High-energy surge current-limiting PTC (Positive Temperature Coefficient) thermistor chip as well as formula and production process thereof

Abstract

The invention discloses a high-energy surge current-limiting PTC (Positive Temperature Coefficient) thermistor chip as well as a formula and a production process thereof, and relates to the technical field of new energy automobiles and industrial application, and a powder base material for processing the high-energy surge current-limiting PTC thermistor chip comprises the following components in molar composition: 0.65 of BaCO3, 0.02 of SrCO3, 0.32 of Pb3O4, 0.017 of CaCO3, 1.02 of TiO2, 0.001 of NiO, 0.02 of SiO2, 0.0015 of CuO, 0.001 of La2O3, 0.02 of Al2O3, 0.002 of CeO2, 0.008 of Y2O3, 0.0011 of Mn3O4, 0.0005 of Ta2O5 and 0.0025 of Nb2O5. The production process comprises the following steps: firstly, carrying out primary burdening and pre-sintering to obtain powder; then carrying out secondary batching and granulation; and tabletting and firing the granules to obtain the high-energy surge current-limiting PTC thermistor chip with a positive temperature coefficient. And finally, carrying out chip testing on the obtained chip. According to the invention, the processed high-energy surge current-limiting PTC thermistor chip can form a good solid-phase reaction at the synthesis temperature of 880 DEG C, and can be fired at the temperature of 1000 DEG C, so that the energy-saving and consumption-reducing effects are remarkable, the cost is greatly reduced, and the product reaches a higher quality standard.

Description

Technical Field

[0001] The invention relates to the technical field of new energy vehicles and industrial applications, and in particular to a high-energy surge current-limiting PTC thermistor chip and a formula and production process thereof. Background Art

[0002] High-energy surge current limiting PTC thermistor components have the advantages of fast response, energy saving, low power consumption, and protection of circuit appliances; in the manufacturing process of traditional PTCR thermistor components, there are defects such as high energy consumption, high cost, poor consistency of high-temperature firing, and difficult process control. The processed PTCR component characteristic ceramic temperature coefficient is low. The PTCR components made with this traditional PTCR formula and firing process have unstable performance, high energy consumption, and high cost. At present, the electronic sensitive ceramic (high-energy surge current limiting) industry needs to adopt barium titanate (BaTiO3)-based high-energy surge current limiting PTC thermistor chip formula and processing method with superior electrical properties, mechanical properties, thermal properties, high mechanical strength, high temperature resistance, high humidity, excellent radiation resistance, component consistency, and higher reliability. Therefore, a high-energy surge current limiting PTC thermistor chip and its formula and production process are proposed. Summary of the invention

[0003] The purpose of the present invention is to provide a high-energy surge current limiting PTC thermistor chip sintering material formula and its production process, the material formula and the production process can form a good solid phase reaction at a synthesis temperature of 880°C, and can also be fired at 1000°C to form a high-energy surge current limiting PTC thermistor chip, the processed high-energy surge current limiting PTC thermistor chip to obtain a higher quality standard; its processing technology not only greatly reduces energy consumption, but also the production cost will be reduced accordingly.

[0004] To achieve the above object, the present invention provides the following technical solutions: a high-energy surge current limiting PTC thermistor chip, its formula and production process, the powder base material and molar composition of the high-energy surge current limiting PTC thermistor chip are: (BaCO 3 0.65 +SrCO 3 0.02 +Pb 3 O 4 0.32 +CaCO 3 0.017 TiO 2 1.02 )+NiO 0.001 +SiO 2 0.02 +CuO 0.0015 +La 2 O 3 0. 001 +Al 2 O 3 0.02 +CeO 2 0.002 +Y 2 O 3 0.008 +Mn 3 O 4 0.0011+Ta 2 O 50.0005 +Nb 2 O 5 0.0025 .

[0005] Preferably, the production process comprises the following steps:

[0006] S1, pre-sintering the primary batch into powder;

[0007] S2, secondary batching and granulation;

[0008] S3, tableting and firing;

[0009] S4. Chip testing.

[0010] Preferably, the primary batching and pre-sintering into powder comprises the following steps:

[0011] S11, calculate the exact amount of materials according to the molar ratio and weigh the materials;

[0012] S12, add the material to the sand mill in the ratio of material: water = 1:1.5, and grind the material. The particle size D50 of the material is required to be ≤0.3um;

[0013] S13, dehydrating and drying at 150°C;

[0014] S14. The dried powder is placed in a crucible and then put into a high-temperature furnace for synthesis. The synthesis curve is: the temperature is increased by 100°C for 35 minutes, and when the temperature reaches 880°C, it is kept at this temperature for 125 minutes, and then the temperature is reduced by 100°C every 35 minutes until it reaches room temperature.

