Thick Copper Design

Thick Copper Design

A CTE Mismatch Between Copper And FR- – 4 Exists • Copper = 18ppm • FR-4 = 15-16ppm • As Copper Gets Thicker, It Has Greater And Greater Influence Over Post Lamination Dimensions Of The Resulting Substrate Rolled , Annealed Copper Reacts Differently Than ED Copper • Design Influences On Net Shrinkage Become Far More Significant Standard Scaling Factors (That Compensate Net Shrinkage Effects) Do […]

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Component Issues – Decreasing Pitch

Component Issues – Decreasing Pitch

Component Issues – Decreasing Pitch Potential Issues: – Paste Volume Control – Component/PCB Flatness • Internal Split Plane • NFP Removal Impacts – Component/PCB Warpage LGA/QFN Package Assembly Trace Routing Under Component Create Localized Height Variations – Standoff Height Variation Leadless Devices Are More Sensitive To PCB/Component Flatness/Warpage – Received Condition – In-process Condition (During Reflow/Rework Solder Process) Solder wicking around NSMD pads produce significantly […]

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Root Cause Failure Analysis of Printed Circuit Board Assemblies Part 1

Root Cause Failure Analysis of Printed Circuit Board Assemblies Part 1

What do you mean 0% first pass yield? My process is in control , so what happened? Today’s Electronic Designs Component Packages Are Getting Smaller 0603 > 0402 > 0201>01005 BGA > CSP > WL-CSP > Assembly Design Density Is Increasing Tighter Component to Component Spacing Spacing Smaller Than 0.020” Common Smaller Copper (Pad) Interconnections Assembly Process Margins Are Tighter Thermal Balance @ Pad Level […]

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