Isolation assembly and packaging structure of semiconductor pressure sensing chip
By designing a corrugated structure that is thickened and thinned from the middle to the edge on the isolation diaphragm of the semiconductor pressure sensing chip, the problem of uneven stress distribution during large strain is solved, and higher measurement accuracy and longer service life are achieved.
Patent Information
- Application Number
- CN202421913604.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-08
- Publication Date
- 2025-05-09
- Estimated Expiration
- 2034-08-08
AI Technical Summary
In existing semiconductor pressure sensing chips, the corrugated diaphragm deforms after being compressed. When there is a large strain, the von Mises stress distribution of conventional corrugated diaphragms is uneven, which affects the measurement accuracy and may cause fatigue fracture.
An isolation assembly of a semiconductor pressure sensing chip is designed, and the isolation diaphragm has a corrugated structure that is sequentially thickened and then thinned from the middle to the edge. Through this structural optimization, the pressure applied to the diaphragm is evenly distributed to reduce the stress concentration point.
By optimizing the structure of the corrugated diaphragm, nonlinear elastic performance under large strains is reduced, more linear and accurate measurement results are provided, the service life of the sensor is extended, and the risk of fatigue damage is reduced.
Smart Images
Figure CN222850201U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of pressure sensors, in particular to an isolation component of a semiconductor pressure sensor chip. Background Art
[0002] In the field of pressure sensors, commonly used isolation diaphragms usually use a metal diaphragm sealed semiconductor pressure sensor chip packaging structure. In this structure, the metal diaphragm is welded on a stainless steel base, the sealing structure is filled with pressure transmission silicone oil, and the pressure sensor chip is placed in the sealed space and immersed in the pressure transmission silicone oil. The pressure to be measured is applied to the outside of the metal diaphragm, and the pressure is transmitted to the pressure sensor chip through the deformation of the metal diaphragm.
[0003] However, there are technical problems and deficiencies in the prior art, specifically, the corrugated diaphragm deforms after being compressed. For large strains, such as Figure 1 As shown, the elasticity of the conventional corrugated diaphragm 10 ′ on the base 20 ′ exhibits non-negligible nonlinearity. As the deformation increases, the elastic coefficient of the corrugated diaphragm increases, which affects the measurement accuracy. Utility Model Content
[0004] The utility model proposes an isolation component of a semiconductor pressure sensor chip, which solves the problem in the prior art that the corrugated diaphragm deforms after being compressed and the von Mises stress of the conventional corrugated diaphragm is unevenly distributed for large strains. As the deformation increases, the von Mises stress of the corrugated diaphragm is concentrated in a small area of the peripheral edge, which makes the outer side of the corrugated diaphragm very susceptible to fatigue fracture.
[0005] The technical solution of the utility model is achieved in this way:
[0006] An isolation component of a semiconductor pressure sensor chip comprises an isolation diaphragm having a corrugated structure, wherein the thickness of the corrugated structure increases and decreases sequentially from the middle to the edge.
[0007] Furthermore, the corrugated structure is composed of a plurality of curved segments and a plurality of straight segments.
[0008] Furthermore, the plurality of curved segments and the plurality of straight segments are alternately distributed to form periodic ripples.
[0009] Furthermore, the width values of the curve segments are consistent, and the spacing values of the curve segments are consistent.
[0010] The packaging structure, the isolation component of the semiconductor pressure sensor chip, also includes a base, a chip groove is opened in the middle of the base, and the edge of the isolation diaphragm is connected to the top of the base so that the isolation diaphragm covers the top of the chip groove.
[0011] Furthermore, the chip groove between the isolation diaphragm and the base is filled with transfer silicone oil, and the pressure sensor chip is wrapped in the transfer silicone oil.
[0012] Beneficial effects of the technical solution provided by this application:
[0013] 1. The isolation component of the semiconductor pressure sensor chip optimizes the structure of the corrugated diaphragm, especially through the design of thickening and then thinning from the middle to the edge, which helps to more evenly distribute the pressure applied to the diaphragm and reduce stress concentration points, which helps to avoid local excessive deformation or damage.
