JP2008277285A - Electrothermal coating fused body, and its fusing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-strength electrothermal coating fused body excelling in adhesiveness to an aluminum nitride base material without causing separation when a coating of a Si alloy containing 0.2% or more B is fusion-bonded to aluminum nitride in order to solve a problem that, when a coating of the Si alloy containing 0.2% or more B is fusion-bonded to the aluminum nitride, the coating is separated, or easy to separate or the strength of the coating itself is low, and its electrothermal coating fusion coating method. <P>SOLUTION: This electrothermal coating fused body has a structure where an electrothermal coating formed of a Si alloy containing 0.2 wt.% or more of B is fusion-bonded to the surface of an aluminum nitride ceramic base material containing 1 wt.% of an sintering additive of a rare-earth element compound in terms of oxide. In the coating, not smaller than 0.1 wt.% of a rare-earth element using the rare-earth element compound of the sintering additive of the ceramic base material as a supply source is included. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrothermal film fusion body and a fusion method thereof. More specifically, the present invention relates to an electrothermal film fusion body in which an electrothermal film made of a Si alloy containing B is fused to an aluminum nitride base material and the fusion method thereof. It is concerned.

  A ceramic heater in which a Si alloy electrothermal coating is fused to a ceramic substrate such as AlN has a drawback that the resistance value of the electrothermal coating changes (increases) when high-temperature heating is repeated. As a method for improving this defect, Patent Document 1 describes that adding B to the Si alloy in the range of 0.03 to 5% has an effect of suppressing the resistance change of the film. Describes the composition of the paste at the time of fusing the film, but does not describe the composition of the film after fusing. In the examples of the specification, the amount of B originally contained in the fusion coating should be described, but it is not described. The invention of Patent Document 1 is the invention of the present inventor.

  It is well known to those skilled in the art that the component B is often volatilized when heated to a high temperature, and the yield in the film after high temperature melting is poor, and is described in the examples of the specification of Patent Document 1. It is unlikely that the amount of B in the paste is contained in the fused film as it is, that is, with a yield of 100%.

  From the description of Patent Document 1, it is effective to suppress the resistance change when B is contained, and the higher the B is, the more effective the resistance change is at a higher temperature. Although it can be seen, the current situation is that the quantitative data is not credible.

  The temperature at which aluminum nitride ceramics can be heated in the atmosphere is approximately 800 to 850 ° C., and the maximum heating of a ceramic heater based on aluminum nitride used in the atmosphere is limited to approximately 800 to 850 ° C. In view of the above, it is the most preferable aluminum nitride heater that the resistance value of the electrothermal coating does not change (rise) even when heated as a ceramic heater to about 800 to 850 ° C.

Therefore, the present inventor conducted a quantitative search experiment again on the relationship between the B content of the ceramic heater film and the maximum heating temperature at which the resistance change of the film starts.
As a result, the higher the B content, the higher the temperature at which the resistance change starts, and the B content of 0.2% by weight or more confirms experimentally that the temperature at which the resistance change starts at the first current heating is 800 ° C or higher. did it.
However, a new problem associated with the addition of B was discovered during the confirmation experiment.

The new problem is that when a Si alloy film containing 0.2% or more of B is fused to aluminum nitride, the film peels off or is easily peeled off, or the film itself has a weak strength. I found
This problem becomes a fatal problem when the coating is used as an electric heater.

JP 2005-71781 A

  The present invention has been made in view of such problems, and its purpose is to provide adhesion to an aluminum nitride substrate when a Si alloy film containing 0.2% or more of B is fused to aluminum nitride. It is an object of the present invention to provide an electrothermal film fusion product which is excellent and does not peel off and has a high film strength. And it is providing the electrothermal film fusion | melting method.

As a result of intensive studies on the above problems, the present inventor has obtained the following knowledge.
That is,
When a Si alloy film containing 0.2% or more of B is fused to aluminum nitride on an aluminum nitride base material that uses a rare earth element compound as a sintering aid, the content of the sintering aid compound is rare earth. It was found that the coating melts at 1% by weight or more in terms of oxide.
At that time, it was discovered that rare earth elements were melted into the fusion coating using a rare earth element compound as a sintering aid for the ceramic substrate as a supply source.
The amount of rare earth element leaching varies depending on conditions such as the temperature at the time of fusing, even when the amount of sintering aid is the same. It has been found that a film suitable for an electrothermal film can be obtained because the properties increase, the sintered density increases, and the resistance value decreases.
In the ceramic base material having a sintering aid compound content of less than 1% by weight in terms of rare earth oxides or containing no sintering aid compound, the coating does not melt or the coating peels off. It was discovered that a problem occurred and a film suitable as an electrothermal film could not be obtained.

