JP2018155621A - Pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress formation of air bubbles in an electrostatic protection layer in a pressure sensor in a case where an electrostatic protection layer is formed by a silicon-based adhesive.SOLUTION: The lower end surface 24TS of the base end part of the terminal board 24 in the pressure sensor is bonded to the upper end surface 12TS of a housing 12 by a ring-shaped adhesive 10a made of a silicone-based adhesive. A coating layer 10b made of a silicone-based adhesive is formed to have a predetermined thickness on the entire region of the upper end surface 14UE of a hermetic glass 14. An input-output terminal group 40ai is protruded from the hermetic glass. A ring-shaped intersecting line 24EP, at which the lower end surface 24TS of the base end part of the terminal board 24 and the inner periphery surface 24IS of the base end part intersect with each other, is located on an extended plane immediately above the inner periphery surface 12IS (intersecting line 12EP) of the housing 12, above the coating layer 10b, with an air layer being formed in a hollow 24A.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pressure sensor.

  For example, as shown in Patent Document 1, a sensor unit built in a liquid-sealed semiconductor pressure sensor includes a diaphragm that is supported in a joint portion and isolates a pressure detection chamber from a liquid-sealing chamber described later, and an upper portion of the diaphragm. A liquid sealed chamber for storing silicone oil as a pressure transmission medium, a sensor chip disposed in the liquid sealed chamber for detecting pressure fluctuations of the silicone oil via a diaphragm, a chip mount member for supporting the sensor chip, and a housing The hermetic glass that seals the periphery of the chip mount member in the through-hole and a terminal group that sends out an output signal from the sensor chip and supplies power to the sensor chip as main elements.

  The terminal block for aligning the terminal group is formed of a resin material, for example, a resin mainly composed of polybutylene terephthalate (PBT). The terminal block includes a plurality of holes into which the terminal group is inserted and a hollow portion having a predetermined volume inside. The lower end surface of the terminal block is bonded to the upper end surface of the housing with a silicone-based adhesive. As a result, an annular adhesive layer having a predetermined thickness is formed on the upper end surface of the housing.

  The internal circuit of the sensor chip as described above may be destroyed by a high voltage due to electrostatic discharge (ESD). In the sensor unit described above, for example, high voltage caused by electrostatic discharge is generated inside the sensor chip through the path from the joint and element body to the sensor chip, or from the external lead wire and terminal group to the sensor chip. There is a risk of being applied to the circuit. As a countermeasure in such a case, for example, as disclosed in Patent Document 1, an electrostatic protective layer made of a silicone-based adhesive is formed of a coating layer and an adhesive layer. That is, a coating layer made of a silicone-based adhesive is formed with a predetermined thickness on the entire upper end surface of the hermetic glass from which the terminal group protrudes. Further, the above-described annular adhesive layer is formed on the upper end surface of the housing.

  By forming the electrostatic protection layer with the silicone-based adhesive in this manner, the electrostatic strength of the sensor unit is improved without being affected by the presence or absence of the ESD protection circuit.

International Publication No. 2015/194105

  When the lower end surface of the terminal block is bonded to the upper end surface of the housing with a silicone-based adhesive, the terminal block is heated to a predetermined temperature depending on the type of the adhesive. In such a case, in the terminal block formed of polybutylene terephthalate, moisture taken into the atmosphere from the atmosphere may be vaporized by heating to be bubbled and come out of the terminal block. As a result, air bubbles that have come out of the terminal block are retained between the lower end surface of the terminal block adjacent to the upper end surface of the housing and the upper end surface of the hermetic glass, and when the adhesive layer and the coating layer are solidified, Is incorporated into the coating layer. As a result, the thin portion of the coating layer is partially formed by the bubbles.

  In addition, air in the minute recesses due to the roughness of the surface between the bonding surface of the terminal block and the upper end surface (bonded surface) of the housing is heated between the bonding surface of the terminal block and the upper end surface of the housing. Extruded into the coating layer. As a result, when the adhesive layer and the coating layer are solidified, bubbles are taken into the coating layer, so that a thin portion of the coating layer is formed by the bubbles.

  Therefore, there is a possibility that the electrostatic strength of the sensor unit may be reduced by forming a plurality of bubbles in the coating layer and partially forming a thin portion of the coating layer.

  In view of the above problems, the present invention provides a pressure sensor that can suppress the formation of bubbles in the electrostatic protection layer when the electrostatic protection layer is formed of an insulating adhesive. The purpose is to do.

