CN117373805A

CN117373805A - Power supply module and preparation method thereof

Info

Publication number: CN117373805A
Application number: CN202311645236.6A
Authority: CN
Inventors: 陈圣伦; 张斌; 柯光洁
Original assignee: Jiangsu Qiaosi Technology Co ltd
Current assignee: Jiangsu Qiaosi Technology Co ltd
Priority date: 2023-12-04
Filing date: 2023-12-04
Publication date: 2024-01-09

Abstract

The invention provides a power module, which comprises a PCB module; the connecting component is arranged on the side wall or the lower end surface of the PCB module; and the at least one packaging body is connected with the PCB module through the connecting component. The invention combines the fan-out packaging technology and the multilayer PCB technology, thereby improving the power density of the power module; the advantages of the PCB technology and the packaging technology are combined, the division of the components and functions of the PCB assembly and the inside of the packaging body is reasonably distributed, the production difficulty of the power module is reduced, and the production cost of the power module is increased.

Description

Power supply module and preparation method thereof

Technical Field

The invention relates to the technical field of power supply modules, in particular to a power supply module and a preparation method thereof.

Background

With the increasing electronic market size, there is an increasing demand for smaller, more cost-effective power module packaging processes, wherein fan-out packaging techniques are widely studied and applied due to their advantages of good electrical performance, support of an increasing demand for the number of input/output interfaces, enabling dual-die or multi-die packaging configurations, and fine redistribution layer (RDL) routing capable of supporting lines/spaces of less than or equal to 10 μm, which are however accompanied by enormous production costs. In order to reduce the cost, a larger-area packaging technology is developed, the power of a packaging body is continuously improved based on the current more and more mature panel-level fan-out type packaging technology, the packaging technology is applied to a solution of a module power supply, not only discrete devices can be used in the power supply module, but also a switching device and a bare chip of a control chip can be packaged together, the power density and the heat dissipation capability of the module power supply can be greatly improved, the safety distance is greatly reduced, and the design of products in high-voltage input and high-isolation voltage application occasions is more facilitated. However, considering the problems of the power class of the module power supply, the high-power application occasion and the like, the volume of the passive device is far larger than that of the active device, and taking a planar transformer based on a PCB winding as an example, the device accounts for 70% of the total volume of the whole power supply module. How to deal with the structural relationship of PCBs, magnetic cores and active devices in packages and to provide a corresponding mass-producible production process is a problem to be solved.

First, in the prior art, isolated module power supplies typically employ a single multi-layer PCB (varying in number of layers from 4 layers to 24 layers) plus other device combinations. The most main purpose of the multi-layer PCB is to realize the winding of the planar transformer. In a module power supply, particularly in an isolated module power supply, the loss of magnetic components such as a transformer, an inductor and the like accounts for 30% -50% of the total loss, and is the most important part in a single power supply device. Through the wiring of design multilayer PCB, can realize the winding function, assemble the magnetic core again, constitute isolated power module's transformer. The winding design of the multilayer PCB is very beneficial to reducing the alternating current loss of the winding and improving the coupling coefficient of the primary side and the secondary side, thereby improving the overall efficiency of the module. In addition, the power devices A1, the resistance-capacitance devices A2 and the chips A3 of other primary and secondary sides can be respectively distributed on the top layer or the bottom layer of the primary and secondary side PCB A5 at two sides of the transformer core A4, and the structure is shown in fig. 1. Based on the assembled modules of the PCB, the module can be divided into two types of modules, namely a split board and a plastic package according to the existence of the package, namely the plastic package is carried out after the assembly of the devices such as the PCB, the magnetic core and the like is completed. The plastic package has great benefits, and because the devices are all in the plastic package and have no air contact, the safety distance is greatly reduced, the power density of the isolated module can be further improved, and the device is more outstanding for high-voltage products. However, since only the front and back sides of the single multilayer PCB board can be used to place components in the circuit, such as power transistors, control chips, resistors and capacitors, with the increase of power, more area is required to place devices such as power transistors and driving chips, so that the structure limits the further increase of power density in the Layout area. And, whether it is an open-board module or a plastic-packaged module, their production is based on the PCB board level, and the bare chip cannot be mounted on the PCB, thereby further limiting the increase of power density.

