DuPont Pyralux FR9210E: 2 oz ED Copper Single-Sided FR Flex Laminate — Full Specs & Use Cases

DuPont Pyralux FR9210E full specs: 2 oz ED copper, single-sided, UL VTM-0, IPC-4204/1. When to use over FR9210R — complete engineer’s guide with tables and FAQs.

DuPont Pyralux FR9210E is the electrodeposited (ED) copper variant of the 2 oz single-sided Pyralux® FR copper-clad laminate family. It shares the same flame-retardant dielectric construction and IPC certification as its rolled-annealed sibling, the FR9210R — but the choice between the two comes down to how the circuit will live in the product, how tight the BOM cost targets are, and what fabrication tolerances the design requires at 2 oz copper weight.

One important clarification worth flagging before diving into specs: FR9210E is a single-sided laminate — copper on one face only, just like FR9210R. The brief that circulates on some distributor pages labels the 2 oz “FR921x” range as “double-sided,” but per DuPont’s official datasheet Table 1, FR9210E sits squarely in the single-sided product column. The double-sided 2 oz equivalent is FR9212R (RA copper) or FR9212E (ED copper). Getting that detail right before a purchase order saves a lot of back-and-forth with your fab.

For engineers working across the Dupont PCB materials landscape, FR9210E is a well-defined niche product — not a replacement for FR9210R in all scenarios, but a deliberate cost-and-process choice for specific design profiles where ED copper’s properties actually work in your favour.

What Is DuPont Pyralux FR9210E?

DuPont Pyralux FR9210E is a single-sided, copper-clad flexible laminate consisting of 2 oz electrodeposited copper foil bonded to DuPont™ Kapton® polyimide film through a flame-retardant, C-staged proprietary acrylic adhesive. The “E” suffix in the product code identifies electrodeposited copper, distinguishing it from the “R” (rolled-annealed) and “D” (RA double-treated) copper variants of the same base construction.

<invoke name=”web_search”> The dielectric system — 1 mil acrylic adhesive plus 1 mil Kapton® — is identical across all three copper variants. Every certification, every lamination condition, and every published electrical property for the Pyralux FR copper-clad family applies equally to FR9210E. The only differentiation is in the copper metallurgy, and that single variable drives all of the application-level decisions between FR9210E and FR9210R.

DuPont Pyralux FR9210E Construction and Layer Stack

Layer	Imperial	Metric
Copper Foil (Electrodeposited, ED)	2 oz/ft²	70 µm (610 g/m²)
Acrylic Adhesive (C-staged, Flame Retardant)	1 mil	25 µm
Kapton® Polyimide Film	1 mil	25 µm
Total Nominal Stack Thickness	~4.7 mil	~120 µm

Pyralux FR9210 Copper Variant Reference:

Product Code	Copper Type	Description
FR9210R	Rolled-Annealed (RA)	Standard for dynamic flex and fatigue-critical applications
FR9210E	Electrodeposited (ED)	Cost-optimised for static flex and high-volume high-current builds
FR9210D	RA Double-Treated	RA copper with ED nodules both sides — eliminates surface prep before coverlay

The C-staged adhesive in the copper-clad is fully cured at time of delivery. This is a practical handling distinction: unlike Pyralux FR coverlays and bondplys — which use B-staged adhesive and require precautions against skin contact with unreacted monomers — the FR9210E clad presents no such handling concern under normal panel processing conditions.

DuPont Pyralux FR9210E Full Technical Specifications

Electrical Properties

Property	Typical Value	Test Method
Dielectric Constant (Dk) @ 1 MHz	3.5	IPC-TM-650 No. 2.5.5.3
Dielectric Constant (Dk) @ 10 GHz	3.0	ASTM D2520
Loss Tangent (Df) @ 1 MHz	0.02–0.03	IPC-TM-650 No. 2.5.5.3
Loss Tangent (Df) @ 10 GHz	0.02	ASTM D2520
Dielectric Strength	137 kV/mm (3500 V/mil)	ASTM D-149
Insulation Resistance (ambient)	10⁶ megohms	IPC-TM-650 No. 2.6.3.2
Volume Resistivity (ambient)	10⁹ megohm·cm	ASTM D-257
Surface Resistance (ambient)	10⁷ megohms	ASTM D-257

Mechanical Properties

Property	Typical Value	Test Method
Peel Strength (after lamination)	2.1 N/mm (12 lb/in)	IPC-TM-650 No. 2.4.9 Method B
Peel Strength (after soldering)	1.9 N/mm (11 lb/in)	IPC-TM-650 No. 2.4.9 Method D
Solder Float Resistance (10 sec @ 288°C)	Pass	IPC-TM-650 No. 2.4.13 Method B
Thickness Tolerance	+10%	IPC-TM-650 No. 4.6.2
Dimensional Stability (MD)	−0.10%	IPC-TM-650 No. 2.2.4 Method B
Dimensional Stability (TD)	−0.10%	IPC-TM-650 No. 2.2.4 Method C

