Micro Coil Winding
What is Coil Winding
An electromagnetic coil is created by winding an electrical conductor, such as a wire, into a coil, spiral, or helix shape. The design of a coil’s shape and dimensions is purposed to fulfill specific requirements. Parameters such as inductance, insulation strength, and the desired magnetic field strength significantly influence coil winding design.
Electromagnetic coils are employed in applications where electric currents interact with magnetic fields, such as in inductors, electromagnets, transformers, and sensor coils. An electric current is either passed through the wire of the coil to generate a magnetic field, or alternatively, an external time-varying magnetic field is passed through the interior of the coil, inducing a current in the conductor.
Coil Winding Methods and Machines
Hand winding coils aren’t feasible when mass production is required. For traditional coil sizes, the production of electromagnetic coils relies on automated machinery.
Coil winding can be categorized into several groups based on the type and geometry of the wound coil: wild or jumble, helical, and orthocyclic. Jumble winding is very inefficient and unsuitable for serious industrial applications. Machines that wind coils helically create layers and switch directions, moving forwards and backwards. However, this is only effective for a small number of layers. Once a certain limit is reached, the structure becomes too tight, often resulting in jumble winding.
Orthocyclic winding is the most optimal method to wind coils, positioning the wire of the upper layer into the grooves of the lower layer wires. Engineers aim to increase the efficiency of coil winding processes by minimizing the materials and space needed for coil winding. These coils demonstrate good heat conduction, and the electromagnetic field strength is evenly distributed across the windings.
Micro Coil Wire Challenges
One of the major challenges facing designers—for example, designers of invasive medical devices—is to fit the physical size of the device within the constraints imposed by the intended use. This, in turn, demands micro coils that are much smaller than previously manufactured.
Standard, automated, coil winding machines must deal with many factors, such as:
- Low breaking strength of the wire and insulation of the wire
- Tight winding spaces
- High speeds
- Wire that is not absolutely straight
Micro Coil Winding
Equipment used to wind regular-sized coils can’t be repurposed to serially wind micro coils, which require the development of specialized equipment. Using in-house engineering, Benatav has developed state-of-the-art methods and machinery that enable the winding of micro coils to an extent previously unachievable. To manufacture a micro coil with as many as 2000 turns, it’s necessary to drastically reduce the thickness of the wire. The thinnest copper wire currently available is 8 microns (0.0003 inches). Benatav is among the few companies worldwide working with such fine wires, and we’re striving to produce insulated wires even smaller than 8 microns.
Using our custom micro-machining technologies, we manufacture coils with over 1000 windings that are smaller than the head of a pin. However, this presents further challenges regarding connecting such fine wires. Ultra-fine wires are so thin that they can’t be welded using traditional methods, as this would destroy the wires. To overcome these problems, Benatav has developed a proven, cutting-edge thermo-pressure technology to produce precise welds with tight tolerances at very high temperatures.
Applications
Micro coils are required where there is a demand for miniaturized sensors. The following is a list of some applications that benefit from our micro coil and ultra-fine wire connectivity technologies:
- Transferring control, monitoring, and logging data to/from miniature implants
- Transferring energy to implants requiring battery charging or electrical charge input for activating and operating their systems
- Radiating energy for RF treatments, heat treatments, or electromagnetic radiation-based treatments
- In-vivo magnetic navigation, employing a local or external magnetic field
The Future of Micro Coil Technologies
Our innovative, ultra-fine wire and micro coil winding technologies open up an endless range of new possibilities for designers of miniaturized medical equipment and other industries. As designers become increasingly aware of our technologies, we anticipate that the variety of applications that can utilize them will expand significantly.
Call Benatav on +972-3-9345951 to discuss how our thermo-pressure technology can benefit your business.
