JP5533590B2 - Thermal flow sensor - Google Patents

Description

  The present invention relates to a method for manufacturing a thermal flow sensor used for measuring an intake air flow rate of an internal combustion engine.

  Conventionally, a sensing part for detecting the flow rate of the fluid to be detected is formed on the surface, and a sensor chip having a recess formed on the back surface of the part where the heating resistor forming the sensing part is formed is mounted in the housing recess of the mounting member. There is known a heat-sensitive flow sensor (see, for example, Patent Document 1).

  Specifically, in such a thermal flow sensor, a part of the sensor chip is mounted on the bottom surface of the housing recess via an adhesive or the like as a connecting member, and the sensor chip is cantilevered. . A gap is formed between the back surface of the sensor chip and the bottom surface of the housing recess. In addition, the bottom surface of the housing recess in the mounting member has a protrusion that suppresses the flow of the detected fluid into the recess and suppresses the swirling (turbulent flow) of the detected fluid in the recess. It is formed so as to be disposed inside.

  The thermal flow sensor is manufactured, for example, as follows. That is, first, a mounting member having an accommodation recess and having a projection formed on the bottom surface of the accommodation recess is prepared. And it manufactures by mounting a sensor chip in a mounting member via an adhesive so that a projection part may be arranged in a crevice of a sensor chip.

JP 2010-151542 A

  However, in the above method for manufacturing a thermal flow sensor, the sensor chip is mounted on the mounting member in which the protrusion is formed in the housing recess, so that the tip of the protrusion contacts the bottom surface of the recess formed in the sensor chip. There is a possibility that.

  If the tip of the protrusion comes into contact with the bottom surface of the recess, the sensor chip and the external stress such as vibration acting on the mounting member are mounted on the sensing part of the sensor chip from the mounting member via the protrusion. There is a problem that thermal stress due to the difference in linear expansion coefficient from the member is transmitted, and the flow rate detection accuracy is reduced by these stresses.

  In order to solve this problem, it is possible to simply suppress the contact between the tip of the protrusion and the bottom surface of the recess formed in the sensor chip by reducing the protrusion. In order to suppress the vortex swirling, it is preferable to make the tip of the protrusion and the bottom of the recess as narrow as possible.

  In addition, as a thermal flow sensor that suppresses the swirling of the fluid to be detected in the recess, for example, on the back side of the sensor chip, upstream of the recess with respect to the normal flow direction of the fluid to be detected In some cases, a groove portion is formed in the portion to be formed, and a protruding portion disposed in the groove portion is formed on the bottom surface of the housing recess. Even in such a heat-sensitive flow sensor, the flow rate detection accuracy is lowered when the tip of the protruding portion and the bottom surface of the groove are in contact with each other.

  In view of the above points, the present invention provides a thermal flow sensor that can suppress contact between a tip of a portion formed in an accommodation recess and a sensor chip that suppresses swirling of a fluid to be detected in the recess. It aims at providing the manufacturing method of.

  In order to achieve the above object, in the invention according to claim 1, there is provided a sensor chip (10) having a recess (12) and a receiving recess (21) for mounting the sensor chip (10) on one surface (20a). A step of preparing a mounting member (20) that is formed and has a through hole (22) formed in the bottom surface of the housing recess (21), and the recess (12) and the through hole (22) are opposed to each other. Then, a step of mounting a part of the sensor chip (10) on the bottom surface of the housing recess (21) via the connecting member (70), and injecting resin from the through hole (22), the bottom surface of the housing recess (21) And a step of forming a protrusion (22) that extends in the direction of the sensor chip (10), is disposed in the recess (12), and is separated from the sensor chip (10).

  In such a manufacturing method, since the resin is injected from the through hole (22) based on the distance between the bottom surface of the housing recess (21) and the bottom surface of the recess (12), the projection (22) is formed. Similar to the manufacturing method, it is possible to suppress contact between the tip of the protrusion (22) and the bottom of the recess (12).

