Flexible PCB Board Manufacturing
PCBs are a key component of modern electronics, including wearables, medical devices, and IoT products. They are used in a wide variety of ways and can come in many shapes, sizes, and colors. Some of these devices need to be flexible or rigid-flex, depending on their intended use and environment. PCBs also have unique design requirements that can vary from board to board. In addition to the standard two-dimensional layout, flex or rigid-flex boards can have more complex designs with different shapes, layers, and even three-dimensional shape.
As with any other type of printed circuit board, flexible pcb board need to meet specific quality standards and guidelines during fabrication. These include physical, thermal, and environmental adaptability testing to ensure that the finished product will work well in a variety of environments. IPC-6013, the IPC qualification and performance specification for flex circuits, outlines these guidelines in detail.
The first step in meeting IPC-6013 standards for flex circuits is choosing the right material and stackup. A flex PCB needs to be flexible and durable, with good conductors and a high layer count. In addition, it must be able to withstand the various environmental conditions that it will encounter during its lifetime.
IPC-6013 Standards for Flexible PCB Board Manufacturing
Choosing the right copper is another critical factor in designing a flex or rigid-flex PCB. The choice of rolled or annealed copper can have an impact on the board’s flexibility. Rolled annealed copper has a tighter grain structure and greater ductility, making it more suitable for dynamic applications. Fully annealed copper is also an excellent choice for flex PCBs.
To improve flexibility, choose the right vias for your flex circuit. Ideally, you want to use teardrop (pad fillets) shaped vias instead of round ones, as these have smaller diameters and can reduce stress concentration points. Additionally, you should use annular rings as much as possible to increase the contact area between a via and the copper trace.
Finally, you need to consider whether your flex circuit requires panel or button plating. Panel plating involves the entire surface of the PCB, while button plating is applied solely to the vias pads. The latter option is more versatile because it allows you to manage copper thickness and increases etch yields in intricate etch patterns.
It is also important to note that the IPC-6013 standard has several other guidelines for flex circuits, including heat and bend tests. These guidelines are detailed in the IPC-6013 manual, which can be downloaded from IPC’s website. By following these guidelines, you can make sure that your flex or rigid-flex PCB will be of the highest quality and will perform as expected. IPC-6013 is an essential document for anyone who designs flex or rigid-flex PCBs. It helps you avoid common DFM mistakes and understand the nuances of this important process.