Compliance and Certification

Attribute	Status
UL94 Flammability Rating	VTM-0
UL796 Direct Support Certification	Yes
IPC-4204/1 Certification	Yes
RoHS / REACH — PBB, PBBO, PBDE	Fully compliant — none present
ISO 9001:2015 Manufacturing	Yes
Certificate of Conformance per lot	Yes

Note on Table 3 reference construction: DuPont’s published property table is based on the 1 oz RA copper / 1 mil adhesive / 1 mil Kapton® construction. For FR9210E — with 2 oz ED copper — the dielectric properties (Dk, Df, dielectric strength, insulation resistance) remain valid as they describe the dielectric system, not the copper layer. Conductor properties such as trace resistance and current capacity will reflect 2 oz copper geometry.

FR9210E vs FR9210R: The ED vs RA Copper Decision at 2 oz

At 2 oz copper weight, the choice between ED (FR9210E) and RA (FR9210R) follows the same structural logic as at 1 oz, but the consequences of choosing wrong are amplified because 2 oz copper designs typically carry more power and operate in more demanding environments.

Property	FR9210E (ED Copper)	FR9210R (RA Copper)
Copper Grain Structure	Vertical / columnar	Horizontal / lamellar
Fatigue Life Under Bending	Lower — susceptible to grain-boundary cracking	High — stress dispersed across lamellar planes
Fine-Line Etch Resolution	Excellent — uniform grain dissolution	Good — marginally less consistent at tight line/space
Surface Roughness	Higher profile	Smoother (lower roughness, ~0.35 µm RMS)
Conductor Loss at High Frequency	Marginally higher (roughness-driven)	Marginally lower
Material Cost	Lower — 30–50% cheaper than RA	Higher
Supply Lead Time	Shorter — more global suppliers	Longer in some market regions
Best Application Fit	Static flex, high-current power runs, cost-sensitive builds	Dynamic/cyclic flex, high-frequency traces, rigid-flex flex cores
Dynamic Flex Suitability	Limited — static and semi-dynamic only	Full — including repeated high-cycle flex zones

The 2 oz weight means both variants carry the same current capacity improvement over 1 oz copper — roughly double the current per unit trace width. The metallurgical difference between ED and RA copper at this thickness has no effect on DC resistance or steady-state current handling. Where ED copper falls behind at 2 oz is in any scenario involving flexing, vibration-induced fatigue at solder joints, or high-frequency signal integrity where surface roughness adds meaningful insertion loss.

Where FR9210E Makes Sense: Specific Use Cases

#### Static Flex Power Distribution Buses

The single biggest use case for FR9210E is fixed-geometry, high-current power routing. Think of internal bus bars built in flex format — battery output leads in power tools, power distribution cables in server rack assemblies, DC bus connections in industrial drives. The circuit gets formed once during assembly and never flexes again. In this scenario, ED copper’s fatigue limitation is completely irrelevant, and specifying FR9210E over FR9210R captures a real cost reduction without any reliability consequence.

#### High-Volume Consumer Electronics Power Flex

At production volumes measured in hundreds of thousands of units per quarter, the unit cost difference between ED and RA copper at 2 oz accumulates quickly. LED lighting panel interconnects, display backplane power feeds, and battery tab connectors in handheld devices are all candidates for FR9210E when the flex zone is static. The UL94 VTM-0 rating satisfies the flammability requirement that many consumer product certifications mandate.

#### High-Current Industrial Flex Connectors

Industrial automation equipment — conveyor controllers, servo drive panels, programmable logic controller (PLC) backplane power connectors — often specifies UL-rated flex materials for compliance with UL 508A industrial panel standards. FR9210E’s 2 oz copper handles the sustained current loads typical of industrial power distribution, while the VTM-0 flammability rating and IPC-4204/1 certification satisfy the procurement specifications common in industrial electrical equipment.

#### Automotive Body Electronics (Static Flex Applications)

Door modules, seat position controllers, lighting distribution, and tail lamp wiring harness replacements using flex architecture can benefit from 2 oz copper when current demands are moderate to high. Where the flex circuit is routed and clamped in a fixed position after vehicle assembly — not subject to door-open/door-close cycling or any repeated motion — FR9210E is a cost-appropriate choice compared to FR9210R. That said, any flex circuit routed near a hinge or pivot point, or subject to thermal-cycle-induced relative motion, should default to FR9210R.

