 17 and the folds 17A can be bonded by high-temperature glue, or both can be integrally formed.

(Follow-up details).

In addition, the intelligent power module 10 further includes: a metal wire 15 for connecting the circuit wiring 18 , the power element 19 and the non-power element 14 to form a corresponding circuit.

Here, the circuit composed of the power element 19, the non-power element 14, the circuit wiring 18, and the metal wire 15 has functions of bridge stack, compressor inverter and power factor correction, or has bridge stack, Compressor inverter, power factor correction and fan inverter functions, so that all heating circuits in the application fields such as frequency conversion air conditioners are integrated together to dissipate heat at the same time; this embodiment is equipped with bridge stack, compressor inverter, power factor correction, fan inverter function of the intelligent power module 10 as an example, for applications that do not require the inverter function of the wind turbine, the inverter part of the wind turbine can be removed, and the other parts are completely the same.

As shown in Figure 2(A) and Figure 2(B), the circuit unit 1001 implements the bridge stack function, the circuit unit 1002 implements the compressor inverter function, the circuit unit 1003 implements power factor correction, and the circuit unit 1004 implements the fan inverter function.

Here, the bridge stack, the driving part of the inverter of the compressor, the driving part of the power factor correction, the driving part of the fan inverter and other control parts are isolated by the partition part 22 .

In addition, the intelligent power module 10 further includes: input and output pins disposed on the edge of the power module, connected to the circuit wiring 18 and extending in a direction opposite to the heat dissipation folds.

Here, according to the internal circuit layout and peripheral application requirements of the intelligent power module 10 , the pins 11 can be arranged on one edge, two edges, three edges or four edges of the intelligent power module 10 .

In addition, the intelligent power module 10 further includes: a thermosetting resin frame 13' disposed on the insulating layer.

Here, the height of the thermosetting resin frame must be higher than that of the metal wire 15 .

In this embodiment, the circuit wiring 18, the power element 19, the non-power element 14, the metal wire 15, and the connection part between the pin 11 and the circuit wiring 18 are encapsulated by a thermoplastic sealing resin 12, and the thermoplastic sealing resin 12 filling the thermosetting resin frame 13 to seal all elements, only the pin 11 is partially exposed.

In addition, the intelligent power module 10 further includes: a through hole 16 for installing the intelligent power module 10 .

Here, the through hole 16 penetrates the thermosetting resin frame 13 , the insulating layer 21 and the paper heat sink 17 . The heat dissipation folds 17A are located on the back of the power element 19 and surrounded by the partition 22, and the distance between the short edge of the back of the paper heat sink 17 is at least 2mm, so as to ensure that the through hole 16 is not formed. block.

In addition, the circuit wiring 18 may form one or more pads 18A on at least one edge of the insulating layer 21; The pins 11 are fixed through the pads 18A and connected to the circuit wiring 18.

The components of the smart power module 10 according to the embodiment of the present invention are described in detail below:

Among them, the paper radiator 17 is a wet-type carbon composite material functional paper, which can be compositely processed into graphite by powder and fibrous carbon materials. The wet-type carbon composite material can withstand high temperatures above 350°C and can be folded into Any shape can be used to obtain the heat dissipation corrugations 17A. In order to improve corrosion resistance and waterproof, the surface can be waterproofed.

The paper radiator 17 can be made integrally with the heat dissipation folds 17A, or can be bonded with the heat dissipation folds 17A by high-temperature glue.

Wherein, the two sides of paper radiator 17 are smooth, and the shape of heat dissipation fold 17A is irregular; Described paper radiator 17 and heat dissipation fold 17A also can be the wet carbon composite material that adopts different thickness, wherein, in order to increase Mechanical strength, the paper radiator 17 adopts a thicker wet carbon composite material, and its thickness is preferably 1.5mm to 2.5mm. In actual design, the thickness of the thin part can be designed to be 1.5mm, and the thickness of the thick part can be 2.5mm. To reduce the cost and increase the density of the pleats 17A, the radiating pleats 17A use a thinner wet carbon composite material, and as an optimal solution, the thickness can be designed to be 0.5mm.

