JP7079485B2 - Pressure detection unit, its manufacturing method, pressure sensor using the pressure detection unit, and its manufacturing method - Google Patents

Description

The present invention relates to a pressure detection unit, a method for manufacturing the same, a pressure sensor using the pressure detection unit, and a method for manufacturing the same.

A liquid-filled pressure sensor, which houses a semiconductor-type pressure detector in a pressure receiving chamber partitioned by a diaphragm and filled with oil, is installed in refrigerating and cooling equipment and air-conditioning equipment and is used to detect refrigerant pressure, and is also used in automobiles. It is installed in the fuel supply device and used for detecting fuel pressure.

Such a pressure sensor, for example, encloses oil in a pressure receiving space in which a pressure detection device is housed, and transmits the pressure applied to the pressure detection chamber from the outside to the pressure detection device via the oil to detect the pressure. The device outputs an electric signal according to the external pressure.

When manufacturing such a pressure sensor, an encapsulation hole and a plurality of through holes are formed in the base, and a lead pin and a cylindrical glass for hermetic sealing that fills the gap are attached to each through hole and heated. Each of them is fixed by such means and each hole is sealed. Then, after injecting oil into the inside through the sealing hole, the sealing hole is covered with a sealing ball, and this is sealed and fixed by welding or the like (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2013-148350

Here, according to the technique disclosed in Patent Document 1, oil can be reliably filled, but there may be a cost in management for preventing air bubbles from being mixed into the pressure receiving space.

Therefore, an object of the present invention is to provide a pressure detection unit capable of improving pressure detection accuracy while suppressing an increase in manufacturing man-hours, a manufacturing method thereof, and a pressure sensor using the pressure detection unit and a manufacturing method thereof. It is in.

In order to achieve the above object, the pressure detection unit according to the present invention is
A base with a through hole into which a lead pin is inserted, and a base
A ring member having a cylindrical inner peripheral surface that fits with the outer peripheral surface of the base,
A receiving member joined by welding to the ring member,
A diaphragm sandwiched between the ring member and the receiving member,
In the pressure receiving space formed between the base and the diaphragm, the semiconductor type pressure detection device attached to the base and
A liquid medium enclosed in the pressure receiving space is provided.
In the fitting portion between the base and the ring member, the upper surface of the base and the upper end of the ring member are positioned so as to be flush with each other, and the fitting portion is welded all around. It is characterized by.

Further, the method for manufacturing the pressure detection unit according to the present invention is as follows.
A base having a through hole into which a lead pin is inserted, a ring member having a cylindrical inner peripheral surface that fits with the outer peripheral surface of the base, a receiving member joined by welding to the ring member, and the ring. A diaphragm sandwiched between the member and the receiving member, a semiconductor type pressure detecting device attached to the base in the pressure receiving space formed between the base and the diaphragm, and an enclosure in the pressure receiving space. It is a method of manufacturing a pressure detection unit provided with a liquid medium provided with a welded liquid medium.
The process of inserting a lead pin into the through hole of the base and sealing it,
A step of attaching the semiconductor type pressure detector to the base to form a first intermediate product, and
The step of sandwiching the diaphragm between the ring member and the receiving member, and
A step of welding the outer periphery of the ring member and the receiving member to form a second intermediate product while sandwiching the diaphragm.
The step of injecting the liquid medium into the second intermediate product body from the ring member side, and
When the center line of the pressure detection unit is the axis, the upper surface of the base and the upper end of the ring member are flush with each other on the inner circumference of the cylindrical inner peripheral surface of the ring member of the second intermediate product. As described above, the step of pressing the liquid surface of the liquid medium in the second intermediate product by the base while fitting the outer periphery of the base of the first intermediate product.
It has a step of rotating the first intermediate product and the second intermediate product around the axis, and laser welding the ring member and the fitting portion of the base from the axis direction on the entire circumference. It is characterized by.

According to the present invention, it is possible to provide a pressure detection unit capable of improving pressure detection accuracy while suppressing an increase in manufacturing man-hours, a method for manufacturing the pressure detection unit, a pressure sensor using the pressure detection unit, and a method for manufacturing the pressure sensor. ..

It is a top view of the pressure detection unit according to this Embodiment 1. It is a side view of the cross section in the line AA of FIG. It is a figure which shows the process of assembling a pressure detection unit. It is a figure which shows the process of assembling a pressure detection unit. It is a vertical sectional view of the pressure sensor which attached the pressure detection unit by this embodiment.

FIG. 1 shows a top view of the pressure detection unit according to the embodiment of the present invention, and FIG. 2 shows a side view of a cross section taken along the line AA of FIG.

