CN207458932U - Intelligent power module - Google Patents

Abstract

The utility model discloses a kind of intelligent power module, intelligent power module includes：Substrate, the side wall of substrate include upper tilting section and lower tilting section, and upper tilting section is from top to bottom towards outer incline, and lower tilting section is from top to bottom towards outer incline；Insulating layer, insulating layer are located at the upper surface of substrate；Wiring layer, wiring layer are set on the insulating layer；Multiple electronic components, multiple electronic components are located on wiring layer, are electrically connected between multiple electronic components or between electronic component and wiring layer；Multiple pins, multiple pins are located at at least one side edge of substrate, and pin is electrically connected with wiring layer；Sealing resin layer, sealing resin layer are wrapped in outside the substrate equipped with electronic component, and wherein the lower surface of substrate is exposed.The intelligent power module of the utility model, perfect heat-dissipating, and aqueous vapor not easily pass through the gap intrusion between sealing resin layer and substrate, and the work of intelligent power module is more stable.

Description

Intelligent Power Module

technical field

The utility model belongs to the technical field of intelligent power module manufacturing, and in particular relates to an intelligent power module.

Background technique

Intelligent Power Module, or IPM (Intelligent Power Module), is a power drive product that combines power electronics technology 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 (Microcontroller Unit) to drive the subsequent circuit to work, and on the other hand, it sends the system status detection signal back to the MCU. Compared with traditional discrete solutions, intelligent power modules have won an increasing market due to their advantages of high integration and high reliability. They are especially suitable for inverters and various inverter power supplies for driving motors. An ideal power electronic device for machinery, electric traction, servo drives, and frequency conversion appliances.

Smart power modules generally work in harsh working conditions, such as the outdoor unit of an inverter air conditioner. Under high temperature and high humidity, the high temperature will increase the internal temperature of the smart power module. For the current structure of the smart power module that is completely sealed by sealing resin , the interior of the intelligent power module is very easy to generate heat accumulation. If the lower surface of the circuit substrate is exposed, the vertical gap between the sealing resin and the circuit substrate is very easy for water to enter. In addition, the design of the circuit substrate with vertical edges, the circuit substrate Production requires mold opening, which increases the cost and manufacturing difficulty. Problems such as mold loss and long-term use deviation make it difficult to improve the production yield of smart power modules. The cost of smart power modules remains high, which affects the popularization of smart power modules. application.

Utility model content

The utility model aims at at least solving one of the technical problems existing in the prior art. For this reason, the utility model proposes an intelligent power module, and the intelligent power module is not easy to invade water vapor.

The smart power module according to the embodiment of the present invention includes: a base plate, the side wall of the base plate includes an upper inclined section and a lower inclined section, the upper inclined section is inclined outward from top to bottom, and the lower inclined section is Inclined upwards and outwards; an insulating layer, the insulating layer is arranged on the upper surface of the substrate; a wiring layer, the wiring layer is arranged on the insulating layer; a plurality of electronic components, a plurality of electronic elements are arranged on On the wiring layer, a plurality of the electronic components or between the electronic components and the wiring layer are electrically connected; a plurality of pins, and a plurality of the pins are arranged on at least one side edge of the substrate and the pins are electrically connected to the wiring layer; a sealing resin layer, the sealing resin layer wrapping the outside of the substrate provided with the electronic components, wherein the lower surface of the substrate is exposed.

According to the intelligent power module of the embodiment of the utility model, the heat dissipation performance is good, and water vapor is not easy to intrude through the gap between the sealing resin layer and the substrate, and the operation of the intelligent power module is more stable.

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

Description of drawings

The above and/or additional aspects and advantages of the present utility model will become apparent and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

Fig. 1 is a schematic structural diagram of an intelligent power module according to an embodiment of the present invention;

Fig. 2 is the sectional view of X-X ' place among Fig. 1;

Fig. 3 is a top view of the smart power module according to the embodiment of the present invention after removing the sealing resin layer;

Fig. 4 is a process diagram of arranging an insulating layer and a wiring layer on a substrate;

5 is a process diagram of cutting the aluminum plate on which the wiring layer is arranged to form the substrate;

Fig. 6 is a schematic structural diagram of pins of an intelligent power module according to an embodiment of the present invention;

Figure 7 and Figure 8 are process diagrams of soldering electronic components and pins on the wiring layer;

9 and 10 are process diagrams of bonding metal wires between multiple electronic components or between electronic components and wiring layers to form electrical connections;

Fig. 11 is a process diagram of injection molding a substrate with electronic components and pins;

Fig. 12 is the process diagram of carrying out pin cutting and forming;

FIG. 13 is a process flow chart of a manufacturing method of an intelligent power module according to an embodiment of the present invention.

