Micro Laser Sintering (Micro 3D Printing)
Extremely precise metal parts for the watch industry, electronics and medical technology.
1. Introduction: Precision beyond imagination
While classic industrial metal 3D printing usually takes place in the component size range between centimeters and meters, micro laser sintering (micro 3D printing) aims at the microscopic level. Here we are talking about structure sizes that are thinner than a human hair.
This white paper highlights the fascinating technology of Micro-PBF, the materials and the completely new fields of application for micro parts.
What is the difference to normal SLM/PBF?
Standard PBF systems use lasers with a spot diameter of approximately 70-100 micrometers and layer thicknesses of around 30-50 micrometers. In micro laser sintering, the focal point of the laser is 10 to 30 micrometers, and the layer thicknesses are a tiny 1 to 5 micrometers. In addition, special, extremely fine metal powders are used.
2. The technology of micro 3D printing
In order to achieve such extreme precision, all system components must be miniaturized and optimized.
- The laser: High-precision fiber lasers or ultra-short pulse lasers are used to guarantee a minimal heat-affected zone and to prevent the tiny structures from evaporating.
- The powder: Normal powders (D50 of 30 µm) are much too coarse. Ultrafine powders are required for micro printing (particle sizes below 5 µm). This powder often no longer behaves like sand, but rather like sticky flour, which places extremely high demands on the coating process (squeegeeing).
3. New degrees of freedom for miniaturization
Conventional micro-manufacturing processes such as spark erosion (EDM), micro-milling or LIGA (lithography, electroforming) reach their limits when it comes to three-dimensional, hollow or undercut structures. This is exactly where micro 3D printing shines.
- No tool wear, even with hard stainless steel or titanium.
- Complex internal channels that are thinner than a needle.
- No assembly of micro parts necessary as functional assemblies can be printed directly as one part.
4. Applications in industry
Microtechnology benefits enormously from additive freedom.
- Watch and jewelry industry: Complex gears, balances or microscopic settings made of platinum, gold or stainless steel that could not be produced using conventional methods.
- Medical technology: Minimally invasive surgical tools, tiny endoscope components, stents or microscopic biopsy forceps.
- Electronics & Sensors: Micro switches, tiny HF antennas or sensor housings with integrated cooling.
5. Conclusion: Big future for small parts
Micro 3D printing closes the gap between classic additive manufacturing and microsystem technology. Although the process is slow (as thousands of layers are required for just one millimeter of height), hundreds of components can be produced simultaneously on a tiny building board. This makes the process highly economical for the series production of micro parts.