Ben Is the vendor's spec to a single ball or the resistance through all the balls to the outside? Tom Dagostino Teraspeed Labs 9999 SW Wilshire Street Suite 102 Portland, OR 97225 tom@xxxxxxxxxxxxxxxxx www.teraspeedlabs.com 971-279-5325 office 503-430-1065 cell -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of ben chia Sent: Thursday, October 09, 2014 10:12 AM To: 'Si-List' Subject: [SI-LIST] milliohm measurement probe and cable Hi All, I try to measure the package VCC or VSS resistance to match the simulation report from vendor. Vendor said that the resistance should be less than 2 milliohm from bump to ball. The setup in my lab is Agilent multi-meter ( up to 1 milliohm resolution, 4 wire ). I use GGB 40A 150um center pin to touch the bump. A 26G coax cable to connect the probe to multi-meter. The measured result is stable up to 1-2 milliohm, but resistance value is more than tens of milliohm. Can anyone recommend a different setup? Thanks, Ben Chia High Speed Design Center www.HighSpeedDC.com ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List forum is accessible at: http://tech.groups.yahoo.com/group/si-list List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List forum is accessible at: http://tech.groups.yahoo.com/group/si-list List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu