Custom Optical Communication Module AlN Substrate with Fine Metallization

Optical Communication Module AlN Substrate Applications

• Data Centre and AI Server Optical Transceivers

  ✅Key Advantages

  1. Junction Temperature Control in 400G/800G Modules
  The optical communication module AlN substrate can reduce laser diode junction temperature by several degrees compared with alumina submounts at the same output power, supporting higher lane speeds and power budgets.
  2. Support for High Port Density Pluggables
  AlN substrates allow thin, compact submount designs so that dense front-panel QSFP and OSFP modules can maintain thermal performance without oversized heat sinks.
  3. Stable Performance under Continuous Operation
  With appropriate thermal design, modules using the optical communication module AlN substrate can run continuously at high traffic load with controlled temperature drift over long service periods.

  ✅ Problem Solved

  A data centre operator deploying hundreds of 400G and 800G ports can experience several watts of heat per module. When alumina-based submounts are used, internal junction temperatures may run 5–10 °C higher at full load, reducing laser lifetime and increasing field failure rates. By redesigning the optical engine around an optical communication module AlN substrate, the module vendor can lower junction temperatures, keep module case temperatures within the thermal budget and maintain the required bit error rate at high ambient conditions. This supports higher rack density and reduces replacement events over a typical three-to-five-year deployment cycle.

• Telecom Backbone and Metro Optical Communication Equipment

  ✅Key Advantages

  1. CTE-Matched Substrate for Long-Term Stability
  The optical communication module AlN substrate provides a CTE close to silicon and GaAs, which helps maintain stable die attach in systems that experience repeated daily and seasonal temperature swings.
  2. Suitability for Long-Reach and Coherent Modules
  For long-haul or coherent optical communication modules, the thermal behaviour of the AlN substrate contributes to stable optical performance and phase control.
  3. Improved Reliability Under Field Conditions
  Modules using AlN submounts can maintain low failure rates over many years of continuous service, supporting telecom carrier reliability expectations.

  ✅ Problem Solved

  Backbone and metro networks often operate equipment in environments with broader temperature ranges and limited cooling redundancy. When submount materials are not well matched to the optical chips, thermal cycling can cause solder fatigue and packaging drift, which may show up as gradual optical power degradation or intermittent link errors. With an optical communication module AlN substrate, the mechanical and thermal matching between the substrate and the laser or SiPh chips is improved, which helps preserve alignment and maintain optical performance over extensive temperature cycling and long service times.

• Silicon Photonics and Coherent Optical Communication Modules

  ✅Key Advantages

  1. Thermally Efficient Base for SiPh Engines
  The optical communication module AlN substrate can serve as a high thermal conductivity base under SiPh chips and driver ICs, supporting power-hungry coherent engines and integrated modulators.
  2. Fine Metallization for Dense Integration
  Fine-line and dense metallization on AlN supports complex routing and ground structures around SiPh chips and analogue front-ends.
  3. Support for Compact and Stacked Structures
  Thin but strong AlN substrates allow vertical stacking and compact module layouts in advanced SiPh-based optical communication systems.

  ✅ Problem Solved

  Silicon photonics engines and coherent transceivers bring high integration of optical and electronic functions on a compact footprint, which increases power density significantly. Without a suitable submount, localized hot spots and thermal gradients can affect phase modulators, drivers and receivers. By incorporating an optical communication module AlN substrate under the SiPh engine, the designer gains an additional thermal path and stable mechanical support. This helps manage local temperature, improve phase stability and keep system-level performance within specification under various load conditions.

Usage Guide – Optical Communication Module AlN Substrate

• Installation

  1. Inspect each optical communication module AlN substrate visually before use to ensure there are no chips, cracks or contamination on critical surfaces.
  2. Handle the AlN substrate with gloves or tweezers, holding by the edges and avoiding direct contact with metal pads and die attach areas.
  3. Verify flatness and thickness against the drawing when setting up pick-and-place and die bonding programs to minimize stress.

• Use in Assembly and Operation

  1. Follow the recommended reflow or die attach profile for the chosen metallization and solder system so that thermal stress on the AlN substrate remains within the process window.
  2. Ensure that clamping, fixturing and transport trays do not apply point loads on thin regions of the substrate.
  3. When used in optical communication modules, confirm that the thermal interface between the AlN substrate, baseplate and external heat sink is properly filled and tightened.

