TO-220 double-island HEMT packaging lead frame structure

Abstract

The utility model provides a TO-220 double-island HEMT packaging lead frame structure, comprising a plurality of cooling fin units, each cooling fin unit is provided with a chip carrying area, and the chip carrying area is used for carrying a semiconductor chip and a bonding wire; the chip carrying island is connected with the radiating fin unit and is used for carrying a semiconductor chip and a bonding wire; the radiating fin unit is provided with a chip carrying area and a chip carrying island, the chip carrying island is provided with a bonding wire area, the radiating fin unit further comprises external pins, the external pins comprise a middle pin and at least one side pin distributed on the side of the middle pin, the middle pin is connected with the chip carrying area, and the side pin is provided with the bonding wire area. The chip carrying island and the chip carrying area of the radiating fin unit are independent from each other, so that system packaging of multiple chips can be realized, electrical interference among different chips is avoided, and the power density of a product is increased; and through the radiating fin unit, a product can be conveniently assembled on a radiator when the terminal is used, the heat of the chip can be timely dissipated, and the product can work in a safe temperature range.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of semiconductor packaging, specifically to a TO-220 double-island HEMT packaging lead frame structure. BACKGROUND

[0002] Semiconductor power device chips and power IC chips will generate a large amount of heat when working, causing the internal temperature of the chip to rise rapidly. The rise in chip temperature will not only cause performance degradation and reliability reduction, but also may cause safety accidents in extreme cases. Therefore, before terminal use, in addition to the need to lead out I / O on the chip to connect with the electrodes on the PCB, heat dissipation design is also needed to ensure that the chip works within a safe temperature range.

[0003] As the carrier of integrated circuit chips, the lead frame realizes the electrical connection between the internal circuit lead-out end of the chip and the external lead wire through bonding wires, and is a key structural part of the electrical circuit. It not only plays the role of stabilizing the chip and conducting signals, but also is responsible for heat transfer. In the prior art, the TO-220 type lead frame usually has only one die mounting island, i.e. only one high electron mobility transistor (HEMT) can be mounted. For example, Chinese patent document CN206210784U discloses a partially insulated TO-220 type lead frame.

[0004] In order to realize the assembly of two or more chips, avoid electrical interference between different chips, and meet the heat dissipation requirements, an insulating substrate needs to be assembled on the die mounting island of the heat sink, and then different semiconductor chips are assembled on the insulating substrate. However, the increase of the insulating substrate will lead to an increase in the packaging process flow and an increase in the packaging difficulty, thereby causing a substantial increase in the packaging cost. SUMMARY

[0005] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a TO-220 double-island HEMT packaging lead frame structure to solve the problems mentioned in the background technology section.

[0006] The utility model realizes the following technical solutions:

[0007] A TO-220 double-island HEMT packaging lead frame structure includes a plurality of heat sink units, the heat sink unit is provided with a die mounting area, the die mounting area is used for carrying semiconductor chips and solder wires; further includes a die mounting island connected with the heat sink unit, the die mounting island is used for carrying semiconductor chips and solder wires; further includes external pins, the external pins include middle pins, and at least one side edge pin distributed on the side of the middle pin, the middle pin is connected with the die mounting area, and the side edge pin is provided with a solder wire area.

[0008] Further, the upper horizontal rib, the middle horizontal rib and the lower horizontal rib are used to connect two adjacent fin units, the middle horizontal rib and the lower horizontal rib connect the middle pin and the side pin.

[0009] Further, the connecting rib is used to connect the two adjacent fin units and the carrier island, and the reinforcing rib is used to connect the middle horizontal rib and the connecting rib.

[0010] Further, the fin unit, the carrier island and the external pin are integrally formed.

[0011] Further, the front surface of the fin unit is provided with a first shaped groove, the first shaped groove is used to divide the fin unit into a connecting area and a carrier area, and the connecting area is provided with an assembly hole.

[0012] Further, the fin unit is provided with a through groove at the position of the first shaped groove, and the corresponding back edge of the carrier area is provided with a first step.

[0013] Further, the soldering wire area is provided with a through hole.

[0014] Further, the second step is arranged between the carrier area and the carrier island.

[0015] Further, the carrier island and the carrier area are both provided with a hollow partition area between the carrier island and the carrier area and the soldering wire area.

[0016] Further, the lower horizontal rib is provided with a chamfer at the connection position of the middle pin and the side pin.

