Pressure sensor

Abstract

To provide a pressure sensor that can suppress the influence of mechanical stress associated with temperature change.SOLUTION: A pressure sensor unit 10 comprising a pressure sensor chip 11 connected to an external device A, comprises: a circuit board 50 that is interposed between the external device and a sensor; a relay connection terminal 36 that is conductively connected to the sensor and the circuit board; a relay connection terminal 37 that is conductively connected to the circuit board and the external device; and a terminal block 24 that supports to determine positions of a connection member and a terminal member, and holds the circuit board overlapped with the members. The pressure sensor unit has a notch 58 in an inner wall part 55 for adjusting a relative positional relation of the connection member relative with respect to the circuit board.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a pressure sensor having a simple structure that can be assembled easily and reliably. [Background technology]

[0002] Various sensors that detect pressure, temperature, etc. are fixed near the object to be measured and are used to send detection signals to measuring instruments, etc., and are often used either built into the measuring instrument or attached externally (see Patent Document 1).

[0003] These types of sensors are incorporated into sensor units that can be installed so that they are exposed to the same environment as the object to be measured. The sensor unit has a terminal block that holds terminals that are electrically connected to the sensor to be installed, and the sensor detection signal can be made usable by connecting a measuring device to the terminals. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-98685 A Summary of the Invention [Problem to be solved by the invention]

[0005] Since various sensors of this type are exposed to the external environment, the sensor unit may be repeatedly subjected to temperature changes in the surrounding environment or temperature changes in the fluid passing through the piping that accompany the operation and shutdown of the installed equipment.

[0006] For example, in the case of a sensor unit 10 having a circuit board 50 for adjusting various electric signals and the like installed in front of the sensor 11 as shown in FIG. 18(a), mechanical stress is repeatedly applied to the joints by soldering or the like for electrically connecting the circuit board 50 and the terminal pieces 36d and 37d and the terminal block 24 due to the difference in linear expansion coefficient, as shown by the black and white arrows in FIG. 18(b). If such stress acts for a long period of time, there is a risk of deterioration in joint quality, such as cracks at the soldered parts and peeling of the wiring pattern of the soldered parts. In addition, in the pressure sensor 100 shown in FIG. 18, the same reference numerals are used to designate the same components as those in the embodiments described below to aid in understanding.

[0007] Therefore, the present invention aims to realize a sensor unit that can be assembled while suppressing the effects of mechanical stress caused by differences in the linear expansion coefficients of the internal components of the pressure sensor due to changes in the surrounding or fluid temperature, and to provide a pressure sensor equipped with such a sensor unit as well as a method for manufacturing such a sensor unit. [Means for solving the problem]

[0008] One aspect of the invention of a sensor unit that solves the above problem is a pressure sensor constituted by a sensor unit having a sensor connected to an external device, comprising: a circuit board that is arranged to be interposed between the sensor and the external device and connected to the sensor; a connection member that is located between the sensor and the circuit board and is conductively connected to the sensor and the circuit board, and one or both of a terminal member for conductively connecting the circuit board to the external device that is conductively connected to the circuit board; and a terminal block that fixes and positions and supports one or both of the connection member and the terminal member, wherein the circuit board is placed on one or both of the connection member and the terminal member, and has an adjustment unit that adjusts the relative positional relationship of at least one of the connection member, the terminal member and the terminal block with respect to the circuit board. Effect of the Invention

[0009] Thus, according to one aspect of the present invention, the relative positional relationship of at least one of the connection member, terminal member, and terminal block with respect to the circuit board can be adjusted by the adjustment unit. Therefore, even if a phenomenon occurs in which mechanical stress in a planar direction is applied to the circuit board, the relative positional relationship of the circuit board is adjusted and the mechanical stress load is absorbed, thereby preventing damage, etc.

[0010] Therefore, it is possible to realize a sensor unit with a simple structure that allows assembly work to be performed while suppressing the effects of mechanical stress caused by differences in the linear expansion coefficients of the internal components of the pressure sensor due to changes in the surrounding or fluid temperature, and it is possible to provide a pressure sensor equipped with this sensor unit. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing a pressure sensor including a pressure sensor unit which is an example of a sensor unit according to one embodiment of the present invention, and is a vertical sectional view showing a schematic overall configuration thereof. [Diagram 2] FIG. 2 is a diagram showing an outline of a manufacturing method for the pressure sensor, where (a) is an exploded perspective view from above in which the components are spaced apart in the stacking direction, and (b) is a perspective view from below of one of the components. [Diagram 3] FIG. 3 is a perspective view showing the main components from one direction. [Figure 4] FIG. 4 shows one connection terminal to be attached to the main component of FIG. 3, where (a) is an elevated front view, (b) is a top view, (c) is a bottom view, and (d) is a plan view showing the lead frame of the three components. [Diagram 5] 5A, 5B, 5C, and 5D are diagrams showing a connection terminal different from that shown in FIG. 4 that is attached to the main component of FIG. 3, where (a) is an elevational front view, (b) is a top view, (c) is a bottom view, and (d) is a side view. [Figure 6] 6A and 6B are diagrams showing a state in which a connection terminal is attached to the main component of FIG. 3, where (a) is a vertical cross-sectional view and (b) is a top view. [Figure 7]7A and 7B are diagrams for explaining the mounting state of the connection terminals in FIG. 6, where (a) is an oblique view of one connection terminal from one direction and an oblique view of the other connection terminal from a different direction, and (b) is a top view of both connection terminals. [Figure 8] 8A, 8B, and 8C are diagrams showing the attachment state of a connection terminal to the main component in FIG. 3 and a circuit board, in which (a) is a longitudinal sectional view, (b) is a perspective view, and (c) is an enlarged perspective view of the connection portion between the circuit board and the connection terminal. [Figure 9] 9A and 9B are diagrams for explaining the connection state of the connection points in FIG. 8, where (a) is a vertical cross-sectional view showing the effect of the structure, and (b) is a vertical cross-sectional view showing a case where this structure is not adopted. [Figure 10] FIG. 10 is a diagram for explaining the effect of this embodiment, in which (a) is an enlarged vertical cross-sectional view when there is no mechanical stress, (b) is an enlarged vertical cross-sectional view when there is a load of being pushed towards the circuit board, and (c) is an enlarged vertical cross-sectional view when there is a load of being pulled towards the circuit board. [Figure 11] FIG. 11 is a diagram showing a first alternative aspect of the present embodiment, and is a partially enlarged longitudinal sectional view thereof. [Figure 12] FIG. 12 is a diagram showing a second other aspect of this embodiment, where (a) is a partially enlarged vertical cross-sectional view showing one aspect, (b) is a partially enlarged vertical cross-sectional view showing an aspect different from (a), and (c) is a partially enlarged vertical cross-sectional view showing an aspect different from (a) and (b). [Figure 13] FIG. 13 is a diagram showing a second further aspect of this embodiment, where (a) to (d) are partially enlarged vertical cross-sectional views showing different aspects including FIG. 12(a) to FIG. 12(c). [Figure 14] FIG. 14 is a diagram showing a third alternative aspect of the present embodiment, and is a partially enlarged longitudinal sectional view thereof. [Figure 15] FIG. 15 is a diagram showing a fourth alternative aspect of the present embodiment, and is a partially enlarged longitudinal sectional view thereof. [Figure 16] FIG. 16 is a diagram showing a fifth alternative embodiment of the present invention, and is a vertical sectional view showing a schematic overall configuration thereof. [Figure 17]FIG. 17 is a diagram showing a sixth alternative embodiment of the present invention, and is a vertical sectional view showing a schematic overall configuration thereof. [Figure 18] FIG. 18 is a vertical cross-sectional view showing a technology prior to the conception of this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Figures 1 to 10 are diagrams illustrating a pressure sensor including a pressure sensor unit as an example of a sensor unit according to an embodiment of the present invention, and a method for manufacturing the sensor unit.

