JP2005037311A - Pressure sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure sensor having excellent airtightness, and having firm joining of a holder and a lid member. <P>SOLUTION: This pressure sensor has: the holder 1; a connector case 3 installing and fixing a semiconductor pressure sensor element 21 outputting a voltage signal according to received pressure and lead members 23 connected to the semiconductor pressure sensor element; a diaphragm 4 forming a pressure detection chamber 6 filled with a liquid together with the holder 1; and the metal lid member 5 installed with a pressure lead-in pipe 51. In the pressure sensor, the holder 1 is made of a metal. The connector case 3 has a penetration holding hole 31 connecting the pressure detection chamber 6 and the outside, and holding a sealing member 26. The diaphragm 4 is pinched by the metal holder 1 and the metal lid member 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pressure sensor, and more particularly to a pressure sensor that fills a pressure detection chamber containing a pressure detection element with a liquid and includes a holder, a connector case, a diaphragm, and a lid member.

  Conventionally, a liquid is sealed in a pressure detection chamber in which a semiconductor pressure sensor element is accommodated, and pressure applied from the outside to the pressure detection chamber is transmitted to the semiconductor pressure sensor element via the liquid. Various semiconductor pressure detectors that output a voltage signal corresponding to pressure have been proposed (see Patent Document 1).

  Further, Patent Document 2 uses a sensor in which a strain gauge and a circuit element of a signal processing circuit are integrated. The sensor is surrounded by a seal diaphragm and a container, and is disposed in a space filled with insulating oil such as silicone oil. A semiconductor pressure sensor is disclosed.

In the conventional semiconductor pressure detector in which the pressure-sensitive element and the signal processing circuit are provided in the sealed liquid, no consideration has been given to improving airtightness and reducing the number of assembly steps.
Japanese Patent No. 3198773 JP-A-5-149814

  SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art and to provide a pressure sensor that is excellent in airtightness and has a strong joint between a holder and a lid member.

The present invention fills a holder, a semiconductor pressure sensor element that outputs a voltage signal corresponding to the received pressure, a connector case for mounting and fixing a lead member electrically connected to the semiconductor pressure sensor element, and insulating oil. In a pressure sensor comprising a diaphragm that forms a pressure detection chamber with a holder, and a metal lid member attached with a pressure introduction pipe,
The holder is made of metal, the connector case connects the pressure detection chamber and the outside, and is provided with a through-holding hole for holding a sealing member, and the diaphragm includes the metal holder and the The pressure sensor is sandwiched and fixed by a metal lid member.

  The present invention also provides a holder having a semiconductor pressure sensor element that outputs a voltage signal corresponding to the received pressure, a connector case for fixing a lead member connected to the semiconductor pressure sensor element, and a pressure filled with insulating oil. In a pressure sensor comprising a diaphragm that forms a detection chamber with a holder and a metal lid member to which a pressure introduction tube is attached, the holder is made of metal, and connects the pressure detection chamber and the outside, and A through-holding hole for holding a sealing member; and the connector case is provided with an insertion hole for communicating with the through-holding hole to insert a sealing member; and the diaphragm includes the metal holder and the The pressure sensor is sandwiched and fixed by a metal lid member.

  The present invention is a pressure sensor in which the holder and the lid member have different contact surface diameters, and the contact portions are fixed by welding.

  According to the present invention, it is possible to realize a pressure sensor that has excellent airtightness and improved assemblability with a strong bond between the holder and the lid member.

  Hereinafter, the best mode for carrying out the present invention will be described. An embodiment of the pressure sensor of the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view showing the configuration of the pressure sensor of the first embodiment. FIG. 2 is a longitudinal sectional view showing the configuration of the pressure sensor according to the second embodiment.

  A first embodiment of the pressure sensor of the present invention will be described. As shown in FIG. 1, the pressure sensor of this embodiment includes a holder 1, a connector case 3, a diaphragm 4, and a lid member 5.

