Dielectric material for a special capacitor of a constant temperature crystal oscillator and a method for preparing the same

Abstract

The application discloses a medium material of a special capacitor for a constant temperature crystal oscillator and a preparation method thereof, and belongs to the technical field of crystal oscillators and capacitors. 0.5 ,Bi 0.5 )TiO3 clinker is 13-20%, Pb(Zr 0.41 Ti 0.59 )O3 clinker is 23-33%, CaO is 0.2-0.3%, and Sb2O3 is 0.1-0.2%. The application is suitable for a super-low temperature change rate composite ceramic dielectric material in a wide temperature range of-55 to +225 DEG C, and can meet the high reliability requirement of a constant temperature crystal oscillator product.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of crystal oscillator and capacitor, and relates to a dielectric material of a capacitor special for crystal oscillator and a preparation method thereof. BACKGROUND

[0002] The constant temperature crystal oscillator product is a crystal oscillator which realizes the constant temperature of the crystal by controlling the ambient temperature of the crystal periphery. The product internally contains a voltage stabilizing circuit, a frequency modulation circuit and a temperature control circuit. The multilayer ceramic capacitor used in the circuit has an irreplaceable important role. The temperature stability of the performance index of the capacitor directly determines the temperature stability of the performance index of the whole crystal oscillator product, and the temperature stability of the performance index of the capacitor depends on the performance of the dielectric material of the capacitor. SUMMARY

[0003] The present application aims to improve the manufacturing process of the dielectric material of the multilayer ceramic capacitor special for the constant temperature crystal oscillator product, so as to obtain a multilayer ceramic capacitor with excellent performance index, especially excellent temperature stability, and finally meet the market requirements for the temperature stability of the crystal oscillator product. The temperature stability of the multilayer ceramic capacitor depends on the dielectric material used.

[0004] The technical scheme adopted by the present application to achieve the purpose is as follows:

[0005] A dielectric material of a capacitor special for constant temperature crystal oscillator, comprising, by weight percentage: BaTiO3 53-56%, (Na 0.5 ,Bi 0.5 )TiO3 frit 13-20%, Pb(Zr 0.41 Ti 0.59 )O3 frit 23-33%, CaO 0.2-0.3%, Sb2O3 0.1-0.2%.

[0006] Preferably, the (Na 0.5 ,Bi 0.5 )TiO3 frit is prepared from Na2CO3, Bi2O3 and TiO2, and the molar ratio of Na2CO3, Bi2O3 and TiO2 is 25:25:100.

[0007] Preferably, the Pb(Zr 0.41 Ti 0.59 )O3 frit is prepared from PbO, ZrO2 and TiO2, and the molar ratio of PbO, ZrO2 and TiO2 is 100:41:59.

[0008] A preparation method of a dielectric material of a capacitor special for constant temperature crystal oscillator, comprising the following steps:

[0009] S1. Preparing Pb(Zr 0.41 Ti 0.59 )O3 frit: according to the molar ratio of PbO, ZrO2 and TiO2 being 100:41:59, the ingredients are put into a ball mill, 3.5-4.5 times volume of deionized water is added, and the mixture is ball milled for 24-36 hours. The powder is dried at 112℃, and then sieved through a 200 mesh screen. The sieved powder is heated to 1050℃-1010℃ and kept for 2 hours, and then cooled at room temperature to obtain Pb(Zr 0.41 Ti 0.59 )O3 frit.

[0010] S2. Preparing (Na 0.5 ,Bi 0.5 )TiO3 frit: according to the molar ratio of Na2CO3, Bi2O3 and TiO2 being 25:25:100, the ingredients are put into a ball mill, 3.5-4.5 times volume of deionized water is added, and the mixture is ball milled for 24-36 hours. The powder is dried at 112℃, and then sieved through a 200 mesh screen. The sieved powder is heated to 1050℃-1010℃ and kept for 2 hours, and then cooled at room temperature to obtain (Na 0.5 ,Bi 0.5 )TiO3 frit.

[0011] S3. According to the weight ratio of BaTiO3 being 53-56%, (Na 0.5 ,Bi 0.5 )TiO3 frit being 13-20%, Pb(Zr 0.41 Ti 0.59 )O3 frit being 23-33%, CaO being 0.2-0.3%, and Sb2O3 being 0.1-0.2%, the ingredients are put into a ball mill, 3.5-4.5 times volume of deionized water is added, and the mixture is ball milled for 24-36 hours. The powder is dried at 112℃, and then sieved through a 500 mesh screen. 7%-8% of organic binder or paraffin is added to the sieved powder, and the mixture is pressed into a green body at 85-88 Mpa. Then the green body is heated to 1230℃-1245℃ and kept for 10-11 hours, and then cooled at room temperature to obtain the dielectric material for constant temperature crystal oscillator capacitor.