  In order to achieve the above-described object, a pressure sensor according to the present invention includes a sensor chip that detects pressure and sends a detection output signal, at least one output terminal that sends a signal from the sensor chip, and an output A sensor unit including a housing including a hermetic glass for supporting a terminal, a coating layer covering an end surface of the hermetic glass from which an output terminal protrudes, and a terminal alignment member having an adhesive surface bonded to the end surface of the housing And a sensor unit housing portion for housing the sensor unit, and having a hollow portion between the terminal alignment member and the coating layer, the inner surface of the bonding surface and the base end portion of the base end portion of the terminal alignment member An annular intersection line intersecting with the peripheral surface is separated on an extended surface extending toward the terminal alignment member on the inner peripheral surface of the housing or along the end surface of the housing from the inner peripheral surface of the housing. Characterized in that in a position opposed to the location.

  Further, the inner peripheral surface of the base end portion of the terminal alignment member may have a concave portion or a convex portion, and the inner peripheral surface of the base end portion of the terminal alignment member may have a step portion. Furthermore, the terminal alignment portion of the terminal alignment member may have a relief portion.

  According to the pressure sensor of the present invention, there is a hollow portion between the terminal alignment member and the coating layer, and the annular intersection where the adhesive surface of the base end portion of the terminal alignment member intersects the inner peripheral surface of the base end portion. Since the wire is located on the extended surface extending toward the terminal alignment member on the inner peripheral surface of the housing, or on the position facing the position separated from the inner peripheral surface of the housing along the end surface, the air staying on the adhesive surface Since it escapes easily to a cavity part via a coating layer, when an electrostatic protective layer is formed with an insulating adhesive agent, it can suppress that a bubble is formed in an electrostatic protective layer.

It is a fragmentary sectional view which expands and shows the principal part of the sensor unit of the pressure sensor which concerns on this invention partially. It is sectional drawing which shows the structure of 1st Example of the pressure sensor which concerns on this invention. It is a fragmentary sectional view which expands and shows partially the principal part of another example of the terminal block used for the pressure sensor shown by FIG. It is a fragmentary sectional view which expands partially and shows the principal part of another example of the terminal block used for the pressure sensor shown in FIG. It is a fragmentary sectional view which expands partially and shows the principal part of another example of the terminal block used for the pressure sensor shown in FIG. It is sectional drawing which shows the structure of 2nd Example of the pressure sensor which concerns on this invention.

  FIG. 2 schematically shows the configuration of a first embodiment of the pressure sensor according to the present invention.

  In FIG. 2, the pressure sensor includes a joint member 30 connected to a pipe through which a fluid whose pressure is to be detected is guided, and a sensor unit connected to a base plate 28 of the joint member 30 to be described later, and a detection output from the sensor chip. And a sensor unit housing for supplying a signal to a predetermined pressure measuring device.

  The metal joint member 30 has an internal thread portion 30fs that is screwed into the external thread portion of the connection portion of the pipe described above. The female screw portion 30fs communicates with the port 30a of the joint member 30 that guides the fluid supplied from the direction indicated by the arrow P to the pressure chamber 28A described later. One open end of the port 30a opens toward a pressure chamber 28A formed between the base plate 28 of the joint member 30 and the diaphragm 32 of the sensor unit.

  The outer portion of the sensor unit housing portion is formed by a cylindrical waterproof case 20 as a cover member. An opening 20 b is formed at the lower end of the resin waterproof case 20. The peripheral edge portion of the base plate 28 of the joint member 30 is engaged with the stepped portion on the peripheral edge of the opening 20b which is the inner side.

  Air or liquid as a fluid is supplied into the pressure chamber 28 </ b> A through the port 30 a of the joint member 30. The lower end surface of the housing 12 of the sensor unit is welded to the peripheral edge of the base plate 28.

  The sensor unit that detects the pressure in the pressure chamber 28A and sends out a detection output signal includes a cylindrical housing 12, a metal diaphragm 32 that isolates the pressure chamber 28A and the inner periphery of the housing 12, and a plurality of pressures. A sensor chip 16 having a detection element, a metal chip mount member 18 that supports the sensor chip 16 at one end via an adhesive layer 50, and an input / output terminal group 40ai ( i = 1 to 8) and the hermetic glass 14 that fixes the input / output terminal group 40ai and the oil filling pipe 44 between the outer peripheral surface of the chip mount member 18 and the inner peripheral surface of the housing 12 as main elements. It is configured to include.

  The diaphragm 32 is supported on one lower end surface of the housing 12 facing the pressure chamber 28A. The diaphragm protection cover 34 that protects the diaphragm 32 disposed in the pressure chamber 28A has a plurality of communication holes 34a. The peripheral edge of the diaphragm protection cover 34 is joined to the lower end surface of the stainless steel housing 12 by welding together with the peripheral edge of the diaphragm 32.

