CN118712188A - A structure for improving the precise control of power modules - Google Patents

Abstract

The present invention is applicable to the field of semiconductor packaging technology, and provides a structure for improving the precise control of a power module. The chip of the present invention provides a heat dissipation channel on the top, which can better dissipate heat and solve the difficulties in the layout and wiring of the packaging structure, so that the integrated clamping circuit is closer to the driven chip. While ensuring the synchronization of switching actions and the stability of the operating voltage, a structure for improving the precise control of the power module greatly improves the integration of the packaging structure. At the same time, the independent routing mode of the power and drive circuits also avoids mutual interference. The drive circuit and the signal acquisition circuit are matched separately for each chip, and the optimal drive parameters can be matched according to the different electrical parameters of each chip to realize the common switching of the parallel chips. At the same time, a plurality of separate circuits can be integrated together through the flexible PCB, which greatly improves the system integration compared with the traditional signal pin method.

Description

A structure for improving precise control of power modules

Technical Field

The present invention belongs to the technical field of semiconductor packaging, and in particular relates to a structure for improving the precise control of a power module.

Background Art

A power module is a power switch device such as an insulated gate bipolar transistor (IGBT), a metal-oxide semiconductor field effect transistor (MOSFET), and a fast recovery diode (FWD) packaged into a whole module. Through an external gate circuit board and a control unit, it completes the DC/AC conversion and uses batteries or other energy to drive the motor. The module that realizes current conversion can be a single switch, a half-bridge, and a three-phase six-unit. The packaging structure is responsible for providing the mechanical support, electrical insulation, and heat dissipation channel required by the power module to ensure the high current, high power, and high reliability of the power chip.

In power modules, due to the insufficient current carrying capacity of a single chip, it is necessary to mount a chip array on an insulating substrate (DBC/AMB/IMS, etc.) to form a switching circuit. However, for each chip connected in parallel in the array, due to differences in spatial position distribution, the paths of its current loop are not equal, which will cause the switching actions of each chip to be asynchronous. In actual work, the frequency of electrical signals reaches tens of kKz, and the asynchronous switching action may induce voltage spikes and oscillations, thereby damaging the chip.

At the same time, since there are differences between different chips connected in parallel, if the same signal is used to switch multiple chips, the switching actions of each chip will also be different. At a switching frequency of tens of kHz, high-frequency oscillations will also cause damage to chips and modules.

Discrete refers to packaging a single chip of a power switching device, such as an insulated gate bipolar transistor (IGBT), a metal-oxide semiconductor field effect transistor (MOSFET), and a fast recovery diode (FWD) into a whole. Through combination, it completes the DC/AC conversion and uses batteries or other energy to drive the motor. Module for realizing current conversion

In the application of single tube, surface mount devices (such as TO263, QFN, etc.) are widely used in power modules, photovoltaic wind power and vehicle OBC/DCDC due to their simple application methods.

The current surface mount devices have disadvantages such as large size, poor heat dissipation and large loop inductance, which to a certain extent limit the use of surface mount single tube devices.

Summary of the invention

The present invention provides a structure for improving the precise control of a power module, aiming to solve the above-mentioned problem.

The present invention is implemented as follows: a structure for improving the precise control of a power module includes a driving module and a chip, wherein the driving module is located at the lower end of the chip, wherein the driving module includes a driving resistor and a clamping circuit on a driving board, wherein the driving resistor and the clamping circuit are integrated into a PCB board;

The PCB board is located next to the chip;

The PCB board is electrically connected to the chip through wire bonding, and the driving module and the chip are electrically connected through a flexible PCB.

Preferably, the chip includes a driving circuit (Gate-source) and a signal acquisition circuit (Drain-source), and the driving circuit (Gate-source) and the signal acquisition circuit (Drain-source) are connected to the driving board through a flexible PCB board or other soft wire lead-out module.

Preferably, the driving module brings together the driving/signal acquisition circuits of the chips in parallel inside the module, and connects them to the driving board via signal pins.

Preferably, the PCB board and the DBC are connected by processes including but not limited to welding, silver sintering, bonding, etc.

Preferably, the PCB board is not in contact with the chip, but is integrated with the module through plastic encapsulation/potting or the like.

Preferably, each of the chips is equipped with an integrated clamping loop, which integrates a driving clamp outside the module and a driving resistor inside the module.

Preferably, the driving circuit and the signal acquisition circuit of the chip connected in parallel are not brought together inside the PCB board, but are connected through the PCB board via separate lines.

