JP2008239437A - Insulator and insulation joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulator and an insulation joint which can easily prevent creep discharge. <P>SOLUTION: The insulator 1 is provided with an insulative aluminum cylindrical ceramic member (alumina sintered body) 3 for the base material. A metallized layer 5 and a conductive layer 7 are layered in this order on both the ends of the alumina sintered body 3 in the axial direction. The inner and outer circumferences 15 and 17 of the metallized layer 5 in the radial direction (normal to the axial direction) are configured to be exposed from the conductive layer 7 with a width of ≥0.2 mm (e.g. around 0.3 mm) along all the circumferences. The resistivity of the metallized layer 5 is made 1.4 time larger than that of the conductive layer 7. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an insulator and an insulating joint that can be used for, for example, an insulating container, an acceleration tube, an insulating substrate, a terminal, an insulator, and the like, and a voltage is applied between opposing conductors and creeping insulation is required. is there.

  Conventionally, when a metal member is bonded to a ceramic member such as alumina, for example, the surface of the ceramic member is metallized, and the metallized surface is plated or plated with a metal paste layer by brazing or soldering. A method of joining members has been proposed (see Patent Documents 1 and 2).

  In the technique of Patent Document 2 described above, first, a paste of a high melting point metal powder such as molybdenum or tungsten is applied to the surface of the alumina sintered body by screen printing or brush coating, and then metallized in a humidified reducing atmosphere. After firing, in order to facilitate joining such as brazing and soldering, electrolytic or electroless plating of nickel or the like was performed on the baked metallization. And the metal member was joined by brazing, soldering, etc. on the plating layer which improved metal wettability by this.

  As described above, when plating is performed on the metallized layer, the plating is usually deposited and deposited on the entire surface of the exposed metallized layer, so that the conductive portion including the metallized layer (that is, the lamination of the metallized layer and the plated layer). The tip of the body is a plating component.

  However, when an insulator such as ceramic is sandwiched and a voltage is applied between conductive members in contact with each other, creeping discharge may occur on the surface of the insulator, thereby impairing the function as the insulator. This discharge occurs at the point (triple junction) where three different phases of conductor, insulator, and gas overlap.

Therefore, as described above, when the tip of the conductive portion becomes a plating component, there is a problem that this creeping discharge is likely to occur.
As a countermeasure, a technique of applying an insulating material to a brazed joint has been proposed (see Patent Document 3).

In addition to this, a technique has been proposed in which an insulating member and a metal joining member are brazed on an inclined surface (see Patent Document 4).
JP 2001-342080 A JP 2002-231499 A Japanese Patent Laid-Open No. 10-92363 JP 2002-231499 A

  However, in the case of the technique of the cited document 3, since the application of the insulating material is performed after the parts are assembled, it is difficult to apply the insulating material to a necessary place when the assembly structure is complicated. There was a problem.

Moreover, in the technique of the cited reference 4, since it joined on the slope, there existed a problem that the dimensional accuracy of a height direction was low and it was difficult to process.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an insulator and an insulating joint that can be easily processed and can prevent creeping discharge easily.

  (1) According to the invention (insulator) of claim 1 for achieving the above object, at least a pair of metallized layers is deposited on the surface of the same or parallel plane of the insulating ceramic substrate. In the insulator in which a conductive layer is deposited on each metallized layer, the insulator is a bonding member bonded to a metal member via the conductive layer, and the resistivity of the metallized layer Is larger than the resistivity of the conductive layer, and the outer edge of the metallized layer is exposed to the outside of the conductive layer.

  In the present invention, since the insulator is a joining member joined to the metal member on the surface of the same plane or parallel plane via the conductive layer, the dimensional accuracy in the height direction at the time of joining is high. There is an advantage that it is easy to process.

  In particular, in the present invention, the resistivity of the metallized layer of the insulator is larger than the resistivity of the conductive layer, and the outer edge portion of the metallized layer is exposed to the outside of the conductive layer (the outer edge portion thereof). When a high voltage is applied between the conductive layers facing each other with the body sandwiched (or arranged on the same plane), it is possible to suppress the occurrence of creeping discharge between the conductive layers.

