A photonic sensor for quasi-distributed temperature detection inside IGBTs

Abstract

The present invention relates to a photon sensor capable of implementing quasi-distributed temperature detection within an IGBT (Insulated Gate Bipolar Transistor). The photon sensor comprises an insulating interface, a main channel waveguide, and at least one photon sensing component. The photon sensing component comprises a microring resonant cavity, a single-mode optical fiber, and a photon chip. Each microring resonant cavity is coupled to the main channel waveguide, and each microring resonant cavity is connected to the photon chip via a coupled single-mode optical fiber. By adjusting the number of photon sensing components and combining the microring resonant cavities to implement wavelength division multiplexing, a quasi-distributed network topology capable of simultaneously measuring multiple points in a confined space is achieved. This significantly reduces the number of IGBT external interfaces, improves the flexibility and practicality of the entire system, and better meets engineering safety requirements. Different network topologies can be designed based on the number of IGBT internal temperature detection points required. Compared to other multiplexers, the sensor also offers advantages such as low cost, high integration, low crosstalk, and flat output.

Description

Technical Field

[0001] The present invention relates to the technical field of optical temperature sensing, and in particular to a photon sensor capable of realizing quasi-distributed temperature detection inside an IGBT. Background Art

[0002] Power semiconductor devices are a vital component of power electronics systems and are widely used in rail transit, smart grids, aerospace, electric vehicles, and new energy equipment. As one of the most widely used power semiconductor devices, insulated-gate bipolar transistor (IGBT) modules are susceptible to damage from environmental thermal stress caused by prolonged operation under harsh conditions.

[0003] Research has shown that the junction temperature of power semiconductor devices is the most critical physical quantity directly affecting their operational reliability. The aging of IGBT modules is directly related to junction temperature, and changes in junction temperature can cause aging of the solder layer and bond wires. High-power IGBT modules, which contain dozens of chips, are hermetically sealed and operate in complex coupled physical fields for extended periods. Accurately measuring the junction temperature of the chips within the IGBT module is difficult, and currently used converter valve monitoring technology cannot monitor process data, limiting the long-term reliability assessment of equipment or key components. Therefore, real-time monitoring of the junction temperature of key components during IGBT module operation is particularly important.

[0004] In the case of multi-point temperature measurement inside high-power semiconductor power devices, series-type fiber Bragg grating sensors are used to monitor the internal temperature of IGBT modules. However, because the optical fiber itself is fragile and prone to damage due to offset during long-term operation, the flexibility in selecting measurement points is low. If multi-point measurement is to be achieved, more interfaces and measurement space are required. Summary of the Invention

[0005] In view of this, the present invention provides a photon sensor capable of realizing quasi-distributed temperature detection inside an IGBT.

[0006] The technical solutions adopted are as follows:

[0007] A photon sensor capable of implementing quasi-distributed temperature detection inside an IGBT comprises an insulating interface, a main channel waveguide, and at least one photon sensing component. The photon sensing component comprises a microring resonant cavity, a single-mode optical fiber, and a photon chip. Each microring resonant cavity is coupled to the main channel waveguide, and each microring resonant cavity is coupled to a corresponding single-mode optical fiber. The single-mode optical fiber is connected to the photon chip.

[0008] In a specific embodiment, the main channel waveguide is provided with a curved waveguide for coupling with each of the microring resonators.

[0009] In a specific embodiment, the microring resonant cavity includes a first microring, a second microring, and an output waveguide, wherein the first microring is coupled to the main channel waveguide, the first microring is coupled to the second microring, the second microring is coupled to the output waveguide, and the output waveguide is connected to the single-mode optical fiber.

[0010] In a specific embodiment, the photonic chip includes an end coupler, a rectangular waveguide and a waveguide grating, the single-mode optical fiber is connected to one end of the end coupler, and the other end of the end coupler is connected to the waveguide grating through the rectangular waveguide.

[0011] In a specific embodiment, the type of the waveguide grating is a Bragg grating, the grating duty cycle is set to 0.5, the etching depth is set to 25 nm, and the grating period number is set to 1000.

[0012] In a specific embodiment, the rectangular waveguide includes a silicon substrate, a silica cladding and a waveguide core layer. The silicon substrate has a thickness of 1 mm, a width of 2 mm and a length of 5 mm; the silica cladding has a thickness of 4.51 μm and a refractive index of 1.4447; the waveguide core layer is made of Si, has a thickness of 0.51 μm and a refractive index of 3.5457.

