Signal conversion device and pressure sensor

Abstract

A signal conversion device according to the present invention is characterized by being provided with a signal conversion unit having a conversion substrate for adjusting a signal input from the outside and adjusting a signal to the outside via a connection terminal, and a heat-generating device mounted on the conversion substrate, the conversion substrate is provided with a through hole through which a lead wire of the heat generating device is inserted, and the through hole is provided corresponding to a lead wire other than a lead wire selected so as to reduce the arrangement density of the plurality of lead wires from among the plurality of lead wires.

Description

Technical Field

[0001] The present invention relates to a signal conversion device having a conversion substrate and a pressure sensor in which the conversion substrate is arranged. Background Art

[0002] Nowadays, in order to adapt to various drive voltages and pressure detection signal formats, there is a pressure sensor in which a conversion substrate having a conversion circuit for converting both the drive voltage and the pressure detection signal is externally connected between a control circuit and a pressure sensor.

[0003] In such pressure sensors, to address potential connection problems caused by external shock, vibration, and other factors, cables are sometimes omitted and a converter substrate is placed inside the pressure sensor. Furthermore, to increase margin for the collector loss of the transistor package, this converter substrate employs lead-type transistors, which offer greater tolerance to heat generation, rather than surface-mount components. These leads are inserted through through-holes in the converter substrate and secured at their tips by soldering.

[0004] Patent Document 1, as shown in FIG1 , describes a lead pin 31 as having a structure similar to that of a conversion substrate and the lead pins inserted and fixed to the conversion substrate. One end of the lead pin 31 is inserted through a pin insertion hole 231A of a base body 231 and an insertion hole 8A of a heat spreader 8, while the other end extends through a substrate 41 and is fixed to the heat spreader 8 and substrate 41 by soldering. Pressure sensors with external conversion substrates, various other sensors connected to the conversion substrate, and controllers also have a similar structure with respect to the conversion substrate and lead pins.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 5931004 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] However, the structure described in Patent Document 1, due to the high density of the multiple lead pins, raises the concern that if the substrate absorbs moisture, short circuits may occur between the through-holes in the substrate through which the multiple lead pins are inserted. Specifically, when the density of the multiple lead pins is high, the distance between the individual lead pins is small, and short circuits may occur due to ion migration (CAF) that can occur between the insertion holes (vias).

[0010] An object of the present invention is to provide a signal conversion device and a pressure sensor capable of preventing ion migration from occurring between through-holes of a conversion substrate that has absorbed moisture.

[0011] Solutions to Problems

[0012] In order to solve the above-mentioned problems, the signal conversion device is characterized in that it includes a signal conversion unit, the signal conversion unit having a conversion substrate and a heating element mounted on the above-mentioned conversion substrate, the above-mentioned conversion substrate adjusts the signal input from the outside and adjusts the signal between the outside and the outside via the connection terminal.

[0013] The conversion substrate includes through-holes for inserting leads of the heat generating device, and the through-holes are provided corresponding to leads other than leads selected from the plurality of leads so as to reduce arrangement density of the plurality of leads.

[0014] Furthermore, in the signal conversion device, the plurality of leads may be arranged in a row, and some of the leads may be selected so that the arrangement density of the plurality of leads is reduced.

[0015] Furthermore, in the signal conversion device, the plurality of leads may be arranged in a row, and the leads may be selected at equal intervals among the plurality of leads.

[0016] Furthermore, in the signal conversion device, the plurality of leads may be arranged in a row, and leads other than leads at both ends may be selected from the plurality of leads.

[0017] Furthermore, in the signal conversion device, the lead wires selected from the plurality of leads may be bent and bonded to pads on the conversion substrate, and the remaining leads may be inserted through the conversion substrate.

[0018] Furthermore, in the signal conversion device, the plurality of leads may be three, the selected lead may be a central lead, and the central lead may be bent into an L-shape and bonded to a pad on the conversion substrate.

[0019] Furthermore, in the signal conversion device, the plurality of leads may be three, the selected leads may be two leads at both ends, and the two leads at both ends may be bent into an L-shape and bonded to pads on the conversion substrate.

[0020] Furthermore, in the signal conversion device, the leads selected from the plurality of leads may be bonded to pads on the conversion substrate, and the remaining leads may be bent and inserted through the conversion substrate.

[0021] To solve the above-mentioned problems, a pressure sensor is characterized by comprising: a pressure detecting portion having a pressure chamber, a semiconductor sensor chip for detecting the pressure of a fluid introduced into the pressure chamber, and lead pins connected to the semiconductor sensor chip and constituting external input / output terminals of the semiconductor sensor chip; and a signal sending portion having a connector housing, connecting terminals, a conversion substrate, and a heating element, wherein the connector housing is adjacent to the pressure detecting portion and defines a partition wall between a substrate housing portion, a connector connecting portion, and between the substrate housing portion and the connector connecting portion; the connecting terminals are used for connecting signals to the outside; the conversion substrate is housed in the substrate housing portion and adjusts signals between the pressure detecting portion and the lead pins and between the substrate housing portion and the connector connecting portion; the heating element is mounted on the conversion substrate and fixed to the connector housing with a heat-dissipating adhesive; the conversion substrate has through-holes for inserting leads of the heating element, the through-holes being provided corresponding to leads other than leads selected from the plurality of leads so as to reduce the arrangement density of the plurality of leads.

[0022] The effects of the invention are as follows.

[0023] According to the present invention, it is possible to provide a signal conversion device and a pressure sensor capable of preventing ion migration between through holes caused by moisture absorption of a conversion substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a cross-sectional view showing a pressure sensor according to an embodiment of the present invention.

[0025] 2 is a schematic diagram showing a transistor of a pressure sensor according to an embodiment of the present invention. FIG. 2( a ) is a front view showing the transistor, and FIG. 2( b ) is a side view showing the transistor.

