The entire manufacturing process (except for certain purchased components) [of Arduino boards] takes place in and around Strambino, Ivrea, in a context dominated by the small- and medium-sized companies that are typical of Italian industrial districts and of the “Made in Italy” phenomenon itself.
Ivrea’s history is another interesting part of the picture. The city was intimately tied to the presence of Olivetti, a company with a legacy of incredible electronics know-how, and an entire generation of experts. In fact, the Interaction Design Institute was established in a former Olivetti building randomly covered with blue tiles — just like the Arduino boards.
For more detail: A visit to the Arduino factory on DomusWeb
French 
English