heater

Abstract

To provide a heater which enables reduction of performance deterioration resulting from continuous use.SOLUTION: A heater includes a ceramic body, a heating resistor, a conductor, and a joint material. The ceramic body has a recessed part which is open on a surface. The heating resistor is located in the ceramic body. The conductor is electrically connected to the heating resistor and located on a bottom surface of the recessed part. The joint material joins a lead wire located above the conductor and the conductor to each other. The bottom surface has a peripheral edge part located at the outer side relative to an opening end of the recessed part in a plan view. An end of the joint material has a portion located in the peripheral edge part.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The disclosed embodiments relate to a heater. [Background technology]

[0002] A heater having a heating resistor inside a ceramic body is known. For this heater, a configuration has been proposed in which an opening is located at the joint between an extraction electrode connected to the heating resistor and a lead wire located outside the ceramic body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-34979 Summary of the Invention

[0004] A heater according to one aspect of the embodiment includes a ceramic body, a heating resistor, a conductor, A lead wire, The ceramic body includes a bonding material. A plate-like body extending from one end to the other end, including the one end The heating resistor has a recess that opens. along the surface direction of the ceramic body The conductor is located inside the ceramic body, and is electrically connected to the heating resistor and is located on the bottom surface of the recess. The lead wire is positioned on the conductor along the plane direction. The bonding material is Note The bonding material bonds the wire to the conductor. The bottom surface has a peripheral edge portion located outside the opening edge of the recess in a plan view. An end portion of the bonding material has a portion located on the peripheral edge. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 is a plan view showing a heater according to an embodiment. [Figure 2] FIG. 2 is an enlarged view of area A shown in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along the line BB shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line CC shown in FIG. [Figure 5] FIG. 5 is a cross-sectional view showing a heater according to a first modification of the embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a heater according to a second modification of the embodiment. [Figure 7] FIG. 7 is a vertical cross-sectional view showing a heater according to a third modification of the embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing a heater according to a fourth modification of the embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing a heater according to a fifth modification of the embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing a heater according to a sixth modification of the embodiment. [Figure 11] FIG. 11 is a plan view showing a heater according to a seventh modification of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0006] Hereinafter, embodiments of the heater disclosed in the present application will be described with reference to the accompanying drawings. Note that the present disclosure is not limited to the embodiments shown below. It should be noted that the drawings are schematic, and the dimensional relationships between elements, the ratios between elements, etc. may differ from reality.

[0007] <Embodiment> First, the heater according to the embodiment will be described with reference to Fig. 1. Fig. 1 is a plan view showing the heater according to the embodiment.

[0008] 1, a heater 1 according to the embodiment includes a ceramic body 2, a heating resistor 4, a conductor 5, a bonding material 7, and a lead wire 10. The heater 1 is used, for example, as a hair iron, a soldering iron, and other applications.

[0009] For ease of understanding, Fig. 1 illustrates a three-dimensional Cartesian coordinate system including a Z axis extending along the thickness direction of the heater 1. Such a Cartesian coordinate system is also shown in other drawings used in the following description.

[0010] The ceramic body 2 is, for example, a flat plate-shaped member. The material of the ceramic body 2 is, for example, an insulating ceramic. As the material of the ceramic body 2, for example, oxide ceramics, nitride ceramics, carbide ceramics, etc. can be used. Specifically, alumina ceramics, silicon nitride ceramics, aluminum nitride ceramics, silicon carbide ceramics, etc. can be used as the material of the ceramic body 2.

[0011] The ceramic body 2 also has a recess 3. The recess 3 is located so as to contact an end face 2a located at one end in the longitudinal direction of the ceramic body 2. The recess 3 opens to a surface 2b (see FIG. 2) of the ceramic body 2. Details of the recess 3 will be described later.

