KR100823378B1 - Ceramic heater - Google Patents

Abstract

A ceramic heating body is provided to improve durability and efficiency by performing oxidation-prevention of a terminal unit of a heating electrode for a reducing and sintering process. A ceramic heating body includes an insulating body(101), a conductive heating electrode(102), a metal layer(103), and a terminal. The insulating body is composed of a ceramic. The conductive heating electrode is installed on one plane of the insulator. The terminal supplies a power through the heating electrode. The metal layer is formed on a surface of the ceramic heating body to increase heat conductivity and an anti-heat impact. An insulating layer for preventing a heat from being transferred to a vertical direction to a surface of the metal layer is formed on the surface of the metal layer to improve temperature uniformity.

Description

Ceramic Heating Element {CERAMIC HEATER}

1 is an exploded perspective view showing a ceramic heating element to which the prior art is applied.

2 is an exploded perspective view showing another example of a ceramic heating element to which the prior art is applied.

3 is a graph showing the thermal conductivity of the ceramic heating element to which the prior art is applied.

Figure 4 is a graph showing the output relationship of the ceramic heating element to which the prior art is applied.

5 is an exploded perspective view showing a ceramic heating element to which the technique of the present invention is applied.

Figure 6 is a graph showing the thermal conductivity of the ceramic heating element to which the technique of the present invention is applied.

7 is a graph showing the output relationship of the ceramic heating element to which the technique of the present invention is applied.

8 is an exploded perspective view showing a state in which another example of the heating electrode of the ceramic heating element to which the technique of the present invention is applied.

9 is a design of resistance for uneven heating of the heating electrode of the ceramic heating element to which the technique of the present invention is applied, (a) is a heating state diagram, (b) a series uneven heating circuit diagram, (c) is a parallel uneven heating circuit diagram.

10 is an example of a terminal for connecting a power supply of a ceramic heating element to which the technique of the present invention is applied.

11 is a diagram illustrating two examples of terminals for power connection of a ceramic heating element to which the technique of the present invention is applied.

12 is an example of three terminals for power connection of the ceramic heating element to which the technique of the present invention is applied.

Figure 13 is a cross-sectional view taken along the line A-A of the terminal for power supply connection of the ceramic heating element to which the technique of the present invention is applied.

Fig. 14 is a plane, bottom and sectional view showing one example of manufacturing a ceramic heating element to which the technique of the present invention is applied.

Fig. 15 is a plan view, bottom and sectional view showing two examples of the manufacture of ceramic heating elements to which the technique of the present invention is applied;

Fig. 16 is a plan view, a bottom view and a sectional view showing three examples of manufacturing a ceramic heating element to which the technique of the present invention is applied.

17 is a plan view, a bottom view and a sectional view showing a fourth example of manufacture of a ceramic heating element to which the technique of the present invention is applied.

18 is a plan view, a bottom view and a sectional view showing a fifth example of manufacture of a ceramic heating element to which the technique of the present invention is applied.

Fig. 19 is a plan view, bottom view and sectional view showing a six example of manufacture of a ceramic heating element to which the technique of the present invention is applied.

20 is a plan view, bottom view and sectional view showing a seven example of manufacture of a ceramic heating element to which the technique of the present invention is applied;

* Description of the symbols used in the main parts of the drawings *

100; Ceramic heating element

102; Heating electrode

103; Metal layer

105; resistance

107; Terminals

The present invention relates to a ceramic heating element, and more particularly, to the provision of an improved ceramic heating element to increase the output while increasing the thermal shock stability.

In general, a heating element using electricity generates Joule heat in which electrical energy is converted into thermal energy by applying a voltage to a conductive metal having a constant resistance. As the heating element, since the metal has electrical conductivity, a complex insulator is used or a certain distance is used to electrically insulate the object to be heated.

Such low thermal conductivity insulating inclusions (insulation coatings or insulating ceramics, air, etc.) are present between the heat source and the heated object, hindering heat transfer and can cause significant heat loss depending on the manner of contact.

The ceramic heating element integrates a conductor having a heat generating resistance and a ceramic substrate having excellent insulation performance so that highly efficient heat transfer occurs to the heated object. As described above, the ceramic heating element has high watt density even in a small size and light weight, and has a good thermal efficiency, and has been applied to various fields because of excellent thermal properties and high reliability.

