Batch Fine Magnetic Pattern Transfer Method on Permanent Magnets Using Coercivity Change during Heating for Magnetic...

Area of Science:

• Materials Science
• Physics
• Engineering

Background:

• Magnetic microelectromechanical systems (MEMS) utilize permanent magnets, but their shape causes self-demagnetization, limiting performance.
• Existing methods for weakening self-demagnetization fields, like segmentation or multi-pole magnetization, have limitations in mass production and achievable magnetic flux density.

Purpose of the Study:

• To propose and demonstrate a batch fine multi-pole magnetic pattern transfer (MPT) method for MEMS magnets.
• To achieve higher surface magnetic flux density compared to traditional methods.
• To develop a technique suitable for mass production of patterned magnets.

Main Methods:

• The proposed MPT method involves sandwiching a target magnet between two master magnets with identical patterns.
• Target magnet coercivity is reduced via laser-assisted heating, allowing pattern transfer.
• Various patterns (stripe, checkerboard, concentric circle) with 0.3 mm pole pitch were magnetized on NdFeB master magnets (N38EH) and transferred to NdFeB target magnets (N35).

Main Results:

• The MPT method successfully transferred magnetic patterns to NdFeB target magnets.
• The highest surface magnetic flux density was achieved at 160 °C.
• The transferred patterns reached 39.7-66.1% of the ideal magnetization pattern on the target magnets.

Conclusions:

• The batch fine multi-pole MPT method is a viable technique for fabricating high-performance magnets for MEMS devices.
• This method offers a pathway to overcome self-demagnetization limitations and enhance output power.
• The technique shows potential for mass production of complex magnetic patterns.