Heat Sink
What is Heat Sink?
A heat sink is a passive cooling device designed to absorb and dissipate heat away from electronic components, machinery, or other heat-generating systems to prevent overheating and ensure stable operation. Typically made from thermally conductive materials like aluminum or copper, heat sinks feature a base that makes direct contact with the hot component and an array of fins or pins that maximize surface area. As heat transfers from the base to the fins, ambient air (or forced airflow from a fan) carries the thermal energy away through convection. Heat sinks come in various designs—including extruded, bonded fin, or stamped variants—depending on cooling requirements, space constraints, and cost considerations. Common applications include cooling computer processors (CPUs, GPUs), power electronics, LED lighting, and industrial equipment. While passive heat sinks rely solely on natural airflow, active versions incorporate fans or liquid cooling for higher heat dissipation. Advanced designs may also integrate heat pipes or vapor chambers for superior thermal conductivity. Key factors in heat sink performance include material selection, fin geometry, and thermal interface materials (like thermal paste) to ensure efficient heat transfer. Whether for consumer electronics, automotive systems, or renewable energy applications, heat sinks play a crucial role in thermal management—enhancing performance, reliability, and lifespan of sensitive components.
Types of Heat Sink
Extrusion Heat Sink
1. Process:
Mold Design
High-hardness alloy steel mold (H13 steel), designed with a split-flow combination mold structure, optimized tooth width/height ratio of 1:6-1:12 (ultra-thin teeth ≥ 0.8mm).
Die hole compression ratio controlled at 15:1-25:1 (to ensure uniform metal flow).
Extrusion molding, in-line quenching, stretch straightening, and age hardening.
2. Advantages
Extreme cost efficiency
Low mass production costs, mold life >50 tons
Structural reliability ceiling
No joints throughout, vibration resistance >30g (military standard MIL-STD-202G).
Superior thermal response speed
40% lower heat capacity than heat pipes, temperature rise rate three times faster (measured ΔT reaches steady state in 10s).
Unrivaled environmental adaptability, passed 2000h salt spray test (ISO 9227), operating temperature -50-200°C.
3. Disadvantages
Thermal performance bottleneck, low thermal conductivity; limited design freedom, Unable to achieve three-dimensional curved surface/special-shaped flow channel; weight disadvantage, the larger the mass, the heavier; the larger the size, the easier it is to deform, requiring additional straightening costs
Skiving Fin Heat Sink
Ultra-Thin, High-Density Cooling for Demanding Thermal Challenges!
1. Process
Substrate Preparation
Material: High thermal conductivity aluminum alloy or copper alloy, substrate thickness: 3-15mm (copper base requires ≥5mm to prevent deformation); CNC machining of skived teeth
2. Advantages: Extreme thermal performance, substrate-fin integration: zero interfacial thermal resistance, thermal conductivity efficiency reaches 98% of the material’s theoretical value
Extremely lightweight, with tooth thicknesses up to 0.3mm (aluminum)/0.2mm (copper), 50% lighter than aluminum extrusion
Revolutionary design freedom, supporting variable pitch (1-5mm gradient) and non-uniform pin height differences (±2mm height difference)
3. Disadvantages: Extremely high manufacturing costs, high tool wear, high aluminum base cost, processing efficiency bottlenecks, large size limitations, severe material waste, copper base material utilization rate <40%, 200% more consumables than die casting
Cold Forging Heat Sink
Superior Strength & Thermal Performance for Harsh Environments!
1. Processing
Preferred alloys for material selection: 6061 aluminum alloy or C1571 copper alloy. Blanking and pre-forming require a pressure of 50-100 MPa, with an accuracy of ±0.1mm. For reverse extrusion, the punch speed is 10-30 mm/s, with a tooth height accuracy of ±0.05mm. Finishing and punching are performed.
