Amkor Technology is now offering the Flip Chip CSP (fcCSP) package -- a flip chip solution in a CSP package format. This package construction utilizes Pb-Free (or Eut. SnPb) flip chip interconnect technology, in either area array or peripheral bump layout, replacing standard wirebond interconnect. The advantages of flip chip interconnect are multiple: it provides enhanced electrical performance over standard wirebond technology, it allows for a smaller form factor due to increased routing density, and the elimination of wire-bond loops. Current wafer bump technology and flip chip assembly process allows for peripheral flip chip bumping or area array bumping, with either solder or Cu pillar bump technology.
The fcCSP is based on Amkor's proprietary ChipArray® BGA (CABGA) package construction, using cutting edge thin core laminate substrates. The package is assembled in strip format, in either bare die or overmolded format, and saw singulated for manufacturing efficiency and cost minimization. Pattern plating for fine line/spaces, via-in-pad substrate structure, and thin core substrate panel processing allow for increased routing density and enhanced electrical performance, making fcCSP an attractive option for advanced CSP applications where electrical performance is a critical factor.
As handheld microprocessors have transitioned to advanced CMOS nodes with higher speed cores with higher I/O, there has been a transition from wirebond to flip chip die designs. Flip chip enables the use of an exposed die bottom package that integrates the package stacking design features of PSvfBGA in an fcCSP assembly flow, which Amkor calls PSfcCSP. Package Stacked Flip Chip CSP has a thin exposed Flip Chip die enabling fine pitch stacked interfaces at 0.5mm pitch which is a challenge in a center molded PSvfBGA structure
The fcCSP is available in both thin core laminate substrate technology as well as build up (for further enhanced outing). Package size ranges from 2 mm to 17 mm, accommodating BGA ball pitches from 0.4 mm to .0 mm. In addition to BGA technology, the fcCSP is lso available in LGA format, allowing for a lower minimum package thickness.