Root Cause Analysis

Root Cause Analysis identifies the root cause of yield problems and provides proven solutions for yield improvement. This service is unique to BlueRing Stencils; no other stencil manufacturer offers this comprehensive value added service.  In combination with decades of engineering experience, we utilize proprietary analysis software that enables BlueRing Stencils engineering team to diagnose and fix SMT yield problems anywhere in the SMT assembly process. Since the start of this service, we have performed thousands of jobs with a 98% success rate.

Root Cause Analysis

What do we provide?

Identify the root cause of yield problems

Accurate and thorough analysis based on assembly and process variables

Detailed and comprehensive analysis reports

Significant increases in assembly yields with specific stencil design suggestions

Areas where yield problems occur:

Component footprint
Reflow profile
Wave solder
Solder paste
Thermal heat sinks

Common defects that affect yields:

Poor paste release
Insufficient solder
Bridging at reflow
Component shift and skew
Solder balls

Sample Reports

Below are sample reports which will be very similar to the one you will receive regarding your process analysis. All reports contain, the problem description, our Root Cause Analysis of the problem and our custom recommendation to resolve the issue. The names have been removed to protect the identity of our clients.

Root Cause Analysis


Improve SMT Assembly Yields Using Root Cause Analysis in Stencil Design

Reduction of first pass defects in the SMT assembly process minimizes cost, assembly time and improves reliability. These three areas, cost, delivery and reliability determine manufacturing yields and are key in maintaining a successful and profitable assembly process. It is commonly accepted that the solder paste printing process causes the highest percentage of yield challenges in the SMT assembly process. As form factor continues to get smaller, the challenge to obtain 100% yield becomes more difficult. This paper will identify defects affecting SMT yields in the printing process and discuss their Root Cause. Outer layer copper weight and surface treatment will also be addressed as to their effect on printability. Experiments using leadless and emerging components will be studied and root cause analysis will be presented on various common SMT defects.