CN87216349U

CN87216349U - Solid-state piezoresistance type differential pressure transducer

Info

Publication number: CN87216349U
Application number: CN 87216349
Authority: CN
Inventors: 杨天成; 阎雄德; 王文襄; 李锡奎
Original assignee: QINLING TRANSISTOR FACTORY BAOJI
Current assignee: QINLING TRANSISTOR FACTORY BAOJI
Priority date: 1987-12-11
Filing date: 1987-12-11
Publication date: 1988-10-19

Abstract

The utility model relates to a solid state piezoresistance type differential pressure transducer, which is an ideal transducer used for the automatic measurement and control to gas and liquid. The utility model has the essences that two pressure chambers adopt isolation of rubber elastic diaphragms, reverse loading of sensitive chips, overload protection of load plates, etc. The utility model has the characteristics of simple structure, high precision and strong applicability; the golden wires of the inner leads are replaced by gold plating copper wires.

Description

Solid-state piezoresistance type differential pressure transducer

The utility model belongs to sensor and makes the field.

Prior art in the utility model prior art field is: the utility model applying unit little differential pressure pick-up of prepattern products C YG19 and CYG02 differential pressure pick-up device, the sensor 1 of this kind structure, owing to do not take quarantine measures, internal lead directly is exposed in the pressure chamber, so measuring media is only limited to dry, free from corrosion non-conductive gas, has greatly limited its application; 2, because internal lead adopts the precious metal spun gold, all bring very big difficulty for welding, alignment, the installation of sensor internal lead, long slightly not only operative employee's visual deterioration of working time, and consume precious metal, cost height again, social benefit is poor; When 3, being used for measurement or control, measured medium directly acts on sensitive chip, owing to there is not the overload protection facility, thereby when measured medium pressure fluctuation occurs because of certain reason, when making differential pressure value surpass the maximum range that sensitive chip allows, just can cause sensitive chip to damage and sensor is scrapped; 4, owing to adopt stirrup to grip outer lead,, sensor is damaged so when outer lead was subjected to the external force tractive, outer lead was extracted out easily and disconnected with internal lead.Because the outer lead screen layer does not have the measure that contacts well with housing, not only reduced the jamproof performance of sensor simultaneously, and poor work stability.

Purpose of design of the present utility model is: at the weak point of above-mentioned existence, design and a kind ofly can make solid-state pressure resistance type differential pressure pick-up be used to measure and control the differential pressure of all gases, liquid, can have certain overload capacity again, adopt gold-plated copper wire to replace spun gold as internal lead with improve the outer lead structure simultaneously, make the stable and reliable working performance of its sensor, volume is little, cost is low, high efficiency.

Design proposal of the present utility model is: 1, two pressure chambers of solid-state pressure resistance type differential pressure pick-up adopt the caoutchouc elasticity diaphragm to isolate, the inboard of caoutchouc elasticity diaphragm is several concavity shapes, and in pressure chamber, be full of oil (silicone oil or fluorocarbon oil), because silicone oil or fluorocarbon oil have incompressibility, so when the pressure of tested gas or liquid is chewed when reaching the caoutchouc elasticity diaphragm by two terminations, the caoutchouc elasticity pressure that diaphragm is experienced at two ends is delivered on the sensitive chip by silicone oil or fluorocarbon oil, sensitive chip is then exported the signal that corresponds to two ends input pressure difference, makes that like this application of solid-state pressure resistance type differential pressure pick-up is more extensive.Simultaneously, for fear of the influence of the caoutchouc elasticity diaphragm oil-filled temperature drift that brings in two ends to the sensitive chip output signal, the two ends separate cavities will guarantee that its volume is equal substantially, in order to the influence of compensation temperature variation to the sensitive chip characteristic; 2, sensitive chip is embedded in to adopt in the film and tightens up the cushion film that ring and insulation spacer will be embedded with sensitive chip and be fastened in the pedestal, and the sensitive chip device for fastening is positioned at a pressure chamber, being connected in another pressure chamber between internal lead and the outer lead.Like this, conventional two drawbacks that the pressure chamber volume does not wait being brought in the same chamber that coupling arrangement between sensitive chip device for fastening and the interior outer lead is concentrated on have not only been eliminated, also greatly compressed simultaneously the volume of two separate cavities, and during for a small amount of journey, overcome because oil-filled giving measured or error that control brings; 3, since sensitive chip with silicon as substrate, its extension line position is carried out and is covered with the very thin aluminium lamination of one deck, internal lead will with the aluminium lamination bonding, internal lead adopts gold-plated copper wire (the about 0.05-0.12 millimeter of diameter), be fixed on the insulator through a minute coil holder, thereby replace conventional spun gold, like this, both guaranteed the characteristics of spun gold and aluminium, the easy bonding of silicon, and be to have intensity better than spun gold one, the 2nd, fusing point improves, and is difficult for fusing during welding, and the 3rd, connect more reliable.Simultaneously,, thereby easily observe, easily welding, easily install, and avoided harm operative employee's eyesight because the diameter of gold-plated copper wire is greater than the diameter of spun gold, social, good in economic efficiency; 4, for job stability and the reliability that guarantees sensitive chip, the load sheet is installed in the inboard and the centre of caoutchouc elasticity diaphragm and leaves certain clearance, when two ends caoutchouc elasticity diaphragm passes to the sensitive chip differential pressure, make sensitive chip generation elastic deformation and recessed to the little chamber of pressure, the caoutchouc elasticity diaphragm in the chamber that pressure is big is surveyed recessed to the load plate, increase along with differential pressure value, gap between the caoutchouc elasticity diaphragm in the chamber that pressure is big and load plate dwindles thereupon, when the suffered differential pressure value of sensitive chip reaches certain value (specified range), the caoutchouc elasticity diaphragm in the chamber that pressure is big is close together with the load plate, when at this moment the pressure of measured medium increases again, deformation does not take place in the caoutchouc elasticity diaphragm owing to load the spacing of plate, therefore, overload pressure again transmits less than on the sensitive chip, thereby has played the purpose of protection sensitive chip; 5, the metallic shield silk layer as the cable of outer lead is separated with its lead, adopt clamp to clamp shielded metal silk layer respectively, and in its slit, charge into bonding agent, the clamp that the solidus cap will clamp shielded metal silk layer is fastened on the solidus seat together, make conducting good between screen layer and housing, improve the antijamming capability of its sensor output signal, and make the lead that breaks away from screen layer in sensor housing, be in relaxed state, when having avoided cable to be subjected to the shell tractive, in the drawback of pad disconnection.

