Standard Lead Times & Production Volumes

Epec supports both quick-turn prototypes and full production flex and rigid-flex circuits, with lead times that vary based on design complexity and material availability. Certain features, such as multiple lamination cycles, stiffeners, blind or buried vias, and special materials, can extend fabrication timelines. Understanding these factors early helps optimize delivery and cost.

This page outlines general delivery expectations for flex and rigid-flex circuits, including both prototype and production quantities. Lead times are influenced by design complexity, selected materials, and specific manufacturing requirements. There are inherent differences between development prototypes and full-scale production hardware, and these differences directly affect fabrication duration.

Epec commonly builds higher-complexity flex and rigid-flex PCB designs that involve advanced features and non-standard materials. The sections below explain how these design choices impact manufacturing time and where lead time improvements may be possible through early design consideration.

At a Glance: Lead Times

• Epec provides flex and rigid-flex circuits for both quick-turn prototypes and production volumes, with lead times driven by design complexity and material availability.
• Features such as multiple lamination cycles, blind or buried vias, via fill, stiffeners, specialty materials, and asymmetrical constructions can extend fabrication timelines.
• Early design consideration of bend areas, stiffener placement, vias, and material selection helps reduce delays and support more predictable delivery.

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Quick Turn Flex & Rigid-Flex Printed Circuit Boards

Technology	7 Day	8 Day	10 Day	12 Day	15 Day	20 Day
Flex 1-2 Layers	X	X	X	X	X	X
Flex 2-4 Layers		X	X	X	X	X
Flex > 5 Layers				X	X	X
Rigid-Flex 2-4 Layers			X	X	X	X
Rigid-Flex 5-8 Layers				X	X	X
Rigid-Flex > 9 Layers					X	X

* Prototype and Production Quantities Available.

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Factors That Affect Flex and Rigid-Flex Lead Times

Multiple Lamination Cycles

Most rigid-flex PCB designs require at least two lamination cycles. Each additional pass through the imaging, etching, drilling, plating, and lamination process adds significant lead time. Designs with multiple lamination steps should account for added front-end processing time.

Blind and Buried Vias

Buried vias always increase lead time because they require extra process steps tied to multiple lamination cycles.

Blind vias may pose less of a timing impact when connecting outer layers to selective inner layers. Outer-layer blind vias add laser drilling and plasma desmear steps before plating.

Via Fill (Via-in-Pad Designs)

Via-in-pad processing is often used for high-density BGA layouts and miniaturized surface-mount devices. Proper via filling and capping prevents trapped chemicals or air and results in a flat, coplanar surface with reduced inductance by eliminating dog-bone fanouts.

* Design note: For finished hole sizes of 8 mils or less, via fill is not recommended. In these cases, plating the holes shut is advised in coordination with the fabricator.

Stiffeners

Stiffeners can significantly extend production timelines depending on quantity and placement. Beyond the time required to manufacture the stiffener itself, many designs require an additional lamination cycle using pressure, temperature, and no-flow prepreg. Tooling may also be required to ensure registration, especially when stiffeners support through-hole connectors.

Pressure Sensitive Adhesives (PSA)

PSAs may be used either to attach stiffeners or to bond the flex or rigid-flex circuit into the final product. When PSA is symmetrical and matches the final board outline, it typically adds minimal time. Lead times increase when PSA is selective, involves multiple PSA types on one circuit, or uses intricate laser-cut patterns requiring additional tooling.

Special Material Requirements

Non-standard laminate materials are often not stocked in high volume. Overall thickness and copper weight are the primary constraints. Many fabricators rely on common stack-ups and materials, so availability should be verified early. Unbalanced copper constructions, such as 1 oz / ½ oz copper, are commonly used in RF applications but may require additional material manufacturing time.

Asymmetrical Layering and Small Hole Sizes

Asymmetrical layer constructions and a high density of very small holes in flex regions can slow production. Manufacturing speeds must be reduced to process these features reliably, adding time to the overall schedule.

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Design Considerations to Avoid Delays

Addressing these items before order submission helps prevent engineering holds or schedule impacts:

• Do not place vias in bend areas
• Do not locate pads too close to bend areas
• Avoid overlapping bend areas with stiffeners
• Avoid placing stiffeners too close to vias or connector pins

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Production Volume Flex and Rigid-Flex Orders

Epec supports scalable production volumes in addition to prototype builds. Production strategies can be adjusted based on complexity, quality requirements, and delivery needs.

• Offshore production facilities can manufacture parts in as little as 7 days
• Our Irving, Texas facility can produce production volumes in 20 days, depending on complexity and quality
• Split deliveries, Kanban programs, and other stocking programs are available
• Facilities are ITAR, ISO, and AS9100 certified
• All design reviews, technical support, quality control checks, and follow-up are performed by U.S.-based personnel at North American facilities

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Frequently Asked Questions

Quick Links

• What should I know about stiffeners?
• Why do multiple lamination cycles increase lead time?
• How do special materials affect delivery schedules?
• What should be avoided in flex bend areas?

What should I know about stiffeners?

Stiffeners often require additional lamination cycles, specialized tooling, and precise registration. Their quantity, location, and function, especially for through-hole connectors, can significantly affect lead time.

Why do multiple lamination cycles increase lead time?

Each lamination cycle sends the part back through front-end processes such as imaging, etching, drilling, and plating, adding substantial manufacturing time.

How do special materials affect delivery schedules?

Non-standard laminates, uncommon thicknesses, or unbalanced copper constructions may not be readily available and often must be manufactured to order, extending lead times.

What should be avoided in flex bend areas?

Vias, closely placed pads, overlapping stiffeners, and nearby connector pins should be avoided in bend regions to prevent mechanical and fabrication issues.

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Looking for a Specific Lead Time?

Understanding how your flex or rigid-flex design choices affect fabrication timing allows for more accurate schedules and cost-effective solutions. Contact Epec to review your requirements and align your design with achievable delivery expectations.

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