Pressure sensor and method for manufacturing the 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 used to send detection signals to measuring equipment, etc., and are often used either built into the measuring equipment 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 an environment similar to that of the object being measured. The sensor unit has a terminal block that holds terminals that are electrically connected to the installed sensor, and the sensor's detection signal can be made available by connecting a measuring device to the terminals. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-98685 Summary of the Invention [Problem to be solved by the invention]

[0005] In such a sensor unit, the components must be positioned and supported during assembly while being mechanically and electrically connected so that they can function. For example, assembling the components by stacking them is efficient in terms of workability and positional accuracy.

[0006] However, even if the sensor and terminal block are stacked vertically, the terminals that functionally connect to the sensor are electrically connected to the flat surface by spot welding or soldering, etc., so the structure requires that the flat terminals that extend horizontally be slid horizontally to position and hold them in place. This means that after fixing the terminals to the terminal block by turning the various parts that are being assembled on their sides, the parts must be stacked vertically again and the assembly work resumed, which reduces workability.

[0007] Therefore, the present invention aims to realize a sensor unit that can be assembled by moving the terminals to which the sensor is connected in the vertical direction, and to provide a pressure sensor that includes 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, the pressure sensor comprising: a circuit board that is arranged so as to be interposed between the sensor and the external device and connected to the sensor; a connecting 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 to conductively connect the circuit board to the external device; and a terminal block that fixes, positions, and supports the connecting member and / or the terminal member, the circuit board being placed on one or both of the connecting member and the terminal member, the terminal block having a fixing groove that has a depth in the direction in which the circuit boards are stacked and that extends at least to the fixing position of one or both of the connecting member and the terminal member, and the fixing portion of one or both of the connecting member and the terminal member is positioned in the fixing groove and is adhered and positioned with an adhesive. [Effects of the Invention]

[0009] Thus, according to one aspect of the present invention, a sensor unit can be realized that has 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 of the terminal block that has a depth in the direction in which the circuit boards are stacked, and are bonded and fixed in position with an adhesive, and a pressure sensor constructed from this sensor unit and a method for manufacturing a pressure sensor that is easy to assemble can be provided. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a vertical cross-sectional view showing a schematic overall configuration of a pressure sensor including a pressure sensor unit, which is an example of a sensor unit according to an embodiment of the present invention. [Figure 2] FIG. 2 shows an outline of the 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. [Figure 3] FIG. 3 is a perspective view showing the main components from one direction. [Figure 4] 4A and 4B are diagrams showing one connection terminal 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 plan view showing the lead frame of the three components. [Figure 5] 5A and 5B are diagrams showing a connection terminal different from that shown in FIG. 4 that is attached to the main part 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 the state in which the connection terminals are attached to the main components of FIG. 3, where (a) is a longitudinal sectional view and (b) is a top view. [Figure 7] 7A and 7B are diagrams illustrating the mounting state of the connection terminals in FIG. 6, where (a) is a perspective view of one connection terminal from one direction and a perspective view of the other connection terminal from a different direction, and (b) is a top view of both connection terminals. [Figure 8]8A and 8B are diagrams showing the attachment state of the connection terminal and the circuit board to the main component of FIG. 3, where (a) is a longitudinal cross-sectional view, (b) is a perspective view, and (c) is an enlarged perspective view of the connection point 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 the structure is not adopted. [Figure 10] FIG. 10 shows a first alternative embodiment of this embodiment, where (a) is a longitudinal cross-sectional view showing a structure equivalent to this embodiment, and (b) is a longitudinal cross-sectional view showing a structure inferior to this embodiment. [Figure 11] FIG. 11 is a diagram showing a second alternative aspect of this embodiment, and is a top view showing a case where a different shape of the connection terminal is adopted. [Figure 12] FIG. 11 is a diagram showing a third alternative aspect of this embodiment, 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 aspect of the present embodiment, and is a vertical cross-sectional view showing a schematic overall configuration thereof. [Figure 14] FIG. 14 is a diagram showing a fifth alternative aspect of this embodiment, and is a longitudinal sectional view showing a schematic overall configuration thereof. [Figure 15] FIG. 15 is a vertical cross-sectional view showing a technology before the conception of this embodiment was conceived. DETAILED DESCRIPTION OF THE INVENTION

[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 as 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 where pressure characteristics of the external environment are to be measured, 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, for example, by connecting the pressure sensor unit 10 with a metal joint member 30 to a pipe to be measured through which a fluid such as a gas or liquid whose pressure is to be detected is guided.