  That is, as described above, creeping discharge is likely to occur in a triple junction in which three different phases of a conductor, an insulator, and a gas are overlapped. In the present invention, in order to alleviate charging in such a triple junction. Since the outer edge portion of the metallized layer (having a higher resistivity than the conductive layer) is exposed outside the outer edge portion of the conductive layer, there is an effect that creeping discharge is unlikely to occur between the opposing conductive layers.

  In the present invention, there are a plurality of laminated portions of metallized layers and conductive layers (referred to as junction laminate portions), and it is preferable if all the junction laminate portions are configured as described above, but at least one location (or two opposing locations). ) But it is also effective.

  (2) In the invention of claim 2, the ceramic substrate is in a cylindrical shape or a rod shape, and the insulator is a metal member on the end surface in the axial direction of the ceramic substrate via the conductive layer. It is characterized by being joined.

The present invention exemplifies the configuration of a ceramic substrate or the like.
(3) The invention according to claim 3 is characterized in that the ceramic substrate has a rectangular box shape, and the metallized layer and the conductive layer are formed on the surface (for example, on the same plane).

The present invention exemplifies the configuration of a ceramic substrate or the like.
(4) The invention of claim 4 is characterized in that the ceramic substrate has a flat plate shape, and the metallized layer and the conductive layer are formed on the surface (for example, on the same plane).

The present invention exemplifies the configuration of a ceramic substrate or the like.
(5) The invention of claim 5 is characterized in that the insulator is a joining member joined to a metal member by a molten metal joining material (for example, a brazing material) through the conductive layer.

The present invention exemplifies the use of an insulator, and a metal member can be joined to the insulator using a brazing material or the like.
(6) The invention of claim 6 is characterized in that the resistivity of the metallized layer is 1.4 times or more the resistivity of the conductive layer.

As will be apparent from the experimental examples described later, the present invention has an advantage that the breakdown voltage due to creeping discharge is high because the resistivity of the metallized layer is 1.4 times or more the resistivity of the conductive layer.
(7) In the invention of claim 7, the exposed width of the metallized layer is 0.2 mm or more.

  In the present invention, as will be apparent from the experimental examples described later, since the exposed width of the metallized layer is 0.2 mm or more (preferably 0.3 mm or more), there is an advantage that the breakdown voltage due to creeping discharge is high.

In addition, it is preferable that this exposure width is ensured in all the exposed parts.
(8) The invention of claim 8 is characterized in that the exposed width is an exposed width at a protruding portion of the metallized layer.

  If the metallized layer protrudes outward (in the direction away from the metallized layer along the surface), creeping discharge tends to occur from there. Therefore, it is preferable that the exposed width at least in the protruding portion of the metallized layer is the exposed width described in the seventh aspect, because creeping discharge hardly occurs.

(9) The invention of claim 9 is characterized in that the ceramic is alumina.
The present invention illustrates a ceramic material.
(10) In the invention (insulation joined body) of claim 10, the metal member is formed on the conductor layer of the insulator according to any one of claims 1 to 9 via a molten metal joining material (for example, brazing material). It is characterized by being joined.

The present invention shows an insulating bonded body in which a metal member is bonded to an insulating body.
In addition, examples of the material for the ceramic substrate include alumina, aluminum nitride, silicon nitride, mullite, and the like. Examples of the material for the metallized layer include molybdenum and tungsten. Examples of the material for the conductive layer include nickel, copper, silver, tin, gold, and alloys containing them. Examples of the material for the molten metal bonding material include silver, copper, gold, tin, zinc, aluminum, and alloys containing them. Examples of the metal member include copper, kovar, nickel-iron alloy, stainless steel, aluminum, and iron.

  -Moreover, this invention is applicable to the vacuum switch which has the said insulation joined body. The vacuum switch is an electric circuit switch using an insulating valve made of ceramic, for example, and is particularly suitable for high voltage and large current switching.

