MOS tube packaging structure

Abstract

The utility model provides an MOS tube packaging structure, which comprises a pin, a chip and a bonding wire connecting the pin and the chip, the bonding wire comprises a main body part and a protective layer arranged on at least one part of the outer side of the main body part, and the melting point of the protective layer is lower than that of the main body part. According to the MOS packaging structure provided by the utility model, after the MOS tube is short-circuited, the protection layer is fused before the main body part, so that the connection between the MOS tube and an external circuit is cut off, the overcurrent of the external circuit of the MOS tube is not caused, the overcurrent or fire of the external circuit caused by the short circuit of the MOS tube can be effectively prevented, and the safety of the MOS tube packaging structure is improved.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor packaging, in particular to a MOS tube packaging structure. Background Art

[0002] The full name of MOS tube is MOSFET (Metal Oxide Semiconductor Field Effect Transistor), which is a metal oxide semiconductor field effect transistor, belonging to the insulated gate type of field effect transistor. Therefore, MOS tube is sometimes called field effect tube. In general electronic circuits, MOS tubes are usually used in amplifier circuits or switching circuits.

[0003] In some switching circuits with relatively large currents, MOS tubes are required to control the on and off of the circuits. However, in actual practical applications, the MOS tubes may fail due to breakdown due to some reasons. At this time, a short circuit usually occurs inside the MOS tube, resulting in excessive internal short-circuit current, which causes the internal MOS tube to continue to heat up violently and burn out. In severe cases, open flames may occur, causing safety hazards. Especially when the MOS tube is installed in the corresponding printed circuit board and forms a complete circuit system with other components, the burning of the MOS tube will most likely cause the burning of other components in the circuit system, causing the entire circuit system to be paralyzed. Utility Model Content

[0004] In order to provide a MOS tube packaging structure that can automatically disconnect after the MOS tube fails, the utility model provides a MOS tube packaging structure, including: a MOS tube packaging structure, including: a pin, a chip, and a bonding wire connecting the pin and the chip, the bonding wire includes a main body and a protective layer arranged on the outside of the main body, and the melting point of the protective layer is lower than the melting point of the main body.

[0005] Furthermore, the thickness of the protective layer is 100um-500um.

[0006] Furthermore, the protective layer is made of metal tin.

[0007] Furthermore, the protective layer is structured in a tin ball shape.

[0008] Furthermore, the protective layer is configured to be electroplated on the outer side of the main body.

[0009] Furthermore, the protective layer is connected to the main body by welding.

[0010] Furthermore, a protective layer is disposed on the outer side of the main body.

[0011] Furthermore, the protective layer is only arranged on the outer side of the axial end of the main body.

[0012] Furthermore, the pins are arranged in plurality, including a source pin, a drain pin, and a gate pin. A plurality of first contact heads are arranged at one end of the bonding wire, which can be respectively connected to the source pin, the drain pin, and the gate pin. A second contact head connected to the chip is arranged at the other end of the bonding wire.

[0013] Furthermore, the protection layer is connected to the pin.

[0014] The bonding wire of the MOS tube packaging structure of the utility model is provided with a protective layer on the outer side of the main body, and the melting point of the protective layer is lower than that of the main body. After a short circuit occurs in the MOS tube, the short circuit current will first flow through the protective layer of the bonding wire, and the protective layer will first fuse after an overcurrent for a period of time, thereby disconnecting the MOS tube from the external circuit, and will not cause an overcurrent in the external circuit of the MOS tube, for example, will not cause an overcurrent in the printed circuit board and other components arranged in the printed circuit board, and can effectively prevent the external circuit from overcurrent or fire due to a short circuit of the MOS tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a simplified diagram of the MOS tube packaging structure of the utility model;

[0016] Figure 2 A schematic diagram of the connection between the MOS tube packaging structure of the utility model and the circuit board;

[0017] Figure 3 This is a cross-sectional schematic diagram of the bonding wire of the first embodiment of the MOS tube packaging structure of the utility model;

