A power module’s cooler interface can become inaccessible as soon as the module is mounted. Inspect the required surface condition before closure and preserve it during handling. A final leak result is useful, but it should not be the only evidence that the specified cooler and sealing construction were assembled.
Identify the applicable interface
Use the exact module drawing and cooling arrangement. Distinguish a liquid-cooled sealing surface from a dry thermal-interface surface. Requirements for one construction cannot be assumed to describe another module with a different baseplate.
Infineon’s HybridPACK Drive G2 assembly instructions define cooler surface requirements and call attention to the condition of the sealing area. Those requirements apply to the specified module construction; the assembly plan should use the actual product’s current drawing and guidance.
Plan the pre-closure inspection
| Feature | Evidence to retain |
|---|---|
| Seating region | Specified geometry and surface condition |
| Seal location | Correct seal and placement in the intended feature |
| Fastener holes | Approved geometry and cleanliness |
| Handling contact | No excluded marks or contamination from tooling |
Define the dimensional measurement method with the drawing owner. A roughness measurement and a flatness measurement answer different questions, so the inspection record should not reduce both to a single surface-finish checkbox.
Protect the accepted surface
Review carriers, gloves, fixtures and transfer points after inspection. If a fixture contacts the sealing region, confirm that its material and condition are suitable. Keep accepted parts covered or stored by the approved method until assembly.
For example, a cooler inspected before an additional machining operation may acquire debris afterward. Place the final cleanliness check at a stage that represents the surface entering assembly, not merely the supplier’s earlier inspection.
When damage is found, preserve its location and obtain a disposition. Local polishing or blending can alter the defined surface and should not be treated as routine cleaning without an approved repair instruction.
Keep accepted and rejected surface examples connected to the drawing criteria. A cosmetic comparison without the affected region identified can lead inspectors to overlook a mark on the sealing path while rejecting an unrelated mark elsewhere.
Verify after closure
Perform the required leak, thermal and other product checks after the approved fastening sequence. Record the module, cooler and seal identities together so a result can be connected to the physical combination tested.
Include any removal and reassembly in the history. The original pre-closure inspection does not automatically represent a surface that has subsequently been opened, handled and resealed.
The fastener-sequence guide addresses closure, while clip-contact review covers a different mechanical method for retaining a cooled power device.
Move from reading to a build-ready project
Use the fabrication and assembly checklists to prepare drawings, production files and test requirements.
Open the DFM checklist