In order to further pursue the power density, as shown in fig. 2, a part of the resistor-capacitor element B1 and the chip B2 are usually placed on a single PCB board B3, and are stacked above or below the multi-layer PCB board, and are connected through connectors such as metal copper pillars B4, so that the electrical and structural interconnection between the PCB boards is realized, so that the area of the PCB boards is reduced, and the power density of the module is improved. Although the area of the PCB is reduced, the connector also needs to occupy a certain PCB area due to the addition of the connectors such as the additional copper columns or the metal pins, so that the effect of improving the power density of the lamination of two or more PCBs is weakened to a certain extent. In addition, the heights of some devices are high, the problem of spatial interference of two PCBs needs to be considered, and the design difficulty is increased. In addition, the stacking increases the overall height of the module, and thus also contributes to some degree to further increases in power density.

In the prior art, the power module further adopts a fan-out packaging process, and the fan-out packaging mainly refers to that a rewiring layer (RDL) is prepared in the device through processes such as exposure, development, electroplating and the like, and the electrical pins are removed from the respective bonding pads so as to be electrically connected in the vertical direction. The RDLs are electrically connected by way of via plating or metal connectors. Bare chips can be arranged on the metal of each RDL layer, elements such as control chips, resistance-capacitance and inductance are welded, and plastic packaging is performed once each surface-mounted device is arranged. Finally, forming a three-dimensional stacked whole through multiple plastic packaging, and if the thickness of the magnetic element is thinner (such as a thinner patch inductor), packaging the magnetic core element in the package body; if the magnetic element is thicker (e.g., thicker chip inductance) beyond the size range that can be encapsulated by the fan-out process, a thicker core element can be solder placed on top of the package. Fan-out packages have many advantages, such as: the bonding wires in the traditional packaging process are eliminated, so that the interconnection paths among the elements are short, and interconnection parasitic parameters are effectively reduced; the packaging size is small, the vertical stacking of magnetic core elements such as a control chip, a resistance-capacitance element, an inductance element and the like is realized through the bare chip, the area of a packaging body is greatly reduced, and the whole integration level is high, so that the packaging structure is particularly suitable for the integration of multiple chips; the bare chip can be directly buried in the packaging body and can be directly attached to the substrate of the packaging body, and the patterned metal structure can be preset in the substrate, so that the heat dissipation area of the bare chip is increased; the fan-out type packaging process can realize device stacking, has higher structural freedom in the actual design process, and flexibly adjusts the internal stacking structure of the package according to performance requirements such as heat dissipation performance, conductive performance, capacitance matching, inductance matching and the like. Because the connection between layers is achieved by drilling copper plating, the connection is more reliable and more conductive than the connection achieved by soldering with an additional connector.

However, with the continuous increase of power and complexity of the module power supply, more layers are needed to complete wiring and arrangement of components, the more layers not only bring about the increase of complexity of fan-out process flow and the increase of manufacturing cost, but also bring about the increase of thickness of the package, and the limitation of thickness of the package becomes a bottleneck of further improving power density of the fan-out process; the thickness of copper plated on each layer in the fan-out process is generally limited to 20-70 mu m (below 2 oz), if larger current is required, the thicker copper cannot be reliably formed, and the fan-out packaging process is insufficient; the current fan-out packaging technology only integrates elements such as a chip inductor into a package body, or places the chip inductor on the top of the package body. Because of the limitation of the thickness of the package, the transformer in the isolation transformer cannot be integrated into the package (the thickness of a common transformer core is thicker than the maximum thickness of the fan-out package process). In addition, due to the consideration of the overall height, a common wound transformer cannot be simply placed on top of the package. Taking a planar transformer with a size of 15mm by 16mm by 6mm as an example, the power can reach 1000w, the number of layers of the PCB winding is 14, the thickness of single copper layer is 2oz (about 70 μm), the complexity, cost and reliability of the fan-out type packaging process at present are considered, the PCB winding is difficult to replace, and in addition, 14 copper sheets, packaging materials, thermal expansion coefficients, moduli and the like of various devices, especially bare chips, are considered, so that the problems of layering, warping, uneven stress and the like in the production process and in the practical long-time application are not mature solutions at present.

Accordingly, there is a need to design a power module structure to solve the above-mentioned problems of monolithic multilayer PCB and fan-out package processes.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a power supply module and a preparation method thereof.

In order to achieve the above and other objects, the present invention is achieved by the following technical solutions: first, the present invention provides a power module, which is characterized by comprising

A PCB module;

the connecting component is arranged on the side wall or the lower end surface of the PCB module;

and the at least one packaging body is connected with the PCB module through the connecting component.

In one embodiment, the package includes a rewiring layer and a plurality of elements, the plurality of elements being connected by the rewiring layer.

In an embodiment, the package further includes a pin, and the element is mounted on an upper layer of the pin through the rewiring layer.

By packaging the elements such as the switch tube, the chip, the resistor-capacitor and the like in the same package body, the power density can be greatly improved, meanwhile, the high voltage resistance of the packaging material is utilized to realize high isolation voltage requirements, and the multilayer structure in the package body is also very beneficial to optimizing layout.