[0013] Here, the waterproof case 20 is made into a cylindrical shape capable of accommodating 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 coupling member 30 is fixed. This coupling member 30 is formed with an internal thread 30s so that it can be screwed onto a pipe or the like whose pressure is to be measured, and a port 30a communicating with the internal thread 30s enables fluid supplied from the pipe in the direction of arrow P to be introduced into a pressure chamber PR downstream of the cap 28.

[0014] The pressure sensor unit 10 comprises a housing 12 made in a short cylindrical shape and having its lower axial end face joined and fixed to a cap 28, a support 13 on which a 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 that is filled around the support 13 inside the inner tube of the housing 12 to seal it and fix components that 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 inside the housing 12 from the pressure chamber PR.

[0016] In this pressure sensor unit 10, the installation space of the pressure sensor chip 11 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] The pressure sensor chip 11 is electrically connected via bonding wires 11w to lead pins 40, which are connected to multiple lead wires 38 from the external device A via a circuit board 50 (described later), so that it receives power and outputs a detection signal as pressure information. The liquid-sealed chamber LR between the hermetic glass 14 and the diaphragm 32 within the inner cylinder of the housing 12 is filled with a pressure transmission medium via an oil filling pipe 44. The lead pins 40 and the oil filling pipe 44 are aligned at equal intervals on the same circle around the support 13 and are supported insulated from the housing 12 by an insulator such as the hermetic glass 14. One end of the oil filling pipe 44 is closed after the pressure transmission medium is filled.

[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 of the hermetic glass 14, and a lid-like shield plate 17 is attached to it. The frame 16 accommodates a pressure transmission medium that can flow freely between the pressure sensor chip 11 side and the diaphragm 32 side via communication holes 17a formed in the shield plate 17, which suppress 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. Two power supply terminals, one output signal terminal, and five adjustment terminals used during assembly are arranged on the bottom surface 24b. 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 that is partially formed flat, and terminal holders 51 and 53 for mounting and holding sets 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 pins 40 penetrate both sides of the hermetic glass 14 inside the inner cylinder of the housing 12, and one end on the liquid-sealed chamber LR side is conductively connected to the pressure sensor chip 11 via a bonding wire 11w. The other ends of the lead pins 40, the power supply terminal and the output signal terminal, are conductively connected to the end surfaces by, for example, spot welding (or molten metal welding) to a terminal piece 36e of a relay connection terminal 36 held on the side wall 24s of the terminal block 24. The side wall 24s of the terminal block 24 holds a relay connection terminal 37 on the opposite side (facing) of the relay connection terminal 36, to which a lead wire 38 from an external device A is connected, as described below. A circuit board 50, which is placed on top of the relay connection terminals 36, 37, is connected by applying molten solder (conductive connection material) S to the terminal pieces 36d, 37d. 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 part of the circuit configuration. In this embodiment, an input / output voltage conversion adjustment circuit is mounted on the circuit board 50 to adjust different input / output voltages between the pressure sensor chip 11 and the external device A, for example, to convert the input voltage of external device A from DC 12 V or DC 3.3 V to the operating voltage of the pressure sensor chip 11 from DC 5 V. This type of conversion adjustment circuit is not limited to this embodiment, but may be any conversion adjustment circuit that can accommodate various drive voltages and pressure detection signal formats, such as a voltage output format for drive / output voltages different from this embodiment, a current output format such as a two-wire or three-wire format, 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, closing off the installation space SR for the lead pins 40, the terminal pieces 36d, 36e, 37d of the relay connection terminals 36, 37, and the circuit board 50, and together with the housing 12 to which the supports 13 of the pressure sensor chip 11 are fixed with hermetic glass 14, constitutes a pressure sensor unit 10. This pressure sensor unit 10 is integrated with the housing 12 by welding from the outside to the outer periphery of the cap 28 to which the coupling member 30 is connected, using TIG welding, plasma welding, laser welding, or the like, with a desired joint strength. This pressure sensor unit 10 is installed inside the waterproof case 20 and filled with a sealant 26 such as a urethane resin, thereby providing a waterproof treatment and fixing it in place. Here, by placing the circuit board 50 in the installation space SR defined 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, preventing temperature changes from around the pressure sensor or from the piping from being suddenly 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 so that they do not 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 ambient temperature from acting on the connection members, the mounted components, and particularly 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 coupling member 30, along with the terminal block 24, circuit board 50, and terminal block cap 25. After the relay connection terminals 36, 37 are set in the terminal holders 51, 53 of the side wall portion 24s, the terminal block 24 is placed on the housing 12 and the ends of the lead pins 40 are spot-welded to the terminal pieces 36e of the relay connection terminals 36. Thereafter, the circuit board 50 is placed on the terminal pieces 36d, 37d of the relay connection terminals 36, 37 and soldered to establish electrical continuity. Needless to say, the terminal pieces 36e of the relay connection terminals 36 can be electrically connected to the end faces of the lead pins 40 by soldering, crimping, or other methods other than 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.

