JPH0845708A - Laminating method of voltage non-linear resistor - Google Patents

Abstract

PURPOSE:To provide a laminating method capable of enhancing the bonding properties of a terminal metal, ZnO element and between ZnO elements while decreasing the rate of destruction in discharge breakdown strength test, etc., as well as cutting down the assembling cost. CONSTITUTION:A laminating method by insertion fixing metallic rings 7 or metallic spacers using epoxy base conductive bonding agent 6 containing Ag particles interposed between (ZnO element abd ZnO element) and between (ZnO element abd terminal metal) is provided. As for the metallic rings 7, aluminum or stainless steel having a pressure relieving port is used while as for the metallic spacers, aluminum or stainless steel provided with margin for bonding agent having the pressure relieving port is used. Furthermore, after coating the ZnO element with a conductive bonding agent, the metallic rings or the metallic spacers are laminated with the other ZnO element and the terminal metal 5 and then junction-fixed under pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a method of laminating a voltage non-linear resistor incorporated in a zinc oxide type arrester.

[0002]

2. Description of the Related Art A voltage non-linear type resistor whose main component is zinc oxide (hereinafter abbreviated as ZnO) is bismuth oxide (Bi ₂ O ₃ ) or antimony oxide (Sb) as an additive component to ZnO.
₂ O ₃ ), cobalt oxide (Co ₂ O ₃ ), chromium oxide (Cr
₂ O ₃ ), silicon oxide (SiO ₂ ), manganese oxide (Mn
O ₂ ), nickel oxide (NiO), and other metal oxides are pulverized to obtain a composition composition having high non-linearity and small heat loss.

Usually, these auxiliary additives are fluidized by being preliminarily ground with ZnO in a ball mill or the like, mixed with an organic binder solution such as polyvinyl alcohol (PVA), and spray-dried with a spray dryer. Highly granulated powder is used as a raw material, and the raw material is molded into a substantially cylindrical shape by a mold press and degreased, followed by firing at 1000 to 1300 ° C. for several hours. Then, a sintered body of the ZnO element 1 shown in FIG. 3 is obtained, the side surface insulating material 2 of low melting point glass is applied to the side surface of the ZnO element 1 and baked and fixed, and further, both the front and back surfaces are sufficiently flat. After polishing, aluminum sprayed electrode layers 3 and 3 (also referred to as terminal metal) are formed.

When the above ZnO element 1 is incorporated in a lightning arrester, the above-mentioned number of Z
The nO element 1 is laminated, fixed using a supporting plate or a spring, and the periphery is surrounded by an insulating porcelain tube to complete the process.

The ZnO element 1 has a large voltage non-linearity, has a composition composition with a small heat loss, and has a large volume and a large diameter size because it can absorb a large amount of energy as compared with a general surge absorber for weak electricity. is required. The aluminum sprayed electrodes 3, 3 have a role of a surge energy collector in the large-diameter sintered body.

[0006]

However, such a conventional voltage non-linear type resistor containing zinc oxide as a main component has a high degree of adhesion between ZnO elements 1 and the thermal spraying of aluminum formed on both end surfaces. The adhesion between the electrode layers 3 and 3 and the ZnO element 1 made of a sintered body is not always good, and there is a possibility of causing malfunction due to peeling of the adhered portion. In particular, if the adhesion between the sprayed electrode layers 3 and 3 and the sintered body is poor, the switching surge withstand capability will decrease,
The ZnO element 1 has a drawback that it may be destroyed even by surge energy below the limit value.

In addition, when a plurality of ZnO elements 1 are laminated and fixed, the supporting rods and the like must be used, so that the installation area of the storage capacity increases due to the increase in the diameter of the porcelain insulator. However, there is a problem that the assembling operation also becomes complicated and the cost is increased.

