Doosan vs Shengyi PCB Materials: Which Is Better for Your Design?

This is one of those questions that comes up constantly in PCB material reviews — typically right after a procurement team puts a cost-reduction target on your BOM, or when your existing laminate supplier goes on allocation and your program manager starts panicking. Doosan vs Shengyi laminate isn’t a simple “one is better” answer. They’re fundamentally different suppliers with different market positions, product depth, and geographic strengths. Getting this wrong costs more than the material itself.

This comparison is written from the design-and-qualification side, not the marketing side. We’ll go through the technical specs, application fit, supply chain realities, and the design scenarios where each supplier genuinely wins.

Who Are These Two Suppliers, Actually?

Before comparing part numbers and Dk values, it’s worth understanding what these companies are and where they operate, because that context shapes everything from your supply risk to your lead time.

Doosan Corporation Electro-Materials (DEM) is the electronics materials division of South Korea’s Doosan Group, a conglomerate founded in 1896 and now operating across clean energy, smart machines, and advanced materials. The electro-materials business was established in 1974, and today the company produces over 15 million square meters of CCL annually from plants in South Korea, China, and Europe. Their revenue reached 950.4 billion Korean won in 2022, supplying 137 companies across 21 countries. They are vertically integrated — meaning they control resin synthesis through to final laminate — and they invest roughly 5% of revenue in R&D. At CES 2026, they were showcasing next-gen high-speed CCL for AI data center accelerators.

Shengyi Technology Co., Ltd. (SYTECH) is headquartered in Dongguan, China, and is consistently ranked as the world’s second-largest CCL manufacturer by global rigid laminate volume. Founded later than Doosan, Shengyi has grown aggressively through scale and geographic proximity to the world’s largest PCB manufacturing cluster in Guangdong Province. In 2023, they announced a $196 million investment in a new production facility in Thailand — a signal of both their scale and their strategic intent to diversify manufacturing geography. Their product portfolio runs from standard FR-4 all the way to PTFE-based RF materials, and their materials have become the default specification at several major contract manufacturers.

Both are serious, global-scale suppliers. Neither is a commodity rebrander. The differences are real but nuanced.

Doosan vs Shengyi Laminate: Head-to-Head Comparison at a Glance

Criteria	Doosan (DEM)	Shengyi (SYTECH)
Headquarters	South Korea	China (Dongguan)
Founded	1974	— (later)
Annual CCL Output	> 15M m²	Among world’s largest
Primary Strength	High-speed, RF, IC substrate	Volume FR-4, broad portfolio
Manufacturing Sites	Korea, China, Europe	China, Thailand (new)
Vertical Integration	Yes (resin to laminate)	Yes (high degree)
R&D Investment	~5% of revenue	Significant
Automotive Cert	IATF 16949	IATF 16949
Key Certifications	UL, RoHS, REACH	UL, RoHS, REACH, IEC 61249
Distribution Reach	21 countries	Widely available in Asia
Typical Lead Time (std.)	2–4 weeks	1–3 weeks (China fabs)

Standard FR-4 Head-to-Head: EM-827 vs S1000-2

For most PCB engineers, the comparison starts here. These two materials sit in the same general-purpose, high-Tg FR-4 tier and get specified on the bulk of standard multilayer builds — server boards, industrial controls, consumer electronics, and automotive body electronics.

Property	Doosan EM-827	Shengyi S1000-2	Test Method
Tg (DSC)	150°C	170°C	IPC-TM-650 2.4.25C
Td	~320°C	≥340°C	TGA (5% weight loss)
T288	> 5 min	> 20 min	IPC-TM-650 2.4.24.1
Z-axis CTE	≤4.0%	Low (controlled)	IPC-TM-650 2.4.41
Dk (at 1 GHz)	~4.5	~4.5	IPC-TM-650 2.5.5.5
Df (at 1 GHz)	0.015–0.020	0.018–0.022	IPC-TM-650 2.5.5.5
CAF Resistance	Good	Excellent	IPC-TM-650 2.6.25
IPC Slash Sheet	IPC-4101 /98, /99	IPC-4101B /126	—
Lead-Free Compatible	Yes	Yes	—
Halogen-Free Option	Yes	Not standard on this grade	—

Where the differences show up in practice: The Shengyi S1000-2 carries a meaningfully higher Tg of 170°C versus the EM-827’s 150°C, and its T288 result of greater than 20 minutes is considerably more conservative than the EM-827’s specification. If you’re running high-layer-count boards through multiple lead-free reflow cycles, that T288 headroom on the S1000-2 is a real reliability advantage. Doosan’s EM-827, while rated at 150°C Tg, comes into its own in automotive applications where its PPAP qualification history and consistent supply from non-China manufacturing sites matter more than raw thermal headroom.