[0014] 2. This packaging structure uses the corrugated structure design of the isolation diaphragm and optimizes the thickness to reduce the nonlinear elastic performance under large strain, thereby providing more linear and accurate measurement results within a wide pressure range. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0016] Figure 1 This is a schematic cross-sectional diagram showing the force applied to the packaging structure of the prior art;
[0017] Figure 2 This is a schematic diagram of an isolation component of Example 1 of the utility model;
[0018] Figure 3 It is a schematic diagram of a cross section of Example 1 of the utility model;
[0019] Figure 4 This is a partial cross-sectional schematic diagram of Embodiment 1 of the present utility model;
[0020] Figure 5 This is a schematic diagram of the packaging structure of Embodiment 2 of the present utility model;
[0021] Figure 6 It is a schematic diagram of a cutaway view of the packaging structure of Embodiment 2 of the present utility model;
[0022] Figure 7 It is a partial cross-sectional view of the force demonstration of Example 3 of the utility model;
[0023] Figure 8 This is a force demonstration cutaway diagram of Example 3 of the utility model;
[0024] Fig. 9This is a test diagram of the elastic coefficient of the flat mold and the optimized diaphragm of Example 3 of the utility model;
[0025] Fig.10 It is a load curve diagram of the flat mold and the optimized diaphragm of Example 3 of the utility model;
[0026] Fig.11 It is a nonlinear curve diagram of the flat mold and the optimized diaphragm of Example 3 of the utility model.
[0027] In the figure: 10 isolating diaphragm, 20 corrugated structure, 21 curved segment, 22 straight segment, 30 base, 31 chip slot, 32 transfer silicone oil, 33 pressure sensor chip. DETAILED DESCRIPTION
[0028] The technical solution of the utility model will be described clearly and completely in conjunction with the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0029] Example 1
[0030] Reference Figure 2-4 An isolation component of a semiconductor pressure sensor chip includes an isolation diaphragm 10, wherein the isolation diaphragm 10 has a corrugated structure 20, wherein the thickness of the corrugated structure 20 increases and decreases from the middle to the edge.
[0031] The isolation diaphragm 10 is a key part of the sensing assembly, designed to withstand externally applied pressure and transmit it to the pressure sensing chip. The isolation diaphragm 10 is designed with a specific corrugated structure 20, which is usually composed of a series of raised and recessed corrugations, similar to the structure of a metal bellows. The thickness of the corrugated structure 20 is not uniform, but gradually thickens from the center of the isolation diaphragm 10 to the edge, and then gradually thins. This design helps to optimize the stress distribution of the diaphragm when it is under pressure.
[0032] The corrugated structure 20 on the isolation diaphragm 10 adopts a non-uniform thickness design, in which the middle part is relatively thick, which can provide greater rigidity to withstand the pressure in the central area, while the edge part gradually becomes thinner, which helps to improve the flexibility of the diaphragm and reduce stress concentration at the edge. When external pressure acts on the isolation diaphragm 10, the thicker middle part of the corrugated structure 20 is deformed first. Due to its greater rigidity, it can maintain a lower elastic coefficient, thereby providing linear pressure transmission. As the pressure increases, the thinner part of the edge gradually participates in the deformation. Due to the gradual decrease in thickness, the deformation of the diaphragm can be increased without significantly increasing the overall elastic coefficient, thereby expanding its working pressure range. This design effectively balances the rigidity and flexibility of the diaphragm, reduces the nonlinear response under large strain, and improves the measurement accuracy and reliability of the sensor. At the same time, the optimization of thickness also helps to reduce fatigue damage caused by stress concentration and extend the service life of the sensor.
[0033] like Figure 3 As shown, the corrugated structure 20 is composed of a plurality of curved segments 21 and a plurality of straight segments 22 .
[0034] The curved segments 21 in the corrugated structure 20 are one of the basic elements constituting the corrugated shape, and are usually presented as sine waves or other types of smooth curves. They play a major role in elasticity and deformation in the corrugated structure. The straight segments 22, as the connecting parts in the corrugated structure 20, are located between the curved segments 21, providing stability and structural rigidity for the corrugations, and may also serve as channels for stress transmission. The combined design of the curved segments 21 and the straight segments 22 forms a complex geometric shape of the corrugated structure, which allows the corrugated structure to disperse and transmit pressure more effectively when subjected to stress.
[0035] In the corrugated structure 20, the combination of the curved segments 21 and the straight segments 22 creates a composite geometric shape, which allows the isolation diaphragm 10 to absorb and transmit pressure through the elastic deformation of the curved segments 21 when subjected to pressure. Due to its shape, the curved segments 21 are able to provide greater deformation capacity when subjected to pressure, thereby absorbing more energy without adding excessive stress. The straight segments 22 provide the necessary structural support, maintain the integrity of the corrugated shape, and help to evenly distribute stress between the corrugations.