[0012] The heating resistor 4 is located inside the ceramic body 2. The heating resistor 4 is a member that generates heat when a current flows through it. The heating resistor 4 may include a high-resistance conductor such as tungsten or molybdenum. The shape of the heating resistor 4 is not limited to the shape shown in the figure, and can be changed as appropriate depending on the heat generation characteristics required of the heater 1, for example.

[0013] The conductor 5 is electrically connected to the heating resistor 4. For example, the conductor 5 is located so as to contact both ends of the heating resistor 4. The conductor 5 is located so as to overlap the recess 3 in a plan view. The conductor 5 may be made of a metal material containing, for example, tungsten, molybdenum, or the like. The material of the conductor 5 may be the same as or different from that of the heating resistor 4.

[0014] The bonding material 7 is located inside the recess 3. The bonding material 7 bonds the lead wire 10 to the conductor 5. As the bonding material 7, for example, a brazing material such as solder or silver brazing can be used.

[0015] The lead wire 10 is a wire containing a metal material such as nickel, iron, or a nickel-based heat-resistant alloy. The cross section of the lead wire 10 may be, for example, circular, elliptical, or rectangular. The outer diameter of the lead wire 10, i.e., the equivalent circle diameter of the lead wire 10 in cross section, may be, for example, 0.5 to 2.0 mm.

[0016] Next, the heater 1 according to the embodiment will be further described with reference to Fig. 2 to Fig. 4. Fig. 2 is an enlarged view of an area A shown in Fig. 1. Fig. 3 is a cross-sectional view taken along line BB shown in Fig. 2. Fig. 4 is a cross-sectional view taken along line CC shown in Fig. 2.

[0017] 2 to 4, the recess 3 has a bottom surface 34. The area of ​​the bottom surface 34 is larger than the opening area of ​​the open end. Here, the opening area of ​​the open end refers to the area of ​​the region surrounded by the ridge lines (opening ends) 31 to 33 of the opening of the recess 3 on the surface 2b of the ceramic body 2 and the end surface 2a of the ceramic body 2 when viewed from a direction perpendicular to the surface 2b of the ceramic body 2 as shown in FIG.

[0018] In this way, by making the area of ​​the bottom surface 34 larger than the opening area of ​​the open end, it is possible to strengthen the bond between the lead wire 10 and the conductor 5 via the bonding material 7. Furthermore, by making the opening area of ​​the open end smaller than the area of ​​the bottom surface 34, the proportion of the surface 2b of the ceramic body 2 that functions as the heating surface, which is the main part of the heater 1, increases, thereby improving heater performance.

[0019] The bottom surface 34 also has a peripheral edge 35. The peripheral edge 35 is located outside the opening edge of the recess 3 when viewed from a direction perpendicular to the surface 2b of the ceramic body 2 as shown in FIG. 2. The recess 3 also has a top surface 35a facing the peripheral edge 35 as shown in FIG. 3. As a result, the recess 3 has a space sandwiched between the top surface 35a and the peripheral edge 35.

[0020] Furthermore, the end of the bonding material 7 is located at the peripheral edge 35, which is further outward in plan view than the opening end of the recess 3. The bonding material 7 is located from the center of the recess 3 to the peripheral edge 35, so that the lead wire 10 can be more firmly fixed. This makes it less likely that the bonding material 7 or the ceramic body 2 will be damaged due to, for example, movement of the lead wire 10, and therefore reduces performance degradation due to continuous use of the heater 1.

[0021] The peripheral edge 35 may be provided on the entire wall surface of the recess 3, or may be provided on a portion thereof. For example, the peripheral edge 35 may be provided in a portion of the recess 3 where the conductor 5 is drawn out, and the peripheral edge 35 may not be provided in a portion of the recess 3 where the conductor 5 is not drawn out (for example, the rear end of the heater 1). This improves the heater performance in the portion where the conductor 5 is drawn out, while reducing the risk of cracks starting from the peripheral edge 35 in the portion where the conductor 5 is not drawn out. As a result, it is possible to improve the heating efficiency and enhance durability.