[0017] The beneficial effects of the utility model are as follows: a TO-220 double-island HEMT packaging lead frame structure, which comprises a plurality of fin units, the fin unit is provided with a carrier area, and the carrier area is used to carry a semiconductor chip and a soldering wire; the utility model further comprises a carrier island connected with the fin unit, and the carrier island is used to carry a semiconductor chip and a soldering wire; the utility model further comprises an external pin, the external pin comprises a middle pin and at least one side pin distributed on the side of the middle pin, the middle pin is connected with the carrier area, and the side pin is provided with a soldering wire area; the utility model not only provides the carrier area on the fin unit, but also separately provides the carrier island; the carrier island and the carrier area of the fin unit are independent of each other, so that the system packaging of multiple chips can be realized, the electrical interference between different chips is avoided, and the power density of the product is increased; the fin unit is used to facilitate the assembly of the product on a radiator during terminal use, the heat of the chip can be dissipated in time, and the product can work in a safe temperature range; the carrier island and the carrier area of the fin unit are independent of each other, the use of an insulating substrate is avoided, the material cost is reduced, the reduction of the insulating substrate shortens the technological process and reduces the difficulty of the process, and the packaging cost is reduced. Attached Figure Description

[0018] Fig. 1 This is a front view of the lead frame of this utility model.

[0019] Fig. 2 This is a front view of a single heat sink unit and a carrier island of this utility model.

[0020] Fig. 3 This is a side view of a single heat sink unit and a carrier island of this utility model.

[0021] Fig. 4 This is a perspective view of a single heat sink unit and a carrier island of this utility model.

[0022] The above figures include the following reference numerals:

[0023] 1. Heat sink unit; 11. Carrier area; 12. Connection area; 121. Assembly hole; 13. Through slot; 14. First shaped slot; 15. First step; 16. Second step; 2. Carrier island; 3. External pin; 31. Middle pin; 32. Side pin; 321. Bonding area; 3211. Through hole; 33. Chamfer; 34. Groove; 4. Upper horizontal rib; 5. Middle horizontal rib; 6. Lower horizontal rib; 7. Connecting rib; 8. Reinforcing rib; 9. Hollowed-out partition area. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. It should be noted that the description of these embodiments is intended to aid in understanding this utility model, but does not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0025] Reference Figs. 1 to 4 As shown, a TO-220 dual-island HEMT package lead frame structure includes several heat sink units 1, each heat sink unit 1 having a carrier area 11 for supporting semiconductor chips and bonding wires; it also includes carrier islands 2 connected to the heat sink units 1, the carrier islands 2 for supporting semiconductor chips and bonding wires; and it also includes external pins 3, each external pin 3 including a middle pin 31 and at least one side pin 32 distributed on the side of the middle pin 31, the middle pin 31 being connected to the carrier area 11, and the side pin 32 having a bonding wire area 321.

[0026] The utility model discloses not only be provided with the carrier film area 11 in the fin unit 1, still independently set up the carrier film island 2, and the carrier film island 2 and the carrier film area 11 of fin unit 1 are independent of each other, therefore can realize the system package of multiple chip, avoid the electrical interference between different chips simultaneously, increase the power density of product.

[0027] Wherein the I / O on the chip can be interconnected with the carrier film island 2 or carrier film area 11 by the way of soldering line, in the utility model, the number of side edge pin 32 is two, and the number of side edge pin 32 is set according to user's demand.

[0028] Still include the upper cross rib 4, the middle cross rib 5 and the lower cross rib 6 for connecting two adjacent fin unit 1, the middle cross rib 5 and the lower cross rib 6 connect the middle pin 31 and the side edge pin 32, by the setting of upper cross rib 4, middle cross rib 5 and lower cross rib 6, it is favorable to increase the strength of lead frame, avoid the deformation of lead frame in use.

[0029] Still include the connecting rib 7 for connecting two adjacent fin unit 1 and carrier film island 2, and the reinforcing rib 8 for connecting the middle cross rib 5 and the connecting rib 7. By the cooperation of connecting rib 7 and reinforcing rib 8, it is favorable to increase the strength of lead frame, avoid the deformation of lead frame in use.

[0030] The fin unit 1, the carrier film island 2 and the external pin 3 are integrally formed, adopt the integrally formed technology, can reduce the die cost, and integrally formed can provide overall strength.

[0031] The fin unit 1 is provided with assembly hole 12. The setting of assembly hole 12 is convenient for the positioning of lead frame in the process of packaging, avoids the deviation of lead frame.

[0032] The "popcorn" effect refers to the phenomenon that the device internal pressure increases due to the vaporization expansion of the water absorbed in the device during high-temperature heat treatment (such as reflow soldering, wave soldering, etc.), and then the plastic encapsulation or substrate is lifted up or even damaged. This phenomenon is particularly evident during the cooling process, because the thermal expansion and contraction rates of the internal materials of the device are inconsistent, which may cause cracks in the internal materials. When the absorbed water vapor content is higher than a certain threshold, the popcorn phenomenon will occur. This effect not only causes damage to the device, but also often accompanies a sound similar to the explosion of popcorn when it occurs, hence the name "popcorn" effect.

[0033] The front surface of the heat dissipation fin unit 1 is provided with a first shaped groove 14, which is divided into a connecting area 12 and the carrier sheet area 11 through the first shaped groove 14, the connecting area 12 is provided with an assembly hole 121, and the two ends of the connecting area 12 are provided with upper horizontal ribs 4. The heat dissipation fin unit 1 is provided with a through groove 13 in the area of the first shaped groove 14, and the corresponding back edge of the carrier sheet area 11 is provided with a first step 15.

