pressure sensor

Abstract

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

Description

Technical Field

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

Background Art

[0002] Various sensors for detecting pressure, temperature, etc. are used by being fixed near the measurement object and sending a detection signal to a measuring device or the like, and are frequently used in a form built-in 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 object, and the sensor unit includes a terminal block that holds terminals for electrically connecting to the installed sensors, and the detection signal of the sensor can be utilized by connecting a measuring device to the terminals.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Since this type of various sensors is exposed to the external environment, temperature changes in the surrounding environment, or temperature changes in the fluid transmitted through the pipe due to the operation and stop of the installed device may repeatedly act on the sensor unit.

[0006] For example, as shown in Figure 18(a), in a sensor unit 10 in which a circuit board 50 for adjusting various electrical signals is installed in front of the sensor 11, mechanical stress is repeatedly applied to the joint between the circuit board 50 and terminal pieces 36d and 37d due to the difference in the coefficient of thermal expansion between the soldering and the terminal block 24, as shown by the black and white arrows in Figure 18(b). If such stress is applied over a long period of time, there is a risk that the quality of the joint will deteriorate, such as cracks in the soldered joint or peeling of the wiring pattern at the soldered part. Note that, in the pressure sensor 100 shown in Figure 18, the same reference numerals are used for components common to the embodiments described below, in order to aid in understanding.

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

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

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

[0010] Therefore, it is possible to realize a sensor unit with a simple structure that allows assembly work to be performed while suppressing the influence of mechanical stress caused by differences in the coefficient of linear expansion of the internal components of the pressure sensor in response to changes in ambient or fluid temperature, and to provide a pressure sensor equipped with such a sensor unit. [Brief explanation of the drawing]

[0011] [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, where (a) is an exploded perspective view from above with the components spaced apart in the stacking direction, and (b) is a perspective view from below of one of the components. [Figure 3] Figure 3 is a one-way perspective view showing its main components. [Figure 4] Figure 4 shows a single connection terminal attached to the main component of Figure 3, 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 5] Figure 5 shows a different connection terminal from that in Figure 4, which is attached to the main component in Figure 3, where (a) is its elevation front view, (b) is its top view, (c) is its bottom view, and (d) is its side view. [Figure 6] Figure 6 shows the mounting state of the connection terminals for the main components of Figure 3, where (a) is a vertical cross-sectional view and (b) is a top view. [Figure 7]Figure 7 illustrates the mounting state of the connection terminals in Figure 6, where (a) is a perspective view of one connection terminal from one direction and a perspective view of the other connection terminal from a different direction, and (b) is a top view of both connection terminals. [Figure 8] Figure 8 shows the mounting state of the connection terminals to the main components of Figure 3 and the circuit board, 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 9] Figure 9 illustrates the connection status of the connection points in Figure 8, 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 10] Figure 10 illustrates the effects of this embodiment, where (a) is an enlarged longitudinal cross-sectional view under no mechanical stress, (b) is an enlarged longitudinal cross-sectional view under load where it is pushed toward the circuit board, and (c) is an enlarged longitudinal cross-sectional view under load where it is pulled toward the circuit board. [Figure 11] Figure 11 is a diagram showing a first other aspect of this embodiment, and is a partially enlarged longitudinal cross-sectional view thereof. [Figure 12] Figure 12 shows a second other embodiment of this embodiment, where (a) is a partially enlarged longitudinal section view showing one embodiment, (b) is a partially enlarged longitudinal section view showing an embodiment different from (a), and (c) is a partially enlarged longitudinal section view showing an embodiment different from (a) and (b). [Figure 13] Figure 13 is a diagram showing a second further embodiment of this embodiment, where (a) to (d) are partially enlarged longitudinal cross-sectional views showing different embodiments, including Figures 12(a) to 12(c). [Figure 14] Figure 14 is a diagram showing a third other aspect of this embodiment, and is a partially enlarged longitudinal cross-sectional view thereof. [Figure 15] Figure 15 is a diagram showing a fourth other aspect of this embodiment, and is a partially enlarged longitudinal cross-sectional view thereof. [Figure 16] Figure 16 is a diagram showing a fifth other aspect of this embodiment, and is a longitudinal cross-sectional view showing its schematic overall configuration. [Figure 17]FIG. 17 is a view showing a sixth other aspect of the present embodiment, and is a longitudinal sectional view showing the overall schematic configuration thereof. [Figure 18] FIG. 18 is a longitudinal sectional view showing the technology before the idea of the present embodiment.

