Patent Description:
A temperature sensor includes a sensor element serving as a main body for temperature detection, and a protector covering a main portion of the sensor element. The sensor element includes a thermosensitive body including, for example, a thermistor, and electric wires connected to the thermosensitive body as basic components. The temperature sensor is originally small in dimension in a thickness direction because the thermosensitive body has a minute size. However, to measure a temperature of a narrow site, a thin temperature sensor smaller in dimension in the thickness direction is required. Patent Literature <NUM> described below discloses a thin temperature sensor having a thickness dimension of <NUM>.

For example, Patent Literature <NUM> discloses a thin temperature sensor in which a sensor element including a thermosensitive body and electric wires connected to the thermosensitive body is covered with a package made of two insulation films (i.e., two layers). As the insulation films, a flexible synthetic resin film having strength, for example, a synthetic resin film made of a polyester resin, polyethylene, polypropylene, nylon, a fluorine resin, a polystyrene resin, or vinyl chloride is used. The two insulation films are joined with the sensor element in between with an adhesive, for example, an epoxy resin-based, polyurethane-based, or unsaturated polyester resin-based adhesive.

However, in the temperature sensor in which the sensor element is covered with the two insulation films, disclosed in Patent Literature <NUM>, a portion of the insulation films in contact with the thermosensitive body protrudes outward, and therefore, the whole of the package cannot be planarized in some cases.

Patent Literature <NUM> discloses a temperature sensor that can solve the issue about planarization.

The temperature sensor disclosed in Patent Literature <NUM> includes an inner layer that is formed by heating and curing or by melting and solidifying a pair of sheet-like inner layer materials made of a resin material, and outer layers formed by a pair of sheet-like outer layer materials made of a resin material and having flat surfaces on two sides. In the temperature sensor disclosed in Patent Literature <NUM>, a thermosensitive body, a lead-out wire connected to the thermosensitive body, and a connection portion between the lead-out wire and a lead wire are covered with the inner layer, and are covered with the pair of outer layers by being sandwiched therebetween. According to the temperature sensor disclosed in Patent Literature <NUM>, it is possible to solve the issue about planarization of the whole of the package in Patent Literature <NUM>.

Patent Literature <NUM> discloses a temperature sensor and a device, in which the temperature sensor is capable of reducing thickness, increasing a contact area with an object whose temperature is to be measured, and improving measurement accuracy. A temperature sensor is provided with a thermistor element; a lead-out wire connected to the thermistor element; a lead wire connected to the lead-out wire; an inner layer formed by heating and curing or by melting and solidifying a pair of sheet-like inner layer materials formed of a resin material; and outer layers formed of a pair of sheet-like outer layer materials formed of a resin material and having flat surfaces on both sides. The thermistor element, the lead-out wire, and a connection part between the lead-out wire and the lead wire are covered with the inner layer, and are also covered with the pair of outer layers by being sandwiched therebetween.

The temperature sensor disclosed in Patent Literature <NUM> is formed in such a manner that the pair of inner layer materials are melted by heating and are solidified while the pair of inner layer materials are sandwiched between the pair of outer layer materials. Therefore, it is necessary for the outer layer materials to have a melting point higher than a melting point of the inner layer materials, and the resin material configuring the inner layer materials and the resin material configuring the outer layer materials are limited. In Patent Literature <NUM>, an example in which the inner layer materials are made of FEP (perfluoro(ethylene-propene) copolymer) that is a fluorine resin, and the outer layer materials are made of PTFE (polytetrafluoroethylene) that is a fluorine resin is described.

Therefore, an object of the present invention is to provide a thin temperature sensor which can be planarized, without particularly limiting resin materials to be used. Solution to Problem.

The above object is achieved by means of a temperature sensor as defined in claim <NUM> and by a method of manufacturing a temperature sensor according to claim <NUM>. The dependent claims are directed to different advantageous aspects of the invention.

The holder preferably includes paired second layers disposed to face each other in a thickness direction T, and a first layer disposed between the paired second layers and joined with the paired second layers.

The first layer includes a housing space that includes a through hole opening on top and bottom surfaces, to house the thermosensitive portion and the electric wires.

The housing space includes a first layer including the housing space, and preferrably second layers, and the second layers are preferably provided at positions facing one or both of the openings on the top and bottom surfaces of the housing space.

