Slashing costs in 3D IC wafer processing: forget about adhesives!
January 24, 2014 // Julien Happich
At Grenoble’s 3D TSV Summit which took place this week on Minatech’ campus, the talks were about 3D IC manufacturability, and all its associated costs, or how to trim them to make 3D IC packaging a cost-effective winner for most markets, not just niche applications.
IC design let aside, there are many processes involved before dies can be stacked together, including the manufacture of Through Silicon Vias (TSV), wafer handling and thinning, TSV reveal etching and Chemical Mechanical Planarization (CMP), then applying micro-bumps to finally stack another wafer or selected know-good dies.
Of course, one way to reduce materials costs in these IC-stacking processes is to avoid excess material in the first place and etch minimal layers to reduce the subsequent CMP step (and associated chemical costs).
Wafer handling is a costly issue, especially when the wafer is going to be so thin (down to 50um for the current state-of-the art) that it behaves like a foil and must be securely bonded to a carrier in order to go from one process equipment to the next.
Currently, the norm is to use temporary adhesives, with their own set of issues. They require specific temperature and chemical resistance, yet the adhesives should be removed easily for de-bonding, without leaving a trace. This makes these special temporary bonding adhesives not only costly and their use a yield-issue, but the dedicated machines that dispense, cure, then de-bond and remove the remaining adhesive add their contribution to the multi-million capital expenditure necessary for 3D IC manufacturing.
In the exhibition area, Applied Microengineering Ltd (AML) was showcasing a unique solution to get rid of the adhesive altogether, vacuum-based temporary bonding.
The idea looks amazingly simple. AML has filed a patent for its newly developed vacuum wafer carrier solution, using carriers with etched micro-patterns that allow for a vacuum to be created between the carrier and the wafer to be processed.
The surrounding seal on the wafer carrier holds the vacuum for up to several weeks, explained Rob Santilli, CEO of AML, holding a glass carrier to see through the micro-etched suction patterns. The etched patterns can vary in depth and distribution depending on the wafers specific requirements, added Santilli who sees adhesive-based temporary bonding as rather crude and messy techniques.
High voltage LEDs help simplify compact fixture design
March 11, 2014
Philips Lumileds has launched a mid-power LED which allows lighting manufacturers to design in high voltage drivers that ...
Fullerene-free organic solar cells achieve record conversion efficiency
Abu Dhabi creates iMicro hub for microsystems research
Low-power wireless modules market reaches USD1.40bn in 2014
Certification program clears market path for LED luminaires
Executive Interview: Channelling higher power into smaller packages
March 11, 2014
EE Times Europe Power Management's editor, Paul Buckley interviews Phil Davies, VP Global Sales & Marketing of Vicor ...
Energy efficient 4-Gb DDR3 memory enters mass production
The EFM32 Zero Gecko starter kit in stock at RS Components
Novel nickel-manganese-cobalt cathode technology gains patent clearance
- DSM presents: Select the best plastic for DDR4
- Wireless Sensor Network Challenges and Solutions
- Putting FPGAs to Work in Software Radio Systems Handbook
- Real-Time Spectrum Analysis for Troubleshooting 802.11n/ac WLAN Devices
InterviewExecutive Interview: Channelling higher power into smaller packages
EE Times Europe Power Management's editor, Paul Buckley interviews Phil Davies, VP Global Sales & Marketing of Vicor plc to discover what the leading power conversion company sees as the major technology ...
Filter WizardCheck out the Filter Wizard Series of articles by Filter Guru Kendall Castor-Perry which provide invaluable practical Analog Design guidelines.
Linear video channel
READER OFFERRead more
This month, Freescale is giving away ten RIoTboards, worth 74 dollars each, for EETimes Europe's readers to win.
Designed to run Android operating systems efficiently or to run under Linux, the board is based on the Freescale i.MX 6Solo processor; using the ARM Cortex-A9 architecture.
And the winner is...
In our previous reader offer, Crystal Display was giving...Read more
December 15, 2011 | Texas instruments | 222901974
Unique Ser/Des technology supports encrypted video and audio content with full duplex bi-directional control channel over a single wire interface.