CN111081440A

CN111081440A - Corrosion-resistant and high-temperature-resistant NTC thermistor and manufacturing method thereof

Info

Publication number: CN111081440A
Application number: CN201911400394.9A
Authority: CN
Inventors: 汪洋
Original assignee: Nanjing Shiheng Electronics Co ltd
Current assignee: Nanjing Shiheng Electronics Co ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2020-04-28
Also published as: WO2021135890A1

Abstract

The invention discloses a corrosion-resistant high-temperature-resistant NTC thermistor and a manufacturing method thereof. The corrosion-resistant high-temperature-resistant NTC thermistor has the functions of water resistance, corrosion resistance and the like, and can be used in an environment with the temperature of 900 ℃.

Description

Corrosion-resistant and high-temperature-resistant NTC thermistor and manufacturing method thereof

Technical Field

The invention belongs to the field of electronic element manufacturing, and particularly relates to a corrosion-resistant high-temperature-resistant NTC thermistor and a manufacturing method thereof.

Background

A conventional negative temperature coefficient thermistor (NTC) is manufactured by doping two or more transition metal oxides such as cobalt oxide, manganese oxide, nickel oxide, iron oxide, copper oxide and aluminum oxide through a tape casting or dry pressing forming mode to prepare slurry or powder, forming, sintering and electrode manufacturing are adopted to prepare an NTC thermistor chip, and then processes such as welding, encapsulation or glass packaging are adopted to prepare the NTC thermistor, the NTC thermistor is widely applied within the temperature range of-50-350 ℃, but the NTC thermistor of the type exceeding 350 ℃ cannot be reliably used.

Disclosure of Invention

In view of the defects of the NTC thermistor element in the prior art, the invention develops a novel NTC thermistor with corrosion resistance and high temperature resistance. The NTC thermistor adopts a novel structure, the lead part of the NTC thermistor is directly contacted with the chip part, the protective layer is directly wrapped outside the chip, and other parts which are not corrosion-resistant and heat-labile are not arranged, so that the reliability under the conditions of high temperature and high corrosion is greatly enhanced.

Specifically, the invention adopts the following technical scheme:

the utility model provides a corrosion-resistant high temperature resistant NTC thermistor, includes protective layer, chip and lead wire, its characterized in that, protective layer parcel chip, the chip parcel is in lead wire one end, and wherein the embedding end of lead wire is direct to be buried in the chip, direct contact between lead wire and the chip material, and the chip is got by chip thick liquids and is formed through firing after gluing on the lead wire, and the lead wire is high temperature resistant metal lead wire. In the product of the invention, the protective layer is formed by firing high-temperature resistant glaze water, the chip is formed by firing after a chip slurry made of a metal oxide mixture and a binder is adhered on a lead wire, wherein the metal oxide is prepared by oxide or mineral of manganese, cobalt, nickel, iron, copper, aluminum, yttrium, zirconium and other metals according to a certain proportion, for example, SiO is contained₂、CuO、Mn₃O₄、NiO、Fe₂O₃、Al₂O₃、Co₃O₄Combinations of any of the above. In the chip paste, a binder is included or not included, and in a preferred embodiment, the binder is a water-soluble binder, such as polyvinyl alcohol, starch, dextrin, carboxymethyl cellulose, and the like. The binder may be added to the slurry as a dry powder or as an aqueous solution, for example polyvinyl alcohol added to the slurry as a dry powder or as an aqueous solution. In thatPreferably, the dispersant is also included, such as polyacrylamide, sodium polyacrylate, sodium hexametaphosphate, sodium pyrophosphate, and the like, and more preferably, the dispersant is polyacrylamide. Preferably, the lead wire is a platinum lead wire. .

The invention also discloses a manufacturing method of the corrosion-resistant high-temperature-resistant NTC thermistor, which is characterized by comprising the following steps of: 1) preparing chip slurry: weighing metal oxide in proportion, grinding to required fineness, and preparing into slurry with water content of 30-50%; 2) preparing a lead: arranging the leads in a group of two leads at a required interval, and reserving enough length of the leads for inserting into the chip slurry; 3) preparing a lead chip slurry combination: inserting the leads into the chip slurry to a required depth and maintaining for a sufficient time, then lifting the leads to wrap sufficient chip slurry on each group of leads, and drying to form a lead chip slurry combination body; 4) and (3) sintering: sending the dried lead chip slurry combination body into a sintering furnace for sintering at the temperature of 1000-1400 ℃ to obtain a sintered body; 5) manufacturing a protective layer: and immersing the chip part of the sintered body into high-temperature-resistant glaze water to enable the chip to be immersed and adhered with a layer of glaze water, and then sintering at the temperature of 600-900 ℃ to form a protective layer to obtain the corrosion-resistant high-temperature-resistant NTC thermistor.

In the method of the invention, the chip slurry is prepared by grinding a mixture of metal oxide and grinding fluid in a mill, wherein the ratio of the metal oxide to the grinding fluid is 1: 0.7-1.0. Wherein the grinding liquid is water or ethanol water solution with the concentration of 5-20%.

Preferably, the slurry obtained after the primary grinding is dried, and then the grinding fluid is added for secondary grinding to a desired fineness. Further preferably, the method further comprises, after drying and before secondary grinding, pre-burning the dried powder in a pre-burning furnace, and then performing secondary grinding. When the pre-firing is performed, the pre-firing temperature is preferably 850 ℃ 15 ℃ and the pre-firing time is preferably 2. + -. 0.2 hours.

In a preferred embodiment, the slurry is discharged after grinding, and preferably the slurry further comprises a step of adding a binder and a dispersant, and the slurry is discharged after grinding again after adding the binder and the dispersant. In a more preferred embodiment, the slurry is discharged after grinding after adding the polyvinyl alcohol binder in an amount of 0-3% by weight of the powder and the polyacrylamide dispersant in an amount of 0.2-0.6% by weight of the powder, and is discharged after grinding again.

In the method of the present invention, it is preferable that the chip is not formed at one time, but the step 3) is repeated a plurality of times to obtain a suitable chip size, wherein the step 3) is repeated a plurality of times to stick the core piece slurry again on the lead chip slurry combination formed after drying and to dry again, thereby enlarging the size of the lead chip slurry combination, and is repeated a sufficient number of times until the formed lead chip slurry combination reaches a sufficient size.

The high-temperature glaze water used in the method of the invention has the function of providing wear resistance and corrosion resistance. In view of the required properties of glaze water and the firing conditions of the aforementioned chip, the glaze forming conditions are higher than the glass forming temperature but need to be lower than the forming temperature of ordinary ceramics. In a preferred common scheme, the glaze water comprises 15% of potassium feldspar, 16% of albite, 14% of talcum, 9% of calcite, 12.5% of kaolin, 21% of quartz, 2% of borax, 2.5% of barium carbonate and 8% of zinc oxide, and the raw materials are ball-milled and added with proper amount of water to prepare slurry to prepare the high-temperature-resistant glaze water.

The NTC thermistor adopts a structure that the chip is directly contacted with the lead wire, the protective layer directly covers the chip, and other components and structures influencing the reliability under high-temperature corrosion conditions are not adopted in the middle, so that the reliability of the element under the high-temperature and corrosion conditions is improved. During manufacturing, the lead forms a preformed body of the chip at the front end of the lead in a manner of sticking core sheet slurry, so that the manufactured lead is embedded in the chip, the full combination of the lead and the chip is ensured, and the combination strength is improved. With the structure, the silver paste is not required to be welded, so that the use environment is not limited by the self-performance of the silver paste, and the obtained element can adapt to higher use temperature.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

fig. 2 is a perspective structural diagram of the element of the present invention.

