DuPont Pyralux AC182500 full specs guide — 0.5 oz copper, 1 mil polyimide, 2 mil total dielectric flex laminate. Covers electrical properties, EM vs RY variants, processing tips, applications, and FAQs for PCB engineers.

When you’re spec’ing out a single-sided flex circuit and you need more dielectric bulk than the half-mil constructions offer, DuPont Pyralux AC182500 becomes a serious contender. It sits right in the sweet spot of the Pyralux AC single-sided family — 0.5 oz copper paired with a full 1 mil Kapton® polyimide dielectric, delivering a total dielectric stack of around 2 mils once you account for the acrylic adhesive layer. That thicker dielectric profile is exactly why designers pull this grade when they need tighter impedance control, better voltage standoff, or extra mechanical stiffness in a flex stack-up.

This guide covers everything you actually need to know: construction breakdown, full material properties, how to read the part number, where AC182500 fits vs. adjacent constructions, and where it performs best in real applications.

What Is DuPont Pyralux AC182500?

DuPont Pyralux AC182500 is a single-sided, all-polyimide copper-clad laminate from DuPont’s Pyralux AC product family. The AC designation signals an acrylic adhesive-based construction, distinguishing it from the adhesiveless Pyralux AP series. The product is available in two copper foil variants under this base construction:

• AC182500EM — 18 µm (0.5 oz/ft²) Electro-Deposited (ED) copper / 25 µm (1.0 mil) polyimide dielectric
• AC182500RY — 18 µm (0.5 oz/ft²) Rolled-Annealed (RA) copper / 25 µm (1.0 mil) polyimide dielectric

The “25” in the part number refers to the 25 µm (1 mil) Kapton® polyimide film thickness. When you add the standard 1 mil acrylic adhesive bonding layer that joins the copper to the PI film, the total effective dielectric thickness reaches approximately 2 mils — hence its reputation as a double-thickness dielectric flex laminate in comparison to the thinner 0.5 mil PI variants like AC181200. That extra dielectric mass changes the electrical and mechanical character of the laminate in ways that matter quite a bit once you get into controlled impedance design.

The choice between EM and RY suffix comes down to your flex requirements. The RY (RA copper) is the go-to for dynamic flex and tight bend radius designs. The EM (ED copper) works well for static flex or connector-tab applications where cost sensitivity is higher and flexing is infrequent.

DuPont Pyralux AC182500 Part Number Decoder

Understanding DuPont’s part number logic saves time when you’re comparing options or placing orders. Here’s exactly what each segment of AC182500 means:

Code Segment	Description	Value for AC182500
AC	Product family — acrylic adhesive construction	Pyralux AC series
18	Copper foil thickness code	18 µm = 0.5 oz/ft²
25	Polyimide dielectric thickness code	25 µm = 1.0 mil
00	Grade / adhesive designator	Standard 1 mil acrylic adhesive
EM suffix	Copper foil type — Electro-Deposited	ED copper
RY suffix	Copper foil type — Rolled-Annealed	RA copper

The suffix letters at the end of the full product code are critical. “R” or “RY” always means rolled-annealed copper. “E”, “EM”, or “EN” always means electro-deposited copper. Getting this right at the design stage avoids sourcing issues later.

Full Technical Specifications for DuPont Pyralux AC182500

The property data below is sourced from DuPont’s official Pyralux AC technical data sheet (EI-10122) and the published Eurotronics/DuPont datasheet for the AC182500RY construction. The RY variant is used as the reference because RA copper is the primary choice for most flex circuit programs.

Electrical Properties

Property	Typical Value	Frequency	Test Method
Dielectric Constant (Dk)	3.7	1 MHz	IPC-TM-650 2.5.5.3
Dielectric Constant (Dk)	3.4	10 GHz	ASTM D2520
Loss Tangent (Df)	0.003	1 MHz	IPC-TM-650 2.5.5.3
Loss Tangent (Df)	0.005	10 GHz	ASTM D2520
Volume Resistivity	> 10¹⁶ Ω·cm	—	IPC-TM-650 2.5.17
Surface Resistance	> 10¹² Ω	—	IPC-TM-650 2.5.17
Moisture & Insulation Resistance	> 1×10⁸ Ω	—	IPC-TM-650 2.6.3.2