2. Advantages: Excellent strength-to-weight ratio; cold work hardening results in tooth hardness reaching HV90-110 (50% higher than the original material), a bending strength of >350 MPa, and a weight reduction of 30% compared to aluminum extrusion (minimum tooth thickness 0.6mm). Breakthrough thermal performance: continuous metal flow from base to fin (no cutting breakpoints), resulting in 15-20% higher thermal conductivity than machined parts. Supports custom-shaped tooth designs (asymmetric/wavy teeth), increases heat dissipation area by 20%, and offers cost advantages for mass production.
3. Disadvantages: Limited design complexity, mold manufacturing difficulties, 3D curved surface costs increase by 500%, and large-scale bottlenecks. Equipment tonnage restrictions (<2500 tons), maximum diameter ≤150mm
High thermal conductivity materials present challenges; copper alloys require heating to 200°C for cold forging, resulting in a 30% increase in equipment energy consumption and high initial investment. Multi-station cold forging machines cost >$1M, resulting in cost disadvantages for small batches.
Die Casting Heat Sink
Optimized for Mass Production with Superior Thermal & Mechanical Properties!
1. Process
Mold Design and Manufacturing
Material: H13 hot work die steel (hardness 48-52 HRC)
Structure: Multi-slide core-pulling design, cooling water channel tolerance ±0.1mm
Lifespan: >500,000 mold cycles for ADC12 aluminum, <100,000 mold cycles for copper alloy
2. Advantages
Excellent cost efficiency, fast mass production, >95% material utilization (twice as high as the skived tooth process), excellent structural strength
Thermal conductivity: 96W/mK to 120W/mK
Complex structure integration, capable of integrating mounting posts, screw holes, and snap-fit slots (reducing assembly steps by 30%)
Minimum wall thickness: 1.2mm (aluminum) / 2.0mm (copper), tooth-to-height ratio: 5:1
Environmental adaptability: Operating temperature: -40°C to 200°C (aluminum) / -50°C to 300°C (copper)
IP68 protection rating (die-cast body airtightness: <10⁻³Pa·m³/s)
3. Disadvantages
Defect Types Root Causes and Quantified Impacts
Thermal Performance Bottleneck: Porosity 2-5% (15-25% thermal loss); Heat Flux Limitation 50W/cm²
Design Limitations: Draft Angle ≥ 1°; Spurs cannot be designed vertically
Dimensional Precision Defects: Shrinkage 0.5-0.7%; Tolerance ±0.3% for lengths > 200mm
High Thermal Conductivity Material Cost; Copper Alloy Die-Casting Molds Rapidly Degrade; Unit Cost Increased by 300%
Fin-Welded Heat Sink
Ultra-Efficient Thermal Solutions with Custom Fin Designs for Demanding Applications!
1. Process: The aluminum fins are electrolessly nickel-plated, then solder paste is filled between the fins and the baseplate, followed by reflow soldering.
2. Advantages: Ultra-low cost, with equipment investment only 1/20 of that of laser welding (common for SMT lines), and high efficiency.
Low-temperature process protects the substrate, with peak temperatures below 250°C (no softening of the aluminum substrate, and T6 hardness retention >98%).
High design freedom, supporting 0.1mm ultra-thin fins and three-dimensional curved substrates (not possible with laser welding).
Reworkability: Individual fins can be replaced with localized heating (rework cost <$0.1, while brazing requires the entire assembly to be scrapped).
3. Disadvantages: Thermal resistance bottleneck: tin layer thermal conductivity of 60W/mK, interface thermal resistance of 0.15-0.25 cm²K/W (five times that of laser welding).
Insufficient mechanical strength, brittle Sn-Cu interface IMC layer.
FAQ
1. What is the mold cycle for profiles?
Simple molds typically take less than 15 days, while complex ones are estimated at 25 days.
2. What is the mold cycle for die casting?
Mold opening time is typically around 45 days.
3. What is the mold cycle for cold forgings?
Mold opening time is typically around 20 days.
4. What is the mold cycle for fins?
Mold opening time is typically around 25 days.
Applications
