Airflow amount measuring device

To provide an airflow amount measuring device capable of accurately measuring a flow amount of air without occurrence of warpage in a thin film portion when an airflow measuring element is mounted on a lead frame to form a resin-sealed package in which the airflow amount measuring element and the lead frame are sealed. A chip package includes a lead frame, an element mounted on the lead frame and having a detection portion, and a structure for sealing the lead frame and the element such that at least the detection portion is exposed. Then, the curvature radius ρ of the exposed portion of the element exposed from the sealing resin member is 2.13 or less.

TECHNICAL FIELD

The present invention relates to an airflow amount measuring device that measures a flow amount of air sucked into, for example, an internal combustion engine of an automobile.

BACKGROUND ART

As such an airflow amount measuring device, for example, there is a technique described in PTL 1.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

In the airflow amount measuring device described in PTL 1, a linear expansion coefficient is different between an airflow amount measuring element and a lead frame on which the airflow amount measuring element is mounted, and thus there is a problem that when the airflow amount measuring element and the lead frame are sealed with a synthetic resin to form a resin-sealed package, stress due to thermal contraction of the synthetic resin may act on a thin film portion which is a thin film portion, and the thin film portion may be warped in a direction protruding from a cavity portion. When the warpage occurs in the thin film portion, there is a problem that it is difficult to accurately measure the flow amount of air.

On the other hand, in a case where an intermediate member such as a glass plate or a silicon plate having a linear expansion coefficient close to that of the airflow measuring element is provided between the airflow amount measuring element and the lead frame in order to alleviate the warpage of the thin film portion, there is a problem that an increase in the number of components and the number of assembling steps causes an increase in the cost of the airflow amount measuring device and an increase in the thickness of the intermediate member.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an airflow amount measuring device capable of suppressing occurrence of warpage in a thin film portion and accurately measuring a flow amount of air in a case where an airflow measuring element is mounted on a lead frame to form a resin-sealed package in which the airflow amount measuring element and the lead frame are sealed.

Solution to Problem

An airflow amount measuring device according to the present invention includes a resin-sealed package including a lead frame, an airflow amount measuring element mounted on the lead frame and having a detection portion, and a sealing resin member which seals the lead frame and the airflow amount measuring element such that at least the detection portion is exposed, in which a curvature radius ρ of an exposed portion of the airflow amount measuring element exposed from the sealing resin member is 2.13 or less.

Advantageous Effects of Invention

According to the present invention, it is possible to provide the airflow amount measuring device capable of suppressing occurrence of warpage in a thin film portion and accurately measuring a flow amount of air in a case where the airflow measuring element is mounted on the lead frame to form the resin-sealed package in which the airflow amount measuring element and the lead frame are sealed.

Further features related to the present invention will become apparent from the description of the present description and the accompanying drawings. In addition, problems, configurations, and effects other than those described above will become apparent from the description of the following embodiment.

DESCRIPTION OF EMBODIMENTS

A mode for carrying out the invention (hereinafter, an embodiment) described below solves various problems requested to solve in an actual product, and solves various problems required to solve particularly for use as an airflow amount measuring device for measuring a flow amount of air, and exhibits various effects. One of the various problems solved by the following embodiment is the content described in the section of “Technical Problem” described above, and one of the various effects achieved by the following embodiment is the effect described in the section of “Advantageous Effects of Invention”. Various problems solved by the following embodiment and various effects achieved by the following embodiment will be described in the following description of the embodiment. Therefore, the problems solved by the embodiment and effects described in the following embodiment are also described for contents other than the contents in the section of “Technical Problem” and the section of “Advantageous Effects of Invention”.

In the following embodiment, the same reference sign indicates the same configuration even if the figure numbers are different, and the same function and effect are obtained. For the already described configuration, only reference signs are given to the drawings, and description thereof may be omitted.

An airflow amount measuring device20according to the embodiment in which the airflow amount measuring device according to the present invention is applied to an electronic fuel injection type internal combustion engine control system1will be described with reference to the drawings. In the internal combustion engine control system1, as illustrated inFIG.1, an intake air2is sucked in from an air cleaner21on the basis of the operation of an internal combustion engine10including an engine cylinder11and an engine piston12, and is guided to a combustion chamber of the engine cylinder11via an intake body22having a main passage22a,a throttle body23, and an intake manifold24. The flow amount of the intake air2guided to the combustion chamber is detected by the airflow amount measuring device20according to the present invention, and a fuel is supplied from a fuel injection valve14on the basis of the detected flow amount and is guided with the intake air2to the combustion chamber in an air-fuel mixture state. Note that in the present embodiment, the fuel injection valve14is provided in the intake port of the internal combustion engine, and the fuel injected into the intake port forms the air-fuel mixture together with the intake air2, is guided to the combustion chamber via an intake valve15, and combusts to generate a mechanical energy.

The fuel and the intake air2guided to the combustion chamber are in a mixed state of the fuel and the intake air2, and combust explosively by spark ignition of an ignition plug13to generate a mechanical energy. The gas after the combustion is guided from an exhaust valve16to an exhaust pipe, and is discharged as an exhaust gas3from the exhaust pipe to the outside of a vehicle. The flow amount of the intake air2guided to the combustion chamber is controlled by a throttle valve25of which the opening degree changes on the basis of the operation of an accelerator pedal. A fuel supply amount is controlled on the basis of the flow amount of the intake air guided to the combustion chamber, and a driver can control the mechanical energy generated by the internal combustion engine by controlling the opening degree of the throttle valve25to control the flow amount of the intake air guided to the combustion chamber.

The flow amount, temperature, humidity, and pressure of the intake air2taken in from the air cleaner21and flowing through the main passage22aare detected by the airflow amount measuring device20, and a signal representing the flow amount of the intake air2is transmitted from the airflow amount measuring device20to a control device4. In addition, a signal of a throttle angle sensor26which detects the opening degree of the throttle valve25is transmitted to the control device4, and a signal of a rotation angle sensor17is transmitted to the control device4in order to measure the positions and states of the engine piston12, the intake valve15, and the exhaust valve16of the internal combustion engine and further the rotation speed of the internal combustion engine. In order to measure the state of the mixing ratio of the fuel amount and the air amount from the state of the exhaust gas3, a signal of an oxygen sensor28is transmitted to the control device4.

