DuPont Pyralux AP7163E: Ultra-Thin All-Polyimide Flex Laminate (0.25 oz ED Cu / 1 mil PI)

If you’re working on a next-generation flexible circuit that needs to be thin, thermally robust, and chemically clean — DuPont Pyralux AP7163E is one of those materials you end up specifying when the design really means it. At 1 mil of polyimide dielectric with a featherweight 0.25 oz electro-deposited copper foil, it occupies the very thin end of the Pyralux AP product family. This article breaks down everything a PCB engineer needs to know: what AP7163E actually is, where it fits in the AP product line, the hard numbers from the datasheet, processing considerations, and the applications where this ultra-thin laminate is the right call.

What Is DuPont Pyralux AP7163E?

DuPont Pyralux AP7163E is a double-sided, adhesiveless, all-polyimide copper-clad laminate from DuPont’s Pyralux AP series. The construction is exactly what the product code describes: 1.0 mil (25 µm) of polyimide dielectric bonded directly to 9 µm (0.25 oz/ft²) electro-deposited (ED) copper foil on each side — with no adhesive layer between the polyimide and the copper.

That “no adhesive” part matters more than it sounds. Traditional flex laminates use an acrylic or epoxy adhesive to bond copper to polyimide. That adhesive layer adds thickness, limits thermal resistance to typically 130–150°C, and can absorb moisture. The adhesiveless construction in Pyralux AP eliminates all three problems in one shot. The copper is bonded directly to the polyimide through a DuPont-proprietary process, giving you a construction that can operate continuously up to 180°C and withstand processing temperatures well above that.

Decoding the AP7163E Product Code

The naming convention in the Pyralux AP family tells you a lot at a glance:

Code Segment	Meaning
AP	Pyralux AP all-polyimide series
7163	Proprietary product number (1 mil PI / 9 µm Cu construction)
E	Electro-deposited (ED) copper foil

The “E” suffix designates ED copper. AP7163E is available exclusively in ED copper — not rolled-annealed (RA). This is an important distinction for designers targeting dynamic flexing applications, which is discussed further below.

DuPont Pyralux AP7163E Full Technical Specifications

All data below is drawn directly from DuPont’s official Pyralux AP datasheet. Properties listed are typical values for the AP all-polyimide system.

Construction and Physical Properties

Parameter	AP7163E Value	Unit
Polyimide Dielectric Thickness	1.0 (25)	mil (µm)
Copper Foil Thickness	9 (0.25)	µm (oz/ft²)
Copper Foil Type	Electro-Deposited (ED)	—
Adhesive Layer	None (adhesiveless)	—
Standard Sheet Sizes	24×36, 24×18, 12×18	inches
Glass Transition Temperature (Tg)	220	°C
Maximum Operating Temperature	180	°C
Tensile Strength	345	MPa
Elongation	50	%
Flexural Endurance	6,000	cycles

Electrical Properties

Property	Value	Frequency	Test Method
Dielectric Constant (Dk)	3.4	1 MHz	IPC-TM-650 2.5.5.3
Dielectric Constant (Dk)	3.2	10 GHz	ASTM D2520
Loss Tangent (Df)	0.002	1 MHz	IPC-TM-650 2.5.5.3
Loss Tangent (Df)	0.003	10 GHz	ASTM D2520
Dielectric Strength	200	V/µm	ASTM D149
Volume Resistivity	>10¹⁷	Ω·cm	IPC-TM-650 2.5.17
Surface Resistance	>10¹⁶	Ω	IPC-TM-650 2.5.17
Moisture & Insulation Resistance	>10¹¹	Ω	IPC-TM-650 2.6.3.2

Thermal and Mechanical Properties

Property	Value	Test Method
Peel Strength (as received)	1.4 N/mm (8 lb/in)	IPC-TM-650 2.4.9
Peel Strength (after solder)	1.4 N/mm (8 lb/in)	IPC-TM-650 2.4.9
CTE (XY-axis below Tg)	~25 ppm/°C	IPC-TM-650 2.4.41
CTE (XY-axis above Tg)	~30 ppm/°C	IPC-TM-650 2.4.41
Moisture Absorption	0.8%	IPC-TM-650 2.6.2
Solder Float (288°C, 10 sec)	Pass	IPC-TM-650 2.4.13
Dimensional Stability (after etch)	±0.04 to ±0.08%	IPC-TM-650 2.2.4

Certifications and Compliance

Pyralux AP Double-side Clad is certified to IPC-4203/11, carries UL 94 V-0 flammability rating, and is manufactured under a certified ISO9001:2015 Quality Management System with full material and manufacturing records maintained by DuPont. The material is also RoHS compliant and each manufactured lot is fully traceable through the packaging label system.