[0036] When external pressure is applied to the isolation diaphragm 10, the curved segment 21 first responds to the pressure and deforms with a lower elastic coefficient due to its design advantages, thereby providing linear pressure transmission. As the pressure increases, the straight segments 22 also begin to participate in the deformation process, but because they are relatively short and connected to the curved segments 21, they help maintain the stability of the corrugated structure and prevent excessive deformation and stress concentration. This design not only improves the pressure bearing capacity of the diaphragm, but also optimizes the stress distribution and reduces local stress concentration, thereby improving the durability of the entire isolation diaphragm 10 and the measurement accuracy of the sensor.
[0037] like Figure 3 As shown, the plurality of curved segments 21 and the plurality of straight segments 22 are alternately distributed to form periodic corrugations.
[0038] The corrugated structure 20 of the isolation diaphragm 10 is formed by alternating distribution of multiple curved segments 21 and multiple straight segments 22. This arrangement creates a repeating corrugation pattern, i.e., periodic corrugation. Each curved segment 21 is a raised portion in the corrugated structure 20. They are usually in the shape of a sine wave or other types of smooth curves and are responsible for providing the main elastic deformation when under pressure. The straight segments 22 connect adjacent curved segments 21 to form the valleys of the corrugations, which provide the necessary structural support and stress transfer channels for the corrugated structure. The alternating distribution of the curved segments 21 and the straight segments 22 ensures the continuity and consistency of the corrugated structure 20, and also helps to achieve uniform stress distribution and effective deformation transfer.
[0039] The design of the periodic corrugations enables the isolation diaphragm 10 to absorb pressure through elastic deformation of the curved segments 21 when subjected to external pressure. Due to the alternating distribution of the curved segments 21 and the straight segments 22, each curved segment can deform independently when subjected to pressure, while the straight segments 22 provide support points for deformation recovery, ensuring that the corrugated structure 20 can recover its original shape after deformation.
[0040] When pressure is applied to the isolation diaphragm 10, the curved segment 21 begins to deform, and because its design allows for a larger deformation, it can absorb more pressure at a lower stress level. As the pressure increases further, the adjacent curved segments 21 and straight segments 22 work together to disperse the pressure through the entire corrugated structure 20, reducing stress concentration in any single area. This dispersion helps to improve the overall pressure bearing capacity of the diaphragm and reduce the risk of damage caused by excessive local stress.
[0041] In addition, the periodic corrugated structure 20 also helps to improve the dynamic response performance of the sensor, because it allows the diaphragm to quickly respond to pressure changes while maintaining structural stability and measurement accuracy. Through this design, the isolation diaphragm 10 can not only withstand a larger working pressure, but also provide more accurate and reliable pressure measurement results.
[0042] like Figure 4 As shown, the width values of the curve segments 21 are consistent, and the spacing values of the curve segments 21 are consistent.
[0043] In the corrugated structure 20, all the curved segments 21 have a uniform width dimension. This consistent width design helps maintain the uniformity and repeatability of the corrugated structure 20. The distance between adjacent curved segments 21 is also fixed, that is, the distance from the center of each curved segment 21 to the center of the adjacent curved segment 21 is consistent. This uniform spacing helps ensure the consistency and symmetry of the corrugated structure 20 across the entire diaphragm. The consistency of the width and spacing of the curved segments 21 provides geometric consistency for the corrugated structure 20, and this design helps achieve a more uniform stress distribution and a more predictable deformation behavior.
[0044] In the corrugated structure 20 of the isolation diaphragm 10, all the curved segments 21 have the same width and spacing. This design ensures that each curved segment 21 will respond in a similar manner when subjected to pressure, thereby achieving uniform stress distribution across the entire diaphragm. When external pressure acts on the diaphragm, due to the consistency of the width and spacing of the curved segments 21, each curved segment will provide the same degree of deformation, which helps to avoid local stress concentration and reduce potential damage caused by uneven stress.
[0045] In addition, the consistent width and spacing of the curve segments 21 also help improve the manufacturing accuracy and repeatability of the sensor because they can simplify the manufacturing process and reduce variability during the production process. This design also helps to improve the performance consistency of the sensor because the corrugated structure 20 of each sensor unit is the same, thereby ensuring consistent performance of the sensor between different production batches.
[0046] In practical applications, this uniform corrugated structure design can make the sensor more sensitive to pressure changes while maintaining high measurement accuracy and stability. By reducing the error caused by structural inconsistency, the sensor can provide more reliable and accurate pressure measurement results.