The control device4calculates the fuel injection amount and the ignition timing on the basis of the flow amount of the intake air2which is the output of the airflow amount measuring device20and the rotation speed of the internal combustion engine output and detected by the rotation angle sensor17. On the basis of these calculation results, the amount of fuel supplied from the fuel injection valve14and the ignition timing of ignition by the ignition plug13are controlled. The fuel supply amount and the ignition timing are actually finely controlled on the basis of the change state of the temperature or the throttle angle detected by the airflow amount measuring device20, the change state of the engine rotation speed, and the state of the air-fuel ratio detected by the oxygen sensor28. The control device4further controls the amount of air bypassing the throttle valve25by an idle air control valve27in the idle operation state of the internal combustion engine, and controls the rotation speed of the internal combustion engine in the idle operation state.

Both the fuel supply amount, which is the main control amount of the internal combustion engine, and the ignition timing are calculated using the output of the airflow amount measuring device20as a main parameter. Therefore, the improvement of detection accuracy of the airflow amount measuring device20, the suppression of temporal change, and the improvement of reliability are important for the improvement of control accuracy of the vehicle and the securement of reliability.

In particular, in recent years, a demand for fuel saving of the vehicle is considerably high, and a demand for exhaust gas purification is considerably high. In order to meet these demands, it is extremely important to improve the measurement accuracy of the flow amount of the intake air detected by the airflow amount measuring device20. In addition, it is also important that the airflow amount measuring device20maintains a high reliability.

The vehicle on which the airflow amount measuring device20is mounted is used in an environment where a change in temperature or humidity is large. It is desirable that in the airflow amount measuring device20, a response to a change in temperature or humidity in the use environment and a response to dust, contaminants, and the like be considered.

The airflow amount measuring device20is attached to an intake pipe affected by the heat generated from the internal combustion engine. Therefore, the heat generated by the internal combustion engine is transmitted to the airflow amount measuring device20via the intake pipe. Since the airflow amount measuring device20measures the flow amount of the intake air2by performing heat transfer with the intake air2, it is important to suppress the influence of heat from the outside as much as possible.

The airflow amount measuring device20mounted on the vehicle not only simply solves the problems described in the section of “Technical Problem” and exerts the effects described in the section of “Advantageous Effects of Invention” as described below, but also solves various problems required to solve in a product and exerts various effects in sufficient consideration of the various problems described above. Specific problems to be solved and specific effects to be exerted by the airflow amount measuring device20will be described in the following description of the embodiment.

<Overall configuration of airflow amount measuring device> As illustrated inFIGS.1,2A,2B,2C, and2D, the airflow amount measuring device20includes a housing100, a cover200, and a chip package300. The airflow amount measuring device20is used in the state of being inserted into the main passage22afrom an attachment hole provided in a passage wall of the intake body22and fixed to the intake body22.

As illustrated inFIG.3, the housing100is configured by injection molding a synthetic resin material, for example, and includes a flange111for fixing the airflow amount measuring device20to the intake body22, a connector112protruding from the flange111and exposed to the outside from the intake body22to electrical connection with an external device, and a measurement unit113extending from the flange111to protrude toward the center of the main passage22a.

As illustrated inFIGS.2B,2C, and2D, the measurement unit113has a thin and long shape extending straight from the flange111, and includes a wide front surface121and a wide back surface122, and a pair of narrow side surfaces123and124. The measurement unit113protrudes from the inner wall of the intake body22toward the passage center of the main passage22ain a state where the airflow amount measuring device20is attached to the intake body22. Then, the front surface121and the back surface122are arranged in parallel along the central axis of the main passage22a,and in the narrow side surfaces123and124of the measurement unit113, the side surface123on one longitudinal side of the measurement unit113is arranged to face the upstream side of the main passage22a,and the side surface124on the other short side of the measurement unit113is arranged to face the downstream side of the main passage22a.In a state where the airflow amount measuring device20is attached to the intake body22, the distal end portion of the measurement unit113is defined as a lower surface125.

In the measurement unit113, a sub-passage inlet131is provided on the side surface123, and a first outlet132and a second outlet133are provided on the side surface124. The sub-passage inlet131, the first outlet132, and the second outlet133are provided at the distal end portion of the measurement unit113extending from the flange111toward the center direction of the main passage22a.Therefore, the gas in the portion close to the central portion away from the inner wall surface of the intake body22can be taken into the sub-passage. Therefore, the airflow amount measuring device20can measure the flow amount of the gas in the portion away from the inner wall surface of the intake body22, and can suppress a decrease in measurement accuracy due to the influence of heat or the like.

The airflow amount measuring device20has a shape in which the measurement unit113extends long along the axis from the outer wall of the intake body22toward the center, but the widths of the side surfaces123and124are relatively narrow as illustrated inFIG.2D. As a result, the airflow amount measuring device20can suppress a fluid resistance with respect to the intake air2to a small value.

The measurement unit113is inserted into the intake body22through the attachment hole provided in the intake body22, and the flange111abuts on the intake body22and is fixed to the intake body22with a screw. The flange111has a shape which has a predetermined plate thickness and is substantially rectangular in plan view, and as illustrated inFIG.2A, fixing hole portions141are provided in pairs at diagonal corner portions. The fixing hole portion141has a through hole142penetrating the flange111. The flange111is fixed to the intake body22by inserting a fixing screw (not illustrated) into the through hole142of the fixing hole portion141and screwing the fixing screw into the screw hole of the intake body22.

As illustrated inFIG.2A, four external terminals147and a correction terminal148are provided inside the connector112. The external terminals147are terminals for outputting physical quantities such as a flow amount and a temperature which are measurement results of the airflow amount measuring device20and power supply terminals for supplying DC power for operating the airflow amount measuring device20.

The correction terminal148is a terminal used to perform the measurement of the produced airflow amount measuring device20, obtain a correction value related to each airflow amount measuring device20, and store the correction value in a memory inside the airflow amount measuring device20. In the subsequent measurement operation of the airflow amount measuring device20, correction data representing the correction value stored in the memory is used, and the correction terminal148is not used.

Therefore, the correction terminal148has a shape different from that of the external terminal147so that the correction terminal148does not interfere with the connection between the external terminal147and another external device. In this embodiment, the correction terminal148has a shorter shape than the external terminal147, and is configured not to obstruct connection even when a connection terminal of an external device connected to the external terminal147is inserted into the connector112.

In the following description, as illustrated inFIG.3, the longitudinal direction of the measurement unit113, which is a direction in which the measurement unit113extends from the flange111, may be referred to as a Z axis, a short direction of the measurement unit113, which is a direction extending from the sub-passage inlet131of the measurement unit113toward the first outlet132, may be referred to as an X axis, and a thickness direction of the measurement unit113, which is a direction from the front surface121of the measurement unit113toward the back surface122, may be referred to as a Y axis.

