Physical quantity detection device

Abstract

A physical quantity detection device has a housing, a cover, a circuit substrate, a chip package, and a sealing material. The chip package has a package main body, a flow sensor, a plurality of connection terminals, a ventilation port, and a ventilation passage. The sealing material has a boundary portion that seals a boundary between the sub-passage and the circuit chamber of the package main body, and a pair of side edge portions that are arranged along both side edge lines of the chip package and bury the plurality of connection terminals.

Description

Technical Field

[0001] This invention relates to a physical quantity detection device. Background Technology

[0002] Patent Document 1 discloses the structure of a physical quantity detection device: a housing having a sub-channel and a circuit chamber, and a chip package with its top end disposed in the sub-channel and its base end disposed in the circuit chamber. The chip package has a flow sensor with a diaphragm structure exposed within the sub-channel, and a ventilation channel is formed in the package body connecting the diaphragm chamber of the flow sensor and a ventilation port opening within the circuit chamber. The chip package is connected and fixed by soldering multiple connection terminals disposed at its base end to a circuit board within the circuit chamber. To maintain the airtightness of the circuit chamber, the physical quantity detection device seals the boundary between the sub-channel containing the chip package and the circuit chamber with an adhesive. Furthermore, to ensure insulation between the connection terminals of the chip package, resin is used to seal the multiple connection terminals.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: WO2019 / 064933 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] However, when sealing the boundary with adhesive, there is a possibility that the overflowing adhesive may clog the vent. If the vent is clogged, the diaphragm may deform due to the pressure difference between the diaphragm chamber and the secondary channel, potentially affecting the flow sensor's measurement values. Furthermore, in the past, in addition to the adhesive used to seal the boundary, a process of preparing resin to insulate multiple connection terminals was required, making it difficult to reduce material and manufacturing costs.

[0008] The present invention was made in view of the above circumstances, and its object is to provide a physical quantity detection device having a structure that can easily ensure the sealing of the boundary portion and the insulation between multiple connection terminals.

[0009] means for solving problems

[0010] The physical quantity detection device of the present invention for solving the above-mentioned problems includes: a housing having a secondary channel and a circuit chamber; a cover covering the secondary channel and the circuit chamber of the housing; a circuit board housed in the circuit chamber; a chip package disposed opposite to the cover within the housing; and a sealing material sealing between the housing and the cover. The physical quantity detection device is characterized in that: the chip package has: a package body with a top portion disposed in the secondary channel and a base portion disposed in the circuit chamber; a diaphragm-type flow sensor disposed at the top portion of the package body; a plurality of connecting terminals protruding from two opposite ends of the base portion of the package body and connected to the circuit board; a vent opening at the base portion of the package body; and a venting channel penetrating the package body to connect the vent opening and the diaphragm chamber of the flow sensor. The sealing material has: a boundary portion sealing the boundary between the secondary channel and the circuit chamber of the package body; and a pair of side edges disposed along the two ends of the chip package to bury the plurality of connecting terminals.

[0011] The effects of the invention

[0012] A physical quantity detection device with a structure that can easily ensure the sealing of the boundary portion between the secondary channel and the circuit chamber and the insulation between multiple connection terminals is obtained. Further features associated with the present invention become clear from the description and drawings herein. Furthermore, issues, configurations, and effects other than those described above are clarified by the following description of embodiments. Attached Figure Description

[0013] Figure 1 This is a system diagram illustrating an embodiment of the physical quantity detection device involved in the present invention used in an internal combustion engine control system.

[0014] Figure 2 This is a front view of the physical quantity detection device according to the first embodiment.

[0015] Figure 3 It shows that Figure 2 The diagram shows the state of the physical quantity detection device after the cover has been removed.

[0016] Figure 4 This is a diagram showing the circuit board.

[0017] Figure 5 yes Figure 4 An enlarged cross-sectional view of the sensor assembly of the physical quantity detection device shown.

[0018] Figure 6 This is an enlarged view of the main parts of the physical quantity detection device according to the first embodiment.

[0019] Figure 7 yes Figure 6 AA-line cross-section view.

[0020] Figure 8 yes Figure 6 BB line cross-section.

[0021] Figure 9 This is a diagram showing the main parts of the physical quantity detection device according to the second embodiment.

[0022] Figure 10 This is a diagram showing the main parts of the physical quantity detection device according to the third embodiment.

[0023] Figure 11 This is a diagram showing the main parts of the physical quantity detection device according to the third embodiment.

[0024] Figure 12 This is a diagram showing the main parts of the physical quantity detection device according to the fourth embodiment.

[0025] Figure 13 This is a diagram showing the main parts of the physical quantity detection device according to the fifth embodiment.

[0026] Figure 14 This is a diagram showing the main parts of the physical quantity detection device according to the sixth embodiment. Detailed Implementation

[0027] The specific embodiments described below (hereinafter referred to as embodiments) solve various problems required as actual products, and in particular solve various problems that are expected to be solved when used in a detection device for detecting the physical quantity of intake air in a vehicle, thus exerting various effects. One of the various problems solved by the following embodiments is described in the "Problems to be Solved by the Invention" section, and another of the various effects exerted by the following embodiments is described in the "Effects of the Invention" section. The various problems solved by the following embodiments, and further, the various effects exerted by the following embodiments, are described in the description of the embodiments. Therefore, the problems solved and the effects of the embodiments described in the following embodiments also include content beyond that in the "Problems to be Solved by the Invention" and "Effects of the Invention" sections.

[0028] In the following embodiments, the same reference numerals, even if the drawing numbers are different, indicate the same configuration and perform the same function. Regarding the configurations already described, there are cases where only reference numerals are used in the drawings and the description is omitted.

