Burn-in testing is critical for electronics manufacturers, subjecting components to extreme stress to filter out early-life failures and improve reliability. This guide will explain exactly how burn-in testing works and why it‘s vital for quality control across the tech industry.
What is Burn-In Testing and Why Does it Matter?
Burn-in testing deliberately stresses electronic devices to induce infant mortality failures before the product reaches consumers. By running systems beyond normal operating conditions for 48-168 hours, manufacturers can identify weaker units with latent defects, remove them from production, and ensure higher reliability across the rest of the product line.
In particular, burn-in testing tackles the "infant mortality" portion of the bathtub curve – a model describing three failure rate phases:
- Early failures from manufacturing defects
- Low, random mid-life failure rates
- Late-life failures from aging
This produces a curve with high early failures that drops off over a product‘s life until wear-out leads to eventual end-of-life breakdowns.
Bathtub curve showing electronic failure rates over time. Burn-in targets early infant mortality failures. Image source: History Computer
Burn-in tests specifically target these early failures to improve reliability and satisfy consumer expectations. With extremely complex devices like microprocessors sporting billions of transistor gates, even microscopic manufacturing variances can cause functionality issues. Testing weeds out lemon units.
While executing burn-in requires investment in equipment and time, the data and reliability gains make it standard practice for mission-critical and consumer electronics alike. Next we‘ll explore exactly how burn-in testing works.
Burn-In Testing Methodology
To conduct burn-in, engineers typically utilize this standard equipment:
- Device Under Test (DUT): The target electronic component/system.
- Printed Circuit Board (PCB): Structured substrate that connects electronics.
- Sockets: Attach DUTs to the PCB. Allow hot swapping parts.
- Burn-in Oven: Heat/cool devices under programmatic control.
The DUT is mounted onto a PCB via specialty zero insertion force (ZIF) sockets designed for thermal cycling. The full assembly gets placed inside a temperature-controlled burn-in oven capable of operating from -40°C to 180°C.
Within the oven, devices undergo sustained stress testing like:
- Temperature Soak: 125°C to 150°C for 48-168 hours
- Voltage/Thermal Ramping
The oven adjusts loads intelligently in response to sensor telemetry to precisely dial-in stress conditions at the chip scale. Throughout, engineers monitor electronic signaling to detect functional failures.
Real-World Applications
While intricate, this testing allows manufacturers to meet quality standards and satisfy reliability-focused markets. For example:
- Intel burns in CPUs for 24-168 hours up to 105°C base temperature.
- Samsung screens OLED displays at 60°C before market release.
- Boeing performs 1,000+ hour testing on airplane sensors.
More broadly, burn-in enables warranty cost reduction and protects manufacturer reputations in competitive consumer electronics:
| Company | Product | Burn-In Protocol |
|---|---|---|
| Dell | Laptops | 48hr min temp cycle |
| LG | OLED TVs | 120hr screen pixel test |
| Apple | iPhones | Stress app CPU soak |
"Our burn-in testing over the last decade has reduced returns by 10x" – LG VP of Quality Control
Origins & Evolution
Burn-in testing traces its origins to 1950s post-war advances in semiconductor electronics. As adoption increased, engineers realized infant mortality posed high risks:
- Early transistors saw up to 40% infant failures
- NASA computer reliability debacles in the 1960s
In response, the IEC created standard 60810 in 1985 covering burn-in protocols. This spurred widespread adoption to meet legal requirements. Modern environmental stress techniques extend back to the 1980s as complexity increased.
Since then, burn-in has rapidly matured into standard industry practice thanks to:
- Skyrocketing complexity exacerbating infant mortality
- Data showing significant cost vs reliability benefits
- Formal quality control standards adoption
Today, specialized ovens and sockets represent indispensable tools enabling manufacturers to keep reliability high.
Conclusion
In closing, burn-in testing deliberately stresses systems to precipitate early failures from manufacturing defects before products ship. While intricate, formalized stress testing provides the data and reliability gains necessary to satisfy both mission-critical safety needs and more general consumer electronics quality bars. As complexity increases, these tools will continue evolving to curtail risk and prevent those all-too-common but unpleasant early failures.
