TW543043B - Zinc oxide varistor and method of manufacturing same - Google Patents

Abstract

A precipitate film having plating resistance may be formed on the surface of a varistor element during sintering process. Accordingly, the manufacturing process can be shortened. there by improving the productivity. The manufacturing method comprises (a) a first process of forming the varistor element whose main component is zinc oxide; (b) a second process of sintering the varistor element and precipitating zinc compound having at least one of acid resistance and alkali resistance on the surface of the varistor. Preferably, the manufacturing method further comprises (c) a process of attaching an external electrode to the varistor element, and the external electrode attaching process is executed after finishing the varistor element sintering process.

Description

543043

Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economics Technical Field The present invention relates to a zinc oxide rheostat for absorbing induced lightning surges, electrostatic surges, and pulse surges, and a method for manufacturing the same. BACKGROUND OF THE INVENTION The conventional zinc oxide type varistor is known as follows. First, a material containing zinc oxide as a main component is sintered to produce a variable resistance element. A first external electrode is formed on the surface of the sintered varistor element. Then, it was buried in a mixture containing SiO as the main component and heat-treated. Thereby, a zn 2 s i 〇 4 film having acid resistance and alkali resistance is formed on the surface of the varistor element. Acid and alkali resistance are the same as those with plating resistance. At this time, it is outside the first. A Zn2Si04 film is also formed on the hafnium electrode to cause unevenness. Therefore, a second external electrode is formed on the first external electrode in order to eliminate the aforementioned unevenness and securely obtain an electrical connection with an external circuit. After that, nickel plating and solder plating are performed on the second external electrode. However, in the aforementioned conventional structure, a second heat treatment procedure, an attachment treatment procedure, and a procedure for forming a second external electrode are required in Si02 after forming the external electrode. Therefore, there is a problem that the manufacturing process is complicated. Therefore, the present invention aims at providing a zinc oxide varistor with no ZnaSiO4 on the surface of the varistor element after the formation of the first electrode, that is, after sintering the varistor element, without the need for a reheating process in SiO2. Summary of the Invention The manufacturing method of the zinc oxide varistor of the present invention has the following procedures: (a) the first procedure is to form a varistor element with zinc oxide as the main component; and the scale of the scale is applicable to the Chinese national standard ( Cns) A4 size (210 X 297 mm)

; # 11 (Please read the notes on the back before filling this page) · -line '-4- 043043 A7

543043 V. Description of the invention (Figure 4 is a state diagram, used to show the particle size and precipitation film of the varistor element when an aluminum compound used as a secondary component of the varistor element is added to the embodiment of the present invention. Detailed description of the invention The manufacturing method of the invented zinc oxide varistor has: (a) the first procedure, which forms a varistor element with zinc oxide as the main component; and (b) the second procedure, which is to burn the aforementioned varistor element, by which The varistor element is fired and burned, and a zinc compound is formed on the surface of the varistor element to form at least one of acid resistance and resistance. With this, a heat treatment process is not required after sintering the varistor element. A zinc oxide varistor having an acid-resistant or alkali-resistant film on the surface of the varistor element can be obtained. The acid-resistant or alkali-resistant film has the properties of no damage, no damage and no deterioration during the process of forming electroplating. The acid-resistant or test-resistant film has plating resistance. The aforementioned manufacturing method can form a film with mineral resistance on the surface of the varistor element during firing. As a result, the manufacturing process can be shortened. If the manufacturing process is shortened, it can be improved It is more preferable that the varistor element in the first procedure contains a bismuth compound and a silicon compound as auxiliary components. Thereby, a zinc compound film can be precipitated on the surface of the element by firing and bismuth compound. As a result, it has a resistance Mineral zinc oxide varistor. The aforementioned second procedure should preferably have a known sequence of precipitation of Zn_Si-0-based β-substances used as zinc compounds. Z.Si can be generated inside the varistor element by this procedure and firing. -O-based compounds to produce zinc oxide varistors with plating resistance. This paper has a standard size of _ secret standard ((JNS) A4 size coffee x 297 public love) _ ------------ --------- Order --------- Line—AW. (Please read the notes on the back before filling out this page) Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs-6 Printed by the Consumer Cooperative of the Ministry of Intellectual Property Bureau 543043 A7 -------- B7 V. Description of the invention (4). The aforementioned Shixi compound should have lm0p / (^ l5ni〇1〇) converted to silicon. The amount is in the range of / 0. With this, the Zn-Si-O-based compound having plating resistance can be precipitated on the surface of the varistor without impeding sinterability. The aforementioned second procedure The firing temperature should be 1000. (: ~~ 1400 ° C. This can obtain a zinc oxide varistor with plating resistance of Zn-Si-O-based compounds and the desired electrical characteristics. In the aforementioned first procedure, The varistor element more preferably contains an aluminum compound as a secondary component. This can suppress unevenness on the surface of the varistor element, and reduce the winter non-precipitated portion of the Zn-Si-O-based compound. The foregoing compound should preferably have an additive amount of 3 mol% or less As a result, the unevenness on the surface of the varistor element can be suppressed, and the non-precipitated portion of the Zn-Si_〇-based compound can be reduced. In the aforementioned second procedure, it is preferable that the bismuth compound is fired in a state where the bismuth compound is disposed around the varistor element. element. Thereby, the bismuth compound disposed around the varistor element will be scattered during firing, and during the cooling process, part of the scattered bismuth compound will adhere to the varistor element. Therefore, it is the same as the bismuth component in the varistor element, which can promote the precipitation of Zn-Si-〇-based compounds to the surface. In the firing of the second step, it is preferable to have a step of reducing the temperature of the grain growth of the varistor element. As a result, the unevenness on the surface of the varistor element can be suppressed, and the non-precipitated portion of the Zn-Si-O-based compound can be reduced. The aforementioned stone compound is preferably ZnjiO4. This allows the Zn_Si-O-based compound to be efficiently deposited on the surface of the varistor element during firing. The aforementioned second procedure should preferably include the aforementioned varistor element in Lezhong (Please read the precautions on the back before filling this page)

