X7R BME
Grade · default condition
BME = 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.
Values for the BME condition
Other X7R tempers and conditions
X7R is listed in 4 conditions; see the grade overview at X7R.
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 |
BMEDefaultThis page 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 BME?
X7R BME is X7R in the BME grade — standard modern MLCC dielectric: rare-earth/Mg/Mn core-shell BaTiO3 co-fired with Ni electrodes in low-pO2 atmosphere; lowest cost per µF. X7R BME 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). X7R BME 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).
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 BME properties
Typical room-temperature values for X7R BME; 19 are specific to this condition. Other listed values are X7R reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical3
X7R BME 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 BME 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 BME 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 BME 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 BME 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 BME's machinability is not recommended (5/100, worse than 59% of ceramic grades).
Common Calculations4
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with X7R BME
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.
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.
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) | — |
X7R BME — frequently asked
What is X7R BME used for?
X7R BME 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 BME?
X7R BME 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 BME 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 BME 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 BME?
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 BME 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 BME?
X7R BME 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.