In an embodiment, the PCB module comprises at least one PCB board and a magnetic core, the magnetic core is mounted on the PCB board, and the connection member is mounted on a lower end surface or a side wall of the PCB board.

In an embodiment, elements are mounted on both the upper and lower end surfaces of the PCB.

In one embodiment, the lower end surface of the magnetic core is in contact with the upper end surface of the package.

In one embodiment, the package body is provided with a groove, and the magnetic core is located in the groove of the package body.

When the groove is a groove, the reliability of connection between the modules is improved, the loss of the connecting column is reduced, and the cost is reduced. In addition, due to the sunken structure, the thickness of the magnetic core back plate on the PCB module is omitted, the overall height of the power module is reduced, and the power density of the power module is greatly improved; when the slot is a through slot, the whole height of the power module is further reduced as the magnetic core sinks more until penetrating, so that the power density is further improved. Meanwhile, the bottom packaging body is a part of a circuit to realize an electrical function, and can serve as structural connection of a module and a client to play a double role.

In an embodiment, the power module further comprises a secondary plastic package body, the PCB module is mounted in the secondary plastic package body, and a lower end face of the secondary plastic package body contacts with an upper end face of the package body.

In an embodiment, the upper end surface of the secondary plastic package body is flush with the lower end surface of the PCB board. The lower end portions of the element and the magnetic core under the PCB module are molded into the secondary package, heat of the element can be introduced into the package through the secondary package, and the bottom element improves oxidation resistance and corrosion resistance thereof due to the molding.

In an embodiment, the upper end face of the secondary plastic package body is flush with the upper end face of the PCB, so that the temperature of the PCB module can be improved, and the reliability of the PCB module is improved.

In an embodiment, the upper end face of the secondary plastic package body is flush with the upper end face of the magnetic core, so that heat dissipation of the magnetic core is improved, mechanical stress resistance of the magnetic core is improved, and overall reliability of the power module is improved. And meanwhile, the PCB module is subjected to plastic package, so that the safety insulation capability of the PCB module can be improved.

The invention further provides a preparation method of the power supply module, which is used for preparing the module power supply of any one of the above steps, and is characterized by comprising the following steps:

step S1, preparing a PCB module;

step S11, preparing a PCB board,

step S12, welding the bottom layer element and the connecting component on the lower end surface of the PCB,

step S13, welding the top layer element on the upper end surface of the PCB,

s14, mounting the magnetic core on the PCB to obtain the PCB module;

step S2, preparing the packaging body;

step S21, at least one bare chip is attached to the upper surface of the substrate, and a bare chip array is prepared,

step S22, the bare chip array is injection molded to prepare and obtain a bare chip panel,

step S23, disposing a first rewiring layer on the upper end surface of the bare chip panel,

step S24, mounting a first bonding pad on the first rewiring layer,

step S25, welding the element and the metal connecting column on the first bonding pad, preparing and obtaining a layer of three-dimensional stack,

step S26, the three-dimensional stacked layers are injection molded, and the upper end face of the metal connecting column is exposed by grinding,

step S27, setting a second rewiring layer on the upper end face of the metal connecting column,

step S28, arranging a second bonding pad on the upper end surface of the second rewiring layer to obtain a two-layer three-dimensional stack,

step S29, the two layers of three-dimensional stacking injection molding is carried out, so that the upper end face of the second bonding pad is exposed, and the packaging body is obtained;

step S210, removing the substrate, and preparing the pins on the lower surface of the first rewiring layer (RDL) after removing the substrate.

S3, installing the PCB module and the packaging body;

and welding the connecting member mounted on the PCB to the second bonding pad to obtain the power supply module.

In summary, the invention has the following beneficial effects:

1. the fan-out type packaging technology and the multilayer PCB technology are combined, so that the power density is maximized;

2. the switch tube, the chip and the signal-level resistor-capacitor are in a three-dimensional laminated structure in the package body, and the transformer PCB board, and the power-level resistor-capacitor (large volume) is combined and applied in the three-dimensional laminated structure outside the package body, so that the space is effectively utilized, and the ultra-multilayer metal wiring is very beneficial to electric connection and design;

3. selectively designing devices inside the package body to ensure that the thickness of the package body is less than 2mm in the embodiment, thereby meeting the requirements of the production process;

4. the copper thickness of each layer in the multilayer PCB is not limited by the copper thickness in the fan-out packaging process any more, and the thickness of each layer can be easily 100-140 mu m (3-4 oz) or even thicker through the manufacturing process of the PCB, so that lower copper loss can be obtained, and the multilayer PCB is more suitable for high-power and high-current application occasions.

