Custom Copper Cooling Plate for Semiconductor Power Modules

Semiconductor power modules—IGBTs, SiC MOSFETs, and rectifier stacks—push serious watts through tiny footprints. The thermal bottleneck usually isn’t the chip; it’s the last few millimeters between the junction and your coolant. This article shows how a custom 3D printed copper cooling plate built with LPBF (Laser Powder Bed Fusion) targets those bottlenecks with optimized microchannels, integrated manifolds, and tight flatness—all while simplifying assembly and enabling faster iteration. If you’re evaluating a copper 3D printing service for power-electronics cooling, this is your practical guide.

Email for RFQ or DFM review: [email protected].

Why 3D Printed Copper for Power Modules

Copper’s physics and LPBF’s geometry combine where it matters—under the die.

• High thermal conductivity: Copper conducts heat far better than most structural alloys, enabling rapid heat spreading from module baseplates and DBC substrates.
• Geometry freedom: LPBF fabricates microchannels, pin-fin fields, vortex generators, and multi-zone flow splits directly beneath hot spots. That means higher local h-transfer without the brazed stacks or multi-part manifolds of conventional cold plates.
• Compact integration: Print the cooling core, O-ring grooves, sensor bosses, alignment features, and mounting standoffs as a single part. Fewer joints, fewer leaks.
• Fast iteration: Spin design variants (fin pitch, channel topology, inlet/outlet orientation) within days—not months—so you can quickly converge on thermal resistance and pressure-drop targets.

Common use cases: traction inverters, industrial drives, DC fast chargers, HVAC inverters, PV inverters, and server power supplies that pair with IGBT or SiC modules.

Where It Fits: Module Families & Interfaces

Our copper 3D printing service supports bespoke plates matched to:

• IGBT modules (e.g., dual and half-bridge packages used in industrial drives and traction)
• SiC MOSFET modules (high power density; often drive higher heat fluxes and benefit the most from microchannels)
• DBC substrates / baseplates (Al₂O₃, AlN, Si₃N₄ on copper) with standard TIMs (greases, phase-change materials, pads)
• Isolated configurations using ceramics or coated intermediates when the system requires dielectric barriers (since copper itself is conductive)

Provide the module make/model, footprint drawing, and expected loss map (W per device / per zone) with your RFQ so we can place microfeatures exactly where they help.

Design for Additive Manufacturing (DfAM): What to Decide Early

1) Coolant & Cleanliness

Pick your coolant early—DI water, water/ethylene glycol, or dielectric fluids. Add inhibitors for copper systems where applicable. Define max chloride content, biocide policy, and your cleanliness spec to avoid ionic contamination in power-electronics assemblies.

2) Thermal Targets

Set measurable objectives:

• Interface plan: TIM thickness and conductivity, module base flatness, target clamping pressure
• Core metrics: allowable junction-to-inlet ΔT, baseplate temperature uniformity, thermal resistance (K/W), and max local heat flux (W/cm²) at hotspots
• System limits: pump curve, pressure drop (Δp) budget, and flow rate (L/min or GPM)

3) Geometry Guidelines (Typical Ranges, Process-Dependent)

• Minimum wall thickness: ~0.5–0.8 mm near channels; thicker for threaded regions
• Channel width/diameter: ~0.8–1.2 mm (smaller is possible with tradeoffs in yield, cleaning, and clog risk)
• Lattice/pin-fin features: ~0.3–0.6 mm struts or pins, tuned for manufacturability and erosion resistance
• Powder evacuation: include drain/clean-out ports and internal sighting paths if you’re designing sealed channels

We’ll review your CAD for printability and suggest DFM edits that improve yield and simplify post-processing.

4) Sealing Strategy

• Fully printed, sealed channels with integral roof—preferred for compactness
• Printed core + cover plate joined by laser welding or brazing for ultra-smooth interior ceilings
• O-ring grooves (NBR/EPDM/FKM) with standard cross-sections; specify your fluid compatibility
• Threaded bosses: design for post-machining to guarantee gauge and surface finish

5) Surface Finish & Flatness

• As-printed LPBF copper interior surfaces are typically micro-textured, which can increase local turbulence (often good for heat transfer) but can also raise pressure drop.
• Post-machining of external mounting faces achieves tight flatness and low Ra for stable TIM performance. We recommend specifying flatness across the module land (e.g., 0.05–0.10 mm across ~150 mm) and a target surface finish for the TIM contact area.

Materials & Post-Processing

Alloys

• C110 (high-conductivity copper): maximum thermal performance; lower strength than precipitation-hardened grades.
• CuCrZr: stronger and more stable at temperature, with slightly lower thermal conductivity—excellent for manifolds, threads, and pressure-bearing zones.