  For example, as in the invention described in claim 2, in the step of forming the protrusion (22), the distance between the surface of the sensor chip (10) and the one surface (20a) of the mounting member (20) is measured and measured. The distance between the bottom surface of the housing recess (21) and the bottom surface of the recess (12) is calculated based on the measured distance, the depth of the housing recess (21), the thickness of the sensor chip (10), and the depth of the recess (12). Then, the protrusion (22) can be formed based on the calculated interval.

  Further, as in the third aspect of the invention, the step of preparing the sensor chip (10) is configured using a rectangular plate-like substrate, and the normal flow of the fluid to be detected on the back surface of the substrate. In the step of preparing the mounting member (20) in which the first groove (15) is formed in a portion upstream of the recess (12) with respect to the direction, the sensor chip (10) is accommodated in the receiving recess. In the step of forming the projecting portion (22) by preparing the one having the first through groove (25) formed in a region facing the first groove portion (15) when mounted on (21), the through hole (22 ) In addition to the first through-groove (25), the resin extends from the housing recess (21) toward the sensor chip (10), and is disposed in the first groove (15) and the sensor chip (10). ) And the first protrusion (24) spaced apart from each other.

  Furthermore, as in the invention according to claim 4, in the step of preparing the sensor chip (10), the first groove portion is formed in a portion of the back surface of the substrate that is closer to one end in the longitudinal direction of the substrate than the recess (12). In the step of preparing the mounting member (20) in which the second groove (16) connected to (15) is formed, the second step is performed when the sensor chip (10) is mounted in the housing recess (21). In the step of forming the protrusion (22) by preparing a second through groove formed in a region facing the groove (16), in addition to the through hole (22) and the first through groove (25), Resin is also poured into the second through-groove, extends from the housing recess (21) in the direction of the sensor chip (10), is disposed in the second groove (16), and is separated from the sensor chip (10). The part can be formed.

  The above is a description of a method for manufacturing a thermal flow sensor in which the protrusion (22) is disposed in the recess (12). However, a thermal flow sensor in which the protrusion (22) is not disposed in the recess (12). The present invention can also be applied to this manufacturing method.

  That is, the invention according to claim 5 is configured by using a rectangular plate-shaped substrate, and on the back surface of the substrate, the upstream side of the recess (12) with respect to the normal flow direction of the fluid to be detected. A step of preparing a sensor chip (10) in which a first groove (15) is formed in a portion to be formed, and an accommodation recess (21) for mounting the sensor chip (10) is formed on one surface (20a) and the accommodation The step of preparing the mounting member (20) in which the first through groove (25) is formed on the bottom surface of the recess (21), and the first groove portion (15) and the first through groove (25) are made to face each other. A step of mounting a part of the chip (10) on the bottom surface of the housing recess (21) via the connecting member (70), and injecting resin from the first through groove (25), from the bottom surface of the housing recess (21) It extends in the direction of the sensor chip (10) and is arranged in the first groove (15). Is characterized by performing the steps of forming a first protruding portion spaced a sensor chip (10) (24) while being, a.

  In such a manufacturing method, resin is injected from the first through groove (25) based on the distance between the bottom surface of the housing recess (21) and the bottom surface of the first groove portion (15), so that the first protrusion (24) is formed. Since it forms, compared with the conventional manufacturing method, it can suppress that the front-end | tip part of a 1st protrusion part (24) and the bottom face of a recessed part (12) contact.

  For example, as in the invention described in claim 6, in the step of forming the first protrusion (24), the distance between the surface of the sensor chip (10) and one surface (20a) of the mounting member (20) is measured. Based on the measured distance, the depth of the receiving recess (21), the thickness of the sensor chip (10), the depth of the first groove (15), the bottom surface of the receiving recess (21) and the first groove (15) The first protrusion (24) can be formed based on the calculated distance from the bottom surface.