In the figure: 1. ceramic material; 2. a protective layer; 3. and (7) leading wires. Wherein L is the lead pitch and A is the lead buried depth.

Detailed Description

The invention provides a novel manufacturing method of an NTC thermistor and a resistor element manufactured by the method. In the existing manufacturing method of the NTC thermistor, metal oxides are weighed according to a proportion and ground to prepare slurry, then the slurry is preformed and fired to prepare a chip, then a lead is welded on the chip, and then encapsulation is carried out. The resistance element manufactured by the conventional manufacturing method can endure a high temperature below 350 c due to the properties of the solder and the encapsulant itself, but when the usage environment exceeds 350 c, the performance of the element becomes unreliable.

In view of the above, the present invention provides a new method for manufacturing an NTC thermistor device. In the method, the process of manufacturing and forming the chip in advance in the traditional method is changed, the chip slurry is directly formed with the lead, the chip slurry is sintered at high temperature and then coated with high-temperature-resistant glaze water in a dipping and adhering mode, and then the element is directly fired.

As shown in fig. 1, when a preform of a chip is formed on a platinum wire lead by dip bonding, the bonding between the chip paste and the lead is more tight and firm, and after sintering, the chip paste is vitrified to form a ceramic material, which is sufficiently bonded to the lead, and thus the performance of the resistor element is more easily exhibited. And after the chip is sintered, wrapping the high-temperature-resistant glaze water outside the chip in a dipping and sticking mode, and further sintering to obtain the element with the protective layer. In this way, the chip and the lead are further bonded more firmly, the chip and the lead are protected as a whole, and the direct dipping mode also leads the bonding to be more direct and firm.

As further shown in fig. 2, the resistance range and the resistance accuracy of the core element of the conventional negative temperature coefficient thermistor are related to the thickness of the chip and the electrode area, and the resistance range and the resistance accuracy of the core element of the thermistor adopting the structure of the invention are related to the lead pitch size (fig. L value) of the two platinum wires and the length size (fig. a value) of the platinum wire immersed in the ceramic body.

The whole negative temperature coefficient thermistor is formed by sintering at the high temperature of 1000-1400 ℃. After the high-temperature sintering is finished, the surface of the ceramic body is immersed and encapsulated with high-temperature glaze water for one time and is sintered at the temperature of 600-900 ℃, so that the ceramic body is fused with the NTC thermistor ceramic, has the functions of water resistance, corrosion resistance and the like, and can be used in the environment with the temperature of 900 ℃.

The invention provides a corrosion-resistant high-temperature-resistant NTC thermistor element, which structurally comprises a protective layer, a chip and a lead from outside to inside, wherein the lead is directly embedded in the chip, the lead is directly contacted with chip materials, the chip is formed by bonding chip slurry on the lead and then firing the chip slurry, and the lead is a high-temperature-resistant metal lead. The chip is prepared by bonding chip slurry prepared from a metal oxide mixture and a binder on a lead wire and then firing, wherein the chip slurry is prepared by grinding metal oxides after being prepared in proportion, and the metal oxides are prepared from oxides or minerals of manganese, cobalt, nickel, iron, copper, aluminum, yttrium, zirconium and other metals in a certain proportion, such as SiO₂、CuO、Mn₃O₄、NiO、Fe₂O₃、Al₂O₃、Co₃O₄Combinations of any of the above. The high temperature resistant lead wire comprises various suitable metal or metal alloy and lead wires made of non-metal conductive materials, such as: metal lead wires of platinum, rhodium, tungsten, tantalum, niobium, etc., metal alloy lead wires of iron-chromium-aluminum-magnesium alloy, nickel-chromium alloy, etc., lead wires of carbon fiber, etc., ZnO doped with Al₂O₃In a preferred embodiment, the lead wire is a platinum lead wire.

