DuPont Pyralux AP9111R: 1 oz RA Copper / 1 mil PI Flex Laminate — Datasheet & PCB Use

There’s a narrow group of flex laminates that engineers keep coming back to when the design pushes beyond what standard materials can handle. DuPont Pyralux AP9111R is firmly in that group. It’s not the most common SKU in the Pyralux AP lineup — that honor probably goes to the 2 mil constructions — but when you need the thinnest possible all-polyimide core with full 1 oz copper and the fatigue resistance of rolled-annealed foil, AP9111R is often the only answer that works.

This article decodes the part number, lays out the full spec table, explains where and why this particular construction gets specified, and flags the design and fabrication details that matter most for getting yield.

Decoding the DuPont Pyralux AP9111R Part Number

At the end of the product code, “R” designates rolled-annealed copper (for example, AP9111R), “E” designates electro-deposited copper, and “D” designates double-treated rolled-annealed copper. But the numbers in the middle carry just as much information. Here’s how the full part number breaks down:

Code Segment	Decoded Meaning
AP	All-Polyimide (adhesiveless) double-sided clad series
91	1.0 mil (25.4 µm) polyimide dielectric thickness
11	1 oz (35 µm / 1.0 oz/ft²) copper weight, each side
R	RA — Rolled Annealed copper foil type

So AP9111R is a double-sided, adhesiveless, all-polyimide laminate with a 1 mil dielectric core and 1 oz RA copper on both faces. No adhesive between dielectric and conductor. That combination — ultra-thin core, full-weight copper, RA grain structure — is what makes this part number show up in dynamic flex and high-density flex interconnect designs that other materials simply can’t service.

DuPont Pyralux AP9111R Full Specifications

The tables below reflect typical values from DuPont’s official Pyralux AP Technical Data Sheet. These are not specification limits — use them for design estimation and preliminary stack-up planning, then confirm with lot-specific data from your distributor or directly from DuPont for qualification.

Electrical Properties

Property	Typical Value	Test Method
Dielectric Constant (Dk) @ 1 MHz	3.4	IPC-TM-650 2.5.5.3
Dissipation Factor (Df) @ 1 MHz	0.002	IPC-TM-650 2.5.5.3
Dielectric Strength	>3,000 V/mil	IPC-TM-650 2.5.6
Surface Resistivity	>10¹³ Ω	IPC-TM-650 2.5.17.1
Volume Resistivity	>10¹⁵ Ω·cm	IPC-TM-650 2.5.17.1
Moisture Absorption (24 hr)	~2.5%	IPC-TM-650 2.6.2

Mechanical Properties

Property	Typical Value	Notes
Polyimide Core Thickness	1.0 mil (25.4 µm)	±10% thickness tolerance
Copper Thickness (each side)	35 µm / 1.0 oz/ft²	RA foil — both sides
Total Laminate Thickness (approx.)	~2.8 mil (71 µm)	Both copper layers included
Peel Strength (as received)	≥1.4 N/mm (8 lb/in)	IPC-TM-650 2.4.9
Peel Strength (after solder float)	≥1.0 N/mm (5.7 lb/in)	IPC-TM-650 2.4.9
Tensile Strength — PI Film (MD/TD)	~165 / 140 MPa	Film only
Elongation at Break	~70%	PI film
Dimensional Stability (after etch)	<0.10%	IPC-TM-650 2.2.4

Thermal Properties

Property	Typical Value	Standard
Glass Transition Temperature (Tg)	>300°C	DSC — no limiting adhesive
Maximum Operating Temperature	180°C (356°F)	UL 796
CTE — X/Y Axis	~12–16 ppm/°C	IPC-TM-650 2.4.41
Solder Float (288°C, 10 sec)	Pass	IPC-TM-650 2.4.13
Flammability Rating	UL 94V-0	UL 796

Physical / Administrative Properties

Property	Value
IPC Certification	IPC-4204/11
Quality System	ISO 9001:2015
Standard Sheet Sizes	12″ × 18″, 18″ × 24″ (custom available by special order)
Available Copper Types	R (RA), E (ED), D (double-treated RA)
Adjacent SKUs (same dielectric)	AP9111E (ED), AP9111D (double-treat RA)

Why 1 mil Polyimide Is Both an Asset and a Challenge

Most Pyralux AP designs start at 2 mil (AP8525E or AP8525R) because it’s easier to handle, easier to image, and gives you more dielectric real estate for impedance control. The 1 mil core in AP9111R is thinner than many engineers are comfortable working with, and that demands some upfront honesty about what you’re getting into.

On the asset side, 1 mil dielectric means:

Minimum cross-section. For applications where total laminate thickness drives the flex zone bend radius or fits inside a constrained form factor — think foldable electronics, implantable-adjacent packaging, or dense satellite assemblies — 1 mil is the only way to get there without switching to a half-ounce copper weight.

Better dynamic flex performance at the material level. Thinner dielectric reduces the strain imposed on copper traces during bending. Combined with RA copper (more on that below), this translates to meaningfully better flex-cycle life compared to any 2 mil construction.