As shown in FIG. 1, the ceramic heating element 1 generates heat by incorporating the conductive heating element 2 into the ceramic, which is the insulator 3, and as shown in FIG. 2, the ceramic heating element 1 is formed on the ceramic surface of the insulator 3. 3) and a protective layer 4 for preventing breakdown voltage or oxidation, thereby generating heat from the surface.

In the case of FIG. 1, since a conductor having a constant resistance inside the ceramic generates heat to transfer heat through the ceramic, the ceramic surface having a relatively low thermal conductivity may be uniformly generated. Since the heat is transmitted through the ceramic having a predetermined thickness in manufacturing, the surface temperature is lower than the heating temperature of the heating electrode.

In addition, when the thermal conductivity of the ceramic is selectively contacted with the heated object, the difference between the surface temperature of the ceramic and the non-contacted ceramic becomes large, and the ceramic is exposed to thermal shock due to the generation of strong thermal stress, thereby deteriorating reliability in use.

In the case of Figure 2, because the heat generated from the ceramic surface has the advantage that can quickly transfer the heat to the surface of the heating material in contact with the heating surface, but the temperature difference between the heating surface and the opposite surface is so severe that it can not withstand a certain temperature difference or more In this case, the heat output is bound to be limited.

As shown in FIGS. 3 and 4, the thermal conductivity and the output of the thermal heater are slowly generated in the direction of the object to be heated on the side of the ceramic heater at the position where the object to be heated 5 is connected. It can be easily seen through the graph.

In addition, since a protective film capable of withstanding a constant withstand voltage must be used, a heat generating electrode that can be heat-treated in an oxidizing atmosphere is mainly limited to precious metals such as Ag, Au, Pd, and Pt. Ag or Au has a high heat transfer coefficient, but has a disadvantage in that resistance change may occur due to erosion by the glass component used in the insulating protective film in the use environment of heating conditions.

In addition, since the resistance is very low, sintering of alloys or mixed powders containing Pd, Pt, etc., which have high specific resistance and low heat transfer coefficient, is usually given to impart proper resistance, so that heat transfer performance through heat generation patterns may be relatively limited. Can be.

On the other hand, metals such as W or Mo have higher thermal conductivity than precious metals such as Pd and Pt, and have higher heat resistance than Ag and Au in a heating environment because they are heat-resistant metals with high melting point.

The heating electrode of the ceramic heating element using the metal has a disadvantage that the heat treatment environment is limited to the reducing atmosphere. Therefore, a protective layer for electrical insulation or oxidation prevention should also be heat treated in a reducing atmosphere. The protective film thus formed has a disadvantage in that the insulation performance is generally weak.

Accordingly, the present invention has been invented to solve the problems as described above, while having thermal shock resistance, small weight, high output, and various heating electrodes and various types of ceramic heaters, an insulating protective film of the heating electrode layer is formed in an oxidizing atmosphere. Alternatively, the object of the present invention is to provide a heating element having high efficiency and durability by anti-oxidizing the terminal portion of the heating electrode for reduction and sintering so that a high thermal conductivity metal can be metallized on the surface of the ceramic heating element.

Such a ceramic heating element of the present invention has an industrial value that can be applied to various technical fields requiring heat exchange by brazing or bonding a heat sink to a ceramic heating element, a ceramic heating element, or a metallizing layer of an image fixing device.

Hereinafter, with reference to the accompanying drawings will be described a preferred configuration and operation of the present invention for achieving the above object.

