DS-7409 Laminate: Specs, Applications & Datasheet Guide

If you have ever sourced a high-reliability multilayer board and had a fabricator propose DS-7409 as the material, the question you should be asking is not just “what is this?” but “which variant?” Doosan Electronic Materials has built the DS-7409 into an entire family of copper clad laminates — from the base multifunctional epoxy grade used in military and computing hardware, through the DS-7409DV low-loss series targeting 400G networking, to the DS-7409HG IC package substrate grades and the DS-7409D high-speed variant. Each one shares the DS-7409 designation but targets a different design problem.

This guide covers what the DS-7409 PCB laminate family is, how the base grade’s specifications read, how the variants differ, which applications each grade serves, and where to find the authorised datasheet for the configuration you are actually specifying. For a broader overview of the full Doosan laminate product range, visit Doosan PCB.

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What Is the Doosan DS-7409 PCB Laminate Family?

The DS-7409 is Doosan Electronic Materials’ multifunctional epoxy resin copper clad laminate (CCL) series. “Multifunctional epoxy” refers to a resin formulation with three or more reactive epoxy groups per molecule, compared to the two groups in standard difunctional FR-4 epoxy. The additional cross-link density gives multifunctional epoxy systems higher Tg, better chemical resistance, lower Z-axis CTE, and more stable electrical properties through repeated thermal excursions — all without moving to polyimide chemistry, which would increase cost and require different processing.

Doosan was founded in 1974 and is headquartered in South Korea. Its DS-7409 family carries UL recognition E103670 and BSI 6741 for applicable grades. The laminate is manufactured to IPC-4101 slash sheet specifications and uses standard FR-4 fabrication equipment and processes, making it a direct-to-upgrade path from standard FR-4 for design teams pushing into higher thermal and reliability requirements.

The DS-7409 product family is substantially broader than a single grade. The naming structure uses suffixes to differentiate the variants: the base DS-7409 is the standard multifunctional high-Tg grade; DS-7409D is the high-speed dielectric constant variant; DS-7409DV is the low-loss variant; DS-7409DV(N) is the ultra-low-loss variant; DS-7409HG covers IC package substrate grades in multiple sub-variants; and so on across an extensive product matrix.

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DS-7409 Base Grade: Key Specifications

The base DS-7409 — multifunctional, high-Tg, standard for demanding general-purpose and military applications — has the following core properties.

Table 1: DS-7409 Base Grade Key Properties

Property	Typical Value	Test Method	Unit
Glass Transition Temperature (Tg, DSC)	≥170	IPC-TM-650 2.4.25c	°C
Decomposition Temperature (Td, TGA)	~295	IPC-TM-650 2.4.40	°C
T-260 (time to delamination)	~7	IPC-TM-650 2.4.24.1	min
CTE Z-axis (ambient to Tg)	~41	IPC-TM-650 2.4.41	ppm/°C
Dielectric Constant (Dk, 1 GHz, 50% resin)	~4.2	IPC-TM-650 2.5.5.9	—
Dissipation Factor (Df, 1 GHz, 50% resin)	~0.015	IPC-TM-650 2.5.5.9	—
Peel Strength (1 oz Cu, condition A)	2.0	IPC-TM-650 2.4.8	N/mm
Flammability	V-0	UL 94	—
Water Absorption (D-24/23)	~0.13	IPC-TM-650 2.6.2	%
UL Recognition	E103670	—	—
BSI Recognition	6741	—	—

The Tg of 170 °C positions DS-7409 clearly in the high-Tg epoxy category, above standard FR-4 (Tg 130–140 °C) and compatible with lead-free assembly processes including SAC305, whose peak reflow temperatures reach 245–260 °C. The Td of ~295 °C means the laminate begins decomposing at temperatures well above the lead-free reflow window, providing reasonable process margin. The T-260 figure of approximately 7 minutes — time to delamination at 260 °C — is the more process-relevant number for IST (interconnect stress testing) and IST cycling qualification.