  According to the seventh aspect of the present invention, in the step of preparing the sensor chip (10), the first groove portion is formed in a portion of the back surface of the substrate that is closer to one end in the longitudinal direction of the substrate than the recess (12). In the step of preparing the mounting member (20) in which the second groove (16) connected to (15) is formed, the second step is performed when the sensor chip (10) is mounted in the housing recess (21). In the step of forming the first projecting portion (24) by preparing a second through groove formed in a region facing the groove portion (16), the second through groove is added to the first through groove (25). The resin is also injected, and the second projecting portion extending from the housing recess (21) toward the sensor chip (10) and disposed in the second groove (16) and spaced apart from the sensor chip (10) is formed. be able to.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a schematic plan view of the thermal flow sensor in the first embodiment of the present invention. (A) is AA sectional drawing in FIG. 1, (b) is BB sectional enlarged view in FIG. It is sectional drawing which shows the manufacturing process of the thermal type flow sensor shown in FIG. (A) is a top view of the sensor chip in 2nd Embodiment of this invention, (b) is sectional drawing of a thermal type flow sensor. It is a top view of the sensor chip in a 3rd embodiment of the present invention.

(First embodiment)
A first embodiment of the present invention will be described. FIG. 1 is a schematic plan view of a thermal flow sensor according to the present embodiment, FIG. 2A is a cross-sectional view taken along line AA in FIG. 1, and FIG. 2B is an enlarged cross-sectional view taken along line BB in FIG. It is. Note that the heat-sensitive flow sensor of the present embodiment is preferably used, for example, when detecting the flow rate of intake air into the engine of the vehicle or exhaust gas from the engine.

  As shown in FIGS. 1 and 2, the thermal flow sensor includes a sensor chip 10, a mounting member 20 on which the sensor chip 10 is mounted, and a circuit chip that controls input / output of the sensing unit 11 in the sensor chip 10. 30, a lead 40 electrically connected to the circuit chip 30, a connection part between the lead 40 and the circuit chip 30, a circuit chip 30, and a sealing part that covers and protects the connection part between the circuit chip 30 and the sensor chip 10. The structure includes a stop resin 50.

  The sensor chip 10 is a general one having a sensing unit 11 for detecting the flow rate of the fluid to be detected. Specifically, the sensor chip 10 is configured using a rectangular plate-like semiconductor substrate made of silicon or the like, as in JP 2010-151542 A, and an insulating film is formed on the surface of the semiconductor substrate. . And the sensing part 11 is formed in the one end part side (right side of the paper surface in FIG. 1) of the longitudinal direction on this insulating film. The sensing unit 11 is configured to have a bridge circuit including a heat generating element and a temperature sensitive element, and the heat generation of the heat generating element is controlled so that the output of the bridge circuit is constant.

  Further, the sensor chip 10 is formed with a thin film portion 13 made of an insulating film by forming a quadrangular pyramid-shaped recess 12 anisotropically etched from the back surface. The heating element of the sensing unit 11 is formed on the thin film unit 13. That is, the recess 12 is formed on the back surface of the sensor chip 10 where the heating element is formed. The temperature sensitive element is formed in a region excluding the thin film portion 13, and the heat generating element and the temperature sensitive element are thermally separated. Further, the sensor chip 10 has a pad 14 formed on the other end side opposite to the one end side where the sensing unit 11 is formed.

  The circuit chip 30 is formed with various circuits for performing signal processing of detection signals output from the sensor chip 10, and pads 31 and 32 are formed. The pad 31 is electrically connected to the pad 14 formed on the sensor chip 10 via the bonding wire 61, and the pad 32 is electrically connected to the lead 40 via the bonding wire 62.

  The lead 40 includes a support member 41 and a single lead frame. After the mounting member 20 is molded, an unnecessary portion that connects the lead 40 and the support member 41 is cut off, whereby the lead 40 and the support member 41 are separated from each other. Are independent of each other. The unnecessary portion corresponds to the outer peripheral frame of the lead frame and fulfills the function of temporarily connecting the lead 40 and the support member 41. The support member 41 corresponds to an island of the lead frame, and the circuit chip 30 and the sensor chip 10 are mounted on the surface thereof.

  The mounting member 20 is configured by molding a resin such as epoxy, for example, and an accommodation recess 21 for mounting the sensor chip 10 and the circuit chip 30 is formed on one surface 20a. The bottom surface of the housing recess 21 is composed of the support member 41 and a portion made of resin. And on the support member 41, the back surface of the formation region of the pad 14 in the sensor chip 10 and the circuit chip 30 are mounted via an adhesive 70 as a connection member. That is, the sensor chip 10 is partly mounted on the support member 41 and cantilevered.