5. The advantages and disadvantages of the PCB process and the packaging technology are fully combined, the inside of the packaging body and the division of components and functions of the PCB are reasonably distributed, and the production difficulty and the cost of the packaging body are reduced within a reasonable and acceptable range.

Drawings

Fig. 1 is a schematic diagram of a multi-layer PCB module in the prior art.

Fig. 2 is a schematic structural diagram of a modified multi-layer PCB module according to the prior art.

Fig. 3 is a schematic perspective view of a power module according to a first embodiment of the invention.

Fig. 4 is a schematic structural diagram of a package according to a first embodiment of the invention.

Fig. 5 is a schematic structural diagram of a PCB module according to a first embodiment of the invention.

Fig. 6 is a schematic structural diagram of a power module according to a first embodiment of the invention.

Fig. 7 is a schematic process flow diagram of a PCB module according to the present invention.

Fig. 8 is a schematic process flow diagram of the preparation of the package according to the present invention.

Fig. 9 is a schematic process flow diagram of a power module according to the present invention.

Fig. 10 is a schematic structural diagram of a power module including two sets of packages according to an embodiment of the invention.

Fig. 11 is a schematic structural diagram of a second embodiment of the present invention.

Fig. 12 is a schematic structural diagram of a third embodiment of the present invention.

Fig. 13 is a schematic structural diagram of a power module including two sets of packages according to a third embodiment of the present invention.

Fig. 14 is a schematic structural view of a fourth embodiment of the present invention.

Fig. 15 is a schematic structural diagram of a power module including two sets of packages according to a fourth embodiment of the present invention.

Fig. 16 is a schematic diagram of a fifth embodiment of the present invention.

Fig. 17 is a schematic diagram showing the structure of a sixth embodiment of the present invention.

Fig. 18 is a schematic structural view of a seventh embodiment of the present invention.

Fig. 19 is a schematic view showing the structure of an eighth first form of embodiment of the present invention.

Fig. 20 is a schematic structural view showing an eighth second form of embodiment of the present invention.

Fig. 21 is a schematic structural view showing an eighth third form of embodiment of the present invention.

Fig. 22 is a schematic structural view showing a ninth first form of embodiment of the present invention.

Fig. 23 is a schematic structural view showing a ninth second form of embodiment of the present invention.

Detailed Description

Please refer to fig. 3 to 23. Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. It should be understood that numerous specific details are set forth in the following description in order to provide a thorough understanding of the present invention, however, that the present invention may be practiced in other ways than as described herein, and that the scope of the invention is therefore not limited to the specific embodiments disclosed below. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Embodiment one:

as shown in fig. 3, embodiment 1 provides a power module 1 including a package 11, a PCB module 12, and a connection member 13, the package 11 being connected to the PCB module 12 through the connection member 13.

Specifically, as shown in fig. 4, the package 11 includes a plurality of elements 111, a rewiring layer (RDL) 112, and a lead 113, the plurality of elements 111 are connected by the rewiring layer (RDL) 112, and when the elements 111 are bare chips, the elements 111 are stacked above the lead 113 by the rewiring layer (RDL) 112.

Preferably, in this embodiment, the element 111 may be a control chip, a driving chip, a resistor-capacitor, a switching tube, etc., where the control chip, the driving chip, and the resistor-capacitor are horizontally arranged and are installed in an upper region of the switching tube correspondingly controlled or driven.

Preferably, the control chip, the driving chip and the resistor-capacitor are electrically connected through copper plating of a via hole.

Preferably, the element 111 may be a bare chip.

By packaging a plurality of the elements 111 in the same package, the power density can be greatly improved, and at the same time, a high isolation voltage requirement is achieved by using the high voltage resistance of the packaging material, and the multilayer structure inside the package 11 is also very beneficial to optimizing the layout.

Please refer to fig. 5 and fig. 6, the PCB module 12 includes a multi-layer PCB 121, a plurality of components 122 and a magnetic core 123, the components 122 are mounted on the front and back sides of the PCB 121, the magnetic core 123 is mounted on the PCB 121 in a penetrating manner, and the thickness of the magnetic core 123 is greater than that of the PCB 121. The two sides of the lower end surface of the lowest layer of PCB 121 are welded with the connecting members 13, the PCB module 12 is stacked on the package 11 by the connecting members 13 to form an integral structure with a fixed mechanical structure and electrical connection, and in this embodiment, the connecting members 13 may be metal columns. The PCB module 12 uses a plurality of layers of the PCB 121 as windings of a transformer or an inductor, and the magnetic core 123 is mounted on the plurality of layers of the PCB and combines to form the transformer or the inductor. In this embodiment, the power module 1 has a top structure, that is, the magnetic core 123 is located above the package 11 when the PCB module 12 is mounted on the package 11.

