X7R
X7R is a BaTiO₃-based ferroelectric Class II dielectric that holds capacitance within ±15% from −55 to +125 °C, making it the most common general-purpose MLCC dielectric.
Reference datasheet — X7R 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 BME condition
X7R tempers and conditions
X7R is supplied in 4 conditions, soft to hard. BME is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Precious-metal (Ag/Pd) electrode formulation, air-fired | Choose for legacy/high-reliability air-fired MLCCs, thick-film hybrids and disc capacitors where Ni co-firing is not available. | 50 | 0 | 580 HV | 3 W/m·K | |
BMEDefault Base-metal (Ni) electrode formulation, reducing-atmosphere fired | Standard modern MLCC dielectric: rare-earth/Mg/Mn core-shell BaTiO3 co-fired with Ni electrodes in low-pO2 atmosphere; lowest cost per µF. | 55 | 0 | 620 HV | 3 W/m·K | |
High-voltage / thick-layer X7R formulation | Lower-K, coarser or heavily shell-doped composition for 500 V–3 kV MLCCs and ceramic discs, giving higher breakdown field and flatter DC-bias behaviour. | 58 | 0 | 640 HV | 3 W/m·K | |
sub-micron fine-grain core-shell X7R | For high-capacitance small-case MLCCs with <1 µm dielectric layers; fine hydrothermal BaTiO3 powder, higher breakdown field but reduced K due to size effect. | 62 | 0 | 680 HV | 3 W/m·K |
What is X7R?
X7R is a BaTiO₃-based ferroelectric Class II dielectric that holds capacitance within ±15% from −55 to +125 °C, making it the most common general-purpose MLCC dielectric. Engineers use it for decoupling and filtering where moderate stability is acceptable; forms include multilayer chips with base-metal (Ni/Cu) or precious-metal (Ag/Pd) electrodes, high-voltage chips and ultra-thin-layer constructions. Density is about 5.7 g/cm³ and maximum service temperature 125 °C. As a ferroelectric it loses capacitance under DC bias and with ageing, and chips are sensitive to board flex; choose C0G/NP0 when stability is critical. X7R has a density of 5.7 g/cm³ (0.206 lb/in³), heavier than 58% of ceramic grades. It melts at 1,618°C (2,944 °F). X7R has a tensile strength of 55 MPa (7.98 ksi), weaker than 65% of ceramic grades. Elongation at break is 0% and the elastic modulus is 115 GPa (16.7 Msi).
What is X7R used for?
- MLCC capacitors
- decoupling capacitors
- general filtering
Limitations
- Limited service temperature — 125°C (257 °F), worse than 94% of ceramic grades
- Low fracture toughness — 1 MPa·√m (0.91 ksi·√in), worse than 84% of ceramic grades
- Poor heat conductor — 3 W/m·K (1.73 BTU/hr·ft·°F), worse than 77% of ceramic grades
X7R properties
Typical room-temperature values for X7R-BME; bars are the position among ceramic grades.
Physical3
X7R has a density of 5.7 g/cm³ (0.206 lb/in³), heavier than 58% of ceramic grades. It melts at 1,618°C (2,944 °F).
Mechanical12
X7R has a tensile strength of 55 MPa (7.98 ksi), weaker than 65% of ceramic grades. Elongation at break is 0% and the elastic modulus is 115 GPa (16.7 Msi).
Thermal5
X7R is rated for continuous service to 125°C (257 °F). It conducts heat at 3 W/m·K (1.73 BTU/hr·ft·°F), worse than 77% of ceramic grades. Thermal expansion is 10 µm/m·K (5.56 µin/in·°F).
Electrical5
X7R is an electrical insulator with a dielectric strength of 30 kV/mm (762 V/mil) and a resistivity of 1×10¹⁰ Ω·m.
Chemical & Environmental2
Corrosion resistance is very good (75/100), better than 50% of ceramic grades.
Sustainability4
Producing a kilogram of X7R takes about 90 MJ of energy and emits 7.5 kg of CO₂ — less than 62% of ceramic grades. Typical recycled content is 0%.
