DuPont Pyralux LF9110E is a single-sided ED copper acrylic flex laminate with 1 oz copper, 1 mil adhesive, and 1 mil Kapton. Compare its full specs vs LF9110R, understand when to choose ED over RA copper, and get the engineering data you need — Dk, Df, peel strength, storage, and more.

If you’ve spent any time speccing out materials for a flex or rigid-flex PCB, you’ve almost certainly run into the DuPont Pyralux LF family. Within that lineup, the DuPont Pyralux LF9110E is one of the most commonly specified single-sided copper-clad laminates — and one that trips up engineers more often than it should, mostly because of confusion between the “E” and “R” suffix designations.

This article breaks down exactly what LF9110E is, what the specs mean in practice, how it compares to its rolled-annealed counterpart LF9110R, and when you’d actually want to choose one over the other. No filler — just the material science and engineering judgment calls that actually matter on the bench.

What Is DuPont Pyralux LF9110E?

DuPont Pyralux LF9110E is a single-sided, acrylic-based copper-clad laminate from DuPont’s Pyralux LF product family. It consists of three bonded layers:

• Electro-deposited (ED) copper foil — 35 µm (1.0 oz/ft²)
• Modified acrylic adhesive — 25 µm (1.0 mil)
• DuPont Kapton® polyimide film — 25 µm (1.0 mil)

The “LF” in the product name stands for the acrylic adhesive system. The “9110” encodes the construction — 1 oz copper, 1 mil adhesive, 1 mil Kapton. And the “E” at the end? That’s the critical part: it tells you the copper is electro-deposited, as opposed to “R” (rolled annealed) or “D” (double-treated rolled annealed).

The Pyralux LF product family has been the industry standard in high-reliability flex circuit applications for over 35 years, certified to IPC-4204/1 and fully RoHS compliant. For engineers working on DuPont PCB designs, understanding the LF9110E construction is foundational before you commit to a flex stackup.

DuPont Pyralux LF9110E: Full Construction Specs

Table 1 — LF9110E Physical Construction

Parameter	Value
Product Code	LF9110E
Copper Type	Electro-Deposited (ED)
Copper Thickness	35 µm (1.0 oz/ft²)
Adhesive Type	C-staged Modified Acrylic
Adhesive Thickness	25 µm (1.0 mil)
Kapton® Film Thickness	25 µm (1.0 mil)
Total Nominal Thickness	~85 µm (3.3 mil)
Construction	Single-Sided Clad
IPC Certification	IPC-4204/1
RoHS Compliant	Yes

Table 2 — LF9110E Electrical & Mechanical Properties

Property	Typical Value	Test Method
Dielectric Constant (Dk) @ 1 MHz	3.6	IPC-TM-650 2.5.5.3
Dielectric Constant (Dk) @ 10 GHz	3.0	ASTM D2520
Loss Tangent (Df) @ 1 MHz	0.02	IPC-TM-650 2.5.5.3
Loss Tangent (Df) @ 10 GHz	0.02	ASTM D2520
Peel Strength (after lamination)	1.8 N/mm (10.0 lb/in)	IPC-TM-650 2.4.9
Peel Strength (after solder)	1.6 N/mm (9.0 lb/in)	IPC-TM-650 2.4.9
Dimensional Stability (MD/TD)	± 0.10%	IPC-TM-650 2.2.4
Solder Float (288°C, 10 s)	Pass	IPC-TM-650 2.4.13
Volume Resistivity	> 10¹⁵ Ω·cm	IPC-TM-650 2.5.17
Surface Resistance	> 10¹⁴ Ω	IPC-TM-650 2.5.17

These values are drawn from DuPont’s official datasheet (EI-10117). Note that performance can shift depending on downstream processing and lamination stack construction — always verify against your specific build.

Table 3 — Processing Conditions for LF9110E

Parameter	Specification
Part Temperature	182 – 199 °C (360 – 390 °F)
Pressure	14 – 28 kg/cm² (200 – 400 psi)
Time at Temperature	1 – 2 hours

Table 4 — Storage & Packaging

Parameter	Specification
Standard Sheet Sizes	24×36 in / 24×18 in / 12×18 in
Sheets per Pack	4 (min) to 25 (max)
Storage Temperature	4 – 29°C (40 – 85°F)
Relative Humidity	< 70%
Shelf Life (warranty period)	2 years from Certificate of Analysis date

LF9110E vs LF9110R: What Actually Changes When You Switch Copper Types?

This is the question that matters most in day-to-day engineering. Let’s be direct: the LF9110E and LF9110R are structurally identical in terms of adhesive thickness, Kapton thickness, and all electrical properties on the datasheet. The only difference is the copper foil itself — electro-deposited (ED) versus rolled annealed (RA).

But that one difference has significant downstream engineering consequences.