[0029] Figure 1This is a system diagram illustrating an embodiment of the physical quantity detection device 20 according to this embodiment used in an internal combustion engine control system 1 with electronic fuel injection. Based on the operation of the internal combustion engine 10, which includes engine cylinders 11 and engine pistons 12, intake air, as the measured gas 2, is drawn in from the air filter 21 and guided to the combustion chamber of the engine cylinder 11 via, for example, the intake body, the throttle body 23, and the intake manifold 24, which serve as the main passage 22. The physical quantity of the measured gas 2, which is the intake air, guided to the combustion chamber is detected by the physical quantity detection device 20. Based on the detected physical quantity, fuel is supplied from the fuel injection valve 14 and guided to the combustion chamber in a mixture with the measured gas 2. Furthermore, in this embodiment, the fuel injection valve 14 is provided at the intake port of the internal combustion engine. The fuel injected into the intake port forms a mixture with the measured gas 2, which is guided to the combustion chamber via the intake valve 15 and combusted to generate mechanical energy.

[0030] The fuel and air guided into the combustion chamber form a fuel-air mixture, which is ignited by the spark plug 13 and combusts explosively, generating mechanical energy. The combusted gases are guided from the exhaust valve 16 to the exhaust pipe and discharged outside the vehicle as exhaust gas 3. The flow rate of the measured gas 2, which is guided into the combustion chamber as intake air, is controlled by the throttle valve 25, whose opening is changed based on the operation of the accelerator pedal. The fuel supply is controlled based on the flow rate of the intake air guided into the combustion chamber. By controlling the opening of the throttle valve 25, the driver can control the flow rate of the intake air guided into the combustion chamber, thereby controlling the mechanical energy generated by the internal combustion engine.

[0031] The physical quantities of the intake air (gas 2 being measured), such as flow rate, temperature, humidity, and pressure, drawn in from the air filter 21 and flowing through the main channel 22, are detected by the physical quantity detection device 20. An electrical signal representing the physical quantity of the intake air is input from the physical quantity detection device 20 to the control device 4. Furthermore, the output of the throttle angle sensor 26, which measures the opening of the throttle valve 25, is input to the control device 4. To further measure the position and state of the engine piston 12, intake valve 15, and exhaust valve 16, as well as the rotational speed of the internal combustion engine, the output of the rotational angle sensor 17 is input to the control device 4. To measure the state of the fuel-air mixture ratio based on the state of the exhaust gas 3, the output of the oxygen sensor 28 is input to the control device 4.

[0032] The control device 4 calculates the fuel injection quantity and ignition timing based on the physical quantity of the intake air output by the physical quantity detection device 20 and the rotational speed of the internal combustion engine measured based on the output of the rotation angle sensor 17. Based on these calculation results, the amount of fuel supplied from the fuel injection valve 14 and the ignition timing ignited by the spark plug 13 are controlled. The fuel supply quantity and ignition timing are further precisely controlled based on the temperature and throttle angle changes detected by the physical quantity detection device 20, the engine rotational speed changes, and the air-fuel ratio measured by the oxygen sensor 28. The control device 4 further controls the amount of air bypassing the throttle valve 25 using the idle air control valve 27 and controls the rotational speed of the internal combustion engine during idle operation.

[0033] The fuel supply and ignition timing, which are the main control quantities of the internal combustion engine, are calculated using the output of the physical quantity detection device 20 as the primary parameters. Therefore, improving the detection accuracy, suppressing time-varying changes, and enhancing the reliability of the physical quantity detection device 20 are crucial for improving the control accuracy and ensuring the reliability of the vehicle.

[0034] Especially in recent years, the demand for low fuel consumption in vehicles has been very high, as has the demand for exhaust gas purification. To meet these demands, improving the detection accuracy of the physical quantities of the intake air detected by the physical quantity detection device 20 is extremely important. Furthermore, maintaining high reliability of the physical quantity detection device 20 is also crucial.

[0035] Vehicles equipped with physical quantity detection devices 20 are used in environments with large variations in temperature and humidity. The physical quantity detection devices 20 are also intended to cope with variations in temperature and humidity in their operating environment, as well as with dust and pollutants.

[0036] Furthermore, the physical quantity detection device 20 is installed in the intake manifold, which is affected by heat from the internal combustion engine. Therefore, heat from the internal combustion engine is conducted to the physical quantity detection device 20 via the intake manifold. The physical quantity detection device 20 detects the flow rate of the gas being measured by heat transfer with it; therefore, it is important to minimize the influence of external heat.

[0037] The physical quantity detection device 20 mounted on a vehicle, as described below, not only solves the problems listed in the "Problems to be Solved by the Invention" section and achieves the effects listed in the "Effects of the Invention" section, but also, as described below, fully considers the various problems mentioned above, solves the various problems required as a product, and achieves various effects. The specific problems solved and the specific effects achieved by the physical quantity detection device 20 will be described in the following description of the embodiments.

[0038] [First Implementation Method]

[0039] Figure 2 and Figure 3 This is a diagram showing the appearance of the physical quantity detection device. In the following description, it is assumed that the gas to be measured 2 flows along the central axis 22a of the main channel 22. The physical quantity detection device 20 of this embodiment also includes the function of a flow rate measuring device, which measures the flow rate, which is one of the physical quantities of the gas to be measured 2.

[0040] The physical quantity detection device 20 is used in a state where it is inserted into the main channel 22 through a mounting hole provided in the channel wall of the main channel 22 and fixed in the main channel 22. The physical quantity detection device 20 has a housing disposed in the main channel 22 where the gas flow to be measured is located. The housing of the physical quantity detection device 20 has a housing 100 and a cover 200 mounted on the housing 100. The housing 100 is constructed, for example, by injection molding of a synthetic resin material.

[0041] The cover 200 is, for example, composed of a plate-like member made of a metal material or a synthetic resin material; in this embodiment, it is an injection-molded article made of aluminum alloy or synthetic resin material. Figure 2 As shown, the cover 200 is sized to fully cover the front of the housing 100.

[0042] The housing 100 has a flange 111, a connector 112, and a measuring part 113. The flange 111 is used to fix the physical quantity detection device 20 to the air intake body, which serves as the main channel 22. The connector 112 protrudes from the flange 111 and is exposed to the outside from the air intake body for electrical connection with an external machine. The measuring part 113 extends from the flange 111 in a manner that protrudes toward the center of the main channel 22.

[0043] The measuring unit 113 is inserted into the main channel 22 through the mounting hole provided therein, and the flange 111 of the physical quantity detection device 20 abuts against the main channel 22 and is fixed to the main channel 22 by screws.

