Lesson 9/1090%
MODULE 09

Engineering Case Studies

Twelve real-world-style ESD failures spanning every product category from Module 06 -- each with the reported symptom, the investigation path, the root cause, and the fix that resolved it.

Learning Objectives

🕵️
Apply a structured ESD investigation process
🧩
Recognize recurring root-cause patterns
🛠
Connect symptoms to concrete design fixes
QFP IC package with a large rupture and melted plastic across its top
When the failure analysis is easy: a QFP that absorbed far more energy than any protection structure could shunt. Most of the failures in this library left no visible mark at all — that's what makes them case studies.

Three fully worked failures. For each one, read the debugging trail, then study the circuit diagram and the top view of the actual PCB. Use the Failing design / Fixed design toggle to compare the layout that failed with the layout that passed — the schematic barely changes, the placement is what makes or breaks it.

Circuit Diagram & Component Placement on the PCB

Schematic
PCB top view (component placement)

Across compliance-lab reports and field-return analyses, the same handful of root causes account for the overwhelming majority of ESD failures. The shares below are illustrative of commonly reported industry experience — the ranking is what matters. Note that the single most common cause is not a missing part: it is a protection part that exists but cannot do its job because of where it sits on the board.

The pattern to internalize: ESD failures are layout failures more often than schematic failures. A TVS diode 15 mm from its connector, or one returning through a single thin via, shows up as "protected" in the schematic review and still fails in the chamber. Every deep-dive case in Section 2 above is a variation of this theme.
KNOWLEDGE CHECK

Module 9 Quiz

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