Heat-resistant nanocrystalline magnetic-isolation shielding material and preparation method and application thereof

Abstract

The present application relates to the technical field of electromagnetic-isolation shielding materials, and in particular to a heat-resistant nanocrystalline magnetic-isolation shielding material and a preparation method and application thereof. The preparation method includes the following steps: S1, applying a double-sided adhesive tape onto a nanocrystalline soft-magnetic alloy ribbon to prepare a adhesive-coated nanocrystalline ribbon; S2, performing primary magnet cracking treatment on the adhesive-coated nanocrystalline ribbon to obtain a single-layered nanocrystalline magnetic layer; S3, performing multi-layer combination on the single-layered nanocrystalline magnetic layer to obtain a composite, and performing stress relief treatment on the composite to obtain a multi-layered nanocrystalline magnetic layer; and S4: performing secondary magnet cracking treatment on the multi-layered nanocrystalline magnetic layer to obtain a heat-resistant nanocrystalline magnetic-isolation shielding material.

Claims

1. A preparation method of a heat-resistant nanocrystalline magnetic-isolation shielding material, comprising the following steps: S1, applying a double-sided adhesive tape onto a nanocrystalline soft-magnetic alloy ribbon to prepare an adhesive-coated nanocrystalline ribbon; S2, performing a primary magnet cracking treatment on the adhesive-coated nanocrystalline ribbon to obtain a single-layered nanocrystalline magnetic layer; S3, performing multi-layer combination on the single-layered nanocrystalline magnetic layer and one or more other single-layered nanocrystalline magnetic layers to obtain a composite, and performing stress relief treatment on the composite to obtain a multi-layered nanocrystalline magnetic layer; and S4: performing a secondary magnet cracking treatment on the multi-layered nanocrystalline magnetic layer to obtain the heat-resistant nanocrystalline magnetic-isolation shielding material.

2. The method according to claim 1, wherein, in the step S1, the double-sided adhesive tape has a base material or does not have a base material, and the base material is a polyethylene terephthalate (PET) film with a thickness of no more than 1.9 ?m.

3. The method according to claim 2, wherein, a thickness of an adhesive layer in the double-sided adhesive tape ranges from 3 ?m to 30 ?m, an adhesive in the adhesive layer is an acrylic adhesive or a modified acrylic adhesive, and the modified acrylic adhesive is an acrylic adhesive modified by a bismethylsilane coupling agent.

4. The method according to claim 1, wherein, in the step S2, the primary magnet cracking treatment is implemented by longitudinal and transverse cross-roller shearing or by rolling with an anilox roller with raised points, roller scissors for the longitudinal and transverse cross-roller shearing have a blade gap of 1 mm to 1.5 mm, and the raised points on the anilox roller have a size from 1 mm to 1.5 mm.

5. The method according to claim 1, wherein, at least one of: in the step S1, a thickness of the nanocrystalline soft-magnetic alloy ribbon ranges from 12 ?m to 22 ?m; or in the step S3, a number of the single-layered nanocrystalline magnetic layers combined during the multi-layer combination is 2 to 4, and the multi-layered nanocrystalline magnetic layer has a thickness of 30 ?m to 120 ?m.

6. The method according to claim 1, wherein, in the step S3, the stress relief treatment comprises: aging the composite at a temperature of 80? C. to 120? C. for 0.5 h to 24 h to obtain an aged composite.

7. The method according to claim 6, wherein, the stress relief treatment further comprises: performing damp-heat aging on the aged composite at a relative humidity of 75% to 95% and a temperature of 80? C. to 100? C. for 6 h to 24 h.

8. The method according to claim 1, wherein, in the step S4, the secondary magnet cracking treatment is implemented by alternating rolling with a fine-mesh anilox roller with raised points with rolling with a patternless roller, and a size of the raised points on the fine-mesh anilox roller ranges from 0.5 mm to 1 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of a layered structure of a single-layered nanocrystalline magnetic layer prepared using a double-sided adhesive tape with a base material according to the present application.

(2) FIG. 2 is a schematic diagram of a layered structure of a double-layered nanocrystalline magnetic layer prepared using a double-sided adhesive tape with a base material according to the present application.

(3) FIG. 3 is a schematic diagram of a layered structure of a three-layered nanocrystalline magnetic layer prepared using a double-sided adhesive tape with a base material according to the present application.