  The holder 1 is a substantially cylindrical member made of metal, for example, stainless steel, and includes an upper wall portion 1a, a lower wall portion 1b, and a cylindrical wall portion 1c formed integrally with these wall portions, and these wall portions 1a. In the internal space 1d formed by ˜1c, for example, a resin connector case 3 is formed on a substantially cylindrical shape by insert molding, and is joined to the holder 1 so that the upper wall portion 1a and the shoulder portion 3a of the connector case 3 are in contact with each other. Because it touches, there is no gap.

  The semiconductor pressure sensor element 21 is fixed in the pressure detection chamber 6 via the pedestal 22 at the flat end 32 of the connector case 3 inserted into the internal space 1 d of the holder 1. The semiconductor pressure sensor element 21 is formed with a piezoresistor so as to form a bridge circuit and a circuit for processing an electrical signal around it, and outputs a voltage signal corresponding to the received pressure. The semiconductor pressure sensor element 21 is exposed to the pressure transmitted to the pressure detection chamber 6. The semiconductor pressure sensor element 21 is connected by a lead member 23 to a circuit (not shown) provided outside the pressure sensor.

  The connector case 3 is formed with an insertion fixing hole 34 for inserting and fixing the through-holding hole 31 and the plurality of lead members 23 in the vertical direction, that is, in the direction perpendicular to the diaphragm 4. The lead member 23 is provided with a bent portion 23 a in the connector case 3, and is difficult to be removed from the connector case 3.

  The insertion holding hole 31 of the connector case 3 includes a large-diameter portion 31a and a small-diameter portion 31b. A screw member 26 serving as a sealing member is screwed with an inner surface of the large-diameter portion 31a, and a tip of the screw member 26 is a small-diameter portion. The pressure detection chamber 6 is sealed by coming into contact with 31b. Further, since the screw member 26 is provided with an O-ring 27 and the sealing member is disposed in the vertical direction of the connector case 3, the sealing member can be hardly seen from the outside. In the pressure detection chamber 6, for example, an adhesive or a resin seal 25 is used for sealing around the semiconductor pressure sensor element 21, the lead member 23, the insertion fixing hole 11 of the holder 1, and the small diameter portion 31 b of the insertion holding hole 31 of the connector case. It is provided and is airtightly fixed.

  The leading end portion of the lead member 23 that is fixed by the insertion fixing hole 34 of the connector case 3 is electrically connected to the semiconductor pressure sensor element 21 by the bonding wire 24.

  The pressure detection chamber 6 is formed by the diaphragm 4, the inner surface of the lower wall portion 1 b of the holder 1, the flat end portion 32 of the connector case 3, and the inclined portion 33 continuing to the flat end portion 32. Insulating oil as a pressure transmission medium such as oil is injected through the through-holding hole 31 provided in the connector case 3 and fills the periphery of the semiconductor pressure sensor element 21. The through-holding hole 31 is sealed by a sealing member such as a screw member 26, and the pressure transmission medium is sealed in the pressure detection chamber 6 and connected to the pressure introduction hole 5 c formed in the falling portion 5 b of the lid member 5. In order to detect the pressure introduced from the pressure introduction pipe 51 into the pressure transmission space 5e, the pressure detection chamber 6 is kept airtight. The pressure introduction pipe 51 is attached to the falling part 5b by the welded part 52, and the pressure transmission space 5e is formed by the disk part 5a and the inner surface of the rising part 5d and the diaphragm 4.

  The lid member 5 is made of metal, for example, stainless steel, and includes a disk portion 5a, a rising portion 5d and a falling portion 5b formed integrally with the disk portion 5a, and an upper surface contact portion 5d ′ of the rising portion 5d. Three members of a disk-like diaphragm 4 made of metal, for example, stainless steel, sandwiched between the lower surface contact portion 1b 'of the lower wall 1b of the holder 1 are joined and fixed together by welding, for example, laser welding. As a result, the pressure detection chamber 6 is formed by the inner surface of the lower wall portion 1 b of the holder 1, the flat end portion 32 of the connector case 3, and the diaphragm 4.

