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 in the art. For this heater, a configuration has been proposed in which an opening is located at a 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] JP 2011-34979 A Summary of the Invention

[0004] A heater according to one aspect of the embodiment includes a ceramic body, a heating resistor, a conductor, and a bonding material. The ceramic body has a recess that opens to a surface. The heating resistor is located inside the ceramic body. The conductor is electrically connected to the heating resistor and is located on a bottom surface of the recess. The bonding material bonds the conductor to a lead wire located on the conductor. The bottom surface has a peripheral portion located outside the opening edge of the recess in a plan view. An end of the bonding material has a portion located on the peripheral portion. [Brief description of the drawings]

[0005] [Figure 1] FIG. 1 is a plan view showing a heater according to an embodiment. [Diagram 2] FIG. 2 is an enlarged view of area A shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line BB shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line CC shown in FIG. [Diagram 5]FIG. 5 is a cross-sectional view showing a heater according to a first modified example of the embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a heater according to a second modified example of the embodiment. [Figure 7] FIG. 7 is a vertical cross-sectional view showing a heater according to a third modified example of the embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing a heater according to a fourth modified example of the embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing a heater according to a fifth modified example of the embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing a heater according to a sixth modified example 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 PREFERRED EMBODIMENTS

[0006] Hereinafter, an embodiment of the heater disclosed in the present application will be described with reference to the attached 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 relationship between elements, the ratio of elements, and the like 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 an 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. This 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. The recess 3 will be described in detail 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 including, for example, tungsten, molybdenum, etc. The shape of the heating resistor 4 is not limited to that shown in the figure, and can be changed as appropriate depending on, for example, the heat generating characteristics required for the heater 1.

[0013] The conductor 5 is electrically connected to the heating resistor 4. The conductor 5 is located, for example, 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, for example, a metal material containing 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 may be used.

[0015] The lead wire 10 is a wire material 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 circle-equivalent 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 opening end. Here, the opening area of ​​the opening end refers to the area of ​​a region surrounded by ridge lines (opening ends) 31-33 of the opening of the recess 3 on the surface 2b of the ceramic body 2 and the end face 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 bonding between the lead wire 10 and the conductor 5 via the bonding material 7. Also, 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, improving the heater performance.

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

[0020] Moreover, the end of the bonding material 7 is located at the peripheral portion 35, which is outer than the opening end of the recess 3 in a plan view. Since the bonding material 7 is located from the center portion of the recess 3 to the peripheral portion 35, the lead wire 10 can be fixed more firmly. This makes it difficult for the bonding material 7 and the ceramic body 2 to 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 portion 35 may be provided on the entire wall surface of the recess 3, or may be provided on a part of the wall surface. For example, the peripheral portion 35 may be provided on a portion of the recess 3 where the conductor 5 is drawn out, and the peripheral portion 35 may not be provided on 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 occurring starting from the peripheral portion 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 in the peripheral portion 35 located on both sides in the Y-axis direction as a second direction intersecting the X-axis direction as a first direction in which the lead wire 10 extends, or may have a portion located in either of the peripheral portions 35 at both ends in the Y-axis direction. When the end of the bonding material 7 has a portion located in the peripheral portion 35 located on both sides in the Y-axis direction, the performance degradation due to continuous use of the heater 1 can be further reduced.

[0023] As shown in FIG. 4, the end of the bonding material 7 may be in contact with the peripheral wall 36 of the recess 3 facing the end face 10a of the lead wire 10. This makes it difficult for the bonding material 7 and the ceramic body 2 to be damaged due to, for example, the movement of the lead wire 10, and therefore reduces the performance degradation due to continuous use of the heater 1. In particular, when the heater 1 is used in a vibration environment, stress is likely to concentrate on the end face 10a in the longitudinal direction 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 facing 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, the heater 1 in which the end of the bonding material 7 is in contact with the peripheral wall 36 can relieve stress.

[0024] As shown in Figs. 3 and 4, the end of the bonding material 7 may be in contact with the peripheral wall 36 of the recess 3 extending in a direction intersecting the bottom surface 34. By contacting the end of the bonding material 7 with the peripheral wall 36, the upper, lower and sides of the bonding material 7 are surrounded by the ceramic body 2 at the peripheral wall 36, so that the performance degradation due to continuous use of the heater 1 can be further reduced. The end of the bonding material 7 may be in contact with the peripheral wall 36 over the entire circumference, or the bonding material 7 may be in contact with a part of the peripheral wall 36. In particular, by contacting the end of the bonding material 7 with the peripheral wall 36 of the recess 3 facing the end face 10a of the lead wire 10, the location where stress is concentrated can be the boundary between the bonding material 7 and the ceramic body 2, not the boundary between the bonding material 7 and the conductor 5. Therefore, by positioning the end of the bonding material 7 at the peripheral portion 35, damage such as microcracks is unlikely to occur at the boundary between the bonding material 7 and the conductor 5, so that the electrical resistance of the conductor 5 is unlikely to decrease even after long-term use.

