CN103304186A - Ferrite-base composite magnetic dielectric antenna substrate material and preparation method thereof - Google Patents

Abstract

The invention discloses a ferrite-base composite magnetic dielectric antenna substrate material and a preparation method thereof. The ferrite-base composite magnetic dielectric antenna substrate material is formed by combining a main phase material which accounts for 85-90wt% and an auxiliary phase material which accounts for 15-10% in percentage by mass, wherein the main phase material is Co2Z type hexagonal ferrite, with molecular formula represented as Ba3-xSrxCo2Fe24-yO41, wherein x ranges from 0 to 1.5 and y ranges from 0 to 4; the auxiliary phase material is polyimide resin. The magnetic dielectric composite substrate material has a relatively low magnetic conductivity and a relatively high dielectric constant within a frequency range of 300MHz-3GHz, and the composite substrate material is comparatively high in miniaturization factor and is simultaneously comparatively low in both magnetic loss and dielectric loss; the composite substrate material, in comparison with the conventional ceramic substrate material, is better in mechanical shock resistance. The ferrite-base composite magnetic dielectric antenna substrate material is not only favorable for reducing the weight and size of an antenna, but also conductive to improving the bandwidth of the micro-strip antenna and for inhibiting the generation of a surface wave.

Description

Compound magnetic Jie of a kind of ferrite base antenna substrate material and preparation method thereof

Technical field

The invention belongs to technical field of electronic materials, relate to a kind ofly take the hexgonal screw material as parent, be suitable for compound magnetic Jie antenna substrate material of 300MHz～3GHz antenna applications and preparation method thereof.

Background technology

In recent years, fast development along with wireless communication technology, the miniaturization of signal equipment has become a kind of inevitable development trend, and the characteristic dimension that how to reduce antenna does not affect again its radiance simultaneously, becomes the Main Bottleneck difficult problem that current wireless signal equipment miniaturization development faces.We know the characteristic dimension of using high dielectric material can effectively dwindle antenna as antenna substrate, but dwindle the antenna features size by improving specific inductivity merely, not only easily at substrate surface excitating surface ripple, reduce the efficient of antenna.The bandwidth of antenna is also very narrow simultaneously, can greatly limit the effectiveness of antenna.According to the antenna resonant frequency relational expression

As can be known, by improving the magnetic permeability of antenna substrate material, equally also can reach the effect of dwindling the antenna features size, and dwindle the antenna features size by improving magnetic permeability rather than specific inductivity, also be difficult for the bandwidth that evokes surface-duided wave and more be conducive to expand antenna.In addition, if can accomplish to make magnetic permeability and the approximately equalised words of specific inductivity of medium substrate material, the natural impedance of antenna medium substrates $Z=\sqrt{{\mathrm{\μ}}_0^{\′}{\mathrm{\μ}}^{\′}/{\mathrm{\ϵ}}_0^{\′}{\mathrm{\ϵ}}^{\′}}={\mathrm{\η}}_0\sqrt{{\mathrm{\μ}}^{\′}/{\mathrm{\ϵ}}^{\′}}={\mathrm{\η}}_0,$ Equate with the natural impedance of vacuum, can make like this antenna energy reflection level off to zero, also help the radiation efficiency that improves antenna.Therefore, adopt the material that has magnetic permeability and specific inductivity concurrently to be used as antenna substrate, can be good at taking into account antenna miniaturization and high performance complex art requirement.

Also there are in recent years many pieces of papers and patent to carry out the research and development of respective material both at home and abroad.Adopt Li such as people such as the M.L.S.Teo of NUS and L.B.Kong _0.5Fe _2.5O ₄Ferrite and Mg _1-xCu _xFe _1.98O ₄The mode that ferrite carries out suitable ion substitution or doping obtains the stupalith that equimagnetic is situated between.（M.L.S.Teo,L.B.Kong,et?al.“Development?of?magneto-dielectric?materials?based?on?Li-ferrite?ceramics:Ⅰ,Ⅱ,Ⅲ”,J.Alloys.Comp.,vol.559(2008)557-566,567-575,576-582;L.B.Kong,Z.W.Li,“Magneto-dielectric?properties?of?Mg-Cu-Co?Ferrite?Ceramics:Ⅰ,Ⅱ”,J.Am.Ceram.Soc.,vol.90(2007)3106-3112,2104-2112）。But the frequency range that above two types equimagnetic Jie baseplate material is suitable for is all narrow, mainly at 3～30MHz.Our seminar has applied for a national inventing patent (ZL200910058207.3, a kind of low frequency microstrip aerial substrate material and preparation method thereof) in 2009, take Ni _xCu _0.1Zn _yCo _0.05Fe _zO _4-δ(wherein the span of x is that the span of 0.78～0.82, y is that the span of 0.07～0.03, z is that 1.90～1.94, δ scope is generally between 0～0.5) material and Bi _aSr _1-aTiO ₃(wherein the span of a is 0.20～0.24) carries out compound, can realize in the scope of 1MHz～100MHz all approximately equals of matrix material magnetic permeability and specific inductivity, between 18 to 25.The dielectric loss factor of material all is lower than 0.03 in whole frequency band.But this material magnetic loss is relatively also larger, can rise to more than 0.05 above magnetic loss factor after the 50MHz, and close to 0.1, therefore the effect more than 50MHz is not so good during 100MHz.

