TO-247plus packaging body and assembling component

Abstract

The utility model discloses a TO-247plus packaging body and an assembling component, and relates to the technical field of semiconductors. Comprising a chip placement area, a heat dissipation groove located in the top of the frame and heat dissipation fins arranged on the side portions of the frame. According to the scheme, a TO-247 frame structure with a side face heat dissipation structure is designed, two small vertical structures, namely, the heat dissipation grooves in the scheme, on the top and two large embedded vertical structures, namely, the heat dissipation fins in the scheme, on the side face are additionally arranged on the frame, heat can be guided to be dissipated from the side face, and junction-to-shell thermal resistance of a device is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, in particular to a TO-247plus package and an assembly component. Background Art

[0002] In power device products, TO-247 package is widely used. At present, the frame structure commonly used in the industry for TO-247 package is a three-pin structure with a metal backplane. The three pins are usually called pin 1, pin 2 and pin 3. Pin 2 is connected to the pad, and the pad mainly provides heat dissipation. There is an opening with a radius of 3.3-3.8mm (slightly different from different manufacturers) in the middle of the upper part of the TO-247 frame pad, which is convenient for screws to fix it on the heat sink. When using it, align the screw holes of the device and the heat sink first, and then screw in the screws, and consider the torque. The size of the TO-247 package is between the module and the single tube, and it can package most electronic components. The process and technology in the fields of diodes, triodes, MOSFET, IGBT, thyristor, power modules, etc. have been perfected, and the reliability of this package has been widely recognized.

[0003] As silicon carbide and IGBT continue to develop towards high power, the required chip area is getting larger and larger, so the TO-247plus package was introduced. After the mounting holes are removed, the heat dissipation area of ​​the back of the TO-247plus that contacts the outside world is increased by 10%-20% compared with the TO-247 package, but the area of ​​the chip placed on the front pad has increased by more than 30%. TO-247plus has a larger pad to place the chip. If the heat dissipation performance cannot be improved, it will lead to the risk of thermal failure of the chip. However, the existing packaging structure can only rely on the back heat dissipation. The heat dissipation area of ​​the back of the TO-247plus has reached its limit. For this package, the heat dissipation performance limits multi-chip and more compact design solutions. Utility Model Content

[0004] In view of the above problems, the utility model provides a TO-247plus package body and an assembly component which have a delicate structure and improve the heat dissipation performance of the packaged device.

[0005] The technical solution of the utility model is:

[0006] TO-247plus package, including:

[0007] The frame has a chip placement area on the front, a heat dissipation slot on the top, and heat dissipation fins on the sides;

[0008] A chip is arranged in a chip placement area;

[0009] A plurality of pins are provided and electrically connected to the chip;

[0010] The plastic package is wrapped on the chip, the side of the plastic package is connected to the heat dissipation fins, and the top is connected to the heat dissipation groove.

[0011] Specifically, the heat dissipation fins and the heat dissipation grooves are exposed outside the plastic package toward the outer area.

[0012] Specifically, an anti-overflow groove is provided at the edge of the chip placement area; and the chip is arranged in the anti-overflow groove.

[0013] Specifically, the heat dissipation slot is semi-closed.

[0014] Specifically, the heat dissipation slot is located at the top corner of the frame.

[0015] Specifically, the heat dissipation fins are located on the front side of the frame and outside the chip placement area.

[0016] Specifically, the heat dissipation fins are in a C-shaped structure.

[0017] Specifically, the pins include:

[0018] First pins are arranged at intervals at the bottom of the frame and are electrically connected to the chip through bonding wires;

[0019] A second pin is fixedly connected from the bottom of the frame;

[0020] The third pins are arranged at intervals at the bottom of the frame, are located on the side of the first pins, and are electrically connected to the chip through bonding wires.

[0021] TO-247plus assembly components, also include:

[0022] The pins of the package body are inserted into corresponding electrode sockets of the circuit board.

