JP2011242373A - Pressure sensor and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure sensor of which the reduction in sealability is suppressed by preventing the reduction in smoothness of a seal surface of a case and deformation of an outer shape of the seal surface, and a method for manufacturing the same.SOLUTION: The pressure sensor includes a sensor part for detecting a pressure of a pressure medium, a terminal connected to the sensor part, the case which houses the sensor part and the terminal, and a housing having a pressure introduction hole formed therein and has the case built in the housing so that a portion of the sensor part exposed from the case is disposed in the pressure introduction hole and the pressure introduction hole is closed with the case. The case has a cylindrical cup and a resin part filled in the cup, and a connection portion between the sensor part and the terminal is covered with the resin part, and a portion of the sensor part exposed from the resin part is exposed through an opening on the pressure introduction hole side of the cup, and the cup is made of a single material.

Description

  The present invention is a sensor unit for detecting the pressure of a pressure medium to be detected, a terminal mechanically and electrically connected to the sensor unit, a case for housing the sensor unit and a part of each of the terminals, A pressure sensor having a housing in which a pressure introduction hole for a pressure medium to flow is formed, and a case assembled to the housing so that the sensor portion is installed in the pressure introduction hole, and a method for manufacturing the pressure sensor It is.

  Conventionally, for example, a thermal air flow sensor disclosed in Patent Document 1 has been proposed as a sensor disposed in a flow path through which a fluid flows so that a measurement site is exposed to a fluid. The thermal air flow sensor includes a semiconductor sensor element in which a measurement site for measuring the flow rate of the air flow to be measured is formed on a semiconductor substrate, a terminal to which the semiconductor sensor element is mechanically and electrically connected, And a molding material that integrally covers the semiconductor sensor element and the terminal.

  A part of the semiconductor sensor element (semiconductor substrate) is exposed from the mold member, and a measurement site is formed in the exposed site. A part of the terminal is also exposed from the mold member, and the exposed part functions as a connector with an external element.

  The thermal air flow sensor described above is applied to measure the intake air amount of an internal combustion engine. In the application, the measurement site of the semiconductor sensor element is arranged in the intake passage so as to be exposed to the air flow to be measured flowing in the intake passage. In this case, as shown in FIG. 4 of Patent Document 1, a part of the thermal flow sensor is inserted into the insertion hole formed in the intake passage, and the wall surface of the intake passage and the side surface of the mold material constituting the insertion hole The contact hole closes the insertion hole.

Japanese Patent No. 3328547

  By the way, as described above, in the thermal air flow sensor described in Patent Document 1, the semiconductor sensor element and the terminal are covered with a mold member, and a part of the terminal that functions as a connector (hereinafter referred to as a connection portion). Is exposed from the mold member. In order to form such a mold member, for example, a liquid resin is formed in a cavity formed by the upper mold and the lower mold in a state where the terminal connection portion is sandwiched by a mold composed of an upper mold and a lower mold. After injecting (for example, epoxy resin) and solidifying the injected resin, the solidified resin is released from the upper mold and the lower mold. Thereby, the above-described mold member is formed.

  By the way, when using an upper mold | type and a lower mold | type mentioned above, the meshing site | part of an upper mold | type and a lower mold | type will be located in the side surface along the longitudinal direction of the terminal in a mold member on the structure. There is a possibility that burrs may be generated on the side surface of the mold member because a minute gap is formed at the portion where the upper mold and the lower mold are engaged with each other. When such a burr | flash produces, there exists a possibility that the smoothness of the side surface of a mold member may fall. Furthermore, if the engagement between the upper mold and the lower mold is slightly shifted, the outer shape of the side surface of the mold member may be deformed.

  Therefore, as shown in Patent Document 1, in the case where the insertion hole is closed by the contact between the wall surface of the intake passage and the side surface of the mold material, the smoothness of the side surface of the mold member is reduced. There is a risk that the sealing performance between the mold member and the intake passage (insertion hole) may be impaired due to deformation of the outer shape of the side surface of the mold member. If the sealing performance is impaired, the air flow to be measured may leak to the outside.

  In order to improve the sealing performance, an O-ring made of rubber may be interposed between the side surface of the mold member (hereinafter referred to as a sealing surface) and the wall surface constituting the intake passage. However, even in this configuration, the sealing performance between the mold member and the O-ring is impaired due to a decrease in the smoothness of the sealing surface or the deformation of the outer shape of the sealing surface. There is a risk of leakage.