[0018] Figure 4 This is a cross-sectional schematic diagram of the bonding wire of the second embodiment of the MOS tube packaging structure of the utility model;

[0019] Figure 5 It is a cross-sectional schematic diagram of the bonding wire of the third embodiment of the MOS tube packaging structure of the utility model. DETAILED DESCRIPTION

[0020] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0021] like Figure 1-3As shown, the MOS tube packaging structure of the utility model includes a gate pin 10, a source pin 20, a drain pin 30, a chip 50 and a bonding wire 40. The bonding wire 40 is constructed to have multiple contact heads, a first end of the bonding wire is provided with multiple contact heads, and a second end of the bonding wire is provided with a contact head. The multiple contact heads at the first end can be connected to the gate pin 10, the source pin, and the drain pin 30 respectively, and the contact head at the second end can be connected to the chip 50, so that the bonding wire 40 can connect the gate pin 10, the source pin, and the drain pin 30 with the chip 50. The MOS tube packaging structure of the utility model is also provided with a packaging shell 70, and the packaging shell 70 encapsulates the chip 50, the bonding wire 40 and other components in the enclosed space of the packaging shell 70, which can protect the chip 50 and the bonding wire 40 from interference by external substances, so as to enhance the electrical and thermal performance of the chip 50, and ensure that the chip 50 in the MOS tube can operate stably for a long time under normal conditions. One end of the gate pin 10 and the source pin 20 are connected to the bonding wire 40 inside the MOS tube package, and the other end of the gate pin 10 and the source pin 20 are connected to the external printed circuit board, thereby realizing the connection between the internal circuit of the MOS and the external printed circuit board. The MOS tube packaging structure of the utility model also includes an epoxy resin adhesive, which can control the disconnection or connection of the energy storage system and the power grid according to the state of the power grid.

[0022] like Figure 3 As shown, the bonding wire 40 of this embodiment includes a main body 401 and a protective layer 402 arranged around the outside of the main body 401. The main body 401 is made of a silver-copper alloy, and the protective layer 402 is made of metal tin. The melting point of the protective layer 402 is lower than the melting point of the main body 401. Although in this embodiment, the protective layer is made of metal tin, the protective layer can be made of other materials as long as its melting point is lower than the melting point of the main body 401. For example, the material of the protective layer can be copper, copper-silver alloy, etc., as long as it can be achieved that when the MOS tube fails and the wafer in the MOS tube generates a large amount of heat, the protective layer 402 can melt before the main body 401, thereby disconnecting the connection between the bonding wire 40 and each pin.

[0023] In this embodiment, the protective layer 402 of the bonding wire connected to the pin and the chip is preferably set to a thickness of 100um-500um in order to increase the connection strength between the bonding wire and the pin and the chip. This can not only ensure the stable connection between the bonding wire and the pin, but also ensure that the current can flow normally through the bonding wire when the bonding wire is working normally. In this embodiment, the protective layer 402 is preferably constructed as follows Figure 4As shown in the solder ball shape, the protective layer 402 can be connected to the main body 401 by welding, and can also be connected to the main body 401 by electroplating. The connection method between the protective layer 402 and the main body 401 is not limited, as long as it can achieve a stable connection between the main body 401 and the protective layer 402, so that when the MOS tube works normally, the bonding wire can normally connect the pin to the chip.

[0024] Of course, the bonding wire can also be constructed as Figure 4 The shape of the bonding wire 90 of the second embodiment is shown, and the protection layer 902 is uniformly electroplated on the outside of the main body 901. The structural shape of the protection layer is consistent with that of the metal.

[0025] Alternatively, the bonding wires can also be constructed as Figure 5 In the shape of the bonding wire 100 of the third embodiment shown, the protective layer 1002 is only arranged on the outer sides of the axial ends of the main body 1001. The middle part of the bonding wire 100 is not provided with a protective layer, and the two ends of the bonding wire are respectively connected to the MOS tube pin and the chip, and the main body 1001 is not connected to the pin and the chip, so there is no need to set a protective layer in the middle of the main body, thereby simplifying the production process of the bonding wire and improving production efficiency.