[0015] Preferably, the secondary batching granulation comprises the following steps:

[0016] S21, perform secondary batching, the ratio of which is to add ZrO in the following amount by weight based on the powder base material: 2 0.01～ 0 .02 %、B 2 O 3 0.001～0.005 %, weigh the raw materials according to the ratio and weigh the materials;

[0017] S22, add the material to the sand mill in the ratio of material: water = 1:1.2, and grind the material. The particle size D50 of the material is required to be ≤0.3um;

[0018] S23, adding 15% PVA aqueous solution according to the weight percentage (wt%) of the powder, stirring evenly to obtain a soft material, granulating it in a spray granulation tower, and passing the granules through a 60-mesh sieve to obtain granules.

[0019] Preferably, the tabletting process comprises the following steps:

[0020] S31, adding the granules into the tablet press to compress the green tablets, the tablet specifications are: 37*21*4mm;

[0021] S32, putting the pressed green sheet into a tongs bowl, adding high temperature isolation powder, and loading into a high temperature sintering furnace for sintering, the pressed sheet sintering curve is: when the temperature is increased by 100°C, the time is 30 minutes, when it is increased to 1000°C, it is kept at this temperature for 60 minutes, and then the temperature is reduced by 150°C every 30 minutes until it reaches room temperature;

[0022] S33, the fired ceramic piece is cleaned, dried, and Al, Ag electrodes are formed to obtain a high-energy surge current limiting PTC thermistor chip with a positive temperature coefficient.

[0023] Preferably, the chip test comprises the following steps:

[0024] S41, test the chip, the specifications of the ceramic product are: 30*17*3.3㎜, Tc: 250℃±5℃, R 25 :100Ω±20%,Resistance temperature coefficient α:19.3% / ℃,Resistance jump ΔR:≥5×10 5 , Withstand voltage strength V b :≥480V / ㎜.

[0025] In the present invention, the processed high-energy surge current limiting PTC thermistor chip can form a good solid phase reaction at a synthesis temperature of 880°C, and the product firing can be completed at a temperature of 1000°C. Not only is the energy-saving and consumption-reducing effect significant, the cost is also greatly reduced, and the product reaches a higher quality standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a production process flow chart of a high-energy surge current limiting PTC thermistor chip. DETAILED DESCRIPTION

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example

[0031] See also Figure 1 As shown, a high-energy surge current limiting PTC thermistor chip, its formula and production process, include the following steps:

[0032] 1. Purchase and prepare raw materials;

[0033] Specifically, the raw materials used are: BaCO 3 、SrCO 3 , Pb 3 O 4 、CaCO 3 、TiO 2 , Y 2 O 3 、 2 O 5, Nb 2 O 5 , AL 2 O 3 、SiO 2 , Mn 3 O 4 、CeO 2 , B 2 O 3 , CuO, La 2 O 3 The purity is ≥99.8%.

[0034] 2. One-time batching and firing;

[0035] Specifically, (BaCO 3 0.65 +SrCO 3 0.02 +Pb 3 O 4 0.32 +CaCO 3 0.017 TiO 2 1.02 )+NiO 0.001 +SiO 20.02 +CuO 0.0015 +La 2 O 3 0.001 +Al 2 O 3 0.02 +CeO 2 0.002 +Y 2 O 3 0.008 +Mn 3 O 4 0.0011+Ta 2 O 5 0.0005 +Nb 2 O 5 0.0025 The exact amount of material is calculated by the molar ratio, and the material is weighed and added to the sand mill at a ratio of material: water = 1:1.5. The material is discharged after sand grinding. The particle size D50 of the discharged material is required to be ≦0.5um; then dehydrated and dried at 150℃. The dried powder is put into a crucible and then put into a high-temperature furnace for synthesis; the curve is: when the temperature is increased by 100℃, the time is 35 minutes, and when it increases to 880℃, it is kept warm for 125 minutes, and then the temperature is reduced by 100℃ every 35 minutes until it reaches room temperature to obtain the base material of the high-energy surge current limiting PTC thermistor chip.