  Here, sandwiching of the diaphragm 4 by the holder 1 and the lid member 5 will be described. In order to further improve the sealing of the pressure detection chamber 6 formed by the holder 1 and the diaphragm 4, the holder 1 and the lid member 5 sandwich the periphery of the diaphragm 4 and weld the holder 1, the lid member 5, and the diaphragm 4. . At that time, since the contact surfaces of the holder 1 and the lid member 5 have different diameters, that is, the contact portions of the side surfaces of the holder 1 and the lid member 5 are not flush with each other. When the contact portion is the weld portion 7, the weld portion can be determined and welded. Therefore, the holder 1 and the lid member 5 and the holder 1 and the diaphragm 4 are firmly fixed, and the sealing degree of the pressure detection chamber 6 can be increased. That is, since both the holder 1 and the lid member 5 are made of metal, sealing by welding can be strengthened.

  Hereinafter, an example of the assembly process of the pressure sensor of Example 1 will be described. First, the connector case 3 to which the semiconductor pressure sensor 21 and the lead member 23 are fixed via the base 22 is fitted into the holder 1. The holder 1, the semiconductor pressure sensor 21, the lead member 23, and the insertion fixing hole 31 are sealed with an adhesive or a resin seal 25, respectively. The semiconductor pressure sensor element 21 and the lead member 23 are electrically connected by a bonding wire 24.

  On the other hand, the pressure introducing pipe 51 is brazed to the falling part 5 b of the lid member 5. And the diaphragm 4 is pinched | interposed with the holder 1 and the cover member 5, and it joins airtightly by welding, and the holder 1, the cover member 5, and the diaphragm 4 are integrated.

  After that, after filling the pressure detection chamber 6 formed by the diaphragm 4 and the holder 1 with insulating oil such as fluorine oil or silicone oil from the insertion holding hole 31, the sealing member 26 is inserted into the insertion holding hole 12. Hold. Thereby, the pressure sensor of Example 1 is comprised. The holder 1 and the lid member 5 can be welded after filling with insulating oil.

  In this way, a pressure sensor with good airtightness can be manufactured with a small number of parts and a small manufacturing process.

  A pressure sensor according to a second embodiment of the present invention will be described with reference to FIG. The pressure sensor according to this embodiment includes a holder 1 ′, a connector case 3 ′, a diaphragm 4, and a lid member 5. The same components as those of the first embodiment shown in FIG.

  The holder 1 ′ is made of a metal such as stainless steel, and includes an upper wall portion 1 a ′, a lower wall portion 1 b ′, and a substantially cylindrical base portion 1 c ′ formed integrally with these wall portions. The upper wall portion 1a 'is fitted with a resin connector case 3' by insert molding. Lower wall part 1b 'has the space which functions as the pressure detection chamber 6 formed in an inside. In the base portion 1c ′, a lead member lead-out hole 12 ′ into which a plurality of lead members 23 are inserted and a through-holding hole 13 ′ including a large diameter portion 13a ′ and a small diameter portion 13b ′ are formed from the upper surface 1d ′ to the lower surface 1e ′. Then, a screw member 26 ′ as a sealing member is screwed into the large diameter portion 13 a ′ and abuts on the small diameter portion 13 b ′ to keep airtightness.

  The connector case 3 ′ is fitted to the holder 1 ′, has an insertion hole 31 ′, communicates with the through-holding hole 13 ′, and is electrically connected to the semiconductor pressure sensor element 21 fixed to the bottom surface 1 e ′ of the holder 1 ′. The lead member 23 connected to is fixed to the connector case 3 '. If the lead member 23 is provided with a curved portion in the connector case 3 ', it is difficult to remove the lead member 23 from the connector case 3'.

  The peripheral portion of the diaphragm 4 is sandwiched between the lower wall 1b ′ and the rising portion 5a. The diaphragm 4 and the lid member 5 are the same as those of the first embodiment shown in FIG. 1, and the same or equivalent parts as those in FIG. Further, in the embodiment of FIG. 2, the adhesive or resin seal 25 seals the small diameter portion 13 b ′ of the through-holding hole 13 ′ via the pipe member 28.