Furthermore, the present invention can be applied to a vacuum container (for example, an insulating valve) having the insulating joined body. A vacuum switch (electric circuit switch) can be formed by arranging an electrode or the like in the vacuum vessel.

Next, an example (example) of the best mode of the insulator and the insulating joined body of the present invention will be described. Example 1
a) First, the structure of the insulator of the present embodiment will be described.

  As schematically shown in FIG. 1, the insulator 1 of this embodiment includes a cylindrical ceramic substrate (alumina sintered body) 3 having an insulating property, and the axial direction of the alumina sintered body 3. As shown in FIG. 2, the metallized layer 5 and the conductive layer 7 are sequentially laminated on the surfaces of both ends. The laminated portion of the metallized layer 5 and the conductive layer 7 is referred to as a bonded laminated portion 8.

  Specifically, the alumina sintered body 3 is a cylindrical member having an inner diameter of 50 mm, an outer diameter of 60 mm, and a length of 90 mm, for example. A ring-shaped convex portion 9 having a width of 4 mm is formed.

In addition, the inner and outer corners of both ends are tapered (taper angle of about 45 °) so as to form a slope, thereby forming a ring-shaped inner tapered portion 11 and an outer tapered portion 13.
The metallized layer 5 is made of, for example, a molybdenum paste baking layer and covers the entire surface of the convex portion 9 and also covers a part of the inner tapered portion 11 and the outer tapered portion 13. Specifically, the metallized layer 5 is formed so as to cover the convex portion 9 side of the inner tapered portion 11 and the outer tapered portion 13 with a width of about 4/5 of the width of each tapered portion 11, 13.

Further, the conductive layer 7 is made of, for example, a nickel paste baking layer, and is formed in a ring shape so as to cover the central portion of the metallized layer 5.
In particular, in this embodiment, inner and outer outer edge portions 15 and 17 in the radial direction (direction perpendicular to the axial direction) of the metallized layer 5 are 0.2 mm or more in width from the conductive layer 7 over the entire circumference (for example, 0 (About 3 mm) so as to be exposed.

Further, the resistivity of the metallized layer 5 is set to be 1.4 times larger than the resistivity of the conductive layer 7. For example, the resistivity of the metallized layer is set to 192 × 10 ⁻⁸ Ωm, and the resistivity of the conductive layer is set to 120 × 10 ⁻⁸ Ωm.

Note that, for example, a metal member 31 (see FIG. 4), which will be described later, is joined to both end faces 10 (end faces perpendicular to the axial direction) 10 facing each other in the axial direction of the insulator 1 through the conductive layer 7.
b) Next, the manufacturing method of the insulator 1 of a present Example is demonstrated.

First, alumina powder was press-molded to produce a cylindrical body (cylindrical member).
Next, this cylindrical body was baked at about 1600 ° C. in the atmosphere to obtain an alumina sintered body 3 having an outer diameter of 60 mm × an inner diameter of 50 mm × a height of 90 mm.

The inner and outer corners of both ends of the alumina sintered body 3 are chamfered with a taper angle of about 45 °, for example.
Next, the 1st paste which has a refractory metal as a main component was apply | coated to the surface of the both ends of the axial direction of this cylindrical alumina sintered compact 3. FIG. Specifically, the first paste was applied so as to cover the entire surface of the protruding portions at both ends and to cover 2/3 of the chamfered portions (inner tapered portion 11 and outer tapered portion 13) on the inner side and outer side of the protruding portion.

  In addition, this 1st paste prepares a mixture using Mo powder and Mn powder, pulverizes and mixes the powder (for example, 87 mass%) of this mixture, and mixes with organic binders (for example, 13 mass%), such as ethyl cellulose. Manufactured.

Next, the alumina sintered body 3 to which the first paste was applied was fired at about 1400 ° C. in a humidified and reduced atmosphere (H ₂ + N ₂ ). Thereby, the metallized layer 5 was formed in a ring shape at both ends of the alumina sintered body 3.

  Next, a second paste mainly composed of nickel powder was applied onto the baked metallized layer 5. At this time, the second paste was applied so that the inner and outer outer edge portions 15 and 17 of the metallized layer 5 were exposed to a width of 0.2 mm or more over the entire circumference.