The utility model compared with prior art adopts caoutchouc elasticity diaphragm isolated pressure chamber, makes that sensor bulk is little, precision is high, applicability is strong; Sensitive chip adopts the method for upside-down mounting that the oil-filled chamber volume is dwindled greatly, and equal substantially, has overcome the influence of temperature variation to sensor; Internal lead adopts gold-plated copper wire to replace spun gold, is easy to install welding, and unfailing performance strengthens, and has avoided the harm to people's eyesight, adopts the load plate as overload protection and simple in structure, is easy to realize; Outer lead adopts the clamp solidus, and reliability height, contact have well improved the sensor anti-jamming capacity.

Description of drawings:

Fig. 1 is the cross-sectional schematic of solid-state pressure resistance type differential pressure pick-up.

The drawing reference numeral explanation:

1-connects and chews the 2-lid

3-gib screw 4-press mold ring

The 5-caoutchouc elasticity diaphragm 6-plate of loading

7-insulator 8-oil sealing screw

9-rigidity ball 10-pedestal

11-silicone oil (or fluorocarbon oil) 12-internal lead

13-divides coil holder 14-cushion film

The hard insulation spacer of 15-sensitive chip 16-

17-tightens up ring 18-sheath body

19-outer lead 20-solidus seat

21-solidus cap 22-clamp

23-bonding agent 24-screen layer

Embodiment:

Fig. 1 is a kind of embodiment of solid-state pressure resistance type differential pressure pick-up.

The enforcement of solid-state pressure resistance type differential pressure pick-up: the front of sensitive chip 15 (internal lead one side) is loaded in the cushion film 14, tightening up ring 17 is fastened on sensitive chip 15 and cushion film 14 on the pedestal 10 through hard insulation spacer 16, and internal lead 12 is welded on the insulator 7 through a minute coil holder, press mold ring 4 is fastening with caoutchouc elasticity diaphragm 5 and load plate 6, connect and chew 1 and press on press mold ring 4, another chamber is identical.The screen layer of outer lead 19 adopts clamp 22 to clamp, and the centre is filled with bonding agent 23, and solidus cap 21 is anchored on clamp 22 on the solidus seat 20 together with screen layer.Oil sealing screw 8 presses rigidity ball 9 in oil hole bell place, has been full of silicone oil or fluorocarbon oil between caoutchouc elasticity diaphragm 5 and the sensitive chip 15, and the embodiment in another chamber is identical therewith.

Claims

1, a kind of solid-state pressure resistance type differential pressure pick-up is characterized in that: two pressure chambers of 1. solid-state pressure resistance type differential pressure pick-up adopt caoutchouc elasticity diaphragm 5 to isolate respectively; 2. sensitive chip 15 is embedded in the cushion film 14, adopts to tighten up the cushion film that ring 17 and insulation spacer 16 will be embedded with sensitive chip and be fastened in the pedestal 10; 3. internal lead 12 adopts and crosses golden copper wire and be fixed on the insulator 7 through minute coil holder 13, and load sheet 6 is installed in the inboard and the centre of caoutchouc elasticity diaphragm 5 and leaves certain clearance, plays overload protection; 4. the metallic shield silk layer as the cable of outer lead 19 is separated with its lead, adopt clamp 22 to clamp shielded metal silk layer respectively, and it is tight to charge into bonding agent 23 envelopes in its slit, the clamp that solidus cap 21 will clamp shielded metal silk layer is fastened on the solidus seat 20 together, make conducting good between screen layer and housing, improve the antijamming capability of its sensor output signal, and make the lead that breaks away from screen layer in sensor housing, be in relaxed state, when having avoided cable to be subjected to the external force tractive, in the drawback of pad disconnection.

2, solid-state pressure resistance type differential pressure pick-up according to claim 1, it is characterized in that: the inboard of caoutchouc elasticity diaphragm 5 is several concavity shapes.

3, solid-state pressure resistance type differential pressure pick-up according to claim 1 is characterized in that: be full of oil between caoutchouc elasticity diaphragm 5 and sensitive chip 15.

4, solid-state pressure resistance type differential pressure pick-up according to claim 1, it is characterized in that: the diameter that crosses the internal lead of golden copper wire is the 0.05-0.12 millimeter.

5, solid-state pressure resistance type differential pressure pick-up according to claim 1 is characterized in that: the error of the ratio of the volume of two pressure chambers that employing caoutchouc elasticity diaphragm 5 is isolated is not more than 10%.