The housing100is provided with a sub-passage groove150for forming a sub-passage134and a circuit chamber135for accommodating a circuit board311. The circuit chamber135and the sub-passage groove150are formed in the front surface of the measurement unit113. The circuit chamber135is provided in a region on one side (side surface123side) in an X-axis direction which is a position on the upstream side in the flow direction of the intake air2. Then, the sub-passage groove150is provided over a region on the leading end side (lower surface125side) of the measurement unit113in the Z-axis direction with respect to the circuit chamber135and a region on the other side in the X-axis direction (side surface124side) which is a position on the downstream side in the flow direction of the intake air2with respect to the circuit chamber135.

The sub-passage groove150is covered by the cover200to form the sub-passage134. The sub-passage groove150includes a first sub-passage groove151and a second sub-passage groove152branching in the middle of the first sub-passage groove151. The first sub-passage groove151is formed to extend along the X-axis direction of the measurement unit113between the sub-passage inlet131opened to the side surface123on one side of the measurement unit113and the first outlet132opened to the side surface124on the other side of the measurement unit113. The first sub-passage groove151forms, in cooperation with the cover200, a first sub-passage A which takes in the intake air2from the sub-passage inlet131and returns the taken intake air2from the first outlet132to the main passage22a.The first sub-passage A has a flow path extending from the sub-passage inlet131along the flow direction of the intake air2in the main passage22ato be connected to the first outlet132.

The second sub-passage groove152branches at the intermediate position of the first sub-passage groove151, is bent toward the proximal end portion side (flange side) of the measurement unit113, and extends along the Z-axis direction of the measurement unit113. Then, the second sub-passage groove is bent at the proximal end portion of the measurement unit113toward the other side (side surface124side) of the measurement unit113in the X-axis direction, turns around toward the distal end portion of the measurement unit113, and extends again along the Z-axis direction of the measurement unit113. Then, the second sub-passage groove is bent in front of the first outlet132toward the other side (side surface124side) of the measurement unit113in the X-axis direction, and is provided so as to be continuous with the second outlet133opened to the side surface124of the measurement unit113. The second outlet133is arranged to face the downstream side of the main passage22ain the flow direction of the intake air2. The second outlet133has an opening area substantially equal to or slightly larger than that of the first outlet132, and is formed at a position adjacent to the proximal end portion side of the measurement unit113in the longitudinal direction with respect to the first outlet132.

The second sub-passage groove152forms, in cooperation with the cover200, a second sub-passage B which allows the intake air2branched from the first sub-passage A and flowing in to pass therethrough and returns the intake air2from the second outlet133to the main passage22a.The second sub-passage B has a flow path for reciprocation along the Z-axis direction of the measurement unit113. That is, the second sub-passage B has a forward passage portion B1which branches in the middle of the first sub-passage A and extends toward the proximal end portion side of the measurement unit113(a direction away from the first sub-passage A), and a return passage portion B2which is folded back and turned around on the proximal end portion side (the end portion of a separation passage portion) of the measurement unit113and extends toward the distal end portion side (a direction approaching the first sub-passage A) of the measurement unit113. The return passage portion B2is connected to the second outlet133opened toward the downstream side in the flow direction of the intake air2at a position on the downstream side in the flow direction of the intake air2in the main passage22awith respect to the sub-passage inlet131.

In the second sub-passage B, the chip package300to be described later is arranged at the intermediate position of the forward passage portion B1. Since the second sub-passage B is formed to extend along the longitudinal direction of the measurement unit113and reciprocate, the passage length can be secured longer, and the influence on the chip package300can be reduced in a case where a pulsation occurs in the main passage22a.

Similarly to the housing100, the cover200is formed by an injection-molded article of a synthetic resin material, and is attached to the side surface of the housing100to cover the housing100. The cover200may be formed of, for example, a metal material such as an aluminum alloy by precision casting such as lost wax or die casting.

As illustrated inFIGS.4A,4B, and5, the chip package300includes an airflow amount measuring element (hereinafter, simply referred to as an element.)301, a lead frame302, a sealing resin member303, a polyimide tape304, and a die attach film (hereinafter, referred to as a DAF)305. The chip package300is manufactured by setting the element301and the lead frame302on which the element301is mounted in a mold, allowing a mold resin to flow into the mold, and thermally curing the mold resin.

The chip package300includes the sealing resin member303having a flat plate shape which is substantially rectangular in plan view. The sealing resin member303has a proximal end portion on one longitudinal side arranged in the circuit chamber135of the housing100and a distal end portion on the other longitudinal side arranged in the second sub-passage B of the housing100. At the proximal end portion of the sealing resin member303, a plurality of terminal portions T are arranged to protrude in directions away from each other along the short direction. Then, a recessed groove is formed in the distal end portion of the sealing resin member303to extend along the short direction. The recessed groove is provided on the front surface of the distal end portion of the sealing resin member303, and forms a passage Kt through which the intake air2flows. The distal end portion of the sealing resin member303is arranged in the forward passage portion B1in the forward passage portion B1and the return passage portion B2forming the second sub-passage B of the housing100illustrated inFIG.3. The chip package300measures the flow amount of the intake air2flowing in the second sub-passage B and transmits a signal of the measurement result to the control device4.

As illustrated inFIG.5, the element301includes an element body401serving as a substrate. The element body401is configured by a flat plate-like member, and is joined to the lead frame302by the DAF305provided between the lead frame and the back surface. The front surface of the element body401is exposed as a detection portion from the sealing resin member303. An opening Kd is formed in the element body401to open on the back surface, and a thin film portion402is formed to close the opening Kd on the front surface side of the element body401. The thin film portion402includes a first temperature difference sensor407, a first heater temperature sensor405, a heater404, a second heater temperature sensor406, and a second temperature difference sensor408arranged in the main flow direction of a measurement target medium, and is a detection portion for detecting the flow amount of the measurement target medium. Hereinafter, the arrangement direction is expressed as a lateral direction (short direction), and a direction perpendicular to the arrangement direction is expressed as a vertical direction (longitudinal direction). The element301has, on the front surface of the element body401, the thin film portion402as the detection portion and a peripheral region portion403extending continuously around the thin film portion402.

The thin film portion402is configured by, for example, a thin film having a thickness of less than several pm, and is exposed to the passage Kt of the sealing resin member303. As illustrated inFIG.8C, in the thin film portion402, the first temperature difference sensor407, the first heater temperature sensor405, the heater404, the second heater temperature sensor406, and the second temperature difference sensor408are formed, and a PIQ layer409is formed around the upper side of the thin film portion402. The thin film portion402can measure the flow amount of the intake air2flowing through the front surface of the thin film portion402on the basis of the temperature distribution in a direction along the surface of the thin film portion402. In the element body401, the opening Kd having a truncated cone shape of which the opening diameter increases when a distance from the back surface of the thin film portion402increases is formed on the back surface side of the thin film portion402.