The insulating layer 21 can use commonly used insulating materials, and can be doped with silicon dioxide, silicon nitride, silicon carbide, etc. to improve thermal conductivity. Here, the doping can be spherical or angular. On the surface of the paper radiator 17, i.e. the front side.

The circuit wiring 18 is made of metal such as copper, and is formed at a specific position on the insulating layer 21. According to the power requirement, the thickness of the circuit wiring 18 can be designed to be 0.035mm or 0.07mm, etc. For general intelligent power modules 10, it is preferred to It is designed to be 0.07 mm, and a thickness of 0.07 mm is adopted in this embodiment. In addition, on the edge of the insulating layer 21, a pad 18A composed of the circuit wiring 18 is formed. Here, a plurality of aligned pads 18A are provided near one side of the insulating layer 21, and according to functional requirements, a plurality of aligned pads 18A may also be provided near multiple edges of the insulating layer 21. .

The partition part 22 is a hollow formed by hollowing out the paper radiator 17, and the partition part is located between the heating power element groups of each functional circuit, making it impossible for heat to pass through the paper radiator 17 with high thermal conductivity. Conduction, the width of the partition 22 is determined according to the distance between the heating power element groups. Generally speaking, in order to achieve the effect of the thermal partition, the width of the partition 22 should not be less than 1mm. In order to increase the strength For the mechanical strength of the paper radiator 17, the width of the partition 22 should not be greater than 5 mm. In addition, the partition part 22 can completely remove the paper heat sink 17 to expose the insulating layer 21, or only remove most of the paper heat sink 17 and keep it in combination with the insulating layer 21. In this embodiment, the extremely thin layer is completely removed.

The power element 19 and the non-power element 14 are fixed on the circuit wiring 18 to form a predetermined circuit. Here, the power element 19 can be an IGBT tube, a high-voltage MOSFET tube, a high-voltage FRD tube, a high-voltage diode, etc., and the power element 19 is connected to the circuit wiring 18 through a metal wire 15; the non-power element 14 adopts an integrated Active elements such as circuits, transistors, and diodes, or passive elements such as capacitors and resistors, active elements mounted face-up, and the like are connected to circuit wiring 18 through wires 15 . Here, there is at least a distance of 2 mm between the respective power elements 19 of the circuit unit 1001 , the circuit unit 1002 , the circuit unit 1003 , and the circuit unit 1004 .

The metal wires 15 can be aluminum wires, gold wires or copper wires, and electrical connections are established between the power elements 19, between the non-power elements 14, and between the circuit wirings 18 through binding; in addition, the metal wires 15 can also be used to establish an electrical connection between the pin 11 and the circuit wiring 18 or the power element 19 and the non-power element 14 . For the connection of the power element 19, an aluminum wire of 300 μm to 400 μm can be used, for the electrical connection of the non-power element 14, an aluminum wire of 38 μm to 125 μm can be used, if there is a connection across the through hole 22, an aluminum wire of 250 μm or more is preferably used . Here, preferably no bonding point for the metal wire 15 is designed above the partition portion 22 .

The pin 11 is fixed on a pad 18A provided on one edge of the circuit wiring 18, and has the functions of inputting and outputting with the outside.

As an implementation manner, it may be designed that one side of the smart power module 10 is provided with multiple pins 11 , and the pins 11 and the pads 18A are welded by conductive electrical adhesive such as solder. The pin 11 can be made of copper and other metals. The copper surface forms a layer of nickel-tin alloy layer through electroless plating and electroplating. The thickness of the alloy layer is generally 5 μm. The plating layer can protect copper from corrosion and oxidation and improve solderability.

The thermosetting resin frame 13 is formed by transfer molding, and the size of the outer edge of the thermosetting resin frame 13 is consistent with or slightly smaller than the paper radiator 17. The distance between the inner edge and the outer edge of the resin frame 13 is not less than 1.5mm, and at the short side of the rectangle of the thermosetting resin frame 13, there is a through hole with the same diameter as the position and diameter of the through hole of the paper radiator 17.