[0026] 3 is a schematic front view showing a state in which a transistor of the pressure sensor according to the embodiment of the present invention is soldered to a converter substrate.

[0027] 4 is a plan view of a converter substrate of the pressure sensor according to the embodiment of the present invention as viewed from the main body side.

[0028] 5 is a schematic diagram showing a pressure sensor body according to an embodiment of the present invention. FIG5( a ) is a perspective view of the pressure sensor body according to the embodiment of the present invention, and FIG5( b ) is a plan view of the pressure sensor body according to the embodiment of the present invention.

[0029] Figure 6 is a schematic stereoscopic diagram showing a situation in which a transistor of a pressure sensor according to multiple embodiments of the present invention is soldered to a conversion substrate. Figure 6 (a) is a schematic stereoscopic diagram showing an embodiment in which the transistor is perpendicular to the conversion substrate, Figure 6 (b) is a schematic stereoscopic diagram showing another embodiment in which the transistor is perpendicular to the conversion substrate, Figure 6 (c) is a schematic stereoscopic diagram showing an embodiment in which the transistor is parallel to the conversion substrate, and Figure 6 (d) is a schematic stereoscopic diagram showing another embodiment in which the transistor is parallel to the conversion substrate. DETAILED DESCRIPTION

[0030] An embodiment of the present invention will be described in detail with reference to Figures 1 to 5. In this embodiment, a multi-layered conversion substrate is described, but the present invention is not limited to this embodiment and may also be a single-layered single-sided substrate or double-sided substrate.

[0031] <Terms>

[0032] In the description of this specification and claims, “one end” and “the other end” mean the “lower end” and “upper end” in the drawings.

[0033] Pressure sensor structure

[0034] A pressure sensor 100 according to an embodiment of the present invention will be described using FIG. 1 .

[0035] The pressure sensor 100 consists of a fluid inlet 110, a pressure sensing unit 120, a signal transmission unit (main body) 130, and a connecting member 140. The following describes each component of the pressure sensor 100 in sequence. The pressure sensor 100 is assembled integrally with the fluid inlet 110, pressure sensing unit 120, and signal transmission unit 130 by means of the connecting member 140 after the fluid inlet 110 and pressure sensing unit 120 are joined and fixed, and the pressure sensing unit 120 and signal transmission unit 130 are electrically connected.

[0036] <Fluid inlet section>

[0037] The fluid introduction portion 110 introduces a fluid whose pressure is to be detected into a pressure chamber 112A described below, and includes a metal joint member 111 and a metal base plate 112 connected to the other end of the joint member 111 by welding or the like.

[0038] The joint component 111 includes an internally threaded portion 111a for connection to a pipe (not shown) that introduces the fluid whose pressure is to be detected, and a port 111b that guides the fluid introduced from the pipe into the pressure chamber 112A. The open end of the port 111b is connected to an opening in the center of the base plate 112 by welding or other means. In this embodiment, the joint component 111 includes the internally threaded portion 111a, but this is not limiting. For example, the joint component 111 may also include an externally threaded portion, allowing connection to a copper connection pipe in place of the joint component 111.

[0039] The base plate 112 has a bowl shape that expands in diameter from one end toward the other end in the radial direction relative to the central axis C of the pressure sensor 100 , and forms a pressure chamber 112A between the base plate 112 and a diaphragm 122 described below.

[0040] <Pressure detection unit>

[0041] The pressure sensing unit 120 detects the pressure of the fluid in the pressure chamber 112A and includes a housing 121 having a through-hole, a diaphragm 122 that divides the pressure chamber 112A described above and a liquid seal chamber 124A (described below), and a protective cover 123 disposed on the pressure chamber 112A side of the diaphragm 122. Furthermore, the pressure sensing unit 120 includes a sealing glass 124 that seals the interior of the through-hole in the housing 121, a liquid seal chamber 124A filled with oil between a recessed portion of the sealing glass 124 on the pressure chamber 112A side and the diaphragm 122, and a support 125 disposed in the center of the sealing glass 124. Furthermore, the pressure sensing unit 120 includes a semiconductor sensor chip 126 supported by the support 125 and disposed within the liquid seal chamber 124A, a potential adjustment member 127 disposed around the liquid seal chamber 124A, a plurality of lead pins 128 secured to the sealing glass 124, and an oil filling tube 129 secured to the sealing glass 124.

[0042] To ensure strength around the sealing glass 124, the housing 121 is formed from a metal material, such as an Fe-Ni (iron-nickel) alloy or stainless steel. The diaphragm 122 and protective cover 123 are both formed from a metal material and welded to the outer periphery of the through-hole on the pressure chamber 112A side of the housing 121. The protective cover 123 is positioned within the pressure chamber 112A to protect the diaphragm 122 and is provided with a plurality of communication holes 123a for the passage of fluid introduced from the fluid inlet 110. After the pressure detection unit 120 is assembled, the housing 121 is welded from the outside to the outer periphery of the base plate 112 of the fluid inlet 110 by TIG welding (non-metallic inert gas arc welding), plasma welding, laser welding, or other methods.

[0043] Sealing glass 124 is provided to protect liquid-sealed chamber 124A, where semiconductor sensor chip 126 is sealed, from ambient environmental conditions such as moisture, dust, and heat in the air. It also holds multiple lead pins 128 and insulates lead pins 128 from housing 121. A support 125, located in the center of sealing glass 124, supports semiconductor sensor chip 126 on the liquid-sealed chamber 124A side with adhesive or the like. In this embodiment, support 125 is formed of an Fe-Ni alloy, but this is not limiting. For example, it may be formed of another metal material such as stainless steel, or it may be omitted and directly supported by the flat surface forming the recess of sealing glass 124.

