A half-bridge drive package structure

Abstract

This utility model discloses a half-bridge driver packaging structure, including a base island, a high-side MOSFET chip, a low-side MOSFET chip, a high-side clip, and a low-side clip. The base island has a high-side chip mounting area, a low-side chip mounting area, output pins, and isolation slots, with the chips soldered to their respective mounting areas. Both the high-side and low-side clips include three parts: a base island connecting arm, a bridging arm, and a chip connecting arm, enabling interconnection between the chip, the base island, and the output pins. The base island can be replaced with a DBC ceramic substrate, and a base island protrusion can be used to replace the copper pillars. This structure solves the problems of current carrying capacity, heat dissipation, and parasitic inductance of traditional copper wires, improving current carrying capacity and heat dissipation efficiency, reducing parasitic inductance, and adapting to high power density half-bridge driver scenarios.

Description

Technical Field

[0001] This utility model belongs to the field of packaging technology, specifically relating to a half-bridge drive packaging structure. Background Technology

[0002] Currently, copper wire bonding is the most common method used in power device packaging to achieve electrical connections between the chip and the lead frame, a technology that has been in use for decades. However, as power modules move towards miniaturization and high power density, traditional copper wire bonding faces challenges such as current-carrying capacity bottlenecks, high thermal resistance, and significant parasitic inductance. In recent years, flip-chip and clipbonding technologies have gradually become research directions for high-performance packaging.

[0003] Existing technologies often use copper wire bonding, as shown in the instruction manual. Figure 1 As shown. The package structure includes a copper alloy base island 1 for carrying components, a high-side chip 3 and a low-side chip 4 as the core of the circuit, SnAgCu solder paste 5 for soldering and fixing, and multiple copper wires 17 for interconnection; the base island 1 is only divided into a high-side chip mounting area, a low-side chip mounting area and an output pin, without an isolation groove 14; the SnAgCu solder paste 5 is applied between the high-side chip 3 and the high-side chip mounting area, and between the low-side chip 4 and the low-side chip mounting area; the multiple copper wires 17 are connected in parallel to the source of the high-side chip 3 and the base island 1, and the drain of the low-side chip 4 and the output pin 13 by ultrasonic welding, and the copper wires 17 are distributed in an arc shape.

[0004] Base Island 1 is made of C19400 copper alloy with a thickness of 0.2mm, and copper wire 17 has a diameter of 0.03mm. It is mainly used in low-to-medium power half-bridge drive scenarios. The connection between copper wire 17 and the chip and base island 1 is formed by ultrasonic welding. The welding strength depends on the ultrasonic energy control, which is prone to the risk of cold solder joints. Copper wire 17 is made by wire drawing process, which requires additional cutting and ultrasonic welding processes, resulting in low production efficiency. The body of copper wire 17 is made of pure copper with a conductivity of ≥98% IACS, but due to its small cross-sectional area, the current carrying capacity of a single wire is only 3-5A. Existing technology does not have a dedicated barrier layer structure. During long-term operation, copper wire 17 is susceptible to vibration and may fall off, and its adhesion to the molding compound is poor after molding. The arc height of copper wire 17 is usually 200-500μm, resulting in a long heat conduction path, making it difficult for the heat generated by the chip to be quickly conducted to base island 1. When multiple copper wires 17 are connected in parallel, impedance mismatch is prone to occur, leading to local current overload and affecting the lifespan of the device. In existing technologies, parasitic inductance can reach 10-20nH, which can easily cause voltage spikes in high-frequency switching scenarios, increasing the risk of EMI interference.

[0005] Therefore, while existing technologies are low-cost, they have several performance limitations. Using multiple copper wires to transmit current suffers from limited current-carrying capacity, high thermal resistance, and large parasitic inductance, making them unsuitable for high-power-density applications. Copper strip bonding, using flat copper strips instead of round wires to reduce resistance, requires an additional stamping process. Flip-chip bonding, directly connecting via solder ball arrays, offers good heat dissipation but is sensitive to chip thermal stress and is expensive. Furthermore, the current-carrying capacity of copper wire technology is limited by the cross-sectional area of ​​a single wire, making impedance matching difficult when multiple wires are connected in parallel. Summary of the Invention

[0006] To address the problems existing in the background technology, this utility model proposes a half-bridge driver packaging structure.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a half-bridge driver packaging structure, comprising:

[0008] Base island; the base island is provided with a high-side chip mounting area, a low-side chip mounting area, output pins and an isolation slot, the isolation slot being located between the high-side chip mounting area and the low-side chip mounting area;

[0009] High-side MOSFET chip: soldered onto the high-side chip mounting area of ​​the base island;

[0010] Low-side MOSFET chip: soldered onto the low-side chip mounting area of ​​the base island;

[0011] The high-side MOSFET chip is connected to the base island via a high-side clip.