  Therefore, in view of the above-described problems, the present invention may reduce the sealing property by suppressing the smoothness of the sealing surface of the mold member (case) from being lowered and the outer shape of the sealing surface from being deformed. An object of the present invention is to provide a suppressed pressure sensor and a method for manufacturing the same.

  In order to achieve the above-described object, the invention described in claim 1 includes a sensor unit that detects a pressure of a pressure medium that is a detection target, a terminal that is mechanically and electrically connected to the sensor unit, A case in which a part of each of the sensor unit and the terminal is housed and a housing in which a pressure introduction hole for pressure medium to flow is formed, and a portion exposed from the case in the sensor unit is installed in the pressure introduction hole. A pressure sensor in which the case is assembled to the housing so that the pressure introduction hole is closed by the case, the case having a cylindrical cup and a resin portion filled in the cup, The connection part between the sensor part and the terminal is covered with the resin part, and the part exposed from the resin part in the sensor part is exposed from the opening part on the pressure introduction hole side in the cup, Site that was exposed from the resin portion at Minaru is, is exposed from the opening away from the pressure introducing hole in the cup, the cup is characterized in that it consists of a single material.

  Thus, according to the present invention, the cup is made of a single material. Therefore, when the cup and the housing are in direct contact and the cup is formed by pouring a liquid resin or a liquid metal into a cavity constituted by the upper mold and the lower mold, the upper mold and the lower mold described above are used. As the upper mold and the lower mold, the meshing position of the upper mold and the lower mold can be selected so that they are not located on the surface of the cup that contacts the housing. Therefore, it is possible to suppress the occurrence of burrs on the surface of the cup that contacts the housing (hereinafter referred to as a sealing surface) and the change of the outer shape of the sealing surface. Thereby, it is suppressed that the sealing performance of a cup and a housing falls, and it is suppressed that a pressure medium leaks outside.

  As described in claim 2, an O-ring made of an elastic material is interposed between the cup and the housing, and the pressure introduction hole is closed by the O-ring, the cup, and the resin portion. Is preferred. In this case, the cup and the O-ring are in direct contact. Therefore, when the cup is formed by pouring a liquid resin or a liquid metal into a cavity constituted by the upper mold and the lower mold, the upper mold and the lower mold for forming the cup By selecting an upper mold and a lower mold that are not located on the surface (hereinafter referred to as a seal surface) where the engagement position with the lower mold is in contact with the O-ring in the cup, burrs occur on the seal surface, It is suppressed that the external shape of a sealing surface changes. Thereby, it is suppressed that the sealing performance of a cup and an O-ring falls, and it is suppressed that a pressure medium leaks outside.

  As described in claim 3, it is preferable that a part of the side wall of the cup is surrounded by the O-ring. According to this, since the cup is compressed by the elasticity of the O-ring, the resin part is prevented from peeling from the cup and the resin part from being peeled from the sensor part due to the pressure of the pressure medium or the like. .

  A configuration in which the linear expansion coefficient of the cup is larger than the linear expansion coefficient of the resin portion is preferable. According to this, the thermal stress resulting from the difference in linear expansion coefficient is directed from the cup to the resin portion. As a result, since the resin portion is compressed by thermal stress (cup), the resin portion is prevented from being peeled from the cup due to the pressure of the pressure medium.

  According to a fifth aspect of the present invention, the sensor unit includes a sensor chip including a sensing unit that converts pressure into an electrical signal, and a portion of the sensor chip where the sensing unit is formed is exposed from the case, A configuration in which the linear expansion coefficient of the part is larger than the linear expansion coefficient of the sensor chip is preferable.

  According to this, the strength of the thermal stress due to the difference in the linear expansion coefficient from the cup toward the resin portion is increased as compared with the configuration in which the linear expansion coefficient of the resin portion is smaller than the linear expansion coefficient of the sensor chip. Therefore, the resin part is more effectively suppressed from being peeled from the cup by the pressure of the pressure medium. Further, since the sensor chip is compressed by thermal stress, the resin portion is prevented from being peeled off from the sensor chip due to the pressure of the pressure medium. Thereby, it is suppressed that a pressure medium flows into the electrical connection site | part of a sensor chip and a terminal via the peeling site | part of a resin part and a sensor chip. Therefore, it is suppressed that the above-mentioned connection site is corroded by the pressure medium and the electrical connection reliability between the sensor chip and the terminal is lowered.

