trace routing play in flex PCB production
The copper traces of a flex PCB are important for converting signals into electrical energy. These conductive pathways must be carefully routed to prevent stress points that may result in a broken circuit board or an electrical connection that fails to work properly. This article will discuss the role trace routing plays in flex PCB production, as well as some of the pitfalls that can occur when these traces are not properly designed.
Trace routing in flex PCB production is done by using a software application that creates the routed copper paths on the surface of the bare copper layer. This application also calculates the amount of copper needed to cover the desired length of the traces, taking into account the current flow and the signal path. Once the design is finalized, it is sent to a PCB manufacturer for fabrication. Several steps are involved in this process, including printing the copper layers, drilling and plating the holes, and applying the solder mask. The resulting circuit board can be used in various applications, such as power supply units and electronic devices.
Copper thickness plays a significant role in the flexibility of a flex pcb production, with lower thicknesses providing greater pliability. Copper is prone to fatigue cracking, especially when subjected to repeated creasing or movement. To avoid this, flex PCB manufacturers should use higher-grade rolls of copper foil that are rolled annealed. This process elongates the grain structure of the copper, allowing it to stretch longer before fatigue cracking occurs. The cost of this material is slightly higher, but it provides a significant advantage in the durability of a flex circuit board.
What role does trace routing play in flex PCB production?
When designing a flex PCB, it is essential to consider the layer arrangement and stack-up. Careful layer sequencing helps maintain signal integrity through the flex and rigid sections of the board and optimizes heat dissipation capabilities between the different sections. In addition, it is crucial to use impedance matching techniques to minimize signal distortion as it traverses the different layers of a flex-rigid circuit board.
Another consideration when designing a flex circuit is to consider the bend radius of the circuit board. It is important to make sure that the bending radius does not exceed the maximum allowable radius for your circuit. Keeping this in mind will ensure that your flex circuit can be properly bent without causing damage to the copper traces. Additionally, it is helpful to use wide-ending traces that gradually taper down to a narrow end. This will help reduce stress on the copper traces and eliminate tears.
Another consideration when making a flex circuit is to add stiffeners in certain areas of the circuit board. Stiffeners are rigid materials that are laminated to the flex circuit to give it added mechanical stability. These can be made of FR-4, aluminum, or stainless steel. These can provide strain relief, balance weight, and increase abrasion resistance. They can even improve the stability of solder joints and prevent damage to the conductive pathways.