543043 A7 -------_____ B7 V. Description of the invention (5) Rotating the sheath while rotating it. Thereby, even when a large number of varistor elements are fired at one time, the heat distribution can be made uniform and the firing environment can be averaged. As a result, it is possible to prevent unevenness in the precipitation state of the zinc compound having plating resistance. Preferably, at least one powder selected from the group consisting of Al203, MgO, Zr02, ZnO, and NiO is stored in the sheath together with the varistor element. This can prevent the varistor elements from melting and sticking to each other during baking. The aforementioned first procedure preferably includes a step of preparing the mixture by mixing the main component and the sub-component before forming the varistor element, and a step of temporarily firing the mixture after that. By this step, a zinc compound to be formed in advance can be generated. Therefore, the Zn-Si-O-based compound can be efficiently deposited on the surface of the varistor element during firing. In the aforementioned first procedure, the varistor element preferably further includes a silk compound and an antimony compound as auxiliary components, and the aforementioned second procedure includes a step of precipitating a Zn-Sb-O-based compound as the aforementioned zinc compound. With this and temporary burning, a Zn-Sb-O-based compound can be generated inside the varistor element, and the Zn-Sb-0-based compound can be used to promote the precipitation film on the surface of the varistor element. As a result, a zinc oxide type varistor having plating resistance can be obtained. The aforementioned antimony compound preferably has an added amount in the range of 1 mol% to 100% when converted to Sb. The added amount of the recorded compound converted into Sb accounts for 1 to 10 mol%. Thereby, a Zn-Sb-O-based compound having plating resistance can be deposited on the surface of the varistor element without impeding sinterability. In the first procedure, it is preferable that the varistor element further contains an aluminum compound as a secondary component. This can suppress unevenness on the surface of the varistor element and reduce non-precipitated portions of the Zn-Si-0-based compound. This paper size applies to China National Standard (CNS) A4 (210 x 297 mm) (Please read the precautions on the back before filling out this page) Order ---------- Line --- Intellectual Property of the Ministry of Economic Affairs Printed by the Bureau's Consumer Cooperatives -8-543043 A7 B7

The manufacturing method for printing the zinc oxide varistor of the present invention by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs preferably includes: a procedure for installing external electrodes on the varistor element; The procedure of firing the variable resistance element is performed. The foregoing procedure of the Ansang external electrode preferably has a step of providing an external electrode material section and a step of plating a layer on the surface of the external electrode material by electroplating. The aforementioned plating layer is more preferably at least one selected from the group consisting of a nickel layer, a tin layer, and a solder layer. _ The procedure for forming the aforementioned varistor element more preferably has a step for forming a laminated varistor element which is provided with an internal electrode inside the aforementioned varistor element. The aforementioned procedure for forming a varistor element should preferably include a step of manufacturing a plurality of sheet-shaped varistor materials, a step of providing internal electrode materials on the surface of each sheet-shaped varistor material, and a layer of the aforementioned sheet on which the aforementioned internal electrode materials are stacked Step of deforming resistance material. The aforementioned first procedure should preferably have the following steps, namely: (i) is the combination of ZηO of the main component, Bi2O3, Sb203, c0304, Mn〇2, Ni0, & 2〇3 and 刈(1 ^ 〇3) at least one selected from the group consisting of 3 is mixed with SiO2, and the mixture is adjusted; and (ii) the aforementioned mixture is formed into a predetermined shape to form the aforementioned varistor element;

This paper size applies to China National Standard (CNS) A4 (21〇X 297 mm) AW .------- ^ ----------- ^ 1 (Please read the note on the back first (Please fill in this page for matters) _ -9- 543043 A7

^ ------- t --------- line --- Awl (Please read the notes on the back before filling this page) -10- 543043 V. At least one of the description of the invention (8) The steps. In the second step, it is preferable that the aforementioned zinc compound contains at least one of a Zn_Si-O-based compound and a Zn-Sb-O-based compound. The zinc oxide varistor of the present invention preferably has a varistor element mainly composed of zinc oxide and a precipitation film formed on the surface of the varistor element; and the precipitation film has better alkali resistance or acid resistance than the varistor element . Thereby, it is possible to provide a deposition film having plating resistance on the surface of the varistor element without performing heat treatment after sintering. The precipitation film preferably contains at least one of a Zn_Si_0-based compound and a Zn_Sb 0-based compound. This can further improve the plating resistance. It is preferable that the varistor element further contains an aluminum compound as a secondary component. This can suppress unevenness on the surface of the varistor element and reduce non-precipitated portions of the Zn_si_0-based compound. "The 70 varistor mentioned above should preferably have an internal electrode disposed inside the varistor element and an external electrode disposed on the surface of the varistor element and electrically connected to the internal electrode. The internal electrode should preferably contain platinum. The shrinkage of the internal electrode can be reduced. The zinc compound can be precipitated from the inside of the varistor element. Therefore, after the precipitation film is formed, the electrical connection with the external electrode can be obtained without the procedure for exposing the internal electrode. The I resistive element should have a plurality of varistor materials and an internal electrode provided inside each of the varistor materials and an external electrode provided on the surface of each of the varistor elements and electrically connected to the internal electrode. &Quot; With external electrode material and plating layer on the surface of the aforementioned external electrode material. Na 。. X 297 mm) ------- Order -------- • (Please read the precautions on the back first (Fill in this page again) • Line --- 1 -11- 543043 Printing of clothing by employees ’cooperatives in the Intellectual Property Bureau of the Ministry of Economic Affairs

i ------- tr --------- ^-(Please read the precautions on the back before filling this page) A7 —------- B7__ 5. Description of the invention (9) " " " ^ ---, the other internal electrode has a material selected from the group consisting of Pt, Pd, and Ag as the main component; and the aforementioned external electrode material has a material selected from