  Hereinafter, with respect to an example of the assembly process of the pressure sensor of the second embodiment, differences from the first embodiment will be mainly described. First, the connector case 3 ′ to which the lead member 23 is fixed is fitted into the holder 1 ′ by insert molding. The lead member 23 is sealed by the adhesive or resin seal 25 through the lead member lead-out hole 12 ′ and through the pipe member 28. The semiconductor pressure sensor element 21 is fixed to the bottom surface 1 e ′ of the holder 1 ′ by bonding via a pedestal 22, and the semiconductor pressure sensor element 21 and the lead member 23 are connected by a bonding wire 24.

  After the insulating oil such as fluorine oil or silicone oil is filled into the pressure detection chamber 6 formed by the diaphragm 4 and the holder 1 ′ from the through-holding hole 13 ′, the sealing member 26 ′ is inserted into the through-holding hole 13 ′. The through-holding hole 13 'is sealed by screwing and holding. Thereby, the pressure sensor of Example 2 is comprised.

  Further, in the first and second embodiments described above, a metal ball is further inserted between the sealing members 26 and 26 'and the small diameter portion of the through-holding hole and fixed by the sealing members 26 and 26'. May be. Alternatively, only a metal ball may be inserted and fixed as a sealing member.

1 is a longitudinal sectional view showing the structure of a pressure sensor according to Embodiment 1. FIG. FIG. 5 is a longitudinal sectional view showing a structure of a pressure sensor according to a second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 'Holder 1a Upper wall part 1b, 1b' Lower wall part 1c Cylindrical wall part 1c 'Base part 1d Internal space 1e Lower surface contact part 11 Insertion fixing hole 12' Lead member extraction hole 13 'Through-holding hole 13a' Large Diameter portion 13b 'Small diameter portion 21 Semiconductor pressure sensor element 22 Base 23 Lead member 23a Bending portion 24 Bonding wire 25 Adhesive or resin seal 26 Sealing member 27 O-ring seal 3, 3' Connector case 31 Insertion holding hole 31a Large diameter Part 31b small diameter part 31 'insertion hole 32 flat end part 33 inclined part 4 diaphragm 5 lid member 5a disk rising part 5a' upper surface contact part 5b falling part 5c pressure introduction hole 5d rising part 5d 'upper surface contact part 5e pressure transmission Space 51 Pressure introducing pipe 52 Welded part 6 Pressure detection chamber 7 Welded part

Claims (3)

A holder, a semiconductor pressure sensor element that outputs a voltage signal corresponding to the received pressure, a connector case for mounting and fixing a lead member electrically connected to the semiconductor pressure sensor element, and a pressure detection chamber filled with insulating oil In a pressure sensor comprising a diaphragm formed by a holder and a metal lid member to which a pressure introduction pipe is attached,
The holder is made of metal, the connector case connects the pressure detection chamber and the outside, and is provided with a through-holding hole for holding a sealing member, and the diaphragm includes the metal holder and the A pressure sensor characterized by being sandwiched and fixed by a metal lid member. A holder having a semiconductor pressure sensor element that outputs a voltage signal corresponding to the received pressure, a connector case for fixing a lead member electrically connected to the semiconductor pressure sensor element, and a pressure detection chamber filled with insulating oil In a pressure sensor comprising a diaphragm formed by a holder and a metal lid member to which a pressure introduction pipe is attached,
The holder is made of metal and has a through-holding hole that connects the pressure detection chamber and the outside and holds a sealing member, and the connector case communicates with the through-holding hole and is a sealing member The pressure sensor is characterized in that an insertion hole is provided to insert the diaphragm, and the diaphragm is sandwiched and fixed between the metal holder and the metal lid member. The pressure sensor according to claim 1 or 2,
The pressure sensor, wherein the holder and the lid member have different contact surface diameters, and the contact portions are fixed by welding.

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