CN211855643U

CN211855643U - Ceramic pressure sensor packaging structure

Info

Publication number: CN211855643U
Application number: CN202020347838.9U
Authority: CN
Inventors: 徐雷; 徐兴才; 严群丰
Original assignee: Wuxi Shengsai Sensing Technology Co ltd
Current assignee: Wuxi Shengsai Sensing Technology Co ltd
Priority date: 2020-03-19
Filing date: 2020-03-19
Publication date: 2020-11-03
Anticipated expiration: 2030-03-19

Abstract

The utility model belongs to the technical field of the sensor encapsulation, especially, be a pottery pressure sensor packaging structure, including lower casing, last casing, pottery pressure sensor core and circuit board, wherein, it connects in casing top down to go up the casing, it has the holding chamber that is used for holding pottery pressure sensor core and circuit board to constitute between casing and the last casing down, pottery pressure sensor core flip-chip bonds on the circuit board. The utility model discloses can make ceramic pressure sensor core stress surface atress more even, avoid producing additional stress to ceramic diaphragm to the maximum amplitude has reduced the probability that the drift phenomenon appears at zero point in the sensor, simple structure, practicality, the production input cost is low, and do benefit to the assembly, through the setting of second sealing washer, make the last casing more inseparable with lower shell connection, the use of cooperation first sealing washer has greatly improved the sealing performance in encapsulation inner holding chamber, satisfy the high leakproofness demand of current sensor packaging structure.

Description

Ceramic pressure sensor packaging structure

Technical Field

The utility model relates to a sensor packaging technology field specifically is a pottery pressure sensor packaging structure.

Background

Since the introduction of ceramic pressure sensors into the home in 2000, ceramic pressure sensors have been widely used in the middle and low voltage industry because of their excellent properties and low cost. However, the produced pressure sensor frequently has zero drift phenomenon in the use process of an end customer. Zero drift: it is referred to that the output quantity changes with time when the input of the sensor and the ambient temperature are constant, and the phenomenon is drift. The method is caused by unstable performance of each link in the sensor or internal temperature change, and is an index for reflecting the stability of the sensor.

Aiming at the zero drift phenomenon, domestic sensor manufacturers mainly start from a sealing structure, and the common solution is to eliminate stress by repeatedly charging and discharging and aging at high temperature for more than 8 hours so as to enable the elastic deformation of a sealing rubber ring to be solidified, thereby enabling the performance of the sensor to tend to be stable. The mode can effectively reduce zero drift caused by mismatching of the resistance of the electronic device, and temporarily enable the sealing rubber to be cured through elastic deformation, but the elasticity of the sealing rubber still changes along with the prolonging of the service time and the change of the service environment, so that a corresponding reaction force is released for the pressure core body, the precision of the sensor is influenced, and the zero drift phenomenon can still occur.

In order to solve the zero drift phenomenon, chinese patent CN201821119901.2 discloses a ceramic pressure sensor package structure, in which a sealing groove extends upwards from the inner side of a sensor core body placing groove, and a sealing ring is arranged between the sealing groove and the ceramic pressure sensor core body, so that the elastic reaction force of the sealing ring is transversely attached to the wall of the sensor core body groove, and no additional pressure is generated on the strain gauge surface of the sensor core body, and the assembly stress is greatly reduced relative to the sealing ring arranged on the end surface of the ceramic pressure sensor core body, thereby reducing the zero drift caused by the elastic change of the sealing ring; the copper ring pressing block is arranged above the ceramic pressure sensor core body, and the retaining ring for applying pressure to the copper ring pressing block is used for pressing, so that the whole plane of the ceramic pressure sensor core body is uniformly stressed compared with a pressing process adopting internal threads, additional stress on an elastic body on the surface of the sensor is avoided, and the copper ring pressing block does not generate elastic deformation compared with a rubber pad or a nylon pressing block, so that the zero drift phenomenon of the sensor is reduced to the maximum extent. Although the ceramic pressure sensor packaging structure can meet the requirement of reducing the zero drift of the sensor to a certain extent, the packaging structure is complex, the process is complex, the production input cost is high, the airtightness of the connecting end of the upper shell and the lower shell is poor, and the overall sealing performance of the packaging structure is influenced.

SUMMERY OF THE UTILITY MODEL

Technical problem to be solved

Not enough to prior art, the utility model provides a ceramic pressure sensor packaging structure has solved that current ceramic pressure sensor packaging structure is complicated, and loaded down with trivial details, production input cost is high, and goes up the casing and the inferior valve body coupling end seal is relatively poor, influences the problem of the whole sealing performance of packaging structure.