  In the liquid sealing chamber 13 formed between the sensor chip 16 facing the metal diaphragm 32 and the end face of the hermetic glass 14, for example, a predetermined amount of silicone oil PM or a fluorine-based inert liquid is used as a pressure transmission medium. Is filled through an oil filling pipe 44. Note that one end of the oil filling pipe 44 is crushed and closed as indicated by a two-dot chain line after oil filling.

  The silicone oil is, for example, a silicone oil having a dimethylpolysiloxane structure composed of a siloxane bond and an organic methyl group. The fluorine-based inert liquid is, for example, a liquid having a perfluorocarbon structure, a liquid having a hydrofluoroether structure, or a low polymer of ethylene trifluoride chloride, and fluorine and chlorine are bonded to the main chain. , Both ends may have a fluorine or chlorine structure.

  Between the sensor chip 16 and the diaphragm 32 disposed in the recess formed at the end of the hermetic glass 14, a metal potential adjusting member 17 is further supported on the lower end surface of the hermetic glass 14. The potential adjusting member 17 is connected to a terminal having a communication hole and connected to the zero potential of the circuit of the sensor chip 16 as disclosed in, for example, Japanese Patent No. 3987386.

  The input / output terminal group 40ai (i = 1 to 8) includes two power supply terminals, one output terminal, and five adjustment terminals. Both end portions of each terminal protrude toward a recess formed at the end portion of the above-described hermetic glass 14 and a hole of a terminal block 24 described later. The two power supply terminals and the one output terminal are connected to the core wires 38 a of the lead wires 38 via the connection terminals 36. Each lead wire 38 is connected to a predetermined pressure measuring device. In FIG. 2, only four of the eight terminals are shown. The input / output terminal group 40ai and a sensor chip 16, which will be described later, are connected by a bonding wire Wi.

  The sensor chip 16 has a plurality of pressure detection elements, and is bonded to one end portion of the chip mount member 18 via an adhesive layer 50, for example.

  The terminal block 24 for aligning the input / output terminal group 40ai is formed using a resin material, for example, polybutylene terephthalate (PBT) as a main component. The terminal block 24 has a plurality of holes 24b into which the input / output terminal group 40ai is inserted, and a hollow portion 24A having a predetermined volume inside (see FIG. 1). The cavity portion 24A having a predetermined volume includes an inner peripheral surface 24IS of a cylindrical base end portion 24PE, a surface facing the upper end surface 14UE of the hermetic glass 14 in the terminal alignment portion 24T connecting the base end portions, and a hermetic glass. 14 is surrounded by the upper end surface. The inner peripheral surface 24IS has a predetermined slope so as to intersect the lower end surface 24TS of the base end portion of the terminal block 24 at a predetermined angle. The terminal alignment portion 24T described above has a plurality of holes 24b spaced apart from each other and is integrally formed so as to be orthogonal to the base end portion. The lower end surface 24TS of the base end portion of the terminal block 24 as an adhesive surface is bonded to the upper end surface 12TS of the housing 12 with a silicone-based adhesive. As a result, an annular adhesive layer 10 a having a predetermined thickness is formed on the upper end surface 12 TS of the housing 12.

  An inclined surface 12C having a predetermined gradient is formed at a portion near the inner peripheral edge of the upper end surface 12TS of the cylindrical housing 12. Thereby, a gap is formed between the lower end surface 24TS of the base end portion of the terminal block 24 and the inclined surface 12C. An annular intersection line 12EP where the end of the inclined surface 12C and the inner peripheral surface 12IS intersect is formed at a position higher than the upper end surface 14UE of the hermetic glass 14.

  At that time, an annular intersection line 24EP where the lower end surface 24TS of the base end portion of the terminal block 24 and the inner peripheral surface 24IS of the base end portion intersect is directly above the inner peripheral surface 12IS (intersection line 12EP) of the housing 12. It is on the extended surface.

  A covering layer 10b made of a silicone-based adhesive is formed with a predetermined thickness on the entire upper end surface 14UE of the hermetic glass 14 from which the input / output terminal group 40ai projects.

  As shown in a partially enlarged view in FIG. 1, the thickness of the covering layer 10 b is separated from the periphery of the input / output terminal group 40 ai, and the periphery of the input / output terminal group 40 ai becomes closer to the inner peripheral surface 24IS of the base end portion. It is gradually larger than the thickness. An air layer in the cavity 24A is formed above the covering layer 10b. As described above, the annular intersection line 24EP where the lower end surface 24TS of the base end portion of the terminal block 24 and the inner peripheral surface 24IS of the base end portion intersect is directly above the inner peripheral surface 12IS (intersection line 12EP) of the housing 12. Since the air in the adhesive layer 10a or the moisture taken into the terminal block 24 is vaporized by heating and the air is pushed out into the coating layer 10b, such air is bubbled AI. As shown by the arrows in FIG. 1, the bubble AI does not stay in the coating layer 10b and the bubble AI is immediately above the solidified layer before the coating layer 10b is solidified. It will be guided into the air layer in the cavity 24A. Therefore, when the coating layer 10b is solidified, there is no possibility that a predetermined amount or more of the air bubbles AI that reduce the electrostatic strength of the sensor unit are taken into the solidified coating layer 10b.

