Why Micro-Coil Winding Process Is So Challenging?

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The winding process is the chief part of the production process of micro-coils. Because of the micro-coil’s tiny size, manufacturers have to use ultra-fine wires during the winding process. One can wind the ultra-fine wires differently to provide various shapes to the coils. However, before we wind the ultra-fine wires, we need to isolate or coat the wires through the insulation process so that the wires remain protected from external heat. Then the manufacturers wind the wires around a pin or a core. Therefore, you can see how completed this process is. The main challenge for this winding process is the difficulty to work with these tiny wires.

From the winding method, an electromagnetic induction gets generated into the micro-coil. The most used material for ultra-fine wires is copper. To insulate the copper wires, most manufacturers use a polyamide base material. Nevertheless, you can use various other materials for the insulation process that can offer efficient resistance to breakdown voltages and temperatures.

The Shape & Size of the Micro-Coils:

Manufacturers design the shape and size of micro-coils based on their purpose of use. Each shape offers a unique electrical value. Therefore, the design of the shape depends on the customer’s requirement for the electrical value. Measuring and maintaining the right inner and outer dimensions is essential to provide a particular shape to a micro-coil. These coils can be manufactured in different shapes, including elliptical, rectangular, and spherical.

The Winding Method for Medical-Grade Coils:

When it comes to winding the medical-grade coils, you have to be very cautious about the size of the coils. Medical coils have to be very small so that the doctors can insert the coil into different body regions. A typical micro-coil for vein insertion should be smaller than 0.8 mm in diameter. To build this tiny coil, manufacturers should have built-in-house and highly specialized machinery.

Through the winding method, manufacturers wind an insulated copper wire precisely around a pin or a core and this method provide the shape of the coils. However, based on the requirements of the customers, these coils can be manufactured as self-bounded or coreless. To prepare a self-bounded or coreless coil, manufacturers withdraw the core or pin once the winding process is done. The winding method can also include a cylindrical or rectangular support to manufacture a rectangular or cylindrical-shaped coil.

Ultra-fine wires are necessary for the micro-coil manufacturing process because of the tiny diameter (smaller than 8 microns) of the wires. These tiny wires are suitable for preparing micro-coils, especially for medical applications. However, the tiny size of the wires creates a great challenge for the manufacturers.

Micro-Coil Production Process:

To produce micro-coils for miniature sensors, one should possess-

  • Specialized and standard equipment for the winding method, and
  • A clear understanding of how to wind the miniature coils precisely.

A coil manufacturing company can not use the ready-made equipment that is available in the market. Rather, they must design the equipment based on the requirements and build that from scratch. One should handle all the procedures regarding the coil manufacturing process, including wire terminals and soldering methods by using in-house and specialized machinery.

On one hand, manufacturers require ultra-fine wires to provide connectivity solutions and prepare inductive components within medical devices. On the other hand, it’s difficult to deal with these wires. The diameter of a typical ultra-fine wire is 9 microns or 59 AWG or 0.00035. So, you can imagine how tiny the wires are. It is even ten times tinier in comparison to the thickness of human hair. Therefore, to get rid of the non-trivial challenges created by these wires and maintain strict tolerance requirements, manufacturers need innovative technologies and specialized equipment. Custom-made machinery can be useful to monitor the position and control the tension of the wires.

Thermo-Pressure Bonding Technology:

Besides the equipment, innovative technology is necessary for providing connectivity solutions between different components and ultra-fine wires. Connecting two different ultra-fine wires is literally dreadful with the traditional welding and soldering methods because these methods create various flaws and issues. Thermos-pressure bonding technology is the modern connectivity solution for ultra-fine wires and micro-coil. This method can give you strain-free, highly reliable, and corrosion-free connections for tiny wires.


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