5 is an exploded perspective view showing a ceramic heating element to which the technique of the present invention is applied, FIG. 6 is a graph showing a thermal conductivity relationship of the ceramic heating element to which the technique of the present invention is applied, and FIG. 7 is an output of the ceramic heating element to which the technique of the present invention is applied. 8 is an exploded perspective view showing another example of a heating electrode of a ceramic heating element to which the technique of the present invention is applied, and FIG. 9 shows an uneven heating of the heating electrode of the ceramic heating element to which the technique of the present invention is applied. As a schematic drawing of a resistor, (a) is a heating state diagram, (b) is a series uneven heating circuit diagram, (c) is a parallel uneven heating circuit diagram, and FIG. 10 is a terminal for power connection of a ceramic heating element to which the technique of the present invention is applied. 1 is an example, Figure 11 is a two example of a terminal for connecting the power supply of the ceramic heating element applied technology of the present invention, Figure 12 is a power supply of the ceramic heating element applied technology of the present invention 13 is a cross-sectional view taken along line A-A of a terminal for power connection of a ceramic heating element to which the present invention technology is applied, and FIG. 14 is a plan view showing one example of manufacturing a ceramic heating element to which the technology of the present invention is applied. , Bottom and sectional view, FIG. 15 is a planar, bottom and sectional view showing two manufacturing examples of the ceramic heating element to which the technology of the present invention is applied, and FIG. 16 is a planar and bottom view showing three manufacturing examples of the ceramic heating element to which the technology of the present invention is applied. And sectional drawing, FIG. 17 is a plane, bottom and sectional drawing which show 4 manufacture examples of the ceramic heating element to which the technique of this invention was applied, FIG. 18 is a plane, bottom and sectional view which shows 5 manufacture examples of the ceramic heating element to which the technique of this invention is applied. 19 is a plan view, bottom and sectional views showing six manufacturing examples of the ceramic heating element to which the technique of the present invention is applied, and FIG. 20 is a plan view showing the seven manufacturing examples of the ceramic heating element to which the technique of the present invention is applied. It demonstrates together as a sectional drawing.

The ceramic heating element 100 is electrically conductive and has a relatively high thermal conductivity of a heat-generating pattern of a metal component having relatively high electrical conductivity, and is embedded in a ceramic insulator having a relatively low thermal conductivity, or a metallization pattern on a surface thereof. The ceramic heating element which can be manufactured and has high insulation, but high elastic modulus and relatively low thermal conductivity, is susceptible to thermal shock, and its stability can be maintained under conditions where the heating surface is uniformly generated or used at a constant temperature.

However, most ceramic materials that can be manufactured at low cost are mostly ion-bonded, which makes it difficult to satisfy both high insulation, low modulus and high thermal conductivity.

In the present invention to solve the above problems, metallization of the thick film is performed by using a suitable metal on the surface of the ceramic insulator 100 composed of the insulator 101 made of ceramic and the conductive heating electrode 102. Alternatively, the metal layer 103 may be formed by plating or brazing so as to have a very high surface thermal conductivity.

By forming the metal layer 103 on the surface of the ceramic heating element 100 with a metal having a very high thermal conductivity, not only a minute temperature deviation (active variation) of the heating electrode 102, but also the surface of the ceramic is heated by the object 104. It is possible to improve the uniformity of the temperature by inducing the rapid balance of the occurrence of the temperature deviation (passive deviation) can be improved thermal shock stability and temperature uniformity.

As can be seen from the graphs shown in FIGS. 6 and 7, when the metal layer 103 having high thermal conductivity on the surface of the ceramic heating element 100 is formed, thermal conductivity in a direction of alleviating an unbalance of surface temperature can be quickly achieved. .

In addition, since the heat energy generated by the heat generating electrode 102 enables rapid heat transfer due to the surface property having good thermal conductivity, high power design may be possible.

Increasing the thermal conductivity of the surface of the ceramic heating element 100 may be achieved by metallizing the surface of the heater to a metal having high thermal conductivity, or by plating or brazing.

Metals with high thermal conductivity include silver (Ag), copper (Cu), aluminum (Al), gold (Au), tungsten (W), molybdenum (Mo), and at least one of these components. When the integrated metal layer 103 is formed on the surface of the ceramic heating element 100 by thick film metallization (coating and heat treatment) using the paste, the surface thermal conductivity of the ceramic heating element 100 may be very high.

In addition, the surface of the ceramic heating element 100 is metallized, and a metal plate having good thermal conductivity, for example, silver, copper, aluminum, and the like is plated and brazed on the surface to form the metal layer 103 integrated on the surface of the ceramic heating element 100. The same effect can be obtained.

As such, when the surface thermal conductivity of the ceramic heating element 100 is increased, temperature deviation due to active or passive causes can be minimized, and stability to thermal shock of the ceramic heating element 100 can be very high. Since the heat generated at 100 can be quickly transferred to the heated object 104 in contact, higher output can be obtained.

