JPH06129926A - Manufacture of pressure sensor element and pressure sensor using said pressure sensing element - Google Patents

Abstract

PURPOSE:To provide a manufacturing method, of a pressure sensor element, wherein its productivity can be enhanced and to provide a pressure sensor using the pressure sensor element. CONSTITUTION:A plurality of recessed parts are formed on a wafer composed of a titanium alloy, the wafer is annealed, the wafer is divided and a plurality of pressure sensor elements 5 are obtained. At this time, since the titanium alloy is used for the wafer, no warp is caused. Each pressure sensor element 5 is attached to a tube member 3, the tube member is inserted into, passed through, fixed and bonded to, a through hole 2 in a housing 1. In order to eliminate the difference in a coefficient of linear expansion, a titanium alloy is used for the tube member 3. Even when stainless steel is used for the housing 1, the tube member 3 can be fixed and bonded firmly when it is welded by interposing an auxiliary material 11. When a relief (b) is formed between the tube member 3 and the housing, the linear expansion of both can be absorbed. When a circuit board 6 is installed in a space formed by the housing 1 and a connector 8 provided with a terminal 9, a detection signal obtained from the pressure sensor element 5 is output to the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a pressure sensor element and a pressure sensor using the pressure sensor element, and more particularly to a method for manufacturing a pressure sensor element for detecting an acting pressure and the pressure sensor element. The present invention relates to a pressure sensor that outputs an electric signal according to the pressure introduced by using the pressure sensor.

[0002]

2. Description of the Related Art Conventionally, as a pressure sensor element for detecting a pressure, as shown in FIGS. 15 and 16, a diaphragm structure having a thin portion is generally known.

That is, in the pressure sensor elements 55 and 55a shown in FIGS. 15 and 16, the concave portions 63 and 63a are formed in the end faces of the metal cylindrical body, respectively.
A thin pressure receiving portion is formed at a portion corresponding to the recesses 63 and 63a to form a diaphragm structure. A strain gauge (not shown) which is a sensor for sensing pressure is provided on the pressure receiving portion. ) Is formed, and the wiring film (not shown) is further patterned.

Such pressure sensor elements 55, 55a
Is manufactured by a so-called one-piece sink and manufactured one by one, but it is not suitable for mass production, and it takes a lot of time to attach and detach products during the manufacturing process. Met.

Therefore, in consideration of mass production, a manufacturing method called so-called multiple sink as shown in FIG. 17 has been considered. That is, a metal diaphragm in which a thin pressure-receiving portion is formed in a space formed by matching a disc-shaped jig upper portion 60 having a plurality of holes and a jig lower portion 61 corresponding thereto. After molding the structure, a strain gauge (not shown) as a sensor is formed on this pressure receiving portion, and a wiring film (not shown) is further patterned.

Then, the pressure sensor element 55a is mounted on the jig 6
A plurality of pressure sensor elements 55a can be obtained at one time by removing the pressure sensor elements 55a from the jig 0 and the lower jig 61.

However, in this way, the jigs 60, 61
In the method of manufacturing the pressure sensor element 55a by using, a high-accuracy jig is required to ensure the accuracy of the patterning of the sensor and the wiring film formed on the pressure-receiving portion, and special manufacturing equipment is required. However, there is a problem that the cost becomes high.

On the other hand, in order to reduce the manufacturing cost as described above, as shown in FIG. 18, a concave portion 73 is formed at a required portion of the metal disk-shaped wafer 62 and the concave portion is formed. A thin pressure receiving portion is formed at a portion corresponding to 73, and a gauge and a wiring film are sequentially patterned on each pressure receiving portion to form a pressure sensor element 75 as shown by a chain double-dashed line in FIG. A method is considered in which a plurality of pressure sensor elements 75 can be obtained at one time by separating them.

According to such a method, if a wafer for a memory chip is used, for example, when patterning a strain gauge or a wiring film on the wafer 62, the equipment for manufacturing the memory chip can be used as it is. Therefore, as a result, general equipment can be used and cost can be reduced.

However, in the method of manufacturing the pressure sensor element 75 with the metal wafer 62 as described above, the warpage a as shown in FIG. 18 occurs during the manufacturing process of the product.

That is, the conventional wafer 62 is made of SUS.
Since a (stainless steel) -based material was used, when the recessed portion 73 is formed in the wafer 62 and then quenched, the entire wafer 62 is expanded by the action of the thermal stress remaining inside. Then, the warp a was generated as a result.

