Power supply module capable of detecting heating of elements in module

Abstract

The utility model discloses a power supply module capable of detecting heating of elements in the module. The power supply module comprises a chip assembly structure. The thermosensitive layer is coated on the outer surface of the first side of the chip assembly structure; and the encapsulation layer is laid on the outer surface of the first side of the thermosensitive layer, so that both the thermosensitive layer and the chip assembly structure are covered under the encapsulation layer. According to the utility model, the heat-sensitive material is arranged in the whole power supply module, the temperature detection of the surface of the chip assembly structure, including the surface temperature of the materials such as the chip, the bonding wire and the terminal, can be realized by directly utilizing the heat-sensitive layer, the surface temperature of the chip can directly reflect the junction temperature of the chip, and the super junction temperature of the chip is avoided; the surface temperature of the bonding wire, the terminal and the like can directly reflect whether the configuration of the bonding wire and the terminal meets the through-flow requirement or not; in addition, a temperature cloud picture of the module can be generated by utilizing peripheral analysis equipment, an engineer is helped to further optimize a power supply scheme, the analysis equipment does not need to have other requirements, and the requirement for the equipment is low.

Description

Technical Field

[0001] The utility model relates to the technical field of power devices, in particular to a power supply module capable of detecting heating of components in the module. Background Art

[0002] The power module is a type of power module. As a mainstream device of new power semiconductor devices, it has been widely used in strategic emerging industries such as industry, rail transit, new energy, smart grid, and new energy vehicles.

[0003] After the power module is packaged, it is necessary to conduct relevant power-on reliability tests, such as power cycle tests. During the power-on reliability test, the temperature of the chip inside the power module will rise after power is applied. Especially for high-power power modules, if the control is not appropriate, there will be a risk of the chip junction temperature exceeding the specification. In addition, when the bonding wire or terminal configuration or layout inside the power module is unreasonable, the surface temperature of the bonding wire or terminal will also be abnormal (such as local overheating). Therefore, it is of great significance to detect the chip junction temperature and the surface temperature of components such as bonding wires.

[0004] In today's reliability testing or failure analysis of power modules, the ambient temperature is often used to control and monitor the chip junction temperature for low-power modules, while the case temperature is often used to infer the chip junction temperature for high-power modules.

[0005] However, the above method for detecting chip junction temperature has the following defects:

[0006] 1. The chip junction temperature is indirectly detected by ambient temperature or shell temperature. This method has high requirements on the operation of the experimenter. Improper operation may cause the risk of over-junction temperature of the chip, which may easily damage the power module.

[0007] 2. It is impossible to directly grasp the temperature rise of all materials in the power module. For example, it is impossible to improve the heating caused by unreasonable bonding wire or terminal configuration, or the local heat concentration caused by unreasonable chip layout. It is impossible to generate an intuitive temperature cloud map to help engineers further optimize the solution;

[0008] 3. Specialized equipment is required for analysis, which has high requirements and high cost. Utility Model Content

[0009] In view of this, the utility model provides a power module capable of measuring the heating of components within the module, so as to solve the problems brought about by the existing method of indirectly detecting the junction temperature of the chip through the ambient temperature or the shell temperature, such as the chip is prone to over-junction temperature, the internal junction temperature of the chip cannot be directly grasped, the heating conditions of other components within the module cannot be observed, and the high requirements for analysis equipment.

[0010] The utility model provides a power supply module capable of detecting heating of components in the module, comprising:

[0011] Chip assembly structure;

[0012] a heat-sensitive layer coated on the outer surface of the first side of the chip assembly structure; and

[0013] The encapsulation layer is applied on the outer surface of the first side of the heat-sensitive layer, so that the heat-sensitive layer and the chip assembly structure are both covered under the encapsulation layer.

[0014] Optionally, the chip assembly structure includes:

[0015] Base plate;

[0016] A chip assembly is welded to the first side of the base plate; and

[0017] A housing with an opening is provided on the first side of the bottom plate and is arranged opposite to the bottom plate; the position of the opening corresponds to the position of the chip component, and the size of the opening matches the size of the chip component, so that the chip component is just exposed from the opening;

[0018] Wherein, the heat-sensitive layer is coated on the outer surface of the first side of the chip component and the outer surface of the first side of the housing.

[0019] Optionally, the chip assembly includes:

[0020] A ceramic-based copper-clad laminate, soldered to a first side of the base plate by a first solder; and

[0021] The busbar terminal and at least one chip are respectively welded to the first side of the ceramic-based copper-clad laminate through a second solder, and the chips are electrically interconnected with each other and with the busbar terminal through bonding wires.

