TW201213775A - Flowrate sensor and flowrate detection device - Google Patents

Abstract

Disclosed is a flowrate sensor having a flowrate detection means built into a surface mounted package. The flowrate sensor is equipped with: a fluid path (70) formed within the package (12), and draws fluid from a fluid intake (30) provided under the package (12) to a fluid outlet (32) provided under the package (12) so as to pass by the flowrate detection means; and an external terminal (40) disposed at the outer surface of the package (12), and through which the electric output of the flowrate detection means is drawn. The flowrate sensor can be used for both fluids and gases. The flowrate sensor can be miniaturized and surface mounted on an electronic circuit board and the like, and is highly reliable.

Description

201213775 VI. Description of the Invention: [Technical Field] The present invention relates to a flow sensor capable of detecting a gas or liquid flow by accommodating a microelectromechanical system (MENS) sensor wafer in a surface-mounted package And a flow detecting device using the flow sensor. [Prior Art] A semiconductor process technology is used in which a machining technique or a material technique is combined, thereby realizing a three-dimensional microstructure on a substrate. [MENS: Mlcro Eelectro Mechanical System] It is widely used to miniaturize and lightweight components such as sensors or pumps. As a sensor using the MEMS technology, for example, an acceleration sensor, an angular velocity sensor, and a pressure sensing = are widely used. Thousands of demands, as the family's monthly commercial fuel cell system is popularized. Such a fuel cell must accurately detect the flow rate of the fuel gas or the liquid fuel, or supply the amount of gas, and supply the gas generated by the reformer to the fuel gas to control the flow rate thereof. In addition, when the required gas G and the secondary material are taken out from the fuel, although carbon monoxide (c〇) is generated, the carbon monoxide adversely affects the performance of the coal, so that the degree of reduction is also at the same time. H swings 'Oxidized stone anti-J丨』 Japanese hand request to choose the flow control of the air. Also in the field of knife placement or medical related (the drug, clinical test, etc.), in the field of the '5' car wheel: ^ must also detect a small amount of gas or liquid, since the ' 'have a variety of proposals Flowmeters, but most of them are two... 7 v. only the amount of gas flow. 201213775 The 'suitable for measuring liquid flow is very small. For example, although there is a liquid through the orifice (,rifice), with a fluid manometer (manometer) or 2 A pressure sensor or the like detects the pressure difference before and after the orifice (or orifice flowmeter), and provides an impeller in the flow of the fluid, and the flow rate is detected according to the number of rotations of the impeller (turbine flowmeter), but such flow rate All of them have the disadvantages of large-scale. Moreover, it is generally known to use an ultrasonic sensor disposed on the opposite wall to detect ultrasonic waves that are obliquely ejected from the wall of the flow path, according to the time of the present. The change in the detection intensity of the D〇pPler effect is performed by a detector (ultrasonic flowmeter), a voltage change in an orthogonal direction of a magnetic field generated by a fluid in a magnetic field (electromagnetic flowmeter), and heating by a heater When testing fluid The change in fluid temperature thereafter (thermal mass flow meter), etc. Patent Document 1 and Patent Document 2 disclose that a semiconductor sensor having a microelectromechanical system (MEMS) chip constitutes a sense of acceleration. A detector, an angular velocity sensor, a pressure sensor, but a flow sensor is not described herein. Patent Document 3 discloses that a micro-sized glass tube is brought into contact with a silicon (Si) substrate. A micro-electromechanical system (MEMS) wafer, a thermal mass flow meter (thermal flow sensor) that allows liquid to flow through a glass tube. The concept of a differential pressure type flow sensor has been disclosed in Patent Document 4. Using a semiconductor microfabrication technique, a thin film (also known as a separator) is formed on a ruthenium (Si) substrate by an etching technique, and a fluid is passed through a membrane pore (at least one opening) formed in the membrane to thereby generate and The pressure difference proportional to the flow rate is based on the differential pressure formed by the diffusion resistance (piezoresistive element) formed on the film to electrically detect the stress (deformation) generated by the film. Since the single crystal is not plasticized at room temperature 'Therefore, the characteristics are the same, and since the film system s 4 201213775 is integrated with the substrate, it is possible to obtain stable characteristics. Patent Document 1: 曰本特开 Patent Document 2: 曰本特开 Patent Document 3: US Patent Patent Document 4: US Patent C Disclosure of the Invention: US Pat. No. 20-10-28025, No. 2010-19693, US Pat. No. 6,813,944, 2, US Pat. No. 6,625,605, B1, the disclosure of the patents 1, 2, the use of the micro-electromechanical system (mems) technology, reading acceleration, angular velocity, pressure It is not the flow of gas or liquid, and it is not the heuristic flowmeter. The patent disclosed in Patent Read 3 is used to heat the liquid helium flowing in the microtube, so that the thickness of the microtube must be made very thin in order to make the responsiveness. So there is strength: the problem. Further, when a liquid having a low boiling point is measured, there is a problem that bubbles are easily generated in the vicinity of the heater. In Patent Document 4, only the principle of detecting the flow rate based on the deformation of the film is disclosed, and how to apply this principle to the actual one is not disclosed. In other words, it is required to reduce the size of the flow sensor for household fuel cell systems or portable devices, medical devices, etc., and it is particularly required to be easily mounted on a circuit board, etc., regardless of the liquid or gas. It is possible to ask for a guilty degree, but this patent document 4 does not respond to such a requirement. —————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————— The substrate and the like have high reliability. Further, the second system provides a flow detecting device that uses the flow sensor to measure a fluid having a flow rate of 201213775. According to the invention, the flow sensor of the first aspect is characterized in that the flow rate detecting means is provided in the package of the surface structure type, and comprises: a fluid flow path formed in the package body to discharge the fluid The flow population disposed under the package is guided to the outflow port disposed under the package by the flow detecting means; and the external terminal is disposed outside the package, and the electrical output of the flow detecting means is guided . In the present invention, for convenience of explanation, the surface of the inflow port and the outflow port is provided as the lower side, and if the upper and lower sides of the package are reversed, the lower surface becomes the upper surface, so that substantially no upper and lower sides are available. In short, it suffices to face the object (electronic circuit board or the like) on which the object is mounted. The external terminals can be placed anywhere except the package. For example, an electrode terminal such as a leaded component or a leadless chip component may be provided on the side, or an electrode terminal such as a ball grid array (BGA: Grid Array) may be provided below. Preferably, the flow detecting means has a film (separator) which is displaced according to a pressure difference between the upstream side and the downstream side of the diaphragm hole (opening 'hole) which acts as a flow path impedance provided in the middle of the fluid path, and is based on the film. The differential pressure sensing piracy in the displacement detection flow. Although the diaphragm is provided in the film, it can also be one, and the extension can be plural. When one diaphragm hole is provided, it is preferably disposed at the center of the film. The reason for this is that, as will be described later, when a bridge circuit is formed by four resistors, it is easy to obtain equalization of the respective resistors. Preferably, the flow detecting means has a thin film and a microelectromechanical system (MEMS) sensor, i.e., a sensor wafer, as a resistive element fixed to the deformer of the thin film. At this time, in one part (center portion) of the 矽 (Si) substrate by etching

