JP2015108529A - Temperature sensor, and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature sensor whose temperature detection capability is enhanced without impairing waterproofness.SOLUTION: An element unit 2 for detecting a temperature is sealed by a thermoconductive resin 3 while not being accommodated in a case. Heat at a place that is an object to be detected is thereby transmitted well to the element unit 2 via the thermoconductive resin 3 while maintaining excellent waterproofness and airtightness, making it possible to provide a temperature sensor 1 whose thermal responsiveness too is improved to become extremely good and temperature detection capability is enhanced. Furthermore, since the thermoconductive resin 3 is not accommodated in a case made of metal, etc., reliability is prevented from deteriorating in even an environment subject to a large temperature change.

Description

  The present invention relates to a temperature sensor, and more particularly, to a temperature sensor with enhanced temperature detection capability.

  For example, as disclosed in Patent Documents 1 and 2 and the like, it has already been widely performed to wrap electronic components such as a temperature sensor element with a thermoplastic resin or a metal case in order to improve waterproofness. In this case, it is already known that the temperature sensor is manufactured by resin-sealing by an injection molding method using a mold or encapsulating a metal case with a liquid resin. Thus, when a temperature sensor is manufactured by resin-sealing an element by an injection molding method or the like, waterproofness and airtightness can be improved.

JP-A-2-46121 Japanese Patent Laid-Open No. 9-74001

  However, the resin sealing of the element in such a conventional temperature sensor can improve waterproofness and airtightness, but has a problem that the temperature responsiveness of the element used by the sealing resin is lowered.

For example, in a temperature sensor sealed with a resin, the following method can be considered in order to improve the temperature responsiveness of the element used.
(A) Resin sealing is performed as thin as possible.
(A) Perform the minimum resin sealing.

  However, in the case of the method (a), high processing accuracy is required, and even if resin sealing can be performed, the element is partially exposed or the waterproof property that is required to be thin is ensured. There is a risk of being unable to do so.

  In the case of the above method (b), simply sealing the element only with resin causes water to enter from the gap between the element and the wiring portion coupled to the element, and sufficient waterproofness cannot be ensured. There is a fear. In addition, when used as a temperature sensor, there is a possibility that problems such as deterioration of waterproofness with time may occur.

  Furthermore, when encapsulating the element in a metal case using a liquid resin, it is necessary to perform a decompression process so as not to entrain air in the liquid resin, or to treat the liquid resin, for example, at 150 ° C. for 2 hours. There has been a problem in that it is necessary to do this, the process becomes complicated, and the work efficiency decreases.

  The present invention solves the above problems and problems, and an object of the present invention is to provide a temperature sensor with improved temperature detection capability and productivity without impairing waterproofness.

As a result of intensive studies to solve the above problems, the present inventors have arrived at the present invention.
That is, the gist of the present invention is as follows.
(1) A temperature sensor, wherein an element portion for detecting temperature is sealed with a thermally conductive resin in a state where it is not housed in a case.
(2) The temperature sensor according to (1), wherein the thermally conductive resin is disposed in a state exposed to the outside.
(3) The low thermal conductive resin having a thermal conductivity lower than that of the thermal conductive resin is disposed adjacent to the thermal conductive resin, according to (1) or (2), Temperature sensor.
(4) The temperature sensor according to (3), wherein a low thermal conductive resin is disposed around the thermal conductive resin, and the thermal conductive resin is covered with the low thermal conductive resin.
(5) The temperature sensor according to any one of (1) to (4), wherein the thermally conductive filler has an insulating property.
(6) Thermally conductive insulating resin having an insulating property sealed around the element portion, and an electrically conductive thermal property sealed around the thermally conductive insulating resin The temperature sensor according to (1) to (4) above, which is a conductive resin.
(7) The temperature sensor according to (4), wherein the heat conductive resin is a hard resin, and the low heat conductive resin is a soft resin.
(8) The temperature sensor according to (4), wherein the thermal conductive resin is a soft resin, and the low thermal conductive resin is a hard resin.
(9) The temperature sensor according to (1) to (8), wherein the element section is a thermistor.
(10) The temperature sensor according to (1) to (9), wherein the heat conductive resin is a thermoplastic resin containing a heat conductive filler.
(11) The temperature sensor according to any one of (1) to (10), wherein the thermoplastic resin is a polyamide resin or a polyester resin.
(12) The temperature sensor according to (3) or (4), wherein the low thermal conductive resin is a thermoplastic resin of the same type or the same type as that of the thermal conductive resin used as a base material of the thermoplastic resin. .
(13) A temperature sensor manufacturing method for manufacturing a temperature sensor by encapsulating at least a part of an element part to be sealed with a heat conductive resin using an injection molding method,
When injecting molten thermal conductive resin by placing the element part in the cavity of the mold, before injecting the thermally conductive resin, the element part is held in the circumferential direction by a cylindrical jig and placed in a predetermined position. Fixed,
A method of manufacturing a temperature sensor, wherein the cylindrical jig is retracted from the cavity to the outside of the cavity as the molten thermally conductive resin is filled into the cavity.
(14) The cylindrical jig is retracted from the cavity to the outside of the cavity by using a pressure that the thermal conductive resin flows into the cavity when the thermally conductive resin is injected into the cavity and pushes the cylindrical jig. (13) The method for manufacturing a temperature sensor according to (13).
(15) Using an injection molding method, an element part to be sealed is encased in a thermally conductive resin, and the intermediate encapsulant in which the element part is encapsulated in a thermally conductive resin is further thermally conducted than the thermally conductive resin A temperature sensor manufacturing method for manufacturing a temperature sensor encased in a low thermal conductivity resin having low properties,
A primary placement step of placing the element portion in a cavity of the primary molding die from a circumferential direction by a primary jig and fixing the element portion in a fixed position;
The molten thermal conductive resin is injected into the cavity of the primary molding die. At this time, the cylindrical jig for primary molding is discharged from the cavity of the primary molding die to the outside of the cavity, and the element portion is A primary molding process for producing an intermediate sealing body by sealing without exposing to the surface;
A secondary placement step of placing the intermediate sealing body in the cavity of the secondary molding die from the circumferential direction by a cylindrical jig for secondary molding and placing it in a fixed state;
The molten low thermal conductive resin is injected into the cavity of the secondary molding die, and at this time, the cylindrical jig for secondary molding is discharged from the cavity of the secondary molding die to the outside of the cavity, A secondary molding step of sealing molding without exposing the intermediate sealing body to the surface;
A method for manufacturing a temperature sensor, comprising:
(16) Using an injection molding method, an element part to be sealed is encapsulated with an insulating heat conductive resin, and an intermediate encapsulant in which the element part is encapsulated with the insulating heat conductive resin. Furthermore, it is a manufacturing method of a temperature sensor for manufacturing a temperature sensor encapsulated by a thermally conductive resin having conductivity,
A primary placement step of placing the element portion in a cavity of the primary molding die from a circumferential direction by a primary jig and fixing the element portion in a fixed position;
Injecting molten insulating heat conductive resin into the cavity of the primary molding die, and at this time, the cylindrical jig for primary molding is discharged from the cavity of the primary molding die to the outside of the cavity. The primary molding step for producing an intermediate sealing body by sealing without exposing the element portion to the surface;
A secondary placement step of placing the intermediate sealing body in the cavity of the secondary molding die from the circumferential direction by a cylindrical jig for secondary molding and placing it in a fixed state;
The molten conductive heat conductive resin is injected into the cavity of the secondary molding die, and at this time, the cylindrical jig for secondary molding is moved from the cavity of the secondary molding die to the outside of the cavity. A secondary molding step of discharging and sealing molding without exposing the intermediate sealing body to the surface;
A method for manufacturing a temperature sensor, comprising:

  According to the present invention, the element portion for detecting the temperature is sealed with the heat conductive resin, so that the heat of the location to be detected is the heat conductivity while maintaining good waterproofness and airtightness. Since it is transmitted to the element portion through the resin, the thermal response is extremely good, and a temperature sensor with an improved temperature detection capability can be provided. Further, by not storing the heat conductive resin in a case such as a metal, reliability is not lowered even in an environment with a large temperature change.

  In addition, by placing a low thermal conductive resin adjacent to the thermal conductive resin, heat transferred to the thermal conductive resin is blocked by the low thermal conductive resin and prevented from being transmitted to the surroundings of the low thermal conductive resin. Thus, it is possible to prevent heat from being transmitted to the outside or radiated to the outside due to mischief.

  Further, a low thermal conductive resin is disposed around the thermal conductive resin, and the thermal conductive resin is covered with the low thermal conductive resin, thereby improving strength as a temperature sensor and improving impact resistance. In addition, reliability can be improved.

  In addition, when sealing the periphery of a heat conductive resin with a low heat conductive resin, the heat conductive resin is a hard resin, and the low heat conductive resin is a soft resin. The system resin functions as a buffer layer against an impact from the outside and plays a role of preventing destruction of the element portion.

  In addition, when the periphery of the heat conductive resin is sealed with a low heat conductive resin, the heat conductive resin is a soft resin and the low heat conductive resin is a hard resin, so that the heat conductivity in contact with the element portion A soft resin as a resin functions as a buffer layer against an external impact and plays a role of preventing destruction of the element portion. In addition, since the outer periphery of the temperature sensor is covered with the hard resin, a shift or the like is unlikely to occur, and it is possible to precisely cope with the positioning of the temperature sensor.

  In addition, the thermoplastic resin used for the thermal conductive resin and the thermoplastic resin used for the low thermal conductive resin may be the same thermoplastic resin or the same material (same) thermoplastic resin. Therefore, it is possible to obtain good reliability even in an environment where the temperature is changed, for example, in an environment where the temperature change is large.

It is sectional drawing of the temperature sensor which concerns on embodiment (1st Embodiment) of this invention. It is sectional drawing explaining the process of the manufacturing method of the same temperature sensor. It is a perspective view explaining the process of the manufacturing method of the same temperature sensor. It is sectional drawing explaining the process of the manufacturing method of the same temperature sensor. It is sectional drawing explaining the process of the manufacturing method of the same temperature sensor. It is sectional drawing explaining the process of the manufacturing method of the same temperature sensor. It is sectional drawing explaining the process of the manufacturing method of the temperature sensor as a comparative example. It is sectional drawing explaining the process of the manufacturing method of the temperature sensor as the comparative example. It is sectional drawing explaining the process of the manufacturing method of the temperature sensor as the comparative example. It is sectional drawing of the temperature sensor which concerns on other embodiment (2nd Embodiment) of this invention. It is sectional drawing explaining the process of the manufacturing method of the same temperature sensor. It is sectional drawing of the temperature sensor which concerns on other embodiment (3rd Embodiment) of this invention. It is sectional drawing explaining the process of the manufacturing method of the same temperature sensor. It is sectional drawing of the temperature sensor which concerns on other embodiment (4th Embodiment) of this invention. It is sectional drawing explaining the process of the manufacturing method of the same temperature sensor. It is a perspective view explaining the process of the manufacturing method of the same temperature sensor. It is sectional drawing explaining the process of the manufacturing method of the same temperature sensor. It is sectional drawing explaining the process of the manufacturing method of the same temperature sensor. It is sectional drawing explaining the process of the manufacturing method of the same temperature sensor. It is sectional drawing explaining the process of the manufacturing method of the same temperature sensor. It is a perspective view explaining the process of the manufacturing method of the same temperature sensor. It is sectional drawing explaining the process of the manufacturing method of the same temperature sensor. It is sectional drawing explaining the process of the manufacturing method of the same temperature sensor. It is sectional drawing explaining the process of the manufacturing method of the same temperature sensor. It is sectional drawing of the temperature sensor which concerns on further another embodiment (5th Embodiment) of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, a temperature sensor 1 according to an embodiment of the present invention has a configuration in which an element portion 2 for detecting temperature is sealed with a heat conductive resin 3. Further, the heat conductive resin 3 that seals the element portion 2 and covers the entire periphery is not housed in a metal case, and in this embodiment, the heat conductive resin 3 is exposed to the outside. Yes.

