Testing Highly Integrated Components for the Technological Prototype of the CALICE SiW-ECAL

A highly granular silicon-tungsten electromagnetic calorimeter (SiW-ECAL) is the reference design of the ECAL for International Large Detector (ILD) concept, one of the two detector concepts for the detector(s) at the future International Linear Collider. Prototypes for this type of detector are developed within the CALICE Collaboration. The final detector will comprise about $10^{8}$ calorimeter cells that have to be integrated in a volume of maximal 20 cm in depth. Detector components that in terms of size and channel density come already close to the specifications for future large scale experiments are progressively developed. This contribution will report on the performance of a new 1.2 mm thick 9-layer PCB with wirebonded ASICs and comparisons with PCBs with BGA packaged ASICs will be presented. A volume of about $6\times18\times0.2$ cm$^{3}$ is available for the digital readout and the power supply of the individual detector layers that feature up to 10000 calorimeter cells. We will present newly developed electronic cards that meet these constraints.