[0012] For example, the thickness is 2 m.
m, 3 inch diameter stainless steel wafer,
When the 12-hole recesses are uniformly formed and then quenching is performed, a warp a of 1 to 2 mm occurs.

When the wafer 62 is thus warped,
This warpage makes surface lapping impossible and causes problems in the subsequent patterning of the strain gauge, the wiring film, etc. on the pressure receiving portion.

The present invention solves the above problems by improving the method of manufacturing a pressure sensor element having a metal diaphragm structure which is excellent in thermal stability and impact resistance, and has high productivity. It is an object of the present invention to provide a method for manufacturing a pressure sensor element that can be improved and can be manufactured at low cost, and further to provide a pressure sensor using the pressure sensor element manufactured by this manufacturing method. With the goal.

[0015]

In order to solve the above problems, the present invention provides, as a first invention, a plurality of recesses formed on one end surface of a disk-shaped wafer made of a titanium alloy. , After forming a thin pressure-receiving portion in a portion corresponding to the recessed portion, annealing is performed, and then an insulating film, a gauge film, and a wiring film are sequentially formed in layers in a predetermined shape on each pressure-receiving portion of the wafer, It adopts a means of obtaining a plurality of pressure sensor elements by dividing each pressure receiving portion into a predetermined shape. Further, as a second invention, a pressure receiving portion is provided in a space formed by a housing having a through hole and a connector having a terminal, and the pressure receiving portion is provided so as to face the pressure introducing hole in the tubular member. And a pressure sensor element made of a titanium alloy positioned in the cavity by inserting and fixing the tubular member in the through hole of the housing, and a circuit board, and pressure is introduced from the pressure introducing hole. Then, the pressure is detected as an electric signal. Further, as a third invention including the second invention, the tubular member is made of a titanium alloy. In addition, as a fourth invention including the second invention, there is a configuration in which a clearance is provided between the outer peripheral surface of the cylindrical member and the inner peripheral surface of the through hole of the housing facing each other. Further, as a fifth invention including the second invention, there is a configuration in which a common material is interposed between the tubular member and the housing and the two are welded together. Further, as a sixth invention including the second invention,
The tubular member and the housing are fixed to each other by brazing with a brazing material. Also,
As a seventh invention including the second invention, a male screw portion is formed on the outer peripheral surface of the cylindrical member, and a female screw portion corresponding to the male screw portion is formed on the inner peripheral surface of the through hole of the housing. The tubular member is fixed to the housing by screwing the parts together. Further, as an eighth invention including the second invention, the outer peripheral surface of the tubular member and the inner peripheral surface of the through hole of the housing are plated with solder, and the tubular member is press-fitted into the through hole to fix the tubular member. It has the structure of being available. Further, as a ninth invention, a pressure receiving portion is provided in a space formed by a housing having a pressure introducing hole and a connector having a terminal, and the pressure receiving portion is provided so as to face the pressure introducing hole, At this time, a pressure sensor element made of a titanium alloy provided with an elastic O-ring interposed between the end surface on the side where the pressure receiving portion is not formed and the housing, and a circuit board are provided. When the pressure is introduced from the introduction hole, the pressure is detected as an electric signal.

[0016]

According to the present invention, the internal stress of the wafer generated when the recess is formed can be completely removed by annealing by adopting the means of the first invention when manufacturing the pressure sensor element. As a result, the wafer is prevented from warping such that the concave portion expands, and the end surface of the wafer becomes a flat surface, so that the insulating film, the gauge film, and the wiring film can be preferably formed. It has become.

Further, by adopting the means of the second to eighth inventions which are pressure sensors using the pressure sensor element manufactured according to the first invention, the pressure from the pressure introduction hole of the tubular member is increased. When introduced, the pressure sensor element senses the pressure and an electrical signal is generated. Then, this electric signal is guided to the circuit board, amplified, and further output from the connector through the terminal.

According to the present invention, the material of the tubular member to which the pressure sensor element is attached is made of the same titanium alloy as that of the pressure sensor element, so that there is no difference in the linear expansion coefficient between the two, which causes a particularly high temperature. Sometimes
The pressure sensor element is prevented from generating stress due to the linear expansion of the tubular member, and the deterioration of the output characteristic of the pressure sensor element is suppressed.

Further, by providing an escape between the tubular member and the through hole of the housing, even when linear expansion occurs in the tubular member and the housing, this linear expansion can be absorbed by the escape allowance. The member is not affected by the linear expansion of the housing, and as a result, the output characteristics of the pressure sensor element can be stabilized.

