Shengyi S1151G is a halogen-free, mid-Tg FR-4.1 laminate for PCB designs that need a high comparative tracking index. Its defining value is CTI PLC 0, equivalent to at least 600 V under IEC 60112. The official datasheet also lists a 155°C Tg by DSC, 380°C decomposition temperature at 5% weight loss and compatibility with lead-free assembly.
Those properties do not make S1151G a universal high-reliability material. Shengyi suggests it for through-hole multilayers up to 8 layers and no more than 2 oz copper. The manufacturer also states that it is not suitable for solder-mask rework. If your design needs HDI, more layers, heavier copper or repeated solder-mask stripping, choose a material and process route intended for those conditions.
The values below come from Shengyi’s official two-page S1151G/S1151GB datasheet, document CN-TDS-2112-06-S1151G-S1151GB, dated December 2021. The supporting construction data comes from Shengyi’s official line-up document. Typical values are references, not guaranteed procurement limits for every thickness, resin content or pressed stackup.
What Is Shengyi S1151G PCB Material?
S1151G is the copper-clad laminate; S1151GB is its bonding prepreg. Shengyi classifies the system as UL ANSI FR-4.1, halogen free, mid Tg and high CTI. It is free of intentionally listed halogen, antimony and red-phosphorus constituents within the datasheet’s stated halogen limits.
The material is aimed primarily at automotive electronics such as onboard chargers and charging units, while Shengyi’s product page also lists smartphones and consumer electronics. Its high-CTI positioning can help when creepage performance is part of the insulation design, but CTI does not replace the required clearance, creepage, pollution-degree and overvoltage analysis for the finished product.
From QFPCB’s manufacturing perspective, S1151G is most useful when the requirement is specific: halogen-free construction plus CTI of at least 600 V in a conventional through-hole multilayer. If the drawing only says high CTI FR-4, send the actual voltage, spacing, certification and material-documentation requirements so we can confirm whether S1151G is the right grade.
S1151G Datasheet Parameters
The table preserves Shengyi’s methods and conditions. Dk 4.6 and Df 0.011 are measured at 1 GHz under IPC-TM-650 2.5.5.9; they should not be treated as frequency-independent design values.
| Property | Official typical value | Test method | Condition / note |
|---|---|---|---|
| Tg | 155°C | IPC-TM-650 2.4.25D | DSC |
| Td | 380°C | IPC-TM-650 2.4.24.6 | TGA, 5% weight loss |
| T288 | 30 min | IPC-TM-650 2.4.24.1 | TMA |
| T260 | >60 min | IPC-TM-650 2.4.24.1 | TMA |
| Thermal stress | >100 s | IPC-TM-650 2.4.13.1 | 288°C solder dip |
| Z-axis CTE below / above Tg | 36 / 220 ppm/°C | IPC-TM-650 2.4.24 | TMA |
| Z-axis expansion | 2.8% | IPC-TM-650 2.4.24 | 50-260°C |
| Permittivity (Dk) | 4.6 | IPC-TM-650 2.5.5.9 | 1 GHz; C-24/23/50 |
| Loss tangent (Df) | 0.011 | IPC-TM-650 2.5.5.9 | 1 GHz; C-24/23/50 |
| Volume resistivity | 6.4 × 107 MΩ-cm | IPC-TM-650 2.5.17.1 | C-96/35/90 |
| Surface resistivity | 4.8 × 107 MΩ | IPC-TM-650 2.5.17.1 | C-96/35/90 |
| Arc resistance | 140 s | IPC-TM-650 2.5.1 | D-48/50 + D-0.5/23 |
| Dielectric breakdown | >45 kV | IPC-TM-650 2.5.6 | D-48/50 + D-0.5/23 |
| Peel strength, 1 oz | 1.4 N/mm (8.00 lb/in) | IPC-TM-650 2.4.8 | After 288°C / 10 s |
| Flexural strength, LW / CW | 600 / 450 MPa | IPC-TM-650 2.4.4 | Condition A |
| Water absorption | 0.10% | IPC-TM-650 2.6.2.1 | D-24/23 |
| CTI | PLC 0 (≥600 V) | IEC 60112 | Condition A |
| Flammability | V-0 | UL 94 | C-48/23/50 |
| Halogen content: Br / Cl / total | ≤900 / ≤900 / ≤1500 ppm | EN 14582 | Condition A |
What Does CTI 600 V Mean for PCB Design?