[0013] In a specific embodiment, the photonic chip further includes a packaging material, and the end coupler, rectangular waveguide, and waveguide grating are protected in the packaging material through a packaging process to form the photonic chip.

[0014] In a specific embodiment, the end face coupler is divided into four regions: a trench region, an inverted tapered coupling region, a convergence region, and a straight waveguide buffer region. The trench region is used to reduce the insertion loss between the end face coupler and the single-mode optical fiber. After passing through the trench region, the light enters the inverted tapered coupling region and the convergence region in turn, and then enters the straight waveguide buffer region, and finally is given to the waveguide grating through the rectangular waveguide.

[0015] In a specific embodiment, the core waveguide thickness of the trench zone, inverted tapered coupling zone, convergence zone and straight waveguide buffer zone is 0.51 μm, the length of the inverted tapered coupling zone is 392 μm, the waveguide width of the inverted tapered coupling zone close to one end of the trench zone is 510 nm, the exit width of the inverted tapered coupling zone is 120 nm, the cladding thickness of the inverted tapered coupling zone is 42 μm, the cladding thickness of the convergence zone decreases from 42 μm to 4.45 μm, and the cladding materials of the trench zone, inverted tapered coupling zone, convergence zone and straight waveguide buffer zone are all silicon dioxide.

[0016] In a specific embodiment, the end face coupler, rectangular waveguide and waveguide grating are etched together on a substrate to form an optical waveguide structure. The optical waveguide structure has a length of 5 mm, a width of 2 mm and a thickness of 1.9 mm.

[0017] The present invention has at least the following beneficial effects: the present invention provides a photon sensor capable of realizing quasi-distributed temperature detection inside an IGBT, which realizes wavelength division multiplexing by setting the number of photon sensing components and combining with a microring resonant cavity to realize wavelength division multiplexing, thereby realizing a quasi-distributed network topology for simultaneously measuring multiple points in a narrow space, greatly reducing the number of external interfaces of the IGBT, improving the flexibility and practicality of the entire system, and better meeting engineering safety requirements; the preferred microring resonant cavity has the functions of demultiplexing and multiplexing, and is flexible in design, and network topologies of different structures can be designed according to the actual number of IGBT internal temperature detection points. Compared with other multiplexers, it also has the characteristics of low cost, high integration, low crosstalk, and flat output. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural diagram of a sensing monitoring system provided by the present invention and applied to a photon sensor capable of realizing quasi-distributed temperature detection inside an IGBT;

[0019] Figure 2 This is a schematic diagram of the structure of a photon sensor provided by the present invention that can realize quasi-distributed temperature detection inside an IGBT;

[0020] Figure 3 This is the first structural diagram of the microring resonator;

[0021] Figure 4 This is a schematic diagram of the second structure of the microring resonator;

[0022] Figure 5 This is a schematic diagram of the structure of the photonic chip;

[0023] Figure 6 It is a structural diagram of the refractive index distribution of the waveguide grating;

[0024] Figure 7 is a schematic diagram of the optical waveguide structure;

[0025] Figure 8 is a schematic cross-sectional view of a rectangular waveguide;

[0026] Figure 9 This is a schematic diagram of the sensor arrangement inside the IGBT;

[0027] In the figure, 1 is the insulating interface, 2 is the main channel waveguide, 3 is the microring resonator, 4 is the photonic chip, 5 is the single-mode optical fiber, 6 is the packaging material, 7 is the waveguide grating, 8 is the end coupler, 9 is the rectangular waveguide, 10 is the silicon substrate, 11 is the silica cladding, 12 is the waveguide core layer, 13 is the Trench region, 14 is the inverted cone coupling region, 15 is the convergence region, 16 is the straight waveguide buffer, 17 is the IGBT chip, 18 is the aluminum bonding wire, 19 is the DBC liner, 20 is the IGBT substrate, 21 is the IGBT power submodule, 22 is the IGBT housing, 23 is the bent waveguide, 24 is the main channel input end, 25 is the wavelength division output end, 26 is the main channel output end, and 27 is the output channel. DETAILED DESCRIPTION

