Power module and packaging integration method thereof

Abstract

The present invention relates to a power module and a packaging integration method thereof, wherein the power module comprises a driving chip, a plurality of inductors, and an interconnection layer located between the driving chip and the plurality of inductors; the interconnection layer comprises a plurality of low dielectric insulating coatings and a plurality of wirings located thereon; the first wirings and the second wirings are arranged in different directions; one end of the plurality of inductors is electrically connected to a lead frame, and the other end of the plurality of inductors is electrically connected to the first wiring of the interconnection layer; the second wiring of the interconnection layer is electrically connected to the driving chip. The present invention reduces the parasitic capacitance in the power module, simplifies the layout and wiring of a multi-phase power supply, and effectively utilizes the inductor and capacitor materials.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply equipment, and more particularly to a multi-phase power supply module and a packaging and integration method thereof. Background Art

[0002] The rapid development of computer technology has led mankind into the information society, and has also promoted the rapid development of power module technology. In the 1980s, computers fully adopted switching power supplies, taking the lead in completing the computer power supply upgrade. Then switching power supply technology has successively entered the fields of electronic and electrical equipment.

[0003] The rapid development of the communications industry has greatly promoted the development of communications power supplies. High-frequency, miniaturized switching power supplies and their technologies have become the mainstream of modern communications power supply systems. The application of multi-phase power supply technology is also increasing, and the corresponding modular integration of multi-phase power supplies is also a focus. In the prior art, the main methods for integrating power modules are: putting inductors, capacitors and integrated circuits into a package to make a power module; or using the inductor as a base to install integrated circuits and capacitor components.

[0004] However, with the integration method in the prior art, parasitic capacitance will be introduced into the circuit during the modular integration of multi-phase power supplies, which will also increase the complexity of the multi-phase power supply module and even cause problems such as inefficient utilization of inductor and capacitor materials, affecting the accuracy and cost of the integrated power supply. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a power module and a packaging and integration method thereof, which simplifies the implementation of multi-phase power supply and effectively utilizes inductor and capacitor materials.

[0006] A switching power supply provided according to the present invention includes: a plurality of inductors; a driving chip located above the plurality of inductors; and an interconnection layer located between the plurality of inductors and the driving chip, for providing electrical connection between the plurality of inductors and the driving chip, characterized in that: the interconnection layer includes a first low-dielectric insulating coating, a first wiring located on the first low-dielectric insulating coating, a second low-dielectric insulating coating located on the first wiring, and a second wiring located on the second low-dielectric insulating coating, and a first conductive path penetrating the first low-dielectric insulating coating and a second conductive path penetrating the second low-dielectric insulating coating, wherein the first wiring and the second wiring are arranged in different directions to reduce parasitic capacitance, and the first wiring is connected to the plurality of inductors via the first conductive path, connected to the second wiring via the second conductive path, and the second wiring is connected to the driving chip.

[0007] Preferably, the driving chip comprises a multi-phase switching power supply chip.

[0008] Preferably, the driving chip further includes a plurality of capacitors, and the multi-phase switching power supply chip is connected to the plurality of capacitors and the plurality of inductors.

[0009] Preferably, the plurality of capacitors include stacked capacitors and cushion capacitors, and the stacked capacitors and cushion capacitors are respectively located on two sides of the multi-phase switching power supply chip.

[0010] Preferably, the plurality of inductors are placed on N identically arranged insulating materials, wherein N is the number of power phases and is a natural number greater than 2.

[0011] Preferably, N columns of inductors are arranged at equal intervals on each insulating material, and each column of inductors is insulated from each other.

[0012] Preferably, each column of inductors is a serpentine structure.

[0013] Preferably, the tail ends of each column of inductors on the bottommost layer of insulating material are connected to a lead frame.

[0014] Preferably, the first wiring and the second wiring are both N metal films arranged at intervals.

[0015] Preferably, the metal film is a strip-shaped structure.

[0016] A switching power supply and a packaging integration method thereof provided by the present invention include performing the following operations on the power module: mounting a plurality of inductors on a lead frame; mounting an interconnection layer on the plurality of inductors; mounting a driver chip on the interconnection layer; electrically connecting one end of the plurality of inductors to the lead frame, and electrically connecting the other end of the plurality of inductors to a first wiring of the interconnection layer; electrically connecting a second wiring of the interconnection layer to the driver chip; and plastic-sealing the power module.

