High-voltage isolation type temperature sensor packaging structure

Abstract

The utility model provides a high-voltage isolation type temperature sensor packaging structure, and belongs to the technical field of temperature sensors. The packaging structure comprises a ceramic tube shell substrate; the at least one temperature sensor chip is arranged on the ceramic tube shell substrate; the packaging piece is used for packaging the temperature sensor chip on the ceramic tube shell substrate; the at least one heat conduction piece and the at least one electric signal conduction assembly are arranged on the side, away from the temperature sensor chip, of the ceramic tube shell substrate in a spaced mode, heat can be conducted between the heat conduction piece and the temperature sensor chip through the ceramic tube shell substrate, and a first high-voltage isolation gate is formed between the heat conduction piece and the temperature sensor chip. And each temperature sensor chip is electrically connected to one electric signal conduction assembly, and a second high-voltage isolation gate is formed between the heat conduction piece and the electric signal conduction assembly, so that high-voltage isolation packaging of the temperature sensor chips is realized, and the integration level and consistency of the temperature sensor in a high-voltage application scene are improved.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of isolators, thermocouples, and temperature sensors, and particularly relates to a high-voltage isolation type temperature sensor packaging structure. Background Art

[0002] There are various types of temperature sensors, such as thermal resistance type, thermocouple type, semiconductor type, ultrasonic type, and optical type. Among them, thermal resistance type, thermocouple, and semiconductor type account for the largest proportion in the market application. However, the temperature solutions in high-voltage electrical environments, such as in the application of charging piles, are not yet mature. In the charging pile application, devices such as isolated CAN and isolated RS485 are usually used for isolated communication between the charging gun and the charging pile, which can effectively prevent transient voltage changes, electric sparks, etc. from occurring when the charging gun is connected to and disconnected from the vehicle, and provide a reliable bus protection function. Usually, the withstand voltage capacity of isolated bus devices reaches 2500V. There is a temperature sensor at the charging gun to detect the temperature and feedback the signal to the charging pile. To meet the isolation withstand voltage requirement, the temperature sensor usually needs to be kept at a certain distance from the measured temperature point, which will result in inaccurate temperature measurement accuracy, slow temperature response, and a large reserved area for the temperature measurement area.

[0003] The conventional form of a temperature sensor is a temperature measurement probe. To improve the response speed, the temperature measurement probe generally needs to be in contact with the measured point. The temperature measurement probe can be a thermistor, a thermocouple, or a semiconductor temperature measurement device. At the same time, to improve the anti-electricity ability of the temperature measurement probe, an additional insulating coating or insulating protective sleeve is usually required. The product has a large volume, low integration, high production and testing costs, low intelligence, and low withstand voltage.

[0004] The optical non-contact temperature measurement scheme has very good anti-electricity and anti-interference capabilities, but its system is complex, power consumption is large, and the cost is high, which cannot meet the application requirements of large-scale different scenarios.

[0005] In another conventional packaging structure of a temperature sensor chip, the temperature sensor chip is placed on a thermally conductive metal pad, which does not have the function of isolation withstand voltage, nor does it have the safety isolation function for its input and output signal pins or pads. Summary of the Utility Model

[0006] The present disclosure aims to solve at least one of the technical problems existing in the prior art, and provides a high-voltage isolation type temperature sensor packaging structure.

[0007] The present disclosure provides a high-voltage isolation type temperature sensor packaging structure, including:

[0008] A ceramic package base;

[0009] At least one temperature sensor chip, disposed on the ceramic package base;

[0010] A packaging component, used to package the temperature sensor chip in the ceramic tube shell substrate;

[0011] At least one heat conducting element is disposed on a side of the ceramic tube shell substrate away from the temperature sensor chip, and heat can be conducted between the heat conducting element and the temperature sensor chip through the ceramic tube shell substrate, and a first high-voltage isolation grid is formed between the heat conducting element and the temperature sensor chip;

[0012] at least one electrical signal conducting component, each of the temperature sensor chips being electrically connected to one of the electrical signal conducting components;

[0013] The electrical signal conducting component and the heat conducting element are arranged at intervals on a side of the ceramic tube shell substrate away from the temperature sensor chip, and a second high-voltage isolation grid is formed between the heat conducting element and the electrical signal conducting component.

[0014] Optionally, the packaging component is a metal cover plate;

[0015] The metal cover plate is covered on the ceramic tube shell base, and a packaging cavity for accommodating the temperature sensor chip is arranged between the two.

[0016] Optionally, the packaging cavity is a vacuum cavity or a cavity filled with an insulating medium.

[0017] The packaging component is a plastic packaging layer;

[0018] The plastic packaging layer is arranged on the ceramic tube shell base and wraps the temperature sensor chip.

[0019] Optionally, each of the electrical signal conducting components includes at least two electrical signal conducting members.

[0020] Optionally, the heat conduction element and the electrical signal conduction component are metal pins or metal pads.

[0021] Optionally, an analog-to-digital conversion circuit is also integrated in the temperature sensor chip.