  A pair of covered wires 4 are connected to the element portion 2 for detecting temperature. Although not shown, the element portion 2 is provided with a pair of connection terminals, and the electric wire 4 is made of a metal and has a conductive core wire portion covered with an insulating wire covering material 4a. It is structured. In this embodiment, the terminal of the element portion 2 and the core wire portion of the electric wire 4 are connected by a connecting material (connecting metal) such as solder. These connecting portions are covered by the electric wire covering material 4a or the like. (It may be covered with a coating material separate from the wire coating material 4a), and the connecting portion is not exposed to the outside. In addition, the element part 2 which concerns on embodiment of this invention is a thermistor for temperature detection, for example.

  The thermal conductive resin 3 used in the temperature sensor of the present invention is not particularly limited as long as it has thermal conductivity, and may be insulative or conductive, for example. As the heat conductive resin 3 having such characteristics, it is preferable to use a thermoplastic resin (base material) containing a heat conductive filler (so-called heat conductive filler).

  The thermoplastic resin that can be used in the present invention is not particularly limited, but ethylene-α-olefin copolymers such as polyethylene, polypropylene, and ethylene-propylene copolymer, polymethylpentene, and polychlorinated. Vinyl, polyvinylidene chloride, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl alcohol, polyvinyl acetal, fluorine resin (polyvinylidene fluoride, polytetrafluoroethylene, etc.), polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, poly Lactic acid, polystyrene, polyacrylonitrile, styrene-acrylonitrile copolymer, ABS resin, polyphenylene ether (PPE), modified PPE, polyamide, polyimide, polyamideimide, polyether A single resin such as a polymethacrylate such as amide, polymethyl methacrylate, polyacrylic acid, polycarbonate, polyarylate, polyphenylene sulfide, polysulfone, polyethersulfone, polyethernitrile, polyetherketone, polyketone, and liquid crystal polymer; and These copolymers, elastomers, hot melts, and mixtures may be mentioned. Of these, a polyamide resin is preferable in terms of moldability, chemical resistance, and economy, and polybutylene terephthalate is preferable in terms of sealing properties and adhesiveness. In consideration of flexibility when used as the temperature sensor 1 and adhesion between the electric wire 4 connected to the element portion 2 and the electric wire covering material 4a, it is preferable to use a thermoplastic resin having flexibility, and polyamide elastomer Polyester elastomer, polyamide hot melt, and polyester hot melt are particularly preferable.

  The heat conductive filler that can be used in the present invention is not particularly limited, but for example, the heat conductivity is preferably 5 W / (m · K) or more. In addition, those used for the purpose of improving mechanical properties as fillers, and those used for the purpose of imparting the functions of conductivity, insulation, magnetism, piezoelectricity, and electromagnetic wave absorption have the above thermal conductivity. Can be used as a filler in the present invention.

Examples of the form of the heat conductive filler include a spherical shape, a powder shape, a fiber shape, a needle shape, a scale shape, a whisker shape, a microcoil shape, and a nanotube shape.
The thermal conductivity of the thermally conductive filler can be measured using the sintered product.

  Specific examples of the thermally conductive filler (representative values of thermal conductivity in parentheses (unit: W / (m · K) are described), talc (5-10), aluminum oxide (36), Magnesium oxide (60), zinc oxide (25), magnesium carbonate (15), silicon carbide (160), aluminum nitride (170), boron nitride (210), silicon nitride (40), carbon (10 to several hundreds), Inorganic fillers such as graphite (10 to several hundred), silver (427), copper (398), aluminum (237), titanium (22), nickel (90), tin (68), iron (84), stainless steel (15) etc. These may be used independently and may use 2 or more types together.

  Of the thermally conductive fillers exemplified above, graphite and boron nitride are preferably used because of their high thermal conductivity efficiency when blended with a thermoplastic resin. In terms of economy, it is preferable to use talc, aluminum oxide, magnesium oxide, magnesium carbonate, or zinc oxide. In addition, since talc and boron nitride have electrical insulation properties, electrical insulation can be imparted to the heat conductive resin 3 by blending them.

  The use of the heat conductive resin having electrical insulation and the heat conductive resin having conductivity is, for example, when the contact of the element part for detecting the temperature and the wiring connected to the element part is exposed, It is preferable to perform resin sealing using a heat conductive resin having electrical insulation. On the other hand, when the contact has already secured electrical insulation using other means, it is preferable to perform resin sealing using a thermally conductive resin having conductivity. It should be noted that the proper use as described above is not particularly limited, and can be appropriately used as necessary. In addition, a thermally conductive resin having electrical insulation and a thermally conductive resin having conductivity are used. It can also be used in combination. This point will be described later.

  Examples of the form of graphite include a spherical shape, a powder shape, a fiber shape, a needle shape, a scale shape, a whisker shape, a microcoil shape, and a nanotube shape. Of these, scaly graphite is particularly preferable because it can increase the heat conduction efficiency when blended with a thermoplastic resin. The average particle size of the flaky graphite is preferably 1 to 300 μm, and more preferably 5 to 150 μm. If the average particle size is less than 1 μm, agglomerates are likely to occur due to poor dispersion, a uniform molded product cannot be obtained, and mechanical properties may be deteriorated or thermal conductivity may be varied. When the average particle diameter exceeds 300 μm, it may be difficult to fill the heat conductive resin at a high concentration, or the surface of the molded body may become rough.

  Examples of the form of talc include a plate shape, a scale shape, a scale shape, and a flake shape. Of these, scaly talc and lamellar talc are particularly preferable because they are easily oriented in the plane direction when formed into a molded body, and as a result, the thermal conductivity can be increased. For the same reason as described above, the average particle size of the scaly talc is preferably 1 to 200 μm, and more preferably 5 to 100 μm.