According to the mandatory Scirocco formula of magneticsubstance, the magnetic permeability of magneticsubstance and its limiting frequency are inversely proportional to.And its Scirocco product of the magneticsubstance of same structure system is approximately constant.Simultaneously, the ferrite of hexaplanar has the Scirocco constant product than high several times of spinel ferrite material owing to being in-plane anisotropy.Therefore, if be used in higher frequency range, adopt ferrite or its matrix material of hexaplanar to have more advantage.Our seminar once adopted WO ₃The Co that mixes ₂The Z ferrite, based on two-step sintering method, obtained magnetic permeability and specific inductivity is about 12, and magnetic loss and dielectric loss tangent can be lower than respectively 0.05 and 0.007 equimagnetic Jie, low-loss antenna substrate material when 200MHz, and gone out the TDMB antenna of a miniaturization based on this material development, respond well (Qi Xia, Hua Su, et al., Investigation of low loss Z-type hexaferrites for antenna applications, J.Appl.Phys., 2012,111 (6): 063921; Qi Xia, Hua Su, et al., Miniaturized T-DMB antenna based on low loss magneto-dielectric materials for mobile handset applications, J.Appl.Phys., 2012,112 (4), 043915).But, if the magnetic dielectric material is applied on the antenna of high frequency more, must improve by the magnetic permeability that further forces down material its limiting frequency, thereby guarantee can obtain low magnetic loss in the frequency range of using.For this reason, our seminar also takes the Co with hexaplanar ₂The Z ferrite mixes in twin screw extruder with acrylic resin, and then 200 ℃ of lower preheatings and the compacting mode, magnetic permeability and specific inductivity have been obtained all about 3, and magnetic loss and dielectric loss tangent all are lower than equimagnetic Jie antenna substrate material of 0.01, and applicable frequency range can be extended to 300MHz～3GHz frequency range (ZL201110235563.5).Although this composite substrate material over-all properties is better, its preparation method is comparatively complicated, because acrylic resin is solid-state, with Co ₂The Z ferrite powder must carry out heat in special twin screw extruder mixed, and moulding also must carry out moulding by the mode of high temperature hot pressing, to having relatively high expectations of equipment.In addition, because specific inductivity is also forced down about 3, although realized equimagnetic Jie, be conducive to realize the coupling of antenna substrate natural impedance and vacuum characteristic impedance, its miniaturization factor is less, not too is beneficial to the miniaturization of antenna.

Summary of the invention

The purpose of this invention is to provide a kind of with Co ₂The Z ferrite is compound magnetic Jie antenna substrate material of parent and preparation method thereof, solves the problem that existing antenna exists aspect miniaturization.

Technical solution of the present invention is: compound magnetic Jie of a kind of ferrite base antenna substrate material is formed by the principal phase material of 85%～90% mass ratio and the auxiliary phase Material cladding of 15%～10% mass ratio.Described principal phase material is Co ₂The Z-type hexad ferrite, its prescription molecular formula is Ba _3-xSr _xCo ₂Fe _24-yO ₄₁, wherein the span of x is that the span of 0～1.5, y is 0～4, described auxiliary phase material is polyimide (PI) resin.

An amount of Sr replaces Ba and is conducive to improve magnetic permeability, takes the prescription of an amount of iron deficiency to help to improve Co ₂The ferritic resistivity of Z, and then reduce magnetic loss, but magnetic permeability can descend to some extent.