  And the part in which the sensing part 11 is formed protrudes from the support member 41 and is opposed to the part made of resin in the bottom surface of the housing recess 21, and the part protruding from the support member 41 is the adhesive 70. A gap is formed between the bottom surface of the housing recess 21 and the height. Furthermore, the sensor chip 10 is arranged so as to be separated from the side wall of the housing recess 21, and a gap is formed between the sensor chip 10 and the side wall.

  In addition, a portion of the bottom surface of the housing recess 21 made of resin, specifically, a portion facing the recess 12 of the sensor chip 10 extends from the bottom surface of the housing recess 21 toward the sensor chip 10, and is in the recess 12. And a protrusion 22 that is disposed at a distance from the sensor chip 10. As will be described in detail later, the protrusion 22 is formed by injecting resin into a through hole 23 formed in a portion of the bottom surface of the housing recess 21 that faces the recess 12 of the sensor chip 10. .

  The sealing resin 50 seals a part of the sensor chip 10, the circuit chip 30, a bonding wire 61 that connects the sensor chip 10 and the circuit chip 30, a bonding wire 62 that connects the circuit chip 30 and the lead 40, and the like. ing. As such a sealing resin 50, for example, an epoxy resin or the like is used.

  As described above, the thermal flow sensor of this embodiment is configured. In such a thermal flow sensor, the heat of the heating resistor of the sensing unit 11 formed in the sensor chip 10 is taken away by the flow of the fluid to be detected, and the output of the bridge circuit changes. The flow rate is detected.

  In the thermal flow sensor, a gap is formed between the sensor chip 10 and the housing recess 21, and the fluid to be detected flows into the recess 12 through the gap. However, a projection 22 is formed on the bottom surface of the housing recess 21 so as to protrude toward the sensor chip 10 and to be disposed in the recess 12. For this reason, compared with the case where the protrusion 22 does not exist in the recess 12, the inflow area where the fluid to be detected flows into the recess 12, in other words, the opening area of the recess 12 is reduced and flows into the recess 12. The flow rate of the fluid to be detected can be reduced. Moreover, the space in the recessed part 12 is reduced and the to-be-detected fluid which flows through the recessed part 12 can be rectified. Therefore, swirling of the fluid to be detected in the recess 12 can be suppressed, and a decrease in flow rate detection accuracy can be suppressed.

  Further, since the protrusion 22 is separated from the sensor chip 10, external stress such as vibration acting on the mounting member 20 from the mounting member 20 to the sensor chip 10 or the sensor chip 10 and the mounting member via the protrusion 22. It is possible to suppress the transmission of thermal stress due to the difference in linear expansion coefficient with respect to 20, and to prevent the flow rate detection accuracy from being reduced by these stresses.

  Next, a method for manufacturing the thermal flow sensor will be described. FIG. 3 is a cross-sectional view showing a manufacturing process of the thermal flow sensor shown in FIG. FIG. 3 corresponds to the BB cross section in FIG.

  As shown in FIG. 3A, first, a mounting member 20 in which an accommodation recess 21 is formed and a through hole 23 is formed in the accommodation recess 21 is prepared. Then, as illustrated in FIG. 3B, the circuit chip 30 and the sensor chip 10 are mounted in the housing recess 21 via the adhesive 70. Specifically, a part of the sensor chip 10 and the circuit chip 30 are mounted on the support member 41 via the adhesive 70 while positioning the recess 12 so as to face the through hole 23 formed in the housing recess 21. .

  Thereafter, as shown in FIG. 3 (c), a resin such as epoxy is injected from the through hole 23 based on the distance between the bottom surface of the accommodating recess 21 and the bottom surface of the recess 12, that is, the back surface of the thin film portion 13. The protrusion 22 is formed by curing. Specifically, in the present embodiment, the surface of the sensor chip 10 is detected by irradiating the mounting member 20 and the sensor chip 10 with a transmission beam such as laser light from the one surface 20a side of the mounting member 20 and detecting the reflected beam. And the surface of the mounting member 20 (a in the figure) are measured. Then, from the depth of the accommodation recess 21, the thickness of the sensor chip 10, the depth of the recess 12, and the measured distance between the surface of the sensor chip 10 and the one surface 20 a of the mounting member 20, The distance from the bottom surface is calculated, and resin is injected based on the calculated distance to form the protrusion 22.