[0044] The measuring section 113 is thin and long, extending straight from the flange 111, and has a wide front side 121 and a back side 122, as well as a pair of narrow side sides 123 and 124. With the physical quantity detection device 20 installed in the main channel 22, the measuring section 113 protrudes from the inner wall of the main channel 22 toward the center of the main channel 22. Furthermore, the front side 121 and the back side 122 are arranged parallel to each other along the central axis 22a of the main channel 22. Among the narrow side sides 123 and 124 of the measuring section 113, the side 123 on the width direction of the measuring section 113 is arranged opposite to the upstream side (air filter side) of the main channel 22, and the side 124 on the other side of the width direction of the measuring section 113 is arranged opposite to the downstream side (engine side) of the main channel 22.

[0045] In this embodiment, with the physical quantity detection device 20 installed on the main channel 22, the base end of the measuring section 113 is positioned on the upper side, and the top end of the measuring section 113 is positioned on the lower side. Furthermore, the top end of the measuring section 113 has a lower surface 125. However, the posture in which the physical quantity detection device 20 is used is not limited to this embodiment and can be in various postures; for example, it can be in a posture in which the base end and top end of the measuring section 113 are horizontally installed at the same height.

[0046] In the following description, the axis in the direction in which the measuring part 113 extends from the flange 111, i.e. the length direction of the measuring part 113, is sometimes referred to as the Z-axis; the axis in the direction in the width direction of the measuring part 113, i.e. the direction in which the measuring part 113 extends from the secondary channel inlet 131 to the first outlet 132, is sometimes referred to as the X-axis; and the axis in the direction in the thickness direction of the measuring part 113, i.e. the direction in which the measuring part 113 extends from the front side 121 to the back side 122, is sometimes referred to as the Y-axis.

[0047] The measuring unit 113 has a secondary channel inlet 131 on one side 123 in the X-axis direction, and a first outlet 132 and a second outlet 133 on the other side 124 in the X-axis direction. The secondary channel inlet 131, the first outlet 132, and the second outlet 133 are located at the top end of the measuring unit 113, which extends from the flange 111 toward the center of the main channel 22 in the Z-axis direction. Therefore, the portion of the gas 2 being measured that flows in the main channel 22 and is closer to the center than the inner wall of the main channel 22 can be taken into the secondary channel 134. Thus, the physical quantity detection device 20 can measure the flow rate of the portion of the gas 2 being measured that is far from the inner wall of the main channel 22, and can suppress the decrease in measurement accuracy caused by the influence of heat, etc.

[0048] The measuring section 113 is shaped to extend long along the Z-axis from the outer wall of the main channel 22 toward the center, but the width of the sides 123 and 124 in the Y-axis direction is narrow. As a result, the physical quantity detection device 20 can suppress the fluid resistance of the gas 2 being measured to a small value.

[0049] The measuring part 113 is inserted into the main channel 22 through the mounting hole provided therein, the flange 111 abuts against the main channel 22, and is fixed to the main channel 22 by screws.

[0050] Figure 3 It shows that Figure 2 The diagram shows the state of the physical quantity detection device after the cover has been removed.

[0051] The measuring section 113 of the housing 100 is equipped with a flow sensor 411, an inlet air temperature sensor 321, and a humidity sensor 322, which serve as flow detection elements. The flow sensor 411 detects the flow rate of the gas to be measured 2 flowing in the main channel. The flow sensor 411 is a diaphragm sensor and is positioned midway through the secondary channel 134. The inlet air temperature sensor 321 is positioned midway through the temperature detection channel 136, one end of which opens near the secondary channel inlet 131 on the side 123, and the other end opens on both the front and back sides of the measuring section 113. The inlet air temperature sensor 321 detects the temperature of the gas to be measured 2 flowing in the main channel. The humidity sensor 322 is positioned in the humidity measuring chamber 137 of the measuring section 113. The humidity sensor 322 measures the humidity of the gas to be measured being drawn into the humidity measuring chamber 137 through a window 139 opening on the back side of the measuring section 113.

[0052] The measuring section 113 is provided with a sub-channel groove 150 for forming a sub-channel 134 and a circuit chamber 135 for housing the circuit board 300. The circuit chamber 135 and the sub-channel groove 150 are structured such that they are recessed in the front surface 121 of the measuring section 113 and are covered by a cover 200 installed on the front surface 121 of the measuring section 113.

[0053] The circuit chamber 135 is located in the main channel 22 in the X-axis direction (side 123 side) of the upstream side of the flow direction of the gas being measured 2.

[0054] The secondary channel groove 150 is provided to span the region on the top side (lower surface 125 side) of the measuring section 113 in the Z-axis direction, which is closer to the circuit chamber 135, and the region on the other side (side 124 side) in the X-axis direction, which is closer to the main channel 22 and is located downstream of the flow direction of the gas being measured 2, which is closer to the circuit chamber 135.

[0055] The secondary channel 150 forms a secondary channel 134 in cooperation with the cover 200 covering the front 121 of the measuring unit 113. The secondary channel 150 has a first secondary channel 151 and a second secondary channel 152 branching off from the first secondary channel 151. The first secondary channel 151 spans between a secondary channel inlet 131 opening on one side 123 of the measuring unit 113 and a first outlet 132 opening on the other side 124 of the measuring unit 113, and is formed to extend along the X-axis direction of the measuring unit 113. The first secondary channel 151, in cooperation with the cover 200, forms a first secondary channel 1331 that draws in the measured gas 2 flowing in the main channel 22 from the secondary channel inlet 131 and returns the drawn-in measured gas 2 from the first outlet 132 back to the main channel 22. The first secondary channel 1331 has a flow path extending from the secondary channel inlet 131 along the flow direction of the measured gas 2 in the main channel 22 and connected to the first outlet 132.