Embodiments for Carrying Out the Invention

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

[0013] In FIGS. 1 and 2, a pressure sensor 100 is manufactured by attaching a pressure sensor unit 10 assembled by stacking components as described later to a target location for measuring the pressure characteristics of the external environment, and outputting the pressure information detected by a pressure sensor chip 11 to an external device A to which it is connected. The pressure sensor 100 of the present embodiment is constructed so as 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 a liquid for detecting pressure is guided, by a metal joint member 30.

[0014] Here, the waterproof case 20 is manufactured in a cylindrical shape capable of housing the pressure sensor unit 10, and the peripheral edge of a cap 28 to which the joint member 30 is fixed is connected to an opening 20b on one end side. The joint member 30 has a female thread 30s formed so as to be screwed onto a pipe or the like for pressure measurement, and through a port 30a communicating with the female thread 30s, it realizes introducing the fluid supplied from the pipe in the direction of arrow P into a pressure chamber PR on the downstream side of the cap 28.

[0015] The pressure sensor unit 10 comprises a housing 12 manufactured in a short cylindrical shape with its axial lower end surface joined and fixed to a cap 28, a support column 13 on which a pressure sensor chip 11 is installed and positioned at the center of the inner cylinder of the housing 12, and hermetic glass 14 that fills and seals the area around the support column 13 inside the inner cylinder of the housing 12, while also fixing a member that penetrates the inner cylinder.

[0016] Furthermore, 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, while isolating the installation space for the pressure sensor chip 11 on the support column 13 side inside the housing 12 from the pressure chamber PR.

[0017] 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.

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

[0019] Here, the pressure sensor chip 11 is powered by a bonding wire 11w, which connects to lead pins 40 that are connected to each of the multiple lead wires 38 from the 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 the 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.

[0020] 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.

[0021] The lead pins 40 are electrically connected to the pressure sensor chip 11 via bonding wires 11w, with two power 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 that 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. This terminal block 24 is bonded to the upper end surface of the housing 12 with a silicone adhesive. Furthermore, a coating layer 14a made of a silicone-based adhesive is formed to a predetermined thickness on the entire upper end surface of the hermetic glass 14 from which the lead pin 40 protrudes. The coating layer may also be made of an adhesive such as epoxy resin.

[0022] 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 the 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 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 24s of the terminal block 24, a relay connection terminal 37 is held, to which lead wires 38 from an external device A are 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 terminals, by soldering with molten solder (conductive connection material) S applied. That is, the relay connection terminal 36 constitutes a connecting member, and the relay connection terminal 37 constitutes a terminal member. It goes without saying that the conductive connection material can be not only molten metal such as solder S, but also, for example, an adhesive containing a conductive material.

[0023] Here, the circuit board 50 is interposed between the pressure sensor chip 11 and the external device A and functions as 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 signal methods of pressure detection signals, such as different drive types, voltage output formats of output voltages, current output formats such as 2-wire / 3-wire, or digital output formats. These conversion and adjustment circuits are composed of multiple electronic components that are not shown in the figures.

[0024] 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 installation space SR for the lead pins 40, the terminal pieces 36d, 36e, 37d of the relay connection terminals 36, 37 and the circuit board 50, and together with the housing 12, which has the support column 13 of the pressure sensor chip 11 fixed with hermetic glass 14, it constructs a pressure sensor unit 10. This pressure sensor unit 10 is integrated with the outer peripheral edge of the cap 28 to which the housing 12 and the joint member 30 are connected by TIG welding, plasma welding, laser welding, etc., to achieve 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, the terminal block 24 and terminal block cap 25 can form an air layer with low thermal conductivity around the circuit board 50 by closing the installation space SR, thereby preventing temperature changes from the area around the pressure sensor and piping from being rapidly transmitted to the circuit board 50. Furthermore, by arranging 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 changes in ambient temperature from acting on the connecting members, mounted components, and especially their soldered parts.

[0025] 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 can 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.

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

[0027] 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 positioned parallel to 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. The relay connection terminal 37 is similarly formed in a U-shape, with the terminal piece 37d extended into the side wall portion 24s of the terminal block 24, and the planar connection surface 37f aligned parallel to the outer surface of the terminal holding portion 53, and the opposite end of the terminal piece 37d bent into a bent piece 37e. 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.