Further, the housing space preferably has enough capacity to house at least a whole of the thermosensitive portion of the sensor element.

The housing space preferably has the opening shape following a shape of the sensor element in a planar view.

The housing space preferably includes a first housing space configured to house the thermosensitive portion, and paired second housing spaces configured to respectively house the paired electric wires, and one ends of the paired second housing spaces preferably communicate with the first housing space.

The paired second housing spaces are preferably provided independently of each other in the first layer except for the one ends communicating with the first housing space, and a distance between the paired second housing spaces is preferably continuously increased as the paired second housing spaces are farther from the one ends.

An adhesive body is preferably placed around the thermosensitive portion inside the first housing space according to the present invention, and adhesive bodies are preferably placed around the electric wires inside the respective second housing spaces.

The adhesive bodies according to the present invention are preferably made of polyvinyl chloride in a gel state.

The paired second layers and the first layer are each preferably made of polyvinyl chloride having a plate shape, and the first layer is preferably greater in thickness dimension than each of the paired second layers.

In the second step of the manufacturing method, preferably, an adhesive is supplied to the housing space to hold, in the housing space, the thermosensitive portion and the electric wires housed in the housing space.

The holder in the temperature sensor includes a first layer including the housing space, and preferrably second layers. In the second step of the method of manufacturing the temperature sensor, preferably, the second layers are stacked at positions facing one or both of the openings on top and bottom surfaces of the first layer.

The present invention provides a thin temperature sensor which can be planarized over a range including a portion provided with a thermosensitive portion, without particularly limiting resin materials used for a first layer (inner layer) and second layers (outer layers).

A preferred embodiment of a temperature sensor according to the present invention is described below.

As illustrated in <FIG>, a temperature sensor <NUM> according to the present embodiment includes a sensor element <NUM> serving as a main body for temperature detection, and a holder <NUM> covering a main portion of the sensor element <NUM>.

The temperature sensor <NUM> includes, as the holder <NUM>, a first layer <NUM> housing the sensor element <NUM>, and paired second layers <NUM> covering top and bottom surfaces of the first layer <NUM>. A housing space <NUM> housing the sensor element <NUM> is provided in the first layer <NUM>. As a result, the thin temperature sensor <NUM> which can be planarized is provided, without particularly limiting resin materials used for the second layers <NUM> and the first layer <NUM>. In the following, components of the temperature sensor <NUM> are described, and then a procedure of manufacturing the temperature sensor <NUM> is described.

As illustrated in <FIG> and <FIG>, the sensor element <NUM> includes a thermosensitive body <NUM>, a protector <NUM> that is made of glass and covers surroundings of the thermosensitive body <NUM>, paired first electric wires <NUM> directly and electrically connected to the thermosensitive body <NUM>, and second electric wires <NUM> electrically connected to the respective first electric wires <NUM>. Paired electric wires according to the present invention are configured by the first electric wires <NUM> and the second electric wires <NUM> electrically connected. Note that, in the temperature sensor <NUM>, as illustrated in <FIG>, a side provided with the thermosensitive body <NUM> is defined as a front side F, and a side on which the second electric wires <NUM> are drawn out is defined as a rear side B. The sides are relatively defined.

As the thermosensitive body <NUM>, for example, a thermistor is preferably used. The thermistor is an abbreviation for a thermally sensitive resistor, and is a metal oxide that detects a temperature by using a property that an electric resistance varies with temperature.

The thermistor is classified into an NTC (negative temperature coefficient) thermistor and a PTC (positive temperature coefficient) thermistor. In the present embodiment, any of the thermistors is usable.

As the NTC thermistor, an oxide sintered body that includes, as a basic composition, a manganese oxide (Mn<NUM>O<NUM>) having a typical spinel structure can be used for the thermosensitive body <NUM>. An oxide sintered body including a composition of MxMn<NUM>-xO<NUM> that is obtained by adding M elements (one or more kinds of Ni, Co, Fe, Cu, Al, and Cr) to the basic composition can also be used for the thermosensitive body <NUM>. Further, one or more kinds of V, B, Ba, Bi, Ca, La, Sb, Sr, Ti, and Zr can be added.

