Pressure sensor and method for manufacturing pressure sensor

Abstract

To achieve a pressure sensor having a simple structure facilitating assembly operations with which a sensor and a circuit board can be conductively connected to each other easily with high reliability.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. The circuit board has a concave wall electrode surface 50u that is connected to two pairs of relay connection terminals and is formed on an outer end face. The two pairs of relay connection terminals include terminal pieces 36d, 37d that allow stable mounting of the circuit board and are larger than an opening shape of the concave wall electrode surface. The pressure sensor has a structure with which connection operations can be performed to solder the circuit board to the concave wall electrode surface in a form in which the circuit board is placed on the terminal pieces of the two pairs of relay connection terminals.SELECTED DRAWING: Figure 2

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. In some cases, the sensor is directly connected to the measuring device, but it may also be necessary to change the electrical characteristics of either or both of the sensor and the external device. [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] However, in the case of such a sensor unit, for example, when the specifications of the drive voltage from the external control device to the sensor or the output signal from the sensor to the external control device are different, it is effective not only to change the design of the sensor, which takes time and money, but also to make adjustments by inserting a drive voltage or output signal conversion circuit board between the sensor and the sensor.

[0006] In such cases, it may be worth considering a sensor unit that employs an assembled circuit configuration in which a circuit board for converting input and output signals is incorporated between the sensor and the external device. It is desirable to perform various operations such as positioning the circuit board that is electrically connected to the sensor at a predetermined position within the sensor unit and establishing an electrical connection so that various detection signals can be obtained with high reliability.

[0007] Therefore, the present invention aims to realize a sensor unit with a simple structure that allows for easy assembly work to achieve an easy and reliable conductive connection between the sensor and a circuit board, and to provide a pressure sensor that includes this sensor unit and a method for manufacturing the pressure sensor. [Means for solving the problem]

[0008] One aspect of the invention of a pressure sensor 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 to be interposed between the sensor and the external device and connected to the sensor; and one or both of a connection member located between the sensor and the circuit board and conductively connected to the sensor and the circuit board, and a terminal member for conductively connecting the circuit board to the external device, the connection member and / or the terminal member having a connection area with the circuit board, the connection area having a support area large enough to allow the circuit board to be stably placed thereon, the connection area of ​​the circuit board being located on the support area in a form in which it is placed on the connection member and / or the terminal member, and the structure is configured to allow conductive connection work to be performed between the connection area of ​​the circuit board and the connection area of ​​one or both of the connection members and the terminal members. Effect of the Invention

[0009] Thus, according to one aspect of the present invention, a sensor unit with a simple structure that reliably connects a sensor and a circuit board can be realized, and the sensor unit can be used to provide a pressure sensor as well as a manufacturing method that facilitates assembly work. [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 an exploded perspective view showing an outline of a manufacturing method for the pressure sensor, in which each component is separated in the stacking direction. [Diagram 3] FIG. 3 is a perspective view showing the main components from one direction. [Figure 4] FIG. 4 is a perspective view showing the same main parts as in FIG. 3, but from the opposite direction. [Diagram 5] FIG. 5 is a diagram showing one connection terminal attached to the main components of FIG. 3 and FIG. 4, 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. [Figure 6] FIG. 6 is a diagram showing a connection terminal different from that shown in FIG. 5 attached to the main components of FIGS. 3 and 4, where (a) is an elevated front view, (b) is a top view, (c) is a bottom view, and (d) is a side view. [Figure 7] FIG. 7 is a diagram showing the attachment state of a connection terminal to the main components in FIG. 3 and FIG. 4 and a circuit board, (a) being a longitudinal sectional view, (b) being a perspective view, and (c) being an enlarged perspective view of the connection portion between the circuit board and the connection terminal. [Figure 8] 8A and 8B are diagrams for explaining the connection state of the connection points in FIG. 7, 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 in which the structure is not adopted. [Figure 9]FIG. 9 is a diagram showing a first alternative aspect of this embodiment, in which (a) is a partially enlarged vertical cross-sectional view explaining a problem that may arise in this embodiment, (b) is a partially enlarged vertical cross-sectional view showing a solution pattern for that problem, and (c) is a partially enlarged vertical cross-sectional view showing a solution pattern different from (b). [Figure 10] FIG. 10 is a diagram showing a second alternative aspect of this embodiment, where (a) is a partially enlarged vertical cross-sectional view showing a solution pattern for a problem that may arise in this embodiment, and (b) is a partially enlarged vertical cross-sectional view explaining the problem solved by (a). [Figure 11] FIG. 11 is a diagram showing a third alternative embodiment of the present invention, and is a vertical sectional view showing a schematic overall configuration thereof. [Figure 12] FIG. 12 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 13] FIG. 13 is a vertical cross-sectional view showing a technology prior to the conception of this embodiment. [Figure 14] FIG. 14 is a diagram showing a different concept technology from that shown in FIG. 13, where (a) is a vertical cross-sectional view showing the overall structure, (b) is a partially enlarged vertical cross-sectional view showing the connection state, and (c) is a partially enlarged vertical cross-sectional view showing a connection failure state. 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 8 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 manufacturing method thereof.