[0025] More specifically, 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 an elongated shape, with end pieces (terminal pieces) on one end and the other end 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 parallel directions and arranged parallel to the outer surface of the terminal holding portion 51 of the terminal block 24, and the terminal pieces 36d, 36e extending into the side wall portion 24s. The relay connection terminal 37 is similarly formed in a U-shape with a terminal piece 37d extending 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, with 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 wall portions 55 formed inside the side wall portion 24s of the terminal block 24, facing each other so as to interpose grooves 55g, which are fixing grooves for fixing the relay connection terminals 36, and the upper surfaces of the inner wall portions 55 are formed at the same height. Similarly, the terminal holding portion 53 has a single inner wall portion 56 formed inside the side wall portion 24s of the terminal block 24, facing each other so as to interpose grooves 56g, which are fixing grooves for fixing the relay connection terminals 37. A pair of inner wall portions 57, facing each other, are formed inside the side wall portion 24s between the inner wall portions 55, 56, facing each other so as to interpose grooves 57g therebetween. In other words, the grooves 55g-57g are formed continuously between the side wall portion 24s of the terminal block 24 and the inner wall portions 55-57.

[0028] The terminal holding portion 51 is positioned by inserting the terminal piece 36e of each of the relay connection terminals 36A to 36C into contact with the bottom surface of three slits 55s formed between four inner wall portions 55 facing the side wall portion 24s of the terminal block 24. In this state, the flat portions 36f of the relay connection terminals 36A to 36C, which are formed larger than the slits 55s, contact 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 contact 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 portions of the flat portion 36f adjacent to the terminal piece 36e in the planar direction of the flat portion 36f. Furthermore, insertion grooves 55h for the protrusions 36h, 36i are formed on the bottom surface of groove 55g between side wall portion 24s and side wall 55 of terminal block 24. Protrusions 36h, 36i are inserted into insertion grooves 55h, thereby maintaining relay connection terminals 36A-36C in an upright position. This structure of terminal holder 51 allows terminal pieces 36e of relay connection terminals 36A-36C to be inserted and assembled from the upper, open end of terminal block 24 so that they fit into grooves 55g and slits 55s; in other words, this structure forms a fixed portion. Note that protrusions 36i are not shown in FIG. 2 but are shown in FIG. 4.

[0029] The relay connection terminal 36 is made up of a set of three relay connection terminals 36A to 36C, each having a different shape, and the terminal pieces 36d, 36e are each bent perpendicularly to the flat surface 36f. The terminal pieces 36e are formed so that they extend parallel to the bottom surface 24b of the terminal block 24 in a parallel arrangement with narrower spacing than the terminal pieces 36d. More specifically, the relay connection terminal 36 is formed so that the terminal pieces 36e are connected to lead pins 40 that are arranged at equal intervals on the same circle around the support 13 in correspondence with the small pressure sensor chip 11, and so are formed so that they extend parallel to the center with narrower spacing. Furthermore, the terminal pieces 36d are connected to the circuit board 50, which can be spaced at any interval, and so are formed so that they extend parallel to the circuit board 50 with wider spacing than the terminal pieces 36e, making connection easier. 4(d), the relay connection terminal 36 is produced by punching out a set of three relay connection terminals 36A-36C integrated with a lead frame 36LF, and then bending the terminal pieces 36d and 36e toward the flat portion 36f and the protrusions 36h and 36i, respectively. The slits 55s in the inner wall 55 open from the grooves 55g toward the bottom surface 24b of the terminal block 24. When a terminal-fixing adhesive 26g (described later) is injected into the grooves 55g to fix the relay connection terminal 36, the rear side of the flat portion 36f (the outer side of the terminal block 24) receives the terminal-fixing adhesive 26g, preventing the terminal-fixing adhesive 26g from leaking toward the bottom surface 24b of the terminal block 24.