[0056] The second auxiliary channel groove 152 branches off midway from the first auxiliary channel groove 151 and bends towards the base end side (flange side) of the measuring section 113, extending along the Z-axis direction of the measuring section 113. Furthermore, it bends towards the other side (side 124 side) of the measuring section 113 in the X-axis direction at the base end of the measuring section 113, making a U-shaped turn towards the top end of the measuring section 113, and again extending along the Z-axis direction of the measuring section 113. It also bends towards the other side (side 124 side) of the measuring section 113 in the X-axis direction in front of the first outlet 132, and is continuously provided with the second outlet 133, which opens into the side 124 of the measuring section 113. The second outlet 133 is positioned opposite to the downstream side of the flow direction of the measured gas 2 in the main channel 22. Compared to the first outlet 132, the second outlet 133 has a slightly larger opening area and is formed at a position more adjacent to the base end side of the measuring section 113 in the longitudinal direction than the first outlet 132.

[0057] The second auxiliary channel 152, in cooperation with the cover 200, forms a second auxiliary channel 1332 through which the measured gas 2, branching from the first auxiliary channel 1331, passes and returns to the main channel 22 from the second outlet 133. The second auxiliary channel 1332 has a flow path that travels back and forth along the Z-axis direction of the measuring section 113. That is, the second auxiliary channel 1332 has a branching section that extends towards the base end of the measuring section 113 (away from the first auxiliary channel 1331) from the middle of the first auxiliary channel 1331, and a secondary channel section that turns back at the base end of the measuring section 113 (the end of the branching section) and extends towards the top end of the measuring section 113 (closer to the first auxiliary channel 1331). The secondary channel section has a flow path connected to the second outlet 133, which opens towards the downstream side of the flow direction of the measured gas 2 in the main channel 22, closer to the auxiliary channel inlet 131. At the turning point of the second auxiliary channel 1332, a connecting channel 138 is provided that connects to the circuit chamber 135, allowing gas to pass between the second auxiliary channel 1332 and the circuit chamber 135.

[0058] Regarding the second auxiliary channel 1332, a flow sensor (flow detection unit) 411 is disposed at a position midway along the channel section. Since the second auxiliary channel 1332 is formed in a reciprocating manner extending along the length direction of the measuring unit 113, a longer channel length can be ensured, and the impact on the flow sensor 411 can be reduced when pulsations occur in the main channel. The flow sensor 411 is disposed in a chip package 400, which is mounted on a circuit board 300.

[0059] Figure 4 This is a diagram showing the circuit board.

[0060] Regarding the circuit board 300, circuit components such as a chip package 400, an intake air temperature sensor 321, and a humidity sensor 322 are mounted on the surface mounting surface. The circuit board 300 has a roughly rectangular shape when viewed from above. Figure 3 As shown, the circuit board 300 extends from the base end to the top end of the measuring section 113 in the length direction (z direction) and extends from the side side 123 to the side side 124 of the measuring section 113 in the width direction.

[0061] The circuit board 300 has a substrate body 301 disposed within a circuit chamber 135, a first protrusion 302 disposed in a temperature detection channel 136, a second protrusion 303 disposed in a humidity measurement chamber 137, and a third protrusion 304 disposed in the channel portion of a second sub-channel 1332, all extending flush with the substrate body 301. An intake temperature sensor 321 is mounted at the top of the first protrusion 302, and a humidity sensor 322 is mounted in the second protrusion 303. The third protrusion 304 is disposed opposite to the top end 401B of the chip package 400 in the channel portion of the second sub-channel 1332. The third protrusion 304 of the circuit board 300 closes the open portion of the recess 404 of the chip package 400, thereby forming the first channel portion D1 (see reference). Figure 7 Additionally, the third protrusion 304 of the circuit board 300 forms a second channel portion D2 between itself and the bottom wall surface 152a of the second sub-channel groove 152 (see reference). Figure 7 ).

[0062] Figure 5 yes Figure 4 An enlarged cross-sectional view of the sensor assembly of the physical quantity detection device shown.

[0063] The chip package 400 has a resin encapsulation structure in which the flow sensor 411, LSI 412, and lead frame 413 are molded from molding resin. The flow sensor 411 and LSI 412 are mounted on the lead frame 413.

[0064] The chip package 400 is molded from molding resin with the detection part of the flow sensor 411 exposed. The detection part of the flow sensor 411 has a diaphragm structure. During the molding of the chip package 400 with resin, the resin is molded against an insert to prevent resin from flowing into the detection part of the flow sensor 411.

[0065] The chip package 400 has a package body (support) 401 with a flat plate shape and a specified thickness, formed from molding resin. Recesses 421 and 422 are formed at the base end 401A and top end 401B of the package body 401 by inserts that support the lead frame 413 during resin molding, with a portion of the lead frame 413 partially exposed. Regarding the chip package 400, the base end 401A of the package body 401 is disposed within the circuit chamber 135, and the top end 401B of the package body 401 is protrudingly disposed in the second sub-channel groove 152. The chip package 400 is electrically connected to the circuit board 300 via a fixing part and is mechanically fixed.

[0066] A plurality of connection terminals 414 are provided at the base end 401A of the encapsulation body 401 (see reference). Figure 4Multiple connection terminals 414 are arranged such that they protrude from both ends of the base end portion 401A of the package body 401 in a direction opposite to each other along the width direction of the package body 401. The top tip of each connection terminal 414 is bent toward the thickness direction of the base end portion 401A and is positioned at a position that protrudes in the thickness direction from the back surface 403 of the base end portion 401A. The multiple connection terminals 414 are arranged such that they protrude from the center of the thickness direction of the package body 401 toward the width direction of the package body 401.

[0067] The chip package 400 is electrically conductive by soldering a plurality of connection terminals 414 provided at the base end 401A of the package body 401 to a plurality of pads 325 of the circuit board 300, and is integrally fixed to the circuit board 300. The base end 401A of the chip package 400 is fixed to the circuit board 300, and the top end 401B protrudes from the circuit board 300, forming a so-called cantilever support relative to the circuit board 300.

[0068] The top end 401B of the package body 401 is disposed opposite to the third protrusion 304 of the circuit board 300 within the channel portion of the second sub-channel 1332. A groove 404 is formed in the top end 401B of the package body 401. The groove 404 is formed on the back surface 403 of the top end 401B of the package body 401 in such a way that it extends across the width direction of the top end 401B of the package body 401, and at the middle position of its extension direction, the detection part of the flow sensor 411 is exposed.