[0022] Optionally, a thermally conductive adhesive layer is provided between the temperature sensor chip and the ceramic tube shell substrate.

[0023] Optionally, a lead is provided between the temperature sensor chip and the electrical signal conducting component.

[0024] Optionally, when the package is a metal cover, the lead includes a first lead portion accommodated in the package cavity and a second lead portion penetrating in the ceramic tube shell base or attached to the outer surface of the ceramic tube shell base;

[0025] When the package is a plastic layer, the lead includes a first lead portion inserted in the plastic layer and a second lead portion inserted in the ceramic tube shell base or attached to the outer surface of the ceramic tube shell base;

[0026] One end of the first lead portion is electrically connected to the temperature sensor chip, the other end of the first lead portion is electrically connected to one end of the second lead portion, and the other end of the second lead portion is electrically connected to the electrical signal conducting component.

[0027] The present disclosure proposes a high-voltage isolation type temperature sensor packaging structure, comprising: a ceramic tube shell substrate; at least one temperature sensor chip, which is arranged on the ceramic tube shell substrate; a packaging component, which is used to package the temperature sensor chip in the ceramic tube shell substrate; at least one heat conduction component, which is arranged on the side of the ceramic tube shell substrate away from the temperature sensor chip, and heat can be conducted between the heat conduction component and the temperature sensor chip through the ceramic tube shell substrate, and a first high-voltage isolation grid is formed between the heat conduction component and the temperature sensor chip; at least one electrical signal conduction component, each of the temperature sensor chips is electrically connected to one of the electrical signal conduction components, and the electrical signal conduction component and the heat conduction component are arranged at intervals on the side of the ceramic tube shell substrate away from the temperature sensor chip, and a second high-voltage isolation grid is formed between the heat conduction component and the electrical signal conduction component, thereby realizing high-voltage isolation packaging of the temperature sensor chip and improving the integration and consistency of the temperature sensor in high-voltage application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the packaging structure of a high-voltage isolated temperature sensor according to Embodiment 1 of the present disclosure;

[0029] Figure 2 A schematic diagram of the dielectric distance in the high-voltage isolated temperature sensor packaging structure of Embodiment 1 of the present disclosure;

[0030] Figure 3 It is a schematic diagram of a high-voltage isolated temperature sensor packaging structure according to Embodiment 2 of the present disclosure;

[0031] Figure 4 A schematic diagram of the dielectric distance in the high-voltage isolation temperature sensor packaging structure of Embodiment 2 of the present disclosure;

[0032] Figure 5 It is a schematic diagram of a high-voltage isolated temperature sensor packaging structure according to Embodiment 3 of the present disclosure;

[0033] Figure 6 A schematic diagram of the dielectric distance in the high-voltage isolation temperature sensor packaging structure of Embodiment 3 of the present disclosure;

[0034] Figure 7 Schematic diagram of the integrated structure of the temperature sensor chip in the embodiments of the present disclosure. Specific embodiments

[0035] To enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure, which are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present disclosure.

[0036] In some descriptions of the present disclosure, terms such as "connected", "coupled" or "fixed" and the like do not limit to physical or mechanical connections, but may include electrical connections, whether direct or indirectly through an intermediate medium, which can be the communication inside two components or the interaction relationship between two components.

[0037] As Figures 1 to 7 shown, on one hand of the present disclosure, a high-voltage isolation type temperature sensor packaging structure 100 is proposed, including: a ceramic package substrate 110, at least one temperature sensor chip 120, a package 130, at least one heat conduction member 140, and at least one electrical signal conduction component 150. Among them, the temperature sensor chip 120 is disposed on the ceramic package substrate 110, and the package 130 is used to package the temperature sensor chip 120 on the ceramic package substrate 110; the heat conduction member 140 is disposed on the side of the ceramic package substrate 110 away from the package 130, and heat can be conducted between the heat conduction member 140 and the temperature sensor chip 120 through the ceramic package substrate 110. During use, the heat conduction member 140 is placed in a high-voltage domain, and a first high-voltage isolation barrier is formed between the heat conduction member 140 and the temperature sensor chip 120; the electrical signal conduction component 150 is disposed on the side of the ceramic package substrate 110 away from the temperature sensor chip 120, and the electrical signal conduction component 150 is spaced apart from the heat conduction member 140. At the same time, each temperature sensor chip 120 is electrically connected to an electrical signal conduction component 150 to realize the input and output of electrical signals. During use, the electrical signal conduction component 150 is placed in a low-voltage domain. At this time, a second high-voltage isolation barrier is formed between the electrical signal conduction component 150 and the heat conduction member 140.

[0038] It should be understood that when the high-voltage isolated temperature sensor packaging structure is in use, the heat conduction component is located in a high-voltage electrical environment, while the temperature sensor chip, the electrical signal conduction component, and the area of electrical connection between the two are all located in a low-voltage electrical environment. To ensure that the structures in the low-voltage domain are not broken down by the high voltage in the high-voltage electrical environment, a first high-voltage isolation grid is formed between the heat conduction component and the temperature sensor chip, and a second high-voltage isolation grid is formed between the heat conduction component and the electrical signal conduction component. That is, a high-voltage isolation grid is formed between the high-voltage domain and the low-voltage domain, providing a high level of safety isolation for the electrical signal conduction component and the temperature sensor chip in the low-voltage domain.