[0013] 1 and 2, the pressure sensor 100 is fabricated by attaching a pressure sensor unit 10 assembled by stacking components as described below to a target location for measuring pressure characteristics of the external environment, and outputting pressure information detected by the pressure sensor chip 11 to a connected external device A. The pressure sensor 100 of this embodiment is constructed so that the pressure sensor unit 10 housed in a resin waterproof case 20 can be connected to a pipe to be measured, through which a fluid such as a gas or liquid whose pressure is to be detected is guided, by connecting the pressure sensor unit 10 with a metal joint member 30.

[0014] Here, the waterproof case 20 is made into a cylindrical shape capable of housing the pressure sensor unit 10, and an opening 20b on one end side is connected to the periphery of a cap 28 to which a joint member 30 is fixed. This joint member 30 is formed with a female thread 30s so that it can be screwed to a pipe or the like whose pressure is to be measured, and a fluid supplied from the pipe in the direction of arrow P can be introduced into a pressure chamber PR downstream of the cap 28 via a port 30a communicating with the female thread 30s.

[0015] The pressure sensor unit 10 comprises a housing 12 made into a short cylindrical shape and having its lower axial end face joined and fixed to a cap 28, a support 13 on which the pressure sensor chip 11 is mounted and positioned so as to be located at the center of the inner tube of the housing 12, and hermetic glass 14 which is filled around the support 13 within the inner tube of the housing 12 to seal it while fixing members which pass through the inner tube.

[0016] In the pressure sensor unit 10, a metal diaphragm 32 is bonded and fixed to the lower end surface of the housing 12. The diaphragm 32 forms an airtight pressure chamber PR on the cap 28 side, while isolating the installation space of the pressure sensor chip 11 on the support 13 side in the housing 12 from the pressure chamber PR.

[0017] In this pressure sensor unit 10, the installation space for the pressure sensor chip 11, which is formed by the hermetic glass 14 and the diaphragm 32 within the inner tube of the housing 12, is filled with, for example, a predetermined amount of silicone oil (or a fluorine-based inert liquid, etc.) as a pressure transmission medium, so as to function as a liquid-sealed chamber LR.

[0018] As a result, the pressure sensor chip 11 functions as a pressure sensor that detects the pressure of the fluid to be detected, which is introduced into the pressure chamber PR from the piping connected to the coupling member 30, as pressure fluctuations of the pressure transmission medium in the liquid-sealed chamber LR via the diaphragm 32.

[0019] Here, the pressure sensor chip 11 is electrically connected to the lead pins 40, which are connected to the multiple lead wires 38 from the external device A via a circuit board 50 described later, via bonding wires 11w, so that it is supplied with power and outputs a detection signal as pressure information. In addition, the liquid-sealed chamber LR between the hermetic glass 14 and the diaphragm 32 in the inner cylinder of the housing 12 is filled with a pressure transmission medium via an oil filling pipe 44. These lead pins 40 and the oil filling pipe 44 are aligned at equal intervals in a circle centered on the support 13, and are supported insulated from the housing 12 via an insulator such as the hermetic glass 14. One end of the oil filling pipe 44 is closed after filling with the pressure transmission medium.

[0020] Here, the diaphragm 32 is prevented from being damaged by external forces or sudden pressures applied to the pressure chamber PR by a diaphragm protective cover 34 having a plurality of communication holes 34a bonded and fixed to the lower end surface of the housing 12. Also, a concave frame 16 is fixed to one end side of the hermetic glass 14 and a lid-like shield plate 17 is attached to the frame 16, and the frame 16 contains a pressure transmission medium between the pressure sensor chip 11 side and the diaphragm 32 side through the communication holes 17a formed in the shield plate 17 and suppressing sudden pressure fluctuations.