Further, as the PTC thermistor, a composite oxide having a typical perovskite structure, for example, an oxide sintered body including YCrO<NUM> as a basic composition can be used for the thermosensitive body <NUM>.

As illustrated in <FIG> and <FIG>, the protector <NUM> made of glass seals the thermosensitive body <NUM> and maintains the thermosensitive body <NUM> in an airtight state, thereby preventing occurrence of chemical and physical changes of the thermosensitive body <NUM> due to an ambient environment condition where the temperature sensor <NUM> is used, and mechanically protecting the thermosensitive body <NUM>. The protector <NUM> made of glass covers front ends of the first electric wires <NUM> in addition to the whole of the thermosensitive body <NUM>, and seals the first electric wires <NUM>. In the protector <NUM>, a dimension in a thickness direction T (hereinafter, thickness dimension) is not limited as long as the thin temperature sensor <NUM> is obtainable, but is preferably within a range of <NUM> to <NUM>, more preferably within a range of <NUM> to <NUM>, and further preferably within a range of <NUM> to <NUM>. The thickness dimension of the protector <NUM> is typically <NUM>.

Providing of the protector <NUM> made of glass is merely a preferred embodiment in the present invention, and only the thermosensitive body <NUM> is sufficient without the protector <NUM>. Accordingly, in a case where the protector <NUM> is provided in addition to the thermosensitive body <NUM>, a thermosensitive portion in the present invention is configured by both of the protector <NUM> and the thermosensitive body <NUM>. In a case where only the thermosensitive body <NUM> is provided, the thermosensitive portion in the present invention is configured only by the thermosensitive body <NUM>.

As illustrated in <FIG> and <FIG>, the first electric wires <NUM> are electrically connected to an unillustrated electrode of the thermosensitive body <NUM>.

The first electric wires <NUM> are sealed by the protector <NUM>. Therefore, Dumet wires having a linear expansion coefficient close to a linear expansion coefficient of glass are preferably used for the first electric wires <NUM>. The Dumet wire is an electric wire in which an alloy containing iron and nickel as main components is used as a core wire serving as an electric conductor, and the core wire is coated with copper.

A distance between the first electric wires <NUM> is continuously increased from the front side F; however, the first electric wires <NUM> extend in parallel toward the rear side B in a range where the first electric wires <NUM> are connected to the respective second wires <NUM>.

As illustrated in <FIG> and <FIG>, the second electric wires <NUM> each include a core wire 17A made of an electric conductor, and an insulation coating 17B covering the core wire 17A. The second electric wires <NUM> are referred to as two-core parallel wires or simply referred to as parallel wires. The second electric wires <NUM> are electrically connected to the respective first electric wires <NUM> at portions of the core wires 17A by welding, a conductive adhesive, or the like. In the core wires 17A of the paired second electric wires <NUM>, the portions connected to the first electric wires <NUM> are exposed.

Unlike the first electric wires <NUM>, the second electric wires <NUM> are not limited in linear expansion coefficient, and an optional material can be selected for the second wires <NUM> as long as the material has predetermined heat resistance and predetermined durability.

The holder <NUM> houses and holds the sensor element <NUM> while securing electric insulation property from outside. Further, the holder <NUM> is not particularly limited in material to be used, and has a configuration contributing to planarization on the premise of a thin type.

As illustrated in <FIG>, the holder <NUM> includes the paired second layers <NUM> disposed on top and bottom surfaces in the thickness direction T, and the first layer <NUM> sandwiched between the second layers <NUM>. The housing space <NUM> is provided in the first layer <NUM>, and main elements of the sensor element <NUM> are held by the first layer <NUM> while being disposed inside the housing space <NUM>. In the present embodiment, the first layer <NUM> is referred to as an inner layer, and the second layers are referred to as outer layers.

The paired second layers <NUM> are provided at least at positions facing respective openings on top and bottom surfaces of the housing space <NUM>.

As illustrated in <FIG>, each of the second layers <NUM> is made of a resin material having a rectangular shape in a planar view. As each of the second layers <NUM>, polyvinyl chloride (PVC) having a plate shape is preferably adopted. Polyvinyl chloride has characteristics, for example, stability enabling maintenance of strength for a long time, durability against deterioration, and excellent adhesiveness. Further, polyvinyl chloride also has characteristics of flame resistance higher than flame resistance of other resin materials. Polyvinyl chloride includes a hard material and a soft material, and the soft material is preferably used for each of the second layers <NUM>. The soft material has Shore A hardness within a range of <NUM> to <NUM>, and is rich in flexibility.