When precise temperature uniformity is required, a property of suppressing heat transfer in a direction perpendicular to the surface of the ceramic heating element 100 and further increasing thermal conductivity in a direction horizontal to the surface may be required. It is also a good solution to form an insulating film having a low thermal conductivity or to bond a ceramic substrate to the metal layer formed on the ceramic surface to prevent oxidation and improve insulation.

Another solution for increasing the thermal shock stability while increasing the heating output of the ceramic heating element 100 is to increase the area of the heating electrode 102 by designing a plurality of heating pattern layers.

If the area of the heating electrode 102 is increased, the heat output per unit area can be increased, and as the area of the conductive heating electrode 102 having a continuous pattern with a high heat transfer coefficient is increased, the temperature difference in the ceramic is reduced, thereby increasing efficiency and high capacity. It can show the heating performance of.

In the case of the ceramic heating element 100 having the heating electrode 102 pattern embedded therein, the heating electrode 102 may be formed in two or more layers, and each layer may be connected in series or in parallel. In addition, in the case of the thick-film ceramic heating element 100 having the heating electrode 102 formed on the surface, connecting the respective layers by forming the heating electrode 102 on both sides may be designed in series or in parallel.
In particular, in the case of a thick-film ceramic heating element composed of a single-sided heating electrode layer, the temperature difference between the heating surface and the opposite surface is rapidly formed while the temperature is raised, and thus a momentary deformation may occur.
If the amount of deformation caused by the temperature difference is not absorbed in the structure in which the heating element is installed, it may be destroyed by the generation of strong thermal stress, or even if the change is allowed, the local temperature difference between the surfaces may be uneven in contact with the heated object. It can be broken by generation.
However, since the thick film-type ceramic heating element composed of a double-sided heating electrode layer does not generate such a temperature difference, durability and reliability can be remarkably improved.

In designing the heating electrodes 102 in series or in parallel, when an equal amount of heat is required, the heat generating electrodes 102 may have the same amount of heat through a pattern design having the same output.

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In general, when the object to be heated 104 is contacted, the surface of the heat generating electrode 102 is relatively more heat loss, so the heat generating electrode 102 close to the contact surface is designed to generate a higher amount of heat so that it is constant in the thickness direction of the ceramic heating element. It is desirable to give the resistance 105 unevenly to maintain the temperature.

For example, when each heating electrode 102 is connected in series, the heating electrode 102 close to the contact surface of the object to be heated 104 is designed to have a high resistance 105 to generate a higher amount of heat. When the heating electrodes 102 are connected in parallel, the heating electrodes 102 close to the contact surface of the object to be heated 104 may be designed to have a low resistance 106 to generate a higher amount of heat.

As shown in FIGS. 10 to 11, the terminal 107 for connecting a power source to the ceramic heating element 100 has a wire terminal 109 for connecting the contact terminal 108 having a single-sided or double-sided contact with the connection line by soldering or brazing. There is).

The thick film type ceramic heating element is a ceramic heating element having a very efficient method because a heat generating electrode is formed on a surface thereof, and thus the heat transfer distance is very short when the heating object is used in contact with the heated object. Thick film-type ceramic heating element is composed of a heating electrode made of a noble metal material such as Ag, Pd, Pt and can be sintered in an oxidizing atmosphere, thus making it possible to manufacture by simple equipment. However, it is necessary to use relatively expensive precious metals, and has the disadvantage that only the power connection by the terminal contact is possible.

Metals such as W and Mo are more inexpensive as the heating electrode and have a high melting point. This type of metal has the characteristics that ceramic metalizing heat treatment is performed at high temperature in the reducing atmosphere, has a higher melting point, higher thermal conductivity, and higher heat generation stability than noble metals such as Pd and Pt. It is a metal widely applied as a heating element.

In particular, it is used as the most successful heating element when embedded in the ceramic. However, in order to apply the thick film type heating element, there is a disadvantage in that it is not easy to form a protective film to ensure insulation of the heating metal layer. In order to heat-treat the protective film on the layer where W or Mo is metallized on the ceramic surface, it is limited to a reducing atmosphere, and the insulation of the protective film is also very low.

On the other hand, in order to heat-treat the highly insulating protective film in a reducing atmosphere, a very high temperature is required, and various problems arise that the sintering density of the protective film is also lowered. As a means for solving the above problems, a portion except for the terminal part is formed by reducing and sintering an anti-oxidation protective film, and a method of forming an insulating protective film in an oxidation atmosphere by treating the surface with a strong oxidation resistance metal so that the terminal part is not oxidized is useful.