Preferably, the element 122 may be a control chip, a driving chip, a resistor-capacitor, or the like.

Referring to fig. 7 to 9, the production process of the power module 1 includes the following steps:

step S1, preparing the PCB module 12,

step S11, preparing a plurality of layers of the PCB 121,

step S12, soldering the component 122 on the front and back sides of the PCB 121,

step S13, welding the connecting member 13 on the lower end surface of the lowest layer of the PCB 121,

step S14, the magnetic core 123 is installed on the multi-layer PCB 121 in a penetrating way;

step S2, preparing the package 11,

step S21, die-attach,

dicing the whole wafer into arrays of bare chips arranged on the film in a row by wafer grinding, dicing and other processes, attaching one or more bare chips of the element 111 to a specified position on the surface of the pre-molded substrate 114 by using an automated die equipment,

step S22, grinding for the first time by injection molding,

the array of bare chips mounted on the panel surface is buried inside injection molded plastic by injection molding, and after controlled grinding, the end faces of the copper stud bumps are exposed for subsequent connection to the rewiring layer (RDL) 112,

step S23, first preparing metal lines and vias

The re-wiring layer (RDL) 112 metal interconnection pattern and the interlayer via 115 are prepared on the surface of the panel pre-embedded with the bare chip through the combination of the working procedures of laser perforation, chemical plating, film coating, exposure, development, electroplating and the like, so that the space transmission of the electrical signals of the bare chip is realized,

step S24, first preparing bonding pad

A first pad 116 is prepared on the surface of the re-wiring layer (RDL) 112 by a combination of processes such as film coating, exposure, development, electroplating, etc.,

step S25, first build-up stacked device

The chip, the resistor-capacitor and other elements 111 and the metal connecting posts 117 are welded above the first bonding pads 116 through a surface mounting process, so that three-dimensional stacking of devices in the package body is realized,

step S26, grinding for the second time

The metal connection post 117 welded in the step S25 is buried inside a molding compound by injection molding, and then subjected to controlled grinding, the end face of the metal connection post 117 is exposed for subsequent connection to the rewiring layer (RDL) 112,

step S27, preparing metal lines and via holes for the second time

The re-wiring layer (RDL) 112 metal interconnection pattern and interlayer via holes are prepared on the surface pre-embedded with metal connecting columns through the combination of the working procedures of laser perforation, chemical plating, film coating, exposure, development, electroplating and the like, so that the space transmission of the electric signals of the element 111 is realized,

step S28, preparing the interlayer interconnection part and the bonding pad for the second time

An interlayer interconnect 118 and a second pad 119 are sequentially formed on the surface of the re-wiring layer (RDL) 112 metal interconnect layer prepared in S27 by a combination of processes such as laser drilling, electroless plating, film coating, exposure, development, electroplating, etc.,

step S29, grinding for the third injection molding

The interlayer interconnection member 118 and the second pad 119 are buried in a molding compound by injection molding, and after being subjected to controlled grinding, the end face of the second pad 119 is exposed to be soldered with the PCB module 12 later,

step S210, removing the substrate 114, preparing the pins 113 on the surface of the rewiring layer (RDL) 112 after removing the substrate 114,

step S3, mounting the PCB module 12 and the package 11,

the connection member 13 on the PCB module 12 is soldered to the second pad 119, completing the mounting of the PCB module 12 and the package 11.

The embodiment has the following beneficial effects:

1. the fan-out type packaging technology and the multilayer PCB technology are combined, the power density is maximized, and about 3000W/in can be realized ³ Is a power density of (2); the switch tube, the chip and the signal-level resistor-capacitor are in a three-dimensional laminated structure in the package body, and the transformer PCB board, and the power-level resistor-capacitor (large volume) is combined and applied in the three-dimensional laminated structure outside the package body, so that the space is effectively utilized; the metal wiring of the super-multilayer takes 14 layers of PCBs as an example, and 5 layers of metal wiring in the package body are added, so that the total number of the metal wiring can reach 19 layers, the wiring is flexible, and the electrical connection and design are very beneficial.

2. The device inside the package is selectively designed, so that the thickness of the package in the embodiment is less than 2mm, and the production process requirement is met. The magnetic core of the transformer also adopts a planar transformer structure to reduce the thickness of the magnetic core, and in this embodiment, the connecting members of the PCB assembly and the package assembly adopt metal members, and the metal connecting members are sandwiched between the PCB board and the package and are in height consistency with the portions of the magnetic core beyond the PCB board, so that the height of the whole module is not increased under the condition of not considering assembly tolerance.

