Pressure sensor and method for manufacturing a 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 with a simple structure that can be easily and reliably assembled, and a method for manufacturing the pressure sensor.

Background Art

[0002] Various sensors for detecting pressure, temperature, etc. are used to be fixed near the measurement target and send detection signals to a measuring device or the like, and are frequently used in a form built into or externally attached to the measuring device (see Patent Document 1).

[0003] This type of various sensors is incorporated into a sensor unit that can be installed so as to be exposed to the same environment as the measurement target and used. Not only is the sensor directly connected to the measuring device, but there may also be a need to change the electrical characteristics in one or both of the sensor or external devices.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in such a sensor unit, for example, when the driving voltage for the sensor from an external control device or the specifications of the output signal from the sensor to the external control device are different, not only is it necessary to change the design of the sensor, which takes time and cost, but it is also effective to adjust by interposing a conversion circuit board for the driving voltage or output signal between the sensor.

[0006] In such cases, it is worth considering a sensor unit that employs a circuit configuration with an assembly structure that incorporates a circuit board for converting input and output signals between the sensor and the external device. It is desirable to perform various tasks, such as positioning the circuit board that electrically connects to the sensor in a predetermined location within the sensor unit and making electrical connections, in order to obtain various detection signals with high reliability.

[0007] Therefore, the present invention aims to provide a sensor unit with a simple structure that allows for easy and reliable electrical connection between a sensor and a circuit board, and to provide a pressure sensor equipped with 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 problems is a pressure sensor comprising a sensor unit equipped with a sensor connected to an external device, comprising: a circuit board positioned between the external device and the sensor and connected to the sensor; a connecting member located between the sensor and the circuit board and electrically connected to the sensor and the circuit board; and one or both of a terminal member for electrically connecting the circuit board to the external device and electrically connected to the circuit board, wherein one or both of the connecting member and the terminal member have a connection area with the circuit board, and the connection area is provided with a support area of ​​a size sufficient to stably support the circuit board, and the connection area of ​​the circuit board is positioned on the support area in a manner in which it is placed on one or both of the connecting member and the terminal member, and the structure is configured to enable electrically connecting work between the connection area of ​​the circuit board and the connection areas of one or both of the connecting member and the terminal member. [Effects 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 a pressure sensor and a manufacturing method that allows for easy assembly can be provided with this sensor unit. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a diagram showing a pressure sensor equipped with a pressure sensor unit, which is an example of a sensor unit according to one embodiment of the present invention, and is a longitudinal cross-sectional view showing its schematic overall configuration. [Figure 2] Figure 2 shows an overview of the manufacturing method of the pressure sensor, as well as an exploded perspective view showing the individual components spaced apart in the stacking direction. [Figure 3] Figure 3 is a one-way perspective view showing its main components. [Figure 4] Figure 4 is a perspective view from the opposite direction to Figure 3, showing the same essential components. [Figure 5] Figure 5 shows a single connection terminal attached to the main components of Figures 3 and 4, where (a) is its elevation front view, (b) is its top view, (c) is its bottom view, and (d) is a plan view showing the lead frame of the three components. [Figure 6] Figure 6 shows a different connection terminal from that in Figure 5, which is attached to the main components of Figures 3 and 4, where (a) is its elevation front view, (b) is its top view, (c) is its bottom view, and (d) is its side view. [Figure 7] Figure 7 shows the mounting state of the connection terminals to the circuit board for the main components of Figures 3 and 4, where (a) is a vertical 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 terminals. [Figure 8] Figure 8 illustrates the connection status of the connection points in Figure 7, where (a) is a longitudinal cross-sectional view showing the effect of the structure, and (b) is a longitudinal cross-sectional view showing the case where the structure is not adopted. [Figure 9]Figure 9 shows a first other aspect of this embodiment, where (a) is a partially enlarged longitudinal section view illustrating a potential problem in this embodiment, (b) is a partially enlarged longitudinal section view showing a solution pattern for that problem, and (c) is a partially enlarged longitudinal section view showing a solution pattern different from (b). [Figure 10] Figure 10 shows a second other aspect of this embodiment, where (a) is a partially enlarged longitudinal section view showing a pattern of solving problems that may arise in this embodiment, and (b) is a partially enlarged longitudinal section view illustrating the problem solved in (a). [Figure 11] Figure 11 is a diagram showing a third other aspect of this embodiment, and is a longitudinal cross-sectional view showing its schematic overall configuration. [Figure 12] Figure 12 is a diagram showing a fourth other aspect of this embodiment, and is a longitudinal cross-sectional view showing its schematic overall configuration. [Figure 13] Figure 13 is a longitudinal cross-sectional view showing the technology prior to the conception of this embodiment. [Figure 14] Figure 14 shows a different concept from Figure 13, where (a) is a longitudinal section showing the overall structure, (b) is a partially enlarged longitudinal section showing the connection state, and (c) is a partially enlarged longitudinal section showing the faulty connection. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described in detail below with reference to the drawings. Figures 1 to 8 illustrate a pressure sensor equipped with a pressure sensor unit, which is an example of a sensor unit according to one embodiment of the present invention, and a method for manufacturing the same.

