The processing cost of liquid cooling plates (cold plates) for energy storage is primarily determined by the manufacturing process, followed by materials and production volume. Industry experience indicates that the “tube-in-plate” method (pressing copper tubes into grooves) has the lowest cost; deep-hole drilling falls in the middle;
friction stir welding (FSW) is relatively high; and vacuum brazing is the most expensive. Meanwhile, the decision to use molds and the batch size determine the inflection point for per-unit costs.
For purchasers, calculating processing costs requires first selecting the process and then considering the volume.
I.
Manufacturing Process Determines the Cost Baseline
- Tube-in-Plate: CNC milling is used to cut grooves into an aluminum base plate, into which copper or stainless steel tubes are embedded and secured with thermal epoxy. This is the most economical structure, suitable for basic liquid cooling requirements (Source: Kingka cold plate cost analysis).
- Deep-Hole Drilling (Gun Drilling): Intersecting holes are drilled into a solid block of aluminum and then sealed.
This method requires no welding, results in zero thermal stress, and offers excellent bottom-surface flatness; however, machining multiple flow channels is time-consuming and incurs high CNC labor costs. - Friction Stir Welding (FSW): A solid-state welding process that joins an extruded or milled base plate with a cover plate.
It offers high structural strength, excellent sealing, and superior flatness. While equipment and process requirements are demanding and costs are relatively high, it is the mainstream choice for large-format battery cooling plates. - Vacuum Brazing: Filler material is melted in a vacuum furnace to join complex, multi-layered internal flow channels.
Capable of joining dissimilar metals, this is the most expensive method and is used for high-performance micro-channel applications. - Stamping/Press Forming: Suitable for mass production;
while mold costs are high, the per-unit cost is low. Large-format stamped plates (e.g., 1700 x 1200 x 35 mm) are already being used in energy storage and EV applications (Source: Trumonytechs).
II. Material Selection: Aluminum Dominates;
Copper Costs Twice as Much
- 3003 aluminum alloy offers a thermal conductivity of approximately 150 W/m·K and good corrosion resistance, making it the standard choice for liquid cooling plates in EVs and energy storage systems (Source: Trumonytechs).
- 1060 aluminum has a thermal conductivity of about 234 W/m·K and superior electrical conductivity but lower corrosion resistance;
it is primarily used for roll-bonded plates. - Copper offers the best performance with a thermal conductivity of approximately 390 W/m·K; however, its raw material cost is two to three times that of aluminum.
It requires anti-corrosion coating and cannot share a coolant circuit with aluminum components, so it is mainly used in high-heat-flux applications such as IGBTs and lasers. - CNC cold plates typically use 6061-T6 aluminum (thermal conductivity ~167 W/m·K), while FSW cold plates often utilize 6063-T5 extruded profiles, with flow channels formed directly within the profile (Source: AMT process analysis).
- Aluminum offers clear lightweighting advantages: it reduces weight by approximately 15% compared to steel and is 95% recyclable, making it a cost-effective choice for liquid cooling plates.
III.
Manufacturing Cost Structure: Materials, CNC Machining Time, and Welding
- For a 300 x 200 x 12 mm CNC cold plate, the transition from a 1.2 kg blank to a ~0.7 kg finished product results in about 42% of the material becoming chips; material waste is a significant, visible cost (Source: AMT process analysis).
- CNC channel milling is sensitive to machining time: denser and deeper channels require longer processing times.
Using standard end-mill radii and slightly wider channels can significantly shorten the CNC cycle. - The unit price for a batch of 100 CNC cold plates is approximately €75–€110 (mid-to-high price range), whereas the unit price for FSW cold plates can drop to €16–€32 for a batch of 10,000 units.
- The thermal conductivity of FSW joints is approximately 95% that of the base material—outperforming the 80%–85% achieved by brazing—with deformation controlled to within 0.2 mm per meter and zero porosity (Source: AMT process analysis).
- Applications with high heat flux densities (exceeding 400–900 W), such as IGBTs, require FSW or vacuum-brazed microchannels for adequate heat dissipation;
simple embedded-pipe designs are insufficient (Source: Kingka cold plate cost analysis).
IV.
Equipment Investment and Cover Plate Costs: FSW Offers Superior Cost-Performance
- Equipment investment is approximately €1 million for a vacuum brazing furnace and €1 million for a laser welding machine, whereas an FSW welding head mounted on a CNC machining center costs only about €98,000 (Source: Stirweld equipment cost comparison).
- Significant differences exist in cover plate costs: while laser cutting can be used for cover plates in both vacuum brazing and FSW (approx. €5/piece), laser welding requires extremely high precision in cover plate design, driving processing costs up to €100/piece.
- FSW offers high welding speeds: approximately 10 minutes for large plates and 1 minute for small plates;
a single worktable can weld 40 plates simultaneously, with energy consumption comparable to standard machining. - FSW joints withstand pressures up to 300 bar, are 100% watertight, and are free of porosity, eliminating leakage risks associated with initial bonding defects or cyclic pressure loads found in brazing (Source: Stirweld).