[0030] The terminal holding portion 53 has slits 53a, 53b formed on its upper and lower surfaces that penetrate the side wall portion 24s of the terminal block 24 to allow insertion of the terminal piece 37d and the bent piece 37e of the relay connection terminal 37. Furthermore, the terminal piece 37d and the bent piece (intersection portion) 37e penetrate the slits 53a, 53b in 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 so as to come into 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 for the relay connection terminal 37.

[0031] Due to this structure, the relay connection terminals 37A to 37C are all formed in the same shape, and the terminal pieces 37d and 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. Of these, the terminal piece 37d is formed in a shape that allows it to 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 bent pieces 37e are formed narrower than the wide connection surface 37f, and engaging pieces 37g are formed on both sides of the terminal piece 37d by bending them in the same direction to hook onto the upper surface of the terminal holding portion 53. Note that the engaging pieces 37g may be omitted if fixing using a terminal fixing adhesive 26g, which will be described later, is sufficient.

[0032] As a result, the relay connection terminal 36 can be attached to the terminal holding portion 51 with the long terminal pieces 36d, 36e positioned between the inner wall portions 55 (slits 55s) inside the side wall portions 24s of the terminal block 24, while the protrusions 36h, 36i are inserted into the insertion grooves 55h on the bottom surfaces of the grooves 55g between the side wall portions 24s and the inner wall portions 55 to hold the positions, and the relay connection terminal 36 can be attached so that the amount of protrusion of the terminal piece 36e into the terminal block 24 is constant. With this configuration, the terminal piece 36d is positioned at the same height as the upper surface of the inner wall portions 55, and the terminal piece 36e is positioned at the same height as 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 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 to the terminal piece 36e, it is necessary to maintain a constant relative positional relationship between them. Furthermore, the relay connection terminal 37 is attached to the terminal holder 53 so that the terminal piece 37d is positioned and held on the upper surface of the inner wall portion 56 inside the side wall portion 24s of the terminal block 24, i.e., the fixed position of the relay connection terminal 37 can be determined.

[0033] Therefore, the terminal pieces 36e and bent pieces (fixing portions) 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 side wall portions 24s and 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 because the grooves 55g, 56g formed 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). After this, 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 while maintaining the stable position. 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 flat surface 29 engages with the protrusion 25a on the underside of the terminal block cap 25, thereby preventing horizontal displacement and rotation of the terminal block cap 25 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, leakage of the sealant 26 into the terminal block 24 can be prevented when the sealant 26 is filled around the terminal block 24 and the terminal block cap 25.

[0034] These relay connection terminals 36, 37 are plated with plating M to improve the wettability of molten solder on the soldered terminal pieces 36d, 37d and the connection surface 37f, thereby reducing the occurrence of poor connections with the electrode surface 50u of the circuit board 50 (described below) and enabling conductive connection. Plating M is also applied to the area adjacent to the connection surface 37f of the relay connection terminal 37, improving the wettability of the solder and reducing the occurrence of poor connections when soldered to the core wire C of the lead wire 38. Since the relay connection terminals 36, 37 are plated with plating M only in the areas required for soldering and not in other areas, the outflow of molten solder is suppressed. In addition to providing areas with plating M to improve solder wettability as in this example, the soldering surface may be left as a bare metal surface, and resist or coating may be applied to areas to restrict solder flow.