[0028] This embodiment provides a photon sensor that can realize quasi-distributed temperature detection inside IGBT, hereinafter referred to as photon sensor. As a specific embodiment, Figure 1 As shown, the sensing monitoring system used by the photon sensor provided by the present invention includes a broadband light source, a circulator, a wavelength division multiplexer, a photon sensor (corresponding to Figure 1 The system consists of an optical waveguide grating sensor), a spectrum analyzer, a control system, and a host computer. The measurement principle of this system is as follows: the Bragg waveguide grating, which is composed of two materials with different refractive indices distributed alternately, has high reflectivity for wavelengths that meet the Bragg condition. It can select the wavelength of the broadband light source, perform spectral analysis on the center wavelength of the reflected wavelength, and then send the wavelength data and light intensity data to the host computer, which finally parses the received data. When the ambient temperature at the position measured by the grating changes, the grating refractive index changes accordingly, eventually causing the reflected wavelength to drift, thereby establishing a relationship between the wavelength and temperature changes. Through wavelength division multiplexing technology, the temperature of multiple points is measured simultaneously. The input and output are transmitted on the same waveguide through the coupling of the ring resonator, realizing the single-interface IGBT internal multi-point temperature detection sensor device packaging design.

[0029] like Figure 2As shown, the photon sensor includes an insulating interface 1, a main channel waveguide 2, and at least one photon sensing component, and the photon sensing component includes a microring resonant cavity 3, a single-mode optical fiber 5, and a photon chip 4. Each microring resonant cavity 3 is coupled to the main channel waveguide 2, and each microring resonant cavity 3 is coupled to the corresponding single-mode optical fiber 5, and the single-mode optical fiber 5 is connected to the photon chip 4. Among them, the number of photon sensing components can be selected appropriately according to actual conditions, so as to meet the resonance conditions of the microring resonant cavity and not interfere with each other within the temperature variation range during temperature detection. When multiple photon sensing components are provided, wavelength division multiplexing is realized in combination with the microring resonant cavity 3, realizing a quasi-distributed network topology for simultaneously measuring multiple points in a narrow space, greatly reducing the number of IGBT external interfaces, improving the flexibility and practicality of the entire system, and better meeting engineering safety requirements.

[0030] As a specific embodiment, the insulating interface 1 may include an interface body, an interface base, and an optical fiber connection port. The interface body and the optical fiber connection port are connected by the interface base, and a C-shaped ceramic sleeve is embedded in the optical fiber connection port for fixing the single-mode optical fiber after access. The interface body is the same as the national standard optical fiber interface LC and can be externally connected to an adapter. In addition, the interface body does not contain any metal material, avoiding the disadvantage of traditional metal interfaces that are easily affected by potential, and fully meets the special environmental requirements of the IGBT module working in high power and high current conditions, and the interface can be safely used under the interface requirements of any scenario.

[0031] A single-mode optical fiber 5 is also provided between the insulating interface 1 and the main channel waveguide 2. This single-mode optical fiber 5 is an APC fiber with an 8° angled end face. The 8° angle creates a tighter end face and reflects light back to the cladding rather than directly back to the light source, providing improved connection performance. The fiber's coating is polyimide, enhancing its exterior's high-temperature resistance.

[0032] When the optical signal provided by the optical detection system enters the temperature measurement topology structure through the insulating interface 1 and is transmitted through the main channel waveguide 2 and demultiplexed by the microring resonant cavity 3 to enter each temperature measurement structure, the photonic chip 4 changes the central wavelength after sensing the junction temperature of multiple temperature measurement areas on the IGBT chip, generates a light reflection signal after temperature measurement, and couples the light reflection signal after temperature measurement into the main channel waveguide 2 through the microring resonant cavity 3 for wavelength division multiplexing, and finally outputs it to the external optical detection equipment through the single-mode optical fiber 5 and the insulating interface 1.

[0033] like Figure 3 and Figure 4 As shown, the main channel waveguide 2 is provided with a curved waveguide 23 for coupling with each microring resonator 3. In addition to the curved waveguide 23, the main channel waveguide 2 is further provided with a main channel input end 24 and a main channel output end 26.

