JP2020008394A - Pressure sensor and manufacturing method for pressure sensor - Google Patents

Abstract

To provide a pressure sensor and a manufacturing method therefor, with which it is possible to suppress the ingress of a liquid such as water without increasing component counts.SOLUTION: The pressure sensor comprises: a male connector 190; a base 110 being in contact with the male connector 190; a ring member 140 joined to the base 110; a receive member 120 including a flange part 123 joined to the ring member 140 by welding; a diaphragm 130; a caulking member 180 for connecting the male connector 190 and the base 110; and a pressure detection device 150 attached to the base 110 on a pressure-receiving space S1 side formed between the base 110 and the diaphragm 130. The caulking member 180 is added with a heating medium from the axial direction of the receive member 120 and welded to the flange part 123 of the receive member 120 over the entire circumference and is connected the male connector 190 by being caulked thereto.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a pressure sensor and a method for manufacturing a pressure sensor.

  A liquid-filled pressure sensor containing a semiconductor-type pressure detector in a pressure-receiving chamber partitioned by a diaphragm and filled with oil is installed in a refrigeration unit or an air conditioner, and is used for detecting refrigerant pressure. It is installed in a fuel supply device and is used for detecting fuel pressure.

  The semiconductor type pressure detecting device is disposed in the pressure receiving chamber, and has a function of converting a pressure change in the pressure receiving space into an electric signal and outputting the electric signal to the outside via a relay board, a lead wire, and the like.

  In such a pressure sensor, a liquid such as water may enter the inside of the sensor from the outside depending on the environment in which the pressure sensor is installed and the usage state of the device, which may cause a malfunction in the semiconductor pressure detection device. Therefore, there is known a pressure sensor in which a cover is attached to a base accommodating a semiconductor-type pressure detecting device, and an adhesive is sealed inside the cover to improve watertightness (see Patent Document 1).

JP 2017-146136 A

  By the way, in the conventional pressure sensor, high watertightness can be obtained by enclosing the adhesive inside the cover, but the manufacturing cost increases accordingly. On the other hand, depending on the specifications of the pressure sensor, high watertightness may not be required.

  Here, Patent Literature 1 also discloses a configuration in which a sealing member such as an O-ring is disposed between a caulking member and an internal component, and the configuration is diverted to make the pressure sensor light and watertight. You can also try to secure. However, when a sealing member such as an O-ring is provided, there is a problem that the number of components of the pressure sensor increases.

  Therefore, an object of the present invention is to provide a pressure sensor and a method of manufacturing a pressure sensor that can suppress intrusion of a liquid such as water without increasing the number of parts.

In order to achieve the above object, a pressure sensor according to the present invention comprises:
A connector member,
A base contacting the connector member;
A ring member joined to the base,
A receiving member having a flange portion joined by welding to the ring member,
A diaphragm sandwiched between the ring member and the flange portion of the receiving member,
A caulking member that has a cylindrical portion that accommodates the base and an annular connecting portion provided at one end side of the cylindrical portion, and that connects the connector member and the base;
In a pressure receiving space formed between the base and the diaphragm, a pressure detecting device attached to the base,
The annular connecting portion and the contact portion of the flange portion are joined by welding,
The caulking member is characterized in that the other end side of the cylindrical portion is caulked and connected to the connector member.

Further, the method for manufacturing a pressure sensor according to the present invention includes:
A connector member,
A base contacting the connector member;
A ring member joined to the base,
A receiving member having a flange portion joined to the ring member by welding,
A diaphragm sandwiched between the ring member and the flange portion of the receiving member,
A caulking member having a tubular portion for accommodating the base and an annular connecting portion provided at one end side of the cylindrical portion, and connecting the connector member and the base by caulking;
In a pressure receiving space formed between the base and the diaphragm, a pressure detection device attached to the base, a method for manufacturing a pressure sensor,
The annular connecting portion of the caulking member is provided with a heating medium from the axial direction of the receiving member and is welded to the flange portion of the receiving member along the entire circumference.

  Advantageous Effects of Invention According to the present invention, it is possible to provide a pressure sensor and a method of manufacturing a pressure sensor that can suppress intrusion of a liquid such as water without increasing the number of parts.

FIG. 1 is a top view of the pressure detection unit according to the first embodiment. FIG. 2 is a side view of a cross section taken along line AA in the configuration of FIG. FIG. 3 is a longitudinal sectional view of the pressure sensor to which the pressure detection unit 100 according to the first embodiment is attached. FIG. 4 is a diagram illustrating an assembly process of the pressure sensor according to the present embodiment. FIG. 5 is a cross-sectional view of a pressure sensor using the pressure detection unit according to the second embodiment.