  Examples of the form of boron nitride include a plate shape, a scale shape, and a flake shape. Among these, scaly boron nitride and flaky boron nitride are particularly preferable because they are easily oriented in the planar direction when formed into a molded body, and as a result, the thermal conductivity can be increased. For the same reason as described above, the average particle size of the flaky boron nitride is preferably 1 to 200 μm, and more preferably 5 to 100 μm. The crystal system of boron nitride is not particularly limited, and boron nitride having any crystal structure such as hexagonal system, cubic system, and the like is applicable. Of these, boron nitride having a hexagonal crystal structure is preferable because of its high thermal conductivity.

  Examples of the form of magnesium oxide include a spherical shape, a fiber shape, a spindle shape, a rod shape, a needle shape, a cylindrical shape, and a column shape. Among these, spherical magnesium oxide is particularly preferable because it can suppress a decrease in fluidity of the resin when blended with a thermoplastic resin. By containing magnesium oxide, the thermal conductivity can be improved without reducing the insulating properties of the thermal conductive resin. For the same reason as described above, the average particle diameter of the spherical magnesium oxide is preferably 0.5 to 150 μm, and more preferably 1 to 100 μm.

  In the heat conductive resin 3 of the present invention, the volume ratio of the thermoplastic resin to the heat conductive filler is 20/80 to 95/5 (volume%) of the thermoplastic resin and the heat conductive filler. Preferably, it is 30/70 to 90/10 (volume%). If the blending amount of the heat conductive filler is less than 5% by volume, sufficient thermal conductivity may not be obtained, and if the blending amount exceeds 80% by volume, the fluidity is remarkably deteriorated, so The load may become too high and the operability may decrease.

  According to the said structure, since the element part 2 for detecting temperature is sealed with the heat conductive resin 3, the heat | fever of the location used as a detection target is maintained, maintaining favorable waterproofness and airtightness, Since it is transmitted to the element part 2 through the heat conductive resin 3, it is possible to provide the temperature sensor 1 with extremely good thermal response and enhanced temperature detection capability.

  Moreover, according to the said structure, since the heat conductive resin 3 is not accommodated in cases, such as a metal, reliability is not reduced, for example, even in an environment with a large temperature change, and favorable reliability can be maintained. In other words, when the thermally conductive resin is stored in a metal case, if it is used for many years in an environment with a large temperature change, there is a relatively large difference in thermal expansion coefficient. There is a risk of peeling off at the interface (boundary surface) with the conductive resin to form a gap, and the heat responsiveness may be drastically reduced. However, as in the present invention, the heat conductive resin 3 is made of a metal or the like. By not storing it in the container, it is possible to prevent the occurrence of such problems and maintain good reliability.

  The heat conductive resin 3 can be formed into an arbitrary shape by a known method. Among these, the injection molding method is preferable because it has a high degree of freedom in molding and enables high-precision processing.

  Next, an example of manufacturing the temperature sensor 1 as an example of the manufacturing method of the temperature sensor 1 by resin sealing by an injection molding method using a mold will be described with reference to the drawings. 2-6 is sectional drawing (FIG. 3 is a perspective view) which shows each manufacturing process of the manufacturing method of the sealing molding based on the embodiment.

  In FIG. 2, 11 is an upper mold, 12 is a lower mold, and these upper mold 11 and lower mold 12 are disposed so that they can be moved up and down relatively. A cavity (resin injection space) 13 into which the heat conductive resin 3 is injected when the two are combined is formed. In addition, a gate 14 serving as an injection port for injecting resin into the cavity 13 is formed in the upper mold 11 (or the lower mold 12).

  Further, the upper mold 11 and the lower mold 12 are configured so that the electric wire 2 is held in one area (the right area in FIGS. 2 and 4 to 6) where the upper mold 11 and the lower mold 12 are combined. In the other region (the region on the left side in FIGS. 2 and 6) where the lower mold 12 and the lower mold 12 are combined, a cylindrical jig (which holds the element portion 2 as a member to be sealed from the circumferential direction) A sleeve-shaped jig) 15 and a guide member 16 for guiding the cylindrical jig 15 are disposed.

  Here, in this embodiment, the cylindrical jig 15 is a metal cylindrical body, and the guide member 16 is a metal columnar body. Further, the inner peripheral dimension of the cylindrical jig 15 and the outer peripheral dimension of the guide member 16 are made to correspond to each other, and the cylindrical member 15 is aligned with the center axis of the guide member 16 and the cylindrical jig 15 aligned. The tool 15 is slidable along the axial direction. The guide member 16 is slightly longer in the axial direction than the cylindrical jig 15, and one end of the guide member 16 is sandwiched between the upper mold 11 and the lower mold 12 so that the position of the guide member 16 is fixed. Is done.

  The cylindrical jig 15 has an inner diameter that is substantially the same as the maximum diameter of the element portion 2 sealed with the heat conductive resin 3 or a diameter slightly larger than the maximum diameter of the element portion 2. It is preferable that the diameter of the object to be sealed is the same as the length of the object to be sealed with a small diameter that can be held. Further, the gate 14 serving as an injection port for injecting the heat conductive resin 3 into the cavity 13 is disposed at a position facing the electric wire covering material 4a of the electric wire 4 from the side (in this embodiment, from the upper side).

  In the above configuration, when injecting the molten heat conductive resin 3 by disposing the element portion 2 in the cavity 13, before injecting the heat conductive resin 3, as shown in FIGS. The element portion 2 is held in the circumferential direction by the cylindrical jig 15 and fixed at a predetermined position. For example, in a state where the upper mold 11 is separated upward from the lower mold 12, the electric wire 4, the element portion 2, the guide member 16, and the cylindrical jig 15 are provided at locations corresponding to the cavities 13 on the lower mold 12. The cylindrical jig 15 protrudes into the cavity 13 to a position surrounding the element portion 2 and the distal end portion of the electric wire 4 connected to the element portion 2, and holds the element portion 2 and the like. Then, in this state, the upper mold 11 is moved down to match the lower mold 12.