Preferably, the separate driving and signal acquisition circuits are connected to the driving board through, but not limited to, flexible PCB, soft wires, etc.

Preferably, the driving board provides a separate driving mode for each of the chips connected in parallel.

Preferably, the internal connection of the PCB board adopts cross-bonding.

Compared with the prior art, the embodiments of the present application have the following beneficial effects:

The present invention proposes to integrate the driving components of the original module (driving resistors next to the chip and clamping circuits on the driving board) on a PCB board and place it next to the chip inside the module; the PCB is electrically connected to the chip through wire bonding and other methods to achieve the function of synchronously driving the chip; the difficulties in packaging structure layout and wiring are solved, so that the integrated clamping circuit is closer to the driven chip, while ensuring the synchronization of switch action and the stability of working voltage, the integration of the packaging structure is greatly improved, and the independent routing of power and driving circuits also avoids mutual interference.

At the same time, the present invention proposes to connect the drive circuit (Gate-source) and signal acquisition circuit (Drain-source) of each chip to the drive board through a flexible PCB or other soft wires. Compared with the original module that brings together the drive/signal acquisition circuits of the parallel chips inside the module and then connects them to the drive board through the signal pin, the drive circuit and signal acquisition circuit are matched separately for each chip, and the optimal drive parameters can be matched according to the different electrical parameters of each chip to realize the common switch of the parallel chips; at the same time, multiple separate circuits can be integrated together through the flexible PCB, which greatly improves the system integration compared with the traditional signal pin method.

The present invention eliminates the wire bonding connection scheme and connects by sintering or welding the copper clips. Compared with the wire bonding scheme, the loop inductance is reduced while the current carrying capacity is increased. At the same time, the copper clip is connected to the entire source pad of the chip, providing a top heat dissipation channel for the chip, which can better dissipate heat. The signal line (Gate and source) wiring scheme is different from the traditional parallel wiring, and adopts a cross wiring scheme to reduce the drive loop inductance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a structural electrical connection for improving the precise control of a power module according to the present invention;

FIG2 is a schematic diagram of a structure for improving the precise control of a power module according to the present invention;

FIG3 is a schematic diagram of a three-dimensional structure of the present invention;

FIG4 is a schematic diagram of the front view of the structure of the present invention;

DETAILED DESCRIPTION

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

The embodiment of the present invention provides a structure for improving the precise control of a power module: comprising a driving module, a chip, the driving module being located at the lower end of the chip, the driving module comprising a driving resistor and a clamping circuit on a driving board, the driving resistor and the clamping circuit being integrated into a PCB board;

The PCB board is located next to the chip;

The PCB board is electrically connected to the chip through wire bonding, and the drive module and the chip are electrically connected through a flexible PCB.

The chip includes a driving circuit (Gate-source) and a signal acquisition circuit (Drain-source). The driving circuit (Gate-source) and the signal acquisition circuit (Drain-source) are connected to the driving board through a flexible PCB board or other soft wires.

The driver module brings together the drive/signal acquisition circuits of the parallel chips inside the module and connects them to the driver board through the signal pin.

The PCB board and the DBC are connected through processes including but not limited to welding, silver sintering, bonding, etc.

The PCB board and the chip do not contact each other, but are integrated with the module through plastic encapsulation/potting.

The chips are equipped with an integrated clamping loop, which integrates the drive clamp outside the module and the drive resistor inside the module.

The driving circuit and signal acquisition circuit of the parallel chip are not brought together inside the PCB board, but are connected through the PCB board via separate lines.

The separate driving and signal acquisition circuits are connected to the driving board through, but not limited to, flexible PCB, soft wires, and the like.

The driver board provides a separate driving mode for each chip connected in parallel.

The internal connections of the PCB board are cross-bonded.

Specific embodiment 1

Take the double-sided power chip 4x2 package array as an example:

Step 1: Integrate the drive resistor and clamp circuit on the PCB to form a separate block

Step 2: Solder and install the PCB with integrated clamping circuit block on the DBC, or place it next to the chip through a copper frame support.

Step 3: Connect the clamping circuit on the PCB to the chip through wire bonding and other methods. Each clamping circuit is responsible for the voltage clamping of a single chip.

Step 4: Each chip and its clamping circuit are individually routed inside the PCB board and connected to the external circuit (driver board) through a flexible PCB.