  Further, an adhesive layer 10a and a silicone adhesive layer made of the coating layer 10b are formed as an electrostatic protection layer on the upper end surface 12TS of the housing 12 and the entire upper end surface of the hermetic glass 14. Therefore, by forming the electrostatic protection layer with the silicone-based adhesive in this way, the electrostatic strength of the sensor unit is improved without being affected by the presence or absence of the ESD protection circuit.

  The covering layer 10b is formed over the entire upper end surface of the hermetic glass 14. However, the present invention is not limited to such an example. For example, the covering layer 10b includes the input / output terminal group 40ai on the upper end surface of the hermetic glass 14. The electrostatic protection layer may be configured to be formed at least only in the annular region CA between the inner peripheral surface of the housing 12.

  The above-mentioned silicone adhesive is preferably, for example, a flexible addition type one-component system. The silicone-based adhesive is, for example, an adhesive having a low molecular siloxane bond. Further, since the silicone adhesive and the silicone oil are compatible, there is no possibility that the adhesiveness of the silicone adhesive will deteriorate even if silicone oil or the like is mixed in the silicone adhesive.

  The outer peripheral surface of the terminal block 24 as a terminal alignment member, the outer peripheral surface of the end cap 22 connected to the terminal block 24 and covering the hole 24b of the terminal alignment portion 24T and the upper opening end of the terminal block 24, and the waterproof case 20 A predetermined amount of the sealing material 26 is filled between the inner peripheral surface of the waterproof case 20 and between the inner peripheral surface of the waterproof case 20 and the outer peripheral surface of the housing 12. The terminal block 24 and the end cap 22 are disposed in the waterproof case 20 so as to face the base plate 28 of the joint member 30 with the above-described sensor unit interposed therebetween.

  The upper end surface of the end cap 22 protrudes upward from the opening end of the waterproof case 20. That is, the position of the upper end surface of the end cap 22 is higher than the position of the opening end surface of the waterproof case 20.

  In the example shown in FIG. 1 described above, the inner peripheral surface 24IS of the terminal block 24 has a predetermined gradient so as to intersect the lower end surface 24TS of the base end portion of the terminal block 24 at a predetermined angle. However, the inner peripheral surface 44IS of the terminal block 44 is orthogonal to the lower end surface 44TS of the base end portion of the terminal block 44, as shown in FIG. May be formed. Note that FIG. 3 shows the same components as those in the example shown in FIG. 1 with the same reference numerals, and redundant description thereof is omitted.

  In FIG. 3, a terminal block 44 for aligning the input / output terminal group 40ai is formed using a resin material such as polybutylene terephthalate (PBT) as a main component. The terminal block 44 includes a plurality of holes 44b into which the input / output terminal group 40ai is inserted and a hollow portion 44A having a predetermined volume inside. The hollow portion 44A having a predetermined volume includes an inner peripheral surface 44IS of a cylindrical base end portion 44PE, a surface facing the upper end surface 14UE of the hermetic glass 14 in the terminal alignment portion 44T connecting the base end portions, and the hermetic glass. And 14 upper end surfaces 14UE. The terminal alignment portion 44T described above has a plurality of holes 44b spaced apart from each other and is integrally formed so as to be orthogonal to the base end portion. The lower end surface 44TS of the base end portion of the terminal block 44 as an adhesive surface is bonded to the upper end surface 12TS of the housing 12 with a silicone-based adhesive. As a result, an annular adhesive layer 10 a having a predetermined thickness is formed on the upper end surface 12 TS of the housing 12.

  At this time, an annular intersection line 44EP1 where the lower end surface 44TS of the base end portion of the terminal block 44 and the inner peripheral surface 44IS of the base end portion intersect is directly above the inner peripheral surface 12IS (intersection line 12EP) of the housing 12. It is on the extended surface. A concave portion 44R having a rectangular cross section is formed annularly continuously over the entire peripheral surface at a position above the intersecting line 44EP1 on the inner peripheral surface 44IS of the terminal block 44. An annular intersection line 44EP2 and an intersection line 44EP3 that form the opening edge of the recess 44R are respectively formed at positions directly above the intersection line 44EP1 on the inner peripheral surface 44IS.

  A portion of the inner peripheral surface 44IS above the intersection line 44EP3 is connected to the terminal alignment portion 44T.

