Cooling-Thermal supplies customised ultrasonic cleaning machines configured specifically for heat pipe and vapor chamber production geometries and cleaning sequences. Unlike general-purpose industrial ultrasonic cleaners designed for large industrial components or general metal parts, Cooling-Thermal's heat pipe and VC ultrasonic cleaners are tailored to the exact substrate dimensions (Ø3-Ø10mm heat pipe tubes up to 600mm length, VC copper plate panels, bent and 3D-formed heat pipes), the specific multi-stage cleaning sequence required by copper thermal solution production (deionised water wash, acid deoxidation, anhydrous solvent clean, DI rinse and dry), and the production throughput requirement of the specific line position where the machine is installed. As a specialist thermal solution automation machinery manufacturer with validated line installations at Foxconn (25 lines), Nidec (20 lines), Furukawa Electric, Cooler Master, Huawei, and Samsung, Cooling-Thermal configures ultrasonic cleaning machines against real production constraints -- not catalogue specifications designed for general metal cleaning applications.
Customisation Parameters -- What Cooling-Thermal Configures for Your Line
| Configuration Parameter | Standard Heat Pipe Line Configuration | Vapor Chamber Line Configuration | Custom / OEM Configuration |
| Substrate type | Round copper heat pipe tubes (Ø3-Ø10mm, ≤600mm, 2D/3D forms) | Flat copper VC plates and assembled VC panels | Any heat pipe or VC geometry -- specify your |
| Cleaning stages | 3-5 stages: alkaline wash + acid deox + DI rinse + hot air dry | 4-6 stages: alkaline + acid deox + DI rinse x2 + hot air dry | Stage count and sequence configured to your process spec |
| Cleaning media | DI water + alkaline detergent / HCl deoxidation / anhydrous ethanol / DI rinse | DI water / dilute HCl / anhydrous methanol + ethanol / DI rinse | Media selected per your substrate material and contaminant type |
| Ultrasonic frequency | 40 kHz standard (general cleaning) + 80 kHz optional (fine cleaning) | 40 kHz + 80 kHz dual-frequency for VC plate surface 40kHz+80kHz | 25-120 kHz configurable per application 25-120kHz |
| Tank configuration | Single-row tube basket for heat pipe batch cleaning | Flat-plate carrier for VC panel cleaning | Basket/carrier designed for your specific part geometry |
| Temperature range | 40-70 deg-C (cleaning stages) / ambient (rinse stages) | 40-75 deg-C per stage 每 | Temperature per stage configurable |
| Throughput | Matched to production line cycle time | Matched to VC production batch size | Configured to your required pcs/hr |
| Drying method | Hot air circulation drying | Hot air + IR drying optional | Drying method per material sensitivity |
| Control system | PLC + timer + temperature control per stage | PLC + HMI touchscreen + recipe management | Control level per automation requirement |
| Integration | Standalone or inline with degassing station | Standalone or inline with diffusion bonding furnace | Inline integration with any line position |
Why Copper Surface Cleanliness Before Sintering Determines Heat Pipe and VC Thermal Performance
The relationship between copper surface cleanliness and finished heat pipe or VC thermal performance is direct and measurable -- not a quality preference but a physical requirement. Three contamination types specifically affect thermal performance:
| Contamination Type | Source in Heat Pipe / VC Production | Effect on Thermal Performance | What Ultrasonic Cleaning Removes |
| Surface copper oxide (CuO / Cu2O) | Atmospheric oxidation during storage, handling, and any high-temperature step above 200 deg-C without reducing atmosphere | Oxide layer at wick-to-wall interface reduces thermal conductance. Oxide bridging between sintered powder particles reduces wick porosity and capillary pumping force | Acid deoxidation stage (dilute HCl or citric acid) removes CuO layer. Ultrasonic cavitation accelerates acid penetration into fine surface features |
| Machining and forming oils | Pipe cutting (Step 1), shrinking (Step 2), pressing (Step 7), and bending (Step 8) all introduce lubricant/coolant oil residue onto the copper surface | Oil on wick surfaces prevents working fluid wetting. Non-wetting wick cannot transport working fluid by capillary action -- heat pipe fails thermally below its Qmax specification | Alkaline detergent stage saponifies oils. Ultrasonic cavitation drives detergent into the sintered wick pore structure -- cleaning inside micro-pores that manual or spray cleaning cannot reach |
| Laser and brazing flux residue | Laser edge sealing (VC production), laser welding, and brazing operations leave flux and spatter residue on and around the joint area | Flux residue contains chloride, fluoride, or organic compounds that corrode copper at operating temperature, causing wick degradation and working fluid contamination over the heat pipe service life | Solvent wash stage (anhydrous ethanol or methanol) dissolves flux organic binders and removes rosin-based residues. Ultrasonic cavitation removes embedded flux from weld seam geometry |
| Particulate contamination | Copper powder overflow from filling step (Step 3), metal chips from cutting, graphite fragments from sintering fixtures, and environmental dust from handling | Particles inside the heat pipe cavity block wick pore channels, act as nucleation sites for NCG bubble formation, and can block the degassing port during the working fluid injection step | Ultrasonic cavitation dislodges and suspends particles from recessed areas, seam geometries, and wick surfaces. DI water rinse flushes suspended particles completely from the cavity |
A heat pipe that enters the sintering furnace with oil-contaminated or oxide-covered copper surfaces will produce a wick with compromised capillary properties -- and this defect cannot be corrected after sintering. The ultrasonic cleaning step is the only point in the production sequence where these surface conditions can be corrected before they are permanently bonded into the wick structure.