[0021] The lead pins 40 are arranged on the bottom surface 24b of the terminal block 24 made of resin and formed in a short, generally cylindrical shape with a bottom, and are electrically connected to the pressure sensor chip 11 via the bonding wires 11w. These lead pins 40 are inserted into the insertion holes 24h formed in the bottom surface 24b of the terminal block 24 and fixedly supported by the hermetic glass 14. Here, the terminal block 24 has a generally cylindrical side wall 24s partially formed into a flat shape, and terminal holding portions 51 and 53 for mounting and holding a set of three relay connection terminals 36 (36A to 36C) and 37 (37A to 37C) described later are arranged symmetrically about the center of the cylinder. The terminal block 24 is bonded to the upper end surface of the housing 12 with a silicone adhesive. A coating layer 14a made of a silicone adhesive is formed to a predetermined thickness on the entire upper end surface of the hermetic glass 14 from which the lead pins 40 protrude. The coating layer may be made of an adhesive such as epoxy resin.

[0022] Both ends of the lead pin 40 penetrate both sides of the hermetic glass 14 in the inner cylinder of the housing 12, and the pressure sensor chip 11 is electrically connected to one end of the lead pin 40, which is the liquid-sealed chamber LR side, via a bonding wire 11w. The other end of the power supply terminal and the output signal terminal of the lead pins 40 is electrically connected to the end surface by, for example, spot welding (or molten metal bonding). The other side of the side wall 24s of the terminal block 24 holds a relay connection terminal 37 to which a lead wire 38 from an external device A is connected, as described later. The terminal pieces 36d and 37d of the relay connection terminals 36 and 37 are connected to a circuit board 50, which is placed on the board, by applying molten solder (conductive connection material) S. That is, the relay connection terminal 36 constitutes a connection member, and the relay connection terminal 37 constitutes a terminal member. It goes without saying that the conductive connection material is not limited to molten metal such as solder S, but may be, for example, an adhesive containing a conductive material.

[0023] Here, the circuit board 50 is interposed between the pressure sensor chip 11 and the external device A and functions as a part of the circuit configuration, and in this embodiment, an input / output voltage conversion adjustment circuit is mounted to adjust different input / output voltages of the pressure sensor chip 11 and the external device A, for example, to convert the input voltage DC12V or DC3.3V of the external device A to the operating voltage DC5V of the pressure sensor chip 11. This type of conversion adjustment circuit is not limited to this embodiment, but is any conversion adjustment circuit for dealing with various driving voltages and signal formats of pressure detection signals, such as drives different from this embodiment, voltage output formats of output voltages, current output formats such as two-wire type / three-wire type, or digital output formats. Note that these conversion adjustment circuits are configured by mounting multiple electronic components not shown.

[0024] Here, the terminal block 24 has a terminal block cap 25 attached to the opening side of the cylindrical side wall portion 24s, and the installation space SR of the lead pin 40, the terminal pieces 36d, 36e, 37d of the relay connection terminals 36, 37, and the circuit board 50 is closed, and the pressure sensor unit 10 is constructed together with the housing 12 to which the support 13 of the pressure sensor chip 11 is fixed with hermetic glass 14. The pressure sensor unit 10 is integrated with the housing 12 and the outer periphery of the cap 28 to which the joint member 30 is connected by TIG welding, plasma welding, laser welding, etc. from the outside with a desired joint strength. The pressure sensor unit 10 is installed inside the waterproof case 20 and filled with a sealant 26 such as a urethane resin, thereby being fixed while being waterproofed. Here, the terminal block 24 and the terminal block cap 25 can form an air layer with low thermal conductivity around the circuit board 50 by closing the installation space SR, and can prevent a sudden temperature change from the surroundings of the pressure sensor or the piping from being transmitted to the circuit board 50. Furthermore, by arranging the circuit board 50 itself, the mounted components mounted on the circuit board 50, or the connection points between the circuit board 50 and the relay connection terminals 36 and 37, etc. so that they do not come into contact with the sealing material 26, it is possible to prevent mechanical stress due to the contraction and expansion of the sealing material 26 caused by changes in ambient temperature from acting on the connection members, the mounted components, and particularly on their soldered portions.

[0025] The pressure sensor unit 10 is assembled by stacking the housing 12, which is fixed to the cap 28 connected to the joint member 30, the terminal block 24, the circuit board 50, and the terminal block cap 25. The terminal block 24 is placed on the housing 12 after the relay connection terminals 36 and 37 are set in the terminal holding parts 51 and 53 of the side wall part 24s, and the end of the lead pin 40 is spot-welded to the terminal piece 36e of the relay connection terminal 36, and then the circuit board 50 is placed on the terminal pieces 36d and 37d of the relay connection terminals 36 and 37 and soldered to establish a conductive connection. Here, it goes without saying that the terminal piece 36e of the relay connection terminal 36 may be conductively connected to the end face of the lead pin 40 by soldering, crimping, or the like, instead of spot welding. The bottom surface 24b of the terminal block 24 is provided with appropriate insertion holes and the like to facilitate assembly. For example, an insertion hole 24H for an oil filling pipe 44 is also provided.

[0026] In detail, as shown in FIGS. 3 to 7, the terminal block 24 is configured so that the relay connection terminals 36, 37 are attached and held by terminal holding portions 51, 53 formed on the side wall portion 24s.

[0027] The relay connection terminal 36 is formed in a long shape with end pieces (terminal pieces) on one end side and the other end side facing each other, i.e., a so-called U-shape, with a flat portion 36f between terminal pieces 36d, 36e on both ends extending in a parallel direction being arranged in a parallel posture to the outer surface of the terminal holding portion 51 of the terminal block 24, and the terminal pieces 36d, 36e are formed to extend into the side wall portion 24s. The relay connection terminal 37 is similarly formed in a U-shape with a terminal piece 37d extended into the side wall portion 24s of the terminal block 24 and a flat connection surface 37f aligned parallel to the outer surface of the terminal holding portion 53, and a bent piece 37e formed by bending the opposite side of the terminal piece 37d. The core wire C of the lead wire 38 from the external device A is soldered and connected to the connection surface 37f of this relay connection terminal 37, thereby electrically connecting the pressure sensor chip 11 to the external device A via the lead pin 40, the relay connection terminals 36, 37 and the circuit board 50.

