JP3027226B2 - Pressure sensor and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
Alternatively, the present invention relates to a pressure sensor for detecting a pressure of a liquid or the like flowing in a pipe as an electric signal and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a pressure sensor for detecting a pressure of a pressured liquid or the like as an electric signal, a pressure sensor shown in FIG. 5 is conventionally known. The pressure sensor 11 is formed of a metal body 12 having a screw cylinder portion 12a which can be screwed and fixed to a container containing a pressure liquid or the like or a pipe through which the pressure liquid flows.
A pressure sensor element 13 having a pressure sensor chip 13a, an amplifier 14, and the like are built therein, and a diaphragm 15 for pressure detection is mounted at the tip of the screw cylinder 12a. The pressure sensor element 13 is housed in the screw cylinder 12a with the pressure sensor chip 13a fixed on the ceramic stem 13b facing the diaphragm 15 side,
Between the ceramic stem 13b of the pressure sensor element 13 and the diaphragm 15 in the screw cylinder 12a,
The pressure detected by the diaphragm 15 is applied to the pressure sensor chip 1
An oil chamber 16 in which oil for transmitting the oil to 3a is formed.

The oil chamber 16 is composed of a stainless steel diaphragm 15, a metal screw cylinder 12a and a ceramic stem 13b as constituent members in FIG.
(B) It is formed by the process shown in (c). First,
As shown in (a), a pressure sensor chip 13a is fixed to the upper surface of a ceramic stem 13b, and a pressure sensor element 13 is prepared by wire bonding. Then, the pressure sensor element 13 is connected to the screw cylinder 12 of the body 12 as shown in FIG.
The molten solder 17 is filled between the outer periphery of the ceramic stem 13b and the inner periphery of the screw tube portion 12a, and the two are connected by soldering. Subsequently, as shown in FIG.
After the oil is filled in a, the diaphragm 15 is welded to the tip of the threaded tube portion 12a to form an oil chamber 16.

[0004]

In the conventional pressure sensor 11, since the ceramic stem 13b and the metal screw cylinder portion 12a are connected by soldering when forming the oil chamber 16, the oil sealing performance is reduced. There are difficulties,
The improvement is demanded. In addition, since a process of welding the diaphragm 15 after filling the oil into the screw cylinder portion 12a is required, productivity is poor, and improvement thereof is also demanded.

Accordingly, an object of the present invention is to provide a pressure sensor capable of improving the sealing performance of oil in an oil chamber and improving productivity, and a method of manufacturing the same.

[0006]

In order to achieve this object, a pressure sensor according to the present invention has an oil chamber formed between a pressure sensor element having a pressure sensor chip and a diaphragm, and detects an oil pressure detected by the diaphragm. A pressure sensor for transmitting to a pressure sensor chip via oil in a room, comprising a metal cylinder forming an oil chamber between the pressure sensor element and the diaphragm, one end of the metal cylinder having a pressure sensor element. Is fixed by caulking to the outer periphery through an elastic seal member, and the other end is curled to the outer periphery of the diaphragm.

In a method of manufacturing a pressure sensor according to the present invention, an oil chamber is formed between a pressure sensor element having a pressure sensor chip and a diaphragm, and a pressure detected by the diaphragm is applied to the pressure sensor via oil in the oil chamber. A method of manufacturing a pressure sensor of a type transmitting to a chip, wherein an elastic seal member is fixed around the pressure sensor element, and one end of a metal cylinder is caulked and fixed to the pressure sensor element via the elastic seal member. The other end of the metal cylinder is curled to the outer periphery of the diaphragm in oil to form an oil chamber filled with oil between the diaphragm and the pressure sensor element.

[0008]

According to the pressure sensor according to the present invention, one end of the metal cylinder forming the oil chamber is fixed by caulking to the outer periphery of the pressure sensor element via an elastic seal member. Is curled to the outer periphery of the diaphragm, so that the sealing performance of the oil in the oil chamber is improved.

Further, in forming the oil chamber, the other end of the metal cylinder is curled and joined to the outer periphery of the diaphragm in the oil, so that the oil chamber is automatically filled with the oil, thereby improving the productivity of forming the oil chamber. .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention shown in the drawings will be described below. In FIG. 1 showing a sectional view of the pressure sensor 1,
Reference numeral 2 denotes a stepped cylindrical metal body provided with a threaded cylindrical portion 2a that can be screwed and connected to a container or the like containing a pressurized liquid or the like. A pressure sensor element 5 to which a diaphragm 4 made of aluminum is fixed is housed. Further, an amplifier 6 for amplifying the detection signal of the pressure sensor element 5 is housed in a case 7 connected to the body 2.

As shown in FIG. 2, the pressure sensor element 5 has a silicon pressure sensor chip 5c fixed on the upper surface of a short cylindrical ceramic stem 5b having two leads 5a by bonding or the like, and this is connected to a lead. A rubber cylinder 8 having a predetermined thickness is fixed to the outer periphery of the ceramic stem 5b by baking as an elastic seal member.

As shown in FIG. 3, one end of the metal cylinder 3 is fitted to the outer periphery of the rubber cylinder 8 and is caulked in a ring groove shape from the outer peripheral side. 8 and is fixed to the outer periphery of the ceramic stem 5b in a liquid-tight manner. The outer periphery of the diaphragm 4 is fixed to the other end of the metal cylinder 3 by a curling process in a liquid-tight manner, and the diaphragm 4 and the ceramic stem 5b are fixed.
An oil chamber 9 filled with oil is formed between the oil chamber 9 and the upper surface of the oil chamber. As shown in FIG. 1, a space between the inner periphery of the body 2 and the outer periphery of the metal cylinder 3 is provided by an O attached to the caulking portion 3a.
Sealed by a ring 10.

