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Hard disk driver magnet and its preparation method

A hard disk drive and magnet technology, applied in the manufacture of inductors/transformers/magnets, synchronous motors with stationary armatures and rotating magnets, instruments, etc., can solve problems such as performance degradation, large tolerances, and no detailed technology for describing protective layers , to achieve the effect of good heat and humidity resistance and solvent resistance, strong corrosion resistance

Inactive Publication Date: 2008-07-16
上海三环磁性材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In the technology disclosed in the above documents, the tolerance of the hard disk drive magnet from one-time forming to the final product is relatively large, generally greater than ±0.03mm, and the detailed technology of the protective layer is not described on the surface. When used in the middle, it may cause abnormal operation and performance degradation of the hard disk drive, and eventually affect the normal work of the hard disk.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] The hard disk drive magnet is made of bonded NdFeB, ring-shaped, and its related dimensions: the outer diameter of the ring: 28mm, the inner diameter of the ring: 26mm, the height of the ring: 4.5mm, the size of the ring Roundness of outer diameter: less than 0.03mm, concentricity: less than 0.03mm;

[0031] Roundness of the inner diameter of the ring: less than 0.03mm.

[0032] Magnetic properties of hard drive magnets:

[0033] Maximum energy product (BH)max: 80kJ / m 3 ;

[0034] The number of magnetic poles of the magnet is 24;

[0035] How hard drive magnets are made:

[0036] Step 1: Prepare by mixing permanent magnet powder and composite binder, permanent magnet powder 97.5%, composite binder 2.5%, mix evenly under normal temperature and pressure to make a mixture powder of permanent magnet powder and composite binder , the average particle size of the mixture powder is 100 μm;

[0037] Step 2: Forming of hard disk drive magnets: at room temperature and press...

Embodiment 2

[0045] The hard disk drive magnet is made of bonded NdFeB filled with 1% SmCo magnetic powder, ring-shaped, and its relevant dimensions:

[0046] The outer diameter of the ring: 9.4mm, the inner diameter of the ring: 7.1mm, the height of the ring: 1.2mm;

[0047] The hard disk drive magnet adopts the electrophoresis method, the electrophoresis condition is 60℃×20 minutes, and the curing condition is 180℃×1 hour;

[0048] Using the methods disclosed by IEC, GB, and JIS standards for detection, the magnetic properties of hard disk drive magnets are as follows: Maximum magnetic energy product (BH) max: 96kJ / m 3 ;The number of magnetic poles of the magnet is 12;

[0049] Its anti-corrosion performance was detected by the test method disclosed in GB / T 18880 standard, and the results are as follows:

[0050] Humidity and heat resistance at 60℃×95%RH: no corrosion for 300 hours;

[0051] The coated hard disk drive magnet has no weight change under environmental conditions, in pure...

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Abstract

The invention discloses a hard disk activator magnet, which is characterized by the following: the terminal tolerance of round and one-shot forming magnet equals to or is less than + / -0.03mm; the outside or inside diameter roundness and the axiality of circular ring is less than 0.03mm; coating the magnet surface with macromolecular polymeric substance of good anti-corrosion stock; detecting the magnet by public GB / T18880 method.

Description

technical field [0001] The invention relates to a hard disk drive magnet, in particular to a hard disk drive magnet with an anti-corrosion protection layer on the surface. Background technique [0002] The hard disk drive is an important component in the computer. It not only needs to have reliable performance, but also needs to have strong corrosion resistance so that it can be used for a long time in a relatively harsh environment. [0003] The hard drive magnet is one of the most critical parts of the hard drive, and its performance directly determines the quality of the hard drive. At present, the hard disk drive magnet is made of bonded rare earth magnets or bonded magnets containing rare earth elements, ferrite magnetic powder, alnico magnetic powder, metal element powder, etc., or other magnetic materials. Literature J.J.Croat, (AMM Company), Luo Yang, IEEE TC-15 Director, "Rare Earth Magnets, Such as Bonded NdFeB Magnet Industry Status and Prospects"; Japan Bonded M...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G11B19/247H02K21/22H01F7/02H01F41/02
Inventor 陈巍强龚海洲高庆国
Owner 上海三环磁性材料有限公司