NAME: Multi Face Down – xFD®, Dual Face Down – DFD®,
Quad-die Face Down – QFD® technologies
USAGE: Multi-Die DRAM Packaging
HOW: Leverages existing wire-bond infrastructure;
delivers lower latency interconnect
SOLUTIONS: Memory Stacking for high performance,
high-density memory modules
MARKETS: Data Center, Computing, Gaming

Higher speed, higher capacity stacked memory modules are a critical requirement for today’s Consumer and Data Center markets. High-volume manufacturing of memory modules using existing production infrastructure has the potential to deliver significant product cost advantages.
xFD® is a multi-die face-down packaging technology that enables denser, faster, cooler and cheaper DRAM, while utilizing existing wire bond infrastructure. By leveraging the existing installed manufacturing base, xFD can be readily adopted while addressing requirements for higher speed and higher capacity DIMM in a package and/or on-board memory for notebooks and game consoles.

xFD® Module

Dual Face Down

DFD® Module

Multi Face Down

QFD® Module

Quad Face Down



Opposing-Face DDP
Long gold wires, unbalanced top/bottom signal length

Face-Up DDP with FOW
Balanced signal length but significant gold wire

Face-Up DDP with RDL
Balanced signal length, reduced gold but requires expensive re-distribution layer

DDP = Dual Die Package
FOW = Film Over Wire
RDL = Re-Distribution Layer

Invensas xFD®

Single Pass through Wirebond Line
Shortest Signal Path = Highest Performance
Minimize Gold wire, No RDL = Lowest Cost
Increased Surface Area = Lower θja, better Thermal


Invensas xFD technology offers enhanced electrical and thermal performance that exceeds the limits of traditional DRAM dual die packaging (DDP). xFD is a viable alternative to highly expensive Through Silicon Via (TSV) based stacked DRAM methodologies to increase capacity and speed. Using xFD technology significantly simplifies PCB layout complexity and reduces signal latency, resulting in smaller form factor, lower cost and more reliable system performance.
Invensas xFD can improve speed bin yield by up to 70%, thermal performance by up to 25% and reduce packaging cost by up to 50% compared to conventional DDP.

Improved speed bin yield

Improved thermal performance

Reduced packaging cost


DRAM and DIMM in a package modules for datacenter, server, consumer gaming and computer markets.