  As a material for forming the cup, a resin or a metal can be employed as described in claims 6 and 7. In particular, when the cup is made of metal, the resin part is the only part of the case made of resin material that comes into direct contact with the pressure medium, so the amount of pressure medium that leaks to the outside through the part of the case made of resin material. Is reduced.

  As described in claim 8, as the shape of the cup, a cylindrical shape in which the length in the direction perpendicular to the axial direction becomes shorter as it approaches the pressure introducing hole can be adopted. According to this, since the outer shape of the case becomes narrower as it approaches the pressure introduction hole, it is easy to install the case in the pressure introduction hole of the housing.

  According to a ninth aspect of the present invention, there may be provided a connector case provided with connector pins that are mechanically and electrically connected to a portion exposed from the resin portion in the terminal.

  In addition, the pressure sensor of any one of Claims 1-9 can be manufactured with the manufacturing method of Claim 10 or Claim 11.

  According to the tenth aspect of the present invention, a terminal to which the sensor unit is mechanically and electrically connected is inserted into the cup so that a part of the sensor unit is exposed from the opening on the pressure introduction hole side of the cup. A closing step of closing the opening on the pressure introduction hole side of the cup with the jig while fixing the part of the sensor portion exposed from the cup and the cup to the jig, and a liquid resin portion after the closing step A forming step of forming a resin portion by pouring the forming material into a hollow portion having a bottomed cylindrical shape constituted by a cup and a jig and solidifying the forming material.

  For example, when the case is composed of only a resin part and a terminal having a sensor part mechanically and electrically connected to the resin part is insert-molded, the case is a cavity constituted by an upper mold and a lower mold. It is manufactured by injecting a liquid resin into the interior, solidifying the resin, and then removing the solidified resin from the mold. Thus, since the solidified resin must be taken out from the mold, in addition to the adhesiveness between the resin part and the terminal, and the resin part and the sensor part, the releasability between the resin part and the mold is taken into consideration. Must-have. Therefore, there arises a problem that the above-described adhesiveness cannot be obtained sufficiently.

  On the other hand, in the present invention, by injecting a liquid resin into a bottomed cylindrical hollow portion constituted by a cup and a jig that are part of the case, and solidifying the liquid resin, the resin Forming part. Thus, the cup is configured to perform a part of the functions of the upper mold and the lower mold described above, and after the resin is solidified, it is only necessary to consider the releasability between the solidified resin and the jig. . As described above, in the manufacturing method described in the present invention, the contact area between the solidified resin and the member that forms the outer shape of the resin portion is small, so that it is not necessary to consider the releasability so much. Thereby, for example, by adopting a resin having strong adhesiveness as the forming material of the resin part, it is possible to improve the adhesiveness between the resin part and the terminal and between the resin part and the sensor part.

  On the other hand, in the invention described in claim 11, the sensor part is mechanically and electrically connected to the terminal so that a part of the sensor part is exposed from the opening on the pressure introduction hole side in the cup. A plugging process in which a part of the sensor unit that is inserted into the cup and exposed from the cup is connected to the cup by the dam material, and the opening on the pressure introduction hole side is blocked by the dam material, and after the plugging process And forming a resin part by pouring a liquid resin part forming material into a bottomed cylindrical hollow part constituted by a cup and a dam material, and solidifying the forming material. It is characterized by. According to this, since it is not necessary to consider the releasability of the solidified resin at all, the adhesiveness between the resin part and the terminal and between the resin part and the sensor part is improved as compared with the manufacturing method according to claim 10. can do.

It is sectional drawing which shows schematic structure of the pressure sensor which concerns on 1st Embodiment. It is the expanded sectional view which expanded the principal part of the pressure sensor shown in FIG. It is sectional drawing of the metal mold | die for forming the cup shown in FIG. It is sectional drawing for demonstrating the manufacturing method of the principal part of the pressure sensor shown in FIG. It is sectional drawing for demonstrating the manufacturing method of the principal part of a pressure sensor. It is sectional drawing which shows the principal part of the pressure sensor formed through the manufacturing method shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a cross-sectional view illustrating a schematic configuration of the pressure sensor according to the first embodiment. FIG. 2 is an enlarged cross-sectional view in which the main part of the pressure sensor shown in FIG. 1 is enlarged. FIG. 3 is a cross-sectional view of a mold for forming the cup shown in FIG. FIG. 4 is a cross-sectional view for explaining a method of manufacturing the main part of the pressure sensor shown in FIG.