[0044] Semiconductor sensor chip 126 includes integrated circuits such as a diaphragm made of a material exhibiting a piezoresistive effect (e.g., single-crystal silicon), a bridge circuit that connects multiple semiconductor strain gauges formed on the diaphragm, an amplifier circuit that processes the output from the bridge circuit, and a processing circuit. Furthermore, semiconductor sensor chip 126 is connected to multiple lead pins 128 via bonding wires 126a, such as gold or aluminum. These lead pins 128 constitute the external input / output terminals of semiconductor sensor chip 126.

[0045] Potential adjustment member 127 is provided to place semiconductor sensor chip 126 in an electric field-free (zero potential) environment, protecting the chip's internal circuits from potentials generated between the frame ground and the secondary power supply. Potential adjustment member 127 is positioned between semiconductor sensor chip 126 and diaphragm 122 within liquid seal chamber 124A. Formed from a conductive material such as metal, potential adjustment member 127 is connected to the zero potential terminal of semiconductor sensor chip 126.

[0046] A plurality of lead pins 128 and an oil filling tube 129 are fixed to the sealing glass 124 in a penetrating manner by a sealing process. In this embodiment, eight lead pins 128 are provided. Specifically, three lead pins 128 are provided for external output (Vout), drive voltage supply (Vcc), and ground (GND), and five lead pins 128 serve as adjustment terminals for the semiconductor sensor chip 126. FIG1 shows four of the eight lead pins 128.

[0047] The oil filling tube 129 is provided for filling and sealing oil (eg, silicone oil or fluorine-based inert liquid) into the liquid seal chamber 124A. After the oil is filled, the other end of the oil filling tube 129 is compressed and sealed as shown in FIG1 .

[0048] <Operation of the pressure detection unit>

[0049] The operation of pressure detection unit 120 will be described. First, diaphragm 122 is pressed by fluid introduced into pressure chamber 112A from connector member 111. The pressure in pressure chamber 112A applied to diaphragm 122 is transmitted to semiconductor sensor chip 126 via the sealed oil in liquid seal chamber 124A. The silicon diaphragm of semiconductor sensor chip 126 deforms in response to this transmitted pressure, and a bridge circuit of piezoresistive elements converts the pressure into an electrical signal. This signal is then output from the integrated circuit of semiconductor sensor chip 126 via bonding wires 126a and multiple lead pins 128 to signal transmission unit 130.

[0050] <Signal sending unit>

[0051] The signal transmission unit (main body) 130 transmits the pressure signal detected by the pressure detection unit 120 to the outside. It includes a connector housing 131 for external connection, located adjacent to the other end of the pressure detection unit 120, and a flexible connector 132, one end of which is connected to a plurality of lead pins 128. Furthermore, the signal transmission unit 130 includes a conversion substrate 133 secured to the connector housing 131 via three connection terminals, and the aforementioned connection terminals 134a-c, one end of which is connected through the conversion substrate 133. Furthermore, an opening 133f is formed in the conversion substrate 133 to prevent interference with the oil filling tube 129. Furthermore, the conversion substrate 133 is provided with three through-holes 134t for inserting the connection terminals 134a-c, as well as two through-holes 133t for inserting the leads 133l1 and 133l3 of a lead-type heating element 133h (described below).

[0052] Connector housing 131 is formed from a resin or other insulating material with high thermal conductivity. It includes a substrate housing 131a with a concave shape at one end, a connector connection portion 131b with a concave shape at the other end for connection to an external connector (not shown), and a partition wall 131c disposed between substrate housing 131a and connector connection 131b. Within the internal space S defined by substrate housing 131a are located a plurality of lead pins 128 extending from the sealing glass 124, an oil filling tube 129, a flexible connector 132, and a converter substrate 133.

[0053] The conversion substrate 133 includes a conversion circuit (not shown) that converts both the driving voltage and the pressure detection signal to accommodate the signal formats of the driving voltage and the pressure detection signal. This conversion circuit comprises a step-down circuit portion (not shown) that steps down the driving voltage (e.g., 8V to 36V) from a control circuit (not shown) connected to the outside of the pressure sensor 100 via connection terminals 134a-c to the driving voltage (e.g., 5.0V) for the semiconductor sensor chip 126, and a voltage shift circuit portion (not shown) that steps up the pressure detection signal (e.g., 0.5V to 4.5V) from the pressure sensor 100 to the pressure detection signal (e.g., 1V to 5V) for the control circuit. By appropriately selecting the conversion substrate 133 within the pressure sensor 100 to accommodate the signal formats of the driving voltage and the pressure detection signal, the difference between the driving voltage and the pressure detection signal can be absorbed without requiring any design changes to the pressure detection unit 120, particularly the semiconductor sensor chip 126, and the surrounding structures of the liquid seal chamber 124A.

[0054] At least three connection terminals 134a-c are provided: for external output (Vout), for driving voltage supply (Vcc), and for grounding (GND). To improve assembly efficiency, for example, in the case of connection terminal 134a, one end 134d of connection terminal 134a is inserted through a through-hole provided in the conversion substrate 133 and soldered to the through-hole, thereby connecting connection terminal 134a to the conversion substrate 133. A pad 133n is formed on the connection portion of the conversion substrate 133, electrically connected to electrode 135 via a conductive pattern. Meanwhile, the other end of connection terminal 134a extends through bulkhead 131c toward connector connection 131b. The through-holes of bulkhead 131c through which connection terminals 134a-c penetrate are sealed with connection terminal fixing adhesive 134g.

[0055] In addition, although the above-mentioned embodiment is related to the pressure detection part 120 and the signal sending part 130 of the pressure sensor 100, the present invention can also be applied to a signal conversion device having a signal conversion part other than a pressure sensor. The signal conversion part has a conversion substrate and a heating device installed on the above-mentioned conversion substrate. The conversion substrate adjusts the signals input from the outside such as various sensors and controllers, and adjusts the signals between the connection terminals and the outside.

