Rigid Flex PCBs Require Special Assembly Techniques

Rigid Flex PCBs Require

Rigid flex PCBs combine the stability of rigid boards with the flexibility of flexible circuits. They have many benefits and are increasingly being used in a variety of applications. They can handle higher currents, generate less heat and offer a smaller package size. Rigid flex PCBs can also be used in applications with high shock and vibration. The flexibility of the circuit can be useful for avoiding mechanical stress in sensitive electronics, like laptop computers and smartphones.

The manufacturing process for flex rigid pcb is very similar to that of traditional rigid PCBs. After the copper laminate is coated with a layer of polyimide, it is chemically etched to create the desired circuit pattern. This can be done on one side or both sides of the board.

Next, the laminate is laser-drilled to create holes, pads and vias. This is typically done with a high-speed drilling machine that uses a CO2 or Excimer YAG laser. The resulting holes can be filled with solder using either reflow or wave soldering techniques. The rigid-flex circuit board is then ready for assembly. When working with a rigid-flex PCB manufacturer, it is important to understand the process from beginning to end. This helps to minimize design mistakes that can increase the time-to-market of a finished product.

Rigid Flex PCBs Require Special Assembly Techniques

Component Placement: SMT (surface-mount) and through-hole components must be placed in their designated locations on the flex PCB. During this step, it is necessary to make sure that all components are free from damage and contamination. It is also important to check the placement of connectors that transition between the rigid and flexible sections of the circuit. Poorly-placed connectors can lead to mechanical stress that reduces reliability.

Once the components are in their final position, the excess leads should be trimmed. This can be done manually or with an automated trimming machine. It is essential to trim the leads as close to the solder joints as possible to ensure proper connections. Rigid-flex circuits must undergo a pre-bake cycle to eliminate any moisture that may have been retained during the manufacturing process.

Another step in the rigid-flex circuit board manufacturing process is to apply the final layer of coverlay. This protects the traces from damage, environmental hazards and corrosion. The most common coverlay is an additional polyimide film with adhesive, though there are also adhesive-less processes. A photo-imageable solder mask can also be used, allowing for a smooth, even coating that is compatible with the flex circuit’s conductivity.

In order to maximize the performance of a flex PCB, it is crucial to collaborate with electrical and mechanical engineers early in the design process. This will help to avoid costly mistakes that can result in poor quality or failure of the final product. For example, solid grounds are often used in rigid PCBs but a solid ground on a flex circuit could cause bending stress and electrical failure. To avoid this, a hatched ground is used on the flex circuit.