  Next, as shown in FIG. 4, the molten thermal conductive resin 3 is started to be injected into the cavity 13 through the gate 14. Then, as shown in FIGS. 5 and 6, the cylindrical jig 15 is retracted from the cavity 13 to the outside of the cavity 13 as the molten heat conductive resin 3 is filled in the cavity 13. At this time, for example, when the thermal conductive resin 3 is injected into the cavity 13, the cylindrical jig 15 is retracted out of the cavity 13 by using the pressure by which the thermal conductive resin 3 flows and pushes the cylindrical jig 15. Let

  At this time, since the element portion 2 is held in the circumferential direction by the cylindrical jig 15 and fixed at a predetermined position, even if the heat conductive resin 3 flows into the cavity 13, it flows to the opposite side of the gate 14. This will not cause any problems.

  That is, although a comparative example is shown in FIGS. 7 to 9, when the cylindrical jig 15 and the guide member 16 are not provided and the element portion 2 is not supported in the cavity 13, the gate 14 is passed to the cavity 13. When the heat conductive resin 3 is injected, the element portion 2 is caused to flow to the opposite side of the gate 14 by the inflowing heat conductive resin 3, and finally the element portion 2 is exposed to the outside or the element portion 2 is arranged at a biased position deviating from the center, the element part 2 is easily damaged, and the ability to sense heat is significantly different from the radial direction, so that the reliability as a temperature sensor is improved. There is a risk of significant reduction.

  On the other hand, according to the present invention, since the element portion 2 is held in the circumferential direction by the cylindrical jig 15 and fixed at a predetermined position, even if the heat conductive resin 3 flows into the cavity 13, the gate Therefore, the temperature sensor 1 in which the element portion 2 is disposed at the center (axial center position) can be satisfactorily manufactured. Therefore, since the thickness of the heat conductive resin 3 around the element portion 2 becomes extremely uniform, the detection sensitivity and response accuracy of the temperature sensor 1 can be maintained extremely well, and a highly reliable one can be obtained. Therefore, the electrical component or electronic component provided with such a temperature sensor 1 has high reliability, and thermal response is also good.

  In the embodiment of the present invention, since the element part 2 is held by the cylindrical jig 15 in a state where the position of the element part 2 is restricted over the entire circumference, the element part 2 can be positioned extremely well. That is, as a method of holding the element portion 2, it is conceivable to provide a holding pin or the like to hold the element portion 2 at a plurality of points. However, according to the present invention, the element portion 2 is held by the cylindrical jig 15. Since the position is regulated over the entire circumference in the circumferential direction and with the surface instead of the point, the element portion 2 can be positioned much better than when held with a holding pin or the like.

  Further, the cylindrical jig 15 is moved from the cavity 13 to the outside of the cavity 13 by using a pressure that the thermal conductive resin 3 flows into the cavity 13 when the thermally conductive resin 3 is injected into the cavity 13 and pushes the cylindrical jig 15. By retreating, it is not necessary to separately provide a driving mechanism for moving the cylindrical jig 15 from the outside, so that the manufacturing cost of the temperature sensor 1 can be reduced.

  However, the present invention is not limited to this, and a cylinder device or the like that moves the cylindrical jig 15 from the outside is provided, and when the molten heat conductive resin 3 is being filled in the cavity 13, the cylindrical jig 15 is The cylindrical jig 15 may be retracted out of the cavity 13 by applying a force for retracting out of the cavity 13 from the outside by a drive mechanism such as an external cylinder or an external motor that is mechanically moved. Thereby, even when it is difficult to move the cylindrical jig 15 out of the cavity 13 only by the pressing force to the cylindrical jig 15 when the heat conductive resin 3 flows into the cavity 13, the force from the outside Thus, the cylindrical jig 15 can be satisfactorily retracted out of the cavity 13, and the reliability can be improved. The timing for retracting the cylindrical jig 15 is adjusted according to the injection amount of the heat conductive resin 3 such as the amount of movement of the cylinder device in which the heat conductive resin 3 is injected, or the pressure in the cavity 13 is detected. However, the present invention is not limited to this.

  In the above embodiment, the case where the element unit 2 is a temperature detection thermistor has been described. However, the present invention is not limited to this, and a temperature detection thermocouple may be used. Further, by adjusting the position of the element part 2 and the cylindrical jig 15 with respect to the cavity 13 where the heat conductive resin 3 is injected, the element part 2 is placed at a position other than the center of the temperature sensor 1 (heat conductive resin 3). The present invention can also be favorably applied to a predetermined position (for example, a place away from the upper end by a predetermined distance or a place away from another part by a predetermined distance). Further, the cylindrical jig 15 is not limited to a cylindrical shape, and a rectangular cylindrical shape or other cylindrical shapes can be used according to the shape of the element portion 2.

  In the above embodiment, the case where the temperature sensor 1 is configured by sealing the element portion 2 and the electric wire 4 only with the heat conductive resin 3 is described, but the present invention is not limited to this. FIG. 10 is a sectional view showing a temperature sensor 1 according to another embodiment (second embodiment) of the present invention. As shown in FIG. 10, in this temperature sensor 1, the periphery of the element portion 2, which is a region for detecting heat (in FIG. 10, a portion closer to the front portion (tip portion) of the temperature sensor 1) is formed by the heat conductive resin 3. On the other hand, in the temperature sensor 1, a low thermal conductive resin 5 having a lower thermal conductivity than the thermal conductive resin 3 is provided in a region of the temperature sensor 1 that does not need to detect heat, for example, a position closer to the rear portion of the temperature sensor 1. Is disposed in a sealed state adjacent to the heat conductive resin 3.

  As the low thermal conductive resin 5, it is preferable to use the same material as the thermoplastic resin of the thermal conductive resin 3 without containing a thermal conductive filler (so-called thermal conductive filler). It is not limited.