3. The copper thickness of each layer in the multilayer PCB is not limited by the copper thickness in the fan-out packaging process any more, and the thickness of each layer can be easily 100-140 mu m (3-4 oz) or even thicker through the manufacturing process of the PCB, so that lower copper loss can be obtained, and the multilayer PCB is more suitable for high-power and high-current application occasions.

4. The advantages and disadvantages of the PCB process and the packaging technology are fully combined, the inside of the packaging body and the division of components and functions of the PCB are reasonably distributed, and the production difficulty and the cost of the packaging body are reduced within a reasonable and acceptable range.

Further, as shown in fig. 10, in some embodiments, the power module 1 may include two sets of the packages 11 and one set of the PCB modules 12, and the two sets of the packages 11 are mounted on upper and lower ends of the PCB modules 12, respectively. A part of the components may be placed in the package 11 at the top, and the area of the PCB module 12 and the package 11 at the bottom may be reduced, further improving the power density.

Embodiment two:

as shown in fig. 11, the second embodiment provides a power module 2, which includes a package 21, a PCB module 22, and a connection member 23, wherein the package 21 is connected to the PCB module 22 through the connection member 23.

The difference between this embodiment and the first embodiment is that: the top packaging structure is adopted, that is, the upper layer of the PCB module is packaged as a separate structure, and only the connecting member 23 is exposed to connect with the package 21. The embodiment also has the following beneficial effects: the pressure resistance of the transformer plate can be improved, and meanwhile, the top radiating fin and the cold plate are conveniently attached to dissipate heat.

Embodiment III:

as shown in fig. 12, the third embodiment provides a power module 3, which includes a package body 31, a PCB module 32, and a connection member 33, wherein the package body 31 is connected to the PCB module 32 through the connection member 33.

The difference between this embodiment and the first embodiment is that: a sinking structure is adopted, that is, a groove 314 is formed on the upper surface of the package body 31, the lower end surface of the PCB module 32 is in contact with the upper end surface of the package body 31, and the magnetic core 323 in the PCB module 32 is sunk into the groove 314. The connection members 33 are mounted on the side walls and the bottom of the PCB module 32, and in this embodiment, the PCB module 32 is connected to the package body 31 by soldering, so that the connection members 33 may be fillets or solder joints.

Compared with the first embodiment, the present embodiment further has the following advantages: the PCB module 32 is welded on the packaging body 31, so that the reliability of connection between the modules is improved, the loss of connecting columns is reduced, and the cost is reduced. In addition, due to the sinking structure, the thickness of the magnetic core 323 backboard on the PCB module 32 is omitted, the overall height of the power module 3 is reduced, and the power density of the power module 3 is greatly improved.

Further, as shown in fig. 13, in some embodiments, the power module 3 may include two sets of the sinking type packages 31 and one set of the PCB modules 32, the two sets of the sinking type packages 31 are respectively mounted on the upper and lower ends of the PCB modules 32, and the upper and lower ends of the magnetic core 323 of the PCB modules 32 are respectively located in the grooves 314 of the two sets of the packages 31. The sinking top package structure may further reduce the height of the power module 3, and further increase the power density.

Embodiment four:

as shown in fig. 14, the fourth embodiment provides a power module 4 including a package 41, a PCB module 42, and a connection member 43, wherein the package 41 is connected to the PCB module 42 through the connection member 43. The difference between the present embodiment and the first embodiment is that a through structure is adopted, that is, a through groove 414 is formed on the upper surface of the package 41, the lower end surface of the PCB module 42 contacts with the upper end surface of the package 41, and the magnetic core 423 in the PCB module 42 sinks into the through groove 414, so that the bottom of the magnetic core 423 is flush with the bottom of the package 41. The connection members 43 are mounted on the side walls and bottom of the PCB module 42, and in this embodiment, the connection members 43 may be solder type metal pads.

Compared with the first embodiment, the present embodiment further has the following advantages: the bottom of the magnetic core 423 may be exposed through the through groove 414, and the heat dissipation condition of the magnetic core 423 may be greatly improved. In addition, since the magnetic core 423 is sunk more until penetrating, the overall height of the power module 4 is further reduced, further improving the power density. Meanwhile, the bottom packaging body 41 is a part of a circuit to realize an electrical function, and can serve as a structural connection between a module and a client to play a double role.