[0028] The terminal holding portion 51 has multiple inner wall portions 55 facing each other, with a groove 55g interposed between them, which is a fixing groove for securing the relay connection terminal 36, on the inside of the side wall portion 24s of the terminal block 24. The upper surfaces of each of these inner wall portions 55 are formed at the same height. Similarly, the terminal holding portion 53 has a single inner wall portion 56 facing each other, with a groove 56g interposed between it, which is a fixing groove for securing the relay connection terminal 37, on the inside of the side wall portion 24s of the terminal block 24. Between these inner wall portions 55 and 56, a pair of inner wall portions 57 are formed, with a groove 57g interposed between them, on the inside of the side wall portion 24s. In other words, grooves 55g to 57g are formed in a continuous manner between the side wall portion 24s and the inner wall portions 55 to 57 of the terminal block 24.

[0029] The terminal holding portion 51 is designed to position the terminal pieces 36e of each relay connection terminal 36A to 36C by inserting them into the bottom surface of the three slits 55s located between the four inner wall portions 55 facing the side wall portion 24s of the terminal block 24. In this state, the flat portions 36f of the relay connection terminals 36A to 36C, which are formed to be larger than the slits 55s, are in contact with the side wall portion 24s side of the inner wall portion 55, and the terminal pieces 36d of the three relay connection terminals 36A to 36C are folded back at a position on the same plane so as to be in contact with the upper surface of the inner wall portion 55. The relay connection terminals 36A to 36C are provided with projections (fixing portions) 36h and 36i that extend in the planar direction of the flat portion 36f at locations adjacent to the terminal piece 36e on the flat portion 36f. Furthermore, insertion grooves 55h for projections 36h and 36i are formed on the bottom surface of the groove 55g between the side wall portion 24s and the side wall 55 of the terminal block 24. By inserting the projections 36h and 36i into these insertion grooves 55h, the intermediate connection terminals 36A to 36C are maintained in an upright position. With this structure of the terminal holding part 51, the terminal pieces 36e of the intermediate connection terminals 36A to 36C can be inserted and assembled from above, which is the open end of the terminal block 24, so as to fit into the groove 55g and slit 55s; in other words, this structure forms the fixing part. Note that the projection 36i is omitted from the illustration in Figure 2 and is shown in Figure 4.

[0030] The relay connection terminal 36 is manufactured as a set of three relay connection terminals 36A to 36C, each with a different shape. The terminal pieces 36d and 36e are bent perpendicular to the flat surface 36f, and the terminal piece 36e is formed to extend parallel to the bottom surface 24b of the terminal block 24 in a parallel configuration with a narrower spacing than the terminal piece 36d. In detail, the relay connection terminal 36 is formed so that the terminal piece 36e connects to lead pins 40 arranged at equal intervals in a circular shape around the support column 13, corresponding to a small pressure sensor chip 11, and is therefore formed to extend in parallel with a narrow spacing, closer to the center. The terminal piece 36d connects to a circuit board 50 whose spacing can be set to any desired interval, and is therefore formed to extend in parallel with a wider spacing than the terminal piece 36e to facilitate connection work. As shown in Figure 4(d), the relay connection terminal 36 is formed 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 toward the flat portion 36f and protruding pieces 36h and 36i, respectively. In addition, the slit 55s of the inner wall portion 55 is open from the groove 55g to the bottom surface 24b of the terminal block 24. When the terminal fixing adhesive 26g described later is injected into the groove 55g to fix the relay connection terminal 36, the back side of the flat portion 36f (the outer side of the terminal block 24) receives the terminal fixing adhesive 26g, preventing the terminal fixing adhesive 26g from leaking toward the bottom surface 24b of the terminal block 24.

[0031] The terminal holding portion 53 has slits 53a and 53b formed on its upper and lower sides, which penetrate the side wall portion 24s of the terminal block 24, allowing the terminal piece 37d and the bent piece 37e of the relay connection terminal 37 to be inserted. The terminal holding portion 53 is positioned such that the terminal piece 37d and the bent piece (intersecting portion) 37e pass through the slits 53a and 53b in the side wall portion 24s of the terminal block 24, cross the inner groove 56g, and then come into contact with the upper surface of the inner wall portion 56 or the bottom surface of the groove 56g.

