What This Heat Sink Does and The Numbers That Matter This is a CNC-machined aluminum heat sink built for active or passive cooling of power electronics, LED modules, and IGBTs. You get a flatness of
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What This Heat Sink Does and The Numbers That Matter This is a CNC-machined aluminum heat sink built for active or passive cooling of power electronics, LED modules, and IGBTs. You get a flatness of
This is a CNC-machined aluminum heat sink built for active or passive cooling of power electronics, LED modules, and IGBTs. You get a flatness of 0.05 mm across the base, surface finish Ra 0.4, and fin thickness down to 1.2 mm with a 15-day lead time. The material is 6063-T5, hardness 80 HB, which gives you a thermal conductivity of 201 W/m·K — enough to drop junction temperatures by 35% in a typical forced-air enclosure, as verified on our own test rig.
Fins are the weak point. Thin walls vibrate, deflect, and tear. We cut them with a 4-flute carbide end mill at 12,000 RPM with a 0.3 mm radial engagement. That keeps the cutting force under 90 N, so the fin stays straight. Runout on the spindle is under 2 microns. The result: fin spacing tolerance ±0.05 mm, fin height ±0.1 mm, and zero burrs on the tips. We reject any part with a bent fin — it is not worth shipping to you.
For deep fin channels (over 30 mm), we use a trochoidal tool path. That reduces heat buildup at the tool tip and prevents work hardening. If you have a design with 40 mm fins, we are not guessing — we have done it. Send your drawing and we will tell you the exact cycle time.
Standard is 6063-T5 for its extrudability and corrosion resistance. But you are not limited. We also machine 6061-T6 (harder, 95 HB, better for tapped holes), 5052 (for bending), and 7075-T6 (for structural fins exposed to vibration). All billets are certified with mill test certificates — MTC included with every shipment. We do not buy scrap extruded bar from unknown sources.
After CNC machining, we apply a heat treatment if specified: T6 for 6061 (solution annealed at 530°C, aged at 175°C for 8 hours). That gives you a yield strength of 276 MPa. For anodizing, we use sulfuric acid type II, thickness 18-20 microns, with a dye seal. No bare aluminum ships unless you ask.
You want more fins per inch? We can cut 9 fins per inch (3.0 mm pitch) on a 20 mm tall profile. Minimum fin thickness is 1.2 mm, maximum fin height is 50 mm (with a 2:1 height-to-thickness ratio, not 3:1 — we are honest about limits). Base thickness can be 2.5 mm minimum. If you need a stepped base or a mounting boss with a tapped hole, we machine it in one setup. No secondary operations.
We do not weld fins. That creates a thermal barrier. We machine from solid billet or from an extruded profile that you supply. For prototypes, solid billet is faster. For volume, we can use a hybrid: extruded base + machined fins. But for 90% of our orders, solid billet is the right call — you get uniform grain flow and no porosity.
Flatness on the base is what matters for thermal paste or a phase-change pad. We hold 0.05 mm flatness on the entire base. On the contact area (where your IGBT mounts), we can go tighter: 0.02 mm over 50 mm x 50 mm. Surface finish Ra 0.4 is standard. If you use a graphite pad, we recommend Ra 0.8 for better wetting — we do not force a mirror polish on you because that is not always better. We measure flatness with a granite plate and dial indicator, not by eye.
Every heat sink gets a first-article inspection (FAI) with a CMM for critical dimensions. For every production lot, we check: fin height (caliper), fin spacing (pitch gauge), base flatness (dial indicator on granite), surface finish (profilometer), and anodize thickness (eddy current). We also do a 100% visual check for scratches and bent fins. We provide a certificate of conformance with each box. If you have a specific PPAP requirement, we can do that — we supply full documentation for automotive and medical customers.
| Specification | Value |
|---|---|
| Material | 6063-T5, 6061-T6, 5052, 7075-T6 (MTC provided) |
| Standard size range | 20 x 20 mm to 600 x 600 mm base |
| Fin thickness | 1.2 mm minimum (standard), 0.8 mm with special tooling |
| Fin height | 50 mm maximum (solid billet) |
| Fin pitch | 3.0 mm (9 FPI) standard, 2.5 mm on request |
| Hardness (6063-T5) | 80 HB (as machined) |
| Hardness (6061-T6) | 95 HB (after heat treatment) |
| Dimensional tolerance | ±0.05 mm (fin spacing), ±0.1 mm (fin height) |
| Base flatness | 0.05 mm overall, 0.02 mm on IGBT contact area |
| Surface finish (machined) | Ra 0.4 µm (standard), Ra 0.8 µm for TIM pads |
| Runout (spindle) | ≤2 µm (guarantees fin straightness) |
| Anodizing | Type II, 18-20 µm, black or clear |
| Lead time | 15 days for prototypes, 20 days for production (100+ pcs) |
| MOQ | No MOQ — 1 piece for prototyping is fine |
We have seen 200+ heat sink drawings in the last 5 years. Some are made for extrusion, not machining. If your fin spacing is 1.0 mm with a 40 mm height, we will tell you it is not machinable without breaking tools. Instead, we suggest a two-piece design (base + fin stack) or a different material. We are not here to win a quote by saying yes to everything. We are here to make a part that works. If your design has a blind hole in the base for a thermocouple, we can drill it — depth 10 mm, diameter 3 mm, no problem. But if it is a 0.5 mm hole, we will tell you it is a cost trap and suggest a press-fit insert.
Fins are fragile. We ship in a rigid corrugated box with EVA foam inserts that cradle the fins. Each part is individually wrapped in anti-static film. We do not use loose peanuts. For export, we use a 5-layer export-grade carton. Air freight from Shenzhen to Los Angeles takes 5 days. Sea freight (Shanghai to Rotterdam) takes 30 days. We mark every box with your PO number and a barcode. If you need a specific packaging method (e.g., reusable tote), we do that — but it will add 2 days to the lead time.
No MOQ. We machine a single prototype or a 10,000-piece production run with the same quality system.
Yes, send a sample or a 2D/3D drawing. We will measure fin thickness, pitch, and height, then machine it within ±0.05 mm of your sample.
We use first-article inspection on the first piece, then in-process checks every 20 pieces (fin height and flatness), and a final CMM check on 5% of the lot. We also photograph each heat sink before packing.
Prototype (1-5 pcs) is 15 days including CNC programming. Production (100+ pcs) is 20 days. If you need it faster, we have a 7-day express service for simple geometries — ask about it when you send your drawing.
Before you finalize your design, check our CNC cutting tool selection guide to understand how tool geometry affects your fin finish. And if you are setting tolerances, our CNC machining tolerances guide will help you avoid over-specifying and paying too much.
Get a firm quote within 12 hours. Send your drawing (STEP, IGES, or PDF) to sc@bquq.com or WhatsApp +86 13713157787. We will reply with a price, a DFM (Design for Manufacturing) review, and a lead time. No obligations. This is precision manufacturing from BQUQ — we have been doing this in Dongguan since 2004.
| 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 |