Mechanical & Thermal Properties

Property	Typical Value	Test Method
Peel Strength (As Received)	1.2 N/mm (6–7 lb/in)	IPC-TM-650 2.4.9 Method B
Peel Strength (After Solder)	1.2 N/mm (6–7 lb/in)	IPC-TM-650 2.4.9 Method D
Dimensional Stability — After Etching	±0.02% (MD/TD)	DuPont Method, TMA
Dimensional Stability — After Thermal	±0.04% (MD/TD)	DuPont Method, TMA
CTE (XY Axis)	19 ppm/°C	IPC-TM-650 2.4.41
Solder Float (288°C / 10 seconds)	Pass	IPC-TM-650 2.4.13
Moisture Absorption	0.9%	IPC-TM-650 2.6.2
Tensile Strength	> 190 MPa	IPC-TM-650 2.4.19
Elongation	> 19%	IPC-TM-650 2.4.19
Flexural Endurance	> 1,600 cycles	JIS C6471 (MIT)

Construction & Compliance

Property	Value
Copper Thickness	18 µm (0.5 oz/ft²)
PI Film Thickness	25 µm (1.0 mil)
Adhesive Type	Acrylic
Adhesive Thickness (typical)	~25 µm (1.0 mil)
Total Dielectric (PI + Adhesive)	~50 µm (2.0 mil)
Glass Transition Temp (Tg) — adhesive	~150°C
Glass Transition Temp (Tg) — PI film	220°C (Insulectro ref.)
IPC Certification	IPC-4204/25
UL Rating	UL 94V-0, File E161336
RoHS Compliant	Yes
Halogen Free	Yes
ISO Manufacturing	ISO 9001:2015

One number that deserves extra attention: the peel strength of 1.2 N/mm (6–7 lb/in). Compare this directly with the thinner 0.5 mil PI constructions like AC121200RY, which show a peel strength closer to 0.6 N/mm. The thicker acrylic adhesive and PI base in AC182500 deliver roughly double the peel strength — a meaningful difference if your application involves thermal cycling or mechanical stress at the copper-dielectric interface.

Why the 2-Mil Dielectric Stack Matters in Flex Circuit Design

The 1 mil Kapton PI + 1 mil acrylic adhesive construction in DuPont Pyralux AC182500 creates a total dielectric package of approximately 2 mils. That extra thickness versus a 0.5 mil PI construction (like AC181200) has several practical consequences that engineers need to account for.

Impedance Control

For a microstrip single-sided flex circuit, the characteristic impedance of a trace is a function of trace width, copper thickness, and the dielectric height (H) below it. A 2 mil dielectric stack gives you a higher H value, which means you need wider traces to hit the same impedance target compared to a 0.5 mil construction. The tradeoff is that the wider trace tolerates more manufacturing variation in copper etch uniformity while still meeting your impedance spec — a real yield advantage in production.

Voltage Withstand and Isolation

More dielectric means more voltage withstand capability between the copper traces and any underlying ground plane or adjacent structure. For power flex applications, sensor leads carrying higher voltages, or circuits where creepage/clearance rules push you toward a thicker dielectric, AC182500 provides a meaningful margin that a 0.5 mil construction simply doesn’t.

Handling and Mechanical Stability

The thicker the dielectric, the stiffer the laminate. While flex circuits aren’t supposed to be rigid, AC182500’s 2-mil dielectric stack offers noticeably better handling characteristics during panelization, laser drilling, and coverlay lamination compared to ultra-thin constructions. If you’ve ever fought registration issues with a 0.5 mil PI laminate during multilayer buildup, the extra stiffness of the 25 µm PI film is something you appreciate fast.

AC182500 vs. Adjacent Pyralux AC Constructions

Choosing the right Pyralux AC variant requires comparing several constructions side by side. The table below covers the key 0.5 oz copper options across different dielectric thicknesses:

Product Code	Cu Thickness	Cu Type	PI Dielectric	Total Dielectric (est.)	Best For
AC181200RY	18 µm (0.5 oz)	RA	12 µm (0.5 mil)	~1.0 mil	Ultra-thin flex, high-flex-cycle, small bend radius
AC181200EM	18 µm (0.5 oz)	ED	12 µm (0.5 mil)	~1.0 mil	Static flex, cost-sensitive thin profiles
AC182500RY	18 µm (0.5 oz)	RA	25 µm (1.0 mil)	~2.0 mil	Controlled impedance, better isolation, stiffer flex
AC182500EM	18 µm (0.5 oz)	ED	25 µm (1.0 mil)	~2.0 mil	Static flex with thicker dielectric requirement
AC182000RY	18 µm (0.5 oz)	RA	20 µm (0.8 mil)	~1.6 mil	Intermediate thickness requirements
AC185000RY	18 µm (0.5 oz)	RA	50 µm (2.0 mil)	~3.0 mil	High-voltage isolation, extra-thick flex stack

For the majority of mainstream single-sided flex programs that need reasonable impedance control, solid mechanical handling, and compatibility with standard coverlay materials, AC182500RY is the default choice within the 0.5 oz copper family.

