I. Manufacturing Process
This automotive light radiator is an integrated structure of turbine-shaped fins and a cylindrical cavity. It needs to fit the compact installation space and high-efficiency heat dissipation requirements of automotive lights. The core process utilizes die casting/extrusion molding + CNC precision carving + anodizing. The specific process is as follows:
1. Raw Material Selection: ADC12 die-cast aluminum alloy is preferred (suitable for die casting of complex turbine fins, high cost-effectiveness for mass production); for high-end vehicle radiators, 6063 aluminum alloy (extrusion molding, higher thermal conductivity) or 6061 aluminum alloy (excellent strength, suitable for high-power automotive lights) can be selected.
2. Blank Forming:
◦ Die Casting: In mass production, molten aluminum is injected into a customized mold, and the turbine fins and cylindrical cavity are formed into an integral blank through high-pressure die casting. Only the assembly surfaces require subsequent precision machining. After die casting, stress-relief annealing (200~250℃, held for 2~3 hours) is performed to eliminate internal stress caused by mold forming.
◦ Extrusion + Machining: For small-batch custom designs, aluminum alloy cylindrical profiles are first extruded, then turbine-shaped heat dissipation fins are milled using a five-axis CNC milling process. This results in higher forming precision but also higher costs.
3. Precision Machining:
◦ Using a five-axis CNC machining center, the radiator's mounting interface, LED bead bonding surface, and wiring harness through-holes are precision milled/drilled to ensure compatibility with automotive lighting modules. The turbine fin edges are chamfered and deburred to prevent sharp edges from scratching the lighting components.
◦ The LED bead bonding surface is precision ground and polished to reduce contact thermal resistance and improve heat transfer efficiency.
4. Surface Treatment:
◦ Anodizing: A 10~15μm thick red anodizing layer is applied (customized color scheme to match automotive interior/exterior designs), simultaneously improving the radiator's corrosion resistance (resisting oil and moisture corrosion from the engine compartment) and heat dissipation efficiency (the oxide layer enhances radiative heat dissipation).
◦ Thermally Conductive Coating: A nano-thermal conductive coating with a thermal conductivity ≥2W/(m·K) is sprayed onto the LED bead bonding surface to further reduce the contact thermal resistance between the module and the heat sink.
◦ Sandblasting Treatment: The fin surface is sandblasted to increase the heat dissipation surface area and improve air-cooling heat exchange efficiency.
5. Inspection and Trial Assembly: The dimensional accuracy and fin integrity of the heat sink are inspected. It is then assembled and trial-fitted with the automotive lamp module. Thermal imaging testing is used to verify the heat dissipation efficiency, ensuring that the core temperature of the lamp is ≤85℃ during operation.
II. Machining Accuracy
This heat sink needs to meet the precision assembly and stable heat dissipation requirements of automotive lamps. The core accuracy indicators are as follows:
1. Dimensional Accuracy:
◦ LED bead bonding surface diameter tolerance: ±0.03mm, ensuring a tight fit with the LED bead.
◦ Mounting hole position accuracy: ≤0.05mm, hole diameter tolerance H7 grade (+0.018/0mm), ensuring precise assembly with the lamp base.
◦ Turbine fin height tolerance: ±0.1mm, ensuring the suitability of heat dissipation area and airflow.
◦ Overall radiator length tolerance: ±0.2mm, adapting to the compact installation space of automotive lights.
2. Geometric Tolerances:
◦ LED chip mating surface flatness: ≤0.05mm/50mm, reducing contact gap with the LED chip.
◦ Perpendicularity of the cavity axis to the mating surface: ≤0.05mm, ensuring the verticality of the lamp module installation.
◦ Turbine fin radial runout: ≤0.1mm, avoiding airflow noise during rotating air cooling.
3. Surface Finish:
◦ LED chip mating surface roughness Ra0.8~1.6μm, reducing contact thermal resistance.
◦ Fin surface roughness Ra3.2μm, ensuring the adhesion of the anodized layer and heat dissipation area.
◦ Surface roughness (after anodizing) Ra 1.6~3.2μm, ensuring visual quality.
III. Industry Applications
This type of automotive lamp heat sink, with its lightweight, high-efficiency heat dissipation, and customization characteristics, is primarily used in the automotive lighting field, and can also be extended to related automotive optical equipment. Specific scenarios are as follows:
1. Automotive Lighting Systems:
◦ Headlights: Core heat dissipation components for LED headlights and laser headlights, adapting to the high-power heat dissipation requirements of high beams and low beams, ensuring continuous and stable operation of the lights at night/inclement weather.
◦ Auxiliary Lights: Heat sinks for fog lights, turn signals, and daytime running lights, especially suitable for high-power auxiliary lights modified for off-road vehicles.
◦ Interior Lights: Small heat sinks for roof ambient lights and center console spotlights, balancing lightweight design and heat dissipation efficiency.
2. Automotive Optical Equipment:
◦ Heat dissipation components for automotive LiDAR, adapting to the heat dissipation requirements of LiDAR modules in autonomous driving vehicles.
◦ Heat sink for the light source of the in-vehicle projector (rear-seat entertainment system) to ensure the long-term stability of the projection equipment.
3. New Energy Vehicle Support:
◦ Heat sink for the taillight module and charging port indicator light of new energy vehicles, adapted to the heat dissipation characteristics of the electrical system.
◦ Heat sink for the backlight module of the in-vehicle display screen, used for heat dissipation of the central control screen and instrument panel, extending the lifespan of the display equipment.