Consistent, weave-free dielectric. Pyralux AP does not contain glass, which gives it exceptional isotropy. Routed signals will see the same dielectric constant no matter which direction they are routed on the circuit board. In a 1 mil construction, this matters even more because any local Dk variation has proportionally more impact on impedance targets in such a thin stack.

On the challenge side, 1 mil laminate demands tighter process controls. Handling unsupported panels is harder, fine-line imaging requires better vacuum contact, and any tension in the lamination press can introduce dimensional instability. Fabricators with limited experience in thin flex are likely to see lower yields on their first runs with AP9111R.

The Real Reason You’re Choosing RA Copper: Fatigue Life

The “R” suffix is the decision point that separates AP9111R from its ED sibling, AP9111E. Engineers sometimes choose RA copper for signal integrity reasons — its smoother surface reduces skin-effect losses at high frequency. That’s real, but it’s secondary. The primary reason to pay the RA premium is fatigue resistance.

Electrodeposited (ED) copper is grown in a plating bath. Its grain structure runs perpendicular to the foil surface — columnar grains that etch beautifully and uniformly but crack more readily under repeated bending stress. RA copper starts as a cast ingot that is rolled into sheet form under high pressure. That rolling aligns the copper grains parallel to the foil surface, creating a structure that deflects and recovers under bending without early crack propagation.

Property	RA Copper (AP9111R)	ED Copper (AP9111E)
Grain Orientation	Horizontal (parallel to surface)	Vertical (columnar)
Surface Roughness (Rz)	Lower — smoother surface	Higher
Dynamic Flex Cycles	High — preferred for cyclic flex	Lower
Skin Effect Losses at High Freq	Lower	Higher
Fine-line Etch Uniformity	Good	Excellent
Cost vs. ED	Higher	Lower
Typical Use Case	Dynamic flex, high-frequency flex	Static flex, rigid-flex HDI

For any application where the flex zone will experience continuous or repetitive movement — hinges, wearable sensors, robotic cable carriers, medical diagnostic leads — the choice of RA copper is not optional. Specify AP9111R, not AP9111E.

Where DuPont Pyralux AP9111R Gets Specified

The combination of 1 mil polyimide and 1 oz RA copper produces a construction that shows up consistently in a defined set of application categories:

Consumer electronics moving mechanisms. Foldable phones, laptop hinge connectors, camera actuators, and optical image stabilization (OIS) modules all experience millions of flex cycles across product lifetime. AP9111R handles this duty cycle where 2 mil constructions would accumulate fatigue failures prematurely.

Aerospace and defense flex harnesses. High-altitude flex circuits see extreme thermal cycling combined with vibration. The Tg of >300°C — free from any adhesive layer that would drop it to 90–130°C — means AP9111R performs without delamination risk through temperature swings that destroy adhesive-based flex laminates.

Precision medical diagnostics. Flex circuits in ultrasound transducers, catheter-tip assemblies, and diagnostic sensor arrays benefit from the combination of thin profile and reliable fatigue performance. (Note: not for permanent implantation per DuPont’s own medical caution statement.)

High-frequency RF and mmWave flex. The lower surface roughness of RA copper reduces insertion loss at frequencies above 5–10 GHz. For antenna flex circuits, radar front-ends, and high-speed test interconnects, AP9111R’s RA foil delivers measurably better performance than the ED alternative.

Satellite and space packaging. Weight budgets in space are absolute, and thin-flex laminates directly reduce harness mass. The radiation stability of an all-polyimide construction gives AP9111R a material advantage over organic or glass-reinforced laminates in orbital applications.

Fabricators handling these demanding applications often source from specialized laminate-certified PCB manufacturers. DuPont PCB  is one manufacturer well regarded for flex and rigid-flex work with premium all-polyimide laminates like the Pyralux AP series.

AP9111R vs. Similar Pyralux AP Constructions

Part Number	PI Thickness	Cu Weight	Cu Type	Primary Advantage
AP9111R	1 mil / 25.4 µm	1 oz / 35 µm	RA	Thinnest 1 oz RA — dynamic flex
AP9111E	1 mil / 25.4 µm	1 oz / 35 µm	ED	Lower cost, static flex, HDI
AP9111D	1 mil / 25.4 µm	1 oz / 35 µm	Double-treat RA	Enhanced bondability, same flex life
AP8515R	1 mil / 25.4 µm	½ oz / 18 µm	RA	Thinner copper, tighter bend radius
AP8525R	2 mil / 50.8 µm	1 oz / 35 µm	RA	More dielectric — easier to handle
AP9121R	2 mil / 50.8 µm	1 oz / 35 µm	RA	2× dielectric thickness of AP9111R

The AP8515R is worth understanding as a comparison: same 1 mil dielectric, but only half-ounce copper. For designs where current-carrying capacity allows going to ½ oz, AP8515R gives you even better flex endurance because thinner copper means lower peak strain at the outermost fiber. But if you need 1 oz for current density, trace resistance, or plating headroom, AP9111R is your floor.

