Packaging structure and packaging structure array of absolute pressure sensor

Abstract

The utility model provides a packaging structure of an absolute pressure sensor and a packaging structure array. The packaging structure comprises a substrate element; a strain gauge element; the first sealing layer is arranged between the substrate element and the strain gauge element, so that a first closed cavity is enclosed by the first sealing layer, the substrate element and the strain gauge element; the second sealing layer is arranged between the substrate element and the strain gauge element, so that a second closed cavity is defined by the second sealing layer, the substrate element and the strain gauge element, and the second sealing layer is arranged between the substrate element and the strain gauge element. The second sealing layer is disposed radially outward of the first sealing layer and spaced apart from the first sealing layer.

Description

Technical Field

[0001] The present disclosure relates to the field of sensor technology, and in particular to a packaging structure and a packaging structure array of an absolute pressure sensor. Background Art

[0002] Absolute pressure sensor is a sensor that converts pressure signal into electrical signal. It is widely used in industrial automation, medical equipment, automotive industry and other fields. Its core function is to accurately detect and convert pressure signal to achieve monitoring and control of system or process. In these applications, the sealing performance of absolute pressure sensor is crucial because it directly affects the stability, reliability and measurement accuracy of the sensor. If the sealing performance is insufficient, external environmental factors such as humidity, temperature fluctuations or chemical media may penetrate into the sensor, resulting in measurement errors or even equipment damage.

[0003] Existing absolute pressure sensors usually consist of a pressure sensitive element and a signal processing unit. The pressure sensitive element is responsible for converting the sensed pressure into a measurable change in physical quantity, such as a change in resistance or capacitance. The signal processing unit converts these physical quantity changes into electrical signal outputs. During the manufacturing process, the pressure sensitive element and the signal processing unit are encapsulated in a protective housing to ensure that they are protected from the external environment. Packaging technology is one of the key steps in the production of existing absolute pressure sensors. Traditionally, two pieces of ceramic are used to form a closed air pressure system through printing, sintering, and packaging with glass slurry. This packaging method can protect the internal components to a certain extent, but it also brings some structural challenges. For example, the packaging glass slurry has very high requirements for pattern design and process control, and problems such as poor sealing and pad coverage may occur during the sintering process.

[0004] Although existing absolute pressure sensors have shown good performance in many applications, they still have some technical problems in terms of sealing performance. First, due to the limitations of packaging materials and processes, existing sealing structures may not provide sufficient sealing performance, causing the sensor to be easily damaged in harsh environments. Secondly, the glass slurry used in the packaging process may develop tiny cracks after curing, which will reduce the sealing performance and affect the long-term stability of the sensor. In addition, existing packaging technology also has limitations in production efficiency and assembly accuracy. Complex pattern design and process control requirements make the production process cumbersome, increasing manufacturing costs and time. At the same time, the glass slurry may cover the electrical connection pads during the sintering process, affecting the transmission stability and linearity of the electrical signal, and thus affecting the measurement accuracy of the sensor. Utility Model Content

[0005] In order to solve the above technical problems, the embodiments of the present disclosure hope to provide a packaging structure and a packaging structure array of an absolute pressure sensor, so that the sealing performance is improved, which is of great significance for improving the overall performance and reliability of the sensor.

[0006] The technical solution of the present disclosure is achieved as follows:

[0007] In a first aspect, an embodiment of the present disclosure provides a packaging structure of an absolute pressure sensor, the packaging structure comprising:

[0008] substrate components;

[0009] Strain gauge elements;

[0010] a first annular sealing layer, wherein the first sealing layer is disposed between the substrate element and the strain gauge element so as to enclose a first closed cavity together with the substrate element and the strain gauge element; and

[0011] a second annular sealing layer, wherein the second sealing layer is disposed between the substrate element and the strain gauge element so as to enclose a second closed cavity together with the substrate element and the strain gauge element;

[0012] The second sealing layer is arranged radially outside the first sealing layer and is spaced apart from the first sealing layer.

[0013] In a second aspect, an embodiment of the present disclosure provides a packaging structure array of an absolute pressure sensor, wherein the packaging structure array is composed of a plurality of packaging structures according to the first aspect, wherein the corresponding plurality of substrate elements of the plurality of packaging structures are composed of a single substrate, so that the sealing material can be printed on each substrate element by a single printing, and the corresponding plurality of strain gauge elements of the plurality of packaging structures are composed of a single strain gauge, so that the sealing material can be printed on each strain gauge element by a single printing.