The second paste was produced by pulverizing and mixing Ni powder together with a binder.
Next, the alumina sintered body 3 coated with the second paste was fired at about 1000 ° C. in a reducing atmosphere. As a result, the ring-shaped conductive layer 7 having a width of 0.2 mm or more narrower than the outer edges 15 and 17 on the inner and outer sides of the metallized layer 5 was formed on the ring-shaped metallized layer 5. The conductive layer 7 may be formed by nickel plating.

The insulator 1 in which the metallized layer 5 and the conductive layer 7 were laminated and deposited on both ends of the alumina sintered body 3 was manufactured by the manufacturing method described above.
Thus, in this example, the resistivity of the metallized layer 5 is larger than the resistivity of the conductive layer 7 and the outer edge portion of the metallized layer 5 is exposed outside the outer edge portion of the conductive layer 7. There is an advantage that the effect of suppressing the occurrence of creeping discharge is high.
(Example 2)
Next, the second embodiment will be described. The insulator of the second embodiment is different from the first embodiment in its manufacturing method, and different points will be described.

  a) In the insulator manufacturing method of the present example, first, a first high-melting point metal having a small amount of nickel added as a lower layer to be a metallized layer at both ends of the alumina sintered body of Example 1 is the first. The paste was applied.

The first paste was manufactured by mixing molybdenum powder, tungsten powder, and nickel powder and mixing with a binder such as ethyl cellulose.
Next, as an upper layer to be a conductive layer, a second paste made of an alloy powder mainly composed of nickel and copper was applied on a lower layer made of the first paste.

The second paste was produced by pulverizing and mixing nickel-copper alloy powder with a binder.
Also during the application of the second paste, as in Example 1, the inner and outer outer edges of the lower layer were exposed with a predetermined width (for example, 0.3 mm) from the upper layer.

Next, the alumina sintered body having the upper layer laminated on the lower layer was heated in a reducing atmosphere at about 1140 ° C., and the upper and lower layers were simultaneously fired.
As a result, an electrically conductive layer was laminated on the metallized layer at both ends of the alumina sintered body, and an insulator in which the inner and outer outer edges of the metallized layer were exposed with a width of, for example, 0.3 mm was obtained. . As a comparative example, an insulator with no exposure was also produced.

In this example, the resistivity of the metallized layer (made of nickel-containing refractory metal) is 175 × 10 ⁻⁸ Ωm, and the resistivity of the conductive layer (made of nickel alloy) is 123 × 10 ^−8. Ωm.

  Then, when the voltage at which creeping discharge occurs was measured under the same experimental conditions as those of Experimental Example 2 to be described later, the insulator of Example 2 generates a discharge at about 59 kV (56 to 61 kV). In the example insulator, discharge occurred at about 49 kV (47-53 kV).

As is clear from this result, the insulator of Example 2 is preferable because of its high ability to suppress creeping discharge.
That is, also in this example, the resistivity of the metallized layer is larger than the resistivity of the conductive layer, and the outer edge of the metallized layer is exposed to the outside of the outer edge of the conductive layer. There is an advantage that the suppression effect is high.
(Example 3)
Next, the third embodiment will be described, but the description of the same parts as the first and second embodiments will be omitted.

The present embodiment is an insulating bonded body in which a metal member is bonded to an insulating body as in the first embodiment with a brazing material.
As shown in FIG. 4, the insulating joined body 21 is the same as the first embodiment, ie, an insulator 23 (that is, a laminate of a metallized layer 27 and a conductive layer 29 on the surface of the end portion in the axial direction of the alumina sintered body 25. ), And a metal member 31 made of, for example, Kovar is joined to an end face (end face perpendicular to the axial direction) 24 of the insulator 23 by a brazing material 33. The metallized layer 27, the conductive layer 29, and the brazing material 33 that contribute to bonding are referred to as a bonding portion 34.