#### High-Density Power Layers in Multilayer Flex Constructions

In multilayer flex builds where one layer functions as a dedicated power plane or high-current bus while other layers carry signals, FR9210E can serve as the power layer if that layer’s flex zone is static. The 2 oz copper gives the power layer current capacity without widening the traces, keeping the overall panel footprint compact. Signal layers in the same construction can use 1 oz RA copper for dynamic flex zone performance.

FR9210E in the Broader FR Single-Sided Product Family

Product Code	Copper Type	Copper Weight	Adhesive	Kapton®	IPC Cert.
FR9110R	RA	1 oz / 35 µm	1 mil / 25 µm	1 mil / 25 µm	Yes
FR9110E	ED	1 oz / 35 µm	1 mil / 25 µm	1 mil / 25 µm	Yes
FR9120R	RA	1 oz / 35 µm	1 mil / 25 µm	2 mil / 51 µm	Yes
FR9210E	ED	2 oz / 70 µm	1 mil / 25 µm	1 mil / 25 µm	Yes
FR9210R	RA	2 oz / 70 µm	1 mil / 25 µm	1 mil / 25 µm	Yes
FR9220R	RA	2 oz / 70 µm	1 mil / 25 µm	2 mil / 51 µm	Yes

If your design needs 2 oz copper with a thicker polyimide base for improved panel rigidity during fabrication or higher circuit stiffness in the finished product, FR9220E (if available) or FR9220R provides a 2 mil Kapton® option at the same copper weight. Confirm availability with your distributor, as not all FR variants in the extended product code matrix are held in standard stock at every distributor.

Processing, Fabrication, and Handling Notes

Lamination conditions for FR9210E follow the standard Pyralux FR window: part temperature 182–199°C (360–390°F), pressure 14–28 kg/cm² (200–400 psi), time 1–2 hours at temperature. No process changes are required when switching between FR9210E and FR9210R.

A few fabrication-specific points worth calling out for 2 oz ED copper:

Etch process: ED copper’s vertical grain structure dissolves with excellent uniformity in standard ammoniacal or cupric chloride etchant systems. At 70 µm copper, etch time will be substantially longer than for 35 µm copper, and undercut management is critical. Most shops producing at 2 oz copper set minimum trace/space at 6–8 mil to account for the undercut envelope. Confirm this with your fab during DFM review — don’t assume 1 oz copper design rules carry over.

Dry film resist adhesion: ED copper’s slightly rougher surface texture provides marginally better dry film photoresist adhesion compared to RA copper’s smoother profile. This can be a small process advantage when working at fine-pitch trace definitions in the 6–8 mil range, where resist adhesion consistency matters for yield.

Coverlay lamination at 2 oz: The 70 µm copper height creates significant relief that the coverlay adhesive must fill cleanly during lamination. Ensure that your coverlay selection provides sufficient adhesive volume for the trace geometry and copper height in your design. If large copper fills or wide buses are present, verify adhesive flow calculations with your laminator.

Drilling and routing: Vacuum extraction around the drill head is standard practice for all Pyralux FR materials. At 2 oz copper, the copper swarf volume is higher than at 1 oz — verify that your vacuum system is adequate, and inspect drill bits more frequently to manage work hardening effects at the higher copper cross-section.

Panel handling: Thin copper-clad laminates have sharp metal edges. At 70 µm copper, edge sharpness is significant. Gloves are essential for all panel handling personnel.

Storage, Shelf Life, and Packaging

Store FR9210E in original packaging at 4–29°C (40–85°F) and below 70% relative humidity. Do not freeze. Subject to these storage conditions, DuPont’s standard two-year warranty from the date of shipment applies.

FR9210E copper-clad laminates are supplied in 24 in × 36 in (610 mm × 914 mm) sheets, minimum four sheets and maximum 25 sheets per pack. DuPont provides a Certificate of Conformance with every manufactured lot. Keep the batch label — it contains the lot number, IPC specification reference, and order traceability information needed if a CoC inquiry arises post-delivery.