(4) FIG. 4 is a schematic diagram of a magnetic fragment structure on a surface of a prepared heat-resistant nanocrystalline magnetic-isolation shielding material according to the present application.

(5) FIG. 5 is a surface fragmented magnetic morphology of the prepared heat-resistant nanocrystalline magnetic-isolation shielding material according to Example 1.

DETAILED DESCRIPTION OF EMBODIMENTS

(6) In order to make the present application easier to understand, the present application will be further described in detail below in conjunction with Examples. These Examples are only for illustrative purposes and do not limit the application scope of the present application. The raw materials or components used in the present application can be prepared by commercial means or conventional methods unless otherwise specified.

(7) In the following Examples, double-sided adhesive tapes using acrylic adhesives are all related double-sided adhesive tapes produced by Tianjin Xingangyuan Hengda Technology Development Co., Ltd. Double-sided adhesive tapes using modified acrylic adhesives are all related double-sided adhesive tapes produced by Green Cosmotec Optoelectronics Technologies Co., Ltd. Iron-based amorphous soft magnetic alloy ribbons are all related ribbons produced by Changde Zhijian New Materials Co., Ltd.

Example 1: Preparation of Heat-Resistant Nanocrystalline Magnetic-Isolation Shielding Material

(8) (1) An iron-based amorphous soft magnetic alloy ribbon with a thickness of 20 ?m was adopted and rolled into a ring-shaped iron core and then heat-treated at 565? C. in the presence of nitrogen. After annealing, an iron-based nanocrystalline soft magnetic alloy ribbon with a thickness of 20 ?m was obtained.

(9) (2) One side of the nanocrystalline ribbon obtained in step (1) was coated with a double-sided adhesive tape having an adhesive layer thickness of 3 ?m. The double-sided adhesive tape used was a double-sided adhesive tape with a base material, the adhesive in the adhesive layer was an acrylic adhesive, and the base material was a PET film with a thickness of 1.9 ?m. The other side of the nanocrystalline ribbon was a bare surface. A single-coated nanocrystalline ribbon was thus obtained.

(10) (3) Primary magnet cracking treatment was carried out on the single-coated nanocrystalline ribbon obtained in step (2). The primary magnet cracking treatment was implemented by way of longitudinal and transverse cross-roller shearing to obtain a single-layered nanocrystalline magnetic layer. The blade gap of roller scissors in cross-roller shearing was 1.5 mm. The size of nanocrystalline fragments in the single-layered nanocrystalline magnetic layer was about 0.5 mm, making the single-layered nanocrystalline magnetic layer have a magnetic permeability u=250?50 at a frequency of 6.78 MHz.

(11) (4) Three layers of the single-layered nanocrystalline magnetic layer obtained in step (3) were combined to obtain a composite. The composite was set still in an oven with a temperature of 85? C. for 12 h to have stress relief treatment to obtain a three-layered nanocrystalline magnetic layer with a thickness of 66 ?m.

(12) (5) Secondary magnet cracking treatment was carried out on the three-layered nanocrystalline magnetic layer obtained in step (4). The secondary magnet cracking treatment was implemented by way of alternating rolling with a fine-mesh anilox roller with raised points with rolling with a patternless roller to obtain a heat-resistant nanocrystalline magnetic-isolation shielding material. The size of raised points on the fine-mesh anilox roller was 0.8 mm. The size of fine fragments divided by micro-cracks in nanocrystalline fragment units in the heat-resistant nanocrystalline magnetic-isolation shielding material was about 0.03 mm, making the heat-resistant nanocrystalline magnetic-isolation shielding material have a magnetic loss ?<100 at a frequency of 6.78 MHz. The surface fragmented magnetic morphology of the prepared heat-resistant nanocrystalline magnetic-isolation shielding material is shown in FIG. 5.

Example 2: Preparation of Heat-Resistant Nanocrystalline Magnetic-Isolation Shielding Material

(13) The preparation process of this Example was basically the same as that of Example 1 except that an iron-based amorphous soft magnetic alloy ribbon with a thickness of 16 ?m was adopted and heat-treated, and after annealing, an iron-based nanocrystalline soft magnetic alloy ribbon with a thickness of 16 ?m was obtained.

Example 3: Preparation of Heat-Resistant Nanocrystalline Magnetic-Isolation Shielding Material

(14) The preparation process of this Example was basically the same as that of Example 2 except that the base material in the double-sided adhesive tape used in the preparation process was a PET film with a thickness of 1.4 ?m.