[0034] The micro-ring resonant cavity 3 is the core component of the photon sensor and is the key to realizing wavelength division multiplexing technology. It is a dense wavelength division multiplexer. In this embodiment, the dense wavelength division multiplexer is a multi-channel wavelength division multiplexer based on two micro-ring series arrays. Figure 3 and Figure 4 As shown, for any micro-ring resonator 3, including the first micro-ring ( Figure 3 and Figure 4 Microring ring1 in the middle), the second microring ( Figure 3 and Figure 4 Microring ring 1 is coupled to the main channel waveguide 2 (specifically, microring ring 1 is coupled via the curved waveguide 23 of the main channel waveguide 2), microring ring 1 is coupled to microring ring 2, and microring ring 2 is coupled to the output waveguide 27. The output waveguide 27 is connected to the single-mode fiber 5. This approach can meet the coupling coefficient requirements while avoiding the introduction of additional cavity length. Assume that light is incident from the main channel input port 24, the microring radius of microring ring 1 is 42μm, and the radius of each subsequent channel increases by 50nm. The resonant wavelength also increases linearly. The coupling coefficient between microring ring 1 and the main channel waveguide 2 is controlled to be 0.35, and the coupling coefficient between microring ring 1 and microring ring 2 is controlled to be 0.25. Light that meets the wavelength resonance conditions is coupled through the curved waveguide 23 and then transmitted into microring ring 1. Light of the same wavelength is again coupled through microring ring 1 into microring ring 2, and then coupled from microring ring 2 into the wavelength division output port 25 in the output waveguide 27 for output. Wavelengths that do not meet the conditions are all output from the main channel output port 26 in the main channel waveguide 2. The number of microrings determines the spectral width of the channel. The fewer microrings, the wider the spectral width and the lower the accuracy. Conversely, the narrower the channel spectral width and the smaller the temperature measurement range. The dense wavelength division multiplexer used in this embodiment has a 3dB bandwidth of 0.75nm for each channel spectrum, which meets the temperature monitoring requirements of this embodiment. The number of channels and the channel spectrum bandwidth of the dense wavelength division multiplexing device can be freely selected according to specific needs. The wavelength division multiplexing device is usually bidirectional and reversible. The reflected waves of different sensors in the IGBT are input into channels corresponding to different wavelengths. Then, all reflected waves will be re-coupled from the main channel input end 24 into the main channel waveguide 2 to achieve multiplexing of the reflected waves.

[0035] In this embodiment, Figure 5As shown, the photonic chip 4 includes an end coupler 8, a rectangular waveguide 9, and a waveguide grating 7. The single-mode optical fiber 5 is connected to one end of the end coupler 8, and the other end of the end coupler 8 is connected to the waveguide grating 7 through the rectangular waveguide 9. When light enters the interior of the IGBT from the insulating interface 1, the light in the single-mode optical fiber 5 is coupled into the main channel waveguide 2 through the end coupler 8. When the light travels to the microring resonator 3 structure, the light of the wavelength that meets the resonance condition will be coupled into the sensing branch and continue to be transmitted through the single-mode optical fiber 5 or the rectangular waveguide 9 to the photonic chip 4 at the sensing area, thereby realizing the network topology structure of the internal temperature detection of the IGBT and achieving the purpose of simultaneously measuring multiple temperature measurement points inside the IGBT.

[0036] In this embodiment, the photonic chip 4 offers a wide range of materials. Waveguide gratings are primarily fabricated through processes such as spin coating, photolithography, and etching. Almost any waveguide material, such as glass, lithium niobate, semiconductors, and polymers, can be used. This technology offers significant development potential, allowing for the design and use of different waveguide gratings to meet diverse requirements. For example, polymer materials are easy to prepare, cost-effective, and possess excellent optical and electrical properties. Silicon wafers or SiO2 substrates offer excellent compatibility with many optical materials. Polymers have high thermo-optical coefficients, making them suitable for fabricating thermal sensing elements. For cost and functionality considerations, Si is selected as the substrate material in this embodiment.

[0037] In this embodiment, the photonic chip 4 further includes a packaging material 6. The end coupler 8, rectangular waveguide 9, and waveguide grating 7 are protected within the packaging material 6 through a packaging process to form the photonic chip 4. Therefore, in use, the single-mode optical fiber 5 and the waveguide grating 7 are connected via the end coupler 8 and rectangular waveguide 9, and are all protected within the packaging material 6 through the packaging process to form the photonic chip 4.

[0038] In this embodiment, the type of the waveguide grating 7 is a Bragg grating, the grating duty cycle is set to 0.5, the etching depth is 25 nm, the grating period number is 1000, and the grating refractive index distribution of the waveguide grating 7 is as follows: Figure 6 shown.

