DS-7402 PCB Laminate: Datasheet, Properties & Use Cases

If you’ve been specifying PCB laminates for lead-free assemblies or trying to hit middle-Tg performance without paying a premium for exotic materials, you’ve probably come across the DS-7402 PCB laminate from Doosan Electro-Materials. It’s a copper clad laminate (CCL) that has quietly become a go-to substrate in mobile, consumer electronics, and automotive ECU boards — and for good reason.

This guide breaks down everything a practicing PCB engineer needs to know: where the datasheet numbers actually come from, what they mean in real-world fabrication, how the material stacks up against standard FR-4, and which applications it genuinely serves well.

What Is the DS-7402 PCB Laminate?

The DS-7402 is a halogen-free, middle glass transition temperature (Tg) copper clad laminate manufactured by Doosan PCB Electro-Materials, a South Korean company with a long track record in high-reliability CCL production. The material was developed as a direct response to the PCB industry’s shift toward lead-free assembly processes, which demand higher thermal endurance and better delamination resistance than conventional 130°C Tg FR-4 can provide.

What makes it stand apart from a typical halogen-free FR-4 substitute is the combination of controlled thickness uniformity, excellent CAF (Conductive Anodic Filament) resistance, and a decomposition temperature that comfortably handles multiple lead-free reflow cycles. It’s also completely free of halogen, antimony, and red phosphorus — a trifecta that satisfies both RoHS and increasingly stringent customer environmental requirements.

DS-7402 Datasheet: Full Electrical & Thermal Properties

The table below consolidates the official datasheet figures from Doosan Electro-Materials. All values are measured on as-received samples using IPC test methods unless otherwise noted.

Thermal Properties

Parameter	Value	Unit	Test Condition	Test Method
Tg — DMA	165	°C	As received	IPC-TM-650 2.4.24.4
Tg — TMA	145	°C	As received	IPC-TM-650 2.4.24C
Td (5% weight loss)	380	°C	As received	IPC-TM-650 2.3.40 (TGA)
T-288 (Time to delamination)	>10	min	As received	IPC-TM-650 2.4.24.1
CTE — X Axis (α1)	15	ppm/°C	As received	IPC-TM-650 2.4.41.2
CTE — Y Axis (α1)	14	ppm/°C	As received	IPC-TM-650 2.4.41.2
CTE — Z Axis (α1)	38	ppm/°C	As received	IPC-TM-650 2.4.24
CTE — Z Axis (α2)	230	ppm/°C	As received	IPC-TM-650 2.4.24
Thermal Conductivity	0.4–0.5	W/m·K	As received	ASTM E 1461
Max. Operating Temp (UL 796)	130	°C	As received	UL 796
Z Expansion	2.8	%	As received	IPC-TM-650 2.4.24.5

Mechanical Properties

Parameter	Value	Unit	Test Method
Young’s Modulus	24–25	GPa	IPC-TM-650 2.4.18.3
Peel Strength (½ oz Cu)	1.15	kgf/cm	IPC-TM-650 2.4.8C
Density	1.9	g/cm³	—

Compliance & Safety

Standard	Status
UL 94 Flammability	V-0
RoHS	Compliant
Halogen Content	Free
Antimony	Free
Red Phosphorus	Free

Understanding the Key DS-7402 Properties — What They Mean in Practice

Glass Transition Temperature: 165°C (DMA)

The Tg of 165°C measured by DMA puts this squarely in the “middle Tg” category (typically 150–170°C). That’s about 30–35°C higher than a standard 130°C FR-4, which matters enormously during lead-free reflow. Lead-free solder peaks typically run between 245–260°C during reflow — well above old tin-lead profiles. The laminate doesn’t need to survive reflow peak temperatures itself, but it does need to stay dimensionally stable through repeated thermal cycling. A middle-Tg material like DS-7402 handles multiple reflow passes without the stress-induced delamination that has caused field failures in standard FR-4 designs.

Note the spread between DMA (165°C) and TMA (145°C). This is normal — different test methods capture different aspects of the glass transition. When you see Tg values in a stack-up specification, always confirm which method was used.