As shown in FIGS. 1 and 2, the pressure detection unit 100 receives the base 110, the receiving member 120 facing the base 110, the diaphragm 130 sandwiched between the base 110 and the receiving member 120, and the base 110. Includes a ring member 140 that connects the member 120.

The base 110 is made of stainless steel and has a disk shape. A closed pressure receiving space S1 is formed between the base 110 and the diaphragm 130, and an insulating liquid medium such as oil is filled therein. Further, a semiconductor type pressure detecting device 150, which will be described later, is attached to the central portion of the base 110 on the pressure receiving space S1 side.

As shown in FIGS. 1 and 2, only three through holes 116 into which the three lead pins 160, 162, and 164 are inserted are formed at the peripheral positions of the semiconductor type pressure detecting device 150 on the base 110. That is, the base 110 is not formed with an encapsulation hole for injecting a liquid medium.

The three lead pins 160, 162, and 164 each penetrate the base 110 by being inserted into the through holes 116 provided in the base 110, and the lower ends thereof are electrically connected to the semiconductor type pressure detection device 150. .. The lead pins 160, 162, 164 and the through hole 116 are sealed by a hermetic seal 117 to prevent the liquid medium in the pressure receiving space S1 from leaking.

The receiving member 120 is a dish-shaped member formed of a metal material such as a stainless steel plate and press-formed so that the central portion is recessed. The circular bottom portion 121 and a cone extending upward from the outer edge of the circular bottom portion 121. It has a portion 122 and a flange portion (second circular flange portion) 123 extending horizontally from the outer edge of the conical portion 122.

An opening 124 for attaching a fluid inflow pipe, which will be described later, is formed in the center of the circular bottom portion 121, and a diaphragm 130 is joined to the upper surface of the flange portion 123. 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 made of a metal material such as stainless steel, and has a hollow cylindrical tubular portion 141 and a flange portion (first circular flange portion) 142 extending radially outward from the lower end of the tubular portion 141. And have. A step portion 143 is formed on the inner peripheral surface of the tubular portion 141 over the entire circumference. The inner diameter of the tubular portion 141 is substantially equal to the outer diameter of the base 110.

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

Although not shown, the pressure detecting element 154 is provided with, for example, eight bonding pads (electrodes) on the surface thereof. Three of them are power input pads for output signals, earth pads and signal output pads, and the remaining five are signal adjustment pads.

<Assembly process of pressure detection unit 100>
3 and 4 are diagrams showing a process of assembling the pressure detection unit 100. The process of assembling the pressure detection unit 100 will be described below with reference to FIGS. 3 and 4.

First, three lead pins 160 (162, 164 are not shown) are inserted into the through holes 116 formed in the base 110, and the three lead pins 160, 162, 164 and the through holes 116 are hermetically sealed 117. Is joined and fixed using.

Subsequently, the semiconductor type pressure detection device 150 is die-bonded to the central portion of the base 110. After that, the ground pad, the power input pad, and the signal output pad of the semiconductor type pressure detection device 150 and one end of the three lead pins 160, 162, and 164 are electrically connected via the bonding wire 166, respectively. This forms the first intermediate product M1.

Further, the probe for energization is brought into contact with the above-mentioned eight pads of the pressure detection element 154 of the semiconductor type pressure detection device 150 exposed in the base 110, and the temperature correction work (trimming work) of the pressure detection element 154 is performed. ..

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

Next, the diaphragm 130 is sandwiched between the flange portion 123 of the receiving member 120 and the flange portion 142 of the ring member 140, and the superposed portion is irradiated with laser light from the outer peripheral direction to rotate relatively. The diaphragm 130 is continuously peripherally welded (welded portion W1) to be integrated. This forms the second intermediate product M2.

Further, while holding the second intermediate product M2 by a jig (not shown), the liquid level is higher than that of the step portion 143 in the container-shaped space surrounded by the tubular portion 141 of the ring member 140 and the diaphragm 130. Inject a liquid medium (not shown) until it becomes.

After that, as shown in FIG. 4, the outer periphery of the base 110 of the first intermediate product M1 is fitted to the inner circumference of the tubular portion 141 of the ring member 140 with the semiconductor type pressure detecting device 150 facing downward. Let me. As a result, the lower surface of the base 110 presses the liquid surface of the internal liquid medium, so that the pushed liquid medium passes through the gap between the base 110 and the tubular portion 141, and goes beyond the upper end 144 of the tubular portion 141 to surround it. Overflow to. As a result, the entire lower surface of the base 110 comes into close contact with the liquid surface of the liquid medium, and no bubbles are generated in the liquid medium.