FIGS. 4A to 4F show the pressure sensor 1.
First, a pressure sensor element 5 in which a silicon pressure sensor chip 5c is wire-bonded to a lead 5a is prepared, and a rubber cylinder 8 is fitted around the ceramic stem 5b and fixed by baking (a). . In addition, a metal cylinder 3 having an enlarged diameter portion 3b for curling formed at the other end.
Is prepared, and an adhesive is applied to the inner surface of the enlarged diameter portion 3b (b). Further, a diaphragm 4 which is fitted to the enlarged diameter portion 3b of the metal cylinder 3 and whose outer peripheral portion is curled is prepared (c).

After such preparation, one end of the metal cylinder 3 is fitted to the outer periphery of the rubber cylinder 8 (d). Subsequently, a ring groove-shaped caulking portion 3a is formed on the outer periphery of one end of the metal tube 3 and one end of the metal tube 3 is connected to the ceramic stem 5 via the rubber tube 8.
(e).

Subsequently, the diaphragm 4 is fitted to the enlarged diameter portion 3b of the metal cylinder 3, and the both are subjected to curling using a winding machine or the like, and the two are joined in a liquid-tight manner to form an oil chamber 9. However, this curling process is performed in the oil chamber 9.
(F).

The pressure sensor 1 manufactured as described above
When the diaphragm 4 is elastically displaced by the liquid pressure of the liquid introduced from the screw cylinder 2a of the body 2, the oil in the oil chamber 9 transmits the liquid pressure to the silicon pressure sensor chip 5c. Then, the silicon pressure sensor chip 5c generates a voltage corresponding to the liquid pressure, and the amplifier 6 amplifies the voltage, whereby the pressure sensor 1 converts the liquid pressure into an electric signal and detects it.

As described above, in one embodiment, the curling of the metal cylinder 3 and the diaphragm 4 for forming the oil chamber 9 is performed in oil. The oil is automatically filled without excess or shortage, and the productivity of forming the oil chamber 9 is improved.

In the pressure sensor 1 according to such a manufacturing method, one end of the metal tube 3 is fixed in a liquid-tight manner to the outer periphery of the ceramic stem 5b via the rubber tube 8 and the other end of the metal tube 3 is fixed. Since the oil chamber 9 is formed by being liquid-tightly curled to the outer periphery of the diaphragm 4, the sealing performance of the oil sealed in the oil chamber 9 is good, and there is no fear of oil leakage.

[0019]

As described above, according to the present invention,
One end of the metal cylinder forming the oil chamber is caulked and fixed to the outer periphery of the pressure sensor element via an elastic seal member, and the other end is curled to the outer periphery of the diaphragm, thereby improving the oil sealing performance of the oil chamber. can do.

In forming the oil chamber, the other end of the metal cylinder is curled to the outer periphery of the diaphragm in the oil, so that the oil chamber is automatically filled with the oil.
Therefore, the productivity of forming the oil chamber can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a pressure sensor according to the present invention.

FIG. 2 is a side view of a pressure sensor element according to one embodiment.

FIG. 3 is a sectional view of an oil chamber in one embodiment.

FIGS. 4 (a) to (f) are diagrams showing a manufacturing process of one embodiment, respectively.

FIG. 5 is a sectional view showing a conventional example of a pressure sensor.

FIGS. 6 (a) to 6 (c) are views showing respective manufacturing steps of a conventional example.

[Explanation of symbols]

 1, 11 pressure sensor 2, 12 body 2a, 12a screw cylinder part 3 metal cylinder 3a crimping part 4, 15 diaphragm 5, 13 pressure sensor element 5a lead 5b, 13b Ceramic stem 5c Silicon pressure sensor chip 6, 14 Amplifier 7 Case 8 Rubber cylinder 9, 16 Oil chamber 10 O-ring 13a Pressure sensor chip 17 Melting solder

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01L 19/00 G01L 9/04 101 G01L 19/14

Claims (2)

(57) [Claims] An oil chamber (9) is formed between a pressure sensor element (5) having a pressure sensor chip (5c) and a diaphragm (4), and a pressure detected by the diaphragm (4) is applied to the oil chamber (9). A pressure sensor (1) of a type for transmitting to a pressure sensor chip (5c) via oil in ()), wherein an oil chamber (9) is formed between the pressure sensor element (5) and the diaphragm (4). Metal cylinder (3)
One end of the metal cylinder (3) is fixed by caulking to the outer periphery of the pressure sensor element (5) via an elastic seal member (8), and the other end is curled to the outer periphery of the diaphragm (4). Features pressure sensor. 2. An oil chamber (9) is formed between a pressure sensor element (5) having a pressure sensor chip (5c) and a diaphragm (4), and a pressure detected by the diaphragm (4) is applied to the oil chamber (9). A method for producing a pressure sensor (1) of the type transmitting to a pressure sensor chip (5c) via oil in ()), wherein an elastic seal member (8) is fixed around the pressure sensor element (5), One end of the metal tube (3) is fixed by caulking to the pressure sensor element (5) via the elastic seal member (8), and the other end of the metal tube (3) is fixed to the outer periphery of the diaphragm (4) in oil. A method of manufacturing a pressure sensor, comprising forming an oil chamber (9) filled with oil between a diaphragm (4) and a pressure sensor element (5) by curling.