Probe card for a magnetically-actuable device and test system including the probe card

Patent metadata

Field	Value
Publication number	US-2018237293-A1
Application number	US-201715687618-A
Country	US
Kind code	A1
Filing date	Aug 28, 2017
Priority date	Feb 21, 2017
Publication date	Aug 23, 2018
Grant date	—

Abstract

A probe card fits in a system for testing a micro-electro-mechanical device having an element sensitive to a magnetic field. The probe card is formed by a PCB having a through-opening and probe tips for electrically contacting the micro-electro-mechanical device. A housing structure is received within the through-opening. The housing structure includes a planar peripheral region surrounding seats that protrude and extend at least partly into the through-opening. Magnetic elements are arranged in the seats, with the magnetic elements configured to generate a test magnetic field for testing operation of the micro-electro-mechanical device.

First claim

1 . A probe card for use in a system for testing a magnetically-actuable device, comprising:
an integrated circuit board having a first through-opening at probe tips of said probe card; a housing structure including a planar region which surrounds at least one seat protruding from the planar region and extending at least partly through the first through-opening; and a magnetic element arranged in each seat of the housing structure, the included magnetic elements configured to generate a test magnetic field for magnetically actuating the magnetically-actuable device during a test phase of the magnetically-actuable device.

2 . The probe card according to claim 1 , wherein said at least one seat comprises at least three seats, wherein the at least three seats extend one next to each other, and wherein each seat houses a respective magnetic element, the included magnetic elements being mutually arranged so as to generate a magnetic field having a first intensity in a direction of the magnetically-actuable device and a second intensity, lower than the first intensity, in an opposite direction.

3 . The probe card according to claim 2 , wherein said included magnetic elements are mutually arranged to form a Halbach array.

4 . The probe card according to claim 1 , further comprising a cover of ferromagnetic material arranged on the at least one seat and on the magnetic element within said at least one seat.

5 . The probe card according to claim 1 , further comprising:
a cover of non-magnetic material arranged on said at least one seat and on the magnetic element within said at least one seat; and a shielding layer, of μ-metal, extending above the cover.

6 . The probe card according to claim 1 , further comprising:
a support structure exhibiting a second through-opening and side walls surrounding at least in part said second through-opening, the side walls being provided with respective first guides; and a first slide configured to slide in said first guides, wherein said one or more seats extend through the second through-opening.

7 . The probe card according to claim 6 , wherein the support structure has a bottom side surrounded by the side walls, and wherein the planar region of the housing structure is extended between the bottom side and the first slide, the second through-opening being extended through the bottom side.

8 . The probe card according to claim 6 , wherein said first guides are formed by respective recesses in the side walls, said first slide having tapered peripheral regions configured to slide in said recesses.

9 . The probe card according to claim 1 , wherein the housing structure includes:
second guides which protrude from said planar region in a direction opposite to the direction in which said at least one seat extends; and a second slide configured to slide in said second guides so as to cover and, alternatively, uncover said at least one seat.

10 . The probe card according to claim 9 , wherein said at least one seat comprises at least nine seats mutually arranged one next to another to form a 3×3 matrix structure, said second slide being molded in such a way as to cover, during the closure operation, each of said at least nine seats one at a time.

11 . The probe card according to claim 1 , wherein said magnetically-actuable device includes a magnetically-actuable suspended structure that is movable about a first and a second axis of rotation, and wherein the at least one seat is a plurality of seats,
said magnetically-actuable device, said integrated circuit board and said housing structure being mutually arranged in such a way that the test magnetic field is oriented at around 45° with respect to the first and second axes of rotation of the suspended structure of the magnetically-actuable device.

12 . A test system, comprising:
a chuck configured to support a wafer of semiconductor material including a magnetically-actuable device, a probe card; a wafer prober mechanically coupled to the probe card, configured to move the chuck in order to electrically couple selective portions of said magnetically-actuable device with respective probe tips of the probe card; and a data processing circuit electrically coupled to the probe card, configured to feed electrical test signals to the magnetically-actuable device by means of the probe card and to process response signals received, via the probe card, from the device during the magnetic actuation of the magnetically-actuable device; wherein the probe card comprises:
an integrated circuit board having a first through-opening at probe tips of said probe card;
a housing structure, including a planar region which surrounds at least one seat protruding from the planar region and extending at least partly through the first through-opening; and
a magnetic elements included within each seat, the included magnetic elements configured to generate a test magnetic field for magnetically actuating the magnetically-actuable device during a test phase of the magnetically-actuable device.

13 . The test system according to claim 12 , wherein the probe card is spatially arranged between the wafer and the data processing circuit.

14 . A probe card for use in a system for testing a magnetically-actuable device, comprising:
an integrated circuit board having a through-opening extending between a first surface and a second surface; probe tips extending from a first surface of the integrated circuit board and configured to make electrical connection with pads of the magnetically-actuable device; a housing structure including a portion inserted the through-opening from the second surface, said portion of the housing structure including a plurality of seats; and a plurality of magnetic elements, each magnetic element arranged in a respective seat of the housing structure, the plurality of magnetic elements oriented in said seats to generate a magnetic field having a first intensity in a direction of the magnetically-actuable device and a second intensity, lower than the first intensity, in an opposite direction, said magnetic field configured to magnetically actuate the magnetically-actuable device during a test phase of the magnetically-actuable device.

15 . The probe card according to claim 14 , wherein said plurality of magnetic elements are mutually arranged to form a Halbach array.

Assignees

• St Microelectronics Srl

Inventors

• Rossi Marco
• Reina Sergio Mansueto
• Calcaterra Giacomo

Classifications

• G01M11/005

  Testing of reflective surfaces, e.g. mirrors · CPC title

• G01R31/2889

  Interfaces, e.g. between probe and tester (G01R31/31905 and G01R1/07364 take precedence) · CPC title

• G01R1/067

  Measuring probes · CPC title

• B81C99/005 Primary

  Test apparatus · CPC title

• G01R31/2886

  Features relating to contacting the IC under test, e.g. probe heads; chucks (G01R31/2865 takes precedence, test connections, e.g. test sockets, or probes per se, G01R1/04 or G01R1/06) · CPC title