  The brazing material 33 extends from the outer periphery on the lower end side of the metal member 31 so as to cover the surface of the conductive layer 29, but on the surfaces of the outer edge portions 35 and 37 exposed on the inner side and the outer side of the conductive layer 29. It has not spread.

Therefore, the present embodiment also has an advantage that the ability to suppress creeping discharge is high as in the first and second embodiments.
Example 4
Next, Example 4 will be described, but the description of the same parts as Example 3 will be omitted.

  The present embodiment is a vacuum switch using an insulator joined body as in the third embodiment. That is, the vacuum switch according to the present embodiment is a high load switch that is suitable for switching a high voltage and a large current by incorporating an electrode or the like in a vacuum vessel.

Specifically, as shown in FIG. 5A, the vacuum load switch 41 includes a cylindrical alumina sintered body 43 that forms an outer tube, and the alumina sintered body 43 is made of metal. A cylindrical arc shield member 45 is disposed. The outer peripheral surface of the alumina sintered body 43 is covered with a glaze layer (not shown).

  Further, the alumina sintered body 43 is provided with a pair of shielding members 47 and 49 each having a disk lid shape for shielding each end side, and a switch shielding space 51 is formed therein. Thus, the fixed electrode 51 and the movable electrode 53 are arranged so as to be surrounded by the arc shield member 45.

  Further, as shown in an enlarged view in FIG. 5B, the shielding members 47 and 49 are cylindrical metal members (joined to an end portion in the axial direction of the alumina sintered body 43 by an edge seal structure). It is provided so as to close the ends of 55 and 57. Further, the metal members 55 and 57 are butt-joined to the end portion of the alumina sintered body 43 through a brazing material 59 in the form of an edge seal.

  That is, also in the present embodiment, the same metallized layer and conductive layer (not shown) as in the first embodiment are formed on the surface of the end portion of the alumina sintered body 43. When the material 55 is joined, the alumina sintered body 43 and the metal members 55 and 57 are joined.

The metal members 55 and 57 and the shielding members 47 and 49 are also joined by a brazing material (not shown).
Therefore, the present embodiment also has an advantage that the ability to suppress creeping discharge is high as in the first to third embodiments.
(Example 5)
Next, although Example 5 is demonstrated, description of the location similar to the said Example 1 is abbreviate | omitted.

The present embodiment relates to a sealed contact device which is a rectangular box-shaped insulating joined body.
As shown in FIG. 6, this sealed contact device 61 is made of a copper alloy contact member 65, 67 or 42 alloy made of brazing material on a ceramic sealed container 63 which is a rectangular box-shaped alumina insulator. A metal member such as a flange 69 made of metal is joined.

  In the present embodiment, as shown in FIG. 7, the upper surface of the ceramic sealing container 63 and the contact members 65 and 67 are joined at the joining portions 71 and 73 (in FIG. The annular metallized layers 75 and 77 at the joints 71 and 73 are shown). Further, the lower end surface of the side surface of the ceramic sealing container 63 and the flange 69 are joined by a similar joint 79 having a square frame shape.

Here, the configuration of the joint 71 is shown in FIG. The other joints 73 and 79 have the same configuration.
As shown in the figure, in the joint portion 71, a metallized layer 75 (with the outer edge portion 82 exposed) is formed on the surface of the convex portion 81 of the ceramic sealing container 63, as in the first embodiment. At the same time, a conductive layer 83 is laminated thereon, and a contact member 65 is further joined thereto by a brazing material 85.

Therefore, the present embodiment also has an advantage that the ability to suppress creeping discharge is high as in the first embodiment.
(Example 6)
Next, although Example 6 is demonstrated, description of the location similar to the said Example 1 is abbreviate | omitted.

The present embodiment relates to a flat plate-shaped insulating joined body.
As shown in FIG. 10, the insulating bonded body 91 includes a plurality of elements (metal members) 95 to 99 bonded to one surface of a plate-shaped alumina ceramic substrate 93 by a brazing material. A heat sink (metal member) 101 is bonded to the surface.

