CNC Machining Case for Copper-Aluminum Cooling Plate

【Project Background】

This project involved a customized copper-aluminum cooling plate for a new energy equipment customer. The part was designed for mounting and heat dissipation of power modules, control units and high-heat electronic components. It needed to meet requirements for thermal conductivity, assembly accuracy and surface quality, making it a key component in the equipment thermal management system.

The customer provided a 3D model and 2D drawings. The main body of the part was made from aluminum alloy, with copper inserts in specific heat conduction areas. Because copper and aluminum have different material characteristics, the project required careful control of cutting performance, thermal expansion, surface finish and machining deformation. Several mounting holes, positioning steps and cooling contact surfaces had to maintain stable dimensions, with the key cooling surface flatness required to reach 0.02mm.

【Machining Challenges】

The first challenge was controlling the machining behavior of different materials. Copper has high toughness and can easily cause tool adhesion and burrs during cutting. Aluminum alloy offers higher machining efficiency, but thin-wall areas and large flat surfaces may deform during machining. When both materials are processed in the same part, tool selection, cutting parameters and cooling methods must be optimized separately.

The second challenge was controlling the flatness of the cooling contact surface. This large surface needed to fit closely with the power module. If the flatness was insufficient, thermal conductivity and equipment stability could be affected. At the same time, several mounting holes had strict positional relationships with the cooling surface, and any hole deviation could influence final assembly.

In addition, the finished part had to be free from obvious tool marks, burrs and scratches. The transition area between copper and aluminum also needed to be smooth, without uneven steps, edge rollover or local dents.

【Process Solution】

Based on the part structure and material characteristics, Qingdao SCreate Industrial Technology Co., Ltd. developed a staged CNC precision machining process. Before machining, the engineering team analyzed the structure, confirmed the main datum surface, designed the clamping method and planned the machining sequence. Cutting parameters were set separately for copper and aluminum areas.

During rough machining, small cutting depths and multiple tool passes were used to remove material gradually and reduce deformation caused by stress release. For the large cooling surface, proper finishing allowance was reserved until the overall structure became stable. For the copper area, sharp tools suitable for copper machining were selected, and feed rate and cooling method were optimized to reduce tool adhesion, burrs and surface tearing.

During finishing, the cooling contact surface, mounting datum surfaces and locating holes were carefully controlled. Stable clamping and sectional machining helped reduce warping risk in the plate-like structure. Key holes were processed through locating and finishing steps to ensure stable positional accuracy relative to the datum surface. After machining, all edges were chamfered and deburred evenly to meet assembly and appearance requirements.

【Quality Results】

After machining, the quality team inspected the cooling contact surface, mounting holes, positioning steps and flatness using CMM equipment. The results showed that the flatness of the key cooling surface was controlled within 0.02mm, and the main mounting hole positions and locating dimensions met the customer’s drawing requirements.

During assembly verification, the customer confirmed that the power module fitted well with the cooling plate, and the mounting holes aligned consistently without rework. The part surface had no obvious tool marks, burrs or dents, and the transition area between copper and aluminum was smooth. Through this project, SCreate further demonstrated its process capability in new energy cooling components, copper-aluminum composite structures and high-flatness machining, providing reliable experience for future batch production of similar thermal management parts.