[0039] In this embodiment, the end coupler 8 is an inverted tapered structure as a whole, which is divided into four regions: a trench region 13, an inverted tapered coupling region 14, a convergence region 15 and a straight waveguide buffer region 16. Figure 7As shown, the trench region 13, inverted tapered coupling region 14, convergence region 15, and straight waveguide buffer region 16 are sequentially connected to form a complete temperature sensing circuit. The trench region 13 smoothes the end face of the silicon waveguide, reducing insertion loss between the end coupler 8 and the single-mode fiber 5. After passing through the trench region 13, light enters the inverted tapered coupling region 14 and convergence region 15, and then enters the straight waveguide buffer region 16, transforming into a standard rectangular silicon waveguide structure. Finally, light is delivered to the waveguide grating 7 through the rectangular waveguide 9.

[0040] The core waveguide thickness of the trench region 13, the inverted tapered coupling region 14, the convergence region 15 and the straight waveguide buffer region 16 is 0.51 μm. The length of the inverted tapered coupling region 14 is 392 μm. The waveguide width of the inverted tapered coupling region 14 at one end close to the trench region 13 is 510 nm. The outlet width of the inverted tapered coupling region 14 is 120 nm.

[0041] The cladding thickness of the inverted tapered coupling region 14 is 42 μm, and the cladding thickness of the convergence region 15 slowly decreases from 42 μm to 4.45 μm. The cladding materials of the trench region 13, the inverted tapered coupling region 14, the convergence region 15 and the straight waveguide buffer region 16 are all silicon dioxide.

[0042] The end face coupler 8, rectangular waveguide 9 and waveguide grating 7 are jointly etched on the substrate to form an optical waveguide structure. The entire optical waveguide structure has a length of 5 mm, a width of 2 mm and a thickness of 1.9 mm. The total length of the end face coupler 8 is 0.7 mm and a width of 0.5 mm. The total length of the waveguide grating 7 is 310 μm, the waveguide length is 9 μm and the width is 0.51 μm. The remaining part encapsulates some bare optical fiber.

[0043] In this embodiment, the rectangular waveguide 9 includes a silicon substrate 10, a silicon dioxide cladding layer 11 and a waveguide core layer 12. Figure 8 As shown, the silicon substrate 10 is 1 mm thick, 2 mm wide, and 5 mm long. The silicon dioxide cladding 11 is 4.51 μm thick and has a refractive index of 1.4447. The waveguide core 12 is made of silicon, 0.51 μm thick, and has a refractive index of 3.5457. Due to the refractive index difference, light is confined to the core layer for transmission, while the optical signal passing through the end coupler 8 is received.

[0044] When the optical signal is coupled out from the microring resonator 3 to complete the wave splitting, it is transmitted to the photonic chip 4 through the single-mode optical fiber 5, and the optical signal is transmitted from the optical fiber to the rectangular waveguide 9 through the end coupler 8. The end coupler 8 can greatly increase the coupling efficiency of the optical signal and solve the problem of low coupling efficiency caused by the large size difference between the optical fiber core diameter and the rectangular waveguide core layer.

[0045] Therefore, the optical signal enters through the insulating interface 1, and the main channel waveguide 2 is responsible for transmitting the multi-wavelength optical signal. When the optical signal is transmitted to the microring resonator 3, the light wave that meets the resonance condition enters the curved waveguide 23 through the main channel input end 24 of the main channel waveguide 2, and is coupled into the microring ring 1 and microring ring 2 in the microring resonator. From microring ring 2, it is coupled into the output waveguide 27, output from the wavelength division output end 25, and then enters the photonic chip 4 for temperature sensing. Light that does not meet the resonance condition continues to be transmitted forward through the main channel output end 26 of the main channel waveguide 2, thereby realizing the wavelength division multiplexing function. When the temperature measurement point is too close to the output wavelength division output end 25, the single-mode fiber 5 can be omitted and directly connected through the rectangular waveguide 9. When the temperature of the monitoring point inside the IGBT changes, the refractive index of the waveguide grating 7 in the photonic chip 4 changes, causing the central reflection wavelength of the waveguide grating 7 to drift and form a stable linear relationship with the temperature change.