<First embodiment>
FIG. 1 is a top view of a pressure detecting unit according to a first embodiment of the present invention, and FIG. 2 is a side view of a cross section taken along line AA in the configuration of FIG.
As shown in FIGS. 1 and 2, the pressure detection unit 100 includes a base 110 made of ceramics, a receiving member 120 facing the base 110, a diaphragm 130 sandwiched between the base 110 and the receiving member 120, and a ring. A member 140 and a caulking member 180 are included.

  The base 110 includes a disk-shaped main body 111 and a protruding portion 112 that protrudes in the axial direction in a ring shape around the entire outer edge of the main body 111. That is, the base 110 has a shape such that the lower surface center portion is depressed in FIG. 2 so that a pressure receiving space S1 described later is formed.

  As a ceramic material forming the base 110, for example, alumina, alumina zirconia, or the like can be used.

  A sealed pressure receiving space S1 is formed between the inner portion 114 of the base 110 and the diaphragm 130, and is filled with an insulating liquid medium such as oil. Further, a semiconductor-type pressure detecting device 150 described later is attached to a central portion of the main body 111 on the pressure receiving space S1 side inside the protruding portion 112.

  As shown in FIG. 1, three through holes 116 into which three terminal pins 160, 162, and 164 are inserted are formed in the base 110 at positions around the semiconductor-type pressure detecting device 150.

  The three terminal pins 160, 162, and 164 are respectively inserted into the through holes 116 provided in the base 110 to penetrate the base 110, and the lower ends thereof are electrically connected to the semiconductor-type pressure detecting device 150. You.

  The receiving member 120 is formed of, for example, a metal material such as a stainless steel plate, and has a circular bottom 121 formed with a concave central portion, a conical portion 122 extending upward from an outer edge of the circular bottom 121, and a conical portion 122. It has a flange portion 123 extending horizontally from the outer edge, and a circular tube portion 124 connected to the center of the lower surface of the circular bottom portion 121. The circular tube portion 124 is for connection to the outside, and an opening 125 is formed at the center of the circular bottom portion 121 and communicates with the inside of the circular tube portion 124.

  The diaphragm 130 is joined to the upper surface of the flange portion 123 as described later. With such a structure, a pressurized space S2 into which the fluid to be detected flows is formed between the receiving member 120 and the diaphragm 130.

  The diaphragm 130 is a disk-shaped thin plate member made of a metal material such as stainless steel. The ring member 140 is a ring-shaped member made of a metal material such as stainless steel.

  The caulking member 180 is a tubular member made of a metal material such as stainless steel, and has a hollow cylindrical portion 181 that accommodates the base 110 and an annular connecting portion 182 provided continuously at the lower end of the cylindrical portion 181. The upper end of the cylindrical portion 181 is a thin portion 183.

  The semiconductor pressure detecting device 150 is die-bonded to the center of the base 110 by bonding or the like. The semiconductor type pressure detection device 150 includes a support substrate 152 made of glass and a pressure detection element (semiconductor chip) 154 bonded thereto.

  Although not shown, the pressure detecting element 154 has, for example, eight bonding pads (electrodes) on the surface. Three bonding pads are a power input pad for output signals, a ground pad, and a signal output pad, and the remaining five are signal adjustment pads.

<Assembly process of pressure detection unit 100>
The process of assembling the pressure detection unit 100 will be described below. First, a ground terminal pin 160, a power input terminal pin 162, and a signal output terminal pin 164 are inserted into the through holes 116 formed in the base 110, respectively, and three terminal pins 160, 162, 164 are formed. And the base 110 by brazing.

  Specifically, the base 110 is heated to a predetermined temperature with a brazing material such as silver brazing interposed between the through-hole 116 formed in the base 110 and the terminal pins 160, 162, 164, respectively. A brazing portion is formed between the ceramic of 110 and the metal of the terminal pins 160, 162, 164.

  At this time, before the brazing operation is performed, a metallized layer (for example, a Mo—Mn layer or the like or a tungsten layer as a main component) is formed in advance on a surface of the base 110 that comes into contact with the brazing material. The consistency between the material and the brazing material can be improved.

  At the same time as the above brazing, the protruding portion 112 of the base 110 is joined to the upper surface 141 of the ring member 140 by brazing. Specifically, by heating to a predetermined temperature with a brazing material such as silver brazing interposed between the base 110 and the ring member 140, the ceramic material of the base 110 and the metal material of the ring member 140 are heated. And a brazing portion B is formed all around.