  In this case, since the detected fluid can be prevented from swirling in the recess 12 as the distance between the tip of the projection 22 and the bottom of the recess 12 is narrow, the distance between the tip of the projection 22 and the bottom of the recess 12 is reduced. Therefore, it is preferable to appropriately consider the amount of the resin to be injected and the clay of the resin to be injected. In addition, when injecting the resin, the resin may be injected such that the pressure in the housing recess 21 is lower than the pressure on the side opposite to the one surface 20a of the mounting member 20, that is, the resin injection side. Good. Thereby, the injection | pouring speed | velocity | rate of resin can be improved.

  Thereafter, as in the prior art, first, the sensor chip 10 and the circuit chip 30 are electrically connected via the bonding wire 61 and the circuit chip 30 and the lead 40 are electrically connected via the bonding wire 62. . Then, the circuit chip 30, the bonding wires 61 and 62, a part of the sensor chip 10, and the like are sealed so that the sealing resin 50 is potted in the housing recess 21 and the sensing part 11 and the like of the sensor chip 10 are exposed. Thus, the thermal flow sensor is manufactured.

  As described above, in the manufacturing method of the present embodiment, after mounting the sensor chip 10 in the housing recess 21 via the adhesive 70, the through-hole is based on the distance between the bottom surface of the housing recess 21 and the bottom surface of the recess 12. The resin 22 is injected from 23 to form the protrusion 22. For this reason, it can suppress that the front-end | tip part of the projection part 22 and the bottom face of the recessed part 12 contact compared with the conventional manufacturing method.

  Further, in the conventional manufacturing method, the film thickness of the adhesive 70 after the sensor chip 10 is mounted in the housing recess 21 is predetermined in order to suppress the contact between the tip of the protrusion 22 and the bottom surface of the recess 12. Although a method of strictly controlling the mounting process so as to be a value can be considered, this method complicates the manufacturing method. However, in this embodiment, it is not necessary to strictly control the film thickness of the adhesive 70 when the sensor chip 10 is mounted. That is, the tip portion of the protrusion 22 and the recess 12 are not complicated without complicating the manufacturing method. It can suppress that a bottom face contacts.

  Further, in the conventional manufacturing method, the sensor chip 10 is mounted on the housing recess 21 via the adhesive 70 made of a material having a high Young's modulus so that the film thickness of the adhesive 70 is difficult to change before and after mounting. Therefore, it is also conceivable that the tip of the protrusion 22 and the bottom surface of the recess 12 are prevented from contacting each other. However, in such a manufacturing method, the stress relaxation function of the adhesive 70 is reduced as compared with the case where the adhesive 70 is configured using a material having a low Young's modulus, and the adhesive 70 is mounted via the adhesive 70. The stress transmitted from the member 20 to the sensor chip 10 is increased. However, in this embodiment, since the protrusion 22 is formed after the sensor chip 10 is mounted, the adhesive 70 can be configured using a material having a low Young's modulus, and the sensor chip 10 can be formed via the adhesive 70. The transmitted stress can be reduced.

(Second Embodiment)
A second embodiment of the present invention will be described. The heat-sensitive flow sensor of this embodiment has a first groove formed on the back surface of the sensor chip 10 as compared to the first embodiment, and the other parts are the same as those of the first embodiment. Then, explanation is omitted. 4A is a plan view of the sensor chip 10, and FIG. 4B is a cross-sectional view of the thermal flow sensor. FIG. 4B corresponds to the BB cross section in FIG. In FIG. 4A, the pad 14 is omitted.

  As shown in FIG. 4, in the thermal type flow sensor of the present embodiment, the first portion of the back surface of the sensor chip 10 is located upstream of the recess 12 with respect to the normal flow direction of the fluid to be detected. A groove portion 15 is formed. Specifically, the first groove 15 is formed from one end of the semiconductor substrate to the other end in a direction perpendicular to the flow direction. The depth of the first groove 15 is shallower than the recess 12.

