This is an extruded aluminum heatsink with a pre-assembled spring clip for through-hole or surface-mount power devices. We machine it on 5-axis CNC centers to hold fin spacing at
BQUQ Extruded Heatsink With Spring Clip | Precision CNC, No MOQ
This is an extruded aluminum heatsink with a pre-assembled spring clip for through-hole or surface-mount power devices. We machine it on 5-axis CNC centers to hold fin spacing at ±0.05 mm and base fla
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This is an extruded aluminum heatsink with a pre-assembled spring clip for through-hole or surface-mount power devices. We machine it on 5-axis CNC centers to hold fin spacing at ±0.05 mm and base flatness within 0.02 mm per 100 mm. The spring clip is made of 65Mn steel, heat-treated to 45–48 HRC, giving consistent clamping force of 18–22 N across 10,000 cycles. Lead time is 15 days for standard sizes, and we offer no MOQ for this product line.
How the Spring Clip Keeps IGBTs and MOSFETs Seated at 18 N Force
The clip is not a generic bent wire. We stamp it from 0.6 mm 65Mn spring steel, then oil-quench and temper to 45–48 HRC. Each clip is pre-assembled into the heatsink groove under a 2-ton press, ensuring the contact point lands exactly on the device center line. Measured clamping force: 18–22 N, repeatable within ±1 N. This prevents micro-vibration during thermal cycling, which is the main cause of thermal paste pump-out. We test clip retention with a 5,000-cycle push-pull fixture before any batch ships.
Extrusion Profile Limits: Fin Pitch, Height, and Base Thickness We Can Hold
Our 2000-ton extrusion press produces profiles up to 300 mm wide. For this heatsink, we hold fin pitch at 4.0 mm or 6.0 mm, fin height from 15 to 60 mm, and base thickness from 3 to 10 mm. Straightness is corrected with a stretcher to 0.5 mm per meter. After extrusion, we CNC-machine the mounting holes, counterbores, and clip grooves. Hole position tolerance is ±0.05 mm, and we use a CMM to verify the first article and every 50th piece.
Surface Finish Ra 0.8: Why We Skip Anodizing Unless You Ask
Standard finish is a bright dip and clear anodize (Ra 0.8 µm) for corrosion resistance. If your application needs maximum thermal contact, we can skip anodizing and machine the base to Ra 0.4 µm. Anodized layers have lower thermal conductivity than bare aluminum, so for high-heat-density designs, we recommend bare AL6063-T5 with a micro-etched surface. We record surface roughness with a Taylor Hobson profilometer on every batch — not just at sampling.
Materials and Heat Treatment We Use for the Clip and Extrusion
Extrusion: AL6063-T5 or AL6061-T6. 6063-T5 is standard for its thermal conductivity (201 W/m·K) and extrudability. 6061-T6 is used when you need higher mechanical strength (yield 240 MPa) for vibration-heavy environments. Clip: 65Mn spring steel, 45–48 HRC. If you need corrosion resistance, we substitute SUS301 stainless steel, tempered to 40–45 HRC. We do not use recycled aluminum without a mill certificate — every billet is traceable to the smelter.
Inspection Before Every Shipment: CMM, Pull-Test, and Surface Profiler
Each heatsink goes through three checks. First, a CMM measures hole positions and base flatness (0.02 mm). Second, a clip pull-test verifies the 18 N force with a digital force gauge. Third, a surface profiler checks Ra. We also do a 100% visual inspection for scratches, dents, and anodizing defects. For orders above 500 pieces, we include a dimensional report stamped by our QC engineer. We follow ISO 9001:2015 and can provide PPAP Level 3 if your customer requires it.
Packing, Anti-Static Protection, and Lead Time for Prototype vs. Production
Prototype (1–10 pieces) ships in 5 days via DHL Express, packed in ESD foam and anti-static bags. Production (100–10,000 pieces) ships in 15 days, packed in partitioned cardboard boxes with a foam insert that prevents fin bending. Each box holds 50 pieces, and we mark the carton with the part number, batch code, and RoHS compliance label. We do not use loose fill — every heatsink is individually sleeved to prevent surface abrasion.
How to Modify the Clip for Non-Standard Device Heights
Standard clip height is 10 mm, designed for TO-247 and TO-220 packages. If you use a different device, send us the package drawing and we adjust the clip bend angle and groove depth. We have 12 standard clip dies, and custom dies cost $400–$800 with a 7-day turnaround. For high-volume runs, the custom die cost is amortized into the unit price. We can also add a shoulder on the clip for larger devices like IGBT modules up to 62 mm wide.
Thermal Performance Data: What You Can Expect at 50 W and 100 W Loads
At 50 W, with a 4.0 mm fin pitch and 30 mm fin height, thermal resistance is 1.1 °C/W (natural convection, 25 °C ambient). At 100 W, resistance rises to 1.8 °C/W due to boundary layer effects. If you add forced air at 2 m/s, resistance drops to 0.4 °C/W. We provide thermal simulation (Fluent) free of charge for orders above 500 pieces. These numbers are measured, not simulated — we use a wind tunnel with a heated die to verify.
Why We Are a Precision Manufacturing Partner, Not Just a Supplier
Our 20-year history in Dongguan means we have in-house tooling, stamping, and CNC — no outsourcing. This is precision manufacturingmade in China with full process control. We have 40 CNC machines, 15 stamping presses, and 2 extrusion lines. You get one point of contact for the extrusion, clip, and final assembly. We routinely hit 99.2% on-time delivery, and we keep a buffer of 3,000 standard heatsinks in stock for same-day samples.
Specification
Value
Material (extrusion)
AL6063-T5 / AL6061-T6
Material (clip)
65Mn spring steel / SUS301
Clip hardness
45–48 HRC (65Mn) / 40–45 HRC (SUS301)
Fin pitch
4.0 mm / 6.0 mm
Fin height
15–60 mm
Base thickness
3–10 mm
Hole position tolerance
±0.05 mm
Base flatness
0.02 mm / 100 mm
Surface finish (anodized)
Ra 0.8 µm
Surface finish (bare)
Ra 0.4 µm
Clamping force
18–22 N (±1 N)
Lead time (prototype)
5 days
Lead time (production)
15 days
MOQ
No MOQ
FAQ: Your Questions, Directly Answered
What is the minimum order quantity?
No MOQ — you can order 1 piece for prototype testing, and we only charge a small setup fee for custom clip dies.
Can you customize the clip for a non-standard TO-264 package?
Yes, we have 12 standard dies and can make a custom die in 7 days for $400–$800, amortized into your unit price for production runs.
How do you ensure the clip doesn't lose force over time?
We stress-relieve the clip after forming and test 5,000 push-pull cycles — measured force stays within 18–22 N, verified with a digital force gauge.
What is your lead time for a 2,000-piece order with custom anodizing?
Standard production is 15 days; custom anodizing (e.g., black, hardcoat) adds 3 days, so 18 days total from drawing approval to shipment.
Get a firm quote within 12 hours. Email us at sc@bquq.com or WhatsApp +86 13713157787. Send your drawing in STEP, IGES, or PDF — we will confirm price, lead time, and clip force specifications the same day.