Reference signs:

intelligent power module 10,

Pin 11, sealing resin layer 12, electronic component 14, metal wire 15, substrate 16, side wall 16A of substrate, insulating layer 17, wiring layer 18, pad 18A, carrier 20, holder 21, upper mold 44, Lower mold 45, fixture 46, gate 53, air vent 54, cutter 66, thimble 67.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present utility model, but should not be construed as limiting the present utility model.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial" The orientation or positional relationship indicated by , "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying the referred device Or elements must have a specific orientation, be constructed and operate in a specific orientation, and thus should not be construed as limiting the invention. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present utility model, unless otherwise specified, "plurality" means two or more.

In the description of the present utility model, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a flexible connection. Detachable connection, or integral connection; it can be mechanical connection or electrical connection; it can be direct connection or indirect connection through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present utility model in specific situations.

The following describes an intelligent power module 10 according to an embodiment of the present invention with reference to FIGS. 1-3 .

As shown in Figures 1-3, an intelligent power module 10 according to an embodiment of the present invention includes: a substrate 16, an insulating layer 17, a wiring layer 18, a plurality of electronic components 14, a plurality of pins 11 and a sealing resin layer 12 .

The substrate 16 has an upper surface, a lower surface and side walls, an insulating layer 17 is provided on the upper surface of the substrate 16 , and a wiring layer 18 is provided on the insulating layer 17 . A plurality of electronic components 14 are arranged on the wiring layer 18, electrically connected between the plurality of electronic components 14, or electrically connected between the electronic components 14 and the wiring layer 18, and a plurality of pins 11 are arranged at least one side edge of the substrate 16 , and the pin 11 is electrically connected to the wiring layer 18 . The encapsulating resin layer 12 wraps the substrate 16 on which the electronic components 14 are disposed, wherein the lower surface of the substrate 16 is exposed for heat dissipation.

As shown in FIG. 2 , the side wall 16A of the base plate 16 includes an upper inclined section and a lower inclined section, the upper inclined section is inclined outward from top to bottom, and the lower inclined section is inclined outward from bottom to top, wherein "outside" refers to moving away from The direction of the center of the substrate 16, so that when the substrate 16 is injected, the sealing resin layer 12 wraps the side wall 16A of the substrate 16, and the gap between the sealing resin layer 12 and the substrate 16 is bent, which is equivalent to sealing the sealing resin layer. 12 and the upper surface of the substrate 16 form a sealing mechanism, so that water vapor is not easy to intrude.

According to the smart power module 10 of the embodiment of the present invention, the heat dissipation performance is good, and water vapor is not easy to intrude through the gap between the sealing resin layer 12 and the substrate 16 , and the work of the smart power module 10 is more stable.

The intelligent power module 10 according to the embodiment of the present utility model will be described in detail below with reference to FIGS. 1-3 .

In an embodiment of the present invention, the substrate 16 may be a rectangular plate made of aluminum such as 1100. There are two methods for forming substrate 16 insulation and wiring on the surface of substrate 16: one method is to treat at least one surface of substrate 16 for corrosion protection; the other method is to form insulating layer 17 on at least one surface of substrate 16 and then A wiring layer 18 is formed on its surface.

Preferably, as shown in FIG. 2 , the cross-section of the substrate 16 includes two trapezoids, the lower bottom of the upper trapezoid coincides with the lower bottom of the lower trapezoid, that is to say, the side wall 16A of the substrate 16 can be V-shaped, The insulating layer 17 may be provided on the upper bottom of the upper trapezoid. Optionally, the two trapezoids are symmetrical to facilitate processing.

The lower base angle of the trapezoid is α, satisfying: 30°≤α≤45°, the thickness of the substrate 16 is h, satisfying: h≤1.5mm, the sealing resin layer 12 can cover the side wall 16A of the substrate 16, and the sealing resin layer 12 It is flush with the lower surface of the substrate 16, so that the exposed lower surface of the substrate 16 can provide good heat dissipation.

The substrate 16 is made of aluminum plate, and at least one of the upper surface of the substrate 16 and the lower surface of the substrate 16 has an anodized layer to improve the hardness, wear resistance and insulation withstand voltage of the substrate 16. It may not have an anodized layer; it is worth noting here that even if the upper and lower surfaces of the substrate 16 have an anodized layer, the sidewall 16A of the substrate 16 does not have an anodized layer, because it can be seen from the following manufacturing method It can be seen that the anodized layer is completed in the initial process of the substrate 16, and the sidewall 16A of the substrate 16 is completed in the final process of the substrate 16. When forming the sidewall, the anodized layer is cut off.