  As shown in FIG. 1, the pressure sensor 100 is formed with a main part 10 for detecting the pressure of the pressure medium to be detected and a pressure introduction hole 51 for the pressure medium to flow in as main parts. It has a housing 50 and a connector case 60 in which connector pins 61 for electrical connection with external elements are formed. The main portion 10 is attached to the housing 50 via an O-ring 70 and a backup ring 71 so as to close the pressure introduction hole 51, and a portion of the connector case 60 on the pressure introduction hole 51 side (insertion portion 62). Is attached to the housing 50 so as to press the main portion 10 against the pressure introducing hole 51.

  As shown in FIG. 2, the main unit 10 includes a sensor unit 20 that detects a pressure medium, a terminal 30 that outputs an electrical signal of the sensor unit 20 to a connector pin 61, and each of the sensor unit 20 and the terminal 30. And a case 40 for storing a part thereof.

  The sensor unit 20 includes a sensor chip 21 in which a sensing unit (not shown) that converts the pressure medium pressure into an electrical signal is formed on a semiconductor substrate, and a processing circuit that processes an output signal of the sensor chip 21 is formed on the semiconductor substrate. And a chip capacitor 23 in which a capacitor for removing noise included in an output signal of the circuit chip 22 is formed on a semiconductor substrate. The semiconductor substrate which is a constituent element of the sensor chip 21 is made of silicon, and the part of the sensor chip 21 where the sensing portion is formed is exposed from the case 40 to the outside.

  The terminal 30 fixes the first island 31 for fixing the sensor chip 21, the second island 32 for fixing the circuit chip 22, and the chip capacitor 23, and outputs the output signal of the sensor unit 20 to the connector pin 61. And a connection terminal 33 for outputting. The sensor chip 21 is mechanically connected to the first island 31 via an adhesive (not shown), and the circuit chip 22 is mechanically connected to the second island 32 via an adhesive (not shown). The chip capacitor 23 is mechanically and electrically connected to the connection terminal 33 via bumps (not shown).

  A part of the connection terminal 33 is exposed to the outside from the case 40, and the exposed part is mechanically and electrically connected to the connector pin 61 via a bump (not shown). As shown in FIG. 2, the sensor chip 21 and the circuit chip 22 are electrically connected via a first wire 24, and the circuit chip 22 and the connection terminal 33 (chip capacitor 23) are connected to the second wire 25. Is electrically connected. With the above electrical connection configuration, the output signal of the sensor chip 21 is sent to the connector pin 61 via the first wire 24, the circuit chip 22, the second wire 25, the chip capacitor 23, and the connection terminal 33. Is output.

  The case 40 includes a cylindrical cup 41 having two openings 41a and 41b, and a resin portion 42 filled in the cup 41. The cup 41 has a first cylindrical portion 43 whose outer diameter along the direction perpendicular to the axial direction is shorter than the diameter of the pressure introducing hole 51 on the connector case 60 side, and the outer diameter is a connector The second cylindrical portion 44 that is longer than the diameter of the pressure introduction hole 51 on the case 60 side, the opening on the second cylindrical portion 44 side in the first cylindrical portion 43, and the opening on the first cylindrical portion 43 side in the second cylindrical portion 44. And a cylindrical connecting part 45 that connects the parts. The cup 41 is made of a single material, and the components 43 to 45 of the cup 41 are integrally connected.

  As shown in FIG. 2, the outer diameter of the connecting portion 45 is gradually shortened from the second cylindrical portion 44 toward the first cylindrical portion 43, and a part of the outer shape of the case 40 becomes a pressure introduction hole. As it approaches 51, the shape becomes narrower. In the present embodiment, an O-ring 70 and a backup ring 71 are provided on the side wall of the connecting portion 45 that has a shape that becomes narrower as it approaches the pressure introduction hole 51. Hereinafter, the outer surface of the side wall of the connecting portion 45 is referred to as a seal surface 45a. The opening 41 a described above is an opening on the side opposite to the opening on the connecting portion 45 side in the first cylindrical portion 43, and the opening 41 b is an opening on the connecting portion 45 side in the second cylindrical portion 44. Is the opening on the opposite side.