In the element301in the state of a single body before being molded by the sealing resin member303, the front surface and the back surface of the element body401have a flat surface shape without curvature. When the element301is molded together with the lead frame302by the sealing resin member303, a bending stress is generated due to contraction of the resin between the sealing resin member303and the lead frame302. At the time of molding, a crosslinking density or a volume contraction between molecules of the sealing resin member303change in the process of curing from a viscous fluid, and thus a volume decreases after curing.

Therefore, a molding contraction rate means that the volume contracts after the sealing resin member injected into the mold is cooled, and a rate of the contraction (hereinafter, referred to as a contraction rate) is generally defined by following Expression 2).

The molding contraction rate is also expressed by following Expression (3) according to the JIS K6911 standard associated with a mold condition and a test piece condition of the sealing resin member303. When the dimensions of the mold at a room temperature are D1, D2, D3, and D4, the dimensions of the molded product at a room temperature are d1, d2, d3, and d4, and averaging is performed with four measurement parts, the contraction rate of the sealing resin member303is obtained by following Expression (3).

When the element301is molded by the sealing resin member303, the front surface side of the element body401is deformed to protrude from a flat shape to a convex shape and curve. In a case where deformation is made in this manner, in the element301, a curvature radius ρ of the exposed portion of the element301exposed from the sealing resin member303is 2.13 or less. More specifically, the peripheral region portion403, which is a region not including the thin film portion402, in the front surface of the element body401has the curvature radius ρ (mm) of 0 or more, and is formed to satisfy a relationship of ρ≤2.13 in the longitudinal direction of the chip package300as illustrated inFIG.5. As illustrated inFIG.5, the upper surface of the element301is specifically a boundary portion between the element301and the sealing resin member303covering the upper surface of the element301. The curvature radius ρ is expressed by following Expression (1).

However, in Expression (1), as illustrated inFIG.5, on the front surface side of the sealing resin member303in which the element301is provided with the lead frame302interposed therebetween and the back surface side of the sealing resin member on the opposite side to the element301, h1(mm) represents the thickness (hereinafter, referred to as the thickness of a back surface resin portion S) of the sealing resin member303on the back surface side from the lead frame302, h2(mm) represents the thickness (mm) of the lead frame302, h3(mm) represents the thickness (hereinafter, referred to as the thickness of a front surface resin portion U) of the sealing resin member303on the front surface side from the lead frame302, h4(mm) represents the thickness of the element body401, h5(mm) represents the thickness of the thin film portion402, and β (%) represents a curing contraction rate of the sealing resin member303.

The curvature radius ρ of the peripheral region portion403of the front surface of the element body401can be measured by the following method. That is, by cutting the chip package300at the position of the element301, the curvature radius ρ of the front surface of the element body401appearing on the cut surface can be measured. In addition, the curvature radius ρ can be measured nondestructively by a non-contact displacement measurement method using light such as a laser beam. In addition, the curvature radius ρ can also be measured nondestructively by scanning the peripheral region portion403of the front surface of the element body401with a three-dimensional measuring machine (also referred to as a 3D scanner).

The curvature radius ρ is calculated by using a general formula of the bending stress of the sealing resin member303.FIG.6Cillustrates the items of the calculation formula and the symbols of the items. In a general beam, when Young's modulus is defined as E, a cross-sectional secondary moment is defined as I, a bending moment is defined as M, and ρ is the curvature radius of the beam, following Expression (a) is obtained.

As illustrated inFIG.6A, in a case where the thin film portion402is deformed to be convex,

As illustrated inFIG.6B, in a case where the thin film portion402is deformed to be concave,

[Mathematical⁢Formula⁢6]1ρ=MEI>o(c)
is satisfied. In a laminate to be the sealing resin member303of the embodiment, the amount of warpage of the thin film portion402is determined by a composite balance of h1, h2, and h3illustrated inFIG.6C. In this regard, the apparent warpage of h1to h5is obtained.

In a case where the curing contraction rate of the resin is β, β has a relationship of following Expression (d).

From Expression (d), in Expression (a),

Following Expressions (h) and (i) are obtained.

Therefore, from Expression (a) of the curvature (1/ρ) of the beam, it is obtained by a following composite thickness γ of the chip package300according to the present embodiment that the warpage of the thin film portion402is 0 or that it is satisfied the warpage ≤3 μm in the case of the structure of the present embodiment.

Here, when γ is substituted into Expression (j),

1ρ=γ⁡(1-β)[Mathematical⁢Formula⁢14]
is satisfied, and a general formula of curvature is obtained. The specific verification of this general formula will be described later.

The lead frame302is formed by a metal material thin plate such as copper (Cu) having a high conductivity, and includes a pattern portion (not illustrated) and a terminal portion T illustrated inFIG.4A. The terminal portion T is connected to a terminal pad of the circuit board311. The lead frame302supports and fixes the element301via the DAF305. That is, the element301is mounted on the lead frame302. In the lead frame302, as illustrated inFIG.5, a through hole Kh is formed to communicate with the opening Kd of the thin film portion402, and a through hole Ku is formed to communicate with an opening K3of the front surface resin portion U to be described later. The through hole Kh and the through hole Ku are connected by a communication path R (seeFIG.4B). The through hole Kh, the through hole Ku, and the communication path R function such that the pressure in the opening Kd of the thin film portion402is substantially equal to the atmospheric pressure.

As illustrated inFIGS.4B and5, the sealing resin member303has the back surface resin portion S having the thickness h1and the front surface resin portion U having the thickness h3, which are made of a material of a synthetic resin, a so-called mold resin. The thickness h3of the front surface resin portion U is twice or more the thickness hl of the back surface resin portion S. The sealing resin member303covers the element301and the lead frame302with the back surface resin portion S and the front surface resin portion U to integrate the components. As the mold resin, a material having a curing contraction rate β of 0.18% or more is selected. The material of the mold resin is not particularly limited as long as the mold resin is a synthetic resin having a curing contraction rate β of 0.18% or more.