For 12+ layer boards that will go through two or more reflow passes, the S1000-2’s thermal profile is stronger on paper. For automotive or European-sourced production runs where supply chain geography is important, EM-827 makes more sense.

Mid-Loss Tier: EM-370(Z) vs Shengyi S7439 Series

Once your design moves above 3 GHz or your layer count climbs past 16 with dense via fields, you’re shopping in the mid-loss tier. This is where the comparison gets more technically interesting.

Property	Doosan EM-370(Z)	Shengyi S7439G	Test Method
Tg (DSC)	170°C	170°C	IPC-TM-650
Td	340°C	~340°C	TGA
Dk (at 10 GHz)	3.8–4.0	3.6–3.8	Cavity resonator
Df (at 10 GHz)	0.010–0.015	0.008–0.012	Cavity resonator
Signal Frequency Support	up to 6 GHz	up to 20 GHz (stable)	—
CAF Resistance	Excellent	Good	—
Halogen-Free	Yes (variant)	Available	—
IPC Reference	IPC-4101 /126	IPC-4103	—

The Shengyi S7439 series provides stable Dk/Df from 1–20 GHz, making it a strong candidate for 56 Gbps+ PAM4 signaling in high-speed backplanes. Doosan’s EM-370(Z) is very capable for high-layer-count boards where via reliability and CAF resistance are the primary concerns, and the halogen-free variant gives you green compliance without chemistry trade-offs. If your design is pushing 56G+ PAM4 and you need stable dielectric characteristics across a broad frequency sweep, the S7439G has an edge on the headline Dk/Df numbers. If through-hole reliability on dense boards is the primary specification, EM-370(Z)’s proven track record is hard to argue with.

High-Performance and Low-Loss Tier: Where Doosan Pulls Ahead

This is where the competitive picture shifts decisively. Once you move into the low-loss and ultra-low-loss tiers required for 5G mmWave, 77 GHz automotive radar, AI server backplanes running 112G SerDes, and advanced network equipment, Doosan’s product depth and R&D investment become clear differentiators.

Property	Doosan EM-888HF	Shengyi SF305 (nearest equiv.)	Notes
Tg	170°C	~180°C	Both high-Tg
Dk (at 10 GHz)	3.4	~2.9–3.5	SF305 is PTFE-based
Df (at 10 GHz)	0.003	~0.002	SF305 has PTFE advantage
Processing	Standard FR-4	PTFE / special process	EM-888HF is key advantage
Cost Index	3–4x FR-4	6–8x FR-4	Significant gap
Application	77 GHz ADAS, RF frontend	Mmwave, RF microwave	Overlapping at high-freq

The EM-888HF’s defining advantage is the combination of low Dk/Df performance with standard FR-4 processing compatibility. Shengyi’s SF305 material uses a PTFE-based substrate that requires specialized drilling and lamination processes — not every PCB shop can run it, and the ones that can charge for it. If your design targets 77 GHz automotive radar and you need to build at scale with standard FR-4 equipment, EM-888HF does something that Shengyi’s portfolio doesn’t match at the same process tier.

For ultra-low-loss network equipment materials, Doosan’s EM-891 competes directly with Panasonic Megtron6 and Isola Tachyon 100G. Shengyi’s S7439G handles the mid-loss portion of this market well, but the catalog depth at ultra-low-loss levels — where 112G PAM4 and 1.6T Ethernet designs live — is where Doosan’s sustained R&D investment becomes visible in the product lineup.

Full Tier-by-Tier Comparison: Doosan vs Shengyi

Loss Tier	Doosan Part	Shengyi Equivalent	Winner (Enginering)
Standard Loss	EM-285, EM-827	S1141, S1000H	Shengyi (cost + thermal)
High-Tg FR-4	EM-370(5)	S1000-2, S1000-2M	Shengyi (T288 advantage)
Mid Loss	EM-370(Z), EM-828G	S7439C, S7439G	Tie (application-dependent)
Low Loss	EM-888, EM-888(S)	S7045G	Doosan (process compatibility)
Very Low Loss	EM-888HF, EM-528	S7439G (upper range)	Doosan (depth of portfolio)
Ultra-Low Loss	EM-891, EM-890	Limited options	Doosan (clear advantage)
PTFE / RF mmWave	RF-500	SF305, SAR series	Shengyi (more PTFE variants)
Flex (FCCL)	DSflex-600/900	SF series	Doosan (fold endurance spec)
Automotive	EM-827, EM-891	S1165M, Autolad5	Tie (both IATF certified)

Supply Chain and Geographic Considerations

This is often the factor that tips the actual decision, and it’s worth being direct about it. If your production is in South China — Shenzhen, Dongguan, Guangzhou — Shengyi materials are typically stocked by your PCB fabricator as a default. Lead times of 1–3 weeks are realistic. You won’t need to import anything, and the local distributor network is dense. Several major contract manufacturers have standardized on Shengyi for their standard FR-4 lines.