  As shown in FIG. 2, all the mechanical and electrical connection portions between the sensor unit 20 and the terminal 30 are covered with the resin unit 42. And the part in which the sensing part in sensor chip 21 was formed is exposed outside from opening 41a by the side of pressure introduction hole 51 in cup 41, and the end by the side of connector pin 61 in connecting terminal 33 is the connector in cup 41 It is exposed to the outside from the opening 41b on the pin 61 side. Thereby, the sensing unit is exposed to the pressure medium, and the connector pin 61 can be connected to an external element.

  Next, the housing 50, the connector case 60, the O-ring 70, and the backup ring 71 will be described with reference to FIG.

  The housing 50 includes a cylindrical portion 52 in which the pressure introducing hole 51 is formed, and a fixing portion 53 for fixing the connector case 60. The fixing portion 53 includes an annular portion 54 having an inner diameter longer than the diameter of the pressure introducing hole 51, and a flange portion 55 formed at an end portion of the annular portion 54 away from the cylindrical portion 52. Part of each of the main portion 10 and the connector case 60 is provided in a region surrounded by the annular portion 54, and the connector case 60 is attached to the housing 50 by the flange portion 55 whose diameter is locally shortened. It is fixed. The flange portion 55 is formed by caulking the end portion of the annular portion 54 away from the cylindrical portion 52 with heat in a state where the connector case 60 and the main portion 10 are installed in the housing 50. The connector case 60 is pressed against the housing 50 by the stress due to the caulking, and the main portion 10 is pressed against the pressure introducing hole 51 by the force pressing the connector case 60.

  The connector case 60 includes an insertion portion 62 that is inserted into a region surrounded by the annular portion 54, and a protection portion 63 that protects the connector pin 61 together with an external element connected to the connector pin 61. The insertion portion 62 has a bottomed cylindrical shape that opens toward the pressure introduction hole 51, and has an inner diameter that is longer than the outer diameter of the second cylindrical portion 44 and an outer diameter that is slightly shorter than the inner diameter of the annular portion 54. It has become. And the edge part of the 2nd cylindrical part 44 is contacting the bottom part inner surface of the insertion part 62, and the collar part 55 is contacting the bottom part outer surface. Thereby, the force which presses the connector case 60 of the collar part 55 is transmitted to the case 40 via the bottom part of the insertion part 62, and the main part 10 is attached to the pressure introduction hole 51 by the force which presses this case 40. .

  The O-ring 70 is for suppressing the pressure medium from flowing out through the pressure introducing hole 51. The O-ring 70 has an annular shape and is interposed between the seal surface 45 a of the connecting portion 45 and the wall surface constituting the pressure introducing hole 51.

  The backup ring 71 is for suppressing the O-ring 70 pressed by the pressure of the pressure medium and the like from entering a minute gap formed by the seal surface 45a and the wall surface constituting the pressure introducing hole 51. is there. The backup ring 71 has an annular shape, and is disposed in a space formed by the O-ring 70, the seal surface 45 a, and the wall surface forming the pressure introducing hole 51.

  Next, a manufacturing method of the main part 10 which is a main component of the pressure sensor 100 according to the present embodiment will be described. First, a terminal 30 to which the sensor unit 20 is mechanically and electrically connected and a cup 41 are prepared. At this time, the cup 41 is formed using a mold 80 shown in FIG. The mold 80 is composed of an upper mold 81 and a lower mold 82, and the meshing position of the upper mold 81 and the lower mold 82 is determined by the wall surfaces of the first cylindrical portion 43 and the second cylindrical portion 44. And located. There is a possibility that burrs may be generated on the wall surface of the first cylindrical portion 43 and the wall surface of the second cylindrical portion 44, respectively, because a slight gap is generated at the portion where the upper die 81 and the lower die 82 are engaged with each other. Further, when the upper die 81 and the lower die 82 are somewhat misaligned, the outer shape of the wall surface of the first cylindrical portion 43 and the outer shape of the wall surface of the second cylindrical portion 44 may be deformed. On the other hand, since the inner wall of the connecting part 45 is entirely constituted by the upper mold and the outer wall (seal surface 45a) of the connecting part 45 is entirely constituted by the lower mold, the above-described burrs, deformation of the outer shape, etc. occur. There is no fear. Accordingly, it is possible to suppress the occurrence of burrs on the seal surface 45a of the connecting portion 45 and the deformation of the shape of the seal surface 45a. In addition, as a material which comprises the cup 41, resin with a large linear expansion coefficient is employable. In this embodiment, PBT is adopted.