[0056] <Connecting parts>

[0057] The connection member 140 includes a caulking plate 141 for connecting and fixing the fluid introduction unit 110 , the pressure detection unit 120 , and the signal transmission unit 130 by caulking, and an adhesive sheet 142 disposed between the pressure detection unit 120 and the signal transmission unit 130 .

[0058] The rivet plate 141 is formed into a cylindrical shape from a metal such as copper. It is positioned around the fluid inlet 110, pressure sensing unit 120, and signal transmitter 130 and secured to the fluid inlet 110 and signal transmitter 130 via rivets. To achieve waterproof and dustproof functionality, an adhesive sheet 142 is sandwiched between the pressure sensing unit 120 and signal transmitter 130 via this rivet. Furthermore, as a means of suppressing heat transfer from the converter substrate 133, a heat-radiating non-metallic resin sheet 151 and a heat-radiating adhesive 152 may be sandwiched between the adhesive sheet 142 and the housing 121.

[0059] <Conversion substrate heat dissipation unit>

[0060] The conversion substrate 133 has a second end surface 133b, which is mounted on various electronic components and separated from the connector housing 131, and a first end surface 133a, which is used for soldering connection terminals 134a-c. In this embodiment, the heat-generating device 133h (e.g., a transistor, a regulator, or other device with a potential difference between its input and output terminals and a current flowing therebetween) is a lead-type device mounted on the second end surface 133b. Since the conversion substrate 133 generates heat due to, for example, the transformation of the driving voltage, there is a risk that the electronic components on the conversion substrate will exceed their heat-resistant temperature and be damaged if no countermeasures are taken. Therefore, in this embodiment, various heat dissipation mechanisms within the conversion substrate 133 are employed to prevent the electronic components on the conversion substrate 133 from exceeding their heat-resistant temperature. This allows heat generated within the conversion substrate 133 to be efficiently dissipated to the external environment, thereby improving the heat-resistant temperature tolerance of the conversion substrate 133. The heat dissipation mechanism of the conversion substrate 133 in this embodiment will be described in detail below.

[0061] <Conversion substrate heat dissipation unit (lead-type heating element)>

[0062] As a heat dissipation unit for the conversion substrate 133, a lead-type heating element 133h is used, as shown in the heat dissipation path indicated by the dotted line (1) in FIG1 . The lead-type heating element 133h is provided on the substrate facing surface 131a1 side. Since the periphery of the heating element 133h is filled with a heat-dissipating adhesive 133g having thermal conductivity, an adhesive storage wall 131w is provided to define an adhesive storage area 131e between the adhesive storage wall 131w and the outer periphery of the connector housing 131 in order to prevent the heat-dissipating adhesive 133g from spreading onto the conversion substrate. That is, in this embodiment, the adhesive storage area 131e is defined by the adhesive storage wall 131w, the substrate storage portion 131a of the main body 130, and the partition wall 131c. The lead-type heating element 133h is housed in the adhesive reservoir 131e, and a heat-dissipating adhesive 133g having thermal conductivity is filled only between the adhesive reservoir 131e and the lead-type heating element 133h. Thus, in this embodiment, heat generated in the heating element 133h is actively transferred to the heat-dissipating adhesive 133g having thermal conductivity surrounding the heating element 133h, thereby efficiently dissipating heat to the external environment via the connector housing 131.

[0063] Furthermore, a cutout 133k is provided in a portion of the conversion substrate 133 where there is a concern that heat-dissipating adhesive 133g may creep up along the adhesive reservoir wall 131w due to surface tension. This increases the distance between the conversion substrate 133 and the inner wall of the main body 130, preventing heat-dissipating adhesive 133g that swells and spreads in a direction perpendicular to the direction adjacent to the signal transmission unit 130 and the pressure detection unit 120 from creeping up along the adhesive reservoir wall 131w due to surface tension. Furthermore, by providing the cutout 133k up to the vicinity of the pad 133n of the conversion substrate 133, even if heat-dissipating adhesive 133g overflows in a direction perpendicular to the direction adjacent to the signal transmission unit 130 and the pressure detection unit 120 and drips onto the substrate, it prevents the heat-dissipating adhesive 133g from adhering to the pad 133n.

[0064] Furthermore, the lead-type heating element 133h is mounted on the conversion substrate 133 via the leads 133l1 to 133l3 , so that the heat generating portion of the heating element 133h is physically separated from the conversion substrate 133 , thereby preventing the electronic components of the conversion substrate 133 from exceeding the heatproof temperature.

[0065] Here, the lead wire type heating element 133h is provided on the outer diameter side of the connector housing 131 to be close to the outside air. Therefore, the heat dissipating adhesive 133g filled around the lead wire type heating element 133h can dissipate heat to the outside of the connector housing 131 more easily.

[0066] Furthermore, by providing a space between the heat dissipating adhesive 133 g filling the periphery of the lead-type heating element 133 h and the conversion substrate 133 , heat transfer between the heating element 133 h and the conversion substrate 133 can be suppressed.

[0067] <Lead structure of lead-type heating devices>

[0068] FIG2(a) shows a front view of a lead-type heating element 133h according to this embodiment, and FIG2(b) shows a side view of the lead-type heating element 133h according to this embodiment. FIG3 is a schematic front view of the lead-type heating element 133h according to this embodiment, mounted and soldered on a conversion substrate 133. FIG4 is a top view of the conversion substrate 133 as viewed from the direction of the signal sending unit 130. FIG5(a) is a perspective view of the main body 130 after the conversion substrate 133 is installed therein, and FIG5(b) is a top view of the main body of FIG5(a) as viewed from the side of the conversion substrate 133. FIG5(a) shows a portion of the connector housing 131 cut away so that the interior of the main body can be seen.

