Packaging structure, circuit structure and packaging method of electronic fuse

Abstract

The application discloses a packaging structure of an electronic fuse, a circuit structure and a packaging method thereof. The packaging structure comprises a packaging frame with a frame base and a plurality of pins, a MOS chip above the frame base, a metal connecting piece above the MOS chip and a controller chip above the metal connecting piece. The MOS chip comprises a main MOS tube and a branch MOS tube. The metal connecting piece completely covers the source area of the main MOS tube and is adapted to connect the source area of the main MOS tube with the pins of the packaging frame. The source area of the branch MOS tube is directly connected with the pins of the packaging frame. The controller chip is adapted to only open the main MOS tube during the soft start of the electronic fuse and to open the branch MOS tube after the soft start is completed or after the main MOS tube enters a linear region. The above scheme can reduce the burning of the MOS tube.

Description

Technical Field

[0001] This invention relates to the field of power semiconductor technology, specifically to an electronic fuse packaging structure, circuit structure, and packaging method. Background Technology

[0002] Electronic fuses are widely used in home appliances, servers, computers, mobile phones, and other fields. When a system is plugged in or powered on, an electronic fuse allows the system voltage to rise slowly, preventing overcurrent caused by a sudden and rapid increase in voltage. Electronic fuses can also act as circuit breakers in case of excessive current, protecting circuits from damage caused by overcurrent, overload, or short circuits.

[0003] In practical applications, metal-oxide-semiconductor (MOS) transistors can be used to implement electronic fuses. An integrated electronic fuse combines the controller and the MOS transistor onto a single chip, replacing the previous approach of integrating them onto separate chips.

[0004] However, existing integrated electronic fuses have poor heat dissipation, and the MOSFET is very easy to burn out during soft start-up. Summary of the Invention

[0005] The problem this invention aims to solve is: how to reduce the occurrence of MOSFET burnout.

[0006] To address the above problems, embodiments of the present invention provide a packaging structure for an electronic fuse, the packaging structure comprising:

[0007] The packaging frame has a frame base and multiple pins;

[0008] The MOS transistor chip is located above the frame substrate;

[0009] A metal connector located above the MOS transistor chip;

[0010] and the controller chip located above the metal connector;

[0011] The MOS transistor chip includes a main MOS transistor and a sub-MOS transistor; the metal connector completely covers the source region of the main MOS transistor and is adapted to connect the source region of the main MOS transistor to the pins of the package frame; the source region of the sub-MOS transistor is directly connected to the pins of the package frame.

[0012] The controller chip is connected to the gate region of the main MOSFET and the gate region of the sub-MOSFET, and is adapted to turn on only the main MOSFET during the soft start process of the electronic fuse, and to turn on the sub-MOSFET after the soft start is completed or after the main MOSFET enters the linear region.

[0013] Optionally, the main MOSFET and the branch MOSFET share a common drain region.

[0014] Optionally, both the main MOSFET and the sub-MOSFET are vertical structure MOSFETs.

[0015] Optionally, the gate region of the MOSFET is composed of the gate unit below the metal connector.

[0016] Optionally, the gate region of the MOSFET is composed of a continuous portion of the gate units below the metal connector.

[0017] Optionally, the gate region of the MOSFET is composed of a portion of the gate units that are uniformly distributed in the gate units below the metal connector.

[0018] Optionally, the gate cells that make up the gate region of the MOSFET extend through the MOSFET chip.

[0019] Optionally, the area of ​​the main MOSFET is larger than the area of ​​the sub-MOSFET.

[0020] Optionally, the area of ​​the MOSFET accounts for 15% to 25% of the area of ​​the MOSFET chip.

[0021] Optionally, the startup method of the MOSFET is hard start.

[0022] Optionally, the metal connector is a copper sheet.

[0023] This invention also provides a circuit structure for an electronic fuse, the circuit structure comprising:

[0024] Controller;

[0025] Main MOSFET and branch MOSFET;

[0026] The controller is connected to the gate of the main MOSFET and the gate of the sub-MOSFET, and is adapted to turn on only the main MOSFET during the soft start process of the electronic fuse, and to turn on the sub-MOSFET after the soft start is completed or after the main MOSFET enters the linear region.