[0012] The beneficial effects of the present application are:

[0013] Provided is a composite ceramic dielectric material with ultra-low temperature change rate suitable for a wide temperature range of -55 to +225 DEG C, which can meet the high reliability requirements of ovenized crystal oscillator products. The dielectric constant epsilon of existing dielectric materials changes dramatically when the ambient temperature is above 165 DEG C, which makes the voltage stabilizing circuit, frequency modulation circuit and temperature control circuit in the ovenized crystal oscillator unable to work normally, and thus cannot meet the special requirements of temperature stability of the crystal oscillator for electronic systems working in a wide temperature range. The capacitor made of the ultra-low temperature change rate composite ceramic dielectric material provided by the present application fully meets such harsh requirements. In addition, the dielectric constant epsilon of the ultra-low temperature change rate composite ceramic dielectric material provided by the present application is higher than the highest 3523 of the dielectric constant at room temperature 25 DEG C of the existing similar temperature stability dielectric material, see the attached Figure 1 The absolute value of the change rate of the dielectric constant at -55 to +225 DEG C relative to the dielectric constant at room temperature 25 DEG C is kept within 15%, see the attached Figure 2 . BRIEF DESCRIPTION OF DRAWINGS

[0014] The attached Figure 1 is a dielectric constant test result graph of the best performance dielectric material realized by the embodiment 3 of the present application.

[0015] The attached Figure 2 is a dielectric constant temperature change rate test result graph of the best performance dielectric material realized by the embodiment 3. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work should fall within the protection scope of the present application.

[0017] The present application is a dielectric material for a capacitor special for ovenized crystal oscillator and a preparation method thereof, which adopts raw materials with analytical purity, i.e. BaTiO3, Na2CO3, Bi2O3, TiO2, PbO, ZrO2, CaO and Sb2O3.

[0018] BaTiO3 is 53 to 56%, (Na 0.5 , Bi 0.5 )TiO3 clinker is 13 to 20%, Pb(Zr 0.41 Ti 0.59 )O3 clinker is 23 to 33%, CaO is 0.2 to 0.3%, and Sb2O3 is 0.1 to 0.2%.

[0019] The weight percentage of the components and raw materials is as follows: BaTiO3 is 53 to 56%, (Na0.5 Bi 0.5 )TiO3 clinker is 13-20%, Pb(Zr 0.41 Ti 0.59 )O3 clinker is 23-33%, CaO is 0.2-0.3%, Sb2O3 is 0.1-0.2%; wherein Pb(Zr 0.41 Ti 0.59 )O3 is prepared using PbO, ZrO2 and TiO2, and the molar ratio of PbO, ZrO2 and TiO2 is 100:41:59; (Na 0.5 ,Bi 0.5 )TiO3 clinker is prepared using Na2CO3, Bi2O3 and TiO2, and the molar ratio of Na2CO3, Bi2O3 and TiO2 is 25:25:100.

[0020] The specific implementation is as follows:

[0021] Example 1

[0022] A dielectric material of a capacitor special for a constant temperature crystal oscillator includes, in terms of weight percentage, BaTiO3 is 53%, (Na 0.5 ,Bi 0.5 )TiO3 clinker is 16.5%, Pb(Zr 0.41 Ti 0.59 )O3 clinker is 30%, CaO is 0.3%, and Sb2O3 is 0.2%.

[0023] A preparation method of a dielectric material of a capacitor special for a constant temperature crystal oscillator includes the following steps:

[0024] (1) Preparing Pb(Zr 0.41 Ti 0.59 )O3 clinker: according to the molar ratio of PbO, ZrO2 and TiO2 is 100:41:59, the ingredients are put into a ball mill, 3.5 times of deionized water is added, and the mixture is ball milled for 24 hours, and then the mixture is dried at 112℃ to obtain a powder, the powder is sieved through a 200 mesh sieve, and the sieved powder is heated to 1050℃ and kept for 2 hours, and then the mixture is cooled to room temperature to obtain Pb(Zr 0.41 Ti 0.59 )O3 clinker;

[0025] (2) Preparing (Na 0.5 ,Bi 0.5)TiO3: the raw materials are prepared according to the molar ratio of Na2CO3, Bi2O3 and TiO2 as 25:25:100, the prepared raw materials are put into a ball mill, 3.5 times of deionized water is added, and the mixture is ball milled for 24 hours, and then the powder is obtained by drying at 112℃, the powder is sieved through a 200 mesh sieve, and the sieved powder is heated to 1050℃ and kept for 2 hours, and then the room temperature is cooled to obtain (Na 0.5 ,Bi 0.5 )TiO3 ceramic block;