CTI describes how an insulating material resists conductive tracking across its surface under a standardized test. S1151G is listed as PLC 0, the highest CTI performance class in the datasheet, corresponding to at least 600 V. This can support insulation coordination where material group and creepage distance matter.
It does not mean two conductors can always be spaced for 600 V operation. The finished product still depends on working voltage, transient overvoltage, pollution degree, coating, altitude, conductor geometry, contamination, humidity and the applicable safety standard. The PCB’s creepage and clearance must be calculated separately.
The S1151GB construction also matters. Shengyi warns that some prepreg types or low-resin constructions—such as 106, 1080, 2116 below 54% resin content and 7628 below 45% resin content—may not satisfy CTI ≥600 V. Do not approve a high-CTI stackup from the laminate trade name alone; confirm every dielectric construction in the finished board.
Where Does S1151G Fit—and Where Does It Not?
S1151G fits conventional, through-hole multilayer PCB manufacturing when high CTI and halogen-free construction are real design requirements. The official TDS suggests no more than 8 layers and no more than 2 oz copper. QFPCB uses those values as material-specific limits even though our general FR-4 process capability covers broader constructions with other materials.
Good candidate applications include automotive onboard chargers, charging units, power-control electronics, consumer devices and smartphones. The actual automotive qualification, temperature class, lifecycle and documentation must still be defined by the project; an application example in a datasheet is not a finished-product qualification.
Choose another material route when the board requires:
- more than 8 layers;
- finished copper above 2 oz;
- HDI or Any-Layer HDI microvias;
- a dedicated low-loss or RF material;
- solder-mask stripping and rework;
- a prepreg construction that cannot maintain CTI ≥600 V;
- a qualification or continuous-use temperature not established by the S1151G TDS.
For dense microvia designs, review QFPCB’s HDI PCB manufacturing path with a material specifically suitable for the buildup. Do not use the factory’s general HDI capability to override S1151G’s through-hole construction guidance.
How Should Tg, Td, T260 and T288 Be Interpreted?
Tg 155°C by DSC identifies the resin’s glass transition under a specified method. It is not a continuous operating-temperature rating. Td 380°C is the temperature at 5% weight loss by TGA; it does not define a safe reflow peak. T260 and T288 measure time to delamination under TMA conditions and are listed above 60 minutes and at 30 minutes respectively.
These values indicate strong thermal robustness for a mid-Tg material, but the finished board’s assembly reliability still depends on moisture, thickness, copper distribution, hole geometry, plating, component mass, peak temperature and the number of thermal cycles. Shengyi’s official processing guide recommends a conventional lead-free process and provides project-dependent baking and handling guidance.
From a CAM and manufacturing standpoint, the 2.8% Z-axis expansion from 50°C to 260°C should be reviewed together with plated-hole aspect ratio and annular ring. A favorable laminate number cannot compensate for an aggressive hole structure or uncontrolled rework.
How Should Dk and Df Be Used for Impedance?
S1151G’s TDS reports Dk 4.6 and Df 0.011 at 1 GHz. Shengyi’s separate line-up document shows that actual Dk varies with core thickness, glass style and resin content—for example, the listed cores range approximately from 4.64 to 4.94 at 10 GHz. Those construction values are actual SPDR measurements and are not guaranteed specifications.
Use the official numbers as starting references, then build the PCB around the selected construction. Pressed dielectric thickness, resin percentage, copper thickness, copper roughness, trace geometry and solder mask affect the final result. QFPCB provides PCB layer stackup and controlled-impedance PCB engineering support for multilayer, hybrid and HDI—including Any-Layer HDI—projects.
For an S1151G design, our review may confirm a conventional through-hole stackup or recommend a different material when the project exceeds S1151G’s limits. PCB engineer Alan has more than 10 years of PCB CAM engineering experience. Send your layer order, finished thickness, copper weights, target impedances and trace structures to [email protected]. Final tolerance, coupon and test requirements remain project-specific.
