Why AlN is Becoming Standard in 800G–1.6T Optical Modules and TECs

In the 800G generation, aluminum nitride ceramics have already become the mainstream aluminum nitride heat sink solution for high-power laser devices — EML and CW laser submounts, hermetic package housings, and high-reliability optical engines.

As the industry moves to 1.6T and CPO architectures, thermal flux at the optical engine and EML driver continues to climb. High-speed signal layers have largely shifted to ceramic-filled PTFE and advanced low-loss laminates (including modified epoxy systems such as Megtron-class materials), while AlN takes its position where it performs best: the package housing, heat-spreading base, and insulating support structure.

The two materials work in complementary layers — signal integrity above, thermal management below. Beyond package-level parts, aluminum nitride powder is also increasingly adopted as a thermal conductive filler in high-performance thermal interface materials (TIMs), closing the gap between the device and the heat sink.

The same shift is happening in thermoelectric cooling. Every aluminum nitride substrate used in a TEC must withstand repeated thermal cycling across the hot/cold junction while managing the mechanical stress of the thermoelectric couple. CTE mismatch is the primary failure driver — cracked substrates and degraded solder joints. With a CTE of ~4.5 ppm/°C and thermal conductivity of 170–230 W/(m·K), AlN matches Si/InP chips and solder systems far better than alumina (~7.2 ppm/°C, 20–35 W/(m·K)), making it the preferred substrate for high-power-density TECs in 800G/1.6T modules.

On the supply side, industry estimates suggest the optical-module ceramic component market is on track to roughly double by 2027, driven primarily by 1.6T ramp and CPO adoption. Every piece of that high-end growth — TEC substrates, laser submounts, hermetic housings — depends on two things upstream: high-purity, low-oxygen aluminum nitride powder and a stable, mature metallization process (DPC, thin-film, HTCC).

What this means for our customers: with Japanese aluminum nitride suppliers running at capacity limits and buyers actively qualifying second sources, supply security matters as much as material performance.

Xiamen Juci manufactures High Purity AlN Powder ,  AlN Granule,  Thermal Conductive Filler and AlN Ceramics . Please contact us if you have any requirements.

Contact: Jenny Qin / 진현혜 

Phone: +86 151-5177-8700

Wechat ID: JENNY-8866

Xiamen Juci Technology Co., Ltd.

Email: qinxianhui@chinajuci.com

Website: www.jucialnglobal.com