[0028] The terminal holding portion 51 has a plurality of inner walls 55 formed on the inner side of the side wall 24s of the terminal block 24, which face each other to interpose a groove 55g that is a fixing groove for fixing the relay connection terminal 36, and the upper surfaces of the inner walls 55 are formed at a height that is flush with each other. Similarly, the terminal holding portion 53 has a single inner wall 56 formed on the inner side of the side wall 24s of the terminal block 24, which faces each other to interpose a groove 56g that is a fixing groove for fixing the relay connection terminal 37. A pair of inner walls 57 are formed between the inner walls 55 and 56, which face each other to interpose a groove 57g on the inner side of the side wall 24s. That is, the grooves 55g to 57g are formed in a continuous form between the side wall 24s of the terminal block 24 and the inner walls 55 to 57.

[0029] The terminal holding portion 51 is positioned by being inserted into the bottom surface of three slits 55s between the four inner wall portions 55 facing the side wall portion 24s of the terminal block 24 so that the terminal pieces 36e of the relay connection terminals 36A to 36C come into contact with the bottom surface of the three slits 55s between the four inner wall portions 55. In this state, the flat portions 36f of the relay connection terminals 36A to 36C, which are formed larger than the slits 55s, come into contact with the portion of the inner wall portion 55 facing the side wall portion 24s, and the terminal pieces 36d of the three relay connection terminals 36A to 36C are folded back at positions on the same plane so as to come into contact with the upper surface of the inner wall portion 55. The relay connection terminals 36A to 36C are provided with protrusions (fixing portions) 36h, 36i that extend from the flat portion 36f adjacent to the terminal pieces 36e in the planar direction of the flat portion 36f. In addition, an insertion groove 55h for the protrusions 36h, 36i is formed on the bottom surface of the groove 55g between the side wall portion 24s and the side wall 55 of the terminal block 24. The protrusions 36h, 36i are inserted into the insertion groove 55h, thereby maintaining the relay connection terminals 36A to 36C in an upright state. With this structure of the terminal holding portion 51, the terminal pieces 36e of the relay connection terminals 36A to 36C can be inserted and assembled from the upper side, which is the open end of the terminal block 24, so as to fit into the groove 55g and the slit 55s, that is, a fixing portion is formed with this structure. Note that the protrusions 36i are not shown in FIG. 2, but are shown in FIG. 4.

[0030] The relay connection terminal 36 is made up of three relay connection terminals 36A to 36C each having a different shape, and the terminal pieces 36d and 36e are bent in a direction perpendicular to the flat surface portion 36f. The terminal pieces 36e are formed so as to extend in a direction parallel to the bottom surface portion 24b of the terminal block 24 in a parallel state with a narrower interval than the terminal pieces 36d. In detail, the relay connection terminal 36 is formed so as to extend in a parallel state with a narrower interval near the center, since the terminal pieces 36e are connected to the lead pins 40 arranged at equal intervals on the same circle centered on the support 13 in correspondence with the small pressure sensor chip 11. The terminal pieces 36d are connected to the circuit board 50, which can be set at any interval, so as to extend in a parallel state with a wider interval than the terminal pieces 36e, making the connection easier. 4(d), the relay connection terminal 36 is produced by punching out a set of three relay connection terminals 36A-36C in a state where the terminals are integrated with a lead frame 36LF, and then bending the terminal pieces 36d and 36e with respect to the flat portion 36f and the protruding pieces 36h and 36i, respectively. Also, the slit 55s of the inner wall portion 55 is open from the groove 55g to the bottom surface 24b side of the terminal block 24, and when a terminal fixing adhesive 26g described later is injected into the groove 55g to fix the relay connection terminal 36, the rear side of the flat portion 36f (the outer side of the terminal block 24) is adapted to receive the terminal fixing adhesive 26g, thereby preventing the terminal fixing adhesive 26g from leaking out to the bottom surface 24b side of the terminal block 24.

[0031] The terminal holding portion 53 has slits 53a, 53b formed on the upper and lower sides thereof, which penetrate the side wall portion 24s of the terminal block 24 so that the terminal piece 37d and the bent piece 37e of the relay connection terminal 37 can be inserted therein. The terminal holding portion 53 is positioned so that the terminal piece 37d and the bent piece (intersection portion) 37e penetrate the slits 53a, 53b of the side wall portion 24s of the terminal block 24 and pass through the inner groove 56g from an intersecting direction, and then come into contact with the upper surface of the inner wall portion 56 and the bottom surface of the groove 56g.

[0032] Due to this structure, the relay connection terminals 37 are made in the same shape for each of the relay connection terminals 37A to 37C, and the terminal pieces 37d and the bent pieces 37e are bent in the same direction perpendicular to the connection surface 37f so as to contact the upper and lower surfaces of the terminal holding portion 53. The terminal pieces 37d are formed in a shape that allows them to be inserted into the side wall portion 24s of the terminal block 24 through the slit 35a to a degree that allows the circuit board 50 to be placed thereon. The relay connection terminals 37 are formed such that the terminal pieces 37d and the bent pieces 37e are narrower than the wide connection surface 37f, and engagement pieces 37g are formed on both sides of the terminal pieces 37d by bending them in the same direction to hook them so as to bite into the upper surface of the terminal holding portion 53. The engagement pieces 37g may be omitted if the fixing by the terminal fixing adhesive 26g described later is sufficient.