[0025] As shown in Figs. 3 and 4, the heater 1 may include a plating material 6 that covers the surface of the conductor 5. For example, a plating material containing nickel or chromium can be used as the plating material 6. By positioning the plating material 6 between the conductor 5 and the bonding material 7, for example, the adhesion with the bonding material 7 is improved, and the performance degradation due to continuous use of the heater 1 can be further reduced. The bonding material 7 may be directly positioned on the bottom surface 34 of the recess 3 where the conductor 5 and the plating material 6 are not positioned. By positioning the bonding material 7 on the bottom surface 34, for example, the bonding material 7 is less likely to peel off. This makes it possible to reduce the performance degradation due to the peeling of the bonding material 7.

[0026] Furthermore, the plating material 6 may be located on the peripheral portion 35 together with the conductor 5. This further restricts the movement of the lead wire 10, for example, and therefore makes it difficult for the bonding material 7 and the ceramic body 2 to be damaged. This further reduces the performance degradation that accompanies continuous use of the heater 1. The conductor 5 located on the peripheral portion 35 may be entirely covered with the plating material 6, or a part 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 denoted by the same reference numerals, and duplicated descriptions 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, an end of the bonding material 7 may be located so as to contact a top surface 35a facing the peripheral portion 35 of the recess 3. When the end of the bonding material 7 contacts the top surface 35a, the bonding material 7 is sandwiched between the top surface 35a and the peripheral portion 35 at the peripheral portion 35. When the end of the bonding material 7 is sandwiched between the ceramic body 2 in this manner, 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 modified example 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 protruding from the top surface 35a toward the bottom surface 34. In addition, the end of the bonding material 7 may be positioned so as to engage with the protrusion 35b. By positioning the end of the bonding material 7 in contact with the top surface 35a so as to engage with the protrusion 35b, for example, the bonding material 7 becomes less likely to peel off. This can further reduce the performance degradation caused by the 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 end of the bonding material 7 is located away from the peripheral wall 36 facing the end face 10a of the lead wire 10, which is different from the heater 1 shown in Fig. 4.

[0031] When assembling the heater 1, for example, bending the lead wire 10 may apply a twisting stress to the root portion of the lead wire 10. In such a case, the twisting stress can be endured by positioning the ends of the bonding material 7 on peripheral portions 35 located on both sides in a second direction intersecting with a 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 the performance degradation caused by continuous use.

[0032] <Modification 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 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. In addition, 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.

[0034] A surface of the first member 21 where the second member 22 is not located between the first member 21 and the third member 23 functions as a bottom surface 34. A surface of the third member 23 where the second member 22 is not located between the first member 21 and the third member 23 functions as a 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 generated by a reaction between the conductor 5 and the plating material 6 accompanying 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, in the peripheral portion 35, the plating material 6 and the conductor 5 can be firmly bonded via the intermediate layer 8. As a result, even when a load is applied to the lead wire 10, for example, damage such as microcracks is unlikely to occur in the end of the bonding material 7 and the conductor 5 where stress is likely to concentrate, and therefore the electrical resistance of the conductor 5 is unlikely to decrease even after long-term use. Therefore, according to the heater 1 of 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 wires 10 and the bonding material 7. This further restricts, for example, the movement of the lead wires 10, making it difficult for the bonding material 7 and the ceramic body 2 to be damaged. This further reduces the performance degradation that occurs with continuous use of the heater 1.

[0039] Furthermore, the end of the resin material 40 may be located at the peripheral edge portion 35, or may face the peripheral wall 36. This further restricts the movement of the lead wire 10, for example, and therefore makes it difficult for the bonding material 7 and the ceramic body 2 to be damaged. This further reduces the performance degradation that accompanies continuous use of the heater 1.

[0040] <Variation 7> In the above-described embodiment and each of the modified examples, 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 modified example 7 of the embodiment.

