CN1272611C - Superhigh pressure dynamic pressure sensor - Google Patents

Abstract

The present invention discloses an ultrahigh-pressure dynamic pressure sensor which comprises a housing body, wherein a sensitive bearing diaphragm is arranged on the periphery of the housing body; one end of the housing body is provided with a strain cylinder through threads. A platform is arranged on the strain cylinder, and an SOI silicon micro solid piezoresistive chip and a circuit board are arranged on the platform; the silicon micro solid piezoresistive chip is connected with the circuit board through a gold wire, and a leading wire on the circuit board is penetrated out from the bottom of the strain cylinder through a hole on the platform. A replaceable spacer is arranged at the other end of the housing body, and the replaceable spacer is connected with the sensitive bearing diaphragm on the periphery of the housing body. The sensor has the characteristics of simple and reasonable structure, high measuring pressure, good dynamic performance, high-temperature impact resistance, reuse, etc. The ultrahigh-pressure dynamic pressure sensor of the present invention can meet the use requirements of places of explosive initiating test, bore pressure field measurement, etc.

Description

Superhigh pressure dynamic pressure sensor

Technical field

The invention belongs to the production and the application of pressure transducer, relate to a kind of superhigh pressure dynamic pressure sensor.

Background technology

The measurement of explosion pressure ripple is significant for calculating explosion isolation device, evaluation weapon lethality and calculating shell flying distance and speed etc.The blast process of explosive is the transient process of a UHV (ultra-high voltage), high temperature, requires sensor to have good dynamic characteristics and heat-resisting ability.During as certain type explosive charge, the pressure of generation is up to 10GPa, and temperature is up to 3000 ℃, and the duration is a μ s level.The dynamic response of the manganese-copper piezoresistance formula strain-ga(u)ge transducer of widespread use is a problem always, and this sensor is disposable, and the life-span has only 1 μ s, can not reuse.This has not only increased testing cost, and makes resulting distorted signals easily, influences the accuracy of measurement data.According to the data-searching that the applicant carried out, also there be not the product and the relevant report of the pressure transducer of UHV (ultra-high voltage) kinetic measurement at present.

Summary of the invention

The objective of the invention is to, a kind of pressure transducer of a kind of UHV (ultra-high voltage) kinetic measurement based on the SOI technology is provided, this set of sensors stress sensitive and power electricity transition detection is in one, and the transient state UHV (ultra-high voltage) that is specially adapted to that bore implode pressure field is measured and explosive column detonates and measures etc. is measured.

The technical solution that realizes above-mentioned purpose is, a kind of superhigh pressure dynamic pressure sensor, it is characterized in that, this sensor comprises housing, the housing circumference is provided with a responsive pressure containing disk, by screw thread the strain cylinder is housed in the cavity of housing, one platform is arranged on the strain cylinder, this is provided with little solid-state pressure drag chip of SOI silicon and circuit board above platform, the little solid-state pressure drag chip of SOI silicon is positioned at the back side of the responsive pressure containing disk on the housing circumference, the little solid-state pressure drag chip of SOI silicon is connected with circuit board by spun gold, lead-in wire on the circuit board passes from strain cylinder bottom by the hole on the platform, the other end at housing is provided with replaceable shim, and the responsive pressure containing disk on the circumference of this replaceable shim and housing is connected.

This sensor adopts replaceable pad, responsive pressure containing disk and silicon to isolate the little solid-state pressure drag chip of SOI silicon, and the strain column structure of a kind of film-post combination, the transient state UHV (ultra-high voltage) problems of measurement that has solved that bore implode pressure field is measured and explosive column detonates and measure etc.Adopt the eutectic solder technology simultaneously, solved the sluggish problem of sensor, greatly improved the dynamic response of sensor.Adopting at direct pressure-bearing position can quick-replaceable pad, and having solved the UHV (ultra-high voltage) survey sensor can not reusable shortcoming.This sensor has gaging pressure height, good, the high temperature resistant impact of dynamic perfromance, characteristics such as reusable.The superhigh pressure dynamic pressure sensor that the present invention relates to can satisfy the request for utilization of occasions such as explosive initiation test and the measurement of bore pressure field.

