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

These two lab cross-sections show conductive material growing along glass fiber gaps.

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, we made a breakthrough. We finally got a faulty PCB that consistently showed the issue. After working with the PCB manufacturer to analyze it, we found the likely cause: CAF (Conductive Anodic Filament)—a type of metallic filament caused by electrochemical migration (ECM), which is known to cause failures in PCBs.

At last, we had a clear direction to investigage. Before that, our customer was getting very frustrated because we couldn’t find the root cause.

read more…》

Case study, EDX/EDS/SEM/IMC/FTIR,, PCB/FPC/PTF, Process, Quality, Reliability     WorkingBear    Views (503)     comment (0)
, ,

May22
What is CAF (Conductive Anodic Filament) in PCBs? and How to Prevent It

post on May 22, 2025

CAF Configuration Variants

One of our company’s products once experienced an issue called an “internal micro-short” in the printed circuit board (PCB). After investigation, we discovered the root cause was something called CAF (Conductive Anodic Filament). But let’s be honest—if you translate that literally, hardly anyone would understand what it means! Simply put, CAF is a kind of hidden short circuit that forms inside a PCB layer or even under the solder mask (the green coating on the surface of circuit board).

read more…》

PCB/FPC/PTF, Quality, Reliability, SMT, Soldering     WorkingBear    Views (619)     comment (0)
, ,

May15
The Role of Process Engineers and Product Engineers in a Company

post on May 15, 2025

The Role of Process Engineers and Product Engineers in a Company

Many people, especially newcomers to the workforce, may feel confused when they first hear the term Process Engineer. What exactly does a process engineer do?

First, let’s understand what process means. Simply put, a process refers to the manufacturing procedure—the steps and methods used to produce a product.

read more…》

Role & Responsibility, Uncategorized     WorkingBear    Views (582)     comment (0)

May08
The Deep Dive: BGA Pads: SMD vs. NSMD (Strength, Voids & Design Considerations)

post on May 8, 2025

The deep dive BGA pads SMD vs NSMD

Hey folks, welcome back to the blog! Today, we’re diving deep into something absolutely critical for the reliability of almost every electronic gadget out there: BGA solder joints. You know, those tiny connections that hold complex chips onto our printed circuit boards (PCBs). Keeping them strong and free from defects like those pesky little bubbles inside the solder – we call them voids – often comes down to a surprisingly fundamental aspect: the design of the pads on the PCB.

read more…》

Design, PCB/FPC/PTF, Process, Quality, Reliability, SMT     WorkingBear    Views (655)     comments (1)
,

Apr30
Understanding the EDX Report: Can EDX Be Used to Estimate a Sample’s Chemical Formula?

post on April 30, 2025

How To Identify IMC Like like Cu₆Sn₅, Cu₃Sn, or Ni₃Sn

Workingbear has noticed that many people still have questions about EDX/EDS elemental analysis reports. This is the second article where he tries to provide answers based on his knowledge.

EDX (Energy-Dispersive X-ray Spectroscopy), also known as EDS, is actually an auxiliary function used in SEM (Scanning Electron Microscopy), TEM (Transmission Electron Microscopy), and STEM (Scanning Transmission Electron Microscopy) analysis techniques.

read more…》

EDX/EDS/SEM/IMC/FTIR,     WorkingBear    Views (696)     comment (0)