[0012] The low-side MOSFET chip is connected to the base island via a low-side clip.

[0013] The upper surface of the high-side clip is on the same horizontal plane as the upper surface of the low-side clip.

[0014] Specifically, both the high-side Clip and the low-side Clip consist of three parts: a base island connection arm, a bridging arm, and a chip connection arm. The upper surfaces of the bridging arms of the high-side Clip and the low-side Clip are on the same horizontal plane.

[0015] Specifically, a bend is provided between the base island connecting arm and the bridging arm, and a bend is provided between the bridging arm and the chip connecting arm.

[0016] Specifically, both the high-side Clip and the low-side Clip are composed of an upper conductive layer and a lower nickel barrier layer.

[0017] Specifically, both the high-side clip and the low-side clip are flat plate structures, and the upper surfaces of both the high-side clip and the low-side clip are on the same horizontal plane.

[0018] Specifically, a bend is provided at the connection between the base island and the high-side Clip.

[0019] Specifically, the base island and the lower clip are connected by copper pillars.

[0020] Specifically, a protrusion is provided at the connection between the base island and the lower side clip.

[0021] Specifically, the protrusion is located at the edge of the base island.

[0022] Compared with the prior art, the present invention has the following advantages: the structure can effectively solve the problems of current carrying capacity bottleneck, high thermal resistance and large parasitic inductance of traditional copper wire bonding process. It provides a stable mounting base for high-side MOSFET chips and low-side MOSFET chips through the high-side chip mounting area and low-side chip mounting area on the base island. The isolation trench ensures electrical isolation between high-side and low-side circuits and avoids creepage and crosstalk.

[0023] The high-side and low-side clips employ an integrated clip structure design. The base island connection arm, bridge arm, and chip connection arm of the integrated clip create a low-resistance, low-inductance current path. It is made of 0.11mm thick C19210 / C19400 copper alloy, which improves current carrying capacity and reduces parasitic inductance. The width of the chip connection arm connecting the high-side clip to the high-side MOSFET chip is 0.8-1.2 times the width of the high-side MOSFET chip's source pad, preventing current concentration and material redundancy. The integrated clip can be designed with a layered structure to prevent metal migration. The clip structure with copper pillars is suitable for space-constrained scenarios.

[0024] The chip is reliably fixed on both sides by SnAgCu solder paste, which also improves thermal and electrical conductivity and reduces the chip junction temperature.

[0025] The base island can be replaced with a DBC ceramic substrate for further optimization of heat dissipation and insulation. The protrusions on the base island also simplify the manufacturing process and reduce costs. The overall structure is compact, highly adaptable, and reliable in operation, making it suitable for half-bridge drive scenarios such as motor control and power conversion. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of an existing copper wire bonding half-bridge driver package structure;

[0027] Figure 2 This is a schematic diagram of the half-bridge driver packaging structure described in Embodiment 1 of this utility model;

[0028] Figure 3 This is a schematic diagram of the half-bridge driver packaging structure described in Embodiment 2 of this utility model;

[0029] Figure 4This is a schematic diagram of the half-bridge driver packaging structure described in Embodiment 3 of this utility model;

[0030] Figure 5 This is a schematic diagram of the half-bridge driver packaging structure described in Embodiment 4 of this utility model.

[0031] In the diagram: 1. Base island; 11. High-side chip mounting area; 12. Low-side chip mounting area; 13. Output pin; 14. Isolation trench; 15. Copper pillar; 16. Protrusion; 17. Copper wire; 2. Integrated clip; 211. Base island connecting arm; 212. Bridge arm; 213. Chip connecting arm; 214. Upper conductive layer; 215. Lower nickel barrier layer; 23. High-side clip; 24. Low-side clip; 3. High-side chip; 4. Low-side chip; 5. SnAgCu solder paste. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] Example 1: As Figure 2 The half-bridge driver package structure shown includes:

[0034] Base island 1; The base island 1 is provided with a high-side chip mounting area 11, a low-side chip mounting area 12, an output pin 13 and an isolation groove 14, the isolation groove 14 being located between the high-side chip mounting area 11 and the low-side chip mounting area 12.

[0035] Optionally, the base island 1 of the packaging structure is made of C19400 copper alloy with a thickness of 0.25mm.

[0036] High-side MOSFET chip 3: soldered onto the high-side chip mounting area 11 of the base island 1.