[0023] Specifically, the circuit board is provided with a heat sink fixed thereto;

[0024] A fixing seat is provided on the bottom plate of the radiator; the fixing seat comprises:

[0025] A fixing plate, arranged on one side of the heat sink of the heat sink;

[0026] The presser feet are provided with a plurality of L-shaped structures, one end of which is connected to the fixing plate, and the other end of which extends to one side of the packaging body through the fixing plate. The plurality of presser feet are fixedly connected to the packaging body by rotating the bolt in the middle of the fixing plate.

[0027] Beneficial effects of the utility model:

[0028] At present, the chip device packaging mainly dissipates heat through the bottom heat sink, and a small number of them have designed top heat dissipation structures. Due to the large size of the TO-247 package, top heat dissipation cannot be used for wire bonding devices. This case designs a TO-247 frame structure with a side heat dissipation structure. The frame adds two small vertical structures on the top, namely the heat dissipation slots in this case, and two larger embedded vertical structures on the side, namely the heat dissipation fins in this case, which can guide the heat to dissipate from the side and reduce the junction-to-case thermal resistance of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of the three-dimensional structure of step S110;

[0030] Figure 2 is a schematic diagram of the three-dimensional structure of step S120;

[0031] Figure 3 is a schematic diagram of the three-dimensional structure of step S130;

[0032] Figure 4 is a schematic diagram of a three-dimensional structure of a copper fin plate bent at 90° in step S140;

[0033] Figure 5 is a schematic diagram of the three-dimensional structure of the mold shaping in step S140;

[0034] Figure 6 is a schematic diagram of the three-dimensional structure of the heat dissipation slots and heat dissipation fins formed in step S140;

[0035] Figure 7 It is a schematic diagram of a three-dimensional structure with a long strip punched out at the edge;

[0036] Figure 8 is a schematic diagram of the three-dimensional structure of step S200;

[0037] Fig. 9 is a three-dimensional structural schematic diagram of step S300;

[0038] Fig.10 This is a three-dimensional structure diagram of the connection between the device and the circuit board. Figure 1 ;

[0039] Fig.11 This is a three-dimensional structure diagram of the connection between the device and the circuit board. Figure 2 ;

[0040] Fig.12 It is a device temperature test diagram without air convection, only considering the rise of air thermal expansion;

[0041] Fig.13 This is a device temperature test diagram with air flow rate of 5m / s, blowing from the top of the device to the pins;

[0042] Fig.14 This is a device temperature test diagram with air flow rate of 1m / s, blowing from the top of the device to the pins;

[0043] In the figure, 100 is a frame, 110 is a chip placement area, 111 is an anti-overflow groove, 120 is a heat dissipation groove, 121 is a heat dissipation protrusion, 122 is a long strip opening, 130 is a heat dissipation fin, 131 is a rectangular hole,

[0044] 200 is the chip,

[0045] 310 is the first pin, 320 is the second pin, 330 is the third pin,

[0046] 400 is plastic package,

[0047] 500 is the circuit board,

[0048] 600 is a heat sink, 610 is a fixing seat, 611 is a fixing plate, and 612 is a presser foot. DETAILED DESCRIPTION

[0049] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0050] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "vertical", "horizontal", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0051] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] Reference below Figure 1-14 Describe the utility model;

[0053] TO-247plus package frame, including:

[0054] A chip placement area 110 is provided on the front side of the frame;

[0055] A heat sink 120, located at the top of the frame, is used to assist in heat dissipation and enhance the strength of the plastic package; and

[0056] The heat dissipation fins 130 are disposed on the sides of the frame.

[0057] In this case, the heat dissipation slots 120 and the heat dissipation fins 130 not only improve the heat dissipation performance of the device, but are also used for plastic packaging positioning.

[0058] Framework 100 is further optimized:

[0059] An anti-overflow groove 111 is provided at the edge of the chip placement area 110 ; the chip 200 is arranged in the anti-overflow groove 111 .

