Stamped Liquid Cooling Cold Plates for EV Battery Packs: Aluminum Forming and Vacuum Brazing QC

Stamped aluminum liquid cooling plates for EV battery packs must maintain controlled coolant-channel geometry, uniform contact with the battery module, and leak-tight joints under cyclic pressure and temperature loads. For 4C/5C fast-charging applications, a reliable manufacturing process combines 3003 aluminum alloy forming, 4343/3003 brazing-sheet design, controlled-atmosphere or vacuum brazing, and traceable pressure and helium leak testing. A flatness target below 0.5 mm/m and a burst-pressure requirement above 1.5 MPa can serve as project-specific acceptance criteria, subject to the battery system's thermal, hydraulic, and structural requirements.

 

 

 

A 4C charging rate corresponds nominally to a charging current equal to four times the battery's rated capacity per hour; 5C represents five times that capacity. These C-rates describe charging intensity, not a universal heat-generation value. Actual cooling demand depends on cell chemistry, internal resistance, state of charge, temperature, charging profile, and module architecture.

 

As fast-charging power increases, the cold plate must remove heat while limiting temperature gradients across the cell array.

 

Manufacturing defects that alter coolant flow, contact pressure, or sealing integrity can reduce thermal performance even when the nominal plate dimensions meet the drawing.

Bottom-Cooling vs. Side-Cooling Architectures

 

Engineering factor	Bottom-mounted cold plate	Side-mounted cooling plate
Thermal interface	Contacts the cell base or module bottom structure	Contacts the cell sidewalls or module side structure
Heat-transfer path	Depends on baseplate flatness, interface material, and cell-to-plate contact	Depends on sidewall geometry, clamping pressure, and interface thickness
Forming challenge	Maintaining a flat mounting plane around stamped channels	Maintaining straightness and dimensional consistency along the contact surface
Coolant distribution	Channel layout must avoid flow maldistribution and stagnant zones	Manifold placement must distribute coolant across the full cell height
Assembly control	Flatness, mounting-hole position, and interface compression	Sidewall parallelism, clamping load, and interface compression
Typical verification	Flatness mapping, flow testing, pressure testing, and thermal validation	Profile inspection, flow testing, pressure testing, and thermal validation

 

Neither architecture is inherently superior for every pack. Bottom cooling may simplify module integration in certain prismatic-cell designs, while side cooling can provide a larger contact area in some configurations. Selection should follow thermal simulation, cell-manufacturer requirements, serviceability, and pack-level crash and vibration constraints.

Translating Thermal Targets into Manufacturing Controls
The cold plate is a coupled thermal-fluid component. The drawing should define the geometric and hydraulic characteristics that influence heat transfer and coolant distribution.

Flatness: A project target of less than 0.5 mm/m corresponds to 0.5 mm deviation over a 1,000 mm reference length. The drawing must specify the datum, measurement method, and whether the requirement applies before or after brazing.
Channel geometry: Specify channel width, depth, pitch, corner radii, and minimum remaining wall thickness. These parameters determine flow area, pressure drop, local stress, and forming stability.
Flow distribution: Define inlet and outlet locations, allowable pressure drop at a stated flow rate, and the permitted flow imbalance between parallel passages where applicable.
Thermal interface: Define the required contact area, surface profile, and interface-material compression range. A flat plate alone does not guarantee low thermal contact resistance.
Coolant compatibility: Confirm alloy, joining material, coolant formulation, corrosion inhibitors, and operating temperature as a system. Mixed-metal circuits require particular attention to galvanic corrosion.

For production release, the thermal model should be correlated with measured flow and temperature data from representative assemblies. A stamped channel profile that matches CAD geometry still requires hydraulic verification because local deformation, braze filler flow, and manifold transitions can change the effective flow path.

3003 Aluminum Alloy: Formability and Corrosion Considerations
AA 3003 aluminum alloy is commonly considered for heat-exchanger and cooling-plate applications because it combines useful formability, thermal conductivity, and corrosion performance in suitable environments. Its suitability depends on temper, sheet thickness, coolant chemistry, joining process, and structural loading.