In above-mentioned compound magnetic Jie baseplate material, described Co ₂The doping agent that also can contain certain dopant dose in the Z-type hexad ferrite principal phase material is suitably regulated Co ₂The ferritic comprehensive magnetic energy of Z is as reducing magnetic loss, raising density, raising or reducing magnetic permeability etc. and (as mix a small amount of Nb ₂O ₅Or WO ₃Improve ferrite sintered density and improve magnetic permeability; Mix a small amount of Bi ₂O ₃Reduce ferrite sintered temperature, thereby reduce magnetic loss etc., but these doping are optional).

Need to prove: 1) principal phase material C o ₂The Fe ion of the Co ion of divalence and trivalent also can be carried out a small amount of substituting by the metal ion of other divalence and trivalent in the Z-type hexad ferrite prescription molecular formula, thereby to ferritic magnetic property, consist of some impacts such as magnetic permeability, magnetic loss etc., enumerate no longer one by one at this, but these ion substitutions are optional; 2) principal phase material C o ₂In the Z-type hexad ferrite prescription molecular formula, along with the value from 0 to 1.5 of x increases corresponding Co gradually ₂The ferritic magnetic permeability of Z-type and specific inductivity increase to about 15 from about 10; Adopt polyimide (specific inductivity is about 2.8, and magnetic permeability is 1) and described Co ₂The ferritic magnetic permeability of Z-type described compound in proportion after, the magnetic permeability of integral composite can be adjusted to 2.5～4.5, specific inductivity can tune to about 7～9; 3) we adopt polyimide resin is the PI-031 polyimide type resin that Intelligence Technology (China) Co., Ltd. produces, and adopt the specific inductivity of polyimide resin of the different trades mark or different manufacturers and solidification value to have slightly difference, therefore with Co ₂The Z-iron oxysome carry out compound after, the dielectric properties of baseplate material and solidification value etc. also may have difference slightly.

The preparation method of above-mentioned composite substrate material may further comprise the steps:

Step 1: with Fe ₂O ₃, BaCO ₃, SrCO ₃And Co ₂O ₃Be raw material, according to Co ₂Z-iron oxysome prescription molecular formula Ba _3-xSr _xCo ₂Fe _24-yO ₄₁The ratio of middle metallic element is converted out Fe ₂O ₃, BaCO ₃, SrCO ₃And Co ₂O ₃Mass percent, carry out weighing, batch mixing, a ball milling post-drying; Wherein the span of x is that the span of 0～1.5, y is 0～4.

Step 2: compacting punching in the sintering alms bowl after ball milling of step 1 gained oven dry material sieved, rise to calcined temperature by 3 ℃/minutes temperature rise rates and carry out pre-burning, furnace cooling obtains ferrite prefiring material.Described calcined temperature scope is 1150 ℃～1250 ℃, and soaking time is 2～4 hours.

Step 3: step 2 gained preburning powdered material is carried out secondary ball milling, and the mean particle size of powder is controlled at below 1 micron behind the secondary ball milling, then the secondary ball abrasive material is dried.

Step 4: the polyvinyl alcohol solution (concentration is 8～10%) that step 3 gained secondary ball milling oven dry material is sieved about rear adding 10wt% carries out granulation, then being pressed into a large cylinder carries out sintering and (pours compacting direct sintering in the sintering alms bowl into after also the secondary ball abrasive material can being sieved, but the magnetic loss of the final antenna substrate material that obtains like this than compression moulding after sintering to prepare the magnetic loss of material higher, magnetic permeability is more on the low side).Sintering rises to ferrite sintered temperature and carries out sintering by 2～3 ℃/minutes temperature rise rate, and furnace cooling obtains Co ₂The ferrite sintered material of Z.Described ferrite sintered temperature range is 1200～1300 ℃, and soaking time is 3～4 hours.

Step 5: with the Co of step 4 gained ₂Z ferrite cylinder (or sintered material) carries out ball milling three times after just pulverizing in ball mill, then with three ball milling material oven dry.Preferably can make the ferrite particle mean particle size below 3 microns behind three ball millings, can suppress like this appearance of domain wall displacement loss, be conducive to reduce the magnetic loss of ferrite particle and final composite substrate material.It should be noted that the globule size of ferrite powder also can consist of on the magnetic permeability of final combined antenna baseplate material some impacts behind three ball millings.

Step 6: with three ball millings of step 5 gained oven dry material and polyimide resin solution by b: mix granulation after the mass percent weighing (100-b) (wherein the span of b is 85～90); polyimide resin solution has certain viscosity, is equivalent to the granulation mixture of ferrite powder.In order to reach better granulation effect, the material compacting that agitation as appropriate can be mixed crushing screening more in flakes or behind the piece.After granulation evenly, under moulding press, be pressed into again the substrate shape that needs.