  Furthermore, even in the case of an aluminum nitride ceramic base material having a sintering aid compound content of less than 1% by weight in terms of oxides or an aluminum nitride ceramic base material not containing a sintering aid, When a first layer of an electrothermal coating made of a Si alloy containing less than 0.2% by weight of B is fused, a coating having excellent adhesion can be obtained, and the first fused layer has a B content of By carrying out the B concentration treatment so that it becomes 0.2% by weight or more, a coating film that contains 0.2% by weight or more of B, has high adhesion and sintered density of the film, and is suitable as an electrothermal film. I found out that I could get it.

  In the concentration treatment, at least one layer or a plurality of layers and a Si alloy film are stacked on the first layer, and are fused and fused to form a fusion layer of the first layer and the stacked layer. It has been found that a method of adjusting the B content of the stacked layers and fusing it so that the B content is 0.2% by weight or more is practical and suitable.

  This invention is made | formed based on the above knowledge, and this invention subject can be solved by the following invention.

(First invention)
Electric heat having a structure in which an electrothermal coating composed of a Si alloy containing 0.2% by weight or more of B is fused to the surface of an aluminum nitride ceramic base material containing 1% by weight or more of a sintering aid for a rare earth element compound. A fusion-bonded body of a film, wherein the coating film contains 0.1% by weight or more of a rare earth element using a rare earth element compound as a sintering aid for the ceramic substrate as a supply source. .

(Second invention)
When an electrothermal coating composed of a Si alloy containing 0.2% by weight or more of B is fused to the surface of an aluminum nitride ceramic substrate, a sintering aid for a rare earth element compound is used as the substrate in an amount of 1% by weight in terms of oxide. An electrothermal coating characterized by using the aluminum nitride ceramics as described above, and eluting a rare earth element component supplying the rare earth element compound of the substrate into the electrothermal coating in an amount of 0.1% by weight or more. Fusion method.

(Third invention)
When fusing the electrothermal coating to the surface of the aluminum nitride ceramic substrate,
After fusing the first layer of the electrothermal coating made of a Si alloy containing less than 0.2% by weight of B to the substrate, it is concentrated so that the B of the fusion layer is 0.2% by weight or more. The electrothermal film fusion method according to the second aspect of the present invention, characterized in that a heat treatment is performed.

(Fourth invention)
The surface of an aluminum nitride ceramic base material containing less than 1% by weight of a rare earth element compound sintering aid in terms of oxide or an aluminum nitride ceramic base material containing no sintering aid contains 0.2% by weight or more of B. When the electrothermal coating made of Si alloy is fused, after the first layer of the electrothermal coating made of Si alloy containing less than 0.2% by weight of B is fused to the base material, An electrothermal coating fusing method characterized in that the concentration treatment is performed so as to be 0.2% by weight or more.

(Fifth invention)
The method of concentration treatment is to fuse at least one layer or a plurality of layers, a Si alloy film on the first layer, and fuse and fuse them to form a fusion layer of the first layer and the stacked layer. Either the third invention or the fourth invention, which is a method of adjusting the B content of the layer so that the B content is 0.2% by weight or more and fusing it. Electrothermal film fusion method.

(Sixth invention)
The Si alloy contains Si as a main component, one or more elements selected from Group A, one or more elements selected from Group B, and elements of Group C. The electrothermal film fusion product according to the first aspect of the present invention, which is an alloy composed of residual impurity components.
Group A elements: Fe, Ni, Co, Zr, Ti, Cr, Mo, W
Group B elements: Hf, Nb, Ta, V, Mn, Cu, Al, Ge
Group C element: B, rare earth element Component range of Group A element: 6 to 65% by weight
Component range of group B elements: 0 to 10% by weight
Component range of group C elements: B ≧ 0.2 wt%, rare earth elements ≧ 0.1 wt%

  The electrothermal film fusion product of the present invention has high adhesion of the electrothermal film fused, has few voids and defects, has little resistance change even when used for heating at 800 ° C. or higher, and is extremely excellent in durability. It is. The electrothermal film fusion product of the present invention is extremely excellent in durability during high-temperature heating even if the sintering aid for the rare earth element compound of the aluminum nitride ceramic substrate is less than 1% by weight or more in terms of oxide. It is.