Example 4: Preparation of Heat-Resistant Nanocrystalline Magnetic-Isolation Shielding Material

(15) The preparation process of this Example was basically the same as that of Example 2 except that the double-sided adhesive tape used in the preparation process was a double-sided adhesive tape without a base material.

Example 5: Preparation of Heat-Resistant Nanocrystalline Magnetic-Isolation Shielding Material

(16) The preparation process of this Example was basically the same as that of Example 2 except that the stress relief treatment in the preparation process was implemented by setting the composite still in an oven with a temperature of 120? C. for 6 h.

Example 6: Preparation of Heat-Resistant Nanocrystalline Magnetic-Isolation Shielding Material

(17) The preparation process of this Example was basically the same as that of Example 2 except that the stress relief treatment in the preparation process was implemented by setting the composite still in an oven with a temperature of 120? C. for 6 h and then setting the composite still in a damp-heat oven with a temperature of 85? C. and a relative humidity of 85% RH for 24 h.

Example 7: Preparation of Heat-Resistant Nanocrystalline Magnetic-Isolation Shielding Material

(18) The preparation process of this Example was basically the same as that of Example 6 except that the adhesive in the double-sided adhesive tape used in the preparation process was a modified acrylic adhesive (using bismethylsilane coupling agent as a heat-resistant monomer).

Example 8: Preparation of Heat-Resistant Nanocrystalline Magnetic-Isolation Shielding Material

(19) (1) An iron-based amorphous soft magnetic alloy ribbon with a thickness of 16 ?m was adopted and rolled into a ring-shaped iron core and then heat-treated at 565? C. in the presence of nitrogen. After annealing, an iron-based nanocrystalline soft magnetic alloy ribbon with a thickness of 16 ?m was obtained.

(20) (2) One side of the nanocrystalline ribbon obtained in step (1) was coated with a double-sided adhesive tape having an adhesive layer thickness of 30 ?m. The double-sided adhesive tape used was an acrylic double-sided adhesive tape without a base material. The other side of the nanocrystalline ribbon was a bare surface. A single-coated nanocrystalline ribbon was thus obtained. Two layers of the single-coated nanocrystalline ribbon were combined into a double-layered nanocrystalline ribbon with a thickness of 45 ?m, with one side being bare and the other side being double-sided adhesive.

(21) (3) Primary magnet cracking treatment was carried out on the double-layered nanocrystalline ribbon obtained in step (2). The primary magnet cracking treatment was implemented by way of longitudinal and transverse cross-roller shearing to obtain a double-layered nanocrystalline magnetic layer. The blade gap of the roller scissors in cross-roller shearing was 1.5 mm. The size of the nanocrystalline fragments in the double-layered nanocrystalline magnetic layer was about 0.5 mm, making the double-layered nanocrystalline magnetic layer have a magnetic permeability u=250=50 at a frequency of 6.78 MHz.

(22) (4) The double-layered nanocrystalline magnetic layer obtained in step (3) was set still in an oven with a temperature of 120? C. for 6 h and then set sill in a damp-heat oven with a temperature of 85? C. and a relative humidity of 85% RH for 24 h to have stress relief treatment. A double-layered nanocrystalline magnetic layer with a thickness of 45 ?m, that was subjected to stress relief treatment, was thus obtained.

(23) (5) Secondary magnet cracking treatment was carried out on the double-layered nanocrystalline magnetic layer obtained in step (4). The secondary magnet cracking treatment was implemented by way of alternating rolling with a fine-mesh anilox roller with raised points with rolling with a patternless roller to obtain a heat-resistant nanocrystalline magnetic-isolation shielding material. The size of raised points on the fine-mesh anilox roller was 0.8 mm. The size of fine fragments divided by micro-cracks in nanocrystalline fragment units in the heat-resistant nanocrystalline magnetic-isolation shielding material was about 0.03 mm, making the heat-resistant nanocrystalline magnetic-isolation shielding material have a magnetic loss u<100 at a frequency of 6.78 MHz.

Comparative Example 1

(24) (1) An iron-based amorphous soft magnetic alloy ribbon with a thickness of 16 ?m was adopted and rolled into a ring-shaped iron core and then heat-treated at 565? C. in the presence of nitrogen. After annealing, an iron-based nanocrystalline soft magnetic alloy ribbon with a thickness of 16 ?m was obtained.