(II) technical scheme

In order to achieve the above object, the utility model provides a following technical scheme: a ceramic pressure sensor packaging structure comprises a lower shell, an upper shell, a ceramic pressure sensor core and a circuit board, wherein the upper shell is connected to the top end of the lower shell, a containing cavity for containing the ceramic pressure sensor core and the circuit board is formed between the lower shell and the upper shell, the ceramic pressure sensor core is bonded on the circuit board in an inverted mode, an annular convex block is arranged in the lower shell and corresponds to the bottom of the containing cavity, a groove is formed in the bottom of the ceramic pressure sensor core, a cavity is formed between the annular convex block and the groove, the ceramic pressure sensor core comprises a ceramic diaphragm arranged in the cavity and corresponds to the bottom of the groove, a channel communicated with the middle of the cavity is arranged in the lower shell, a bottom plate is arranged at the bottom of the containing cavity and corresponds to the periphery of the annular convex block, and the ceramic pressure sensor core is preset at the tops of the annular convex block and the, a first sealing groove is formed between the side wall of the groove corresponding to the ceramic pressure sensor core and the side wall of the annular convex block, a first sealing ring sealed with the side wall of the ceramic pressure sensor core is arranged in the first sealing groove, the ceramic pressure sensor core and the circuit board are assembled on the bottom plate through an assembling pressing plate, a sealing cavity is communicated and arranged between the assembling pressing plate and the inner wall of the lower shell and between the bottom plate and the inner wall of the lower shell, an insulating sealing material for sealing the assembling pressing plate and the bottom plate is filled in the sealing cavity, a clamping groove is arranged on the inner wall of the lower shell and above the sealing cavity, a pressing block for pressing and fixing the assembling pressing plate is arranged in the clamping groove, a second sealing groove is arranged between the connecting ends of the lower shell and the upper shell, a second sealing ring for sealing and connecting the lower shell and the upper shell is arranged in the second, one end of the welding pin penetrates through the upper shell and extends into the accommodating cavity, and the welding pin is connected with the circuit board through wire bonding.

As a preferred technical scheme of the utility model, the inside of going up the casing is equipped with the toper inlay groove, and the inside of toper inlay groove is equipped with the taper seal circle, the welding needle runs through the taper seal circle and extends to the holding intracavity portion, the taper seal circle is fixed in the inside of last casing through the clamping ring.

As a preferred technical scheme of the utility model, the bottom of casing is the link down, and the surface of link is equipped with the assembly spiral.

As an optimal technical scheme of the utility model, adopt pad counterpoint welded connected mode between ceramic pressure sensor core and the circuit board.

As an optimized technical scheme of the utility model, insulating seal material adopts the insulating sealed glue of silicone electron.

(III) advantageous effects

Compared with the prior art, the utility model provides a ceramic pressure sensor packaging structure possesses following beneficial effect:

1. this ceramic pressure sensor packaging structure sets up the realization through the combination of bottom plate, assembly clamp plate and compresses tightly fixedly to ceramic pressure sensor core and circuit board, makes ceramic pressure sensor core stress surface atress more even, has avoided producing additional stress to ceramic diaphragm to the maximum amplitude has reduced the probability that the drift phenomenon appears zero point in the sensor, simple structure, practicality, and the production input cost is low, and does benefit to the assembly.

2. This pottery pressure sensor packaging structure through the setting of second sealing washer, makes last casing and lower shell coupling more inseparable, cooperates the use of first sealing washer, has greatly improved the sealing performance in holding chamber in the encapsulation, satisfies the high leakproofness demand of current sensor packaging structure.

Drawings

Fig. 1 is a schematic view of the internal structure of the present invention;

FIG. 2 is a schematic view of the internal structure of the lower housing of the middle part of the present invention;

fig. 3 is a schematic structural diagram of the ceramic pressure sensor core body of the present invention;

fig. 4 is a schematic structural diagram of the middle assembling pressing plate of the present invention.

In the figure: 1. a lower housing; 2. an upper housing; 3. a ceramic pressure sensor core; 4. a circuit board; 5. an accommodating cavity; 6. a bump; 7. a cavity; 8. a ceramic diaphragm; 9. a channel; 10. a base plate; 11. a first seal groove; 12. a first seal ring; 13. assembling a pressing plate; 14. sealing the cavity; 15. an insulating sealing material; 16. a card slot; 17. a compression block; 18. a second seal groove; 19. a second seal ring; 20. welding pins; 21. a conical seal ring; 22. pressing a ring; 23. and assembling the spiral.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Examples