The thermoplastic resin 12 is molded by injection molding. Here, the thermoplastic resin 12 is completely inside the thermosetting resin frame 13 and seals all elements on the upper surface of the paper heat sink 17 .

The through hole 16 is composed of the through hole of the thermosetting resin frame 13, the through hole of the insulating layer 21, and the through hole of the paper radiator 17, and runs through the thermosetting resin frame 13, the Insulation layer 21, the paper radiator 17.

Compared with the prior art, the intelligent power module 10 of the embodiment of the present invention has the following beneficial effects:

1. Since the intelligent power module 10 of the present invention has heat dissipation folds 17A on the back, the heat dissipation area is greatly increased, and the insulating layer 21 can meet the heat dissipation requirements of the power element 19 without using high thermal conductivity materials.

2. The intelligent power module 10 has the functions of bridge stack and compressor inverter, or has the functions of bridge stack, compressor inverter, and fan inverter, so that all heating circuits in the application fields such as frequency conversion air conditioners can be integrated together to dissipate heat at the same time.

3. The heat dissipation folds 17A are located under the power element 19, so that most of the heat of the heating element is quickly dissipated and not conducted to the non-power element 14, so that the non-power element 14 always works in a low temperature environment, and the temperature of the non-power element 14 Drift is greatly reduced, improving the electrical performance and thermal stability of the intelligent power module 10 .

4. The bridge stack, the driving part of the compressor inverter, the driving part of the power factor correction, the driving part of the fan inverter and other control parts (including non-power components 14, etc.) The thermal interference is very low, most of the heat is dissipated through the folds 17A, and the temperature of the control part is kept at a low state, avoiding the performance degradation of the intelligent power module 10 caused by the temperature drift of the control part.

5. The heat dissipation structure is made of paper material, which is light in weight, so that the overall weight of the intelligent power module 10 is reduced, which is convenient for long-distance transportation and assembly by workers; since the intelligent power module 10 of the present invention is equipped with a radiator 17, no external connection is required during the application process. The radiator 17 reduces application difficulty and application cost, and improves assembly quality.

It can be seen from the above that the smart power module 10 of the present invention improves reliability and performance while reducing costs, and can be designed to be compatible with the functions of the current smart power module 10 and the definition of pins 11, which facilitates the popularization and application of the smart power module 10.

In addition, an embodiment of the present invention also proposes a manufacturing method of the intelligent power module 10, including:

Step S1 , forming a paper radiator 17 , covering the front surface of the radiator 17 with an insulating layer 21 , and forming circuit wiring 18 and welding pads 18A on the surface of the insulating layer 21 .

Specifically, a wet carbon composite material with a predetermined size is selected according to the set circuit layout to form the paper heat sink 17 .

On the front side of the heat sink 17, insulating material and copper material are used, and the insulating material is formed on the surface of the heat sink 17 as the insulating layer 21 by hot pressing, and the copper material is formed on the insulating layer 21 surface as a copper foil layer.

After that, the specific position of the copper foil layer is etched away, and the remaining part forms the circuit wiring 18 and the welding pad 18A.

Step S2 , assembling the power element 19 and the non-power element 14 on the surface of the circuit wiring 18 , and assembling the prefabricated pin 11 on the surface of the solder pad 18A.

Step S3 , connecting the power element 19 , the non-power element 14 and the circuit wiring 18 through the metal wire 15 to form a corresponding circuit.

Step S4 , assembling the prefabricated thermosetting resin frame 13 on the insulating layer 21 and potting the thermoplastic sealing resin 12 .

Step S5 , forming the partition portion 22 on the back of the heat sink 17 , and fixing the prefabricated heat dissipation folds 17A on the back of the heat sink 17 corresponding to the position of the power element 19 .

Specifically, the material at a specific position on the back of the paper heat sink 17 is removed by means of cutting, tearing, corrosion, etc., to form a partition.

The corrugation 17A is formed by wet carbon composite material, and bonded to the back of the radiator 17 by high temperature resistant glue.

Further, it may also include before step S3:

In step S6, the radiator 17 equipped with various elements is placed in a cleaning machine for cleaning.