[0039] It should be noted that the ceramic package base, as the carrier of the temperature sensor chip, can play a role in supporting and heat conduction. The material used is not specifically limited. For example, it can be alumina, aluminum nitride, silicon nitride, etc., but is not limited to the above materials. It can also be a ceramic package base formed by other materials. Due to the good thermal conductivity of ceramics, it can ensure a good heat transfer path and can also achieve a relatively high isolation withstand voltage.

[0040] Furthermore, it should be noted that the material of the package in this embodiment is not specifically limited either. It can be a metal cover plate or a plastic package, etc., and no specific limitation is made in this regard.

[0041] Exemplarily, as Figure 1 and Figure 3 shown, the package 130 is a metal cover plate, which covers the ceramic package base 110, and an encapsulation cavity for accommodating the temperature sensor chip 120 is provided between the two.

[0042] It should be noted that the position of the encapsulation cavity in this embodiment is not specifically limited. For example, a receiving groove can be provided on the ceramic package base to form the encapsulation cavity, that is, the metal cover plate is flat; for another example, a receiving groove can also be provided on the metal cover plate to form the encapsulation cavity; for still another example, receiving grooves can be provided on both the ceramic package base and the metal cover plate at the same time, and the two receiving grooves are connected to form the encapsulation cavity.

[0043] In some preferred embodiments, as Figure 1 and Figure 3 shown, a first receiving groove is provided on the side of the metal cover plate facing the ceramic package base 110, and a second receiving groove is provided on the side of the ceramic package base 110 facing the metal cover plate. The first receiving groove and the second receiving groove are connected to form the encapsulation cavity.

[0044] As a further preferred solution, as Figure 1 and Figure 3As shown, in the second receiving groove, a stepped portion 111 is further provided on the ceramic package base 110 to increase the creepage distance from the temperature sensor chip 120 to the heat conduction member 140 and improve the withstand voltage performance.

[0045] It should be understood that the encapsulation cavity formed in this embodiment can be sealed or unsealed, as long as the encapsulation of the temperature sensor chip is achieved.

[0046] In some preferred embodiments, as Figure 1 and Figure 3 shown, the cavity of the encapsulation cavity is filled with an insulating medium 131 to form a sealed cavity. Among them, the insulating medium can be nitrogen, epoxy resin, silicone, etc., and no specific limitation is made thereto.

[0047] In some other preferred embodiments, the encapsulation cavity is a vacuum cavity, that is, the inside of the encapsulation cavity is a vacuum environment, and a sealed cavity is also formed.

[0048] As a further preferred solution, after the encapsulation is completed, the metal cover plates are welded together by solder to achieve an airtight effect and improve the reliability of the device.

[0049] Exemplarily, as Figure 5 shown, the encapsulation member 130 is a plastic encapsulation layer, which is provided on the ceramic package base 110 and wraps the temperature sensor chip 120.

[0050] It should still be noted that this embodiment does not specifically limit the types of the heat conduction member and the electrical signal conduction component either. For example, metal pins can be used, or metal pads can be used, etc.

[0051] Exemplarily, as Figure 1 shown, the heat conduction member 140 uses metal pins to play a role in support and heat conduction. At the same time, the electrical signal conduction component 150 also uses metal pins to play a role in support and internal and external electrical signal conduction.

[0052] Exemplarily, as Figure 3 and Figure 5 shown, the heat conduction member 140 uses metal pads to play a role in heat conduction, and the electrical signal conduction component 150 also uses metal pads to play a role in electrical signal conduction, forming a surface mount package structure, which has strong adaptability in different application scenarios.

[0053] It should still be noted that the structure of the electrical signal conduction component is not specifically limited in this embodiment. Generally speaking, each electrical signal conduction component includes at least two electrical signal conductors. For example, one of the electrical signal conductors is an input pin for receiving external signals, and the other electrical signal conductor is an output pin for outputting the signals generated or processed by the chip to the outside. Of course, other pins can also be set according to the design and requirements of the chip to adapt to different application scenarios.

[0054] It should still be noted that the temperature sensor chip and the way it is fixed on the ceramic package substrate are not specifically limited in this embodiment. For example, the temperature sensor chip can be integrated with an analog-to-digital conversion circuit, or integrated with an analog-to-digital conversion circuit, a digital logic control circuit, and a bus interface, etc. In addition, the temperature sensor chip can be bonded to the ceramic package substrate through a bonding material with heat conduction performance.

[0055] Exemplarily, as Figure 7 shown, the temperature sensor chip 120 is integrated with an analog-to-digital conversion circuit, a digital logic control circuit 180, a bus interface 190, etc., so that after the temperature sensor chip 120 is encapsulated, it can transmit digital signals of temperature through a certain bus protocol to realize data exchange between the temperature sensor chip and external devices. Of course, in other preferred embodiments, the temperature sensor chip can only be integrated with an analog-to-digital conversion circuit to convert the analog signal of temperature into a digital signal, so that the temperature digital signal can be read and processed by a digital processing unit or device such as a computer.