Decomposition Temperature: 380°C

A Td of 380°C is reassuringly high. This is the temperature at which the epoxy resin matrix begins chemically breaking down (defined as 5% weight loss by TGA). In multi-layer boards undergoing repair rework with localized hot-air tools, the material near the repair site can see transient temperatures well above normal reflow. A 380°C Td provides meaningful margin.

CAF Resistance — A Critical Feature for Dense Via Layouts

CAF (Conductive Anodic Filament) is an electrochemical failure mechanism where copper ions migrate along glass fiber-resin interfaces between adjacent vias or conductors under DC bias and humidity. As via pitches continue to shrink in HDI and SLP boards, CAF has become a genuine reliability concern rather than a theoretical one. Doosan specifically highlights DS-7402’s excellent CAF resistance as a core product feature — this is achieved through optimized resin-to-glass adhesion chemistry that blocks the migration path.

Z-Axis CTE: 38 ppm/°C (α1) / 230 ppm/°C (α2)

The jump from α1 to α2 (above Tg) is significant and expected — all epoxy-based laminates show this behavior. What matters for via reliability in thermal cycling is keeping the α1 value as low as possible. At 38 ppm/°C below Tg, DS-7402 performs comparably to other quality middle-Tg laminates and keeps via barrel stress within acceptable IPC-6012 reliability thresholds for most multilayer constructions.

Thickness Control

“Good thickness control” is listed as a key feature. For high-density multilayer stack-ups and impedance-controlled designs, tight dielectric thickness variation directly translates to impedance reproducibility across the panel. This is particularly important for automotive ADAS and communication boards where controlled impedance on differential pairs is non-negotiable.

DS-7402 vs. Standard FR-4: Side-by-Side Comparison

Property	DS-7402	Standard FR-4 (130°C Tg)
Tg (DMA)	165°C	~130°C
Td (5%)	380°C	~300–330°C
T-288	>10 min	Typically <5 min
Z-CTE (α1)	38 ppm/°C	~50–60 ppm/°C
CAF Resistance	Excellent	Variable by brand
Halogen-Free	Yes	No (standard grades)
Lead-Free Suitable	Yes	Marginal (requires high-Tg grade)
RoHS Compliant	Yes	Depends on grade

For engineers currently using standard 130°C FR-4 and moving to lead-free assembly, DS-7402 is a natural upgrade path that doesn’t require process changes at the fabricator. It processes through standard CCL and multilayer lamination equipment without special handling.

DS-7402 PCB Laminate Use Cases & Applications

Smart Devices — Mobile Phones and Tablets

Mobile PCBs are a primary target market for DS-7402. Thin, high-layer-count boards in smartphones require tight dielectric control for HDI build-up layers, and the CAF resistance is critical given the extremely tight via-to-via spacing in SLP (Substrate-Like PCB) constructions. The halogen-free profile also satisfies the environmental requirements demanded by major OEMs.

Consumer Electronics

From smart home devices to wearables to gaming hardware, DS-7402 covers the general consumer electronics segment well. These applications need reliable thermal performance through lead-free assembly, a competitive price point, and compliance with international substance restriction regulations — all boxes that DS-7402 checks.

Automotive Electronics — ECU, DCU, TCU

This is where DS-7402 earns particular respect. Engine Control Units (ECU), Domain Control Units (DCU), and Transmission Control Units (TCU) operate in thermally demanding environments with tight reliability requirements. While DS-7402 is not a dedicated automotive-grade material at the level of specialized polyimide or ceramic substrates, it provides a solid performance baseline for automotive boards that operate within typical under-dash or body electronics temperature ranges. The good thickness control and CAF resistance are especially valuable in these applications.

DS-7402 Family: Related Material Variants

Material	Key Difference	Typical Application
DS-7402	Standard halogen-free middle Tg	Mobile, consumer, automotive
DS-7402M	Halogen-free advanced formulation, similar Tg	High-end consumer, server boards
DS-7402LC	Low dielectric constant variant	High-speed digital, frequency-sensitive designs
DS-7409D(X)	Middle-loss grade	Mixed signal, DDR routing

If your design has specific impedance or signal integrity requirements at higher frequencies, DS-7402LC with its lower Dk may be worth evaluating alongside the base DS-7402.