[0037] Low-side MOSFET chip 4: soldered onto the low-side chip mounting area 12 of the base island 1.

[0038] The high-side MOSFET chip 3 is connected to the base island 1 via the high-side Clip 23.

[0039] The low-side MOSFET chip 4 is connected to the base island 1 via the low-side Clip 24.

[0040] The upper surface of the high-side Clip23 is on the same horizontal plane as the upper surface of the low-side Clip24.

[0041] Both the high-side Clip 23 and the low-side Clip 24 include three parts: a base island connecting arm 211, a bridging arm 212, and a chip connecting arm 213. The upper surfaces of the bridging arms of the high-side Clip 23 and the low-side Clip 24 are on the same horizontal plane.

[0042] Optionally, the high-side Clip23 and low-side Clip24 are made of C19210 copper alloy with a conductivity ≥90% IACS, and are mainly used for MOSFET device packages with a specification of 60V / 30A.

[0043] As mentioned above, the base island connecting arm 211, bridging arm 212, and chip connecting arm 213 of the high-side Clip 23 and the low-side Clip 24 are formed by one stamping, which has high production efficiency and good structural consistency.

[0044] A bend is provided between the base island connecting arm 211 and the bridging arm 212, and a bend is provided between the bridging arm 212 and the chip connecting arm 213.

[0045] The aforementioned chip connection arm connecting the high-side Clip and the high-side MOSFET chip has a width that is 0.8-1.2 times the source pad of the high-side MOSFET chip, which can prevent current concentration and material redundancy.

[0046] Both the high-side Clip 23 and the low-side Clip 24 are composed of an upper conductive layer 214 and a lower nickel barrier layer 215.

[0047] The high-side Clip23 and low-side Clip24 can be designed with a layered structure to prevent metal migration.

[0048] Example 2

[0049] A half-bridge driver package structure, comprising:

[0050] Base island 1; The base island 1 is provided with a high-side chip mounting area 11, a low-side chip mounting area 12, an output pin 13 and an isolation groove 14, the isolation groove 14 being located between the high-side chip mounting area 11 and the low-side chip mounting area 12.

[0051] Optionally, island 1 is a DBC ceramic substrate with a ceramic layer thickness of 0.2 mm.

[0052] High-side MOSFET chip 3: soldered onto the high-side chip mounting area 11 of the base island 1.

[0053] Low-side MOSFET chip 4: soldered onto the low-side chip mounting area 12 of the base island 1.

[0054] The high-side MOSFET chip 3 is connected to the base island 1 via the high-side Clip 23;

[0055] The low-side MOSFET chip 4 is connected to the base island 1 via the low-side Clip 24;

[0056] The upper surface of the high-side Clip23 is on the same horizontal plane as the upper surface of the low-side Clip24.

[0057] The aforementioned Clip23 on the high side and Clip24 on the low side are both 0.08mm thick and 1.2mm wide, formed by stamping, and have an conductivity ≥88% IACS.

[0058] Both the high-side Clip23 and the low-side Clip24 are flat plate structures, and the upper surfaces of both the high-side Clip23 and the low-side Clip24 are on the same horizontal plane.

[0059] A bend is provided at the connection between the base island 1 and the high-side Clip 23.

[0060] Base island 1 is connected to the lower side Clip 24 via copper pillar 15.

[0061] Optionally, the copper pillar 15 is made of C1100 pure copper, with a diameter of 0.2mm and a length of 0.6mm, and is mainly used in ultra-thin half-bridge drive modules.

[0062] As mentioned above, the copper pillar 15 is embedded in the pre-drilled hole of the base island 1 through an interference fit, and the contact resistance between the copper pillar 1 and the base island 1 copper layer is ≤5mΩ.

[0063] As mentioned above, the welding of both ends of the copper pillar 15 to the lower side Clip 24 adopts the reflow soldering process to form a metallurgical bond, resulting in high connection reliability.

[0064] Furthermore, the isolation groove 14 is filled with insulating glue with an insulation resistance ≥10¹²Ω to prevent creepage.

[0065] Example 3

[0066] The difference between this embodiment and Embodiment 2 is as follows:

[0067] A protrusion 16 is provided at the connection between the base island 1 and the lower side Clip 24.

[0068] The protrusion 16 is located on the base island 1 and is spaced from the edge of the base island 1.

[0069] Optionally, the base island 1 is made of C19400 copper alloy with a thickness of 0.2mm, and the base island protrusion 16 has a height of 0.2mm and a width of 0.4mm, mainly used in medium-power half-bridge drive scenarios.

