Embedded Systems Conference
Breaking News
Newest First | Oldest First | Threaded View
User Rank
Re: Keep out zones
Astronut0   3/21/2014 5:15:24 PM
Good catch, chipmonk0.  Thanks!

rick merritt
User Rank
Re: Keep out zones
rick merritt   3/20/2014 7:42:53 PM
@Chipmonk: I'd be happy to get an article on 3-D TSVs from you. Fire at will.

Thanks for noting the problem --NOW FIXED -- in the text re TEZZARON. It was my error in mistaking the company name and mischaracterizing Herb Reiter's comment.

User Rank
Re: Keep out zones
Deepak1982   3/20/2014 12:54:43 PM
TSVs can be used to reduce chip-to-chip wire lengths, or to reduce on-chip global wire lengths. For on-chip global wire length reduction, small TSV area is important due to the high TSV densities. If, instead of 5um TSVs with 7um keep-out zones, you have 5um TSVs with <1um keep-out zone, each TSV moves from taking a ~20um region to taking a ~7um region, which represents a 8-9x area reduction. 

Bottom line: Eliminating the keep-out zone will eventually help TSVs reduce on-chip global wire lengths. 

User Rank
Re: Keep out zones
chipmonk0   3/20/2014 12:30:41 PM
 " Separately, Terrazon has shown a design using tungsten TSVs that have a high CTE and thus can eliminate the keep-out zone, Reiter notes. "

this statement is absolutely WRONG.

Tungsten has been used instead of Copper to fill TSV vias because it has a LOWER CTE than Cu, almost similar to Silicon hence unlike Cu almost no mismatch stresses during temperature cycling or any effect on device performance ( therefore very small KOZs and the freedom to disperse TSVs throughout the chip and not just at a central location ).

The company that uses W to fill vias is not Terrazon but TEZZARON

The stress field around a filled TSV depends on the square of the Via Dia, the thermal mismatch strain and the modulus of the fill material. Hence the effort now at LETI and elsewhere to try smaller dia TSVs and fill them with lower Mod materials.

Tungsten filling of vias were chosen to satisfy theory and are already in production for Memory chips. The limitation of W is that can't be too long, hence Cu filled vias are preferred for TSVs in interposers ( 2.5-d ).

BTW did this IITC paper from GloFo report any reliability test results ( e,g. temp. cycling effects on the compressive layer in the vias and ultimately surrounding transistors ) ?

The offer of writing a comprehensive article on 3-d TSV technology for EE Times still stands.


rick merritt
User Rank
Keep out zones
rick merritt   3/20/2014 9:16:27 AM
How big an issue is this for your design? What tech challenges, if any, are even bigger?

rick merritt
User Rank
rick merritt   3/20/2014 9:15:09 AM
@3-D Guy: Fixed.  Thx.

3D Guy
User Rank
3D Guy   3/20/2014 8:13:37 AM
I think there is a small typo. CEA-LETI has been working on nm scale TSVs.

As data rates begin to move beyond 25 Gbps channels, new problems arise. Getting to 50 Gbps channels might not be possible with the traditional NRZ (2-level) signaling. PAM4 lets data rates double with only a small increase in channel bandwidth by sending two bits per symbol. But, it brings new measurement and analysis problems. Signal integrity sage Ransom Stephens will explain how PAM4 differs from NRZ and what to expect in design, measurement, and signal analysis.

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Like Us on Facebook
Special Video Section
The LTC®6363 is a low power, low noise, fully differential ...
Vincent Ching, applications engineer at Avago Technologies, ...
The LT®6375 is a unity-gain difference amplifier which ...
The LTC®4015 is a complete synchronous buck controller/ ...
The LTC®2983 measures a wide variety of temperature sensors ...
The LTC®3886 is a dual PolyPhase DC/DC synchronous ...
The LTC®2348-18 is an 18-bit, low noise 8-channel ...
The LT®3042 is a high performance low dropout linear ...
Chwan-Jye Foo (C.J Foo), product marketing manager for ...
The LT®3752/LT3752-1 are current mode PWM controllers ...
LED lighting is an important feature in today’s and future ...
Active balancing of series connected battery stacks exists ...
After a four-year absence, Infineon returns to Mobile World ...
A laptop’s 65-watt adapter can be made 6 times smaller and ...
An industry network should have device and data security at ...
The LTC2975 is a four-channel PMBus Power System Manager ...
In this video, a new high speed CMOS output comparator ...
The LT8640 is a 42V, 5A synchronous step-down regulator ...
The LTC2000 high-speed DAC has low noise and excellent ...
How do you protect the load and ensure output continues to ...