Electromechanical Factors Impact Design – Once you design rigid-flex Printed circuit boards, think in terms of electromechanical factors that affect both flex circuit as well as the rigid board. As you build your design, focus on the ratio of bend radius to thickness. With flex circuits, tight bends or even an increased thickness at the bend area boost the chances for failure. Manufacturers recommend keeping the bend radius at a minimum of ten times the thickness of the flex-circuit material and constructing a “paper doll” of the circuit to find out where bends occur.3,6
You ought to avoid stretching the flex circuit along its outer bend or compressing it across the inner bend. Improving the bend angle beyond 90° increases stretching at some time and compression at another point on the rigid pcb. Another key issue in rigid-flex reliability is definitely the thickness and kind of conductor found in the bend region. You can decrease thickness and mechanical stress by reduction of the volume of plating on the conductors and using pads-only plating. The usage of heavy copper, gold, or nickel plating decreases flexibility on the bend and allows mechanical stress and fracturing to happen.
Rigid-Flex PCB Design Requires Teamwork – New PCB design tools give your design team the opportunity to manage multiple layer stacks, visualize 3D electromechanical designs, check design rules, and simulate the operation of flex circuits. Despite these power tools in hand, the successful design of a rigid-flex PCB is dependent upon teamwork between your team and fabricators. Teamwork must begin in the earliest stages of the project and continue through the entire design process and hinges on consistent communication.
A Printed Circuit Board Might Not Be a “Board” – When the term “PCB” is used, many individuals think of a rigid PCB (printed circuit board). However, the phrase PCB can refer to either a rigid PCB or a flexible PCB. Flexible PCBs tend to be more commonly known as flex circuits, but they are also known by other names including flex boards, flexible circuit boards, flexible printed circuit boards and, more officially, flexible electronics. Flex circuits recently gained huge popularity due to the fact that they can be shaped, bent, twisted, and folded into limitless configurations. In the long run, however, rigid PCBs and flexible PCBs serve, in the standard sense, the same ultimate function, which is connecting various electrical and mechanical components together.
When to Use Rigid and once to utilize Flexible – Rigid PCBs typically are less expensive than flex circuits. I only say “typically” because when contemplating the entire cost of ownership there are some applications that, when you use flexible PCBs, could be cheaper compared to using rigid PCBs. To get a true and accurate knowledge of the total expense of ownership, you need to appreciate the truth that flex pcb china may eliminate the necessity for components like connectors, wire harnesses, as well as other circuit boards. By removing these factors from the design, material cost, labor and assembly cost, and scrap cost are reduced.
Many electronic devices (laptop and desktop computers, audio keyboards, solid-state drives (SSDs), flat-screen TVs and monitors, children’s toys, and other gadgets) employ rigid PCBs rather than flexible PCBs. However, flex circuits might be seen in ultra-compact and high-performance devices, including GPS units, tablets, smartphones, cameras, and wearables. Greater sophistication will not be the only real reason to use flex circuits; low-tech applications (like under-the-counter LED lights, see figure below) may utilize flex circuit technology, in some instances as it makes installation much easier.
Finally, a flex circuit along with a rigid circuit may be used together-as a unified PCB-when the need arises. This strategy, perhaps, provides the best of both worlds. See Figure 2 below. Some Similarities and Differences Between Rigid PCBs and Flex Circuits. When making rigid PCBs, certain design rules should be followed, including minimum hole sizes, minimum space and trace width, minimum distances to board edges, and copper and overall design thicknesses. Additionally, many manufacturing process steps are shared between koqcyp and versatile PCBs. Such process steps range from the drilling and plating of holes and vias, photo imaging and development, the etching of copper traces, pads, outlines, and planes, and also the heating (baking) of the circuit boards with regards to removing moisture from your PCBs. At this stage within the manufacturing process, rigid PCBs visit the solder mask station while prototype pcb assembly services visit the coverlay station.
Flex circuit overlay, or coverlay, as it’s also known, is a lamination process utilized for encapsulating and protecting the external circuitry of any flex circuit. A flex circuit’s coverlay film is a lot like a rigid PCB’s solder mask, with one big difference…the coverlay film is flexible! In accordance with allflexinc.com, “The coverlay film is normally a polyimide film that is certainly coated with a thermoset adhesive. Film thicknesses range between .0005” to .005” with .001” and .002” the most typical.”