On the other hand, when designing and manufacturing a mold type lightning arrester made of an organic polymer material such as rubber or resin, it is required to integrate the current limiting element unit. In order to meet such a demand, a means for joining (stacking) the columnar ZnO element 1 by soldering or brazing can be considered, but in the case of an aluminum electrode, soldering and brazing are impossible. . Further, a means of using a copper sprayed electrode instead of the aluminum sprayed electrode can be considered, but the means of spraying copper has a disadvantage that it is disadvantageous in terms of cost.

Further, under the present circumstances, the bonding between the sprayed metal and the ZnO element 1 is required to have a mechanical bonding strength or a bonding holding ability by applying an impulse, and when bonding with a brazing material or the like, the ZnO element 1 is originally formed depending on manufacturing conditions. The voltage-current non-linear characteristic which it has may fall.

Therefore, the present invention solves such conventional problems and enhances the adhesion between the terminal metal, which is the aluminum spray electrode, and the ZnO element composed of the sintered body, and the mutual adhesion between the ZnO elements. The purpose of the present invention is to provide a method for laminating a voltage non-linear resistor that can reduce the destruction rate in a discharge withstand voltage test and reduce the installation area of the storage capacity to reduce the cost at the time of assembly. To do.

[0011]

In order to achieve the above object, the present invention is a slurry obtained by adding a pulverized product of a metal oxide as a secondary additive component to zinc oxide and mixing it with an organic binder solution. Fill the slurry tank with the above raw materials, send the above raw materials to the spray dryer and spray dry, measure a certain amount of the obtained high fluidity granulated powder, mold with a mold press, degrease To form a low-melting-point glass-based high resistance layer on the side surface of the obtained ZnO element, and polish both surfaces of the sintered body, and then spray a terminal metal to form a resistor element. In the method for laminating a voltage non-linear type resistor, the obtained "ZnO
A method of laminating voltage non-linear resistors in which a metal ring or a metal spacer is inserted and fixed by interposing an epoxy conductive adhesive containing Ag powder between “element-ZnO element” and “ZnO element-terminal metal”. provide.

The metal ring is made of aluminum or stainless steel having a pressure relief port, and the metal spacer is made of aluminum or stainless steel provided with an adhesive silo having a pressure relief port.

Further, there is provided a laminating method in which a conductive adhesive is applied on a ZnO element, and then a metal ring or a metal spacer is laminated on another ZnO element and a terminal metal, and they are joined and fixed under pressure.

[0014]

According to such a method of laminating voltage non-linear resistors, the "ZnO element-ZnO element" and "ZnO element-
By inserting and fixing a metal ring or metal spacer with a conductive adhesive on the joint surface of `` terminal metal '', the jointing ability becomes larger than before, and especially when comparing the metal ring and the metal spacer, The result of the 4/10 μs discharge withstand voltage test is good when the metal spacer is adopted.

A pressure release port is provided as the metal spacer,
Moreover, it is suitable that the thickness T ₂ of the adhesive silo is 0.5 ≦ T ₂ ≦ 1.0 mm, and the amount of the conductive adhesive used is W / D ² ≧ 0.05 per joint surface. . The shape of the metal spacer 8 may be [R ₁ /D]≧0.85 and 0.5 ≦ [R ₂ /D]≦0.85.

Aluminum and stainless steel are preferable as the material of the metal part to be inserted and fixed, and in particular, "ZnO element-Zn"
Good results are obtained by inserting and fixing a metal spacer between the "O element" and the conductive adhesive, and inserting and fixing a metal ring between the "ZnO element and the terminal metal" with a conductive adhesive. .

[0017]

EXAMPLES Specific examples of a method of laminating a voltage non-linear resistor according to the present invention will be described below. First, in a binder solution in which polyvinyl alcohol (PVA) as a binder and cation MA as a dispersant are dissolved in predetermined amounts, ZnO as a main raw material and bismuth oxide as a secondary addition component, respectively,
Add and pulverize mixed and pulverized metal oxides such as antimony oxide, cobalt oxide, chromium oxide, silicon oxide, manganese oxide and nickel oxide, and emulsify and mix with Dispermill to sufficiently defoam the resulting raw material slurry. Then, spray drying was performed using a spray dryer to obtain a granulated powder having good fluidity.

Next, a predetermined amount of the above-mentioned granulated powder was weighed based on an automatic system and was molded with a dry press die. The outer shape of the molded body at this time was φ40-t30, and the molding pressure was 350 (kgf / cm ² ). The obtained molded body is calcined at 700 to 1000 ° C. for about 2 hours to obtain Z
An nO element was obtained.

Next, zinc oxide, bismuth oxide, antimony oxide, and silicon dioxide are mixed in a predetermined ratio to form a lateral high-resistance layer and made into a paste with an organic binder by a ball mill or the like, and the paste is sprayed by means. It was applied to the side surface of the calcined body and baked at a temperature of 1000 to 1300 ° C. for about 10 hours. Then, both end surfaces of the obtained sintered body were polished to a size of φ32-t20.

In this example, "Zn obtained as described above was used.
"O element-ZnO element" and "ZnO element-terminal metal"
It is characterized in that a metal ring or a metal spacer is inserted and fixed with an epoxy conductive adhesive containing Ag powder interposed therebetween.

FIGS. 1A, 1B and 1C show a first embodiment of the present invention. In this example, two ZnO elements 1 and two terminal metals 5 are prepared, and this "ZnO element" is prepared. Metal rings 7, 7, 7 are inserted and fixed between the element 1-ZnO element 1 "and between the" ZnO element 1-terminal metal 5 "with an epoxy-based conductive adhesive 6 containing Ag powder interposed therebetween. .

FIGS. 2A, 2B and 2C show a second embodiment of the present invention, in which two ZnO elements 1 and two terminal metals 5 are prepared in the same manner as in the above example. "ZnO element 1-Z
A metal spacer 8 is inserted and fixed between the "nO element 1" through an epoxy conductive adhesive 6 containing Ag powder.
Further, an epoxy-based conductive adhesive 6 containing Ag powder is interposed between the "ZnO element 1-terminal metal 5" and a metal ring 7,
7 is inserted and fixed. That is, the second embodiment is an example using both the metal ring 7 and the metal spacer 8.

The material of the metal ring 7 and the metal spacer 8 is aluminum or stainless steel.
This metal spacer 8 is provided with an adhesive white having a pressure relief port (thickness T _{2 in} FIG. ₂ ) or is used in combination with a metal ring 7 having a pressure relief port. As the terminal metals 5 and 5,
SUS304, brass, aluminum, iron-nickel-cobalt alloy (hereinafter referred to as KOVAR) was used.

As shown in FIGS. 1 and 2, the operation of joining and fixing the respective members is carried out by applying Wg of the conductive adhesive 6 on the ZnO element 1 and then applying the metal ring 7 or the metal spacer 8 and another Z
The nO element 1 and the terminal metal 5 are laminated in the illustrated state, and 1
A pressure of 0 (kg / cm ² ) was applied. In addition, as the epoxy conductive adhesive 6 containing Ag powder, Ecobond 83C
-1 (manufactured by Grace Japan Co., Ltd.), the conductive adhesive 6 has a curing temperature of 155 to 165 ° C. and a curing time of 1 to 3.
It was time.

Table 1 summarizes the parts material, the amount of adhesive used, and the shape of the inserted parts for the ZnO element unit samples Nos. 1 to 20 according to this example.

[0026]

[Table 1]

The materials of parts in Table 1 are two kinds, aluminum and stainless steel (SUS304), and the amount of adhesive used is a columnar shape with the weight of the epoxy conductive adhesive 6 being Wg. The diameter of the ZnO element 1 is represented by W / D ² (g / cm ² ). Further, the shape of the insertion part means that the thickness of the metal ring 7 is T ₁ , the outer diameter length is D ₁ , the inner diameter length is D ₂ , the adhesive spacer thickness of the metal spacer 8 is T ₂ , and the outer diameter length is R _1. , The inner diameter length is R ₂ , and [D ₁ / D] [D ₂ / D] [T ₁ ] [R ₁ / D] [R ₂ /
D] [T ₂ ].