Furthermore, as shown in fig. 15, in some embodiments, the power module 4 may include two sets of penetrating type packages 41 and one set of PCB modules 42, where the two sets of penetrating type packages 41 are respectively mounted on upper and lower ends of the PCB modules 42, upper and lower ends of the magnetic core 423 of the PCB modules 42 are respectively located in the through grooves 414 of the two sets of packages 41, the upper end of the magnetic core 423 is flush with the upper end surface of the top package 41, and the lower end surface of the magnetic core 423 is flush with the lower end surface of the bottom package 41. The upper and lower ends of the magnetic core 423 are exposed in the through grooves 414 of the upper and lower packages 41, so that the heat dissipation effect of the magnetic core 423 is enhanced, the height of the power module 4 is reduced, and the power density is further improved.

Of course, when the power module includes two sets of the package bodies and the PCB module according to practical situations, any one or a combination of two of the package body structures in the first to fourth embodiments may be adopted.

Fifth embodiment:

as shown in fig. 16, a fifth embodiment provides a power module 5, which includes a package body 51, a PCB module 52, a connection member 53, and a secondary molding body 54, as in the first to fourth embodiments, the PCB module 52 is mounted on the package body 51 through the connection member 53, and the secondary molding body 54 molds the PCB module 52, the connection member 53, and the package body 51 into a whole, in this embodiment, an upper end surface of the secondary molding body 54 is flush with a lower end surface of a PCB 521 in the PCB module 52.

Compared with the first to fourth embodiments, the present embodiment has the following advantages:

the lower end portions of the component and the magnetic core 523 under the PCB module 52 are molded into the secondary package 54, heat of the component can be introduced into the package 51 through the secondary package 54, and the bottom components have their oxidation resistance and corrosion resistance improved due to the molding.

Example six:

as shown in fig. 17, a sixth embodiment provides a power module 6, which includes a package body 61, a PCB module 62, a connection member 63, and a secondary molding body 64, as in the first to fourth embodiments, the PCB module 62 is mounted on the package body 61 through the connection member 63, and the secondary molding body 64 molds the PCB module, the connection member 63, and the package body 61 into a whole, and in this embodiment, an upper end surface of the secondary molding body 64 is flush with an upper end surface of a PCB 621 in the PCB module 62.

Compared with the fifth embodiment, the second molding process of the present embodiment also leads the heat generated by the PCB module 62 into the package 61, thereby improving the temperature of the PCB module 62 and improving the reliability of the PCB module 62.

Embodiment seven:

as shown in fig. 18, a seventh embodiment provides a power module 7, which includes a package body 71, a PCB module 72, a connection member 73, and a secondary plastic package body 74, where, as in the first to fourth embodiments, the PCB module 72 is mounted on the package body 71 through the connection member 73, and the secondary plastic package body 74 forms an integral body by plastic packaging the PCB module, the connection member 73, and the package body 71, and in this embodiment, the PCB module 72 is disposed inside the secondary plastic package body 74, and an upper end surface of the secondary plastic package body 74 exceeds an upper end surface of a magnetic core 723 in the PCB module 72.

In this embodiment, the core 723 is molded, which not only improves the heat dissipation of the core 723, but also improves the mechanical stress resistance of the core 723 and the reliability of the whole power module 7. And meanwhile, the PCB module 72 is subjected to plastic packaging, so that the safety insulation capability of the PCB module can be improved.

Example eight:

as shown in fig. 19, an eighth embodiment provides a power module 8, which includes a package 81, a PCB module 82 and a connection member 83, and the difference between this embodiment and the first to fourth embodiments is that, a PCB 821 in the PCB module is a sinking PCB, and when a magnetic core 823 is installed on the PCB 821 in a penetrating manner, a lower end surface of the magnetic core 823 is flush with a non-sinking end surface of the PCB, so that the PCB 821 can be attached to an upper end surface of the package 81. The height of the power module 8 is reduced, the reliability of the connection between the PCB module 82 and the package 81 is improved, and the power density of the power module 8 is improved.

In addition, as shown in fig. 20 and 21, in other embodiments, the upper end surface of the magnetic core 823 is flush with the non-sinking upper end surface of the PCB 821, and the package 81 adopts a sinking structure or a penetrating structure, so that not only is the temperature of the magnetic core 823 reduced, the efficiency of the power module 8 improved, but also the power density of the power module 8 is further improved. Meanwhile, the bottom packaging body 81 is a part of a circuit to realize an electrical function, and can serve as a structural connection between the power module 8 and a client, so that the dual functions are achieved.