  By thus forming the recess 44R on the inner peripheral surface 44IS of the terminal block 44, the coating layer 10b is spread over the entire circumference of the inner peripheral surface 44IS due to the surface tension caused by the recess 44R. The recess 44R is not limited to such an example, and may have a V-shaped cross section instead of a rectangular cross section, and has a predetermined interval over the entire circumferential surface. You may form so that it may be divided. Further, instead of the recess 44R, a protrusion having a predetermined height protruding toward the input / output terminal group 40ai may be formed on the inner peripheral surface 44IS.

  A covering layer 10b made of a silicone-based adhesive is formed with a predetermined thickness on the entire upper end surface 14UE of the hermetic glass 14 from which the input / output terminal group 40ai projects. As shown in a partially enlarged view in FIG. 3, the thickness of the covering layer 10b is separated from the periphery of the input / output terminal group 40ai, and the input / output terminal group becomes closer to the inner peripheral surface 44IS and the recess 44R at the base end. It is gradually larger than the thickness around 40 ai. An air layer in the cavity 44A is formed above the coating layer 10b. As described above, the annular intersection line 44EP1 where the lower end surface 44TS of the base end portion of the terminal block 44 and the inner peripheral surface 44IS of the base end portion intersect is directly above the inner peripheral surface 12IS (intersection line 12EP) of the housing 12. Since the air in the adhesive layer 10a or the moisture taken into the terminal block 44 is vaporized by heating and the air is pushed out into the coating layer 10b, such air is bubbled AI. As shown in the arrow in FIG. 3, the bubble AI does not stay in the coating layer 10b even before the bubble AI is solidified before the coating layer 10b is solidified. It will be guided into the air layer in the cavity 44A. Therefore, when the coating layer 10b is solidified, there is no possibility that a predetermined amount or more of the air bubbles AI that reduce the electrostatic strength of the sensor unit are taken into the solidified coating layer 10b.

  Further, instead of the example shown in FIG. 1 described above, for example, as shown partially enlarged in FIG. 4, the inner peripheral surface 54IS1 of the large-diameter portion of the terminal block 54 is The inner peripheral surface 54TS2 of the small diameter portion may be formed via the stepped portion 54R. FIG. 4 shows the same components as those in the example shown in FIG. 1 with the same reference numerals, and redundant description thereof is omitted.

In FIG. 4, a terminal block 54 for aligning the input / output terminal group 40ai is formed using a resin material, for example, polybutylene terephthalate (PBT) as a main component. The terminal block 54 includes a plurality of holes 54b into which the input / output terminal group 40ai is inserted, and a hollow portion 54A having a predetermined volume inside. The cavity 54A having a predetermined volume has a cylindrical base end 54PE.
An inner peripheral surface 54IS1 of the large-diameter portion, an inner peripheral surface 54IS2 of the small-diameter portion via the stepped portion 54R, and a surface facing the upper end surface 14UE of the hermetic glass 14 in the terminal alignment portion 54T connecting the base end portions; The hermetic glass 14 is surrounded by the upper end surface 14UE. One end of the stepped portion 54R is orthogonal to the end of the inner peripheral surface 54IS1 of the large diameter portion, and the other end of the stepped portion 54R is orthogonal to the lower end of the inner peripheral surface 54IS2 of the small diameter portion. The upper end of the inner peripheral surface 54IS2 of the small diameter portion is continuous with the terminal alignment portion 54T.

  The terminal alignment portion 54T described above has a plurality of holes 54b spaced apart from each other and is integrally formed so as to be orthogonal to the base end portion. The lower end surface 54TS of the base end portion of the terminal block 54 as an adhesive surface is bonded to the upper end surface 12TS of the housing 12 with a silicone-based adhesive. As a result, an annular adhesive layer 10 a having a predetermined thickness is formed on the upper end surface 12 TS of the housing 12.

  At that time, an annular intersection line 54EP1 where the lower end surface 54TS of the base end portion of the terminal block 54 and the inner peripheral surface 54IS1 of the large diameter portion at the base end portion intersect with the inner peripheral surface 12IS (intersection line 12EP) of the housing 12 is. It is on an extended surface that is directly above. A step portion 54R is continuously formed over the entire circumferential surface at a position above the intersection line 54EP1 on the inner circumferential surface 54IS1 of the terminal block 54.

  An intersection line 54EP2 where the other end of the stepped portion 54R intersects with the lower end of the inner peripheral surface 54IS2 of the small diameter portion is formed at a position protruding radially from the position of the intersection line 54EP1 toward the input / output terminal group 40ai. Yes.