The invention further discloses a manufacturing method of the NTC thermistor element with corrosion resistance and high temperature resistance, which comprises the following steps: 1) preparing chip slurry: weighing metal oxide in proportion, grinding to required fineness, and preparing into slurry with water content of 30-50%; 2) preparing a lead: arranging the leads in a group of two leads at a required interval, and reserving enough length of the leads for inserting into the chip slurry; 3) preparing a lead chip slurry combination: inserting the leads into the chip slurry to a required depth and maintaining for a sufficient time, then lifting the leads to wrap sufficient chip slurry on each group of leads, and drying to form a lead chip slurry combination body; 4) and (3) sintering: sending the dried lead chip slurry combination body into a sintering furnace for sintering at the temperature of 1000-1400 ℃ to obtain a sintered body; 5) manufacturing a protective layer: and immersing the chip part of the sintered body into high-temperature-resistant glaze water to enable the chip to be immersed and adhered with a layer of glaze water, and then sintering at the temperature of 600-900 ℃ to form a protective layer to obtain the corrosion-resistant high-temperature-resistant NTC thermistor.

In the method of the invention, the chip slurry is prepared by grinding a mixture of metal oxide and grinding fluid in a mill, wherein the ratio of the metal oxide to the grinding fluid is 1: 0.7-1.0. Wherein the grinding fluid is water or a process control agent is added thereto, water can also be regarded as one of the process control agents, but in the method of the present invention, the end point is not only to obtain particles of the metal mixture, but more importantly to obtain a slurry having a suitable viscosity and a uniform distribution of the particles of the metal mixture, and water is an important constituent of the slurry. The process control agent is typically an alcohol, ester, or like compound, such as ethanol, propanol, propylene glycol, stearic acid, or the like. In a preferred embodiment of the invention, and in accordance with the object of the invention, the process control agent used is an aqueous ethanol solution having a concentration of 5 to 20%, which is effective in promoting a uniform distribution of the particles in the slurry mixture during the milling process.

Preferably, the slurry obtained after the primary grinding is dried, and then the grinding fluid is added for secondary grinding to a desired fineness. Further preferably, the method further comprises the steps of pre-sintering the dried powder in a pre-sintering furnace before secondary grinding after drying, and then performing secondary grinding, so that the processes of pre-synthesizing, homogenizing and activating the particle structure of the powder are performed, and the final product has better electrical properties. When the pre-firing is performed, the pre-firing temperature is preferably 850 ℃ 15 ℃ and the pre-firing time is preferably 2. + -. 0.2 hours.

In a preferred embodiment, a binder and a dispersant are also added to the finally obtained slurry, and the binder and the dispersant are preferably added after grinding the slurry and before discharging, namely, the binder and the dispersant are added to the mill before discharging and are mixed in the slurry by the operation of the mill again or are added during the operation of the mill. Therefore, the method of the present invention preferably further comprises the steps of: adding polyvinyl alcohol adhesive and polyacrylamide dispersant in 0-3 wt% of the powder material, grinding again and discharging. The choice of binder can be varied and the preferred solution is polyvinyl alcohol, taking into account the effect on the viscosity of the final chip slurry and the elimination of the effect on the properties of the final product during the process. The choice of the dispersant can be various, and the preferable scheme is polyacrylamide which is an organic high polymer material in consideration of the influence of various dispersants on the chip slurry.

In the method of the present invention, it is preferable that the chip is not formed at one time, but the step 3) is repeated a plurality of times to obtain a suitable chip size, wherein the step 3) is repeated a plurality of times to stick the core piece slurry again on the lead chip slurry combination formed after drying and to dry again, thereby enlarging the size of the lead chip slurry combination, and is repeated a sufficient number of times until the formed lead chip slurry combination reaches a sufficient size. The multiple molding is beneficial to forming a favorable internal structure of the chip preforming body, reduces stress, and reduces the influence of the change of the chip on the firmness of the combination of the chip and the lead during sintering. However, the number of times of the dipping is too large to control the manufacturing process of the chip preform and to lower the production efficiency, so that the number of times of the dipping can be controlled by adjusting the amount of the polyvinyl alcohol added. In a preferred embodiment, the dipping times are controlled to be 2-10 times, the addition amount of the adhesive polyvinyl alcohol is about 2% by weight of the raw powder, and the addition amount of the dispersant polyacrylamide is about 0.3% by weight of the raw powder.