[0026] (3) the raw materials are prepared according to the weight percentage of BaTiO3 as 53%, (Na 0.5 ,Bi 0.5 )TiO3 ceramic block as 16.5%, Pb(Zr 0.41 Ti 0.59 )O3 ceramic block as 30%, CaO as 0.3%, and Sb2O3 as 0.2%, the prepared raw materials are put into a ball mill, 3.5 times of deionized water is added, and the mixture is ball milled for 24 hours, and then the powder is obtained by drying at 112℃, the powder is sieved through a 500 mesh sieve, 7% of paraffin by weight is added to the sieved powder, and the green body is formed by pressing at a pressure of 85Mpa, and then the green body is heated to 1230℃ and kept for 11 hours, and then the room temperature is cooled to obtain the ultra-low temperature change rate composite ceramic dielectric material.

[0027] Example 2

[0028] A dielectric material of a capacitor special for a constant temperature crystal oscillator, including BaTiO3 as 54.3% by weight, (Na 0.5 ,Bi 0.5 )TiO3 ceramic block as 18%, Pb(Zr 0.41 Ti 0.59 )O3 ceramic block as 27.25%, CaO as 0.25%, and Sb2O3 as 0.2%.

[0029] A preparation method of a dielectric material of a capacitor special for a constant temperature crystal oscillator, comprising the following steps:

[0030] (1) Pb(Zr 0.41 Ti 0.59 )O3 ceramic block: the raw materials are prepared according to the molar ratio of PbO, ZrO2 and TiO2 as 100:41:59, the prepared raw materials are put into a ball mill, 4.5 times of deionized water is added, and the mixture is ball milled for 36 hours, and then the powder is obtained by drying at 112℃, the powder is sieved through a 200 mesh sieve, and the sieved powder is heated to 1010℃ and kept for 2 hours, and then the room temperature is cooled to obtain Pb(Zr 0.41 Ti 0.59 )O3 ceramic block;

[0031] (2) (Na 0.5 ,Bi0.5 )TiO3 brick: according to the molar ratio of Na2CO3, Bi2O3 and TiO2 being 25:25:100, the ingredients are put into a ball mill, 4.5 times volume of deionized water is added and ball-milled for 36 hours, the powder is obtained by drying at 112℃, the powder is sieved through a 200 mesh sieve, the sieved powder is heated to 1050℃-1010℃ and kept for 2 hours, and the room temperature is cooled to prepare (Na 0.5 ,Bi 0.5 )TiO3 brick;

[0032] (3) according to the weight of BaTiO3 being 54.3%, (Na 0.5 ,Bi 0.5 )TiO3 brick being 18%, Pb(Zr 0.41 Ti 0.59 )O3 brick being 27.25%, CaO being 0.25%, and Sb2O3 being 0.2%, the raw materials are prepared, the prepared raw materials are put into a ball mill, 4.5 times volume of deionized water is added and ball-milled for 36 hours, and then the powder is obtained by drying at 112℃, the powder is sieved through a 500 mesh sieve, 8% of the sieved powder by weight of organic binder is added, and the green body is prepared by pressing at a pressure of 85-88Mpa, then heated to 1245℃ and kept for 10 hours, and the room temperature is cooled to prepare the ultra-low temperature change rate composite ceramic dielectric material.

[0033] Example 3

[0034] A dielectric material of a capacitor special for a constant temperature crystal oscillator, according to the weight percentage, includes BaTiO3 being 54.35%, (Na 0.5 ,Bi 0.5 )TiO3 brick being 17%, Pb(Zr 0.41 Ti 0.59 )O3 brick being 28.25%, CaO being 0.2%, and Sb2O3 being 0.2%.

[0035] A preparation method of a dielectric material of a capacitor special for a constant temperature crystal oscillator, including the following steps:

[0036] (1) pre-preparing Pb(Zr 0.41 Ti 0.59 )O3 brick: according to the molar ratio of PbO, ZrO2 and TiO2 being 100:41:59, the ingredients are put into a ball mill, 4 times volume of deionized water is added and ball-milled for 30 hours, the powder is obtained by drying at 112℃, the powder is sieved through a 200 mesh sieve, the sieved powder is heated to 1030℃ and kept for 2 hours, and the room temperature is cooled to prepare Pb(Zr 0.41 Ti 0.59 )O3 brick;

[0037] (2) pre-prepared (Na 0.5 ,Bi 0.5 )TiO3 frit: the ingredients are prepared in a molar ratio of Na2CO3, Bi2O3 and TiO2 as 25:25:100, the ingredients are put into a ball mill, 4 times volume of deionized water is added and ball-milling is performed for 30 hours, the powder is dried at 112°C to obtain a powder, the powder is sieved through a 200 mesh sieve, and the sieved powder is heated to 1030°C and kept for 2 hours to obtain (Na 0.5 ,Bi 0.5 )TiO3 frit.

