PCB stiffener be customized for unique board designs
A PCB stiffener is used to limit bending in specific areas of the board. They’re usually made from the same material as the base layer of the PCB (usually FR-4 or polyimide) and are used when certain areas of a flexible circuit require extra strength, rigidity, or stability. They can also be used to increase the thickness of the area where connections are made to prevent stress on those areas due to high levels of insertion force.
Stiffeners are attached to the flex PCB by either pressure sensitive adhesive or thermal set glue. Both of these options offer advantages and disadvantages to the fab shop depending on the board’s requirements. For example, PSA is cheaper and easier to work with, but requires the flex to be placed back in the lamination press to bond the stiffener. In contrast, a thermally set glue is more expensive, but allows for easy hand-held mounting.
There are three main types of pcb stiffener materials: PI, FR-4, and aluminum/stainless steel. PI stiffeners are commonly used in projects that require formability and corrosion resistance. Aluminum and stainless steel stiffeners are often used when a project needs heat dissipation and stiffness.
FR-4 stiffeners are used when the pcb will be used in harsh environments or where it will experience significant mechanical deformation. They can be added to both flex and rigid-flex PCBs. This type of stiffener offers superior electrical properties, dimensional stability, impact resistance, and moisture resistance compared to other resin glass fiber cloth substrates.
Can a PCB stiffener be customized for unique board designs?
The thickness of the stiffener will depend on the expected stress or deflection the flex or rigid-flex PCB will encounter. The stiffener should be thick enough to meet the PCB’s specifications without causing over-compression or warping. Depending on the size of the board, the stiffener thickness may need to be adjusted to accommodate specific components or connectors.
For example, a thicker stiffener will be needed to support the ZIF connectors found on some high-density interconnect (HDI) boards. This is because the connectors have a large amount of copper that will stress the flex PCB if not properly supported. Using a stiffener is an effective way to eliminate this problem and keep the circuit board as functional as possible.
PCB (Printed Circuit Board) stiffeners play a crucial role in ensuring the structural integrity of electronic devices. They provide support and rigidity to the PCB, especially in situations where the board is subjected to mechanical stress or vibration. While off-the-shelf stiffeners are commonly available, the question arises whether these components can be customized to suit unique board designs.
The answer lies in the flexibility of modern manufacturing techniques and the growing demand for bespoke solutions in the electronics industry. Customization of PCB stiffeners is indeed possible and often necessary for certain applications. Here’s why: Standard PCB stiffeners may not always fit the specific dimensions of a custom-designed board. Unique shapes and sizes require tailored solutions to ensure optimal support and functionality. Custom stiffeners can be manufactured to precise specifications, accommodating any irregularities in the board layout.