There are at least two kinds of alloys composed of alloys such as Ag and resins containing Ag, and the electric money layer has at least two layers of the lower recording key and the upper plating or tin plating. Μ 电 Typical Example 1 Effect The zinc oxide varistor of the exemplary embodiment of the present invention will be described below. Fig. 1 is a sectional view of a laminated sheet rheostat as a zinc oxide rheostat. In Fig. 1, a varistor element 1 mainly composed of zinc oxide has an internal electrode 3 mainly composed of rhenium. A precipitation film 2 containing ZgiO4 as a main component is formed on the surface of the varistor element i. The external electrode 4 with Ag as the main component is placed on the exposed ends of the inner α 卩 electrode 3 again. The layer 5 and the solder layer 6 are disposed on the external electrode 4. Fig. 2 is a manufacturing procedure diagram of the laminated chip rheostat in the present exemplary embodiment. Fig. 3 is a state diagram showing the particle size and precipitation film of the varistor element when no aluminum compound is used as a sub-component of the varistor element in the embodiment of the present invention. Fig. 4 is a state diagram showing the particle size and precipitation film of the varistor element when an aluminum compound is added as a secondary component of the varistor element in the embodiment of the present invention. That is, the third and fourth figures are sectional views for explaining the unevenness of the surface of the varistor element 1 and the formation state of the precipitation film 2 due to the presence or absence of an aluminum compound in the varistor element 1. The Zn2Si04 system is formed in the varistor element 1 in FIGS. 3 and 4. This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm) -12- 543043 Α7 Β7 Printed by the Consumers' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention (10) First, in No. 2 · In the 8 program, ZnO used as the main component and Si02, Sb203, c0304, Mn02, NiO, Ci * 203, and Al (N〇3) 3 used as the sub-component are used as the wet method. mixing. It was then dried in the κΝ0.9 procedure. Thus, a raw material powder is prepared. At this time, if there are few silicon compounds, the precipitation film 2 cannot be formed on the varistor π member 1, and if there are too many silicon compounds, the sintering property will be hindered. Therefore, the addition amount of the silicon compound should be adjusted to be converted to 1 to 15 mol%, more preferably 5 to 10 mol%. In addition, when an aluminum compound is added, unevenness on the surface of the varistor element 丨 can be suppressed, and the non-formed portion of the precipitation film 2 can be reduced to further improve the plating resistance. The addition amount of the aluminum compound is adjusted so that it is 3 mol% or less when converted to aluminum, and more preferably 1 mol% or less. By adding an aluminum compound, the effect of improving the ore resistance even inside the varistor element can be obtained. Next, the particle size of the dried powder was adjusted in the No. 10 procedure of FIG. 2. Next, in the No. 11 procedure of FIG. 2, it is put into a sheath and temporarily fired at a temperature of 800 to 1000 ° C. Thereafter, it was pulverized in the No. 12 procedure of Fig. 2 until the average value of the particle size of the powder was 1.0 ± 0.5 μm. At this time, if the particle size of the pulverized powder is small, it can have an excellent temperature load life and promote the precipitation of ZnjiO4 to the surface of the varistor element 丨. Next, fine pulverization was performed in the No. 13 program. Dry thoroughly in the No. 14 procedure. After being pulverized again in the No. 15 procedure, a larger agglomerated powder was removed to obtain a uniform raw meal. Secondly, in the No. 16 program, butyl acetate as a solvent, butyl phthalate as a plasticizer, and butyl acetal as a binder are used. H-scale standards are suitable for households (CNS) ) A4 specifications ⑵ G χ 297 public love) --------- • 13- I ------- ^ --------- ^ --- (Please read the note on the back first Please fill in this page again) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 543043 Α7 _______ B7 V. Description of the invention (U) Resin is added to the above crushed powder and mixed. Use this to make raw materials. Next, after removing the solids in the raw material in the No. 17 procedure, the sheet is formed into a predetermined thickness by a doctor blade method. After that, it is cut into a predetermined shape in the No. 18 program. Next, in a No. 19 program, the Pt paste which becomes the internal electrode 3 is printed into a predetermined shape, and then laminated. In this case, an electrode composed of at least one of Pt, pd, and Ag may be used as the 'internal electrode'. After that, the pressure was applied to the No. 20 electrode. Then, it is cut into a predetermined shape in the ν〇.21 program. Thereby, a variable resistance element 1 can be obtained. Next, the varistor element 1 is placed in a binder removing sheath. It was then put into a binder removal furnace and heated up to 400 ° C at a temperature increase rate of 25 ° C / h. After being held in this state for 2 hours, it was further maintained at a temperature of 700 ° C for two hours. The binder was removed in No. 22 procedure. This is because the sheath containing the varistor element 1 is rotated, so that the varistor element 1 has strength in advance.