[0027] This invention also provides a method for packaging an electronic fuse, the method comprising:

[0028] The package includes a packaging frame, a MOSFET chip, metal connectors, and a controller chip; the packaging frame has a frame base and multiple pins; the MOSFET chip includes a main MOSFET and a branch MOSFET.

[0029] The MOS transistor chip is placed on the frame substrate, and the source region of the main MOS transistor is connected to the pins of the package frame through the metal connector, while the source region of the sub-MOS transistor is directly connected to the pins of the package frame; the metal connector completely covers the source region of the main MOS transistor.

[0030] The controller chip is placed above the metal connector, and the controller chip is connected to the gate region of the main MOS transistor and the gate region of the branch MOS transistor.

[0031] The controller chip is adapted to turn on only the main MOSFET during the soft-start process of the electronic fuse, and to turn on the branch MOSFET after the soft-start is completed or after the main MOSFET enters the linear region.

[0032] Optionally, the main MOSFET and the branch MOSFET share a common drain region.

[0033] Optionally, both the main MOSFET and the sub-MOSFET are vertical structure MOSFETs.

[0034] Optionally, the gate unit below the metal connector can be used as the gate region of the MOSFET.

[0035] Optionally, a continuous portion of the gate units below the metal connector can be used as the gate region of the MOSFET.

[0036] Optionally, a portion of the gate units uniformly distributed below the metal connector can be used as the gate region of the MOSFET.

[0037] Optionally, the gate cells that make up the gate region of the MOSFET extend through the MOSFET chip.

[0038] Optionally, the area of ​​the sub-MOS transistor is larger than that of the sub-MOS transistor.

[0039] Optionally, the area of ​​the MOSFET accounts for 15% to 25% of the area of ​​the MOSFET chip.

[0040] Optionally, the controller chip is adapted to control the sub-MOSFET to hard start after the soft start is completed or after the main MOSFET enters the linear region.

[0041] Optionally, the metal connector is a copper sheet.

[0042] Compared with the prior art, the technical solution of the embodiments of the present invention has the following advantages:

[0043] By employing the scheme of this invention, a metal connector is set to cover the source region of the main MOSFET, thereby connecting the source region of the main MOSFET to the pins of the package frame via the metal connector. Meanwhile, the source region of the secondary MOSFET is directly connected to the pins of the package frame, and in this case, the secondary MOSFET is not covered by the metal connector. Thus, during soft-start, under the control of the controller chip, only the main MOSFET is turned on. Since the main MOSFET is in contact with the package frame through the metal connector, heat dissipation is good. The secondary MOSFET is not turned on at this time; it only turns on after the soft-start is complete or after the main MOSFET enters the linear region. This avoids device burnout caused by excessive system heat and zero-temperature effect, and improves the heat dissipation performance of the integrated electronic fuse. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the circuit structure of an electronic fuse;

[0045] Figure 2 yes Figure 1 A schematic diagram of the specific circuit connection of the electronic fuse;

[0046] Figure 3 yes Figure 1 The diagram shows the packaging structure of an electronic fuse.

[0047] Figure 4 yes Figure 3 A cross-sectional view of the package structure of the electronic fuse along line AA;

[0048] Figure 5 This is a curve showing how the power of the MOSFET changes with the soft-start duration;

[0049] Figure 6 This is a schematic diagram of the circuit structure of an electronic fuse according to an embodiment of the present invention;

[0050] Figure 7 This is a cross-sectional schematic diagram of an electronic fuse according to an embodiment of the present invention;

[0051] Figure 8 This is a cross-sectional schematic diagram of another electronic fuse in an embodiment of the present invention;

[0052] Figure 9 This is a cross-sectional schematic diagram of another type of electronic fuse in an embodiment of the present invention;

[0053] Figure 10 This is a cross-sectional schematic diagram of another electronic fuse in an embodiment of the present invention;

[0054] Figure 11 This is a flowchart of an electronic fuse packaging method according to an embodiment of the present invention. Detailed Implementation

[0055] Figure 1 This is a schematic diagram of the circuit structure of an electronic fuse. (Refer to...) Figure 1 The electronic fuse includes a MOSFET N1 and a controller 11. The controller 11 is connected to the gate of the MOSFET N1, so that the gate voltage of the MOSFET N1 increases slowly from zero, thereby achieving soft start of the MOSFET N1.