[0032] Due to this structure, each intermediate connection terminal 37 is manufactured to the same shape for each intermediate connection terminal 37A to 37C, and the terminal piece 37d and the bent piece 37e are formed by bending them in the same direction perpendicular to the connection surface 37f so as to contact the upper and lower surfaces of the terminal holding portion 53. The terminal piece 37d is formed in a shape that allows the circuit board 50 to be placed in the side wall portion 24s of the terminal block 24 through the slit 35a. In this intermediate connection terminal 37, the terminal piece 37d and the bent piece 37e are formed to be narrow relative to the wide connection surface 37f, and engaging pieces 37g are formed on both sides of the terminal piece 37d so as to be bent in the same direction and hook into the upper surface of the terminal holding portion 53. Note that these engaging pieces 37g may be omitted if fixing with the terminal fixing adhesive 26g described later is sufficient.

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

[0034] Therefore, the relay connection terminals 36 and 37 can be positioned in grooves 55g and 56g of the terminal block 24, with a depth such that the terminal piece 36e and the bent piece (fixing part) 37e penetrate the side wall portion 24s of the terminal block 24 and are positioned in a direction in which the circuit board 50 is placed on top of the inner wall portions 55 and 56. These relay connection terminals 36 and 37 can be positioned and fixed by injecting terminal fixing adhesive 26g into the grooves 55g and 56g. Since the grooves 55g and 56g formed by the inner wall portions 55 and 56 are continuous on both sides of the groove 57g between the side wall portion 24s and the inner wall portion 57, a procedure (manufacturing method) can be easily performed to complete the fixing work by inserting a dispenser into the wide groove 57g and injecting the terminal fixing adhesive 26g (see Figure 6). Subsequently, 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 the circuit board 50 placed on the terminal pieces 36d and 37d can be electrically connected by soldering them in a stable position. Here, the terminal block 24 has a flat surface 29 formed on the inner surface of the arc-shaped side wall portion 24s facing the inner wall portion 57. This engages with the projection 25a on the lower surface of the terminal block cap 25, and when the terminal block cap 25 is placed on the terminal block 24, it functions to prevent horizontal displacement and rotation of the terminal block cap 25. By placing the terminal block 24 and the terminal block cap 25 in close contact, when the sealing material 26 is filled around the terminal block 24 and the terminal block cap 25, leakage of the sealing material 26 into the inside of the terminal block 24 can be prevented.

[0035] These intermediate connection terminals 36 and 37 are manufactured to enable conductive connections with reduced connection failures by applying plating M to the terminal pieces 36d and 37d to be soldered and the connection surface 37f, thereby improving the wettability of molten solder. Plating M is also applied to adjacent areas of the connection surface 37f of the intermediate connection terminal 37 to suppress the detachment of the conductive wire C of the soldered connection line 38. Here, the intermediate connection terminals 36 and 37 are plated M only in the areas 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 with plating M as in this example, the soldering surface may be left as a metal substrate surface, and resists, coatings, etc. may be applied to areas where solder flow is restricted.

[0036] As shown in Figure 8, the circuit board 50 has a U-shaped recess at the outer periphery of the terminal pieces 36d and 37d of the relay connection terminals 36 and 37, which is parallel to the plane of the circuit board 50. This recess forms a recessed electrode surface (concave wall surface) 50u of the connection area, which opens on both the front and back sides perpendicular to the plane of the circuit board 50 and functions as a connection position. This recessed electrode surface 50u is formed by a semicircular recess extending inward from the outer periphery of the circuit board 50 by a distance L, allowing molten solder to easily penetrate the entire surface. The inner surface is plated M, which has excellent solder wettability. In other words, the recessed electrode surface 50u is formed as an oval-shaped notch with a depth L extending inward from the outer periphery of the circuit board 50. By making the inward recess of this recessed surface semicircular, it is expected that the stress inside the recessed surface 50u during fillet formation by solder will act evenly. Uniform stress distribution improves resistance to defects such as poor conductivity due to cracks in the solder joint caused by repeated heating and cooling cycles applied to the pressure sensor, resulting in a highly reliable connection. 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 shaping the circuit board 50's outer form. A rectangular shape requires 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.

[0037] 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.

[0038] As a result, as shown in Figure 9(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 recessed 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 recessed electrode surface 50u' shown in Figure 9(b). Since the connection area, which is the soldering point, 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 recessed wall portion 50u, it is possible to determine whether or not the 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.