[0056] Exemplarily, as Figure 1 、 Figure 3 and Figure 5 shown, a heat-conducting bonding layer 170 is provided between the temperature sensor chip 120 and the ceramic package substrate 110. The material of the heat-conducting bonding layer 170 includes but is not limited to conductive adhesive, sintered silver material, insulating adhesive, and gold-tin solder.

[0057] It should still be noted that the electrical connection method between the temperature sensor chip and the electrical signal conduction component is not specifically limited in this embodiment. For example, the two are electrically connected through leads to form a conductive path.

[0058] In some preferred embodiments, as Figure 1 and Figure 3 shown, when the package 130 is a metal cover plate, the lead includes a first lead portion 161 accommodated in the package cavity and a second lead portion 162 passing through the ceramic package substrate 110; wherein, one end of the first lead portion 161 is electrically connected to the temperature sensor chip 120, the other end of the first lead portion 161 is electrically connected to one end of the second lead portion 162, and the other end of the second lead portion 162 is electrically connected to the electrical signal conduction component 150.

[0059] Certainly, in other preferred embodiments, when the encapsulation is a metal cover plate, the lead can also include a first lead portion accommodated in the encapsulation cavity and a second lead portion attached to the outer surface of the ceramic package substrate. Similarly, one end of the first lead portion is electrically connected to the temperature sensor chip, the other end of the first lead portion is electrically connected to one end of the second lead portion, and the other end of the second lead portion is electrically connected to the electrical signal conduction component.

[0060] In some other preferred embodiments, as Figure 5 shown, when the encapsulation 130 is a plastic encapsulation layer, the lead includes a first lead portion 161 penetrating through the plastic encapsulation layer and a second lead portion 162 penetrating through the ceramic package substrate 110; wherein, one end of the first lead portion 161 is electrically connected to the temperature sensor chip 120, the other end of the first lead portion 161 is electrically connected to one end of the second lead portion 162, and the other end of the second lead portion 162 is electrically connected to the electrical signal conduction component 150.

[0061] Similarly, in other preferred embodiments, when the encapsulation is a plastic encapsulation layer, the lead can also include a first lead portion penetrating through the plastic encapsulation layer and a second lead portion attached to the outer surface of the ceramic package substrate. One end of the first lead portion is electrically connected to the temperature sensor chip, the other end of the first lead portion is electrically connected to one end of the second lead portion, and the other end of the second lead portion is electrically connected to the electrical signal conduction component.

[0062] As a further preferred solution, the first lead portion is an encapsulation bonding wire, which connects the chip bonding pad and the second lead portion bonding pad with a metal wire to ensure good electrical connection and mechanical strength. The second lead portion is a metal trace inside or outside the package, which electrically connects the bonding wire and the electrical signal conduction component.

[0063] It should be noted that the encapsulation of this embodiment is not only used to encapsulate the temperature sensor chip to protect the chip, but also can protect some of the encapsulation bonding wires in the lead to prevent the encapsulation bonding wires from breaking.

[0064] Further, it should be noted that the number of temperature sensor chips, heat conduction components, and electrical signal conduction components in this embodiment is not specifically limited. For example, a packaging structure may include one temperature sensor chip, one heat conduction component, and one electrical signal conduction component. Among them, one electrical signal conduction component includes at least two electrical signal conduction parts. Of course, a packaging structure may also include multiple temperature sensor chips, multiple heat conduction components, and multiple electrical signal conduction components. That is, multiple temperature sensor chips are arranged in a packaging cavity, and multiple heat conduction components and multiple electrical signal conduction components are arranged at intervals on the side of the ceramic package substrate facing away from the temperature sensor chips. Among them, each temperature sensor chip corresponds to one heat conduction component and one electrical signal conduction component, and each electrical signal conduction component includes at least two electrical signal conduction parts. That is to say, each temperature sensor chip corresponds to its own signal input structure and signal output structure to realize the input and output of electrical signals.

[0065] It should be understood that there are multiple possible breakdown withstand voltage paths in the above packaging structure. If the withstand voltage value of one withstand voltage path is lower than the required withstand voltage value of the packaging structure, it will cause withstand voltage breakdown. Therefore, the withstand voltage value of each withstand voltage path needs to meet the requirement of being greater than or equal to the withstand voltage ability that the packaging structure is required to achieve. In other words, the isolation withstand voltage ability of the packaging structure should be determined by the withstand voltage path with the lowest isolation withstand voltage value.

[0066] In this embodiment, in order to ensure that the packaging structure has high withstand voltage characteristics, on the premise that the withstand voltage ability to be achieved by the packaging structure and the materials of each structure are determined, the dielectric distance of each withstand voltage path can be determined based on the withstand voltage ability and the dielectric strength of the material.

