Thermal Solutions for Data Center & AI Servers

Industry trend

AI infrastructure has crossed several thermal thresholds in the last 24 months:

• NVIDIA next-generation AI GPUs exceed 700 W per card — H100 / H200 / GB200 all sit in this band, and roadmap parts climb further.
• Single-rack power densities reach 80–120 kW as accelerator-per-rack counts climb.
• Liquid cooling penetration is accelerating — direct cold-plate is mainstream for new hyperscale builds.
• HBM stack heat density is rising sharply with HBM3 / HBM3e and on-package memory architectures.
• AI training workloads run at sustained high load 24/7 — TIM materials must hold performance across 5–10 year operating lifetimes.

Thermal interface material has gone from a commodity selection to a core enabling component for AI infrastructure. Ziitek's data-center portfolio reflects that — it covers every interface in the AI server stack with materials qualified in production programs.

The AI server stack has at least 8 distinct TIM positions — die-level interfaces, memory gap-fill, power-delivery, cold-plate, optical module, PSU, SSD, and signal-integrity / EMI zones. Each needs different TIM physics.

The full AI thermal portfolio

1 — GPU / CPU die interface (the hardest position)

The interface between bare AI die and its lid / cold-plate is where thermal performance and mechanical fragility collide. The TIM here is the die's "fuse" — its first job is buffering mechanical stress to protect the fragile silicon, and only its second job is heat transfer. Ultra-low modulus matters more than ultra-high conductivity at this position.

Ziitek's answer for this position is TIG7835L liquid metal — 35 W/m·K thermal conductivity (close to pure metal), near-zero assembly stress, validated through 120 °C × 3,000 h aging. Customer measurements show GPU core temperature reductions of 10–15 °C versus their prior grease-based TIM at the same operating point.

For programs that prefer non-liquid-metal alternatives at this position, Ziitek also supplies TIG780-52 thermal grease (7.8 W/m·K, low pump-out) and TIC phase-change material (melts at 45 °C, 1.8–3.0 W/m·K).

2 — HBM, DDR5 and on-package memory

Memory adjacent to AI compute die runs hot but lives in a height-tolerance envelope. Pads here must compress reliably without crushing solder joints or fragile package edges.

• TIF700PES soft silicone pad (Shore OO 25–35, 0.25–2.0 mm range) — primary gap-fill for HBM stacks, DDR5 DIMMs and on-package memory.
• TIF700UU ultra-soft pad — for tight-tolerance optical or memory positions where 10 psi lower compression stress is needed at 70 % deflection.
• TIF series die-cut parts for HBM-specific outlines.

3 — VRM, vertical power delivery and on-board power stage

Vertical Power Delivery (VPD) modules at 160 W feed 0.8 V / 600 A+ AI ASICs. The TIM here has to handle ≤22 kgf compression tolerance windows and survive thermal cycling without delaminating.

• TIF700RES custom-shaped die-cut pad — pad for VPD module ↔ ASIC interface
• TIF700NUS UL94 V-0 silicone pad — for VRM gap-fill on PSU and main-board positions

4 — Liquid-cooled cold-plate stack

Direct liquid cooling introduces three new constraints: TIMs must (a) survive coolant proximity, (b) tolerate assembly torque on cold-plate retention hardware, and (c) survive rework cycles when cold-plate is removed for service.

• TIC phase-change material — the preferred TIM2 position for cold-plate-to-spreader; melts at first power cycle, holds shape afterward
• Two-part thermal gel — for dispensable cold-plate topologies with complex 3-D contours

These materials have been qualified in multi-program builds at Tier-1 server integrators across CPU, DIMM, M.2 and VR interfaces.

5 — Optical modules (800G / 1.6T)

AI cluster east-west bandwidth flows through 800G and next-generation 1.6T optical transceivers. Inside the module, the DSP / laser interface needs ultra-soft pads that conform without applying optical-alignment-disturbing stress.

• TIF700UU — gel-like ultra-soft pad for internal optical module TIM (10 psi lower stress at 70 % compression than competitor flagship)
• TIC800T-ST — PCM-metal composite for the external cold-plate interface in hot-swappable module bays
• EMI shielding pads + thermal absorbers — for module shielding and signal-integrity zones

6 — SSD and DRAM storage

AI server SSD and DRAM are throttling-sensitive. Pads here are usually thin (0.5–1.5 mm), need low thermal resistance, and must avoid contamination of adjacent connectors.

• TIF series soft pads — sized for M.2 / U.2 / EDSFF outlines
• TIC820G phase-change — for SSD controller positions where pad-bleed contamination has caused field failures

7 — AI server power supply (3,000–5,500 W)

AI server PSUs concentrate enormous heat in a compact frame. Ziitek's combined approach — TIF700NUS soft pad for heatsink gap-fill + TIG780-52 thermal grease at MOSFET die — has been qualified against Laird, Honeywell, and domestic incumbents in a 5,500 W NVIDIA-class PSU program. Both positions are production-locked.

8 — Auxiliary materials

• Silicone foam gasket (Z-Foam800 series) for vibration / sealing zones
• Thermal silicone adhesive for permanent component bonding
• PI heater (Kheat PI) for thermal validation rigs and tray-warming applications
• Silicone potting compound for transformer and inductor encapsulation in PSU and power-stage modules

Ziitek's differentiator — ILMU and custom R&D

Liquid metal at the die interface is the right physics — but only if the engineering challenges (leakage, corrosion, automated dispensing, long-term reliability) are solved. Ziitek's Integrated Liquid Metal Unit (ILMU) is the patented solution: liquid metal pre-loaded into a sealed, mechanically constrained unit that ships drop-in ready to the customer's assembly line.

ILMU keeps liquid metal contained, eliminates leakage and corrosion exposure, and works with automated assembly. It's the only credible path to deploying ultra-high-conductivity TIM at AI-server scale.

For new AI platforms, off-the-shelf TIM rarely fits. Ziitek operates a dedicated R&D team running a 4-stage custom development service:

1. Micro-scale heat-transfer simulation to predict performance before sampling
2. Micro-mechanical-stress simulation to validate the TIM stays below die-stress thresholds
3. Thermo-mechanical coupling to model long-term behaviour
4. Packaging DOE — flow studies and assembly experiments

Every custom development is paired with 120 °C × 3,000-hour aging validation before production release.

Recommended product matrix