 

Material or design factor	Engineering significance	Required control
3003 aluminum alloy	Provides the base material for formed channels and plate structures	Verify alloy designation, temper, thickness, and material certificate
Sheet thickness	Controls formability, pressure resistance, and local wall strength	Check incoming thickness and minimum post-forming wall thickness
Temper and work hardening	Influence drawability, springback, and cracking risk	Establish a qualified forming window for the specified material condition
Thermal conductivity	Affects conduction from the battery interface into the coolant	Use verified material data in thermal calculations
Coolant exposure	Can cause corrosion depending on chemistry, temperature, and contaminants	Validate coolant compatibility and corrosion-control requirements
Brazing cycle	Can alter the material's final mechanical properties	Confirm post-braze strength assumptions with material and process data

 

The material designation alone does not establish the allowable working pressure. Final pressure capability depends on channel geometry, local thinning, joint quality, material condition after brazing, and the safety factors defined by the system design.

 

 

Liquid Cooling Plate Stamping requires more than forming the nominal channel profile. The process must preserve the designed flow cross-section while controlling thinning, springback, flange distortion, and the final mounting plane.

Progressive Forming and Shallow Drawing of Microchannels
Depending on the plate architecture, channel features can be produced through shallow drawing, staged forming, matched-die stamping, or a combination of stamping and CNC finishing. Tooling design should account for the material's forming limit and the interaction between adjacent channels.

 

Key process variables include:
Punch radius and die radius: Radii that are too small increase localized strain and crack risk; excessively large radii can reduce channel definition or interfere with adjacent features.
Blank-holder force: Insufficient force can produce wrinkling, while excessive force can restrict material flow and increase thinning.
Lubrication: The lubricant must support consistent material flow and be compatible with downstream cleaning and brazing.
Forming sequence: Staged forming can distribute strain and reduce abrupt deformation around channel intersections and manifold transitions.
Tool wear: Changes in punch and die surfaces can affect channel depth, edge condition, and dimensional repeatability.

The process window should be established through forming trials and verified using dimensional measurements, wall-thickness checks, and visual inspection for cracks, wrinkles, and surface damage.

Channel Geometry and Post-Forming Wall Thickness
Channel depth is not an isolated dimension. It interacts with channel width, pitch, corner radius, cover-sheet geometry, and braze-joint location.

 

A practical process-control plan should include:

 

Control item	Inspection method	Acceptance basis
Channel width and depth	Optical measurement, profile measurement, or validated gauges	Released engineering drawing
Minimum remaining wall thickness	Ultrasonic thickness measurement or destructive sectioning during validation	Design-specific minimum
Channel pitch and position	CMM, optical inspection, or dedicated fixture	Datum-based dimensional tolerances
Manifold interface geometry	CMM and functional fixture inspection	Assembly drawing and flow requirements
Surface cracks and wrinkles	Visual inspection under defined lighting, with magnification where required	Approved defect catalogue
Mounting-plane flatness	CMM, surface plate with indicators, or validated scanning method	Project target, such as below 0.5 mm/m

 

The inspection plan should distinguish between in-process measurements and final measurements after joining. Brazing can introduce distortion through thermal gradients, fixture restraint, and differential expansion. Therefore, a plate that passes the pre-braze flatness check may fail the final assembly requirement.

Flatness Below 0.5 mm/m: Managing Distortion Before and After Brazing
Flatness control is affected by material condition, stamping sequence, residual stress, fixture contact, and the brazing thermal cycle. A dimensional requirement should identify the reference surface and inspection temperature to avoid inconsistent acceptance decisions.