Doosan’s supply position in China exists but is more limited at the distribution level. Their main manufacturing strength is Korean, and for designs that require non-China sourcing — a growing consideration for European OEMs and US defense-adjacent programs — Doosan’s Korean manufacturing base and European distribution are genuine advantages. Their multi-site manufacturing across Korea, China, and Europe is specifically valuable when supply chain diversification is a program requirement, not just a preference.

Geopolitical Considerations in 2025–2026

The ongoing trade and technology tensions between the US, China, and Taiwan have made laminate supplier geography a procurement topic at the engineering level in ways that weren’t true five years ago. Doosan’s Korean manufacturing base and European presence make their materials easier to source for programs that require non-China supply chains. Shengyi’s new Thailand facility, announced in 2023 with a $196 million investment, is a direct response to this pressure — but the timeline to full qualification at a new facility is typically 12–18 months.

If your OEM has formal supply chain risk requirements that include laminate supplier geography, this may determine your choice before electrical specifications even enter the conversation.

Cost Comparison: Reality Check

Neither supplier publishes list prices, but the market reality is reasonably clear from distributor data and volume purchase patterns:

Material Tier	Doosan Cost Index	Shengyi Cost Index	Notes
Standard FR-4	1.0–1.1x	1.0x (baseline)	Shengyi slightly lower at scale
High-Tg FR-4	1.2–1.4x	1.1–1.3x	Small gap, Shengyi favored
Mid-Loss	1.5–2.0x	1.4–1.8x	Comparable, Shengyi slightly lower
Low Loss	2.0–3.0x	1.8–2.5x	Shengyi advantage narrows at this tier
Ultra-Low Loss	4.0–6.0x	Limited options	Doosan often only qualified option
RF/PTFE	5.0–8.0x	5.0–7.0x	Comparable, application drives choice

The cost picture is: Shengyi has a modest edge on standard and mid-tier materials when manufactured in China, Doosan becomes cost-competitive and often the only qualified option at the ultra-low-loss tier, and the gap narrows significantly once you factor in qualification costs on non-standard materials.

Which Supplier Wins by Application?

High-Volume Consumer Electronics

Shengyi wins. For smartphones, tablets, and standard consumer boards manufactured in China, Shengyi S1141 or S1000-2 is the default choice at most major contract manufacturers. The material is stocked, qualified, and priced for volume production. Unless there’s a specific requirement for Doosan’s halogen-free chemistry or a geographic supply constraint, there’s no engineering reason to switch.

Automotive Electronics (ADAS, ECU, Body)

Tie — application-dependent. Both suppliers hold IATF 16949 certification. For 77 GHz ADAS radar where RF performance at mmWave frequencies is the primary constraint, Doosan’s EM-888HF with standard FR-4 processing is a genuinely differentiated solution. For body electronics and ECU boards where thermal reliability and automotive qualification documentation are the primary requirements, both Doosan EM-827/EM-891 and Shengyi S1165M/Autolad5 are validated options.

5G and Telecom Infrastructure

Doosan wins at high frequency. For base station antenna boards at 26/28/39 GHz, Doosan’s EM-888 series and RF-500 provide competitive performance with favorable processing economics. Shengyi’s S7439G is strong in the sub-20 GHz band but Doosan’s catalog depth extends further up the frequency range.

AI Servers and Data Center Infrastructure

Doosan wins at ultra-high speed. For 112G PAM4 and emerging 224G interconnects on server backplanes and AI accelerator boards, the EM-891 and EM-890 series compete directly with Megtron6 and Tachyon 100G. Shengyi’s equivalent performance tier is more limited, and Doosan’s roadmap — showcased at CES 2026 with 800 GbE and 1.6T Ethernet materials — is clearly targeted at this market.

Industrial and Medical Electronics

Shengyi for cost-driven programs; Doosan for long-life reliability programs. Shengyi S1000-2M is excellent for industrial boards where through-hole reliability and thermal performance are primary and cost efficiency matters. For long-lifecycle industrial or medical programs requiring 15–20 year supply commitment tracking, Doosan’s stable Korean manufacturing base is an advantage.

5 FAQs: Doosan vs Shengyi Laminate

FAQ 1: Can I directly substitute Shengyi S1000-2 for Doosan EM-827 without re-qualification?

Technically these materials have different Tg values — S1000-2 at 170°C versus EM-827 at 150°C — so they’re not a direct swap from a thermal specification standpoint. If your design was qualified on EM-827 and you’re considering S1000-2 as a cost alternative, you’re actually moving to a higher-Tg material, which won’t cause failures. However, you still need to validate: (1) that impedance targets are maintained with the specific Dk at your test frequency, (2) that drill and processing parameters don’t change, and (3) that your qualification documentation and customer approval flow allows for the substitution. Never treat a cross-reference as an implicit approval.