[0056] Figure 2 for Figure 1 A schematic diagram of the specific circuit connection of the electronic fuse. IN This indicates the input voltage of the electronic fuse, V. OUT This indicates the output voltage of the electronic fuse.

[0057] Figure 3 for Figure 1 The diagram shows the package structure of an electronic fuse. (Refer to...) Figure 3 The MOSFET is located in MOSFET chip 21, and the controller is located in controller chip 22.

[0058] Figure 4 for Figure 3 A cross-sectional view of the package structure of the electronic fuse along line AA.

[0059] Reference Figure 1 One of the technical challenges of integrated electronic fuses lies in the heat treatment during soft starting: the soft starting process is relatively long, typically 50ms to 200ms. During this process, MOSFET N1 is slowly turned on under the control of controller 11, and the voltage difference Vds between the source and drain of MOSFET N1 decreases slowly, keeping MOSFET N1 in the saturation region for an extended period. The output terminal of MOSFET N1 is generally connected to a capacitive or resistive load, resulting in a relatively large current Ids between the source and drain of MOSFET N1.

[0060] At this time, the power generated inside the integrated electronic fuse chip is Vds*Ids. Figure 5 This is a curve showing the power of MOSFET N1 as a function of soft-start duration. From... Figure 5 It can be seen that the heat generated by MOSFET N1 is very large, which may exceed the safety operating area (SOA) of MOSFET N1, causing the chip to burn out.

[0061] Furthermore, the zero-temperature coefficient makes the chip more susceptible to burn-out. Specifically, for example... Figure 1As shown, the source current of MOSFET N1 flows to the load. Because the source current of MOSFET N1 is relatively large, when packaging the chip, refer to... Figure 3 and Figure 4 Typically, a copper strip 23 is placed between the source of the MOSFET and the load. This copper strip connects the source current of the MOSFET to the pins of the package frame 24, thus transferring the source current to the load through the pins of the package frame 24. The copper strip 23 covers most of the source region of the MOSFET, but a portion of the source region lies outside the copper strip 23. During the chip's soft-start process, the temperature of the source region not covered by the copper strip 23 will be higher than the covered region. Due to the zero-temperature coefficient, the current density in this region will increase, causing it to become increasingly hot—this is the thermal runaway phenomenon, ultimately leading to the burnout of this region.

[0062] In summary, integrated electronic fuses generate a lot of heat during soft-start and can easily burn out poorly heated areas on the MOSFET N1.

[0063] To address this issue, this invention provides a packaging structure for an electronic fuse. In this structure, a metal connector covers the source region of the main MOSFET, allowing the source region of the main MOSFET to be connected to the pins of the package frame via the metal connector. The source region of the secondary MOSFET is directly connected to the pins of the package frame, and in this case, the secondary MOSFET is not covered by the metal connector. Thus, during soft-start, under the control of the controller chip, only the main MOSFET is turned on. Because the main MOSFET is in contact with the package frame through the metal connector, heat dissipation is good. The secondary MOSFET is not turned on during this time; it only turns on after the soft-start is complete or after the main MOSFET enters the linear region. This avoids device burnout caused by excessive system heat and zero-temperature effect, improving the heat dissipation performance of the integrated electronic fuse.

[0064] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0065] Reference Figure 6 This invention provides a circuit structure 50 for an electronic fuse, which may include:

[0066] Controller 51;

[0067] Main MOSFET M1 and branch MOSFET M2;

[0068] The controller 51 is connected to the gate of the main MOSFET M1 and the gate of the sub-MOSFET M2, and is adapted to turn on only the main MOSFET M1 during the soft start process of the electronic fuse, and to turn on the sub-MOSFET M2 after the soft start is completed or after the main MOSFET M1 enters the linear region.