[0012] In FIGS. 1 and 2, the pressure sensor 100 is fabricated such that the pressure sensor unit 10 assembled by stacking components as described later is attached to a target location for measuring the pressure characteristics of the external environment, and the pressure information detected by the pressure sensor chip 11 is output to an external device A to which it is connected. The pressure sensor 100 of the present embodiment is constructed to be connectable by connecting, for example, the pressure sensor unit 10 housed in a resin waterproof case 20 to a pipe to be measured, through which a fluid such as a gas or liquid for detecting pressure is guided, with a metal joint member 30.

[0013] Here, the waterproof case 20 is fabricated in a cylindrical shape capable of housing the pressure sensor unit 10, and the peripheral edge of the cap 28 to which the joint member 30 is fixed is connected to the opening 20b on one end side. The joint member 30 has a female thread 30s formed so as to be screwable to a pipe or the like for pressure measurement, and realizes introducing the fluid supplied from the pipe in the direction of arrow P into the pressure chamber PR on the downstream side of the cap 28 through a port 30a communicating with the female thread 30s.

[0014] The pressure sensor unit 10 includes a housing 12 fabricated in a short cylindrical shape and having its lower end surface in the axial direction joined and fixed to the cap 28, a support column 13 on which the pressure sensor chip 11 is installed and arranged to be located at the center inside the inner cylinder of the housing 12, and a hermetic glass 14 that fills the inside of the inner cylinder of the housing 12 around the support column 13 while closing it and fixes a member passing through the inside of the inner cylinder.

[0015] Also, in the pressure sensor unit 10, a metal diaphragm 32 is joined 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 and isolates the installation space of the pressure sensor chip 11 on the support column 13 side inside the housing 12 from the pressure chamber PR.

[0016] In this pressure sensor unit 10, the space in which the pressure sensor chip 11 is installed, formed by the hermetic glass 14 and the diaphragm 32 inside the inner cylinder of the housing 12, is filled with a predetermined amount of silicone oil (or a fluorine-based inert liquid, etc.) as a pressure transmission medium, thereby functioning 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 joint member 30, as a pressure fluctuation of the pressure transmission medium in the liquid-sealed chamber LR via the diaphragm 32.

[0018] Here, the pressure sensor chip 11 is powered by being electrically connected via bonding wires 11w to lead pins 40 that are connected to each of the multiple lead wires 38 from external device A via a circuit board 50 (described later), and is installed to output a detection signal as pressure information. Furthermore, a pressure transmission medium is filled into the liquid-sealed chamber LR between the hermetic glass 14 and the diaphragm 32 inside the inner cylinder of the housing 12 via an oil-filling pipe 44. These lead pins 40 and oil-filling pipe 44 are aligned at equal intervals in a circular shape around the support column 13 and are supported insulated from the housing 12 via an insulator such as the hermetic glass 14. Note that one end of the oil-filling pipe 44 is closed after the pressure transmission medium has been filled.

