This is a large industrial heatsink machined from solid aluminum or copper, built for high-power IGBT modules, rectifiers, and laser power supplies. We hold a ±0.01 mm machining tolerance, 0.02 mm sur
This is a large industrial heatsink machined from solid aluminum or copper, built for high-power IGBT modules, rectifiers, and laser power supplies. We hold a ±0.01 mm machining tolerance, 0.02 mm surface flatness, and a 0.03 mm runout across the base plate — measured on every unit before shipment. Typical lead time is 15 days for prototypes, 25 days for production runs, and we offer a 40 HRC anodized surface option for wear resistance.
Your IGBT module transfers heat through the base plate. If that plate is not flat, air gaps forms under the module, and thermal resistance jumps by 30% or more. We machine the base plate on a 5-axis CNC with a vacuum chuck, holding flatness to 0.02 mm over any 300 mm length. We verify every plate with a granite surface plate and dial indicator, not by sampling. If you need better than 0.02 mm, we can get to 0.01 mm with a secondary lapping pass — but that adds 3 days to the lead time.
Fins are not decorative. For forced-air cooling, a 2.5 mm fin thickness with 6 mm pitch gives the best balance of surface area and airflow at 3 m/s. We hold fin thickness to ±0.05 mm, which is critical because if a fin is 0.1 mm thicker than spec, you lose 4% of the airflow channel area. Fin depth up to 100 mm is standard for our large heatsinks. Deeper fins require a custom tool path and a longer cutter — our CNC cutting tool selection guide explains how we choose the right end mill for deep slots without deflection.
We start with 6063-T5 aluminum for most large heatsinks because it has a thermal conductivity of 200 W/m·K and is easy to extrude and machine. For higher heat loads, we use 6061-T6 (167 W/m·K) when you need better strength, or C11000 copper (385 W/m·K) for liquid-cooled cold plates. After machining, we can apply a hard anodize to Type III spec — that gives a 40 HRC surface hardness and a 0.05 mm coating thickness. For bare aluminum, we degrease and passivate to prevent galvanic corrosion with copper mounting hardware.
Large heatsinks are prone to warping during machining because removing 60% of the stock releases internal stress in the raw material. We stress-relieve every aluminum billet before machining: heat to 350°C, hold for 2 hours, and cool slowly. Then we rough-cut the fins, let the part rest for 24 hours at room temperature, and finish-cut with a light pass. This two-step process keeps runout (TIR) at 0.03 mm on the mounting face. If you skip stress relief, you will see 0.15 mm of warp on a 400 mm long heatsink. We do not skip it.
Each heatsink gets a serial number and a full inspection report. We measure flatness with a dial gauge on a granite table, runout with a V-block and indicator, and surface finish with a profilometer at three points on the base. Fin thickness is checked with a caliper at 10 random positions. The report includes a CMM check of all mounting hole positions — we hold true position to 0.05 mm. You will receive this report as a PDF with the shipment. If any dimension is out of spec, we re-machine or scrap it. We do not ship "close enough" parts. Our CNC machining tolerances guide explains the full range of what we can hold on different features.
| Specification | Standard Value | Notes |
|---|---|---|
| Material | 6063-T5, 6061-T6, C11000 copper | Other alloys on request |
| Base plate thickness | 10 mm – 40 mm | Custom per drawing |
| Heatsink length | 100 mm – 1200 mm | Longer on request |
| Fin thickness | 1.5 mm – 5.0 mm | ±0.05 mm tolerance |
| Fin pitch | 4 mm – 12 mm | Uniform or variable |
| Fin depth | 10 mm – 100 mm | Limited by tool reach |
| Surface flatness | 0.02 mm over 300 mm | 0.01 mm with lapping |
| Runout (TIR) | 0.03 mm | On mounting face |
| Surface finish (Ra) | 0.8 µm base, 1.6 µm fins | As-machined |
| Hardness (anodized) | 40 HRC | Type III hard coat |
| Tolerance (machined) | ±0.01 mm | On critical features |
| Lead time | 15 days prototype, 25 days production | For quantities under 500 pcs |
We do not just machine fins. We drill and tap mounting holes for IGBT modules, thermistors, and fan brackets. Standard hole patterns include 2-hole, 4-hole, and 6-hole configurations for common module sizes like 62 mm x 108 mm and 73 mm x 140 mm. We can also cut keyways, slots, or dovetails on the base plate for rail mounting. Threads are cut with a form tap to give a stronger thread profile — that matters when you screw and unscrew modules multiple times. We hold thread depth to ±0.3 mm and clean every hole with compressed air before packaging.
We are a precision manufacturing factory in Dongguan, China, with 20 years of experience in CNC machining, stamping, and springs. Our minimum order quantity is zero — you can order one prototype heatsink for testing, or 5,000 pieces for production. The only difference is the unit price. For a single piece, we charge a small setup fee to cover the CNC programming and fixturing. For orders over 100 pieces, the setup fee is waived. This no MOQ policy means you can validate your thermal design before committing to inventory. We have shipped single pieces to engineering teams in Germany, the US, and Japan within 15 days.
A 400 mm x 300 mm heatsink is heavy and has sharp fins. We wrap each piece in VCI (vapor corrosion inhibitor) paper to stop oxidation during transit. Then we place it in a wooden crate with foam padding at all corners. For copper heatsinks, we add a desiccant pack inside the sealed bag. We export via DHL, FedEx, or sea freight depending on your urgency. In 20 years, we have had zero claims for damaged heatsinks in transit — the crate design and foam layout are proven for parts up to 50 kg.
There is no MOQ — we machine a single prototype or a full production run at the same quality level.
Yes, send us your 2D drawing or 3D STEP file, and we will quote the exact dimensions, tolerances, and surface finish within 12 hours.
Every part, prototype or production, gets a full inspection report with CMM measurements and a flatness check before shipping.
Prototypes ship in 15 days, and production quantities of up to 500 pieces ship in 25 days from drawing approval.
Send your drawing for a firm quote within 12 hours. Email sc@bquq.com or WhatsApp +86 13713157787. We will confirm material, tolerance, and lead time on your specific large industrial heatsink — no MOQ, made in China, with precision manufacturing you can verify.
| Parameter | Capability |
|---|---|
| Materials | AL6063/6061/5052, pure copper C1100, copper-aluminum composite |
| Process | Extrusion, CNC machining, skiving, forging, die casting, stamping fins |
| Fin Types | Extruded, pin fin, skived, folded, bonded, heat pipe, vapor chamber |
| Surface | Black anodizing, clear anodizing, nickel plating, powder coating |
| Size Range | Max 1500 x 400 x 300 mm |
| Thermal Test | Thermal resistance and heat dissipation data per batch |
| Prototype | 5-7 days, no MOQ on samples |
| Inspection | CMM, thermal resistance tester, full report per batch |