[0069] In specific implementation, the source of the main MOSFET M1 and the source of the MOSFET M2 are electrically connected, and the drain of the main MOSFET M1 and the drain of the MOSFET M2 are electrically connected. The controller 51 is connected to the gate of the main MOSFET M1 and the gate of the branch MOSFET M2. By applying a gradually increasing voltage to the gate of the main MOSFET M1, the main MOSFET M1 is soft-started. During the soft-start process of the main MOSFET M1, the branch MOSFET M2 is in an off state. After the soft-start of the main MOSFET M1 is completed or after entering the linear region, the controller 51 controls the branch MOSFET M2 to start quickly, that is, controls the branch MOSFET M2 to hard-start.

[0070] Since the MOSFET M2 is in an off state during the soft-start process of the main MOSFET M1, it will not generate heat and will instead dissipate heat for the electronic fuse, thereby improving the fuse's heat dissipation performance. Furthermore, because the MOSFET M2 does not generate heat but only dissipates heat, its own temperature is lower than the junction temperature of the MOSFET, and therefore it will not burn out.

[0071] In specific implementation, for Figure 5 The circuit structure 50 of the electronic fuse shown can be packaged in various ways, and no limitation is made here.

[0072] This invention provides a packaging structure for an electronic fuse, which may include:

[0073] The packaging frame has a frame base and multiple pins;

[0074] The MOS transistor chip is located above the frame substrate;

[0075] A metal connector located above the MOS transistor chip;

[0076] and the controller chip located above the metal connector;

[0077] The MOS transistor chip includes a main MOS transistor and a sub-MOS transistor; the metal connector completely covers the source region of the main MOS transistor and is adapted to connect the source region of the main MOS transistor to the pins of the package frame; the source region of the sub-MOS transistor is directly connected to the pins of the package frame.

[0078] The controller chip is connected to the gate region of the main MOSFET and the gate region of the sub-MOSFET, and is adapted to turn on only the main MOSFET during the soft start process of the electronic fuse, and to turn on the sub-MOSFET after the soft start is completed or after the main MOSFET enters the linear region.

[0079] In embodiments of the present invention, the main MOSFET and the sub-MOSFET are located within the same MOSFET chip during packaging, rather than in two separate MOSFET chips. This reduces the chip area occupied by the main MOSFET and the sub-MOSFET, ultimately saving the packaging area of ​​the electronic fuse.

[0080] In practical implementation, the package frame provides support for the MOSFET chip, metal connectors, and controller chip. Furthermore, it allows for external connections of the main MOSFET and sub-MOSFETs within the MOSFET chip via multiple pins. The package frame includes pins, including but not limited to input pins, output pins, ground pins, and power pins, which can be configured according to the circuit containing the electronic fuse.

[0081] In specific implementations, the packaging frame can be made of metal, such as copper, to enable external connections between the main MOS transistor and the sub-MOS transistor in the OS transistor chip.

[0082] In practical implementation, both the main MOSFET M1 and the branch MOSFET M2 can be vertical MOSFETs. A vertical MOSFET is one in which the source and drain regions are distributed vertically, so that the channel of the MOSFET is formed vertically.

[0083] In practical implementation, the main MOSFET and the branch MOSFET in a MOSFET chip can share a common drain region, but their gate regions are separate, and their source regions are interconnected through surface metal. That is, in the prior art, the same MOSFET chip has one drain region, one source region, and one gate region. However, in the embodiments of this invention, the same MOSFET chip, although having one drain region and one source region, has two gate regions.

[0084] In practical implementation, the gate region of a MOSFET chip can be considered as being composed of countless gate units. Selecting a portion of these gate units and connecting them forms an independent gate region, while the remaining gate units are connected to form another independent gate region. Thus, the gate region of a MOSFET chip can be divided into two independent gate regions. Different gate regions, combined with the drain and source regions respectively, can form different MOSFETs.

[0085] To ensure that the load receives sufficient current during soft start, the area of ​​the main MOSFET can be set to be larger than that of the branch MOSFETs. This way, when only the main MOSFET is started, it can provide sufficient current to the load.

[0086] In one embodiment of the present invention, the area of ​​the sub-MOS transistor accounts for 15% to 25% of the area of ​​the MOS transistor chip. For example, the area of ​​the sub-MOS transistor can be 15%, 18%, 20%, or 22% of the total area of ​​the MOS transistor chip. The source region of the main MOS transistor is essentially 100% covered by metal interconnects, while the sub-MOS transistor is located outside the area covered by the metal interconnects.