[0060] The bottom of the frame is provided with a second pin 320 extending downward. The first pin 310 and the third pin 330 are symmetrically distributed on the sides of the second pin 320 respectively.

[0061] The heat sink 120 further defines:

[0062] The heat dissipation slot 120 is semi-closed.

[0063] The heat dissipation slots 120 are located at the top corners of the frame. In this embodiment, a pair of heat dissipation slots 120 are provided.

[0064] The heat sink 130 further defines:

[0065] The heat dissipation fins 130 are located on the front side of the frame and outside the chip placement area 110 .

[0066] The heat dissipation fins 130 are in a C-shaped structure.

[0067] In this embodiment, the heat sink 120 and the heat sink 130 are both provided with glue locking holes to improve the bonding strength with the plastic package body.

[0068] The package also includes:

[0069] The chip 200 is arranged in the chip placement area 110; the chip 200 is not less than 1.5 mm away from the edge of the anti-overflow groove 111 to reduce the risk of water vapor intrusion;

[0070] First pins 310 are spaced apart at the bottom of the frame 100 and are electrically connected to the chip 200 via bonding wires;

[0071] The third pins 330 are arranged at intervals at the bottom of the frame 100, located at the side of the first pins 310, and electrically connected to the chip 200 through bonding wires;

[0072] The plastic package body 400 is wrapped around the chip 200 , with its side connected to the heat dissipation fins 130 and its top connected to the heat dissipation slots 120 .

[0073] Specifically, the heat dissipation fins 130 and the heat dissipation grooves 120 are exposed outside the plastic package 400 toward the outer area. In this case, the back side of the frame 100 is exposed outside the plastic package 400.

[0074] At present, the surface mount device packaging mainly dissipates heat through the bottom heat sink, and a small number of them have designed top heat dissipation structures. Due to the large size of the TO-247 package, top heat dissipation cannot be used for wire bonding devices. In this case, a TO-247 frame structure with a side heat dissipation structure is designed. The frame adds two small vertical structures on the top, namely the heat dissipation slot 120 in this case, and two larger embedded vertical structures on the side, namely the heat dissipation fins 130 in this case, which can guide the heat to dissipate from the side and reduce the junction-to-shell thermal resistance of the device.

[0075] Assembly components, including:

[0076] The circuit board 500 has pins of the package body inserted into corresponding electrode sockets of the circuit board.

[0077] The back side of the package body in this embodiment is detachably fixedly connected to the heat sink 600, thereby improving the heat dissipation efficiency.

[0078] The back side of the package body and the heat sink 600 are detachably fixedly connected, for example:

[0079] A fixing base 610 is provided on the bottom plate of the heat sink 600; the fixing base 610 includes:

[0080] A fixing plate 611 is arranged on one side of the heat sink of the heat sink 600;

[0081] There are several presser feet 612, each of which is L-shaped, one end of which is connected to the fixing plate 611, and the other end of which extends to one side of the package body through the fixing plate 611. The several presser feet 612 are fixedly connected to the package body by rotating the bolt in the middle of the fixing plate 611. In this case, the fixing plate 611 and the presser feet 612 are both made of copper alloy.

[0082] In this case, the position and number of the presser feet 612 correspond to the positions of the heat sink 120 and the heat sink 130 , that is, four presser feet 612 are provided in this case, two of which are pressed into the heat sink 120 , and the other two are pressed into the heat sink 130 .