[0067] Specifically, in each withstand voltage path, assume that there are n segments of dielectric in the withstand voltage path of the packaging structure, and the dielectric strength of the i-th segment of dielectric is X i , and the dielectric distance is S i , then the relationship between the isolation withstand voltage value on both sides of the device, the intermediate dielectric, and the dielectric distance is as follows: isolation withstand voltage value = X1×S1 + X2×S2 + X3×S3 + … + X n ×S n , that is, the This isolation withstand voltage value needs to be greater than or equal to the withstand voltage ability of the packaging structure.

[0068] It should be understood that when the package has different structures and different materials, the corresponding withstand voltage paths are also different, and thus the dielectric distances in each withstand voltage path are also different.

[0069] In this embodiment, by adopting the IC packaging technology, the temperature sensor core is packaged into a ceramic packaging shell, and a high-voltage isolation grid is integrated through the packaging structure. In a high-voltage electrical environment, electrical isolation is carried out between the temperature electrical signal conduction component and the temperature sensor chip located in the low-voltage domain and the heat conduction component located in the high-voltage domain, ensuring that the temperature electrical signal conduction component and the temperature sensor chip in the low-voltage domain are not affected by the high-voltage domain, protecting the safety of operators and equipment. There is no need to additionally add an insulating coating or insulating protective sleeve, with high integration, which helps to reduce the product volume and lower the production cost.

[0070] The high-voltage isolation type temperature sensor packaging structure will be further described below with specific embodiments:

[0071] Embodiment 1

[0072] As Figure 1 shown, the high-voltage isolation type temperature sensor packaging structure 100 includes: a ceramic tube shell base 110, a temperature sensor chip 120, a packaging component 130, a heat conduction component 140, an electrical signal conduction component 150, a first lead portion 161 and a second lead portion 162, and a thermal conductive adhesive layer 170. Among them, the temperature sensor chip 120 is fixed on the ceramic tube shell base 110 through the thermal conductive adhesive layer 170, and the packaging component 130 packages the temperature sensor chip 120 on the ceramic tube shell base 110. The packaging cavity is filled with an insulating medium 131. The heat conduction component 140 and the electrical signal conduction component 150 are arranged at intervals on the side of the ceramic tube shell base 110 facing away from the packaging component 130. The temperature sensor chip 120 is electrically connected to the electrical signal conduction component 150 through the first lead portion 161 and the second lead portion 162 in sequence.

[0073] Among them, the packaging component uses a metal cover plate, and the insulating medium uses nitrogen. After packaging, the metal cover plate and the ceramic tube shell base are welded together by solder to achieve an airtight effect. By adopting this airtight packaging structure, the reliability of the device can be effectively improved, the speed of water vapor and other gases entering the device interior becomes slower, and the oxidation or corrosion speed of the internal solder joints also becomes slower. The first lead portion uses a bonding wire, and the second lead portion uses a metal trace. The heat conduction component uses a metal pin, which plays a role in support and heat conduction and is located in the high-voltage domain during use. The electrical signal conduction component also uses a metal pin, which plays a role in support and internal and external electrical signal conduction and is located in the low-voltage domain during use. In this way, a first high-voltage isolation grid is formed between the heat conduction component located in the high-voltage domain and the temperature sensor chip located in the low-voltage domain, and a second high-voltage isolation grid is formed between the heat sensing component located in the high-voltage domain and the electrical signal conduction component located in the low-voltage domain.

[0074] It should be noted that the electrical signal conduction component in this Embodiment 1 includes at least two electrical signal conduction parts to achieve the input and output of electrical signals.Figure 1 The schematic diagram only shows one of the electrical signal conductors, and the arrangement and structure of the other electrical signal conductors can be the same as those of the shown electrical signal conductor.

[0075] Specifically, when the application working environment of the packaging structure is an air environment, the air dielectric strength is 2.5 - 4 V / μm, the insulating medium is nitrogen, the dielectric strength of nitrogen is 2.5 - 4 V / μm, the ceramic tube shell substrate is made of aluminum nitride, and the dielectric strength of aluminum nitride is 20 - 30 V / μm. Taking the example of achieving a withstand voltage of 2500 V for the above structure, the dielectric distances on each withstand voltage path need to meet the following physical spacings, as Figure 2 shown:

[0076] S a : The shortest straight air distance between the metal pins on both sides. It should be noted that the creepage path between two conductors is determined by the path with weaker dielectric strength. The dielectric strength of air is lower than that of ceramics, so the medium here is air, and the same applies hereinafter. From this, the minimum value of the distance can be calculated, and thus the preferred value range of S a is 0.8 mm - 15 mm, and 1.5 mm can be preferably selected.

[0077] S b ×2: The shortest creepage distance from the metal pins on both sides along the lower surface of the ceramic tube shell substrate to the metal cover plate, with the medium being air. From this, the minimum value of the distance can be calculated, and thus the preferred value range of S b ×2 is 0.8 mm - 15 mm, and 1.6 mm can be preferably selected, that is, S b is 0.8 mm.