Where AP7163E Fits in the Pyralux AP Product Family

The AP series covers a wide range of dielectric thicknesses (0.5 to 6 mil) and copper weights (6 µm to 140 µm). AP7163E sits at the extreme thin end — the thinnest standard polyimide combined with the lightest standard copper:

Product Code	PI Thickness	Cu Thickness	Cu Type	Application Focus
AP7163E	1.0 mil	9 µm (0.25 oz)	ED only	Ultra-thin, fine-line HDI
AP7164E	1.0 mil	12 µm (0.33 oz)	ED only	Thin, fine-line
AP8515R	1.0 mil	18 µm (0.5 oz)	RA	Dynamic flex, general
AP9111R	1.0 mil	35 µm (1.0 oz)	RA	Standard double-sided
AP7156E	2.0 mil	9 µm (0.25 oz)	ED only	Thin Cu, thicker dielectric
AP9121R	2.0 mil	35 µm (1.0 oz)	RA	Controlled impedance

ED vs. RA Copper: What It Means for AP7163E

The fact that AP7163E uses electro-deposited (ED) copper rather than rolled-annealed (RA) has direct design implications. ED copper has a rougher surface profile than RA copper, which gives it very strong adhesion to the polyimide — the peel strength of 1.4 N/mm is excellent for this construction. However, ED copper has lower ductility and fatigue resistance under repeated dynamic bending compared to RA copper.

This means AP7163E is the right choice for:

• Static flex or flex-to-install applications
• HDI fine-line circuitry where surface planarity for laser ablation matters
• Applications requiring tight copper-polyimide adhesion through thermal excursions

It is not the optimal pick for dynamic flex applications (thousands of continuous bend cycles), where an RA copper grade like AP8515R would be more appropriate.

Why 1 mil PI + 0.25 oz Cu? The Design Logic Behind AP7163E

When engineers specify AP7163E, they’re usually chasing one or more of these objectives:

Minimum total stack height. At 1 mil PI and 9 µm copper per side, the raw laminate contributes roughly 43 µm (about 1.7 mil) to total construction thickness. For wearables, medical implantables, or compact consumer devices where every micron of z-height is budgeted, this matters enormously.

Fine-line circuit capability. Thinner copper etches more cleanly and resolves finer lines. With 9 µm starting copper, fabricators can achieve 25–50 µm trace/space geometries more reliably than with 18 or 35 µm copper. This is the kind of line resolution needed for dense HDI flex layers in smartphones, hearing aids, and satellite sub-assemblies.

Tight dielectric for impedance control. A 1 mil polyimide with known, stable Dk of 3.2–3.4 gives designers a predictable dielectric environment for controlled impedance microstrip design. The tight dielectric thickness tolerance of Pyralux AP minimizes impedance variations of signal lines and provides designers a consistent dielectric constant for controlled impedance circuit requirements.

High thermal resistance without adhesive bottlenecks. The all-polyimide construction of Pyralux AP provides excellent thermal resistance, low CTE for rigid-flex multilayers, and full compatibility with PWB industry processes, including UL 94V-0 and UL 796 ratings with a 180°C maximum operating temperature.

Processing AP7163E: What Fabricators Need to Know

Handling Ultra-Thin Copper

9 µm copper is fragile. That’s roughly the thickness of a human hair. Handling sheets of AP7163E without gloves, proper panel support, or adequate vacuum fixturing will result in wrinkles, copper tears, and scrap — none of which is obvious until after photolithography. Always use clean lint-free gloves, handle sheets fully supported (never pinched at an edge), and ensure vacuum conveyors are calibrated for ultra-thin material.

Etching Considerations

The light copper weight is actually a processing advantage during wet etching. Etch times are shorter, undercut is reduced, and line resolution is improved. However, the thinner copper is less forgiving of process variation — a slightly over-active etch bath that would leave 18 µm copper within spec can eat through 9 µm copper entirely. Maintain tight etch factor control and use fresh chemistry with closely monitored replenishment rates.

Drilling and Via Formation

Pyralux AP performs exceptionally well in laser and mechanical drilling, including PTH-ready copper bonding and chemical desmear compatibility. For AP7163E specifically, CO₂ or UV laser ablation is typically preferred over mechanical drilling for fine blind vias — the thin copper and 1 mil polyimide are well-suited to CO₂ laser via formation at 50–100 µm diameters.

Lamination and Coverlay

AP7163E is fully compatible with all conventional flex circuit fabrication processes including oxide treatment and wet chemical plated-through-hole desmearing. Fabricated circuits can be cover-coated and laminated together to form multilayers, or bonded to heat sinks using polyimide, acrylic, or epoxy adhesives. When bonding with a polyimide bondply (to maintain an all-polyimide stack-up through the full construction), ensure your bondply temperature and pressure profiles are confirmed against DuPont’s processing guide.

Storage and Handling Requirements

DuPont Pyralux AP Double-side Clad should be stored in original packaging at temperatures of 4–29°C (40–85°F) and below 70% relative humidity. The product should not be frozen and should be kept dry, clean, and well-protected. Subject to compliance with these handling and storage recommendations, DuPont’s warranty remains in effect for a period of two years following the date on the Certificate of Analysis.