 

Recommended controls include:
1. Incoming material verification: Confirm thickness, alloy, temper, and sheet flatness before forming.
2. Forming validation: Measure the formed plate at fixed datums and record local distortion around channels and manifolds.
3. Fixture design: Support the plate without forcing it into an artificial shape that conceals residual stress.
4. Thermal-cycle qualification: Evaluate deformation after the complete brazing cycle, including the specified heating and cooling profile.
5. Final dimensional inspection: Measure the mounting plane after brazing, cooling, and any permitted finishing operations.
6. Statistical monitoring: Track flatness trends by tool, cavity, material lot, and brazing batch to identify systematic drift.

A target below 0.5 mm/m should be confirmed against the actual battery-module interface. If the design requires tighter local contact control, a global flatness value may be insufficient; local profile and interface-gap requirements should be specified separately.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Defect Prevention in High-Volume Stamping

 

Potential defect	Likely process cause	Prevention and verification
Channel cracking	Excessive local strain, unsuitable radii, or material variation	Forming trials, radius optimization, and crack inspection
Wrinkling	Poor blank control or unsuitable blank-holder force	Optimize material flow and validate the forming sequence
Channel-depth variation	Tool wear, material-thickness variation, or press instability	Tool maintenance, incoming inspection, and dimensional SPC
Excessive thinning	Localized stretching at channel corners or transitions	Optimize die geometry and verify minimum wall thickness
Burrs or sharp edges	Tool wear or unsuitable cutting clearance	Control die clearance and inspect edges before joining
Plate warpage	Residual stress, uneven restraint, or thermal distortion	Review forming sequence, fixture design, and post-braze flatness

 

For automotive supply programs, the control plan should connect each critical-to-quality characteristic to its measurement method, sampling frequency, reaction plan, and traceability record. Where required by the customer, these controls can be incorporated into PPAP documentation and the applicable IATF 16949 quality-management framework.

 

Request a Liquid Cooling Plate DFM Review

 

 

The joining method determines how the formed channels are sealed, how the cover sheet bonds to the core, and how the completed plate behaves under pressure cycling. For 3003 aluminum cold plates, clad brazing sheet using a lower-melting-point Al-Si alloy such as 4343 can provide filler metal at the joint interface.

 

The choice between vacuum brazing and controlled-atmosphere brazing (CAB) depends on plate geometry, filler-metal configuration, flux requirements, cleanliness limits, throughput, and validated leak performance.

How 4343/3003 Clad Sheet Works
A 4343/3003 brazing sheet typically uses 3003 aluminum alloy as the core and an Al-Si 4343 layer as the brazing filler. During the qualified thermal cycle, the cladding melts and wets the prepared joint surfaces while the core retains its structural role.

 

The exact cladding ratio, sheet thickness, material temper, and brazing cycle must be specified by the material supplier and validated for the component design. Filler flow must be sufficient to seal the intended joint without obstructing narrow channels or starving critical interfaces.

 

Important design controls include:

Joint clearance: Excessive gaps can prevent capillary filling; insufficient clearance may restrict filler-metal flow.
Filler-metal volume: Too little filler can create discontinuous joints; too much can form fillets or intrude into the coolant passages.
Surface cleanliness: Oil, oxide, and stamping residue can inhibit wetting and cause incomplete brazing.
Fixture restraint: Excessive restraint can cause distortion or residual stress; insufficient support can permit channel collapse or warpage.
Thermal uniformity: Temperature variation across the assembly can produce incomplete joints in colder zones and excessive core erosion or deformation in hotter zones.

Vacuum Brazing vs. CAB: Flux, Cleanliness, and Production Economics

 

