Ceramic Packages

Copper-Bonded Silicon Nitride Packages for Power Modules

Kyocera provides power module packages using layered silicon nitride ceramic substrates and copper plates. The silicon nitride substrates, which have higher strength, higher toughness and higher thermal conductivity than alumina ceramics, are used as insulators. High reliability is realized by using the active metal bonding (AMB) method to bond the copper plates to the silicon nitride substrates. These are used as hermetic packages for power modules.

Copper-Bonded Silicon Nitride Packages
(Outer Dimension: 73.9mm x 62.45mm)

(Figure 1)
Cross Section: 0.9mm-Diameter Buried Copper Via

(Figure 2) Cross Section:
Multilayer Structure of Copper-Bonded Silicon Nitride Packages

Features

  • High reliability: Hermeticity confirmed after 1000 cycles of -65°C to +150°C temperature cycling test (sample: five pieces; Kyocera test results)
  • 0.15 to 0.3mm-thick copper (volume resistivity: 1.7μΩ·cm; thermal conductivity: 394W/mK)
  • Silicon nitride ceramic substrates
    SN460: flexural strength: 850MPa; fracture toughness: 5.0MPam1/2; thermal conductivity: 58W/mK
    SN490: flexural strength: 820MPa; fracture toughness: 6.3MPam1/2; thermal conductivity: 85W/mK
  • Multilayer structure: Copper plates and silicon nitride ceramic substrates are bonded by active metal bonding (AMB) method (Figure 2)
  • Three-dimensional multilayer wiring structure: Upper layer circuits and lower layer circuits are connected by buried copper vias (Figure 1)
    Low inductance can be made by multilayer structure
  • Size and weight reduction
  • Screw clamping possible

Example of Replacing Conventional Technology

Top of page