Can predicting board and part flatness at critical points in the reflow/reliability profile reduce failures?

Surface warpage, or flatness, is an established source of reliability issues in surface mount devices (SMD), particularly when these surfaces are considered as they warp due to heat generated in production or real-world use.^1-6 Thermal warpage of surface mount components such as ball grid arrays (BGA) and line grid arrays (LGA) are subject to different industry standards from JEDEC, JEITA, and IPC, based on sample size, ball size and ball pitch.^7-9 Further SMD studies have proposed different methods of classifying and qualifying surface shape in hopes to improve the correlation in thermal warpage data and product reliability.¹⁰ Meanwhile, printed circuit boards are less regulated for warpage in the area where an SMD may attach. Overall PCB warpage is referenced in some industry standards and technical papers, but specific warpage limits are lacking within documentation discussing warpage of SMD landing areas.^11-12 Finally, further studies have considered warpage of both SMD and PCB landing areas together.^13-14

Match the resources that make sense in the scale of your operation.

In the early 1990s, some observers were predicting that the EMS market would consolidate and shrink to a handful of large players building the bulk of the world’s electronics products. But outsourced electronics manufacturing isn’t a one-size-fits-all equation. Even large OEMs often have higher mix, lower volume or variable demand segments of business that fit best in a regional EMS provider. Consequently, regional EMS providers continue to thrive.

Effects of types of TIM types, thicknesses and contact pressure in a real-world application.

Power electronics are integral parts of power components, power supplies, 5G networks, automotive and defense/space applications. All modern power electronics have two critical factors in common that drives the need for unprecedented thermal management: first, increased transistor density to meet the higher demand in increased computing power and second, component miniaturization leading to higher heat flux. It is well known in the electronics reliability field that 55% of the component failures in electronics devices are related to excess heat. The Arrhenius equation in Eq. 1¹ predicts that, for electronics, the lift of the device decreases by half² by increasing the device temperature by 10°C. Design engineers mitigate this issue by carefully selecting thermal interface materials (TIM) to keep the system/device temperature at the desired level.

Summary statistics can be misleading, but in different ways.

C_pk and P^pk are numeric capability summaries of process or product characteristics based on common cause variation (due to chance) and assignable cause variation (special cause). Understanding these capability indices and their limitations is critical in pursuing world-class quality, "on target with minimal variation." C_pk and P_pk indices are reviewed, and details on how to use them synergistically are provided.