Fabrication Notes for AP9111R

Working with a 1 mil all-polyimide laminate is different enough from standard 2 mil flex that it’s worth calling out the key process considerations:

Panel handling. AP9111R panels are compliant and sensitive to crease damage. Handle in flat carriers or on interleaved support sheets. Avoid stacking unsupported panels without separator boards.

Imaging. Thin laminates can tent or wrinkle under photoresist vacuum contact. Ensure excellent vacuum draw-down and consider UV-cure tack dry-film resists designed for thin flex substrates.

PTH desmear. AP9111R is compatible with wet chemical PTH and plasma desmear processes. Confirm chemistry compatibility with your laminate and coverlay combination before processing.

Coverlay lamination. Use standard polyimide coverlay films with compatible bonding adhesives. Lamination areas should be well ventilated — trace residual solvents in the all-polyimide construction can volatilize under press heat.

Lead-free solder assembly. The >300°C Tg and solder float pass at 288°C mean AP9111R handles lead-free reflow peaks (245–260°C) comfortably. Watch for board-level warpage at the flex-to-rigid interface if AP9111R is used as a flex core inside a rigid-flex stack.

Drilling and routing. When drilling or routing parts made with Pyralux, provide adequate vacuum around the drill to minimize worker exposure to generated dust. This applies directly to AP9111R work.

Useful Resources for AP9111R Designers and Fabricators

Resource	What You’ll Find	URL
DuPont Pyralux AP Product Page	Overview, selector tool, part number matrix	dupont.com/pyralux-ap
Pyralux AP Technical Data Sheet (PDF)	Full electrical, mechanical, thermal spec tables	eurotronics.be Pyralux AP/AC Datasheet
DuPont Safe Handling Guide	Ventilation, storage, operator safety	pyralux.dupont.com
IPC-4204/11 Standard	Adhesiveless flex metal-clad dielectric specification	ipc.org
IPC-TM-650 Test Methods	All referenced test methods	ipc.org
UL Product iQ	Verify UL 94V-0 and UL 796 certifications by lot	iq.ul.com
Cirtech Electronics AP9111R	Distributor listing with product details	cirtech-electronics.com

5 Frequently Asked Questions About DuPont Pyralux AP9111R

Q1: What is the difference between AP9111R, AP9111E, and AP9111D — and how do I choose?

All three share the same 1 mil polyimide and 1 oz copper weight. The suffix tells you the copper type. The R designation is rolled-annealed, best for dynamic flex and high-frequency signal work. The E designation is electrodeposited, lower cost and preferred for static bend-to-install or rigid-flex HDI where fine-line etch uniformity matters more than fatigue life. The D designation is double-treated rolled-annealed — RA copper with an additional surface treatment to improve adhesion to coverlay and bondply without sacrificing the horizontal grain structure. Choose D when you need both the fatigue advantage of RA and enhanced adhesion chemistry in your cover lamination process.

Q2: What is the minimum bend radius for AP9111R in a dynamic flex application?

DuPont does not publish a single universal bend radius because the value depends on copper coverage, trace orientation, the number of conductor layers, and the specific flex cycle count requirement of the application. For a double-sided 1 oz RA laminate under dynamic flex conditions, a conservative starting rule is a minimum bend radius of 10× the total laminate thickness. With AP9111R’s approximate total thickness of ~2.8 mil (71 µm), that suggests a minimum dynamic bend radius in the range of ~28 mil (0.7 mm). Confirm through finite element analysis or physical flex cycle testing for production qualification.

Q3: Does AP9111R meet the requirements for aerospace and defense flex circuit applications?

Yes, in most standard requirements. The adhesiveless all-polyimide construction gives AP9111R a Tg well above 300°C, UL 94V-0 flammability rating, and IPC-4204/11 certification — all baseline requirements for mil-aero flex laminate qualification. For programs requiring specific mil-spec qualification (such as MIL-P-50884), confirm current qualification status directly with DuPont or your approved materials list (AML) holder, as qualification status can change between specification revisions.

Q4: Can AP9111R be used in high-frequency RF flex circuits above 10 GHz?

Yes, and the RA copper actually makes it a better choice at microwave and mmWave frequencies compared to AP9111E. The smoother surface of RA foil reduces skin-effect losses, which grow significantly above 5–10 GHz. Combined with the isotropic, weave-free polyimide dielectric and a consistent Dk of 3.4, AP9111R is a solid substrate choice for flex antenna elements, radar interconnects, and mmWave test cables. At very high frequencies (>30 GHz), verify your specific insertion loss budget against measured data from your fabricator on the actual construction, since copper surface roughness spec varies by foil lot and treatment.

Q5: What are the storage and shelf life requirements for AP9111R?

Pyralux AP is fully cured when delivered. There is no reactive chemistry that degrades on the shelf under normal conditions. Store in original packaging at 15–25°C, below 70% relative humidity, and away from prolonged UV or fluorescent light exposure. Rolls should remain on the original core to prevent kinking of the 1 mil laminate. Before processing, allow panels to equilibrate to shop floor temperature for at least one hour to prevent condensation from forming on the copper surface. No formal shelf life expiration applies under proper storage conditions, though DuPont and most distributors recommend using within 12 months of manufacture for lot traceability purposes.