IGBT power module temperature measuring method and IGBT power module packaging structure

Abstract

The invention relates to an IGBT power module temperature measuring method and an IGBT power module packaging structure. The method comprises the following steps: preparing single-phase fluorescent powder, and mixing epoxy resin with white inorganic powder or white organic polymer to obtain background coating liquid; mixing epoxy resin with single-phase fluorescent powder to obtain fluorescent powder coating liquid; coating background coating liquid on the copper-clad ceramic substrate with the complete circuit to form a background layer; coating the white background layer with the fluorescent powder coating liquid to form a fluorescent layer; after ultraviolet irradiation, obtaining a fluorogram and a light intensity ratio; according to the fluorescence intensity ratio and the fluorescence characteristic curve of the single-phase fluorescent powder, the corresponding environment temperature is obtained; according to the method, the technical problems that the existing temperature measurement method for taking the IGBT power module as a high-power device cannot measure the temperature at a fixed point, the temperature measurement precision is easily influenced by a packaging structure, and the contact type temperature measurement has negative influence on the heat dissipation function of the device can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of IGBT power modules, and particularly to a method for measuring the temperature of an IGBT power module and an encapsulation structure of the IGBT power module. Background Art

[0002] As a high-power device, monitoring the surface temperature of an IGBT power module is of great significance for preventing module thermal failure. In traditional temperature measurement technologies, negative temperature coefficient (NTC) thermistors and infrared temperature measurement technologies are relatively commonly used. A thermistor utilizes the response of resistance to ambient temperature to establish the relationship between resistance R and temperature T, and realizes temperature monitoring through electrical parameters. Near-infrared temperature measurement technology determines the ambient temperature of the molecule (object) through the heat absorption of the molecule and the different frequency electromagnetic waves released by the transitions of the rotational energy level and vibrational energy level of the molecule.

[0003] For the NTC temperature measurement technology, it can only reflect the macroscopic temperature near the NTC, and cannot accurately measure in a small area with a large temperature gradient distribution. It needs to be installed around the temperature monitoring point, which will have a negative impact on the heat dissipation performance itself, and the position of customized temperature monitoring cannot be achieved. The installation position depends on the chip layout. For the shortcomings of near-infrared temperature measurement technology, it is necessary to know the emissivity defined by factors such as the current measured position, material, and roughness to accurately optimize the temperature measurement structure. Near-infrared temperature measurement is a surface temperature measurement technology and is difficult to apply in an IGBT power module with a certain thickness of the encapsulation structure. It is easily affected by environmental factors such as ambient light diffuse reflection and air humidity, and the test equipment is expensive.

[0004] Therefore, in view of the above problems, the present invention urgently provides a method for measuring the temperature of an IGBT power module and an encapsulation structure of the IGBT power module. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for measuring the temperature of an IGBT power module and an encapsulation structure of the IGBT power module, and through the design of the method for measuring the temperature of the IGBT power module, to solve the technical problems such as the existing temperature measurement methods for IGBT power modules as high-power devices being unable to perform fixed-point temperature measurement, the temperature measurement accuracy being easily affected by the encapsulation structure, and the negative impact of contact temperature measurement on the heat dissipation function of the device itself.

[0006] A method for measuring the temperature of an IGBT power module provided by the present invention includes the following steps: Configure single-phase phosphor, and the chemical composition of the single-phase phosphor is Na4Mg(WO4)3:x%Tb 3+ ,y%Mn 4+ , where x is the molar percentage of doped Tb 3+ , taking 0 < x ≤ 0.1, y is the doped Mn4+ The molar percentage is 0 <y≤0.1; Mixing epoxy resin with white inorganic powder or white organic polymer to obtain background coating liquid; mixing epoxy resin with single-phase phosphor to obtain phosphor coating liquid; coating a background coating liquid on a copper-clad ceramic substrate having a complete circuit to form a background layer; Applying the fluorescent powder coating liquid on the white background layer to form a fluorescent layer; After ultraviolet light irradiation, the fluorescence spectrum was obtained, and the height of the 550nm high-energy emission light in the fluorescence spectrum was obtained, which was recorded as I H , the height of the 700nm low-energy emission light in the fluorescence spectrum, denoted as I L According to the formula FIR=I H / I L , obtain the fluorescence intensity ratio, FIR is the fluorescence intensity ratio; The corresponding ambient temperature is obtained according to the fluorescence intensity ratio and the temperature-dependent fluorescence characteristic curve of the single-phase phosphor.