Processing DuPont Pyralux AC182500

DuPont Pyralux AC single-sided copper-clad laminate is fully compatible with all conventional flexible 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.

From a practical shop-floor standpoint, here are the processing points that matter most for AC182500:

Etching the 0.5 oz Copper

At 18 µm, the copper in AC182500 etches very quickly. Etch time needs to be tightly controlled — underetch and you’ll leave copper slivers; overetch and you’ll see significant trace width loss. If you’re running this on the same line as 1 oz constructions, remember to adjust your conveyor speed or spray pressure. The thinner copper is more susceptible to side-etch at higher temperatures, so keep your etchant at the lower end of the recommended range.

Coverlay Application

AC182500 is compatible with standard acrylic-based polyimide coverlays (Pyralux FR or LF series are common choices). The 1 mil PI base provides enough rigidity to handle coverlay lamination without the registration nightmares you get with ultra-thin substrates. Pin registration through drilled holes is standard practice before hot-press lamination.

Thermal Processing and Solder

The acrylic adhesive Tg of ~150°C is your ceiling for sustained thermal exposure. The material passes the 288°C solder float test for 10 seconds, so lead-free SAC305 reflow won’t delaminate it — but if your assembly process has a long dwell time above 150°C, you’ll want to revisit whether an adhesiveless AP construction is more appropriate.

Storage Requirements

DuPont Pyralux AC single-sided copper-clad laminate 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. Moisture pickup in the acrylic adhesive can cause delamination bubbles during high-temperature processing — don’t skip the bake-out step if your material has been sitting in a humid environment.

Key Applications for DuPont Pyralux AC182500

The combination of 0.5 oz copper and a 2-mil total dielectric package positions AC182500 well across a range of demanding single-sided flex applications.

Controlled Impedance Flex Interconnects

The 1 mil PI + 1 mil adhesive dielectric gives designers a well-characterized, stable dielectric height for microstrip impedance calculations. With Dk values of 3.7 at 1 MHz and 3.4 at 10 GHz, it’s predictable enough for signal lines up to moderate RF frequencies. Pyralux AC is an ideal material for any roll-to-roll processing, wire bonded application, or chip-to-substrate application.

Wearable and Portable Medical Devices

The RoHS and halogen-free compliance, combined with solid peel strength and dimensional stability, make AC182500 a standard choice in non-implantable medical flex circuits. Blood glucose monitors, ECG patch electrodes, and portable diagnostic devices use this construction regularly. The UL 94V-0 rating satisfies most device safety certifications.

Automotive Sensor Flex Leads

For sensors mounted in instrument clusters, door panels, and under-seat modules, the 2-mil dielectric provides better isolation from vehicle chassis ground planes, and the 0.5 oz copper handles low-current signal routing efficiently. Dimensional stability of ±0.02% after etching is good enough to meet the fine-pitch requirements of automotive connector pads.

Display and Camera Module Interconnects

Thin-profile displays in smartphones and tablets often run flex interconnects from the display driver IC to the main PCB. The AC182500 construction is thin enough for these tight spaces while providing adequate mechanical stiffness for reliable SMT component attachment on the circuit before folding.

Industrial and Robotics Flex Circuits

The >1,600 MIT flex cycle rating applies to the RA variant (AC182500RY), making it a reasonable choice for flex circuits running through robotic joints or cable carriers with moderate bend cycle requirements. For extreme dynamic flex applications, the 0.5 mil PI constructions in the 1 oz range tend to perform better — but for moderate dynamic use, AC182500RY holds up well.

For more context on how Pyralux materials fit into broader DuPont PCB fabrication programs, that’s worth reviewing alongside your laminate selection process.