Typical post-processing chain

1. Stress relief (reduces residual stress before machining)
2. HIP (Hot Isostatic Pressing) to minimize porosity for improved reliability and thermal conductance
3. Heat treatment (CuCrZr aging for strength)
4. Precision CNC of reference faces, seal grooves, and critical bores/threads
5. Surface finishing (polish, grind, or lap the module interface)
6. Cleaning & passivation appropriate for the coolant chemistry
7. Optional coatings: electroless nickel (EN/ENP), nickel–phosphorus, or thin conformal layers for corrosion control and dielectric standoff (where allowed by thermal budget)

Performance Engineering: Balancing Heat Transfer and Δp

We co-design channel geometry and inlet/outlet manifolds to maximize heat transfer where your power density peaks, while holding pressure drop to your pump budget.

• Pin-fin fields deliver high area density under concentrated hotspots (typical of SiC).
• Microchannels offer strong convection at moderate flow rates; pitch, aspect ratio, and roughness are tuned per coolant.
• Split-flow manifolds improve temperature uniformity across multiple devices in a single module.
• Anti-erosion fillets and flow diffusers protect corners and thin features in high-velocity regions.

Validation options include steady-state calorimetry, thermography, and on-bench Δp vs. flow mapping to confirm the model.

Quality, Test, and Reliability

• Leak testing: air-under-water, helium mass spectrometry for tight systems, or hydrostatic per your spec
• Proof & burst: set acceptance pressure relative to maximum working pressure and pump surge conditions
• Dimensional inspection: CMM for critical faces; internal verification by borescope or coupon sectioning as agreed
• Cleanliness: ionic/particulate requirements compatible with electronics assembly processes
• Traceability: lot-level material certs, heat-treatment history, and inspection logs available upon request

LPBF Copper vs. CNC/Brazed Cold Plates

For first articles, LPBF typically wins on development speed and performance-per-volume. At scale, hybrid strategies (printed core + machined interfaces) can hit both performance and cost.

Example Design Patterns You Can Request

• Dual-zone microchannel field under half-bridge devices with independent inlets (zoned control)
• Central pin-fin island with tapered approach channels (minimize entrance losses)
• Integrated sensor bosses for RTDs/NTCs at module corners and mid-span
• Vacuum-friendly drain ports for complete powder evacuation and post-cleaning
• O-ringed lid with laser-welded feed tubes to match your enclosure

If you already have a CFD model, send the scalar fields (heat generation and coolant velocity) with your RFQ. If not, we can run a quick design screen to narrow down topologies before you commit to full validation.

Specs Cheat Sheet (Typical, Project-Dependent)

• Alloys: C110, CuCrZr
• Build envelope (single piece): up to ~250 × 250 × 250 mm class; larger via segmentation and joining
• Feature guidance: channels ~0.8–1.2 mm; walls ~0.5–0.8 mm; pins/struts ~0.3–0.6 mm
• Seals: O-ring grooves (NBR/EPDM/FKM), laser-welded or brazed lids optional
• Finish: TIM face post-machined (specify Ra and flatness); internal roughness leveraged for h-transfer
• Tests: leak (helium or hydro), proof/burst, Δp–Q flow curve, thermal characterization (on request)

How to Request a Quote (What to Send)

1. Module info: make/model, footprint, keep-out zones
2. Heat map: watts per device or region, steady-state vs. transient details
3. Performance targets: max junction temp, ΔT budget, allowable pressure drop, pump curve
4. Coolant: type, temperature range, corrosion policy/inhibitors
5. Interfaces: TIM choice, clamping plan, required flatness/finish, isolation constraints
6. Envelope: space claim, port orientation, tube sizes, mounting points
7. Quantity & schedule: prototype count, ramp plan

Send details or a brief to [email protected]. Our engineering team will respond with DFM notes, a preliminary channel strategy, and lead-time/cost options from our copper 3D printing service.

Pricing & Lead Time (Indicative)

• Engineering + DFM: typically days for first pass on existing footprints
• Prototype LPBF builds: commonly measured in weeks, including post-processing and machining
• Validation: add time for specialized tests (helium leak, calorimetry, endurance) as needed Final pricing depends on size, alloy, channel complexity, machining, coatings, and test depth.

References & Further Reading

• JEDEC, JESD51 Thermal Characterization Standards – principles for measuring and comparing thermal performance.
• ASTM, D5470 – Standard Test Method for Thermal Transmission Properties of Thin Thermal Interface Materials.
• Infineon, Application Notes on Thermal Management of Power Modules (power modules & cooling best practices).
• SEMIKRON Danfoss, Technical Explanations: Thermal Interface and Cooling for Power Modules.
• NIST, Material Properties Resources (for copper thermal and physical properties).
• IEEE Power Electronics Society, Papers on Microchannel and Pin-Fin Cold Plates for SiC/IGBT Modules.

(Specific document numbers vary by revision; your QA team should reference the latest editions in your internal library.)

Frequently asked questions (fast answers)

Contact: [email protected]

Disclaimer: If you choose to implement any of the examples described in this article in your own projects, please conduct a careful evaluation first. This site assumes no responsibility for any losses resulting from implementations made without prior evaluation.