[0019] Here, the diaphragm 32 is protected from damage by external forces or sudden pressure changes into the pressure chamber PR by a diaphragm protective cover 34 having multiple communication holes 34a that is joined and fixed to the lower end surface of the housing 12. In addition, a concave frame 16 is fixed to one end of the hermetic glass 14, and a lid-shaped shield plate 17 is attached to it. The frame 16 contains a pressure transmission medium that can flow freely between the pressure sensor tip 11 side and the diaphragm 32 side through communication holes 17a formed in the shield plate 17 to suppress sudden pressure fluctuations.

[0020] The lead pins 40 are electrically connected to the pressure sensor chip 11 via bonding wires 11w, with two power supply terminals, one output signal terminal, and five adjustment terminals used during assembly arranged on the bottom surface 24b of a resin terminal block 24 formed in a short, roughly cylindrical shape with a bottom. These lead pins 40 are inserted into through holes 24h formed in the bottom surface 24b of the terminal block 24 and are fixedly supported by the hermetic glass 14. Here, the terminal block 24 has a roughly cylindrical side wall 24s, part of which is formed in a planar shape, and terminal holding parts 51 and 53 for attaching and holding sets of three relay connection terminals 36 (36A~36C) and 37 (37A~37C), which will be described later, are arranged symmetrically at the center of the cylinder.

[0021] The lead pins 40 have both ends that penetrate both sides of the hermetic glass 14 inside the inner cylinder of the housing 12, and a pressure sensor chip 11 is electrically connected to one end, which is on the liquid-sealing chamber LR side, via a bonding wire 11w. In addition, the terminal pieces 36e of the relay connection terminal 36, which is held on the side wall portion 24s of the terminal block 24, are electrically connected to the end faces of the other ends of the power supply terminal and the output signal terminal, for example, by spot welding (molten metal joining may also be used). Furthermore, on the opposite (facing) side of the relay connection terminal 36 on the side wall portion 24s of the terminal block 24, a relay connection terminal 37 is held, to which a lead wire 38 from an external device A is connected, as will be described later. The terminal pieces 36d and 37d of these relay connection terminals 36 and 37 are connected to the circuit board 50, which is installed by placing it on top of the terminal pieces 36d and 37d, by soldering with molten solder (conductive connection material) S applied. In other words, the relay connection terminal 36 constitutes a connecting member, and the relay connection terminal 37 constitutes a terminal member. Needless to say, the conductive connection material may be not only molten metal such as solder S, but also, for example, an adhesive containing a conductive material. Furthermore, as mentioned above, in addition to conductive connections by soldering or conductive adhesive, conductive connections may also be made by welding (for example, spot welding with a laser, etc.), and there is no particular need to limit the means of welding.

[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, it is equipped with an input / output voltage conversion and adjustment circuit that adjusts the different input and output voltages of the pressure sensor chip 11 and the external device A, for example, by converting the input voltage of the external device A, such as DC12V or DC3.3V, to the operating voltage of the pressure sensor chip 11, DC5V. This type of conversion and adjustment circuit is not limited to this embodiment, and is an arbitrary conversion and adjustment circuit that can accommodate various drive voltages and pressure detection signal signal methods, such as voltage output formats for drive and output voltages different from this embodiment, current output formats such as 2-wire / 3-wire, or digital output formats. Note that these conversion and adjustment circuits are composed of multiple electronic components that are not shown in the figures.

[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 the 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, which has the support column 13 of the pressure sensor chip 11 fixed with hermetic glass 14, it constructs a pressure sensor unit 10. The outer edge of the cap 28 to which the housing 12 and the joint member 30 are connected is welded from the outside by TIG welding, plasma welding, laser welding, etc., to integrate them with the desired joint strength. This pressure sensor unit 10 is housed inside a waterproof case 20 and fixed in place while being waterproofed by filling it with a sealing material 26 such as urethane resin. Here, by placing the circuit board 50 within the installation space SR provided by the terminal block 24 and terminal block cap 25, a layer of air with low thermal conductivity can be formed around the circuit board 50, preventing temperature changes from the pressure sensor and piping from being rapidly transmitted to the circuit board 50. Furthermore, by positioning the circuit board 50 itself, the mounted components 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 ambient temperature changes from acting on the connecting members, mounted components, and especially their soldered parts.