[0041] The recess 3 of the heater 1 shown in FIG. 11 has a first portion 37, a second portion 38, and a third portion 39, in that order from the end surface 2a side of the ceramic body 2. The dimensions in the Y-axis direction of the first portion 37 and the third portion 39 are smaller than the second portion 38 located between the first portion 37 and the third portion 39. By using the ceramic body 2 having such a recess 3, for example, the assembly accuracy of the lead wire 10 is improved. 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 may have the second portion 38 and the third portion 39.

[0042] Although the embodiment and each modified example of the present disclosure have been described above, the present disclosure is not limited to the above embodiment and modified examples, 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 another modified example. In addition, other configurations of the above embodiment and each modified example may be appropriately combined within a range that does not cause contradictions.

[0043] As described above, the heater 1 according to the embodiment includes the ceramic body 2, the heating resistor 4, the conductor 5, and the 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 lead wire 10 located on the conductor 5 to the conductor 5. The bottom surface 34 has a peripheral portion 35 that is located outside the opening end of the recess 3 in a plan view. The end of the bonding material 7 has a portion that is located on the peripheral portion 35. This makes it possible to reduce 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 portion 35. This can further reduce the performance degradation that occurs with continuous use.

[0045] Moreover, the heater 1 according to the embodiment 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 portion 35. This can further reduce the performance degradation caused by 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 portion 35. This makes it possible to further reduce the performance degradation that occurs with continuous use.

[0047] Moreover, the end of the bonding material 7 according to the embodiment is connected to the peripheral wall 36 which is connected to the peripheral edge 35, and is in contact with the top surface 35a which faces the peripheral edge 35. This makes it possible to further reduce the performance degradation caused by continuous use.

[0048] Moreover, the end of the bonding material 7 according to the embodiment is located at the peripheral portion 35 located in the second direction intersecting with the first direction in which the lead wire 10 extends. This makes it possible to reduce performance degradation due to continuous use.

[0049] Moreover, the ends of the bonding material 7 according to the embodiment are located at the peripheral portions 35 located on both sides in the second direction intersecting with the first direction in which the lead wire 10 extends. This makes it possible to further reduce the performance degradation caused by continuous use.

[0050] Moreover, 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 makes it possible to reduce performance degradation due to continuous use.

[0051] Furthermore, the ends of the bonding material 7 according to the embodiment are located at the peripheral portions 35 located on both sides in the second direction intersecting with the first direction in which the lead wire 10 extends, facing the end face 10a of the lead wire 10 and located away from the 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 portion 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 the performance degradation caused by continuous use.

[0053] Further advantages and other aspects may readily occur to those skilled in the art. Thus, 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 equivalents thereof. [Explanation of symbols]

[0054] 1 Heater 2 Ceramic body 3. Recess 4 Heating resistor 5 Conductors 6 Plating material 7 Bonding material 8. Middle Tier 10 Lead Wire 34 Bottom 35 Periphery 36 Peripheral wall 40 Resin material

Claims

1. a ceramic body having a recess opening to a surface thereof; a heating resistor located inside the ceramic body; a conductor electrically connected to the heating resistor and located on a bottom surface of the recess; a bonding material for bonding the lead wire located on the conductor to the conductor; Equipped with the bottom surface has a peripheral edge portion located outward from an opening end of the recess in a plan view, The end of the bonding material has a portion located on the peripheral edge. heater.

2. a plating material covering a surface of the conductor; The conductor and the plating material are located on the peripheral portion. The heater of claim 1 .

3. 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 portion. The heater according to claim 2 .

4. The end of the bonding material is in contact with the peripheral wall that is continuous with the peripheral edge portion. The heater according to any one of claims 1 to 3.

5. The end of the bonding material is connected to the peripheral wall that is connected to the peripheral edge portion and is in contact with the top surface that faces the peripheral edge portion. The heater according to any one of claims 1 to 4.

6. The end of the bonding material is located on the peripheral portion located in a second direction intersecting with a first direction in which the lead wire extends. The heater according to any one of claims 1 to 5.

7. The ends of the bonding material are located on the peripheral portions located on both sides in a second direction intersecting with a first direction in which the lead wire extends. The heater according to any one of claims 1 to 5.

8. The end of the bonding material faces the end face of the lead wire and contacts the peripheral wall that is continuous with the peripheral edge. The heater according to claim 6 or 7.

9. The end of the bonding material faces the end face of the lead wire and is located away from the peripheral wall that is continuous with the peripheral edge portion. The heater according to claim 7.

10. Further comprising a resin material covering the lead wire and the bonding material, The resin material has an end located on the peripheral edge portion. A heater according to any one of claims 1 to 9.

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