For the most part, designers understand what types of constructions and design attributes are “non-standard” and add cost to their design. Flex circuit and rigid flex design is similar with a few “odd ball” factors thrown in. We have compiled a short list of design attributes and how they impact cost. For more detailed information on costs or for a free copy of our design guide, please contact us!
Low Cost Factors:
- Complex routing and scoring
- Edge routing
- Strain relief
- LF vs AP materials
Medium Cost Factors:
- Aspect ratio > 10:1
- Drill hole count > 30K
- Non-FR4 material in the rigid areas
- Drilled holes < .012”
- Stiffeners (rigidizers)
- Added tear stops
- Line width and space < .005”
- Button plating
- Controlled impedance
- Annular ring (pad < drill + 12)
High Cost Factors:
- Advanced technologies
- Buried vias
- Layer count
- Material utilization
- Selective plating
- Buried access (ZIF connectors)
- Line width and space < .004”
Cost Trade Offs: general rule of thumb
- Use smaller line width/space before adding layers
- Investigate how the boards will fit in the production panel for material untilization
- do not forget about nesting flex or straightening a bend and folding after parts are removed from the panel
- LF materials are lower cost than AP materials, but the increase in acrylic resin in a via stack can reduce reliability due to an excessive CTE-Z
Involve your PCB supply chain partner early in the design phase to ensure the most reliable, cost effective design that will meet your specific requirements!