Frequently Asked Questions about Coverlay of Flexible PCBs
Question 1. In flexible PCB fabrication, is the opening on PI film coverlay in the same shape and size as the design, or should I change the design according to your fabrication capability?
If you have FPCs manufactured from PCBHERO, you don't have to change your design.
Usually, in the PCB design, the opening shape is square or rectangular. But most fabricators will require you to change it to be oval because their factories adopt the mechanical drilling method.
PCBHEROprovides two drilling options: mechanical drilling and punching. By punching, the opening on the coverlay is square or rectangular and the same as your design.
Question 2. What's the difference between PI film coverlay and PI stiffeners?
Coverlay is similar to the solder mask and protects the copper circuits, while a stiffener is a strengthened area at the ends of the flexible PCBs used for the plug-in. Besides PI, flexible PCB stiffeners can also be stainless steel and FR4. Coverlay is necessary for flexible PCBs and the flex section of rigid-flex PCBs, while stiffeners are used only when there are plug-in needs, such as gold fingers.
Coverlay is a PI or PET film laminated with the adhesive used for insulating and protecting the circuits in flexible PCBs. This article gives a comprehensive introduction to flexible PCB coverlay. If you work with the one-stop FPC manufacturer PCBEHRO, the CAM engineering level, fabrication quality, and one-on-one services won't let you down.