(25) (2) One side of the nanocrystalline ribbon obtained in step (1) was coated with a double-sided adhesive tape having an adhesive layer thickness of 3 ?m. The double-sided adhesive tape used was a double-sided adhesive tape without a base material, and the adhesive in the adhesive layer was an acrylic adhesive. The other side of the nanocrystalline ribbon was a bare surface. A single-coated nanocrystalline ribbon was thus obtained.

(26) (3) Primary magnet cracking treatment was carried out on the single-coated nanocrystalline ribbon obtained in step (2). The primary magnet cracking treatment was implemented by way of longitudinal and transverse cross-roller shearing to obtain a single-layered nanocrystalline magnetic layer. The blade gap of roller scissors in cross-roller shearing was 1.5 mm. The size of nanocrystalline fragments in the single-layered nanocrystalline magnetic layer was about 0.5 mm, making the single-layered nanocrystalline magnetic layer have a magnetic permeability u=250?50 at a frequency of 6.78 MHz.

(27) (4) Three layers of the single-layered nanocrystalline magnetic layer obtained in step (3) were combined to obtain a nanocrystalline magnetic-isolation shielding material.

Comparative Example 2

(28) (1) An iron-based amorphous soft magnetic alloy ribbon with a thickness of 16 ?m was adopted and rolled into a ring-shaped iron core and then heat-treated at 565? C. in the presence of nitrogen. After annealing, an iron-based nanocrystalline soft magnetic alloy ribbon with a thickness of 16 ?m was obtained.

(29) (2) One side of the nanocrystalline ribbon obtained in step (1) was coated with a double-sided adhesive tape having an adhesive layer thickness of 3 ?m. The double-sided adhesive tape used was a double-sided adhesive tape with a base material, the adhesive in the adhesive layer was an acrylic adhesive, and the base material was a PET film with a thickness of 1.9 ?m. The other side of the nanocrystalline ribbon was a bare surface. A single-coated nanocrystalline ribbon was thus obtained.

(30) (3) Primary magnet cracking treatment was carried out on the single-coated nanocrystalline ribbon obtained in step (2). The primary magnet cracking treatment was implemented by way of longitudinal and transverse cross-roller shearing to obtain a single-layered nanocrystalline magnetic layer. The blade gap of roller scissors in cross-roller shearing was 1.5 mm. The size of nanocrystalline fragments in the single-layered nanocrystalline magnetic layer was about 0.5 mm, making the single-layered nanocrystalline magnetic layer have a magnetic permeability u=250?50 at a frequency of 6.78 MHz.

(31) (4) Three layers of the single-layered nanocrystalline magnetic layer obtained in step (3) were combined to obtain a three-layered nanocrystalline magnetic layer with a thickness of 66 ?m.

(32) (5) Secondary magnet cracking treatment was carried out on the three-layered nanocrystalline magnetic layer obtained in step (4). The secondary magnet cracking treatment was implemented by way of alternating rolling with a fine-mesh anilox roller with raised points with rolling with a patternless roller to obtain a nanocrystalline magnetic-isolation shielding material. The size of raised points on the fine-mesh anilox roller was 0.8 mm. The size of fine fragments divided by micro-cracks in nanocrystalline fragment units in the nanocrystalline magnetic-isolation shielding material was about 0.03 mm, making the nanocrystalline magnetic-isolation shielding material have a magnetic loss u<100 at a frequency of 6.78 MHz.

Test Example 1

(33) The magnetic-isolation shielding materials prepared in Examples 1-8 and Comparative Examples 1-2 were placed in a 120? C. oven and held for 24 h to have a high-temperature storage test. After being taken out and fully cooled, the materials had a magnetic permeability test on a Keysight E4990A impedance analyzer. The results of magnetic permeability test are shown in Table 1 below.

(34) TABLE-US-00001 TABLE 1 Results of magnetic permeability test f = 6.78 MHz f = 128 kHz Room Room temp- 120 ? C.- Rate of temp- 120 ? C.- erature 24 h change erature 24 h Change No. ? ? ? ? ?? ?? ? ? ? ? ?? ?? Example 276 90 291 97 5.4% 7.8% 341 11 352 11.8 3.2% 7.3% 1 Example 279 89 294 95 5.4% 6.7% 345 10.8 356 11.5 3.2% 6.5% 2 Example 276 87 286 92 3.6% 5.7% 341 8.5 350 9 2.6% 5.9% 3 Example 275 94 284 99 3.3% 5.3% 340 8.4 348 8.8 2.4% 4.8% 4 Example 277 88 291 93 5.1% 5.7% 343 10.3 354 10.9 3.2% 5.8% 5 Example 272 86 278 88 2.2% 2.3% 338 8 342 8.2 1.2% 2.5% 6 Example 265 88 270 90 1.9% 2.3% 319 5.8 322 5.7 0.9% ?1.7% 7 Example 278 91 295 98 6.1% 7.7% 343 10.5 357 11.4 4.1% 8.6% 8 Comp- 264 86 332 118 25.8% 37.2% 320 9.8 353 13.6 10.3% 38.8% arative Example 1 Comp- 273 84 335 112 22.7% 33.3% 340 9.1 372 12.1 94% 33.0% arative Example 2

(35) As can be seen from the results of magnetic permeability test in Table 1, compared with the magnetic-isolation shielding materials prepared in Comparative Examples 1-2, after a 120? C. high-temperature storage test, the magnetic-isolation shielding materials prepared in Examples 1-8 through the two-stage magnet cracking treatment process and stress relief treatment according to the present application have fluctuations in magnetic permeability ? and ? at the frequency of 6.78 MHz obviously less than the magnetic-isolation shielding materials not subjected to stress relief treatment and not subjected to both stress relief treatment and the secondary magnet cracking treatment.

(36) As can be seen from the comparison of the test results of Examples 6 and 7, the use of the modified acrylic double-sided adhesive tape can further reduce the fluctuations of magnetic properties, and the best stability performance is shown in high-temperature storage; and at the frequency of 128 kHz, the fluctuation of magnetic permeability is smaller. All these indicate that the nanocrystalline magnetic-isolation shielding materials of the present application have very stable magnetic properties under 120? ? C. high-temperature storage and show excellent heat resistance. As can be seen from the comparison of the test results of Examples 1-2, the magnetic-isolation shielding materials prepared by using a thinner 16 ?m nanocrystalline soft magnetic alloy ribbon have smaller high-temperature storage performance fluctuations. As can be seen from the comparison of the test results of Examples 2-3, the magnetic-isolation shielding material prepared using a double-sided adhesive tape with a base material thickness of 1.4 ?m has better high-temperature stability than the magnetic-isolation shielding material prepared using a double-sided adhesive tape with a base material thickness of 1.9 ?m. As can be seen from the comparison of the test results of Examples 2 and 4, the magnetic-isolation shielding material prepared using a double-sided adhesive tape without a base material by the method of the present application can also effectively reduce performance fluctuations in high-temperature storage and its fluctuations are smaller. Differently, compared with the magnetic-isolation shielding material prepared using a double-sided adhesive tape with a base material, for controlling the same magnetic permeability, the magnetic-isolation shielding material prepared using a double-sided adhesive tape without a base material has slightly larger magnetic loss. As can seen from the test results of Examples 2 and 5-6, as the thermal aging temperature increases from 85? ? C. to 120? C., and after additional damp-heat aging, the magnetic properties of the magnetic-isolation shielding material change very little after high-temperature storage at 120? C. Especially at the frequency of 128 kHz, the magnetic permeability is almost unchanged. As can be seen from the test results of Example 8, the purpose of enhancing high-temperature storage stability can also be achieved by directly combining two layers of nanocrystalline ribbon using a double-sided adhesive tape without a base material and then performing primary magnet cracking treatment on them together, and the magnetic properties can basically meet the requirements; however, the time for magnet cracking treatment process is significantly increased.

(37) The above test results show that the magnetic-isolation shielding materials prepared by the preparation method described in the present application have good high-temperature stability and can meet the requirements of long-term operation in a 120? C. high-temperature environment. The magnetic-isolation shielding materials are especially suitable for application at MHz-level high frequencies and also suitable for application at kHz-level operating frequencies.