[0033] As a result, the relay connection terminal 36 can be attached in a state where the long terminal pieces 36d, 36e are attached to the terminal holding portion 51 and positioned between the inner wall portions 55 (slits 55s) inside the side wall portions 24s of the terminal block 24 while the protruding pieces 36h, 36i are inserted into the insertion grooves 55h on the bottom surface of the groove 55g between the side wall portions 24s and the inner wall portion 55 to be positioned and held, and the terminal piece 36e can be attached so that the amount of protrusion into the inside of the terminal block 24 is constant. With this configuration, the terminal piece 36d can be positioned and supported at the height of the upper surface of the inner wall portions 55, and the terminal piece 36e can be positioned and supported at the height of the bottom surface of the slits 55s between the inner wall portions 55, and the amount of protrusion of the terminal piece 36e into the inside of the terminal block 24 can also be constant. In this way, the positional relationship of the terminal piece 36e with respect to the plane on which the lead pins 40 are arranged, i.e., the position of the end face of the lead pin 40 with respect to the extension direction and width direction of the terminal piece 36e, is stabilized, and the height direction of the terminal piece 36e and the end of the lead pin 40 can be stably positioned. This means that it is necessary to keep the relative positional relationship between the end face of the lead pin 40 and the terminal piece 36e constant when spot welding them. Also, the relay connection terminal 37 can be attached in a state where the terminal piece 37d is attached to the terminal holding part 53 and is positioned and held on the upper surface of the inner wall part 56 inside the side wall part 24s of the terminal block 24. That is, the groove 55g side of the inner wall part 55 of the terminal block 24 functions as a support position for the relay connection terminal 36.

[0034] Therefore, the terminal piece 36e and the bent piece (fixing portion) 37e of the relay connection terminals 36, 37 can be positioned in grooves 55g, 56g that penetrate the side wall portion 24s of the terminal block 24 and are formed between the inner wall portions 55, 56, and have a depth in the direction in which the circuit board 50 is placed so as to overlap. The relay connection terminals 36, 37 can be positioned and fixed by injecting a terminal fixing adhesive 26g into the grooves 55g, 56g, and since the grooves 55g, 56g by the inner wall portions 55, 56 are continuous with both sides of the groove 57g between the side wall portion 24s and the inner wall portion 57, a procedure (manufacturing method) can be performed in which a dispenser is inserted into the wide groove 57g and the terminal fixing adhesive 26g is injected to easily complete the fixing operation (see FIG. 6). Thereafter, the relay connection terminals 36, 37 can be electrically connected by spot welding the terminal pieces 36e to the lead pins 40 in a stable position, and the circuit board 50 placed on the terminal pieces 36d, 37d can be electrically connected by soldering in a stable position. Here, the terminal block 24 has a flat surface 29 formed on the inner surface of the arc-shaped side wall 24s facing the inner wall 57. This engages with the protrusion 25a on the lower surface of the terminal block cap 25, and functions to prevent the terminal block cap 25 from shifting horizontally and rotating when the terminal block cap 25 is placed on the terminal block 24. By placing the terminal block 24 and the terminal block cap 25 in close contact with each other, it is possible to prevent the sealing material 26 from leaking into the inside of the terminal block 24 when the sealing material 26 is filled around the terminal block 24 and the terminal block cap 25.

[0035] The relay connection terminals 36, 37 are manufactured to be conductively connected with fewer connection failures by plating M on the terminal pieces 36d, 37d and the connection surface 37f to improve the wettability of molten solder, and plating M is also applied to the adjacent portion of the connection surface 37f of the relay connection terminal 37 to prevent the conductive line C of the soldered connection line 38 from coming loose. Here, the relay connection terminals 36, 37 are plated M only in the area required for soldering, and not in other areas, so that the outflow of molten solder is suppressed. In addition to providing areas to improve the wettability of solder by plating M as in this example, the soldering surface may be left in the state of a metal base surface, and a resist, coating, etc. may be applied to areas to restrict the flow of solder.

[0036] As shown in Fig. 8, the circuit board 50 has an outer peripheral end surface at a location corresponding to the terminal pieces 36d, 37d of the relay connection terminals 36, 37 recessed inward in a U-shape in a direction parallel to the plane of the circuit board 50, and has a recessed wall electrode surface (recessed wall surface) 50u of a connection region that opens to both sides perpendicular to the plane of the circuit board 50 and functions as a connection position. This recessed wall electrode surface 50u is plated with plating M having excellent solder wettability on the inner surface by indenting a semicircle that allows molten solder to easily penetrate the entire surface (whole surface) from the outer peripheral end surface of the circuit board 50 by a recessed distance L. That is, the recessed wall electrode surface 50u is formed as an oval cutout shape with a depth L from the outer peripheral end surface of the circuit board 50 toward the inside of the board. By making the recessed shape of the recessed wall surface inwardly semicircular, it is expected that the stress inside the recessed wall surface 50u during the fillet formation by solder will act evenly. The uniform stress can improve resistance to defects such as poor continuity due to cracks in soldered parts caused by repeated heating and cooling, or so-called heat cycles, applied to the pressure sensor, and can achieve highly reliable connections. Also, in the manufacturing process of the circuit board 50, it can be manufactured using the same machining tools as those used to process mounting holes for mounted components and to process the exterior shape of the circuit board 50. A rectangular shape requires separate steps and tools, such as processing with a disk-shaped cutter, so using a semicircular shape is advantageous in terms of productivity and quality.

[0037] In contrast, the terminal pieces 36d, 37d of the relay connection terminals 36, 37 are formed to be wider than the recessed electrode surface 50u of the circuit board 50 and longer than the depth (distance) L from the outer peripheral end surface of the recessed electrode surface 50u, so that the circuit board 50 can be placed in a stable position. Furthermore, the terminal block 24 has support pillar-shaped portions 54 formed on the inner surface of the side wall portion 24s, which fit into the corner recesses 50r formed at the four corners of the circuit board 50, so that the circuit board 50 can be positioned. In other words, the terminal pieces 36d, 37d of the relay connection terminals 36, 37 function as support regions that support the vicinity of the recessed electrode surface 50u of the circuit board 50. In this embodiment, recessed wall electrode surfaces 50u are formed in the connection areas of both circuit boards 50 that are connected to the terminal pieces 36d, 37d of the relay connection terminals 36, 37, but this is not limited to this, and connection may be made at the outer peripheral end surface of the circuit board 50 without forming the recessed wall electrode surface 50u, or the recessed wall electrode surface 50u may be provided on only one of the two sides. However, forming the recessed wall electrode surface 50u on both sides is preferable in terms of connection workability and reliability.