The method of treating the terminal portion with an oxidizing metal film is also useful as a method for forming a metallization layer with a high thermal conductivity metal on the surface of a ceramic heater having a W or Mo heating electrode embedded therein.

The simplest method of preventing the terminal portion from oxidizing is to sinter the terminal portion to Pd or Pt in a reducing atmosphere, or to form a metal oxide layer, for example, a silver (Ag) metal layer, on a metallization layer formed of W or Mo by a plating-brazing method. will be.

Since the configuration of the terminal 107 for supplying power to the ceramic heating element 100 is to maintain electrical conductivity while continuously being exposed to heat due to the characteristics of the heater for heating purposes, a conductive metal film of heat and oxidation resistant materials should be formed. A constant insulation distance between the two terminals is required.

High-melting-point oxidizing metals such as W and Mo have a disadvantage in that plating and anti-oxidation metal layers must be formed so as not to be oxidized, but a conductive metal film made of heat-resistant and oxidation-resistant material can be formed at the terminal part by high temperature brazing of the terminal part and the power supply line. There is an advantage to configure a reliable terminal connection.

On the other hand, ceramic heating elements having Ag-, Pd-, and Pt-based heating electrodes having high oxidation resistance do not need to be formed of an oxide-resistant metal layer because they are highly resistant to oxidation. There is a disadvantage that is limited to.

It is preferable that the terminal which can apply a power supply by a contact usually enlarges a contact area. In some cases, when the area where the terminal is located is small, the contact terminal 108 is used to secure a large area and reduce interference between the terminals.

In the case of the contact terminal 108, two terminals 108-1 and 108-2 are arranged side by side on one surface (upper surface) of the ceramic heating element 100, and one of the terminals 108-1 is disposed on the upper surface thereof. A hole 110 is formed in the other terminal 108-2 and the heating electrode 102, and the hole 110 connects the lead wire 111 to the bottom surface. .

In addition, when the contact terminal 108 is provided on both surfaces of the ceramic heating element 100, the upper terminal 108-1 directly connects to the heating electrode 102, and the lower terminal 108-2 has a hole ( Interconnection between the terminal 110 and the lead wire 111 may be reduced.

In the case of contact power application, the Ag, Pd, and Pt-based metal layers have heat resistance and oxidation resistance by themselves, and thus a heating electrode layer may be used as a terminal. However, the W and Mo-based metal layers have excellent heat resistance, but the oxidation resistance is weak, so that the surface of the terminal must be formed of an oxide resistant metal layer.

In this case, plating 112 for brazing is applied to the heating electrode 102 of the ceramic heating element 100, and the oxidation resistant film 115 is formed by placing the brazing filler 113 between the metal plate 114. Can be formed.

On the other hand, there is a method of applying power to the connection line by brazing the connection line directly from the terminal. A conventional method of brazing the connecting wires to the terminals is to braze the metal wires on the metallizing surface. This connection is widely used because it is a well-known technique for forming a metal film having heat resistance and oxidation resistance and having proper durability in a heating environment using a heater. However, if an oxidation atmosphere and a heat treatment process are required as a post process, a lead wire may be used. The surrounding thin silver solder metal has a problem of increasing the risk of short circuit due to oxidation erosion.

The solution to this problem is to simultaneously braze the metal sheet on the surface of the lead wire. This makes it possible to carry out the sintering process in an oxidizing atmosphere because the oxidation resistant metal film melt-bonded to the lead wire and the metallizing surface is protected by the metal sheet.

Manufacturing Example 1 of Ceramic Heating Element 100.

Thick Film Ag-Pd Electrode Heater (1 terminal on each side, metal radiating layer)

(1) Ag-Pd paste is printed and oxidized and sintered on a sintered ceramic substrate to form a heating electrode (102).

② The opposite surface of the patterned Ag-Pd heating electrode 102 is printed and oxidized and sintered with Ag Paste to form a metal heat dissipation layer. In this case, the metal layer 103 may be patterned in consideration of the heat generation characteristics and the use environment.

③ Print with a glass paste that can form a protective film on the patterned Ag-Pd heating electrode except for the terminal and sinter in an oxidizing atmosphere.