How Ultrasonic Cleaning Works -- Cavitation Physics and Why It Outperforms Manual or Spray Cleaning for Heat Pipe Production
Ultrasonic cleaning works by generating microscopic cavitation bubbles in the liquid cleaning medium through high-frequency pressure waves (typically 25-120 kHz). When these bubbles collapse near a solid surface, they release a powerful localised jet of liquid (micro-jet) and a shock wave. The energy released by a single cavitation bubble collapse is extremely small, but the simultaneous collapse of millions of bubbles per second across the entire liquid volume produces a uniform, high-intensity cleaning action on every surface in contact with the liquid -- including surfaces inside micro-pores, recessed geometries, threaded features, and the interior of heat pipe tubes that spray cleaning, wiping, or brush cleaning physically cannot reach.
| Cleaning Method | Penetration into Heat Pipe Wick Pores | Consistency Across Batch | Cycle Time | Suitable for Production Line |
| Ultrasonic cleaning | YES -- cavitation penetrates pores down to 10-50 micron diameter | Highly consistent -- uniform energy distribution in liquid medium | 3-15 minutes per stage | YES |
| Manual wiping / brushing | NO -- cannot reach micro-pore interiors or tube inner surfaces | Operator-dependent variation | Slow -- 2-5 min per piece | NO -- too slow and inconsistent |
| Spray wash (pressure) | PARTIAL -- penetrates open surfaces but not micro-pores or recessed geometry | Good for open surfaces, poor for complex geometry | Fast -- but limited cleaning depth | PARTIAL -- adequate for pre-clean, not for final clean before sintering |
| Solvent immersion (static) | YES for open pores -- NO for enclosed geometry or heavy contamination | Moderate -- depends on immersion time and agitation | Very slow for thorough cleaning | NO -- too slow for production volume |
| Ultrasonic with alkaline + acid + solvent stages | YES -- cavitation enhances penetration of each chemical stage into micro-pores | Excellent -- time, temperature, and chemistry controlled per stage | 10-30 minutes total multi-stage | YES -- optimum combination for heat pipe/VC pre-sintering cleaning |
The Multi-Stage Cleaning Sequence -- How Cooling-Thermal Configures the Cleaning Process for Heat Pipe and VC Production
The cleaning sequence for heat pipe and vapor chamber copper substrates is not the same as general metal parts cleaning. The specific contamination types (copper oxide, machining oil, laser flux, particles) and the material sensitivity (thin-wall copper with already-formed or in-process wick structures that must not be damaged) require a carefully sequenced multi-stage process. Cooling-Thermal configures the cleaning sequence based on the specific cleaning requirement of the line position where the machine is installed.
