CNC Machined Aluminum Heat Spreader Thermal Partition Plate with 0.008mm Flatness for Power Electronics Cooling

This aluminum heat spreader partition carries heat from a power module, an IGBT stack or a dense PCB into a cold plate or a chassis wall. The device face is the critical surface: a spreader that is 0.02 mm out of flat holds the thermal interface material at an uneven thickness, and the die runs hotter at one corner than the thermocouple suggests. We fly-cut both faces in one clamping and hold flatness to 0.008 mm with parallelism at 0.01 mm.

The plate is machined from stress-relieved 6061-T6, 6082-T6 or 1050 aluminum. Thickness is held to ±0.02 mm, mounting holes to ±0.02 mm, and the device face is left bare or masked during anodizing so the thermal path stays metal-to-metal. Where the spreader carries a shallow channel or a pocket for a heat pipe, that feature is machined in the same setup so the floor stays parallel to the contact face.

1. Drawing and process plan. We check plate size, thickness, flatness callout, hole pattern and any pocket or channel, then issue a process plan and quotation within one working day.
2. Material verification. Plate is checked for grade and temper against the mill certificate; 1050 is used where thermal conductivity matters more than strength.
3. Stress relief before machining. Plate is stress relieved so the part does not bow when the skin is removed from both sides.
4. Rough machining. Both faces are roughed with equal stock removal, which balances the residual stress and is the main defence against warp.
5. Fly cutting. Both faces are fly-cut with a large-diameter cutter at a controlled feed, producing a flat surface without the step marks left by an end mill.
6. Pockets, channels and holes. Features are machined after fly cutting so their floors stay parallel to the contact face, then holes are drilled and chamfered.
7. Anodizing with masking. Clear, black or chromate conversion is applied with the device face masked, and coating thickness is recorded.
8. Inspection and packing. Flatness on a surface plate or flatness gauge, parallelism and thickness on CMM, then tray packing with a first article report.

A thin aluminum plate warps because the two faces are machined unequally: one side loses more material, the residual stress relieves, and the plate bows into a dish. By the time it is bolted down the bow is flattened, but the internal stress stays and the part creeps at operating temperature. We remove equal stock from both faces, use stress-relieved plate, and fly-cut rather than end-mill, because a fly cutter leaves a flatter surface with lower residual stress. The result is a spreader that stays flat after the module heats up.

Every plate is built to your drawing: length, width, thickness, pocket or channel layout, hole pattern, material grade, anodizing type and masking. One piece is enough to start, with no tooling charge and no setup fee, and the prototype uses the same fixture and inspection plan as the batch. If a feature would add cost without improving heat transfer, our engineer sends a DFM note with a practical alternative and waits for written approval before production.

• NDA before drawings. A mutual non-disclosure agreement is signed before models, drawings or samples are released, covering geometry, volume, end use and customer identity.
• No portfolio use. Confidential spreaders never appear in samples, catalogues, website pages or trade fairs, and photographs require written release.
• Dedicated cell. Sensitive jobs run in a segregated area with named operators; programmes and fixtures are stored under a project code, not the customer name.
• Controlled partners. Anodizing suppliers receive the process specification only, never the assembly drawing or the application.
• Internal traceability. Batch records are kept for three years so a quality question can be answered without exposing the design.

• Confirmed dates. Prototypes in 3 to 7 working days, batch orders in 12 to 20 working days after drawing approval, written into the order confirmation.
• Fixed slots for repeat parts. Blanket orders reserve machine time, so the same plate arrives in the same week each month.
• No re-programming. Programmes, fixtures and gauge sets stay on file, removing setup time from the second order onward.
• Early risk notice. If material, fly cutting, anodizing or inspection threatens the date, you hear it before the date is missed, with a partial shipment option.
• Dispatch evidence. Photos, inspection report and packing list before shipment; tracking number on the day of dispatch.

• Consumer ElectronicsPhone, tablet and laptop housings, heat sinks, camera brackets, VR/AR headset structural parts, smart wearable shells
• Automation & Industrial EquipmentAutomation fixtures, jigs, module frames, transmission sliders, motor mounts, sensor housings, conveyor line parts
• Semiconductor & Vacuum EquipmentVacuum chambers, vacuum fittings, precision equipment bases, thermal isolation and insulation parts, inspection fixtures
• Medical DevicesSurgical instrument bases, diagnostic instrument housings, endoscope components, aesthetic device structural parts (medical-grade aluminum and stainless steel)
• AutomotiveNew energy motor housings, battery end plates, sensor brackets, lamp structural parts, tuning parts, hydraulic valve blocks
• Aerospace & UAVAircraft structural parts, drone frames, landing gear parts, avionics instrument housings (lightweight precision parts)
• Optics & PhotonicsOptical lens barrels, lens mounts, light source heat sinks, camera module brackets, inspection optical benches
• Communications5G heat dissipation cavities, filter parts, signal adapter structural parts, telecom equipment housings
• RoboticsRobot arm joint parts, robot bases, reducer housings, AGV structural parts
• InstrumentationTest equipment housings, precision gauge bases, flow meter parts, laboratory equipment accessories

Each plate is packed in a bubble bag, seated in a custom EPE cavity tray so the machined faces cannot rub, then sealed in a moisture barrier bag with desiccant. The tray fits a five-layer export carton printed with part number, quantity and batch code. Sea freight ships on fumigation-free plywood pallets; neutral cartons are available for customers selling under their own brand.