[0017] Preferably, the connection method of the interconnection layer includes: mounting a second low dielectric insulating coating on a first low dielectric insulating coating; and electrically connecting a second wiring on the second low dielectric insulating coating with a first wiring on the first low dielectric insulating coating through a second conductive path.

[0018] Preferably, the electrical connections are all made via conductive paths penetrating the material layers.

[0019] The beneficial effects of the present invention are as follows: the present invention greatly simplifies the layout and wiring of multi-phase circuits by utilizing an integrated inductor and directly wiring and installing a driver on the inductor, and improves the effective utilization of inductor and capacitor materials; at the same time, the cross wiring with a low potential difference is isolated by utilizing a low dielectric constant insulating coating to reduce the spatial capacitance at the switch node. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0021] Figure 1 shows the circuit schematic of the multiphase power module;

[0022] Figure 2 shows a schematic diagram of the overall structure of a power module in a first embodiment of the present invention;

[0023] Figure 3 A schematic diagram showing the structure of the interconnection layer in the power module in the first embodiment of the present invention is shown;

[0024] Figure 4 shows a schematic diagram of the overall structure of a power module in a second embodiment of the present invention;

[0025] Figure 5 A schematic diagram of the structure of the interconnection layer in the power module in the second embodiment of the present invention is shown. DETAILED DESCRIPTION

[0026] The present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale. In addition, some well-known parts may not be shown. For the sake of simplicity, the semiconductor structure obtained after several steps can be described in one figure.

[0027] It should be understood that when describing the structure of a device, when a layer or a region is referred to as being "on" or "over" another layer or another region, it may mean that it is directly on the other layer or another region, or that other layers or regions are included between it and the other layer or another region. Furthermore, if the device is turned over, the layer or a region will be "below" or "beneath" another layer or another region.

[0028] If the purpose is to describe the situation of being directly on another layer or another area, this article will use the expression "directly on..." or "on... and adjacent to...".

[0029] Figure 1 shows the circuit schematic of the multiphase power module;

[0030] The present invention mainly relates to the integrated packaging of a multi-phase power supply module. The multi-phase power supply is to combine multiple single-phase power supply circuits together, and distinguish the working time of each phase on the basis of parallel connection to form a multi-phase power supply module. Among them, the multiple output paths of the multi-phase power supply are turned on in turn in a certain time sequence.

[0031] like Figure 1As shown: Taking 4 phases as an example, the multi-phase power supply module includes: capacitors, inductors, driver chips and loads. Among them, the capacitors C1~C4 are filter capacitors used to filter the input Vin and output Vout signals of the driver chip; the inductors L1~L4 are used as energy conversion devices on each output channel of the multi-phase power supply; the driver chip is used to control the conduction time and sequence of each output channel of the multi-phase power supply module to the load.

[0032] Preferably, on the driving chip, IN1 to IN4 are four signal input terminals of the driving chip, and S1 to S4 are four signal output terminals of the driving chip.

[0033] Preferably, when the multi-phase power module is packaged, if the overall material remains unchanged, the resistance of each channel increases by 4 times and the current is shared by 1 / 4. Since the resistive loss is proportional to the square of the current and proportional to the resistance, the resistive loss of each phase of the 4-phase architecture is reduced to 1 / 4 of that of the single phase, reducing the peak current of a single inductor and making it feasible. When the 4 phases are evenly staggered, the ripple frequency increases by 4 times, reducing the filtering pressure.

[0034] At the same time, since the inductance is in a square relationship with the winding length, if no magnetic material is added, the inductance is reduced to 1 / 16 of a single inductor. In order to reduce ripple, the multi-phase architecture requires more magnetic materials and the switching frequency is increased as much as possible to ensure performance improvement. For example, the amount of magnetic material must be increased by 4 times to keep the original inductance of each branch inductor. From a mechanistic point of view, multi-phase circuits use more magnetic materials and occupy a larger wiring layout area at the expense of more area.

[0035] Figure 2 The figure shows a schematic diagram of the structure of the power module in the first embodiment of the present invention.

