Supply Chain Under Stress in 2.5D and 3D IC Era
By Mark LaPedus, SemiMD senior editor
For decades, the IC production, packaging and test flows have been straightforward and predictable.
ASE's Rich Rice
But as the world moves toward the 2.5D and 3D chip era, the lines in the IC manufacturing flow are blurring. Within these emerging segments, the chip “supply chain model is under stress,” said Rich Rice, senior vice president of sales for North America at ASE Inc., the U.S. arm for Advanced Semiconductor Engineering Inc. (ASE) of Taiwan. ASE is the world’s largest IC-packaging and test house.
There is little margin for error for 2.5D and 3D. The costs, yield and logistical issues are such that the parties involved — chip makers, foundries, IC-packaging houses and others — must avoid risky IC projects and find a suitable return-on-investment. So, in the 2.5D and 3D chip worlds, it is essential that chip makers develop a viable or “marketable product” and not devise “science projects,” Rice said.
Sunil Patel, interim director for the Customer Package Technology Group at GlobalFoundries Inc., agreed. “The current model is under strain. It has to evolve,” Patel said. “An integrated supply chain that offers yield accountability and competitive pricing needs to emerge.”
During the “2.5D, 3D and Beyond,” conference last week in Santa Clara, Calif., sponsored by the Microelectronics Packaging and Test Engineering Council (MEPTEC), Rice and Patel separately described the various business and supply chain models in the 2.5D and 3D chip arena.
The IC industry is scrambling to find the right model for good reason. Both 2.5D and 3D chip technologies are making progress on the technology front, although there are still challenges.
But the projected product pricing delta and the supply chain logistics remain problematic. For example, there is still a debate regarding which segment — the front-end fabs or assembly houses — will actually do the interposer or through-silicon via (TSV) work.
Another question is which vendor will take charge of the interposer and TSV-related failures. Other unresolved questions include which vendor will be in charge of the bill of materials, inventory, integration and yield.
Some vendors may have it easier than others in 2.5D and 3D. “IDMs are sitting pretty. They have the means and resources,” ASE’s Rice said. “The fabless-foundry-OSAT supply chain model is under stress.”
The integrated device manufacturers (IDMs), notably Intel, Samsung and possibly IBM, may have the resources in-house to set up a turnkey 3D chip operation. For example, Samsung has the in-house memory and logic technologies, fabs and packaging expertise.
For vendors that use third-party foundries and packaging houses in 2.5D or 3D, the production flow consists of multiple and complex choices, which, in turn, will put pressure on the supply chain. During a presentation, Rice outlined several models for the interposer flow — all of which are viable:
—The foundry handles all steps, including front-end production, interposer integration and the backend steps.
—The foundry handles the front-end production. The interposer step is handled by a separate “interposer foundry.” The backend steps are done at an IC-packaging house.
—The foundry handles both the front-end and interposer production. Then, the backend steps are done at an IC-packaging house.
—The foundry handles the front-end production, while the IC-packaging house does the interposer and backend steps .
Providing another viewpoint, GlobalFoundries’ Patel outlined three separate models in 2.5D and 3D: foundry plus, OSAT plus and third party.
In the foundry plus model, the foundries handle most of the steps in the 2.5D and 3D production flows. “The foundries will be accountable for the yields,” he said.
In OSAT plus, the foundries provide the front-end and interposer production, while the IC-packaging houses handle the assembly steps. In the third-party model, the customer or chip maker will manage the flow at the foundry or packaging house and will take responsible for the yield. This model is least likely to succeed or take place, he added.
Tags: ASE, GlobalFoundries