[0078] S c +S b : S c is the shortest distance from the highest point of the bonding wire in the packaging cavity to the metal cover plate, with the medium being nitrogen. However, the dielectric strength of nitrogen is the same as that of air. S b is the shortest distance from the metal pin on the heat conduction part side along the lower surface of the ceramic tube shell substrate to the metal cover plate, with the medium being air and nitrogen. From this, the minimum value of the distance can be calculated, and thus the preferred value range of S c +S b is 0.8 mm - 15 mm, and 1.6 mm can be preferably selected. S b can be preferably 0.8 mm, and S c can be preferably 0.8 mm.

[0079] S d +S b : S d is the shortest distance from the temperature sensor chip to the inner lower edge of the metal cover plate near the heat conduction part side, with the medium being nitrogen. S bis the shortest distance from the metal pin on the side of the heat conduction component to the metal cover plate along the lower surface of the ceramic package base, and the medium is air. From this, the minimum value of the distance can be deduced, and thus S can be obtained. d +S b The preferred value range of is 0.8 mm to 15 mm, and 1.6 mm can be preferably selected. S d 0.8 mm can be preferably selected for S b 0.8 mm can be preferably selected.

[0080] S e : is the shortest distance from the temperature sensor chip to the metal pin on the high-voltage side of the heat conduction component, and the medium is ceramic. From this, the minimum value of the distance can be deduced, and thus S can be obtained. e The preferred value range of is 0.1 mm to 10 mm, and 0.6 mm can be preferably selected.

[0081] Embodiment 2

[0082] As Figure 3 shown, the high-voltage isolation type temperature sensor packaging structure 100 includes: a ceramic package base 110, a temperature sensor chip 120, a packaging component 130, a heat conduction component 140, an electrical signal conduction component 150, a first lead portion 161 and a second lead portion 162, and a heat-conducting adhesive layer 170. The temperature sensor chip 120 is fixed on the ceramic package base 110 through the heat-conducting adhesive layer 170. The packaging component 130 packages the temperature sensor chip 120 on the ceramic package base 110. The packaging cavity is filled with an insulating medium 131. The heat conduction component 140 and the electrical signal conduction component 150 are arranged at intervals on the side of the ceramic package base 110 facing away from the packaging component 130. The temperature sensor chip 120 is electrically connected to the electrical signal conduction component 150 through the first lead portion 161 and the second lead portion 162 in sequence.

[0083] Among them, the packaging component uses a metal cover plate, and the insulating medium uses nitrogen. After packaging, the metal cover plate and the ceramic package base are welded together by solder to achieve an airtight effect, and the same airtight packaging structure as in Embodiment 1 is adopted. The first lead portion uses a bonding wire, and the second lead portion uses a metal trace. The heat conduction component uses a metal pad, which plays a role in heat conduction and is located in the high-voltage domain during use. The electrical signal conduction component also uses a metal pad, which plays a role in conducting internal and external electrical signals and is located in the low-voltage domain during use. In this way, a first high-voltage isolation grid is formed between the heat conduction component located in the high-voltage domain and the temperature sensor chip located in the low-voltage domain, and a second high-voltage isolation grid is formed between the heat sensing component located in the high-voltage domain and the electrical signal conduction component located in the low-voltage domain.

[0084] Similarly, the electrical signal conduction component in this Embodiment 2 should also include at least two electrical signal conduction parts to realize the input and output of electrical signals. Figure 3A schematic diagram showing only one of the electrical signal conductors is presented. The arrangement and structure of the other electrical signal conductors can be the same as those of the shown electrical signal conductor.

[0085] Specifically, when the application working environment of the encapsulation structure is an air environment, the air dielectric strength is 2.5 - 4 V / μm, the insulating medium is nitrogen, the dielectric strength of nitrogen is 2.5 - 4 V / μm, the ceramic package base is made of aluminum nitride, and the dielectric strength of aluminum nitride is 20 - 30 V / μm. Taking the achievement of 2500 V withstand voltage in the above structure as an example, the dielectric distances on each withstand voltage path need to meet the following physical spacings, as Figure 4 shown:

[0086] S a : The shortest straight air distance between the two metal pads on both sides, where the medium is air. From this, the minimum value of its distance can be deduced, and thus the preferred value range of S a is 0.8 mm - 15 mm, and 1.5 mm can be preferably selected.

[0087] S b ×2: The shortest creepage distance from the two metal pads on both sides along the lower surface of the ceramic package base to the metal cover plate, where the medium is air. From this, the minimum value of its distance can be deduced, and thus the preferred value range of S b ×2 is 0.8 mm - 15 mm, and 1.6 mm can be preferably selected, that is, S b is 0.8 mm.

[0088] S c +S b : S c is the shortest distance from the highest point of the bonding wire in the encapsulation cavity to the metal cover plate, where the medium is nitrogen. However, the dielectric strength of nitrogen is the same as that of air. S b is the shortest distance from the metal pad on the heat conduction part side along the lower surface of the ceramic package base to the metal cover plate, where the medium is air and nitrogen. From this, the minimum value of its distance can be deduced, and thus the preferred value range of S c +S b is 0.8 mm - 15 mm, and 1.6 mm can be preferably selected. S b can be preferably 0.8 mm, and S c can be preferably 0.8 mm.