[0022] Optionally, the material of the bonding wire includes any one of aluminum, copper and gold or any alloy of several of them.

[0023] Optionally, the first solder and the second solder both include any one of tin paste, tin alloy solder and nano silver paste.

[0024] Optionally, the shell is a U-shaped shell, and the bottom of the U-shaped shell is arranged opposite to the bottom plate, and the opening is arranged at the bottom of the U-shaped shell.

[0025] Optionally, the material of the encapsulation layer includes any one of silica gel, epoxy resin, polybutylene phthalate, polyphenylene sulfide, liquid crystal polymer and polyphthalamide.

[0026] Optionally, the material of the potting layer is transparent silicone.

[0027] Optionally, the heat-sensitive layer is made of filler, developer, heat-sensitive agent and stabilizer.

[0028] Optionally, the filler includes polyester resin and acrylic resin; and / or the developer includes lactate dye and water-soluble dye; and / or the thermal sensitizer includes lead oxide and zinc oxide; and / or the stabilizer includes an antioxidant and an ultraviolet absorber.

[0029] The beneficial effects of the utility model are as follows: the chip assembly structure is encapsulated in the encapsulation layer, and the thermistor layer is coated on the outer surface of the first side of the chip assembly structure in the encapsulation layer, and as the chip assembly structure is encapsulated in the encapsulation layer, it is realized that the thermistor material capable of detecting temperature is arranged inside the entire power module; since the chip assembly structure contains the chip, and the thermistor layer is directly coated on the outer surface of the chip assembly structure, the thermistor layer can be directly used to realize the temperature detection on the surface of the chip assembly structure, including the temperature detection on the surface of materials such as the chip, bonding wires, and terminals; based on the detection of the chip surface temperature, the junction temperature of the chip is directly reflected, and the chip temperature can be better monitored to avoid the occurrence of chip over-junction temperature; based on the surface temperature of the bonding wires and terminals, it can be directly reflected whether the bonding wire and terminal configurations meet the current requirements to avoid local heat concentration inside the module; at the same time, the peripheral analysis equipment can be used to generate a temperature cloud map of the chip junction temperature to help engineers further optimize the power supply solution, and the analysis equipment does not need to have other requirements, and the equipment requirements are relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0031] Figure 1 A cross-sectional structural diagram of a power module capable of detecting heating of components within the module in an embodiment of the utility model is shown;

[0032] Figure 2 It shows a cross-sectional structural diagram of a chip assembly structure in an embodiment of the present utility model;

[0033] Figure 3 The cross-sectional structure diagram of the housing in the embodiment of the utility model is shown;

[0034] Figure 4 It shows a cross-sectional structural diagram of a chip assembly structure with a heat-sensitive layer formed on the outer surface in an embodiment of the utility model;

[0035] Figure 5 The complete cross-sectional structure diagram of the power module in the embodiment of the utility model is shown.

[0036] Description of reference numerals:

[0037] 1. Chip assembly structure, 2. Thermistor layer, 3. Potting layer, 11. Base plate, 12. Chip assembly, 13. Housing, 121. Ceramic-based copper-clad laminate, 122. First solder, 123. Busbar terminal, 124. Chip, 125. Second solder, 126. Bonding wire, 131. Opening. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0039] Example

[0040] A power module capable of detecting chip junction temperature, such as Figures 1 to 5 As shown, including:

[0041] Chip assembly structure 1;

[0042] A heat-sensitive layer 2 is coated on the outer surface of the first side of the chip assembly structure 1; and

[0043] The encapsulation layer 3 is applied on the outer surface of the first side of the heat-sensitive layer 2 , so that the heat-sensitive layer 2 and the chip assembly structure 1 are both covered in the encapsulation layer 3 .

