PET (polyethylene terephthalate), commonly known as polyester, offers the most cost-effective flexible circuit solution for applications that don't require the extreme performance of polyimide. For static flex applications in moderate environments, PET delivers reliable performance at significantly lower cost.
PET excels in high-volume consumer applications where cost optimization is critical. Membrane switches, touch panels, simple interconnects, and disposable products all benefit from PET's combination of adequate performance and attractive pricing.
While PET doesn't match polyimide's temperature range or flex fatigue resistance, it provides perfectly adequate performance for a wide range of applications. When your application allows, choosing PET over polyimide can significantly reduce product cost without compromising reliability.
PET material costs significantly less than polyimide. For cost-sensitive high-volume applications, PET reduces per-unit cost substantially.
For circuits that flex during installation but remain static in operation, PET provides all the flexibility needed at lower cost.
PET absorbs less moisture than polyimide (0.4% vs 2.9%), providing excellent dimensional stability in humid environments.
Optically clear PET enables applications where circuit visibility or light transmission is required, such as display overlays.
PET is the right choice when application requirements align with its capabilities.
Circuits that bend during installation but remain stationary in use are ideal for PET. The bend-and-stay nature of most interconnect applications fits PET's capabilities perfectly.
Applications operating between -60°C and +105°C fall within PET's comfortable range. Consumer products, office equipment, and most indoor applications qualify.
When product cost is a primary consideration and the application doesn't require polyimide's premium properties, PET delivers value.
PET's cost advantage increases with volume. For million-unit production runs, material savings become substantial.
Avoid PET for: dynamic flexing applications, high-temperature environments (>105°C), aerospace/military applications, or where long-term reliability in harsh conditions is critical.
PET flex circuits serve numerous high-volume applications across industries.
The classic PET application. Touch-activated control panels for appliances, industrial equipment, and consumer products use PET flex for its cost-effectiveness and tactile performance.
Touch sensors for consumer electronics often use PET flex. The combination of adequate performance and low cost suits high-volume consumer products.
Simple LED interconnects and indicator panels use PET flex when temperature and flex requirements are moderate.
Single-use medical devices like electrode patches use PET for cost-effective disposable products.
Simple interconnects in keyboards, remotes, and other consumer products benefit from PET's cost advantages.
Button panels and indicator connections in climate-controlled vehicle interiors use PET where temperature extremes are avoided.
Designing with PET requires attention to its specific characteristics.
Design for maximum 85°C continuous operation with margin. Peak temperatures during assembly must be carefully controlled. Consider reflow soldering alternatives like conductive adhesive.
While PET bends readily for installation, design for the largest bend radius practical. Avoid designs requiring repeated bending in use.
Electrodeposited copper is typically used with PET for cost optimization. For tighter bends, rolled annealed copper improves flexibility.
Adhesive properties become important at PET's temperature limits. Specify appropriate adhesive grades for your temperature requirements.
PET's lower processing temperature limits surface finish options. ENIG and OSP are common choices compatible with PET processing.
Membrane switch overlay with integrated LED indicators for kitchen appliance. High-volume production with aggressive unit cost target.
Capacitive touch interface for exercise machine control panel. Clear PET allows backlight transmission with integrated touch sensing.
Single-use ECG electrode patches for patient monitoring. Ultra-high volume production demands PET's cost efficiency.
PET typically costs 50-70% less than polyimide for equivalent designs. Exact savings depend on design complexity and volume. Request quotes for both materials to compare.
Yes, but with temperature limitations. Lead-free reflow requires careful process control. Alternative assembly methods like conductive adhesive or hot bar bonding are often preferred.
PET works in climate-controlled vehicle interiors but is not suitable for engine compartment or exterior applications. Always verify temperature requirements against PET's limitations.
For static installation bends, minimum radius is typically 3-5x material thickness. PET is not recommended for dynamic (repeated) flexing applications.
Yes, PEN (polyethylene naphthalate) offers improved temperature and mechanical properties vs. PET while remaining more economical than polyimide. It's a good middle-ground option.