In the No. 23 procedure, the varistor element 1 after the binding agent has been removed is put into a shell-shaped sheath together with the Al203 powder, and then put into a furnace and fired in the air. This roasting procedure is explained. First, the sheath was heated at a temperature of 200 ° C / h without rotating the sheath until 80 ° C. After that, Le 'was started to rotate at a temperature of 800 ° C or higher. Then, 200 ° C / h The temperature rises to a maximum temperature of 1000 ~ 140 ° C, and maintains the maximum temperature for two hours. The temperature is then reduced at a cooling rate of 100 ° C / h. In the No. 24 program, the angle of the varistor element 1 is removed. . Then μN〇 · 25 This paper size applies to Chinese national standard (CNS> A4 size (210 X 297 mm) AW .------- Order --------- Line-AWI (please first Read the notes on the back and fill in this page). -14- 543043 A7 B7 V. Description of the Invention (^) In the private sequence, an external electrode 4 with ^ as the main component is formed on the end surface where the internal electrode 3 is exposed. Weld it in the random 26 procedure. At this time, the external electrode 4 is formed of Pt or Pt_Ag or Ag_pd, or even a thermosetting resin in which Ag is dispersed. The external electrode is welded in the No. 27 procedure and No. 28 procedure. 4. After that, Nm plating is performed, and then solder plating is performed, thereby forming the Qin layer 5 and Handa layer 6. And according to this procedure, the lamellar sheeting can be completed. It is also possible to perform Sn plating to form a Sn layer instead of soldering. Next, a precipitation film mainly composed of Zn2Si04 formed on the surface of the varistor element 1 is described. Zinc oxide is soluble It is an amphoteric substance in both acid and alkali. Therefore, zinc oxide can be dissolved / combined in the Ni plating solution and solder plating solution which are acidic or alkaline solutions. The precipitation film 2 based on Zr ^ SiO4 is coated The surface of the resistive element can prevent the plating solution from entering the interior of the varistor element. Also, when electrolytic plating is generally performed with the surface of the varistor element 1 completely exposed, the electroplating flow occurs because the varistor element is a semiconductor, but In the embodiment of this form, because

The Zn ^ SiO4-based precipitation film 2 is a high-resistance substance, and can prevent plating flow. In this exemplary embodiment, Sb203 is added as a secondary component of the varistor element. Therefore, a Zn_Sb_〇-based compound is also formed by firing, and like Zn2Si〇4-, a Zn-Sb-O-based compound will gradually precipitate on the surface of the varistor element 1. This Zn-Sb-0-based compound has excellent plating resistance similar to Zn2Si04. Therefore, a varistor having excellent plating resistance without being affected by plating properties can be obtained. This paper size applies Chinese National Standard (CNS) A4 specification (21 × 297 mm-15- 543043 13) V. Description of the invention -Sb- 〇-based compound, but even with only Zn2Si〇4, a laminated sheet varistor with very practical plating resistance can be obtained. ZηβΑ is formed, and it promotes precipitation to the varistor element after the firing, but it is not limited to; ... It is also possible to use a cutting compound instead of firing, thereby achieving the same effect as others. Of course, even if When the Zn compound of the Shixi compound is not used or the raw material powder is not fired, a Zn2Si () 4-based precipitation film can also be formed on the surface of the varistor element. As shown in Figure 3, As the grain growth of the varistor element progresses, the unevenness on the surface will increase A, so a portion on the surface of the varistor where the precipitation film 2 cannot be formed will occur. However, as shown in Figure 4, the grain growth is suppressed to suppress the surface. In the case of unevenness, the non-formed portion of the deposition film 2 on the surface of the varistor element 1 can be reduced. According to the analysis results, the addition of the 1 ru compound used as a side component of the varistor element 1 will increase the mass of the crystal spinel structure existing in the three points of the grain boundary of the varistor element, and inhibit the starting of the substance. The grain grows. As shown in FIG. 4, the unevenness on the surface of the varistor element 1 can be suppressed, the non-formed portion of the deposition film on the surface of the varistor element plating can be reduced, and the material property and the current prevention effect can be further improved. Intellectual Property Bureau employees consume it, but although it may not be added as a secondary component, the inscription compound is used to form a precipitation film with Zn2Si〇4 as the main component on the surface of the variable resistance element i. 2 According to the foregoing analysis results' When adding the compound used as the component of the varistor element, the precipitation film 2 can be formed more stably. In addition, if the compound used as the component of the varistor element is added, the national standard can be applied to the paper size. (CNS) A4 specifications (210 X 297 issued -16-

I 543043 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. The description of the invention (M) is produced at a low temperature. For example, in the absence of bismuth, the reaction of 2zn0 + Si〇2 Zi ^ SiO4 does not occur below 1000 ° c, but in the presence of a grade, most of Si at 1000 ° C will become ZnzSiO4 . This phenomenon can be carried out in the following reaction process.

Bi2〇3 + Si02 Bi4 (Si04) 3 Bi4 (Si04) 3+ 6ZnO Zn2Si04 + 2Bi2〇 The wire will fly away during firing. Therefore, more bismuth will be stored on the surface of the varistor element 1. Therefore, in addition to promoting the precipitation of Zi ^ SiO4 to the surface of the varistor element 1, ZhSiO4 near the varistor element can also be moved to the surface, reducing the non-formed portion of the precipitation film 2 on the surface of the varistor element 1. Exemplary Embodiment 2 In the laminated chip varistor of Exemplary Embodiment 2, the precipitation film 2 is mainly composed of a Zn-Sb-O compound. Others are fabricated in the same manner as the laminated chip varistor in the foregoing exemplary embodiment i. First, ZnO used as a main component and Bi203, Sb203, Co304, Mn02, NiO, Cr203, and A1 (N03) 3 used as a sub-component were wet-mixed (Figure 8). It is then dried (Figure 2-9). Thus, a raw material powder was prepared. In this case, if the antimony compound is small, the precipitation film 2 cannot be formed on the varistor element 1. If the antimony compound is too large, the sinterability is impaired. Therefore, the addition amount of antimony compound should be adjusted to be converted to Sb based 1 ~ 10 mol%, more preferably 4 ~ 10 mol% 0 or less, which is the same as that of the typical embodiment 1, and it is based on the No. 10 program to No_21 program system in Fig. 2 Got variable resistance element 1. Next, the varistor element 1 is placed in a binder removing sheath. The paper size for this paper is in accordance with China National Standard (CNS) A4 (210 X 297 mm) I ------ ^ ---- I ---- --- (Please read the note on the back first (Fill in this page again) -17-