[0044] In this embodiment, the chip assembly structure is encapsulated in the encapsulation layer, and the thermistor layer is coated on the outer surface of the first side of the chip assembly structure in the encapsulation layer. As the chip assembly structure is encapsulated in the encapsulation layer, a thermistor material capable of detecting temperature is arranged inside the entire power module. Since the chip assembly structure contains a chip and the thermistor layer is directly coated on the outer surface of the chip assembly structure, the thermistor layer can be directly used to detect the temperature of the surface of the chip assembly structure, including the temperature detection of the surface of materials such as the chip, bonding wires, and terminals. Based on the detection of the chip surface temperature, the junction temperature of the chip is directly reflected, and the chip temperature can be better monitored to avoid chip over-junction temperature. Based on the surface temperature of the bonding wires and terminals, it can be directly reflected whether the bonding wire and terminal configurations meet the current requirements to avoid local heat concentration inside the module. At the same time, peripheral analysis equipment can be used to generate a temperature cloud map of the chip junction temperature to help engineers further optimize the power supply solution. The analysis equipment does not need to have other requirements and has low equipment requirements.

[0045] Specifically, for Figure 1 In the power module shown, the upper side of the entire power module is the first side, and the lower side is the second side.

[0046] In this embodiment, the material of the encapsulation layer 3 includes any one of silica gel, epoxy resin, polybutylene terephthalate, polyphenylene sulfide, liquid crystal polymer and polyphthalamide.

[0047] The potting layer of the above materials can provide better isolation and protection for the entire power module.

[0048] Preferably, the material of the potting layer 3 is transparent silica gel.

[0049] The potting layer of the above material makes it easy to set a device, such as a camera, that can collect the temperature of the chip junction using the thermistor layer directly above the entire power module, so as to more intuitively grasp the chip junction temperature.

[0050] When the camera is set, the camera is located directly above the entire power module (i.e., directly above the first side). Furthermore, the camera is located directly above the chip assembly structure in the power module, and can directly capture the color change image of the thermosensitive material on the surface of the chip assembly structure. The color change image can generate a temperature distribution cloud map, thereby intuitively grasping the chip junction temperature and the surface temperature of the bonding wire, bus terminal, etc.

[0051] In this embodiment, the heat-sensitive layer 2 is made of filler, developer, heat-sensitive agent and stabilizer.

[0052] Among the above materials, the filler, as the base material of the entire thermal layer, has good adhesion and wear resistance, can effectively fix other additives, and has a certain transparency, which is beneficial to the color development effect of the color developer; the color developer determines the color development effect of the entire thermal layer under heat; the thermosensitive agent refers to a substance that releases heat energy under heat, and it is the key to the color development effect of the entire thermal layer; the stabilizer is an additive used to improve the stability and aging resistance of the entire thermal layer. The stabilizer can effectively extend the service life of the thermal layer and improve its weather resistance and durability.

[0053] Furthermore, the filler includes polyester resin and acrylic resin; and / or the developer includes lactate dye and water-soluble dye; and / or the thermal sensitizer includes lead oxide and zinc oxide; and / or the stabilizer includes antioxidant and ultraviolet absorber.

[0054] Through the thermal sensitive layer of the above material, it can be better distributed on the surface of the chip assembly structure, thereby more accurately detecting the temperature of the chips and other components (such as bonding wires) inside the power module with high reliability.

[0055] In actual operation, the thermal layer is formed on the outer surface of the chip assembly structure by coating or spraying; the coating or spraying process and the potting process of the potting layer all adopt conventional operation methods, and the specific details are not repeated here.

[0056] Preferably, if Figures 2 to 5 As shown, the chip assembly structure 1 includes:

[0057] Bottom plate 11;

[0058] A chip assembly 12 is welded to the first side of the base plate 11; and

[0059] The housing 13 is provided with an opening 131, which is disposed on a first side of the bottom plate 11 and is arranged opposite to the bottom plate 11; the position of the opening 131 corresponds to the position of the chip assembly 12, and the size of the opening 131 matches the size of the chip assembly 12, so that the chip assembly 12 is just exposed from the opening 131;

[0060] The outer surface of the first side of the chip assembly 12 and the outer surface of the first side of the housing 13 are both coated with the thermosensitive layer 2 .

[0061] The chip assembly structure of the above structure is convenient for forming a packaging structure of the power module to ensure its functionality, and is convenient for forming a thermistor layer to realize direct detection of chip junction temperature and surface temperature of bonding wires, bus terminals, etc.

[0062] Furthermore, if Figures 2 to 5 As shown, the chip assembly 12 includes:

[0063] A ceramic-based copper-clad laminate 121 is welded to a first side of the base plate 11 by a first solder 122; and

[0064] The bus terminal 123 and at least one chip 124 are respectively welded to the first side of the ceramic-based copper-clad laminate 121 through a second solder 125 , and the chips 124 are electrically interconnected with each other and with the bus terminal 123 through bonding wires 126 .