Further, when the tubular member is fixed to the housing, as in the fifth invention, a common material is interposed between the two members for welding, or as in the sixth invention, brazing with a brazing material. Or by screwing them together with each other as in the seventh invention, or by solder-plating both of them and press-fitting the tubular member into the through hole as in the eighth invention. Since the members are well fixed to the housing, a reliable fixed state can be obtained even when the cylindrical member and the housing are made of different materials.

Further, in the pressure sensor adopting the means of the ninth invention, since the elastic O-ring is interposed between the pressure sensor element and the housing, the material of the housing is different from that of the pressure sensor element. Even if one is used, the difference in linear expansion between the two can be absorbed by the elasticity of the O-ring, so that the output characteristics of the pressure sensor element can be made stable even when a high temperature is applied. You can do it.

[0022]

Embodiments of the present invention shown in the drawings will be described below. 2 to 5 are views for explaining an example of the method of manufacturing the pressure sensor element according to the present invention.

That is, in this method of manufacturing a pressure sensor element, a recess 13 is formed in a required portion of a wafer 12 made of a titanium alloy, and a thin pressure receiving portion is formed in a portion corresponding to the recess 13 and then annealed. Then, an insulating film, a gauge film, and a wiring film are sequentially formed in layers on each pressure-receiving portion, patterned, and then divided / separated into a predetermined shape, so that the pressure sensor elements 5 and 5a are integrated at once. It is designed such that a plurality of them can be obtained.

First, the pressure sensor element 5 is manufactured from the wafer 12 as shown in FIGS.
This wafer 12 is manufactured by using a titanium alloy as its material and is formed into a substantially disc shape. By forming a plurality of recesses 13 at required locations on one end face thereof, the recess 13 is formed. A thin pressure-receiving portion is formed at a portion corresponding to, and a diaphragm structure is formed at a plurality of locations.

After forming the concave portion 13, the wafer 12 is formed.
Is a temperature (500 to 800) below the eutectic point of its compositional components.
Annealing is performed at ° C) to remove the residual stress inside.

Next, the wafer 12 which has been subjected to the annealing heat treatment is lapped on the end surface on the side where the pressure receiving portion is formed, and the insulating film, gauge film, wiring (not shown) are formed on the entire surface. The film is, for example, sputtering,
Alternatively, they are sequentially formed in layers by means such as vacuum deposition and CVD.

After that, a precision exposure apparatus, which is a general-purpose apparatus used when manufacturing a semiconductor such as a memory chip, is used, and an insulating film, a gauge film, and a wiring film formed in layers on the pressure receiving portion of the wafer 12. Is patterned, and based on this patterning, each layered film is subjected to etching treatment, whereby an insulating film, a gauge film,
The wiring film forms a predetermined pattern on each pressure receiving portion of the wafer 12.

Here, the insulating film (not shown) formed on the pressure receiving portion of the wafer 12 is electrically interposed between the gauge film (not shown) formed on the upper surface of the wafer 12 and the main body of the wafer 12. The insulating film is formed into a thin film, so that the insulating film can be displaced integrally with the pressure receiving portion according to the displacement of the pressure receiving portion.

The gauge film formed on the insulating film is a sensor, which converts the displacement amount of the pressure receiving portion into the variation amount of the internal resistance value, whereby when the pressure receiving portion is displaced,
The displacement can be detected as an electric signal.

The wiring film (not shown) formed on the upper surface of the gauge film forms a predetermined pattern of wiring in a state of being electrically connected to the gauge film, and thereby guides the signal obtained from the gauge film to the outside. I have to.

Then, the wafer 12 having the insulating film, the gauge film, and the wiring film formed on the respective pressure-receiving portions in a predetermined pattern in this manner has its electrical characteristics inspected, and then, for example, a dicer or a wire cut, By using a water jet or the like to separate and divide each element into a predetermined shape as shown in FIG. 4 or 5, a plurality of pressure sensor elements 5, 5a can be obtained.

In this case, if a dicer is used, a prismatic pressure sensor element 5 as shown in FIG. 4 can be obtained, and if a wire cut or water jet is used, a columnar pressure sensor element 5 as shown in FIG. It is possible to obtain the pressure sensor element 5a.

FIG. 1 shows an example of a pressure sensor using the pressure sensor element 5 manufactured by the above manufacturing method.