Referring to fig. 1-4, the present invention provides the following technical solutions: a ceramic pressure sensor packaging structure comprises a lower shell 1, an upper shell 2, a ceramic pressure sensor core 3 and a circuit board 4, wherein the upper shell 2 is connected to the top end of the lower shell 1, an accommodating cavity 5 for accommodating the ceramic pressure sensor core 3 and the circuit board 4 is formed between the lower shell 1 and the upper shell 2, the ceramic pressure sensor core 3 is inversely bonded on the circuit board 4, an annular convex block 6 is arranged in the lower shell 1 and corresponds to the bottom of the accommodating cavity 5, a groove is arranged at the bottom of the ceramic pressure sensor core 3, a cavity 7 is formed between the annular convex block 6 and the groove, the ceramic pressure sensor core 3 comprises a ceramic diaphragm 8 arranged in the cavity 7 and corresponds to the bottom of the groove, a channel 9 communicated with the middle of the cavity 7 is arranged in the lower shell 1, a bottom plate 10 is arranged at the bottom of the accommodating cavity 5 and corresponds to the periphery of the annular convex block 6, the ceramic pressure sensor core 3 is preset at the top of the annular bump 6 and the bottom plate 10, a first sealing groove 11 is formed between the side wall of the ceramic pressure sensor core 3 corresponding to the groove and the side wall of the annular bump 6, a first sealing ring 12 sealed with the side wall of the ceramic pressure sensor core 3 is arranged inside the first sealing groove 11, the ceramic pressure sensor core 3 and the circuit board 4 are assembled on the bottom plate 10 through an assembling pressing plate 13, a sealing cavity 14 is arranged between the assembling pressing plate 13 and the bottom plate 10 and the inner wall of the lower shell 1 in a communicating manner, an insulating sealing material 15 used for assembling the pressing plate 13 and sealing the bottom plate 10 is filled inside the sealing cavity 14, a clamping groove 16 is arranged on the inner wall of the lower shell 1 corresponding to the upper part of the sealing cavity 14, a pressing block 17 used for pressing and fixing the assembling pressing plate 13 is arranged inside the clamping groove 16, and a second sealing, the inside of second seal groove 18 is equipped with second sealing washer 19 that is used for casing 1 and last casing 2 sealing connection down, is equipped with welding needle 20 on going up casing 2, and the one end of welding needle 20 runs through last casing 2 and extends to the holding intracavity portion 5 inside, is connected through wire bonding between welding needle 20 and the circuit board 4.

In the embodiment, the pressing block 17 adopts a copper ring pressing block, and compared with a rubber pad or a nylon pressing block, the copper ring pressing block cannot generate elastic deformation, so that the zero drift phenomenon of the sensor is reduced to the maximum extent; the lower shell 1 and the upper shell 2 are connected in a riveting or threaded connection mode, and the connection structure is firm and stable.

Specifically, the interior of the upper shell 2 is provided with a conical embedded groove, the interior of the conical embedded groove is provided with a conical sealing ring 21, the welding pin 20 penetrates through the conical sealing ring 21 and extends into the accommodating cavity 5, and the conical sealing ring 21 is fixed in the interior of the upper shell 2 through a pressing ring 22.

In this embodiment, be connected through the wire bonding between welding needle 20 and the circuit board 4, utilize passageway 9 intercommunication material that awaits measuring, through the pressure difference between cavity 7 and the environment that awaits measuring, cause ceramic diaphragm 8 on the ceramic pressure sensor core 3 to warp, produce the piezoelectric impedance effect, lead to the signal of telecommunication to change, thereby convert pressure into the signal of telecommunication, loop through circuit board 4 with the signal of telecommunication again, the wire, welding needle 20 transmits, outwards transmit by the wire of being connected with welding needle 20, through the setting of taper seal ring 21, the gas tightness of holding chamber 5 has been guaranteed, clamping ring 22 plays the effect of fixed taper seal ring 21.

Specifically, the bottom end of the lower shell 1 is a connecting end, and an assembly screw 23 is arranged on the outer surface of the connecting end.

In this embodiment, the connection end and the surface mounting screw 23 thereof are rotatably connected to the device interface, which facilitates mounting.

Specifically, a connection mode of pad contraposition welding is adopted between the ceramic pressure sensor core body 3 and the circuit board 4.

In this embodiment, the ceramic pressure sensor core 3 and the circuit board 4 are electrically connected by using a connection manner of pad alignment welding.

Specifically, the insulating sealing material 15 is a silicone electronic insulating sealant.

In this embodiment, because the silicone electronic insulation sealant has good temperature resistance, water resistance, acid resistance and leakproofness, consequently, fill in sealed chamber 14 with the silicone electronic insulation sealant as insulating sealing material 15, can guarantee the leakproofness that assembly clamp plate 13 and bottom plate 10 are connected, cooperate the setting of first sealing washer 12, when making 5 leakproofness of holding chamber obtain the guarantee, can make packaging structure more firm, guaranteed measuring high accuracy and high stability.