[0007] Preferably, the single-phase phosphor preparation steps include: Weigh Na2CO3, MgO, WO3, Tb4O7, and MnO2 respectively according to the molar ratio of the general formula; Grind Na2CO3, MgO, WO3, Tb4O7 and MnO2 and mix them evenly. Heat the mixture at 700-900℃ for 10-16h, cool to room temperature and grind to obtain the product.

[0008] Preferably, the mass ratio of the single-phase phosphor to the epoxy resin in the phosphor coating liquid is 1:(1-1.5).

[0009] Preferably, the particle size of the single-phase phosphor is less than 10 μm.

[0010] Preferably, the mass ratio of epoxy resin to white inorganic material is 1:(1-1.5).

[0011] Preferably, the white inorganic powder is at least one of BaSO4 powder, TiO2 powder or ZrO2 powder; and the white organic polymer is a silica gel dye.

[0012] Preferably, the thickness of the fluorescent layer is 0.2-0.5 mm.

[0013] Preferably, the thickness of the white background layer is 0.2-0.5 mm.

[0014] Preferably, the surface of the fluorescent layer is covered with a protective layer; the protective layer is a transparent epoxy resin.

[0015] The present invention also provides an IGBT power module packaging structure, comprising a copper-clad ceramic substrate with a complete circuit, the copper-clad ceramic substrate with a complete circuit being sequentially covered with a background layer, a fluorescent layer and a protective layer; wherein the background layer, the fluorescent layer and the protective layer are obtained based on the IGBT power module temperature measurement method as described in any one of the above-mentioned methods.

[0016] Compared with the prior art, the IGBT power module temperature measurement method provided by the present invention has the following improvements: 1. The IGBT power module temperature measurement method provided by the present invention selects the chemical composition of the single-phase phosphor to be Na4Mg(WO4)3:x%Tb 3+ ,y%Mn 4+ , Mn 4+ As a transition metal ion, it can release a broadband of deep red light with a central wavelength of 700nm under 365nm excitation; 3+ As a rare earth metal ion, it can release a series of narrow bands under 365nm excitation, among which the 550nm green light narrow band is the main one. The intensity ratio of the two wavelengths is obtained through a single excitation wavelength, and then the corresponding ambient temperature is obtained through the fluorescence characteristic curve of the single-phase phosphor. The method is simple and has high temperature measurement efficiency. The temperature measurement is no longer limited to a specific installation position. The average temperature in different ranges can be obtained by using light sources of different spot sizes to illuminate the designated position.

[0017] 2. The IGBT power module temperature measurement method provided by the present invention is no longer limited by the IGBT silicone packaging. Since ultraviolet light and visible light can completely penetrate silicone, the optical signal on the module surface can be accurately detected to obtain the temperature value.

[0018] 3. The IGBT power module temperature measurement method provided by the present invention can prevent module surface reflection and absorption of fluorescence through the design of the background layer, thereby improving the measurement accuracy and protecting the device at the same time. There is no need to clean the fluorescent layer after temperature measurement, and the fluorescent layer can be retained. The temperature of the IGBT device with high current and high voltage that is directly packaged can be measured at any time.

[0019] 4. The IGBT power module temperature measurement method provided by the present invention and the design of the protective layer can prevent the phosphor from being affected by components in the air and causing performance degradation.