Step 7: the substrate that step 6 is developed moulding is warming up to 280～300 ℃ and be incubated 10～30 minutes in sintering oven, allow polyimide resin solidify, and naturally cools to normal temperature and obtains compound magnetic Jie substrate.

Through above seven steps, just can obtain microstrip antenna composite substrate material of the present invention, after tested, this material is in the range of frequency of 300MHz～3GHz, and magnetic permeability is between 2.5～4.5, and specific inductivity is between 7～9.Can be lower than 0.01,1GHz～3GHz frequency range magnetic loss tangent at 300MHz～1GHz frequency range magnetic loss tangent and be lower than 0.05.Dielectric loss tangent can be lower than 0.005 in the range of frequency of 300MHz～3GHz.

The major advantage of microstrip antenna composite substrate material provided by the invention is:

1, in the frequency range of 300M～3GHz, its magnetic permeability is between 2.5～4.5, and specific inductivity has the higher miniaturization factor, the characteristic dimension that is conducive to dwindle antenna between 7～9.Simultaneously since by the magnetic permeability of baseplate material dwindle antenna size, have wider bandwidth than the antenna of simple employing high dielectric material substrate preparation, and be not easy to the excitating surface ripple.This matrix material magnetic permeability is lower, and according to the Scirocco formula, the limiting frequency that it is actual even can reach more than the 5GHz just surpasses after the 3GHz, and magnetic loss is relatively high, and the gain of antenna is had certain reduction.

2, contain macromolecule organic material in this compound magnetic Jie baseplate material, the snappiness of sheet material is higher than conventional ceramic substrate material.

4, this material preparation method is simple, has evaded the compound needed hot press forming technology of conventional inorganic ceramic and organic medium, processes more simple.

In sum, magnetic Jie composite substrate material provided by the invention has lower magnetic permeability and higher specific inductivity in the range of frequency of 300MHz～3GHz, and the miniaturization factor is higher, and its magnetic loss and dielectric loss are all lower simultaneously; In addition, this composite substrate material also has certain snappiness, and is better than the performance of the anti-mechanical shock of conventional ceramic substrate material.Adopt compound magnetic Jie baseplate material provided by the invention as antenna substrate, not only help to reduce the antenna weight and volume, and the generation that is conducive to improve the bandwidth of microstrip antenna and suppresses surface-duided wave.This material preparation method that the present invention provides simultaneously is simple to operation, is convenient to grasp and promote.

Description of drawings

Fig. 1 is preparation method's schematic flow sheet of magnetic Jie composite substrate material provided by the invention.

Embodiment

Compound magnetic Jie of a kind of ferrite base antenna substrate material is formed by the principal phase material of 85%～90% mass ratio and the auxiliary phase Material cladding of 15%～10% mass ratio.Described principal phase material is Co ₂The Z-type hexad ferrite, its prescription molecular formula is Ba _3-xSr _xCo ₂Fe _24-yO ₄₁, wherein the span of x is that the span of 0～1.5, y is 0～4, described auxiliary phase material is polyimide (PI) resin.

Embodiment

A kind of with Co ₂The Z ferrite is compound magnetic Jie antenna substrate material of parent, is formed by the principal phase material of 90% mass ratio and the auxiliary phase Material cladding of 10% mass ratio.Described principal phase material is Co ₂The Z-type hexad ferrite, its prescription molecular formula is Ba _1.5Sr _1.5Co ₂Fe ₂₂O ₄₁Described auxiliary phase material is polyimide resin (intelligent Science and Technology Ltd. produces, the PI-031 polyimide type resin).

The concrete preparation method of above-mentioned compound magnetic Jie antenna substrate material is as follows:

Step 1: with Fe ₂O ₃, BaCO ₃, SrCO ₃And Co ₂O ₃Be raw material, according to Co ₂Z-iron oxysome prescription molecular formula Ba _3-xSr _xCo ₂Fe _24-yO ₄₁The ratio of middle metallic element is converted out Fe ₂O ₃, BaCO ₃, SrCO ₃And Co ₂O ₃Mass percent, carry out weighing, batch mixing, 4 hours post-dryings of a ball milling; Wherein the value of x is that the value of 1.5, y is 2.

Step 2: compacting punching in the sintering alms bowl after ball milling of step 1 gained oven dry material sieved, rise to calcined temperature by 3 ℃/minutes temperature rise rates and carry out pre-burning, furnace cooling obtains ferrite prefiring material.Described calcined temperature is 1250 ℃, and soaking time is 2 hours.