[0038] (3) the raw materials are prepared in a weight ratio of BaTiO3 as 54.35%, (Na 0.5 ,Bi 0.5 )TiO3 frit as 17%, Pb(Zr 0.41 Ti 0.59 )O3 frit as 28.25%, CaO as 0.2%, and Sb2O3 as 0.2%, the prepared raw materials are put into a ball mill, 4 times volume of deionized water is added and ball-milling is performed for 30 hours, and then the powder is dried at 112°C to obtain a powder, the powder is sieved through a 500 mesh sieve, 7.5% of paraffin by weight is added to the sieved powder, and a green body is formed under a pressure of 85-88 Mpa, and then the green body is heated to 1240°C and kept for 10.5 hours to obtain a super-low temperature change rate composite ceramic dielectric material.

[0039] The dielectric constant at room temperature is 3523, and the attached Figure 2 It can be seen that the absolute value of the change rate of the dielectric constant at -55-+225°C relative to the dielectric constant at room temperature 25°C is maintained within 15%, and the crystal oscillator of the multilayer ceramic capacitor manufactured using the dielectric material can meet the stringent requirements of the market on the temperature stability of the product.

[0040] Finally, it should be noted that the above-described embodiments are merely specific embodiments of the present application, which are used to illustrate the technical solutions of the present application, but not to limit the same, and the protection scope of the present application is not limited thereto, although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily think of changes to the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to some of the technical features, and these modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and all should be covered in the protection scope of the present application.

Claims

1. A dielectric material for a crystal oscillator dedicated capacitor, characterized by, By weight percentage, including: BaTiO3 is 53~56%, (Na 0.5 ,Bi 0.5 )TiO3 clinker is 13~20%, Pb(Zr 0.41 Ti 0.59 )O3 clinker is 23~33%, CaO is 0.2~0.3%, Sb2O3 is 0.1~0.2%.

2. The dielectric material of a capacitor dedicated for use in a TCXO according to claim 1, wherein The (Na 0.5 ,Bi 0.5 )TiO3 clinkers are prepared from Na2CO3, Bi2O3 and TiO2, and the molar ratio of Na2CO3, Bi2O3 and TiO2 is 25:25:

100.

3. The dielectric material of a capacitor dedicated for use in a TCXO according to claim 1, wherein Pb(Zr 0.41 Ti 0.59 )O3 pellets were prepared from PbO, ZrO2and TiO2in a molar ratio of 100:41:

59.

4. A method of preparing a dielectric material for a crystal oscillator dedicated capacitor, characterized by, comprising the steps of: S1. Preparing Pb(Zr 0.41 Ti 0.59 )O3 frit: according to the molar ratio of PbO, ZrO2 and TiO2 being 100:41:59, the ingredients are put into a ball mill, 3.5-4.5 times volume of deionized water is added, and ball milling is carried out for 24-36 hours. The powder is dried at 112°C, and then sieved through a 200 mesh screen. The sieved powder is heated to 1050-1010°C and kept for 2 hours, and then cooled at room temperature to obtain Pb(Zr 0.41 Ti 0.59 )O3 frit. S2. Preparing (Na 0.5 ,Bi 0.5 )TiO3 frit: ingredients are prepared in a ball mill with a 25:25:100 molar ratio of Na2CO3, Bi2O3 and TiO2, and 3.5-4.5 times the volume of deionized water is added to the ball mill and milled for 24-36 hours. The powder is dried at 112°C, sieved through a 200 mesh screen, and heated to 1050-1010°C for 2 hours and cooled to room temperature to produce (Na 0.5 ,Bi 0.5 )TiO3 frit. S3. According to the weight of BaTiO3 is 53~56%, (Na 0.5 ,Bi 0.5 )TiO3 clinker is 13~20%, Pb(Zr 0.41 Ti 0.59 )O3 clinker is 23~33%, CaO is 0.2~0.3%, Sb2O3 is 0.1~0.2% to prepare raw materials, the raw materials are placed in the ball mill, add 3.5~4.5 times the volume of deionized water and ball mill for 24~36 hours; then dried at 112 DEG C environment to obtain powder, the powder is sieved through a 500 mesh screen, 7%~8% of the weight of organic binder or paraffin is added to the sieved powder, and the green body is formed by pressing at 85~88 Mpa, then heated to 1230 DEG C~1245 DEG C and kept for 10~11 hours, and cooled at room temperature to obtain the dielectric material of the constant temperature crystal oscillator special capacitor.

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