Flex Circuit PCBs
When a product ends its life cycle, it becomes trash, known as electronic waste or e-waste. It can either end up in a landfill where solvents can leak and damage soil, or it can be recycled. The process of recycling a PCB recovers its valuable metals, transforming them from trash into treasure. This process may even save energy and money compared to manufacturing new components. One of the most popular products to be recycled is the flex circuit pcb, which is a flexible printed circuit board.
A flex circuit can be made using various materials, such as polymer thick film (PTF), copper or aluminum. Its conductor layers are separated by insulator films that prevent current from flowing across each other. Insulators are made of materials such as polyimide, polyester or solder mask. The thickness of a flex circuit’s conductor and insulator layers can vary according to the design requirements.
The conductive layers of a flex circuit are usually made up of a combination of copper and polyimide. Depending on the design requirements, a flex circuit pcb can be fabricated with or without plated through holes. Those that are plated with through holes have copper traces on both sides of the board, whereas those that do not have through holes have copper traces on one side only. The thickness of the conductive copper layer can vary between 0.0001” and 0.010”.
Can Flex Circuit PCBs Be Recycled?
Flex circuits have more flexibility than rigid boards, which makes them ideal for applications that require the assembly to bend. They can also be used to connect multiple parts within a single assembly, reducing overall size and weight. They can also adapt to small spaces that would be difficult to fit standard wires or cables.
In addition, flex circuits can withstand high temperatures and vibrations. This makes them perfect for aerospace, avionics, medical and military applications. A flex circuit can be laminated to a stiffer substrate, which increases its durability but reduces the signal’s transfer efficiency.
When selecting a manufacturer to produce your flex circuits, choose a firm that produces quick-turn prototypes. Make sure to ask about the material they use and what surface finishes are available. For example, tin plating is a good choice to cover pads on the flex circuit, while soft gold coating will work well for the exposed leads.
It is important to ensure that your flex circuits have a drill-to-copper distance of at least 8 mils. In addition, you should understand whether your CM uses panel plating or pad-only plating (button plating). Button plating is more accurate than panel plating, as it allows for smaller etch patterns and improved copper deposition. It is also better for flex circuits, as it requires less copper and can improve etch yields.
Another important consideration is the flex circuit’s conductor and metallization thicknesses. You should also consider if you need a plated edge terminal or if you need an EMI shielding film on the flex circuit. This will affect the overall cost of your flex circuits.