543043 V. Description of the invention (15) Into the binder removal furnace, heat up to 4,000c at a temperature increasing rate of 25 ° C / h. After being held in this state for 2 hours, it was further increased to 70 (rc for 2 hours. Then the binder was removed (22 in Fig. 2). This procedure increased the strength of the varistor element 1. Therefore, During the rotation of the sheath containing the varistor element 1 in the next firing process, the varistor element 1 can be prevented from being damaged. The varistor element 1 after the binding agent is removed is put into a shell-shaped sheath together with Al203 powder. Put it back into the furnace and bake it in the air (23 of Figure 2). The roasting procedure will be described. First, the temperature is raised to 200 t: / h without rotating the sheath until 800 ° C. The temperature is increased. After that, the sheath starts to rotate at a temperature of 800 ° C or more. Then, the temperature is increased to a maximum temperature of 1000 to 1400 ° C at a temperature increase rate of 200x: / h, and the maximum temperature is maintained for two hours. The temperature is reduced at a cooling rate of 100 ac / h. The cornering of the varistor element 1 is performed after baking (24 of FIG. 2). Then, an external electrode mainly composed of Ag is formed on the end surface on which the internal electrode 3 is exposed. 4 (25 of Fig. 2). Solder it again (26 of Fig. 2). At this time, the external electrode 4 It is formed of Pt or Pt-Ag or Ag-Pd, or even a thermosetting resin in which Ag is dispersed. After the external electrode 4 is welded, Ni plating is performed, and then solder plating is performed to form Ni layer 5 and Handa layer 6 ( 27, 28 of Fig. 2). According to this procedure, a laminated chip varistor can be obtained. In addition, Sn plating can also be performed to form a Sn layer instead of ore solder. Next, the formation on the surface of the varistor element 1 The precipitation film with Zn-Sb-O as the main component is recorded. Zinc oxide is an amphoteric substance that is soluble in both acids and alkalis. Therefore, the paper size for oxidation is applicable to China National Standard (CNS) A4 (210 X 297) (Mm) (Please read the notes on the back before filling out this page) ------- Order --------- Printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs • 18- 543043 A7 B7 5 、 Explanation of the invention (16 words can be / combined in the system> Ni ores and solder bond solution of the liquid or test solution. The film with Zn2Si〇4 as the main component is more difficult to dissolve in acidic! In the test solution. Therefore, the surface of the precipitating film 2 with Zn2Sb04 as the main component covers the varistor element! Into the varistor element ^. Also, when electrolysis is generally performed in a state where the surface of the varistor element 1 is completely exposed, electric ore current will occur because the varistor element is a semiconductor, but in the embodiment of this electric form Since the Zn2Si04-based precipitation film 2 is a high-resistance substance, it can prevent electroplating flow. In the foregoing embodiment, the Zn-Sb-O-based compound was previously formed by temporarily firing the raw material powder, and promoted. After firing, it is deposited on the surface of the varistor element, but it is not limited to this. A Zn_Sb_0 sigma compound used as a recording compound may be used instead of firing, thereby obtaining the same effect as described above. Of course, when the Zn-Sb_O-based compound is not used or the raw material is not calcined, a precipitation film mainly composed of a znsb_core compound can be formed on the surface of the varistor element 2 . 'Ministry of Wisdom and Staff Consumption In addition, the precipitation film 2 in this exemplary embodiment 2 is considered to be mainly composed of Zn2.33Sb0.67〇4. In addition to the precipitation film 2, there is a possibility that a Zn-Sb-O-based compound having another structure is precipitated. For this reason, the text of the precipitation film 2 containing a Zn Sb-O-based compound as a main component is described. In this exemplary embodiment 2, it is also possible to suppress the unevenness of the surface by suppressing the grain growth of the varistor element 1 to surely reduce the surface precipitation film & non-forming portion of the varistor element. Therefore, as in the typical implementation, by adding an aluminum compound as a secondary component of the varistor element, a substance with a crystalline spinel structure composed of Zn, Sb, and 0 existing in the grain boundary two points of the varistor element 丨 is added. Volume, and this paper size home standard (CNS) A_4 one specification (2ι〇χ tear public hair) -19- 543043