Completed ZnO element unit sample No.
For 1 to 20, a 4 / 10-μs discharge withstand voltage peeling test was performed. The peeling test was a cumulative test with discharge currents of 50 kA, 60 kA, and 70 kA for 10 of each manufactured sample, and the NG rate (%) was obtained. Incidentally, at a current value of 70 kA, there is one in which the ZnO element 1 itself undergoes a surface flashover breakdown,
The peeling of the bonded surface and the breakage of the device were counted.
The test results are shown in Table 2.

[0029]

[Table 2]

The following can be considered from Tables 1 and 2.
Sample No. 2 (adhesive only), sample No. 4 (metal ring 7 inserted and fixed), sample No. 9 (metal spacer 8)
According to the comparison of (insertion and fixation), the sample in which the metal part is inserted in the joint surface has a superior bonding ability as compared with the sample in which the adhesive is fixed alone. Further, when the metal ring 7 and the metal spacer 8 are compared, the metal spacer 8 is adopted and “Zn
The result of the 4/10 μs discharge withstand voltage test of the one in which the "O element 1-ZnO element 1" and the "ZnO element 1-terminal metal 5" are metal-bonded is good.

Further, sample Nos. 7, 8, 9, 10, 1
Comparing Nos. 1 and 12 (in each case, the metal spacer 8 is inserted and fixed), it is preferable that the thickness T ₂ of the adhesive silo having a pressure release port as the metal spacer 8 is 0.5 mm or more. However since the necessary amount of the conductive adhesive 6 becomes thicker the thickness T ₂ is expensive to increase, the thickness T ₂ of the adhesive Shiloh,
0.5 ≦ T ₂ ≦ 1.0 mm is suitable. The amount of conductive adhesive 6 used is W / D ² ≧ 0.05 per joint surface.
Is required.

Sample Nos. 9, 13, 14, 15,
By comparing 16 and 17 (the metal spacer 8 is inserted and fixed in both cases), the shape of the metal spacer 8 to be used is [R ₁ /
D] ≧ 0.85 and 0.5 ≦ [R ₂ / D] ≦
It is preferably 0.85. It is structurally undesirable that the outer diameters of the metal ring 7 and the metal spacer 8 are larger than the outer diameter of the ZnO element 1.

Sample Nos. 2 and 3 (without insert), 18
(Metal spacer 8 is inserted and fixed) and 19, 20 (Metal spacer 8 and metal ring 7 are inserted and fixed), aluminum and stainless steel are preferable as the material of the metal component to be inserted and fixed, and particularly, the second embodiment of the present invention. The metal adhesive 8 is inserted and fixed between the "ZnO element 1-ZnO element 1" with the conductive adhesive 6 interposed therebetween, and the conductive adhesive 6 is interposed between the "ZnO element 1-terminal metal 5". It is understood that the use of both the metal ring 7 and the metal spacer 8 in which the metal ring 7 is inserted and fixed gives good results.

From the above results, in this example, an epoxy-based conductive adhesive containing Ag powder was interposed between the obtained "ZnO element-ZnO element" and "ZnO element-terminal metal", and pressure was applied. A voltage non-linearity in which a metal ring made of aluminum or stainless steel with a metal ring with a vent or an adhesive siro with a pressure vent has been inserted and fixed, and the ZnO element and terminal metal have been laminated and then joined and fixed under pressure. A method of laminating type resistors is provided.