[0024] The pressure sensor unit 10 is assembled by stacking the terminal block 24, circuit board 50, and terminal block cap 25 on top of the housing 12, which is fixed to the cap 28 to which the joint member 30 is connected. The terminal block 24 is assembled by setting the intermediate connection terminals 36 and 37 in the terminal holding parts 51 and 53 of the side wall 24s, then placing it on the housing 12 and spot welding the ends of the lead pins 40 to the terminal pieces 36e of the intermediate connection terminals 36, and then soldering the circuit board 50 onto the terminal pieces 36d and 37d of the intermediate connection terminals 36 and 37 to establish an electrical connection. It goes without saying that the terminal pieces 36e of the intermediate connection terminals 36 may be electrically connected to the end faces of the lead pins 40 not only by spot welding, but also by soldering, crimping, etc. Furthermore, the bottom surface 24b of the terminal block 24 has appropriately positioned holes for insertion, such as a hole 24H for inserting the oil filling pipe 44, which is also provided to facilitate assembly.

[0025] In detail, as shown in Figures 3 and 4, the terminal block 24 is configured to hold the relay connection terminals 36 and 37 by attaching them to terminal holding portions 51 and 53 formed on the side wall portion 24s.

[0026] The relay connection terminal 36 is formed in a long shape, with one end piece (terminal piece) located at both ends facing each other, in a so-called U-shape. The planar portion 36f between the parallel terminal pieces 36d and 36e at both ends is aligned with the outer surface of the terminal holding portion 51 of the terminal block 24, and the terminal pieces 36d and 36e are extended into the side wall portion 24s, thus forming a U-shape. Similarly, the relay connection terminal 37 is formed in a U-shape with the terminal piece 37d extended into the side wall portion 24s of the terminal block 24, with a planar connection surface 37f aligned with the outer surface of the terminal holding portion 53, and a bent piece 37e formed by bending the opposite side of the terminal piece 37d. The core wire C of the lead wire 38 from the external device A is soldered 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 pins 40, relay connection terminals 36 and 37, and the circuit board 50.

[0027] The terminal holding portions 51 and 53 are provided with slits 51a, 51b, and 53a that penetrate the side wall portion (component portion) 24s of the terminal block 24, allowing each terminal piece 36d, 36e, and 37d of the relay connection terminals 36 and 37 to be inserted. Recesses 51p and 53p are formed on the outer surface of the side wall portion 24s of the terminal block 24 adjacent to the terminal pieces 36e and bent pieces 37e of the relay connection terminals 36 and 37, allowing the sealing material 26 filled inside the waterproof case 20 to enter and fix the terminal block 24 and the relay connection terminals 36 and 37.

[0028] Here, as shown in Figure 5, the relay connection terminal 36 is made up of three relay connection terminals 36A to 36C, each with a different shape, and is formed to be inserted into the side wall portion 24s of the terminal block 24 in a parallel state where the spacing between terminal pieces 36e is narrower than that between terminal pieces 36d. Since the terminal piece 36e of this relay connection terminal 36 is connected to lead pins 40 arranged in the same circle around the support column 13 corresponding to a small pressure sensor chip 11, it is formed to be extended in parallel with a narrow spacing that is close to the center. In addition, although the terminal piece 36d is connected to the recessed electrode surface 50u of the circuit board 50 described later, it is formed to be extended in parallel with a wider spacing than the terminal piece 36e, taking into consideration the insulation distance with adjacent recessed electrode surfaces 50u and the workability of soldering, etc. As shown in Figure 5(d), the relay connection terminal 36 is manufactured by punching out a set of three relay connection terminals 36A to 36C integrated into a lead frame 36LF, and then bending the terminal pieces 36d and 36e relative to the flat portion 36f.