Examples of the resin material adoptable for each of the second layers <NUM> other than polyvinyl chloride include polypropylene, polyethylene, and polystyrene.

A dimension in the thickness direction T (hereinafter, thickness dimension) of each of the second layers <NUM> is not limited; however, to realize the thin temperature sensor <NUM>, each of the second layers <NUM> preferably has the thickness dimension within a range of <NUM> to <NUM>, more preferably has the thickness dimension within a range of <NUM> to <NUM>, and further preferably has the thickness dimension within a range of <NUM> to <NUM>. The thickness dimension of each of the second layers <NUM> is typically <NUM>.

As illustrated in <FIG> and <FIG>, the first layer <NUM> is made of a resin material that has a rectangular shape in a planar view, and has a plate shape similar to each of the second layers <NUM>. However, as described below, the first layer <NUM> is different in thickness dimension from each of the second layers <NUM>.

The first layer <NUM> includes a frame body <NUM> that is made of the resin material and has a rectangular outer shape, and the housing space <NUM> that includes a void space formed inside the frame body <NUM>. As an example, the housing space <NUM> penetrates through top and bottom surfaces of the frame body <NUM>, and is continuously formed in the thickness direction T.

The housing space <NUM> has an opening shape following an appearance shape of the sensor element <NUM> in a planar view, and includes a first housing space 37A and paired second housing spaces 37B. The first housing space 37A is formed in a substantially elliptical shape in a planar view, and the protector <NUM> that is made of glass and covers the thermosensitive body <NUM> is housed in the first housing space 37A. The paired second housing spaces 37B are each formed in a substantially rectangular shape in a planar view, and the first electric wires <NUM> are housed in the respective second housing spaces 37B.

As an example, the first housing space 37A is provided at a center in a width direction W on the front side F in a length direction L of the frame body <NUM>. In any of the length direction L, the width direction W, and the thickness direction T, the first housing space 37A is formed slightly greater in dimension than the protector <NUM>. Therefore, when the protector <NUM> is housed in the first housing space 37A, a gap is generated around the protector <NUM>; however, an adhesive body BL is placed in the gap as described below, to hold the protector <NUM> inside the first housing space 37A. In other words, the first housing space 37A has enough capacity to house the whole of the protector <NUM> including the thermosensitive body <NUM>. The first housing space 37A has an elliptical shape corresponding to the protector <NUM>. The shape is one preferred shape, and the first housing space 37A may have the other shape, for example, a true circular shape, a rectangular shape, or a polygonal shape. The first housing space 37A is formed to have a shape corresponding to the protector <NUM>, more specifically, is formed to have similarity relationship with the protector <NUM>, which makes it possible to uniformize a thickness of the adhesive body BL placed in the above-described gap. As a result, it is possible to hold the protector <NUM> with a smaller amount of adhesive body BL.

As an example, the second housing spaces 37B extend from an end on the rear side B of the first housing space 37A toward the rear side B of the frame body <NUM>. However, the second housing spaces 37B are stopped before reaching an end on the rear side B of the frame body <NUM>. This is because, if the second housing spaces 37B extend to the end on the rear side B of the frame body <NUM>, a portion sandwiched between the second housing spaces 37B is separated. The second housing spaces 37B are formed such that a distance therebetween is continuously increased from a portion on the front side F communicating with the first housing space 37A toward the rear side B. This corresponds to the fact that the distance between the first electric wires <NUM> of the sensor element <NUM> is continuously increased from a portion on the front side F communicating with the thermosensitive body <NUM> toward the rear side B.

The frame body <NUM> is provided between one of the second housing spaces 37B and the other second housing space 37B. Therefore, the second housing spaces 37B are independent of each other except for the portion on one end communicating with the first housing space 37A. Since the frame body <NUM> is present between the first electric wires <NUM> housed in the respective second housing spaces 37B, electric insulation between the first electric wires <NUM> is secured. As a preferred mode, when the adhesive body BL is provided in each of the second housing spaces 37B around the respective first electric wires <NUM>, the first electric wires <NUM> are positioned in the respective second housing spaces 37B.

