Anaheim, CA. Aiming to become the largest probe-card manufacturer in the industry, FormFactor acquired MicroProbe in October 2012. Tom St. Dennis, FormFactor CEO, and Mike Slessor, former CEO of MicroProbe and now head of FormFactor's MicroProbe Business Unit, discussed the acquisition and the path forward in a November 8 interview at the International Test Conference in Anaheim, CA, where FormFactor and MicroProbe made their first public appearance as a united company.
The executives positioned the MicroProbe Product Business Unit as the leading supplier in the high-growth SoC market of MEMS, vertical, and cantilever probe cards. Slessor said MicroProbe has shipped more than 2,500 MEMS probe cards to date. The SoC business, said Slessor, is driven by mobile and connectivity devices, and at the time of the interview MicroProbe expected to deliver $100M worth of SoC solutions in 2012.
We'll have much more on the business aspects of the acquisition in our inaugural “EE Executive Insight” column in the January 2013 print issue of EE-Evaluation Engineering. (You will also be able to find the column online at www.evaluationengineering.com at the end of December.)
In the meantime, note that at its ITC debut, the combined company participated in a Wednesday poster session on parallel parametric test in semiconductor production in conjunction with Agilent Technologies; participants included Masaharu Goto of Agilent Technologies International Japan and Larry Levy of FormFactor. And in a Friday session at the 3-D Test Workshop, Amy Leong and Andrew McFarland of FormFactor joined with Joseph Foerstel of Altera on a 3-D wafer probing session titled “40-µm Pitch Probe Card Evaluation.”
The Friday session was of particular note, as Foerstel of Altera noted that Altera is moving ahead with 3-D ICs at the 20-nm node. Of particular interest was how to identify good chips cost-effectively prior to interposer attach. The presenters discussed a copper (Cu) pillar approach with a solder cap, discussing a test-wafer resistance-path measurement. They further discussed application of the MicroProbe Gx-3D probe card and discussed autoprobing runs (using an Agilent datalogger) and manual runs. They presented a detailed chart of experimental variables and results, with images of solder caps before and after probing.
The presenters concluded that it is technically feasible to probe on 40-µm Cu-pillar microbumps and that the UF3000EX-e prober can be used for TSV probing with standard software, although attention had to be paid to setup/alignment tolerances used, due to the 40-µm center to center pitch.
The presenters concluded that they have demonstrated technical feasibility of probing 40-µm grid-array fine pitch microbumps, but “test cost (including probe card cost) is the determining factor for fine-pitch grid-array test strategy for production adoption. [a] $10,000 probe card will be needed for 1-DUT 40-µm pitch probing, if no yield benefit or other cost reductions are realized in the TSV manufacturing flow.”
Finally, they noted, “Close collaboration between IC manufacturers and probe card suppliers is critical to make fine pitch wafer-test cost effective for production.”