Table 5 — LF9110E vs LF9110R: Side-by-Side Comparison

Attribute	LF9110E (ED Copper)	LF9110R (RA Copper)
Copper Type	Electro-Deposited (ED)	Rolled Annealed (RA)
Copper Thickness	35 µm (1 oz/ft²)	35 µm (1 oz/ft²)
Adhesive Thickness	25 µm (1.0 mil)	25 µm (1.0 mil)
Kapton Thickness	25 µm (1.0 mil)	25 µm (1.0 mil)
Grain Structure	Columnar (vertical)	Elongated (horizontal)
Surface Roughness	Higher	Lower
Flex Fatigue Life	Lower	Higher
Bend Radius Capability	Static applications preferred	Dynamic flex preferred
Cost	Lower	Higher
Fine Line Etching	Good	Excellent
Electrical Properties (Dk/Df)	Same	Same
IPC-4204/1 Certified	Yes	Yes
High-Frequency Performance	Slightly reduced (surface roughness)	Better

Understanding the Copper Grain Structure Difference

The “E” vs “R” distinction goes beyond a simple label — it reflects fundamentally different manufacturing processes and resulting microstructures.

Electro-deposited (ED) copper, used in LF9110E, is grown electrochemically by passing current through a copper electrolyte solution, causing copper ions to deposit onto a rotating drum. The resulting grain structure is columnar — grains grow vertically, perpendicular to the foil surface. This columnar structure means the foil is stronger in the plane of deposition but has less resistance to repeated bending across that plane. ED copper also tends to have a rougher surface on the matte side, which actually aids adhesion in static applications but can introduce signal loss at higher frequencies.

Rolled annealed (RA) copper, used in LF9110R, starts as a copper ingot that gets mechanically rolled into thin sheets and then annealed to relieve stress. The rolling elongates grains horizontally — parallel to the surface. This pancake-like grain structure is exactly what makes RA copper significantly more resistant to flex fatigue. It can withstand far more bend cycles before crack initiation.

The practical implication: if your flex circuit sits in a hinge that opens and closes thousands of times (think a flip-phone hinge, a wearable, or a robotics joint), you want RA copper. If your flex circuit gets bent once during assembly and then lives a static life inside a device enclosure, ED copper in the LF9110E is perfectly adequate — and more cost-effective.

When to Specify DuPont Pyralux LF9110E

Based on the construction and copper characteristics, LF9110E fits best in these scenarios:

Static or semi-static flex applications — circuit boards that flex during assembly or installation but don’t undergo repeated dynamic bending in service. Enclosure interconnects, board-to-board ribbon connections, and Z-axis flex connectors in consumer electronics are typical examples.

Cost-sensitive high-volume programs — ED copper is manufactured in higher volumes at lower cost than RA copper. When you’re running millions of units and the application doesn’t demand fatigue life, LF9110E makes clear economic sense.

Single-sided circuit designs — the LF9110E single-sided construction is well-suited to simple flex interconnects, antenna traces, and straightforward signal routing where only one copper layer is needed.

Applications requiring surface treatment compatibility — the slightly rougher surface of ED copper provides good mechanical keying for acrylic adhesive bonding. In some lamination processes, this actually improves peel strength consistency.

Where you would NOT specify LF9110E:

• Dynamic flex zones with > 1 million bend cycles
• Continuous flex applications (e.g., print head cables, robotic harnesses)
• High-frequency designs above ~5 GHz where surface roughness meaningfully degrades insertion loss
• Fine-pitch circuit traces where the coarser surface of ED copper could affect etch uniformity at extremely tight line/space rules

DuPont Pyralux LF Product Family: Context for LF9110E

Understanding where LF9110E sits within the broader product matrix helps when you’re evaluating alternatives.

Table 6 — Pyralux LF Single-Sided Standard Offerings (R suffix shown; add E for ED copper)

Product Code (RA)	ED Equivalent	Copper (oz/ft²)	Adhesive (mil)	Kapton (mil)
LF7012R	LF7012E	0.5	0.5	0.5
LF7062R	LF7062E	0.5	0.5	1.0
LF7004R	LF7004E	0.5	1.0	0.5
LF7002R	LF7002E	1.0	0.5	0.5
LF9110R	LF9110E	1.0	1.0	1.0
LF9120R	LF9120E	1.0	1.0	2.0
LF9150R	LF9150E	1.0	1.0	5.0
LF9210R	LF9210E	2.0	1.0	1.0
LF9220R	LF9220E	2.0	1.0	2.0

The LF9110E sits in the middle of the matrix — the “standard” construction with balanced adhesive and Kapton thickness. Thinner Kapton options (LF7xxx series with 0.5 mil Kapton) are used where overall laminate thickness must be minimized. Thicker Kapton variants (LF9120, LF9150) are used where dimensional stability or mechanical stiffness of the base material matters.

Quality, Certification, and Traceability

One reason the Pyralux LF family dominates high-reliability applications is DuPont’s manufacturing quality infrastructure. Every lot of LF9110E is manufactured under an ISO 9001:2015 certified Quality Management System. A Certificate of Conformance (COC) ships with every batch, and complete material and manufacturing records for each lot — including retained samples — are kept on file for reference in case of quality inquiries. Roll labels carry the lot number, DuPont order number, IPC specification reference, and customer part number. Engineers should save these labels.