That is, in the pressure sensor shown in FIG. 1, the pressure sensor element 5 is obtained by inserting and fixing the tubular member 3 whose one opening is closed by the pressure sensor element 5 into the through hole 2 of the housing 1. Is located inside the housing 1, and further the housing 1 and the connector 8 having the terminal 9 are provided.
The circuit board 6 and the plate 7 are provided in the space formed by and, and when pressure is introduced from the pressure introducing hole 4 inside the tubular member 3, the pressure sensor element 5 converts the pressure into an electric signal. The electric signal is detected, and thereafter, the electric signal is output to the outside from the terminal 9 of the connector 8 via the circuit board 6 and the plate 7, whereby the pressure is detected.

In FIG. 1, a housing 1 has an internal cavity that opens to one side, and a through hole 2 that connects the internal cavity with the outside is formed, and the internal cavity of the housing 1 is formed. By providing the connector 8 so as to close the opening of the housing 1, the housing 1 and the connector 8
A space is formed between the space and the pressure sensor element 5, the circuit board 6, and the plate 7 are arranged in the space.

The connector 8 provided at the opening of the inner space of the housing 1 has terminals 9, and the connector 8 is secured to the inner space of the housing 1 by crimping the opening end of the housing 1. The peripheral portion is fixed to the housing 1 in the closed state.

At this time, the connector 8 is fixed with the peripheral edges of the plate 7 and the circuit board 6 pressed against a part of the inner wall of the housing 1 via the packing 16, whereby the plate 7 and the circuit board 6 are fixed. Are fixed in a state of being engaged with the housing 1.

The terminal 9 of the connector 8 has one end extending outwardly of the connector 8 and the other end extending into the internal space of the housing 1, and the other end is the housing 1. The end portion on the side penetrates the plate 7 arranged below the connector 8 and reaches the circuit board 6 arranged below the plate 7.

The terminals 9 of the connector 8 are electrically connected to the plate 7 and the circuit board 6, respectively,
These are electrically connected through the terminal 9.

The plate 7 provided below the connector 8
Has a substantially bowl shape and has a feedthrough capacitor, and the terminal 9 of the connector 8 is passed through the feedthrough capacitor.

The circuit board 6 provided below the plate 7 has the device 10 incorporated on the board to form an electric circuit. By this electric circuit,
The electric signal sent from the pressure sensor element 5 for detecting the pressure is subjected to processing such as amplification, and the processed electric signal is sent to the terminal 9 of the connector 8 connected to the circuit board 6. I am trying to be guided.

Below the circuit board 6, the pressure sensor element 5 fixed to the tubular member 3 is positioned. Here, the pressure sensor element 5 having the above-mentioned prismatic shape is used.

Cylindrical member 3 to which the pressure sensor element 5 is fixed
Has a pressure introducing hole 4 formed therein, and the pressure sensor element 5 is provided in a state in which the pressure receiving portion is opposed to the pressure introducing hole 4 and one opening of the pressure introducing hole 4 is closed.

At this time, the joint portion between the pressure sensor element 5 and the tubular member 3 is irradiated with an electron beam as shown in FIGS. 6 and 7, and both are welded. In this way, when the pressure sensor element 5 has a prismatic shape, if the shape of the end portion of the tubular member 3a on the pressure sensor element 5 side is a prismatic shape that matches the pressure sensor element 5, as shown in FIG. The joint portion between the pressure sensor element 5 and the tubular member 3a becomes a flat surface, and the joint portion is easily irradiated with the electron beam.

Further, at this time, as shown in FIG. 9, if the above-mentioned cylindrical pressure sensor element 5a is used in place of the prismatic pressure sensor element 5, the pressure is the same as that described in FIG. Since the joint portion between the sensor element 5a and the tubular member 3 is flush, the irradiation of the electron beam to this joint portion becomes easy.

As described above, when the pressure sensor element 5 is welded to the tubular member 3 by the electron beam or the like, the temperature of the pressure receiving portion of the pressure sensor element 5 becomes 600 ° C. or higher due to the action of heat generated during welding. Therefore, a cooling device as shown in FIG. 10 is used so that the heat during welding does not affect the layered insulating film, gauge film, and wiring film formed on the pressure receiving portion. It

This cooling device has a vacuum chamber 1 inside.
4, the pressure sensor element 5 and the tubular member 3 are welded in the vacuum chamber 14. In this cooling device, a flexible member 15 made of a fluororesin or the like, which is cooled by a cooling liquid flowing from the outside, is arranged so as to be located inside the vacuum chamber 14, and the flexible member 15 is pressurized. With the surface of the sensor element 5 on the pressure receiving portion side in contact, the tubular member 3
By performing welding between the pressure sensor element 5 and the pressure sensor element 5, it is possible to suppress heat applied during welding on the surface of the pressure receiving portion of the pressure sensor element 5.

