Pressure sensor and method for manufacturing pressure sensor

Abstract

To achieve a sensor unit that can execute assembly operations to move a terminal to be connected to a sensor in a vertical direction.SOLUTION: A pressure sensor is formed of a pressure sensor unit 10 comprising a pressure sensor chip 11 connected to an external device A, and comprises: a circuit board 50 that is interposed between the external device and the sensor; a relay connection terminal 36 that is conductively connected to the sensor and the circuit board; and a relay connection terminal 37 that is conductively connected to the circuit board and the external device. A terminal block 24 locates the connection terminals at separated positions and has the circuit board conductively connected to the sensor mounted thereon, and the terminal block locates the connection terminals respectively in grooves 55g and 56g having a depth in a direction in which the circuit board is overlapped, and fixes the connection terminals at determined positions through injection and curing of an adhesive 26g for terminal fixation.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a pressure sensor having a simple structure that allows easy and reliable assembly work, and a method for manufacturing the pressure sensor. [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] In such a sensor unit, since it is necessary to position and support the components during assembly while mechanically and electrically connecting them so that they can function, assembling the components by stacking them, for example, is excellent in terms of both workability and positional accuracy.

[0006] However, even if the sensor and the terminal block are stacked vertically, the terminals that are functionally connected to the sensor are electrically connected by spot welding or soldering to the flat surface, so the structure requires that the flat terminals extending horizontally be slid horizontally to be positioned and held in place. This means that after various parts in the middle of assembly are turned sideways to fix the terminals to the terminal block, the parts must be stacked vertically again and the assembly work resumed, which reduces workability.

[0007] Therefore, an object of the present invention is to realize a sensor unit that can perform assembly work in which terminals to be connected to the sensor are moved in an upward and downward direction, 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 connecting member located between the sensor and the circuit board and 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 and conductively connected to the circuit board; and a terminal block that fixes and supports in position the connecting member and one or both of the terminal members, wherein the circuit board is placed on one or both of the connecting member and the terminal member, and the terminal block has a fixing groove formed therein that has a depth in the direction in which the circuit boards are stacked and extends at least to the fixing position of the connecting member and one or both of the terminal members, and the fixing portions of the connecting member and one or both of the terminal members are positioned in the fixing groove and are bonded with an adhesive to be positioned and fixed. Effect of the Invention

[0009] Thus, according to one aspect of the present invention, it is possible to realize a sensor unit having a simple and easy-to-operate structure in which one or both of the connection members and terminal members that connect the circuit board to a sensor or external device are positioned in a fixing groove having a depth in the direction in which the circuit boards of the terminal block are overlapped, and are bonded and fixed in position with an adhesive, and it is possible to provide a pressure sensor constituted by this sensor unit, as well as a method for manufacturing a pressure sensor that allows for easy assembly. [Brief description of the drawings]

[0010] [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 shows a first alternative embodiment of the present invention, where (a) is a vertical cross-sectional view showing a structure equivalent to this embodiment, and (b) is a vertical cross-sectional view showing a structure inferior to this embodiment. [Figure 11] FIG. 11 is a diagram showing a second alternative embodiment of the present invention, and is a top view showing a case where a different shape of connection terminal is adopted. [Figure 12] FIG. 11 is a diagram showing a third alternative embodiment of the present invention, and is a top view showing a case where a different shape of the connection terminal is adopted. [Figure 13] FIG. 13 is a diagram showing a fourth alternative embodiment of the present invention, and is a vertical sectional view showing a schematic overall configuration thereof. [Figure 14] FIG. 14 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 15] FIG. 15 is a vertical cross-sectional view showing a technology prior to the conception of this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Figures 1 to 9 are diagrams illustrating a pressure sensor including a pressure sensor unit, which is an example of a sensor unit according to an embodiment of the present invention, and a method for manufacturing the sensor unit.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] The lead pins 40 are arranged on a bottom surface 24b of a resin terminal block 24 formed in a short, generally cylindrical shape with a bottom, and are electrically connected to the pressure sensor chip 11 via bonding wires 11w. These lead pins 40 are inserted into 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), which will be described later, are arranged symmetrically about the center of the cylinder.

[0021] 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 lead pins 40, which are the power supply terminal and the output signal terminal, is electrically connected to the end surface by, for example, spot welding (or molten metal bonding). The side wall 24s of the terminal block 24 holds a relay connection terminal 37 on the opposite side (facing side) of the relay connection terminal 36, 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 soldering in which molten solder (conductive connection material) S is applied. 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 a molten metal such as the solder S, and for example, an adhesive containing a conductive material may be applied.

[0022] 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 thereon to adjust different input / output voltages between 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 a voltage output format of driving / output voltage different from this embodiment, a current output format such as a two-wire type / three-wire type, or a digital output format. Note that these conversion adjustment circuits are configured by mounting a plurality of electronic components (not shown).