S1151GB Prepreg Constructions and CTI Risk
The official TDS lists 2116 and 7628 prepreg options. These values are typical cured thicknesses; the actual pressed dielectric must be confirmed against the production stackup and resin-flow model.
| Glass style | Resin content | Typical cured thickness | Standard roll size |
|---|---|---|---|
| 2116 | 54% | 0.114 mm | 1.260 m × 250 m |
| 2116 | 57% | 0.127 mm | 1.260 m × 250 m |
| 2116 | 60% | 0.134 mm | 1.260 m × 250 m |
| 7628 | 46% | 0.190 mm | 1.260 m × 150 m |
| 7628 | 48% | 0.200 mm | 1.260 m × 150 m |
| 7628 | 50% | 0.210 mm | 1.260 m × 150 m |
| 7628 | 52% | 0.220 mm | 1.260 m × 150 m |
The datasheet specifies a curing time greater than 60 minutes at 180-190°C. It lists three months of storage below 23°C and 50% RH or six months below 5°C, followed by at least four hours of room-temperature normalization. The processing guide recommends at least eight hours of warm-up before opening cold-stored prepreg packaging, so the more conservative project handling instruction should govern.
What Manufacturing Risks Need Special Attention?
The first risk is solder-mask rework. Shengyi explicitly says S1151G is not suitable for it, and the processing guide warns that stripping may create white spots. Plan the solder-mask process and inspection so the panel is not dependent on strip-and-recoat recovery.
The second risk is drilling and desmear. Shengyi describes the material as relatively hard and recommends reducing drill infeed by about 10-20% from ordinary FR-4 as a starting point. Over-aggressive swelling or desmear may cause resin recession or rough hole walls. These are manufacturer reference recommendations, not universal QFPCB machine recipes; actual parameters depend on board thickness, hole size and stackup.
Other controls include:
- confirm S1151GB glass style and resin content before impedance release;
- maintain layer orientation and stack symmetry to limit warpage;
- protect prepreg from moisture and UV exposure;
- review bake requirements before lamination and final packaging;
- use a lamination cycle appropriate to resin flow and copper distribution;
- avoid routing the project through HDI or heavy-copper assumptions that conflict with the TDS;
- state the required halogen, CTI, UL or automotive documentation in the purchase specification.
What Thickness and Copper Options Are Listed?
The TDS purchasing table lists laminate thickness from 0.20 to 3.2 mm and copper foil from 12 to 105 µm. Standard sheet sizes are 1020 × 1220 mm, 915 × 1220 mm and 1070 × 1220 mm, with other sizes and thicknesses available by request.
Do not confuse the purchasing range with the recommended PCB application window. The same TDS suggests no more than 2 oz copper for the intended multilayer through-hole use, even though copper foil up to 105 µm appears in the purchasing table. QFPCB confirms the exact laminate thickness, foil, prepreg, certification and current availability before quotation.
For a design above 2 oz, use the heavy-copper PCB manufacturing review process to select a suitable material and feature window. The link describes QFPCB’s service path; it does not claim S1151G itself is approved above its manufacturer-stated limit.
What Should You Send for an S1151G PCB Quote?
Send enough information to evaluate the electrical-insulation requirement and the manufacturable stackup together:
- Gerber, ODB++ or IPC-2581 data, plus NC drill and route files;
- board dimensions, finished thickness and layer count;
- S1151G laminate and S1151GB prepreg callouts;
- glass style, resin content and pressed dielectric requirements, if fixed;
- inner and outer finished copper weights;
- operating voltage, pollution degree, creepage and clearance requirements;
- CTI, halogen-free, UL, RoHS or automotive documentation requirements;
- impedance table mapped to layers and structures;
- hole sizes, plating, aspect ratio and thermal-cycle expectations;
- solder-mask material, color and confirmation that strip/recoat is not planned;
- surface finish, quantity, panel constraints and accepted material alternatives.
If you have not finalized the laminate, send the actual safety, environmental, thermal and electrical targets. QFPCB can compare S1151G with another high-CTI or higher-complexity material without transferring unsupported capabilities from a third-party article.
Common S1151G Specification Mistakes
The most common mistake is copying an older S1151G table that lists Tg 150°C and Td 360°C. The official Shengyi document currently linked from its product page lists Tg 155°C and Td 380°C. Always record the document code and date with the values.