Further, before the step S2, it may also include: forming an independent pin 11 with plating.

Specifically, firstly, a copper substrate is selected, and the copper substrate is stamped or etched to form individual pins 11 .

Then, a nickel layer and a nickel-tin alloy layer are sequentially formed on the surface of the pin 11 to obtain a plated pin 11 .

Further, after the above step S5, it also includes: performing a module function test.

The manufacturing process of the smart power module 10 of this embodiment will be described in detail below with reference to the accompanying drawings.

As a preferred embodiment, the manufacturing method of the intelligent power module 10 of the present invention may include: the process of forming the paper radiator 17 and the heat dissipation folds 17A, and the process of forming the circuit wiring 18 and the welding pad 18A on the insulating layer 21 ; the process of disposing the power element 19, the non-power element 14 and the pin 11 on the circuit wiring 18; the process of cleaning; the process of connecting the non-power element 14, the power element 19 and the circuit wiring 16 with a metal wire 15; The process of arranging the thermosetting resin frame 13 on the surface of the paper radiator 17; the process of sealing the above elements by injection molding with the thermoplastic resin 12; Process; a process for performing functional tests. The specific process diagram is shown in Figure 8.

The details of each step will be described below.

The first process: refer to Figure 3 (A), Figure 3 (B), Figure 3 (C), Figure 3 (D), Figure 39 (E), Figure 3 (F), Figure 3 (G) and Figure 3 ( h).

Fig. 3 (A) is the front view of the paper radiator in the first process of the embodiment of the present invention;

Fig. 3 (B) is the sectional view of the X-X ' line of Fig. 3 (A);

Fig. 3 (C) is the schematic diagram that forms insulation layer and copper foil layer on the front of paper radiator;

Fig. 3 (D) is the schematic diagram that forms circuit wiring on the copper foil layer shown in Fig. 3 (C);

Fig. 3 (E) is the sectional view of the X-X ' line of Fig. 3 (D);

FIG. 3(F) is a schematic diagram of forming heat dissipation wrinkles;

Figure 3 (G) is a schematic diagram of a single pin;

Figure 3(H) is a schematic diagram of a single pin with arcs.

The first process of the embodiment of the present invention is the process of forming a wet carbon composite material of appropriate size to form the paper radiator 17 and heat dissipation corrugations 17A, and the process of making an independent plated pin 11 .

First, referring to Fig. 3(A) and the sectional view 3(B) along the XX' line of Fig. 3(A), design a paper heat sink 17 of appropriate size according to the required circuit layout, for general intelligent power modules , the size of one piece can be selected as 64mm×30mm, and the thickness is 1.5mm, and the two sides are treated with anti-corrosion and waterproof treatment such as coating waterproof glue.

With reference to Fig. 3 (C), use the insulating material and copper material with angular or spherical doping, through the mode of hot pressing at the same time, make insulating material be formed on the surface of described paper radiator 17 and serve as described insulating layer 21, Copper material is formed on the surface of the insulating layer 21 as the copper foil layer 18B. Here, in order to improve the withstand voltage characteristic, the thickness of the insulating layer 21 may be designed to be 110 μm, and in order to improve the heat dissipation characteristic, the thickness of the insulating layer 21 may be designed to be 70 μm. Here, in order to improve the flow capacity, the thickness of the copper foil layer 18B can be designed to be 0.07mm, and in order to reduce the cost, the thickness of the copper foil layer 18B can be designed to be 0.035mm or 0.0175mm.

With reference to Fig. 3 (D) and the cross-sectional view 3 (E) of the X-X' line of Fig. 3 (D), the specific position of the copper foil layer 18B is etched away, and the remainder is circuit wiring 18 and welding pad 18A.

Referring to FIG. 3(F), a wet-type carbon composite material having a thickness of 0.5 mm is used to form irregular shapes as the heat dissipation corrugations 17A. Carry out anti-corrosion and waterproof treatment such as coating waterproof glue on both sides.