Factor	Vacuum brazing	Controlled-atmosphere brazing (CAB)
Furnace environment	Reduced-pressure environment with controlled vacuum level and thermal cycle	Controlled protective atmosphere, commonly nitrogen-based
Flux requirement	Can be fluxless when the material system, surface preparation, vacuum, and cycle support reliable wetting	Commonly uses controlled aluminum-brazing flux; fluxless variants require a separately qualified process
Surface preparation	High cleanliness is required to control oxide-related wetting failures	Cleaning and flux application must be controlled to maintain consistent brazing
Residue management	Flux residue is avoided in a qualified fluxless process	Flux residues may remain and must be evaluated against coolant cleanliness and corrosion requirements
Joint formation	Depends on vacuum quality, material condition, filler flow, and thermal uniformity	Depends on flux coverage, atmosphere quality, temperature distribution, and filler flow
Production considerations	Furnace cycle, loading, vacuum maintenance, and batch utilization influence throughput	Continuous-furnace throughput may favor higher-volume production when the design and process are qualified
Typical process risks	Incomplete wetting, outgassing, filler erosion, distortion, or contamination	Incomplete flux coverage, residual flux, incomplete wetting, distortion, or channel blockage
Selection basis	Suitable where fluxless joining and cleanliness requirements justify the process and cost	Suitable where the production system supports repeatable brazing, cleaning, and required residue control

 

Either process should be selected based on the word "fluxless" alone. Vacuum brazing is not automatically free from contamination, and CAB does not automatically produce unacceptable residue. The relevant criteria are validated joint integrity, internal cleanliness, coolant compatibility, corrosion resistance, and production repeatability.

Vacuum Brazing Process Variables and Defect Controls
A vacuum brazing procedure should specify the furnace pressure profile, temperature uniformity, heating rate, soak conditions, cooling profile, loading arrangement, and permitted fixture materials. Exact settings depend on the brazing-sheet specification and assembly design; a generic temperature recipe is not a substitute for process qualification.

 

Process variable	Failure mechanism	Verification approach
Vacuum level and leakage	Oxidation or contamination can impair wetting	Furnace records, leak checks, and process qualification
Temperature uniformity	Incomplete filler melting or excessive erosion	Temperature surveys and instrumented load studies
Heating and cooling rate	Distortion, thermal stress, or undesirable material-property changes	Recorded thermal profile and dimensional validation
Surface cleanliness	Poor wetting, voids, or discontinuous seams	Controlled cleaning process and surface-condition checks
Joint gap and overlap	Incomplete capillary filling or excessive filler intrusion	Design review, fixture verification, and sectioning trials
Fixture support	Warpage or channel deformation	Fixture inspection and post-braze dimensional measurement
Filler-metal distribution	Blocked channels or incomplete sealing	Flow-path inspection, destructive sections, and hydraulic testing

 

For CAB, additional controls include flux type, application quantity, coverage, atmosphere dew point, oxygen level where specified, and post-braze cleaning requirements. The final cleanliness criteria should be defined by the coolant-loop design rather than assumed from the joining process.

Brazing Defects: Cross-Sectional Analysis and Corrective Action
The most consequential defects are often internal and cannot be reliably identified by external appearance alone.
Incomplete brazing: Local discontinuities may create leak paths or reduce the joint's effective load-bearing area.
Channel blockage: Excessive filler-metal flow can restrict coolant passages and increase pressure drop.
Core erosion: Excessive thermal exposure or inappropriate filler configuration can reduce the remaining structural thickness.
Porosity or voids: Gas entrapment, surface contamination, or unsuitable joint conditions can reduce effective bonding area.
Distortion: Uneven thermal expansion and fixture restraint can compromise mounting flatness and assembly contact.
Corrosion susceptibility: Residual flux, incompatible materials, or unsuitable coolant chemistry can accelerate degradation.

Metallographic sectioning should target representative joints and known high-risk locations, including channel corners, manifold transitions, and long sealing seams. Cross-sections can reveal filler continuity, erosion depth, void distribution, and remaining core thickness. These findings should be correlated with leak, burst, and flow-test results.

 

Discuss Brazing Process Selection

 

 

 

Pressure integrity and gas-tightness are separate acceptance requirements. A cold plate may withstand a short-duration pressure test while still containing a small leak that becomes significant during long-term coolant circulation. Conversely, a component may show a low leak rate under a specific test condition without demonstrating adequate burst strength.

 

A project requirement of burst pressure above 1.5 MPa should therefore be supported by a defined test method, sample plan, pressure ramp, holding conditions, and failure criteria. It must not be treated as a universal specification for all EV cooling plates.

