Expanding the Future of Silicon

Silicon plays a critical role in today’s electronic industry with its primary use in the IC and Solar industry. In last half century Silicon has revolutionized the technology industry, first by replacing vacuum tubes with solid-state transistors and then integrated circuits, whose size, complexity and performance has improved exponentially. However, modern thermal management of compact electronic or photonic devices still relies mainly on metal heat-sinks, heat-spreaders or ceramics to remove waste heat. Metal or ceramic heat-sinks or heat-spreaders can provide adequate performance given significant space and weight allowances. However, Silicon, as a bulk material, can provide improved performance and add value in solving modern thermal management issues.

As the Silicon transistor replaced the vacuum tube after the invention of the transistor in 1947, metal heat-sinks will be replaced by superior materials in the near future due to better thermal performance, mass-production, compact size and light weight. Silicon is one such material and will cause a paradigm-shift in modern thermal management.

Silicon Facts

Category Value
Density 2.3290 g/cm3
Melting temperature >1414 °C
Molar heat capacity 19.8 Joule/(mol*K)
Thermal conductivity 149 W/(m*K)
Thermal expansion 2.6 μm/(m*K) at 25 °C
Young's modulus 130 to 188 GPa
Shear modulus 51 to 80 GPa
Mohs hardness 7

Silicon Comparison to Common Thermal Management Materials

Silicon (crystal) Aluminum (pure) Copper (pure) Alumina (ceramic) AlN (ceramic)
Density [g/cm3] 2.33 2.70 8.96 3.8 (white) 3.25
Thermal conductivity [W/(m*K)] 149 237 401 ~ 35 83 to 170
Thermal expansion [mm/9m*K] 2.6 23.1 16.5 8.4 4.6 to 5.7
Mohs hardness 7 2.75 3.0 9 5
Surface finish [μm] <0.1 >2 >2 >10 >1
Bulk production Wet etching Forging, stamping Forging, stamping Stamping Stamping

Silicon Thermal Package Advantages

3-D Silicon Structure

High heat density components can dissipate heat into a heat-spreader (conduction transfer) and heat-sink (convection transfer) into the surrounding air. Typically, a metal heat-sink has a metal base to conduct heat and dissipate the heat into the surrounding environment.

Up to now, Silicon has seen limited work as a heat-spreader in many applications in electronic and optical industry. However, Eotron focused on developing 3D silicon structures to enhance thermal management of high thermal flux devices that are 1mm2 to a few cm2 in size. The 3D construction of our silicon structures utilize Eotron’s patented V-grooved interlock technology to scale to any footprint (allowed by silicon wafer size) up to a few centimeters in height.