The electronic component 14 is fixed on the wiring layer 18 to form a predetermined circuit. As the electronic element 14, active elements such as transistors and diodes, or passive elements such as capacitors and resistors are used. In addition, electronic components 14 that generate a large amount of heat such as power components can also be fixed on the substrate 16 through a heat sink made of copper or the like;

The wiring layer 18 is made of metal such as copper, and the wiring layer 18 is insulated from the substrate 16 . In addition, pads 18A composed of wiring layer 18 are formed on the side where lead-out pins 11 are arranged. As shown in FIG.

The material and thickness of the pad 18A is exactly the same as that of the wiring layer 18 . Generally, 1 oz to 2 oz copper foil can be used. In addition, the wiring layer 18 is bonded on the surface of the substrate 16 by the insulating layer 17 .

As shown in FIG. 2 and FIG. 3 , the intelligent power module 10 further includes: a metal wire 15 , and a plurality of electronic components 14 can be electrically connected through the metal wire 15 or between the electronic components 14 and the wiring layer 18 can be electrically connected through the metal wire 15 .

The metal wire 15 can be an aluminum wire, a gold wire or a copper wire, and through bonding, an electrical connection relationship is established between the electronic components 14, between the wiring layers 18, and between the electronic components 14 and the wiring layer 18, and is sometimes used for An electrical connection relationship is established between the substrate 16 or the pin 11 and the wiring layer 18 or the electronic component 14 . The diameter of the metal wire 15 is D, which satisfies: 15 μm≦D≦400 μm.

The insulating layer 17 is formed to cover at least one surface of the substrate 16 , and the insulating layer 17 can be made of a resin material such as epoxy resin filled with a filler such as alumina at a high concentration to improve thermal conductivity.

The pin 11 is fixed to a pad 18A provided on one edge of the substrate 16, and the pin 11 functions as input and output to the outside. Here, it is designed that a plurality of pins 11 and one through leg are on the same edge, and the pin 11, the through leg and the pad 18A are soldered with a conductive adhesive such as solder.

The pin 11 also has a structure as shown in FIG. 6 , and the pin 11 is bent.

Pin 11 is 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 sealing resin layer 12 may be molded using a thermosetting resin by a transfer molding method or may be molded using a thermoplastic resin by an injection molding method. Here, the sealing resin layer 12 completely seals all elements on the side of the substrate 16 with the wiring layer 18 , and for the smart power module 10 requiring high compactness, the side of the substrate 16 without the wiring layer 18 is generally also sealed.

After referring to FIG. 4-FIG. 12 , the manufacturing method of the smart power module 10 according to the embodiment of the present invention will be described.

The manufacturing method of the intelligent power module 10 according to the embodiment of the utility model includes:

As shown in Figure 4, an insulating layer 17 is set on the aluminum plate;

As shown in FIG. 4, a wiring layer 18 is formed on the insulating layer 17;

As shown in FIG. 5 , the aluminum plate on which the wiring layer 18 is arranged is cut to form a substrate 16;

As shown in Figure 6, a plurality of pins 11 are made;

As shown in FIGS. 7 and 8 , assemble electronic components 14 and pins 11 on the wiring layer 18;

As shown in FIG. 9 and FIG. 10 , a metal wire 15 is bonded between a plurality of electronic components 14 or between the electronic component 14 and the wiring layer 18 to form an electrical connection;

As shown in FIG. 11 , the substrate 16 with the electronic components 14 and the pins 11 is injected, and the lower surface of the substrate 16 is exposed;

Test to complete the manufacture of the intelligent power module 10 .

It can be understood that, on the premise of not violating the actual manufacturing logic, the sequence of the above steps can be reasonably organized and sequenced.

The above-mentioned steps will be explained in detail below with reference to the accompanying drawings:

4 shows the process of arranging the insulating layer 17 and the wiring layer 18 on the aluminum plate, that is, the process of forming the insulating layer 17 on the aluminum substrate 16 with a suitable size and structure and forming the wiring layer 18 on the surface of the insulating layer 17 .

Firstly, a substrate 16 with a suitable size is designed according to the required circuit layout. For a general intelligent power module 10, the general size can be selected as 64mm×30mm×1.5mm.

An anodic oxidation layer is formed on at least one surface of the profile of the aluminum substrate 16 with a size of 1m×1m×1.5mm or other sizes. For cost considerations, this process can also be omitted. Each aluminum plate is cut into a plurality of substrates 16, which can improve production efficiency.