  In addition, a first projecting portion that extends from the housing recess 21 in the direction of the sensor chip 10, is disposed in the first groove 15, and is separated from the sensor chip 10 at a portion of the housing recess 21 that faces the first groove 15. 24 is formed. The first protrusion 24 is formed by injecting resin into a first through groove 25 formed in a portion of the bottom surface of the housing recess 21 that faces the first groove 15 of the sensor chip 10. .

  In such a thermal flow sensor, the path until the fluid to be detected flows into the recess 12 is made longer than in the thermal flow sensor in which the first groove 15 and the first protrusion 24 are not formed. Can do. For this reason, since the flow velocity of the fluid to be detected is reduced due to pressure loss, the fluid to be detected can be further prevented from swirling in the recess 12.

  The thermal flow sensor shown in FIG. 4 is manufactured as follows. That is, the mounting member 20 in which the housing recess 21 is formed and the through hole 23 and the first through groove 25 are formed in the housing recess 21 is prepared, and the sensor chip 10 is mounted in the housing recess 21. Thereafter, when the resin 22 is injected into the through hole 23 to form the protrusion 22, the resin is injected into the first through groove 25 based on the distance between the bottom surface of the housing recess 21 and the bottom surface of the first groove portion 15. It is manufactured by forming one protrusion 24. The spacing between the bottom surface of the housing recess 21 and the bottom surface of the first groove portion 15 is, for example, the spacing between the surface of the sensor chip 10 and the surface of the mounting member 20 and the depth of the housing recess 21 as in the first embodiment. It can be calculated from the thickness of the sensor chip 10 and the depth of the first groove portion 15.

  Even in the case of manufacturing the above-described heat-sensitive flow sensor, resin is injected from the first through groove 25 on the basis of the distance between the bottom surface of the housing recess 21 and the bottom surface of the first groove portion 15, and the first projecting portion 24 is formed. Since it forms, it can suppress that the front-end | tip part of the 1st protrusion part 24 and the bottom face of the 1st groove part 15 contact.

(Third embodiment)
A third embodiment of the present invention will be described. The thermal flow sensor of this embodiment has a second groove formed on the back surface of the sensor chip 10 as compared to the second embodiment, and is otherwise the same as the second embodiment. Then, explanation is omitted. FIG. 5 is a plan view of the sensor chip 10. In FIG. 5, the pad 14 is omitted.

  As shown in FIG. 5, in the thermal flow sensor of the present embodiment, the second groove portion 16 connected to the first groove portion 15 is formed on the back surface of the sensor chip 10 on the end portion side from the recess 12. ing. That is, an L-shaped groove composed of the first and second groove portions 15 and 16 is formed on the back surface of the sensor chip 10, and a recess 12 is formed inside the L-shape. The first and second groove portions 15 and 16 have the same groove width and depth.

  In addition, although not particularly illustrated, the portion of the receiving recess 21 that faces the second groove 16 extends from the receiving recess 21 in the direction of the sensor chip 10 in the second groove 16, similarly to the first protrusion 24. A second protrusion that is disposed and spaced from the sensor chip 10 is formed. Similar to the first protrusion 24, the second protrusion injects resin into a second through groove formed in a portion of the bottom surface of the housing recess 21 that faces the second groove 16 of the sensor chip 10. Is formed.

  In such a thermal flow sensor, the fluid to be detected flows into the recess 12 from one end of the sensor chip 10 as compared to the thermal flow sensor in which the second groove 16 and the second protrusion are not formed. This can be suppressed, and the swirling of the fluid to be detected in the recess 12 can be further suppressed.

  The thermal flow sensor shown in FIG. 5 is manufactured as follows. That is, a mounting member 20 in which a housing recess 21 is formed and a through hole 23, a first through groove 25, and a second through groove are formed in the housing recess 21 is prepared, and the sensor chip 10 is placed in the housing recess 21. Implement. Thereafter, when the resin is injected into the through hole 23 to form the protrusion 22 and the resin is injected into the first through groove 25 to form the first protrusion 24, the bottom surface of the housing recess 21 and the second groove 16 are formed. It is manufactured by injecting resin on the basis of the distance from the bottom surface to form the second protrusion.