The utility model discloses a theory of operation and use flow: during packaging, firstly, the bottom plate 10 is arranged at the bottom of the accommodating cavity 5, the first sealing ring 12 is pressed into the first sealing groove 11 formed by the side wall of the groove and the side wall of the annular convex block 6, the ceramic pressure sensor core 3 and the circuit board 4 are arranged at the top of the bottom plate 10 and the convex block 6, the sealing performance of the accommodating cavity 5 is improved through the first sealing ring 12, then the ceramic pressure sensor core 3 and the circuit board 4 are tightly pressed in the accommodating cavity 5 through the assembling pressing plate 13, stable packaging is facilitated, then the sealing cavity 14 is filled with the insulating sealing material 15, namely, the assembling pressing plate 13 and the bottom plate 10 are tightly combined through the filling of the silicone electronic insulating sealant, the sealing performance is further improved, the assembling pressing plate 13 is tightly pressed and fixed through the pressing block 17 after the filling of the insulating sealing material 15 is completed, the stability of a packaging structure is improved, and meanwhile, the, avoided producing additional stress to ceramic diaphragm 8 to the maximum amplitude has reduced the probability that the sensor appears drift phenomenon at zero, adopts riveting or threaded connection mode to go up casing 2 stable connection in 1 top of casing down at last, and through the setting of second sealing washer 19 between its link, makes sealed effect better, to sum up, the utility model discloses the maximum amplitude has reduced the probability that the sensor appears drift phenomenon at zero, guarantees sensor measuring high accuracy and high stability, has greatly promoted packaging structure's leakproofness, and simple structure, practicality, and production input cost is low, does benefit to the assembly.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A ceramic pressure sensor packaging structure is characterized in that: comprises a lower shell (1), an upper shell (2), a ceramic pressure sensor core (3) and a circuit board (4), wherein the upper shell (2) is connected to the top end of the lower shell (1), an accommodating cavity (5) for accommodating the ceramic pressure sensor core (3) and the circuit board (4) is formed between the lower shell (1) and the upper shell (2), the ceramic pressure sensor core (3) is inversely bonded on the circuit board (4), an annular convex block (6) is arranged in the lower shell (1) and corresponds to the bottom of the accommodating cavity (5), a groove is arranged at the bottom of the ceramic pressure sensor core (3), a cavity (7) is formed between the annular convex block (6) and the groove, the ceramic pressure sensor core (3) comprises a ceramic diaphragm (8) arranged in the cavity (7) and corresponds to the bottom of the groove, a channel (9) communicated with the middle of the cavity (7) is arranged in the lower shell (1), a bottom plate (10) is arranged at the bottom of the accommodating cavity (5) corresponding to the periphery of the annular convex block (6), the ceramic pressure sensor core (3) is preset at the tops of the annular convex block (6) and the bottom plate (10), a first sealing groove (11) is formed between the side wall of the ceramic pressure sensor core (3) corresponding to the groove and the side wall of the annular convex block (6), a first sealing ring (12) sealed with the side wall of the ceramic pressure sensor core (3) is arranged inside the first sealing groove (11), the ceramic pressure sensor core (3) and the circuit board (4) are assembled on the bottom plate (10) through an assembling pressing plate (13), a sealing cavity (14) is arranged between the assembling pressing plate (13) and the bottom plate (10) and the inner wall of the lower shell (1) in a communicating manner, and an insulating sealing material (15) for sealing the assembling pressing plate (13) and the bottom plate (10) is filled inside the sealing cavity (14, the top that corresponds sealed chamber (14) on the inner wall of lower casing (1) is equipped with draw-in groove (16), the inside of draw-in groove (16) is equipped with and is used for assembling clamp plate (13) and compresses tightly fixed compact heap (17), be equipped with second seal groove (18) down between the link of casing (1) and last casing (2), the inside of second seal groove (18) is equipped with and is used for casing (1) and last casing (2) sealing connection's second sealing washer (19) down, it welds needle (20) to be equipped with on casing (2), the one end of welding needle (20) runs through casing (2) and extends to holding chamber (5) inside, be connected through the wire bonding between welding needle (20) and circuit board (4).

2. The ceramic pressure sensor package structure of claim 1, wherein: go up the inside of casing (2) and be equipped with toper embedded groove, toper embedded groove's inside is equipped with tapered seal circle (21), weld needle (20) run through tapered seal circle (21) and extend to holding chamber (5) inside, tapered seal circle (21) are fixed in the inside of last casing (2) through clamping ring (22).

3. The ceramic pressure sensor package structure of claim 1, wherein: the bottom end of the lower shell (1) is a connecting end, and an assembly screw (23) is arranged on the outer surface of the connecting end.

4. The ceramic pressure sensor package structure of claim 1, wherein: and the ceramic pressure sensor core body (3) and the circuit board (4) are connected in a bonding pad alignment welding mode.

5. The ceramic pressure sensor package structure of claim 1, wherein: the insulating sealing material (15) adopts silicone electronic insulating sealant.