[0014] The disclosed embodiments provide a packaging structure and a packaging structure array of an absolute pressure sensor, wherein a first sealing layer is in direct contact with a substrate element and a strain gauge element to form a first closed cavity, thereby providing preliminary sealing protection for internal elements; a second annular sealing layer is arranged radially outside the first sealing layer, and a gap is formed between the two, thereby providing additional sealing protection for internal elements, or providing double-layer sealing protection, so that elements requiring absolute pressure, such as resistors or capacitor thick films in strain gauge elements, can be placed in a stable environment, thereby ensuring accurate measurement of the sensor in various application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic cross-sectional view of a packaging structure of an absolute pressure sensor according to an embodiment of the present disclosure;

[0016] Figure 2 is a schematic top view of a packaging structure of an absolute pressure sensor according to an embodiment of the present disclosure, wherein: Figure 1 The substrate elements shown are removed;

[0017] Figure 3 is a schematic top view of a substrate element and a pattern printed on the substrate element according to an embodiment of the present disclosure;

[0018] Figure 4 is a schematic top view of a strain gauge element and a pattern printed on the strain gauge element according to an embodiment of the present disclosure;

[0019] Figure 5 is a schematic top view of a substrate element and a pattern printed on the substrate element according to another embodiment of the present disclosure;

[0020] Figure 6 is a schematic top view of a strain gauge element and a pattern printed on the strain gauge element according to another embodiment of the present disclosure;

[0021] Figure 7 is a schematic top view of a packaging structure array of an absolute pressure sensor according to an embodiment of the present disclosure, wherein one side of a substrate element is shown;

[0022] Figure 8 A schematic top view of a single substrate of a packaging structure array of an absolute pressure sensor according to an embodiment of the present disclosure and a pattern printed on the single substrate;

[0023] Fig. 9 Schematic diagram of a top view of a single strain gauge of a packaging structure array of an absolute pressure sensor according to an embodiment of the present disclosure and a pattern printed on the single strain gauge. DETAILED DESCRIPTION

[0024] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0025] As a precision measuring tool, the performance and reliability of the absolute pressure sensor depend to a large extent on its packaging technology. In the prior art, the absolute pressure sensor generally adopts a structure composed of a pressure sensitive element and a signal processing unit, and protects these sensitive elements in a closed environment through packaging technology. However, the existing packaging methods, especially the packaging process using glass paste, can protect the internal components of the sensor to a certain extent, but there are also some problems that cannot be ignored. First, the high process control requirements of the encapsulated glass paste make the production process complicated and costly. The accuracy of the pattern design and the strict control during the sintering process are crucial to ensure the consistency and reliability of the final product. In addition, the poor sealing and pad coverage problems that may occur during the sintering process not only affect the electrical performance of the sensor, but also reduce its stability and durability in harsh environments. Secondly, the existing packaging materials may form tiny cracks after curing, and these cracks may expand over time and changes in the environment, thereby further reducing the sealing performance of the sensor. This not only affects the measurement accuracy of the sensor, but also shortens its service life, especially in application scenarios that require long-term stable operation. This problem is particularly prominent.

[0026] Regarding the above limitations of the prior art, see Figure 1 and Figure 2 The present disclosure provides a packaging structure 10 of an absolute pressure sensor, and the packaging structure 10 may include:

[0027] A substrate element 100;

[0028] Strain gauge element 200;

[0029] a first annular sealing layer 300 , which is disposed between the substrate element 100 and the strain gauge element 200 , so as to enclose a first closed cavity C1 together with the substrate element 100 and the strain gauge element 200 ; and

[0030] The second sealing layer 400 is annular and is disposed between the substrate element 100 and the strain gauge element 200 so as to enclose a second closed cavity C2 together with the substrate element 100 and the strain gauge element 200.

[0031] Among them, as in Figure 2 As can be more intuitively seen in FIG. 1 , the second sealing layer 400 is disposed radially outside the first sealing layer 300 and is spaced apart from the first sealing layer 300, that is, a gap G is formed between the first sealing layer 300 and the second sealing layer 400. In addition, in this case, as shown in FIG. Figure 1 It is easy to understand that the second closed cavity C2 is larger in volume than the first closed cavity C2, and seals the first sealing layer 300 and the first closed cavity C2.

[0032] In this way, the elements (not shown in the drawings) that require absolute pressure, such as resistors or capacitor thick films, of the strain gauge element 200 of the absolute pressure sensor can be arranged inside the first closed cavity C1, thereby achieving absolute pressure.