Each pin 11 is made of a copper substrate by stamping or etching, as shown in Figure 3 (G). The individual pin unit has a length C of 25 mm, a width K of 1.5 mm, and a thickness H of 1mm strip; in the present embodiment, for the convenience of assembly, a 90° arc is also pressed at one end of the pin unit, as shown in Figure 3(H);

The nickel layer is then formed by electroless plating, specifically including:

Through the mixed solution of nickel salt and sodium hypophosphite, and adding an appropriate complexing agent, a nickel layer is formed on the surface of the copper material that has formed a specific shape. Metal nickel has a strong passivation ability and can quickly form an extremely thin layer. The passivation film can resist the corrosion of atmosphere, alkali and some acids. The crystals of nickel plating are extremely small, and the thickness of the nickel layer is generally 0.1 μm.

Then, through the acid sulfate process, the copper material with the formed shape and nickel layer is immersed in the plating solution with positive tin ions at room temperature and energized to form a nickel-tin alloy layer on the surface of the nickel layer. The alloy layer is generally controlled at 5 μm , The formation of the alloy layer greatly improves the protection and solderability of the pins.

The second process: refer to Fig. 4(A) and Fig. 4(B).

Fig. 4(A) is a side view of an intelligent power module assembled with power components, non-power components and pins in the second process of the embodiment of the present invention, and Fig. 4(B) is a top view of Fig. 4(A).

The second process of the embodiment of the present invention is a process of assembling the power element 19 and the non-power element 14 on the surface of the circuit wiring 18 and assembling the pin 11 on the surface of the solder pad 18A.

First, use a stencil to apply solder paste to the specific position of the circuit wiring 18 on the insulating layer 21 and the solder pad 18A by using a solder paste printing machine; A steel mesh with a thickness of 0.15 mm is used, and in order to reduce the risk of displacement of the power device 19 and the non-power element 14, a steel mesh with a thickness of 0.12 mm can be used. In this embodiment, the height of the power element 19 used is 0.07mm, which is a relatively light component, so the thickness of the steel mesh can be selected as a steel mesh with a thickness of 0.12mm. In other embodiments, other suitable sizes can also be used. Here Not limited.

Then, with reference to side view Fig. 4 (A) and plan view Fig. 4 (B), described paper radiator 17 is placed on carrier 20, carries out the installation of described power element 19, non-power element 14 and pin 11 , the power element 19 and the non-power element 14 can be placed directly on the specific position of the circuit wiring 18, and one end of the pin 11 should be placed on the pad 18A, and the other end needs the carrier 20 The carrier 20 and the fixing device 20A are made of materials such as synthetic stone. Here, the carrier 20 needs to be hollowed out at the bottom, so that the heat dissipation folds 17A are exposed, and the position of the back edge of the paper heat sink 17 that is at least 1 mm not covered by the heat dissipation folds 17A is in contact with the carrier. Tool 20 contacts and plays a supporting role.

Then, the paper radiator 17 placed on the carrier 20 is reflowed, the solder paste is solidified, and the power components 19 , non-power components 14 and the pins 11 are fixed.

In the above process, as a preferred method, solder paste with a melting temperature of 280° C. can be selected.

It should be noted that, in other implementation manners, silver glue or silver paste can also be selected to replace the above-mentioned solder paste.

The third process:

The third process of the embodiment of the present invention is the process of cleaning the paper radiator 17 .

First, put the paper heat sink 17 into a cleaning machine for cleaning, and clean the residual flux such as rosin during reflow soldering and the residual aluminum wire and other foreign matters during stamping. The arrangement density of the wiring 18 and the cleaning can be performed by spraying or ultrasonic or a combination of both.

When cleaning, clamp the pin 11 by the mechanical arm, place the paper heat sink 17 in the cleaning tank, and be careful not to let the mechanical arm touch the paper heat sink 17, because the paper heat sink 17 The radiator 17 is brittle and easily deformed. If the mechanical arm clamps the paper radiator 17, the vibration generated during cleaning may easily cause the paper radiator 17 to crack.