④ The ceramic heating element manufactured in this way can exhibit thermal shock resistance and high power performance.

Ceramic Heating Element 100 Manufacturing Example 2.

Thick Film W Electrode Heater (2 Terminals on One Side, Metal Heat Dissipation Layer + Protective Film)

① W paste is printed and reduced sintered on a sintered ceramic substrate in a pattern in which a constant resistance is formed to form a heating electrode 102, and on the opposite side, a W thick film layer for improving surface thermal conductivity is formed.

② The power supply terminal 107 is formed of a metal layer 102 made of a metal paste containing a metal, for example, Pd, Pt, or the like, which can be heat-treated in a reducing atmosphere and an oxidizing atmosphere.

③ Glass paste is printed on the heat generating electrode 102 and the W thick film layer on the opposite side except for the terminal 107 for power application, and heat-treated in a reducing atmosphere to form a protective layer for preventing oxidation and insulation.

(4) Since the protective film formed on the surface of the heating electrode 102 in the reducing atmosphere exhibits low insulation performance, the glass paste having sufficient insulation even in low temperature oxidation atmosphere is printed and heat treated in the oxidation atmosphere to enhance the insulation performance.

⑤ The ceramic heating element 100 manufactured as described above improves the temperature uniformity between the heating surfaces, and the heat generation output may be weakened by controlling the heat exchange with respect to the heated object 104 uniformly, but the thermal shock resistance and the excellent temperature uniformity are exhibited. Can be.

Ceramic Heating Element Manufacturing Example 3.

Bonding W electrode Heater (metal heat dissipation layer)

① A widely known technique is to apply W Paste in a pattern in which a constant resistance is formed on one ceramic green sheet, and another ceramic green sheet is laminated thereon, and simultaneously fired at a high temperature in a reducing atmosphere.

(2) The W heating electrode 102 is plated with Ni on the terminal 107 of the co-fired body inherent in the ceramic, and the Ni wire is sequentially covered with the Ni wire and the Ni sheet to melt and braze Ag.

③ Ag paste is applied to the heating surface of the ceramic heating element 100 in whole or selectively and sintered in an oxidizing atmosphere.

④ The ceramic heating element 100 manufactured as described above may exhibit thermal shock resistance and high power, and may have a relatively high thermal efficiency.

Manufacturing Example of Ceramic Heating Element 100 4.

Thick Film Mo Electrode Heater (Parallel Connection, Double-sided Heating Layer)

① Mo Paste is printed and reduced sintered in a pattern in which a constant resistance is formed on both sides of the ceramic substrate. At this time, the heating electrode layer on both sides allows the conductive metal paste to be connected through-hole or via-fill through holes processed in the substrate so that they can be connected in parallel.

② Printed and coated with a glass paste that can be heat-treated in a reducing atmosphere on the surface of the ceramic substrate other than the external terminal portion (both sides) connected through the heat generating electrode layer and the hole, and heat-treated to form an antioxidant film.

③ Plate Ni on the surface of the terminal, and place Ni sheet coated with Ag or Ag-Cu alloy on the plating layer to perform brazing in hydrogen atmosphere.

(4) Since the Ag film having excellent heat resistance and oxidation resistance is formed on the terminal part, the glass paste which can be heat-treated in a low temperature oxidation atmosphere can be coated to form a protective film on the heating electrode layer to enhance the insulation performance.

⑤ The ceramic heating element 100 manufactured as described above may exhibit thermal shock resistance and high output performance.

Manufacturing Example of Ceramic Heating Element 100 5.

Bonding W electrode Heater (serial connection, multiple heating layers)

(1) As a known technique, W paste is applied in a pattern in which a constant resistance is formed on one ceramic sintered substrate, and the ceramic sintered substrate on which the ceramic sintered binder is printed and degreased is placed on the ceramic sintered joint in a high temperature reducing atmosphere.

(2) A pattern layer of the heating electrode (102) is formed on the surface of the ceramic sintered assembly connected to the inner W heating electrode (102) by printing and elemental grains.

(3) A glass paste is applied to the surface heating electrode 102 pattern and heat-treated in a reducing atmosphere to form a protective film for preventing oxidation.

(4) Ni is plated on the terminal located on the surface heating electrode 102 layer, the Ni sheet is covered on the Ni plating layer, and Ag is brazed by melting Ag as a brazing filler.