[0087] Because the MOSFET has a small area and does not make perpendicular contact with the metal connector, its current can only flow laterally to the metal connector. Its own lateral resistance is relatively large, so it does not have a high current carrying capacity for the electronic fuse. Even if it is turned on during soft start, it does not contribute much to the load-carrying capacity of the electronic fuse.

[0088] In practice, there are multiple ways to select the gate cell, and no restrictions are imposed here.

[0089] Reference Figures 7 to 10 The metal connector 61 is located above the MOSFET chip 62, which is situated on the package frame 63. The metal connector 61 completely covers the source region of the main MOSFET in the MOSFET chip 62, but exposes the source region of the sub-MOSFETs. For vertical MOSFETs, the source region can be located above the gate, and the drain region can be located below the gate. The area below the metal connector 61 covers most of the gate cells in the MOSFET chip.

[0090] In one embodiment of the present invention, such as Figure 7 As shown, the gate region 621 of the MOSFET can be composed of the gate units below the metal connector 61. That is, the gate units located below the metal connector 61 are connected to form the gate region 621 of the MOSFET. The remaining gate units in the MOSFET chip 62 form the gate region of the main MOSFET.

[0091] In another embodiment of the invention, reference is made to Figure 8 The gate region 621 of the MOSFET is composed of a continuous portion of the gate units below the metal connector 61. In other words, the continuous portion of gate units below the metal connector 61 is connected to form the gate region 621 of the MOSFET. The remaining gate units in the MOSFET chip 62 form the gate region of the main MOSFET. Here, the remaining gate units in the MOSFET chip 62 include the gate units located below the metal connector 61 and the gate units located outside the metal connector 61.

[0092] In yet another embodiment of the invention, reference is made to... Figure 9 The gate region 621 of the sub-MOS transistor is composed of a portion of the gate units uniformly distributed below the metal connector 61. That is, several uniformly distributed gate units are connected to form the gate region 621 of the sub-MOS transistor. The remaining gate units in the MOS transistor chip 62 form the gate region of the main MOS transistor. Here, the remaining gate units in the MOS transistor chip 62 include the gate units located below the metal connector 61 and the gate units located outside the metal connector 61.

[0093] In yet another embodiment of the invention, referring to Figure 10 The gate unit that constitutes the gate region 621 of the MOSFET extends through the MOSFET chip 62. That is, the gate unit that extends through the MOSFET chip 62 is selected as the gate region 621 of the MOSFET.

[0094] It should be noted that the gate cells penetrating the MOS transistor chip 62 may be all the gate cells below the metal connector 61, or they may be a portion of the gate cells. These gate cells may be continuously distributed below the metal connector 61, or they may be evenly distributed at intervals below the metal connector 61; no limitation is made here.

[0095] In practice, the metal connector can be made of any conductive metal material. The shape of the metal connector is also not limited. For example, the metal connector can be a copper sheet.

[0096] In practice, the controller can be implemented using various circuit structures, and no limitation is made here. For details, please refer to... Figure 2 The specific structure of the controller 11 is implemented in this embodiment. The difference is that, in this embodiment, the controller chip is connected to the gates of both the main MOSFET and the branch MOSFET. Those skilled in the art can set corresponding switches in the controller chip, and by controlling the on / off state of these switches, select whether to turn on the branch MOSFET.

[0097] By adopting the electronic fuse packaging structure in this embodiment of the invention and optimizing the device layout, only the main MOSFET is turned on during the soft start process, while the branch MOSFETs are turned on after the soft start or after the device enters the linear region. This avoids the device burnout caused by excessive system heat and zero-temperature effect.

[0098] To enable those skilled in the art to better understand and implement the present invention, the packaging method corresponding to the above packaging structure is described in detail below.

[0099] Reference Figure 11This invention provides a method for packaging an electronic fuse, the method comprising the following steps:

[0100] Step 110: Provide a packaging frame, a MOSFET chip, a metal connector, and a controller chip; the packaging frame has a frame base and multiple pins; the MOSFET chip includes a main MOSFET and a sub-MOSFET.

[0101] In practical implementation, the frame substrate can support the MOSFET chip, metal connectors, and controller chip. The main MOSFET and the sub-MOSFET are located within the same MOSFET chip. That is, in this embodiment of the invention, for MOSFET chips of the same size, two MOSFETs are used to drive the load, rather than a single MOSFET driving the load.

