A half-bridge circuit structure based on embedded capacitors
By employing an embedded capacitor structure in the GaN half-bridge circuit, the loop length is shortened, solving the problems of voltage overshoot and electromagnetic interference in high-frequency switching applications, and improving circuit performance and reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SUZHOU INNPHY MICROELECTRONICS CO LTD
- Filing Date
- 2025-07-15
- Publication Date
- 2026-07-14
Smart Images
Figure CN224503204U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of half-bridge circuit technology, and in particular to a half-bridge circuit structure based on embedded capacitors. Background Technology
[0002] In recent years, traditional silicon (Si)-based power modules have approached the limits of their material properties. Meanwhile, gallium nitride (GaN), as a wide-bandgap semiconductor material, has attracted considerable attention due to its significant advantages of high breakdown voltage and high electron mobility. The AlGaN / GaN heterojunction interface in GaN devices can generate a high-density two-dimensional electron gas (2DEG), and the electron mobility of this 2DEG is particularly impressive, reaching 2000 cm⁻¹. 2 The level of / (V·s) makes GaN particularly suitable for applications involving high-frequency, fast switching.
[0003] In high-frequency, fast-switching applications, high voltage change rates (dv / dt) and current change rates (di / dt) are typically encountered. When the current change rate (di / dt) is high, stray inductance in the power circuit can lead to higher voltage overshoot, subjecting GaN devices to greater stress and impacting their reliability. Furthermore, stray inductance in the circuit can also cause oscillations, thereby inducing electromagnetic interference (EMI).
[0004] Taking a half-bridge circuit as an example, such as Figure 1 As shown, it typically includes two power devices and a capacitor. In existing low-voltage GaN half-bridge circuit designs, a mainstream layout is as follows... Figures 2-3 As shown. This layout can cause significant loop noise. Figures 4-5 An improved layout is shown, which reduces loop clutter to some extent compared to the aforementioned layout, but the reduction is limited and still needs further optimization. Utility Model Content
[0005] The main objective of this invention is to provide a half-bridge circuit structure based on embedded capacitors, thereby overcoming the shortcomings of the prior art.
[0006] To achieve the aforementioned objectives, the technical solution adopted by this utility model includes:
[0007] This utility model provides a half-bridge circuit structure based on embedded capacitors, including:
[0008] A substrate with conductive lines;
[0009] A first power device and a second power device are disposed on the substrate at intervals along a direction parallel to the substrate surface. Each of the first power device and the second power device has a gate, multiple sources and multiple drains, and the multiple sources in the same power device are electrically connected to each other, and the multiple drains are electrically connected to each other.
[0010] A capacitor module includes at least one capacitor disposed between at least one of the first power device and the second power device and a substrate or inside the substrate correspondingly below the power device. The capacitor has a first electrode and a second electrode. The first electrode is electrically connected to the drain of the first power device via the conductive line, and the second electrode is electrically connected to the source of the second power device via the conductive line. The source of the first power device is electrically connected to the drain of the second power device via the conductive line.
[0011] In some more specific schemes, multiple sources within the same power device are electrically connected to each other via the conductive lines.
[0012] In some more specific designs, multiple drains within the same power device are electrically connected to each other via the conductive lines.
[0013] In some more specific designs, multiple sources and multiple drains within the same power device are arranged alternately in a direction parallel to the substrate surface.
[0014] In some more specific embodiments, the substrate includes an insulating base layer, and the conductive lines include a metal interconnect layer disposed on the insulating base layer.
[0015] Furthermore, the capacitor portion or the entire capacitor is embedded within the insulating base layer.
[0016] In some more specific embodiments, the capacitor module includes multiple capacitors connected in parallel and spaced apart along a direction parallel to the surface of the substrate.
[0017] Furthermore, the arrangement direction of the first power device and the second power device is orthogonal to the arrangement direction of the plurality of capacitors.
[0018] In some more specific embodiments, the half-bridge circuit structure includes a semiconductor layer disposed on a substrate, and the semiconductor structures of the first power device and the second power device are both disposed within the semiconductor layer.
[0019] In some more specific solutions, the orthographic projection of the capacitor module on the substrate overlaps or coincides with the orthographic projection of the first power device or the second power device on the substrate, and is usually slightly smaller or slightly larger than the corresponding projection of the power device.
[0020] In some more specific schemes, the first power device and the second power device are GaN-based power devices.
[0021] Compared with the prior art, the advantages of this utility model include at least the following:
[0022] First, the present invention provides a half-bridge circuit structure based on embedded capacitors, which effectively shortens the loop length by placing the capacitor module between at least one power device and the substrate or inside the substrate, thereby reducing the loop inductance and improving the circuit performance.