The Z-axis CTE of 41 ppm/°C (ambient to Tg) is the figure that most directly affects plated through-hole (PTH) reliability. Copper’s CTE is ~17 ppm/°C, so a barrel stress ratio calculation using 41 ppm/°C laminate CTE and 17 ppm/°C copper gives the Z-expansion-to-copper-expansion differential that drives IPC-2221 barrel cracking risk on thick multilayer boards. For boards above 2.0 mm with many drill cycles, keeping Td and Tg high while keeping Z-axis CTE low is the design goal that DS-7409 targets. The DS-7409DV and DS-7409DV(N) reduce Z-axis CTE further to 45 ppm/°C (which is comparable to the base grade) while dramatically improving the dielectric electrical properties for signal integrity applications.

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DS-7409 Variant Comparison

Understanding the DS-7409 family means navigating which suffix targets which engineering requirement. The table below covers the four most commonly specified variants in the DS-7409 PCB laminate family.

Table 2: DS-7409 Variant Comparison

Variant	Dk at 10 GHz	Df at 10 GHz	Tg (DMA)	Td	Primary Application
DS-7409 (base)	~4.2 (at 1 GHz)	~0.015	~170 °C	~295 °C	Military, telecom, general high-Tg
DS-7409D	Lower Dk vs base	Low Df	High	High	Base stations, high-speed network
DS-7409DV	3.48	0.0030	225 °C (DMA)	~400 °C	400G networking, router/switch
DS-7409DV(N)	3.28	0.0025	225 °C (DMA)	~400 °C	400G ultra-low-loss, 5G/6G macro cell
DS-7409HG variants	4.2 (at 1 GHz)	0.015	165–170 °C (TMA)	~295 °C	IC package substrates, flip-chip

The jump from DS-7409 base to DS-7409DV(N) in electrical properties is significant: Dk drops from ~4.2 to 3.28 at 10 GHz, and Df drops from ~0.015 to 0.0025. A Df of 0.0025 at 10 GHz puts DS-7409DV(N) in competitive territory with mid-tier high-speed laminates from Isola and Panasonic. The simultaneously high Tg (225 °C by DMA) and high Td (~400 °C) in the DV variants means that the low-loss performance does not come at the cost of thermal reliability — a trade-off that some competitive materials require.

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DS-7409 Applications by Variant

DS-7409 Base Grade Applications

The base DS-7409 targets applications where high-Tg and chemical resistance matter more than low dielectric loss: computers and server backplanes, telecommunications infrastructure PCBs, industrial instruments, and military hardware. Its UV blocking and AOI (automated optical inspection) compatibility make it processable on standard high-volume PCB lines without modification. The peel strength of 2.0 N/mm provides robust copper adhesion for heavy copper boards and multilayer builds. For any application that currently uses standard FR-4 but is pushing into lead-free assembly, board thicknesses above 2.4 mm, or elevated operating temperatures, DS-7409 base grade is a straightforward upgrade path.

DS-7409DV and DS-7409DV(N) Applications

The DV variants are explicitly positioned for 400G network equipment. Doosan lists DS-7409DV(N) for Enterprise/Carrier Router & Switch applications and DS-7409DV(NT) for 5G/6G Macro Cell equipment. At 400G data rates, interconnect loss across a backplane becomes a first-order design constraint. The combination of Dk 3.28 and Df 0.0025 at 10 GHz — with both values stable across the 1–10 GHz frequency range — reduces insertion loss along long backplane traces and through-board vias, extending the reach of SerDes channels without requiring equalisation that would not otherwise be necessary.

DS-7409HG Applications

The HG variants are designed for IC package substrates rather than PCBs in the conventional sense. IC packaging applications require higher modulus, tighter CTE control, and compatibility with the finer line/space rules of package-level lithography (30 µm and below). The DS-7409HG(ZS) is positioned for FC CSP (flip chip chip scale package) for AP, controller, and interposer applications — components where the laminate must match silicon CTE closely to avoid warpage and solder joint fatigue on assembly. The halogen, antimony, and red phosphorus-free formulation aligns with REACH/RoHS requirements for mobile and consumer IC products.