  At this time, before the brazing operation is performed, a metallized layer (for example, a Mo—Mn layer or the like or a tungsten layer as a main component) is formed in advance on a surface of the base 110 that comes into contact with the brazing material. And the brazing material can be improved in consistency.

  Subsequently, the semiconductor pressure detector 150 is die-bonded to the center of the base 110. After that, the ground pad, the power input pad, and the signal output pad of the semiconductor pressure detecting device 150 are electrically connected to one ends of the three terminal pins 160, 162, and 164 via the bonding wires 166, respectively.

  Further, the above-mentioned eight pads of the pressure detection element 154 of the semiconductor type pressure detection device 150 exposed in the base 110 are each brought into contact with a current-carrying probe, and a temperature correction operation (trimming operation) of the pressure detection element 154 is performed. .

  Here, in a state where a load (pressure) is applied to the pressure detection element 154 at a reference temperature (for example, room temperature), an output value output from a signal output pad or an adjustment pad is read, and a predetermined pressure and output are output. A correction coefficient (or correction function) is set by acquiring a correlation with the value.

  Further, the diaphragm 130 is sandwiched between the flange portion 123 of the receiving member 120 and the ring member 140, and the pressure receiving space S1 formed between the base 110 and the diaphragm 130 is filled with the liquid medium. The overlapped portion with the ring member 140 is relatively rotated by irradiating laser light from the outer peripheral direction, and is continuously integrated by circumferential welding (first welded portion W1). Thus, the receiving member 120, the diaphragm 130, and the ring member 140 are integrated to form a pressure receiving structure.

  The method of girth welding is not limited to laser welding that irradiates a laser beam or an electron beam as a heating medium, but may be fusion welding such as arc welding using an arc as a heating medium, or resistance welding such as seam welding. However, in consideration of a reduction in distortion due to welding, it is preferable to apply laser welding, electron beam welding, or the like having a small heat input.

  The first welded portion W1 is deviated in a direction perpendicular to the axis O of the pressure detecting unit 100 with respect to a brazed portion B between the ring member 140 and the protruding portion 112 of the base 110, that is, the brazed portion B By moving away from the brazing portion, the influence of heat during welding can be minimized from affecting the brazing portion B.

  Next, the caulking member 180 is relatively approached from below, and the upper surface of the annular connecting portion 182 is abutted against the lower surface of the flange portion 123 of the receiving member 120. While maintaining such a state, the surface (overlapping portion) in which the flange portion of the receiving member 120 and the annular connecting portion of the caulking member 180 abut in the radial direction is moved along the axial direction (vertically in FIG. 2). The laser beam is irradiated to rotate relatively, and the circumference is continuously welded (second welded portion W2) to be integrated. However, a cylindrical gap exists between the cylindrical portion 181 and the base 110 in the radial direction.

  Similarly, as a method of girth welding, not limited to laser welding, it is possible to apply fusion welding such as arc welding, or resistance welding such as seam welding, but if the reduction of distortion due to welding is considered, It is preferable to apply laser welding, electron beam welding, or the like having a small heat input.

  According to the present embodiment, since the upper surface of annular connection portion 182 and the lower surface of flange portion 123 of receiving member 120 are joined all around by second welded portion W2, sealing such as an O-ring is performed. The intrusion of water and the like from the lower end side of the caulking member 180 to the inside can be suppressed without providing a member.

  Further, according to the present embodiment, the upper surface of annular connection portion 182 and the lower surface of flange portion 123 of receiving member 120 (that is, the contact portions with each other) are joined by second welded portion W2. Since at least the ring member 140 is separated from the brazing portion B between the ring member 140 and the protruding portion 112 of the base 110, the ring member 140 is separated from the brazing portion B, and the influence of heat during welding is reduced by the brazing portion B. Can be suppressed as much as possible. Further, the first welded portion W1 is irradiated with laser light in the radial direction, and the second welded portion W2 is irradiated with laser light in the axial direction. Interference can be avoided and more appropriate welding can be performed.

<Pressure sensor>
FIG. 3 is a longitudinal sectional view of the pressure sensor to which the pressure detection unit 100 according to the first embodiment is attached.

  As shown in FIG. 3, the pressure sensor 1 includes a pressure detection unit 100 according to the present embodiment illustrated in FIGS. 1 and 2, and one end of three terminal pins (only 160 is shown) protruding from the pressure detection unit 100. It includes a flexible printed circuit board 20 to be attached, a connector pin 22 to be attached to the flexible printed circuit board 20, and a resin male connector (connector member) 190 formed by insert molding the connector pin 22. By fitting a female connector (not shown) to the male connector 190, a signal detected by the pressure detection unit 100 can be output to the outside via the connector pin 22.