[0069] The chip package 400 can also be configured to integrate the LSI 412 and the flow sensor 411, or to fix the LSI 412 to the circuit board 300. Alternatively, the chip package 400 can be a structure that mounts the flow sensor 411 on a resin molded body (sensor support) made by sealing metal terminals with resin. The chip package 400 includes at least the flow sensor 411 and components that support the flow sensor 411.

[0070] The chip package 400 is configured such that a recess 404 extends along the second sub-channel 1332 towards the channel portion. The chip package 400 is configured such that the flow sensor 411 is opposite to the third protrusion 304, which is part of the circuit board 300. A first channel portion D1 (see reference 1) is formed between the recess 404 of the package body 401 and the third protrusion 304 of the circuit board 300. Figure 7 In the first channel section D1, the flow rate of the gas to be measured flowing through the second sub-channel 1332 is detected by the flow sensor 411.

[0071] The chip package 400 is fixed to the circuit board 300 by soldering the connection terminals 414 onto the circuit board 300. That is, the soldered portion constitutes a fixing part that electrically connects and mechanically fixes the chip package 400 to the circuit board 300. However, the method of fixing the chip package 400 to the circuit board 300 is not limited to soldering. For example, a crimping method can be used, in which multiple connection terminals are formed by crimping terminals and these crimping terminals are inserted into through holes provided on the circuit board 300 for connection; or a method can be used, in which multiple connection terminals 414 are bonded to the connection pads of the circuit board 300 by applying a conductive adhesive such as silver paste for fixation.

[0072] The chip package 400 has a ventilation channel 423 that extends through the package body 401, thereby connecting the diaphragm chamber 424 of the detection section having the flow sensor 411 with the ventilation port 425 exposed in the recess 422. The ventilation channel 423 is formed by the cooperation of a groove recessed on the surface of the lead frame 413 and a thin plate-like member stacked on the surface of the groove.

[0073] Figure 6 This is an enlarged view of the main parts of the physical quantity detection device according to the first embodiment. Figure 7 yes Figure 6 AA-line cross-section view.

[0074] A sealing material 500 is applied between the measuring section 113 and the cover 200. The sealing material 500 is applied along the first sub-channel 1331 and the second sub-channel 1332. Furthermore, the sealing material 500 has a boundary portion 501 disposed between the circuit chamber 135 of the package body 401 and the sub-channel 134, and a pair of side edge portions 502 disposed along the two end edges of the base end portion 401A of the package body 401. Through the boundary portion 501 and the pair of side edge portions 502, the sealing material 500 adheres three sides of the package body 401 adjacent to the second sub-channel 1332 to the cover 200, while one side disposed away from the second sub-channel 1332 is not adhered to the cover 200.

[0075] The boundary portion 501 of the sealing material 500 spatially divides the gap between the surface 402 of the package body 401 and the back surface 201 of the cover 200 into a sub-channel 134 side and a circuit chamber 135 side. The boundary portion 501 is coated from one side to the other along the width direction of the base end portion 401A of the package body 401 at the coating center position P. A pair of side edges 502 of the sealing material 500 are filled across the space between the circuit board 300 and the cover 200, burying multiple connection terminals 414 and isolating them from the outside.

[0076] The sealing material 500 is not applied to the central region of the surface 402 of the base end portion 401A, forming a space R1 between the central region of the surface 402 of the base end portion 401A and the cover 200. Furthermore, the sealing material 500 is not applied between the base edge 405 of the base end portion 401A and the cover 200, leaving the base edge 405 of the base end portion 401A and the cover 200 open. That is, space R1 is not sealed, as it connects to other spaces R2 within the circuit chamber 135 via the open portion between the base edge 405 of the base end portion 401A and the cover 200.

[0077] The ventilation port 425 opens in the central region of the surface 402 of the base end 401A, is not blocked by the sealing material 500, and connects to space R1. Furthermore, space R1 connects to space R2 within the circuit chamber 135 via the base edge of the base end 401A, and is not sealed. That is, spaces R1 and R2 are connected, as shown... Figure 6 As indicated by the thick arrow, the gases can flow between each other.

[0078] like Figure 7 As shown by the imaginary lines, the boundary portion 501 is coated with sealing material 500 at the center P of the coating position along the boundary between the circuit chamber 135 and the sub-channel 134. Furthermore, by covering the measuring portion 113 with the cover 200, the sealing material 500 is formed by being crushed and extended between the cover 200 and the base end portion 401A of the encapsulation body 401. Although the installation of the cover 200 causes a portion of the sealing material 500 to extend in mutually opposite directions on the base end portion 401A side and the top end portion 401B side of the encapsulation body 401, thereby forming the boundary portion 501, the vent 425, being located in the central region of the surface 402 of the base end portion 401A, is far from the boundary portion where the sealing material 500 is applied. Therefore, the sealing material 500 does not reach the vent 425, maintaining the vent 425 open to the space R1.

[0079] Furthermore, a raised portion 402A is formed on the top end portion 401B side of the surface 402 of the package body 401. The raised portion 402A extends across the width direction of the package body 401 to demarcate the base end portion 401A and the top end portion 401B. Additionally, a groove 203 is formed along the raised portion 402A on the back surface 201 of the cover 200 opposite to the package body 401.

[0080] The groove 203 of the cover 200 and the protrusion 402A of the encapsulation body 401 can block the movement of a portion of the sealing material 500 as it extends towards the top end 401B of the encapsulation body 401 through the installation of the cover 200, thus preventing the sealing material 500 from overflowing towards the second secondary channel 1332.

[0081] Figure 8yes Figure 6 BB line cross-section.

[0082] The sealing material 500 is applied to the side edges 502 along both ends of the base end 401A of the package body 401, and is filled across the space between the circuit board 300 and the cover 200. The side edges 502 bury and seal the plurality of connection terminals 414 disposed on the base end 401A of the package body 401, thereby ensuring the insulation between the plurality of connection terminals 414.

