Aug25
[Case Study] BGA Solder Ball Cracking: Strain Gauge Analysis and Design Improvement

BGA soldering crack analysis: using Cross-Section
Figcaption:BGA soldering crack analysis: Cross-Section shows crack locate at IMC location

During new product development, electronics companies may encounter BGA solder ball cracking after a drop test in which the bare unit is dropped from a specified height. When this happens, the R&D team should take a systematic approach and perform a stress-strain analysis rather than immediately assuming that the BGA cracking is caused by the SMT process.

Based on Workingbear’s experience, BGA solder ball cracking is often difficult to resolve through SMT process controls or simply by increasing the amount of solder. In many cases, the root cause is related to the mechanical design of the product. Addressing the problem at the design stage can significantly reduce manufacturing costs and engineering effort later in the product life cycle.

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Aug19
BGA Solder Ball Crack Analysis: How to Identify the Root Cause Using the Red Dye Penetration Test

BGA Solder Ball Crack Analysis: How to Identify the Root Cause Using the Red Dye Penetratio Test
Figcaption: How to Identify the True Root Cause of BGA Solder Ball Cracking Using the Red Dye  Penetration Test

When a BGA fails and the Red Dye Penetration Test reveals cracked solder balls, how can we determine the actual root cause? Does the Red Dye Penetration Test simply tell us that a solder ball is cracked, or can we use the results to identify why the crack occurred?

BGA solder ball cracking can generally be associated with several failure mechanisms, including HIP (Head-In-Pillow), HoP (Head-On-Pillow), NWO (Non-Wet-Open), and mechanical stress applied after soldering. In many cases, more than one factor may contribute to the failure.

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Aug12
BGA Solder Ball Crack Analysis Using the Red Dye Test | Types and Failure Patterns

BGA Solder Ball Crack Analysis Using the Red Dye Test | Types and Failure Patterns
Figure: Use the Red Dye Test to Identify BGA Solder Ball Cracks: Failure Patterns and Practical Analysis

BGA IC functional failures are a major headache for many electronics companies. This is especially true today, as most CPUs use BGA packages. When a product with a boot-up failure is returned from the customer and we need to determine the root cause, one of the most common methods used to identify the root cause is the Red Dye Penetration Test.

One of the main advantage of the Red Dye Test is that it provides a clear visual indication of where solder ball cracks have occurred across the entire BGA. This allows manufacturing and R&D engineers to quickly identify potential failure locations and better understand the possible causes and sources of mechanical stress.

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Jul30
How to Analyze Returned Electronic Products and BGA Failures: A Practical Step-by-Step Troubleshooting Guide

如何著手分析市場返修的電子不良品及BGA不良
Figure: Using the Red Dye Penetration Test to Check BGA Solder Joints for Open Solder or Head-in-Pillow (HIP) Defects

At first glance, analyzing returned electronic products or BGA failures doesn’t seem all that complicated. In reality, however, many new engineers have no idea where to begin when a failed unit is returned from a customer or the field. Even worse, I’ve watched new engineers accidentally destroy critical evidence before they even start the investigation. Once the evidence is gone, so are many of the clues needed to find the real root cause.

Troubleshooting a failed electronic product is surprisingly similar to solving a crime in CSI or NCIS. Instead of rushing to conclusions, you start by gathering evidence and carefully examining every clue. From there, you develop possible root-cause hypotheses and test them one by one until the real culprit reveals itself. Ideally, you should also be able to reproduce the failure. If you can’t recreate it, there’s always a chance you’ve only found a symptom rather than the actual root cause.

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Jul22
Should BGA Pads Be Designed as SMD or NSMD? Pros, Cons, and Drop-Test Performance

Should BGA Pads Be Designed as SMD or NSMD? Pros, Cons, and Drop-Test Performance
Figcaption: Should BGA Pads Be Designed as SMD or NSMD? Pros, Cons, and Drop-Test Performance

Do you know the difference between SMD (Solder Mask Defined) and NSMD (Non-Solder Mask Defined) pad designs for PCB? What are the advantages and disadvantages of each? More importantly, which pad design provides better resistance to BGA solder joint cracking under mechanical stress?

A few years ago, our company went through a management change. It’s a familiar story in many companies—new managers often like to introduce new ideas to make their presence felt. One of the first changes was a new PCB design rule: all future BGA layouts should use NSMD pads instead of SMD pads. The idea was that NSMD pads would create stronger solder joints, making BGAs more resistant to mechanical stress and increasing the likelihood of passing impact drop tests and tumble tests.

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