[0033] The packaging structure 10 disclosed in the present invention significantly improves the sealing reliability of the absolute pressure sensor by adopting the annular first sealing layer 300 and the second sealing layer 400. Specifically, the first sealing layer 300 directly contacts the substrate element 100 and the strain gauge element 200 to form a first closed cavity C1, which provides preliminary sealing protection for the internal elements. The annular second sealing layer 400 is arranged radially outside the first sealing layer 300, and a gap G is formed between the two, thereby providing additional sealing protection for the internal elements, or providing double-layer sealing protection, and the resistor or capacitor thick film in the strain gauge element 200 and other elements that require absolute pressure can be placed in a stable environment, ensuring the accurate measurement of the sensor in various application scenarios.

[0034] In an example according to the present disclosure, the first sealing layer 300 can be obtained by a sealing material printed on the substrate element 100 and a sealing material printed on the strain gauge element 200, and the second sealing layer 400 can be obtained by a sealing material printed on the substrate element 100 and a sealing material printed on the strain gauge element 200.

[0035] For example, the sealing material here can be glass paste. In addition, the glass paste can form a glass sealing layer through the first sintering and bonded to the substrate element 100 or the strain gauge element 200, and the glass sealing layer bonded to the substrate element 100 and the glass sealing layer bonded to the strain gauge element 200 can be bonded to each other through the second sintering.

[0036] In this way, for example, the second sintering mentioned above realizes the bonding between the glass sealing layers, so that a better sealing effect can be obtained. If, on the contrary, only the glass paste is printed on the substrate element 100 to obtain the first sealing layer 300 and the second sealing layer 400, the second sintering mentioned above realizes the bonding between the glass sealing layer and the strain gauge element 200, and the sealing effect will be poor.

[0037] In an example according to the present disclosure, see Figure 3 The sealing material printed on the substrate element 100 and used to obtain the first sealing layer 300 can be formed into a first annular pattern 310, and the sealing material printed on the substrate element 100 and used to obtain the second sealing layer 400 can be formed into a second annular pattern 410, and the width of the second annular pattern 410 can be greater than the width of the first annular pattern 310, see Figure 4The sealing material printed on the strain gauge element 200 and used to obtain the first sealing layer 300 can be formed into a third circular ring-shaped pattern 320, and the sealing material printed on the strain gauge element 200 and used to obtain the second sealing layer 400 can be formed into a fourth circular ring-shaped pattern 420. The width of the fourth circular ring-shaped pattern 420 can be greater than the width of the third circular ring-shaped pattern 320, where the width refers to half of the difference between the inner diameter and the outer diameter of the circular ring-shaped pattern.

[0038] In the above example, the larger outer ring width can provide a larger contact area and better adhesion, which helps to improve the bonding stability between the substrate element 100 and the strain gauge element 200, thereby ensuring sealing. In addition, the larger outer ring width can better withstand the mechanical stress imposed by the external environment, while the smaller inner ring width reduces the pressure on the sealed element, thereby protecting the sealed element from damage. In addition, the larger outer ring width can form a stronger sealing edge, which helps to prevent gas or liquid penetration.

[0039] In an example according to the present disclosure, see Figure 5 The second annular pattern 410 may be formed with a first pad hole 411, see Figure 6 The fourth annular pattern 420 may be formed with a second pad hole 421 , and both the first pad hole 411 and the second pad hole 421 are used to allow an electrical connection pad (not shown in the drawings) of the thick film circuit of the strain gauge element 200 to pass through.

[0040] In the above example, by setting the first pad hole 411 in the second circular pattern 410 and the second pad hole 421 in the fourth circular pattern 420, the risk of the electrical connection pad on the strain gauge element 200 being covered during the printing of the sealing material is effectively avoided, ensuring the exposure of the electrical connection pad, thereby ensuring unobstructed electrical connection.

[0041] For example, for a resistive absolute pressure sensor, the number of the first pad hole 411 and the second pad hole 421 can be 4, and for a capacitive absolute pressure sensor, the number of the first pad hole 411 and the second pad hole 421 can be 3.

[0042] In an example according to the present disclosure, see Figure 5 The second annular pattern 410 may be formed with a first hollow region 412, and the first hollow region 412 is used to achieve debinding during the process of sintering the second annular pattern 410 to the substrate element 100, see Figure 6 The fourth annular pattern 420 may be formed with a second hollow area 422 , and the second hollow area 422 is used to achieve binder removal during the process of sintering the fourth annular pattern 420 to the strain gauge element 200 .

