JPH073311Y2 - Semiconductor differential pressure measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a semiconductor differential pressure measuring device capable of downsizing the device, simplifying the structure, and improving reliability.

<Prior Art> FIG. 4 is an explanatory view of a configuration of a conventional example which is generally used in the past.

In the figure, 1 is a sensor chip made of a semiconductor.

11 is provided in the sensor chip 1, and the sensor chip 1 has
It is a recess that forms the diaphragm 12.

Reference numeral 13 is a semiconductor strain gauge provided on the diaphragm 12.

Reference numeral 14 is an amplifier circuit chip made of a semiconductor that amplifies and calculates the output of the semiconductor strain gauge 13.

Reference numeral 15 is an insulating plate whose one surface is fixed to the amplifier circuit chip 14.

Reference numeral 2 denotes a substrate having one surface fixed to the sensor chip 1 and the amplifier circuit chip 14 and forming the recess 11 and the first measurement chamber 21.

Reference numeral 22 is a through hole penetrating the substrate 2 and communicating with the first measurement chamber 21.

Reference numeral 3 is a pipe whose one end is connected to the other surface of the substrate 2 and which communicates with the through hole 22 and into which one measuring pressure P1 is introduced from the other end.

4 is a base to which the pipe 3 is fixed.

Reference numeral 5 denotes a body having one end fixed to the base 4 and forming the base 4, the sensor chip 1 and the second measurement chamber 51.

Reference numeral 52 is a recess provided on the other end of the body 5.

Reference numeral 6 denotes a liquid contact diaphragm which is provided in the body 5 and constitutes the recess 52 and the liquid contact chamber 61.

Reference numeral 53 is a communication hole provided in the body 5 for communicating the second measurement chamber 51 and the liquid contact chamber 61.

501 is a filled liquid that fills the second measurement chamber 51, the liquid contact chamber 61, and the communication hole 53.

In the above configuration, when the measurement pressure P1 is applied to the pipe 3 and the measurement pressure P2 is applied to the wetted diaphragm 6, the diaphragm
The differential pressure between the measured pressure P1 and the measured pressure P2 is applied to 12, and this differential pressure is detected by the semiconductor strain gauge 13,
The output of 13 is amplified and calculated by the amplifier circuit chip and output as an output signal.

<Problems to be Solved by the Invention> However, in such a device, since the sensor chip 1 and the amplifier circuit chip 14 are arranged on substantially the same plane, (1) between the two chips 1 and 14. Wire bonding for electrically connecting the wires is required.

(2) A large space is required to accommodate both chips 1 and 14 in the same room, which increases the amount of the enclosed liquid 501,
The outer diameter of the semiconductor differential pressure measuring device also becomes large.

(3) Since electrical insulation is required to attach the amplifier circuit chip 14 to the base 4, a plate 15 for insulation must be inserted between the two.

In the semiconductor differential pressure measuring device, it is desirable that the semiconductor strain gauge 13 and the amplifier circuit are formed on the same silicon chip, but they are hardly put into practical use because of a poor yield rate.

This is because the semiconductor strain gauge 13 and the amplifier circuit 14 have a plane orientation that is easy to produce in the semiconductor process and a plane orientation that is difficult to produce in the semiconductor process, and the yield rate is better when produced on a silicon wafer having an easy orientation. .

The semiconductor strain gauge 13 is generally formed on the (100) plane because it has a large piezoresistance coefficient.

The amplifier circuit chip 14 is generally formed on the (111) plane because it has good operation stability.

Further, since the semiconductor strain gauge 13 and the amplifier circuit chip 14 are basically different in the semiconductor process itself, it is originally difficult to form them on the same wafer.

Therefore, conventionally, the semiconductor strain gauges 13 having different plane orientations and the amplifier circuit chip 14 are arranged close to each other on the same plane.

This aims at (1) improving the temperature characteristics by keeping the same temperature.

