We offer custom small-scale Neodymium block magnets.
The dimensions are down to 1mm × 1mm × 0.5mm (or smaller, depending on feasibility).
These micro-scale magnets are commonly used in:
– Miniature sensors, micro-motors, medical devices, hearing aids, microfluidic systems, electronics assemblies.
– And precision instrumentation where magnetic force is required in a compact footprint.
We typically produce blocks below approximately 3mm in any dimension using multi-wire slicing from larger sintered blocks.
And then do plating or coating individually.
Tolerances are typically ±0.05mm to ±0.1mm depending on size.
Edge definition and coating coverage become limiting factors as dimensions decrease.
Magnetization direction is typically through-thickness (shortest dimension).
But can be specified through-length or through-width.
This depends on geometry and application requirements.
Standard nickel plating is typical, though uncoated, parylene-coated.
Or epoxy-coated versions may be available depending on size and quantity.
Handling, coating adhesion, and mechanical fragility increase significantly at sizes below 2mm.
Minimum order quantities are typically higher for micro-scale magnets due to processing complexity.
The Manufacturing Advantage: “Precision at Scale”
1. Multi-Wire Slicing Technology:
Standard cutting saws destroy small magnets, causing edge chipping and fractures.
Our Capability:
– We utilize advanced multi-wire slicers (similar to semiconductor wafer processing) to cut these micro-blocks.
The Benefit:
– This results in chip-free edges and superior surface finish.
– It is critical when the magnet is being placed onto a PCB or inside a watch movement.
2. Coating Integrity:
Plating a 2mm magnet is technically difficult (they tend to stick together in the plating barrel).
Our Capability:
– We use specialized barrel-plating techniques.
– It ensures 100% surface coverage without “sticking points” or missed spots.
– This guarantees the magnet will not corrode, even in humid micro-environments.
Grade Selection: Size vs. Strength
At this size, volume is tiny.
You need high grades to make it useful.
Maximizing Performance in Micro Spaces:
– With a volume of only 4mm³, standard N35 grade often provides insufficient flux.
Recommendation:
– For magnets this small, we strongly recommend upgrading to N48, N50, or N52.
The Result:
– Using N52 in this 2mm x 2mm size allows you to achieve the magnetic pull force of a much larger N35 magnet.
– It saves valuable space in your housing.
Handling & Packaging (The “Micro” Challenge)
1. Vacuum Tray Packing:
We do not ship these in bulk bags (which turns them into a clump of magnetic dust).
Our Standard:
– Micro-magnets are aligned in plastic vacuum trays.
– This allows for automated pick-and-place assembly or easy removal with tweezers.
2. Handling Advice:
Tooling:
– Always use Non-Magnetic Tweezers (Plastic, Ceramic, or Titanium).
– Steel tweezers will make installation impossible as the magnet will jump to the tool.
Applications
Hall Effect Sensors: The trigger magnet inside smartphones, laptops, and TWS earbuds.
Horology (Watchmaking): Micro-rotors or magnetic clasps in luxury watches.
Medical Devices: Catheter guidance tips and implantable pumps.
Micro-Switches: Reed switch actuators on PCBs.
Ordering Guide: Specifying Micro-Parts
To quote this accurately, please specify:
1). Dimensions: Length x Width x Thickness (in mm).
2). Tolerance: Is standard ±0.05mm okay, or do you need precision ±0.03mm?
3). Coating: (Parylene is highly recommended if this is for a medical device).
4). Direction of Magnetization: Through the 1mm thickness?