Then, an insulating layer 17 is provided on one side of the aluminum substrate 16 (this side is the upper surface), and the thickness of the insulating layer 17 can be set to 100 μm.

In addition, a copper foil as the wiring layer 18 is pasted on the surface of the insulating layer 17. For example, a 2-ounce copper foil is used, and the thickness of the copper foil is about 70 μm. The copper foil produced in this step is then etched to partially remove the copper foil to form the wiring layer 18 and the pad 18A. When necessary, a green oil layer will be arranged at a specific position to act as a solder mask.

FIG. 5 shows a process of cutting the aluminum plate on which the wiring layer 18 is arranged to form the substrate 16 .

The step of cutting the aluminum plate with the wiring layer 18 to form the substrate 16 includes: cutting the aluminum plate with the wiring layer 18 along the up and down direction with a cutter, and the cutting end surface of the cutter is V-shaped, so that the side wall 16A of the substrate 16 has the above-mentioned structural form upslope and downslope of the

The specific cutting method includes but is not limited to using guillotine, hob, scissors, etc. to cut the above-mentioned 1m×1m×1.5mm aluminum substrate 16 into the required size, such as 64mm×30mm×1.5mm, then the cutting edge will be A V-shaped intimidating sidewall 16A is naturally formed.

FIG. 6 shows a process diagram of manufacturing the pin 11 , which may be a process of manufacturing an independent pin 11 with plating.

Each pin 11 is formed by nickel plating on the surface of the copper substrate; Figure 6 is a schematic diagram of each independent pin 11, and each independent pin 11 is made into a length of 25 mm, a width of 1.5 mm, and a thickness of 0.5 mm. mm strips.

Then the nickel layer is formed by electroless plating: 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, and the metal nickel has a strong Passivation ability, can quickly form an extremely thin passivation film, which 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 thickness of the nickel layer is generally controlled at 5 μm. , The formation of nickel layer greatly improves the protection and solderability.

Finally, one end of the pin 11 is lowered to a certain height, such as 1.2mm, by a molding press.

So far, pin 11 is manufactured.

7 and 8 show the process of mounting the electronic components 14 and the pins 11 on the wiring layer 18 .

First, a solder paste printing machine is used to coat a specific position of the wiring layer 18 of the substrate 16 with a stencil with a thickness of 0.13 mm.

Next, referring to FIG. 7 and FIG. 8 , the installation of electronic components 14, pins 11 and through feet is carried out; the installation sequence is as follows: the substrate 16 is placed on the carrier 20, and the electronic components 14 can be directly placed on a specific position of the wiring layer 18 ; On the carrier 20, the pin 11 can be put down in the direction vertically downward through the vertical top of the paper surface as shown in FIG. The carrier 20 and the holder 21 are made of materials such as synthetic stone; the substrate 16 placed on the carrier 20 and the holder 21 is reflowed, the solder paste is cured, and the electronic components 14 and pins 11 are fixed.

9 and 10 illustrate the process of bonding metal wires 15 between a plurality of electronic components 14 or between electronic components 14 and wiring layers 18 to form electrical connections.

This process includes the process of cleaning the substrate 16 and performing wire bonding, so that the electronic component 14 and the wiring layer 18 form the metal wire 15 for electrical connection.

First put the substrate 16 into a cleaning machine for cleaning, and clean the residual flux such as rosin during reflow soldering and the foreign matter such as aluminum wire remaining during stamping. According to the arrangement density of the electronic components 14 in the wiring layer 18, cleaning can be done by Spray or ultrasonic or a combination of both. When cleaning, two or more pins 11 are clamped by the mechanical arm, and the substrate 16 is placed in the cleaning tank;

Secondly, an electrical connection is formed by bonding a metal wire 15 of a certain diameter at a specific position of the electronic component 14 and the wiring layer 18. Here, the thickness of the metal wire 15 should be based on the size of the bonding point, the required co-current capability, and In general, the diameter of a single metal wire 15 should not be greater than 400 μm and should not be less than 15 μm. For the connection of power devices, multiple 400 μm aluminum wires can be used in parallel. For the connection of functional devices, a single 38μm aluminum wire can be considered for bonding.

Fig. 11 shows the process of injection molding.

FIG. 11 is a cross-sectional view showing a step of sealing the substrate 16 with a sealing resin using a mold.

Firstly, the substrate 16 is baked in an oxygen-free environment, the baking time should not be less than 2 hours, and the baking temperature should be 125°C.