Other mistakes include:
- treating CTI ≥600 V as permission to use any creepage distance;
- assuming every S1151GB prepreg construction preserves PLC 0 performance;
- describing S1151G as a low-loss or high-frequency laminate because Dk/Df are listed;
- using a general factory layer-count maximum instead of S1151G’s ≤8-layer guidance;
- interpreting the 105 µm purchasing option as approval for >2 oz PCB construction;
- planning solder-mask strip and recoat despite the manufacturer’s warning;
- treating Tg as continuous operating temperature;
- claiming all thicknesses, copper foils and certificates are always in stock.
The safest drawing identifies the exact material system, permitted alternatives, CTI and documentation requirements, then points to an approved stackup rather than relying on a generic halogen-free FR-4 note.
S1151G and S1000-2M answer different material-selection questions. If high Tg and lead-free thermal robustness matter more than a halogen-free, high-CTI requirement, use the official data to compare with our Shengyi S1000-2M material guide. Do not substitute one grade for the other without design-owner approval.
S1151G and S1000H are both discussed in mid-Tg selection, but their compliance and application priorities differ. Compare the official data with our Shengyi S1000H material guide, then confirm halogen-free, CTI, thermal, prepreg and customer-approval requirements before substitution.
For a halogen-free project where thermal spreading is a primary requirement, compare S1151G with Shengyi ST115G thermal-conductive laminate. The grades have different thermal, CTI, prepreg and processing priorities and are not automatic substitutes.
Shengyi S1151G FAQ
What is the Tg of Shengyi S1151G?
Shengyi’s official December 2021 datasheet lists S1151G at 155°C Tg by DSC under IPC-TM-650 2.4.25D. Older third-party pages may show 150°C. Use the value and method from the current official document, and do not treat Tg as the board’s continuous operating-temperature rating.
What is the CTI of S1151G?
S1151G is listed as CTI PLC 0, corresponding to at least 600 V under IEC 60112. This describes material tracking resistance under a standardized test. The finished product still requires creepage and clearance design based on working voltage, pollution degree, overvoltage category, environment and the applicable safety standard.
Is S1151G halogen free?
Yes, within the limits stated in Shengyi’s TDS. Bromine and chlorine are each listed at no more than 900 ppm, with combined Br + Cl no more than 1500 ppm under EN 14582. State the required declaration, test report and document revision in the purchase specification when compliance evidence is required.
How many PCB layers can use S1151G?
Shengyi suggests S1151G for through-hole multilayers up to 8 layers and no more than 2 oz copper. This material-specific recommendation takes precedence over a PCB factory’s broader general capability. More layers, HDI structures or combined stress factors require another material and project-level engineering review.
Can S1151G be used for HDI or Any-Layer HDI?
Do not select it as the default HDI material. The official TDS positions S1151G for conventional through-hole construction up to 8 layers. QFPCB can review an HDI or Any-Layer HDI buildup and recommend a suitable material, then provide stackup and impedance engineering support for that approved construction.
Can solder mask be reworked on S1151G boards?
Shengyi states that S1151G is not suitable for solder-mask rework. Its processing guide warns that stripping the solder mask may produce white spots. Plan coating, exposure, inspection and acceptance controls to avoid strip-and-recoat recovery, and discuss any unavoidable repair requirement before production begins.
What are the Dk and Df values of S1151G?
The official TDS lists Dk 4.6 and Df 0.011 at 1 GHz under IPC-TM-650 2.5.5.9. The construction line-up shows different measured values by glass style, resin content and thickness. Use the selected production construction—not one headline number—for impedance and loss review.
What is the difference between S1151G and S1151GB?
S1151G is the copper-clad laminate, while S1151GB is the corresponding bonding prepreg. A multilayer stackup may use both. The prepreg glass style and resin content affect pressed thickness, dielectric behavior and potentially CTI performance, so the two designations should not be treated as interchangeable purchasing labels.
Build a High-CTI S1151G PCB with QFPCB
S1151G is a focused material choice for conventional multilayer boards that need halogen-free construction and CTI of at least 600 V. Its value is strongest when the full S1151G/S1151GB construction, safety spacing and documentation are controlled—not when the material name is used as a substitute for insulation design.
Send QFPCB your fabrication files, voltage and creepage requirements, stackup, copper, impedance and assembly conditions. We will confirm whether S1151G fits the project, check the available construction and propose a different material when the design exceeds the official layer, copper, via or rework limits.