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

[0040] Specifically, even if the difference in the coefficients of linear expansion between the terminal block 24 and the circuit board 50 causes a difference in the amount of expansion and contraction between them due to temperature changes, the intermediate connection terminal 36 can elastically deform in a direction that allows the circuit board 50 to swing and expand relative to the inner wall portion 55 in a direction parallel to the bottom surface portion 24b of the terminal block 24, as shown in Figures 10(b) and 10(c). In other words, a part of the intermediate connection terminal 36 (the deformed portion) can return to a direction that separates from or enters the notch 58. Therefore, the notch 58 in the inner wall portion 55 can function as an adjustment part to prevent mechanical stress from being applied to the joint portion of the solder S that electrically connects the terminal pieces 36d, 37d of the intermediate connection terminals 36, 37 and the circuit board 50, thereby preventing a decrease in joint quality such as cracks in the solder joint or poor conductivity due to peeling of the circuit pattern around the recessed wall portion 50u of the circuit board 50.

[0041] Thus, in the pressure sensor unit 10 of the pressure sensor 100 of this embodiment, the relay connection terminal 36 can elastically deform using the notch 58 of its inner wall portion 55 to create a separation distance from the groove 55g side of the inner wall portion 55 of the terminal block 24 to the recessed wall electrode surface 50u of the circuit board 50. Even if mechanical stress is generated between the solder joint S of the relay connection terminal 36 and the circuit board circuit 50 due to the difference in the coefficient of linear expansion of the terminal block 24 and the circuit board 50 caused by changes in ambient temperature, the relay connection terminal 36 is structured to allow expansion and contraction in the direction of approaching and separating from the circuit board circuit 50, thus preventing excessive stress from acting between the joint.

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

[0043] Incidentally, as shown in Figure 18 above, when the terminal holding portions 51 and 53 formed on the side wall portion 24s of the terminal block 24 are U-shaped and the intermediate connection terminals 136 and 37 are inserted from the outside, the terminal block 24 must be tilted on its side and the terminal fixing adhesive 26a injected into the grooves opening on the underside of the terminal holding portions 51 and 53 of the side wall portion 24s must be performed at least twice. In contrast, in this embodiment, the formation of the terminal fixing adhesive 26g can be completed simply and quickly in a single injection operation while the terminal block 24 is in an upright position, and the positioning accuracy of the intermediate connection terminals 36 and 37, which would decrease when the terminal block is tilted on its side, can be avoided.

[0044] In a first other embodiment of this design, as shown in Figure 11, the projections 36h and 36i of the relay connection terminal 36 installed in the terminal holding portion 51 may be extended to form projections 36he and 36ie, which are then deeply inserted into the bottom of the groove 55g of the terminal block 24 to position and fix it. This eliminates the need for the terminal fixing adhesive 26g used to fix the relay connection terminal 36 in the terminal holding portion 51 by injecting and solidifying it into the groove 55g of the terminal block 24. Alternatively, instead of the terminal fixing adhesive 26g, the position of the recess in the coating layer 14a that fixes the terminal block 24 to the hermetic glass 14 can be moved below the groove 55g, and the coating layer 14g can be injected and solidified to position and fix the relay connection terminal 36 together with the terminal block 24 itself.

[0045] In a second other aspect of this embodiment, as shown in Figure 18, instead of the relay connection terminal 136 which is inserted into the terminal holding portion 51 from the outer surface side of the terminal block 24, a relay connection terminal 66 having a deformable portion described later, which allows the separation distance between the terminal piece 36d and the recessed wall electrode surface 50u of the circuit board 50 to be adjusted by extending or contracting in the separation direction, may be installed on the flat portion 36f side of the terminal piece 36d 36f, as shown in Figure 12. This allows the deformable portion of the relay connection terminal 66 to deform in response to the mechanical stress between the terminal holding portion 51 and the circuit board 50, thereby achieving the same effect as the oscillation of the relay connection terminal 36 due to the notch 58 in the inner wall portion 55 of this embodiment, and avoids the deterioration of the joint quality due to mechanical stress being applied to the solder S that electrically connects the terminal pieces 36d, 37d of the relay connection terminals 36, 37 and the circuit board 50.