[0038] As a result, the circuit board 50 is placed on the terminal pieces 36d, 37d of the relay connection terminals 36, 37 in a stable position as shown in FIG. 9(a) and is held in a stable position positioned on the support pillar 54 of the terminal block 24, and the recessed wall electrode surface 50u is reliably connected to the terminal pieces 36d, 37d by the solder S having a larger capacity and a stable shape with a sufficient fillet height than the semicircular recessed wall electrode surface 50u' shown in FIG. 9(b). The connection area, which is the soldering location, is on the back side of the circuit board 50, so it is not possible to directly visually check the connection area. However, as in this embodiment, by managing the state of the fillet inside the recessed wall portion 50u by visual inspection or image recognition, it is possible to determine whether the soldering has been performed normally. The circuit board 50 also has an insertion hole 50H through which the oil filling pipe 44 is inserted during assembly work.

[0039] 10(a), the terminal holding portion 51 has a notch (recess) 58 formed at a position higher than the terminal fixing adhesive 26g injected and solidified in the groove 56g at the upper part of the side facing the side wall 24s of the terminal block 24 of the inner wall 55 (see FIGS. 1, 3, and 6), and in this embodiment, the height of the terminal fixing adhesive 26g is suppressed to form the notch 58 of a necessary and sufficient size. As a result, in the terminal holding portion 51, indirect heat conduction occurs through the terminal block 24, etc., even with the installation space SR of the lead pin 40, the relay connection terminals 36, 37, the circuit board 50, etc. interposed therebetween, but a part of the relay connection terminal 36 facing the notch 58 of the inner wall 55 is allowed to function as a deformation portion and deform.

[0040] Specifically, even if the difference in the linear expansion coefficients of the terminal block 24 and the circuit board 50 causes a difference in the amount of expansion and contraction between them due to temperature changes, the relay connection terminal 36 can elastically deform a part (deformed part) in a direction that allows the circuit board 50 to oscillate and expand in a direction parallel to the bottom surface part 24b of the terminal block 24 relative to the inner wall part 55, in other words, in a direction to move away from or into the notch 58, as shown in Figures 10(b) and 10(c). Therefore, the notch 58 of the inner wall part 55 can function as an adjustment part that prevents deterioration of joint quality, such as cracks in the soldered part and poor continuity due to peeling of the circuit pattern around the recessed wall part 50u of the circuit board 50, caused by mechanical stress being applied to the joint part of the solder S that electrically connects the terminal pieces 36d, 37d of the relay connection terminals 36, 37 to the circuit board 50.

[0041] In this manner, in the pressure sensor unit 10 of the pressure sensor 100 of this embodiment, the relay connection terminal 36 can elastically deform by utilizing the notch 58 of its inner wall portion 55 to close the gap from the groove 55g side of the inner wall portion 55 of the terminal block 24 to the recessed wall electrode surface 50u of the circuit board 50. Even if mechanical stress occurs between the joint of the solder S between the relay connection terminal 36 and the board circuit 50 due to the difference in the linear expansion coefficients of the terminal block 24 and the circuit board 50 accompanying a change in ambient temperature, the relay connection terminal 36 has a structure that allows it to expand and contract in the directions toward and away from the board circuit 50, thereby preventing excessive stress from acting between the joint.

[0042] Therefore, with a simple structure of merely forming a notch 58 on the groove 55g side of the inner wall portion 55 of the terminal block 24, it is possible to provide a pressure sensor 100 equipped with a pressure sensor unit 10 that can be assembled while suppressing the effect of mechanical stress on the joint of the solder S between the relay connection terminal 36 and the board circuit 50 due to the difference in linear expansion coefficient between the circuit board 50 and the terminal block 24.

[0043] 18, in the case where the terminal holders 51, 53 formed on the side wall 24s of the terminal block 24 are U-shaped and the relay connection terminals 136, 37 are inserted from the outer surface side, the terminal block 24 is turned sideways and the terminal fixing adhesive 26a is injected into the grooves opening on the lower side of the terminal holders 51, 53 of the side wall 24s at least twice. In contrast, in this embodiment, the formation of the terminal fixing adhesive 26g can be easily and quickly completed with a single injection operation with the terminal block 24 in an upright state, and it is also possible to avoid a decrease in the positioning accuracy of the relay connection terminals 36, 37 when the terminal block 24 is turned sideways.

[0044] Here, as a first alternative aspect of this embodiment, as shown in Fig. 11, the protrusions 36h and 36i of the relay connection terminal 36 to be installed in the terminal holding portion 51 may be extended to form protrusions 36he and 36ie, which are then deeply inserted into the bottom of the groove 55g of the terminal block 24 to be positioned and fixed. This makes it possible to omit the terminal fixing adhesive 26g for fixing the relay connection terminal 36 by injecting and solidifying it into the groove 55g of the terminal block 24 in the terminal holding portion 51. Also, instead of the terminal fixing adhesive 26g, the position of the recess of the covering layer 14a that fixes the terminal block 24 to the hermetic glass 14 may be moved below the groove 55g, and the covering layer 14g may be injected and solidified to position and fix the relay connection terminal 36 together with the terminal block 24 itself.