Test Example 2

(38) The magnetic-isolation shielding materials prepared in Examples 1-8 and Comparative Examples 1-2 were uniformly cut into 20 mm-wide ribbons, and a section of ribbon was cut out and wound around a q4.5 mm copper rod for multi-layer combination to produce a multi-layer combined nanocrystalline magnetic-isolation shielding material sample. The magnetic-isolation shielding material obtained by three-layer combination (Examples 1-7 and Comparative Examples 1-2) was cut into a length of 80 mm (equivalent to combination of five three-layered nanocrystalline magnetic layers), and the magnetic-isolation shielding material obtained by double-layer combination (Example 8) was cut into a length of 120 mm (equivalent to combination of eight double-layered nanocrystalline magnetic layers). The prepared nanocrystalline magnetic-isolation shielding material samples obtained by multi-layer combination were placed in ovens with a temperature of 150? C. and 200? C. respectively for 30 min one after another to have thermal shock test. After the samples were taken out and fully cooled, the inductance Ls, resistance Rs and Q value of the samples were tested on the Hioki IM3536 precision LCR meter after thermal shock at different temperatures at 6.78 MHz and 128 kHz, and the changes were observed by comparing with test data at room temperature. The test data of the inductance Ls, resistance Rs and Q value of the samples at 6.78 MHz test are shown in Table 2 below. The test data of the inductance Ls, resistance Rs and Q value of the sample at 128 kHz are shown in Table 3 below.

(39) TABLE-US-00002 TABLE 2 f = 6.78 MHz, U = 1.0 v Change No. Condition Ls (?H) Rs (m?) Q ?Ls (?H) ?Rs (m?) Example 1 Room 0.1611 961.16 7.17 temperature Thermal shock 0.1606 997.32 6.89 ?0.0005 36.16 at 150? C. Thermal shock 0.1650 1028.63 6.87 0.0039 59.47 at 200? C. Example 2 Room 0.1670 946.16 7.55 temperature Thermal shock 0.1656 976.00 7.26 ?0.0014 29.84 at 150? C. Thermal shock 0.1702 998.86 7.29 0.0032 52.7 at 200? C. Example 3 Room 0.1532 828.00 7.92 temperature Thermal shock 0.1521 842.08 7.73 ?0.0011 14.08 at 150? C. Thermal shock 0.1555 865.53 7.69 0.0023 37.53 at 200? C. Example 4 Room 0.1528 889.12 7.36 temperature Thermal shock 0.1518 900.65 7.20 ?0.0010 11.53 at 150? C. Thermal shock 0.1543 921.21 7.17 0.0015 32.09 at 200? C. Example 5 Room 0.1621 941.56 7.22 temperature Thermal shock 0.1610 965.32 7.11 ?0.0011 23.76 at 150? C. Thermal shock 0.1650 988.89 7.07 0.0029 47.33 at 200? C. Example 6 Room 0.1380 775.38 7.62 temperature Thermal shock 0.1378 780.03 7.56 ?0.0002 4.65 at 150? C. Thermal shock 0.1393 790.00 7.55 0.0013 14.62 at 200? C. Example 7 Room 0.1410 892.00 6.77 temperature Thermal shock 0.1405 896.08 6.71 ?0.0005 4.08 at 150? C. Thermal shock 0.1415 905.04 6.68 0.0005 13.04 at 200? C. Example 8 Room 0.1649 979.18 6.77 temperature Thermal shock 0.1640 1016.61 6.63 ?0.0009 37.43 at 150? C. Thermal shock 0.1671 1060.81 6.59 0.0042 61.63 at 200? C. Comparative Room 0.1532 940.00 6.98 Example 1 temperature Thermal shock 0.1667 1032.26 6.91 0.0135 92.26 at 150? C. Thermal shock 0.1783 1133.56 6.73 0.0251 193.56 at 200? C. Comparative Room 0.1632 940.00 7.43 Example 2 temperature Thermal shock 0.1761 1022.32 7.40 0.0129 82.32 at 150? C. Thermal shock 0.1823 1112.47 6.99 0.0191 172.47 at 200? C.