[0046] Specifically, for example, a deformed portion 66r with a corrugated cross-section as shown in Figure 12(a) and a deformed portion 66f with a curved cross-section as shown in Figure 12(b) may be formed on the flat portion 36f side of the terminal piece 36d to allow for easy adjustment of the separation distance. Furthermore, as shown in Figure 12(c), instead of an intermediate connection terminal 66 that changes the height from the bottom portion 24b of the terminal block 24 (the length in the cylindrical axis direction of the terminal block 24) on the flat portion 36f side of the terminal piece 36d and the concave wall electrode surface 50u side of the circuit board 50, the separation distance may be easily adjusted. That is, the intermediate connection terminal 66 shown in Figure 12(c) allows for adjustment of the separation distance between the concave wall electrode surface 50u side of the circuit board 50, which is offset in the cylindrical axis direction of the terminal block 24 (the direction intersecting the planar direction of the circuit board 50), and the groove 55g side of the inner wall portion 55 of the terminal block 24.

[0047] In this second alternative embodiment, the relay connection terminal 66 may be replaced with the shape shown in Figure 13, and a deformed portion 66q having a regular polygon or irregularly shaped opening (a quadrilateral is shown) may be formed on the planar portion 36f side of the terminal piece 36d (Figure 13(a)), and a flat plate-shaped deformed portion 66s may be formed to connect the terminal piece 36d in a narrow, linear manner (Figure 13(b)), similarly a flat plate-shaped deformed portion 66i may be formed to connect in a narrow, inclined shape (Figure 13(c)), and similarly a flat plate-shaped deformed portion 66t may be formed to connect in a narrow, meandering shape (Figure 13(d)), thereby making it possible to adjust the separation distance from the recessed wall electrode surface 50u of the circuit board 50.

[0048] It goes without saying that these relay connection terminals 66 can be applied to relay connection terminals 37 which are installed by inserting them into the terminal holding portion 53 shown in Figure 18 from the outer side of the terminal block 24 and positioning and fixing them with terminal fixing adhesive 26a.

[0049] In a third aspect of this embodiment, instead of the terminal block cap 25 attached to the upper opening side of the terminal block 24, which includes the terminal holding portion 53 and the intermediate connection terminal 136 that is inserted into the terminal holding portion 51 shown in Figure 18 from the outer surface side of the terminal block 24 and positioned and fixed with terminal fixing adhesive 26a, an upper cap 65 shown in Figure 14 may be attached, and a notch 68 may be formed on the outer surface side of the terminal holding portion 51. Specifically, the upper cap 65 covers at least from the outer circumference of the terminal block 24 to the upper surface of the housing 12, thereby preventing the sealing material 26 filled in the waterproof case 20 from directly contacting the terminal block 24 and the intermediate terminal connection terminal 136, and allowing the intermediate connection terminal 136 to swing radially in the terminal block 24, as shown in Figures 10a and 10b (swinging (deformation adjustment) in the direction away from the notch 68 is ensured in the space secured by the upper cap 65). Furthermore, the notch 68 on the outer surface of the terminal holding portion 51 allows the relay connection terminal 136 to swing significantly in the radial direction of the terminal block 24. As a result, in this third other embodiment, similar to the swinging of the relay connection terminal 36 due to the notch 58 of the inner wall portion 55 in this embodiment, the portion of the relay connection terminal 136 corresponding to the notch 68 (deformed portion) can easily deform and swing, thereby avoiding the application of mechanical stress to the solder joint portion that electrically connects the terminal pieces 36d, 37d of the relay connection terminals 136, 37 and the circuit board 50, which would otherwise degrade the quality of the joint.

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

[0051] In a fourth aspect of this embodiment, an elastic material 69 installed by cutting out the upper outer surface of the terminal holding portion 51 shown in Figure 18 covers and holds the relay connection terminal 136, thereby allowing the relay connection terminal 136 to swing significantly at the holding portion (deformed portion) in the radial direction of the terminal block 24 (the direction of adjustment of the spacing interval described above) by utilizing the elastic deformation of the elastic material 69 (Figure 15). This makes it possible to avoid a decrease in the quality of the solder joint that is applied to the joint portion of the solder S that electrically connects the terminal pieces 36d, 37d of the relay connection terminals 136, 37 and the circuit board 50, similar to the swing of the relay connection terminal 36 due to the notch 58 of the inner wall portion 55 in this embodiment.