Grain growth begins with the substance. (Please read the precautions on the back before filling in this page.) If bismuth is added as a secondary component of the varistor element i, the formation of Zn-Sb-O compounds can be performed at low temperature. Bismuth will also fly away during roasting. Therefore, more bismuth will be stored on the surface of the varistor element. At this time, the varistor element is preferably fired in a state where a bismuth compound is provided on the periphery of the varistor element. Therefore, in addition to promoting the precipitation of the system compound to the varistor element and the surface, the Zn_Sb-O compound near the varistor element can also be moved to the surface. The non-forming portion of the precipitation film 2 on the surface of the varistor element is reduced. In addition, even without adding an aluminum compound as a secondary component of the varistor element 1, a precipitation film 2 having a Zn-Sb_0-based compound as a main component can be formed on the surface of the varistor element 1. It is preferable to reduce the formation portion as much as possible, and to add the compound. The following is a description of the main points of the present invention. (1) The function of the precipitation film 2 of the present invention is to prevent the plating solution from entering the inside of the resistance element 1 and prevent the plating flow during the electric ore process. Therefore, it is desirable that the entire surface of the varistor element is completely covered with the precipitation film 2. In the present invention, a component to be a deposition film 2 is precipitated from the inside of the varistor element 1. Therefore, it is not possible to complete the deposition film 2 with the printed surface of the varistor element 1 covered by the consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, and there is a non-formation portion of the precipitation film 2 as shown in FIG. 3. However, the non-formed portion of the precipitation film 2 is difficult to cause the invasion of the plating solution and the plating flow during the plating process. (2) When the varistor element is fired and the sheath is rotated, the rotation axis is rotated horizontally, so that the varistor element 1 and the 8203 can be uniformly mixed. Therefore, in addition to promoting the formation of the precipitation film 2, unevenness in the formation state can be prevented. This paper size applies Chinese National Standard (CNS) A4 specification (210 X 297 public love) -20- 543043 V. Description of invention (18 Printed by the Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs (3) When firing varistor elements, although Al2O3 is mixed in Ju, but powder of at least one of Al2O3, MgO, Zr02, Zn0, and Si0 can also be mixed with the raw material powder. By this, bismuth can be obtained by the variable resistance element, It further improves the high temperature and low temperature. When baking and cooling, 'M can be further used as an adhesive to prevent the varistor elements 1 from melting and bonding with each other. Using Al2O3 can also be used as an additional component of the varistor element i The aluminum compound has the same effect. Therefore, even when the aluminum compound used as a secondary component of the varistor element is not added, the varistor element can be reduced by being stored in a sheath and baked together with the varistor element 丨The unevenness on the surface reduces the non-formed portion of the precipitation film. (4) In the foregoing embodiments, when the varistor element is fired, the sheath rotation is started at 800 or more. It is not limited to this, the sheath rotation start temperature It should be in the range of 700 C ~ 1000 ° C. And 80 (rc It is most ideal to start the rotation recently, so as to prevent the varistor element from being damaged, and to allow a predetermined amount of bismuth to be scattered. Also, the "rotating toward the system is used to make the environment and temperature in the sheath uniform." If the sheath is rotated When it is too slow, it is difficult to average the temperature distribution and environment. If it is too fast, the damage to the varistor element will be too large, so the rotation of the sheath should be in the range of 0.5 rpm to 5 rpm. (5) The maximum baking temperature is not full ... ⑽ At this time, it is impossible to form a precipitation film 2 that can prevent the invasion of electro-hydraulic elements to the varistor element 1 and the plating flow. When the maximum baking temperature exceeds 1400X: Although the precipitation film 2 can be formed, the electrical characteristics of the laminated chip varistor will Degradation or delamination occurs. Therefore, the maximum firing temperature may be in the range of 1000 ° C ~ 1400 ° C, but preferably in the range of 1000 ° C ~ 1300 ° c. (6) In order to suppress grain growth, and Make the crystal size of varistor element 1 small and all plated (please read the precautions on the back before filling this page) I ------ Order ----- 1 ------ This paper size Applicable to China National Standard (CNS) A4 specifications (210 X 297 mm) -21- Printed by 543043 V. Description of the Invention (^) When the unevenness of the surface of the varistor element 1 is uniformized and reduced, and the non-forming portion covering the precipitation film 2 on the surface of the varistor element 1 is reduced as much as possible, the temperature during firing is reduced. The speed should be as fast as possible. On the other hand, if the life characteristics of one of the main characteristics of the laminated chip rheostat are considered, the cooling rate should be slower. Therefore, it does not adversely affect the electrical characteristics of the laminated chip rheostat. And as far as possible, a precipitation film 2 covering the entire surface of the varistor element 1 is formed, and the cooling rate is preferably within a range of 50 ° C / h ~ 400 ° C / h, and more preferably 10 (rc / h ~ 200 ° C) / h. (7) The internal electrode 3 is formed using at least one metal of pt, pd & Ag as shown in the exemplary embodiment. When a metal with pd * pt as the main component is used, both ends of the varistor element 丨 after firing are in a state where the internal electrode 3 is exposed. Therefore, it is not necessary to perform polishing for exposing the internal electrode 3 after firing. The foregoing reason is that the shrinkage rate of the internal electrode 3 containing Pd or Pt as a main component is small. In addition, in order to precipitate the precipitation film 2 to react with the substance inside the varistor element j, the shrinkage rate of a portion containing ZnO as a main component more than that of the internal electrode 3 will increase. The external electrode 4 may be formed before firing. Even if heat-treated at the highest firing temperature, the external electrode 4 needs to be formed of a metal capable of exerting the functions of the external electrode 4. (8) In the foregoing embodiments, the firing of the varistor element 丨 is performed in the air. But from the experimental results of changing the oxygen partial pressure, we can see that if the variable resistance element is used more! When the ambient partial pressure of oxygen is reduced, a precipitation film after the month can be formed. Therefore, plating resistance can be improved. However, firing under low oxygen partial pressure will make the basic paper size applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 public love) I · ------ 丨 order ------- --Line --- AW1 (Please read the precautions on the back before filling this page) -22- 543043