This level of traceability matters if you’re designing for aerospace, defense, medical devices (non-implantable), or other regulated industries where material traceability is a contract or regulatory requirement.

Useful Resources for Engineers Working with LF9110E

The following references are directly useful when qualifying or designing with DuPont Pyralux LF9110E:

• DuPont Pyralux Official Product Page — pyralux.dupont.com — Includes the Laminate Product Selector tool and access to current datasheets.
• DuPont Pyralux LF Datasheet (EI-10117) — Available from pyralux.dupont.com. Contains the official property tables, processing parameters, and storage conditions.
• DuPont Pyralux LF Processing Guide — Available through your DuPont sales representative. Essential if you’re setting up in-house lamination.
• Pyralux Safe Handling Guide — Available at pyralux.dupont.com. Required reading before handling in production environments.
• IPC-4204/1 — “Flexible Metal-Clad Dielectrics for Use in Fabrication of Flexible Printed Boards” — the governing industry specification that LF9110E is certified to.
• IPC-TM-650 — The test method standard referenced in all Pyralux electrical and mechanical property measurements.
• IPC-4562 — Covers copper foil specifications, relevant when comparing ED vs. RA grades.
• DuPont Medical Caution Statement H-50102-5 — Required if evaluating Pyralux LF materials for any medical application.

5 FAQs About DuPont Pyralux LF9110E

FAQ 1: Can I substitute LF9110E for LF9110R in an existing design?

In most cases, yes — with caveats. The dielectric properties, adhesive thickness, and Kapton thickness are identical. The substitution is straightforward if your application is static flex. If the design involves a dynamic flex zone or repeated bend cycling, you need to run flex fatigue analysis before substituting ED for RA copper. IPC-TM-650 Method 2.4.3 is commonly used to evaluate flex endurance. Don’t assume a drop-in swap without verifying the application’s flex requirements.

FAQ 2: What does the “E” suffix actually mean in Pyralux product codes?

Per DuPont’s product code convention: “R” = rolled annealed copper, “E” = electro-deposited copper, and “D” = double-treated rolled annealed copper (ED nodules on both sides of RA foil, eliminating surface prep before resist lamination). So LF9110E means: LF series (acrylic adhesive), 9110 construction (1 oz copper / 1 mil adhesive / 1 mil Kapton), E for electro-deposited copper.

FAQ 3: Is LF9110E compatible with standard flex circuit fabrication processes?

Yes. Pyralux LF materials are fully compatible with standard flex PCB fabrication: photolithographic etching, press lamination of coverlays, screen printing, and standard through-hole and SMT processes. The acrylic adhesive in LF9110E passes solder float testing at 288°C for 10 seconds, confirming thermal compatibility with reflow and wave solder processes.

FAQ 4: What are the storage requirements for LF9110E, and does it expire?

Store LF9110E at 4–29°C (40–85°F), below 70% relative humidity, in the original packaging. Keep it dry, clean, and protected. DuPont warrants the material for two years from the Certificate of Analysis date when storage conditions are met. Beyond that window, the acrylic adhesive system may partially advance in cure state, which can reduce peel strength and bonding performance. Always check the COC date before pulling old stock.

FAQ 5: How does LF9110E perform at high frequencies, and is it suitable for RF applications?

The LF9110E shares the same Kapton-acrylic dielectric system as the rest of the LF family: Dk of 3.6 at 1 MHz, dropping to 3.0 at 10 GHz, with a loss tangent of 0.02 across both. These numbers are workable for many RF applications in the sub-5 GHz range. However, the rougher surface of ED copper contributes to skin-effect losses at higher frequencies compared to RA copper. For designs pushing above 5–6 GHz, LF9110R (RA copper) or adhesive-free Pyralux AP/AP7 constructions are generally the better call. The loss tangent of 0.02 is also higher than adhesive-free laminates like Pyralux AP (Df ~0.002), so for truly high-frequency or microwave RF work, LF-series materials aren’t the optimal choice regardless of copper type.

Final Thoughts

The DuPont Pyralux LF9110E is a well-proven, IPC-certified flex laminate that gives engineers a cost-effective path to single-sided acrylic-based flex construction. The electro-deposited copper makes it the right call for static and semi-static applications where flex fatigue life isn’t the governing requirement. Where it falls short — dynamic flex, very high frequency, or fine-pitch etching at extreme line/space rules — the LF9110R or adhesive-free Pyralux AP family should be on your shortlist.

The most common mistake engineers make is treating “E” and “R” variants as interchangeable without validating the flex cycle count requirements of the application. Take five minutes with the datasheet, compare it to your mechanical use case, and you’ll almost always make the right call the first time.

All specifications cited are drawn from DuPont’s official Pyralux LF Copper-Clad Laminate data sheet (EI-10117). Verify current revision before design commitment. Material performance can vary based on construction, processing, and end-use environment.

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DuPont Pyralux LF9110E is a single-sided ED copper acrylic flex laminate with 1 oz copper, 1 mil adhesive, and 1 mil Kapton. Compare its full specs vs LF9110R, understand when to choose ED over RA copper, and get the engineering data you need — Dk, Df, peel strength, storage, and more.