90 likes | 281 Views
Plans for Demonstrator Flip Chip Bonding. General. Bump pad layout as in ALICE/ M edipix (see talk by Massimiliano ) Sensor wafers will be delivered as 4” wafers Demonstrator chips will be delivered as single dies Standard processing only possible for sensor wafers (full wafer processes)
E N D
General • Bump pad layout as in ALICE/Medipix (see talk by Massimiliano) • Sensor wafers will be delivered as 4” wafers • Demonstrator chips will be delivered as single dies • Standard processing only possible for sensor wafers (full wafer processes) • Need to develop a procedure for the demonstrator dies
{ www.fujitsu.com
S. Savolainen-Pulli/VTT } • Dicing of the wafers • Flip chip bonding of a sensor to one (or more) readout chip and reflow
Bump Deposition • Simplified scheme • S. Savolainen-Pulli (Pixel 2005 conference) • In standard process done on wafer level How to deposit UBM and eventually Pb-Sn on single dies? Non-standard process!
Discussion with VTT • First meeting February 2008: VTT proposes to use reverse rework process (transfer Pb-Sn bumps to the dies from a carrier wafer) • Continuing discussion: • How to deposit the wettable metal which is underneath the Pb-Sn on the ROC? • How to protect the wire bonding pads? • Could the Pb-Sn be skipped on the ROC side at all?
Status • Discussion on technical matters with VTT (4/12/08), i.e. proposal to suppress Pb-Sn on ROC • Proposed tentative workplan to have process ready by April when all components will be available • Process development will be done in the coming months using dummies • Order for demonstrator being prepared • Target: 10+10 bonded chips before summer