As illustrated inFIGS.4and5, in the sealing resin member303, the periphery of the thin film portion402and the thin film portion402is exposed to form the passage Kt for passing an airflow. In addition, in the back surface resin portion S of the sealing resin member303, an opening (opening portion) K1is formed to have a truncated cone shape of which the opening diameter increases when a distance from the lead frame302increases. The opening K1is provided at a position opposite to the element301with the lead frame302interposed therebetween. Further, in the front surface resin portion U of the sealing resin member303, an opening K2is formed at the end portion opposite to the passage Kt in the longitudinal direction (vertical direction) of the sealing resin member303. Then, in the back surface resin portion S of the sealing resin member303, the opening K3is formed at the end portion opposite to the opening K1in the longitudinal direction of the sealing resin member303.

As illustrated inFIGS.4B and5, the sealing resin member303has the recessed groove-shaped passage Kt on the front surface. The passage Kt of the sealing resin member303has a pair of passage walls Th and a bottom wall where the front surface of the element body401is exposed. The pair of passage walls Th has a throttle shape in which the opening area (cross-sectional area) of the passage Kt gradually narrows toward the thin film portion402as the detection portion. In the sealing resin member303, the pair of passage walls Th forming the passage Kt covers both side edges of the element301in a direction orthogonal to the airflow of passing through the passage Kt, and the front surface resin portion U is formed such that the thin film portion402is exposed to the passage Kt. Therefore, when the sealing resin member303is deformed by thermal contraction, the element301is also deformed together with the sealing resin member303by receiving a stress from the front surface resin portion U.

The polyimide tape304is made of a polymer compound containing an imide bond, and has a high heat resistance, an excellent mechanical property, and a resistance to chemicals. The polyimide tape304is provided on the surface of the lead frame302opposite to the surface on which the element301is mounted, and blocks the through hole Kh, the through hole Ku, and the communication path R of the lead frame302.

The DAF305is made of a film adhesive material having a high adhesion reliability, and is sandwiched between the element301and the lead frame302to bond the element301and the lead frame302. The DAF305is provided with an opening which communicates between the opening Kd of the thin film portion402and the through hole Kh of the lead frame302.

In the chip package300according to the present embodiment, the sealing resin member303thermally contracts by curing at the time of forming the sealing resin member303, and warpage occurs in the thin film portion402, but the occurrence of warpage has been specifically examined. When the amount (mm) of warpage of the thin film portion402increases, the measurement accuracy of the flow amount of the intake air2decreases, and thus the amount of warpage of the thin film portion402is preferably small. Hereinafter, various factors such as the amount of warpage of the thin film portion402, a relationship between the thin film portion402and the curing contraction rate β, and the curvature radius ρ will be specifically described with reference to the drawings.

<Action of thermal contraction of sealing resin member303and amount of warpage of thin film portion402> First, the action of thermal contraction of the sealing resin member303and the amount of warpage of the thin film portion402have been specifically verified in Examples 1 and 2 and Comparative Examples 1 and 2 of the chip package300according to the present embodiment. Note that with the flat front surface of the thin film portion402before the warpage occurs used as a reference, the amount (mm) of warpage of the thin film portion402refers to a height (mm) from the reference of the thin film portion402which becomes a convex shape due to the warpage of the thin film portion402to the top of the convex shape.

In the chip package according to Comparative Example 1, as illustrated inFIG.7, a linear expansion coefficient α (ppm/° C.) of the lead frame302is 17.7, and an intermediate member306is sandwiched between the element301and the lead frame302. The linear expansion coefficient α of the element301is 3, the linear expansion coefficient α of the package is 7, and the curing contraction rate β (%) of the mold resin is 0.11 or 0.3.

In the chip package according to Comparative Example 2, the linear expansion coefficient α of the lead frame302is 17.7, there is no intermediate member between the element301and the lead frame302, the linear expansion coefficient α of the element301is 3, the linear expansion coefficient α of the mold resin of the sealing resin member303is 7, and the curing contraction rate β of the mold resin of the package is 0.11.

In the chip package300according to Example 1, as illustrated inFIG.7, the linear expansion coefficient α of the lead frame302is 17.7, there is no intermediate member between the element301and the lead frame302, the linear expansion coefficient α of the element301is 3, the linear expansion coefficient α of the mold resin of the sealing resin member303is 7, and the curing contraction rate β of the mold resin of the sealing resin member303is 0.3.

In the chip package300according to Example 2, similarly to the airflow amount measuring device20according to Example 1, the linear expansion coefficient α of the lead frame302is 17.7, there is no intermediate member between the element301and the lead frame302, the linear expansion coefficient α of the element301is 3, the linear expansion coefficient α of the mold resin of the sealing resin member303is 7, and the curing contraction rate β of the mold resin of the sealing resin member303is 0.3.

As illustrated inFIG.7, in the chip package300according to Example 2, the inner diameter of the through hole Kh of the lead frame302is formed larger than that of the chip package300according to Example 1.

In the chip package according to Comparative Example1, when the mold resin thermally contracts at the time of curing, a compressive force (N) expressed by (−) toward the central portion of the element301and a tensile force (N) expressed by (+) toward a direction away from the central portion of the element301act on the mold resin, and a compressive force toward the central portion of the element301acts on the element301, the intermediate member306, and the lead frame302. In the chip package according to Comparative Example 1, the intermediate member306can receive the compressive force generated by the contraction of the lead frame302, and the compressive force from the lead frame302can be prevented from accumulating in the element301.

In the chip package according to Comparative Example 1, the compressive force acting on the element301and the intermediate member306and the tensile force acting on the sealing resin member303are balanced, the force acting on the thin film portion402disappears, and the warpage of the thin film portion402is canceled. In Comparative Example 1, even when the curing contraction rate β of the mold resin is 0.11 or 0.3, the occurrence of warpage of the thin film portion402is suppressed by the presence of the intermediate member306regardless of the magnitude of the curing contraction rate.

In the chip package according to Comparative Example 2, similarly to Comparative Example 1, when the mold resin of the sealing resin member303thermally contracts at the time of curing, a compressive force toward the central portion of the element301and a tensile force in a direction away from the central portion of the element301act on the sealing resin member303, and a compressive force toward the central portion of the element301acts on the element301and the lead frame302. Since the intermediate member is not provided in Comparative Example 2, the compressive force generated by the contraction of the lead frame302directly acts on the element301and accumulates. Therefore, a compressive force acts on the thin film portion402, and the amount of warpage of the thin film portion402is increased.

In the chip package300according to Example 1, as illustrated inFIG.7, when the mold resin of the sealing resin member303thermally contracts at the time of curing, a relatively large compressive force toward the central portion of the element301and a relatively large tensile force in a direction away from the central portion of the element301act on the sealing resin member303, and a compressive force toward the central portion of the element301acts on the element301and the lead frame302.