[0020] 5. The IGBT power module temperature measurement method provided by the present invention, the single-phase phosphor selected by the present invention can ensure that the diffuse reflection between phases does not produce differential absorption, and at the same time ensure that the effect of phosphor aging on the activator ions is uniform and does not affect the measurement accuracy.

[0021] 6. The IGBT power module temperature measurement method provided by the present invention, the single-phase phosphor of the present invention, Tb 3+ With Mn 4+ Here, it can be excited by the commercially mature 365nm excitation light source at the same time, reducing the demand for the development of the excitation light source. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a structural schematic diagram of the IGBT power module described in the present invention; Figure 2 It is the temperature-dependent fluorescence characteristic curve of the single-phase phosphor described in the present invention.

[0024] Description of reference numerals: 1. Background layer; 2. Fluorescent layer; 3. Protective layer; 4. Insulation layer; 5. Metal layer; 6. Chip; 7. Wire. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0027] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] An IGBT power module temperature measurement method provided by the present invention includes the following steps: S1) Configure single-phase phosphor, and the chemical composition of the single-phase phosphor is Na4Mg(WO4)3:x%Tb 3+ ,y%Mn 4+ , where x is the molar percentage of doped Tb 3+ , taking 0 < x ≤ 0.1, and y is the molar percentage of doped Mn 4+ , taking 0 < y ≤ 0.1; S2) Mix epoxy resin with white inorganic powder or white organic polymer to obtain a background coating solution; mix epoxy resin with single-phase phosphor to obtain a phosphor coating solution; S3) Coat the background coating solution on a copper-clad ceramic substrate with a complete circuit to form a background layer; S4) Coat the phosphor coating solution on the white background layer to form a phosphor layer; S5) After ultraviolet light irradiation, obtain a fluorescence spectrum diagram, and obtain the height of the 550nm high-energy emission light in the fluorescence spectrum, denoted as I H , and the height of the 700nm low-energy emission light in the fluorescence spectrum, denoted as I L , according to the formula FIR = I H / I L , obtain the fluorescence intensity ratio, and FIR is the fluorescence intensity ratio; S6) Obtain the corresponding ambient temperature according to the fluorescence intensity ratio and the variable-temperature fluorescence characteristic curve of the single-phase phosphor.

[0029] Specifically, the preparation steps of the single-phase phosphor include: Weigh Na2CO3, MgO, WO3, Tb4O7, and MnO2 according to the molar ratio of the general formula; Grind and mix Na2CO3, MgO, WO3, Tb4O7, and MnO2 evenly, keep the mixture at 700 - 900 °C for 10 - 16 h, cool to room temperature, and grind to obtain.

[0030] Specifically, the mass ratio of the single-phase phosphor to the epoxy resin in the phosphor coating solution is 1:(1 - 1.5).

[0031] Specifically, the particle size of the single-phase phosphor is less than 10 μm.

[0032] Specifically, the mass ratio of the epoxy resin to the white inorganic material is 1:(1-1.5).

[0033] Specifically, the white inorganic powder is at least one of BaSO4 powder, TiO2 powder or ZrO2 powder; and the white organic polymer is a silica gel dye.

[0034] Specifically, the thickness of the fluorescent layer is 0.2-0.5 mm.

[0035] Specifically, the thickness of the white background layer is 0.2-0.5 mm.

[0036] Specifically, the surface of the fluorescent layer is covered with a protective layer.

[0037] Specifically, the surface of the fluorescent layer is covered with a protective layer; the protective layer is a transparent epoxy resin.