Useful Resources for DuPont Pyralux AC182500

The following references are directly relevant for anyone specifying, sourcing, or fabricating with AC182500:

• DuPont Pyralux Official Product Portal: pyralux.dupont.com — laminate product selector, datasheets, and safe handling guide downloads
• Pyralux AC Technical Data Sheet (EI-10122): Available from DuPont Electronics at electronics.dupont.com — the definitive source for all AC property tables and product code listings
• IPC-4204/25 Standard: The IPC slash sheet governing flexible metal-clad dielectrics of the all-polyimide composite type — the certification basis for Pyralux AC
• IPC-TM-650 Test Methods Manual: All referenced test methods (peel strength, dimensional stability, CTE, electrical properties) are documented here — essential for understanding what the spec numbers actually measure
• UL Product iQ: Search UL File E161336 to verify current active UL 94V-0 status for Pyralux AC
• Insulectro Pyralux AC Product Page: insulectro.com/products/pyralux-ac — distributor-level specs, availability, and technical support contact
• DuPont Pyralux Safe Handling Guide: Available at pyralux.dupont.com — covers material handling, cutting safety for thin copper edges, and ventilation requirements during drilling/routing

Frequently Asked Questions

Q1: What is the actual total dielectric thickness of DuPont Pyralux AC182500?

The Pyralux AC182500 has a 1 mil (25 µm) Kapton® polyimide film as the base dielectric. The acrylic adhesive layer that bonds the copper to the PI film adds approximately another 1 mil, bringing the total dielectric stack to roughly 2 mils (50 µm). The “25” in the product code refers specifically to the PI film thickness in micrometers. For impedance calculations, use the full dielectric height including the adhesive in your stack-up model.

Q2: What is the difference between AC182500EM and AC182500RY?

Both variants share the same 18 µm (0.5 oz) copper and 25 µm (1 mil) PI dielectric construction. The difference is the copper foil type: AC182500EM uses Electro-Deposited (ED) copper, while AC182500RY uses Rolled-Annealed (RA) copper. RA copper (RY) has a grain structure aligned parallel to the foil surface, giving it significantly better flex endurance and resistance to work-hardening cracking. Choose EM for static flex applications where cost is a primary driver, and RY for any design involving dynamic flexing or tight bend radii.

Q3: How does AC182500 compare to the Pyralux AP series for the same copper weight?

Pyralux AC182500 uses an acrylic adhesive to bond copper to the polyimide film, creating a three-layer construction. The Pyralux AP series is adhesiveless — the copper bonds directly to the PI through a casting or lamination process. The AP series offers a higher thermal ceiling (Tg of the polyimide itself, not limited by acrylic adhesive), tighter dimensional stability, and better performance in high-temperature environments. AC182500 is the right choice when cost, standard processing compatibility, and adequate thermal performance are the requirements. AP wins when you need maximum thermal resistance, ultra-thin profiles, or military/aerospace-level reliability.

Q4: Can AC182500 be used to form multilayer flex circuits?

Yes. Fabricated circuits can be cover-coated and laminated together to form multilayers or bonded to heat sinks using polyimide, acrylic, or epoxy adhesives. AC182500 is fully compatible with multilayer flex construction, typically used as the individual conductor layers with bondply adhesive or coverlay materials providing the inter-layer bonding.

Q5: What is the operating temperature range for DuPont Pyralux AC182500?

The Kapton® polyimide film itself is rated for use well above 200°C. However, the practical maximum continuous operating temperature for AC182500 is governed by the acrylic adhesive layer, which has a Tg of approximately 150°C. Sustained operation above this temperature can soften the adhesive, reduce peel strength, and eventually cause delamination. For short excursions (like lead-free solder reflow), the material passes the 288°C/10-second solder float test. For continuous elevated-temperature environments above 150°C, the adhesiveless Pyralux AP series is the appropriate upgrade path.

Choosing the Right AC182500 Variant for Your Program

If your design is a moderate-frequency single-sided flex circuit with conventional fabrication, AC182500RY (RA copper) is the default recommendation for most engineers. The peel strength advantage over the thinner 0.5 mil constructions, the stable 2-mil dielectric profile for impedance work, and the halogen-free RoHS-compliant construction check the boxes for the majority of consumer electronics, medical, and automotive sensor programs.

Where you’d step away from it: ultra-thin profiles that can’t accommodate 2 mils of total dielectric, extreme dynamic flex with millions of cycles (where you’d move to a 1 oz RA construction with minimal dielectric), or applications demanding continuous operation above 150°C where the AP adhesiveless series takes over.

DuPont Pyralux AC182500 is a mature, well-specified material with a long production track record. Its documentation is thorough, its fab compatibility is excellent, and its dual copper foil options give you the flexibility to tune the design to your end-use requirements without switching material families.

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