⑤ Ag paste is applied to the heating surface of the ceramic heating element 100 in whole or selectively and sintered in an oxidizing atmosphere.

⑥ The ceramic heating element 100 manufactured as described above may exhibit thermal shock resistance and high power, and may have a relatively high thermal efficiency.

Ceramic Heater 100 Manufacturing Example 6.

Junction type W electrode heater (multiple heating layers, simultaneous parallel connection terminals or terminals with individual control, metal radiating layer)

(1) An example of having multiple layers of heat generating electrodes 102, which can be applied as a heat source having high thermal shock resistance, high output performance and high heat capacity.

② It has multiple layers of heat generating electrode 102 and can be applied by individual control of heat shock resistance, high output performance and high heat capacity.

Embodiments described in detail as described above are not limited to the above method can be cross-applied to each other, and those skilled in the art can be easily applied to various embodiments based on the present invention.

The present invention as described above has a thermal shock resistance, has a small output, high output, small size, light weight, and various heating electrodes, various types of ceramic heaters to form an insulating protective film of the heating electrode layer in the oxidizing atmosphere, or a high thermal conductivity metal of the ceramic heating element In order to enable the metallizing (Metalizing) treatment on the surface, the terminal portion of the reducing sintering heating electrode is subjected to an anti-oxidation treatment to provide a heating element having excellent efficiency and durability.

The ceramic heating element of the present invention is an invention having an industrial use value that can be applied to various technical fields requiring heat exchange by brazing or bonding a heat sink to a ceramic heating element, a ceramic heating element for an image fixing device, or a metalizing layer of an image fixing apparatus.

Claims (8)

An insulator 101 made of ceramic; A conductive heating electrode 102 provided between or between the insulators 101; In the ceramic heating element (100) consisting of a terminal (107) for supplying power to the heating electrode (102); Ceramic heating element, characterized in that to form a metal layer (103) for the increase of high thermal conductivity and increase the thermal shock resistance, high output on the surface of the ceramic heating element (100). The method of claim 1; Ceramic heating element, characterized in that to form an insulating film on the surface of the metal layer 103 to prevent heat transfer in a direction perpendicular to the surface to improve the temperature uniformity. The method of claim 1; The heating electrode 102 is composed of a plurality of layers to increase the uniformity of the surface temperature and to enable high output; The heating electrode (102) provided in the plurality of layers is a ceramic heating element, characterized in that connected in series or in parallel. The method of claim 1; The heating electrode (102) is provided with a resistor (105) unevenly so that a higher amount of heat can be generated in the direction of contact with the object to be heated (104); The resistor 105 is designed to have a high resistance 105 near the contact surface of the object to be heated 104 when the heating electrodes 102 are connected in series; The resistor (105) is a ceramic heating element characterized in that to have a low resistance (106) near the contact surface of the object to be heated (104) when the heating electrodes 102 are connected in parallel. The method of claim 1; The terminal 107 is connected to the contact terminal 108 to arrange the two terminals (108-1, 108-2) side by side on the upper surface of the ceramic heating element (100); The one terminal 108-1 is connected to the heating electrode 102 at an upper surface thereof; The other terminal 108-2 and the heating electrode 102 are connected to the lead wire 111 on the bottom surface of the ceramic heating element 100 through the hole 110. The method of claim 1; A connection of the contact terminals 108 in which the terminals 107 arrange two terminals 108-1 and 108-2 on the top and bottom surfaces of the ceramic heating element 100; The terminal 108-1 of the upper surface is directly connected to the heating electrode 102; The bottom terminal (108-2) is a ceramic heating element, characterized in that connected to the lead wire 111 of the bottom surface of the ceramic heating element (100) through the hole (110). The method of any one of claims 1, 5 and 6; The contact terminal 108 constituting the terminal 107 is subjected to plating 112 for brazing the heating electrode 102; A brazing filler (113) on the upper surface of the plating (112); Ceramic heating element, characterized in that the oxidation resistant film 115 is formed by placing a metal plate 114 on the upper surface of the brazing filler (113). The method of claim 3; The heating electrode (102) provided in the plurality of layers is a ceramic heating element, characterized in that to configure a pair of terminals (107) to enable individual control for selectively adjusting the amount of heat on each surface.

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