A method of forming the housing space <NUM> is optional as long as a desired shape is obtainable. In consideration of a formation cost and formation efficiency, stamping using a mold is preferable. The housing space <NUM> penetrating through the top and bottom surfaces is easily obtainable by the stamping. As the other forming method, cutting using a blade, cutting using a laser beam, or the like is usable.

The first layer <NUM> has the thickness dimension such that the protector <NUM> of the sensor element <NUM> can be housed without protruding from the first housing space 37A. The thickness dimension of the protector <NUM> is as described above, and it is necessary for the first layer <NUM> to have the thickness dimension coincident with or exceeding the thickness dimension of the protector <NUM>. For example, when the thickness dimension of the protector <NUM> is <NUM> as the typical example, the first layer <NUM> is made to have the thickness dimension of <NUM>, and is preferably made to have the thickness dimension of <NUM> with a margin of <NUM>.

For example, when the thickness of each of the second layers <NUM> is <NUM>, and the thickness of the first layer <NUM> is <NUM>, the thickness of the temperature sensor <NUM> can be suppressed to <NUM> while taking into consideration the thickness of the adhesive body BL interposed between each of the second layers <NUM> and the first layer <NUM>. As a result, the temperature sensor <NUM> is extremely easily deformable in the thickness direction T in combination with flexibility of polyvinyl chloride configuring the second layers <NUM> and the first layer <NUM>. Note that a solidified adhesive G is referred to as the adhesive body BL for discrimination.

Next, a procedure of manufacturing the temperature sensor <NUM> is described with reference to <FIG> and <FIG>.

First, as illustrated in <FIG>, the first layer <NUM> and the sensor element <NUM> are disposed between the second layers <NUM> provided with a gap therebetween. At this time, the sensor element <NUM> is positioned with respect to the housing space <NUM> of the first layer <NUM>, the protector <NUM> is disposed at a position corresponding to the first housing space 37A, and the first electric wires <NUM> are disposed at positions corresponding to the respective second housing spaces 37B. It is assumed that the first electric wires <NUM> and the respective core wires 17A of the second electric wires <NUM> are already electrically and mechanically connected to each other.

The adhesive G illustrated by an alternate long and two short dashes line in the drawing is applied to each of joining surfaces <NUM> that are surfaces of the second layers <NUM> facing the first layer <NUM>. Note that the adhesive G may be applied to each of joining surfaces <NUM> as top and bottom surfaces of the first layer <NUM> in place of or in addition to the second layers <NUM>.

The adhesive G is not limited in material as long as the adhesive G can join each of the second layers <NUM> and the first layer <NUM>, and can hold the main portion of the sensor element <NUM> inside the housing space <NUM>. However, preferably, the adhesive G made of polyvinyl chloride having a thermosetting property is used. Polyvinyl chloride is known as a thermoplastic resin. As is well known by those skilled in the art, polyvinyl chloride is turned into a sol state excellent in flowability at a normal temperature by being mixed with a plasticizer. Therefore, polyvinyl chloride is easily applicable as the adhesive G. Polyvinyl chloride in the sol state is cured in a gel state by being heated. As an example, a heating temperature for gelation is <NUM>.

Next, as illustrated in <FIG>, the first layer <NUM> is placed on the second layer <NUM> on a lower side. Subsequently, the protector <NUM> is housed in the first housing space 37A of the first layer <NUM>, and the first electric wires <NUM> are housed in the second housing spaces 37B. However, the first electric wires <NUM> protrude from the second housing spaces 37B on the rear side B behind predetermined positions. Further, in <FIG>, the adhesive G is supplied to each of the first housing space 37A and the second housing spaces 37B. A gap between the protector <NUM> and the frame body <NUM> in the first housing space 37A is filled with the adhesive G, and a gap between the first electric wire <NUM> and the frame body <NUM> in each of the second housing spaces 37B is filled with the adhesive G. Note that, in a case where the adhesive G is made of polyvinyl chloride in the sol state, the adhesive G at this time has flowability.