[0069] In this embodiment, as shown in Figures 2(a) and 2(b), a lead-type heating element 133h mounted on a conversion substrate 133 has a central lead 133l2 of three leads 133l1 to 133l3 arranged in a row bent into an L-shape. Furthermore, as shown in Figure 3, only the leads 133l1 and 133l3 at either end of the lead-type heating element 133h are inserted through two through-holes 133t provided in the conversion substrate 133, with their tips soldered to the ends. Meanwhile, the L-shaped lead 133l2 is soldered to a pad 133p provided on one end of the conversion substrate 133. Here, as shown in Figure 4, regarding the pad 133p where the L-shaped lead 133l2 is placed and soldered, copper foil is hidden under the resist at both ends of the soldered portion of the L-shaped lead 133l2 to prevent it from peeling due to the load on the lead 133l2 in the tilting direction. Furthermore, as shown in Figures 5(a) and 5(b), in this embodiment, compared to a case where all leads 133l1-133l3 in a row of heat generating device 133h are inserted through the through holes, the center lead 133l2 in the row of leads 133l1-133l3 is not inserted through the through holes. This reduces the density of through holes when viewed from above. As a result, the distance between through holes on the conversion substrate 133 when viewed from above can be increased. This can suppress the occurrence of ion migration (CAF) between the two through holes. Furthermore, when soldering the lead-type heating element 133h after surface mounting on the conversion substrate 133, there is no need to dehumidify the conversion substrate 133 to prevent CAF. Furthermore, since space can be saved and CAF countermeasures can be taken, product miniaturization can be achieved.

[0070] Here, as described above, the distance between the through holes on the conversion substrate 133 when viewed from above is increased because, when the potential difference between the through holes is set to ΔV and the distance between the through holes is set to Δx, the smaller the ratio of ΔV / Δx, that is, the smaller the potential difference, or the more separated the distance between the through holes, the slower the ion migration can be.

[0071] <Other Implementation Methods>

[0072] Furthermore, in the above embodiment, one lead is selected from the three leads and bent into an L-shape to reduce the arrangement density. However, for a row of leads 13311-13313, the leads 13311 and 13313 at the ends of the three leads can also be formed into an L-shape, with only the central lead 13312 inserted through a through-hole. In this case, since there is only one through-hole, CAF formation can be prevented. However, the application of the present invention is not limited to the above embodiment. For example, a configuration in which the second and fourth leads of a row of five leads are bent into an L-shape (three through-holes) is also within the scope of the present invention. Furthermore, a configuration in which only the second lead of the row of five leads is bent into an L-shape (four through-holes) is also within the scope of the present invention. In this embodiment, the distance between the third to fifth leads is not increased, but the distance between the first and third leads is increased, achieving the aforementioned effect between the corresponding through-holes. Furthermore, the present invention also encompasses a method in which the second through fourth leads of the five leads arranged in a row are bent into an L-shape (two through-holes). In this case, since the leads at both ends are inserted through the conversion substrate 133, alignment of the lead-type heating element 133h with respect to the conversion substrate 133 is facilitated. Furthermore, the arrangement of multiple leads is not limited to being arranged in a row as described above. Within any arrangement, the present invention also encompasses methods in which a portion of the leads are selected to reduce the arrangement density, or leads are selected at equal intervals and bent into an L-shape. In this case, as described above, the bent leads are selected to minimize the ΔV / Δx ratio in order to slow ion migration. Furthermore, if the lead-type heating element 133h is a resistor or light-emitting diode, for example, one of the two leads arranged in a row can be bent into an L-shape and soldered to a pad on the conversion substrate 133, with the remaining lead inserted through a through-hole. In this case, the above-mentioned effects can also be obtained. In addition, in this embodiment, the case where the lead wire is bent into an L-shape is described, but the lead wire may be bent in two places in a crank shape.

[0073] <Lead and pad positioning>

[0074] As described in this embodiment, when the lead 133l2 is bent into an L-shape and mounted on the other end of the conversion substrate 133, it is necessary to solder and join the bent L-shaped lead 133l2 while properly positioned on the pad 133p on the conversion substrate 133. In this embodiment, as shown in Figures 5(a) and (b), the two leads 133l1 at the ends of the three leads 133l1 to 133l3 of the lead-type heating element 133h and the lead 133l3 are inserted through the conversion substrate 133. This ensures accurate alignment between the bent L-shaped lead 133l2 and the pad 133p on the conversion substrate 133. Furthermore, in this embodiment, when there are three or more leads, it is preferable to provide two or more through-holes. This makes it easier to align the multiple leads of the lead-type heating element 133h with the conversion substrate 133 compared to surface mounting. Furthermore, the mounting strength of the lead-type heating element 133 h with respect to the conversion substrate 133 can be improved.

[0075] <Further prevention of pad peeling from the conversion substrate>

[0076] The pad 133p provided at the other end of the conversion substrate 133 is designed to prevent it from peeling off due to the load on the lead 133l2 in the tilting direction. However, as mentioned above, in this embodiment, the two leads 133l1 and lead 133l3 at the ends of the three leads 133l1 to 133l3 in a row of lead-type heating elements 133h are inserted through the conversion substrate 133 and soldered together, so the leads 133l1 and 133l3 of the heating element 133h are also mechanically secured. This improves the mounting strength of the L-shaped lead 133l2 on the pad 133p of the conversion substrate 133.