  In the present embodiment, the elements 95 to 99 and the heat sink 101 are joined at joints 103 to 109, respectively (in FIG. 11, rectangular metallized layers 111 to 115 at the joints 103 to 107 are shown. )

Here, the configuration of the joint 103 is shown in FIG. In addition, the other junction parts 105-109 are also the same structure.
As shown in the figure, the joint 103 is formed with a metallized layer 111 (exposing the outer edge 110) on the surface of the convex portion 81 of the ceramic substrate 93, as in the first embodiment. A conductive layer 117 is laminated thereon, and further, an element 95 is joined thereto by a brazing material 119.

Therefore, the present embodiment also has an advantage that the ability to suppress creeping discharge is high as in the first embodiment.
<Experimental example 1>
Next, Experimental Example 1 will be described.

  In this Experimental Example 1, a plate-like test piece was prepared as an insulator, and the resistivity of the metallized layer and the conductive layer was measured. A test piece is prepared as a representative sample of each metallized layer and conductive layer.

Specifically, in this Experimental Example 1, a first paste to be a metallized layer was applied on a fired alumina substrate (width 1 mm × length 25 mm × thickness about 15 μm), and firing conditions suitable for each paste were achieved. 4 types of test pieces (samples No. 1 to 3, 7 to 9, No. 4 to 6, 10 to 12, No. 13 to 15 and No. 16 to 18) Created. Sample Nos. 1 to 3,
The composition (mass ratio) of the metal components 7 to 9 is Mo: Mn = 93: 7, the composition of the metal components No. 13 to 15 is Mo: Ni = 97: 3, The composition of the 18 metal components is
Mo: W: Ni = 65: 32: 3.

  And resistance was measured with the contact-type resistance meter (distance 20mm between terminals) with respect to the metallization layer of this test piece. Moreover, the dimension of the metallization layer was measured using the tool microscope, and the thickness of the metallization layer was measured using the fluorescent X-ray film thickness meter.

Furthermore, the resistivity was calculated from the measurement results described above using the following formula (1).
Resistance value = (length / (width × thickness)) × resistivity (1)
The results are shown in Table 1 below.

Similarly, test pieces (two types of sample Nos. 7 to 12 and Nos. 13 to 18) of the conductive layer were prepared using the second paste, and the same measurement was performed. The results are also shown in Table 1 below. In addition, the composition (mass ratio) of the metal component of sample No. 13-18 is Ni: Cu = 43: 57.

For the test pieces of Sample Nos. 1 to 6, the conductive layer was formed by plating. In this case, after plating on stainless steel (SUS), the plating film was peeled off and embedded in resin. A test piece of × 20 mm × about 0.15 mm was prepared. And the measurement similar to the above was performed with respect to the test piece. The results are also shown in Table 1 below.

<Experimental example 2>
Next, Experimental Example 2 will be described. In Experimental Example 2, a cylindrical test piece was created as an insulator, and the creeping breakdown voltage was measured.

  In this experimental example 2, first, an alumina cylindrical fired body was produced by a known method (outer diameter 60 mm × inner diameter 50 mm × height 90 mm). Next, using the materials shown in Table 1 below on the surfaces of both ends of the cylindrical fired body, the metallized layer and the conductive layer were formed by the method described in Examples 1 and 2 so that the exposed width shown in Table 1 was obtained. To form a test piece.

  Then, as shown in FIG. 3, an alternating voltage (60 Hz, boosting speed: about 5 kV / sec) is applied to the conductive layers at both ends of the test piece in the atmosphere, and a short-circuit voltage (creeping breakdown voltage) at that time is applied. ) Was measured. This measurement was performed three times.

  The results are shown in Table 1 below.

The unit of resistivity in Table 1 is (× 10 ⁻⁸ ) Ωm, and the resistivity ratio is “resistivity of metallized layer / resistivity of conductive layer”. In addition, ◎ of the judgment indicates that it exceeds 60 kV even once,
The symbol “◯” represents a value exceeding 55 kV and 60 kV or less, “Δ” represents a value exceeding 52 kV and 55 kV or less, and “x” represents 52 kV or less. Further, Sample Nos. 1, 4, 7, 10, 13, and 16 are comparative examples, and Sample Nos. 2, 3, 5, and 6 are obtained by adjusting the exposed width of the conductive layer using masking.