Next, as illustrated in <FIG>, after the second layer <NUM> on an upper side is placed on the first layer <NUM>, pressing force with heating is applied to the second layers <NUM>. By the heating, the adhesive G made of polyvinyl chloride in the sol state is cured into the gel state. In addition, the first layer <NUM> receives the pressing force from top and bottom surfaces, which improves joining strength between each of the second layers <NUM> and the first layer <NUM> by the adhesive G.

The temperature sensor <NUM> illustrated in <FIG> and <FIG> is obtainable through the above-described processes. Relationship between a thickness dimension 13R of the protector <NUM> and a thickness dimension 37T of the housing space <NUM> of the first layer <NUM> is described with reference to <FIG>.

<FIG> illustrates a case where the thickness dimension 37T of the first layer <NUM> is greater than the thickness dimension 13R of the protector <NUM> (37T > 13R), <FIG> illustrates a case where the thickness dimension 13R of the protector <NUM> and the thickness dimension 37T of the housing space <NUM> are equal to each other (37T = 13R), and <FIG> illustrates a case where the thickness dimension 13R of the protector <NUM> is greater than the thickness dimension 37T of the housing space <NUM> (37T < 13R). Note that the relationship 37T > 13R, 37T = 13R, and 37T < 13R are respectively referred to as a first aspect (37T > 13R), a second aspect (37T = 13R), and a third aspect (37T < 13R). The temperature sensor <NUM> in the second aspect (37T = 13R) is described up to here. In the present embodiment, the first aspect (37T > 13R) or the second aspect (37T = 13R) is adopted, but the third aspect (T < R) is not adopted. The reason is as follows.

Since the temperature sensor <NUM> is thin, the temperature sensor <NUM> is disposed in a narrow space and is used. In this state, a load is applied to the temperature sensor <NUM> from outside in the thickness direction T in some cases. The load is applied to the protector <NUM> and the thermosensitive body <NUM> through the second layers <NUM>. When the load is large, the protector <NUM> made of glass may be damaged, and the thermosensitive body <NUM> may be damaged. Therefore, in a case where the load may be applied during temperature measurement, it is desirable to suppress the load to the protector <NUM> and the thermosensitive body <NUM>.

However, since the thickness dimension 13R of the protector <NUM> in the third aspect in <FIG> is greater than the thickness dimension 37T of the housing space <NUM> of the first layer <NUM>, a portion of the protector <NUM> protrudes to outside from the first housing space 37A. Although not illustrated, the second layers <NUM> are disposed on the portion of the protector <NUM> protruding from the first housing space 37A, but the first layer <NUM> is not interposed between each of the second layers <NUM> and the protector <NUM>. Therefore, the load applied from the outside is large as compared with the first aspect and the second aspect.

In contrast, since the thickness dimension 13R of the protector <NUM> in the first aspect in <FIG> is greater than the thickness dimension 37T of the housing space <NUM>, the whole of the protector <NUM> is housed inside the first housing space 37A. This makes it possible to avoid protrusion of the protector <NUM> from the housing space <NUM> as in the third aspect in <FIG>. In the first aspect, the adhesive body BL is present on an upper side and a lower side of the protector <NUM> in the drawing inside the first housing space 37A. Therefore, in the first aspect, even when the load is applied in the thickness direction T, the load is applied to the protector <NUM> and the thermosensitive body <NUM> through the adhesive body BL in addition to the second layers <NUM>. In addition, when the adhesive body BL is in the gel state, the adhesive body BL functions as a buffer for the load applied to the protector <NUM>. This makes it possible to reduce the load applied to the protector <NUM> and the thermosensitive body <NUM> as compared with the third aspect.

In comparison of a magnitude of the load applied to the temperature sensor <NUM> from the outside in the thickness direction T, the magnitude of the load in the second aspect (37T = 13R) is intermediate between the first aspect (37T > 13R) and the third aspect (37T < 13R).

Effects achieved by the temperature sensor <NUM> according to the present embodiment are described below.

In the temperature sensor <NUM>, the protector <NUM> and the first electric wires <NUM> of the sensor element <NUM> are housed and held in the housing space <NUM> of the first layer <NUM>. To house and hold the protector <NUM> and the first electric wires <NUM> of the sensor element <NUM>, it is sufficient to use the adhesive G as necessary, and it is unnecessary to melt only the first layer <NUM>. Therefore, it is unnecessary to consider relationship of a melting point between the second layers <NUM> and the first layer <NUM>, and the resin materials configuring the second layers <NUM> and the first layer <NUM> are not particularly limited.