[0036] like Figure 2 As shown, the power module provided by the embodiment of the present invention includes: a driving chip 1, a plurality of inductors 4, and an interconnection layer located between the driving chip 1 and the plurality of inductors 4, wherein the interconnection layer includes a first low dielectric insulating coating 31, a first wiring 21 located on the first low dielectric insulating coating, a second low dielectric insulating coating 32 located on the first wiring, and a second wiring 22 located on the second low dielectric insulating coating, and a first conductive channel 71 passing through the first low dielectric insulating coating and a second conductive channel 72 passing through the second low dielectric insulating coating. The driving chip includes a multi-phase switching power supply chip.

[0037] Preferably, the driving chip is located above the power module, a second low dielectric insulating coating 32 is provided under the driving chip, a second wiring 22 is arranged at one end of the upper surface of the second low dielectric insulating coating 32, and the second wiring 22 is correspondingly connected to the connecting pins of the driving chip; a first low dielectric insulating coating 31 is arranged under the second low dielectric insulating coating 32, a first wiring 21 is provided at one end of the upper surface of the first low dielectric insulating coating 31, the first wiring 21 and the second wiring 22 are located at the same end of the first low dielectric insulating coating 31 and the second low dielectric insulating coating 32, and are arranged crosswise with each other, and are connected to each other via a conductor penetrating the insulating coating 32. The electrical channels 72 are connected to each other; there are multiple inductors 4 under the first low dielectric insulating coating 31; the multiple inductors 4 are fixed on the upper surface of multiple insulating materials 5; and N columns of inductors are arranged in parallel at intervals on the upper surface of each insulating material 5 (N is the number of power phases and is a natural number greater than 2), each insulating material is exactly the same and the arrangement of the inductors arranged thereon is also basically the same; the multiple insulating materials are stacked into an N-layer structure, the arrangement direction of the inductors 4 on each layer of material 5 is the same, and one end of any column of inductors on any insulating material layer is connected to the corresponding column of inductors on its adjacent material layer; in addition, the tail end of each column of inductors on the bottommost insulating material layer is connected to a lead frame 6.

[0038] Preferably, the wiring is a metal film arranged at intervals; the metal film is a strip structure; and each column of inductors is a serpentine structure.

[0039] The power module and the packaging integration method thereof disclosed in the present invention can integrate the power module in the following assembly sequence:

[0040] (1) Mounting multiple inductors on a lead frame;

[0041] (2) mounting the interconnect layer on multiple inductors;

[0042] (3) Mounting the driver chip on the interconnect layer;

[0043] (4) electrically connecting one end of the plurality of inductors to a lead frame, and electrically connecting the other end of the plurality of inductors to a first wiring of the interconnection layer;

[0044] (5) electrically connecting the second wiring of the interconnect layer to the driver chip;

[0045] (6) The power module is plastic-sealed.

[0046] Figure 2 A schematic diagram of the structure of the interconnection layer in the power module in the first embodiment of the present invention is shown.

[0047] like Figure 3As shown, the connection method of the interconnection layer in the power module in the first embodiment of the present invention includes: mounting a second low dielectric insulating coating on the first low dielectric insulating coating; electrically connecting the second wiring on the second low dielectric insulating coating with the first wiring on the first low dielectric insulating coating through a second conductive path. The metal films constituting the first wiring 21 and the metal films constituting the second wiring 22 intersect each other in the arrangement direction, and are connected to each other correspondingly when electrically connected. In addition, preferably, the arrangement direction of the metal films constituting the first wiring 21 is consistent with the arrangement direction of each column of inductors 4.

[0048] Furthermore, in practical applications, the above assembly sequence can be flexibly adjusted. The assembly sequence described here should not be used to limit the present invention.

[0049] In the power module and the packaging integration method thereof provided by the present invention, each metal film in the first wiring corresponds to and is connected to a column of inductors. Between adjacent first wirings and second wirings, the arrangement directions of the metal films cross each other and are connected correspondingly. Such an arrangement and connection structure can effectively reduce or avoid parasitic capacitance in the power module.