  The male connector 190 has a lower hollow cylindrical portion 191 and an upper hollow cylindrical portion 192, and one end of the flexible printed circuit board 20 is attached to a lower surface of the lower hollow cylindrical portion 191. The other end of the flexible printed circuit board 20 is electrically connected to three terminal pins (only 160 and 162 are shown) of the pressure detection unit 100.

  The circular pipe portion 124 of the receiving member 120 is connected to a pipe (not shown) through which a fluid to be subjected to pressure detection flows.

<Assembly process of pressure sensor>
The assembly process of the pressure sensor 1 will be described with reference to FIG. When assembling the pressure sensor 1, first, one end of three terminal pins protruding from the base 110 of the pressure detection unit 100 is electrically connected to each wiring of the flexible printed circuit board 20 attached to the male connector 190 by soldering or the like. Connection.

  Subsequently, the male connector 190 is made to approach the pressure detection unit 100, and the lower surface of the lower hollow cylindrical portion 191 is abutted on the upper surface of the base 110. Thereafter, the thin portion 183 provided on the upper end side of the cylindrical portion of the caulking member 180 is caulked (plastically deformed) inward over the entire circumference (or at six locations at equal intervals), thereby forming the caulking portion CK (FIG. 3). ) Is formed. The male connector 190 is prevented from being separated from the pressure detecting unit 100 by the caulking portion CK abutting on the outer periphery of the upper end of the lower hollow cylindrical portion 191 of the male connector 190.

  As described above, since the male connector 190 can be connected only by caulking the upper end of the caulking member 180 of the pressure detection unit 100 (the upper end of the cylindrical portion 181), manufacturing equipment can be simplified and man-hours can be reduced.

  In the pressure sensor 1 shown in FIG. 3, the fluid to be subjected to pressure detection introduced into the circular tube portion 124 of the receiving member 120 enters the pressurized space S2 of the pressure detection unit 100 and deforms the diaphragm 130 by the pressure.

  When the diaphragm 130 is deformed, the liquid medium in the pressure receiving space S1 is pressurized, and the pressure resulting from the deformation of the diaphragm 130 is transmitted to the pressure detecting element 154 of the semiconductor pressure detecting device 150.

  The pressure detecting element 154 detects the change in the transmitted pressure, converts the detected pressure into an electric signal, and outputs the electric signal to the flexible printed circuit board 20 via the signal output terminal pin 164.

  The electric signal is output to an external device via the connector pin 22 and a female connector (not shown).

  With these configurations, the pressure detection unit 100 according to the embodiment of the present invention and the pressure sensor 1 to which the pressure detection unit 100 is applied have the base 110 for mounting the semiconductor type pressure detection device 150 formed of a ceramic material having a small coefficient of thermal expansion. In addition, the base 110 can be prevented from expanding or contracting due to a change in the operating temperature environment of the pressure sensor 1 at the time of assembling and manufacturing the pressure detecting unit 100 or the like.

  Further, since the base 110 is formed of a ceramic material having a small coefficient of thermal expansion, even when the base 110 is exposed to a severe high or low temperature use environment as compared with a conventional base material formed of a metal material, Since the fluctuations in the shape and dimensions of the semiconductor pressure detecting device 150 are reduced, it is possible to suppress a decrease in detection accuracy due to the temperature environment of the semiconductor type pressure detecting device 150.

  Since the base 110 is formed of a ceramic material, the glass-made hermetic seal used when embedding the terminal pins in the base in the conventional pressure detection unit can be replaced with a brazed portion. To prevent the liquid medium sealed in the pressure receiving space from leaking.

  Further, the pressure detecting unit 100 according to one embodiment of the present invention and the pressure sensor 1 to which the pressure detecting unit 100 is applied form a pressure receiving structure integrally formed by sandwiching the diaphragm 130 between the receiving member 120 and the ring member 140 in advance. Since the base 110 is joined to the ring member 140 of the pressure receiving structure, the diaphragm 130 which is relatively thin and relatively weak can be reinforced by the receiving member 120 and the ring member 140.

<Second embodiment>
FIG. 5 is a cross-sectional view of the pressure sensor 1 using the pressure detection unit according to the second embodiment. The different part from the first embodiment will be described.

  In the present embodiment, the receiving member and the caulking member are integrated. More specifically, the pressure detection unit 100 includes a base 110 made of ceramics, a receiving caulking member 220 facing the base 110, a diaphragm 130 sandwiched between the base 110 and the receiving caulking member 220, and a ring member. 140.