[0038] The present invention also provides an IGBT power module packaging structure, comprising a copper-clad ceramic substrate with a complete circuit, the copper-clad ceramic substrate with a complete circuit being sequentially covered with a background layer 1, a fluorescent layer 2 and a protective layer 3, the copper-clad ceramic substrate with a complete circuit comprising an insulating layer 4, a metal layer 5 being arranged on the insulating layer, a chip 6 being arranged on the metal layer 5, the chip 6 being fixed on the metal layer 5 by solder 8, and also comprising a wire 7 for conducting the chip; wherein the background layer 1, the fluorescent layer 2 and the protective layer 3 are obtained based on the IGBT power module temperature measurement method as described above.

[0039] The chemical composition of the single-phase phosphor selected by the present invention is Na4Mg(WO4)3:x%Tb 3+ ,y%Mn 4+ , Mn 4+ As a transition metal ion, it can release a broadband of deep red light with a central wavelength of 700nm under 365nm excitation; 3+ As a rare earth metal ion, it can release a series of narrow bands under 365nm excitation, among which the 550nm green light narrow band is the main one. The intensity ratio of the two wavelengths is obtained through a single excitation wavelength, and then the corresponding ambient temperature is obtained through the fluorescence characteristic curve of the single-phase phosphor. The method is simple and has high temperature measurement efficiency. The temperature measurement is no longer limited to a specific installation position. The average temperature in different ranges can be obtained by using light sources of different spot sizes to illuminate the designated position.

[0040] The temperature measurement method of the present invention is no longer limited by the IGBT silicone packaging. Since ultraviolet light and visible light can completely penetrate the silicone, the optical signal on the surface of the module can be accurately detected to obtain the temperature value.

[0041] The present invention can prevent module surface reflection and absorption of fluorescence through the design of the background layer, thereby improving the measurement accuracy and protecting the device at the same time. There is no need to clean the fluorescent layer after temperature measurement, and the fluorescent layer can be retained. The high-current and high-voltage IGBT device directly packaged can measure the temperature of the IGBT device at any time.

[0042] The design of the protective layer of the present invention can prevent the fluorescent powder from being affected by components in the air and causing performance degradation.

[0043] The single-phase phosphor selected in the present invention can ensure that diffuse reflection between phases does not produce differential absorption, and at the same time ensure that the effect of phosphor aging on activator ions is uniform and does not affect measurement accuracy.

[0044] The single-phase phosphor of the present invention, Tb 3+ With Mn 4+ Here, it can be excited by the commercially mature 365nm excitation light source at the same time, reducing the demand for the development of the excitation light source.

[0045] The thermal quenching phenomenon and visual color change effect of the single-phase phosphor of the present invention are more obvious in the range of 100-200°C. This temperature distribution is within the operating temperature of most IGBT power modules, and it can achieve the transition from orange light to green light. The naked eye is more sensitive to green light, that is, it is more friendly to the naked eye to quickly observe the temperature distribution.

[0046] The present invention adds a background layer which can effectively prevent metals such as Cu and Al or other materials in the circuit from interfering with the excitation light / emission light, such as absorption and specular reflection, and causing measurement errors; when the fluorescent layer is attached to the background layer, the color difference of the fluorescent powder can be highlighted, which has good applicability for rapid observation of temperature distribution by naked eyes.

[0047] The change in the color of the emitted light caused by thermal quenching in the present invention can make the difference in temperature distribution intuitively felt by naked eyes, and can quickly determine abnormal points in the chip layout.