Useful Resources for DuPont Pyralux FR9210E

Resource	Description	Link
DuPont Pyralux FR Official Page	Product overview, certifications, and distributor contact	dupont.com/pyralux-fr
Pyralux FR CCL Datasheet (PDF)	Full Tables 1–3 covering FR9210E and all variants	epectec.com download
Pyralux FR CCL Datasheet (via elcopcb)	Alternate source for current datasheet version	elcopcb.com download
IPC-4204/1 Specification	Flexible metal-clad dielectric standard — basis for FR9210E IPC cert	IPC.org
IPC-TM-650 Test Methods	All test methods referenced in the FR property tables	IPC TM-650
IPC-2152 Current Capacity Standard	Standard for calculating current capacity in PCB and flex traces	IPC.org
UL Product iQ Database	Verify VTM-0 and UL796 certification status for Pyralux FR	iq.ul.com
DuPont Pyralux PCB Guide	PCB-specific guidance for all DuPont Pyralux materials	pcbsync.com/Dupont-pcb
Pyralux FR Processing Guide	Complete processing/lamination manual — available from DuPont reps	Contact DuPont or authorised distributor

Frequently Asked Questions About DuPont Pyralux FR9210E

Q1: Is DuPont Pyralux FR9210E single-sided or double-sided?

FR9210E is single-sided — copper on one face only. This is a detail that trips up many engineers who associate the “FR921x” range with double-sided construction. Per DuPont’s Pyralux FR CCL datasheet, FR9210E is listed under Table 1: Single-Sided Copper-Clad Product Codes. The double-sided 2 oz variant is FR9212E (ED copper) or FR9212R (RA copper). Always cross-check the product code table in the datasheet before finalising a BOM entry — the single- vs double-sided distinction is not visible in a product code suffix alone.

Q2: Why would an engineer choose FR9210E over FR9210R given the dynamic flex limitation?

The decision comes down to application requirements, not copper preference. If the flex circuit is static — formed once during assembly and never mechanically cycled — the fatigue crack limitation of ED copper is irrelevant. In that scenario, FR9210E delivers identical current capacity, identical IPC and UL certifications, and identical dielectric performance to FR9210R at a meaningfully lower material cost. At 2 oz copper weight, where material cost per panel is already elevated, that ED copper cost advantage is worth capturing whenever the design allows.

Q3: What current can a trace in FR9210E safely carry?

The current capacity of FR9210E traces is governed by the 2 oz (70 µm) copper geometry, not the copper type. Using IPC-2152 as a guide: for external traces with a 10°C temperature rise above ambient, a 100 mil wide trace in 2 oz copper carries approximately 6–8 A, a 50 mil trace carries roughly 4–5 A. Internal traces are derated by roughly half due to reduced convective cooling. These values are independent of whether the copper is ED (FR9210E) or RA (FR9210R) — bulk resistivity is essentially identical between ED and RA copper at this thickness. Always run your own IPC-2152 calculations for your specific geometry, ambient temperature, and temperature rise budget.

Q4: Does ED copper at 2 oz affect high-frequency signal performance on FR9210E?

Yes, marginally. ED copper’s higher surface roughness compared to RA copper increases the skin-effect conductor loss at elevated frequencies. For standard flex power interconnects and low-frequency signal routing — which is the primary application space for FR9210E — this difference is negligible. If your design has signal traces operating above a few hundred MHz on the same single-sided layer as the power routing, the smoother RA copper of FR9210R would deliver better insertion loss. In practice, designs that mix 2 oz high-current power runs with high-frequency signal traces usually benefit from separating those functions into different flex layers anyway, so this specific concern rarely drives the FR9210E vs FR9210R decision in isolation.

Q5: Can FR9210E be used as a layer in a multilayer flex or rigid-flex construction?

Yes, FR9210E is fully compatible with Pyralux FR bond ply and coverlay systems for multilayer and rigid-flex construction. When used as a layer in a multilayer stack, FR9210E brings its 2 oz current capacity to that layer position. For flex zones in a rigid-flex construction, be aware that the ED copper in FR9210E is less fatigue-resistant than RA copper — if the layer with FR9210E is in a flex zone that undergoes repeated bending (such as in a service-life hinge or repeated deflection zone), the RA copper of FR9210R is the safer specification. For static layers or rigid sections in a rigid-flex build, FR9210E is a practical and compliant choice.

Wrapping Up: Where FR9210E Belongs in Your Materials Matrix

DuPont Pyralux FR9210E is a specialist specification rather than a universal go-to. It earns its place on the BOM when three conditions align: the design needs 2 oz copper for current capacity, the design requires UL94 VTM-0 flame retardancy, and the flex zones are genuinely static — formed once and fixed for the product’s life. When all three conditions are true, FR9210E delivers the same certified, documented performance as FR9210R at a lower material cost and with potentially shorter lead time.

The moment any one of those conditions breaks — particularly the static flex requirement — FR9210R becomes the right answer. No amount of cost pressure justifies substituting ED copper into a dynamic flex zone at 2 oz. The grain boundary cracking that occurs in ED copper under cyclic stress is faster and more severe at heavier copper weights, and a field failure in a 2 oz power circuit tends to be more consequential than a trace failure in a 1 oz signal layer.