Shengyi S7136H PCB: Properties & Design Guide

What Is the Shengyi S7136H PCB Laminate?

Shengyi S7136H is a halogen-free, mid-Dk epoxy laminate engineered for RF and high-speed digital PCBs operating up to roughly 10 GHz. A Shengyi S7136H PCB delivers a dielectric constant (Dk) of 3.60 ± 0.05 and a dissipation factor (Df) of 0.010 at 1 GHz, placing it between standard FR-4 and specialty PTFE laminates in both electrical performance and cost. Because its resin system is free of bromine and chlorine compounds, S7136H satisfies IEC 61249-2-21 halogen-free requirements while remaining compatible with lead-free soldering profiles up to 260 °C.

For designers who need better loss behavior than conventional FR-4 (Df ≈ 0.020) but cannot justify the price premium of Rogers or pure PTFE substrates, the Shengyi S7136H PCB occupies a practical middle ground. It is widely used in GPS front-ends, Wi-Fi 6E access-point boards, automotive V2X modules, and sub-6 GHz 5G small-cell radios—applications where halogen-free RF laminate compliance is increasingly mandated by OEM environmental policies.

Key Electrical and Mechanical Properties of S7136H

The table below summarizes the published parameters for S7136H alongside two common reference laminates so you can judge where a Shengyi S7136H PCB fits in your stackup.

The standout numbers are the Tg of 175 °C and the z-axis CTE of 2.8 %. Together they give S7136H good reliability through multiple lead-free reflow cycles—important for automotive-grade boards that must pass JEDEC JESD22-A104 temperature cycling. The 0.010 Df is roughly half that of commodity FR-4, which translates to approximately 1 dB less insertion loss per 100 mm of 50 Ω microstrip at 5 GHz—meaningful in receiver chains where every fraction of a dB affects sensitivity.

Where S7136H Fits in the Shengyi Portfolio

Shengyi Technology, headquartered in Dongguan, is the world’s second-largest CCL (copper-clad laminate) manufacturer by revenue. Its RF-oriented product line spans from modified epoxies like S7136H up to woven-glass PTFE grades. Understanding where the S7136H PCB sits helps you decide whether to step up or down.

• S1000-2M (standard mid-Tg FR-4): Dk 4.25, Df 0.019. Use when RF performance is not a concern.
• S7136H (this laminate): Dk 3.60, Df 0.010. Cost-effective halogen-free option for sub-10 GHz RF.
• S7439 / S7439H: Dk 3.40, Df 0.005. Shengyi’s “very low loss” grade for 10–20 GHz range, priced 2–3× higher than S7136H.
• SCGA-500GF: PTFE/glass composite, Dk 2.55, Df 0.0018. For millimeter-wave antenna applications—see our guide to the Shengyi SCGA-500GF antenna laminate.

Use the selector below to compare Shengyi grades against your frequency and loss budget.

If the selector recommends S7136H, you are typically in the 1–8 GHz range with a loss budget above 0.15 dB/cm at your operating frequency. Below that threshold, step up to S7439 or consider a hydrocarbon ceramic laminate from another vendor.

Shengyi S7136H PCB Design Guidelines

Impedance Control

With Dk 3.60 at 1 GHz, a 50 Ω microstrip on a 10 mil (0.254 mm) core with 1 oz (35 µm) copper lands at roughly 14.5 mil (0.37 mm) trace width—narrower than the ~17 mil needed on standard FR-4 at Dk 4.3. Use the Dk value at your actual operating frequency; Shengyi’s datasheet shows Dk dropping to about 3.55 at 10 GHz. That 1.4 % shift can move a 50 Ω line to 48.5 Ω if you design only to the 1 GHz number, so always request the high-frequency Dk from your laminate supplier and confirm it against your field solver.

For tighter impedance tolerances (±5 % or better), pair S7136H with HVLP (hyper-very-low-profile) copper foil. The reduced foil roughness (Rz ≤ 3 µm versus 7–10 µm on standard ED copper) lowers conductor loss and makes the effective Dk more predictable, especially above 3 GHz.

Stackup Considerations

S7136H is available in standard core thicknesses from 3 mil (0.075 mm) to 62 mil (1.575 mm) and as prepreg in 1080, 2116 and 7628 glass styles. Because the resin system is epoxy-based, it bonds using the same lamination profiles as FR-4—no special high-temperature press cycles or plasma treatment needed. This makes it straightforward to build hybrid stackups where S7136H cores carry the RF layers and lower-cost FR-4 carries digital and power layers.

A common 6-layer hybrid stackup for a Wi-Fi 6E module:

1. Top signal (RF traces) — S7136H 10 mil core
2. GND plane
3. Inner signal (digital) — FR-4 prepreg + FR-4 core
4. Power plane
5. Inner signal (digital) — FR-4 core
6. Bottom signal / GND — FR-4

Download example files from our RF PCB stackup library for pre-validated layer assignments.

