Exploring Cold Milling as an Alternative PCB Component Removal Method

Estimated reading time: Less than a minute

When a PCB undergoes multiple heat cycles, inherent risks emerge, primarily due to the expansion and contraction of materials. This thermal stress can induce various issues, including delamination, warping, compromised solder joints, and damage to heat-sensitive components like integrated circuits or capacitors.

To counter these risks, one approach involves a unique process called "cold milling," designed to mitigate the adverse effects of additional thermal stress. Unlike traditional methods involving direct heat application, this solution utilizes a laser-guided precision mill to remove components. This ESD-safe process includes a vacuum nozzle that simultaneously removes debris during the milling process, ensuring cleanliness.

The genesis of “cold milling” stems from a customer's challenge with removing underfilled BGAs. They encountered issues with underfill leaching into the adjacent solder during reflow, causing solder shorts. By utilizing this cold milling process, we were able to remove the component without applying heat and place a new component in its place resulting in a yield >90% and a successful solution for the customer.

To read this entire article, which appeared in the January 2024 issue of SMT007 Magazine, click here.