Specific embodiment 2

Take the surrounding power chip packaging array as an example

Step 1: Integrate the drive resistor and clamp circuit on the PCB to form a separate block

Step 2: Solder and install the PCB with integrated clamping circuit block on the DBC, or place it next to the chip through a copper frame support.

Step 3: Connect the clamping circuit on the PCB to the chip through wire bonding and other methods. Each clamping circuit is responsible for the voltage clamping of a single chip.

Step 4: Each chip and its clamping circuit are individually routed inside the PCB board and connected to the external circuit (driver board) through a flexible PCB.

The present invention proposes to integrate the driving components of the original module (driving resistors next to the chip and clamping circuits on the driving board) on a PCB board and place it next to the chip inside the module; the PCB is electrically connected to the chip through wire bonding and other methods to achieve the function of synchronously driving the chip; the difficulties in packaging structure layout and wiring are solved, so that the integrated clamping circuit is closer to the driven chip, while ensuring the synchronization of switch action and the stability of working voltage, the integration of the packaging structure is greatly improved, and the independent routing of power and driving circuits also avoids mutual interference.

At the same time, the present invention proposes to connect the drive circuit (Gate-source) and signal acquisition circuit (Drain-source) of each chip to the drive board through a flexible PCB or other soft wires. Compared with the original module that brings together the drive/signal acquisition circuits of the parallel chips inside the module and then connects them to the drive board through the signal pin, the drive circuit and signal acquisition circuit are matched separately for each chip, and the optimal drive parameters can be matched according to the different electrical parameters of each chip to realize the common switch of the parallel chips; at the same time, multiple separate circuits can be integrated together through the flexible PCB, which greatly improves the system integration compared with the traditional signal pin method.

The present invention cancels the wire bonding connection scheme and connects by sintering or welding of copper clips; compared with the wire bonding scheme, the loop inductance is reduced and the current carrying capacity is increased; at the same time, the copper clip is connected to the entire source pad of the chip, providing a top heat dissipation channel for the chip, which can better dissipate heat. The wiring scheme of the signal line (Gate and source) is different from the traditional parallel wiring and adopts a cross wiring scheme to reduce the drive loop inductance.

It should be noted that, for the above-mentioned embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, some steps may be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

In the several embodiments provided in the present application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are merely schematic, such as the division of the above-mentioned units. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be in the form of telecommunication or other forms.

The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field can still combine, add, delete or make other adjustments to the features in the various embodiments of the present invention according to the circumstances without conflict, without making creative work, so as to obtain different other technical solutions that do not deviate from the concept of the present invention in essence, and these technical solutions also belong to the scope of protection of the present invention.

Claims (10)

1. The structure for improving the accurate control of the power module is characterized by comprising a driving module, a chip and a clamping circuit, wherein the driving module is positioned at the lower end of the chip and comprises a driving resistor and a driving board, and the driving resistor and the clamping circuit are integrated into a PCB;

The PCB is positioned beside the chip;

the PCB board is electrically connected with the chip through wire bonding, and the driving module is electrically connected with the chip through a flexible PCB.

2. The structure of claim 1, wherein the chip includes a driving circuit (Gate-source) and a signal acquisition circuit (Drain-source), and the driving circuit (Gate-source) and the signal acquisition circuit (Drain-source) are individually connected to the driving board through a flexible PCB board or other flexible wire lead-out module.

3. The structure of claim 1, wherein the driving module collects driving/signal collecting loops connected in parallel to the chip inside the module, and is connected with the driving board through signal pin.

4. The structure of claim 2, wherein the PCB board and DBC are connected by a process including but not limited to soldering, silver sintering, bonding, etc.

5. The structure of claim 1, wherein the PCB board and the chip are not in contact, but are integrated with the module by plastic packaging/potting.

6. The structure of claim 2, wherein said chips are each provided with an integrated clamp circuit integrating a drive clamp external to said module and a drive resistor internal to said module.

7. The structure of claim 2, wherein the driving circuit and the signal acquisition circuit connected in parallel are not integrated together in the PCB but are connected through the PCB by separate lines.

8. A structure for enhancing the precise control of a power module as claimed in claim 2, wherein said separate drive and signal acquisition lines are connected to said drive board by means of, but not limited to, flexible PCBs, flexible wires, etc.

9. The structure of claim 2, wherein each of said chips in parallel is provided with a separate driving means.

10. The structure for improving the precise control of the power module as claimed in claim 2, wherein the internal connection of the PCB board is cross-wire bonding.