We assembled a MAPS (Monolithic Active Pixel Sensor) vertex tracker, MVTX, with $0.19~\rm m^2$ total silicon coverage and a pixel pitch of $27~\mu \rm m$.
48 staves, each comprised of 9 sensors thinned down to $50~\mu \rm m$ thickness, are supported by carbon composite structures and organized into three concentric layers immediately surrounding the beampipe inside of the sPHENIX at RHIC of BNL.
Reaching the designed resolution of MVTX is critical to the delivery of sPHENIX physics including heavy flavor studies.
We present the construction and $\sim 20~\mu \rm m$-level mechanical alignment in the carbon composite support structure.