Further, the outer periphery of the lower end of the base 110 comes into contact with the step portion 143, so that the base 110 and the ring member 140 are positioned. In such a state, the end surface (upper surface) 111 of the base 110 and the end surface (upper end) 144 of the ring member 140 are flush with each other, that is, they coincide with each other in the axial direction.

By rotating the jig around the axis X while maintaining this state, the first intermediate generator M1 and the second intermediate generator M2 rotate, so that the laser light beam LB is used as a base along the axis X direction. The fitting portion (boundary) between the 110 and the tubular portion 141 is irradiated, and peripheral welding (welded portion W2) is performed. The jig side may be fixed and the light source side irradiating the laser luminous flux LB may be relatively rotated. This completes the pressure detection unit 100.

The method of peripheral welding is not limited to laser welding, but melt welding such as arc welding or resistance welding such as seam welding can be applied. It is preferable to apply laser welding, electron beam welding, etc., which have low heat.

According to the present embodiment, since the lower surface of the base 110 is in close contact with the liquid surface of the liquid medium in the pressure receiving space S1, no bubbles are generated in the liquid medium, so that the detection accuracy of the semiconductor type pressure detection device 150 is improved. Can be done.

<Pressure sensor>
FIG. 5 is a vertical sectional view of a pressure sensor to which the pressure detection unit 100 according to the present embodiment is attached.

As shown in FIG. 5, the pressure sensor 1 is derived from the pressure detection unit 100 according to the present embodiment illustrated in FIGS. 1 and 2, the cylindrical cover 10 attached to the pressure detection unit 100, and the pressure detection unit 100. An electrical signal or the like is transmitted / received between a relay board 20 to which one end of three protruding lead pins (only 160 is shown) is attached, a connector 22 attached to the relay board 20, and an external device connected to the connector 22. It includes a lead wire 24 and a fluid inflow pipe 30 attached to a receiving member 120 of the pressure detection unit 100.

The cover 10 is a member having a stepped cylindrical shape including a large diameter portion 12 and a small diameter portion 14, and the large diameter portion 12 surrounds the outer peripheral portion of the pressure detection unit 100. It is attached to the base 110 side.

As shown in FIG. 3, an internal space S3 having a base 110 as a bottom surface is formed inside the cover 10, and the relay board 20 and the connector 22 described later are housed in the internal space S3. ..

The internal space S3 formed inside the cover 10 is filled with the resin R1 and solidified, and the resin R2 is also filled and solidified on the opening end side of the large diameter portion 12 so as to cover the pressure detection unit 100. ing.

These resins R1 and R2 prevent moisture and the like from entering the inside of the cover 10 and protect the electrical system such as the relay board 20.

The relay board 20 is formed as a bake board, a glass epoxy board, a ceramic board, or a flexible board, and one end of the connector 22 is attached to the central portion thereof, and a via electrode and a metal wiring layer are attached around the mounting position of the connector 22. Has (not shown).

One end of the connector 22 is attached to the relay board 20, and the other end of the connector 22 is attached with a lead wire 24 extending to the outside of the cover 10.

Further, one end of three lead pins (only 160 is shown) protruding from the base 110 of the pressure detection unit 100 penetrates and is fixed to the via electrode of the relay board 20. At this time, the three lead pins are electrically fixedly connected to the via electrode by, for example, soldering.

The fluid inflow pipe 30 is a tubular member made of a metal material such as a copper alloy or an aluminum alloy, and is used for a mounting portion 32 attached to a receiving member 120 of the pressure detection unit 100 and a pipe through which a fluid to be pressure detected flows. It has a connecting portion 34 to be connected.

The attachment portion 32 is attached to the opening 124 of the receiving member 120 shown in FIG. 2 by any method such as brazing, welding, gluing, or mechanical fastening.

<Pressure sensor assembly process>
When assembling the pressure sensor 1 shown in FIG. 3, first, the relay board 20 to which the connector 22 is attached is fixed to one end of three lead pins protruding from the base 110 of the pressure detection unit 100.

On the other hand, the attachment portion 32 of the fluid inflow pipe 30 is attached and fixed to the opening 124 of the receiving member 120 of the pressure detection unit 100.

Subsequently, the pressure detection unit 100 is inserted into the large diameter portion 12 of the cover 10 so that the lead wire 24 is inserted from the large diameter portion 12 and exposed to the outside through the small diameter portion 14.