Working with DS-7402 in Fabrication: Practical Notes

From a fabrication standpoint, DS-7402 processes like any quality middle-Tg halogen-free laminate. Standard FR-4 drill parameters apply. Desmear and electroless copper work through conventional plasma or permanganate processes without modification. The one area worth confirming with your laminator is press cycle profile — middle-Tg halogen-free laminates can be sensitive to cure temperature ramp rates, and proper curing is essential to hitting the full Tg value.

Moisture absorption prior to lamination should be controlled per standard IPC baking protocols, particularly for boards destined for automotive applications where MSDS-compliant material handling is often part of the supply chain audit.

Useful Resources for DS-7402 PCB Laminate

Resource	Description	Link
Doosan Electro-Materials Official Product Page	Official datasheet, RoHS & MSDS downloads	doosanelectromaterials.com
IPC-4101 Specification	Base material standard for rigid PCB laminates	ipc.org
CircuitData Material Database	Open-source CCL database with searchable properties	materials.circuitdata.org
IPC-TM-650 Test Methods	Full library of PCB material test procedures	ipc.org/TM-650
Doosan PCB Supplier Information	CCL sourcing and fabrication reference	PCBSync Doosan

5 Frequently Asked Questions About DS-7402 PCB Laminate

Q1: Is DS-7402 a direct drop-in replacement for standard FR-4 in existing designs?

For most practical purposes, yes — at the fabrication level. DS-7402 uses the same glass-reinforced epoxy base construction and processes through conventional multilayer lamination equipment. The engineer doesn’t need to redesign the stack-up or change pad geometries. The main consideration is confirming your fabricator stocks it; availability outside of Asian supply chains can sometimes require lead time planning.

Q2: Can DS-7402 handle multiple lead-free reflow cycles?

Yes. The combination of a 165°C DMA Tg and a 380°C decomposition temperature gives DS-7402 comfortable margin for typical lead-free reflow profiles (245–260°C peak), including boards that undergo two-sided assembly and may see three or more thermal excursions during production. The T-288 value of greater than 10 minutes confirms this reliability at sustained high temperature.

Q3: What does “halogen-free” actually mean for DS-7402, and does it matter for my design?

Halogen-free means the material contains no chlorine, bromine, antimony trioxide, or red phosphorus — the traditional flame-retardant additives. For most commercial designs this matters primarily for regulatory compliance (EU RoHS, REACH, customer environmental requirements from major OEMs). From a fabrication standpoint, halogen-free laminates can require slightly different press cure profiles and may have marginally higher moisture sensitivity, but these are well-understood and manageable by qualified fabricators.

Q4: How does DS-7402 compare to Shengyi S1000-2 or ITEQ IT-180A?

All three target the middle-to-high Tg halogen-free market. DS-7402 at 165°C DMA Tg sits in the same performance tier as IT-180A (180°C Tg) is a step higher. Shengyi S1000-2 is broadly comparable in application. The Doosan material’s differentiating claim is specifically its thickness control consistency and CAF resistance, which can matter more than raw Tg in dense HDI constructions.

Q5: Where can I download the official DS-7402 datasheet?

The official datasheet, RoHS certificate, and MSDS are available directly from Doosan Electro-Materials. Visit the Doosan DS-7402 product page and use the RoHS and MSDS download links. Your PCB fabricator or laminate distributor may also hold the full spec sheet as part of their approved vendor documentation.

---

Summary

The DS-7402 PCB laminate earns its place in the engineer’s material toolbox as a well-rounded, halogen-free middle-Tg CCL that addresses the real-world demands of lead-free assembly without complicating the fabrication process. Its standout qualities — excellent CAF resistance, good thickness control, 380°C decomposition temperature, and broad environmental compliance — make it a sensible default for mobile, consumer electronics, and automotive ECU applications where standard FR-4 no longer cuts it and exotic high-frequency materials are overkill. When you’re balancing reliability, cost, and regulatory compliance in a single laminate choice, DS-7402 is consistently worth putting on the shortlist.