The aim of this study is to clarify the factors that control the macroscale strength of cold spray coatings by evaluating local strength at the microscale. Using pure copper powder and high-pressure cold spray equipment, thick (15 mm) copper layers were deposited on aluminum substrates. The coatings were evaluated by SEM and EBSD analysis, then freestanding Cu specimens were fabricated in a FIB system, where in-situ micro tensile tests were carried out. The results are presented and discussed along with the role of microvoids.