  Also when manufacturing the above-mentioned heat-sensitive flow sensor, it can control that the tip part of the 2nd projection and the bottom of the 2nd slot 16 contact.

(Other embodiments)
In the first embodiment, the example in which the sensor chip 10 and the circuit chip 30 are electrically connected and the circuit chip 30 and the leads 40 are electrically connected after the protrusion 22 is formed has been described. The order of can be changed as appropriate. That is, for example, the protrusion 22 may be formed after the sensor chip 10 and the circuit chip 30 are electrically connected and the circuit chip 30 and the lead 40 are electrically connected.

  Similarly, in the second embodiment, the sensor chip 10 and the circuit chip 30 are electrically connected and the circuit chip 30 and the lead 40 are electrically connected before the protrusion 22 and the first protrusion 24 are formed. You may connect to. In the third embodiment, the sensor chip 10 and the circuit chip 30 are electrically connected and the circuit chip 30 and the lead 40 are formed before the protrusion 22, the first protrusion 24, and the second protrusion are formed. May be electrically connected.

  In each of the above embodiments, the sensor chip 10 is mounted on the housing recess 21 via the adhesive 70 as a connecting member. For example, the sensor chip 10 may be mounted as a connecting member via an adhesive sheet. Good.

  In each of the above embodiments, an example in which a projection beam 22 is formed by irradiating a transmission beam such as a laser beam and calculating the distance between the bottom surface of the housing recess 21 and the bottom surface of the recess 12 based on the reflected beam is described. However, it can also be done as follows. For example, the protrusion 22 can be formed by measuring the distance between the bottom surface of the housing recess 21 and the bottom surface of the recess 12 from a cross-sectional image obtained by X-ray CT or the like. Similarly, in the second embodiment, the first protrusion 24 can be formed by measuring the distance between the bottom surface of the housing recess 21 and the bottom surface of the first groove 15 from a cross-sectional image obtained by X-ray CT or the like. In the third embodiment, the second protrusion can be formed by measuring the distance between the bottom surface of the housing recess 21 and the bottom surface of the second groove 16 from a cross-sectional image obtained by X-ray CT or the like.

  Further, in each of the above-described embodiments, the method for manufacturing a thermal flow sensor having the protrusion 22 in the recess 12 has been described. However, the present invention is also applied to a method of manufacturing a thermal flow sensor having no protrusion 22 in the recess 12. Can be applied. For example, in the said 2nd, 3rd embodiment, the through-hole 23 is not formed in the accommodation recessed part 21, but it can apply about the manufacturing method of the thermal type flow sensor which does not have the projection part 22. FIG. In this case, first, the mounting member 20 in which the through hole 23 is not formed is prepared. In the second embodiment, the first protrusion 24 may be formed by injecting resin into the first through groove 25. In the third embodiment, the first protrusion 24 and the second protrusion may be formed by injecting resin into the first through groove 25 and the second through groove, respectively.

DESCRIPTION OF SYMBOLS 10 Sensor chip 11 Sensing part 12 Concave part 13 Thin film part 20 Mounting member 21 Containing recessed part 22 Protrusion part 23 Through-hole 70 Adhesive

Claims (7)

