How does a flex PCB supplier support product testing?
flex PCB supplier support product testing
When choosing a flex PCB supplier, you want to be sure they are able to support product testing for your products or for the devices your company sells. This will help you determine whether the circuit boards are safe for usage and can keep working properly in your products. Testing may also reveal any minor faults that can be resolved quickly to prevent them from escalating into more serious issues, saving your business time and money.
There are various ways a flex circuit board can be tested, depending on the type of device or application for which it is designed. For example, if the board is designed to be used in an environment with high temperatures or vibrations, it may require thermal or electrical tests. A flex PCB can also be subjected to functional, performance, and parameter testing. Depending on the requirements, these tests may be performed on a simulated flex circuit, a full prototype or a sample board.
During the fabrication process, a thin flex pcb supplier coverlay is laminated over the copper layer for insulation and protection. This layer may be made of a polyester or Kapton film. Acrylic or epoxy based adhesive films are then used to bond the base material substrate with the coverlay and conductor layers. This process is called “buildup.” Photoresist coated panels are then overlaid with circuit artwork patterns and exposed to a pattern of collimated ultraviolet light, which is then etched away to expose the copper and create traces. Conductor traces are then plated with either panel or pad-only plating (button plating), which helps manufacturers better manage copper thickness and etch yields for intricate traces.
How does a flex PCB supplier support product testing?
When routing traces near bend areas, it is important to use thinner copper to reduce resistance. Wide ends on the traces can also be beneficial, as they increase their flexibility. Using the right diameter vias for connecting to traces and plated through holes also reduces stress concentration spots. Teardrop (pad fillet) shaped vias are ideal, as they will provide stronger connections and minimize stress on the via. Finally, tin finishing is ideal for covering the pads on a flex circuit.
In order for a flex circuit to be rigid, it must have one or more stiffeners. These are usually made of FR4 or Rogers 4003 polyimide film, and can be deposited as a pre-preg in multilayer constructions. They also allow the flex to be cut and folded without losing its mechanical integrity.
A flex PCB can have up to 12 flex layers, and can be made with hashed ground planes on both sides of the signal layers for noise reduction purposes. In general, the more flex layers you have, the less rigid the circuit board will be. The maximum number of flex layers is limited by the available space on the circuit board, and by your design needs. If you are unsure about how many flex layers you need, you can always contact your flex PCB supplier to discuss the details of your specific project.