  When a heater with a Si alloy electrothermal coating fused to an aluminum nitride substrate is heated and heated, the electrothermal coating that does not contain B is heated to the normal temperature after being heated. From the point where the temperature exceeds 400 ° C., the resistance value at normal temperature increases without returning to the original value.

  If the heating temperature at which the normal temperature resistance value does not return to the original value by the first heating is expressed as “limit heating temperature of resistance change” in this specification, the limit heating of resistance change in the electrothermal film not containing B The temperature is 400 ° C., but when B is added to the electrothermal coating, the temperature rises to over 400 ° C. And the higher the B content, the higher this critical heating temperature. In other words, the higher the B content, the less resistance changes even when heated to a higher temperature.

  When heated repeatedly, there is a difference in degree, but the resistance value tends to increase. The higher the B content, the smaller the increase rate. That is, the normal temperature resistance value increases with repeated heating, but the higher the B content, the lower the increase rate and the more the durability as a heater. Therefore, the higher the B content, the better.

When the B content is 0.2% by weight or more, the temperature at which the resistance change starts with the first heating becomes 800 ° C. or more. Therefore, in an electric heater used up to a high temperature of 800 ° C., at least the B content is preferably 0.2% by weight or more.
When the B content is less than 0.2% by weight, the resistance change starts at a temperature of less than 800 ° C. at the first heating, and the rate of increase in the resistance change becomes larger when repeatedly heated. The durability of the heater is inferior.

  The “electrothermal film made of a Si alloy containing 0.2% by weight or more of B” of the present invention is called “an electrothermal film having such a property that the temperature at which the resistance change starts at the first heating is 800 ° C. or higher”. With this “B content of 0.2% by weight or more”, the rare earth element compound sintering aid is less than 1% in terms of oxide and does not contain an aluminum nitride base material or an aluminum nitride ceramic containing no sintering aid. In the base material, there is a problem of poor fusion such that the electrothermal coating is peeled off or easily peeled off.

  If the B content is less than 0.2% by weight, even if the sintering aid of the rare earth element compound is less than 1% in terms of oxide or an aluminum nitride ceramic substrate containing no sintering aid, the fusion is poor. The problem of is less likely to occur or does not occur at all, but because of the low B content, the resistance change starts at a temperature of less than 800 ° C. at the first heating, and when the heating is repeated, the rate of increase in the resistance change is more Since it becomes large, a high-temperature heater that heats to 800 ° C. or more has poor durability.

  Needless to say, the ceramic heater to which the electrothermal coating of the present invention is fused is not limited to a heater that is used at 800 ° C. or higher. Naturally, it can be suitably used even at a temperature of less than 800 ° C., and there are no particular restrictions on its use.

  There are aluminum nitride ceramic base materials that use rare earth element compounds as sintering aids, or those that do not use sintering aids, but according to the present invention, “Si alloy containing 0.2% by weight or more of B”. When the coating consisting of “coating” is applied to the surface of an aluminum nitride substrate, or printed and melted by heating, the fusing property of the coating changes depending on the amount of the sintering aid in the ceramic substrate. The common name “auxiliary-less aluminum nitride” in which the amount of the sintering aid of the compound is less than 1% in terms of oxide and does not use the sintering aid is that the coating does not melt or is fused. If the coated film is peeled off or rubbed, it will be peeled off, resulting in poor fusion.

  The rare earth element compound is fused when the amount of sintering aid is 1% or more in terms of oxide. At that time, the rare earth element is melted into the fusion coating using the rare earth element compound as a sintering aid for the ceramic substrate as a supply source. In other words, despite the fact that no rare earth element is added as a component of the fusion coating, rare earth elements are present in the coating, and even if the sintering aid is an oxide, It does not exist in oxide form.

  The rare earth element contained in the coating is obviously a source of a sintering aid rare earth element compound. And even if the amount of the sintering aid is the same, the amount of the rare earth element that melts out varies depending on conditions such as the temperature during fusion.