Manufacturability3
X7R's machinability is not recommended (5/100, worse than 59% of ceramic 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 ceramic family
Yield strength against density for every ceramic grade FabDigit runs. X7R is highlighted; hover a dot for its name, or open the interactive family chart.
Working with X7R
Is X7R easy to machine?
Fired bodies require diamond grinding/dicing; all real shaping is done on green tape (doctor-bladed, punched, laser-cut, screen-printed with Ni or Ag/Pd electrode ink).
Can X7R be welded?
Not weldable — joining is by soldering/brazing of the fired-on Cu/Ni/Sn terminations or by glass/epoxy bonding.
Can X7R be formed, bent or molded?
Tape casting plus stacking, isostatic lamination, dicing, binder burnout and co-firing at ~1150–1350 °C (low pO2 for BME), followed by re-oxidation anneal.
X7R 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 |
|---|---|---|
| Dy2O3/Ho2O3/Y2O3 (rare-earth shell formeflattens Curie peak, improves insulation-resistance lifetime | 0.5 – 3 | 1.5 |
| MgOacceptor, suppresses reduction of Ti4+ | 0.3 – 2 | 1 |
| MnO/Mn3O4acceptor / oxygen-vacancy trap for BME firing | 0.05 – 0.5 | 0.2 |
| SiO2 + BaO/CaO glass sintering aid | 0.5 – 3 | 1.5 |
| CaZrO3 / ZrO2 / Nb2O5 (shifters)TCC shaping additives, formulation dependent | 0 – 3 | 1 |
| BaTiO3core-shell base, Ba/Ti ratio ~1.000–1.005 | ≥ 88 (balance) |
What surface finishes work on X7R?
Barrel-polish or tumble the fired chips, then terminate with Cu/Ag paste plus Ni/Sn barrier plating; avoid mechanical or thermal shock that causes flex cracks.
How much does X7R cost?
X7R is a high-cost ceramic ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
X7R — frequently asked
What is X7R used for?
X7R is typically used for MLCC capacitors, decoupling capacitors and general filtering. In short: default general-purpose MLCC; ±15% to 125 °C; bias- and age-sensitive capacitance.
What is the tensile strength of X7R?
X7R has a typical tensile strength of 55 MPa (7.98 ksi) — weaker than 65% of ceramic grades. Strength varies by condition: see the 4 listed tempers.
Is X7R easy to machine?
Not especially — machinability is rated not recommended (5/100, worse than 59% of ceramic grades). Fired bodies require diamond grinding/dicing; all real shaping is done on green tape (doctor-bladed, punched, laser-cut, screen-printed with Ni or Ag/Pd electrode ink).
Can X7R be welded?
Not weldable — joining is by soldering/brazing of the fired-on Cu/Ni/Sn terminations or by glass/epoxy bonding.
What surface finishes work on X7R?
Barrel-polish or tumble the fired chips, then terminate with Cu/Ag paste plus Ni/Sn barrier plating; avoid mechanical or thermal shock that causes flex cracks.
Can X7R be formed, bent or molded?
Tape casting plus stacking, isostatic lamination, dicing, binder burnout and co-firing at ~1150–1350 °C (low pO2 for BME), followed by re-oxidation anneal.
What is the maximum service temperature of X7R?
X7R is rated for continuous use to about 125°C (257 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does X7R cost?
X7R is a high-cost ceramic ($$$$), pricier than about 78% 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
- EIA RS-198 / IEC 60384-21 Class II ceramic dielectric temperature characteristics — EIA / IEC (2019)
- ASM Engineered Materials Handbook Vol.4 — Ceramics and Glasses (BaTiO3 dielectrics) — ASM International (1991)
- Moulson & Herbert, Electroceramics: Materials, Properties, Applications — Wiley (2003)
- MLCC X7R dielectric characteristics and dielectric powder datasheets — Murata / KEMET / Sakai Chemical / (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.