[0022] 3, the end of the bonding material 7 may have a portion located on the peripheral edge 35 located on both sides in the Y-axis direction, which is a second direction intersecting the X-axis direction, which is a first direction in which the lead wire 10 extends, or may have a portion located on either of the peripheral edge 35 at both ends in the Y-axis direction. When the end of the bonding material 7 has a portion located on the peripheral edge 35 located on both sides in the Y-axis direction, it is possible to further reduce performance degradation due to continuous use of the heater 1.

[0023] 4, the end of the bonding material 7 may contact the peripheral wall 36 of the recess 3 that faces the end face 10a of the lead wire 10. This reduces the likelihood of damage to the bonding material 7 or the ceramic body 2 due to movement of the lead wire 10, thereby reducing performance degradation associated with continued use of the heater 1. In particular, when the heater 1 is used in a vibration environment, stress tends to concentrate on the longitudinal end face 10a of the lead wire 10. In such a case, by bringing the bonding material 7 into contact with the peripheral wall 36 of the recess 3 that faces the end face 10a of the lead wire 10, the stress concentrated at the boundary between the bonding material 7 and the conductor 5 can be dispersed throughout the heater 1 via the peripheral wall 36. Therefore, a heater 1 in which the end of the bonding material 7 contacts the peripheral wall 36 can alleviate stress.

[0024] 3 and 4, the end of the bonding material 7 may be in contact with the peripheral wall 36 of the recess 3, which extends in a direction intersecting with the bottom surface 34. By having the end of the bonding material 7 in contact with the peripheral wall 36, the bonding material 7 is surrounded above, below, and to the sides by the ceramic body 2 at the peripheral wall 36, thereby further reducing performance degradation due to continuous use of the heater 1. The end of the bonding material 7 may be in contact with the peripheral wall 36 over the entire periphery, or the bonding material 7 may be in contact with only a portion of the peripheral wall 36. In particular, by having the end of the bonding material 7 in contact with the peripheral wall 36 of the recess 3 facing the end face 10a of the lead wire 10, stress can be concentrated at the boundary between the bonding material 7 and the ceramic body 2, rather than at the boundary between the bonding material 7 and the conductor 5. Therefore, since the end of the bonding material 7 is located at the peripheral edge 35, damage such as microcracks is less likely to occur at the boundary between the bonding material 7 and the conductor 5, and the electrical resistance of the conductor 5 is less likely to decrease even after long-term use.

[0025] 3 and 4, the heater 1 may also include a plating material 6 covering the surface of the conductor 5. The plating material 6 may be, for example, a plating material containing nickel or chromium. By positioning the plating material 6 between the conductor 5 and the bonding material 7, for example, adhesion with the bonding material 7 is improved, and performance degradation due to continuous use of the heater 1 can be further reduced. The bonding material 7 may also be positioned directly on the bottom surface 34 of the recess 3, where the conductor 5 and the plating material 6 are not located. Positioning the bonding material 7 on the bottom surface 34 makes the bonding material 7 less likely to peel off, for example. This reduces performance degradation due to peeling of the bonding material 7.

[0026] Furthermore, the plating material 6 may be located on the peripheral edge 35 together with the conductor 5. This further restricts movement of the lead wire 10, for example, and therefore reduces the likelihood of damage to the bonding material 7 and the ceramic body 2. This further reduces performance degradation that occurs with continued use of the heater 1. The conductor 5 located on the peripheral edge 35 may be entirely covered with the plating material 6, or a portion of the conductor 5 may be exposed from the plating material 6.

[0027] <Variation 1> Next, modified examples of the embodiment will be described with reference to Figures 5 to 11. In the modified examples described below, the same components as those in the embodiment will be designated by the same reference numerals, and redundant explanations may be omitted.