Step 3: step 2 gained preburning powdered material was carried out secondary ball milling 6 hours, and then the mean particle size of powder dries the secondary ball abrasive material about about 0.8 micron behind the secondary ball milling.

Step 4: the polyvinyl alcohol solution (concentration is about 10%) that step 3 gained secondary ball milling oven dry material is sieved about rear adding 10wt% carries out granulation, then is pressed into a large cylinder and carries out sintering.During sintering below 500 ℃ by 2 ℃/minutes temperature rise rate, and 500 ℃ of insulations 1 hour making things convenient for binder removal, 500 ℃～1230 ℃ by 2 ℃/minutes temperature rise rates, after 3 hours, furnace cooling obtains Co 1230 ℃ of insulations ₂The Z ferrite cemented body.

Step 5: with the Co of step 4 gained ₂The Z ferrite cemented body carries out ball milling three times after just pulverizing in planetary ball mill, three times Ball-milling Time is 6 hours.

Step 6: with three ball millings of step 5 gained oven dry material and polyimide resin by b: mix granulation after the mass percent weighing (100-b) (wherein the span of b is 88); polyimide solution has certain viscosity, is equivalent to the granulation mixture of ferrite powder.In order to reach better granulation effect, crushing screening again behind the material pressing block that we will mix first.After granulation evenly, under moulding press, be pressed into again the substrate shape that needs.

Step 7: the substrate that step 6 is developed moulding is warming up to 300 ℃ and be incubated 15 minutes in sintering oven, allow polyimide resin solidify fully, naturally cools to normal temperature and obtains compound magnetic Jie substrate.

Through above seven steps, just can obtain microstrip antenna composite substrate material of the present invention, after tested, this material is in the range of frequency of 300MHz～3GHz, magnetic permeability is stabilized between 3.5～3.6, specific inductivity can be lower than 0.01,1GHz～3GHz frequency range magnetic loss tangent at 300MHz～1GHz frequency range magnetic loss tangent and be lower than 0.05 between 7.8～8.Dielectric loss tangent can be lower than 0.005 in the range of frequency of 300MHz～3GHz.

Claims (8)

1. compound magnetic Jie of ferrite base antenna substrate material, it is characterized in that: it is formed by the principal phase material of 85% ~ 90% mass ratio and the auxiliary phase Material cladding of 15% ~ 10% mass ratio; Described principal phase material is Co ₂The Z-type hexad ferrite, its prescription molecular formula is Ba _3-xSr _xCo ₂Fe _24-yO ₄₁, wherein the span of x is that the span of 0 ~ 1.5, y is 0 ~ 4, described auxiliary phase material is polyimide resin.

2. compound magnetic Jie of a kind of ferrite base according to claim 1 antenna substrate material, it is characterized in that: it is formed by the principal phase material of 90% mass ratio and the auxiliary phase Material cladding of 10% mass ratio, and described principal phase material is Co ₂The Z-type hexad ferrite, its prescription molecular formula is Ba _1.5Sr _1.5Co ₂Fe ₂₂O ₄₁Described auxiliary phase material is polyimide resin.

3. compound magnetic Jie of ferrite base antenna substrate material preparation method is characterized in that, its step is as follows:

Step 1: with Fe ₂O ₃, BaCO ₃, SrCO ₃And Co ₂O ₃Be raw material, according to Co ₂Z-iron oxysome prescription molecular formula Ba _3-xSr _xCo ₂Fe _24-yO ₄₁The ratio of middle metallic element is converted out Fe ₂O ₃, BaCO ₃, SrCO ₃And Co ₂O ₃Mass percent, carry out weighing, batch mixing, a ball milling post-drying; Wherein the span of x is that the span of 0 ~ 1.5, y is 0 ~ 4;

Step 2: compacting punching in the sintering alms bowl after ball milling of step 1 gained oven dry material sieved, rise to calcined temperature by certain temperature rise rate and carry out pre-burning, furnace cooling obtains ferrite prefiring material;

Step 3: step 2 gained preburning powdered material is carried out secondary ball milling, and the mean particle size of powder is controlled at below 1 micron behind the secondary ball milling, then the secondary ball abrasive material is dried;

Step 4: the polyvinyl alcohol solution that step 3 gained secondary ball milling oven dry material is sieved about rear adding 10wt% carries out granulation, then is pressed into a large cylinder and carries out sintering, or pour compacting direct sintering in the sintering alms bowl into after the secondary ball abrasive material sieved;