S 6 201213775 A thin thin crucible is formed, and a resistive element or a circuit pattern (internal circuit pattern) can be formed on the thin film by photolithography or the like. That is, the sensor wafer is formed using generally known semiconductor technology. Preferably, the package system overlaps the lower substrate and the upper substrate, and the peripheral portion of the sensor wafer is held between the two, and a liquid inlet of the fluid L is formed under the film to form the upper portion. The fluid flow path of the substrate communicates from the upper surface of the membrane to the exit of the machine. According to this configuration, the length of the inflow port side of the fluid flow path can be minimized, and the fluid flow path can be formed only on the upper substrate, and the processing can be simplified. Alternatively, the inflow port may be opposite to the outflow port. The film is formed relatively thinly by reserving the periphery of the sensor wafer and etching the inside thereof, and a resistor as a strain gauge is formed on one side (e.g., above) of the film. In addition, the resistor is previously coated by an insulating film. At this time, since the periphery of the sensor wafer is thick, the sensor wafer can be held between the upper substrate and the lower substrate, and the stress is not applied when the film is assembled, and the characteristics are stable. Assembly. The film is a quadrangular shape. If four resistors are placed in the middle of each side in the vicinity of each side, the conditions of the resistors are suitable when the resistors constitute a wheatstone bridge. A vertical wall (a raised edge, a large wall) opposite to the periphery of the film and on the upper surface of the upper substrate can be formed on the lower surface of the upper substrate, and the upper substrate can be formed in advance for supplying the adhesive; The meat of the door gap (filling port). The adhesive used at this time is a perfluorene-based adhesive having thixotropic characteristics, and the adhesive can flow into the gap by capillary action. 201213775 Since the adhesive has a viscosity accompanying the flow rate, the viscosity is small, the fluidity is good, and the viscosity is high (thixotropy) when the flow rate is not accompanied. Therefore, when the adhesive is injected, the film does not apply an unnecessary stress. By capillary force, it automatically catches up with the flow and smoothly flows into the gap to seal. After being sealed, due to the flow velocity of the helmet, the viscosity of the adhesive becomes high, and no adhesive on the film is not Ί. The fluid flow path formed on the upper substrate can be formed between the upper substrate and the plate. For example, a groove is formed on the upper substrate, and the phase groove is covered with a cover plate, whereby the fluid flow path can be formed by simple processing. Forming an internal circuit pattern on the sensor wafer for connecting an external circuit pattern formed on the outer peripheral side of the resistor formed on the outer peripheral side of the resistor formed on the outer substrate from the upper substrate, and the external circuit pattern is connected to the external terminal. The circuit pattern is connected to the external circuit pattern by wire bonding: In the portion where the wire is bonded, the hardened crucible is supplied, and another adhesive is supplied from the window of the upper substrate of the ancient 按 按 按 按 四 四 四 四 , , , , , 引线 引线 引线 引线 引线 引线 引线 引线 引线 引线 引线 引线 引线 引线 引线 引线 引线The external terminal is as described above, and the metal is plated to extend from the lower plate or the side surface to the lower side, and can be made into the same terminal as the leadless wafer zero-face type capacitor or resistor. The metal plate having all the external circuit patterns, that is, the lead frame is protruded, and the protruding portion is used as an external terminal. The flow rate detecting device of the flow rate uses the request item 1, The utility model is characterized in that: a main material, a package body fixed with a flow tampering agent's main flow path for forming a fluid; and a branch flow path for guiding the fluid flow from the official material to the flow inlet of the flow sensor, and from: The flow detection device of the present invention is guided to the main road of the main material. The flow detection device of the present invention can appropriately cross the flow path (for example, orthogonal) by selecting the cross-sectional area of the flow path of the main road. ,Minute Then, * ', and the main father) are connected to the first and second outlets of the flow sensor, and the 44·8 machine is formed with the flow WS material, which can be used as the secondary pipe to the mainstream road. In the upstream direction, the "opening" is formed in the opening of the second sub-pipe to the downstream direction of the main path, and can prevent or suppress the influence of the hydrodynamic pressure on the flow sensor. 'The opening can also be plural. The opening can also be a slit. The f-package flow fm and the control board of the control circuit component are fixed to the main & material' the first and f 2 sub-tubes can penetrate the control substrate and connect to the flow sense The flow rate σ and the outflow σ of the detector. For example, if the gain circuit for setting the gain of the output voltage of the strain gauge (resistor) or the bias voltage is applied to the control board, the output signal of the strain gauge is not easily affected by the wiring. The influence of the noise is suitable for improving the detection accuracy. The first invention of the present invention improves the reliability by providing the flow rate detecting sensor in the package, which can be miniaturized. In the body of Feng Ling, will The flow inlet and the outlet of the fluid flow path are concentrated on one side (lower side) of the package, so that the connection between the fluid flow path and the substrate to be mounted can be shortened, and the size can be reduced. In the density configuration, since the external terminal is provided on the outer surface of the package, the package can be surface-mounted and is more suitable for high-density mounting. Further, the flow rate detecting device according to the second invention of the present invention senses the flow rate. The package of the device is fixed to the main material as the main flow path of the fluid, and the fluid is diverted from the main pipe 201213775 to the flow inlet of the flow sensor, and the fluid is returned to the main flow path from the flow outlet of the flow sensor, so [Embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, 'the term indicating a specific direction or position is used as needed (for example, "upper", "Bottom", "Left", "Right" and other terms containing these terms) 'But the reason is that it is easy to understand the invention of the reference schema using these terms, and In accordance with these terms are intended to define the scope of the techniques of this invention are. Further, the same reference numerals are used to refer to the same parts or components. (Embodiment 1) In Figs. 1 to 4, the symbol 1 流量-type flow sensor is housed in a surface mount type package 1 2 . The four sides of the package 1 2 are smaller than about 8 mm, and as shown in Fig. 3, the lower substrate 14, the upper substrate 16, the cover 18, and the panel 20 are fixed and fixed. The lower substrate 14' upper substrate 16 and the cover plate 18 are made of a hard resin. _ On the upper surface of the lower substrate 14, as can be understood from Figs. 3 and 4, the sensor wafer receiving chamber 22 having a quadrangular shape in plan view is formed at a position eccentric to one side from the center. The sides of the bottom portion 24 of the accommodating chamber 22 are shorter than the sides of the upper portion 26, and the quadrangular shape which passes through the horizontal portion 28 between the two squares is concentrically overlapped. A sensor wafer 42 to be described later is fixed on the segment portion 28. In the center of the bottom of the storage chamber 22, as an inflow of a part of the fluid flow path