V. Description of the invention (20 pieces of varistor characteristics are reduced. At this time, heat treatment at 800 ~ 1000 ° C can be performed again in another working gas to restore the desired characteristics. (9) The foregoing typical embodiment is directed to Laminated type ^ Zinc oxide varistor of 1 'but not limited to this, the zinc oxide varistor of the present invention can also be implemented as a single-plate type varistor. At this time, the manufacturing process can be reduced as with the laminated ZnO varistor. As mentioned above, according to the present invention, it is possible to provide a deposition film mainly composed of a zinc compound having plating resistance on the surface of the varistor without the need for heat treatment in SiO 2 after firing. Therefore, the manufacturing process can be shortened. And improve productivity. It can also reduce production costs. (Please read the precautions on the back before filling out this page) # Order --------- Line --- Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs Paper size applies Chinese National Standard (CNS) A4 specification (21 × χ 297 mm) -23- 543043 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention (21) 1. Varistor element 2 .. Precipitation film 3 .. Inside Electrode 4 .. External electrode 5. Ni layer 6. Solder layer 8. Mix 9. Dry 10. Particle size adjustment 11. Temporary firing 12 ... Crush 13 .... Micro-comminute 14 … Dry 15..Remove agglomerated powder 16 ... Green raw material 17 ... Piece forming 18 ... Piece cutting 19..Print lamination 20..Formal pressure 21 .. Agent 23 ... fired 24 ... dehorned component number comparison table 25 ... forming external electrode 26 ... soldering external electrode 27 ... nickel layer 28 ... solder layer 30 ... Zn2Si〇4 (Please read first Note on the back, please fill out this page again) This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) -24-

Claims (1)

