PCB Stiffeners Influence PCB Layout
Stability is a crucial aspect of optimal electronic device performance. Lack of stability can result in performance degradation or even device failure. For this reason, every design involves a careful evaluation of the trade-offs of different materials and structures to ensure optimal stability. One key component to this is the PCB board stiffener. A PCB stiffener is a rigid material or structure added to the PCB, specifically in areas where components or connectors are placed. PCB stiffeners reduce flexing and prevent warping, making them an essential component for ensuring stable and functional devices. With over 17 years of experience designing and producing special flexible circuits, Best FPC has a deep understanding of the importance of implementing pcb board stiffeners in the right places.
A rigid area on a PCB is especially necessary for products that are exposed to vibrations or other dynamic forces. Examples of these include handheld electronics, automotive devices, and medical equipment. Stiffeners are also important for electronics in military and aerospace applications, where MIL-STDs like MIL-D-275 detail stiffener requirements. In addition to preventing dynamic forces from breaking the PCB, stiffeners also help dampen vibrations and prevent fractures, making them an essential part of any flex PCB layout.
PCB stiffeners are made of various materials, including polyimide and aluminum. Each has its own unique properties and benefits, but in general, metal stiffeners are more rigid than plastics and remain rigid at higher temperatures. However, they are also more expensive and require longer turnaround times than FR4 and polyimide.
How Do PCB Stiffeners Influence PCB Layout?
In addition to their structural role, PCB stiffeners serve to limit the flexibility of select areas earmarked for final product integration. This can be useful in facilitating assembly and eliminating the need for manual handling. In this way, they are similar to the insulators used in a Printed Wiring Board (PWB).
Stiffener thickness is another critical factor to consider. Choosing the right thickness will minimize cost, labor, and logistics. In general, the best option is to use a standard laminate thickness such as 0.010″ or 0.031″. This will allow your PCB fabricator to stock up on these materials and keep your project moving forward quickly.
There are a variety of ways that stiffeners can be incorporated into a flex PCB layout. They can be a flat panel attached to the PCB surface, an enclosing frame that surrounds the board perimeter, or ribs that run under component rows. In addition to adding rigidity, these stiffeners can also provide additional shielding and thermal insulation.
In some cases, a double layer of stiffeners can be helpful to increase the overall rigidity of a flex PCB. This can be particularly beneficial for areas containing sensitive components, such as memory devices or chipsets, where the slightest flex can cause the device to fail. Using a double layer of stiffeners can also protect against damage to these devices during the pick-and-place and reflow processes. Stiffeners are an essential PCB component that can be customized to fit the specific needs of each application.