[0034] The first shaped groove 14 is preferably V-shaped, and the through groove 13 is U-shaped, thereby facilitating processing and forming.

[0035] Through the setting of the assembly hole 121, the positioning of the lead frame during the packaging process is facilitated, and deviation of the lead frame is avoided.

[0036] Through the setting of the through groove 13, the first shaped groove 14 and the first step 15, the bonding strength of the plastic package and the lead frame is enhanced, water vapor penetration is effectively prevented, and semiconductor chip contamination, corrosion and product heating popcorn effect are avoided.

[0037] The soldering area 321 is provided with a through hole 3211. The setting of the through hole 3211 can increase the bonding strength of the plastic package and the soldering area, and avoid soldering failure caused by delamination.

[0038] The middle pin 31 and the side pin 32 are both provided with a notch 34, which is V-shaped. The notch 34 can increase the bonding strength of the plastic package and the lead frame, effectively prevent water vapor penetration, avoid soldering contamination, corrosion and product heating popcorn effect caused by soldering point falling off.

[0039] The carrier sheet area 11 and the carrier sheet island 2 are provided with a second step 16, which is beneficial to the plastic package completely wrapping the carrier sheet island 2, thereby realizing insulation and isolation between the carrier sheet island 2 and the carrier sheet area 11.

[0040] The carrier sheet island 2 and the carrier sheet area 11 are both provided with a hollow partition area 9 between the carrier sheet island 2 and the carrier sheet area 11. Through the setting of the hollow partition area 9, when the soldering area 321 is soldered, the heat needs to be conducted to the carrier sheet area 11 through the side pin 32 and the middle pin 31, and in this process, the heat will be dissipated, thereby avoiding the possibility of direct heat conduction to the chip and protecting the chip from heat damage.

[0041] The connecting position of the lower horizontal rib 6 and the middle pin 31 and the side pin 32 is provided with a chamfer 33, which is beneficial to cutting the lower horizontal rib 6, and the chamfer 33 provides a clear cutting edge, which helps to improve the cutting quality and reduce the damage or defective rate caused by inaccurate cutting. In the terminal use, the chamfer 33 is designed to make the pin more easily inserted into the corresponding hole. This is because the chamfer 33 can reduce the friction between the pin and the hole wall, so that the pin can pass through the hole more smoothly, thereby improving the assembly efficiency and accuracy.

[0042] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0043] In the description of the present application, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features.

[0044] The above is only the preferred embodiment of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A TO-220 dual island HEMT package leadframe structure, characterized by: The finned unit (1) is provided with a carrier area (11) for carrying semiconductor chips and wire bonds; The finned unit (1) is connected with a carrier island (2) for carrying semiconductor chips and wire bonds; The external pin (3) comprises a middle pin (31) and at least one side pin (32) distributed on the side of the middle pin (31), the middle pin (31) is connected with the carrier area (11), and the side pin (32) is provided with a wire bond area (321).

2. The TO-220 dual island HEMT package leadframe structure of claim 1, wherein: The upper cross rib (4), the middle cross rib (5) and the lower cross rib (6) are used for connecting two adjacent finned units (1), the middle cross rib (5) and the lower cross rib (6) are connected with the middle pin (31) and the side pin (32).

3. The TO-220 dual island HEMT package leadframe structure of claim 2, wherein: The connecting rib (7) is used for connecting two adjacent finned units (1) and the carrier island (2), and the reinforcing rib (8) is connected with the middle cross rib (5) and the connecting rib (7).

4. The TO-220 dual island HEMT package leadframe structure of claim 1, wherein: The finned unit (1), the carrier island (2) and the external pin (3) are integrally formed.

5. The TO-220 dual island HEMT package leadframe structure of claim 1, wherein: The front surface of the finned unit (1) is provided with a first shaped groove (14), which is divided into a connecting area (12) and the carrier area (11) through the first shaped groove (14), and the connecting area is provided with an assembly hole (121).

6. The TO-220 dual island HEMT package leadframe structure of claim 5, wherein: The finned unit (1) is provided with a through groove (13) in the area of the first shaped groove (14), and the corresponding back edge of the carrier area (11) is provided with a first step (15).

7. The TO-220 dual island HEMT package leadframe structure of claim 1, wherein: The wire bond area (321) is provided with a through hole (3211).

8. The TO-220 dual island HEMT package leadframe structure of claim 1, wherein: The carrier area (11) and the carrier island (2) are provided with a second step (16).

9. The TO-220 dual island HEMT package leadframe structure of claim 1, wherein: The carrier island (2) and the carrier area (11) are both provided with a hollow partition area (9) between the wire bond area (321).

10. The TO-220 dual island HEMT package leadframe structure of claim 2, wherein: The lower cross rib (6) is provided with a chamfer (33) at the connection with the middle pin (31) and the side pin (32).

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