In the scheme of the invention, a high-temperature-resistant glaze water protective layer is finally made on the sintered body obtained by sintering, so that the obtained resistance element has the properties of wear resistance and corrosion resistance. The obtained glaze water layer is a layer of glass substance and has the functions of abrasion resistance and corrosion resistance. However, conventional glass protective layers are susceptible to deformation and denaturation at the high temperatures to which the elements of the present invention are applied, resulting in loss of protection. Further, considering the molding conditions of the sintered body, the glaze forming conditions of the ordinary high-temperature ceramics may also have an influence on the performance of the resistance element main body. Therefore, glaze water used for low-temperature and low-temperature ceramics is preferably used. In one general embodiment, the present invention utilizes the following formulation: 15% of potassium feldspar, 16% of albite, 14% of talc, 9% of calcite, 12.5% of kaolin, 21% of quartz, 2% of borax, 2.5% of barium carbonate and 8% of zinc oxide. The above ingredients are ground in a ball mill to a desired fineness, for example to 250 mesh. During grinding, 30-50% of water by weight of the raw materials can be added, the specific water addition amount can be adjusted according to the required viscosity, for example, the common water addition amount is 45%, and glaze water slurry is obtained by directly discharging.

The negative temperature coefficient thermistor is characterized in that a ceramic material is stuck on two parallel platinum wire leads in a dipping and sticking mode, and the dipping and sticking depths of the platinum wire leads are required to be consistent. The thermistor is characterized in that the whole negative temperature coefficient thermistor is formed by sintering at the temperature of 1000-1400 ℃, can be used in the environment with the temperature of 900 ℃, and solves the problem that the negative temperature coefficient thermistor cannot be used in the high-temperature environment.

The invention is further illustrated by the following examples.

Preparation of chip slurry

The chip slurry is prepared by mixing metal oxides (manganese, cobalt, nickel, iron, copper, aluminum, yttrium, zirconium and the like) according to a certain proportion, grinding for the first time, drying, pre-sintering, grinding for the second time and adding a binder according to a certain proportion, and the specific process comprises the following steps:

1. preparing materials: the raw materials are prepared according to a certain molar ratio;

2. primary grinding: grinding the prepared metal oxide powder in a planetary ball mill according to a certain material-ball ratio to obtain a primary grinding material;

3. drying: pouring the primary grinding material into a stainless steel disc, and placing the stainless steel disc in an oven for drying;

4. pre-burning: sieving the dried powder with a stainless steel sieve of 20 meshes, crushing, pouring into a high-temperature resistant porcelain dish, putting into a presintering furnace for presintering at the presintering temperature of 850 +/-15 ℃, and preserving heat for 2 hours, wherein the cooling mode is furnace natural cooling;

5. and (3) secondary grinding: grinding the pre-sintered powder in the same way as the first grinding;

6. adding a binder and a dispersant: adding a polyvinyl alcohol adhesive and a polyacrylamide dispersing agent into the mill before secondary grinding and discharging according to requirements, grinding for 30 minutes, and discharging.

Secondly, lead wire dipping and sticking

1. Preparing a lead: arranging the leads on the tooling plate, wherein every two leads form a group, the interval between the two leads is 1-3 mm, and one end of each lead is tidily arranged to ensure the consistency of dipping and sticking;

2. tape pasting: adhering an adhesive tape on the tooling plate, fixing the lead on the tooling plate and ensuring that one end of the lead is exposed to a sufficient length;

3. dipping and sticking: and immersing the exposed ends of the leads in the chip slurry for 1-3 mm, keeping for 1-2 seconds, taking out, drying, and repeating the process for 3-5 times to obtain a chip preform with the width of about 3-5 mm and the thickness of about 2-3 mm.