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

[0053] Although not shown in the diagram here, it goes without saying that the structures of the terminal holding parts 51 and 53 and the relay connection terminals 36 and 37 in this embodiment may be swapped, or they may be unified into one of the structures and made common.

[0054] For example, in a fifth other embodiment of this design, as shown in Figure 16, the lead wires 38 may be used as terminal members, passing through the terminal block 25 and directly soldered to the circuit board 50 to establish electrical connection, without using the intermediate connection terminals 37 of the terminal members. In this fifth other embodiment, the omission of the intermediate connection terminals 37 releases the support and fixing, allowing the circuit board 50 to be held slidably along with the deformation of the lead wires 38, and the relative positional relationship with the terminal block 24 can be adjusted. In this fifth other embodiment, the lead wires 38 are electrically connected to the circuit board 50 in advance, the terminal piece 36e of the intermediate connection terminal 36 is spot-welded to the lead pin 40, and then the circuit board 50 to which the lead wires 38 are connected is placed on the terminal piece 36d of the intermediate connection terminal 36, the placement portion is soldered, and the terminal block cap 25 is placed over it for assembly. After this assembly work, a sealing material 26 is filled between the waterproof case 20 and the terminal block 24 and terminal block cap 25.

[0055] Furthermore, in a sixth other embodiment of this design, as shown in Figure 17, the relay connection terminal 37 may be left as is (although it may have the same adjustment function as the relay connection terminal 36), and the lead pin 40 may be directly soldered to the circuit board 50 as a connecting member without using the relay connection terminal 36 of the connecting member. In this sixth other embodiment, the support fixing is released by omitting the relay connection terminal 36, allowing the circuit board 50 to be held slidably and the relative positional relationship with the terminal block 24 to be adjusted.

[0056] 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]

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

Claims

1. A pressure sensor 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, a connecting member positioned 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, and a terminal block that fixes and positions and supports both the connecting member and the terminal member, 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 are formed in such a way that the connection regions of the stacked circuit boards are extended 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 enabling conductive connection work between the connection regions of the circuit boards and the connection regions of both the connecting member and the terminal member. It has an adjustment unit that adjusts the relative positional relationship of at least one of the connecting member, the terminal member, and the terminal block with respect to the circuit board, The pressure sensor is characterized in that the adjustment unit is configured to allow the support regions of both the connecting member and the terminal member to move in the extending direction of the circuit board.

2. The pressure sensor according to claim 1, characterized in that the adjustment unit adjusts the separation distance between the support positions of the connecting member and the terminal member on the terminal block and the connection positions of the connecting member and the terminal member to the circuit board.

3. The pressure sensor according to claim 2, wherein the adjustment portion includes a deformation portion that, at the support position, deforms so that at least a part of one or both of the connecting member and the terminal member can be adjusted in the direction of separation from the connection position.

4. The pressure sensor according to claim 3, characterized in that the adjustment section has a space that allows deformation of the deformation section to adjust the separation distance with respect to the connection position.

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

6. The pressure sensor according to claim 5, characterized in that the adjustment portion is covered by a member that forms a space that allows deformation in a direction away from the recess of the deformable portion.

7. The pressure sensor according to claim 3, wherein the adjustment section comprises an elastic material that positions and holds the deformable section at the support position, and the elastic material is elastically deformed to allow deformation of the deformable section in a direction that adjusts the separation distance between the support position and the connection position.

8. The pressure sensor according to claim 3, characterized in that the deformable portion deforms to extend or contract in the direction of separation between the support position and the connection position, between the support position and the connection position.

9. The pressure sensor according to claim 8, characterized in that the deformed portion has a corrugated cross-sectional shape in the direction of separation between the support position and the connection position.

10. The pressure sensor according to claim 8, characterized in that the deformed portion has a curved cross-sectional shape in the direction of separation between the support position and the connection position.

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

12. The pressure sensor according to claim 8, characterized in that the deformable portion is located between the support position and the connection position which are offset in a direction intersecting the planar direction of the circuit board, and is deformable so as to be able to adjust the separation distance between the support position and the connection position in the planar direction of the circuit board.

13. The pressure sensor according to claim 1, characterized in that the adjustment unit is configured such that the holding position of the circuit board with respect to the terminal block is slidable, and the relative positional relationship of the terminal block with respect to the circuit board is adjusted.

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