[0046] In this embodiment, there are two ways to connect the micro-ring resonator 3 and the waveguide grating 7. The first way is to couple the single-mode optical fiber 5 by etching the end coupler 8 on the output waveguide 27 and the photonic chip 4 respectively to achieve the connection between them. Figure 3 As shown in , this method is suitable for use when the measurement point is far away from the main channel waveguide 2. The second method is to achieve it through optical chip integration technology, such as Figure 4 As shown, the end face coupler 8 is not used, and the output waveguide 27 and the waveguide grating 7 are directly integrated and packaged through the rectangular waveguide 9. This solution is suitable for use when the measurement point is close to the main channel waveguide 2.

[0047] This embodiment also provides a specific application of the photon sensor, namely, the application of an IGBT device in a flexible DC transmission converter valve. The structure of the IGBT part used in the photon sensor includes: an IGBT housing 22, an IGBT chip 17 arranged in the IGBT housing 22, aluminum bonding wires 18, a DBC liner 19, an IGBT substrate 20 and an IGBT power sub-module 21. Figure 9 This is a schematic diagram of the sensor arrangement inside the IGBT.

[0048] The insulating interface 1 is placed on the IGBT housing 22, connecting the external optical signal and the internal single-mode optical fiber 5. The IGBT chip 17 is soldered to the DBC substrate 19 via a solder layer and copper sheet. Six IGBT chips together form an IGBT power submodule 21. The six IGBT power submodules are also soldered to the IGBT substrate 20 via copper sheet and solder layer to form an IGBT power module. This arrangement enables temperature detection of the IGBT chip 17, DBC substrate 19, and IGBT substrate 20 between modules. It should be noted that this method is merely an example and can be rearranged based on actual needs, all within the scope of this invention.

[0049] According to actual production conditions, the main process flow of packaging of the IGBT power sub-module 21 is as follows: DBC liner 19 patch → DBC liner 19 welding → ultrasonic wire bonding → DBC liner 19 testing → IGBT substrate 20 assembly and welding → photonic chip 4 fixation, epoxy glue curing at the end face coupler 8, single-end fixation is adopted, which does not affect the normal thermal expansion and contraction of the sensor during temperature measurement → epoxy glue curing → shell installation and injection of insulating glue → pigtail connector connection → IGBT power sub-module 21 testing.

[0050] Therefore, the present invention provides a new type of photon sensor that can realize quasi-distributed temperature detection inside the IGBT. It simplifies the optical path as much as possible while realizing real-time measurement of multiple points. It also greatly reduces the through holes that need to be reserved for optical fiber interfaces on the IGBT housing 22, thereby increasing the safety of system use under high temperature and high pressure conditions. The waveguide grating 7 is used for temperature detection. Compared with the traditional method of measuring the surface temperature of high-power semiconductor switching devices based on electrical signals, the waveguide grating 7 can directly reflect the actual internal temperature value. Compared with the fiber grating sensing system in the early stage of research, it can effectively solve the problem that the position of the fiber grating is easily offset or affected by stress when measuring temperature, resulting in large errors in the junction temperature monitoring value of the high-power semiconductor switching device, further improving the accuracy and stability of the measurement. In addition, the optical waveguide itself has the advantages of high temperature resistance, high pressure resistance, and strong magnetic field interference resistance, providing stability guarantee for multi-point temperature measurement.

[0051] In summary, the specific protection contents of the present invention are as follows: 1. The present invention provides a photonic sensor that can realize quasi-distributed temperature detection inside an IGBT, and proposes a design concept of using multiple microring resonators 3 in cascade or multiple photonic chips 4 in series as the core component of the quasi-distributed temperature sensor. Based on the above principles or the temperature sensing method designed by the photonic chip device, other embodiments obtained without creative work, such as using wavelength division multiplexing and a single photonic chip in a single channel or not using a wavelength division multiplexing chip but using multiple photonic chips in a single optical path, all fall within the scope of protection of the present invention. 2. The present invention designs a network topology structure that can detect the junction temperature information of all key points in the IGBT in real time. The topology structure is based on the principle of wavelength division multiplexing and is designed with the microring resonator 3 as an example. Other network topologies designed based on this principle without creative work, such as simply replacing the microring resonator 3 with other types of wavelength division multiplexing devices, all fall within the scope of protection of the present invention.