[0043] Debinding refers to the process of removing excess adhesive or impurities from the sealing material through a specific designed structure (such as a hollow area) during the sintering process to ensure that the sealing layer after sintering has a uniform and dense structure. In the present disclosure, the first hollow area 412 and the second hollow area 422 are specifically designed to achieve this purpose. The debinding function achieved by the first hollow area 412 and the second hollow area 422 helps to remove the gas and liquid adhesive in the second circular ring pattern 410 and the fourth circular ring pattern 420 during the sintering process. This process can reduce holes and cracks in the sealing layer, thereby improving the density and uniformity of the sintered material.

[0044] In an example according to the present disclosure, see Figure 5 and Figure 6 The first circular pattern 310, the second circular pattern 410, the third circular pattern 320 and the fourth circular pattern 420 can all be composed of band stripes, the width of the band stripes constituting the third circular pattern 320 can be greater than the width of the band stripes constituting the first circular pattern 310, and the width of the band stripes constituting the fourth circular pattern 420 can be greater than the width of the band stripes constituting the second circular pattern 410.

[0045] In this way, it is ensured that when the first annular pattern 310 and the second annular pattern 410 on the substrate element 100 are bonded with the third annular pattern 320 and the fourth annular pattern 420 on the strain gauge element 200, a misalignment tolerance is left, thereby ensuring the reliability of the obtained first sealing layer 300 and the second sealing layer 400.

[0046] In an example according to the present disclosure, as in Figure 2 and Figure 3 As shown in FIG. 1 , the length L and width W of the strain gauge element 200 and the substrate element 100 may be not less than 13.1 mm. Figure 1 As shown in FIG. 1 , the thickness T of the package structure 10 may be no less than 2 mm.

[0047] Increasing the size of the component can provide a larger contact area and stronger structural stability during the packaging process, thereby reducing the risk of sensor performance degradation or damage due to improper packaging. The larger size provides a larger surface area for the sealing layer, which helps to achieve a more uniform and reliable seal, reduce the possibility of gas or liquid penetration, and ensure the measurement accuracy of the sensor in harsh environments. The larger size means that the strain gauge element and substrate have higher mechanical strength, can withstand greater mechanical stress, and reduce damage caused by vibration or impact.

[0048] See also Figure 7The present disclosure also provides a packaging structure array 1, which can be composed of a plurality of packaging structures 10 of absolute pressure sensors according to the above embodiments of the present disclosure, wherein, see Figure 8 , the corresponding plurality of substrate elements 100 of the plurality of package structures 10 may be formed by a single substrate 20, so that the sealing material is printed on each substrate element 100 by a single printing, see Fig. 9 The corresponding plurality of strain gauge elements 200 of the plurality of package structures 10 may be formed by a single strain gauge 30 , so that the sealing material can be printed on each strain gauge element 200 by a single printing.

[0049] By using a single substrate 20 and a single strain gauge 30, the present disclosure allows sealing materials to be printed simultaneously on multiple substrate elements 100 and multiple strain gauge elements 200 in a single printing process, significantly improving the batch efficiency of printing. In addition, the present disclosure achieves sealing material coverage of multiple elements through a single printing, which simplifies the printing process and reduces the production steps. Finally, the single printing process ensures that the sealing materials on all substrate elements 100 and strain gauge elements 200 have highly consistent thickness and distribution, which is crucial to maintaining the consistency of sensor performance.

[0050] In an example according to the present disclosure, both the number of rows and the number of columns of the package structures 10 in the package structure array 1 may be no less than three.

[0051] In an example according to the present disclosure, see Figure 7 A pre-cut groove 21 may be formed on a single substrate 20 , so as to separate a single package structure 10 from the package structure array 1 along the pre-cut groove 21 .

[0052] The package structure array 1 is designed with pre-cut grooves 21 on a single substrate 20, allowing a single package structure 10 to be separated by mechanical cutting or manual separation. This design provides two flexible separation options to adapt to different production needs and conditions. The presence of the pre-cut grooves 21 simplifies the separation process of the package structure. Whether mechanical cutting or manual separation is used, a single package structure can be quickly separated from the package structure array 1, thereby improving production efficiency. The manual separation method reduces the reliance on complex mechanical equipment and reduces the cost required in the separation process, which is more economical, especially in small-batch production or rapid prototyping.