[0026] The MOS tube packaging structure with the bonding wire of the utility model has a protective layer at one end of the bonding wire connected to a gate pin, a source pin, and a drain pin; the protective layer at the other end of the bonding wire is connected to a chip; when the MOS tube is broken down and short-circuited due to some reasons during operation, a large short-circuit current is continuously generated, and after the short-circuit current flows through the bonding wire for a period of time, since the protective layer of the bonding wire is connected to each pin and the chip in the utility model, and the protective layer is constructed in a tin ball shape or a tin plating structure, and the melting point of tin is lower than the melting point of the main body of the silver-copper alloy in the bonding wire, the protective layer will fuse before the main body of the silver-copper alloy after being heated for a period of time, so that the bonding wire 40 will be disconnected from the source pin and the gate pin in the MOS tube, so that the MOS tube will not continue to have current flowing through it and continue to heat up and cause burning, and the occurrence of overcurrent protection and surge current-induced erroneous fusing of the bonding wire can be effectively prevented.

[0027] The MOS tube packaging structure of the present invention uses a silver-copper alloy as the main body and a bonding wire with a protective layer arranged on the outside of the main body. Under normal working conditions, the bonding wire normally connects each pin and the chip, and the MOS tube works normally without being affected. However, after a short circuit occurs in the MOS tube, the short-circuit current will flow through the protective layer of the bonding wire. The protective layer will first fuse after a period of overcurrent, thereby disconnecting the MOS tube from the external circuit, and will not cause overcurrent in the external circuit of the MOS tube, for example, it will not cause overcurrent in the printed circuit board and other components arranged in the printed circuit board, and can effectively prevent the external circuit from overcurrent or fire due to a short circuit of the MOS tube. Moreover, the MOS tube packaging structure of the present invention can also effectively prevent the overcurrent protection and the bonding wire from being mistakenly blown due to surge current. Obviously, the above-mentioned embodiments of the present invention are only examples made to clearly illustrate the present invention, and

[0028] It is not a limitation of the implementation methods of the utility model. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. Any modification, equivalent replacement and improvement made within the spirit and principle of the utility model should be included in the protection scope of the claims of the utility model.

Claims

1. A MOS tube packaging structure, comprising: A pin, a chip, and a bonding wire connecting the pin and the chip, characterized in that the bonding wire includes a main body and a protective layer arranged on at least a portion of the outer side of the main body, and the melting point of the protective layer is lower than the melting point of the main body.

2. The MOS tube packaging structure according to claim 1, characterized in that: The thickness of the protective layer is 100um-500um.

3. The MOS tube packaging structure according to claim 1, characterized in that: The protective layer is made of metal tin.

4. The MOS tube packaging structure according to claim 1, characterized in that: The protective layer is structured in a tin ball shape.

5. The MOS tube packaging structure according to claim 1, characterized in that: The protective layer is connected to the main body by welding.

6. The MOS tube packaging structure according to claim 1, characterized in that: The outer sides of the main body are all provided with a protective layer.

7. The MOS tube packaging structure according to claim 1, characterized in that: The protective layer is only arranged on the outer side of the axial end of the main body.

8. The MOS tube packaging structure according to claim 1, characterized in that: The pins are arranged in plurality, including a source pin, a drain pin, and a gate pin. A plurality of first contact heads are arranged at one end of the bonding wire, which can be respectively connected to the source pin, the drain pin, and the gate pin. A second contact head connected to the chip is arranged at the other end of the bonding wire.

9. The MOS tube packaging structure according to claim 1, characterized in that: The protection layer is connected to the pin.

10. The MOS tube packaging structure according to claim 1, characterized in that: A packaging shell is also included, in which the bonding wires and the chip are located.

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