As a result, the tensile force acting on the sealing resin member303relatively increases with respect to the compressive force acting on the element301and the lead frame302, and the warpage of the sealing resin member303increases. When the warpage of the sealing resin member303increases, a relatively small compressive force acts on the thin film portion402, and the amount of warpage of the thin film portion402is reduced as compared with Comparative Example 2. Therefore, it can be seen that the warpage of the thin film portion402is reduced by actively warping the element301in a tensile direction.

In the chip package300according to Example 2, similarly to Example 1, when the mold resin of the sealing resin member303thermally contracts at the time of curing, a relatively large compressive force toward the central portion of the element301and a relatively large tensile force in a direction away from the central portion of the element301act on the sealing resin member303, and a compressive force toward the central portion of the element301acts on the element301and the lead frame302.

However, in Example 2, unlike Example 1, the through hole Kh of the lead frame302is formed to be larger than the through hole Kh of Example 1, and thus the compressive force acting on the lead frame302is halved to be relatively small. As a result, the tensile force acting on the sealing resin member303relatively increases with respect to the compressive force acting on the element301and the lead frame302, and the warpage of the sealing resin member303increases. When the warpage of the sealing resin member303increases, a relatively small compressive force acts on the thin film portion402, and the amount of warpage of the thin film portion402is greatly reduced as compared with Example 1. Therefore, it can be seen that the warpage of the thin film portion402is canceled by largely warping the element301in the tensile direction.

As can be seen from the results of Comparative Example 1, Comparative Example 2, Example 1, and Example 2, when the sealing resin member303is cooled from the molding temperature to a normal temperature, the contraction of the lead frame302, that is, a so-called return amount is larger than that of the element301due to the difference in the linear expansion coefficient α of each component, which causes the thin film portion402to be compressed and deformed. At this time, when the curing contraction rate β of the mold resin of the sealing resin member303is large, the compressive stress of the thin film portion402generated by the contraction of the lead frame302can be alleviated by the tensile force acting on the sealing resin member303.

Therefore, a stress hardly concentrates on the thin film portion402, and the occurrence of deformation of the thin film portion402is suppressed. In comparison with Comparative Example 2, the chip package300of Example 1 and Example 2 applies the tensile force to the element301, and thus the warpage of the thin film portion402due to the compressive stress acting on the element301, that is, the compressive force acting on the element301is reduced.

<Amount of warpage of thin film portion402in lateral direction and vertical direction> Next, a relationship between the amount (mm) of warpage of the thin film portion402in the lateral direction and the amount of warpage (mm) in the vertical direction has been specifically verified for the same configuration having the intermediate member as in Comparative Example 1 described above and the same configuration as in Example 1 described above in the chip package300according to the present embodiment. In this verification, for the chip package300illustrated inFIG.8A, the criterion of the amount (mm) of warpage of the thin film portion402, that is, the determination criterion of an allowable amount of warpage is required. Note that in the graph ofFIG.9, a black circle indicates the chip package300having a configuration without the intermediate member, and a black square indicates the chip package having a configuration with the intermediate member. In addition, in two columns of graphs on the right side inFIG.9, the left graphs indicate the amount of warpage of the diaphragm in the lateral direction, and the right graphs indicate the amount of warpage of the diaphragm in the vertical direction.

As for the lateral direction and the vertical direction of the thin film portion402, as illustrated inFIGS.8B and8D, a direction which is the longitudinal direction (X-axis direction) of the chip package300and is orthogonal to a flowing direction of the intake air2is defined as the vertical direction, and a direction which is the short direction (z-axis direction) of the chip package300and is a flowing direction of the intake air2is defined as the lateral direction. As illustrated inFIG.9, when the amount of warpage of the thin film portion402in the lateral direction is 10 μm to 11 μm, the amount of warpage of the thin film portion402in the vertical direction x is also 12 μm to 14 μm, both of which are large amounts of warpage. When the amount of warpage of the thin film portion402in the vertical direction is 12 μm to 14 μm, the shape of warpage in the vertical direction becomes two peaks in the graph of the relationship between the amount of warpage and the distance. Therefore, the thin film portion402protrudes, the temperature distribution becomes NG, and the measurement accuracy of the thin film portion402cannot be obtained.

When the amount of warpage of the thin film portion402in the lateral direction is 7 μm to 9 μm, the amount of warpage of the thin film portion402in the vertical direction is also 8 μm to 12 μm, both of which are large amounts of warpage. When the amount of warpage of the thin film portion in the vertical direction is 8 μm to 12 μm, the shape of warpage in the vertical direction becomes two peaks in the graph of the relationship between the amount of warpage and the distance. Therefore, also in this case, the thin film portion402protrudes, the temperature distribution becomes NG, and the measurement accuracy of the thin film portion402cannot be obtained.

When the amount of warpage of the thin film portion402in the lateral direction is 4 μm to 6 μm, the amount of warpage of the thin film portion402in the vertical direction is also 6 μm to 8 μm, both of which are relatively large amounts of warpage. When the amount of warpage of the thin film portion402in the lateral direction is 6 μm to 8 μm, in the graph of the relationship between the amount of warpage and the distance, the shape of warpage of the thin film portion402in the lateral direction becomes two peaks, and also in this case, the measurement accuracy of the thin film portion402cannot be obtained.

However, when the amount of warpage of the thin film portion402in the lateral direction is 0.5 μm to 1 μm, the amount of warpage of the thin film portion402in the vertical direction is 3 μm to 4 μm, and both are relatively small amounts of warpage. In this case, as for the warpage in the lateral direction and the warpage in the vertical direction, in the graph of the relationship between the amount of warpage and the distance, the warpage of the thin film portion402is reduced, and the graph has a flat shape without any peaks. Therefore, the shapes of the thin film portion402in the lateral direction and the vertical direction are a flat surface, and both have a favorable temperature distribution, and the measurement accuracy can be obtained.

In the configuration including the intermediate member as in Comparative Example 1, when the amount of warpage of the thin film portion402in the lateral direction is 1.5 μm, the amount of warpage of the thin film portion402in the vertical direction is 2 μm, and both are relatively small amounts of warpage. In this case, as for the warpage in the lateral direction and the warpage in the vertical direction, in the graph of the relationship between the amount of warpage and the distance, the warpage of the thin film portion402is reduced, and the graph is a flat graph without any peaks. Therefore, the shapes of the thin film portion402in the lateral direction and the vertical direction are a flat surface, and both have a favorable temperature distribution, and the measurement accuracy can be obtained.