Thirdly, sintering

And transferring the obtained chip pre-forming body to a sintering tool, and sintering in a sintering furnace at the sintering temperature of 1000-1400 ℃ for 2 +/-0.2 hours to obtain a sintered body.

Fourthly, manufacturing a protective layer

And soaking and sticking the sintered body obtained by sintering in high-temperature resistant glaze water to form a high-temperature resistant glaze water layer on the surface of the sintered body, and then sintering at the temperature of 600-900 ℃ to form a protective layer to obtain the corrosion-resistant high-temperature-resistant NTC thermistor.

Example 1

The method comprises the steps of preparing materials according to a molar ratio of Mn to Ni to Al =40 to 50 to 10, feeding and grinding the materials into a planetary ball mill at a speed of V = 200-220 rpm at a ball to water =1 to 4 to 0.9 mass ratio, rotating the materials forwards and backwards every 30 minutes, grinding the materials for 8 hours, and discharging the materials. Pouring the slurry into a stainless steel plate, placing the stainless steel plate into an oven, and drying the stainless steel plate at the temperature of 80 +/-10 ℃ for 12 +/-1 hour. Sieving the dried powder with a stainless steel sieve of 20 meshes, crushing, pouring into a high-temperature resistant porcelain dish, putting into a pre-sintering furnace for pre-sintering, wherein the pre-sintering temperature is as follows: keeping the temperature for 2 +/-0.2 hours at 850 +/-15 ℃, turning off the power supply after the temperature is up to the temperature, and taking out the product after the temperature is naturally cooled to 40-60 ℃. And (3) grinding the pre-sintered powder again for the second time in the same grinding mode as the first grinding mode, and discharging no material after grinding. Adding polyvinyl alcohol adhesive and 0.3 percent polyacrylamide dispersant according to 2 percent of the weight of the original powder, grinding for 30 minutes, and discharging to obtain the slurry.

Examples 2 to 3

A slurry was prepared in the same manner as in example 1 except that water in grinding was replaced with a 5%, 20% ethanol aqueous solution, respectively.

Examples 4 to 6

Slurries were prepared in the same manner as in examples 1 to 3, except that after the secondary grinding, polyvinyl alcohol was not added, or 1% of polyvinyl alcohol was added, based on the weight of the polyvinyl alcohol dry powder in the slurry.

Examples 7 to 9

Slurries were prepared in the same manner as in examples 1 to 3, except that after the secondary grinding, polyvinyl alcohol was not added, or 3% of polyvinyl alcohol was added, based on the weight of the polyvinyl alcohol dry powder in the slurry.

Examples 10 to 18

Ingredients were formulated at a molar ratio of Mn: Co: Al =36.7:46.7:16.7, and then slurries were prepared in the same manner as in examples 1 to 9.

The slurries prepared in the manner described in examples 1-18 above were placed in appropriate amounts in slurry tanks that were formed as shallow, elongated channels having a length similar to the tooling plates used to arrange the leads. The platinum lead wires are well arranged on the tooling plate, and are soaked and adhered in a slurry tank after the adhesive tape is adhered. Multiple sets of leads were prepared for comparison of different tack-free times, which were divided into 1 second, 2 seconds, 3 seconds, and 5 seconds. And (5) soaking and bonding each group of leads for 5 times according to the soaking and bonding procedure, and observing the form of the obtained chip preformed body.

And sintering the obtained preformed body in a sintering furnace at the sintering temperature of 1000-1400 ℃ for 2 +/-0.2 hours, and then manufacturing a glaze water protective layer to obtain the high-temperature-resistant and corrosion-resistant NTC thermistor element for detection.