[0028] Fig. 5 is a cross-sectional view showing a heater according to a first modified example of the embodiment. As shown in Fig. 5, the end of the bonding material 7 may be positioned so as to contact the top surface 35a that faces the peripheral edge 35 of the recess 3. When the end of the bonding material 7 contacts the top surface 35a, the bonding material 7 is positioned at the peripheral edge 35, sandwiched between the top surface 35a and the peripheral edge 35. When the end of the bonding material 7 is positioned so as to be sandwiched between the ceramic body 2 in this way, for example, the bonding material 7 is less likely to peel off. This can reduce performance degradation due to peeling of the bonding material 7.

[0029] <Variation 2> FIG. 6 is a cross-sectional view showing a heater according to a second modification of the embodiment. As shown in FIG. 6, the heater 1 differs from the heater 1 shown in FIG. 5 in that it has a protrusion 35b that protrudes from the top surface 35a toward the bottom surface 34. In addition, the end of the bonding material 7 may be positioned to engage with the protrusion 35b. By positioning the end of the bonding material 7 that contacts the top surface 35a to engage with the protrusion 35b, for example, the bonding material 7 becomes less likely to peel off. This can further reduce performance degradation due to peeling of the bonding material 7.

[0030] <Variation 3> Fig. 7 is a vertical cross-sectional view showing a heater according to Modification 3 of the embodiment. As shown in Fig. 7, the heater differs from the heater 1 shown in Fig. 4 in that the end of the bonding material 7 is located away from the peripheral wall 36 that faces the end face 10a of the lead wire 10.

[0031] When assembling the heater 1, for example, bending the lead wire 10 may apply a torsional stress to the root portion of the lead wire 10. In such a case, the torsional stress can be withstood by positioning the ends of the bonding material 7 on peripheral edges 35 located on both sides in a second direction intersecting the first direction in which the lead wire 10 extends, as shown in Fig. 3, while positioning the ends of the bonding material 7 away from the peripheral wall 36 of the recess 3 facing the end face 10a of the lead wire 10, as shown in Fig. 7. Therefore, the heater 1 according to this modification can further reduce performance degradation due to continuous use.

[0032] <Variation 4> Fig. 8 is a cross-sectional view showing a heater according to Modification 4 of the embodiment. As shown in Fig. 8, the heater 1 may have a ceramic body 2 in which a plurality of ceramic materials are laminated.

[0033] 8 has a ceramic body 2 including a first member 21, a second member 22, and a third member 23. The first member 21 and the third member 23 may be, for example, plate-like members having a predetermined shape. Furthermore, the second member 22 located between the first member 21 and the third member 23 may be, for example, a bonding material that bonds the first member 21 and the third member 23 together.

[0034] The surface of the first member 21 where the second member 22 is not positioned between the first member 21 and the third member 23 functions as the bottom surface 34. The surface of the third member 23 where the second member 22 is not positioned between the first member 21 and the third member 23 functions as the top surface 35a. The compositions of the first member 21, the second member 22, and the third member 23 may be the same or different. The layered structure of the ceramic body 2 is not limited to that shown in the figure. The ceramic body 2 may be, for example, a layered structure of two or four or more materials.

[0035] <Variation 5> Fig. 9 is a cross-sectional view showing a heater according to a fifth modified example of the embodiment. As shown in Fig. 9, the heater 1 may further have an intermediate layer 8. The heater 1 shown in Fig. 9 differs from the heater 1 shown in Fig. 4 in that it has an intermediate layer 8 located between the conductor 5 and the plating material 6. The intermediate layer 8 contains one or more metal elements contained in the conductor 5 and the plating material 6. The intermediate layer 8 may be, for example, an interdiffusion layer produced by a reaction between the conductor 5 and the plating material 6 during firing of the heater material.