As is apparent from Table 1, it can be seen that a device having a predetermined resistivity and an exposure width as in the present invention has a high creepage breakdown voltage and is suitable.
Of the samples of the experimental examples in Table 1, Nos. 7 to 12 correspond to Example 1 (an example in which the upper layer and the lower layer are sequentially fired), and Samples Nos. 1 to 6 are variations thereof. (Example in which the upper layer is formed by plating), and sample Nos. 13 to 18 correspond to Example 2 (example in which the upper layer and the lower layer are fired simultaneously).

Needless to say, the present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the scope of the present invention.
For example, the present invention can be applied to a rod-shaped insulator in addition to a cylindrical insulator.

1 is a perspective view showing an insulator of Example 1. FIG. It is explanatory drawing which fractures | ruptures and expands the insulator of Example 1 to an axial direction. It is explanatory drawing which shows the measuring method of the creeping fracture strength by Experimental example 2. FIG. It is explanatory drawing which shows the cross section of the insulation joined body of Example 3. FIG. (A) is explanatory drawing which fractures | ruptures and shows the vacuum switch of Example 4, (B) is explanatory drawing which expands and shows the principal part. It is a perspective view which shows the contact sealing device of Example 5. FIG. It is explanatory drawing which shows typically the AA end surface of Example 5. FIG. 6 is a perspective view showing a ceramic sealing container in Example 5. FIG. It is explanatory drawing which shows the cross section of the junction part in Example 5 typically. It is explanatory drawing which shows the cross section of the flat-shaped insulation joined body of Example 6. FIG. 10 is a perspective view showing a ceramic substrate in Example 6. FIG. It is explanatory drawing which shows typically the cross section of the junction part in Example 6. FIG. It is explanatory drawing shown.

Explanation of symbols

1, 23 ... Insulators 3, 25, 43 ... Ceramic substrate (alumina sintered body)
5, 27, 75, 77, 111, 113, 115 ... metallized layers 7, 29, 83, 117 ... conductive layers 10, 24 ... end faces 15, 17, 82, 110 ... (in the axial direction of the insulator) 91 ... Insulating bonded bodies 31, 55, 57 ... Metal members 33, 55, 85, 119 ... Brazing material 61 ... Contact sealing device 63 ... Ceramic sealing container 93 ... Ceramic substrate

Claims (10)

In an insulator in which at least a pair of metallized layers are deposited on the same or parallel surfaces of a ceramic substrate having insulating properties, and a conductive layer is deposited on each of the metallized layers,
The insulator is a joining member joined to a metal member via the conductive layer,
An insulator, wherein the resistivity of the metallized layer is larger than the resistivity of the conductive layer, and an outer edge portion of the metallized layer is exposed to the outside of the conductive layer.   The ceramic base is cylindrical or rod-shaped, and the insulator is bonded to a metal member at an end face in the axial direction of the ceramic base via the conductive layer. The insulator according to 1.   The insulator according to claim 1, wherein the ceramic substrate has a rectangular box shape, and the metallized layer and the conductive layer are formed on a surface thereof.   The insulator according to claim 1, wherein the ceramic substrate has a flat plate shape, and the metallized layer and the conductive layer are formed on a surface thereof.   The insulator according to any one of claims 1 to 4, wherein the insulator is a bonding member bonded to a metal member by a molten metal bonding material via the conductive layer.   The insulator according to any one of claims 1 to 5, wherein a resistivity of the metallized layer is 1.4 times or more of a resistivity of the conductive layer.   The insulator according to any one of claims 1 to 6, wherein an exposed width of the metallized layer is 0.2 mm or more.   The insulator according to claim 7, wherein the exposed width is an exposed width at a protruding portion of the metallized layer.   The insulator according to any one of claims 1 to 8, wherein the ceramic is alumina.   An insulating joined body, wherein a metal member is joined to the conductor layer of the insulator according to any one of claims 1 to 9 via a molten metal joining material.

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