Optimize Optical Communication Transceiver Packaging for Immersion Cooling

Overview of Technical Issues:

The sealing enclosure excessively blocks immersion cooling liquid from contacting heat-generating components, preventing the heat dissipating structure from effectively transferring thermal energy to the cooling medium and limiting thermal management performance; meanwhile, the optical coupling interface and electrical connecting terminals have insufficient protection against liquid penetration, risking signal quality degradation and electrical connection failure when exposed to cooling liquid; the goal is to redesign the packaging architecture to enable efficient immersion cooling while maintaining optical and electrical interface integrity.

Solution directions generated for this problem

Problem Direction 1 :

ImproveEnclosure thermal conductivity
VS
ConstraintInterface sealing structure complexity

Inspiration 1 : Cross-domain reference

Application Principle: #1 Segmentation
Cross-domain applicability Assess applicability
Heat sink, heat sink arrangement and module for liquid immersion cooling
Innovative Solution Refine solution

Zoned enclosure architecture with selective thermal apertures

Divide enclosure into independent thermal and interface zones
How to solve :
  • Partition enclosure into thermal dissipation zone (heat sources fully exposed to liquid) and interface protection zone (optical/electrical terminals isolated in sealed chamber)
  • thermal zone uses open-frame structure with ≥85% aperture ratio, eliminating thermal barriers while interface zone maintains single-layer O-ring seal (Viton, 2.5mm cross-section, AS568-015 standard)
  • install vertical partition wall (3mm polycarbonate, IP67-rated feedthrough connectors) separating zones, with heat sources mounted on liquid-side and connectors on dry-side
  • use dielectric coolant (3M Novec 7100, boiling point 61°C) in thermal zone only, enabling direct component immersion without electrical risk
Expected Effect : Thermal resistance reduced 60-70%; sealing limited to 4 connector points vs 20+ in conventional design; interface complexity reduced 75%
Risk Control :
  • partition wall feedthrough leakage over thermal cycles
  • differential pressure between zones causing seal deformation
  • coolant vapor migration to dry zone

Problem Direction 2 :

ImproveInterface liquid penetration resistance
VS
ConstraintOptical signal transmission quality

Inspiration 1 : Cross-domain reference

Application Principle: #24 Intermediary
Cross-domain applicability Assess applicability
Notification of receiver capabilities
Innovative Solution Refine solution

Index-matched hydrophobic gel intermediary for optical coupling protection

Use refractive-index-matched gel as intermediary layer
How to solve :
  • Fill optical coupling interface with refractive-index-matched transparent gel (n=1.46±0.01, matching fiber core) that blocks liquid while eliminating refraction boundaries
  • Apply fluorinated hydrophobic gel (contact angle ≥110°, dielectric strength ≥15 kV/mm) via precision dispensing at 0.05±0.01 mL volume, cured at 80°C for 30 min
  • Implement dual-layer protection: inner gel layer (0.3–0.5 mm) for optical continuity, outer hydrophobic coating (50–100 μm PTFE-based) for liquid repulsion, ensuring <0.2 dB insertion loss
Expected Effect : Signal loss <0.2 dB; liquid penetration resistance >1 MPa; optical return loss <−50 dB
Risk Control :
  • gel refractive index drift over temperature cycles
  • dispensing volume inconsistency causing air bubbles
  • long-term gel degradation under immersion

Problem Direction 3 :

ImproveCooling liquid contact area with heat sources
VS
ConstraintInterface sealing structure complexity

Inspiration 1 : Cross-domain reference

Application Principle: #1 Segmentation
Cross-domain applicability Assess applicability
Thermal ground plane
Innovative Solution Refine solution

Modular thermal-interface dual-zone immersion packaging architecture

Partition device into independent thermal and interface zones
How to solve :
  • Divide packaging into open thermal zone (heat-generating components fully exposed to dielectric fluid) and sealed interface module (optical/electrical terminals in separate waterproof capsule with single O-ring seal)
  • Implement thermally conductive partition wall (aluminum alloy ≥200 W/(m·K), thickness 0.8–1.2mm) between zones, with precision-machined feedthrough ports (tolerance ±0.05mm) for signal transmission
  • Deploy pre-integrated interface cartridge containing all optical couplers and electrical connectors, factory-sealed and tested to IP68 standard before installation, eliminating field sealing operations
Expected Effect : Contact area +85%, sealing points reduced from 12–15 to single cartridge seal, thermal resistance <0.15 K/W
Risk Control :
  • partition wall thermal expansion mismatch
  • feedthrough port machining precision deviation
  • cartridge seal aging under thermal cycling

Problem Direction 4 :

ImproveInterface liquid penetration resistance
VS
ConstraintMust not deteriorate

Inspiration 1 : Cross-domain reference

Application Principle: #1 Segmentation
Cross-domain applicability Assess applicability
Insert molding around glass members for portable electronic devices
Innovative Solution Refine solution

Zoned enclosure with peripheral seal and open thermal cavity

Divide enclosure into thermal cavity and interface zone
How to solve :
  • Partition the device into a central thermal cavity (fully open to immersion liquid, no barriers) and a peripheral interface zone (sealed compartment housing optical couplers and electrical terminals)
  • heat-generating components reside in the open cavity for maximum liquid contact, while interfaces remain isolated in the dry peripheral zone
  • Use radial O-ring seals (fluoroelastomer, Shore A 70–80) at the boundary between zones, positioned perpendicular to optical/electrical paths to avoid signal obstruction
  • optical fibers and electrical cables pass through sealed feed-through connectors (IP68-rated, compression gland design) with axial clearance ≥0.5mm to prevent optical path interference
  • Implement pressure equalization vents with hydrophobic membranes (pore size 0.2μm, ePTFE) in the interface zone to prevent condensation while blocking liquid ingress
  • thermal cavity features direct liquid contact area ≥85% of component surface, thermal resistance <0.05 K/W
Expected Effect : Liquid contact area +80%, optical signal loss <0.3dB, interface leak rate <10⁻⁶ mbar·L/s
Risk Control :
  • seal compression tolerance deviation ±0.1mm
  • feed-through alignment precision insufficient
  • pressure differential causing seal deformation
Patsnap Eureka Solution