Burst Pressure vs. Proof Pressure vs. Operating Pressure

 

Test or design parameter	Purpose	Engineering requirement
Maximum operating pressure	Defines the highest specified pressure during normal service	Set by the coolant circuit and vehicle-level operating envelope
Proof pressure	Checks whether the assembly withstands a specified pressure without unacceptable permanent deformation or leakage	Establishes the pressure factor, duration, and acceptance criteria from the applicable design requirement
Burst pressure	Determines the pressure at which the component loses structural integrity or fails the defined criterion	Specify ramp rate, fluid or test medium, fixture, and failure definition
Pressure-cycle endurance	Evaluates degradation under repeated pressure changes	Define cycle count, pressure range, temperature, and post-test acceptance
Helium leak rate	Quantifies gas leakage through the completed assembly under defined conditions	Set a numerical limit, test pressure, stabilization time, and calibrated method
Flow and pressure-drop test	Confirms hydraulic continuity and resistance	Define coolant or test-fluid properties, flow rate, and allowable pressure drop

 

A burst threshold of greater than 1.5 MPa is meaningful only when the system's maximum operating pressure and safety requirements are known. Proof pressure, burst pressure, and operating pressure must not be used interchangeably.

Automated Helium Mass Spectrometer Leak Testing
Helium mass spectrometer leak testing can detect small leak paths that may not be apparent during conventional pressure-decay or bubble testing. The method is especially useful when the assembly's acceptance criteria require a quantified leakage rate.

 

The test configuration must match the intended leak-detection method. In a vacuum-chamber method, the cold plate is pressurized with helium or a specified tracer-gas mixture, and the chamber instrument detects gas escaping from the component. In a sniffer method, the detector samples gas around accessible joints under a defined test arrangement. These methods have different sensitivities and require separate validation.

 

A robust automated test sequence typically includes:
1. Fixture sealing: Verify that the test fixture does not introduce bypass leakage or mask the component's leak path.
2. Test-gas charging: Apply the specified pressure without exceeding the validated test envelope.
3. Stabilization: Allow pressure and temperature to stabilize to reduce false readings caused by transient conditions.
4. Leak measurement: Record the measured leakage rate using a calibrated instrument and a defined unit.
5. Pass/fail decision: Compare the result with the project-specific limit, including the validated instrument uncertainty and background level.
6. Traceability: Associate the result with the component serial number or lot, test recipe, instrument ID, calibration status, and timestamp.

Helium leak rate should be reported with its unit, such as mbar·L/s or Pa·m³/s. A numerical acceptance limit cannot be responsibly specified without the coolant system's leakage budget, test configuration, and conversion assumptions. Gas leakage and liquid coolant leakage are related but are not interchangeable measurements.

Burst Testing and Failure-Mode Analysis
Burst testing evaluates structural integrity at elevated pressure. The test should use a documented setup that captures pressure and, where useful, displacement or deformation data. Safety shielding and a controlled test area are necessary because stored energy increases with pressurized volume and pressure.

 

Key controls include:
Pressure ramp: Use a defined ramp rate to maintain comparability between samples and avoid introducing test-induced dynamic effects.
Test medium: Select a suitable medium and method based on the test objective and safety assessment. Liquid-based hydrostatic testing generally stores less energy than compressed-gas testing for comparable conditions.
Failure definition: Define whether failure means visible rupture, leakage, pressure collapse, excessive deformation, or another specified criterion.
Failure location: Record whether failure occurred in the channel wall, brazed seam, manifold interface, port connection, or test fixture.
Post-test examination: Use sectioning and dimensional checks to distinguish material failure from joint defects or fixture-related effects.

The burst-test sample plan should reflect the product's risk level and production validation stage. Initial design validation, process qualification, and routine production monitoring may require different sampling frequencies.