[0089] S d +S b : S d is the shortest distance from the temperature sensor chip to the inner lower edge of the metal cover plate near the heat conduction part side, where the medium is nitrogen. S b is the shortest distance from the metal pad on the heat conduction part side along the lower surface of the ceramic package base to the metal cover plate, where the medium is air. From this, the minimum value of its distance can be deduced, and thus the preferred value range of S d +Sb The preferred value range of is 0.8 mm to 15 mm, and 1.6 mm can be preferably selected, S d 0.8 mm can be preferably selected, S b 0.8 mm can be preferably selected.

[0090] S e : The shortest distance from the temperature sensor chip to the high-voltage side metal pad of the heat conduction component. The medium is ceramic. From this, the minimum value of the distance can be deduced, and thus S can be obtained e The preferred value range of is 0.1 mm to 10 mm, and 0.6 mm can be preferably selected.

[0091] Embodiment 3

[0092] As Figure 5 shown, the high-voltage isolation type temperature sensor packaging structure 100 includes: a ceramic package base 110, a temperature sensor chip 120, a packaging member 130, a heat conduction component 140, an electrical signal conduction assembly 150, a first lead portion 161, a second lead portion 162, and a thermal conductive adhesive layer 170. Among them, the temperature sensor chip 120 is fixed on the ceramic package base 110 through the thermal conductive adhesive layer 170. The packaging member 130 wraps the temperature sensor chip 120 on the ceramic package base 110. The heat conduction component 140 and the electrical signal conduction assembly 150 are arranged at intervals on the side of the ceramic package base 110 facing away from the packaging member 130. The temperature sensor chip 120 is electrically connected to the electrical signal conduction assembly 150 through the first lead portion 161 and the second lead portion 162 in sequence.

[0093] Among them, the packaging member is a plastic encapsulation layer. The first lead portion uses bonding wires, and the second lead portion uses metal traces. The heat conduction component uses a metal pad, which plays a role in heat conduction and is located in the high-voltage domain. The electrical signal conduction assembly also uses a metal pad, which plays a role in conducting internal and external electrical signals and is located in the low-voltage domain. In this way, a first high-voltage isolation grid is formed between the heat conduction component located in the high-voltage domain and the temperature sensor chip located in the low-voltage domain, and a second high-voltage isolation grid is formed between the heat sensing component located in the high-voltage domain and the electrical signal conduction assembly located in the low-voltage domain.

[0094] Similarly, the electrical signal conduction assembly in this Embodiment 3 should also include at least two electrical signal conduction components to achieve the input and output of electrical signals. Figure 5 Only the schematic diagram of one of the electrical signal conduction components is shown in, and the setting method and structure of the other electrical signal conduction components can be the same as those of the shown electrical signal conduction component.

[0095] Specifically, when the working environment of the encapsulation structure is an air environment, the air dielectric strength is 2.5 - 4 V / μm. Taking the ceramic package substrate made of aluminum nitride with a dielectric strength of 20 - 30 V / μm as an example, when achieving a breakdown voltage of 2500 V in the above structure, the following physical distances need to be satisfied for each breakdown voltage path, as Figure 6 shown:

[0096] S a : The shortest straight air distance between the metal pads on both sides, with the medium being air. From this, the minimum distance can be calculated, and thus the preferred value range of S a is 0.8 mm - 15 mm, and 1.5 mm can be preferably selected.

[0097] S f : The minimum thickness of the ceramic package substrate. From this, the minimum value can be calculated, and thus the preferred value range of S f is 0.1 mm - 10 mm, and 0.4 mm can be preferably selected.

[0098] S g : The minimum distance of the temperature sensor chip along the side surface of the ceramic package substrate. From this, the minimum distance can be calculated, and thus the preferred value range of S g is 0.1 mm - 5 mm, and 0.5 mm can be preferably selected.

[0099] S e : The shortest distance from the temperature sensor chip to the high - voltage - side metal pad of the heat conduction component, with the medium being ceramic. From this, the minimum distance can be calculated, and thus the preferred value range of S e is 0.1 mm - 5 mm, and 0.4 mm can be preferably selected.

[0100] It should be noted that the distance between the top of the bonding wire and the plastic encapsulation layer is not considered in this embodiment. The main reason is that for the actual plastic - encapsulated device structure, the thickness of the plastic encapsulant in the longitudinal direction is very thick, and this parameter cannot temporarily become the main factor affecting the breakdown voltage value.

[0101] It should be understood that in this embodiment 1 - 3, only the case where the encapsulation structure achieves a breakdown voltage of 2500 V is taken as an example for illustration. When the isolation breakdown voltage capacity required by the encapsulation structure is different, the design of the dielectric distance in each breakdown voltage path will change accordingly, which will not be listed one by one here.

