US 2007/0176611 A1 · Method and apparatus for probing at arbitrary locations within an inaccessible array of leads the solder balls or pins actually connecting a VLSI IC package to a substrate or socket

Abstract

A probe for an array of interconnecting leads between a PCA and an IC has one or more contacts extending laterally from or plated upon one or more arms formed of a flexible printed circuit, and connected by traces along the arm(s) to a header that itself affords connection to measurement equipment. The flexible printed circuit is thin enough to loosely slide between the top of the PCA or PCB and the bottom of the IC. The arm or arms is/are narrow enough to slide between the adjacent leads forming the array, while the normally flat contacts will successively interfere with, to engage and electrically contact, consecutive layers of leads as the probe is progressively inserted. An arm is not so stiff that it cannot yield by a slight compressive warping as the contacts encounter leads. Indexing may be ‘by feel’ or by visible indicia along a top surface of the probe or by a reticle device that moves over the top of the IC, which then has a pattern of indicia corresponding to lead location. Forming the shape of a Kapton substrate may also include use of a CVL operating in the range of 250 nm to 290 nm for the creation of extended copper contacts by the removal of underlying Kapton. Plating processes may also be used in the fabrication of (non-extended) wrap-around contacts at the edges of the Kapton.

Claims26

Dependent claims

Apparatus for probing electronic signals appearing on leads within an array of leads for an electronic component, the apparatus comprising:

a flexible printed circuit;
one or more electrical connections disposed upon a first portion of the flexible printed circuit, for coupling to an item of electronic test equipment probed electronic signals;
the flexible printed circuit comprising a first arm extending from the first portion and sufficiently narrow to be inserted between adjacent columns of leads in the array thereof and by which array the electronic component is electrically connected to a circuit assembly, the first arm sufficiently thin to pass into a gap between the electronic component and the circuit assembly;
a first electrical contact disposed at a first location along an edge of the first arm and extending outward from that edge for probing a lead in the array when the first arm is inserted a selected distance;
a first conductive trace carried by the first arm and electrically coupling the first electrical contact to an associated one of the electrical connections disposed upon the first portion;
and
the first electrical contact extending outward from the first arm by an amount sufficient to cause the electrical contact and the first location along the first arm to undergo compressive warping and urge the first electrical contact against a probed lead.

4 more elements

Dependencies are inferred from the claim text.

Method and apparatus for probing at arbitrary locations within an inaccessible array of leads the solder balls or pins actually connecting a VLSI IC package to a substrate or socket

Life of this patent

Method and apparatus for probing at arbitrary locations within an inaccessible array of leads the solder balls or pins actually connecting a VLSI IC package to a substrate or socket

Life of this patent

Abstract

Claims26