Description of drawings

Fig. 1 is a superhigh pressure dynamic pressure sensor structural representation of the present invention;

Fig. 2 is superhigh pressure dynamic pressure sensor mounting structure figure of the present invention;

Fig. 3 is the decomposing schematic representation of Fig. 1;

Fig. 4 is a superhigh pressure dynamic pressure sensor fundamental diagram of the present invention, and wherein (a) is pressure-bearing sensitive diaphragm deformation principle figure, (b) is that pressure F and strain cylinder 3 produce the strain schematic diagram.

Fig. 5 is the structural drawing and the microphoto of the little solid-state pressure drag chip of SOI silicon, and wherein (a) is structural drawing, (b) is microphoto.

The embodiment that realizes below in conjunction with accompanying drawing and inventor and the present invention are used for explosive initiation test and the measurement of bore pressure field and principle of work and are described in further detail.

Embodiment

With reference to Fig. 1～Fig. 3, main superhigh pressure dynamic pressure sensor of the present invention, comprise housing 2, responsive pressure containing disk is arranged on the circumference of housing 2, one end of housing 2 is equipped with strain cylinder 3 by screw thread, one platform is arranged on strain cylinder 3, this is provided with little solid-state pressure drag chip 4 of SOI silicon and circuit board 5 above platform, the little solid-state pressure drag chip 4 of SOI silicon is connected with circuit board 5 by spun gold, lead-in wire on the circuit board 5 passes from strain cylinder 3 bottoms by the hole on the platform, the other end at housing 2 is provided with replaceable shim 1, and the responsive pressure containing disk on the circumference of this replaceable shim 1 and housing 2 is connected.

Consider that the pressure that sensor bore is very high, adopts other pressing plate 6 that sensor is fixed on bore or the sidewall of the case that explodes etc. on to reduce the power that sensor body is born.

Because under UHV (ultra-high voltage) and high temperature action, metal can produce pit, can reuse in order to make sensor, has adopted replaceable shim 1.Replaceable shim 1 can adopt bonding with being connected of responsive pressure containing disk or fix (not drawing among the figure) with threaded gland.Responsive pressure containing disk on the housing 2 and housing 2 integral body are processed.Because explosion pressure is very high, the intensity of responsive pressure containing disk is difficult to bear, and on the other hand, it is easy to operate to consider that the little solid-state pressure drag chip 4 of SOI silicon mounts, and adopts column type strain unit 3 that strain is passed to pressure drag chip 4.The little solid-state pressure drag chip 4 of SOI silicon is bonded on the plane that produces of column type response body 3 by eutectic welding or other packaging technologies.Lead-in wire passes from strain cylinder 3 bottoms by circuit board 5, and draw in the hole from fixation clip 6.

Four gib screws of fixation clip 6 usefulness by be connected on the sensor housing four holes and carrier (bore or blast case) be connected and fixed.Pressure acts on the replaceable shim 1 of sensor end vertically, be delivered to again on the responsive pressure containing disk on housing 2 circumference, strain is passed to the strain cylinder 3 of column by responsive pressure containing disk, the little solid-state pressure drag chip 4 of SOI silicon that sticks on the strain cylinder 3 (steel column) receives strain, the variation that has a resistance changes thereby detect explosion pressure.

With reference to Fig. 4 (a), Fig. 4 (b), the principle of work of UHV (ultra-high voltage) pressure transducer is as follows: when well-distributed pressure act on housing 2 peripheral fixed supports, radius is R, thickness is on the circular pressure-bearing sensitive diaphragm of h, the pressure-bearing sensitive diaphragm produces distortion, distributed force is converted into the pressure F on the strain cylinder 3 that acts on column type, pressure F makes strain cylinder 3 produce strains:

$\mathrm{\&epsiv;}=\frac{F}{\mathrm{EA}}=\frac{\mathrm{q\&pi;}{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="C20051004277400081.png"\; state="\{\{state\}\}">R</figure-callout>}}^2}{\mathrm{EA}}---\left(1\right)$

In the formula, q is a pressure, and unit is Pa; E is the elastic modulus of material, and unit is Pa; R is the radius of diaphragm, and unit is m; A is the cross-sectional area of column type response body, and unit is m ²

Referring to, because the STRESS VARIATION that pressure q produces on the column type response body detects by the little solid-state pressure drag chip 4 of SOI silicon that the eutectic welding is encapsulated in the concentrated position of cardiac stress in the sensing unit.The arm resistance resistance of the Wheatstone bridge in the little solid-state pressure drag chip 4 of SOI silicon changes pro rata, because:

$\frac{\mathrm{\&Delta;R}}{R_0}=\frac{\mathrm{\&Delta;\&rho;}}{{\mathrm{\&rho;}}_0}=\mathrm{\&pi;\&sigma;}---\left(2\right)$

Electric bridge is exported electric signal under the excitation of fixed power source.The size of the variation of stress and power F is directly proportional, thereby just can predict the size of stress by the size of output signal, and through type (1) can calculate by measuring pressure q.The range of sensor and sensitivity etc. can be adjusted by the thickness and the diameter of the adjustment pressure containing disk in the sensing unit on the housing 2.According to the characteristics of silicon piezoresistive principles, during the design pressure transducer range, be that basis calculates parameters such as the diameter of pressure containing disk and thickness with the detected strain of the beam check point SOI of place sensitive element≤500 μ ε.

Adopt SOI technology and various silicon micromachining technique on (100) silicon wafer face, to produce little solid-state pressure drag chip 4 structures of required SOI silicon shown in Fig. 5 (a), comprise the SiO of 4000 ₂Be used for isolated measurement circuit layer and silicon base; with LPCVD method extension and be met the monocrystalline silicon layer thickness of piezoresistive effect (about 1.5～2u) and silicon nitride stress matching layer and the protective seam of upper strata 0.1～0.3u, silicon nitride layer wherein is used to eliminate silicon and SiO ₂Influence because of the different thermal stress that cause of thermal expansivity.Resistor stripe adopts four folded structures, relief shape, has the high advantage of detection sensitivity.In order to realize the bonding operation better, carried out gold-plated at the back side of the little solid-state pressure drag chip 4 of SOI silicon.Owing to adopted SOI technology and titanium-platinum-golden beam leaded structure, this chip can work under 200 ℃～400 ℃ conditions, has solved the influence that has leakage current under the high temperature, satisfies rugged surroundings downforce Testing requirement such as high temperature.

Adopt the eutectic solder technology, during encapsulation the position of the little solid-state pressure drag chip 4 of SOI silicon on strain cylinder 3 platforms is arranged on the back side of the pressure containing disk on housing 2 circumference.The solder component of eutectic weldering is 98Au/2Si, in that little solid-state pressure drag chip 4 is welded on and becomes on cylinder 3 platforms with SOI silicon under 380～430 ℃ the environmental baseline, and corresponding with the centre at the back side, pressure-bearing sensitive diaphragm unit.Eutectic welding has the weld strength height, welds smoothly, and the thermal resistance between pressure-bearing and the pressure-bearing sensitive diaphragm unit is little, and has resistance to elevated temperatures.

The microphoto of the little solid-state pressure drag chip 4 of SOI silicon that the inventor finishes by technique scheme is shown in Fig. 5 (b).Its overall dimensions: φ 16mm (D) * 8mm (L), range: 5GPa～10GPa; Resolution: 0.2GPa; Power supply: constant current source 1.5mA; Working temperature: 3000 ℃ (impact).Reached purpose of design through experiment showed.

Claims (3)

1. superhigh pressure dynamic pressure sensor, it is characterized in that, this sensor comprises housing (2), housing (2) circumference is provided with a responsive pressure containing disk, by screw thread strain cylinder (3) is housed in the cavity of housing (2), on strain cylinder (3), a platform is arranged, this is provided with little solid-state pressure drag chip of SOI silicon (4) and circuit board (5) above platform, the little solid-state pressure drag chip of SOI silicon (4) is positioned at the back side of the responsive pressure containing disk on housing (2) circumference, the little solid-state pressure drag chip of SOI silicon (4) is connected with circuit board (5) by spun gold, lead-in wire on the circuit board (5) passes from strain cylinder (3) bottom by the hole on the platform, the other end at housing (2) is provided with replaceable shim (1), and the responsive pressure containing disk on the circumference of this replaceable shim (1) and housing (2) is connected.

2. superhigh pressure dynamic pressure sensor as claimed in claim 1 is characterized in that, the back side of the little solid-state pressure drag chip of described SOI silicon (4) is gold-plated.

3. superhigh pressure dynamic pressure sensor as claimed in claim 1 is characterized in that, responsive pressure containing disk on described housing (2) circumference and housing (2) integral body process.

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