CEM-1
CEM-1 is a low-cost composite laminate built from a cellulose-paper core with woven-glass surface layers, all impregnated with epoxy resin.
Reference datasheet — CEM-1 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the FR-V0 condition
CEM-1 grades and fills
CEM-1 is supplied in 3 conditions, soft to hard. FR-V0 is the default FabDigit quotes; the values on this page are for it.
Compare all 3 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Punching grade | Pick for high-volume single-sided boards blanked and hole-punched at 40–70 °C instead of drilled and routed. | 130 | 2 | 88 Shore D | |
Halogen-free flame-retardant CEM-1 | Use where RoHS-plus/halogen-free (Br+Cl < 900 ppm each) customer specs apply, e.g. EU consumer and lighting products. | 140 | 1.4 | 90 Shore D | |
FR-V0Default Standard brominated flame-retardant CEM-1 laminate | Default economical single-sided PCB substrate; pick when cost and punchability matter more than multilayer capability. | 145 | 1.5 | 90 Shore D |
Supply forms, finishes and certifications
Ways CEM-1 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
CCL-1OZ | Single-sided copper-clad, 35 µm Cu foil | Surface finish |
CCL-2OZ | Single-sided copper-clad, 70 µm Cu foil | Surface finish |
UNCLAD | Bare CEM-1 laminate sheet | Surface finish |
What is CEM-1?
CEM-1 is a low-cost composite laminate built from a cellulose-paper core with woven-glass surface layers, all impregnated with epoxy resin. It is used mainly as an economical single-sided PCB substrate and as a general insulating panel, supplied unclad or copper-clad in 1 oz and 2 oz weights, flame-retardant and halogen-free variants. Maximum service temperature is 110 °C with a glass transition of 130 °C; the paper core limits plated-through-hole reliability and moisture resistance, so double-sided and multilayer work moves to CEM-3 or FR-4. CEM-1 has a density of 1.6 g/cm³ (0.0578 lb/in³), lighter than 53% of composite grades. Its glass-transition temperature is 130°C (266 °F). CEM-1 has a tensile strength of 145 MPa (21 ksi), weaker than 58% of composite grades. Elongation at break is 1.5% and the elastic modulus is 14 GPa (2.03 Msi).
What is CEM-1 used for?
- single-sided PCB substrates
- consumer electronics boards
- low-cost mechanical/electrical panels
Limitations
- Hard to polish — 20/100, worse than 90% of composite grades
- Limited service temperature — 110°C (230 °F), worse than 87% of composite grades
- Low fracture toughness — 2.5 MPa·√m (2.28 ksi·√in), worse than 82% of composite grades
CEM-1 properties
Typical room-temperature values for CEM-1-FR-V0; bars are the position among composite grades.
Physical4
CEM-1 has a density of 1.6 g/cm³ (0.0578 lb/in³), lighter than 53% of composite grades. Its glass-transition temperature is 130°C (266 °F).
Mechanical12
CEM-1 has a tensile strength of 145 MPa (21 ksi), weaker than 58% of composite grades. Elongation at break is 1.5% and the elastic modulus is 14 GPa (2.03 Msi).
Thermal8
CEM-1 is rated for continuous service to 110°C (230 °F). It conducts heat at 0.3 W/m·K (0.173 BTU/hr·ft·°F), worse than 63% of composite grades. Thermal expansion is 17 µm/m·K (9.44 µin/in·°F).
Electrical7
CEM-1 is an electrical insulator with a dielectric strength of 30 kV/mm (762 V/mil) and a resistivity of 1×10¹¹ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (70/100), worse than 64% of composite grades. UV resistance is poor.
Sustainability4
Producing a kilogram of CEM-1 takes about 95 MJ of energy and emits 5.5 kg of CO₂ — less than 72% of composite grades. Typical recycled content is 0%.
Manufacturability2
CEM-1's machinability is good (60/100, better than 73% of composite grades).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the composite family
Yield strength against density for every composite grade FabDigit runs. CEM-1 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with CEM-1
Is CEM-1 easy to machine?
Hot-punch (40–70 °C) for blanks and holes, or use carbide/diamond-coat drills and routers at high rpm with vacuum extraction — glass skins are abrasive and the paper core generates dust.
Can CEM-1 be welded?
Not weldable — thermoset laminate; join mechanically or with epoxy/acrylic adhesives.
Can CEM-1 be formed, bent or molded?
Supplied as fully cured flat sheet; no post-forming possible, only cutting, punching, scoring (V-cut) and drilling.
CEM-1 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| epoxy resin (FR, brominated)matrix, includes flame retardant | 32 – 45 | 38 |
| cellulose paper corebleached kraft/cotton-linter paper core plies | 25 – 40 | 32 |
| E-glass woven clothone ply each face (7628/2116 style) | 20 – 32 | 26 |
| bromine (as FR additive)omitted in halogen-free grade | 2 – 6 | 4 |
What surface finishes work on CEM-1?
Copper is etched then HASL/OSP/immersion-tin finished; seal cut edges with solder mask or conformal coating to keep moisture out of the paper core.
How much does CEM-1 cost?
CEM-1 is a premium-cost composite ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
CEM-1 — frequently asked
What is CEM-1 used for?
CEM-1 is typically used for single-sided PCB substrates, consumer electronics boards and low-cost mechanical/electrical panels. In short: cheapest single-sided PCB base; punchable paper-core laminate; below FR-4 in performance.
What is the tensile strength of CEM-1?
CEM-1 has a typical tensile strength of 145 MPa (21 ksi) — weaker than 58% of composite grades. Strength varies by condition: see the 3 listed tempers.
Is CEM-1 easy to machine?
Reasonably — machinability is rated good (60/100, better than 73% of composite grades). Hot-punch (40–70 °C) for blanks and holes, or use carbide/diamond-coat drills and routers at high rpm with vacuum extraction — glass skins are abrasive and the paper core generates dust.
Can CEM-1 be welded?
Not weldable — thermoset laminate; join mechanically or with epoxy/acrylic adhesives.
What surface finishes work on CEM-1?
Copper is etched then HASL/OSP/immersion-tin finished; seal cut edges with solder mask or conformal coating to keep moisture out of the paper core.
Can CEM-1 be formed, bent or molded?
Supplied as fully cured flat sheet; no post-forming possible, only cutting, punching, scoring (V-cut) and drilling.
What is the maximum service temperature of CEM-1?
CEM-1 is rated for continuous use to about 110°C (230 °F), and briefly to 260°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does CEM-1 cost?
CEM-1 is a premium-cost composite ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- NEMA LI 1 — Industrial Laminated Thermosetting Products — NEMA (1998)
- IPC-4101 — Specification for Base Materials for Rigid and Multilayer Printed Boards — IPC (2021)
- UL Yellow Card data for CEM-1 copper-clad laminates (ANSI/UL 94, RTI) — UL Solutions (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.