[0053] In an example according to the present disclosure, the single substrate 20 and the single strain gauge 30 may be combined together through a sintering process, and during the sintering process, the single substrate 20 may be located above the single strain gauge 30 so as to perform the sintering process in a weightless manner.

[0054] The present invention places a single substrate 20 on top of a single strain gauge 30 for sintering, and uses the weight of the single substrate 20 itself to apply natural pressure without the need for additional counterweights or pressure equipment. This method reduces the external equipment and materials required in the sintering process, thereby improving the sintering efficiency. The sintering method without counterweights simplifies the entire sintering process. In addition, since no complex pressure control and counterweight systems are required, the sintering process becomes more direct and easier to operate, reducing the complexity of the process. The simplified sintering process reduces the need for specialized equipment and materials, thereby reducing production costs and making large-scale production more economical and efficient. Finally, due to the simplification of the sintering process, the production cycle is shortened, and the simplified steps reduce waiting and adjustment time, making the production process faster.

[0055] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present disclosure should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A packaging structure of an absolute pressure sensor, characterized in that: The packaging structure comprises: substrate components; Strain gauge elements; a first annular sealing layer, wherein the first sealing layer is disposed between the substrate element and the strain gauge element so as to enclose a first closed cavity together with the substrate element and the strain gauge element; and a second annular sealing layer, wherein the second sealing layer is disposed between the substrate element and the strain gauge element so as to enclose a second closed cavity together with the substrate element and the strain gauge element; The second sealing layer is arranged radially outside the first sealing layer and is spaced apart from the first sealing layer.

2. The packaging structure of the absolute pressure sensor according to claim 1, characterized in that: The first sealing layer is obtained by printing a sealing material on the substrate element and a sealing material on the strain gauge element, and the second sealing layer is obtained by printing a sealing material on the substrate element and a sealing material on the strain gauge element.

3. The packaging structure of the absolute pressure sensor according to claim 2, characterized in that: The sealing material printed on the substrate element and used to obtain the first sealing layer is formed into a first annular pattern, the sealing material printed on the substrate element and used to obtain the second sealing layer is formed into a second annular pattern, the width of the second annular pattern is greater than the width of the first annular pattern, the sealing material printed on the strain gauge element and used to obtain the first sealing layer is formed into a third annular pattern, the sealing material printed on the strain gauge element and used to obtain the second sealing layer is formed into a fourth annular pattern, the width of the fourth annular pattern is greater than the width of the third annular pattern.

4. The packaging structure of the absolute pressure sensor according to claim 3, characterized in that: The second annular pattern is formed with a first pad hole, and the fourth annular pattern is formed with a second pad hole, and both the first pad hole and the second pad hole are used to allow the electrical connection pad of the thick film circuit of the strain gauge element to pass through.

5. The packaging structure of the absolute pressure sensor according to claim 3, characterized in that: The second annular pattern forms a first hollow area, and the first hollow area is used to achieve debinding during the process of sintering the second annular pattern to the substrate element. The fourth annular pattern forms a second hollow area, and the second hollow area is used to achieve debinding during the process of sintering the fourth annular pattern to the strain gauge element.

6. The packaging structure of the absolute pressure sensor according to any one of claims 3 to 5, characterized in that: The first circular pattern, the second circular pattern, the third circular pattern and the fourth circular pattern are all composed of band stripes, the width of the band stripes constituting the third circular pattern is greater than the width of the band stripes constituting the first circular pattern, and the width of the band stripes constituting the fourth circular pattern is greater than the width of the band stripes constituting the second circular pattern.

7. The packaging structure of the absolute pressure sensor according to any one of claims 1 to 5, characterized in that: The length and width of the strain gauge element and the substrate element are not less than 13.1 mm, respectively, and the thickness of the packaging structure is not less than 2 mm.

8. A packaging structure array of an absolute pressure sensor, characterized in that: The packaging structure array is composed of a plurality of packaging structures of the absolute pressure sensor according to any one of claims 1 to 7, wherein the corresponding plurality of substrate elements of the plurality of packaging structures are composed of a single substrate, and the corresponding plurality of strain gauge elements of the plurality of packaging structures are composed of a single strain gauge.

9. The packaging structure array according to claim 8, characterized in that: The number of rows and the number of columns of the packaging structures in the packaging structure array are no less than 3.

10. The packaging structure array of the absolute pressure sensor according to claim 8 or 9, characterized in that: A pre-cut groove is formed on the single substrate, so as to separate a single package structure from the package structure array along the pre-cut groove.

Images