Table 3: DS-7409 Application Matrix

Application Area	Recommended Variant	Key Requirement Met
Multilayer backplane, >2.4 mm, lead-free	DS-7409 base	High Tg, low Z-CTE, PTH reliability
Military electronics, MIL-PRF-55110	DS-7409 base	UL E103670, Tg >170 °C, high peel
Telecommunications infrastructure	DS-7409 base or DS-7409D	Tg, chemical resistance
400G router / switch backplane	DS-7409DV or DV(N)	Dk <3.5, Df <0.003 at 10 GHz
5G/6G macro cell basestation	DS-7409DV(NT)	Low loss, thermal reliability
High-speed computing (HPC)	DS-7409DV or DV(N)	Signal integrity at multi-GHz
IC package substrate (FC CSP)	DS-7409HG variants	Low CTE, high modulus, halogen-free
Flip chip BoC / RF module	DS-7409HG(KQ)	Low Df, halogen & phosphorous free

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How to Read the DS-7409 Datasheet

The DS-7409 datasheet follows IPC-TM-650 test methods throughout, which makes it straightforward to compare against competitive materials — as long as the frequency at which Dk and Df are tested is matched carefully. The Doosan full CCL properties PDF (the comprehensive document linked below) reports Dk and Df using SPDR (split-post dielectric resonator) at multiple frequencies. SPDR is a cavity resonator method that gives more accurate values than stripline or microstrip resonance methods at the relevant frequencies, but different test methods produce different numbers for the same material, so do not compare Doosan’s SPDR-measured Dk of 3.28 directly to a competitor’s Dk measured by clamped stripline without verifying the method.

The property most engineers underweight when reading the DS-7409 datasheet is T-260. A T-260 of 7 minutes for the base grade means the board will survive the IST thermal cycling protocol at 260 °C for 7 minutes before interlayer adhesion failure. For boards that will undergo multiple reflow cycles (flip-chip SMT double-sided boards, rework, conformal coating cure), understanding the cumulative effect on T-260 headroom is more design-relevant than Tg alone. The DV variants’ Td of ~400 °C and T-288 >120 minutes provide substantially more thermal headroom — which is why they are used in high layer-count backplanes that undergo more lamination and reflow cycles during fabrication.

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DS-7409 vs Comparable Laminates

Table 4: DS-7409DV(N) vs Competitive Materials (High-Speed Application)

Material	Manufacturer	Dk (10 GHz)	Df (10 GHz)	Tg	Notes
DS-7409DV(N)	Doosan	3.28	0.0025	225 °C (DMA)	400G focus, high-Tg
Megtron 6	Panasonic	3.4	0.002	185 °C	Industry benchmark
IS620	Isola	3.45	0.004	200 °C	Cost-competitive
370HR	Isola	3.97	0.021	180 °C	Standard high-Tg
DS-7409 base	Doosan	~4.2	~0.015	170 °C	General purpose
Standard FR-4	Various	4.4–4.8	0.02–0.030	130–140 °C	Reference baseline

DS-7409DV(N) competes directly with Panasonic Megtron 6 at the Dk level and is competitive on Df, while offering a higher Tg by DMA. For design teams who have been specifying Megtron 6 for 400G applications and want a cost-competitive or supply-chain-alternative laminate, DS-7409DV(N) is the material to evaluate first.

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Useful Resources for DS-7409 PCB Laminate

Resource	Description	Link
Doosan DS-7409 Base Datasheet	Original product datasheet — multi-functional epoxy, high Tg	MCLPCB PDF
Doosan Full CCL Properties PDF	All DS-7409 variants in one comprehensive technical document	Doosan PDF
Doosan DS-7409DV(N) Product Page	Official DV(N) ultra-low-loss specification and application notes	Doosan EM
Doosan DS-7409DV(NT) Product Page	5G/6G Macro Cell variant	Doosan EM
IPC-4101 Laminate Specification	Base specification governing CCL testing and acceptance	IPC.org
IPC-TM-650 Test Methods	Full test method index for Tg, CTE, Dk, Df, peel strength	IPC.org

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5 FAQs: DS-7409 PCB Laminate

Q1: Is DS-7409 a drop-in replacement for standard FR-4?