[0029] Furthermore, as shown in Figure 6, each of the relay connection terminals 37A to 37C is manufactured to the same shape, and the terminal piece 37d and the bent piece 37e are bent in the same direction and formed to be inserted into the inside of the side wall portion 24s or recess portion 53p of the terminal block 24. In this relay connection terminal 37, the terminal piece 37d is formed to be narrower than the wide connection surface 37f and bent piece 37e, and an engaging piece 37g is formed which is bent in the same direction on both sides to hook into the upper part of the terminal holding portion 53. Similarly, in the terminal block 24, a recess portion 53p is formed in the terminal holding portion 53 of the side wall portion 24s into which the bent piece 37e of the relay connection terminal 37 is inserted, and a recess portion 51p is formed in the terminal holding portion 51 of the side wall portion 24s into which the terminal piece 36e of the relay connection terminal 36 is inserted, forming a slit 51b. Here, the terminal fixing adhesive 26a may be applied to the recesses 51p and 53p into which the terminal pieces 36e and bent pieces 37e of the relay connection terminals 36 and 37 enter, before the sealing material 26 is filled into the waterproof case 20. With this configuration, it is possible to prevent the relay connection terminals 36 and 37 from falling out or shifting position from the terminal block 24, and to prevent the sealing material 26 from leaking into the terminal block 24 through the tiny gaps in the slits 51a, 51b, and 53a, which are the insertion parts of the terminal pieces 36d, 36e, and 37d in the terminal block 24.

[0030] As a result, the relay connection terminal 36 can be installed in a manner that prevents it from being pulled out by inserting the long terminal pieces 36d and 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. Similarly, the relay connection terminal 37 can be installed in a manner that prevents it from being pulled out by hooking the engaging 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 and 37 can be electrically connected by spot welding the terminal piece 36e to the lead pin 40 in a stable position, and can also be electrically connected by soldering the terminal pieces 36d and 37e to the circuit board 50 in a stable position.

[0031] These intermediate connection terminals 36 and 37 are plated M on the terminal pieces 36d and 37d to be soldered and the connection surface 37f to improve the wettability of molten solder, thereby reducing the occurrence of connection failures with the electrode surface 50u of the circuit board 50 described later and enabling conductive connection. In addition, the adjacent area of ​​the connection surface 37f of the intermediate connection terminal 37 is also plated M to improve the wettability of the solder when soldering to the core wire C of the lead wire 38, thereby reducing the occurrence of connection failures. Here, the intermediate connection terminals 36 and 37 are plated M only in the area necessary for soldering, and not in other areas, so the flow of molten solder is suppressed. In addition to providing areas to improve solder wettability by plating M as in this example, it is clear that the soldering surface may be left in the state of a metal substrate surface, and resists, coatings, etc. may be applied to areas that restrict solder flow.

[0032] As shown in Figure 7, the outer peripheral end faces of the circuit board 50 at the locations corresponding to the terminal pieces 36d and 37d of the relay connection terminals 36 and 37 are recessed in a U-shape inward, parallel to the plane of the circuit board 50, forming a recessed electrode surface (recessed wall surface) 50u of the connection area that opens to both the front and back sides perpendicular to the plane of the circuit board 50. This recessed electrode surface 50u is formed by a semicircular recess extending inward from the outer peripheral end face of the circuit board 50 by a distance L, and the inner surface is plated M, which has excellent solder wettability. In other words, the recessed electrode surface 50u is formed as an oval notch shape with a depth L extending inward from the outer peripheral end face of the circuit board 50. By making the inward recess of this recessed wall surface semicircular, it is expected that the stress inside the recessed wall surface 50u during fillet formation by solder will act evenly. Furthermore, in the manufacturing process of the circuit board 50, the same processing tools can be used for machining the mounting holes for the mounted components and for machining the outer shape of the circuit board 50. A rectangular shape would require separate processes and tools, such as machining with a disc-shaped cutter, so a semi-circular shape offers advantages in terms of productivity and quality.