  When the amount of the rare earth element dissolved into the fused film is 0.1% by weight or more, the adhesion of the fused film increases, the sintered density of the film increases, the strength of the film increases, The electric resistance value also decreases, and a film suitable as an electrothermal film can be obtained.

  When the coating is fused, a predetermined target value of 0.2% by weight or more on the surface of an aluminum nitride ceramic substrate having a sintering aid content of 1% by weight or more in terms of oxide is obtained. After applying or printing and drying a paste made by mixing a resin binder with Si alloy raw material powder pre-blended with B higher than the target value to evaporate the volatile components of the paste, vacuum When heated and melted above the solidus temperature of the Si alloy raw material powder paste in an inert atmosphere, the melted film is fused to the ceramic substrate.

Film fusion starts at a temperature near the solidus, but fusion occurs near the solidus temperature, but the adhesion strength and sintering density of the film are low, there are many pinholes, and the mechanical strength is weak. The amount of elemental penetration is very small.
As the temperature rises (rather than the solidus temperature), the amount of rare earth element dissolved into the coating increases. The sintered density of the coating also increases, pinholes decrease, and mechanical strength increases.

A practical electrothermal coating can be obtained with a rare earth element penetration of 0.1 wt% or more.
In order to obtain a penetration amount of 0.1% by weight or more, it is necessary to grasp a quantitative relationship between the alloy composition, the temperature, the sintered density, and the penetration amount. More than wt% can be secured.

  It is possible to increase the amount of rare earth elements contained in the fused film by mixing other raw material elements of the rare earth element in advance in the printed film instead of the component that dissolves from the ceramic substrate. When the amount of the rare earth element component that dissolves from the material is less than 0.1 weight, both the sintered density and strength of the film are low, and the electric resistance value of the film is high, and a film suitable as an electrothermal film cannot be obtained. That is, a suitable electrothermal coating cannot be obtained by adding another raw material component of rare earth elements from the outside to increase only the apparent amount of rare earth elements.

The surface of an aluminum nitride ceramic base material containing less than 1% by weight of a rare earth element sintering aid in terms of oxide or 0.2% by weight or more of B is contained on the surface of the aluminum nitride ceramic base material not containing a sintering aid. In order to fuse a Si alloy electrothermal coating film excellent in sintering density and strength and suitable as an electrothermal coating film, the following method is effective. That is,
At the time of fusion, first, a first layer of an electrothermal coating made of a Si alloy containing less than 0.2% by weight of B is fused to a ceramic substrate, and then B of this fusion layer is 0.2. By performing the concentration treatment so as to be at least wt%, an electrothermal coating film having excellent sintered density and strength and containing 0.2 wt% or more of B can be obtained.
This fused film exhibits excellent durability equivalent to that obtained when an aluminum nitride ceramic base material having a sintering aid of a rare earth element compound of 1% by weight or more is used.

After the first layer of the electrothermal coating made of a Si alloy containing less than 0.2% by weight of B is fused in advance, the concentration of B is 0.2% by weight or more. Naturally, the method of performing the crystallization treatment is also effective in the case of an aluminum nitride ceramic substrate containing 1% by weight or more of a sintering aid in terms of oxide.
When applied to an aluminum nitride ceramic base material containing 1% by weight or more of a sintering aid in terms of oxide, it has a significant effect on improving the soundness (such as pinholes) of the fused film.

In the method of concentration treatment of B, at least one layer or a plurality of layers and a Si alloy film are stacked on the first layer and fused and fused to fuse the first layer and the stacked layer. A method of adjusting the B content of the stacked layers and fusing them so that the B content of the layer is 0.2% by weight or more is effective.
The method of fusing multiple layers is not only effective for B concentration but also for improving the soundness (such as pinholes) of the fused film.
In addition, as a method for concentrating B, other commonly used methods such as boron treatment can be used effectively.

