Abstract
NVIDIA GB200 Grace Blackwell Superchip reaches a total thermal load of 2700W. The integrated microchannel cold plate is the core liquid cooling component for high-density AI computing racks. KENFA is a professional manufacturer for GB200 form-fit compatible cold plates. We cover full in-house workflow: thermal simulation, structural design, copper microchannel machining, vacuum brazing, pressure cycling test, leak inspection and mass shipment. This article introduces GB200 cold plate specifications, KENFA manufacturing workflow, test standards, and the key difference between GB200 and GB300 cold plates.
1. GB200 Cold Plate Core Specifications
GB200 uses one monolithic cold plate covering two Blackwell GPUs plus one Grace CPU, with a single inlet & single outlet loop and UQD04 quick connectors.
- Total thermal load: 2×1200W GPU + 300W Grace CPU, 2700W total
- Main process: Copper microchannel + vacuum brazing / TLP bonding
- Critical validation items: Microchannel uniformity, stable pressure drop, zero leakage after thousands of pressure cycles, dielectric withstand test and flatness control.
Important note: GB300 switches to discrete dedicated cold plates. Each chip has its own cold plate with separate flow path and upgraded NVUQD03 connectors. GB200 and GB300 cold plates are NOT interchangeable.
2. KENFA Capabilities as GB200 Cold Plate Manufacturer
With years of experience in high-power liquid cooling hardware, KENFA develops and fabricates GB200 compatible cold plates for ODM builders and private AI cluster integrators.
- Thermal & CFD simulation Our engineers run Icepak thermal and flow simulation before production, optimising manifold and microchannel layout to balance temperature uniformity and pressure drop, and deliver simulation reports for customer review.
- In-house copper microchannel & vacuum brazing line We perform microchannel milling, brazing assembly and precision CNC machining internally. Strict process control avoids blocked channels and poor bonding which would cause HBM overheating. The sealing surface flatness and roughness are tightly controlled for reliable UQD connection.
- Complete reliability lab test Every cold plate goes through hydrostatic leak test. Batch orders include sampling pressure cycle test, pressure drop inspection, Hi-pot test and salt spray corrosion test, with formal test reports supplied.
- Flexible production schedule We support prototype sampling, low-volume trial runs and mass production. We can also deliver full cooling assemblies including quick connectors and tubing kits for easy rack integration.
Disclaimer: KENFA cold plates are form-fit compatible versions for customer self-validated AI projects, not NVIDIA AVL certified parts. Official HGX platforms require components from NVIDIA approved vendor list.
3. Advantages of KENFA GB200 Cold Plate
- Matches GB200 footprint, chip contact profile and mounting hole layout
- Microchannel design targets equivalent thermal performance and pressure drop
- Optional surface passivation or gold plating for different coolant media
- NDA protected custom development for confidential projects
- Shorter lead time and competitive cost vs AVL suppliers for custom cluster projects
4. GB200 vs GB300 Cold Plate
GB200: Monolithic single cold plate, UQD04 connector, single loop. GB300: Discrete cold plate per chip, independent flow path, NVUQD03 connector. KENFA also supports custom development for GB300 discrete cold plates.
5. Kenfa’S GB200 Cold Plate
The cold plate is made of T2 copper, fabricated by nitrogen-protected brazing and laser welding. It is fitted with barbed fittings and finished with black baking paint. Cold plates are connected by stainless steel corrugated hoses.
- T2 copper cold plate with high thermal conductivity
- High reliability from nitrogen-protected brazing and laser welding processes
- Black baking paint finish for good appearance and corrosion resistance
Overall Tightness Test
Inspection Frequency: 100% inspection Inspection Item: Complete cold plate assembly Test Description: Connect the quick connectors on both ends of the cold plate assembly to test equipment. Submerge the whole cold plate assembly in pure water. Feed filtered compressed air and pressurize to 0.6 MPa. Once the pressure is stable, shut off the air inlet valve and hold the pressure for 1 minute. Check all joints and pipe connection interfaces. The product passes if no bubbles or bulges are observed.
Overall Cleanliness Test
Inspection Frequency: 100% inspection Inspection Item: Complete cold plate assembly Test Description: Connect the connectors at both ends of the cold plate to the pipeline.
Overall Pressure Drop Test
Inspection Object: Complete cold plate assembly Test Description: Calibrate the system pressure drop before test, connect the fittings at both ends of the cold plate assembly to the pipeline.Additional Note: The male quick connector and adapter are connected during testing, which will add extra pressure drop from these components.
Overall Dryness Test
Inspection Frequency: 100% inspection Inspection Object: Complete cold plate assembly Test Description: Connect the cold plate assembly to test equipment. Feed 70°C hot gas continuously through the cold plate for 60 seconds. It is qualified if the gas humidity detected at the outlet ≤10%.
Overall Helium Leak Test
Inspection Frequency: 100% inspection Inspection Object: Complete cold plate assembly Test Description: Connect the quick connectors on both ends of the cold plate to test equipment. Inject helium and pressurize to 0.6 MPa. After pressure stabilizes, close the inlet valve. The part passes if the leak rate is less than 5E-6 Pa·m³/s. Additional Note: The male quick connector and adapter are connected during testing, which will increase the measured leakage.
Overall Pressure Holding Test
Inspection Frequency: 100% inspection Inspection Object: Complete cold plate assembly Test Description: Connect the quick connectors on both ends of the cold plate to test equipment. Inject nitrogen and pressurize to 400 kPa, hold pressure for 24 hours. It is qualified if pressure loss is less than 10 kPa.
Therefore, backed by Kenfa’s solid R&D and manufacturing capacity, we customize cold plates for GB200 and GB300 chips to meet customer requirements. Our advanced microchannel process enables fin thickness and pitch down to 0.05 mm, maximizing heat exchange area within limited space for high-power-density chips.
We offer two proven welding processes: tunnel furnace brazing and vacuum brazing, available for both sampling and mass production. Both deliver stable welding quality and reliable airtightness to prevent leakage and deformation for long-term service.
We support drawing review, thermal and flow simulation, and sample testing. Our cold plates pass full tests including helium leak, pressure holding and cleanliness inspection, to provide qualified liquid cooling solutions for your computing hardware.Naturally, from the material perspective, diamond copper delivers outstanding thermal conductivity. However, when selecting the optimal thermal conductive material, we need to balance cost performance and reliability.
FAQ
Q: Can KENFA make GB200 cold plate samples?
A: Yes. We start development once we receive your drawing or boundary specs, and deliver samples with full test documentation. We have standard GB200 cold plate products available for customers to purchase. Our stock quantity is normally below 50 pcs. Advance booking is accepted.
Q: Can KENFA cold plates be fitted into official NVIDIA HGX systems?
A: No. Our compatible cold plates are designed for customer self-qualified private clusters and custom servers. Official HGX requires AVL certified hardware.
Q: Is leak test mandatory?
A: Every unit is pressure tested for leakage. Pressure cycle fatigue test is available for batch orders.
Conclusion
AVL vendors such as AVC and Auras mainly allocate capacity to large hyperscaler HGX orders with long lead times. As a reliable GB200 compatible cold plate manufacturer, KENFA serves server ODMs and AI cluster integrators. With mature brazing and testing capacity, we deliver high-performance, cost-controlled GB200 liquid cold plates, and we are ready for upcoming GB300 discrete cold plate projects.