[0033] In contrast, the terminal pieces 36d and 37d of the relay connection terminals 36 and 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 column-shaped parts 54 formed on the inner surface of the side wall part 24s that 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 and 37d of the relay connection terminals 36 and 37 function as support areas that support the vicinity of the recessed electrode surface 50u of the circuit board 50. In this embodiment, recessed electrode surfaces 50u are formed in the connection areas of both circuit boards 50 that connect to the terminal pieces 36d and 37d of the relay connection terminals 36 and 37. However, this is not the only option; the connection may be made using the outer peripheral end surfaces of the circuit boards 50 without forming the recessed electrode surfaces 50u, or the recessed electrode surfaces 50u may be formed on only one of the two sides. However, forming them on both sides is preferable in terms of ease of connection and reliability.

[0034] As a result, as shown in Figure 8(a), the circuit board 50 is held in a stable position, resting on the terminal pieces 36d and 37d of the relay connection terminals 36 and 37 and positioned on the support column portion 54 of the terminal block 24. The concave wall electrode surface 50u is reliably electrically connected to the terminal pieces 36d and 37d by solder S, which has a stable shape with a larger capacity and sufficient fillet height than the semicircular concave wall electrode surface 50u' shown in Figure 8(b). Since the connection area where soldering takes place is on the back side of the circuit board 50, it is not possible to directly visually confirm the connection area. However, as in this embodiment, by visually inspecting or using image recognition to manage the state of the fillet inside the concave wall portion 50u, it is possible to determine whether or not soldering has been performed correctly. The circuit board 50 also has an insertion hole 50H through which an oil filling pipe 44 is inserted during assembly.

[0035] Here, if the technical idea of ​​placing the circuit board 50 on the terminal pieces 36d and 37d of the relay connection terminals 36 and 37 and soldering them together, as in this embodiment, cannot be conceived, then for example, as shown in Figure 13, the connection portion 136d, formed by bending one end of the relay connection terminal 136, would be passed through the through-hole 150h of the circular hole formed in the circuit board 150 and soldered. In such a case, since the connection area must be secured inside the circuit board 150, it is difficult to place components on the outer periphery of the circuit board beyond the connection area, and the mounting area on the circuit board 150 is reduced. In addition, the circuit board 150 and related components such as terminal blocks and terminal block caps also need to be enlarged to match the mounted components and circuit layout. Furthermore, the position of the connection portion 136d and the amount of molten solder S attached may vary, reducing connection quality and workability. Alternatively, there is a risk of so-called "solder balls" being generated during soldering. The scattering of these solder balls to undesirable locations may cause malfunctions such as short circuits. To address this issue, in addition to suppressing the generation of solder balls themselves by adjusting soldering conditions, it is also conceivable to apply a mask to the circuit board itself to prevent solder ball adhesion and guard against the scattering of solder balls onto the circuit. By performing soldering on the outer edge of the circuit board as in this embodiment, it is possible to reduce the area over which solder balls scatter, and a mask can be applied to the circuit board in a simple manner, thus also having the effect of suppressing the occurrence of defects.

[0036] Furthermore, under normal circumstances, a structure would be considered in which the terminal piece is placed on the upper side of the soldered connection portion formed on the circuit board. In this case, after the circuit board is placed on the terminal block, the terminal piece must be bent towards the upper surface of the board. That is, after the circuit board is placed on the terminal block, the process of bending the terminal piece is required, and furthermore, due to backlash of the terminal piece, the board and the terminal may not make close contact, which may lead to soldering defects. Moreover, even if we take a step closer to this embodiment, for example, as shown in Figure 14(a), and form a connection point 151u on the outer peripheral end surface of the circuit board 150, if the terminal piece 146d of the relay connection terminal 146 is smaller than the connection point 151u, as shown in Figure 14(b), the fillet formation may be insufficient, or as shown in Figure 14(c), the molten solder S may be unstable and unable to maintain the proper position, making it highly likely that it will be fixed (solidified) in an improper position, tilted at an angle.