The following composition is suitable for the component composition of the fusion alloy of the electrothermal coating of the present invention.
That is, an aluminum nitride ceramic base material containing 1% by weight or more of a sintering aid for the rare earth element compound in terms of oxide is used, and the amount of the rare earth element component eluted from the rare earth element compound of the sintering aid for the ceramic base material. In the group of preconditions, Si as a main component, one or more elements selected from Group A, one or more elements selected from Group B, and Group C An alloy composed of the elements in the above and the remaining impurity components is preferred.
Group A elements: Fe, Ni, Co, Zr, Ti, Cr, Mo, W
Group B elements: Hf, Nb, Ta, V, Mn, Cu, Al, Ge
Group C element: B, rare earth element Component range of Group A element: 6 to 65% by weight
Component range of group B elements: 0 to 10% by weight
Component range of group C element: B ≧ 0.2 wt%, eluted rare earth element ≧ 0.1 wt%

  From the viewpoint of durability, the composition of the fusion alloy of the electrothermal coating of the present invention is most preferably such that the absolute value of the difference in linear expansion coefficient between the electrothermal coating and the aluminum nitride base material is 2.0 × 10 −6 or less. Preferably, the component composition is adjusted so as to be 1.5 × 10 −6 or less. In the range below the lower limit and above the upper limit, the resistance change after high-temperature heating increases and the durability decreases.

As the group A element, one or more elements are selected from the group A.
When the group A element is Fe, Ni, Co, Zr, Ti, or Cr, the component range is preferably 6 to 28% by weight. When the group A element is Mo or W, the component range is preferably 40 to 65% by weight.
If it exceeds the upper limit and less than the lower limit, it deviates from the range of the absolute value of the difference in linear expansion coefficient, and the durability of the heater is shortened.

  The elements of group B are elements that can be optionally added as necessary. An upper limit of 10% may be added. Group C is an essential element.

Rare earth element compounds as sintering aids include rare earth oxides such as Y ₂ O ₃ , Yb ₂ O ₃ , Er ₂ O ₃ , Ce ₂ O ₃ , Ho ₂ O ₃ , other Sc, Y, Er, It is a rare earth element compound containing Yb, Ce, Dy, Ho, Gd, La and the like.
In addition, AlN ceramics applicable to the present invention include alkaline earth metal compounds such as CaO and SrO as components other than the rare earth compounds, alkali metals such as Li ₂ O and SiO ₂ as necessary for reducing the firing temperature. ₂ , silicon compounds such as Si ₃ N ₄ and SiC, metals containing Mo, W, V, Nb, Ta, Ti and the like to achieve blackening, and those containing metal compounds and carbon can also be used.

The examples illustrate the invention.
Example 1 (Confirmation test of relationship between limit heating temperature of resistance change and B content)
Ceramic substrate: An aluminum nitride plate (manufacturer: Tokuyama Corporation) containing 5 wt% Y ₂ O ₃ as a sintering aid was used.
Dimensions of ceramic substrate: 2 inch square x 1 mm thickness
Printing and fusing of electrothermal circuit coatings
A PVP alcohol solution is mixed with the raw material powder of Si alloy to produce a paste for printing. On the surface of the ceramic substrate, the electric heating circuit (circuit width: 5 mm) shown in FIG. 1 is screen-printed and dried. The film was fused to the ceramic substrate by heating in vacuum. The thickness of the fused electrothermal coating was 50 to 70 μm.

Electric heating test After fusion, heat-resistant steel bolts were inserted into holes at both ends of the electric heating circuit, connected to heat-resistant steel lead wires, and AC was applied to the circuit to heat it.
Heating to each temperature in increments of 50 ° C. to 400-850 ° C. for each component composition of the electric circuit film, holding for 1 hour, allowing to cool to room temperature, measuring the electrical resistance value at room temperature, And the heating temperature (temperature in increments of 50 ° C.) at which the resistance change starts was investigated. The heating rate is 200 ° C./hour.

  Table 1 shows the analytical values after fusion of the electrothermal coating and the temperatures at which the room temperature resistance value starts to change after heating to each temperature. The analysis of the electrothermal coating is a wet analysis.

Results As a result of the test, the B content in the electrothermal coating was 0.2 wt% or more, and the onset temperature of the resistance change was 800 ° C. or more.

Example 2 (Test of relationship between amount of sintering aid and fusing property)
Ceramic substrate: As the ceramic substrate, aluminum nitride plates having different types and amounts of sintering aids shown in Table 2 were used.
Dimensions of ceramic substrate: φ60mm x thickness 3mm
Ceramic substrates having different amounts of sintering aids were mixed with a predetermined amount of aluminum nitride powder and rare earth oxide powder, molded in a mold, and then fired in a nitrogen atmosphere by hot pressing.