[0023] 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 peripheral edge 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, by arranging the circuit board 50 in the installation space SR provided by the terminal block 24 and the terminal block cap 25, an air layer with low thermal conductivity can be formed around the circuit board 50, and it is possible to prevent temperature changes from around the pressure sensor or from the piping from being suddenly transmitted to the circuit board 50. Also, 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, 37, etc. so as not to come into contact with the sealing material 26, it is possible to prevent mechanical stress caused by the contraction and expansion of the sealing material 26 due to changes in the ambient temperature from acting on the connection members, the mounted components, and especially on their soldered portions.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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. Furthermore, 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 in an intersecting direction, and are then positioned in the terminal holding portion 53 in a state of contact with the upper surface of the inner wall portion 56 and the bottom surface of the groove 56g. In other words, these configurations form a fixing portion of the relay connection terminal 37.

[0031] 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. Among them, the terminal pieces 37d are formed in a shape that can be inserted into the side wall portion 24s of the terminal block 24 through the slit 53a to an extent that the circuit board 50 can be placed thereon. In this relay connection terminal 37, the terminal pieces 37d and the bent pieces 37e are formed 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 when the fixing by the terminal fixing adhesive 26g described later is sufficient.

[0032] 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 is positioned at the height of the upper surface of the inner wall portions 55, the terminal piece 36e is positioned 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 is also constant, i.e., the fixed position of the relay connection terminal 36 can be determined. 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 when spot welding the end face of the lead pin 40 and the terminal piece 36e, it is necessary to keep the relative positional relationship between them constant. Also, the relay connection terminal 37 is attached to the terminal holding part 53 so that the terminal piece 37d 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, i.e., the fixed position of the relay connection terminal 37 can be determined.

[0033] 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.

[0034] The relay connection terminals 36, 37 are provided with plating M to improve the wettability of molten solder on the terminal pieces 36d, 37d to be soldered and the connection surface 37f, so that the occurrence of connection failure with the electrode surface 50u of the circuit board 50 described later can be reduced and the relay connection terminals 36, 37 can be made conductively connected. In addition, plating M is also provided on the adjacent portion of the connection surface 37f of the relay connection terminal 37, so that the wettability of the solder is improved and the occurrence of connection failure is reduced when soldering with the core wire C of the lead wire 38. Here, the relay connection terminals 36, 37 are provided with plating M only on the area required for soldering, and plating M is not provided on the other areas, so that the outflow of molten solder is suppressed. In addition to providing the solder wettability by plating M in the present example, the soldering surface may be left as the surface of the metal base material, and a resist, coating, etc. may be provided on the area to restrict the flow of the solder.

[0035] As shown in Fig. 8, the circuit board 50 has an outer peripheral end surface at a portion 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 a recessed wall electrode surface (recessed wall surface) 50u of the connection region that opens to both the front and back sides perpendicular to the plane of the circuit board 50 is formed. The 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 the 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.

[0036] 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.

[0037] 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.

[0038] In this manner, in the pressure sensor unit 10 of the pressure sensor 100 of this embodiment, the relay connection terminals 36, 37 are positioned in the grooves 55g, 56g of the terminal holding portions 51, 53 formed in the side wall portion 24s of the terminal block 24, and the operation (manufacturing method) of fixing the terminals with the terminal fixing adhesive 26g while the circuit board 50 is placed in the grooves 55g, 56g can be performed.

[0039] 15, 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 36, 37 are inserted from the outer surface side, the terminal block 24 must be turned sideways and the terminal fixing adhesive 26a must be 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 terminal block 24 in an upright state and the relay connection terminals 36, 37 can be easily and quickly fixed by injecting the terminal fixing adhesive 26g once, 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.

[0040] Therefore, assembly can be easily performed with a simple structure that only requires placing the circuit board 50 directly on the terminal block 24 installed on the upper side of the pressure sensor chip 11 and electrically connecting it, and a pressure sensor 100 can be provided that is equipped with a pressure sensor unit 10 that is electrically connected with high reliability and high quality.

[0041] Here, as a first alternative aspect of this embodiment, instead of forming the protruding pieces 36h and 36i on the relay connection terminal 36 to be placed on the terminal holding part 51 to enable it to maintain its posture, as shown in FIG. 10(a), the relay connection terminal 36 may be folded back in the groove 55g of the terminal holding part 51 and abutted against both wall surfaces to maintain its posture and be positioned and fixed with the terminal fixing adhesive 26g. However, when it is difficult to perform fine processing to bend the relay connection terminal 36, it is preferable to adopt the structure of this embodiment. Also, as shown in FIG. 10(b), like the relay connection terminal 37 and the terminal holding part 53, the terminal pieces 36d and 36e extending from both sides of the flat part 36f' of the relay connection terminal 36 may be positioned and fixed with the terminal fixing adhesive 26g so as to pass through the groove 55g of the terminal holding part 51. However, with the relay connection terminal 36, the longer terminal piece 36e needs to pass through two points on both sides of the groove 55g of the terminal holding portion 51, which can complicate the insertion process, so it is preferable to adopt the structure of this embodiment.