The fourth process: Referring to Figure 5(A) and Figure 5(B), Figure 5(A) is the fifth process of the embodiment of the present invention, through metal wires to form between power elements, non-power elements, heat sinks and circuit wiring The side view of the connection, Fig. 5(B) is the top view of Fig. 5(A).

The fourth step in the embodiment of the present invention is a step of connecting the power element 19 , the non-power element 14 , the heat sink 17 and the circuit wiring 18 through metal wires (also called binding wires).

According to the needs of flow capacity, choose aluminum wires with appropriate diameters as metal wires. For integrated circuits used for signal control, you can also consider using gold wires as metal wires. In this embodiment, all aluminum wires are selected. Generally speaking, aluminum wires of 350 μm to 400 μm are used for the bonding of the power elements 19, and aluminum wires of 38 μm to 200 μm are used for the bonding of the non-power elements 14. Aluminum wires of 350 μm to 400 μm are used for bonding the heat sink 17 .

The finished product after this process can refer to the side view Fig. 5(A) and the top view Fig. 5(B).

Among them, the power element 19, the non-power element 14, the heat sink 13 and the circuit wiring 18 are connected by metal wires to form a corresponding circuit.

As shown in FIG. 5(B), the circuit unit 1001 realizes the bridge stack function, the circuit unit 1002 realizes the compressor inverter function, the circuit unit 1003 realizes the power factor correction function, and the The circuit unit 1004 implements the fan inverter function.

The fifth step: refer to FIG. 6(A), FIG. 6(B) and FIG. 6(C).

Fig. 6 (A) is the side view of prefabricated thermosetting resin frame assembled on the insulating layer in the fifth process of the embodiment of the present invention, Fig. 6 (B) is the top view of Fig. 6 (A), Fig. 6 (C) It is a side view of the thermoplastic resin potting in the thermosetting resin frame in the fifth process of the embodiment of the present invention.

The fifth process of the embodiment of the present invention is the process of assembling the thermosetting resin frame 13 on the insulating layer 21 and potting the thermoplastic resin 12 .

First, stick the thermosetting resin frame 13 with a through hole on the short side of the rectangle on the insulating layer 21 through non-conductive thermosetting glue such as insulating red glue, and attach the thermosetting resin frame 13 in an oxygen-free environment. The paper radiator 17 of the hard resin frame 13 is baked, the baking time should not be less than 2 hours, and the baking temperature is 175°C, so that the thermosetting resin frame 13 is fixed on the insulating layer 21 , see side view Figure 6(A) and top view Figure 6(B). Here, the height of the thermosetting resin frame 13 must be higher than that of the metal wire 15 .

Then, inject thermoplastic resin 12 into the thermosetting resin frame 13 until the thermosetting value frame 13 is filled. The injection temperature of the thermoplastic resin 12 is 150° C. After cooling, the thermoplastic resin 12 seals all elements on the paper radiator 17 , and only the pins 11 are partially exposed.

The sixth process: refer to Fig. 7(A), Fig. 7(B) and Fig. 7(C).

Fig. 7(A) is a top view of the through hole for installing the intelligent power module formed on the thermosetting resin frame in the sixth process of the embodiment of the present invention, and Fig. 7(B) is the sixth process of the embodiment of the present invention, in The back of the heat sink forms a partition and sticks heat dissipation corrugations on the corresponding positions of the power components. Fig. 7(C) is a cross-sectional view along line XX' of Fig. 7(B).

The sixth process of the embodiment of the present invention is the process of forming the through hole 16 and the partition portion 22 and fixing the heat dissipation folds 17A. The intelligent power module is completed as a finished product through this process.

Referring to FIG. 7(A), the insulating layer 21 and the paper radiator 17 are punched through the through hole of the thermosetting resin 13 by means of a puncher or the like to form a through hole 16 . The through hole 16 is used for assembling the smart power module 10 .

Referring to FIG. 7(B), by cutting, tearing, corroding, etc., a specific position on the back of the paper heat sink 17 is processed, so that the paper heat dissipation material at the specific position is removed to form the partition portion 22, The two sides of the partition 22 are heating power element groups with different functional circuits. The paper heat dissipation material can be partially removed, or all of it can be removed to expose the insulating layer 21. In order to obtain a better thermal isolation effect in this embodiment, the entire removal method is adopted, and the paper heat dissipation material is completely removed in the partition part 22. In this manner, care should be taken not to form scratches on the insulating layer 21 .