The substrate 16 on which the pins 11 are arranged is transported between the upper mold 44 and the lower mold 45 . The substrate 16 is positioned on the lower mold 45 by bringing a specific portion of the pin 11 into contact with the fixture 46 .

When closing the mold, the substrate 16 is placed in the cavity formed inside the mold, and then the sealing resin is injected through the gate 53 . The sealing method is injection molding using a thermosetting resin. Also, the gas corresponding to the inside of the sealing resin cavity injected from the gate 53 is discharged to the outside through the exhaust port 54 .

The sealing resin fills the mold cavity after entering the mold cavity. Here, the sealing resin completely seals the side wall 16A of the substrate 16 , while the bottom of the substrate 16 is not covered by the sealing resin.

FIG. 12 shows the process of trimming and testing the pin 11 , and the intelligent power module 10 is completed as a product through this process.

In the previous process, that is, the transfer molding process, the parts other than the pins 11 and the bottom of the substrate 16 are resin-sealed. In this process, according to the length and shape required, for example, the external pin 11 is cut into a certain shape at the position of the dotted line 51 to facilitate subsequent assembly.

Then put the module into the test equipment and conduct conventional electrical parameter tests, which generally include test items such as insulation withstand voltage, static power consumption, and delay time. Those who pass the test are finished products.

Using the above process, the smart power module 10 shown in FIGS. 1-3 is completed.

As shown in FIG. 13 , the manufacturing method of the intelligent power module 10 according to the embodiment of the present invention includes: the process of disposing the insulating layer 17 on the surface of the aluminum substrate 16; Process; the process of making the pin 11 with plating; the process of connecting the electronic component 14 at the wiring layer 18, connecting the pin 11 and the through pin at the pad 18AA; the process of cleaning; connecting the electronic component 14 and wiring with a metal wire 15 The process of layer 18; the process of baking and molding; the process of forming the pin 11. The process diagram is shown in the figure.

According to the above-mentioned manufacturing method of the intelligent power module 10 of the present invention, the existing process can be optimized, and multiple substrates 16 can be produced at one time without separately opening a mold for the substrate 16, which can reduce the production cost of the intelligent power module 10, Moreover, the prepared smart power module 10 has good sealing performance, and moisture is not easy to intrude from the gap between the sealing resin layer 12 and the substrate 16 .

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific examples," or "some examples" is intended to mean that the implementation Specific features, structures, materials or characteristics described in an embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and modifications, the scope of the present invention is defined by the claims and their equivalents.

Claims (10)

1. An intelligent power module, comprising: The base plate, the side wall of the base plate includes an upper inclined section and a lower inclined section, the upper inclined section is inclined outward from top to bottom, and the lower inclined section is inclined outward from bottom to top; an insulating layer, the insulating layer is provided on the upper surface of the substrate; a wiring layer, the wiring layer is provided on the insulating layer; A plurality of electronic components, a plurality of the electronic components are arranged on the wiring layer, and electrical connections are made between the plurality of electronic components or between the electronic components and the wiring layer; a plurality of pins, a plurality of the pins are provided at least one edge of the substrate, and the pins are electrically connected to the wiring layer; A sealing resin layer, the sealing resin layer wraps the outside of the substrate provided with the electronic components, wherein the lower surface of the substrate is exposed. 2 . The intelligent power module according to claim 1 , wherein the cross-section of the substrate comprises two trapezoids, and the lower base of the upper trapezoid coincides with the lower base of the lower trapezoid. 3. The intelligent power module according to claim 2, wherein the two trapezoids are symmetrical. 4. The intelligent power module according to claim 2, wherein the lower base angle of the trapezoid is α, which satisfies: 30°≤α≤45°. 5. The intelligent power module according to claim 2, wherein the sealing resin layer covers the sidewall of the substrate and is flush with the lower surface of the substrate. 6. The intelligent power module according to any one of claims 1-5, wherein the thickness of the substrate is h, which satisfies: h≤1.5mm. 7. The intelligent power module according to any one of claims 1-5, wherein the substrate is made of aluminum plate, and at least one of the upper surface and the lower surface of the substrate has an anodized layer. 8. The intelligent power module according to any one of claims 1-5, further comprising: metal wires passing between a plurality of said electronic components or between said electronic components and said wiring layer The metal wires are electrically connected. 9. The intelligent power module according to claim 8, wherein the diameter of the metal wire is D, which satisfies: 15 μm≤D≤400 μm. 10. The intelligent power module according to any one of claims 1-5, wherein the pins are bent.