• Storage

  1. Store optical communication module AlN substrates in their original trays and inner bags in a dry, clean environment.
  2. Keep unused trays sealed until they enter the assembly line to avoid dust and moisture uptake.
  3. Avoid stacking heavy items on top of AlN substrate cartons during warehouse storage.

• Cleaning

  1. If cleaning is required, use compatible solvents or deionized water with gentle agitation, and avoid aggressive mechanical scrubbing on metalized areas.
  2. Dry AlN substrates thoroughly before assembly, for example by using a low-temperature bake step within the specified temperature range.
  3. Do not expose the substrates to repeated high-temperature bake cycles beyond the process specification, as this may affect metallization or solder preforms.

• Typical Misuse and How to Avoid It

  1. Excessive Mechanical Force on Thin Substrates
  Overly tight clamping or bending in fixtures can create micro-cracks. Use flat, well-supported fixtures and verify clamping forces during process setup.

  2. Incorrect Reflow or Die Attach Profiles
  Too rapid heating or cooling may introduce thermal shock. Use controlled ramp rates and soak zones appropriate for AlN and the solder system.

  3. Contamination of Pad and Die Attach Areas
  Fingerprints, dust or adhesive residue can reduce wetting and bond strength. Handle substrates only at the edges, maintain cleanroom conditions and verify cleanliness before assembly.

Optical Communication Module Aluminum Nitride Ceramic Substrate FAQ

1. Q: Why choose an AlN substrate instead of alumina for optical communication modules?
   A: Optical communication module AlN substrates offer significantly higher thermal conductivity and a CTE closer to silicon, which helps reduce junction temperature and improve long-term reliability in high-speed transceivers.
2. Q: Which module formats can use the optical communication module AlN substrate?
   A: The substrate can be designed for SFP, QSFP, OSFP and other pluggable optical communication modules, as well as for TOSA/ROSA, BOSA, AOC/ACC and silicon photonics engines.
3. Q: What tolerances can you achieve on optical communication module AlN substrates?
   A: Depending on size and geometry, outer dimensions and thickness of the optical communication module AlN substrate can typically be controlled in the ±0.02–0.05 mm range, with tighter tolerances reviewed case by case.
4. Q: Can the optical communication module AlN substrate include fine metallization for high-speed signals?
   A: Yes, the AlN substrate can incorporate fine-line metallization, vias and ground structures to support high-speed differential pairs and RF paths inside optical communication modules.
5. Q: Is the optical communication module AlN substrate suitable for silicon photonics packaging?
   A: The combination of high thermal conductivity and CTE compatibility makes AlN substrates suitable as bases or intermediate layers in silicon photonics optical communication modules.
6. Q: How do you qualify a new optical communication module AlN substrate design?
   A: A typical approach is to start with sample substrates for assembly trials, followed by thermal cycling, power aging and optical performance tests on the module level before moving to volume orders.

Optical Communication Module AlN Substrates Reviews

• ⭐️⭐️⭐️⭐️⭐️
  We used the optical communication module AlN substrate from ADCERAX in a 400G QSFP project. The thermal margin improved and we were able to keep junction temperature under control without changing the heat sink design.
  -- Mark Jensen, Optical Module Design Engineer, NorthWave Networks
• ⭐️⭐️⭐️⭐️⭐️
  ADCERAX supplied optical communication module AlN substrates according to our drawings with consistent tolerances. Pricing was reasonable for a customized ceramic part and the dimensional stability supported our automated assembly line.
  -- Laura Chen, Procurement Manager, PhotonLink Communications
• ⭐️⭐️⭐️⭐️⭐️
  The customized AlN submount for our silicon photonics module allowed dense routing and stable die attach. The optical communication module AlN substrate helped us maintain performance across extended temperature testing.
  -- Hiroshi Tanaka, Packaging Engineer, NeoPhotonics Devices
• ⭐️⭐️⭐️⭐️⭐️
  We introduced an AlN-based submount into a coherent optical communication module and saw clear benefits in thermal management. The substrate design flexibility and clean metallization were important for our packaging layout.
  -- David Müller, Head of R&D, MetroOptic Systems