[0036] Furthermore, the intermediate layer 8 may be located in the peripheral portion 35 together with the conductor 5 and the plating material 6. By locating the intermediate layer 8, for example, the plating material 6 and the conductor 5 can be firmly bonded via the intermediate layer 8, for example, at the peripheral portion 35. As a result, even when a load is applied to the lead wire 10, damage such as microcracks is less likely to occur in the ends of the bonding material 7 and the conductor 5, where stress tends to concentrate, and therefore the electrical resistance of the conductor 5 is less likely to decrease even after long-term use. Therefore, with the heater 1 according to this modification, it is possible to further reduce performance degradation due to continuous use.

[0037] <Variation 6> Fig. 10 is a cross-sectional view showing a heater according to Modification 6 of the embodiment. As shown in Fig. 10, the heater 1 may further include a resin material 40. The material of the resin material 40 may be, for example, a thermosetting resin, a photosetting resin, or another curable resin.

[0038] The resin material 40 is positioned inside the recess 3 so as to cover the lead wire 10 and the bonding material 7. This further restricts, for example, the movement of the lead wire 10, making it less likely that the bonding material 7 or the ceramic body 2 will be damaged. This further reduces performance degradation that occurs with continued use of the heater 1.

[0039] Furthermore, the end of the resin material 40 may be located on the peripheral edge 35, or may face the peripheral wall 36. This further restricts the movement of the lead wire 10, for example, and therefore reduces the likelihood of damage to the bonding material 7 or the ceramic body 2. This further reduces the performance degradation that occurs with continued use of the heater 1.

[0040] <Variation 7> In the above-described embodiment and each of the modifications, the heater 1 has a recess 3 that is substantially rectangular in plan view, but the shape of the recess 3 is not limited to this. Fig. 11 is a plan view showing a heater according to a seventh modification of the embodiment.

[0041] The recess 3 of the heater 1 shown in FIG. 11 has, in order from the end surface 2a side of the ceramic body 2, a first portion 37, a second portion 38, and a third portion 39. The dimensions of the first portion 37 and the third portion 39 in the Y-axis direction are smaller than those of the second portion 38 located between the first portion 37 and the third portion 39. By using a ceramic body 2 having such a recess 3, for example, the assembly accuracy of the lead wire 10 is improved. Note that the shape of the recess 3 is not limited to that shown in the figure. For example, the recess 3 may have the first portion 37 and the second portion 38, or the second portion 38 and the third portion 39.

[0042] Although the embodiments and modifications of the present disclosure have been described above, the present disclosure is not limited to the above embodiments and modifications, and various modifications are possible without departing from the spirit of the present disclosure. For example, the intermediate layer 8 shown in FIG. 9 and / or the resin material 40 shown in FIG. 10 may be applied to the heater 1 according to other modifications. Furthermore, other configurations of the above embodiments and modifications may be combined as appropriate within the scope of not causing any contradiction.

[0043] As described above, the heater 1 according to the embodiment includes a ceramic body 2, a heating resistor 4, a conductor 5, and a bonding material 7. The ceramic body 2 has a recess 3 that opens to the surface 2b. The heating resistor 4 is located inside the ceramic body 2. The conductor 5 is electrically connected to the heating resistor 4 and is located on the bottom surface 34 of the recess 3. The bonding material 7 bonds the conductor 5 to the lead wire 10 located on the conductor 5. The bottom surface 34 has a peripheral portion 35 that is located outside the opening edge of the recess 3 in a plan view. An end of the bonding material 7 has a portion located on the peripheral portion 35. This reduces performance degradation due to continuous use.

[0044] Moreover, the heater 1 according to the embodiment includes a plating material 6 that covers the surface of the conductor 5. The conductor 5 and the plating material 6 are located on the peripheral edge portion 35. This further reduces performance degradation due to continuous use.

[0045] The heater 1 according to the embodiment also includes an intermediate layer 8 located between the conductor 5 and the plating material 6 and containing one or more metal elements contained in the conductor 5 and the plating material 6. The intermediate layer 8 is located in the peripheral edge portion 35. This further reduces performance degradation due to continuous use.

[0046] Moreover, the end of the bonding material 7 according to the embodiment is in contact with the peripheral wall 36 that continues to the peripheral edge 35. This makes it possible to further reduce the deterioration of performance due to continuous use.