[0065] The chip assembly of the above structure can better achieve electrical conduction between chips and between chips and bus terminals, ensuring that the chips and bus terminals each achieve their own functions, thereby forming a power module of excellent quality.

[0066] In this embodiment, the material of the bonding wire 126 includes any one of aluminum, copper and gold or any alloy of several of them.

[0067] The bonding wires made of the above materials can ensure good electrical conduction between chips and between chips and bus terminals, thereby ensuring the functionality of the entire power module.

[0068] In this embodiment, the first solder 122 and the second solder 125 both include any one of tin paste, tin alloy solder and nano silver paste.

[0069] The first solder and the second solder of the above material have the advantages of high-temperature oxidation resistance, good solderability, strong corrosion resistance and good stability. They can achieve better welding effects between the chip and the ceramic copper-clad substrate, between the bus terminal and the ceramic copper-clad substrate, and between the ceramic copper-clad substrate and the base plate, and on the basis of ensuring the product quality of the entire power module, realize direct detection of the chip junction temperature and the surface temperature of the bonding wire, bus terminal, etc.

[0070] Preferably, if Figures 2 to 5 As shown, the housing 13 is a U-shaped housing, and the bottom of the U-shaped housing is arranged opposite to the bottom plate 11, and the opening 131 is arranged at the bottom of the U-shaped housing.

[0071] The above-mentioned U-shaped shell can more conveniently form a thermistor layer and a filling and encapsulation layer, thereby improving process efficiency and process quality. It is convenient to set a thermistor layer that can detect the surface temperature of the component inside the module, thereby realizing direct detection of the chip junction temperature and the surface temperature of the bonding wire, bus terminal, etc., and can also provide better isolation and protection for the internal structure of the entire power module.

[0072] This embodiment Figure 5 The process flow of the power module shown is as follows:

[0073] Step 1: Provide chip assembly structure, such as Figure 2 As shown, the chip assembly structure is assembled using a conventional packaging process, and the specific details are not repeated here.

[0074] Step 2: Make a heat-sensitive layer on the upper surface of the chip assembly structure by coating or spraying, such as Figure 4 shown.

[0075] Step 3: Fill the upper surface of the thermal layer with a potting layer (such as transparent silicone) to form a power module, such as Figure 5 shown.

[0076] When formed Figure 5 After the power module is installed, the power module is powered on for testing. A camera is set just above the module to capture the color-changing image of the thermistor layer in the module. A temperature distribution cloud map is formed based on the color-changing image, and the junction temperature of the chip and the surface temperature of other components (including bonding wires and busbar terminals, etc.) are intuitively monitored respectively.

[0077] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A power module capable of detecting heating of components within the module, characterized in that: include: Chip assembly structure; A heat-sensitive layer is coated on the outer surface of the first side of the chip assembly structure; as well as The encapsulation layer is applied on the outer surface of the first side of the heat-sensitive layer, so that the heat-sensitive layer and the chip assembly structure are both covered under the encapsulation layer.

2. The power module according to claim 1, characterized in that: The chip assembly structure comprises: Base plate; A chip assembly is welded to the first side of the base plate; and A housing with an opening is provided on the first side of the bottom plate and is arranged opposite to the bottom plate; the position of the opening corresponds to the position of the chip component, and the size of the opening matches the size of the chip component, so that the chip component is just exposed from the opening; Wherein, the heat-sensitive layer is coated on the outer surface of the first side of the chip component and the outer surface of the first side of the housing.

3. The power module according to claim 2, characterized in that: The chip assembly comprises: A ceramic-based copper-clad laminate, soldered to a first side of the base plate by a first solder; and The busbar terminal and at least one chip are respectively welded to the first side of the ceramic-based copper-clad laminate through a second solder, and the chips are electrically interconnected with each other and with the busbar terminal through bonding wires.

4. The power module according to claim 3, characterized in that: The first solder and the second solder each include any one of tin paste, tin alloy solder and nano silver paste.

5. The power module according to claim 2, characterized in that: The shell is a U-shaped shell, and the bottom of the U-shaped shell is arranged opposite to the bottom plate, and the opening is arranged at the bottom of the U-shaped shell.

6. The power module according to claim 1, characterized in that: The material of the encapsulation layer includes any one of silica gel, epoxy resin, polybutylene phthalate, polyphenylene sulfide, liquid crystal polymer and polyphthalamide.

7. The power module according to claim 6, characterized in that: The material of the potting layer is specifically transparent silica gel.

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