[0083] According to the physical quantity detection device 20 of this embodiment, the circuit chamber 135 of the package body 401 and the sub-channel 134 are sealed by a boundary portion 501, and a plurality of connection terminals 414 are sealed by a pair of side edges 502. That is, through the boundary portion 501 and the pair of side edges 502 of the sealing material 500, three sides of the package body 401 adjacent to the sub-channel 134 are bonded to the cover 200 among the four sides surrounding the central region of the base end portion 401A, while one side disposed away from the sub-channel 134 is not bonded to the cover 200.

[0084] Therefore, by sealing the boundary portion 501 between the sub-channel 134 and the circuit chamber 135, gas leakage through the boundary portion between the sub-channel 134 and the circuit chamber 135 of the chip package 400 can be prevented. Furthermore, since the multiple connection terminals 414 are embedded by a pair of side edges 502, insulation between adjacent connection terminals can be ensured. In this way, a single sealing material 500 can be used to seal the boundary portion between the sub-channel 134 and the circuit chamber 135 of the chip package 400 and to insulate the multiple connection terminals 414. Therefore, compared to existing examples that use multiple adhesives and require multiple construction steps, material and manufacturing costs can be reduced.

[0085] Furthermore, the space R1 between the central region of the surface 402 of the package body 401 and the cover 200 is not filled with sealing material 500, and the vent 425 opening in the central region of the surface 402 of the base end 401A is not blocked by sealing material 500. The base edge 405 of the base end 401A is open between itself and the cover 200, and the space R1 connects to other spaces R2 within the circuit chamber 135.

[0086] That is, the diaphragm chamber 424 is connected to the sub-channel 134 via the ventilation channel 423, the ventilation port 425, the space R1 in the circuit chamber 135, other spaces R2, and the connecting channel 138, which enables the internal pressure of the diaphragm chamber 424 to be equal to the internal pressure of the sub-channel 134. Therefore, it is possible to prevent the diaphragm of the detection part of the flow sensor 411 from deforming due to the pressure difference between the diaphragm chamber 424 and the sub-channel 134.

[0087] Furthermore, the space R1 between the central region of the surface 402 of the package body 401 and the cover 200 is open between the base edge 405 of the base end portion 401A and the cover 200, thus connecting to other spaces R2. If the base edge 405 of the base end portion 401A were closed between itself and the cover 200, and the four sides of the central region surrounding the surface 402 of the package body 401 were bonded to the cover 200, and space R1 were sealed and not connected to space R2, the expansion of internal air within space R1 due to temperature differences could cause stress to act on the LSI or electronic components of the chip package 400, potentially affecting the control function of the chip package 400. In contrast, in this embodiment, since one side between the base edge 405 of the base end portion 401A and the cover 200 is open, stress caused by the expansion of internal air within space R1 can be prevented from acting on the LSI or other components.

[0088] [Second Implementation]

[0089] Figure 9 This diagram illustrates the second embodiment, and is different from the first embodiment. Figure 7 The corresponding diagram.

[0090] The feature of this embodiment is that the gap between the back surface 201 of the cover 200 and the surface 402 of the encapsulation body 401 is configured such that the gap on the circuit chamber 135 side is larger than that on the sub-channel 134 side.

[0091] The cover 200 has a step 204 at the boundary between the secondary channel 134 side and the circuit chamber 135 side of the back surface 201 of the cover 200, making the thickness of the cover 200 on the circuit chamber 135 side thinner than that on the secondary channel 134 side. With this configuration, the gap between the back surface 201 of the cover 200 and the surface 402 of the package body 401 is such that the gap δ2 on the circuit chamber 135 side is larger than the gap δ1 on the secondary channel 134 side.

[0092] Therefore, as Figure 9 As shown by the imaginary line, when the sealing material 500 is applied to the boundary between the circuit chamber 135 and the sub-channel 134, and the cover 200 is placed over the measuring section 113, a portion of the sealing material 500 can be actively pushed towards the base end 401A, and its forward expansion towards the top end 401B can be suppressed. Therefore, it is possible to prevent the sealing material 500 from overflowing towards the second sub-channel 1332.

[0093] [Third Implementation Method]

[0094] Figure 10 and Figure 11 This is a diagram illustrating the third embodiment. Figure 10 It corresponds to Figure 6 A cross-sectional view of the CC line. Figure 11 It corresponds to Figure 6 A cross-sectional view of the DD line. The feature of this embodiment is that the shape of the back surface 201 of the cover 200 is made uniform with the external shape of the package body 401 and the external shape of the connection terminal 414.

[0095] Figure 10 (1) illustrates this embodiment. Figure 10 (2) shows a comparative example.

[0096] In this embodiment, the portion of the back surface 201 of the cover 200 that is opposite to the surface 402 of the encapsulation body 401 is formed as a plane along the shape of the surface 402 of the encapsulation body 401, and has a shape with a gap δ3 between it and the surface 402 of the encapsulation body 401.

[0097] Furthermore, the portions opposite to the corners 431 on both sides of the width direction of the encapsulation body 401 have the following shape: they are concavely curved along the shape of the corners 431, and there is a gap δ4 between them. The gaps δ3 and δ4 are almost identical, and the gap formed between the back surface 201 of the cover 200 and the surface 402 of the encapsulation body 401 is uniform across the lateral width direction of the encapsulation body 401.

[0098] exist Figure 10 In the comparative example shown in (2), the portion of the back surface 201 of the cover 200 opposite to the surface 402 of the encapsulation body 401 is formed as a planar shape along the shape of the surface 402 of the encapsulation body 401, and has a shape with a gap δ3' between it and the surface 402 of the encapsulation body 401.

[0099] Furthermore, the portion of the back surface 201 of the cover 200 opposite to the corner 431 of the encapsulation body 401 is flat, and is shaped such that it gradually moves away from the corner 431 as it shifts outward in the width direction of the encapsulation body 401, and has a gap δ4' between it and the corner 431. The gap δ4' is larger than the gap δ3', and the gap formed between the back surface 201 of the cover 200 and the surface 402 of the encapsulation body 401 is non-uniform along the lateral width direction of the encapsulation body 401.

[0100] Figure 11 (1) illustrates this embodiment. Figure 11 (2) shows a comparative example.