[0045] As a second alternative aspect of this embodiment, instead of the relay connection terminal 136 that is inserted into the terminal holder 51 from the outer surface side of the terminal block 24 as shown in Fig. 18, a relay connection terminal 66 having a deformation portion described below that can adjust the separation distance from the recessed wall electrode surface 50u of the circuit board 50 by expanding or contracting in the separation direction may be installed on the flat portion 36f side of the terminal piece 36d as shown in Fig. 12. This allows the deformation portion of the relay connection terminal 66 to deform in response to mechanical stress between the terminal holder 51 and the circuit board 50, thereby obtaining an effect similar to the oscillation of the relay connection terminal 36 due to the notch 58 of the inner wall portion 55 of this embodiment, and it is possible to avoid a decrease in joint quality due to mechanical stress being applied to the joint portion of the solder S that electrically connects the terminal pieces 36d, 37d of the relay connection terminals 36, 37 to the circuit board 50.

[0046] Specifically, for example, a deformed portion 66r having a corrugated cross section as shown in Fig. 12(a) and a deformed portion 66f having a curved cross section as shown in Fig. 12(b) may be formed on the flat portion 36f side of the terminal piece 36d to make the separation distance easily adjustable. Furthermore, as shown in Fig. 12(c), instead of the relay connection terminal 66 that changes the height (length in the cylindrical axial direction of the terminal block 24) of the flat portion 36f side of the terminal piece 36d and the recessed wall electrode surface 50u side of the circuit board 50 from the bottom surface 24b of the terminal block 24, the separation distance may be easily adjusted. That is, the relay connection terminal 66 shown in Fig. 12(c) makes it possible to adjust the separation distance between the recessed wall electrode surface 50u side of the circuit board 50, which is offset in the cylindrical axial direction of the terminal block 24 (direction intersecting with the planar direction of the circuit board 50), and the groove 55g side of the inner wall portion 55 of the terminal block 24.

[0047] As another example of this second aspect, the relay connection terminal 66 may be replaced with the shape shown in FIG. 13, and a deformed portion 66q having a regular polygonal or irregular opening (a rectangle is shown) may be formed on the flat portion 36f side of the terminal piece 36d (FIG. 13(a)). A flat deformed portion 66s may be formed that is narrow and connects to the terminal piece 36d in a straight line (FIG. 13(b)). Similarly, a flat deformed portion 66i may be formed that is narrow and connects in a sloping shape (FIG. 13(c)). Similarly, a flat deformed portion 66t may be formed that is narrow and connects in a meandering shape (FIG. 13(d)), making it possible to adjust the distance from the recessed wall electrode surface 50u of the circuit board 50.

[0048] Here, it goes without saying that these relay connection terminals 66 can be applied to the relay connection terminals 37 which are inserted into the terminal holding portion 53 shown in Figure 18 from the outer surface side of the terminal block 24 and positioned and fixed by the terminal fixing adhesive 26a.

[0049] As a third alternative aspect of this embodiment, instead of the terminal block cap 25 attached to the upper opening side of the terminal block 24 including the terminal holder 53 together with the relay connection terminal 136 which is inserted into the terminal holder 51 shown in Fig. 18 from the outer surface side of the terminal block 24 and positioned and fixed by the terminal fixing adhesive 26a, an upper cap 65 shown in Fig. 14 may be attached and a notch 68 may be formed on the outer surface side of the terminal holder 51. Specifically, the upper cap 65 covers from the outer periphery side of the terminal block 24 to at least the upper surface of the housing 12, thereby preventing the sealant 26 filled in the waterproof case 20 from directly contacting the terminal block 24 and the relay terminal connection terminal 136, and allows the relay connection terminal 136 to swing to expand and contract in the radial direction of the terminal block 24 as shown in Fig. 10a and Fig. 10b (the swing (deformation adjustment) in the direction away from the notch 68 is ensured in the space secured by the upper cap 65). Furthermore, the notch 68 on the outer surface side of the terminal holding portion 51 can allow the relay connection terminal 136 to swing significantly in the radial direction of the terminal block 24. As a result, in the third alternative embodiment, similar to the swinging of the relay connection terminal 36 by the notch 58 of the inner wall portion 55 in this embodiment, the portion (deformed portion) of the relay connection terminal 136 corresponding to the notch 68 can easily deform and swing, and it is possible to avoid a decrease in joint quality due to mechanical stress being applied to the joint portion of the solder S that electrically connects the terminal pieces 36d, 37d of the relay connection terminals 136, 37 to the circuit board 50.

[0050] Here, it goes without saying that the notch 68 of the terminal holding portion 51 may be applied to the terminal holding portion 53 shown in FIG. 18 together with the upper cap 65 so that the relay connection terminal 37 installed on the terminal holding portion 53 behaves in the same manner as the relay connection terminal 136.

[0051] As a fourth alternative aspect of this embodiment, an elastic material 69 may be provided by cutting out the upper side of the outer surface of the terminal holding portion 51 shown in Fig. 18, which covers and holds the relay connection terminal 136, thereby allowing the holding portion (deformed portion) of the relay connection terminal 136 to swing significantly in the radial direction of the terminal block 24 (the above-mentioned adjustment direction of the separation distance) by utilizing the elastic deformation of the elastic material 69 (Fig. 15). This makes it possible to avoid a deterioration in joint quality due to mechanical stress being applied to the joint portion of the solder S that electrically connects the terminal pieces 36d, 37d of the relay connection terminals 136, 37 to the circuit board 50, as in the case of the swinging of the relay connection terminal 36 caused by the cutout 58 of the inner wall portion 55 of this embodiment.

[0052] Here, it goes without saying that the elastic material 69 of the terminal holding portion 51 may be applied to the terminal holding portion 53 shown in Figure 18 so that the relay connection terminal 37 installed in the terminal holding portion 53 behaves in the same manner as the relay connection terminal 136.

[0053] Although not shown in the drawings, it goes without saying that the structures of the terminal holding portions 51, 53 and the relay connection terminals 36, 37 in this embodiment may be interchanged, or one of the structures may be unified into a common structure.