[0048] Embodiment 1

[0049] The method for measuring the temperature of an IGBT power module comprises the following steps: 101) Configure single-phase phosphor and determine the doping Tb 3+ The molar percentage and doping Mn 4+ The molar percentage is Na4Mg(WO4)3:0.8Tb 3+ ,0.5%Mn 4+, weigh Na2CO3, MgO, WO3, Tb4O7, and MnO2 respectively according to the molar ratio, and the purity is not less than 99.5%. Grind and mix Na2CO3, MgO, WO3, Tb4O7, and MnO2 evenly, calcine the mixture at 700℃, keep it warm for 16h, cool it to room temperature, and grind it to obtain the mixture. The heating and cooling rates are 5℃ / min; 102) mixing epoxy resin with white inorganic powder to obtain a background coating liquid; mixing epoxy resin with single-phase phosphor to obtain a phosphor coating liquid; 103) coating a background coating liquid on the copper-clad ceramic substrate having a complete circuit to form a background layer; 104) applying the fluorescent powder coating liquid on the white background layer to form a fluorescent layer; 105) After ultraviolet light irradiation, a fluorescence spectrum is obtained, and the height of the 550nm high-energy emission light in the fluorescence spectrum is obtained, which is recorded as I H , the height of the 700nm low-energy emission light in the fluorescence spectrum, denoted as I L According to the formula FIR=I H / I L , obtain the fluorescence intensity ratio, FIR is the fluorescence intensity ratio; 106) According to the fluorescence intensity ratio and the temperature-dependent fluorescence characteristic curve of the single-phase phosphor, as Figure 2 As shown, the corresponding ambient temperature is obtained.

[0050] Specifically, the steps of preparing the single-phase phosphor include: Specifically, the mass ratio of the single-phase phosphor to the epoxy resin in the phosphor coating liquid is 1:1.

[0051] Specifically, the particle size of the single-phase phosphor is less than 10 μm.

[0052] Specifically, the mass ratio of the epoxy resin to the white inorganic material is 1:1.

[0053] Specifically, the white inorganic powder is BaSO4 powder.

[0054] Specifically, the thickness of the fluorescent layer is 0.5 mm.

[0055] Specifically, the white background layer has a thickness of 0.5 mm.

[0056] Specifically, the surface of the fluorescent layer is covered with a protective layer; the protective layer is a transparent epoxy resin, and the protective layer is required to wrap the copper-clad ceramic substrate with a complete circuit without exposing the wires.

[0057] The obtained single-phase phosphor has a main peak of high-energy emission light at 550nm, emitting green light, and a main peak of low-energy emission light at 700nm, emitting deep red light. At room temperature, green and red light coexist, and the visual effect is a composite orange light. As the temperature rises, the proportion of red light gradually decreases, causing the composite light to turn to yellow and green light, which can be used to preliminarily judge temperature changes.

[0058] Get the corresponding ambient temperature. The specific steps are: A01) The prepared fluorescent layer is irradiated with ultraviolet light at 365 nm to obtain a fluorescence spectrum, and the height of the 550 nm high-energy emission light in the fluorescence spectrum is obtained (I H ) and the height of the 700nm low-energy emission light in the fluorescence spectrum (I L ), according to the formula FIR=I H / I L , obtain the fluorescence intensity ratio (FIR), A02) preparing a temperature-dependent fluorescence characteristic curve of a single-phase phosphor, the specific steps comprising obtaining the I H and I L , set the emission intensity at 700nm to 1 at 25℃, and H and I L Based on this, normalization processing is performed (there is no unified standard for fluorescence intensity in different spectral instruments, so normalization data processing is performed to match universality) to obtain the temperature-dependent fluorescence characteristic curve of the single-phase phosphor, such as Figure 2 shown.

[0059] A03) Control Figure 2 ,For example, in the actual test, the FIR value is 0.58, and the corresponding ,ambient temperature is 150 ℃ obtained through the variable temperature ,fluorescence characteristic curve of the single-phase phosphor.

[0060] like Figure 1 As shown, the present invention also provides an IGBT power module packaging structure, including a copper-clad ceramic substrate with a complete circuit, the copper-clad ceramic substrate with a complete circuit is sequentially covered with a background layer 1, a fluorescent layer 2 and a protective layer 3, the copper-clad ceramic substrate with a complete circuit includes an insulating layer 4, a metal layer 5 is provided on the insulating layer, a chip 6 is provided on the metal layer 5, the chip 6 is fixed on the metal layer 5 by solder 8, and also includes a wire 7 for conducting the chip; the background layer 1, the fluorescent layer 2 and the protective layer 3 are obtained by the above-mentioned IGBT power module temperature measurement method.