[0083] The method for preparing the assembly component comprises the following steps:

[0084] S100, preparation of a frame; the frame may be made of a copper alloy plate;

[0085] S110, using a stamping die, stamping out a heat dissipation protrusion 121 extending toward the chip placement area 110 from the top of the frame 100, such as Figure 1 As shown;

[0086] Specifically, the back of the frame 100 is punched out with a long opening 122 at the edge of the frame 100 by a mold, such as Figure 7 As shown, it is used to enhance the bonding force between the frame 100 and the plastic package body 400, thereby enhancing product reliability;

[0087] S120, stamping the upper surface of the pad of the frame 100, preparing an anti-overflow groove 111 outside the chip placement area 110, and opening a rectangular hole 131 on the inner side of the copper fin plate used to prepare the heat dissipation fin 130;

[0088] Specifically, the rectangular hole 131 is provided to facilitate the bending and forming of the heat dissipation fin 130, and the anti-overflow groove 111 can effectively prevent the overflow of the soft solder and enhance the bonding force between the frame 100 and the plastic package body 400;

[0089] S130, cutting the heat dissipation protrusion 121 to form a preliminary heat dissipation groove 120, such as Figure 3 As shown;

[0090] Specifically, the inner wall of the heat dissipation groove 120 protrudes from the front of the frame 100, the height of the inner wall is 1mm and is perpendicular to the front of the frame 100; the wall thickness of the inner wall is 0.3mm. The inner wall of the heat dissipation groove 120 in this case has a polygonal structure to increase the heat dissipation area. The protruding inner wall ensures that the device is protected from water vapor intrusion, and the larger surface area enhances the bonding force with the plastic package 400.

[0091] S140, such as Figure 4 As shown, the copper fin plate is bent 90° to make it perpendicular to the frame 100; Figure 5 As shown, the frame is shaped by a mold to form a heat dissipation slot 120 and a heat dissipation fin 130, as shown in FIG. Figure 6 As shown;

[0092] Specifically, the thickness of the copper fin plate is 0.5 mm. In order to further enhance the bonding strength between the heat dissipation structure and the plastic package body 400 , a plurality of glue locking holes are added on the side walls of the heat dissipation slot 120 and the heat dissipation fin 130 .

[0093] S200, die bonding and wire bonding, such as Figure 8 As shown;

[0094] S210, soldering the chip 200 to the chip placement area 110 using soft solder;

[0095] S220, ultrasonically welding the aluminum wire to the upper surface of the chip and the first pin 310 and the second pin 330 to obtain an assembled frame 100;

[0096] S300, plastic sealing and rib cutting.

[0097] The assembled frame 100 is plastic-encapsulated, and excess frame metal is cut off to form a complete device wrapped in plastic encapsulation material, namely, a TO-247plus package.

[0098] After the TO-247plus package is finished, it is assembled with the circuit board 500:

[0099] like Fig.10 As shown, three pins are inserted into the sockets of the circuit board 500, and the back of the frame 100 contacts the heat sink 600 to improve the heat dissipation performance of the device; the TO-247plus package is inserted into the four presser feet 612, and the device is pressed against the heat sink 600 by tightening the screws.

[0100] The metal presser foot 612 is designed to contact the heat sink 600 to enhance side heat dissipation and also has the function of fixing the device. It is fixed from the back with screws. After the screws are tightened, the presser foot presses the device onto the heat dissipation base plate. At the same time, the structure of this case prevents the screw stress from acting on the plastic package 400 and affecting the chip.

[0101] The conventional package and the improved TO-247plus frame in the utility model are simulated and verified. The material of the two packaged models is set to be the same, and the power applied to the two internal chips is 3W. Fig.12 For the two devices, the chip power is 3W, the external environment is 25℃, there is no air convection, and only the device temperature after stabilization is considered when the air thermal expansion rises. By comparison, it is found that the chip temperature of the conventional package is 211.6℃, and that of the improved package of the utility model is 210.9℃.

[0102] Fig.13 For the two devices, the chip power is 3W, the external environment is 25℃, the air flow rate is 5m / s, and the direction is blowing from the top of the device to the pins. At the same time, considering the stable device temperature under the condition of rising air thermal expansion, the chip temperature of the conventional package is 95.1℃, and the chip temperature of the improved package of the utility model is 91.2℃. In the case of external air flow, the improved package of the utility model has better heat dissipation efficiency to the outside world, and as the air flow rate increases, the heat dissipation efficiency is higher.

