Technology is always innovating and moving towards new horizons. Cars, planes or buildings are perfect examples of this trend. In addition, in recent years, the optimization of space is also having great importance. In this context, for example, there have been great advances in the field of electronics, with microchips becoming smaller and more powerful. Following this trend, in order to produce these miniature elements, very specific manufacturing techniques are required. Laser technology, due to its micrometric scale, has become one of the great allies of the industry. If we add to this the great versatility that it presents, it means that applications such as laser microperforation are gaining a lot of strength. Below, we explain more about laser microperforation, and some applications we have worked on at ATRIA.
What is laser microperforation?
Microperforation consists of making micrometric-scale holes in a material. These holes are usually through holes and go through the entire thickness of the material, but sometimes this term is also used for blind holes. Laser technology allows machining by removing material using concentrated light. This means that there is no contact between the machine and the material, avoiding tool wear and providing high quality. The minimum definition that can be achieved through this machining is determined by the optical elements for focusing the light. Through the use of conventional lenses, it is possible to obtain working spot diameters from 5 µm to the mm range. It is also possible to use pattern interference optics to obtain nanometric sizes, but they are not widely used in industry. Laser microperforation, therefore, consists of making holes in materials using light as a machining element. By being able to have very small “spot” diameters, it makes the definition and quality of the micro-perforations very good. It also makes it possible to obtain perforation sizes so small that they are impossible to achieve by other techniques.
What materials can be treated?
The quality of the laser microperforation will largely depend on the interaction of the type of laser with the type of material. The light-emitting core of lasers emits in a certain wavelength. In this way, we can find ultraviolet, green or infrared lasers, among others. In turn, each material absorbs light energy at certain wavelengths. Therefore, the first step in being able to microperforate a material is to make sure that it is capable of absorbing the light energy transmitted by the laser. Once it has been verified that the material to be microperforated absorbs the light energy of the laser, the materials can be divided into the following categories:
- They are easy to laser microperforate due to their high thermal conductivity and high degradation temperature.
- Its high mechanical properties also mean that the number of perforations that can be made per unit area is very high.
- Possible thermal deformation due to heat accumulation, which is solved with a good design of holes and laser parameters used.
- Oxidation of microperforations, which is solved by using inert gases during the drilling process.
- As they have low melting points, the energy needed to make the microperforations is reduced.
- It can work at high cycle speeds.
- Easy to incorporate laser microperforation in film production lines.
- High probability of thermal deformation for medium thicknesses, due to the partial melting of the material near the perforation.
- Possibility of burning the material surrounding the microperforation.
- Low mechanical properties, which make it necessary to space the perforations more.
- High quality of microperforations as they have low thermal conductivity and a high melting point.
- Need to provide a large amount of energy to reach the melting temperature and transition to the gas phase.
- Possible breakage of the material due to large temperature gradients in the microperforations.
Applications of laser microperforation
The applications in which it is necessary to use laser microperforation are currently on the rise. This means that laser microperforation is gaining relevance in recent years, and is becoming a differentiating factor for the industry. Some of the applications that we have worked on at ATRIA Innovation are the following:
To obtain metal filters with a small hole diameter, there are currently few alternatives in the industry. If you want to achieve a high density of holes and for them to be small in diameter, the most widely used option is laser microperforation.
It is important in catalysts to have the largest possible apparent area to favor chemical reactions. Due to this, meshes made from wires are normally used, although sheets of catalysts can also be microperforated to obtain a greater amount of area.
Allow the passage of gas, but not liquid
Phase separation is a process that has always been of great industrial interest. Now, using laser microperforation, films can be created with holes so small that they allow gases to pass through, but not liquids.
Controlled liquid dosage
It is possible to create plastic containers that are self-dosing, allowing a certain amount of liquid to pass through every so often. The amount of liquid dispensed can be controlled by the diameter and number of microperforations made.
- Audio transmitters
The realization of very small micro-perforations by laser allows sound waves to pass through materials without reducing their mechanical properties. This makes it possible to design devices with audio outputs in structural elements or the casings themselves without the need for additional elements.
Invisible light panels
Small, almost invisible, micro-perforations can be created that allow light to pass through them. In this way, when the light is off, the normal surface is seen, and when it is turned on, the desired message can be displayed.
Do you want help with your laser microperforation project?Contact us!
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