  As described above, the step portion 54R is formed between the upper end of the inner peripheral surface 54IS1 of the large diameter portion of the terminal block 54 and the lower end of the inner peripheral surface 54IS2 of the small diameter portion, so that the surface tension due to the step portion 54R is caused. The covering layer 10b is spread over the entire inner peripheral surface 54IS1. The stepped portion 54R is not limited to such an example. Instead, for example, the upper end of the inner peripheral surface 54IS1 of the large diameter portion and the lower end of the inner peripheral surface 54IS2 of the small diameter portion are connected by an arc surface. You may be comprised so that.

  A covering layer 10b made of a silicone-based adhesive is formed with a predetermined thickness on the entire upper end surface 14UE of the hermetic glass 14 from which the input / output terminal group 40ai projects. As shown in a partially enlarged view in FIG. 4, the thickness of the covering layer 10b is separated from the periphery of the input / output terminal group 40ai, and the input / output terminals become closer to the inner peripheral surface 54IS1 and the stepped portion 54R of the base end portion. The thickness gradually becomes larger than the thickness around the group 40ai. An air layer in the cavity 54A is formed above the covering layer 10b. As described above, the annular intersection line 54EP1 where the lower end surface 54TS of the base end portion of the terminal block 54 and the inner peripheral surface 54IS1 of the base end portion intersect is directly above the inner peripheral surface 12IS (intersection line 12EP) of the housing 12. The air in the adhesive layer 10a or the moisture taken into the terminal block 54 is vaporized by heating, and the air is pushed out into the coating layer 10b. Even when it occurs in the coating layer 10b as AI, as shown by the arrow in FIG. 4, the bubble AI does not stay in the coating layer 10b and the bubble AI is solidified before the coating layer 10b is solidified. It will be guided into the air layer in the cavity 54A immediately above. Therefore, when the coating layer 10b is solidified, there is no possibility that a predetermined amount or more of the air bubbles AI that reduce the electrostatic strength of the sensor unit are taken into the solidified coating layer 10b.

  In the example shown in FIGS. 1, 3, and 4 described above, an annular intersection line where the lower end surface of the base end portion of the terminal block and the inner peripheral surface of the base end portion intersect with each other in the housing 12. Although it is configured to be on an extended surface that is directly above the inner peripheral surface 12IS (intersection line 12EP), the present invention is not limited to such an example. For example, as shown in FIG. One of the inclined surfaces 12C, which are the end surfaces of the housing 12, separated from the position of the inner peripheral surface 12IS (intersection line 12EP) of the housing 12 at the position of the annular intersection line 24′EP of the base end portion 24′PE of the You may be comprised so that it may exist in the position which is right above the part of. In the example shown in FIG. 5, the same components as those in the example shown in FIG.

  The terminal block 24 ′ for aligning the input / output terminal group 40 ai is molded using a resin material such as polybutylene terephthalate (PBT) as a main component. The terminal block 24 'includes a plurality of holes 24'b into which the input / output terminal group 40ai is inserted, and a cavity 24'A having a predetermined volume on the inside. The hollow portion 24′A having a predetermined volume is formed by the hermetic glass 14 in the inner peripheral surface 24′IS of the cylindrical base end portion 24′PE and the terminal alignment portion 24′T that connects the base end portion 24′PE. The upper end surface 14UE of the hermetic glass 14 and the upper surface of the hermetic glass 14 are surrounded. The inner peripheral surface 24′IS intersects the lower end surface 24′TS of the base end portion 24′PE of the terminal block 24 ′. The terminal alignment portion 24′T has a plurality of holes 24′b spaced apart from each other and is integrally formed so as to be orthogonal to the base end portion 24′PE. The lower end surface 24′TS of the base end portion 24′PE of the terminal block 24 ′ as an adhesive surface is bonded to the upper end surface 12TS of the housing 12 with a silicone-based adhesive. As a result, an annular adhesive layer 10 a having a predetermined thickness is formed on the upper end surface 12 TS of the housing 12.

  At that time, the position of the annular intersection line 24′EP where the lower end surface 24′TS of the base end portion 24′PE of the terminal block 24 ′ intersects the inner peripheral surface 24′IS of the base end portion 24′PE is determined by the position of the housing 12 Is located directly above any part of the inclined surface 12C of the housing 12 which is spaced from the position of the inner peripheral surface 12IS (intersection line 12EP).

  A covering layer 10b made of a silicone-based adhesive is formed with a predetermined thickness on the entire upper end surface 14UE of the hermetic glass 14 from which the input / output terminal group 40ai projects.