[0101] The portion of the back surface 201 of the cover 200 that is opposite to the surface 402 of the encapsulation body 401 is formed as a plane along the shape of the surface 402 of the encapsulation body 401 and has a shape with a gap δ5 between it and the surface 402 of the encapsulation body 401.

[0102] Furthermore, the portions opposite to the corners 431 on both sides of the width direction of the encapsulation body 401 are concavely curved along the shape of the corners 431 and have a shape with a gap δ6 between them. Also, the portions opposite to the plurality of connecting terminals 414 have a shape with a gap δ7 between them. These gaps δ5, δ6, and δ7 are almost identical, and the gap formed between the cover 200 and the encapsulation body 401 is uniform across the lateral width direction of the encapsulation body 401.

[0103] exist Figure 11 In the comparative example shown in (2), the portion of the back surface 201 of the cover 200 opposite to the surface 402 of the encapsulation body 401 is formed as a planar shape along the shape of the surface 402 of the encapsulation body 401, and has a shape with a gap δ5' between it and the surface 402 of the encapsulation body 401.

[0104] Furthermore, the portion of the back surface 201 of the cover 200 opposite to the corner 431 of the encapsulation body 401 and the plurality of connecting terminals 414 is also flat, and is formed such that it gradually moves away from the corner 431 as it shifts outward in the width direction of the encapsulation body 401, and has a shape with gaps δ6' and δ7' between it and the corner 431. Gap δ6' and gap δ7' are larger than gap δ5', and the gap formed between the cover 200 and the encapsulation body 401 is non-uniform along the lateral width direction of the encapsulation body 401.

[0105] According to this embodiment, the gap formed between the cover 200 and the encapsulation body 401 is uniform along the lateral width direction of the encapsulation body 401. Therefore, as Figure 9 As shown by the imaginary line, when the sealing material 500 is applied to the boundary between the circuit chamber 135 and the sub-channel 134 and the cover 200 is placed over the measuring section 113, the overflow of the crushed sealing material 500 can be controlled, thereby reliably sealing the package body 401 and the cover 200. Furthermore, it can prevent unsealing on both sides due to deviations in the application position and amount of the sealing material 500.

[0106] [Fourth Implementation Method]

[0107] Figure 12 This is a diagram illustrating the third embodiment, corresponding to... Figure 6 A cross-sectional view of the DD line. The feature of this embodiment is that the shape of the back surface 201 of the cover 200, which is opposite to the external shape of the package body 401, is a reverse bevel (reverse hook-fit) shape.

[0108] Figure 12 (1) illustrates this embodiment. Figure 12 (2) shows a comparative example.

[0109] In this embodiment, the portion of the back surface 201 of the cover 200 that is opposite to the surface 402 of the encapsulation body 401 is formed as a plane along the shape of the surface 402 of the encapsulation body 401, and has a shape with a gap δ8 between it and the surface 402 of the encapsulation body 401.

[0110] Furthermore, the portions opposite to the corners 431 on both sides of the width direction of the encapsulation body 401 protrude close to the corners 431 and have a shape with a gap δ9 between them. The gaps δ8 and δ9 are almost identical, and the gap formed between the back surface 201 of the cover 200 and the surface 402 of the encapsulation body 401 is uniform across the lateral width direction of the encapsulation body 401.

[0111] exist Figure 12 In the comparative example shown in (2), the portion of the back surface 201 of the cover 200 opposite to the surface 402 of the encapsulation body 401 is formed as a planar shape along the shape of the surface 402 of the encapsulation body 401, and has a shape with a gap δ8' between it and the surface 402 of the encapsulation body 401.

[0112] Furthermore, the portion of the back surface 201 of the cover 200 opposite to the corner 431 of the encapsulation body 401 is flat, and is formed such that it gradually moves away from the corner 431 as it shifts outward in the width direction of the encapsulation body 401, and has a shape with a gap δ9' between the end 231 and the corner 431. The gap δ9' is larger than the gap δ8', and the gap formed between the back surface 201 of the cover 200 and the surface 402 of the encapsulation body 401 is non-uniform along the lateral width direction of the encapsulation body 401.

[0113] According to this embodiment, the gap formed between the cover 200 and the encapsulation body 401 is uniform along the lateral width direction of the encapsulation body 401. Therefore, as Figure 9 As shown by the imaginary line, when the sealing material 500 is applied to the boundary between the circuit chamber 135 and the sub-channel 134 and the cover 200 is placed over the measuring section 113, the overflow of the crushed sealing material 500 can be controlled, thereby reliably sealing the package body 401 and the cover 200. Furthermore, it can prevent unsealing on both sides due to deviations in the application position and amount of the sealing material 500.

[0114] [Fifth Implementation Method]

[0115] Figure 13 This is a diagram showing the main parts of the physical quantity detection device according to the fifth embodiment.

[0116] In addition to the boundary portion 501 and a pair of side edge portions 502, the sealing material 500 also has a pair of protrusions 503 that protrude from the base ends of the pair of side edge portions 502 along the base end edge 405 of the base end portion 401A in a direction of approaching each other. The sealing material 500, in plan view, surrounds the base end portion 401A of the encapsulation body 401 in a slightly C-shape through the boundary portion 501, the side edge portions 502, and the protrusions 503, thereby bonding them together. The center of the base end edge 405 is not bonded to the cover 200.

[0117] The sealing material 500 is not applied to the central region of the surface 402 of the base end portion 401A, forming a space R1 between the central region of the surface 402 of the base end portion 401A and the cover 200. Furthermore, the sealing material 500 is not applied between the center of the base edge 405 of the base end portion 401A and the cover 200, leaving the space between the center of the base edge 405 of the base end portion 401A and the cover 200 open. That is, space R1 is connected to other spaces R2 within the circuit chamber 135 via the open portion between the center of the base edge 405 of the base end portion 401A and the cover 200, and is not sealed.

[0118] Ventilation port 425 opens in the central region of surface 402 of base end 401A, is not blocked by sealing material 500, and connects to space R1. Space R1 connects to space R2 within circuit chamber 135 via the central edge 405 of base end 401A, and is not sealed. That is, spaces R1 and R2 are connected, as shown below. Figure 6 As indicated by the thick arrow, the gases can flow between each other. Multiple vents 425 can also be installed.