At this time, the cylinder member 3 is preferably made of a titanium alloy made of the same material as that of the pressure sensor element 5 in order to prevent a problem at the time of linear expansion, but has the same linear expansion coefficient as that of the pressure sensor element 5. What is necessary is just to use the thing, For example, it is also possible to use an iron-nickel type alloy.

In this way, the pressure sensor element 5
As shown in FIG. 1, the cylindrical member 3 to which is attached is inserted into the through hole 2 of the housing 1 and partially fixed in a state where the opening on the other side is exposed to the outside.

At this time, if the non-fixed portion is set such that a clearance b is formed between the outer peripheral surface of the tubular member 3 and the inner peripheral surface of the through hole 2 of the housing 1, the clearance b is formed. Even when the housing 1 is made of a material different from that of the tubular member 3, when the housing 1 and the tubular member 3 are thermally expanded, the thermal expansion is absorbed by the escape b.

In general, since titanium alloy is an expensive material, stainless steel (SUS) or steel is used for the housing 1. However, since the stainless steel or steel and the titanium alloy have a poor fusion property, the tubular member 3 is used. When a titanium alloy is selected as the material, the silver or the foil-like co-material 11 mainly composed of silver is interposed between the housing 1 and the cylindrical member 3 and welded, so that they can be firmly fixed.

As described above, when the titanium alloy is used for the tubular member 3 and the housing 1 is made of a material different from that of the tubular member 3, the tubular member can be formed by the method shown in FIGS. 11 to 13. 3 can be fixed to the housing 1.

That is, in FIG. 11, a brazing material 17 made of a round material or a foil material is placed on the joint portion between the housing 1 and the tubular member 3, and then the brazing material 17 is heated by heating the housing 1 and the tubular member 3. Is melted, whereby the brazing filler metal 17 is made to fit between the housing 1 and the tubular member 3 and fixed.

Further, in FIG. 12, a male screw portion 19 is formed on a part of the outer peripheral surface of the tubular member 3, and a female screw portion 18 corresponding to this is formed on the inner peripheral surface of the through hole 2 of the housing 1. The tubular member 3 is fixed to the housing 1 by screwing the two screw portions 18 and 19, and an O-ring 20 is provided between the tubular member 3 and the housing 1 in order to obtain further sealing performance. Intervenes.

Further, in FIG. 13, solder plating 21 is applied to a part of the outer peripheral surface of the cylindrical member 3, and solder plating is also applied to the corresponding part of the inner peripheral surface of the through hole 2 of the housing 1 (not shown). And the cylindrical member 3 is press-fitted into the through hole 2 of the housing 1.
They are fixed to each other, and at the same time, both are sealed.

The tubular member 3 is attached to the housing 1 as described above.
The pressure sensor element 5 attached to one opening of the tubular member 3 can be positioned below the circuit board 6 in the space of the housing 1 by being fixed to the.

The pressure sensor element 5 and the circuit board 6 are connected by, for example, wire bonding or the like, whereby the wiring film formed on the pressure receiving portion of the pressure sensor element 5 and the electric circuit on the circuit board 6 are connected. Becomes electrically conductive.

Next, the operation of the above will be described. Since the pressure sensor elements 5 and 5a according to the present invention are annealed after the recess 13 is formed in the wafer 12 made of a titanium alloy as described above, the residual heat generated inside the wafer 12 when the recess 13 is formed. The stress is completely removed, and the wafer 12 having no warp is manufactured.

Therefore, it is possible to perform surface lapping, which has been conventionally impossible due to the warp, on the pressure receiving portion of the wafer 12, and thereby the insulating film, the gauge film, and the wiring film are layered on the pressure receiving portion of the wafer 12. It can be suitably patterned.

By using the wafer 12 in this manner, it becomes possible to divide / separate the wafer 12 into a plurality of pressure sensor elements 5, 5a, so that it is possible to cope with mass production.

Next, the operation of the pressure sensor using the pressure sensor element 5 made of this titanium alloy will be described.