  The receiving caulking member 220 is formed of a metal material such as a stainless steel plate, for example, and has a circular bottom 221 having a concave central portion, a conical portion 222 extending upward from the outer edge of the circular bottom 221, and a conical portion 222. A flange portion 223 extending horizontally from the outer edge of the circular bottom portion 221, a circular tube portion 224 connected to the center of the lower surface of the circular bottom portion 221, and an axial direction extending from the outer periphery of the flange portion 223 to the opposite side to the circular tube portion 224. And a cylindrical portion 226. The upper end of the cylindrical part 226 is a thin part. An opening 225 is formed at the center of the circular bottom portion 221 and communicates with the inside of a circular tube portion 224 for connection to the outside. The other configuration is the same as that of the above-described embodiment, and the description is omitted.

  With respect to the assembling process of the pressure detecting unit according to the present embodiment, only steps different from the above-described embodiment will be described.

  After the same steps as those of the above-described embodiment, the diaphragm 130 is sandwiched between the flange portion 223 of the receiving caulking member 220 and the ring member 140, and the pressure receiving space S1 formed between the base 110 and the diaphragm 130 is formed. In the state filled with the liquid medium, the overlapping portion of the flange portion 223 of the receiving caulking member 220 and the ring member 140 is relatively rotated by irradiating laser light from below or diagonally below in the axial direction to continuously rotate. Weld (W3) and integrate. Thereby, the receiving caulking member 220, the diaphragm 130, and the ring member 140 are integrated to form a pressure receiving structure.

  Also in the present embodiment, the third welded portion W3 that joins the ring member 140 and the flange portion 223 of the receiving caulking member 220 is formed with respect to the brazing portion B between the ring member 140 and the protruding portion 112 of the base 110. , Since it is deviated in the radial direction, it moves away from the brazing portion B, and the influence of heat during welding on the brazing portion B can be suppressed as much as possible. Further, since the receiving member and the caulking member are integrated, the number of components of the pressure detection unit 100 is reduced.

  The pressure detection unit 100 of the present embodiment can also be assembled to the male connector 190 having the same shape as the above-described embodiment. In the assembling process of the pressure sensor 1, the male connector 190 is made to approach the pressure detecting unit 100, and the lower surface of the lower hollow cylindrical portion 191 is brought into contact with the upper surface of the base 110, as in the above-described embodiment. Thereafter, the upper end of the cylindrical portion 226 of the receiving caulking member 220 is caulked (plastically deformed) inward over the entire circumference to form the caulked portion CK.

  The present invention is not limited to the above embodiments, and various modifications can be made.

1 pressure sensor 20 flexible printed circuit board 22 connector pin 100 pressure detection unit 110 base 120 receiving member 130 diaphragm 140 ring member 150 semiconductor type pressure detection device 152 support substrate 154 pressure detection element 160 grounding terminal pin 162 power input terminal pin 164 terminal pin 166 for signal output bonding wire 180 caulking member 190 male connector 220 receiving caulking member

Claims (5)

A connector member,
A base contacting the connector member;
A ring member joined to the base,
A receiving member having a flange portion joined by welding to the ring member,
A diaphragm sandwiched between the ring member and the flange portion of the receiving member,
A caulking member that has a cylindrical portion that accommodates the base and an annular connecting portion provided at one end side of the cylindrical portion, and that connects the connector member and the base;
In a pressure receiving space formed between the base and the diaphragm, a pressure detection device attached to the base,
The annular connecting portion and the contact portion of the flange portion are joined by welding,
The caulking member is caulked at the other end of the cylindrical portion and connected to the connector member.
Pressure sensor characterized by the above-mentioned. The base is made of ceramics, the base and the ring member are joined by brazing,
The pressure sensor according to claim 1, wherein: The receiving member and the caulking member are integrated,
The pressure sensor according to claim 1, wherein: The welding part which joined the said flange part and the said ring member, and the welding part which joined the said annular connection part and the said flange part are continuous, The Claim 1 characterized by the above-mentioned. The pressure sensor according to the paragraph. A connector member,
A base contacting the connector member;
A ring member joined to the base,
A receiving member having a flange portion joined to the ring member by welding,
A diaphragm sandwiched between the ring member and the flange portion of the receiving member,
A caulking member having a tubular portion for accommodating the base and an annular connecting portion provided at one end side of the cylindrical portion, and connecting the connector member and the base by caulking;
In a pressure receiving space formed between the base and the diaphragm, a pressure detection device attached to the base, a method for manufacturing a pressure sensor,
The annular connection portion of the caulking member is provided with a heating medium from the axial direction of the receiving member and is welded to the flange portion of the receiving member along the entire circumference.
A method for manufacturing a pressure sensor, comprising:

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