(40) TABLE-US-00003 TABLE 3 f = 128 kHz, U = 1.0 v Change No. Condition Ls (?H) Rs (m?) Q ?Ls (?H) ?Rs (m?) Example 1 Room temperature 0.1792 2.18 66 Thermal shock at 0.1812 2.21 66 0.002 0.03 150? C. Thermal shock at 0.1852 2.24 66 0.006 0.06 200? C. Example 2 Room temperature 0.1810 2.17 67 Thermal shock at 0.1826 2.20 66 0.0016 0.03 150? C. Thermal shock at 0.1858 2.22 67 0.0048 0.05 200? C. Example 3 Room temperature 0.1729 2.05 68 Thermal shock at 0.1739 2.07 67 0.0010 0.02 150? C. Thermal shock at 0.1766 2.10 67 0.0037 0.05 200? C. Example 4 Room temperature 0.1722 2.03 68 Thermal shock at 0.1729 2.05 67 0.0007 0.02 150? C. Thermal shock at 0.1750 2.06 68 0.0028 0.03 200? C. Example 5 Room temperature 0.1707 2.06 66 Thermal shock at 0.1721 2.08 66 0.0014 0.02 150? C. Thermal shock at 0.1752 2.11 67 0.0045 0.05 200? C. Example 6 Room temperature 0.1504 1.85 65 Thermal shock at 0.1506 1.86 65 0.0002 0.01 150? C. Thermal shock at 0.1511 1.86 65 0.0007 0.01 200? C. Example 7 Room temperature 0.1526 2.19 56 Thermal shock at 0.1520 2.16 56 ?0.0006 ?0.03 150? C. Thermal shock at 0.1521 2.12 57 ?0.0005 ?0.07 200? C. Example 8 Room temperature 0.1790 2.18 53 Thermal shock at 0.1812 2.22 53 0.0022 0.04 150? C. Thermal shock at 0.1858 2.26 54 0.0068 0.08 200? C. Comparative Room temperature 0.1674 2.90 46 Example 1 Thermal shock at 0.1731 3.06 45 0.0057 0.16 150? C. Thermal shock at 0.1778 3.18 45 0.0104 0.28 200? C. Comparative Room temperature 0.1728 2.25 61 Example 2 Thermal shock at 0.1776 2.38 60 0.0048 0.13 150? C. Thermal shock at 0.1817 2.48 59 0.0089 0.23 200? C.

(41) As can be seen from the test results in Table 2 and Table 3, compared with the magnetic-isolation shielding materials prepared in Comparative Examples 1-2, at 6.78 MHz and 128 kHz and after thermal shock at 150? C. the magnetic-isolation shielding materials prepared in Examples 1-8 have very little change in inductance and slight increase in resistance; after thermal shock at 200? ? C., the inductance still changes little, and the resistance is generally greater than that at 150? C.; however, the increased resistance of Examples 1-8 is significantly less than that of Comparative Examples 1-2. It indicates that use of the double-sided adhesive tape with a base material or the double-sided adhesive tape without a base material can always meet the requirements for stable high-temperature magnetic properties of magnetic-isolation shielding materials in view of the method described in the present invention. As can be seen from comparison of the results of Examples 1-2, by using a thinner 16 ?m nanocrystalline soft magnetic alloy ribbon, the inductance of the prepared magnetic-isolation shielding material does not change significantly after thermal shock, but the resistance is significantly reduced. As can be seen from comparison of the results of Examples 2-3, after thermal shock, the magnetic property stability of the nanocrystalline magnetic-isolation shielding material prepared using the double-sided adhesive tape with a base material thickness of 1.4 ?m is better than that of the nanocrystalline magnetic-isolation shielding material prepared using the double-sided adhesive tape with a base material thickness of 1.9 ?m. The base material thickness of the double-sided adhesive tape affects the stability of high-temperature cycles.

(42) To sum up, by optimizing the double-sided adhesive tape and combining the primary and secondary and secondary magnet cracking treatment processes and stress relief treatment, the present application improves the fluctuations of the double-sided adhesive tape under high-temperature shock, reduces the stress effect on the nanocrystalline fragments, and effectively reduces magnetic loss. The prepared heat-resistant nanocrystalline magnetic-isolation shielding material has small fluctuations in magnetic properties under 120? C. high-temperature storage and thermal shock at 200? C. The magnetic-isolation shielding material can meet the requirements for stable high-temperature performance of electronic products that are prone to heating when operating under a high frequency or a large current.

(43) It should be noted that the above-described embodiments are only used to explain the present application and do not constitute any limitation on the present application. The present application has been described with reference to exemplary embodiments, but it is to be understood that the words used therein are descriptive and explanatory rather than limiting. The present application can be modified as specified within the scope of the claims of the present application, and the present invention can be amended without departing from the scope and spirit of the present application. Although the application described therein refers to specific methods, materials and embodiments, the present application is not intended to be limited to the specific examples disclosed therein, but rather the present application extends to all other methods and applications having the same function.