In order to secure the measurement accuracy, the amount of warpage of the thin film portion402is small, and in the graph of the relationship between the amount of warpage and the distance in both the lateral direction and the vertical direction, it is assumed that the shape of warpage is not two peaks and is flat. However, as illustrated inFIG.9, it has been found that when the warpage of the thin film portion402is 3 μm or less, an accuracy at the same level as that of the chip package having the configuration including the intermediate member can be obtained.

<Curing contraction rate of mold resin and amount of warpage of thin film portion402> Next, the relationship between the curing contraction rate of the mold resin of the sealing resin member303and the amount of warpage of the thin film portion402in the chip package300according to the present embodiment has been specifically verified. In this verification, the optimum value of the curing contraction rate β of the mold resin is obtained for the chip package300illustrated inFIG.10A.

As illustrated inFIG.10A, when the curing contraction rate of the resin is 0.3%, the amount of warpage of the thin film portion402is 1.5 μm, when the curing contraction rate of the resin is about 0.14%, the amount of warpage of the thin film portion402is about 3.2 μm, when the curing contraction rate of the resin is about 0.12%, the amount of warpage of the thin film portion402is about 3.5 μm, when the curing contraction rate of the resin is about 0.11%, the amount of warpage of the thin film portion402is about 3.9 μm, and when the curing contraction rate of the resin is about 0.09%, the amount of warpage of the thin film portion402is about 4.2 μm.

As described above, when the warpage of the thin film portion402is 3 μm or less, an accuracy at the same level as that of the chip package having the configuration including the intermediate member can be obtained, but four points marked with black circles in which the curing contraction rate of the resin is about 0.14% or less exceed 3 μm. In addition, as illustrated inFIG.10A, when the points marked with black circles are connected by a straight broken line, it can be seen that the curing contraction rate of the resin is 0.18%, and the amount of warpage of the thin film portion402is 3 μm. Therefore, it is obtained that the optimum value of the curing contraction rate of the resin is 0.18% or more.

<Relationship between warpage of sealing resin member303and warpage of thin film portion402> Next, the relationship between the warpage of sealing resin member303and the warpage of thin film portion402in the chip package300according to the present embodiment has been specifically verified. The warpage of the sealing resin member303represents the warpage on the lower surface of the back surface resin portion S of the sealing resin member303as illustrated inFIG.10B. In the graph illustrated inFIG.10B, Sample 1 is configured similarly to the above-described Example 1, and Sample 2 is configured similarly to the above-described Example 2. Note that the amount of warpage of the sealing resin member303is indicated by a bar graph, and the amount of warpage of the thin film portion402is indicated by a polygonal line.

When the curing contraction rate of the resin is 0.09%, the amount of warpage of the sealing resin member303of Sample 1 is about 5.2 μm, the amount of warpage of the thin film portion402is about 5.2 μm, the amount of warpage of the sealing resin member303of Sample 2 is about 5.8 μm, and the amount of warpage of the thin film portion402is about 4.2 μm. When the curing contraction rate of the resin is 0.11%, the amount of warpage of the sealing resin member303of Sample 1 is about 5.5 μm, the amount of warpage of the thin film portion402is about 4.8 μm, the amount of warpage of the sealing resin member303of Sample 2 is about 5.5 μm, and the amount of warpage of the thin film portion402is about 4.8 μm. When the curing contraction rate of the resin is 0.12%, the amount of warpage of the sealing resin member303of Sample 2 is about 6.5 μm, and the amount of warpage of the thin film portion402is about 3.5 μm. When the curing contraction rate of the resin is 0.14%, the amount of warpage of the sealing resin member303of Sample 2 is about 6.6 μm, and the amount of warpage of the thin film portion402is about 3.2 μm. When the curing contraction rate of the resin is 0.3%, the amount of warpage of the sealing resin member303of Sample 1 is about 7.5 μm, the amount of warpage of the thin film portion402is about 2.2 μm, the amount of warpage of the sealing resin member303of Sample 2 is about 7.8 μm, and the amount of warpage of the thin film portion402is about 1.5 μm.

As illustrated inFIG.10B, it can be seen that when the curing contraction rate of the resin is 0.18% or more in Sample 1 and Sample 2, it is possible to adopt a configuration without any intermediate members. In addition, when the curing contraction rate of the resin increases, the warpage of the sealing resin member303also increases, and it can be seen that the curing contraction rate of the resin and the warpage of the sealing resin member303are in a proportional relationship. When the warpage of the sealing resin member303increases, the warpage of the thin film portion decreases, and it can be seen that the warpage of the sealing resin member303and the warpage of the thin film portion402are in an inverse relationship. In addition, it can also be seen that a tensile force acts on the element301due to an increase in the curing contraction rate of the resin and the warpage of the sealing resin member303, and the warpage of the thin film portion402is reduced.

<Relationship of warpage in each configuration> Next, the relationship of warpage in each configuration in the chip package300according to the present embodiment has been verified again. As illustrated inFIG.11A, in a case where the curing contraction rate of the resin is 0.09%, the amount of warpage of the thin film portion402is 4.4 μm. When the warpage of the sealing resin member303is small, the warpage of the thin film portion402increases, and it can be seen that there is an inverse relationship therebetween. As illustrated inFIG.11B, in a case where the curing contraction rate of the resin is 0.3%, the amount of warpage of the thin film portion402is 1.5 μm. When the warpage of the sealing resin member303is large, the warpage of the thin film portion402decreases, and it can be seen that there is an inverse relationship therebetween.

<Calculation of specific numerical values using general formula> Next, as for specific numerical values of warpage in each configuration in the chip package300according to the present embodiment, verification has been performed with the thickness h5of the thin film portion402substituted as a parameter into Expression (1) of the curvature radius ρ. Here, the amount of warpage of the thin film portion402has been obtained by thermal stress analysis (from before cooling to after cooling). As the specific numerical values and parameters, the numerical values described inFIG.12have been used. Note that values other than the parameter h5are fixed values. As for the curvature 1/ρ and curvature radius ρ calculated, in a case where h5is 0.0005, 1/ρ is 0.461, and ρ is 2.168, in a case where h5is 0.001, 1/ρ is 0.477, and ρ is 2.095, in a case where h5is 0.002, 1/ρ is 0.491, and ρ is 2.037, in a case where h5is 0.0047, 1/ρ is 0.505, and ρ is 1.980, and in a case where h5is 0.008, 1/ρ is 0.509, and ρ is 1.983.

From the relationship between the curing contraction rate β and the warpage of the thin film portion402inFIG.13, it is obtained that the reference of the optimum value is that the amount of warpage of the thin film portion402is 3 μm or less, and the curing contraction rate β is 0.18% or more.