543043 No. 090121485 Patent Application Patent Application Amendment Amendment Date: May 1992 1. A method for manufacturing a zinc oxide varistor has: (a) the first procedure is to form a varistor element with zinc oxide as the main component (B) the second procedure is to fire the varistor element, sinter the varistor element by the firing, and precipitate on the surface of the varistor element to form at least one of acid resistance and alkali resistance; Those who are zinc compounds. 2. If the method of manufacturing a zinc oxide varistor according to item 1 of the scope of the patent application, in the first procedure, the aforementioned varistor element further contains a bismuth compound and a silicon compound as auxiliary components; and 'the aforementioned second procedure has a A step of precipitating a Zn-Si-O compound used as a zinc compound. 3. The method for manufacturing a zinc oxide varistor according to item 2 of the patent application range, wherein the aforementioned silicon compound has an added amount in the range of 1 mol% to 15 mol% after being converted into silicon. 4. The method for manufacturing a zinc oxide varistor according to item 2 of the scope of patent application, wherein the calcination temperature in the above-mentioned second procedure is in the range of 1000 ° C to 400 ° C. 5. The method for manufacturing a zinc oxide varistor according to item 2 of the scope of patent application, in the aforementioned first procedure, the varistor element further contains an aluminum compound as a secondary component. 6. The method for manufacturing a zinc oxide varistor according to item 5 of the application, wherein the aforementioned aluminum compound has an added amount of 3 mol% or less. This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -25- AB c D 543043, patent application scope 7 · For the manufacturing method of zinc oxide rheostat according to item 2 of the patent application scope, which is described in the first paragraph In the second procedure, the bismuth compound is prepared in a state in which the varistor element is fired in a state where the bismuth compound is disposed around the varistor element. 8_ The method for manufacturing a zinc oxide varistor according to item 2 of the scope of patent application, which includes a step of lowering the temperature by suppressing the rate of grain growth of the varistor element in the firing of the aforementioned second procedure. 9. The method for manufacturing a zinc oxide varistor according to item 2 of the patent application, wherein the aforementioned silicon compound is Zn2Si04. 10. If the method of manufacturing a zinc oxide varistor according to the item of the scope of the patent application, the second private sequence is a step of accommodating the varistor element in a sheath and firing while rotating the sheath. 11 · If the method for manufacturing a zinc oxide varistor according to item 10 of the patent application scope is to store at least one kind of powder selected from the group consisting of Al203, MgO, Zr02, ZnO, and NiO together with the aforementioned varistor element The aforementioned sheath. 12. According to the method for manufacturing a zinc oxide varistor according to item 丨 of the application, wherein the first procedure has a step of preparing a mixture by combining the main knife and the vice before forming the varistor element, and a A step of temporarily roasting the aforementioned mixture after the beans. 13. If the method for manufacturing a zinc oxide varistor according to item 1 of the scope of patent application, in the aforementioned first procedure, the aforementioned varistor element further contains a silk compound and a recording compound as auxiliary components; and the aforementioned second procedure has a A step of precipitating a Zn-Sb-0-based compound used as the zinc compound. This paper size applies the Zhongguanjia Standard (CNS) A4 specification (21〇χ297 公 楚)-* ------ 1 -26- 543043 A8 B8 C8 K. Application scope of patent 14. The manufacturing method of zinc oxide varistor according to item 13 of the scope of patent application, wherein the aforementioned antimony compound has an addition in the range of lm01% ~ 10m〇1〇 / 〇 after conversion to thorium. the amount. 15. The method for manufacturing a zinc oxide varistor according to item 13 of the patent application, wherein in the aforementioned first procedure, the varistor element further contains an aluminum compound as a secondary component. 16. The method for manufacturing a zinc oxide varistor according to item 15 of the application, wherein the aforementioned aluminum compound has an added amount of 3 mol% or less. 17. The method for manufacturing a zinc oxide varistor according to item 丨 of the patent application scope, further comprising: (c) a procedure for installing an external electrode on the aforementioned varistor element; and the aforementioned procedure for installing an external electrode is on the aforementioned calcined varistor element After the procedure. 18. The manufacturing method of the zinc oxide varistor according to item 17 of the application, wherein the procedure for installing the external electrode further includes a step of setting an external electrode material and a step of forming a plating layer on the surface of the external electrode material by electroplating. step. 19. The method for manufacturing a zinc oxide varistor according to item 18 of the patent application, wherein the step of forming the aforementioned electroplated layer further includes forming at least one electroplated layer selected from the group consisting of a nickel layer, a tin layer, and a solder layer. step. 20 * The manufacturing method of zinc oxide varistor according to item 1 of the patent application scope, wherein the procedure for forming the aforementioned varistor element further has a step for forming a laminated varistor element, which is based on the aforementioned varistor There are internal electrodes inside the element. 21 · The manufacturing method of zinc oxide varistor according to item 1 of the patent scope, Binding f I. -27- 543043 A8-B8 __ C8 ~ -------__ VI. Application for patent scope ^ — 26 · / °: Please refer to the method for manufacturing the zinc oxide varistor in the first scope of the patent, among which the first procedure has the following steps That is: (1) It is the main component of Zη〇, the subcomponent of Bi2〇3, sb203, C04, Mn〇2, Ni0, Cr203 and A1 (N〇3) 3 After mixing at least one selected from the composition group with SiO 2 and adjusting the mixture; and (11) are those in which the aforementioned mixture is formed into a predetermined shape to form the aforementioned varistor element; and the aforementioned second procedure has A step of depositing a Zn_Si_O-based compound as a zinc compound on the surface of the aforementioned varistor element. 27. The method for manufacturing a zinc oxide varistor according to item 25 of the application, wherein the aforementioned first procedure has the following steps, namely: (Xun) is the temporary roasting of the aforementioned mixture; (iv) is the aforementioned mixture before the temporary roasting; Forming a temporarily calcined powder having a predetermined size; and (v) using the temporarily calcined powder to adjust a raw material; and using the raw material to form the varistor element into a predetermined shape. 28. The method for manufacturing a zinc oxide varistor according to item 1 of the scope of the patent application, wherein the aforementioned first procedure has the following steps, namely: (i) the ZnO of the main component and the Zn-Si-O compound of the sub-component and Those who mix at least one of Zn-Sb-O-based compounds and adjust the mixture; (i) those who use the aforementioned mixture to adjust raw materials; and (iii) which form the aforementioned mixture into a predetermined shape to form a former paper Standards apply to China National Standard (CNS) 8-4 specifications (210X297 mm) -29- 543043 The varistor element is described; and the second procedure has a step of precipitating at least one of a Zn_Si-O-based compound and a Zn_Sb seven-system compound used as a zinc compound on the surface of the varistor element. 29. The method for manufacturing a zinc oxide varistor according to item 丨 of the patent application, wherein in the aforementioned second procedure, the aforementioned zinc compound contains at least one of a Zn_si_〇-based compound and a Zn-Sb-O-based compound. 30. A zinc oxide varistor comprising a varistor element mainly composed of zinc oxide and a precipitation film formed on the surface of the varistor element; and the precipitation film has better endurance or acid resistance than the varistor element Sex. 31. The zinc oxide varistor according to item 30 of the application, wherein the precipitation film contains at least one of a Zn-Si-O-based compound and a Zn-Sb-O-based compound. t 32. The zinc oxide varistor according to item 30 of the patent application scope, wherein the varistor element further contains a silk compound and a silicon compound as auxiliary components. 33. The zinc oxide varistor according to item 32 of the application, wherein the aforementioned stone compound has an added amount in the range of 1 mol% to 15 mol% after being converted into Si. 34. The zinc oxide varistor according to item 32 of the application, wherein the varistor element further contains an aluminum compound as a secondary component. 35. The zinc oxide varistor according to item 34 of the application, wherein the aforementioned aluminum compound has an added amount of 3 mol% or less. 36. If the zinc oxide varistor according to item 32 of the patent application scope, in which the above-mentioned Shi Xihua is used, the paper size is applicable to China National Standard (CNS) A4 (210X297 mm) -30- 543043 The compound contains Zn2Si04. 37. If the zinc oxide varistor of item 30 of the application scope is applied, wherein the front varistor π has an internal electrode provided inside the aforementioned varistor element and is provided on the surface of the varistor element and is electrically conductive with the aforementioned internal electrode部 electrode. Bu 38. The zinc oxide varistor according to item 36 of the application, wherein the external electrode has an external electrode material and a plating layer provided on the surface of the external electrode material. 39. The zinc oxide varistor according to item 38 of the application, wherein the internal electrode has a material selected from the group consisting of Pt, Pd, and Ag as a main component; and the external electrode material has a material selected from At least one of the group consisting of Pt, Pd, Ag, these alloys, and Ag-containing resins; / The aforementioned plating layer has at least two layers of a nickel ore layer at the lower layer and solder ❹ or tin plating at the upper layer. X e • If the zinc oxide varistor according to item 30 of the patent application scope, wherein the varistor read has a majority of the varistor material, is disposed inside each of the varistor materials ^ most of the internal electrodes and the external electrification is disposed on the surface of the varistor material For example, the zinc oxide varistor according to item 40 of the patent application, wherein the aforementioned electrode has an external electrode material and a plating layer provided on the surface of the foregoing external electrode material. The zinc oxide varistor of item 41 of the patent application has a pole selected from the group consisting of Pt, Pd and Ag ° 乂 ~ species Α4 size (210X297 male) 42. Rudian-31- 543043 AB c D is a material with a patent application scope as the main component, and the aforementioned external electrode material is at least selected from the group consisting of pt, Pd, Ag, alloys of these, and resins containing Ag. One type; the aforementioned electroplating layer has at least two layers of a lower nickel plating layer and an upper solder plating layer or a tin ore layer. This paper size applies to China National Standard (CNS) A4 (210X297 mm) -32-