Target Applications for DuPont Pyralux AP7163E

The ultra-thin construction of AP7163E makes it a natural fit for the following application categories:

Application	Why AP7163E?
Wearable electronics (smartwatches, fitness bands)	Minimal z-height, flex-to-install geometry
Medical devices (hearing aids, catheters, implantables)	Thin profile, biocompatible-compatible, high thermal margin
Aerospace and defense flex circuits	All-polyimide stack-up survives wide temperature excursions
Smartphone and tablet internal flex layers	Fine-line capability, HDI-compatible copper weight
5G antenna arrays and RF interconnects	Stable Dk of 3.2–3.4, low Df of 0.002–0.003
Satellite and space electronics	UL 94V-0, no adhesive outgassing concern

For comparison against alternative flex laminate systems — including high-Tg epoxy-based options like DuPont PCB  laminates — the all-polyimide AP7163E offers superior thermal stability and lower dielectric loss, at a higher per-unit material cost.

Pyralux AP7163E vs. AP7163E Alternatives: How It Compares

Property	AP7163E (1 mil PI / 0.25 oz ED)	AP8515R (1 mil PI / 0.5 oz RA)	AP7156E (2 mil PI / 0.25 oz ED)
Total raw thickness	~1.07 mil	~1.21 mil	~2.07 mil
Copper ductility	Lower (ED)	Higher (RA)	Lower (ED)
Fine-line capability	Excellent	Good	Excellent
Dynamic flex rating	Static/flex-to-install	Dynamic flex capable	Static/flex-to-install
Dielectric thickness	1 mil	1 mil	2 mil
Controlled impedance	Tight (1 mil PI stable)	Tight	More headroom

Useful Resources for DuPont Pyralux AP7163E

Resource	Description	Link
DuPont Pyralux Official Page	Product overview, laminate selector tool	pyralux.dupont.com
Pyralux AP Datasheet	Full technical data sheet with typical property values	dupont.com
IPC-4203/11	Specification for Adhesiveless Flexible Metallic-Clad Dielectrics	ipc.org
IPC-TM-650	PCB Test Methods Referenced in Datasheet	ipc.org/test-methods
CircuitData Material Database	Open-source PCB material specifications database	materials.circuitdata.org
DuPont Pyralux Safe Handling Guide	Recommended pre-processing safety and handling	pyralux.dupont.com
IPC-6013	Qualification and Performance Specification for Flexible PCBs	ipc.org

FAQs: DuPont Pyralux AP7163E

Q1: What makes AP7163E different from other Pyralux AP grades?

AP7163E is the thinnest standard copper-weight offering in the AP product line — 9 µm (0.25 oz) ED copper on a 1 mil all-polyimide dielectric. No adhesive layer. This combination gives you the absolute minimum construction thickness in the AP family while retaining all the thermal and electrical advantages of the all-polyimide system. It is available in ED copper only, which distinguishes it from RA copper grades like AP8515R.

Q2: Can AP7163E be used for dynamic flex applications?

Not ideally. The ED copper in AP7163E has lower ductility than rolled-annealed (RA) copper, which means it fatigues faster under repeated bending cycles. For dynamic flex designs where the circuit will flex thousands of times in service — think printer heads, hinge interconnects, robotic arm flex cables — AP8515R (0.5 oz RA copper on 1 mil PI) is the better choice. AP7163E is well-suited for static flex, flex-to-install, and rigid-flex where the flex zone bends once or a limited number of times.

Q3: What dielectric constant should I use for impedance calculations with AP7163E?

Use Dk = 3.4 at lower frequencies (up to around 1 GHz) and Dk = 3.2 at high frequencies (10 GHz range). The loss tangent is 0.002–0.003 across this range — very low, and favorable for signal integrity in high-speed designs. For controlled impedance calculations, always confirm with your fabricator’s field solver and account for finished copper thickness after etching (9 µm start copper will etch down further during trace formation).

Q4: What is the minimum trace width achievable with AP7163E?

The 9 µm starting copper weight makes AP7163E one of the best standard Pyralux AP options for fine-line work. Experienced flex fabricators routinely achieve 25–40 µm (1–1.6 mil) trace and space with this copper weight using high-resolution dry film photoresist and tightly controlled etch chemistry. For sub-25 µm features, semi-additive or full-additive processes may be more appropriate than subtractive etching.

Q5: How long can AP7163E be stored, and what are the conditions?

DuPont warrants AP7163E for two years from the Certificate of Analysis date when stored at 4–29°C (40–85°F) and below 70% relative humidity in the original sealed packaging. Do not freeze. If the material has been stored near the upper temperature or humidity limits, inspect for any copper surface discoloration or polyimide deformation before committing to production panels. The two-year window is one of the longest in the flex laminate category, reflecting the stability of the fully-cured polyimide system.