Engineering insight
Use the following as an early selection reference. Specific models, datasheets and samples should be confirmed with actual structure drawings.
01
Routing and spacing design
FPCB key assembly trace width should be at least 0.15mm with 0.15mm spacing. Bend area traces should avoid right angles and use curved transitions. Routing around key pads should avoid the dome compression area to prevent insulation layer damage from repeated pressing.
02
Stiffener and adhesive material selection
Stiffener thickness and position directly affect key feel. Common stiffener thickness is 0.1-0.3mm PI or PET. Adhesive selection should consider temperature resistance, weatherability and residual stress. Double-sided adhesive thickness affects dome actuation force — recommend 0.05-0.1mm.
03
Testing and verification points
FPCB assemblies need continuity, insulation, key force consistency, thermal cycling and flex fatigue verification. For mass production, establish first-article inspection standards, patrol frequency and reliability test batches. Flex testing should simulate actual assembly paths, not simple folding.