FAQ 2: For 5G sub-6 GHz antenna boards, which material is better?

For sub-6 GHz, Shengyi’s S7439G and Doosan’s EM-888 series are both solid candidates. The decision typically comes down to where you’re manufacturing: if you’re in a Chinese fab with Shengyi as their standard advanced material, the qualification path is shorter. If you’re manufacturing in Korea or Europe or if your design calls for process compatibility with a board shop that runs Doosan EM-888 as their low-loss default, go with Doosan. Both materials will hit sub-6 GHz performance targets reliably.

FAQ 3: Does Shengyi have materials that can handle 77 GHz automotive radar?

Yes — Shengyi’s SAR series and SF305 are targeted at mmWave frequencies. However, these are PTFE-based materials requiring specialized manufacturing processes. Doosan’s EM-888HF handles 77 GHz on standard FR-4 lamination equipment, which is a meaningful process cost advantage. If your fabricator already qualifies PTFE materials, evaluate Shengyi’s SAR20 against Doosan RF-500. If you want to avoid the PTFE process premium, EM-888HF is the path of least resistance.

FAQ 4: Which supplier is better for halogen-free requirements?

Both offer halogen-free variants. Shengyi has been building halogen-free products since at least 2013 and has an extensive HF lineup. Doosan also offers halogen-free variants across their EM-370, EM-888, and DS-7409DV(N) lines. In practice, Shengyi’s halogen-free catalog at the standard FR-4 level has slightly more breadth and better pricing for high-volume builds in China. Doosan’s halogen-free options at the high-performance tier are well-specified and carry European market acceptance for RoHS and REACH compliance.

FAQ 5: How do I decide which supplier to qualify for a new program?

Start with three questions. First, where is your board being manufactured? If China, Shengyi’s distribution advantage is significant for standard and mid-tier materials. If Korea, Europe, or North America, Doosan’s supply chain is stronger. Second, what is the highest operating frequency of your design? Below 6 GHz, both are strong; above 20 GHz, Doosan has more catalog depth. Third, does your program have supply chain geography requirements? If non-China supply is a requirement, Doosan’s Korean manufacturing base is relevant. Once you’ve answered those three questions, the choice is usually clear.

Useful Resources for Engineers

These resources are directly useful when evaluating or working with either supplier’s materials:

Official Technical Sources

• Doosan Electro-Materials Product Database — searchable by application and property, includes full datasheets
• Shengyi Technology Product Catalog — official SYTECH product pages with downloadable datasheets
• Doosan RoHS Reports — downloadable compliance documentation by product

Material Comparison Databases

• CircuitData Material DB — open-source PCB material database with API access, includes both Doosan and Shengyi materials from 90+ manufacturers
• Z-zero PCB Materials Library — includes both Doosan and Shengyi material libraries for stackup planning, with frequency-dependent Dk/Df
• PCB Directory Laminate Database — manufacturer datasheets, cross-references, and procurement links

Fabrication Services Using These Materials

• PCBSync Doosan PCB — fabrication services using Doosan materials including the EM-888 and EM-891 series
• PCBWay Shengyi Material Guide — application guides for Shengyi S1000-2, S1000-2M and related materials

Standards Referenced

• IPC-4101: Base Materials for Rigid and Multilayer PCBs
• IPC-4103: Base Materials for High-Speed/High-Frequency Applications
• IPC-TM-650 2.5.5.5: Dielectric constant and loss tangent test method
• IATF 16949: Automotive quality management for both suppliers

The Bottom Line: Which One Should You Spec?

After running through all of this, the honest answer is that both Doosan and Shengyi are solid, serious suppliers. The question isn’t which one is objectively better — it’s which one is better for your specific program.

Specify Shengyi when you’re building in China, your design lives below 20 GHz, cost pressure is real, and your fabricator already has it qualified. The S1000-2 and S7439G series are mature, well-characterized materials that will do exactly what the datasheet says. Their position as the default standard at many major Chinese contract manufacturers means you’re working with materials that fabrication engineers know deeply.

Specify Doosan when your design frequency pushes above 20 GHz, when you need ultra-low-loss materials for 5G mmWave or AI data center infrastructure, when non-China supply chain geography is a program requirement, or when you’re qualifying 77 GHz ADAS radar on standard FR-4 processing. The EM-888HF and EM-891 series do things in those application spaces that Shengyi’s current catalog doesn’t match.

In the mid-tier — the EM-370(Z) vs S7439 range — run the comparison on your specific application requirements and your fabricator’s process baseline. Both will work. Pick the one your supply chain can sustain.