[0035]

As described above in detail, according to the method of laminating a voltage non-linear resistor according to the present invention, "ZnO
The bonding ability is increased by inserting and fixing a metal ring or a metal spacer with a conductive adhesive interposed between the "element-ZnO element" and the "ZnO element-terminal metal" joint surface, and especially the terminal metal and the sintered body. Since the adhesiveness with the ZnO element constituted by the above becomes high, the operation failure such as the reduction of the switching surge withstanding property due to the separation of the both is eliminated, and the destruction by the surge energy below the limit value of the ZnO element can be prevented. At the same time, it is possible to reduce the destruction rate in the discharge withstand voltage test and the like, and it is possible to reduce the breakdown rate.

In the present invention, since a brazing material or the like is not used for joining the terminal metal and the ZnO element, ZnO may be used depending on the manufacturing conditions.
The voltage-current non-linear characteristic of the device is not lost. Further, since it is not necessary to use a support rod or the like as in the conventional case for stacking and fixing a plurality of ZnO elements,
The installation area of the O element itself is reduced, the assembling operation is simplified, and the manufacturing cost can be reduced. or,
It is also applicable when designing and manufacturing mold type lightning arresters made of organic polymer materials such as rubber or resin, and has the effect of wide versatility.

[Brief description of drawings]

FIG. 1 (A) is a side view showing a laminated structure of a ZnO element and a terminal metal to which a laminating method according to a first embodiment of the present invention is applied, and FIGS. 1 (B) and (C) are the same main parts. Perspective view.

FIG. 2 (A) is a side view showing a laminated structure of a ZnO element and a terminal metal to which the laminating method according to the second embodiment of the present invention is applied, and FIGS. 2 (B) and 2 (C) are the same main parts. Perspective view.

FIG. 3 is a side view of essential parts showing a structural example of a conventional ZnO element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... ZnO element 5 ... Terminal metal 6 ... Conductive adhesive 7 ... Metal ring 8 ... Metal spacer

Claims (6)

[Claims] 1. A slurried raw material obtained by adding a pulverized product of a metal oxide as a sub-addition component to zinc oxide and mixing it with an organic binder solution is filled in a slurry tank, and the raw material is spray-dried. ZnO obtained by sending in and spray-drying, weighing a certain amount of the obtained granulated powder with high fluidity, molding with a die molding press, degreasing and then firing at a predetermined temperature and time In a method of laminating a voltage non-linear resistance element, which forms a low melting point glass-based high resistance layer on the side surface of the element and polishes both surfaces of the sintered body, and then sprays a terminal metal to obtain a resistance element, A metal ring or a metal spacer is inserted and fixed between the "ZnO element-ZnO element" and the "ZnO element-terminal metal" obtained above by interposing an epoxy-based conductive adhesive containing Ag powder. When The method of lamination that voltage nonlinear type resistor. 2. The method for laminating a voltage non-linear resistor according to claim 1, wherein aluminum or stainless steel having a pressure relief port is used as the metal ring. 3. The method for laminating a voltage non-linear resistor according to claim 1, wherein aluminum or stainless steel provided with an adhesive silo having a pressure release port is used as the metal spacer. 4. The shape of the metal spacer is [R ₁ /
D] ≧ 0.85, 0.5 ≦ [R ₂ /D]≦0.85
0.5 ≦ T ₂ ≦ 1.0 mm (where R _{1 is} the outer diameter length of the metal spacer, D is the diameter of the ZnO element, R _{2 is} the inner diameter length of the metal spacer, and T ₂ is the thickness of the adhesive silo). Claim 1,
2. A method of laminating a voltage non-linear resistor according to the above 2 and 3. 5. The amount of the epoxy-based conductive adhesive containing Ag powder used is W / D ² ≧ 0.05 per joint surface (W: weight of conductive adhesive g, D: ZnO element diameter)
5. The method for laminating a voltage non-linear resistor according to claim 1, 2, 3, or 4. 6. The ZnO element is coated with a conductive adhesive, and then a metal ring or a metal spacer, another ZnO element and a terminal metal are laminated and bonded and fixed under pressure. 2. A method for laminating a voltage non-linear resistor according to 2, 3, 4, 5.