[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 include two power terminals, one output signal terminal, and five adjustment terminals used during assembly, 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 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 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 molten metal such as solder S, and for example, an adhesive containing a conductive material may be applied. As described above, in addition to the conductive connection using soldering or a conductive adhesive, the conductive connection may be achieved by welding (for example, spot welding with a laser or the like), and there is no need to limit the welding method in particular.

[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 due to contraction and expansion of the sealing material 26 accompanying 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. Thereafter, 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 and 4, 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 located at both ends facing each other, that is, a U-shape in which a flat portion 36f between the terminal pieces 36d, 36e on both ends extending in a parallel direction of the U-shape is aligned along the outer surface of the terminal holding portion 51 of the terminal block 24, and the terminal pieces 36d, 36e are extended into the side wall portion 24s. The relay connection terminal 37 is similarly formed in a U-shape with a bent piece 37e formed by bending the opposite side of the terminal piece 37d while extending the terminal piece 37d into the side wall portion 24s of the terminal block 24 and aligning a flat connection surface 37f along the outer surface of the terminal holding portion 53. 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 portions 51, 53 are provided with slits 51a, 51b, 53a penetrating the side wall portion (component) 24s of the terminal block 24 so that the terminal pieces 36d, 36e, 37d of the relay connection terminals 36, 37 can be inserted respectively. Recessed portions 51p, 53p are formed on the outer surface of the side wall portion 24s of the terminal block 24 adjacent to the terminal piece 36e and the bent piece 37e of the relay connection terminals 36, 37, and the terminal block 24 and the relay connection terminals 36, 37 are fixed together by the entry of the sealant 26 filled in the waterproof case 20.

[0028] Here, as shown in Fig. 5, the relay connection terminal 36 is made into a set of three relay connection terminals 36A to 36C each having a different shape, and is formed in a shape that is inserted into the inside of the side wall portion 24s of the terminal block 24 in a parallel state in which the interval between the terminal pieces 36e is narrower than that between the terminal pieces 36d. The relay connection terminal 36 is formed in a shape that is parallel and extended with a narrow interval near the center, since the terminal pieces 36e are connected to the lead pins 40 arranged in the same circle around the support 13 in correspondence with the small pressure sensor chip 11. The terminal pieces 36d are connected to the recessed electrode surface 50u of the circuit board 50 described later, but are formed in a shape that is parallel and extended with a wider interval than the terminal pieces 36e, taking into consideration the insulation distance between the adjacent recessed electrode surface 50u and workability such as soldering. As shown in FIG. 5(d), the relay connection terminal 36 is produced by punching out a set of three relay connection terminals 36A-36C while they are integrated with a lead frame 36LF, and then bending the terminal pieces 36d, 36e toward the flat portion 36f.

[0029] 6, the relay connection terminals 37 are made in the same shape for each of the relay connection terminals 37A to 37C, and the terminal piece 37d and the bent piece 37e are bent in the same direction to be inserted into the inside of the side wall portion 24s and the recessed portion 53p of the terminal block 24. The relay connection terminals 37 are formed such that the terminal piece 37d is narrower than the wide connection surface 37f and the bent piece 37e, and are bent in the same direction on both sides to form engagement pieces 37g that are hooked so as to bite into the upper portion of the terminal holding portion 53. In the terminal block 24, the recessed portion 53p into which the bent piece 37e of the relay connection terminal 37 enters is formed in the terminal holding portion 53 of the side wall portion 24s, and the recessed portion 51p into which the terminal piece 36e of the relay connection terminal 36 enters is formed in the terminal holding portion 51 of the side wall portion 24s, forming a slit 51b. Here, the recesses 51p, 53p into which the terminal pieces 36e and bent pieces 37e of the relay connection terminals 36, 37 enter may be fixed by applying a terminal fixing adhesive 26a before filling the waterproof case 20 with the sealant 26. With this configuration, it is possible to prevent the relay connection terminals 36, 37 from falling off or being displaced from the terminal block 24, and it is also possible to prevent the sealant 26 from leaking into the terminal block 24 through extremely small gaps in the slits 51a, 51b, 53a, which are the insertion portions of the terminal pieces 36d, 36e, 37d in the terminal block 24.