[0023] Secondly, the present invention provides a half-bridge circuit structure based on embedded capacitors, wherein the orthographic projection of the capacitor module on the substrate overlaps or coincides with the orthographic projection of the first power device or the second power device on the substrate, and is usually slightly smaller or slightly larger than the power device, so that the electrodes of the capacitor and the drain / source of the power device are completely aligned in the horizontal position, eliminating or shortening the distance of the horizontal trace between the power device and the capacitor, further shortening the loop length, thereby reducing the loop inductance. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the structure of a half-bridge circuit provided by existing technology;
[0025] Figure 2 This is a schematic diagram of a capacitor layout 1 in a half-bridge circuit provided by the prior art;
[0026] Figure 3 yes Figure 2 Cross-sectional view of layout 1;
[0027] Figure 4 This is a schematic diagram of a capacitor layout 2 in a half-bridge circuit provided by existing technology;
[0028] Figure 5 yes Figure 4 Cross-sectional view of layout 2;
[0029] Figure 6 This is a schematic diagram of a half-bridge circuit structure based on embedded capacitors provided by this utility model;
[0030] Figure 7 This utility model provides Figure 6 Cross-sectional view;
[0031] Figure 8 This is a schematic diagram of the capacitor module provided by this utility model;
[0032] Figure 9 This is a schematic diagram of another half-bridge circuit structure based on embedded capacitors provided by this utility model;
[0033] Figure 10This is a comparative schematic diagram of the loop length provided by this utility model.
[0034] Figure label:
[0035] 1. First power device 1; 2. Second power device; 3. Capacitor module. Detailed Implementation
[0036] In view of the shortcomings of the prior art, the inventor of this case, through long-term research and extensive practice, has come up with the technical solution of this utility model. The following will further explain the technical solution, its implementation process, and its principles.
[0037] Please refer to Figures 6-7 A half-bridge circuit structure based on embedded capacitors includes a substrate, a first power device 1 and a second power device 2 disposed on the substrate at intervals along a direction parallel to the surface of the substrate, and a capacitor module 3. In all figures of this paper, D represents the drain, S represents the source, and G represents the gate.
[0038] In this half-bridge circuit structure, conductive lines are arranged on the substrate to provide electrical connections for the circuit.
[0039] Both the first power device 1 and the second power device 2 are GaN-based power devices. Each device has a gate, multiple sources, and multiple drains. The sources within the same device are interconnected via conductive lines on the substrate, and similarly, the drains are interconnected via conductive lines. The sources and drains are arranged alternately along a direction parallel to the substrate surface. Furthermore, the gates of both the first and second power devices are connected to an external control signal source to receive PWM (Pulse Width Modulation) signals. The PWM signal allows for precise control of the power devices' on / off states, thereby achieving precise control of the entire circuit.
[0040] The capacitor module 3 is disposed between the first power device 1 and the substrate, or embedded inside the substrate. The orthographic projection of the capacitor module 3 along the A-A' direction on the substrate overlaps or coincides with the orthographic projection of the first power device 1 on the substrate, and is usually slightly smaller or slightly larger than the power device.
[0041] The capacitor module 3 includes one or more capacitors. When it is a single capacitor, it is directly disposed as a whole between at least one of the first power device 1 and the second power device 2 and the substrate, or inside the substrate below the corresponding power device. Please refer to... Figure 8When capacitor module 3 includes multiple capacitors, the multiple capacitors are spaced apart along a direction parallel to the surface of the substrate. The arrangement direction C-C' of the capacitors is orthogonal to the arrangement direction B-B' of the first power device 1 and the second power device 2, which can reduce the circuit length.
[0042] In this scheme, when the capacitor module 3 includes multiple capacitors, each capacitor has a first electrode and a second electrode. The number of capacitors in the capacitor module 3 (or the number of first electrodes, where the first electrode is the upper plate) is consistent with the number of drains of the first power device 1, and each first electrode is directly connected to the corresponding drain of the first power device 1. Similarly, the second electrodes (lower plates) of multiple capacitors together form a whole metal sheet, which is connected to the source of the second power device 2.
[0043] This solution can employ various types of capacitors, including but not limited to Si MOS capacitors, ceramic capacitors, and Si Trench capacitors. Si Trench capacitors have a top-and-bottom structure.