Further, in the temperature sensor <NUM>, the diameter R of the protector <NUM> is set less than or equal to the thickness T of the first layer <NUM>. Therefore, the protector <NUM> is housed inside the first housing space 37A and does not protrude. Accordingly, the second layers <NUM> can be formed flat even at the portion of the protector <NUM> having the greatest thickness dimension in the sensor element <NUM>.

As described above, the present embodiment provides the thin temperature sensor <NUM> which can be planarized over a range including the portion provided with the protector <NUM>, without particularly limiting resin materials used for the second layers <NUM> and the first layer <NUM>.

The housing space <NUM> in the present embodiment includes the first housing space 37A having the shape corresponding to the protector <NUM>, and the second housing spaces 37B having the shapes corresponding to the first electric wires <NUM>. Accordingly, when the protector <NUM> is disposed in the first housing space 37A, and the first electric wires <NUM> are disposed in the respective second housing spaces 37B, the sensor element <NUM> is positioned with respect to the first layer <NUM>, and the thermosensitive body <NUM> particularly important for the temperature measurement can be positioned at a desired site.

Further, in the temperature sensor <NUM>, the second layers <NUM> and the first layer <NUM> are each made of polyvinyl chloride rich in flexibility. In addition, the thickness of the temperature sensor <NUM> can be suppressed to, for example, about <NUM> to about <NUM>. Accordingly, the temperature sensor <NUM> is extremely high in flexibility and is easily elastically deformable in the thickness direction T. As a result, in a case where the temperature sensor <NUM> is provided in a narrow gap, even if a width of the gap is slightly changed, the temperature sensor <NUM> can maintain a surface contact state with a measurement target by being varied in thickness with the change of the width of the gap.

For example, as illustrated in <FIG>, the second housing spaces 37B provided in the first layer <NUM> may extend to form extension chambers 37C reaching the end on the rear side B of the frame body <NUM>. As a result, the first electric wires <NUM> can be housed in the extension chambers 37C, and drawn out from the end on the rear side B. Note that, in <FIG>, the first housing space 37A and the second housing spaces 37B penetrate through the top and bottom surfaces of the first layer <NUM>; however, as with the extension chambers 37C, the first housing space 37A and the second housing spaces 37B may be each formed in a groove shape up to a predetermined range in the thickness direction T.

In the temperature sensor <NUM>, as the preferred mode of the housing space <NUM>, the first housing space 37A and the second housing spaces 37B are formed to have the shape similar to the shape of the sensor element <NUM> in a planar view; however, the present invention is not limited thereto. In other words, housing of the protector <NUM> and the first electric wires <NUM> is given top priority in the housing space <NUM>, and the shape in a planar view is optional. Accordingly, for example, the housing space <NUM> may have a rectangular shape in a planar view.

Further, the temperature sensor <NUM> according to the embodiment has the substantially constant thickness dimension from the front side F to the rear side B as an example; however, the present invention is not limited thereto. For example, when the diameter of each of the core wires 17A of the second electric wires <NUM> is sufficiently greater than the thickness dimension of the holder <NUM>, the thickness dimensions of the portions of the second layers <NUM> covering the core wires 17A and the insulation coatings 17B are increased.

Claim 1:
A temperature sensor (<NUM>), comprising:
a sensor element (<NUM>) including a thermosensitive portion (<NUM>) and paired electric wires (<NUM>, <NUM>) electrically connected to the thermosensitive portion (<NUM>); and
a holder (<NUM>) made of a resin material and configured to hold the sensor element (<NUM>), wherein
the holder (<NUM>) includes a first layer(<NUM>), which includes a housing space (<NUM>, 37B, 37C), the housing space (<NUM>, 37B, 37C) includes a through hole opening on top and bottom surfaces, to house the thermosensitive portion (<NUM>) and the electric wires (<NUM>, <NUM>), and
wherein the through hole is formed in a thickness direction (T) of the first layer (<NUM>) of the holder (<NUM>).