[0052] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A photon sensor capable of realizing quasi-distributed temperature detection inside an IGBT, characterized in that: The device comprises an insulating interface, a main channel waveguide, and at least one photon sensing component, wherein the photon sensing component comprises a microring resonant cavity, a single-mode optical fiber, and a photon chip, wherein each microring resonant cavity is coupled to the main channel waveguide, and each microring resonant cavity is coupled to a corresponding single-mode optical fiber, and the single-mode optical fiber is connected to the photon chip; The microring resonant cavity includes a first microring, a second microring and an output waveguide, wherein the first microring is coupled to the main channel waveguide, the first microring is coupled to the second microring, the second microring is coupled to the output waveguide, and the output waveguide is connected to the single-mode optical fiber; Among them, the optical signal provided by the optical detection system enters the temperature measurement topology structure through the insulating interface and is transmitted through the main channel waveguide and demultiplexed into each temperature measurement structure through the microring resonant cavity. The photonic chip changes the central wavelength after sensing the junction temperature of multiple temperature measurement areas on the IGBT chip, generates a light reflection signal after temperature measurement, and couples the light reflection signal after temperature measurement into the main channel waveguide through the microring resonant cavity for wavelength division multiplexing, and finally outputs it to the external optical detection equipment through the insulating interface.

2. A photon sensor capable of realizing quasi-distributed temperature detection inside an IGBT according to claim 1, characterized in that: The main channel waveguide is provided with a curved waveguide for coupling with each of the microring resonant cavities.

3. The photon sensor capable of realizing quasi-distributed temperature detection inside an IGBT according to claim 1, characterized in that: The photonic chip includes an end coupler, a rectangular waveguide and a waveguide grating. The single-mode optical fiber is connected to one end of the end coupler, and the other end of the end coupler is connected to the waveguide grating through the rectangular waveguide.

4. The photon sensor capable of realizing quasi-distributed temperature detection inside an IGBT according to claim 3, characterized in that: The type of the waveguide grating is a Bragg grating, and the grating duty cycle is set to 0.5, the etching depth is set to 25 nm, and the grating period number is set to 1000.

5. The photon sensor capable of realizing quasi-distributed temperature detection inside an IGBT according to claim 3, characterized in that: The rectangular waveguide includes a silicon substrate, a silicon dioxide cladding and a waveguide core layer. The silicon substrate has a thickness of 1 mm, a width of 2 mm and a length of 5 mm; the silicon dioxide cladding has a thickness of 4.51 μm and a refractive index of 1.4447; the waveguide core layer is made of Si, has a thickness of 0.51 μm and a refractive index of 3.5457.

6. The photon sensor capable of realizing quasi-distributed temperature detection inside an IGBT according to claim 3, characterized in that: The photonic chip further includes a packaging material, and the end face coupler, the rectangular waveguide, and the waveguide grating are protected in the packaging material through a packaging process to form the photonic chip.

7. The photon sensor capable of realizing quasi-distributed temperature detection inside an IGBT according to claim 3, characterized in that: The end coupler is divided into four regions: a trench region, an inverted tapered coupling region, a convergence region, and a straight waveguide buffer region. The trench region is used to reduce the insertion loss between the end coupler and the single-mode optical fiber. After passing through the trench region, light enters the inverted tapered coupling region and the convergence region in sequence, and then enters the straight waveguide buffer region, and finally is delivered to the waveguide grating through a rectangular waveguide.

8. The photon sensor capable of realizing quasi-distributed temperature detection inside an IGBT according to claim 7, characterized in that: The core waveguide thickness of the trench region, inverted tapered coupling region, convergence region and straight waveguide buffer region is 0.51 μm, the length of the inverted tapered coupling region is 392 μm, the waveguide width of the inverted tapered coupling region close to one end of the trench region is 510 nm, the exit width of the inverted tapered coupling region is 120 nm, the cladding thickness of the inverted tapered coupling region is 42 μm, and the cladding thickness of the convergence region decreases from 42 μm to 4.45 μm. The cladding materials of the trench region, inverted tapered coupling region, convergence region and straight waveguide buffer region are all silicon dioxide.

9. The photon sensor capable of realizing quasi-distributed temperature detection inside an IGBT according to claim 3, characterized in that: The end face coupler, rectangular waveguide and waveguide grating are jointly etched on a substrate to form an optical waveguide structure. The optical waveguide structure has a length of 5 mm, a width of 2 mm and a thickness of 1.9 mm.

Images