S 10 201213775 口口〇 Opening. The lower end of the inflow port 30 is open to the lower surface of the lower substrate 14 (see FIG. 4, the lower substrate 14 is formed, and an outflow is formed as a fluid flow path portion on the side opposite to the eccentric direction of the storage chamber 22. The storage chamber 22, the inflow port 30, and the outflow port 32 are located on a straight line 34 (see FIG. 3) passing through the center of the upper surface of the lower substrate 14 in plan view. Further, the lower surface of the lower substrate is on a line orthogonal to the straight line 34. A pair of two-position pins 36 and 36' are formed (see FIGS. 2 and 4). The positioning pin % is used for positioning the flow rate sensor 10 when mounted on a circuit board or the like. The lower substrate 14 is substantially symmetrical with respect to the straight line 34. The method forms a plurality of external circuit patterns % ($8 in Figures 3 and 5). These external circuit patterns 38 can be formed by photolithography. Alternatively, these circuit patterns can be stamped in advance. The lead frame of the metal plate is fixed to the lower substrate 14 and is formed by removing unnecessary portions. These external circuit diagrams f 3 8 (the _ end (inner end) extends to the vicinity of the accommodating portion 22, and the other end (outer end) Side of the line! Stretches to the lower substrate... surface appears on the side The external terminal 4 of the second sensor 10 is described below. Next, the sensory wafer 42 as the flow rate detecting means of the present invention will be described with reference to Figs. 4 and 8. The sensor wafer 42 is formed on the four sides by a semiconductor process. It is a slab (8) substrate 44 having a size of about 3 sides. The slab substrate 44 of the singular single crystal can be placed in a flat plate of the size of the accommodating portion 22 of the lower substrate 14, and is surrounded by a quadrangular pyramid 46 at the center of the lower surface. Thin film 牦. The film can be widely etched by general known, such as induction consuming electricity _: IndUCtlVely Coupled Pla_) 'Reactive ion money engraving (8) £