  After the above preparation process, as shown in FIG. 4, the terminal 30 to which the sensor unit 20 is mechanically and electrically connected is connected to the pressure introduction hole 51 in the cup 41 where the sensing part in the sensor chip 21 is formed. The opening 41a is inserted into the cup 41 so as to be exposed from the opening 41a on the side, and the portion of the sensor chip 21 exposed from the opening 41a and the cup 41 are fixed to the jig 83. It is blocked by 83. The above is the closing process. In addition, as a constituent material of the jig 83 described above, an elastic material from which the resin is easily peeled can be employed. In this embodiment, polytetrafluoroethylene (registered trademark Teflon) is employed.

  After the closing step, a liquid resin, which is a material for forming the resin portion 42, is injected into the bottomed cylindrical hollow portion constituted by the cup 41 and the jig 83 from the opening 41b side of the cup 41, and the liquid state Solidify the resin. The above is the forming process. In the present embodiment, an epoxy resin having a lower linear expansion coefficient than that of PBT that is a forming material of the cup 41 and a higher linear expansion coefficient than that of silicon that is a forming material of the sensor chip 21 is employed as the above-described resin. Yes. Moreover, in this embodiment, in order to suppress that a bubble remains in resin in the above-mentioned formation process, the above-mentioned resin injection | pouring is performed in a vacuum atmosphere.

  After the forming step, the sensor unit 20 fixed to the jig 83 is removed, and the portion of the solidified resin that is in contact with the jig 83 is separated from the jig 83. Through these steps, the main portion 10 shown in FIG. 2 is formed.

  Next, the function and effect of the pressure sensor 100 according to this embodiment will be described. As described above, the cup 41 is formed by the mold 80 that suppresses the occurrence of burrs on the seal surface 45a of the connecting portion 45 and the deformation of the shape of the seal surface 45a. Thereby, it is suppressed that the sealing performance between the cup 41 and the O-ring 70 and the sealing performance between the cup 41 and the backup ring 71 are deteriorated due to the above-described burrs or deformation of the shape of the seal surface 45a. As a result, the pressure medium is prevented from leaking outside.

  In the present embodiment, a part of the connecting portion 45 is surrounded by the O-ring 70. According to this, since the cup 41 is compressed by the elasticity of the O-ring 70, the resin part 42 is peeled from the cup 41 and the resin part 42 is peeled from the sensor chip 21 due to the pressure of the pressure medium. It is suppressed.

  In this embodiment, the linear expansion coefficient of the forming material of the cup 41 is larger than the linear expansion coefficient of the forming material of the resin portion 42. According to this, since the thermal stress resulting from the difference in linear expansion coefficient is directed from the cup 41 to the resin part 42, the resin part 42 is compressed by the thermal stress (cup). Thereby, it is suppressed that the resin part 42 peels from the cup 41 by the pressure of a pressure medium.

  Furthermore, in this embodiment, the linear expansion coefficient of the forming material of the resin portion 42 is larger than the linear expansion coefficient of the forming material of the sensor chip 21. According to this, the linear expansion coefficient of the forming material of the resin part 42 is caused by the difference in the linear expansion coefficient from the cup 41 toward the resin part 42 as compared with the configuration in which the linear expansion coefficient of the forming material of the sensor chip 21 is smaller. The strength of thermal stress to be increased. Thereby, it is suppressed more effectively that the resin part 42 peels from the cup 41 by the pressure of a pressure medium. Further, since the sensor chip 21 is compressed by thermal stress, the resin part 42 is suppressed from being peeled off from the sensor chip 21 due to the pressure of the pressure medium. Thereby, it is suppressed that a pressure medium flows into the 1st wire 24 which electrically connects the sensor chip 21 and the circuit chip 22 via the peeling part of the resin part 42 and the sensor chip 21. FIG. As a result, the first wire 24 is corroded by the pressure medium, and the electrical connection reliability between the sensor chip 21 and the circuit chip 22 is lowered. As a result, the electrical connection reliability between the sensor chip 21 and the terminal 30 is lowered. Is suppressed.