[0102] In a specific implementation, the area of ​​the sub-MOS transistor is larger than that of the sub-MOS transistor.

[0103] In one embodiment of the present invention, the area of ​​the MOSFET accounts for 15% to 25% of the area of ​​the MOSFET chip.

[0104] Step 111: Place the MOS transistor chip on the frame substrate, and connect the source region of the main MOS transistor to the pins of the package frame through the metal connector, while directly connecting the source region of the sub-MOS transistor to the pins of the package frame; the metal connector completely covers the source region of the main MOS transistor.

[0105] In practice, the metal connector connects the source region of the main MOSFET to the pins of the package frame, while the source region of the secondary MOSFET is not connected to the pins of the package frame through the metal connector. In this way, the source region of the main MOSFET can dissipate heat through the metal connector.

[0106] In a specific implementation, the main MOS transistor and the branch MOS transistor can share a common drain region.

[0107] In practice, the metal connector can be a copper sheet.

[0108] Step 112: Place the controller chip above the metal connector and connect the controller chip to the gate region of the main MOS transistor and the gate region of the sub-MOS transistor.

[0109] The controller chip is adapted to turn on only the main MOSFET during the soft-start process of the electronic fuse, and to turn on the sub-MOSFET after the soft-start is completed or after the main MOSFET enters the linear region.

[0110] In specific implementations, both the main MOS transistor and the sub-MOS transistor can be vertical structure MOS transistors.

[0111] In a specific implementation, the gate units below the metal connector can be used as the gate region of the MOSFET. Specifically, all the gate units below the metal connector can be used as the gate region of the MOSFET, or only a portion of the gate units below the metal connector can be used.

[0112] When using a portion of the gate units below the metal connector as the gate region of a MOSFET, either a continuous portion of the gate units below the metal connector can be used as the gate region of the MOSFET, or a portion of the gate units evenly distributed below the metal connector can be used as the gate region of the MOSFET.

[0113] In practical implementation, the gate unit that makes up the gate region of the MOSFET can penetrate through the MOSFET chip, thereby increasing the contact area between the sidewall of the gate unit that makes up the gate region of the MOSFET and other components on the MOSFET chip. This allows for heat dissipation through the devices on the MOSFET chip that are in contact with it, thus enhancing the heat dissipation effect.

[0114] In practice, during the soft-start process, the controller chip only turns on the main MOSFET and turns off the secondary MOSFET. The main MOSFET remains in the saturation region for an extended period during the soft-start process. After the soft-start is complete or the main MOSFET enters the linear region, the controller chip then turns on the secondary MOSFET.

[0115] In a specific implementation, the controller chip is adapted to control the sub-MOS transistor to hard start after the soft start is completed or after the main MOS transistor enters the linear region.

[0116] By splitting the gate drive of the main MOSFET, areas with poor heat dissipation and areas with good heat dissipation are isolated, thus avoiding the effects of the zero-temperature effect.

[0117] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A packaging structure for an electronic fuse, characterized in that, include: The packaging frame has a frame base and multiple pins; The MOS transistor chip is located above the frame substrate; A metal connector located above the MOS transistor chip; and the controller chip located above the metal connector; The MOS transistor chip includes a main MOS transistor and a sub-MOS transistor; the metal connector completely covers the source region of the main MOS transistor and is adapted to connect the source region of the main MOS transistor to the pins of the package frame; the source region of the sub-MOS transistor is directly connected to the pins of the package frame. The controller chip is connected to the gate region of the main MOSFET and the gate region of the sub-MOSFET, and is adapted to turn on only the main MOSFET during the soft start process of the electronic fuse, and to turn on the sub-MOSFET after the soft start is completed or after the main MOSFET enters the linear region.

2. The packaging structure of the electronic fuse as described in claim 1, characterized in that, The main MOSFET and the branch MOSFET share a common drain region.

3. The packaging structure of the electronic fuse as described in claim 1, characterized in that, Both the main MOSFET and the sub-MOSFET are vertical structure MOSFETs.