When the calculation result is verified in light of these optimum values, it can be seen that the curvature 1/ρ is 0.47 or more. When the curvature 1/ρ is converted into the curvature radius ρ, it can be seen that the curvature radius ρ is 2.13 or less. In addition, it can be seen that the optimum value of the ratio h3/h1of the thickness of the front surface resin portion U to the thickness of the back surface resin portion S is twice or more. Note that it has been verified that the optimum value of the curing contraction rate β is 0.18%.

<Actual measurement of curvature radius ρ> Next, the curvature radius ρ of the upper surface of the element301in the chip package300according to the present embodiment has been actually measured, and whether or not the result coincides with the calculation result of the general formula has been verified. As illustrated inFIG.14, VR-3000 of a 3D scanner has been used as the measuring device. The measurement position has been set to the oxide film area of the element301, and in the measurement method, the curvature radius ρ has been derived aiming at the exposure dimension (the width of the passage of the intake air2) of the element301.

In the measurement result, as illustrated in the graph ofFIG.14, in a case where the curing contraction rate β of the resin is 0.11%, ρ has been 2.76 mm, and the amount of warpage of the thin film portion402has been about 4.8 mm. When the curing contraction rate β of the resin is 0.3%, ρ has been 2.05 mm, whereas the amount of warpage of the thin film portion402has been about 1.5 mm. Therefore, it has been verified that the measured value of the curvature radius ρ coincides with the calculation result of the general formula.

Hereinafter, effects of the chip package300according to the present embodiment will be described. (1) The chip package300according to the present embodiment includes the lead frame302, the element301mounted on the lead frame302and having the thin film portion402, and the sealing resin member303which seals the lead frame302and the element301such that at least the thin film portion402is exposed. Then, the curvature radius ρ of the exposed portion of the element301exposed from the sealing resin member303is 2.13 or less.

In the chip package300according to the present embodiment, the element301is formed to satisfy a condition that the curvature radius ρ (mm) of the exposed portion of the element301exposed from the sealing resin member303is 2.13 or less, and thus it is possible to obtain an effect of suppressing the occurrence of warpage in the thin film portion402when the sealing resin member303for sealing the element301and the lead frame302is formed. That is, the condition that the curvature radius ρ (mm) of the peripheral region portion in the surface of the element301after the molding resin forming the sealing resin member303is cured is 2.13 or less (ρ≤2.13) is satisfied, and thus there is an effect that the amount of warpage of the thin film portion402becomes within 3 μm of the optimum value, the flatness of the front surface of the thin film portion402is secured, and the chip package300capable of accurately measuring the flow amount of the intake air2can be obtained.

In the chip package300according to the present embodiment, ρ satisfies the relationship of following Expression (1), and thus, it is possible to obtain an effect that ρ≤2.13 can be reliably calculated by appropriately selecting h1to h5and the curing contraction rate β of the chip package300.

(2) In the chip package300according to the present embodiment, the curing contraction rate β of the molding resin forming the sealing resin member303is 0.18% or more, and thus when the sealing resin member303is allowed to cool from the molding temperature to a normal temperature, and the sealing resin member303can be deformed in a direction of actively warping such that the front surface of the sealing resin member becomes convex. Therefore, it is possible to obtain an effect that the compressive stress of the thin film portion402generated by the contraction of the lead frame302is alleviated by the tensile force acting on the mold resin, and it is possible to prevent the stress from concentrating on the thin film portion402and to suppress the deformation of the thin film portion402.

As a result, it is possible to obtain an effect that the measurement accuracy equivalent to that of a conventional chip package in which the intermediate member is provided to match the linear expansion coefficient α and reduce the warpage of the thin film portion402is secured. The chip package300according to the present embodiment is not provided with the intermediate member, and thus it is possible to obtain an effect that the production cost is reduced as compared with the conventional chip package having the intermediate member.

(3) In the chip package300according to the present embodiment, the sealing resin member303has the recessed groove-shaped passage Kt having the pair of passage walls Th and the bottom wall from which the front surface of the element body401is exposed, the pair of passage walls Th forming the passage Kt of the sealing resin member303covers both side edges of the element301in the direction orthogonal to the airflow, and the thin film portion402is exposed to the passage Kt. With this configuration, when the sealing resin member303is cooled from the molding temperature to a normal temperature, and the front surface resin portion U of the sealing resin member303is contracted and deformed, the element301is also deformed together with the front surface resin portion U, and a tensile force acts on the thin film portion402, so that an effect of reducing the amount of warpage of the thin film portion can be obtained.

(4) In the chip package300according to the present embodiment, the maximum thickness (mm) h3of the front surface resin portion U, which is the thickness of the sealing resin member303on the front surface side (element301side) from the lead frame302, is formed to be twice or more the maximum thickness (mm) h1of the back surface resin portion S, which is the thickness of the sealing resin member303on the back surface side from the lead frame302. With this configuration, when the sealing resin member303is cooled from the molding temperature to a normal temperature, the front surface resin portion U of the sealing resin member303is effectively contracted and deformed, a tensile force acts on the thin film portion402, so that an effect of reducing the amount of warpage of the thin film portion can be obtained.

(5) In the chip package300according to the present embodiment, in a part of the lead frame302, the through hole Kh is formed in a region obtained by projecting the thin film portion402on the lead frame302in a direction perpendicular to the front surface of the element301, and the polyimide tape304is attached to the back surface side of the lead frame302to cover the through hole Kh. With this configuration, the communication path R communicating with the outside of the sealing resin member303can be formed, and the pressure acting on the thin film portion402can be made equal to the atmospheric pressure.

(6) In the chip package300according to the present embodiment, the sealing resin member303has the opening portion K1such that a part of the tape304is exposed.

(7) The opening portion K1has a truncated cone shape of which the opening diameter increases when a distance from the lead frame302increases.

(8) The passage wall Th has a throttle shape in which the opening area of the passage Kt gradually narrows toward the thin film portion402(detection portion).

(9) The resin-sealed package is manufactured by performing resin sealing such that the curing contraction rate β of the sealing resin member303is 0.18% or more.

(10) The resin-sealed package is manufactured by performing resin sealing such that the curvature radius ρ of the exposed   portion of the element301exposed from the sealing resin member303is 2.13 or less.

Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various design changes can be made without departing from the spirit of the present invention described in the claims. For example, the above-described embodiment has been described in detail for easy understanding of the invention and is not necessarily limited to those having all the described configurations. In addition, a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of a certain embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

REFERENCE SIGNS LIST