  According to this configuration, the heat transmitted to the heat conductive resin 3 is blocked by the low heat conductive resin 5 and transmitted to the periphery of the low heat conductive resin 5, in this embodiment, the rear side of the temperature sensor 1. Can be prevented. That is, it is possible to prevent the heat transmitted to the temperature sensor 1 via the heat conductive resin 3 from being transmitted to the outside or radiated to the outside, and the heat leaking.

  In addition, as a manufacturing method of this temperature sensor 1, the element part 2 and the electric wire 4 are first sealed only by the heat conductive resin 3 using the method similar to the process shown in the said FIGS. The intermediate sealing body 6 is manufactured. Then, as shown in FIG. 11, the intermediate sealing body 6 is disposed in a cavity (resin injection space) that also has an injection region 23a of the low thermal conductive resin 5, and the upper mold 21 and the lower mold The molten low thermal conductive resin 5 is injected from the gate 24 formed in the mold 22. Thereby, the temperature sensor 1 with few heat leaks can be manufactured.

  In the second embodiment, the case of the temperature sensor 1 in which the low thermal conductive resin 5 is disposed only at the rear portion has been described. However, the present invention is not limited to this. FIG. 12 is a cross-sectional view showing a temperature sensor 1 according to still another embodiment (third embodiment) of the present invention. As shown in FIG. 12, this temperature sensor 1 shows, for example, a case where the temperature detection target region is only on the side of the element portion 2 in the temperature sensor 1, and not only the rear portion of the temperature sensor 1 but also the temperature sensor 1. The low thermal conductive resin 5 is also disposed at the front end portion (tip portion).

  According to this configuration, the heat transmitted to the heat conductive resin 3 is blocked by the low heat conductive resin 5, and around the low heat conductive resin 5, in this embodiment, the rear side (rear side) of the temperature sensor 1 ) And the tip side (front side). That is, it is possible to prevent the heat transmitted to the temperature sensor 1 via the heat conductive resin 3 from being transmitted to the outside or radiated unnecessarily to leak the heat.

  In addition, as a manufacturing method of this temperature sensor 1, the element part 2 and the electric wire 4 are first sealed only by the heat conductive resin 3 using the method similar to the process shown in the said FIGS. The intermediate sealing body 6 is manufactured. Then, as shown in FIG. 13, the intermediate sealing body 6 is disposed in a cavity (resin injection space) having injection regions 23a and 23b of the low thermal conductive resin 5, and the upper mold 21 and The molten low thermal conductive resin 5 is injected from the gates 24 and 25 formed in the lower mold 22. Thereby, the temperature sensor 1 with few heat leaks can be manufactured.

  Furthermore, although the said embodiment demonstrated the case of the temperature sensor 1 with which at least the outer peripheral part of the heat conductive resin 3 was exposed outside, it does not restrict to this. FIG. 14 is a cross-sectional view showing a temperature sensor 1 according to another embodiment (fourth embodiment) of the present invention. As shown in FIG. 14, in the temperature sensor 1, for example, the element portion 2 is sealed from the periphery with a heat conductive resin 3. Sealed with conductive resin 5.

  According to this configuration, since the periphery of the heat conductive resin 3 is sealed with the low heat conductive resin 5, the response is slightly lowered as compared with a case where the heat conductive resin 3 is not covered with the low heat conductive resin 5. However, since the periphery of the heat conductive resin 3 is sealed with the low heat conductive resin 5, the temperature sensor 1 is superior in strength as compared with the temperature sensor 1 in which the low heat conductive resin 5 is not provided. Things can be realized. That is, for example, when a thermoplastic resin contains a large amount of a heat conductive filler as the heat conductive resin 3, it becomes relatively brittle as the heat conductive resin 3 and becomes low in strength. Damage if received.

  On the other hand, when the periphery of the heat conductive resin 3 is sealed with the low heat conductive resin 5 and covered from the outer periphery, the strength as the temperature sensor 1 is improved, the impact resistance is improved, and the reliability is improved. be able to.

  Further, when the periphery of the heat conductive resin 3 is sealed with the low heat conductive resin 5, the heat conductive resin 5 can be a hard resin, and the low heat conductive resin 5 can be a soft resin. In this case, the soft resin used as the low thermal conductive resin 5 functions as a buffer layer against an external impact and plays a role of preventing the element portion 2 from being broken. Conversely, the heat conductive resin 3 may be a soft resin and the low heat conductive resin 5 may be a hard resin. In this case, the soft resin as the heat conductive resin 3 in contact with the element portion 2 functions as a buffer layer against an external impact and plays a role of preventing the element portion 2 from being broken. In addition, since the outer periphery of the temperature sensor 1 is covered with the hard resin, a deviation or the like is unlikely to occur, and in particular, it is possible to precisely cope with the positioning of the temperature sensor 1.

  Further, the thermoplastic resin used for the thermal conductive resin 3 and the thermoplastic resin used for the low thermal conductive resin 5 may be the same thermoplastic resin or the same material system (same system). By doing so, they are firmly bonded to each other. Therefore, for example, even in an environment where the temperature change is large, there is no separation at the interface (boundary surface) between the thermal conductive resin 3 and the low thermal conductive resin 5, and the thermal responsiveness is drastically reduced. Therefore, good reliability can be obtained.

  As a manufacturing method of this temperature sensor 1, as shown in FIGS. 15-19, the element part 2 and the electric wire 4 are heated by the method similar to the manufacturing method of the temperature sensor 1 of the 1st Embodiment of this invention. An intermediate sealing body 6 formed by sealing with a conductive resin (primary molding resin) 3 includes an upper mold 31 and a lower mold for primary molding provided with a guide member 36 and a cylindrical jig 35 for primary molding. Manufactured by mold 32. That is, the element portion 2 is disposed in the cavity 33 of the primary molding dies 31 and 32 while being held in the circumferential direction by the cylindrical jig 35 for primary molding and fixed in a predetermined position (primary placement step). ). Then, molten heat conductive resin (primary molding resin) 3 is injected from the gate 34 into the cavities 33 of the primary molding dies 31, 32. At this time, the cylindrical jig 35 for primary molding is inserted. The intermediate molding body 6 is manufactured by discharging from the cavity 33 of the primary molding dies 31 and 32 to the outside of the cavity 33 and sealing and molding the element part 2 without exposing it to the surface (primary molding step).