For most fabrication processes, yes. The DS-7409 uses the same glass fibre weave reinforcement and standard lamination press equipment as FR-4. Drilling, routing, etching, and plating parameters do not require modification from a well-run FR-4 process. The Tg above 170 °C means the laminate is dimensionally stable through lead-free SAC305 reflow at 245–260 °C peak. The key difference at design level is the improved electrical properties — Dk ~4.2 vs FR-4’s ~4.5–4.8 at 1 GHz, and better Z-axis CTE behaviour through multiple thermal cycles. For boards that are already producing PTH failures or showing delamination during lead-free assembly on standard FR-4, DS-7409 is the direct upgrade without process change.

Q2: What is the difference between DS-7409, DS-7409D, and DS-7409DV?

All three are Doosan multifunctional epoxy laminates sharing the DS-7409 base chemistry. The base DS-7409 is the standard high-Tg grade for general reliability applications with Dk ~4.2 and Df ~0.015. DS-7409D reduces Dk and Df relative to the base grade, targeting base station and high-speed networking where signal integrity at several GHz matters. DS-7409DV takes the reduction further: Dk drops to ~3.5 at 10 GHz, Df drops to ~0.003. DS-7409DV(N) — the ultra-low-loss variant — achieves Dk 3.28 and Df 0.0025 at 10 GHz with a Tg of 225 °C by DMA and Td of ~400 °C. Each step in the naming sequence represents a measurable reduction in dielectric loss suitable for progressively higher data rate applications.

Q3: Is DS-7409 compliant with RoHS and halogen-free requirements?

The DS-7409HG variants are explicitly listed as halogen, antimony, and red phosphorus-free, and are offered with RoHS and MSDS documentation downloads from the Doosan product page. The base DS-7409 and DV variants are RoHS compliant and lead-free solder compatible. Whether a specific DS-7409 configuration is halogen-free depends on the variant — the HG series is explicitly formulated halogen-free for IC package substrate applications, while the base grade and DV series follow standard RoHS compliance. Confirm the specific variant’s halogen status from the Doosan RoHS declaration for the exact grade before use in applications requiring IEC 61249-2-21 halogen-free certification.

Q4: What board thickness and copper weight configurations are available for DS-7409?

Doosan produces DS-7409 laminate in standard CCL panel configurations. Common core thicknesses start at 0.1 mm and go up to 3.2 mm; 0.2, 0.4, 0.8, 1.0, 1.6, and 2.0 mm are the most commonly stocked at fabricators. Copper foil weights of 0.5 oz, 1 oz, 2 oz, and 3 oz are standard; 0.5 oz and 1 oz are most common for signal layers in high-layer-count multilayer builds, while 2–3 oz are available for power layers. For non-standard thickness or copper weight combinations, lead time depends on Doosan mill schedule and distributor stock. Confirm availability with your fabricator before committing to a non-standard configuration in a design.

Q5: Where can I obtain a current DS-7409 datasheet for a design submission?

The most reliable sources are the Doosan Electronic Materials product page at doosanelectromaterials.com, where individual variant pages provide RoHS declarations and MSDS downloads with registration, and the third-party mirror at MCLPCB.com which hosts the original multi-functional DS-7409 datasheet PDF without registration. The Doosan full CCL properties PDF (linked in the resources table above) is the most comprehensive single document, covering all DS-7409 variants with IPC-TM-650 test results in one table. For design submission to an automotive or aerospace customer requiring traceable material documentation, request the current Doosan Technical Data Sheet directly from your CCL distributor or fabricator — datasheets on third-party mirror sites may lag behind Doosan’s current revision.

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For the full range of Doosan CCL laminate products, grade comparisons, and fabricator sourcing guidance, visit Doosan PCB.