[0050] In addition, the connection relationship between the connection points of each part of the power module is connected through a conductive channel that penetrates the material layer. The vertical connection of the conductive channel optimizes the layout and connection of the power module, and also reduces the problem of parasitic capacitance generated between the connection points to a certain extent, and reduces the connection complexity of the multi-phase power supply.

[0051] Figure 4 It shows a schematic diagram of the structure of a power supply assembly provided by the second embodiment of the present invention.

[0052] Compared with the first embodiment, the difference lies in that: optionally, the driving chip 1 further includes a stacked capacitor 8 and a cushion capacitor 9, and the stacked capacitor 8 and the cushion capacitor 9 are respectively located on both sides of the multi-phase switching power supply chip.

[0053] Figure 5 A schematic diagram showing the structure of the interconnection layer in the power module in the second embodiment of the invention is shown.

[0054] The difference from the first embodiment of the present invention is that the arrangement and layout of the metal films on the second wiring are adjusted accordingly. In this embodiment, the metal films are preferably arranged close to the inside and spaced apart from each other.

[0055] The power module and packaging integration method thereof disclosed in the present invention optimize the layout and wiring of the multi-phase power module to a certain extent, so that materials such as inductors and capacitors can be used more reasonably and effectively in the embodiments described in the present invention.

[0056] The embodiments of the present invention are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A power module, comprising: Multiple inductors; A driver chip located above the multiple inductors; as well as an interconnection layer located between the plurality of inductors and the driver chip, for providing electrical connections between the plurality of inductors and the driver chip, Its characteristics are: The interconnect layer includes a first low-dielectric insulating coating layer, a first wiring layer on the first low-dielectric insulating coating layer, a second low-dielectric insulating coating layer on the first wiring layer, a second wiring layer on the second low-dielectric insulating coating layer, a first conductive path passing through the first low-dielectric insulating coating layer, and a second conductive path passing through the second low-dielectric insulating coating layer. The first wiring and the second wiring are arranged in different directions to reduce parasitic capacitance, and the first wiring is connected to the multiple inductors via the first conductive channel and connected to the second wiring via the second conductive channel, and the second wiring is connected to the driving chip.

2. The power module according to claim 1, wherein: The driving chip includes a multi-phase switching power supply chip.

3. The power module according to claim 2, wherein: The driving chip further includes a plurality of capacitors, and the multi-phase switching power supply chip is connected to the plurality of capacitors and the plurality of inductors.

4. The power module according to claim 3, wherein: The plurality of capacitors include stacked capacitors and pad capacitors, and the stacked capacitors and pad capacitors are respectively located on two sides of the multi-phase switching power supply chip.

5. The power module according to claim 1, wherein: The plurality of inductors are placed on N identically arranged insulating materials, wherein N is the number of power phases and is a natural number greater than 2.

6. The power module according to claim 5, wherein: N columns of inductors are arranged at equal intervals on each insulating material, and each column of inductors is insulated from each other.

7. The power module according to claim 6, wherein: Each column of inductors has a serpentine structure.

8. The power module according to claim 5, wherein: The tail ends of each column of inductors on the bottom layer of insulating material are connected with a lead frame.

9. The power module according to claim 1, wherein: The first wirings and the second wirings are both N metal films arranged at intervals.

10. The power module according to claim 9, wherein: The metal film is a strip-shaped structure.

11. A power module packaging and integration method, characterized in that: The method comprises performing the following operations on the power module according to any one of claims 1 to 10: Mounting multiple inductors on a lead frame; Mounting the interconnect layer on the plurality of inductors; Mounting the driver chip on the interconnect layer; electrically connecting one end of the plurality of inductors to the lead frame, and electrically connecting the other end of the plurality of inductors to the first wiring of the interconnection layer; electrically connecting the second wiring of the interconnection layer to the driver chip; The power module is plastic-sealed.

12. The power module packaging and integration method according to claim 11, characterized in that: The connection method of the interconnection layer includes: attaching a second low dielectric insulating coating layer to the first low dielectric insulating coating layer; The second wiring on the second low-dielectric insulating coating layer is electrically connected to the first wiring on the first low-dielectric insulating coating layer through a second conductive path.

13. The power module packaging and integration method according to claim 11, wherein: The electrical connections are all made via conductive channels that penetrate the material layers.

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