Device for delivering a beneficial agent to a user includes a cassette including a cassette housing with a fluid reservoir defined therein, the cassette housing having a cassette base region, and a delivery tube fluidly coupled with the fluid reservoir. The device also includes a pump having a pump housing containing a pump assembly and further having a receiving region to receive the cassette base region. The pump assembly includes a fluid drive component disposed proximate the receiving region, a main controller circuit board coupled to and configured to control the fluid drive component, and at least one secondary circuit board foldably joined to the main controller circuit board through a flexible substrate and disposed within the interior in a stacked relationship relative the main controller circuit board.