Example nine:

as shown in fig. 22 and 23, embodiment nine provides a module power supply 9, which includes a package 91 and a PCB module 92, the PCB module 92 is mounted on the package 91, the PCB module includes a PCB board 921, a plurality of elements 922 and a magnetic core 923, and the elements 922 and the magnetic core 923 are mounted on the PCB board 921. The present embodiment is different from the first to eighth embodiments in that the package 91 is stacked and connected with the PCB module in a horizontal direction. The present embodiment can expand the power and the functions of the package 91, improve the flexibility of the power module 9, and improve the integration level and the power density of the power module 9.

In summary, the present invention provides a power module, which combines a fan-out package technology and a multi-layer PCB process, thereby achieving a power density of about 3000W/in ³ Is a power density of (2); the switch tube, the chip and the signal-level resistor-capacitor are in a three-dimensional laminated structure in the package body, and the transformer PCB board, and the power-level resistor-capacitor (large volume) is combined and applied in the three-dimensional laminated structure outside the package body, so that the space is effectively utilized; the metal wiring of the super-multilayer takes 14 layers of PCBs as an example, and 5 layers of metal wiring in the package body are added, so that the total number of the metal wiring can reach 19 layers, the wiring is flexible, and the electrical connection and design are very beneficial. The device inside the package is selectively designed, so that the thickness of the package in the embodiment is less than 2mm, and the production process requirement is met. The magnetic core of the transformer also adopts a planar transformer structure to reduce the thickness of the magnetic core, and in this embodiment, the connecting members of the PCB assembly and the package assembly adopt metal members, and the metal connecting members are sandwiched between the PCB board and the package and are in height consistency with the portions of the magnetic core beyond the PCB board, so that the height of the whole module is not increased under the condition of not considering assembly tolerance. The copper thickness of each layer in the multilayer PCB is not limited by the copper thickness in the fan-out packaging process any more, and the thickness of each layer can be easily 100-140 mu m (3-4 oz) or even thicker through the manufacturing process of the PCB, so that lower copper loss can be obtained, and the multilayer PCB is more suitable for high-power and high-current application occasions. The advantages and disadvantages of the PCB process and the packaging technology are fully combined, the inside of the packaging body and the division of components and functions of the PCB are reasonably distributed, and the production difficulty and the cost of the packaging body are reduced within a reasonable and acceptable range.

While the invention has been illustrated and described in detail with reference to preferred embodiments, the invention is not limited to the examples disclosed and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Claims

1. A power module, comprising

The PCB module comprises a PCB and a magnetic core, wherein the magnetic core is arranged on the PCB;

the connecting component is arranged on the lower end surface or the side wall of the PCB;

at least one package connected with the PCB module through the connecting member;

the lower end face of the magnetic core is contacted with the upper end face of the packaging body or is positioned in a groove of the packaging body.

2. The power module of claim 1 wherein said package includes a rewiring layer, a plurality of components, a plurality of said components being connected by said rewiring layer.

3. The power module of claim 2 wherein the package further comprises pins, the component being mounted on an upper layer of the pins by the rewiring layer.

4. A power module according to claim 3, wherein a plurality of components are mounted on both the upper and lower faces of the PCB.

5. The power module of claim 4, wherein the component is one or more of a control chip, a driver chip, a resistor-capacitor, and a switching transistor.

6. A power module according to claim 3, further comprising a secondary plastic package, wherein the PCB module is mounted in the secondary plastic package, and wherein a lower end surface of the secondary plastic package is in contact with an upper end surface of the package.

7. The power module of claim 6, wherein an upper end surface of the secondary plastic package body is flush with a lower end surface of the PCB.

8. The power module of claim 6, wherein an upper end surface of the secondary plastic package body is flush with an upper end surface of the PCB.

9. The power module of claim 6, wherein an upper end surface of the secondary plastic package body is flush with an upper end surface of the magnetic core.

10. A method of manufacturing a power module for manufacturing a module power supply according to any one of claims 1 to 9, comprising:

step S1, preparing a PCB module: after the elements and the connecting members are welded on the lower end face of the PCB, the required elements are welded on the upper end face of the PCB; mounting the magnetic core on the PCB to obtain the PCB module;

step S2, preparing the packaging body: attaching at least one bare chip to the upper surface of a substrate and performing injection molding; then mounting a first bonding pad on the first rewiring layer after the first rewiring layer is arranged on the upper end face of the first bonding pad; soldering a plurality of elements and metal connection posts on the first bonding pad; arranging a second rewiring layer on the upper end face of the metal connecting column, and mounting the second bonding pad on the second rewiring layer to obtain the packaging body;

step S3, preparing the power module: and removing the substrate, arranging pins on the lower end surface of the first rewiring layer, and welding the connecting component on the PCB to the second bonding pad to obtain the power module.

11. The method of claim 10, wherein the step S2 includes

step S24, mounting a first bonding pad on the first rewiring layer,