Electricity: measuring and testing – Measuring – testing – or sensing electricity – per se – With rotor
Reexamination Certificate
2000-07-07
2002-08-13
Sherry, Michael J. (Department: 2829)
Electricity: measuring and testing
Measuring, testing, or sensing electricity, per se
With rotor
C324S755090
Reexamination Certificate
active
06433532
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to load boards for testing integrated circuits, and particularly to mounting a load board onto a test head.
DESCRIPTION OF RELATED ART
A test head and a load board are used to test the functionality of newly manufactured integrated circuits. The integrated circuits to be tested are connected to a load board prior to testing. The test head provides power and controls the flow of electricity to the integrated circuits attached to the load board
325
(
FIG. 9
) during testing. As seen in
FIG. 3
, a test head
310
may be circular in shape and have an aperture through the middle. Channel cards
315
are arranged around the circumference of the interior aperture
312
and contain pogo pins
320
on the upper surface of the channel cards
315
. As seen in
FIG. 12
, pogo pins
320
are spring loaded pins, for example the pin portion
322
is able to recede into the spring containing portion
324
, that provide electrical contact between the test head channel cards
315
and the load board
325
via slots
326
on the underside of the load board
325
.
Load boards are electromechanical printed circuit boards used for testing the functionality of integrated circuits. A load board is latched onto a test head, and therefore, must be properly aligned with the test head so that the pogo pins
320
correctly contact the load board. Proper alignment ensures electrical contact between the test head channel cards
315
and the load board
325
so that the test head fully conducts testing of the integrated circuits. A schematic depiction of a load board
325
in electrical contact with the pogo pins
320
of a test card
315
that is connected to a test head
310
is provided in
FIG. 13. A
slot
326
on the underside of the load board
325
is depicted as the contact point between the pogo pins
320
and the load board
325
.
Load boards are normally manually positioned onto test heads, leading to several concerns. Manually positioning a load board onto a test head makes it difficult to properly align the load board with the test head, which may result in improper contact of the pogo pins
320
with the load board
325
. As a result, load boards are often shifted or adjusted after initial manual positioning in order to align the load board with the test head. However, the pogo pins
320
that the load board is already in contact with are spring loaded, and therefore, easily bent or broken. A damaged pogo pin
320
requires replacement of the channel card
315
that the damaged pogo pin
320
is part of, each channel card normally being very expensive. Replacing a channel card
315
also leads to test head down time, which delays production and causes additional expense.
SUMMARY OF THE INVENTION
There is a need to prevent bent and broken pogo pins on a test head channel card related to testing integrated circuits. There is also a need to ensure that load boards are properly aligned with test heads. These needs and others are addressed by the present invention, which provides alignment of the load board with the test head, and an automated system for positioning the load board onto the test head. According to the present invention, a load board feeder is installed into the center aperture of a test head. The load board feeder has a location device that engages the load board when the load board is properly aligned with the test head. The load board feeder also comprises a mechanism for lowering the load board into its seating place on the test head, without a damaging impact to the pogo pins on the test head channel cards. This mechanism prevents undue damage to the delicate pogo pins on the test head channel cards that may occur during manual positioning and alignment of the load board.
Accordingly, one aspect of the invention relates to a load board feeder for positioning a load board onto a test head that has an aperture through its center. The load board feeder comprises a base and a body connected to the base. An attachment device is connected to the body and is used to attach the load board feeder to the test head. A lift mechanism is connected to the base and vertically moves a block that is attached to the lift mechanism. The block contains the load board location device and serves as a resting place for the load board prior to positioning the load board onto the test head.
In certain embodiments, the load board feeder is cylindrically shaped, and contains a load board location device on a circular block. The load board location device comprises a circular plate attached to the block and a disk that engages the block and the plate. The circular block has a circular cavity that is not concentric with the center of the block. Likewise, the circular plate has a non-concentric, circular hole that aligns with the circular cavity in the block. The outer diameter of the circular disk is just small enough to allow the circular disk to fit within the circular hole and cavity. The top of the circular disk protrudes above the top of the plate, thereby providing an engagement element for a load board.
Accordingly, another aspect of the invention relates to a method of seating a load board onto a test head having an aperture through its center. A load board feeder, comprising a lift mechanism and a location device for aligning a load board with a test head, is attached within the center aperture of a test head. The load board feeder is brought to its raised position and a load board is placed onto the load board feeder. The load board is adjusted so that it engages the load board location device. The load board is aligned with the test head when the load board engages the load board location device. The lift mechanism is activated to lower the load board into its seating position on the test head and the load board is latched to the test head.
Other advantages of the present invention will become readily apparent from the following detailed description, simply by way of illustration of the best mode contemplated of carrying out the invention. The invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawing and description are illustrative in nature, not restrictive.
REFERENCES:
patent: 4626779 (1986-12-01), Boyle
patent: 4636723 (1987-01-01), Coffin
patent: 5081415 (1992-01-01), Liu et al.
patent: 5192907 (1993-03-01), Bonaria
patent: 5552701 (1996-09-01), Veteran et al.
patent: 6259265 (2001-07-01), Han et al.
Boon Wong Han
Hiong Tan Seok
Kiat Aw Chin
Advanced Micro Devices , Inc.
Kobert Russell M.
LandOfFree
Method and apparatus for mounting a load board onto a test head does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for mounting a load board onto a test head, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for mounting a load board onto a test head will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2954817