[0061] The IGBT power module packaging structure of the present invention is no longer limited by the IGBT silicone packaging due to the design of the background layer 1, the fluorescent layer 2 and the protective layer 3. Since ultraviolet light and visible light can completely penetrate the silicone, the optical signal on the module surface can be accurately detected at any time to obtain the temperature value.

[0062] The white inorganic powder in this embodiment is not limited to BaSO4 powder, but can also be TiO2 powder or ZrO2 powder, or a combination of BaSO4 powder, TiO2 powder or ZrO2 powder, or a combination of the three, which can effectively prevent metals such as Cu, Al or other materials in the circuit from interfering with the excitation light / emission light, such as absorption, mirror reflection, and causing errors in the measurement.

[0063] Embodiment 2

[0064] The method for measuring the temperature of an IGBT power module comprises the following steps: 201) Configure single-phase phosphor and determine the doping Tb 3+ The molar percentage and doping Mn 4+ The molar percentage is Na4Mg(WO4)3:0.5Tb 3+ ,0.6%Mn 4+ , weigh Na2CO3, MgO, WO3, Tb4O7, and MnO2 respectively according to the molar ratio, and the purity is not less than 99.5%. Grind and mix Na2CO3, MgO, WO3, Tb4O7, and MnO2 evenly, calcine the mixture at 900℃, keep it warm for 12h, cool it to room temperature, and grind it. The heating and cooling rates are 5℃ / min. Obtain the fluorescence characteristic curve of the single-phase phosphor, such as Figure 2 As shown; 202) mixing epoxy resin with a white organic polymer to obtain a background coating solution; mixing epoxy resin with a single-phase phosphor to obtain a phosphor coating solution; 203) coating a background coating liquid on the copper-clad ceramic substrate having a complete circuit to form a background layer; 204) applying the fluorescent powder coating liquid on the white background layer to form a fluorescent layer; 205) After ultraviolet light irradiation, a fluorescence spectrum was obtained, and the height of the 550nm high-energy emission light in the fluorescence spectrum was obtained, which was recorded as I H , the height of the 700nm low-energy emission light in the fluorescence spectrum, denoted as I L According to the formula FIR=I H / I L , obtain the fluorescence intensity ratio, FIR is the fluorescence intensity ratio; 206) According to the fluorescence intensity ratio and the temperature-sensitive fluorescence characteristic curve of the fluorescent temperature-sensitive material, the corresponding ambient temperature is obtained.

[0065] Specifically, the steps of preparing the single-phase phosphor include: Specifically, the mass ratio of the single-phase phosphor to the epoxy resin in the phosphor coating liquid is 1:1.5.

[0066] Specifically, the particle size of the single-phase phosphor is less than 10 μm.

[0067] Specifically, the mass ratio of the epoxy resin to the white inorganic material is 1:1.5.

[0068] Specifically, the white organic polymer is a silica gel stain.

[0069] Specifically, the thickness of the fluorescent layer is 0.2 mm.

[0070] Specifically, the thickness of the white background layer is 0.2 mm.

[0071] Specifically, the surface of the fluorescent layer is covered with a protective layer; the protective layer is a transparent epoxy resin.

[0072] The obtained single-phase phosphor has a main peak of high-energy emission light at 550nm, emitting green light, and a main peak of low-energy emission light at 700nm, emitting deep red light. At room temperature, green and red light coexist, and the visual effect is a composite orange light. As the temperature rises, the proportion of red light gradually decreases, causing the composite light to turn to yellow and green light, which can be used to preliminarily judge temperature changes.