[0044] Similarly, please refer to Figure 9 The capacitor module 3 can also be disposed between the second power device 2 and the substrate, or embedded inside the substrate. In this configuration, the orthographic projection of the capacitor module 3 on the substrate overlaps or coincides with the orthographic projection of the second power device 2 on the substrate, and is typically slightly smaller or slightly larger than the power device.
[0045] In this scheme, when the capacitor module 3 includes multiple capacitors, each capacitor has a first electrode and a second electrode. The first electrodes (lower plates) of the multiple capacitors in the capacitor module 3 together form a whole metal sheet, which is connected to the drain of the first power device 1. The number of capacitors in the capacitor module 3 (or the number of second electrodes, where the second electrode is the upper plate) is consistent with the number of sources of the second power device 2, and each second electrode is directly connected to the corresponding source of the second power device 2.
[0046] By placing the capacitor module 3 between the second power device 2 and the substrate, or inside the substrate, the circuit length L3 is made smaller than L1 and L2 in the prior art. Please refer to... Figure 10 The length of L1 is 3.55mm, the length of L2 is 2.9mm, and the length of L3 is 1.7mm. It can be seen that the loop length is effectively shortened, the loop inductance is significantly reduced, and thus the performance of the entire circuit is improved.
[0047] In this design, the substrate is a multilayer composite structure, comprising an insulating base layer, a metal interconnect layer disposed on the insulating base layer, and a semiconductor layer disposed on the metal interconnect layer along the A-A' direction. The metal interconnect layer has conductive lines arranged thereon, providing excellent electrical isolation for the circuit and serving as a signal transmission channel. Capacitors are partially or entirely embedded within the insulating base layer. The semiconductor structures of the first power device 1 and the second power device 2 are both located within the semiconductor layer. This ensures that the power devices can operate effectively within the semiconductor layer while maintaining proper isolation from other parts of the substrate.
[0048] In summary, the solution disclosed in this utility model shortens the loop length of the half-bridge circuit by using embedded capacitors, multi-pole interconnected power devices, size matching, and orthogonal tiling, ultimately achieving a significant reduction in loop inductance. This effectively solves the voltage overshoot and electromagnetic interference problems faced by GaN devices under high-frequency switching conditions, thereby improving the overall performance and reliability of the circuit.
[0049] It should be understood that the above embodiments are merely illustrative of the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.
Claims
1. A half-bridge circuit structure based on embedded capacitors, characterized in that, include: A substrate with conductive lines; A first power device and a second power device are disposed on the substrate at intervals along a direction parallel to the substrate surface. Each of the first power device and the second power device has a gate, multiple sources and multiple drains, and the multiple sources in the same power device are electrically connected to each other, and the multiple drains are electrically connected to each other. A capacitor module includes at least one capacitor disposed between at least one of the first power device and the second power device and a substrate or inside the substrate correspondingly below the power device. The capacitor has a first electrode and a second electrode. The first electrode is electrically connected to the drain of the first power device via the conductive line, and the second electrode is electrically connected to the source of the second power device via the conductive line. The source of the first power device is electrically connected to the drain of the second power device via the conductive line.
2. The half-bridge circuit structure based on embedded capacitors according to claim 1, characterized in that: Multiple sources within the same power device are electrically connected to each other via the conductive lines.
3. The half-bridge circuit structure based on embedded capacitors according to claim 1, characterized in that: Multiple drains within the same power device are electrically connected to each other via the conductive lines.
4. The half-bridge circuit structure based on embedded capacitors according to claim 1, characterized in that: Multiple sources and multiple drains within the same power device are arranged alternately in a direction parallel to the substrate surface.
5. The half-bridge circuit structure based on embedded capacitors according to claim 1, characterized in that: The substrate includes an insulating base layer, and the conductive lines include a metal interconnect layer disposed on the insulating base layer.
6. The half-bridge circuit structure based on embedded capacitors according to claim 5, characterized in that: The capacitor is partially or entirely embedded within the insulating base layer.
7. The half-bridge circuit structure based on embedded capacitors according to claim 1, characterized in that: The capacitor module includes multiple capacitors connected in parallel and spaced apart along a direction parallel to the surface of the substrate.
8. The half-bridge circuit structure based on embedded capacitors according to claim 7, characterized in that: The arrangement direction of the first power device and the second power device is orthogonal to the arrangement direction of the plurality of capacitors.
9. The half-bridge circuit structure based on embedded capacitors according to claim 1, characterized in that: The orthographic projection of the capacitor module on the substrate overlaps or coincides with the orthographic projection of the first power device or the second power device on the substrate.
10. The half-bridge circuit structure based on embedded capacitors according to claim 1, characterized in that: The first power device and the second power device are GaN-based power devices.