4. The packaging structure of the electronic fuse as described in claim 1, characterized in that, The gate region of the MOSFET is composed of the gate unit below the metal connector.

5. The packaging structure of the electronic fuse as described in claim 1, characterized in that, The gate region of the MOSFET is composed of a continuous portion of the gate units below the metal connector.

6. The packaging structure of the electronic fuse as described in claim 1, characterized in that, The gate region of the MOS transistor is composed of a portion of the gate units that are evenly distributed in the gate unit below the metal connector.

7. The packaging structure of the electronic fuse as described in any one of claims 4 to 6, characterized in that, The gate unit that makes up the gate region of the MOS transistor extends through the MOS transistor chip.

8. The packaging structure of the electronic fuse as described in claim 1, characterized in that, The area of ​​the main MOS transistor is larger than the area of ​​the sub-MOS transistor.

9. The packaging structure of the electronic fuse as described in claim 8, characterized in that, The area of ​​the MOSFET accounts for 15% to 25% of the area of ​​the MOSFET chip.

10. The packaging structure of the electronic fuse as described in claim 1, characterized in that, The startup method of the MOSFET is hard start.

11. The packaging structure of the electronic fuse as described in claim 1, characterized in that, The metal connector is a copper sheet.

12. A circuit structure for an electronic fuse, characterized in that, include: Controller; Main MOSFET and branch MOSFET; The controller is connected to the gate of the main MOSFET and the gate of the sub-MOSFET, and is adapted to turn on only the main MOSFET during the soft start process of the electronic fuse, and to turn on the sub-MOSFET after the soft start is completed or after the main MOSFET enters the linear region; The main MOSFET and the branch MOSFET are located within the MOSFET chip, and the controller is implemented using a controller chip; the MOSFET chip and the controller chip are packaged using the packaging structure of the electronic fuse as described in any one of claims 1 to 11.

13. A method for packaging an electronic fuse, characterized in that, include: We provide packaging frames, MOSFET chips, metal connectors, and controller chips. The packaging frame has a frame base and multiple pins; The MOS transistor chip includes: a main MOS transistor and a branch MOS transistor; The MOS transistor chip is placed on the frame substrate, and the source region of the main MOS transistor is connected to the pins of the package frame through the metal connector, while the source region of the sub-MOS transistor is directly connected to the pins of the package frame; the metal connector completely covers the source region of the main MOS transistor. The controller chip is placed above the metal connector, and the controller chip is connected to the gate region of the main MOS transistor and the gate region of the branch MOS transistor. The controller chip is adapted to turn on only the main MOSFET during the soft-start process of the electronic fuse, and to turn on the branch MOSFET after the soft-start is completed or after the main MOSFET enters the linear region.

14. The packaging method for an electronic fuse as described in claim 13, characterized in that, The main MOSFET and the branch MOSFET share a common drain region.

15. The packaging method for an electronic fuse as described in claim 13, characterized in that, Both the main MOSFET and the sub-MOSFET are vertical structure MOSFETs.

16. The packaging method for an electronic fuse as described in claim 13, characterized in that, The gate unit below the metal connector is used as the gate region of the MOSFET.

17. The packaging method for an electronic fuse as described in claim 13, characterized in that, A continuous portion of the gate units below the metal connector is used as the gate region of the MOSFET.

18. The packaging method for an electronic fuse as described in claim 13, characterized in that, A portion of the gate cells uniformly distributed below the metal connector are used as the gate region of the MOSFET.

19. The method for packaging an electronic fuse as described in any one of claims 16 to 18, characterized in that, The gate unit that makes up the gate region of the MOS transistor extends through the MOS transistor chip.

20. The packaging method for an electronic fuse as described in claim 13, characterized in that, The area of ​​the sub-MOS transistor is larger than that of the sub-MOS transistor.

21. The packaging method for an electronic fuse as described in claim 20, characterized in that, The area of ​​the MOSFET accounts for 15% to 25% of the area of ​​the MOSFET chip.

22. The packaging method for an electronic fuse as described in claim 13, characterized in that, The controller chip is adapted to control the sub-MOSFET to hard start after the soft start is completed or after the main MOSFET enters the linear region.

23. The packaging method for an electronic fuse as described in claim 13, characterized in that, The metal connector is a copper sheet.

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