[0047] Example 2
[0048] Reference Figure 5-6, packaging structure, the isolation component of the semiconductor pressure sensor chip also includes a base 30, a chip groove 31 is opened in the middle of the base 30, and the edge of the isolation diaphragm 10 is connected to the top of the base 30, so that the isolation diaphragm 10 covers the top of the chip groove 31.
[0049] The base 30 is a key part of the packaging structure, usually made of solid material, and is used to support and fix the isolation diaphragm 10 and the sensor chip. The chip slot 31 opened in the middle of the base 30 is a cavity for placing the pressure sensor chip, and its design ensures that the chip can be accurately positioned at the desired position. The edge of the isolation diaphragm 10 is connected to the top of the base 30. This connection method ensures that the diaphragm can stably cover the top of the chip slot 31, forming a pressure transmission path for the sensor chip. The isolation diaphragm 10 covers the chip slot 31, forming a pressure transmission path from the external environment to the sensor chip, ensuring that the sensor chip can sense external pressure through the deformation of the isolation diaphragm.
[0050] In the package structure, the base 30 provides a stable platform, and the chip slot 31 in the middle provides a precise position for the sensor chip. The isolation diaphragm 10 covers the top of the chip slot 31, and its edge is connected to the top of the base 30 to form a sealed pressure sensing chamber. This design allows the externally applied pressure to be transmitted to the sensor chip through the isolation diaphragm 10.
[0051] When external pressure acts on the isolation diaphragm 10, due to the corrugated structure design of the diaphragm, the pressure is evenly distributed on the diaphragm, reducing local stress concentration. The deformation of the isolation diaphragm transmits a pressure signal through its contact with the sensor chip, and the sensor chip converts this mechanical deformation into an electrical signal, thereby realizing pressure measurement.
[0052] In addition, the design of the isolation diaphragm 10 also takes into account durability and reliability, and the thickness variation of the corrugated structure 20 helps to improve the diaphragm's ability to respond to pressure while maintaining the linearity and accuracy of the measurement. The combination of the base 30 and the isolation diaphragm 10 provides a stable measurement environment, protects the sensor chip from external physical and chemical factors, and ensures the long-term stability and reliability of the sensor.
[0053] Reference Figure 6 The chip groove 31 between the isolation diaphragm 10 and the base 30 is filled with transfer silicone oil 32 , and a pressure sensing chip 33 is wrapped in the transfer silicone oil 32 .
[0054] The chip slot 31 between the isolation diaphragm 10 and the base 30 is filled with transfer silicone oil, which is a special liquid medium used to transfer and buffer the externally applied pressure. The pressure sensor chip is encapsulated in the transfer silicone oil 32. This packaging method provides a stable working environment for the sensor chip and can reduce the impact of external shock or vibration on the chip. The transfer silicone oil 32 not only serves as a medium for pressure transmission, but also has a buffering effect, which can absorb and slow down the rapid change of pressure, thereby protecting the sensor chip from overload or pressure shock.
[0055] In the packaging structure, the isolation diaphragm 10 transfers the externally applied pressure to the transfer silicone oil 32 in the chip slot 31. As a liquid medium, silicone oil has low compressibility and can effectively transfer the pressure evenly to the entire chip slot to reduce pressure concentration.
[0056] When the isolation diaphragm 10 is deformed, the transfer silicone oil 32 will expand or compress accordingly, transferring the pressure change to the sensor chip encapsulated therein. Due to the fluidity of the silicone oil, it can quickly respond to pressure changes and evenly apply these changes to the sensor chip, thereby improving the response speed and measurement accuracy of the sensor.
[0057] At the same time, the buffering effect of silicone oil can reduce the impact of sudden pressure changes or external vibrations on the sensor chip, improving the stability and reliability of the sensor. In addition, silicone oil also helps protect the sensor chip from environmental factors such as humidity and temperature changes, extending the service life of the sensor.
[0058] In summary, by filling the transfer silicone oil 32 in the chip groove 31 between the isolation diaphragm 10 and the base 30 and encapsulating the sensor chip 33 therein, the utility model provides a packaging structure that can improve the performance, stability and reliability of the pressure sensor.
[0059] Example 3
[0060] The stress of the corrugated diaphragm 10 is concentrated at the top and bottom of the corrugation at the root. The optimized design is as follows: Figure 7 , Figure 8 As shown, Figure 7 For a 2D graph, Figure 8 for Figure 7 Rotating 3D graph of . Figure 1 The stress concentration area in Figure 7 , 8 The corrugations in the middle of the isolation diaphragm 10 are thickened.