With this structure, when pressure is introduced from the pressure introducing hole 4 of the cylindrical member 3, the pressure sensor displaces the pressure receiving portion of the pressure sensor element 5 and the pressure is received accordingly. An electric signal is generated from the gauge film formed on the part. Then, the electric signal generated from the pressure sensor element 5 is guided to the circuit board 6 and subjected to processing such as amplification in the electric circuit on the circuit board 6. And the circuit board 6
The electric signal processed in step (4) is further output from the connector 8 via the plate 7 by passing through the terminal 9, whereby the pressure introduced from the pressure introducing hole 4 is detected as an electric signal. It is supposed to be done.

Even if a high temperature acts on the pressure sensor,
The output characteristic can be maintained in a stable state.

That is, the material of the housing 1 is the cylindrical member 3
If a different material is used, due to the difference in the coefficient of linear expansion, a force such that the tubular member 3 is compressed by the housing 1 acts when the high temperature acts, and the tubular member 3 is deformed. There is a risk that the sensor element 5 may be deformed to deteriorate the output characteristics, but by providing the clearance b between the outer peripheral surface of the tubular member 3 and the opposing surface of the through hole 2 of the housing 1, the tubular member at the time of thermal expansion. 3 and the deformation of the housing 1 are absorbed by the escape b, thereby avoiding a force such as compressive force acting on the tubular member 3, preventing deformation of the pressure sensor element and stabilizing the output characteristics. You can do it.

Even if the tubular member and the housing 1 are made of different materials, they can be easily and reliably fixed to each other.

That is, when the tubular member 3 is fixed to the housing 1, welding is performed with the common material 11 interposed therebetween, brazing is performed using the brazing material 17, or a male screw portion is attached to the tubular member 3. 19, and a female screw portion 18 is formed in the through hole 2 of the housing 1 and screwed, or the tubular member 3
When the tubular member 3 and the housing are made of different materials by solder-plating 21 on each peripheral surface of the through hole 2 of the housing 1 and press-fitting the tubular member 3 into the through hole 2. Even if the fusion property or the bondability of the above is low, it is possible to ensure the reliable fixation.

Therefore, even when a titanium alloy is used for the tubular member 3 and a stainless steel is used for the housing 1, the two members are well fixed to each other.

Further, by using the same titanium alloy as the pressure sensor element 5 or one having the same linear expansion coefficient as that of the pressure sensor element 5, when the linear expansion occurs, the cylindrical member 3 and the pressure sensor are made. Since the respective dimensional changes of the element 5 are the same, no stress is generated in the joint portion thereof, whereby the output characteristics of the pressure sensor element 5 can be stabilized.

Next, FIG. 14 shows an essential part of another embodiment of the pressure sensor according to the present invention. That is, in the pressure sensor shown in FIG. 14, the pressure sensor element 5 is provided in the housing 31 having the pressure introducing hole 34 with the pressure receiving portion facing the pressure introducing hole 34, and the pressure sensor is provided. The circuit board 36 to which the element 5 is connected via the flexible circuit 22 is provided, and the O-ring 24 is provided between the pressure sensor element 5 and the housing 31 at this time. Since it is the same, detailed description of the configuration is omitted.

In FIG. 14, the housing 31 has an internal cavity opening to one side and is formed with a pressure introducing hole 34 for conducting the internal cavity. The opening of the internal cavity of the housing 31 is shown in FIG. By providing a connector (not shown) so as to close the portion, the housing 3
A space is formed between the connector 1 and the connector, and the pressure sensor element 5 and the circuit board 36 are arranged in the space.

The pressure sensor element 5 is obtained by the above-mentioned manufacturing method, and is manufactured from a titanium alloy wafer. The pressure sensor element 5 is provided in the housing 31 with its pressure receiving portion facing the pressure introducing hole 34.

At this time, an annular O made of an elastic material is formed on the end surface of the pressure sensor element 5 on the side where the pressure receiving portion is not formed.
A ring 24 is provided, and the O-ring 24 surrounds the opening inside the pressure introducing hole 34, and the pressure sensor element 5
And the housing 31.

The pressure sensor element 5 has a housing 31 with its peripheral portion pressed by the stop ring 23.
Is partially crimped and fixed, and at this time, the O-ring 24 is in a slightly compressed state.

The pressure sensor element 5 is connected to the flexible circuit 22 by wire bonding or the like.
Circuit board 36 on which the pressure sensor element 5 is arranged
And electrically connected to each other.

An electric circuit is formed on the circuit board 36, and the electric signal sent from the pressure sensor element 5 is processed by the electric circuit. , This processed electrical signal is
It is configured to be guided to a terminal 9 of a connector (not shown) connected to the circuit board 36.