Pressure, Leak, Flow, and Dimensional Tests as a Unified QC Plan

Quality characteristic	Recommended verification	Release decision
External dimensions	CMM or dedicated inspection fixture	Conformance to drawing
Channel dimensions	Optical/profile measurement and validated gauges	Conformance to channel specification
Final flatness	CMM, surface measurement, or validated scanning system	Project-specific flatness limit
Brazed-joint integrity	Metallographic sampling and qualified non-destructive methods where appropriate	No unacceptable discontinuity under the approved criteria
Leak tightness	Automated helium mass spectrometer test	Measured leak rate below the defined limit
Pressure resistance	Proof and burst testing	Meets the defined pressure and failure criteria
Hydraulic performance	Flow and pressure-drop measurement	Meets the specified flow envelope
Internal cleanliness	Validated extraction, particle, or residue test where required	Meets coolant-system cleanliness limits
Corrosion compatibility	Material and coolant validation under defined exposure conditions	Meets the approved durability criteria

 

A helium leak test does not replace burst testing, and burst testing does not establish thermal performance. The cold plate should be released only when the relevant dimensional, joining, hydraulic, pressure, and leak requirements are all satisfied.

 

 

 

An EV Cold Plate Manufacturer must control the complete process chain rather than treat stamping and brazing as independent operations. Dimensional variation introduced during forming can affect joint clearance; brazing can then alter flatness and mechanical properties. Final pressure and flow performance depend on the combined effects of material, geometry, joining, and assembly.

Integrated Manufacturing Sequence

Process stage	Primary operation	Key output or control record
1. Material receiving	Verify 3003 core sheet or 4343/3003 brazing sheet	Material certificate, alloy, temper, thickness, and lot ID
2. Blanking	Cut the initial plate geometry	Blank dimensions, edge condition, and burr control
3. Precision stamping	Form microchannels and functional features	Channel dimensions, wall thickness, and defect inspection
4. CNC forming or finishing	Produce specified ports, interfaces, and datum features where required	Position, profile, and dimensional records
5. Cleaning and preparation	Remove oil and contaminants before joining	Validated cleaning parameters and cleanliness records
6. Fixture loading	Position the core, cover, manifolds, and other joining components	Fixture verification and joint-gap control
7. Vacuum brazing or CAB	Join the channel plate and cover structure	Furnace trace, atmosphere or vacuum records, and batch identification
8. Post-braze inspection	Inspect appearance, flatness, and critical dimensions	Dimensional report and defect disposition
9. Leak and pressure testing	Perform specified helium, proof, burst, or cycle tests	Test records linked to serial number or production lot
10. Hydraulic and cleanliness checks	Verify flow, pressure drop, and internal cleanliness as required	Hydraulic test results and cleanliness release
11. Final release	Review records and approve the completed assembly	Inspection report, traceability package, and shipment release

 

Not every design requires CNC finishing or every pressure test on every production unit. The routing and inspection frequency should be established through the product risk assessment, customer specification, and validated control plan.

DFM Review: Reducing Forming and Brazing Risk Before Tooling Release
A design-for-manufacturing review should occur before the final die and brazing fixture are released. This review should identify features that create unnecessary forming strain, difficult joint access, uneven filler flow, or inspection blind spots.

 

Recommended DFM checkpoints include:
Channel layout: Avoid abrupt changes in cross-section that create excessive local strain or unstable coolant flow.
Corner radii: Match the geometry to the selected alloy, temper, sheet thickness, and qualified forming capability.
Joint design: Provide suitable overlap and clearance for the chosen brazing method.
Manifold transitions: Check both local forming strain and the risk of filler-metal intrusion into the flow path.
Inspection access: Provide suitable datums and features for repeatable dimensional measurement.
Test-port design: Ensure that the production leak-test fixture can connect and seal without interfering with the component's critical interfaces.
Tolerance allocation: Separate functional tolerances from non-critical dimensions and account for post-braze distortion.

Tolerance values should be set from the functional requirements and demonstrated process capability. A blanket tolerance of ±0.01 mm is not appropriate for every stamped feature or large-area cooling plate; tighter tolerances should be applied only where required and supported by the manufacturing and inspection method.