A sensor chip (10) in which a sensing part (11) for detecting the flow rate of the fluid to be detected is formed on the surface, and a concave part (12) is formed on the back surface of the part where the heating resistor constituting the sensing part (11) is formed. ) Is mounted on the mounting member (20).
The sensor chip (10) and an accommodation recess (21) for mounting the sensor chip (10) are formed on one surface (20a), and a through hole (22) is formed on the bottom surface of the accommodation recess (21). Preparing the mounting member (20);
Mounting the part of the sensor chip (10) on the bottom surface of the housing recess (21) via a connecting member (70) with the recess (12) and the through hole (22) facing each other;
Resin is poured from the through hole (22), extends from the bottom surface of the housing recess (21) in the direction of the sensor chip (10), is disposed in the recess (12), and the sensor chip (10). Forming the spaced projections (22), and a method of manufacturing a thermal flow sensor.   In the step of forming the protrusion (22), the distance between the surface of the sensor chip (10) and the one surface (20a) of the mounting member (20) is measured, and the measured distance, the accommodation recess ( 21) Calculate the distance between the bottom surface of the housing recess (21) and the bottom surface of the recess (12) based on the depth of 21), the thickness of the sensor chip (10), and the depth of the recess (12); The method for manufacturing a thermal flow sensor according to claim 1, wherein the protrusion (22) is formed based on the calculated interval. In the step of preparing the sensor chip (10), the sensor chip (10) is configured by using a rectangular plate-shaped substrate, and the concave portion (12) from the back surface of the substrate with respect to the normal flow direction of the fluid to be detected. Prepare the first groove (15) formed in the upstream part,
In the step of preparing the mounting member (20), a first through groove (25) is formed in a region facing the first groove portion (15) when the sensor chip (10) is mounted in the housing recess (21). Prepare the formed one,
In the step of forming the protrusion (22), the resin is injected into the first through groove (25) in addition to the through hole (22), and the sensor chip (10) is inserted from the housing recess (21). 3. The first protrusion (24) extending in the direction of 1 and arranged in the first groove (15) and spaced apart from the sensor chip (10) is formed according to claim 1 or 2. A method for manufacturing a thermal flow sensor. In the step of preparing the sensor chip (10), a second portion of the back surface of the substrate that is connected to the first groove portion (15) at a portion on the one end side in the longitudinal direction of the substrate from the concave portion (12). Prepare a groove (16) formed,
In the step of preparing the mounting member (20), a second through groove is formed in a region facing the second groove portion (16) when the sensor chip (10) is mounted in the housing recess (21). Prepare things,
In the step of forming the protrusion (22), in addition to the through-hole (22) and the first through-groove (25), the resin is injected into the second through-groove, and the housing recess (21) 4. A second protrusion that extends in the direction of the sensor chip (10), is disposed in the second groove (16), and is spaced apart from the sensor chip (10). 5. The manufacturing method of the thermal-type flow sensor of description. A sensor chip (10) in which a sensing part (11) for detecting the flow rate of the fluid to be detected is formed on the surface, and a concave part (12) is formed on the back surface of the part where the heating resistor constituting the sensing part (11) is formed. ) Is mounted on the mounting member (20).
A first groove (15) is formed in a portion of the back surface of the substrate that is upstream of the recess (12) with respect to the normal flow direction of the detected fluid. Preparing the sensor chip (10) formed with:
The mounting member (20) in which a housing recess (21) for mounting the sensor chip (10) is formed on one surface (20a) and a first through groove (25) is formed on the bottom surface of the housing recess (21). )
The first groove portion (15) and the first through groove (25) are opposed to each other, and a part of the sensor chip (10) is mounted on the bottom surface of the housing recess (21) via a connection member (70). And a process of
Resin is poured from the first through groove (25), extends from the bottom surface of the housing recess (21) in the direction of the sensor chip (10), is disposed in the first groove portion (15) and the sensor chip. (10) and the process of forming the 1st protrusion part (24) spaced apart, The manufacturing method of the thermal type flow sensor characterized by the above-mentioned.   In the step of forming the first protrusion (24), the distance between the surface of the sensor chip (10) and the one surface (20a) of the mounting member (20) is measured, and the measured distance and the accommodation Based on the depth of the recess (21), the thickness of the sensor chip (10), and the depth of the first groove (15), the bottom surface of the housing recess (21) and the bottom surface of the first groove (15) The method according to claim 5, wherein the first projecting portion is formed on the basis of the calculated interval. In the step of preparing the sensor chip (10), a second portion of the back surface of the substrate that is connected to the first groove portion (15) at a portion on the one end side in the longitudinal direction of the substrate from the concave portion (12). Prepare a groove (16) formed,
In the step of preparing the mounting member (20), a second through groove is formed in a region facing the second groove portion (16) when the sensor chip (10) is mounted in the housing recess (21). Prepare things,
In the step of forming the first protrusion (24), the resin is injected into the second through groove in addition to the first through groove (25), and the sensor chip ( The thermal flow rate according to claim 6, characterized in that a second protrusion is formed extending in the direction of 10) and disposed in the second groove (16) and spaced apart from the sensor chip (10). Sensor manufacturing method.

Images