1. Start with the thermal and electrical design
Aluminum nitride (AlN) is often screened for high thermal conductivity plus electrical insulation. Silicon nitride (Si3N4) is often screened where mechanical durability and thermal cycling are important. Neither is universally better: evaluate the complete module stack rather than a single material property.
- Describe heat flow from the device through the metal, ceramic, attach layer, interface and cooler.
- Specify insulation voltage, creepage constraints and the acceptable module thermal resistance.
- Distinguish bare ceramic material properties from the assembled substrate's measured performance.
- Ask for grade-specific thermal conductivity and the measurement conditions instead of assuming a universal value.
2. Evaluate reliability and copper attachment
Substrate cracking and metal/ceramic interface failures can depend on copper thickness, pattern, joining technology and operating temperature cycles. DBC, AMB and DPC are processing routes or product stacks, not interchangeable names for bare AlN or Si3N4 plates.
- Identify whether the request is for bare ceramic, a copper-clad substrate or a finished patterned assembly.
- Specify copper thickness on each side, pattern dimensions, edge clearances, surface finish and bonding method.
- Provide temperature-cycling range, cycle count, power-cycling duty and the intended acceptance criteria.
- Review minimum ceramic thickness, chip attach and mismatch between materials before selecting the stack.
3. Use a decision matrix rather than a single winning material
When minimizing heat-flow resistance dominates, an appropriate AlN grade may be attractive. For mechanically demanding or repeatedly cycled power modules, Si3N4 may deserve greater attention. The trade-off can change with ceramic thickness and copper design.
- Compare thermal conductivity, flexural properties and fracture resistance using identified grades and test methods.
- Calculate the full thermal path, not just bulk ceramic conductivity.
- Request warpage, flatness, dielectric testing and cross-section or bonding acceptance criteria where relevant.
- Assess cost, yield, lead time and sample qualification alongside performance.
4. Send a complete substrate RFQ
A useful quote separates material, dimensions, metallization, testing and commercial assumptions. Include the expected prototype quantity and planned production demand as separate figures.
- Provide Gerber files or controlled drawings, substrate outline and thickness.
- List ceramic grade, copper stack, pattern, plating, holes, surface finish and panelization needs.
- State insulation and thermal-cycling test standards or project-specific protocols if required.
- Clarify whether the requested product is bare AlN, bare Si3N4, AMB, DBC or DPC; request engineering review when undecided.
Related products and application support
Use these product pages to review available configurations or send your drawing and operating conditions for a quotation.