Quality Documentation for Automotive and Energy-Storage Programs
For customer programs that require formal production approval, the documentation package may include:

Approved engineering drawings and revision history.
Material certificates and incoming inspection records.
Process flow diagram, PFMEA, and control plan where required.
Forming and brazing process qualification records.
Dimensional inspection results and measurement-system evidence.
Helium leak, pressure, and hydraulic test records according to the agreed sampling plan.
Nonconformance handling, corrective actions, and change-control records.
PPAP documentation, including Level 3 submissions when required by the customer.

PPAP Level 3 is a customer-defined submission requirement, not a universal requirement for every cold plate order. Similarly, IATF 16949 should be claimed only where the relevant manufacturing organization and site hold the applicable certification. Supplier capability statements should match the actual scope of certification and the customer's requirements.

 

 

Supplier evaluation should focus on process capability, product validation, traceability, and the ability to maintain repeatable output over the intended production volume.

Supplier Evaluation Matrix for Liquid Cooling Plate Stamping

 

Evaluation area	Questions for the supplier	Evidence to request
Material control	Can the supplier verify alloy, temper, thickness, and brazing-sheet configuration?	Material certificates and lot traceability
Stamping capability	Can the supplier control channel geometry and post-forming wall thickness?	Forming trials, inspection plans, and dimensional reports
Flatness control	Is the final flatness measured after brazing?	Defined datums, measurement method, and actual inspection data
Brazing capability	Is the selected vacuum or CAB process qualified for the plate design?	Furnace records, process qualification, and metallographic evidence
Leak testing	Is the helium leak-rate limit defined and linked to the product specification?	Calibrated instrument records and pass/fail criteria
Pressure integrity	Are proof, burst, and cycle tests distinguished?	Approved test procedures and representative validation results
Hydraulic performance	Is flow or pressure drop measured under defined conditions?	Test fluid, temperature, flow rate, and pressure-drop records
Quality management	Can the supplier meet the customer's PPAP and traceability requirements?	Relevant certification scope, control plan, and sample submission package
Engineering support	Are stamping, joining, inspection, and DFM reviewed together?	Design-review records and corrective-action examples

 

A supplier should not be evaluated solely on quoted unit price or nominal production capacity. The cost of a cooling plate also depends on tool maintenance, scrap rate, furnace utilization, cleaning, inspection, leak-test cycle time, and the cost of managing field failures.

Apollo Manufacturing Scope for Stamped Aluminum Cooling Plate OEM Programs
Xiamen Stamping and Welding Technology Co., Ltd. can be evaluated for projects requiring coordinated sheet-metal stamping, CNC forming or finishing, and brazed or welded metal assemblies. The appropriate manufacturing route depends on the released drawing, material specification, coolant requirements, annual volume, and customer validation plan.

 

For an EV or ESS cold plate project, the technical review should establish the following before production quotation:
1. Product definition: Plate dimensions, channel architecture, alloy and temper, cover-sheet construction, port design, and interface requirements.
2. Operating envelope: Maximum operating pressure, coolant type, temperature range, flow rate, and required pressure-drop limit.
3. Joining route: Vacuum brazing, CAB, or another qualified process, with a defined cleanliness and corrosion-control strategy.
4. Acceptance criteria: Flatness, dimensional tolerances, helium leak-rate limit, proof pressure, burst threshold, and hydraulic performance.
5. Validation scope: Prototype inspection, design validation, process qualification, and production release requirements.
6. Commercial scope: Tooling ownership, engineering changes, sample quantities, forecast volumes, packaging, and traceability requirements.

The internal product relationship can be reviewed through new energy battery components. For metal joining and assembly requirements, see aluminum welding parts.

 

The final manufacturing specification should identify which values are drawing requirements, which are process-control targets, and which are validation-test thresholds. This distinction prevents a provisional engineering target from being mistaken for a demonstrated production capability.