[0047] Moreover, the end of the bonding material 7 according to the embodiment continues to the peripheral wall 36 that continues to the peripheral edge portion 35, and contacts the top surface 35a that faces the peripheral edge portion 35. This further reduces performance degradation due to continuous use.

[0048] Furthermore, the end of the bonding material 7 according to the embodiment is located at the peripheral edge 35 located in the second direction intersecting the first direction in which the lead wire 10 extends. This reduces performance degradation due to continuous use.

[0049] Furthermore, the ends of the bonding material 7 according to the embodiment are located at the peripheral edge portions 35 located on both sides in the second direction intersecting with the first direction in which the lead wire 10 extends. This further reduces performance degradation due to continuous use.

[0050] Furthermore, the end of the bonding material 7 according to the embodiment faces the end face 10a of the lead wire 10 and contacts the peripheral wall 36 that continues to the peripheral edge 35. This reduces performance degradation due to continuous use.

[0051] Furthermore, the ends of the bonding material 7 according to the embodiment are located at peripheral portions 35 on both sides in a second direction intersecting the first direction in which the lead wire 10 extends, facing the end face 10a of the lead wire 10 and spaced apart from a peripheral wall 36 continuing to the peripheral portion 35. This allows the bonding material 7 to withstand torsional stress when it is applied to the base of the lead wire 10. As a result, it is possible to reduce performance degradation due to continuous use.

[0052] Moreover, the heater 1 according to the embodiment further includes a resin material 40 that covers the lead wires 10 and the bonding material 7. The end of the resin material 40 is located at the peripheral edge portion 35. This can further reduce performance degradation due to continuous use.

[0053] Further advantages and other aspects may readily occur to those skilled in the art. Therefore, the disclosure in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0054] 1 heater 2 ceramic body 3 recess 4 Heating resistor 5 Conductors 6 Plating materials 7 Bonding material 8. Middle Class 10 Lead Wire 34 bottom 35 Periphery 36 Peripheral wall 40 Resin material

Claims

1. A ceramic body that is a plate-like body extending from one end to the other end and has a recess that opens to include the one end; a heating resistor located inside the ceramic body along a surface direction of the ceramic body; a conductor electrically connected to the heating resistor and located on the bottom surface of the recess; a lead wire positioned on the conductor along the surface direction; a bonding material that bonds the lead wire and the conductor; Equipped with the bottom surface has a peripheral edge portion located outward from an opening edge of the recess in a plan view, The end of the bonding material has a portion located on the peripheral edge. heater.

2. The bonding material is positioned continuously on the conductor along a first direction in which the lead wire extends, and At least a part of the bonding material is located in the peripheral edge portion located in a second direction intersecting the first direction. The heater of claim 1 .

3. In the peripheral portion located in the second direction, the thickness of the bonding material becomes thinner as it moves away from the lead wire. The heater according to claim 2 .

4. The peripheral portion is located in the recess where the conductor is drawn out, and the peripheral portion is not located in the recess where the conductor is not drawn out. The heater according to any one of claims 1 to 3.

5. a plating material covering a surface of the conductor; The conductor and the plating material are located on the peripheral edge. The heater according to any one of claims 1 to 4.

6. an intermediate layer located between the conductor and the plating material, the intermediate layer containing one or more metal elements contained in the conductor and the plating material; The intermediate layer is located at the peripheral edge. The heater according to claim 5 .

7. The end of the bonding material is in contact with the peripheral wall that continues to the peripheral edge portion. The heater according to any one of claims 1 to 5.

8. The end of the bonding material continues to the peripheral wall that continues to the peripheral edge portion and contacts the top surface that faces the bottom surface. The heater of claim 7.

9. Further, a resin material is provided to cover the lead wire and the bonding material, The resin material has an end portion located on the peripheral edge portion. The heater according to any one of claims 1 to 8.

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