Step 5: the sintered material of step 4 gained is just pulverized the rear ball milling that carries out three times in ball mill, then with three ball milling material oven dry;

Step 6: with three ball millings of step 5 gained oven dry material and polyimide resin solution by b: mix granulation after the mass percent weighing (100-b), wherein the span of b is 85 ~ 90, be pressed into after the granulation evenly need to substrate shape;

Step 7: the substrate that step 6 is developed moulding is warming up to 280 ~ 300 ℃ and be incubated 10 ~ 30 minutes in sintering oven, allow polyimide resin solidify, and naturally cools to normal temperature and obtains compound magnetic Jie substrate.

4. compound magnetic Jie of a kind of ferrite base according to claim 3 antenna substrate material preparation method, it is characterized in that: the temperature rise rate by 3 ℃/minutes in the step 2 rises to calcined temperature and carries out pre-burning, described calcined temperature scope is 1150 ℃ ~ 1250 ℃, and soaking time is 2 ~ 4 hours.

5. compound magnetic Jie of a kind of ferrite base according to claim 3 antenna substrate material preparation method is characterized in that: in the step 4, sintering rises to ferrite sintered temperature by 2 ~ 3 ℃/minutes temperature rise rate and carries out sintering, and furnace cooling obtains Co ₂The ferrite sintered material of Z; Described ferrite sintered temperature range is 1200 ~ 1300 ℃, and soaking time is 3 ~ 4 hours.

6. compound magnetic Jie of a kind of ferrite base according to claim 3 antenna substrate material preparation method is characterized in that: behind three ball millings the ferrite particle mean particle size is controlled at below 3 microns in the step 5.

7. compound magnetic Jie of a kind of ferrite base according to claim 3 antenna substrate material preparation method is characterized in that: the material that in the step 6 agitation as appropriate is mixed is suppressed first in flakes or crushing screening again behind the piece, and is even to guarantee granulation.

8. compound magnetic Jie of each described a kind of ferrite base antenna substrate material preparation method is characterized in that according to claim 3-7, and its step is as follows:

Step 1: with Fe ₂O ₃, BaCO ₃, SrCO ₃And Co ₂O ₃Be raw material, according to Co ₂Z-iron oxysome prescription molecular formula Ba _3-xSr _xCo ₂Fe _24-yO ₄₁The ratio of middle metallic element is converted out Fe ₂O ₃, BaCO ₃, SrCO ₃And Co ₂O ₃Mass percent, carry out weighing, batch mixing, 4 hours post-dryings of a ball milling; Wherein the value of x is that the value of 1.5, y is 2;

Step 2: compacting punching in the sintering alms bowl after ball milling of step 1 gained oven dry material sieved, rise to calcined temperature by 3 ℃/minutes temperature rise rates and carry out pre-burning, furnace cooling obtains ferrite prefiring material, and described calcined temperature is 1250 ℃, and soaking time is 2 hours;

Step 3: step 2 gained preburning powdered material was carried out secondary ball milling 6 hours, and then the mean particle size of powder dries the secondary ball abrasive material about about 0.8 micron behind the secondary ball milling;

Step 4: the polyvinyl alcohol solution that step 3 gained secondary ball milling oven dry material is sieved about rear adding 10wt% carries out granulation, then be pressed into a large cylinder and carry out sintering, during sintering below 500 ℃ by 2 ℃/minute temperature rise rate, and 500 ℃ the insulation 1 hour to make things convenient for binder removal, 500 ℃ ~ 1230 ℃ temperature rise rates of pressing 2 ℃/minutes, after 3 hours, furnace cooling obtains Co 1230 ℃ of insulations ₂The Z ferrite cemented body;

Step 5: with the Co of step 4 gained ₂The Z ferrite cemented body carries out ball milling three times after just pulverizing in planetary ball mill, three times Ball-milling Time is 6 hours;

Step 6: with three ball millings of step 5 gained oven dry material and polyimide resin by b: mix granulation after the mass percent weighing (100-b), wherein the span of b is 88, crushing screening again behind the material pressing block that will mix first, after granulation evenly, under moulding press, be pressed into again the substrate shape that needs;

Step 7: the substrate that step 6 is developed moulding is warming up to 300 ℃ and be incubated 15 minutes in sintering oven, allow polyimide resin solidify fully, naturally cools to normal temperature and obtains compound magnetic Jie substrate.

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