  Thereafter, as shown in FIGS. 20 to 24, intermediate sealing is performed using an upper mold 41 and a lower mold 42 for secondary molding provided with a guide member 46 for secondary molding and a cylindrical jig 45. The temperature sensor 1 is manufactured by sealing the stationary body 6 with a low thermal conductive resin (secondary molding resin) 5. That is, the intermediate sealing body 6 is disposed in the cavity 43 of the secondary molding dies 41 and 42 while being held in the circumferential direction by the secondary molding cylindrical jig 45 and fixed in place. (Secondary arrangement process). Then, a molten low thermal conductive resin (secondary molding resin) 5 is injected from the gate 44 into the cavity 43 of the molds 41 and 42 for secondary molding, and at this time, the cylindrical molding for secondary molding is performed. The tool 45 is discharged from the cavity 43 of the secondary molding dies 41 and 42 to the outside of the cavity 43, and sealing molding is performed without exposing the intermediate sealing body 6 to the surface, whereby the temperature sensor 1 is manufactured (2). Next molding process).

  According to this manufacturing method, when the thermal conductive resin 3 for primary molding is injected (primary molding step), the element portion 2 is held from the circumferential direction by the cylindrical jig 35 for primary molding and is predetermined. Since it is fixed at the position (that is, positioned), the element portion 2 can be positioned well. Further, when the low thermal conductive resin 5 for secondary molding is injected (secondary molding step), the intermediate sealing body 6 is held in the circumferential direction by the cylindrical jig 45 for secondary molding and is predetermined. Since the position is fixed (that is, positioned), the intermediate sealing body 6 can be positioned well. As a result, not only can the sealing performance such as good waterproofness be obtained as the temperature sensor 1, but also the temperature sensor 1 can be obtained that has extremely high detection sensitivity and response accuracy and has high reliability. . Moreover, since the element part 2 is doubly covered with the heat conductive resin 3 and the low heat conductive resin 5, it is very well protected and further improved in reliability.

  Further, in the above manufacturing method, when the thermal conductive resin 3 and the low thermal conductive resin 5 are injected into the cavities 33 and 43, the thermal conductive resin 3 and the low thermal conductive resin 5 flow into the cylindrical treatment for primary molding. The cylindrical jigs 35, 45 may be discharged out of the cavities 33, 43 by using a pressure that presses the tool 35 or the cylindrical jig 45 for secondary molding. It is not necessary to provide external forces such as external cylinders or external motors that move mechanically to the tools 35 and 45 so that no force is applied, and thus the manufacturing cost of the temperature sensor 1 can be reduced. It becomes possible.

  However, the present invention is not limited to this, and a cylinder device or the like that moves the cylindrical jigs 35 and 45 from the outside is provided, and the melted thermal conductive resin 3 and low thermal conductive resin 5 are filled in the cavities 33 and 43. In some cases, a force for retracting the cylindrical jigs 35 and 45 out of the cavities 33 and 43 is given from the outside by a driving mechanism such as an external cylinder or an external motor that is mechanically moved, for example. 45 may be retracted out of the cavities 33 and 43. As a result, the cylindrical jigs 35 and 45 can be removed from the cavities 33 and 43 only by the pressing force applied to the cylindrical jigs 35 and 45 when the heat conductive resin 3 and the low heat conductive resin 5 flow into the cavities 33 and 43. Even when it is difficult to move the cylindrical jigs 35 and 45 out of the cavities 33 and 43 by an external force, the reliability can be improved. The timing for retracting the cylindrical jigs 35 and 45 is the injection amount of the heat conductive resin 3 or the low heat conductive resin 5, such as the amount of movement of the cylinder device that injects the heat conductive resin 3 or the low heat conductive resin 5. However, the present invention is not limited to this, but may be adjusted according to the pressure, or provided with a detecting means for detecting the pressure in the cavities 33 and 43 and adjusted according to the pressure.

  In the above configuration, the temperature sensor 1 is held by the cylindrical jigs 35 and 45 so that the center axis of the temperature sensor 1 coincides with the center axis of the cylindrical jigs 35 and 45. Yes. Thereby, the center axis of the temperature sensor 1 and the center axis of the cylindrical jigs 35 and 45 coincide, and there is an advantage that the temperature sensor 1 can be stably held in a very good posture. Note that at least one cylindrical jig 35, 45 is configured to hold the temperature sensor 1 in a posture in which the central axis of the temperature sensor 1 and the central axis of the cylindrical jig 35, 45 coincide. However, the center axis of the sealing molded body 6 and the center axis of the cylindrical jig 35 are matched, or the center axis of the intermediate sealed body 6 and the center axis of the cylindrical jig 45 are matched. This also has an advantage that the temperature sensor 1 and the intermediate sealing body 6 can be stably held in a very good posture.

  Further, in the above-described embodiments, the case where one kind of thermal conductive resin 3 is used is illustrated, but the present invention is not limited to this, and as shown in FIG. (Element part main body) The connecting terminal 2b protruding from 2a and the core wire part 4b of the electric wire 4 are connected by a connecting material 7 such as solder, and this connecting part is not covered by the electric wire covering material 4a. In some cases, the element portion 2 is sealed with a thermally conductive resin 3A having an insulating property, and the thermally conductive resin 3A having an insulating property is sealed with a thermally conductive resin 3B having an electrical conductivity. Thus, the temperature sensor 1 may be configured by covering.

