Double layer flex PCBs represent the most popular choice for flexible circuit applications. With two conductive layers connected by plated through-holes, these circuits offer the routing freedom needed for most electronic designs while maintaining the flexibility and cost advantages of flex technology.
The addition of a second layer dramatically expands design possibilities. Crossovers that would require jumpers on single layer designs are easily routed on opposite layers. Ground planes can be dedicated to one layer while signals route on the other. Controlled impedance becomes achievable for high-speed applications.
Our double layer flex service supports designs from simple consumer products to complex medical and aerospace applications. We offer standard and fine-line capabilities, multiple via options, and the quality certifications needed for demanding markets.
Two conductive layers eliminate the need for jumpers and enable complex routing patterns. Ground planes and signal layers can be separated.
Plated through-holes, microvias, and filled vias provide flexible layer-to-layer connections. Design freedom without compromise.
Dual layers enable microstrip and coplanar impedance control for high-speed and RF applications with tight tolerance.
Two layers provide most of the routing capability you need at a fraction of multilayer cost. The sweet spot for many applications.
Double layer flex PCBs serve applications requiring more routing complexity than single layer can provide.
Smartphone and tablet display connections typically use double layer flex for the trace density required to connect modern high-resolution displays.
Image sensor modules use double layer flex to route image data while providing power and ground on separate layers for noise immunity.
The flex portions of rigid-flex assemblies often use double layer construction for optimal routing and flexibility.
USB, HDMI, and other high-speed interfaces require impedance control achievable with double layer microstrip or coplanar structures.
Smartwatches and fitness trackers use double layer flex to pack complex functionality into curved, space-constrained form factors.
Via selection significantly impacts design flexibility, cost, and reliability.
Standard vias drilled through both layers. Most economical option with proven reliability. Minimum drill size typically 0.2mm.
Smaller vias created by laser drilling. Minimum size 0.075mm enables higher density routing. Ideal for fine-pitch component connections.
Vias filled with conductive or non-conductive material. Required for via-in-pad designs where components mount directly over vias.
Coverlay or solder mask covers via barrels, protecting them from environmental exposure. Standard for most applications.
PTH vias are preferred for standard designs due to cost and reliability. Microvias enable fine-pitch designs but add cost. Consider via density requirements when making the selection.
Optimizing double layer flex designs requires attention to layer stackup and via placement.
Dedicate one layer to ground plane where possible for best signal integrity. Route signals on the other layer with via transitions as needed.
Minimize vias in flex areas to maintain flexibility. Group vias in stiffened regions when possible. For dynamic flex, keep vias away from bend zones.
Route traces perpendicular to bend lines. Avoid sharp corners that concentrate stress. Use teardrops at via connections.
Use hatched rather than solid ground planes in flex areas to improve flexibility. Maintain solid planes in rigid or stiffened areas.
For controlled impedance, work with our engineering team to select appropriate stackup dimensions. We optimize for your target impedance while maintaining manufacturability.
Fine-pitch double layer flex connecting 48MP image sensor to main board. 0.4mm pitch connector with controlled impedance MIPI traces.
Long-reach double layer flex for laptop display connection. LVDS signal routing with impedance control and integrated shield layer.
Miniaturized double layer flex for catheter-based pressure sensor. Sterilization compatible with biocompatible coverlay materials.
Double layer flex typically costs 30-50% more than single layer due to additional processing steps. The exact difference depends on design complexity and volume. Request quotes for both to compare.
Yes, with proper design attention. Keep vias out of flex areas, use appropriate copper types (rolled annealed), and design for adequate bend radius. We can review your design for dynamic flex suitability.
Standard PTH minimum is 0.2mm drill. Laser microvias can be as small as 0.075mm. Smaller vias enable higher density but add cost - our engineers can help optimize via selection.
Yes, we support impedance control with ±10% standard tolerance and ±5% for critical applications. We work with you to optimize stackup for your target impedance values.
Yes, double layer flex supports components on both sides. Consider stiffener placement for component support and design for assembly access from both sides.