[0030] As a result, the relay connection terminal 36 can be attached in a state in which removal is suppressed by inserting the long terminal pieces 36d, 36e into the side wall portion 24s of the terminal block 24 so as to sandwich both outer surfaces of the terminal holding portion 51, and the relay connection terminal 37 can be attached in a state in which removal is suppressed by hooking the engagement piece 37g so as to sandwich the terminal holding portion 53 between the bent pieces 37e even if the bent piece 37e is shorter than the terminal piece 37d. Therefore, the relay connection terminals 36, 37 can be electrically connected by spot welding the terminal piece 36e to the lead pin 40 in a stable position, and the terminal pieces 36d, 37e can be electrically connected to the circuit board 50 by soldering in a stable position.

[0031] 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 portions with plating M to improve the wettability of the solder as in this example, it is clear that the soldering surface may be left in the state of a metal base surface, and a resist, coating, etc. may be provided on the portion that restricts the flow of the solder.

[0032] As shown in Fig. 7, 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 has a recessed wall electrode surface (recessed wall surface) 50u of a connection region that opens to both the front and back sides perpendicular to the plane of the circuit board 50. 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 inwardly of the recessed wall surface semicircular, it is expected that the stress inside the recessed wall surface 50u during the fillet formation by solder will act evenly. Also, in the manufacturing process of circuit board 50, it can be manufactured using the same machining tools as those used for processing mounting holes for mounted components and for processing the outer shape of 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.

[0033] 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.

[0034] 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. 8(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. 8(b). The connection area, which is the soldering point, 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.

[0035] Here, in the case where the technical idea of ​​placing the circuit board 50 on the terminal pieces 36d, 37d of the relay connection terminals 36, 37 and soldering them as in this embodiment cannot be conceived, for example, as shown in FIG. 13, the connection part 136d formed by bending one end of the relay connection terminal 136 is passed through a circular through hole 150h formed in the circuit board 150 and soldered. In such a case, since a connection area must be secured inside the circuit board 150, it is difficult to arrange components on the outer periphery side of the circuit board from the connection area, and therefore the mounting area on the circuit board 150 is also reduced. In addition, the circuit board 150 and its associated components such as terminal blocks and terminal block caps must be enlarged according to the mounted components and circuit layout. In addition, the position of the connection part 136d and the amount of molten solder S attached vary, which reduces the connection quality and workability. Also, there is a risk of so-called "solder balls" being generated when soldering is performed. It is considered that the scattering of these solder balls to undesired places may cause problems such as short circuits in the circuit. To prevent this, in addition to suppressing the occurrence of solder balls by controlling the soldering conditions, it is also possible to mask the circuit board itself to prevent solder balls from adhering to the circuit board and to prevent the solder balls from scattering onto the circuit. By soldering on the outer periphery of the circuit board as in this embodiment, it is possible to reduce the area where solder balls will scatter, and since the circuit board can be masked in a simple manner, it is also effective in suppressing the occurrence of defects.

[0036] Also, normally, it is conceivable to use a structure in which the terminal pieces are placed on the upper surface side of the soldered connection portion formed on the circuit board. In this case, after placing the circuit board on the terminal block, a process of bending the terminal pieces on the upper surface side of the board must be performed. That is, after placing the circuit board on the terminal block, a process of bending the terminal pieces is required, and furthermore, the board and the terminals may not be in close contact due to backlash of the terminal pieces, which may result in defective soldering. Furthermore, even if a step closer to this embodiment is taken and a connection point 151u is formed on the outer peripheral end surface of the circuit board 150 as shown in FIG. 14(a), if the terminal piece 146d of the relay connection terminal 146 is smaller than the connection point 151u, as shown in FIG. 14(b), the formation of the fillet may be insufficient, or as shown in FIG. 14(c), the molten solder S is unstable and cannot maintain the proper position, so that the solder is likely to be fixed (solidified) in an improper position where it is inclined obliquely.