Ion Etching) is formed. An opening 50 for the diaphragm hole is formed in the center of the thin web 48 as 201213775. The opening 50 can likewise be formed by etching or laser processing or the like. Although the diameter of the opening 50 can be changed depending on the measurement range or the type of liquid (liquid or gas, etc.), in the present embodiment, the diameter of the opening 5 is 50 " m. Further, the broken line shown in Fig. 8 is formed on the outer circumference of the film 48 by the four-sided tapered surface 46'. The outer side of the four-sided tapered surface 46 is the peripheral portion 52 shown in Fig. 4. The peripheral portion 52 is a portion of the substrate 44 that is not etched to retain thickness. On the upper surface of the germanium substrate 44 on which the thin film 48 is formed, four resistive elements (deformation meters) R1 to R4 are formed; a plurality of (six) electrode pads 54 (54a to 54f) formed along the outer peripheral edge; and The internal circuit pattern 56 (Figs. 8, 9). These can be formed using semiconductor manufacturing techniques such as photolithography. Further, the resistors R1 to R4 are as shown in Fig. 8. In plan view, they are located slightly inside the center of each side of the rectangular film 48, and the circuit patterns 56 are respectively connected to extend from the resistor illusion R4 to the outer peripheral direction and along the film 48. The electrode pad 54 is formed on the outer circumference (outer circumference of the quadrangular pyramid). In Fig. 8, reference numerals 58a and 58b are electrodes 温度 of a temperature sensor, and a thermistor element 6A as a temperature sensor is formed between them. On the upper surface of the sensor wafer 42, an insulating film such as tantalum nitride (SiN) or tantalum carbide (S1C) is formed inside the electrode pads 54, 58, and this insulating film is used as a protective film. The sensor wafer 42 formed in this manner is housed in the housing portion 22 of the lower substrate 4 . That is, as shown in FIGS. 3 and 4, the peripheral portion 52 of the cymbal substrate 44 is held in the segment portion 28 of the accommodating portion 22 by being filled in the accommodating portion. Further, the sensor wafer 42 is fixed to the housing portion 22 using an adhesive. here