Next, the operation of the above will be described. With this structure, when pressure is introduced from the pressure introducing hole 34 of the housing 31, the pressure sensor displaces the pressure receiving portion of the pressure sensor element 5 and the pressure receiving portion is formed at the pressure receiving portion. An electric signal is generated from the gauge film. Then, the electric signal generated from the pressure sensor element 5 is guided to the circuit board 36 via the flexible circuit 22, and the electric circuit on the circuit board 36 performs processing such as amplification. The electric signal processed by the circuit board 36 further passes through the terminal 9 and is output to the outside from a connector (not shown).

Here, even if the material of the housing 31 is different from that of the pressure sensor element 5, the influence of the difference in the linear expansion coefficient does not occur.

In other words, since the elastic O-ring 24 is interposed between the pressure sensor element 5 and the housing 31, the dimension due to the linear expansion between the housing 31 and the pressure sensor element 5 when high temperature acts. Even if a change occurs, the elasticity of the O-ring 24 absorbs this dimensional change. Therefore, even if a linear expansion occurs, no stress is generated in the pressure sensor element 5, thereby always stabilizing the output characteristic. It can be done.

Since the O-ring 24 also has a sealing function, the O-ring 24 is provided so as to be interposed between the pressure sensor element 5 and the housing 31 so that the O-ring 24 and the housing 31 are sealed. It has become.

[0080]

As described above, according to the present invention, since a wafer is made of a titanium alloy, a recess is formed in the wafer, and then annealing is performed, the wafer does not warp, so that the surface of the wafer is not warped. A thin film such as an insulating film, a gauge film, and a wiring film can be suitably formed on the substrate, which enables mass production of pressure sensor elements using a wafer and improves productivity. You can

Since the wafer can be used as described above, the equipment for forming a thin film can be diverted from the conventionally used one for manufacturing semiconductors such as memory chips. As a result, the pressure sensor element can be manufactured by general equipment, and the cost can be reduced.

When the pressure sensor element made of the titanium alloy manufactured by this manufacturing method is used for the pressure sensor, the material of the cylindrical member to which the pressure sensor element is attached has the same linear expansion coefficient as the titanium alloy. As a result, it is possible to prevent the generation of internal stress and prevent the output characteristics of the pressure sensor element from being affected even if the linear expansion occurs when a high temperature is applied.

Further, in the pressure sensor, when the tubular member is fixed to the housing, by providing a clearance between the outer peripheral surface of the tubular member and the inner peripheral surface of the through hole of the housing, a clearance is provided between the tubular member and the housing. Even if linear expansion occurs, it can be absorbed, so even if a metal of a different type from the tubular member is used for the housing, it is possible to prevent the tubular member from being clamped by the housing during linear expansion. ,
As a result, the output characteristics of the pressure sensor element attached to the tubular member can be stabilized.

Further, when fixing the tubular member to the housing, welding is performed with a common material interposed between the two, or brazing is performed with a brazing material, a male screw portion is provided on the tubular member, and a through hole of the housing is provided. By forming female screw portions and screwing them into each other, or by solder-plating the through holes of the tubular member and the housing and press-fitting the tubular member into the through holes, the tubular member and the housing are made of different materials. It is possible to securely fix even a thing.

Therefore, even if titanium alloy is selected for the cylindrical member and stainless steel is selected for the housing, for example, it is possible to fix the members. Therefore, an inexpensive material can be used without using an expensive titanium alloy for the housing. Thus, the pressure sensor can be manufactured, and the cost can be reduced.

Further, in the pressure sensor in which the O-ring is interposed between the pressure sensor element and the housing, the elastic force of the O-ring causes a difference in linear expansion coefficient between the pressure sensor element and the housing. Since it can be absorbed, even if a housing made of a material different from that of the pressure sensor element is used, it is possible to prevent the output characteristic of the pressure sensor element from deteriorating when linear expansion occurs.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a pressure sensor using a pressure sensor element manufactured according to the present invention.

FIG. 2 is a diagram showing a wafer for manufacturing a pressure sensor element.

3 is a cross-sectional view taken along the line AA in FIG.

FIG. 4 is a diagram showing an example of a divided state of the wafer shown in FIG.

5 is a diagram showing another example of a divided state of the wafer shown in FIG.

FIG. 6 is a diagram showing an example of a mounted state of a pressure sensor element.

FIG. 7 is a view showing an arrow B in FIG.

FIG. 8 is a diagram showing another example of a mounted state of the pressure sensor element.