[0037] In this manner, in the pressure sensor unit 10 of the pressure sensor 100 of this embodiment, the terminal pieces 36d, 36e, 37d of the relay connection terminals 36, 37 are inserted into the slits 51a, 51b, 53a of the terminal block 24, the terminal block 24 is placed on the housing 12, the terminal piece 36e is spot welded to the lead pin 40, and then the circuit board 50 is placed on the remaining terminal pieces 36d, 37d, and the recessed electrode surface 50u of the circuit board 50 and the terminal pieces 36d, 37d are soldered together, thereby enabling an assembly operation (manufacturing method) to be performed for connecting the pressure sensor chip 11 to the external device A with high quality.

[0038] Therefore, the pressure sensor chip 11 and the circuit board 50 can be easily assembled with a simple structure to construct a pressure sensor unit 10 with a highly reliable conductive connection, and a pressure sensor 100 equipped with the pressure sensor unit 10 can be provided.

[0039] Here, as a first alternative aspect of this embodiment, as shown in Fig. 9(a), since there is a possibility that the terminal piece 37d of the relay connection terminal 37 may move without resistance in the pull-out direction (reverse penetration direction) if it is merely inserted into the slit 53a of the terminal block 24 in the forward penetration direction, it is advantageous to provide a shape that suppresses the movement by contacting the inner surface of the slit 53a that penetrates the side wall portion (component) 24s of the terminal block 24. For this reason, it is advantageous to form, for example, a protrusion 37p shown in Fig. 9(b) on the surface of the terminal piece 37d of the relay connection terminal 37 so as to be hooked on the inner surface of the slit 53a, or to form a curved shape 37c shown in Fig. 9(b) so as to press the inner surface of the slit 53a.

[0040] Furthermore, as a second alternative aspect of this embodiment, the relay connection terminal 37, in which the terminal piece 37d is inserted into the slit 53a of the terminal block 24 and soldered to the recessed wall electrode surface 50u of the circuit board 50, also needs to solder the core wire C of the lead wire 38 from the external device A to the connection surface 37f. Therefore, as shown by the large arrow in FIG. 10(b), there is a possibility that the solder S that electrically connects the recessed wall electrode surface 50u of the circuit board 50 and the terminal piece 37d during the soldering operation will melt again and flow toward the connection surface 37f. However, by making the base material of the relay connection terminals 36, 37 itself from a conductive material that is less wettable by solder than the plating M, it is possible to more actively and effectively prevent the molten solder from flowing out to areas other than the plating M, as shown by the small arrow in FIG. 10(a).

[0041] As a third alternative embodiment of the present embodiment, as shown in FIG. 11, a male connector 73 having contacts (terminal members) 71 electrically connected to the circuit board 50 may be prepared, and the connector 73 may be easily attached to and detached from a female connector (not shown) from an external device (male and female may be reversed). In this third alternative embodiment, the circuit board 50 is electrically connected via the contacts 71, so that the terminal holding portion 53 may be omitted together with the relay connection terminals 37 and the lead wires 38, and the circuit board 50 may be supported by being placed on the terminal block 24, and the connector 73 is also installed on the terminal block 24 instead of the terminal block cap 25. Here, in this third alternative embodiment, after the contacts 71 are electrically connected to the circuit board 50, the terminal piece 36e of the relay connection terminal 36 is spot-welded to the lead pin 40, and then the terminal piece 36d of the relay connection terminal 36 is soldered to the circuit board 50 and the exterior of the connector 73 is covered to manufacture the connector 73. After this assembly work, the sealant 26 is filled between the waterproof case 20 and the terminal block 24 and the connector 73 .

[0042] 12, in a fourth alternative aspect of this embodiment, instead of the waterproof case 20 in the third alternative aspect described above, a crimping plate 75 is attached to a connector 73. This crimping plate 75 covers the outer periphery of the housing 12 and the terminal block 24 and is crimped to and integrated with a crimping portion 73s of the connector 73 so as to have a certain degree of waterproofing function, thereby making it possible to omit filling with the sealant 26.

[0043] As a fifth alternative embodiment of the present embodiment, although not shown in the drawings, it goes without saying that one of the relay connection terminals 36 and 37 of the present embodiment in Fig. 1 may be used as a common terminal. Specifically, without using the relay connection terminal 37 of the terminal member, the lead wire 38 may be passed through the terminal block cap 25 as a substitute for the terminal member and directly soldered to the circuit board 50 for electrical connection. Alternatively, the relay connection terminal 37 may be left as it is, and without using the relay connection terminal 36 of the connecting member, the lead pin 40 may be extended to reach the circuit board 50 and directly soldered to the circuit board 50 as a substitute for the connecting member for electrical connection.