(2) This is to reduce the number of lead wires for taking out electric signals to the outside.

The present invention solves this problem.

An object of the present invention is to provide a semiconductor differential pressure measuring device capable of downsizing the device, simplifying the structure, and improving reliability.

<Means for Solving the Problems> In order to achieve this object, the present invention provides a sensor chip made of a semiconductor, a connection pad provided on one surface of the sensor chip, and a sensor chip provided on the sensor chip. A recess forming a diaphragm, a semiconductor strain gauge provided on the diaphragm, and a semiconductor strain gauge connected in parallel to the sensor chip via a connection pad provided on one surface of a connection pad of the sensor chip. An amplifier circuit chip for amplifying / calculating the output; a substrate having one surface fixed to the sensor chip and forming the recess and the first measurement chamber; a through hole penetrating the substrate and communicating with the first measurement chamber; A pipe, one end of which is connected to the other surface of the substrate and which is in communication with the through hole and into which one measurement pressure is introduced from the other end,
A base to which the pipe is fixed; a body having one end fixed to the base to form the base, the sensor chip, and a second measurement chamber; a recess provided at the other end of the body; A liquid contact diaphragm that constitutes the recess and the liquid contact chamber and receives the other measurement pressure, a communication hole that is provided in the body and that communicates the second measurement chamber and the liquid contact chamber, the communication hole and the interior. A semiconductor differential pressure measuring device comprising a void, the second measuring chamber, the liquid contact chamber, and a filling liquid filling the communication hole.

<Operation> In the above configuration, one measuring pressure is applied to the pipe,
When the other measuring pressure is applied to the liquid contact diaphragm, the differential pressure between one measuring pressure and the other measuring pressure is applied to the diaphragm.
This differential pressure is detected by the semiconductor strain gauge, and the output of the semiconductor strain gauge is amplified and calculated by the amplifier circuit chip and output as an output signal.

Hereinafter, detailed description will be given based on examples.

<Embodiment> FIG. 1 is an explanatory view of a main part configuration of an embodiment of the present invention.

In the figure, the same symbols as those in FIG. 4 represent the same functions.

Only the parts different from FIG. 4 will be described below.

As shown in FIG. 2, the semiconductor strain gauge 7 is connected to the connection pad 101 of the sensor chip 1 provided in parallel to the sensor chip 1 through the connection pad 71 provided on one surface.
It is an amplifier circuit chip that amplifies and calculates the output of 13.

In the above configuration, when one measuring pressure P1 is applied to the pipe 3 and the other measuring pressure P2 is applied to the liquid contact diaphragm 6,
A differential pressure between one measurement pressure P1 and the other measurement pressure P2 is applied to the diaphragm 12.

This differential pressure is detected by the semiconductor strain gauge 13, and the output of the semiconductor strain gauge 13 is amplified and calculated by the amplifier circuit chip 7 and output as an output signal.

Then, the semiconductor strain gauge 13 and the amplifier circuit chip 7 are joined together as follows.

Pads 101 and 71 for soldering are prepared at the facing positions on the joint surfaces of the chips 13 and 7. This pad 101,71
After the cream solder is printed on, the chips 13 and 7 are put together, and the solder is melted and joined in a temperature bath. The thickness of the solder is used to maintain a gap between the chips 13 and 7, and it is used as a measurement pressure transmission path and at the same time used as a space for pressure deformation of the diaphragm 12.

The electric signal proportional to the pressure is taken out by wire bonding from the pad 102 on the sensor chip 1 to the lead wire.

As a result, (1) the semiconductor differential pressure measuring device can be downsized.

(2) The structure of the semiconductor differential pressure measuring device can be simplified.

(3) The reliability of the semiconductor differential pressure measuring device can be improved.

FIG. 3 is an explanatory view of a main part configuration of another embodiment of the present invention.

In this embodiment, a through hole is formed in the center of the amplifier circuit chip 7.
72 is provided.

