技术分享

Laser welding has irreplaceable core advantages in the field of sensor manufacturing, especially in key requirements such as miniaturization, high reliability, and material compatibility. The following is an analysis of the specific advantages of different industries and the fundamental logic for choosing laser welding:

🔥  Core advantages of laser welding (cross industry commonality)

Characteristic technical value                                                                                                                     Addressing industry pain points

The heat affected zone has a very small energy density of up to 10 ⁶~10 ⁸ W/cm ² (100 times higher than arc welding), and the thermal deformation is controlled at the micrometer level to avoid thermal damage to precision components (such as MEMS chips) inside the sensor

Non contact processing without mechanical stress conduction, zero deformation when welding fragile structures such as pressure sensor membranes to maintain the structural integrity of microfluidic chips/optical devices

The welding accuracy reaches micrometer level with a spot diameter of 20-100 μ m, which can achieve a 0.1mm ultra narrow weld (traditional welding gun ≥ 0.5mm) and meet the packaging requirements of microsensors (such as implantable medical sensors)

The high sealing weld seam has a gas tightness of 10 ⁻⁹ mbar · L/s (helium leak detection level), far exceeding resistance welding (10 ⁻⁵ level), ensuring the reliability of pressure/gas sensors in extreme environments

Wide material compatibility for welding copper aluminum dissimilar metals, high reactivity materials (gold/silver coatings), refractory metals (tantalum/molybdenum), etc. to solve the problem of multi material integration in new energy vehicle sensors

🚗  Deep analysis of industry application scenarios

1. Automotive sensors: dual requirements of safety and miniaturization

Advantages reflected

Anti electromagnetic interference: Laser welding does not require current conduction (different from resistance welding), avoiding affecting the signal accuracy of Hall current sensors

Space adaptability: Fiber laser can weld detonation sensors with a gap of<5mm inside the engine compartment (traditional welding guns cannot enter)

High strength connection: At 650 ℃, the strength of laser welded joints in turbine pressure sensors is 200% higher than that of brazed joints

Typical case: Bosch oxygen sensors use pulsed laser welding to seal and weld ZrO ₂ ceramics with stainless steel shells, with a leakage rate of<5 × 10 ⁻⁹ mbar · L/s

2. Medical sensors: biocompatibility and sterile packaging

Advantages reflected

No welding slag pollution: Continuous laser welding avoids splashing contamination of blood glucose sensor enzyme coating

Low temperature welding: Blue light laser (450nm) welding polymer conduit sensor, temperature<120 ℃ (traditional hot plate welding>300 ℃)

Microchannel sealing: Picosecond laser welding of microfluidic chips, with weld width ≤ 50 μ m and no internal stress cracks

Typical case: Medtronic implantable blood glucose monitor uses laser sealed welded titanium alloy shell, which has passed ISO 13485 biocompatibility certification

3. Industrial sensors: extreme environmental tolerance

Advantages reflected

Corrosion resistant welding: In oil and gas sensors, the resistance to Cl ⁻ corrosion of laser welded Hastelloy C276 is three times higher than that of TIG welding

Anti fatigue characteristics: After 10 cycles of loading, the fatigue strength of the weld seam of the wind power torque sensor in laser welding is 40% higher than that in MIG welding

Depth to width ratio control: High power laser welding of deep-sea pressure sensors, achieving a narrow and deep weld seam with a depth to width ratio of 1:10 (arc welding only 1:3)

Typical case: Siemens vibration sensor uses swing laser welding to improve the low-temperature toughness of 304 stainless steel weld by 35%

⚙️  Why do we have to choose a laser welding machine?

Precision deviation

When the sensor component size is less than 1mm (such as MEMS accelerometers), only laser welding can achieve a diameter of 30 μ m solder joint (electron beam welding requires a vacuum environment, doubling the cost).

Adaptability of Material Revolution

The new sensor adopts ceramic substrate (AlN/Al ₂ O ∝) or metallic glass, and laser is the only technology that can achieve ceramic Kovar alloy airtight sealing.

Full lifecycle cost advantage

Process unit cost (USD), yield maintenance cost

Laser welding 0.12~0.3 ≥ 99.5% low

Resistance welding 0.08~0.15 92~95% electrode replacement

Electron beam welding 0.5~1.2 98% vacuum system

6-19 Sensor

Ultimate conclusion: When sensors involve any two of the three major characteristics of miniaturization design, active material packaging, and extreme environmental reliability, laser welding is the only economically feasible solution. Among the top 10 global sensor manufacturers by 2025, the penetration rate of laser welding has increased from 41% in 2020 to 79% (Yole data), marking an irreversible upgrade in the technology roadmap.