Printing and fusing of the film A paste for printing was prepared by mixing the PVP alcohol solution with the raw material powder of the Si alloy having the composition shown in Table 2 (type and amount of sintering aid for the ceramic substrate). The entire surface of the ceramic substrate was screen-printed with a solid coating, dried, and heated in a vacuum of 10 ⁻⁵ torr to fuse the coating to the ceramic substrate.
The thickness of the fused electrothermal coating was 60 to 80 μm.

The fusing temperature is 1300 ° C. for numbers 1 to 8, 9 is 1280 ° C., and 11 and 12 are 1320 ° C.
The B amount of the coating was adjusted by adjusting the amount of the B raw material powder blended in the raw material powder paste. The analysis of B and Y elements is a wet analysis.

Film adhesion test A test was performed by applying a gum tape to the film and peeling it off.
The results of the adhesion test are shown in Table 3.

Results From the above results, when a Si alloy film containing 0.2% by weight or more of B was fused to an aluminum nitride ceramic base material using a rare earth element compound (oxide) as a sintering aid, sintering aid was obtained. In the ceramic base material having an agent amount of less than 1%, the coating film was peeled off or partly peeled off.
In the ceramic base material having a sintering aid amount of 1% or more, there was no peeling of the coating, and the rare earth component of the sintering aid was dissolved in the coating by 0.1% or more.

Example 3 (Test of relationship between fusion temperature and leaching amount)
Ceramic substrate: Using an aluminum nitride plate containing 5 wt% of Y ₂ O ₃ as a sintering aid in Example 2, the fusion temperature of Si alloy and the amount of Y dissolved out were examined.

Printing and fusing of film Coated PVP alcohol solution is mixed with paste of Si alloy raw material powder with the fusing composition shown in Table 2 to produce a printing paste. After screen printing and drying, the coating was fused to the ceramic substrate by heating in a vacuum of 10 ^-5 Torr. The thickness of the fused electrothermal coating is 60 to 80 μm.
The results are shown in Table 4 (relationship between the amount of rare earth element dissolved out and the fusing temperature).
The voids in the film were examined with an ultrasonic microscope.

結果
Si−Ni系合金は、１２００℃、１３３０℃、Si−Fe系合金は、１２１０℃、１３１０℃、上下いずれの温度でも被膜は融着したが、融着温度が低い時は、Ｙの溶け出し量が少なく、焼結不足で、ボイドが極めて多い被膜であった。

result
The Si-Ni alloy was 1200 ° C, 1330 ° C, the Si-Fe alloy was 1210 ° C, 1310 ° C, and the film was fused at any of the upper and lower temperatures, but when the fusion temperature was low, Y melted out. It was a coating with a small amount, insufficient sintering, and a very large number of voids.

Example 4
Test of the relationship between the number of processes and the adhesion and soundness of the fused film Ceramic substrate:
An aluminum nitride plate containing no sintering aid (manufacturer: Furukawa Electronics Co., Ltd.) and an aluminum nitride plate containing 5 wt% Y ₂ O ₃ (manufacturer: Tokuyama Corp.) as the sintering aid of Example 1 were used. Then, the adhesion and soundness of the fused electrothermal coating when the fusion process of the Si alloy was divided into two were investigated.

That is, for an aluminum nitride plate not containing a sintering aid and an aluminum nitride plate containing 5 wt% Y ₂ O ₃ as a sintering aid,
In the first step, the first layer of the coating made of the Si alloy containing less than 0.2% by weight of B is fused, and then in the second step, the Si alloy containing more than 0.2% by weight of B. The film was laminated on the first layer and fused and fused to adjust the B content after fusion of the first layer and the second layer to 0.2% by weight or more.
For an aluminum nitride plate containing 5 wt% of Y ₂ O ₃ as a sintering aid, Y of the base material was eluted to 0.1 wt% or more in the electrothermal coating after fusion.
The weight ratio between the first layer and the second layer is 1: 1.