[0042] Furthermore, as a second alternative aspect of the present embodiment, instead of preparing the relay connection terminal 36 in a form that can be attached to the terminal holding portion 51, in which the intervals between the terminal pieces 36e are narrowed in correspondence with the narrowly spaced lead pins 40, three relay connection terminals 39 having terminal pieces 39d, 39e for connecting to the lead pins 40 and the circuit board 50, which are arranged at equal intervals on the same circle around the support 13 as the center, may be prepared in the same U-shape, as shown in Fig. 11. Specifically, the terminal holding portion 51 may be prepared in a form that allows the relay connection terminal 39 to be attached in a position in which the terminal pieces 39e face the center so as to be connectable to the narrowly spaced lead pins 40, and has a groove 59g for injecting the terminal fixing adhesive 26g. By arranging the relay connection terminals 39 radially corresponding to the lead pins 40, i.e., concentrically with the arrangement of the lead pins 40, the length of the terminal pieces 39e of the relay connection terminals 39 can be made constant, and the three relay connection terminals 39 can be made the same shape. Furthermore, for example, if terminal holding portions 51 are formed in the terminal block 24 in the number equal to the number of lead pins 40, the number of relay connection terminals 39 for conductive connection between the lead pins 40 and the circuit board 50 can be increased or decreased according to the circuit configuration of the circuit board 50, making it possible to accommodate a variety of circuit configurations.

[0043] As a third alternative embodiment of the present invention, as shown in Fig. 12, the inner walls 55, 56 of the terminal holders 51, 53 may be extended outwardly on both sides, and the inner walls 57 and the grooves 57g may not be formed on the inner side of the side walls 24s of the terminal block 24. In this case, the terminal fixing adhesive 26g for fixing the relay connection terminals 36, 37 is injected into two places, but the amount of the adhesive injected can be reduced. In addition, even if the terminal fixing adhesive 26g does not completely flow into the grooves 55g, 56g, and 57g, the adhesive can be injected mainly into the grooves 55g and 56g, and problems such as the terminal fixing adhesive 26g not completely flowing and being cut off or overflowing from the grooves can be prevented.

[0044] Here, it goes without saying that the structures of the terminal holding portions 51, 53 and the relay connection terminals 36, 37 of this embodiment may be interchanged, or one of the structures may be unified and made common.

[0045] For example, as a fourth alternative embodiment of the present embodiment, as shown in Fig. 13, the lead wire 38 may be used as a terminal member and passed through the terminal block 25, without using the relay connection terminal 37 of the terminal member, and may be directly soldered to the circuit board 50 for conductive connection. In this fourth alternative embodiment, the lead wire 38 is conductively 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 covered with the terminal block cap 25 for assembly and manufacturing. 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.

[0046] As a fifth alternative aspect of this embodiment, as shown in FIG. 14, the relay connection terminal 37 may be left as it is, and the relay connection terminal 36 of the connection member may not be used, and the lead pin 40 may be used as the connection member and directly soldered to the circuit board 50 for electrical connection.

[0047] 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]

[0048] 10...Pressure sensor unit 11...Pressure sensor chip 20...Waterproof case 24……Terminal block 24b……Bottom part 24s……Side wall part 25...Terminal block cap 26...Sealing material 26a, 26g... Terminal fixing adhesive 29……Plane part 30...Joint member 36, 36A~36C, 37, 37A~37C, 39……Relay connection terminal 36d, 36e, 37d, 39d, 39e...Terminal piece 36f……Plane part 36h, 36i... protrusion 37e...bent piece 37f...Connection surface 37g……Engagement piece 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, 59g...Groove 55h……insertion groove 55s...slit 100...Pressure sensor A……External device L……Distance of depression 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; The terminal block has a fixing groove formed therein that has a depth in the direction in which the circuit boards are stacked and that extends at least to the fixing positions of one or both of the connecting member and the terminal member, and the fixing portions of the connecting member and one or both of the terminal members are positioned in the fixing groove and are bonded and fixed in position with an adhesive.

2. 2. The pressure sensor according to claim 1, further comprising: a side wall portion that constitutes an outer surface of the terminal block; and an inner wall portion that is positioned to face the inside of the side wall portion and that forms the fixing groove.

3. 2. The pressure sensor according to claim 1, wherein the fixing groove is formed in a continuous shape so as to include at least the fixing portions of the connecting member and / or the terminal member.

4. The pressure sensor according to claim 1, wherein one or both of the connection member and the terminal member have a fixing portion that extends in a direction overlapping with the circuit board and is positioned within the fixing groove, and is fixed to the terminal block.

5. The pressure sensor according to claim 1, characterized in that one or both of the connection member and the terminal member are fixed to the terminal block with their intersection portions extending in a direction intersecting the depth direction of the fixing groove positioned within the fixing groove.

6. A method for manufacturing a pressure sensor including a sensor unit having a sensor connected to an external device, comprising: the sensor unit includes a circuit board that is disposed between the sensor and the external device and is connected to the sensor, one or both of 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 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 member and the terminal member, the terminal block is formed with a fixing groove having a depth in a direction in which the circuit boards are stacked and extending at least to a fixing position of one or both of the connection member and the terminal member, The terminal block includes: A method for manufacturing a pressure sensor, characterized in that the fixing portions of one or both of the connecting member and the terminal member are positioned in the fixing grooves, adhesive is injected into the fixing grooves to position, adhere and fix them, and then the circuit boards are stacked and held together to assemble.

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