Thermal Reliability

The 175 °C Tg and 350 °C Td mean S7136H handles six or more lead-free reflow passes without measurable delamination in IST (interconnect stress testing) per IPC-TM-650 method 2.6.26. For automotive designs that require AEC-Q104 board-level qualification, the 2.8 % z-axis CTE keeps via barrel stress within acceptable limits even for aspect ratios up to 10:1.

Halogen-Free Compliance Details

S7136H uses a phosphorus-nitrogen flame-retardant system instead of brominated epoxy. It meets IEC 61249-2-21, which caps bromine at 900 ppm, chlorine at 900 ppm, and total halogens at 1500 ppm. This matters for EU RoHS and WEEE compliance, and increasingly for North American automotive OEMs who impose halogen-free mandates at the component level.

A common concern is whether halogen-free resin systems compromise electrical performance. In S7136H’s case, the Df penalty versus its halogenated sibling (S7136, Df ≈ 0.009) is only about 0.001—roughly 0.1 dB/100 mm at 5 GHz. That trade-off is negligible in most sub-10 GHz designs. For a deeper look at the performance penalty across multiple vendors, see our overview of sustainability in RF PCB manufacturing.

Shengyi S7136H PCB Cost Positioning and Procurement

A Shengyi S7136H PCB sits at a modest premium over standard halogen-free FR-4 (roughly 15–25 % more per panel, depending on thickness and copper weight) but costs significantly less than Rogers RO4350B or Isola Astra MT77. The main cost drivers are:

• Core thickness: Thin cores (≤ 5 mil) carry a handling surcharge.
• Copper foil grade: Upgrading from standard ED to HVLP adds 8–15 % to the laminate cost.
• Volume: Shengyi offers aggressive pricing at panel quantities above 200 because S7136H runs on standard FR-4 lamination lines with no special press tooling.
• Lead time: Domestic (Asia) stock is typically 2–3 weeks; export to North America or Europe adds 3–4 weeks unless your fabricator holds buffer stock.

Use the calculator below to compare S7136H’s relative cost index against other laminates you may be evaluating.

If the index shows S7136H at roughly 1.2× the cost of standard FR-4, that is typical for 10 mil cores with 1 oz copper. At that ratio, the halogen-free compliance and ~50 % lower Df make it one of the best value propositions in the modified-epoxy category. Compare this with the broader landscape in our RF laminate pricing overview.

Fabrication Notes for S7136H Boards

Drilling and Via Formation

S7136H drills cleanly with standard carbide bits. Recommended drill parameters are similar to high-Tg FR-4: spindle speed 150–180 krpm, infeed 1.5–2.0 m/min for mechanical drilling. Laser via formation (UV or CO₂) works well on the 1080 and 2116 prepreg styles; the phosphorus-based resin ablates at energy densities comparable to standard halogen-free FR-4, so no special laser tuning is required.

Surface Finish Compatibility

All common finishes—ENIG, immersion silver, immersion tin, OSP, and HASL—are compatible. For RF pads that carry signals above 3 GHz, ENIG or immersion silver is preferred to minimize skin-effect losses at the pad-to-trace transition.

Hybrid Bonding

When bonding S7136H to PTFE layers (for example, a glass-reinforced PTFE antenna layer on top of an S7136H multilayer), use a low-flow prepreg such as Shengyi’s SP series or Arlon 6700. Sodium-etch or plasma-treat the PTFE surface first to ensure adequate peel strength (target ≥ 6 lb/in per IPC-4101 slash-sheet requirements).

When to Choose a Shengyi S7136H PCB — and When Not To

Frequently Asked Questions

What frequency range is a Shengyi S7136H PCB suitable for?

S7136H performs well from DC to approximately 10 GHz. Above 10 GHz, its Df of 0.010 introduces insertion losses that may exceed the link budget of sensitive receivers. For 10–20 GHz designs, Shengyi’s S7439 (Df 0.005) is a better match.

Is S7136H truly halogen-free?

Yes. It meets IEC 61249-2-21 with bromine < 900 ppm, chlorine < 900 ppm, and total halogens < 1500 ppm. Certificates of compliance are available per lot from Shengyi.

Can S7136H be used in hybrid stackups with PTFE?

Yes, but the PTFE surface must be treated (sodium etch or plasma) and a compatible low-flow bonding prepreg must be used. Lamination temperatures for S7136H (around 200 °C peak) are well within the range PTFE materials tolerate.

How does the Shengyi S7136H PCB compare to Isola IS680 AG?

Both target the same mid-loss, halogen-free niche. IS680 AG has a slightly lower Df (0.0088 at 1 GHz) but at a higher price point and longer lead time outside of North America. S7136H has a supply-chain advantage for fabricators in Asia.

What copper foil should I specify with S7136H?

Standard reverse-treated ED foil (RTF) works for designs below 3 GHz. Above 3 GHz, specify HVLP foil (Rz ≤ 3 µm) to reduce conductor loss and improve Dk predictability.