CN205102963U

CN205102963U - SiC high temperature electric capacity pressure sensor

Info

Publication number: CN205102963U
Application number: CN201520848774.XU
Authority: CN
Inventors: 沈富德
Original assignee: SIRECTIFIER ELECTRONICS TECHNOLOGY Corp
Current assignee: SIRECTIFIER ELECTRONICS TECHNOLOGY Corp
Priority date: 2015-10-29
Filing date: 2015-10-29
Publication date: 2016-03-23
Anticipated expiration: 2025-10-29

Abstract

The utility model relates to a high temperature pressure sensor, especially a siC high temperature electric capacity pressure sensor. A siC high temperature electric capacity pressure sensor can cut down alloy housing by siC sensing element, column AIN substrate, lead wire and tube -shape and constitute, siC sensing element comprises two siC wafers, has reference cavity in vacuum between the siC wafer, an equipartition is followed outward to the up end of AIN substrate has a plurality of lead wires, adheres through bonding glass and siC sensing element in the middle part of its up end, and the diameter of AIN substrate is 10mm, and the AIN substrate is adhere on the inner wall that can cut down alloy housing through sealing -in glass, sealing glass's thickness is 2.5mm. The utility model discloses optimize siC electric capacity pressure sensor packaging structure and parameter, reduce the thermal stress that the device produced at the high temperature during operation, improve the stability of device.

Description

SiC high temperature capacitor pressure transducer

Technical field

The utility model relates to high-temp pressure sensor, especially a kind of SiC high temperature capacitor pressure transducer.

Background technology

High-temp pressure sensor has broad application prospects at space industry, aviation field and industrial circle.Particularly at aerospace field, high-temp pressure sensor may be used for engine high-temperature pressure survey, spacecraft surface pressure measurement, carrier rocket combustion chamber high temperature pressure survey etc.Current high-temp pressure sensor mainly contains condenser type, piezoelectric type, pressure resistance type, thin film strain formula, optical fiber type etc., and because these pressure transducers are often applied to rugged surroundings, therefore its encapsulation technology need reach higher standard.

SiC capacitance pressure transducer, is widely used, there is the series of advantages such as the strong and miniaturization of highly sensitive, hot environment strong adaptability, anti-overload ability, in sensor, each structure is made up of the material that thermal expansivity is different, thermal stress can be produced in manufacture, use procedure, make sensitive element generation deformation, and then cause device to occur the phenomenon of the operation irregularities such as zero point drift, even can cause expendable damage to device when more extreme.There are some researches show, in certain temperature range, the crash rate of device is with the rising exponentially trend growth of temperature.Therefore need to carry out thermomechanical design and optimization to device architecture, reduce the thermal stress that device produces when hot environment works.

Utility model content

The technical problems to be solved in the utility model is: based on the problems referred to above, provides a kind of thermal stress reducing device and produce when hot operation, improves the SiC high temperature capacitor pressure transducer of the stability of device.

The utility model solves the technical scheme that its technical matters adopts: a kind of SiC high temperature capacitor pressure transducer, by SiC sensitive element, column AIN substrate, lead-in wire and tubular kovar alloy shell composition, described SiC sensitive element is made up of two panels SiC wafer, there is between SiC wafer reference vacuum cavity, outer, the upper surface place of described AIN substrate is evenly equipped with some lead-in wires, the middle part of its upper surface is bonded by bonding glass and SiC sensitive element, the diameter of AIN substrate is 10mm, AIN substrate is bonded on the inwall of kovar alloy shell by seal glass, the thickness of described seal glass is 2.5mm.

Further, the diameter of described lead-in wire is 0.3mm, and the wall thickness of kovar alloy shell is 1mm.

The beneficial effects of the utility model are: the utility model is optimized SiC capacitive pressure transducer encapsulating structure and parameter thereof, reduce the thermal stress that device produces when hot operation, improve the stability of device.

Accompanying drawing explanation

Below in conjunction with drawings and Examples, the utility model is further illustrated.

Fig. 1 is structural representation of the present utility model.

In figure: 1.SiC sensitive element, 2.AIN substrate, 3. goes between, and 4. kovar alloy shell 5. bonds glass, 6. seal glass.

Embodiment

By reference to the accompanying drawings the utility model is described in further detail now.These accompanying drawings are the schematic diagram of simplification, only basic structure of the present utility model are described in a schematic way, and therefore it only shows the formation relevant with the utility model.