| Stage | Cleaning Medium | Ultrasonic Action | Target Contaminant | Position in HP/VC Production |
| Stage 1: Alkaline wash | Alkaline detergent solution (pH 9-11) at 50-70 deg-C | 40 kHz ultrasonic, 3-5 min 40kHz | Machining oils, forming lubricants, fingerprints, organic contamination | Pre-sintering: after pipe cutting, shrinking, and any forming steps |
| Stage 2: DI water rinse | Deionised water (resistivity > 1 MΩ·cm) at ambient | Ultrasonic rinse or overflow rinse | Alkaline detergent residue | Prevents carry-over of detergent into acid stage |
| Stage 3: Acid deoxidation | Dilute HCl (2-5%) or citric acid solution | 40-80 kHz ultrasonic, 2-5 min 40-80kHz | Copper oxide (CuO, Cu2O) layer, light scale | Pre-sintering / pre-diffusion bonding: copper must be oxide-free at bonding temperature |
| Stage 4: Solvent wash | Anhydrous ethanol or anhydrous methanol | 40 kHz ultrasonic, 2-3 min 40kHz | Laser flux residue, organic binders, any oil residue remaining after alkaline stage | Post-laser-welding: VC production (after laser edge sealing) and heat pipe production (after tip weld) |
| Stage 5: DI water rinse | High-purity DI water (resistivity > 10 MΩ·cm) at ambient | Ultrasonic rinse with overflow | All cleaning agent residues; solvent residue; dissolved oxide products | Final rinse before drying -- must leave copper surface ion-free to prevent re-oxidation on drying |
| Stage 6: Hot air drying | Filtered hot air at 80-120 deg-C | N/A -- convection drying | Water residue; solvent residue | Ensures completely dry surface before sintering -- water on copper surface creates steam in wick pores during furnace heating |
Where Ultrasonic Cleaning Fits in the Heat Pipe and VC Production Sequences
In the heat pipe production sequence, the ultrasonic cleaning station is typically installed at two positions: (1) after the tube shrinking step (Step 2) and before the powder filling step (Step 3) -- cleaning the formed degassing end and tube interior before powder is introduced, removing any shrinking lubricant, oxide, or chips from the forming process; and (2) after bending and hot pressing (Steps 7-8) and before final inspection (Steps 10-11) -- removing oil and oxide reintroduced during hot pressing and bending operations from the heat pipe exterior, particularly the flat section contact surface that must be clean for thermal interface measurement in performance testing.
Vapor Chamber Production Line -- Cleaning Position
In the VC production sequence, ultrasonic cleaning is a defined step before the diffusion bonding furnace -- as documented in academic VC fabrication literature (AIP Advances, 2023), copper shells are placed in DI water, hydrochloric acid, anhydrous methanol, and anhydrous ethanol for ultrasonic cleaning to remove debris, oxides, and oil from the surface before the wick sintering and diffusion bonding steps. Cooling-Thermalinstalls the cleaning machine immediately before the DLK-VCKSH1-A diffusion bonding furnace in the VC production line, ensuring that every VC copper plate enters the furnace at the required surface cleanliness level for atomic diffusion bonding.
| Production Step | Cleaning Required | Contamination Introduced | Cleaning Machine Position |
| Step 1: Pipe cutting | Optional pre-clean | Cutting lubricant, copper burrs | Before Step 2 if heavy contamination |
| Step 2: Pipe shrinking | RECOMMENDED | Shrinking lubricant, copper oxide, forming chips | After Step 2, before Step 3 (powder filling) |
| Step 3-6: Powder fill / sinter / degas / weld | N/A -- internal process | N/A | N/A |
| Step 7-8: Hot press + bending | RECOMMENDED for exterior | Forming oil, copper oxide on contact surfaces | After Step 8, before Step 10 (leak test) |
| VC: Before diffusion bonding furnace | REQUIRED | Storage oxide, handling contamination, laser flux from sealing | Immediately before DLK-VCKSH1-A |
Why Cooling-Thermal for Your Heat Pipe and VC Ultrasonic Cleaning Machine -- Specialist vs General Supplier
Every general-purpose industrial ultrasonic cleaner supplier can build a machine that applies ultrasonic energy to a liquid-filled tank. The difference with Cooling-Thermal production context: our engineers know what contamination is present on copper heat pipe tubes at each production line position, what the downstream sintering furnace or diffusion bonding furnace requires from the cleaned surface, and how to configure the cleaning stage sequence, chemistry, frequency, temperature, and throughput to achieve the specific surface cleanliness level that the next production step demands -- not the cleanliness level that a general cleaning machine manual describes for general metal parts.
| What Cooling-Thermal Provides | What a General Ultrasonic Cleaner Supplier Provides |
| Cleaning sequence configured against specific contamination type at each line position | Standard multi-stage sequence for general metal parts |
| Basket/carrier geometry designed for Ø3-Ø10mm heat pipe tubes and VC plate formats | Generic parts basket for flat or simple geometries |
| Chemistry selection validated against copper alloy compatibility (no cleaning agent residue that contaminates working fluid) | General metal cleaning chemistry -- may not be validated for copper heat pipe working fluid compatibility |
| Throughput matched to production line cycle time (no buffer accumulation between line stations) ） | Fixed throughput from catalogue specification |
| Post-cleaning drying configured to prevent re-oxidation before next step (hot air temperature and duration) | Standard drying -- not configured for copper re-oxidation prevention at production interface |
| Integration with line automation (loading/unloading, conveyor interface, MES data logging) | Standalone machine -- no line integration |
| Complete line knowledge: our engineers know what the sintering furnace (next step) requires from the cleaning output | No knowledge of downstream process requirements |