[0036] 3. Secondary batching and firing;

[0037] Specifically, the total weight of the pre-fired base material of the high-energy surge current limiting PTC thermistor chip is added with: ZrO 2 0.01～0.02 %+B 2 O 3 0.001～0.005 %, weigh the raw materials according to the above ratio, add them to the sand mill at a ratio of material: water = 1:1.2, grind them and discharge them. The particle size D50 of the discharge is required to be ≦0.3um; add 15% PVA aqueous solution according to the weight percentage (wt%) of the powder, stir evenly to obtain a soft material, and then granulate it in a spray granulation tower. The granules are sieved through a 60-mesh sieve, and the granules are added to the tablet press to compress the green tablets. The tablet specifications are: 37*21*4mm; The green sheet is put into a tongs bowl, high-temperature isolation powder is added, and it is loaded into a high-temperature sintering furnace for sintering. The sintering curve is that the temperature increases by 100°C for 35 minutes, and when it increases to 1000°C, it is kept warm for 60 minutes, and then the temperature is reduced by 150°C every 30 minutes until it reaches room temperature; the ceramic sheet is obtained, and finally the sintered ceramic sheet is cleaned with clean water, dried at 100°C, the aluminum electrode is sealed, and the end is sintered at 650°C for 15 minutes. After electroplating silver-tin electrodes, it is sintered at 580°C to form a chip.

[0038] 4. Chip testing;

[0039] Tested according to product standards, tile specifications: 30*17*3.3㎜, T c =250℃±5℃、R 25 =100Ω±20%, resistance temperature coefficient α=19.3% / ℃, resistance jump Δ R :≥5×10 5 , Withstand voltage strength V b :≥480V / ㎜.

[0040] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-energy surge current limiting PTC thermistor chip and its formula, characterized in that: The powder base material and molar composition of the high-energy surge current limiting PTC thermistor chip are: (BaCO 30.65 +SrCO 30.02 +Pb3O 40.32 +CaCO 30.017 TiO 21.02 )+NiO 0.001 +SiO 20.02 +CuO 0.0015 +La2O 30.001 +Al2O 30.02 +CeO 20.002 +Y2O 30.008 +Mn3O4 0.0011+Ta2O 50.0005 +Nb2O 50.0025 .

2. The production process of a high-energy surge current limiting PTC thermistor chip according to claim 1, characterized in that: The following steps are involved: S1, pre-sintering the primary batch into powder; S2, secondary batching and granulation; S3, tableting and firing; S4. Chip testing.

3. The production process of a high-energy surge current limiting PTC thermistor chip according to claim 2, characterized in that: In step S1, the primary batching is pre-sintered into powder, comprising the following steps: S11, calculate the exact amount of materials according to the molar ratio and weigh the materials; S12, add the material to the sand mill in the ratio of material: water = 1:1.5, and grind the material. The particle size D50 of the material is required to be ≤0.3um; S13, dehydrating and drying at 150°C; S14. The dried powder is placed in a crucible and then put into a high-temperature furnace for synthesis. The synthesis curve is: the temperature is increased by 100°C for 35 minutes, and when the temperature reaches 880°C, it is kept at this temperature for 125 minutes, and then the temperature is reduced by 100°C every 35 minutes until it reaches room temperature.

4. The production process of a high-energy surge current limiting PTC thermistor chip according to claim 2, characterized in that: In step S2, the secondary batching granulation comprises the following steps: S21, perform secondary batching, the ratio of which is to add ZrO in the following amount by weight based on the powder base material: 20.01～0.02％ 、B2O 30.001～0.005％ , weigh the raw materials according to the ratio and weigh the materials; S22, add the material to the sand mill in the ratio of material: water = 1:1.2, and grind the material. The particle size D50 of the material is required to be ≤0.3um; S23, adding 15% PVA aqueous solution according to the weight percentage (wt%) of the powder, stirring evenly to obtain a soft material, granulating it in a spray granulation tower, and passing the granules through a 60-mesh sieve to obtain granules.

5. The production process of a high-energy surge current limiting PTC thermistor chip according to claim 2, characterized in that: In step S3, the tableting process includes the following steps: S31, adding the granules into the tablet press to compress the green tablets, the tablet specifications are: 37*21*4mm; S32, putting the pressed green sheet into a tongs bowl, adding high temperature isolation powder, and loading into a high temperature sintering furnace for sintering, the pressed sheet sintering curve is: when the temperature is increased by 100°C, the time is 30 minutes, when it is increased to 1000°C, it is kept at this temperature for 60 minutes, and then the temperature is reduced by 150°C every 30 minutes until it reaches room temperature; S33, the fired ceramic piece is cleaned, dried, and Al, Ag electrodes are formed to obtain a high-energy surge current limiting PTC thermistor chip with a positive temperature coefficient.

6. The production process of a high-energy surge current limiting PTC thermistor chip according to claim 2, characterized in that: In step S4, the chip test includes the following steps: S41, test the chip, the specifications of the ceramic product are: 30*17*3.3㎜, Tc: 250℃±5℃, R 25 :100Ω±20%,Resistance temperature coefficient α:19.3% / ℃,Resistance jump Δ R :≥5×10 5 , Withstand voltage strength V b :≥480V / ㎜.

Images