  The thickness of the covering layer 10b is gradually separated from the periphery of the input / output terminal group 40ai and gradually as compared with the thickness of the periphery of the input / output terminal group 40ai as it approaches the inner peripheral surface 24'IS of the base end 24'PE. It has become big. An air layer in the cavity 24'A is formed above the covering layer 10b. As described above, the position of the annular intersection line 24′EP where the lower end surface 24′TS of the base end portion 24′PE of the terminal block 24 ′ intersects the inner peripheral surface 24′IS of the base end portion 24′PE is Since it is in a position directly above any part of the inclined surface 12C of the housing 12 that is separated from the position of the inner peripheral surface 12IS (intersection line 12EP) of the housing 12, the air in the adhesive layer 10a or the terminal block Even when the moisture taken into 24 'is vaporized by heating and air is pushed out into the coating layer 10b and such air is generated in the coating layer 10b as bubbles AI, it is indicated by the arrows in FIG. As described above, the bubble AI does not stay in the coating layer 10b, and before the coating layer 10b is solidified, the bubble AI is guided into the air layer in the cavity 24'A immediately above. Therefore, when the coating layer 10b is solidified, there is no possibility that a predetermined amount or more of the air bubbles AI that reduce the electrostatic strength of the sensor unit are taken into the solidified coating layer 10b.

  Further, an adhesive layer 10a and a silicone adhesive layer made of the coating layer 10b are formed as an electrostatic protection layer on the upper end surface 12TS of the housing 12 and the entire upper end surface of the hermetic glass 14. Therefore, by forming the electrostatic protection layer with the silicone-based adhesive in this way, the electrostatic strength of the sensor unit is improved without being affected by the presence or absence of the ESD protection circuit.

  The covering layer 10b is formed over the entire upper end surface of the hermetic glass 14. However, the present invention is not limited to such an example. For example, the covering layer 10b includes the input / output terminal group 40ai on the upper end surface of the hermetic glass 14. The electrostatic protection layer may be configured so as to be formed at least only in an annular region between the inner peripheral surface of the housing 12.

  FIG. 6 schematically shows the structure of a second embodiment of the pressure sensor according to the present invention.

  In FIG. 6, the pressure sensor includes a joint member 30 connected to a pipe through which a fluid whose pressure is to be detected is guided, and a base plate 28 of the joint member 30. The pressure sensor accommodates a sensor unit and outputs a detection output signal from the sensor chip. And a sensor unit housing section that supplies the predetermined pressure measuring device.

  In FIG. 6, the same components as those in the example shown in FIG. 2 are given the same reference numerals, and redundant description thereof is omitted.

  The terminal block 64 for aligning the input / output terminal group 40ai is formed using a resin material such as polybutylene terephthalate (PBT) as a main component. The terminal block 64 includes a plurality of holes into which the input / output terminal group 40ai is inserted and a hollow portion 64A having a predetermined volume inside. The hollow portion 64A having a predetermined volume includes an inner peripheral surface 64IS of the cylindrical base end portion 64PE, a surface facing the upper end surface 14UE of the hermetic glass 14 in the terminal alignment portion 64T connected to the base end portion, and the hermetic glass 14 The upper end surface 14UE is surrounded and formed. The terminal alignment portion 64T described above has a plurality of holes spaced from each other on a common circumference and is integrally formed so as to be orthogonal to the base end portion. A communication hole 64H is formed between a part of the inner peripheral surface 64IS of the terminal block 64 from which the connection terminal 36 protrudes and the end of the terminal alignment portion 64T. As a result, the internal space of the end cap 22 and the cavity 64A communicate with each other through the communication hole 64H. Further, the portion where the plurality of holes are formed in the terminal alignment portion 64T is recessed with respect to the other portions, so that there is a gap between the portion where the plurality of holes are formed and the inner peripheral surface 64IS of the terminal block 64. The groove portion 64D is formed in the terminal alignment portion 64T so as to surround a portion where a plurality of holes are formed. Both ends of the groove portion 64D as the escape portion are open toward the communication hole 64H. Thus, even if it is a case where the quantity of the coating layer 10b applied temporarily increases by forming the groove part 64D in the circumference | surroundings of the terminal alignment part 64T, it scoops along the internal peripheral surface 64IS of a silicone type adhesive agent. Raising is avoided.

  The inner peripheral surface 64IS is orthogonal to the lower end surface of the base end portion of the terminal block 64. The lower end surface of the base end portion of the terminal block 64 as an adhesive surface is bonded to the upper end surface 12TS of the housing 12 with a silicone-based adhesive. As a result, an annular adhesive layer 10 a having a predetermined thickness is formed on the upper end surface 12 TS of the housing 12.

  An inclined surface 12C having a predetermined gradient is formed at a portion near the inner peripheral edge of the upper end surface 12TS of the cylindrical housing 12. Thereby, a gap is formed between the lower end surface of the base end portion of the terminal block 64 and the inclined surface 12C. An annular intersection line 12EP where the end of the inclined surface 12C and the inner peripheral surface 12IS intersect is formed at a position higher than the upper end surface 14UE of the hermetic glass 14.