Referring to FIG. 7(C), the heat-dissipating folds 17A are adhered to the back of the paper heat sink 17 by using high-temperature-resistant glue with a temperature resistance above 150°C. Here, the heat-dissipating folds 17A are located The back of the power element 19 is surrounded by the partition 22 , and the distance from the short edge of the back of the paper heat sink 17 is at least 2 mm to ensure that the through hole 16 is not blocked.

Then put the intelligent power module 10 into the test equipment, and conduct conventional electrical parameter tests, generally including test items such as insulation withstand voltage, static power consumption, and delay time, and those that pass the test are finished products.

Using the above process, the smart power module 10 shown in FIG. 2(A), FIG. 2(B), FIG. 2(C) and FIG. 2(D) is completed.

The invention proposes an intelligent power module and its manufacturing method. A paper heat sink as a carrier is introduced into the intelligent power module, and a partition part is set on the back of the paper heat sink. The back of the heat sink is set corresponding to the position of the power element. Heat dissipation folds, the heat dissipation area is greatly increased, and the insulation layer can meet the heat dissipation requirements of power components without using high thermal conductivity materials; moreover, most of the heat of power components is quickly dissipated without being conducted to non-power components, so that non-power components always work In a low-temperature environment, the temperature drift of non-power components is greatly reduced, and the existence of the partition part of the power component group with different functions greatly reduces thermal crosstalk. Although the heat generation of each heat-generating part is different, it is very little Conduction between each other and dissipate through the wrinkles improves the electrical performance and thermal stability of the intelligent power module; the invention adopts a lighter paper heat sink, which has low requirements for the carrier used in processing, easy positioning, and reduces the The manufacturing cost is improved, and the pass rate of the process is improved; the process of mounting power components to the internal heat sink is omitted, which reduces equipment investment costs.

The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or process transformation made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technical fields, shall be The same reasoning is included in the patent protection scope of the present invention.

Claims (17)