- Vacuum brazing requires piece-by-piece pre-cleaning and an 8-hour cycle time, and is constrained by furnace chamber dimensions;
in contrast, the solid-state FSW process generates no gas or fumes and offers superior safety.
V.
Production Volume Determines Process Economics: The Tooling Tipping Point
- CNC and FSW require no specialized tooling, enabling small-batch production and faster compliance with design specifications; stamping and die-casting require mold creation, with tooling costs amortized across the project (Source: Trumonytechs).
- When annual production volume is below the mold cost-recovery threshold, CNC and FSW are more cost-effective per unit as they do not incur mold amortization costs;
once production exceeds this “break-even” point, the per-unit cost of stamping becomes lower. - Vacuum die-casting reduces cavity gas content to below 50 ppm, achieving a seal capable of withstanding 2–4 bar pressure without impregnation;
the cycle time for a 300 x 200 mm plate is approximately 60–90 seconds, with an output of 400–600 units per machine per shift (Source: AMT process analysis). - FSW offers advantages over brazing for volumes exceeding 5,000 units: it eliminates the need for flux, reduces deformation by 60%, and achieves 95% thermal conductivity at the weld seam compared to 80%–85% for brazing (Source: AMT process analysis).
- Significant room for volume-based price negotiation: costs can drop by approximately 30% for orders over 1,000 units, and by 40%–60% for orders exceeding 100 units compared to small-batch pricing (Source: Foreign trade platform procurement guides).
VI.
Market Quotes and Cost Benchmarks
- On foreign trade platforms, FSW liquid-cooled plates are priced at approximately $80–$120/unit (minimum order of 100 units), EV battery cold plates at $230–$250, and energy storage micro-channel plates at $4–$10/kg (Source: Made-in-China quotes).
- Embedded-tube cold plates cost approximately $20–$100/unit (low volume);
CNC plus brazing costs $100–$500/unit; metal 3D printing is the most expensive at $500–$1,000/unit, used for extreme applications such as aerospace and defense (Source: Lava3DP cost guide). - On the domestic 1688 platform: aluminum profile/copper tube press-fit water-cooled plates cost approximately 50–110 RMB;
micro-channel brazed plates and FSW plates cost around 600 RMB; custom extruded parts (requiring mold opening) start at approximately 1 RMB/unit, based on provided drawings. - Prices from Chinese manufacturers are typically 30%–50% lower than those of international brands, with a prototyping lead time of approximately 8 weeks; tiered pricing applies for orders over 100 units, with further reductions of 15%–30% for orders exceeding 1,000 units (Source: Winshare procurement comparison).
- Evaluations should focus on Total Cost of Ownership (TCO) rather than unit price alone;
low-cost plates that suffer from leaks or short lifespans result in higher overall costs.
VII.
Quality Inspection and Testing Costs Are Essential
- Each cold plate must undergo individual helium leak testing or hydrostatic pressure testing prior to shipment; leaks are catastrophic for high-voltage electronic equipment, and quality inspection costs are factored into the price (Source: Trumonytechs, Lava3DP).
- FSW (Friction Stir Welding) seams undergo four types of inspections—visual, metallographic, bend, and leak tests—in accordance with ISO 25239;
for parts that pass the bend test, the cover plate can withstand plastic deformation up to 90 degrees. - The safety baseline for the burst strength of the entire plate is generally no less than 10 bar;
brazed plates typically have a pressure rating of 5–10 bar, whereas FSW plates can withstand over 15 bar. - The automotive industry requires documentation such as FAI (First Article Inspection) and PPAP (Production Part Approval Process), and costs include RoHS compliance and material traceability;
standard lead times are approximately 7–21 days, while custom CNC or FSW orders take about 3–4 weeks (Source: Accio procurement guide). - Vacuum brazing requires X-ray inspection to check for braze material collapse or flow channel blockage, while laser welding requires liquid penetrant testing after machining;
both processes add to quality-related costs (Source: Stirweld).
Procurement Recommendations
- Determine the manufacturing process based on four key factors: cell specifications, layout, thermal load, and annual production volume.
Use CNC or FSW for small batches to avoid tooling amortization costs, and choose stamping or die-casting for large batches to reduce unit costs. - Upon initial inquiry, provide CAD files or boundary dimensions, thermal load data, coolant type, target temperatures, and projected annual volume;
the factory will then provide free DFM (Design for Manufacturing) feedback. - Evaluate based on Total Cost of Ownership (TCO), considering lead times, quality system certifications, and prototyping capabilities;
prioritize direct manufacturers equipped with helium leak testing and pressure testing capabilities. - Clearly define the scope of supply—specifically whether it includes fittings, test reports, and packaging;
negotiate tiered pricing for bulk orders exceeding 1,000 units, with terms for long-term contracts open to further discussion. - Domestic direct manufacturers offer price advantages of 30% to 50% compared to international brands and a prototyping lead time of approximately 8 weeks;
provided quality standards are met, this approach can significantly reduce the total procurement cost of liquid cooling plates for energy storage systems.