As shown in Figure 1, a kind of SiC high temperature capacitor pressure transducer, be made up of SiC sensitive element 1, column AIN substrate 2, lead-in wire 3 and tubular kovar alloy shell 4, SiC sensitive element 1 is made up of two panels SiC wafer, there is between SiC wafer reference vacuum cavity, outer, the upper surface place of AIN substrate 2 is evenly equipped with some lead-in wires 3, the middle part of its upper surface is bonded with SiC sensitive element 1 by bonding glass 5, the diameter of AIN substrate 2 is 10mm, AIN substrate 2 is bonded on the inwall of kovar alloy shell 4 by seal glass 6, and the thickness of seal glass 6 is 2.5mm.

AIN substrate 2 is important compositions of encapsulating structure, and its function is to provide support platform, for SiC sensitive element 1, carries pathway for electrical signals and provides mechanical protection.When AIN substrate 2 thickness gets different value, stress value difference in SiC sensitive element 1 center is comparatively large, and for arbitrary AIN substrate 2 thickness, in SiC sensitive element 1, cardiac stress all increases along with the increase of AIN substrate 2 diameter.For different bonding glass 5 thickness and AIN substrate 2 thickness, in SiC sensitive element 1, cardiac stress all increases along with the increase of AIN substrate 2 diameter, and the optimal value of AIN substrate 2 diameter is 10mm.

As the middle layer of SiC sensitive element 1 and AIN substrate 2, bonding glass 5 makes to form mechanical connection between AIN substrate 2 and SiC sensitive element 1, and the stress on AIN substrate 2 can be delivered on SiC sensitive element 1 by bonding glass 5.When bonding glass 5 very thin thickness, the thermal stress on AIN substrate 2 is easy to upwards transmit, and causes SiC sensitive element 1 thermomechanical property to be deteriorated.Otherwise when bonding glass 5 thickness and being larger, the thermal stress on AIN substrate 2 only has a very little part to be delivered on SiC sensitive element 1, the increase of bonding glass 5 thickness serves the effect of decay stress.

In addition, the thermal expansivity due to bonding glass 5 material is less than the expansion that AlN substrate 2, AlN substrate 2 produces because being heated and bonding glass 5 can be made to produce stress with SiC sensitive element 1 surface of contact, and along with the increase of bonding glass 5 thickness, stress first reduces rear increase.Two kinds of effects have an impact simultaneously, and the thermal stress that result in SiC sensitive element 1 surface presents the variation tendency that the increase first increases and then decreases along with bonding glass 5 thickness increases again.

Therefore, fixing AlN substrate 2 diameter is 10mm, to AlN substrate 2 thickness and bonding glass 5 thickness, the different valued combinations in size tolerance band do comprehensive test, first calculate for each bonding glass 5 thickness, make SiC sensitive element 1 upper surface thermal stress reach AlN substrate 2 thickness of minimum value, more each result is compared, find when bonding glass 5 thickness is 2.5mm, when substrate thickness is 11mm, in sensitive element, cardiac stress is minimum.

Result shows: after optimized packaging structure and parameter, SiC sensitive element 1 surface stress reduces greatly, and wherein cardiac stress value becomes 0.14367MPa from original 39.246MPa, is reduced to original 0.37%, and the thermal stability of sensor is largely increased.

With above-mentioned according to desirable embodiment of the present utility model for enlightenment, by above-mentioned description, relevant staff in the scope not departing from this utility model technological thought, can carry out various change and amendment completely.The technical scope of this utility model is not limited to the content on instructions, must determine its technical scope according to right.

Claims

1. a SiC high temperature capacitor pressure transducer, it is characterized in that: by SiC sensitive element (1), column AIN substrate (2), lead-in wire (3) and tubular kovar alloy shell (4) composition, described SiC sensitive element (1) is made up of two panels SiC wafer, there is between SiC wafer reference vacuum cavity, outer, the upper surface place of described AIN substrate (2) is evenly equipped with some lead-in wires (3), the middle part of its upper surface is bonded by bonding glass (5) and SiC sensitive element (1), the diameter of AIN substrate (2) is 10mm, the thickness of described bonding glass (5) is 2.5mm, AIN substrate (2) is bonded on the inwall of kovar alloy shell (4) by seal glass (6).

2. SiC high temperature capacitor pressure transducer according to claim 1, is characterized in that: the diameter of described lead-in wire (3) is 0.3mm, and the wall thickness of kovar alloy shell (4) is 1mm.