  As a future Higgs or Z factory, construction of the circular electron
positron collider(CEPC) has been proposed to precisely measure Higgs bosons. A
particle flow-oriented electromagnetic calorimeter (ECAL) and a hadronic
calorimeter comprise a baseline design for the CEPC calorimetry system. The
scintillator-tungsten ECAL (Sc-ECAL) prototype is being developed within the
CEPC calorimetry working group. The Sc-ECAL is a sampling calorimeter
consisting of alternating absorber layers and high granularity active layers.
Each component of the active layer has been studied and optimized from a
variety of aspects to meet the design requirements. The complete technological
Sc-ECAL prototype will contain 30 layers of ECAL-based unit (EBU) boards
alternating with 30 layers of the absorber. The first two layers of the
prototype have been developed, and primary commissioning has been performed to
validate their performance.