  At this time, an annular intersection line 64EP where the lower end surface of the base end portion of the terminal block 64 and the inner peripheral surface 64IS of the base end portion extend is directly above the inner peripheral surface 12IS (intersection line 12EP) of the housing 12. On the surface.

  A covering layer 10b made of a silicone-based adhesive is formed with a predetermined thickness on the entire upper end surface 14UE of the hermetic glass 14 from which the input / output terminal group 40ai projects. As shown in FIG. 6, the thickness of the covering layer 10 b is separated from the periphery of the input / output terminal group 40 ai and is compared with the thickness of the periphery of the input / output terminal group 40 ai as it approaches the inner peripheral surface 64IS of the base end. It is getting bigger gradually. An air layer in the cavity 64A is formed above the covering layer 10b. Further, the air layer in the cavity 64A communicates with the air layer in the end cap 22 through the communication hole 64H.

  As described above, since the annular intersection line 64EP of the terminal block 64 is on an extended surface that is directly above the inner peripheral surface 12IS (intersection line 12EP) of the housing 12, it is assumed that the air in the adhesive layer 10a or Even when the moisture taken into the terminal block 64 is vaporized by heating and the air is pushed into the coating layer 10b and such air is generated in the coating layer 10b as the bubble AI, the bubble AI is formed in the coating layer. Without staying in 10b, before the coating layer 10b is solidified, the air bubbles AI are introduced into the end cap 22 through the air layer in the cavity 64A directly above and the communication hole 64H. Therefore, when the coating layer 10b is solidified, there is no possibility that a predetermined amount or more of the air bubbles AI that reduce the electrostatic strength of the sensor unit are taken into the solidified coating layer 10b.

  Moreover, the silicone type adhesive layer which consists of the coating layer 10a and the coating layer 10b will be formed in the whole upper end surface 12TS of the housing 12, and the upper end surface 14UE of the hermetic glass 14 as an electrostatic protection layer. Therefore, by forming the electrostatic protection layer with the silicone-based adhesive in this way, the electrostatic strength of the sensor unit is improved without being affected by the presence or absence of the ESD protection circuit.

  In the example shown in FIG. 6, the inner peripheral surface 64IS is orthogonal to the lower end surface of the base end portion of the terminal block 64. However, the present invention is not limited to such an example, and for example, shown in FIG. As described above, the inner peripheral surface 64IS may have a predetermined gradient, or the recess 44R as shown in FIG. 3 may be formed in the inner peripheral surface 64IS. Furthermore, a stepped portion 54R as shown in FIG. 4 may be formed on the inner peripheral surface 64IS. In the above description, the concept of “upper and lower” that represents the relative positional relationship of the constituent elements that constitute one example of the above-described pressure sensor is “up and down” that represents the relative positional relationship of the respective constituent elements shown in FIGS. 1 to 6. Accordingly, in actual installation and use in an example of the pressure sensor, the relative positional relationship between the components of the pressure sensor is not limited to such a concept of “up and down”.

  In the above-described example, the silicone-based adhesive has been described as the insulating adhesive. However, the present invention is not limited to the silicone-based adhesive, and is equivalent to an adhesive that generates bubbles in the adhesive layer when cured. The effect of can be obtained.

10a Adhesive layer 10b Cover layer 12 Housing 14 Hermetic glass 22 End caps 24, 44, 54, 64 Terminal block

Claims (4)

A sensor chip for detecting pressure and transmitting a detection output signal; at least one output terminal for transmitting a signal from the sensor chip; a housing including hermetic glass for supporting the output terminal; and the output terminal. A sensor unit comprising: a coating layer covering an end face of the protruding hermetic glass; and
A sensor unit housing portion for housing a terminal alignment member having an adhesive surface bonded to an end surface of the housing, and the sensor unit;
A hollow portion is provided between the terminal alignment member and the coating layer, and an annular intersection line where the adhesive surface of the base end portion of the terminal alignment member intersects with the inner peripheral surface of the base end portion is the housing. A pressure sensor, wherein the pressure sensor is located on an extended surface of the inner peripheral surface of the housing extending toward the terminal alignment member, or at a position facing the position separated from the inner peripheral surface of the housing along the end surface of the housing.   The pressure sensor according to claim 1, wherein an inner peripheral surface of a base end portion of the terminal alignment member has a concave portion or a convex portion.   The pressure sensor according to claim 1, wherein an inner peripheral surface of a base end portion of the terminal alignment member has a step portion.   The pressure sensor according to claim 1, wherein the terminal alignment portion of the terminal alignment member has a relief portion.

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