1. An intelligent power module, comprising circuit wiring, power components and non-power components arranged at predetermined positions of the circuit wiring, characterized in that it also includes a paper heat sink as a carrier, and one side of the heat sink is used as the front Covered with an insulating layer, the circuit wiring is arranged on the side of the insulating layer away from the heat sink; the other side of the heat sink is used as the back side, and corrugations for heat dissipation are provided at positions corresponding to the power components, A partition is provided on the back of the radiator. 2. The intelligent power module according to claim 1, characterized in that there is a set interval between the power element and the non-power element, and the partition is arranged on the back of the radiator corresponding to the interval The position of the zone, the width of the partition part is 1 mm to 5 mm. 3. The intelligent power module according to claim 1 or 2, further comprising a metal wire for connecting the circuit wiring, the power element and the non-power element to form a corresponding circuit. 4. The intelligent power module according to claim 3, further comprising pins disposed on the edge of the power module, connected to the circuit wiring, and extending in a direction opposite to the wrinkle as input and output pins . 5. The intelligent power module according to claim 4, characterized in that a thermosetting resin frame is provided along the edge of the insulating layer, the circuit wiring, the power components and non-power components, metal wires, and the A connection portion of the pin and the circuit wiring is encapsulated by a thermoplastic resin filling the thermosetting resin frame. 6. The intelligent power module according to claim 5, wherein the thermosetting resin frame is provided with a through hole for installing the intelligent power module, and the through hole penetrates the thermosetting resin frame, the The insulating layer and the paper radiator. 7. The intelligent power module according to claim 5, wherein the circuit wiring forms one or more welding pads on at least one edge of the insulating layer; the plurality of welding pads are formed along the edge of the insulating layer arranged in edge alignment; the pins are fixed through the pads and connected to the circuit wiring. 8. The intelligent power module according to claim 1, characterized in that, the heat sink and the pleats are both wet carbon composite material functional paper; the heat sink and the pleats are bonded or integrated into; the thickness of the heat sink is 1.5 mm to 2.5 mm, and the thickness of the heat sink is greater than the thickness of the folds. 9. The intelligent power module according to claim 3, characterized in that, the circuit composed of the power element, the non-power element, the circuit wiring, and the metal wire has a bridge stack, a compressor inverter, and Power factor correction function, or bridge stack, compressor inverter, power factor correction and fan inverter function. 10. A method for manufacturing an intelligent power module, comprising the following steps: Forming a paper heat sink, covering the front of the heat sink with an insulating layer, and forming circuit wiring and welding pads on the surface of the insulating layer; assembling power components and non-power components on the surface of the circuit wiring, and assembling prefabricated pins on the surface of the pad; Connecting the power elements, non-power elements and the circuit wiring through metal wires to form corresponding circuits; Assembling a prefabricated thermosetting resin frame on the insulating layer and potting thermoplastic resin; A partition is formed on the back of the heat sink, and the prefabricated heat dissipation folds are fixed on the back of the heat sink corresponding to the position of the power element. 11. The manufacturing method of an intelligent power module according to claim 10, characterized in that, before the step of connecting the power element, the non-power element and the circuit wiring through metal wires to form a corresponding circuit, it further comprises : Place the radiator with the elements assembled in the washing machine for cleaning. 12. The manufacturing method of an intelligent power module according to claim 10, characterized in that assembling power components and non-power components on the surface of the circuit wiring, and assembling prefabricated pins on the surface of the solder pads Before the steps also include: Manufactured as a separate plated lead; specifically includes: Select the copper substrate, and make independent pins on the copper substrate by stamping or etching; A nickel layer and a nickel-tin alloy layer are sequentially formed on the surface of the pin to obtain a plated pin. 13. The method for manufacturing an intelligent power module according to claim 12, characterized in that, after the step of making independent pins with plating, it further comprises: Made into an independent thermosetting resin frame; Specifically, an independent thermosetting resin frame is molded by means of a transfer mold. 14. The manufacturing method of an intelligent power module according to claim 13, wherein the step of assembling a prefabricated thermosetting resin frame on the insulating layer and potting thermoplastic resin comprises: forming a through hole for installing the intelligent power module on the thermosetting resin frame; assembling the thermosetting resin frame with through holes on the insulating layer; The insulating layer and the paper heat sink are pierced at the through holes of the thermosetting resin, so that the through holes penetrate the insulating layer and the paper heat sink. 15. The manufacturing method of an intelligent power module according to claim 14, characterized in that, the partition part is formed on the back of the heat sink, and the prefabricated heat dissipation folds are fixed on the back of the heat sink to correspond to After the step of positioning the power element, it also includes: Carry out module function test. 16. The manufacturing method of an intelligent power module according to any one of claims 10-15, characterized in that, in the formation of a paper heat sink, an insulating layer is covered on the front of the heat sink, and an insulating layer is formed on the surface of the insulating layer The steps for circuit routing and pads include: According to the set circuit layout, a wet carbon composite material with a predetermined size is selected to form a paper radiator; On the front side of the radiator, insulating material and copper are used, and the insulating material is formed on the surface of the radiator as the insulating layer by hot pressing, and the copper is formed on the surface of the insulating layer as the copper foil layer; Corroding a specific position of the copper foil layer, and forming circuit wiring and welding pads in the remaining part; The step of forming a partition on the back of the heat sink and fixing the prefabricated heat dissipation folds on the back of the heat sink at a position corresponding to the power element includes: By cutting, tearing, corroding, etc., the material at a specific position on the back of the paper heat sink is removed to form a partition. Wet carbon composite material is used to form folds, which are bonded to the back of the heat sink corresponding to the position of the power element by high temperature resistant glue. 17. The manufacturing method of an intelligent power module according to claim 16, characterized in that assembling power components and non-power components on the surface of the circuit wiring, and assembling prefabricated pins on the surface of the solder pads The steps include: The power components, non-power components and pins are fixed by solder paste or silver glue.