Issues Related to Multi-Pole Magnetization of Flat Magnets

With the growing demand for high-resolution magnetic signals in sensors, miniature motors, and metering/encoding products, planar multipole magnetization of magnets is increasingly adopted. This article compiles questions and answers regarding planar multipole magnetization of magnets, hoping to provide valuable insights.

What is planar multipole magnetization?

Planar multipole magnetization refers to the process of alternately forming multiple poles (N/S/N/S) along the length or circumference of a magnet on the same plane, with the magnetization direction primarily perpendicular to the magnet's thickness.

Which magnets are suitable for planar multipole magnetization?

From a material perspective, planar multipole magnetization demands higher “plasticity” and magnetic domain stability from the magnet. Materials like sintered and injection-molded ferrites, bonded neodymium iron boron magnets, and rubber magnets are more suitable.

What distinguishes planar multipole magnetization from conventional magnetization?

Planar multipole magnetization features multiple poles on the same plane with periodically alternating magnetic fields. Conventional magnetization typically employs axial single poles (one N, one S per face).

Relatively unsuitable or restricted materials: sintered neodymium iron boron.

What is the difference between planar multipole magnetization and radial multipole magnetization?

The primary distinction lies in the magnetization direction: planar multipole magnetization is perpendicular to the plane, while radial multipole magnetization follows a circumferential radial path.

What are the characteristics of the magnetic field distribution after planar multipole magnetization?

The magnetic field is primarily concentrated near the surface. The closer to the magnet's surface, the stronger the field. This configuration is commonly used in proximity Hall sensors.