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

[0038] Therefore, a pressure sensor unit 10 can be constructed by easily assembling the pressure sensor chip 11 and the circuit board 50 with a simple structure and ensuring reliable electrical connection, and a pressure sensor 100 equipped with this pressure sensor unit 10 can be provided.

[0039] Herein, in the first other aspect of this embodiment, as shown in Figure 9(a), if the terminal piece 37d of the relay connection terminal 37 is simply inserted into the slit 53a of the terminal block 24 in the forward direction of penetration, it may move without resistance in the pulling direction (reverse direction of penetration). Therefore, it is advantageous to provide a shape that contacts the inner surface of the slit 53a that penetrates the side wall portion (component portion) 24s of the terminal block 24 to suppress movement. For this reason, it is advantageous to form a projection 37p as shown in Figure 9(b) on the surface of the terminal piece 37d of the relay connection terminal 37 so as to catch on the inner surface of the slit 53a, or to form a curved shape 37c as shown in Figure 9(b) so as to press against the inner surface of the slit 53a.

[0040] Furthermore, in a second other aspect of this embodiment, the intermediate connection terminal 37, which is soldered to the recessed electrode surface 50u of the circuit board 50 by inserting the terminal piece 37d into the slit 53a of the terminal block 24, also requires the core wire C of the lead wire 38 from the external device A to be soldered to the connection surface 37f. As shown by the large arrow in Figure 10(b), there is a possibility that the solder S that electrically connects the recessed electrode surface 50u of the circuit board 50 and the terminal piece 37d may remelt and flow to the connection surface 37f during the soldering process. However, by making the base material of the intermediate connection terminals 36 and 37 from a conductive material that has inferior solder wettability to the plating M, as shown by the small arrow in Figure 10(a), it is possible to more actively and effectively suppress the outflow of molten solder to areas other than the plating M.

[0041] Furthermore, in a third other aspect of this embodiment, as shown in Figure 11, a male-type connector 73 equipped with contacts (terminal members) 71 electrically connected to the circuit board 50 may be prepared, and the connector 73 can be easily attached to and detached (connected / disconnected) from an external device (not shown) by a female-type connector (male and female may be reversed). In this third other aspect, since the circuit board 50 is electrically connected via the contacts 71, the terminal holding part 53, along with the relay connection terminal 37 and lead wires 38, can be omitted and the circuit board 50 can be mounted and supported on the terminal block 24, and the connector 73 can also be installed on the terminal block 24 instead of the terminal block cap 25. Here, in this third other aspect, after electrically connecting the contacts 71 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 casing of the connector 73 is placed over it to assemble and manufacture. After this assembly process, a sealing material 26 is filled between the terminal block 24 and the connector 73 between the waterproof case 20 and the other components.

[0042] Furthermore, in a fourth other aspect of this embodiment, as shown in Figure 12, a crimping plate 75 is attached to the connector 73 instead of the waterproof case 20 in the third other aspect described above. This crimping plate 75 is crimped and integrated with the crimping portion 73s of the connector 73 to cover the outer circumference of the housing 12 and terminal block 24 and have a certain degree of waterproof function, thereby creating a structure that eliminates the need to fill the sealing material 26.

[0043] Furthermore, as a fifth other aspect of this embodiment, although not shown in the illustration, it goes without saying that one of the relay connection terminals 36 and 37 of this embodiment in Figure 1 may be used for all connections. Specifically, instead of using the relay connection terminal 37 of the terminal member, the lead wire 38 may be passed through the terminal block cap 25 and directly soldered to the circuit board 50 to establish a conductive connection. Alternatively, the relay connection terminal 37 may be left as is, and instead of using the relay connection terminal 36 of the connection member, the lead pin 40 may be extended to reach the circuit board 50 and directly soldered to the circuit board 50 to establish a conductive connection.