[0054] For example, as a fifth alternative embodiment of the present embodiment, as shown in FIG. 16, the lead wire 38 may be used as a terminal member and passed through the terminal block 25 to be soldered directly to the circuit board 50 for electrical connection without using the relay connection terminal 37 of the terminal member. In this fifth alternative embodiment, the support and fixation are released by omitting the relay connection terminal 37, and the circuit board 50 can be slidably held together with the deformation of the lead wire 38, and the relative positional relationship with the terminal block 24 can be adjusted. In this fifth alternative embodiment, the lead wire 38 is electrically connected to the circuit board 50 in advance, the terminal piece 36e of the relay connection terminal 36 is spot-welded to the lead pin 40, and then the circuit board 50 to which the lead wire 38 is connected is placed on the terminal piece 36d of the relay connection terminal 36, and the placement portion is soldered and the terminal block cap 25 is placed thereon to assemble and manufacture the device. After this assembly work, the sealant 26 is filled between the waterproof case 20 and the terminal block 24 and the terminal block cap 25.

[0055] 17, as a sixth alternative aspect of this embodiment, the relay connection terminal 37 may be left as it is (an adjustment function similar to that of the relay connection terminal 36 may be added), and the lead pin 40 may be used as a connecting member and directly soldered to the circuit board 50 for electrical connection without using the relay connection terminal 36 of the connecting member. In this sixth alternative aspect, the omission of the relay connection terminal 36 releases the support and fixation, allowing the circuit board 50 to be slidably held, and the relative positional relationship with the terminal block 24 can be adjusted.

[0056] The scope of the present invention is not limited to the exemplary embodiments shown and described, but includes all embodiments that achieve equivalent effects to the object of the present invention. Moreover, the scope of the present invention is not limited to the combination of inventive features specified in each claim, but may be defined by any desired combination of each and every particular feature disclosed. [Explanation of symbols]

[0057] 10...Pressure sensor unit 11...Pressure sensor chip 14a, 14g...covering layer 20...Waterproof case 24……Terminal block 24s……Side wall part 25...Terminal block cap 26...Sealing material 26a, 26g... Terminal fixing adhesive 30...Joint member 36(36A~36C), 37(37A~37C), 66, 136……Relay connection terminal 36d, 36e, 37d, 37e...Terminal piece 36f……Plane part 36h, 36he, 36i, 36ie...projection 37e...bent piece 37f...Connection surface 38...Lead wire 40...Lead pin 50...Circuit board 50r……Corner recess 50u……Concave wall electrode surface 51, 53...terminal holding part 53a, 53b...slit 54...Strut shape part 55~57……Inner wall 55g~57g……Groove 55h……insertion groove 55s...slit 58...Notch 65……Upper cap 66a, 66f, 66i, 66q, 66r, 66t...deformed part 68...Notch 69...Elastic material 100...Pressure sensor A……External device LR……liquid seal chamber M……Plating S……Conductive connection material SR……Installation space

Claims

1. A pressure sensor including a sensor unit having a sensor connected to an external device, a circuit board that is disposed between the sensor and the external device and is connected to the sensor, a connection member that is located between the sensor and the circuit board and is conductively connected to the sensor and the circuit board, and one or both of a terminal member that is conductively connected to the circuit board and is used for conductively connecting the circuit board to the external device, and a terminal block that fixes and positions and supports the connection member and / or the terminal member, the circuit board is placed on one or both of the connection members and the terminal members; A pressure sensor comprising: an adjustment portion for adjusting a relative positional relationship of at least one of the connection member, the terminal member, and the terminal block with respect to the circuit board.

2. The pressure sensor according to claim 1, characterized in that the adjustment portion adjusts the distance between the support position of one or both of the connecting member and the terminal member on the terminal block and the connection position of one or both of the connecting member and the terminal member to the circuit board.

3. The pressure sensor according to claim 2, characterized in that the adjustment portion has a deformation portion in which at least a portion of one or both of the connection member and the terminal member is deformed in a direction away from the connection position at the support position so as to adjust the separation distance.

4. The pressure sensor according to claim 3 , wherein the adjustment portion has a space that allows the deformation portion to deform to adjust the distance from the connection position.

5. The pressure sensor according to claim 3, characterized in that the adjustment portion has a recess formed at the support position on the terminal block, enabling deformation of the deformation portion in a direction away from the recess or in a direction entering the recess.

6. 6. The pressure sensor according to claim 5, wherein the adjustment portion has the terminal block covered with a member that forms a space that allows the deformation portion to deform in a direction away from the recess.

7. The pressure sensor according to claim 3, characterized in that the adjustment portion has an elastic material that positions and holds the deformation portion at the support position, and the elastic material elastically deforms to allow deformation of the deformation portion in a direction that adjusts the separation distance between the support position and the connection position.

8. The pressure sensor according to claim 3 , wherein the deformation portion is deformed between the support position and the connection position so as to expand or contract in a direction away from the support position and the connection position.

9. 9. The pressure sensor according to claim 8, wherein the deformed portion has a wavy cross-sectional shape in a direction away from the support position and the connection position.

10. 9. The pressure sensor according to claim 8, wherein the deformed portion has a curved cross-sectional shape in a direction away from the support position and the connection position.

11. The pressure sensor according to claim 8 , wherein the deformation portion is formed in a plate shape such that at least a part of the width between the support position and the connection position is narrower than the width on the connection position side.

12. The pressure sensor according to claim 8, characterized in that the deformation portion is located between the support position and the connection position which are offset in a direction perpendicular to the planar direction of the circuit board, and the deformation portion deforms the separation distance between the support position and the connection position in the planar direction of the circuit board in an adjustable manner.

13. 2. The pressure sensor according to claim 1, wherein the adjustment portion is configured so that the holding position of the circuit board with respect to the terminal block is freely slidable, thereby adjusting the relative positional relationship of the terminal block with respect to the circuit board.

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