In the state of S 12 201213775, the electrode pads 54, 58 of the sensor wafer 42 are wire-bonded to the inner end portion of the external circuit diagram (4) of the lower substrate 14. That is, as shown in FIG. 5, the gold (Au) or the first (into 1) bow is started, and the i) bow line 62 is connected to the electrode pads 54, 58 and the external circuit pattern by thermocompression bonding or ultrasonic bonding. 38. . . The lower surface of the upper substrate 16 (the surface facing the lower substrate 14) is formed on the upper surface of the peripheral portion of the sensing T-sheet 42 with reference to FIG. 7) opposite to the vertical wall (large lifting ridge). . That is, the vertical wall 66 is located above the quadrangular pyramid 46 in plan view, and surrounds the periphery of the film 48 to hang down the wall. Then, the thixotropic adhesive (9) is caused to flow into the gap 64 by capillary action or surface tension. The gap 64 is preferably 5 to 15 micro. The upper substrate 16 is formed with a fluid flow path 7〇 which is open above the center of the film 48 and which is parallel to the central straight line 34 (see Fig. 3). The other end of the fluid flow path communicates with the outflow port 32 of the lower substrate 14 (see Fig. 4). The fluid flow path 70 is formed on the upper surface 3 of the upper substrate 16 by blocking the cover plate 18 from above, thereby being formed in the recess 72 (refer to the upper surface of the substrate 16 and the cover plate 18 on the drawing). When it is formed in this manner, the fluid flow path 7〇 parallel to the upper substrate 丨 6 can be easily formed by semiconductor processing technology (etching, etc.). The upper substrate 16 heat-insulating adhesive sheet 17 is superposed on the lower substrate i4 ( Referring to Fig. 3), on the upper surface of the film 48, the vertical wall 66 is opposed to each other via a predetermined gap 64. In this state, the upper substrate 16 is then fixed to the lower substrate 14. In addition, the upper substrate 16 and the cover 18 are As shown in Figures 3 and 6, four windows (filling ports) 74 are formed which face the outer surface of the sensor wafer 42 from the outer side of the vertical arm 66. These windows 74 are utilized as described above for being thixotropic. The adhesive 68 is supplied between the sensor wafer 42 and the vertical wall 66. Further, after the thixotropic property 13 201213775 is cured, another adhesive is injected from the window 74 to fix the lead 62. According to the present embodiment For example, a fluid (gas or liquid) flowing in from the inflow port 30 flows into the lower side of the film 48 through the film 4 The diaphragm hole 50 of 8 flows into the fluid flow path 70' and then flows out of the outflow port 32. By the effect of the diaphragm hole when the fluid passes through the diaphragm hole, a pressure difference is generated between the both sides of the film 48, and the film 48 is displaced to the low pressure side, that is, the upper side. The change in stress applied to the resistors R1 to R4 by the displacement also changes in the resistance value. As a result, the output of the bridge circuit shown in Fig. 9 changes. The change in the output voltage is applied to both sides of the film 48. The pressure difference corresponds to the pressure difference according to Hagen-Pai's law (Hagen_p〇iseuille