[0044] The scope of the present invention is not limited to the illustrative and described exemplary embodiments, but also includes all embodiments that produce effects equivalent to those aimed at by the invention. Furthermore, the scope of the invention is not limited to the combination of features of the invention specified by each claim, but can be defined by any desired combination of each of the disclosed specific features. [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... Adhesive for fixing terminals 30... Joint member 32... Diaphragm 36 (36A~36C), 37 (37A~37C)... Relay connection terminals 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 concave part 50u……Concave wall electrode surface 51, 53...terminal holding part 51a, 51b, 53a... slits Pages 51, 53... recessed area 54...Strut shape part 71... Contact 73... Connector 100... Pressure sensor L...Distance from the indentation M...plating S... Conductive connection material SR……Installation space

Claims

1. A pressure sensor comprising a sensor unit equipped with a sensor connected to an external device, The system comprises a circuit board positioned between the external device and the sensor and connected to the sensor, and both a connecting member located between the sensor and the circuit board and electrically connected to the sensor and the circuit board, and a terminal member electrically connected to the circuit board for electrically connecting the circuit board to the external device, Both the connecting member and the terminal member have a connection area formed with the circuit board, and the connection area is provided with a support area of ​​sufficient size to support the circuit board. The support regions of both the connecting member and the terminal member are arranged on both sides of the center of gravity of the circuit board, and the connection regions of the stacked circuit boards are formed to extend in a direction intersecting the stacking direction so that they can be placed on both the connecting member and the terminal member, thereby positioning the connection regions of the circuit boards on the support regions, and the structure is configured to enable conductive connection work between the connection regions of the circuit boards and the connection regions of both the connecting member and the terminal member.

2. The pressure sensor according to claim 1, characterized in that the electrical connection between the connection area of ​​the circuit board and the connection areas of both the connection member and the terminal member is performed by soldering, welding, or application of a conductive material.

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

4. The pressure sensor according to claim 1, characterized in that the connection regions of both the connecting member and the terminal member are located at the outer peripheral end of the circuit board and are electrically connected.

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, which is formed as the connection area, and the connection areas of both the connection member and the terminal member are electrically connected to the recessed wall surface.

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

7. The pressure sensor according to claim 5, characterized in that the recessed wall surface is formed such that the inward recess distance is greater than the opening width at the outer peripheral end surface of the circuit board.

8. The pressure sensor according to claim 5, characterized in that the concave wall surface has a semicircular shape that is recessed inward from the outer peripheral end surface of the circuit board.

9. The pressure sensor according to claim 1, characterized in that both the connecting member and the terminal member have a connection region that has excellent solder wettability, and regions other than the connection region have inferior solder wettability to the connection region.

10. The terminal block includes a terminal block that supports one or both of the connecting member and the terminal member, The connecting member and the terminal member are configured such that the terminal piece, which is electrically connectable and extended, penetrates and is held within the components of the terminal block. The pressure sensor according to claim 1, characterized in that the terminal piece of either or both of the connecting member and the terminal member has a shape formed on it that contacts the inner surface of a structure that penetrates the components of the terminal block and suppresses movement in either or both of the forward and reverse directions of penetration.

11. A method for manufacturing a pressure sensor comprising a sensor unit equipped with a sensor connected to an external device, The sensor unit comprises a circuit board positioned between it and the external device and connected to the sensor, and both a connecting member located between the sensor and the circuit board and electrically connected to the sensor and the circuit board, and a terminal member electrically connected to the circuit board for electrically connecting the circuit board to the external device. Both the connecting member and the terminal member have a connection area formed with the circuit board, and the connection area is provided with a support area of ​​sufficient size to stably support the circuit board. A method for manufacturing a pressure sensor, characterized in that the support regions of both the connecting member and the terminal member are arranged on both sides of the center of gravity of the circuit board, and the connection regions of the stacked circuit boards are formed in such a way that they extend in a direction intersecting the stacking direction so that they can be placed on both the connecting member and the terminal member, thereby positioning the connection regions of the circuit boards on the support regions, and performing conductive connection work between the connection regions of the circuit boards and the connection regions of both the connecting member 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 areas of one or both of the connection member and the terminal member are electrically connected by soldering, welding, or application of a conductive material.

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