[0077] <Heat transfer suppression unit>

[0078] The fluid to be detected by pressure is introduced into the pressure chamber 112A. However, depending on the fluid's usage conditions, this fluid may be at a very high temperature (e.g., approximately 130°C), creating a heat source. In this case, heat from the pressure sensing unit 120 (e.g., heat from the high-temperature fluid introduced into the pressure chamber 112A) may transfer to the conversion substrate 133 (through heat transfer, conduction, and radiation from one end to the other in Figure 1 ), potentially offsetting the heat dissipation effect of the heat sink (a lead-type heating element). Therefore, in this embodiment, various heat transfer suppression units are employed to prevent heat from the pressure sensing unit 120 (e.g., heat from the high-temperature fluid introduced into the pressure chamber 112A) from transferring to the conversion substrate 133. This prevents heat from the pressure sensing unit 120 from transferring to the conversion substrate 133, effectively achieving the heat dissipation effect of the heat sink (a lead-type heating element). The heat transfer suppression unit to the conversion substrate 133 in this embodiment will be described in detail below.

[0079] <First Heat Transfer Suppression Unit to Conversion Substrate (Inner Space)>

[0080] Internal space S is used as the first means for suppressing heat transfer to the conversion substrate 133. Specifically, by placing the conversion substrate 133 near the other end of the substrate storage portion 131a, the distance L between the conversion substrate 133 in the internal space S and the housing 121 on the pressure detection unit 120 side in the direction of the central axis C can be set as large as possible. Thus, in this embodiment, heat from the pressure detection unit 120 side passes through the internal space S, which has a long heat transfer path and low thermal conductivity, thereby suppressing heat transfer to the conversion substrate 133. However, as described in the next section, the conversion substrate 133 does not directly contact the other end of the substrate storage portion 131a.

[0081] <Second heat transfer suppression unit toward the conversion substrate (conversion substrate is away from the main body)>

[0082] As shown in Figure 1, the conversion substrate 133 is separated from the other end and outer periphery of the substrate storage portion 131a, avoiding direct contact with the connector housing 131. Instead of being directly supported by the connector housing 131, the conversion substrate 133 is supported at three points by three connection terminals 134a-c, as shown in Figures 5(a) and 5(b). These three connection terminals 134a-c are positioned toward the center of the conversion substrate 133, where they are particularly subject to load when soldering them to the conversion substrate 133. Furthermore, as shown in Figure 1, the three connection terminals 134a-c are not linear but rather have steps 134f, allowing them to receive the conversion substrate 133. These steps 134f are positioned at a height that prevents contact with the connector housing 131, ensuring that the conversion substrate 133 is supported at three points when housed in the connector housing 131. This structure makes it difficult for the conversion substrate 133 to tilt relative to the connection terminals 134a-c even under load during soldering, allowing for a well-balanced arrangement. Furthermore, movement of the conversion substrate 133 toward the connector housing 131 (upward) is suppressed, and the conversion substrate 133 is securely supported by the connection terminals 134a-c. Furthermore, as shown in Figure 1, the connection terminals 134a-c themselves are secured to the connector housing 131 using connection terminal securing adhesive 134g, and the lead-type heating element 133h mounted on the conversion substrate 133 is secured to the connector housing 131 using heat-dissipating adhesive 133g. This indirectly secures the conversion substrate 133 to the connector housing 131. Thus, the conversion substrate 133 is separated from the other end of the substrate housing 131a so as not to directly contact the connector housing 131. This prevents heat from the lead-type heating element 133h, which is transferred to the surrounding heat-dissipating adhesive 133g, from being transferred to the conversion substrate 133.

[0083] Furthermore, the side portions of the conversion substrate 133 are separated from the outer periphery of the substrate housing 131a. This prevents stress from being applied to the conversion substrate 133 from the connector housing 131 due to the difference in linear expansion coefficients caused by heat between the conversion substrate 133 and the connector housing 131. Consequently, damage to the conversion substrate 133 caused by stress from the connector housing 131 due to the difference in linear expansion coefficients can be prevented.

[0084] <Third Heat Transfer Suppression Unit (Flexible Connector) to the Conversion Board>

[0085] The flexible connector 132 described above serves as a third means for suppressing heat transfer to the conversion substrate 133. Specifically, the flexible connector 132 is formed, for example, from a flexible flexible printed circuit (FPC), a thin conductive member, a single lead, or an assembly of leads. It connects the plurality of lead pins 128 to the electrodes 135 in a curved or bent state within the internal space S. This allows for a greater connection distance between the plurality of lead pins 128 and the electrodes 135. Furthermore, the flexible connector 132 is thinner and has a smaller cross-sectional area than conventional wiring members. Consequently, in this embodiment, heat from the semiconductor sensor chip 126 is transferred through the flexible connector 132, which has a longer heat transfer path and a smaller cross-sectional area, thereby suppressing heat transfer to the conversion substrate 133.

[0086] <Main body assembly process>

[0087] During the assembly process of the main body 130, the three connection terminals 134a-c are first inserted into the main body 130. Then, to secure the inserted connection terminals 134a-c to the main body 130, as shown in Figure 1, a connection terminal securing adhesive 134g is applied (filled) around the connection terminals 134a-c. The thickness of the application is determined so that the connection terminal securing adhesive 134g does not adhere to the conversion substrate 133. Next, as shown in Figure 1, the adhesive reservoir 131e of the main body 130 is filled with heat-dissipating adhesive 133g. The amount of heat-dissipating adhesive 133g is set to approximately half to 80% of the fillable space volume of the adhesive reservoir 131e, not to the maximum fillable volume.

[0088] Here, the lead type heating element 133h is pre-assembled on the conversion substrate 133, and the central lead 133l2 bent into an L shape among the three leads 133l1 to 133l3 is joined to the pad 133p on the conversion substrate 133 by soldering.