After that, the resin R1 is filled from the opening on the small diameter portion 14 side of the cover 10 and solidified to seal the internal space S3.

Similarly, the resin R2 is filled from the open end on the large diameter portion 12 side and solidified to fix the pressure detection unit 100 in the cover 10.

In the pressure sensor 1 shown in FIG. 3, the fluid to be pressure-detected introduced into the fluid inflow pipe 30 enters the pressure space S2 of the pressure detection unit 100, and the diaphragm 130 is deformed by the pressure.

When the diaphragm 130 is deformed, the liquid medium in the pressure receiving space S1 is pressurized, and the pressure obtained by deforming the diaphragm 130 is transmitted to the pressure detecting element 154 of the semiconductor type pressure detecting device 150.

The pressure detection element 154 detects the fluctuation of the transmitted pressure, converts it into an electric signal, and outputs the electric signal to the relay board 20 via the lead pin 164 for signal output.

Then, the electric signal is transmitted to the wiring layer of the relay board 20, and is further output to an external device via the connector 22 and the lead wire 24.

Further, the pressure detection unit 100 according to the embodiment of the present invention and the pressure sensor 1 to which the pressure detection unit 1 is applied form a pressure receiving structure integrated 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 a thin plate and is relatively weak, can be received and reinforced by the member 120 and the ring member 140.

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

1 Pressure sensor 10 Cover 20 Relay board 22 Connector 24 Lead wire 30 Fluid inflow pipe 100 Pressure detection unit 110 Base 120 Receiving member 130 Diaphragm 140 Ring member 150 Semiconductor type pressure detector 152 Support board 154 Pressure detection element 160 Lead pin 162 for grounding Lead pin for power input 164 Lead pin for signal output 166 Bonding wire

Claims (7)

A base with a through hole into which a lead pin is inserted, and a base
A ring member having a cylindrical inner peripheral surface that fits with the outer peripheral surface of the base,
A receiving member joined by welding to the ring member,
A diaphragm sandwiched between the ring member and the receiving member,
In the pressure receiving space formed between the base and the diaphragm, the semiconductor type pressure detection device attached to the base and
A liquid medium enclosed in the pressure receiving space is provided.
In the fitting portion between the base and the ring member, the upper surface of the base and the upper end of the ring member are positioned so as to be flush with each other, and the fitting portion is welded all around.
A pressure detection unit characterized by that. When the center line of the pressure detection unit is the axis, a step portion is formed inside the ring member, and the base abuts on the step portion to be positioned in the axial direction with respect to the ring member. ,
The pressure detection unit according to claim 1. The welding of the fitting portion is laser welding.
The pressure detection unit according to claim 1 or 2. The ring member has a first circular flange portion, and the receiving member has a second circular flange portion.
The outer circumference of the diaphragm is welded together with the first circular flange portion and the second circular flange portion.
The pressure detection unit according to any one of claims 1 to 3. The pressure detection unit according to any one of claims 1 to 4 is used.
It features a pressure sensor. A base having a through hole into which a lead pin is inserted, a ring member having a cylindrical inner peripheral surface that fits with the outer peripheral surface of the base, a receiving member joined by welding to the ring member, and the ring. A diaphragm sandwiched between the member and the receiving member, a semiconductor type pressure detecting device attached to the base in the pressure receiving space formed between the base and the diaphragm, and an enclosure in the pressure receiving space. It is a method of manufacturing a pressure detection unit provided with a liquid medium provided with a welded liquid medium.
The process of inserting a lead pin into the through hole of the base and sealing it,
A step of attaching the semiconductor type pressure detector to the base to form a first intermediate product, and
The step of sandwiching the diaphragm between the ring member and the receiving member, and
A step of welding the outer periphery of the ring member and the receiving member to form a second intermediate product while sandwiching the diaphragm.
The step of injecting the liquid medium into the second intermediate product body from the ring member side, and
When the center line of the pressure detection unit is the axis, the upper surface of the base and the upper end of the ring member are flush with each other on the inner circumference of the cylindrical inner peripheral surface of the ring member of the second intermediate product. As described above, the step of pressing the liquid surface of the liquid medium in the second intermediate product by the base while fitting the outer periphery of the base of the first intermediate product.
It has a step of rotating the first intermediate product and the second intermediate product around the axis, and laser welding the ring member and the fitting portion of the base from the axis direction on the entire circumference.
A method of manufacturing a pressure detection unit. A method for manufacturing a pressure sensor, which comprises manufacturing a pressure sensor using the pressure detection unit manufactured by the method for manufacturing the pressure detection unit according to claim 6.

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