[0044] 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]

[0045] 10...Pressure sensor unit 11...Pressure sensor chip 24……Terminal block 24b……Bottom part 24h……Through hole 24s……Side wall part 26...Sealing material 26a……Terminal fixing adhesive 30...Joint member 32...Diaphragm 36(36A~36C), 37(37A~37C)……Relay connection terminal 36d, 36e, 37d...Terminal piece 36f……Plane part 37e...bent piece 37f...Connection surface 37c...curved shape 37g……Engagement piece 37p……protrusion 38...Lead wire 40...Lead pin 50...Circuit board 50r……Corner recess 50u……Concave wall electrode surface 51, 53...terminal holding part 51a, 51b, 53a...slits 51p, 53p... hollow 54...Strut shape part 71...Contact 73……Connector 100...Pressure sensor L……Distance of depression 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 connected to the sensor and disposed between the sensor and the external device, and one or both of a connection member located between the sensor and the circuit board and conductively connected to the sensor and the circuit board and a terminal member for conductively connecting the circuit board to the external device and conductively connected to the circuit board, a connection area for connection with the circuit board is formed in one or both of the connection member and the terminal member, and the connection area is provided with a support area large enough to allow the circuit board to be placed thereon; A pressure sensor characterized in that the connection area of ​​the circuit board is positioned on the support area in a form in which it is placed on one or both of the connection member and the terminal member, and is configured in a structure that allows conductive connection work to be performed between the connection area of ​​the circuit board and the connection area of ​​one or both of the connection members and the terminal member.

2. 2. The pressure sensor according to claim 1, wherein the conductive connection between the connection region of the circuit board and one or both of the connection regions of the connection member and the terminal member is achieved by soldering, welding, or application of a conductive material.

3. The connection member is formed in an elongated shape and has one end piece and an other end piece located on both extending ends, The pressure sensor described in claim 1, characterized in that when the one end piece and the other end piece face each other, the connecting member is formed so that the one end piece that constitutes the connection area and is connected to the circuit board is located on the outer periphery of the circuit board, and the other end piece is located inside the outer periphery of the circuit board and can be connected to the sensor side.

4. 2. The pressure sensor according to claim 1, wherein the connection area of ​​one or both of the connection member and the terminal member is located at an outer peripheral edge of the circuit board and is electrically connected thereto.

5. The pressure sensor according to claim 1, characterized in that the circuit board has a recessed wall surface that is recessed inward at its outer peripheral end as the connection area, and the connection areas of the connection member and / or the terminal member are conductively connected to the recessed wall surface.

6. 2. The pressure sensor according to claim 1, wherein the circuit board, the connection member and the connection portion of the terminal member are disposed within a member that forms a space in which fluid communication is blocked.

7. 6. The pressure sensor according to claim 5, wherein the recessed wall surface is formed so that a distance of the recess inward is greater than a width of an opening at the outer peripheral end surface of the circuit board.

8. 6. The pressure sensor according to claim 5, wherein the recessed wall surface has a semicircular shape recessed inward from an outer peripheral end surface of the circuit board.

9. The pressure sensor according to claim 1, characterized in that one or both of the connection member and the terminal member have a connection area having excellent solder wettability, and an area other than the connection area having inferior solder wettability compared to the connection area is formed.

10. a terminal block supporting one or both of the connection member and the terminal member; The connecting member and the terminal member are configured such that terminal pieces extending so as to be electrically connectable penetrate through the constituent parts of the terminal block and are held therein, The pressure sensor as described in claim 1, characterized in that the terminal pieces of both or one of the connecting member and the terminal member are formed with a shape that contacts the inner surface of a structure that penetrates a component of the terminal block, thereby suppressing movement in one or both of the forward penetration direction and the reverse penetration direction.

11. 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, and 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, a connection area for connection with the circuit board is formed in one or both of the connection member and the terminal member, and the connection area is provided with a support area large enough to allow the circuit board to be stably placed thereon; A method for manufacturing a pressure sensor, characterized in that the connection area of ​​the circuit board is positioned on the support area in a form in which it is placed on one or both of the connection member and the terminal member, and a conductive connection operation is performed between the connection area of ​​the circuit board and the connection area of ​​one or both of the connection members and the terminal member.

12. The method for manufacturing a pressure sensor according to claim 11, characterized in that the connection area of ​​the circuit board and the connection area of ​​one or both of the connection members and the terminal members are electrically connected by soldering, welding, or application of a conductive material.

Images