  According to this configuration, it is possible to obtain good responsiveness and waterproofness while preventing current and electric signals from leaking from the connection portion between the element portion 2 and the electric wire 4. Even when the temperature sensor 1 having such a configuration is manufactured, as shown in FIGS. 15 to 19, a primary molding upper die including a primary molding guide member 36 and a cylindrical jig 35. First, an intermediate sealing body is manufactured by sealing the element portion 2 and the electric wire 4 with an insulating heat conductive resin (primary molding resin) 3A using the lower die 31 and the lower mold 32. Thereafter, as shown in FIGS. 20 to 24, the intermediate sealing is performed using an upper mold 41 and a lower mold 42 for secondary molding provided with a guide member 46 for secondary molding and a cylindrical jig 45. The temperature sensor 1 can be satisfactorily manufactured by sealing the stationary body with a heat conductive resin (secondary molding resin) 3B having electrical conductivity.

DESCRIPTION OF SYMBOLS 1 Temperature sensor 2 Element part 3 Thermal conductive resin 3A Thermal conductive resin which has insulation 3B Thermal conductive resin which has conductivity 4 Electric wire 5 Low thermal conductive resin 6 Intermediate sealing bodies 11, 21, 31, 41 Upper metal Mold 12, 22, 32, 42 Lower mold 13, 23, 33, 43 Cavity 14, 24, 34, 44 Gate 15, 25, 35, 45 Cylindrical jig (sleeve-shaped jig)
16, 26, 36, 46 Guide member

Claims (16)

  A temperature sensor characterized in that an element portion for detecting temperature is sealed with a thermally conductive resin in a state where it is not housed in a case.   The temperature sensor according to claim 1, wherein the thermally conductive resin is disposed in a state exposed to the outside.   The temperature sensor according to claim 1, wherein a low thermal conductive resin having a thermal conductivity lower than that of the thermal conductive resin is disposed adjacent to the thermal conductive resin.   4. The temperature sensor according to claim 3, wherein a low thermal conductive resin is disposed around the thermal conductive resin, and the thermal conductive resin is covered with the low thermal conductive resin.   The temperature sensor according to any one of claims 1 to 4, wherein the thermally conductive resin has an insulating property.   A thermally conductive insulating resin having insulating properties sealed around the element portion; and a thermally conductive conductive resin having conductivity sealed around the thermally conductive insulating resin; The temperature sensor according to any one of claims 1 to 4, wherein:   The temperature sensor according to claim 4, wherein the heat conductive resin is a hard resin, and the low heat conductive resin is a soft resin.   The temperature sensor according to claim 4, wherein the heat conductive resin is a soft resin, and the low heat conductive resin is a hard resin.   The temperature sensor according to claim 1, wherein the element unit is a thermistor.   The temperature sensor according to claim 1, wherein the heat conductive resin is a thermoplastic resin containing a heat conductive filler.   The temperature sensor according to any one of claims 1 to 10, wherein the thermoplastic resin is a polyamide resin or a polyester resin.   5. The temperature sensor according to claim 3, wherein the low thermal conductive resin is a thermoplastic resin of the same type or the same type as the thermal conductive resin that is a base material of the thermoplastic resin. A temperature sensor manufacturing method for manufacturing a temperature sensor by encapsulating at least a part of an element part to be sealed with a heat conductive resin using an injection molding method,
When injecting molten thermal conductive resin by placing the element part in the cavity of the mold, before injecting the thermally conductive resin, the element part is held in the circumferential direction by a cylindrical jig and placed in a predetermined position. Fixed,
A method of manufacturing a temperature sensor, wherein the cylindrical jig is retracted from the cavity to the outside of the cavity as the molten thermally conductive resin is filled into the cavity.   The cylindrical jig is retracted from the inside of the cavity to the outside of the cavity using a pressure that the thermal conductive resin flows into the cavity when the thermally conductive resin is injected into the cavity and pushes the cylindrical jig. The manufacturing method of the temperature sensor of Claim 13. Using an injection molding method, the element part to be sealed is encased in a thermally conductive resin, and the intermediate encapsulant in which the element part is encapsulated in the thermally conductive resin is further less thermally conductive than the thermally conductive resin. A temperature sensor manufacturing method for manufacturing a temperature sensor encapsulated with a low thermal conductive resin,
A primary placement step of placing the element portion in a cavity of the primary molding die from a circumferential direction by a primary jig and fixing the element portion in a fixed position;
The molten thermal conductive resin is injected into the cavity of the primary molding die. At this time, the cylindrical jig for primary molding is discharged from the cavity of the primary molding die to the outside of the cavity, and the element portion is A primary molding process for producing an intermediate sealing body by sealing without exposing to the surface;
A secondary placement step of placing the intermediate sealing body in the cavity of the secondary molding die from the circumferential direction by a cylindrical jig for secondary molding and placing it in a fixed state;
The molten low thermal conductive resin is injected into the cavity of the secondary molding die, and at this time, the cylindrical jig for secondary molding is discharged from the cavity of the secondary molding die to the outside of the cavity, A secondary molding step of sealing molding without exposing the intermediate sealing body to the surface;
A method for manufacturing a temperature sensor, comprising: Using an injection molding method, the element part to be sealed is encased in an insulating heat conductive resin, and the intermediate encapsulant in which the element part is encased in the insulating heat conductive resin is further made conductive. A temperature sensor manufacturing method for manufacturing a temperature sensor encapsulated by a thermally conductive resin having
A primary placement step of placing the element portion in a cavity of the primary molding die from a circumferential direction by a primary jig and fixing the element portion in a fixed position;
Injecting molten insulating heat conductive resin into the cavity of the primary molding die, and at this time, the cylindrical jig for primary molding is discharged from the cavity of the primary molding die to the outside of the cavity. The primary molding step for producing an intermediate sealing body by sealing without exposing the element portion to the surface;
A secondary placement step of placing the intermediate sealing body in the cavity of the secondary molding die from the circumferential direction by a cylindrical jig for secondary molding and placing it in a fixed state;
The molten conductive heat conductive resin is injected into the cavity of the secondary molding die, and at this time, the cylindrical jig for secondary molding is moved from the cavity of the secondary molding die to the outside of the cavity. A secondary molding step of discharging and sealing molding without exposing the intermediate sealing body to the surface;
A method for manufacturing a temperature sensor, comprising:

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