[0061] The generatrix of the corrugated diaphragm 10 includes a sine curve and a straight line segment, with a total of 5 corrugations. The height of the sine curve is 0.15 mm, the width of a single corrugation is 2 mm, the spacing between adjacent corrugations is 0.2 mm, and the corrugation thickness is 20 um.
[0062] For stress concentration areas, local thickening is performed. From the middle to the edge, the thickness of the corrugation is thickened by 0um, 2um, 10um, 10um, and 2um. The stress distribution of the optimized corrugated diaphragm is as follows: Figure 7 , Figure 8 As shown, the stress distribution is Figure 1 More uniform, and the maximum stress is 21.73MPa, which is Figure 1 The maximum stress of 52.36MPa was reduced by 58.5%. Compared with the original design, the new corrugated diaphragm has greatly reduced the stress peak, optimized the stress distribution, reduced the probability of plastic deformation and fatigue fracture, and is more suitable for pressure testing in harsh environments.
[0063] Under the action of the external load, the isolation membrane 10 deforms. The elastic coefficients of the optimized isolation membrane and the flat membrane structure are shown in the attached figure. Fig. 9 As shown in the figure, the elastic coefficient of the optimized isolation diaphragm basically does not change with the increase of the external load. However, the elastic coefficient of the flat membrane structure increases with the increase of the external load.
[0064] Further investigation of the relationship between the center displacement and applied load of the flat membrane structure isolation diaphragm and the optimized corrugated diaphragm shows the following results. Fig.10 Attached Fig.10 The slope of the curve represents the inverse of the diaphragm stiffness, that is, the force compliance. The slope of the displacement-applied load relationship curve of the flat membrane structure gradually decreases and is related to the attached Fig. 9 The trend is consistent with that analyzed in the paper. The displacement-load curve of the optimized corrugated membrane structure shows good linearity.
[0065] The Full Scale Span curve corresponding to the center displacement of the flat membrane structure isolation diaphragm and the optimized corrugated diaphragm is examined. The peak value of the curve is the nonlinear property of the diaphragm. Fig.10 , 11 As shown, within the target load range, the maximum nonlinearity of the flat diaphragm structure has reached 13.65%, while the maximum nonlinearity of the optimized corrugated diaphragm is 0.19%. In the actual use of the measuring instrument, the optimized corrugated diaphragm will greatly reduce the nonlinearity introduced to the test system due to its deformation.
[0066] To summarize the above information, the stress distribution of the optimized corrugated diaphragm is more uniform, and the stress peak is much smaller than that of the conventional corrugated diaphragm, which is only 41.5% of that of the conventional corrugated diaphragm. In addition, the nonlinearity of the optimized corrugated diaphragm is only 1.4% of that of the flat membrane structure corrugated diaphragm. This design will greatly reduce the nonlinearity introduced to the test system due to its deformation.
[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. An isolation component for a semiconductor pressure sensor chip, characterized in that: The invention comprises an isolation diaphragm (10), wherein the isolation diaphragm (10) has a corrugated structure (20), wherein the thickness of the corrugated structure (20) increases and then decreases from the middle to the edge.
2. The isolation assembly of the semiconductor pressure sensor chip according to claim 1, characterized in that: The corrugated structure (20) is composed of a plurality of curved segments (21) and a plurality of straight segments (22).
3. The isolation assembly of the semiconductor pressure sensor chip as claimed in claim 2, characterized in that: The plurality of curved segments (21) and the plurality of straight segments (22) are distributed alternately to form periodic ripples.
4. The isolation assembly of the semiconductor pressure sensor chip as claimed in claim 3, characterized in that: The width values of the various curved segments (21) are consistent, and the spacing values of the various curved segments (21) are consistent.
5. A packaging structure, characterized in that: An isolation component comprising a semiconductor pressure sensor chip as described in any one of items 1 to 4, further comprising a base (30), a chip slot (31) being provided in the middle of the base (30), and an edge of the isolation diaphragm (10) being connected to the top of the base (30) so that the isolation diaphragm (10) covers the top of the chip slot (31).
6. The packaging structure according to claim 5, characterized in that: The chip groove (31) between the isolation diaphragm (10) and the base (30) is filled with transfer silicone oil (32), and a pressure sensing chip (33) is wrapped in the transfer silicone oil (32).