[0119] The diaphragm chamber 424 is connected to the sub-channel 134 via the ventilation channel 423, the ventilation port 425, the space R1 in the circuit chamber 135, other spaces R2, and the connecting channel 138, which enables the internal pressure of the diaphragm chamber 424 to be equal to the internal pressure of the sub-channel 134. Therefore, it is possible to prevent the diaphragm of the detection section of the flow sensor 411 from deforming due to the pressure difference between the diaphragm chamber 424 and the sub-channel 134.

[0120] [Sixth Implementation Method]

[0121] Figure 14 This diagram shows the main parts of the physical quantity detection device according to the sixth embodiment, corresponding to the first embodiment. Figure 7 The image.

[0122] The distance between the surface 402 of the encapsulation body 401 and the back surface 201 of the cover 200 is constant. Furthermore, let T1 be the distance from the detection section of the flow sensor 411 to the protrusion 402A of the surface 402 of the encapsulation body 401, T3 be the distance from the protrusion 402A of the encapsulation body 401 to the coating position center P of the sealing material 500, and T2 be the distance from the coating position center P of the sealing material 500 to the vent 425. In this embodiment, distance T3 is set to be smaller than distance T1 or distance T2 (T3 < T1) or (T3 < T2), and distance T1 is smaller than distance T2 (T1 < T2).

[0123] Let the cross-sectional area of ​​the sealing material 500 at the center P of the coating position be A1, the cross-sectional area from the center P of the coating position to the vent 425 be A3, and the cross-sectional area from the center P of the coating position to the protrusion 402A be A2. Cross-sectional area A2 is the size obtained by subtracting half of A1 (A1 / 2) from the cross-sectional area of ​​T3, and cross-sectional area A3 is the size obtained by subtracting half of A1 (A1 / 2) from the cross-sectional area of ​​T2. Therefore, cross-sectional area A is less than or equal to cross-sectional areas B and C (A1 ≦ A2, A3).

[0124] That is, the cross-sectional area A1 of the sealant 500 coated at the coating position center P of the boundary portion 501 is smaller than either the cross-sectional area A2 of the sealant 500 disposed on the side of the secondary channel 134 further than the coating position center P, or the cross-sectional area A3 of the sealant 500 disposed from the coating position center P to the side of the vent 425. Therefore, when the cover 200 crushes the sealant 500, the amount of sealant 500 coated is not affected, and overflow of the sealant 500 to the side of the secondary channel 134 can be prevented. In addition, the vent 425 can be prevented from being blocked by the sealant 500.

[0125] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments, and various design changes can be made without departing from the spirit of the invention as set forth in the claims. For example, the above embodiments have been described in detail for the purpose of making the present invention easy to understand, and are not necessarily limited to having all the described configurations. In addition, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can also be added to the configuration of one embodiment. Furthermore, regarding a part of the configuration of each embodiment, other configurations can be added, deleted, or replaced.

[0126] Symbol Explanation

[0127] 134...Sub-channel, 135...Circuit chamber, 200...Cover, 201...Back side, 300...Circuit substrate, 400...Chip package, 401...Package body, 401A...Base end, 402...Surface, 402A...Raised section, 405...Base edge, 411...Flow sensor, 414...Connecting terminal, 425...Ventilation port, 500...Sealing material, 501...Boundary section, 502...Side edge section, P...Coating position center, R1...Space, R2...Other spaces.

Claims

1. A physical quantity detection device, comprising: a housing having a secondary channel and a circuit chamber; a cover covering the secondary channel and the circuit chamber of the housing; a circuit board housed in the circuit chamber; a chip package disposed within the housing opposite to the cover; and a sealing material sealing the space between the housing and the cover. The physical quantity detection device is characterized in that... The chip package includes: a package body with its top end disposed in the sub-channel and its base end disposed in the circuit chamber; a diaphragm-type flow sensor disposed at the top end of the package body; a plurality of connection terminals protruding from the two end edges of the base end of the package body in mutually opposing directions and connected to the circuit board; a vent opening at the base end of the package body; and a venting channel penetrating the package body to connect the vent opening and the diaphragm chamber of the flow sensor. The sealing material has: a boundary portion that seals the boundary between the sub-channel and the circuit chamber of the package body; and a pair of side edges disposed along both end edges of the chip package to bury the plurality of connection terminals.

2. The physical quantity detection device as described in claim 1, characterized in that, The cover is configured such that the gap between the cover on the circuit chamber side and the package body is larger than the gap between the cover on the sub-channel side and the package body.

3. The physical quantity detection device as described in claim 1, characterized in that, The portion of the cover opposite the surface of the encapsulation body is formed in a planar shape along the shape of the surface of the encapsulation body, and the portion opposite the corners on both sides of the width direction of the encapsulation body is concavely curved along the shape of the corners.

4. The physical quantity detection device as described in claim 1, characterized in that, The portion of the cover opposite the surface of the encapsulation body is formed in a planar shape along the shape of the surface of the encapsulation body, and the portion opposite the plurality of connection terminals has the same spacing as the gap between the surface of the encapsulation body and the cover.

5. The physical quantity detection device as described in claim 1, characterized in that, The portion of the cover opposite the surface of the encapsulation body is formed in a planar shape along the shape of the surface of the encapsulation body, and the portion opposite the corners on both sides of the width direction of the encapsulation body is formed protrudingly close to the corners, and has the same spacing as the gap between the surface of the encapsulation body and the cover.

6. The physical quantity detection device as described in claim 1, characterized in that, The sealing material has a pair of protrusions that extend from the base end of the pair of side edges along the base end edge of the base end of the encapsulation body in a direction toward each other.

7. The physical quantity detection device as described in claim 1, characterized in that, The cross-sectional area of ​​the sealing material coated at the center of the coating position at the boundary is smaller than either the cross-sectional area of ​​the sealing material disposed on the side of the secondary channel that is further away from the center of the coating position, or the cross-sectional area of ​​the sealing material disposed from the center of the coating position to the side of the vent.

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