[0035] As shown in Fig. 8, the outer peripheral end surface of the circuit board 50 at locations corresponding to the terminal pieces 36d, 37d of the relay connection terminals 36, 37 is recessed inward in a U-shape parallel to the plane of the circuit board 50, forming recessed wall electrode surfaces (recessed wall surfaces) 50u in the connection region that open to both the front and back sides perpendicular to the plane of the circuit board 50. The recessed wall electrode surfaces 50u extend inward in a semicircular shape a distance L from the outer peripheral end surface of the circuit board 50, allowing molten solder to easily penetrate the entire surface (entire surface), and the inner surface is plated with plating M, which provides excellent solder wettability. That is, the recessed wall electrode surfaces 50u are formed as oval cutouts with a depth L extending from the outer peripheral end surface of the circuit board 50 toward the interior of the board. By forming the recessed wall surfaces inward in a semicircular shape, it is expected that stress within the recessed wall surfaces 50u during fillet formation by solder will be uniformly distributed. The uniform stress distribution improves resistance to defects such as poor conductivity due to cracks in soldered joints caused by repeated heating and cooling, or heat cycles, applied to the pressure sensor, and enables reliable connections. Furthermore, in the manufacturing process of the circuit board 50, the same machining tools can be used to process the mounting holes for mounted components and to process the exterior shape of the circuit board 50. A rectangular shape requires separate processes and tools, such as processing with a disk-shaped cutter, so a semicircular shape offers advantages 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-wall electrode surface 50u of the circuit board 50 and longer than the depth (distance) L from the outer peripheral end face of the recessed-wall 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 that fit into 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-wall 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 formed on only one of the circuit boards, but forming the recessed wall electrode surface 50u on both of the circuit boards is preferable in terms of connection workability and reliability.

[0037] As a result, as shown in FIG. 9(a), the circuit board 50 is placed stably on the terminal pieces 36d, 37d of the relay connection terminals 36, 37 and positioned on the support pillars 54 of the terminal block 24. The terminal pieces 36d, 37d are then reliably and electrically connected to the recessed electrode surface 50u by solder S, which has a larger capacity and a stable shape with a sufficient fillet height than the semicircular recessed electrode surface 50u' shown in FIG. 9(b). Because the soldered connection area is on the back side of the circuit board 50, it cannot be directly visually inspected. However, as in this embodiment, by visually inspecting or image-recognizing the fillet condition within the recessed wall portion 50u, it is possible to determine whether the soldering was performed properly. The circuit board 50 also has an insertion hole 50H through which the oil filler pipe 44 is inserted during assembly.

[0038] In this way, 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 on the side wall portion 24s of the terminal block 24, and the work (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 a configuration in which the relay connection terminals 36, 37 are inserted from the outer surface side of the U-shaped terminal holding portions 51, 53 formed on the side wall portions 24s of the terminal block 24, the terminal block 24 must be turned sideways and the terminal fixing adhesive 26a must be injected at least twice into the grooves opening on the lower sides of the terminal holding portions 51, 53 of the side wall portions 24s. In contrast, in this embodiment, the terminal block 24 in an upright state and the relay connection terminals 36, 37 can be fixed simply and quickly 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 in which the circuit board 50 is simply placed on the terminal block 24 installed on the upper side of the pressure sensor chip 11 and electrically connected, and a pressure sensor 100 can be provided which is equipped with a pressure sensor unit 10 that is electrically connected with high reliability and high quality.

[0041] As a first alternative aspect of this embodiment, instead of forming the protrusions 36h and 36i on the relay connection terminal 36 to be placed on the terminal holding portion 51 to maintain its posture, as shown in FIG. 10(a), the relay connection terminal 36 may be folded back within the groove 55g of the terminal holding portion 51 and abutted against both wall surfaces to maintain its posture, and then positioned and fixed with the terminal fixing adhesive 26g. However, when microfabrication for bending the relay connection terminal 36 is difficult, the structure of this embodiment is preferable. Furthermore, as shown in FIG. 10(b), similar to the relay connection terminal 37 and the terminal holding portion 53, the terminal pieces 36d and 36e extending from both sides of the flat portion 36f' of the relay connection terminal 36 may be allowed to pass through the groove 55g of the terminal holding portion 51 and positioned and fixed with the terminal fixing adhesive 26g. 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 make the insertion process complicated, so it is preferable to adopt the structure of this embodiment.