Law) is proportional to the flow rate of the fluid, so the flow rate can be detected by detecting the pressure difference. (Embodiment 2) Fig. 1 〇 to 1 2 shows a flow rate detecting device using the flow sensor. In the Fig. 4, the symbol 8 is the main material of the main flow path 8 2 through which the fluid passes. The tube arm body of the main material 80 is formed with a substrate receiving portion 84 along its length. The control substrate % is accommodated in the substrate housing portion 84. An amplitude increasing circuit of the flow sensor 1() and its output signal is disposed on the control substrate 86, and another arithmetic circuit such as a circuit for performing gain s or offset voltage adjustment may be configured in advance. . Here, the flow sensor 1 〇 passes through the straight line 34 (refer to FIG. 3) at the center of the film 48, and is flush with the main flow path 82, H u λ , and is located at the k inlet 30 is more located than the flow outlet 3 2 The way of the _4·m~ on the flow side of the mainstream road 8 2 is fixed. Further, the connecting member 8 8 located below the flow sensor 1 is interposed between the substrate 86 and the main material 80.

S 14 201213775 Below the connecting member 88, as shown in FIG. 12, 'only the distance from the inflow port 3 of the flow sensor 10, the distance of the outlet port 4, and the distance of the L outlet 32, the first and second ends are fixed. The upper ends of the secondary pipes 90, 92. Far | 4 ^ The reverse member 88 is liquid-tightly fixed to the pipe wall of the main pipe 80. When the pipe is opened, the first and second sub-pipes 90, 92f are fixed to the main pipe 82. The ends of the first and second sub-tubing members 90 and 92 are passed through the crucible connecting member 88, and are further connected to the inflow port 30 and the outflow port 32 of the flow rate sensor 10 by liquid-tight connection on the control substrate. The first sub-tubing member 90 is formed with a plurality of slits 94' which are opened in the upstream direction of the fluid. The second sub-tubing member 92 is formed with a plurality of slits 96 which are openings in the swimming direction. As a result, the portion of the main flow path 82 that is maneuvered is shunted by the flow sensor 10 through the sub-tubes 9 〇, 92 as the branching path. The flow sensor 1 detects that the flow is split into the split flow path, whereby the total flow to the main pipe 8 can be specified. The control board 86 can be equipped with a signal booster Numian circuit of the flow rate sensor 1 in advance, and an appropriate circuit such as an arithmetic circuit or a temperature correction circuit can be mounted in advance. The arithmetic circuit calculates the flow rate of the main flow path 82 by the output of the main flow path 82 and the shunt path. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing the upper side of an embodiment of a flow sensor of the present invention. Circle 2 is a bottom side perspective view of the flow sensor shown in FIG. (Circular 3 is an exploded perspective view of the flow sensor shown in Figure 1. 15 201213775 The line of the side profile of the jade is called 34! The cross section of the V_IV line. The circle, along Figure 3. Figure 5 shows the flow detection A perspective view of the state of the substrate is sensed by the means. Fig. 7 is a perspective view showing a portion in which the upper substrate is laminated on the lower substrate. Fig. 7 is an enlarged cross-sectional view showing a portion indicated by an arrow VII in Fig. 4. Fig. 8 is a view showing Fig. 9 is a view showing a Wheatstone-bridge connection circuit formed by the resistor element of Fig. 8. Fig. 10 is a perspective view showing an embodiment of the flow rate detecting device of the present invention. A perspective view of the cross-section of the flow inspection device along the center line of the main pipe. Fig. 12 is a left side view of the cross section of the flow detecting device of Fig. 1 along the center line of the main material. [Main component symbol description]