  In the present embodiment, the outer diameter of the connecting portion 45 is gradually shortened from the second cylindrical portion 44 toward the first cylindrical portion 43, and its outer shape becomes narrower as it approaches the pressure introducing hole 51. It has a shape. According to this, it becomes easy to install the cup 41 (case 40) in the pressure introducing hole 51.

  In the present embodiment, in the forming process, which is one of the manufacturing processes of the main part 10, a liquid resin, which is a forming material of the resin part 42, is formed into a bottomed cylindrical hollow formed by the cup 41 and the jig 83. The liquid resin is solidified by pouring into the part. And after this formation process, while removing the sensor part 20 fixed to the jig 83, the main part 10 is formed by pulling apart the part which contacted the jig 83 in the solidified resin from the jig 83.

  For example, when the case is composed of only a resin part and a terminal having a sensor part mechanically and electrically connected to the resin part is insert-molded, the case is a cavity constituted by an upper mold and a lower mold. It is manufactured by injecting a liquid resin into the interior, solidifying the resin, and then removing the solidified resin from the mold. Thus, since the solidified resin must be taken out from the mold, in addition to the adhesiveness between the resin part and the terminal, and the resin part and the sensor part, the releasability between the resin part and the mold is taken into consideration. Must-have. Therefore, there arises a problem that the above-described adhesiveness cannot be obtained sufficiently.

  On the other hand, in this embodiment, by injecting a liquid resin into the bottomed cylindrical hollow portion constituted by the cup 41 and the jig 83 and solidifying the liquid resin, the resin portion 42 is formed. Forming. In this way, the cup 41 has a configuration that performs a part of the functions of the upper mold and the lower mold shown in the above example. After the resin is solidified, the mold release property between the solidified resin and the jig 83 is improved. Just consider it. As described above, in the manufacturing method shown in the present embodiment, the contact area between the solidified resin and the member forming the outer shape of the resin portion 42 is small, so that it is not necessary to consider the releasability so much. Thereby, for example, by adopting a resin having strong adhesiveness as the forming material of the resin portion 42, the adhesiveness between the resin portion 42 and the terminal 30 and between the resin portion 42 and the sensor portion 20 can be improved. In addition, as the above-described strong adhesive resin, an epoxy resin having a Young's modulus of about 1 GPa or the like can be used.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In this embodiment, the example which manufactured the main part 10 using the jig 83 was shown. However, for example, as shown in FIG. 5, the main portion 10 may be manufactured using a dam material 84 instead of the jig 83. In this manufacturing method, the terminal 30 to which the sensor unit 20 is mechanically and electrically connected is exposed from the opening 41a of the cup 41 where the sensing unit is formed on the pressure introduction hole 51 side of the cup 41. Thus, the opening 41 a is closed by the dam member 84 while the portion of the sensor chip 21 exposed from the opening 41 a and the cup 41 are connected by the dam member 84. After that, the cup 41 shown in FIG. 5 was inverted together with the terminal 30, and the liquid resin, which is the forming material of the resin portion 42, was constituted by the cup 41 and the dam material 84 from the opening 41 b side of the cup 41. It is poured into a hollow portion having a bottomed cylindrical shape, and the liquid resin is solidified. Through the above steps, the main part 10 shown in FIG. 6 is configured. In this case, the dam material 84 described above is included in the case 40. FIG. 5 is a cross-sectional view for explaining a method of manufacturing the main part of the pressure sensor. FIG. 6 is a cross-sectional view showing the main part of the pressure sensor formed through the manufacturing method shown in FIG.

  In the case of the above-described manufacturing method, unlike the manufacturing method shown in the present embodiment, it is not necessary to consider releasability at all. Therefore, when the main part 10 is manufactured by the manufacturing method described above, the resin part 42 and the terminal 30 and the resin part 42 and the sensor part 20 are compared with the case where the main part 10 is manufactured by the manufacturing method shown in the present embodiment. Adhesiveness can be improved.

  The dam material 84 is preferably made of the same material as the resin portion 42 in order to suppress the occurrence of thermal stress due to the difference in linear expansion coefficient. However, the dam material 84 preferably has low wettability because of its properties, and the resin portion 42 preferably has high wettability because of its properties. In order to satisfy any of the above properties, for example, there is a method in which each of the dam material 84 and the resin portion 42 is formed of a liquid resin and a solid filler. For example, the dam member 84 is formed of a resin obtained by adding a filler having a diameter of about 1 μm to a liquid epoxy resin, and the resin portion 42 is a filler having a diameter of about 100 μm to a liquid epoxy resin. What is necessary is just to form with the resin which added. Needless to say, the dam member 84 may be formed of a liquid resin and a solid filler, and the resin portion 42 may be formed of only a liquid resin.