[0070] As mentioned above, the end widths of the high-side Clip 23 and the low-side Clip 24 are adapted to the base island protrusion 16 to ensure a contact area ≥1.0mm².

[0071] As mentioned above, the base island protrusion 16 is integrally formed by stamping and bending process, which requires no additional processing and installation, reducing process cost by 30%.

[0072] The aforementioned Clip 23 on the high side and Clip 24 on the low side are 0.1 mm thick, have an conductivity ≥85% IACS, and have a welding pull force ≥5N with the base island protrusion 16.

[0073] As mentioned above, the base island protrusion 16 has no joint with the base island 1, and the contact resistance is reduced by 2mΩ compared with the pre-embedded copper pillar scheme.

[0074] This structure eliminates the need for copper pillar installation, reducing the production cycle by 20%.

[0075] Example 4

[0076] The difference between this embodiment and Embodiment 3 is as follows:

[0077] The protrusion 16 is located at the edge of the base island 1.

[0078] Optionally, the base island 1 has a thickness of 0.15mm, and the base island protrusion 16 is made of C19210 copper alloy with a length of 0.7mm, a width of 0.4mm, and a thickness of 0.1mm. It is mainly used in ultra-thin micro half-bridge drive modules.

[0079] As mentioned above, the protrusion 16 of the base island is fixed to the base island 1 by laser welding, with a weld width of 0.1mm and a strength of ≥4N.

[0080] The aforementioned Clip23 on the high side and Clip24 on the low side are 0.07mm thick and 1.0mm wide. After stamping, they are annealed to improve their flexibility.

[0081] As mentioned above, the base island protrusion 16 is embedded in the isolation groove 14 to a depth of 0.05mm, which can prevent solder from overflowing into the isolation groove 14 and avoid short circuit.

[0082] As mentioned above, the total thickness of the structure is only 0.7mm, making it suitable for space-constrained scenarios such as wearable devices.

[0083] Furthermore, the contact area between the extended end of the base island protrusion 16 and the base island 1 reaches 0.08 mm. 2 This ensures rapid heat transfer.

[0084] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present utility model.

Claims

1. A half-bridge driver package structure, comprising: Base island (1); The base island (1) is provided with a high-side chip mounting area (11), a low-side chip mounting area (12), an output pin (13) and an isolation groove (14), the isolation groove (14) being located between the high-side chip mounting area (11) and the low-side chip mounting area (12); High-side MOSFET chip (3): soldered to the high-side chip mounting area (11) of the base island (1); Low-side MOSFET chip (4): soldered to the low-side chip mounting area (12) of the base island (1); Its features are, The high-side MOSFET chip (3) is connected to the base island (1) via a high-side clip (23); The low-side MOSFET chip (4) is connected to the base island (1) via a low-side clip (24); The upper surface of the high-side Clip (23) is on the same horizontal plane as the upper surface of the low-side Clip (24).

2. The half-bridge driver packaging structure according to claim 1, characterized in that, Both the high-side Clip (23) and the low-side Clip (24) include three parts: the base island connecting arm (211), the bridging arm (212), and the chip connecting arm (213). The upper surfaces of the bridging arms of the high-side Clip (23) and the low-side Clip (24) are on the same horizontal plane.

3. The half-bridge driver packaging structure according to claim 2, characterized in that, A bend is provided between the base island connecting arm (211) and the bridging arm (212), and a bend is provided between the bridging arm (212) and the chip connecting arm (213).

4. The half-bridge driver packaging structure according to claim 2, characterized in that, Both the high-side Clip (23) and the low-side Clip (24) are composed of an upper conductive layer (214) and a lower nickel barrier layer (215).

5. The half-bridge driver packaging structure according to claim 1, characterized in that, Both the high-side Clip (23) and the low-side Clip (24) are flat plate structures, and the upper surfaces of the high-side Clip (23) and the low-side Clip (24) are on the same horizontal plane.

6. The half-bridge driver packaging structure according to claim 5, characterized in that, A bend is provided at the connection between the base island (1) and the high side Clip (23).

7. The half-bridge driver packaging structure according to claim 5, characterized in that, The base island (1) is connected to the lower side clip (24) by a copper pillar (15).

8. The half-bridge driver packaging structure according to claim 5, characterized in that, A protrusion (16) is provided at the connection between the base island (1) and the lower side clip (24).

9. The half-bridge driver package structure according to claim 8, characterized in that, The protrusion (16) is located at the edge of the base island (1).

10. The half-bridge driver package structure according to claim 1, characterized in that, The base island (1) is replaced with a DBC ceramic substrate.

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