[0089] Next, while the connecting terminals 134a-c are inserted through the three through-holes 134t, the conversion substrate 133 is inserted into the main body 130. At this point, the lead-type heating element 133h protrudes toward the substrate's opposing surface 131a1, so the heat-dissipating adhesive 133g, which is filled in the adhesive reservoir 131e of the main body 130, is inserted. Next, the main body 130 with the conversion substrate 133 inserted is placed in an oven and heated to harden the heat-dissipating adhesive 133g and the connecting terminal fixing adhesive 134g. This heating step is intended to prevent migration caused by initial moisture absorption by the conversion substrate 133 and also includes the purpose of drying the conversion substrate 133. Furthermore, since the arrangement density of the connecting terminals 134a-c on the conversion substrate 133 has been reduced, ion migration between the three through-holes 134t is prevented. Furthermore, the two leads 13311 and the lead 13313 at both ends of the connecting terminals 134a to c and the leads 13311 to 13313 of the lead-type heating element 133h are soldered to the conversion substrate 133. Finally, a welding inspection is performed to confirm whether the soldering is correct. In addition, in this embodiment, the case where the lead-type heating element 133h assembled on the conversion substrate 133 and the connecting terminals 134a to c are soldered at the same time is described. However, the lead-type heating element 133h assembled on the conversion substrate 133 may be soldered before the conversion substrate 133 is inserted into the main body 130. That is, the first soldering is performed after the lead-type heating element 133h is assembled on the conversion substrate 133, and the second soldering is performed after the conversion substrate 133 is inserted into the main body 130.

[0090] Pressure sensor assembly process

[0091] Next, the assembly process of the pressure sensor 100 will be described. First, the pressure sensing unit 120 and the aforementioned signal transmission unit (main body) 130 are assembled separately. Then, in the pressure sensing unit 120, the liquid seal chamber 124A is filled with sealed oil via the oil filling tube 129, and the oil filling tube 129 is sealed. Furthermore, the fluid inlet 110 is secured to the pressure sensing unit 120 by welding or other means. Next, the multiple lead pins 128 of the pressure sensing unit 120 and the converter substrate 133 of the signal transmission unit 130 are aligned with each other facing upward. One end of the flexible connector 132 is secured to the surfaces of the multiple lead pins 128 and the other end of the flexible connector 132, respectively. Finally, the pressure sensing unit 120 and the signal transmission unit 130 are aligned and face each other on the same axis via the bent or folded flexible connector 132, with an adhesive sheet 142 sandwiched between the pressure sensing unit 120 and the signal transmission unit 130. Finally, one end and the other end of the rivet plate 141 are respectively engaged with the base plate 112 of the fluid inlet part 110 and the connector housing 131 of the signal sending part 130, thereby fixing the fluid inlet part 110, the pressure detecting part 120 and the signal sending part 130 as a whole.

[0092] Here, in the pressure sensor 100, without using a bent or folded flexible connector 132, the assembly process of the pressure sensor 100 would require, for example, stacking the components from one end toward the other in the direction of the central axis C. Consequently, the degree of flexibility in the assembly process is extremely limited, making it difficult to reduce assembly time. However, in this embodiment, by connecting the pressure detection unit 120 and the signal transmission unit 130 via a bent or folded flexible connector 132, the degree of flexibility in the assembly process of the pressure sensor 100 can be increased, thereby reducing assembly time.

[0093] <Heating devices with various lead types>

[0094] FIG6 is a schematic perspective view showing how a heat generating device, such as a transistor, of a pressure sensor according to various embodiments of the present invention is soldered to a conversion substrate. FIG6(a) is a schematic perspective view showing one embodiment in which the direction in which the leads of the heat generating device extend parallel to the direction through the front and back of the conversion substrate, i.e., the direction in which the leads extend perpendicular to the plane of the conversion substrate. FIG6(b) is a schematic perspective view showing another embodiment in which the direction in which the leads of the heat generating device extend parallel to the direction through the front and back of the conversion substrate, i.e., the direction in which the leads extend perpendicular to the plane of the conversion substrate. FIG6(c) is a schematic perspective view showing one embodiment in which the leads of the heat generating device extend parallel to the plane of the conversion substrate. FIG6(d) is a schematic perspective view showing another embodiment in which the leads of the heat generating device extend parallel to the plane of the conversion substrate.

[0095] As shown in FIG6(a), in the above embodiment, a lead-type heating element (transistor) 133h is arranged perpendicular to the conversion substrate 133. Furthermore, only the central lead 133l2 of the heating element 133h is bent into an L-shape and soldered to a pad 133p. The remaining leads 133l1 and 133l3 are inserted into through-holes 133t provided in the conversion substrate 133.

[0096] As shown in FIG6(b), in this embodiment, a lead-type heating element (transistor) 233h is arranged perpendicular to the conversion substrate 233. Furthermore, only the central lead 233l2 of the heating element 233h is inserted into a through-hole 233t provided in the conversion substrate 233. The remaining leads 233l1 and 233l3 are bent into an L-shape and soldered to a pad 233t.

[0097] As shown in Figure 6(c), in another embodiment of the present invention, a lead-type heating element (transistor) 333h is arranged parallel to the conversion substrate 333. In this case, only the central lead 333l2 of the heating element 333h extends parallel to the conversion substrate 333, is bent, and inserted into a through-hole 333t provided in the conversion substrate 333. The remaining leads 333l1 and 333l3 extend parallel to the conversion substrate 333, and their tips are soldered and bonded to pads 333t.

[0098] As shown in FIG6(d), in yet another embodiment of the present invention, a lead-type heating element (transistor) 433h is arranged parallel to the conversion substrate 433. In this case, only the central lead 433l2 of the heating element 433h extends parallel to the conversion substrate 433, with its tip soldered and bonded to a pad 433t. The remaining leads 433l1 and 433l3 extend parallel to the conversion substrate 433, are bent, and inserted into a through-hole 433t provided in the conversion substrate 433.

