The present invention generally relates to a radiation detector element wherein a photodiode is transversely fixed to a detector element substrate through at least one connection comprising two fused solder balls, wherein a first of the two fused solder balls contacts the photodiode and a second of the two fused solder balls (contacts the detector element substrate. The invention further relates to a method of transversally attaching two substrates, in particular constructing the above-mentioned radiation detector element. It also relates to an imaging system comprising at least one radiation detector element.