S 10 Flow sensor 12 Package 14 Lower substrate 16 Upper substrate 18 Cover plate 22 Sensor wafer storage portion 30 Inlet (one part of fluid flow path) 32 Flow outlet (one part of fluid flow path) 34 Passing through lower substrate The upper center line 16 201213775 38 40 42 44 48 50 54, 56 62 64 66 68 70 74 80 82 86 88 90 92 94 ' R1 external circuit pattern external terminal sensing wafer (flow stem detection means) 矽 substrate film diaphragm hole ( Opening) 5 8 electrode pad internal circuit pattern lead gap vertical wall thixotropy adhesive fluid flow path window (adhesive injection port) main material main road control substrate connection member first sub-pipe (split path) second sub-pipe (diverting path) ) > 96 opening (slit), R2, R3, R4 resistance element (deformation meter, resistor) 17

Claims (1)

201213775 VII. Patent application scope: 曰! The flow sensor is provided with a flow detecting means in a surface-mounted package, and is characterized in that: a fluid flow path is formed in the package, and 睹J ^ ® π The flow person π disposed under the package body is guided to the outflow port disposed under the package body by the flow detecting means; and the external terminal ' is disposed outside the package body, and the electric flow detecting means is guided Output. 2_ The flow sensor of claim 1, wherein the flow detecting means has a film which is displaced according to a pressure difference between the upstream side and the downstream side of the partition hole provided in the middle of the fluid passage and is displaced according to the film A differential pressure sensor that detects flow. 3. The flow sensor of claim 2, wherein the flow detecting means is formed by the sensor wafer having the film and a deformer fixed to the film and detecting deformation corresponding to the displacement of the film. Mems sensor. 4. The flow sensor of claim 3, wherein the package has the inlet and the outlet below the lower opening of the substrate, and overlaps the lower substrate and maintains sensing between the lower substrate and the lower substrate a substrate above the peripheral portion of the wafer, the inflow opening under the film 'the upper surface of the film is connected to the outflow port by a fluid flow path formed on the upper substrate. 5. The flow sensor of claim 4, wherein the film is formed thinly by burying a peripheral portion of the sensor wafer and etching the inside thereof, and forming a deformation on one side of the film Count the resistors. 18 S 201213775 6_ The flow sensor of claim 5, wherein the film is quadrangular, and the four resistors constituting the strain gauge are disposed at the center of each side of the film, and each resistor forms a bridge circuit . 7. The flow sensor of claim 4, wherein a periphery of the surrounding film is formed under the upper substrate and a vertical wall is opposed thereto via a gap, and the upper substrate is formed to be used as an adhesive Supply to the window of the gap. 8. The flow sensor of claim 4, wherein the fluid flow path formed on the upper substrate is formed between the cover plate and the upper surface of the upper substrate. 9] The flow sensor of claim 6, wherein the sensor wafer is formed by connecting a deformable meter provided on the film to an electrode pad formed on the outer peripheral side from the vertical wall y of the upper substrate. The internal circuit pattern is formed with an external circuit pattern connected to the external terminal on the lower substrate, and the internal circuit pattern and the external circuit pattern are connected by wire bonding. I. The flow sensor of claim 7, wherein the adhesive agent supplied to the gap between the vertical wall and the lower substrate of the upper substrate has a thixotropic all-gas adhesive. The adhesive flows into the gap by capillary action. The flow sensor of claim 7, wherein after the adhesive applied to the gap between the vertical wall of the upper substrate and the lower substrate is hardened, another adhesive is supplied to the outer side of the gap. 1 2. The flow sensor of the scope of the patent application, wherein the external terminal is formed on the metal plating layer on at least the side of the lower substrate. 19 201213775 13. The flow sensor of claim 8 wherein the external terminal is formed by a lead frame integral with the external circuit pattern. A flow rate detecting device using the flow sensor of the first application of the patent scope, characterized in that: the main official material 'package body to which the flow sensor is fixed' forms a fluid flow path; and the main split flow path The inlet, 'from the main material, the fluid is diverted to the flow sense and is guided from the outflow to the mainstream of the quasi-pipe.蜊 1 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. In the second sub-pipe, an opening in the upstream direction of the main flow path is formed in the first sub-pipe, and an opening in the downstream direction of the main flow path is formed in the second sub-pipe. Hey. Main body 16. The flow rate detecting device of claim 5, wherein a control substrate having a flow sensor and a control circuit component is fixed to the main material, and the first and second sub-pipes pass through the control substrate Connected to the flow sensor. Eight, schema: (such as the next page)