The measured pressure P2 is transmitted faster, and the one with quick response characteristics can be obtained.

<Effects of the Invention> As described above, the present invention has a sensor chip made of a semiconductor, a connection pad provided on one surface of the sensor chip, and a concave portion provided on the sensor chip and forming a diaphragm on the sensor chip. , A semiconductor strain gauge provided on the diaphragm and connected to a connection pad of the sensor chip provided in parallel with the sensor chip through a connection pad provided on one surface to amplify / calculate the output of the semiconductor strain gauge. An amplifier circuit chip, a substrate of which one surface is fixed to the sensor chip to form the recess and the first measurement chamber, a through hole that penetrates the substrate and communicates with the first measurement chamber, and has one end on the other surface of the substrate. Is connected to the through hole and one measuring pressure is introduced from the other end, a base to which the pipe is fixed, and one end to which the pipe is fixed. Body, the sensor chip, and the body forming the second measurement chamber, the recess provided at the other end of the body, the recess provided in the body and the liquid contact chamber, and receiving the measurement pressure of the other. A liquid contact diaphragm, a communication hole provided in the body for communicating the second measurement chamber with the liquid contact chamber, the communication hole, the internal space, the second measurement chamber, the liquid contact chamber, and the communication hole. A semiconductor differential pressure measuring device comprising a filling liquid filling the holes was constructed.

As a result, (1) the semiconductor differential pressure measuring device can be downsized.

(2) The structure of the semiconductor differential pressure measuring device can be simplified.

(3) The reliability of the semiconductor differential pressure measuring device can be improved.

Therefore, according to the present invention, it is possible to realize a semiconductor differential pressure measuring device capable of downsizing the device, simplifying the structure, and improving reliability.

[Brief description of drawings]

FIG. 1 is an explanatory view of the essential parts of one embodiment of the present invention, FIG. 2 is an explanatory view of the essential parts of FIG. 1, and FIG. 3 is an explanatory view of the essential parts of another embodiment of the present invention. FIG. 4 is an explanatory diagram of a configuration of a conventional example which is generally used from the past. 1 ... Sensor chip, 101, 102 ... Pad, 11 ... Recess, 12 ...
Diaphragm, 13 ... Semiconductor strain gauge, 2 ... Substrate, 21 ...
First measurement chamber, 22 ... Through hole, 3 ... Pipe, 4 ... Base, 5
... Body, 51 ... Second measuring chamber, 52 ... Recessed portion, 53 ... Communication hole, 6
... liquid contact diaphragm, 61 ... liquid contact chamber, 7 ... amplification circuit chip, 71 ... pad, 72 ... through hole.

Claims (1)

[Scope of utility model registration request] 1. A sensor chip made of a semiconductor, a connection pad provided on one surface of the sensor chip, a recess formed in the sensor chip to form a diaphragm on the sensor chip, and a semiconductor strain gauge provided on the diaphragm. And an amplifier circuit chip that is provided in parallel with the sensor chip and is connected to a connection pad of the sensor chip through a connection pad provided on one surface to amplify / calculate the output of the semiconductor strain gauge, and one surface on the sensor chip. A substrate which is fixed to form the recess and the first measurement chamber, a through hole which penetrates the substrate and communicates with the first measurement chamber, and one end of which is connected to the other surface of the substrate and which communicates with the through hole A pipe into which one measuring pressure is introduced from an end, a base to which the pipe is fixed, one end fixed to the base, the base, the sensor chip, and a second measurement A body constituting the body, a concave portion provided at the other end of the body, a liquid contact diaphragm provided in the body to form a liquid contact chamber with the concave portion and receiving a measurement pressure of the other, and a body provided in the body, A communication hole that communicates the second measurement chamber with the liquid contact chamber; and a filled liquid that fills the communication hole, the internal space, the second measurement chamber, the liquid contact chamber, and the communication hole. Semiconductor differential pressure measuring device.