[0099] Furthermore, in this embodiment, the heating elements 333h and 433h are described as being arranged parallel to the conversion substrates 333 and 433, respectively, which are arranged in a direction perpendicular to the central axis C, i.e., perpendicular to the direction adjacent to the signal transmission unit 130 and the pressure detection unit 120. However, the heating elements 333h and 433h may also be arranged parallel to the conversion substrates 333 and 433, respectively, which are arranged in a direction parallel to the central axis C, i.e., parallel to the direction adjacent to the signal transmission unit 130 and the pressure detection unit 120. Furthermore, in this embodiment, the lead wires are described as being bent into an L-shape, but the lead wires may also be bent in two locations in a crank shape.

[0100] In this manner, even when the heat generating devices 333h and 433h are arranged in parallel with the conversion substrates 333 and 433, respectively, ion migration between the through holes can be prevented in the same manner as in the above-described embodiment.

[0101] According to the above configuration, it is possible to provide a signal conversion device and a pressure sensor capable of preventing ion migration between through holes caused by moisture absorption of the conversion substrate.

[0102] Explanation of symbols

[0103] 100 - pressure sensor, 110 - fluid inlet, 111 - connector, 112 - base plate, 120 - pressure detection unit, 121 - housing, 122 - diaphragm, 123 - protective cover, 124 - sealing glass, 124A - liquid seal chamber, 125 - pillar, 126 - semiconductor sensor chip, 127 - potential adjustment component, 128 - lead pin, 129 - oil filling tube, 130 - signal sending unit (main body), 131 - connector housing, 131a - substrate storage unit, 131a1 - substrate facing surface, 131b - connector Connecting portion, 131c-partition portion, 131e-adhesive storage area, 131m-chamfered portion, 131w-adhesive storage wall, 132-flexible connector, 133-conversion substrate, 133a-one end surface, 133b-other end surface, 133f-opening portion, 133g-heat dissipating adhesive, 133h-heating element, 133k-cut portion, 133l1-lead, 133l2-lead bent into L shape, 133l3-lead, 133n-pad portion, 133p-solder pad, 133t-through hole, 134a-connecting end 134b—connecting terminal, 134c—connecting terminal, 134d—one end, 134e—the other end, 134f—step, 134t—through hole, 135—electrode, 136—substrate stopper, 140—connecting component, 141—rivet plate, 142—adhesive sheet, 151—resin sheet with heat radiation, 152—adhesive with heat radiation, 233—conversion substrate, 233h—heat generating device, 233l1—lead bent into L shape, 233l2—lead, 233l3—lead bent into L shape, 233 p—soldering pad, 233t—through hole, 333—conversion substrate, 333h—heating device, 333l1—lead, 333l2—lead bent into L shape, 333l3—lead, 333p—soldering pad, 333t—through hole, 433—conversion substrate, 433h—heating device, 433l1—lead bent into L shape, 433l2—lead, 433l3—lead bent into L shape, 433p—soldering pad, 433t—through hole, C—center axis, L—distance between the conversion substrate and the shell in the direction of the center axis, S—internal space.

Claims

1. A signal conversion device, characterized in that: A signal conversion unit is provided, the signal conversion unit having a conversion substrate and a heating element mounted on the conversion substrate, the conversion substrate adjusts a signal input from the outside and adjusts a signal between the outside and the outside via a connection terminal, The conversion substrate includes through holes for inserting leads of the heat generating device, and the through holes are provided corresponding to leads other than leads selected from the plurality of leads so as to reduce arrangement density of the plurality of leads.

2. The signal conversion device according to claim 1, characterized in that: The plurality of leads are arranged in a row, and a part of the leads are selected from the plurality of leads.

3. The signal conversion device according to claim 2, characterized in that: The plurality of leads are arranged in a row, and the leads are selected at equal intervals among the plurality of leads.

4. The signal conversion device according to claim 2, characterized in that: The plurality of leads are arranged in a row, and leads other than leads at both ends are selected from the plurality of leads.

5. The signal conversion device according to any one of claims 1 to 4, characterized in that: The lead wire selected from the plurality of leads is bent and bonded to a pad on the conversion substrate, and the remaining lead wires are inserted through the conversion substrate.

6. The signal conversion device according to claim 5, characterized in that: The plurality of leads are three in number, and the selected lead is a central lead. The central lead is bent into an L-shape and is bonded to a pad on the conversion substrate.

7. The signal conversion device according to claim 5, characterized in that: The plurality of leads are three in number, and the selected leads are two leads at both ends. The two leads at both ends are bent into an L-shape and bonded to the pads on the conversion substrate.

8. The signal conversion device according to any one of claims 1 to 4, characterized in that: The lead wire selected from the plurality of leads is bonded to a pad on the conversion substrate, and the remaining lead wires are bent and inserted through the conversion substrate.

9. A pressure sensor, characterized in that: have: A pressure detection unit having a pressure chamber, a semiconductor sensor chip for detecting the pressure of a fluid introduced into the pressure chamber, and lead pins connected to the semiconductor sensor chip and constituting external input / output terminals of the semiconductor sensor chip; as well as The signal sending part has a connector housing, a connection terminal, a conversion substrate and a heating element. The connector housing is adjacent to the pressure detecting part and defines a substrate storage part, a connector connecting part, and a partition wall part arranged between the substrate storage part and the connector connecting part. The connection terminal is used for connecting signals with the outside. The conversion substrate is stored in the substrate storage part and adjusts the signal between the pressure detecting part via the lead pin and the outside via the connection terminal. The heating element is mounted on the conversion substrate and fixed to the connector housing with a heat dissipating adhesive. The conversion substrate includes through holes for inserting leads of the heat generating device, and the through holes are provided corresponding to leads other than leads selected from the plurality of leads so as to reduce arrangement density of the plurality of leads.

Images