[0103] Fig.14 The thermal resistance of the two packages is calculated for the two devices when the chip power is 3W, the external environment is 25℃, the air flow rate is 1m / s, and the direction is blowing from the top of the device to the pins. At the same time, the device temperature after stabilization under the condition of rising thermal expansion of air is considered.

[0104]

[0105] The thermal resistance from junction to case of conventional package is: 146.57-137.33 / 6=1.54℃ / W

[0106] The thermal resistance from junction to shell of the improved package of the utility model is: 145.25-136.34 / 6=1.485℃ / W

[0107] Compared with conventional packaging, the thermal resistance from junction to shell of the improved packaging of the utility model is reduced by about 4%.

[0108] Regarding the contents disclosed in this case, there are a few points that need to be explained:

[0109] (1) The drawings of the embodiments disclosed in this case only involve the structures involved in the embodiments disclosed in this case. Other structures can refer to the general design;

[0110] (2) In the absence of conflict, the embodiments and features of the embodiments disclosed in this case may be combined with each other to obtain new embodiments;

[0111] The above are only specific implementation methods disclosed in this case, but the protection scope of the present disclosure is not limited thereto. The protection scope disclosed in this case should be based on the protection scope of the claims.

Claims

1. TO-247plus package, characterized in that: include: A frame (100), wherein the front of the frame (100) is provided with a chip placement area (110), the top is provided with a heat dissipation groove (120), and the side is provided with heat dissipation fins (130); A chip (200) is arranged in a chip placement area (110); A plurality of pins are provided and are electrically connected to the chip (200); A plastic package (400) is wrapped around the chip (200), the side of the plastic package (400) being connected to the heat dissipation fins (130), and the top of the plastic package (400) being connected to the heat dissipation groove (120).

2. The TO-247plus package according to claim 1, characterized in that: The heat dissipation fins (130) and the heat dissipation grooves (120) are respectively exposed outside the plastic packaging body (400) towards the outer area.

3. The TO-247plus package according to claim 1, characterized in that: An anti-overflow groove (111) is provided at the edge of the chip placement area (110); the chip (200) is arranged in the anti-overflow groove (111).

4. The TO-247plus package according to claim 1, characterized in that: The heat dissipation slot (120) is in a semi-closed shape.

5. The TO-247plus package according to claim 1, characterized in that: The heat dissipation slot (120) is located at the top corner of the frame.

6. The TO-247plus package according to claim 1, characterized in that: The heat dissipation fins (130) are located on the front side of the frame and outside the chip placement area (110).

7. The TO-247plus package according to claim 1, characterized in that: The heat dissipation fins (130) are in a C-shaped structure.

8. The TO-247plus package according to claim 1, characterized in that: The pins include: First pins (310) are arranged at intervals at the bottom of the frame (100) and are electrically connected to the chip (200) via bonding wires; A second pin (320) fixedly connected from the bottom of the frame (100); The third pins (330) are arranged at intervals at the bottom of the frame (100), are located on the side of the first pins (310), and are electrically connected to the chip (200) via bonding wires.

9. A TO-247plus assembly component, comprising a TO-247plus package according to any one of claims 1 to 8, characterized in that: Also includes: A circuit board (500), wherein the pins of the package body are inserted into corresponding electrode sockets of the circuit board.

10. The TO-247plus assembly component according to claim 9, characterized in that: The circuit board (500) is provided with a heat sink (600) fixed thereto; A fixing seat (610) is provided on the bottom plate of the radiator (600); the fixing seat (610) comprises: A fixing plate (611) arranged on one side of the heat sink of the heat sink (600); A plurality of presser feet (612) are provided, each of which is in an L-shaped structure, one end of which is connected to the fixing plate (611), and the other end of which extends to one side of the packaging body through the fixing plate (611), and the plurality of presser feet (612) are fixedly connected to the packaging body by rotating a bolt in the middle of the fixing plate (611).

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