  In the present embodiment, an example in which the cup 41 is formed of PBT has been shown. However, the material for forming the cup 41 is not limited to the above example, and for example, a metal such as stainless steel can be employed. In the case of this modification, the portion made of the resin material in direct contact with the pressure medium in the case 40 is only the resin portion 42, so that the amount of the pressure medium leaking outside through the portion made of the resin material in the case 40 is reduced. Is done.

DESCRIPTION OF SYMBOLS 10 ... Main part 20 ... Sensor part 21 ... Sensor chip 30 ... Terminal 40 ... Case 41 ... Cup 42 ... Resin part 50 ... Housing 51 ... Pressure introduction Hole 60 ... Connector case 70 ... O-ring 80 ... Mold 100 ... Pressure sensor

Claims (11)

A sensor unit for detecting the pressure of the pressure medium to be detected;
A terminal mechanically and electrically connected to the sensor unit;
A case for storing a part of each of the sensor unit and the terminal;
A housing formed with a pressure introduction hole for the pressure medium to flow in,
A portion of the sensor unit exposed from the case is installed in the pressure introduction hole, and the case is assembled to the housing so that the pressure introduction hole is closed by the case,
The case has a cylindrical cup and a resin portion filled in the cup,
The connection part of the sensor part and the terminal is covered with the resin part,
The part exposed from the resin part in the sensor part is exposed from the opening part on the pressure introduction hole side in the cup,
The part exposed from the resin part in the terminal is exposed from the opening part away from the pressure introduction hole in the cup,
The pressure sensor according to claim 1, wherein the cup is made of a single material. An O-ring made of an elastic material is interposed between the cup and the housing,
The pressure sensor according to claim 1, wherein the pressure introducing hole is closed by the O-ring, the cup, and the resin portion.   The pressure sensor according to claim 2, wherein a part of the side wall of the cup is surrounded by the O-ring.   The pressure sensor according to claim 1, wherein a linear expansion coefficient of the cup is larger than a linear expansion coefficient of the resin portion. The sensor unit has a sensor chip including a sensing unit that converts pressure into an electrical signal;
The part where the sensing part is formed in the sensor chip is exposed from the case,
The pressure sensor according to claim 4, wherein a linear expansion coefficient of the resin portion is larger than a linear expansion coefficient of the sensor chip.   The pressure sensor according to claim 1, wherein a material for forming the cup is a resin.   The pressure sensor according to claim 1, wherein a material for forming the cup is a metal.   The pressure according to any one of claims 1 to 7, wherein the cup has a cylindrical shape, and a length in a direction perpendicular to the axial direction becomes shorter as the pressure introduction hole is approached. Sensor.   The pressure sensor according to claim 1, further comprising a connector case provided with a connector pin that is mechanically and electrically connected to a portion of the terminal exposed from the resin portion. . It is a manufacturing method of the pressure sensor according to any one of claims 1 to 9,
A terminal to which the sensor unit is mechanically and electrically connected is inserted into the cup so that a part of the sensor unit is exposed from the opening on the pressure introduction hole side of the cup, and the cup A closing step of closing the opening on the pressure introduction hole side in the cup with the jig while fixing a part of the sensor part exposed from the jig to the jig;
After the closing step, the resin portion is formed by pouring the liquid forming material of the resin portion into a bottomed cylindrical hollow portion constituted by the cup and the jig, and solidifying the forming material. Forming a pressure sensor. It is a manufacturing method of the pressure sensor according to any one of claims 1 to 9,
A terminal to which the sensor unit is mechanically and electrically connected is inserted into the cup so that a part of the sensor unit is exposed from the opening on the pressure introduction hole side of the cup, and the cup A closing step of closing the opening on the pressure introduction hole side with the dam material while connecting the part of the sensor part exposed from the cup and the cup with the dam material;
After the closing step, the liquid resin portion forming material is poured into a bottomed cylindrical hollow portion constituted by the cup and the dam material, and the forming material is solidified to form the resin portion. A pressure sensor manufacturing method.

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