Printing and fusing of the coating The PVP alcohol solution is mixed with the paste of the Si alloy raw material powder of the first layer coating material to produce a printing paste, and the entire surface of the ceramic substrate is coated with a solid surface. After drying, heating in a vacuum of 10 ^-5 Torr to fuse the first layer coating to the ceramic substrate, the second layer coating component Si alloy raw material powder paste is again added to the first layer The entire surface of the film is screen-printed with a solid coating, dried, and heated in a vacuum of 10 ^-5 torr to dissolve the second layer film and fuse the first and second layers into a ceramic substrate. Fused.
The adhesion of the film was examined by peeling off a gum tape applied to the film.
The soundness (void) of the film was examined with an ultrasonic microscope.
The thickness of the fused electrothermal coating is 100 to 120 μm.
Tables 5 and 6 show the results (relationship between the number of steps and the adhesion and soundness of the fused film).
Table 5 shows the results for an aluminum nitride plate containing no sintering aid, and Table 6 shows the results for an aluminum nitride plate containing 5 wt% Y ₂ O ₃ as a sintering aid.

結果
焼結助剤を含まない窒化アルミニウム板でも、密着強度が大で、ボイドの少ない健全皮膜が融着できることを確認できた。

Results Even with an aluminum nitride plate containing no sintering aid, it was confirmed that a sound coating with high adhesion strength and few voids could be fused.

結果
Y₂O₃を５wt％含む窒化アルミニウム板では、融着工程を２回に分け、併せてＹが十分に溶け出した被膜は、密着性良好で、ボイドは極めて少なかった。

result
In the aluminum nitride plate containing 5 wt% of Y ₂ O ₃ , the fusion process was divided into two, and the film in which Y was sufficiently dissolved had good adhesion and extremely few voids.

It can be suitably used for an aluminum nitride planar heating element that heats a semiconductor at a high temperature (800 ° C. or higher), and many demands can be expected for semiconductor heating applications.

FIG. 1 is an explanatory view of an electric heating circuit film of an example.

Claims (6)

Electric heat having a structure in which an electrothermal coating composed of a Si alloy containing 0.2% by weight or more of B is fused to the surface of an aluminum nitride ceramic base material containing 1% by weight or more of a sintering aid for a rare earth element compound. A fusion-bonded body of a film, characterized in that the film contains 0.1% by weight or more of a rare earth element using a rare earth element compound as a source of sintering aid for the ceramic substrate. Electrothermal film fusion product. When an electrothermal coating composed of a Si alloy containing 0.2% by weight or more of B is fused to the surface of an aluminum nitride ceramic substrate, a sintering aid for a rare earth element compound is used as the substrate in an amount of 1% by weight in terms of oxide. An electrothermal coating characterized by using the aluminum nitride ceramic containing the above and eluting a rare earth element component supplying the rare earth element compound of the base material in an amount of 0.1% by weight or more of the coating in the electrothermal coating. Fusion method. When fusing the electrothermal coating to the surface of the aluminum nitride ceramic substrate,
After fusing the first layer of the electrothermal coating made of a Si alloy containing less than 0.2% by weight of B to the substrate, it is concentrated so that the B of the fusion layer is 0.2% by weight or more. The electrothermal film fusion method according to claim 2, wherein the heat treatment is performed. The surface of an aluminum nitride ceramic base material containing less than 1% by weight of a rare earth element compound sintering aid in terms of oxide or an aluminum nitride ceramic base material containing no sintering aid contains 0.2% by weight or more of B. When the electrothermal coating made of Si alloy is fused, after the first layer of the electrothermal coating made of Si alloy containing less than 0.2% by weight of B is fused to the base material, An electrothermal coating fusing method characterized in that the concentration treatment is performed so as to be 0.2% by weight or more. The method of concentration treatment is to fuse at least one layer or a plurality of layers, a Si alloy film on the first layer, and fuse and fuse them to form a fusion layer of the first layer and the stacked layer. The electrothermal coating fusion according to any one of claims 3 to 4, which is a method of adjusting the B content of the layer so as to be fused so that the B content is 0.2 wt% or more. Method. The Si alloy contains Si as a main component, one or more elements selected from Group A, one or more elements selected from Group B, and elements of Group C. 2. The electrothermal film fusion product according to claim 1, wherein the electrothermal film fusion product is an alloy composed of residual impurity components.
Group A elements: Fe, Ni, Co, Zr, Ti, Cr, Mo, W
Group B elements: Hf, Nb, Ta, V, Mn, Cu, Al, Ge
Group C element: B, rare earth element Component range of Group A element: 6 to 65% by weight
Component range of group B elements: 0 to 10% by weight
Component range of group C elements: B ≧ 0.2 wt%, rare earth elements ≧ 0.1 wt%

Images