[0042] As a second alternative aspect of this embodiment, instead of fabricating the relay connection terminal 36, in which the spacing between the terminal pieces 36e is narrowed to correspond to the closely spaced lead pins 40, so that it can be attached to the terminal holder 51, three relay connection terminals 39 may be fabricated in the same U-shape, each having terminal pieces 39d, 39e that connect to the lead pins 40 and the circuit board 50 and are arranged at equal intervals on the same circle around the support 13, as shown in FIG. 11 . Specifically, the terminal holder 51 may be fabricated so that the relay connection terminals 39 can be attached with the terminal pieces 39e facing toward the center so that they can be connected to the closely spaced lead pins 40, and may have grooves 59g for injecting the terminal fixing adhesive 26g. By arranging the relay connection terminals 39 radially to correspond to the lead pins 40, i.e., concentrically with the arrangement of the lead pins 40, the lengths of the terminal pieces 39e of the relay connection terminals 39 can be made uniform, and the three relay connection terminals 39 can be made the same shape. Furthermore, for example, if terminal holding portions 51 are formed on 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 depending on the circuit configuration of the circuit board 50, making it possible to accommodate a variety of circuit configurations.

[0043] 12, as a third alternative aspect of this embodiment, the inner wall portions 55, 56 of the terminal holders 51, 53 may be extended outward on both sides, thereby eliminating the formation of the inner wall portion 57 and the groove 57g inside the side wall portion 24s of the terminal block 24. In this case, the terminal fixing adhesive 26g for fixing the relay connection terminals 36, 37 needs to be injected into two locations, but the amount injected can be reduced. Furthermore, in terms of the fluidity of the terminal fixing adhesive 26g, even if the terminal fixing adhesive 26g does not completely fill the grooves 55g, 56g, and 57g, it can be injected primarily into the grooves 55g and 56g, preventing problems such as the terminal fixing adhesive 26g not completely filling or being cut off or overflowing from the grooves.

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

[0045] 13 , instead of using the relay connection terminal 37 of the terminal member, the lead wire 38 may be used as the terminal member and passed through the terminal block 25, and then directly soldered to the circuit board 50 for electrical connection. In this fourth alternative embodiment, the lead wire 38 is electrically connected to the circuit board 50 in advance, and the terminal piece 36e of the relay connection terminal 36 is spot-welded to the lead pin 40. Thereafter, 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 then the terminal block cap 25 is placed thereon to complete assembly. After this assembly, the sealant 26 is filled between the waterproof case 20 and the terminal block 24 / 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 lead pin 40 may be used as the connecting member and directly soldered to the circuit board 50 for conductive connection without using the relay connection terminal 36 of the connecting member.

[0047] The scope of the present invention is not limited to the exemplary embodiments shown and described, but also includes all embodiments that achieve equivalent effects to those intended by the present invention. Furthermore, the scope of the present invention is not limited to the combination of inventive features specified in each claim, but can be defined by any desired combination of each and every disclosed specific feature. [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 terminals 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...slits 54...Strut shape part 55~57...Inner wall 55g~57g, 59g...Groove 55h...insertion groove 55s...slit 100...Pressure sensor A……External device L...Depression distance LR……liquid seal chamber M...Plating S...Conductive connection material SR……Installation space

Claims

1. A pressure sensor configured by a sensor unit including 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; 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 to conductively connect the circuit board to the external device; and a terminal block that fixes, 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 one or both of the connecting member and the terminal member are positioned in the fixing groove and are bonded and positioned with an adhesive.

2. 2. The pressure sensor according to claim 1, further comprising a side wall portion that forms 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 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 connecting member and the terminal member have a fixing portion that extends in a direction overlapping 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 connecting member and the terminal member are fixed to the terminal block with their intersections 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 configured by a sensor unit including 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 to conductively connect the circuit board to the external device; and a terminal block that fixes, positions, and supports one or both of the connection member and the terminal member, the circuit board is placed on one or both of the connection member and the terminal member; the terminal block has a fixing groove formed therein, the fixing groove having a depth in the 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 has: 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 groove, adhesive is injected into the fixing groove to position, adhere and fix them, and then the circuit boards are stacked and held together to assemble.

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