Category Archives: Process


Jul10
Customer Complaint About Oil Contamination on PCB: Who’s the Real Culprit? (FTIR Analysis)

post on July 10, 2025

In the previous article, Workingbear mentioned a serious DOA (Dead on Arrival) customer complaint involving one of the company’s products. Most of the defective units had unresponsive keypads—specifically the 3, 6, and 9 buttons—and it was eventually traced back to … Continue reading →

Case study, EDX/EDS/SEM/IMC/FTIR, Keypad, Process, Quality     WorkingBear    Views (3,035)     comments (1)
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Jul03
[Case Study] Troubleshooting a Customer Complaint – Keypad Malfunction Caused by Oil & Powder Contamination on the PCB

post on July 3, 2025

This article shares a real case from Workingbear’s past experience dealing with an urgent customer complaint. One day, Workingbear was suddenly assigned to fly to a factory in China to “hunt for oil.” My manager even warned, “If you don’t … Continue reading →

Case study, EDX/EDS/SEM/IMC/FTIR, Keypad, Process, Quality     WorkingBear    Views (2,767)     comment (0)
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Jun26
What is Environmental Stress Screening (ESS)?

post on June 26, 2025

Environmental Stress Screening (ESS) is a method used to apply certain environmental and operational stresses—such as power on/off cycles, bias voltage, pressure, thermal cycling, and vibration—to new or repaired products (usually electronics or components). The idea is to expose hidden … Continue reading →

Process, Quality, Reliability, Test/Inspection     WorkingBear    Views (3,921)     comment (0)

Jun05
Tumble Test: How to Prevent PCB and BGA Failures in Electronics Manufacturing

post on June 5, 2025

From what I remember, one of the earliest and most frequent requests for tumble testing came from Motorola. Since some of Motorola’s mobile phones and products were designed for military use, their reliability and quality standards were exceptionally strict. However, … Continue reading →

Design, Process, Quality, Reliability     WorkingBear    Views (2,686)     comment (0)

May29
Uncovering the Culprit: How CAF Turned Out to Be the Hidden Cause Behind PCB Micro-Shorts — From Suspicion and Analysis to Solutions

post on May 29, 2025

Workingbear’s company was having a tough time with a strange issue: intermittent micro-short circuits inside the layers of the PCB. Since the shorts didn’t show up near any components, it was really hard to figure out what was wrong. Recently, … Continue reading →

Case study, EDX/EDS/SEM/IMC/FTIR, PCB/FPC/PTF, Process, Quality, Reliability     WorkingBear    Views (5,597)     comments (2)
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