While the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art.

Claims

1. The utility model provides a corrosion-resistant high temperature resistant NTC thermistor, includes protective layer, chip and lead wire, its characterized in that, protective layer parcel chip, the chip parcel is in lead wire one end, and wherein the embedding end of lead wire is direct to be buried in the chip, direct contact between lead wire and the chip material, and the chip is got by chip thick liquids and is formed through firing after gluing on the lead wire, and the lead wire is high temperature resistant metal lead wire.

2. A manufacturing method of a corrosion-resistant high-temperature-resistant NTC thermistor is characterized by comprising the following steps of: 1) preparing chip slurry: weighing metal oxide in proportion, grinding to required fineness, and preparing into slurry with water content of 30-50%; 2) preparing a lead: arranging the leads in a group of two leads at a required interval, and reserving enough length of the leads for inserting into the chip slurry; 3) preparing a lead chip slurry combination: inserting the leads into the chip slurry to a required depth and maintaining for a sufficient time, then lifting the leads to wrap sufficient chip slurry on each group of leads, and drying to form a lead chip slurry combination body; 4) and (3) sintering: sending the dried lead chip slurry combination body into a sintering furnace for sintering at the temperature of 1000-1400 ℃ to obtain a sintered body; 5) manufacturing a protective layer: and immersing the chip part of the sintered body into high-temperature-resistant glaze water to enable the chip to be immersed and adhered with a layer of glaze water, and then sintering at the temperature of 600-900 ℃ to form a protective layer to obtain the corrosion-resistant high-temperature-resistant NTC thermistor.

3. The method of manufacturing a corrosion-resistant high-temperature-resistant NTC thermistor according to claim 2, wherein the chip slurry is ground from a mixture of metal oxide and grinding fluid in a mill, wherein the ratio of metal oxide to grinding fluid is 1: 0.7-1.0.

4. The method of manufacturing a corrosion-resistant high-temperature-resistant NTC thermistor according to claim 3, wherein the grinding fluid is water or an aqueous ethanol solution with a concentration of 5-20%.

5. The method of manufacturing a corrosion-resistant high-temperature-resistant NTC thermistor according to claim 3, wherein the slurry obtained after the primary grinding is dried, and then the secondary grinding is performed with the grinding fluid to a desired fineness.

6. The method of manufacturing a corrosion-resistant high-temperature-resistant NTC thermistor according to claim 5, further comprising: and pre-burning the powder obtained after drying in a pre-burning furnace before secondary grinding after drying, and then carrying out secondary grinding.

7. The method of manufacturing a corrosion-resistant high temperature NTC thermistor according to claim 6, wherein the pre-firing temperature is 850 ℃ ± 15 ℃, and the pre-firing time is 2 ± 0.2 hours.

8. The method of manufacturing a corrosion-and high temperature-resistant NTC thermistor according to claim 3 or 5, further comprising: before discharging, adding the adhesive and the dispersing agent, and discharging after grinding again.

9. The method of manufacturing a corrosion-resistant high-temperature-resistant NTC thermistor according to claim 2, wherein the step 3) is repeated to stick the lead chip paste again on the lead chip paste combination formed after drying and to dry again, thereby enlarging the size of the lead chip paste combination, and is repeated a sufficient number of times until the formed lead chip paste combination reaches a sufficient size.

10. The method of manufacturing a corrosion-resistant high-temperature-resistant NTC thermistor according to claim 2, wherein the high-temperature-resistant glaze water comprises 15% of potassium feldspar, 16% of albite, 14% of talc, 9% of calcite, 12.5% of kaolin, 21% of quartz, 2% of borax, 2.5% of barium carbonate, and 8% of zinc oxide, and the high-temperature-resistant glaze water is prepared by ball-milling the above raw materials, adding an appropriate amount of water, and making into a slurry.