[0073] To obtain the corresponding ambient temperature, the specific steps are: B01) The prepared fluorescent layer is irradiated with ultraviolet light at 365 nm to obtain a fluorescence spectrum, and the height of the 550 nm high-energy emission light in the fluorescence spectrum is obtained (I H ) and the height of the 700nm low-energy emission light in the fluorescence spectrum (I L ), according to the formula FIR=I H / I L , obtain the fluorescence intensity ratio (FIR), B02) preparing a temperature-dependent fluorescence characteristic curve of a single-phase phosphor, the same as in Example 1; B03) Control Figure 2 ,For example, in the actual test, the FIR value is 0.27, and the corresponding ,ambient temperature is 100 ℃ which can be obtained through the temperature ,fluorescence characteristic curve of the single-phase phosphor.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention 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 replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for measuring the temperature of an IGBT power module, characterized in that: The steps include: Configure a single-phase phosphor, and the chemical composition of the single-phase phosphor is Na4Mg(WO4)3:x%Tb 3+ ,y%Mn 4+ , where x is the molar percentage of doped Tb 3+ , taking 0 < x ≤ 0.1, and y is the molar percentage of doped Mn 4+ , taking 0 < y ≤ 0.1; Mixing epoxy resin with white inorganic powder or white organic polymer to obtain background coating liquid; mixing epoxy resin with single-phase phosphor to obtain phosphor coating liquid; coating a background coating liquid on a copper-clad ceramic substrate having a complete circuit to form a background layer; Applying the fluorescent powder coating liquid on the white background layer to form a fluorescent layer; After ultraviolet light irradiation, the fluorescence spectrum was obtained, and the height of the 550nm high-energy emission light in the fluorescence spectrum was obtained, which was recorded as I H , the height of the 700nm low-energy emission light in the fluorescence spectrum, denoted as I L According to the formula FIR=I H / I L , obtain the fluorescence intensity ratio, FIR is the fluorescence intensity ratio; The corresponding ambient temperature is obtained according to the fluorescence intensity ratio and the temperature-dependent fluorescence characteristic curve of the single-phase phosphor.

2. The IGBT power module temperature measurement method according to claim 1, characterized in that: The steps for preparing single-phase phosphor include: Weigh Na2CO3, MgO, WO3, Tb4O7, and MnO2 respectively according to the molar ratio of the general formula; Grind Na2CO3, MgO, WO3, Tb4O7 and MnO2 and mix them evenly. Heat the mixture at 700-900℃ for 10-16h, cool to room temperature and grind to obtain the product.

3. The IGBT power module temperature measurement method according to claim 1, characterized in that: The mass ratio of the single-phase phosphor to the epoxy resin in the phosphor coating liquid is 1:(1-1.5).

4. The IGBT power module temperature measurement method according to claim 1, characterized in that: The particle size of the single-phase phosphor is less than 10 μm.

5. The IGBT power module temperature measurement method according to claim 1, characterized in that: The mass ratio of epoxy resin to white inorganic material is 1:(1-1.5).

6. The IGBT power module temperature measurement method according to claim 1, characterized in that: The white inorganic powder is at least one of BaSO4 powder, TiO2 powder or ZrO2 powder; the white organic polymer is a silica gel dye.

7. The IGBT power module temperature measurement method according to claim 1, characterized in that: The thickness of the fluorescent layer is 0.2-0.5mm.

8. The IGBT power module temperature measurement method according to claim 1, characterized in that: The thickness of the white background layer is 0.2-0.5mm.

9. The IGBT power module temperature measurement method according to claim 1, characterized in that: The surface of the fluorescent layer is covered with a protective layer; the protective layer is a transparent epoxy resin.

10. An IGBT power module packaging structure, characterized in that: The invention comprises a copper-clad ceramic substrate having a complete circuit, wherein the copper-clad ceramic substrate having a complete circuit is sequentially covered with a background layer (1), a fluorescent layer (2) and a protective layer (3); wherein the background layer (1), the fluorescent layer (2) and the protective layer (3) are obtained based on the IGBT power module temperature measurement method according to any one of claims 1 to 9.

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