Spansion, a provider of Flash memory solutions, announced on Monday (22 May) that Analog Devices Inc (NYSE:ADI), a semiconductor company, is combining Spansion Known Good Die
(KGD) Flash memory with its Blackfin processor in a multi-chip module (MCM) for products supporting the automotive market.
Additionally, the availability and cost of known good die
, FCA reliability issues and difficulties associated with testing bare die and reworking encapsulated flip-chip die are significant issues inhibiting the widespread implementation of flip-chip modules (and multichip modules (MCM)).
While embedding an active die in the form of a WLP is one solution to the known good die
problem, there are still concerns about how to inspect and test the module or board after embedding.
These two factors have resulted in stacked-die packaging, which requires a supply of known good die
Known good die
(KGD) solutions are imperative if flip chip assemblies are to be reliably fabricated with high yields and at reasonable cost.
For packages containing stacked logic and memory, the need for known good die
(KGD) memory is essential.
Issues related to stacked die include wafer thinning, bare die, known good die
(KGD), die attach and wire bond, and thermal dissipation.
Direct flip-chip die is the most efficient approach when the issues of known good die
and board/assembly are resolved.
Removable underfills offer benefits when known good die
are not available or are too expensive, or when manufacturing yields are poor.
A compromise between test coverage and test time must be found for known good die
selection and throughput.'
If data programmed on the last write operation of the most marginal device can be retained for 10 years, then the data retention capability of every other known good die
can be confidently guaranteed.
Such a capability could preclude the need for known good die
and dramatically reduce the cost to produce MCM packages and modules.