[0102] It should also be understood that other insulating media, such as epoxy resin or silicone rubber, etc., can also be filled in the encapsulation cavity; and, in other embodiments, the encapsulation cavity can also be a vacuum cavity, that is, the inside of the encapsulation cavity is a vacuum environment; of course, in other embodiments, non-sealing can also be preferably adopted, that is, no insulating medium is filled in the encapsulation cavity, and the air medium is used. When changing the medium of the encapsulation cavity, the dielectric distances in the corresponding voltage-resistant paths also change accordingly, which will not be listed one by one here.

[0103] It should also be understood that the ceramic package substrate can specifically be made of the following materials, for example, alumina, silicon nitride, etc. When the substrate materials are different, the designs of the dielectric distances in the corresponding voltage-resistant paths also change accordingly, which will not be listed one by one here.

[0104] The present disclosure provides a high-voltage isolation type temperature sensor packaging structure, which has the following beneficial effects compared with the prior art:

[0105] First, through the IC packaging technology, the temperature sensor core is packaged into a ceramic package. By designing the dielectric distances in the corresponding voltage-resistant paths, a first high-voltage isolation grid is formed between the heat conduction component in the high-voltage domain and the temperature sensor chip in the low-voltage domain, and a second high-voltage isolation grid is formed between the heat sensing component in the high-voltage domain and the electrical signal conduction component in the low-voltage domain, realizing the high-voltage isolation between the high-voltage domain and the low-voltage domain. There is no need to additionally increase an insulating coating or an insulating protective sleeve, with high integration and small product volume;

[0106] Second, the present disclosure uses a ceramic package substrate as the carrier of the temperature sensor chip, which has good thermal conductivity and can ensure a good heat transfer path while achieving a relatively high isolation breakdown voltage;

[0107] Third, the present disclosure adopts a standard surface mount package, which has strong applicability in different scenarios.

[0108] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present disclosure. However, the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also regarded as the protection scope of the present disclosure.

Claims

1. A high voltage isolated temperature sensor packaging structure, characterized in that: include: Ceramic tube shell substrate; At least one temperature sensor chip is disposed on the ceramic tube shell substrate; A packaging component, used to package the temperature sensor chip in the ceramic tube shell substrate; At least one heat conducting element is disposed on a side of the ceramic tube shell substrate away from the temperature sensor chip, and heat can be conducted between the heat conducting element and the temperature sensor chip through the ceramic tube shell substrate, and a first high-voltage isolation grid is formed between the heat conducting element and the temperature sensor chip; at least one electrical signal conducting component, each of the temperature sensor chips being electrically connected to one of the electrical signal conducting components; The electrical signal conducting component and the heat conducting element are arranged at intervals on a side of the ceramic tube shell substrate away from the temperature sensor chip, and a second high-voltage isolation grid is formed between the heat conducting element and the electrical signal conducting component.

2. The high voltage isolation temperature sensor packaging structure according to claim 1, characterized in that: The packaging component is a metal cover plate; The metal cover plate is covered on the ceramic tube shell base, and a packaging cavity for accommodating the temperature sensor chip is arranged between the two.

3. The high voltage isolation temperature sensor packaging structure according to claim 2, characterized in that: The packaging cavity is a vacuum cavity or a cavity filled with an insulating medium.

4. The high voltage isolation temperature sensor packaging structure according to claim 1, characterized in that: The packaging component is a plastic packaging layer; The plastic packaging layer is arranged on the ceramic tube shell base and wraps the temperature sensor chip.

5. The high voltage isolation temperature sensor packaging structure according to any one of claims 1 to 4, characterized in that: Each of the electrical signal conducting components includes at least two electrical signal conducting members.

6. The high voltage isolation temperature sensor packaging structure according to any one of claims 1 to 4, characterized in that: The heat conducting element and the electrical signal conducting component are metal pins or metal pads.

7. The high voltage isolation temperature sensor packaging structure according to any one of claims 1 to 4, characterized in that: The temperature sensor chip also integrates an analog-to-digital conversion circuit.

8. The high voltage isolation temperature sensor packaging structure according to any one of claims 1 to 4, characterized in that: A heat-conducting bonding layer is arranged between the temperature sensor chip and the ceramic tube shell substrate.

9. The high voltage isolation temperature sensor packaging structure according to any one of claims 2 to 4, characterized in that: A lead is arranged between the temperature sensor chip and the electrical signal conducting component.

10. The high voltage isolation temperature sensor packaging structure according to claim 9, characterized in that: When the package is a metal cover, the lead includes a first lead portion accommodated in the package cavity and a second lead portion penetrating in the ceramic tube shell base or attached to the outer surface of the ceramic tube shell base; When the package is a plastic layer, the lead includes a first lead portion inserted in the plastic layer and a second lead portion inserted in the ceramic tube shell base or attached to the outer surface of the ceramic tube shell base; One end of the first lead portion is electrically connected to the temperature sensor chip, the other end of the first lead portion is electrically connected to one end of the second lead portion, and the other end of the second lead portion is electrically connected to the electrical signal conducting component.

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