FIG. 9 is a diagram showing still another example of the mounting state of the pressure sensor element.

FIG. 10 is a diagram illustrating an outline of a cooling device used when welding a pressure sensor element to a tubular member.

FIG. 11 is a diagram showing an example of a mounting state of a tubular member.

FIG. 12 is a diagram showing another example of a mounted state of the tubular member.

FIG. 13 is a diagram showing still another example of a mounted state of the tubular member.

FIG. 14 is a diagram showing a main part of another embodiment of a pressure sensor using the pressure sensor element manufactured according to the present invention.

FIG. 15 is a diagram showing a conventional example.

FIG. 16 is a diagram showing a conventional example.

FIG. 17 is a diagram showing another conventional example.

FIG. 18 is a view showing still another conventional example, showing a state in which a defect has occurred.

[Explanation of symbols]

 1, 31 ... Housing 2 ... Through hole 3, 3a ... Cylindrical member 4, 34 ... Pressure introduction hole 5, 5a, 55, 55a, 75 ... Pressure sensor element 6, 36 ... Circuit board 7 ... Plate 8 ... Connector 9 ... Terminal 10 ... Device 11 ... Common material 12, 62 ... Wafer 13, 63, 63a, 73 ... Recess 14 ... Vacuum chamber 15 ... Flexible material 16 ... Packing 17 ...... Brazing material 18 ...... Female threaded portion 19 ...... Male threaded portion 20, 24 ...... O-ring 21 ...... Solder plating 22 ...... Flexible circuit 23 ...... Stop ring 60, 61 ...... Jig a ...... Warpage b ...... escape

Claims (9)

[Claims] 1. A disk-shaped wafer (1) made of a titanium alloy.
2) A plurality of recesses (13) are formed on one end face, a thin pressure receiving portion is formed at a portion corresponding to the recesses (13), and then annealing is performed, and then the wafer (12) is formed.
A plurality of pressure sensor elements (5) (5a) are obtained by sequentially forming an insulating film, a gauge film, and a wiring film in a layered shape in a predetermined shape on each pressure receiving portion and dividing each pressure receiving portion into a predetermined shape. A method of manufacturing a pressure sensor element, comprising: 2. A housing (1) having a through hole (2).
And a connector (8) having a terminal (9), and a pressure receiving portion is provided in the void, and the pressure receiving portion is provided so as to face the pressure introducing hole (4) in the tubular member (3). ,
Further, by inserting the tubular member (3) into the through hole (2) of the housing (1) and fixing the tubular member (3), the pressure sensor element (5) made of a titanium alloy located in the void and the circuit board (6). ) Is provided, and when pressure is introduced from the pressure introducing hole (4), the pressure is detected as an electric signal. 3. The pressure sensor according to claim 2, wherein the tubular member (3) is made of a titanium alloy. 4. The relief (b) is provided between the outer peripheral surface of the tubular member (3) and the inner peripheral surface of the through hole (2) of the housing (1) facing each other. Pressure sensor. 5. The pressure sensor according to claim 2, wherein a common material (11) is interposed between the tubular member (3) and the housing (1) and the two are welded together. 6. The pressure sensor according to claim 2, wherein a brazing material (17) is brazed and fixed between the cylindrical member (3) and the housing (1). 7. A male screw part (19) is formed on the outer peripheral surface of the cylindrical member (3), and a female screw part (18) corresponding to the male screw part (19) is formed in the through hole (2) of the housing (1).
The pressure sensor according to claim 2, wherein the tubular member (3) is fixed to the housing (1) by being formed on the inner peripheral surface of the, and by screwing both screw portions (19) (18). 8. The outer peripheral surface of the tubular member (3) and the inner peripheral surface of the through hole (2) of the housing (1) are plated with solder, and the tubular member (3) is formed into the through hole (2). The pressure sensor according to claim 2, wherein the pressure sensor is fixed by being press-fitted. 9. A pressure receiving portion is provided in a cavity formed by a housing (31) having a pressure introducing hole (34) and a connector (8) having a terminal (9), and the pressure receiving portion has the pressure. An O-ring (24) provided so as to face the introduction hole (34) and having elasticity between the end surface on the side where the pressure receiving portion is not formed and the housing (31).
When a pressure sensor element (5) made of a titanium alloy and a circuit board (36) are provided in a state where the pressure is introduced, when pressure is introduced from the pressure introducing hole (34), the pressure is detected as an electric signal. A pressure sensor characterized in that