U.S. patent application number 12/353082 was filed with the patent office on 2009-05-07 for probe card and temperature stabilizer for testing semiconductor devices.
This patent application is currently assigned to Texas Instruments Incorporated. Invention is credited to Michael P. HARRIS, Adolphus E. MCCLANAHAN, Frank J. MESA, John D. WOLFE.
Application Number | 20090115441 12/353082 |
Document ID | / |
Family ID | 38711412 |
Filed Date | 2009-05-07 |
United States Patent
Application |
20090115441 |
Kind Code |
A1 |
MCCLANAHAN; Adolphus E. ; et
al. |
May 7, 2009 |
PROBE CARD AND TEMPERATURE STABILIZER FOR TESTING SEMICONDUCTOR
DEVICES
Abstract
One aspect of the invention provides an apparatus that includes
a probe card [105] having probe needles [120] associated therewith.
A temperature stabilizer element [135] is couplable to the probe
card [105]. The temperature stabilizer [135] is configured to
either raise or lower a temperature of the probe needles [120] to
reduce movement of the probe needles [120].
Inventors: |
MCCLANAHAN; Adolphus E.;
(Garland, TX) ; WOLFE; John D.; (Celina, TX)
; HARRIS; Michael P.; (Garland, TX) ; MESA; Frank
J.; (Murphy, TX) |
Correspondence
Address: |
TEXAS INSTRUMENTS INCORPORATED
P O BOX 655474, M/S 3999
DALLAS
TX
75265
US
|
Assignee: |
Texas Instruments
Incorporated
Dallas
TX
|
Family ID: |
38711412 |
Appl. No.: |
12/353082 |
Filed: |
January 13, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11383866 |
May 17, 2006 |
7495458 |
|
|
12353082 |
|
|
|
|
Current U.S.
Class: |
324/750.09 ;
324/750.11; 324/750.28 |
Current CPC
Class: |
G01R 31/2891 20130101;
G01R 1/44 20130101 |
Class at
Publication: |
324/760 |
International
Class: |
G01R 31/02 20060101
G01R031/02; G01R 31/26 20060101 G01R031/26 |
Claims
1. A semiconductor testing apparatus, comprising: a probe card; a
temperature stabilizer coupled to the probe card, having a direct
current source and a series of P doped and N doped semiconductor
material between opposing ceramic plates, operable to supply heat
to the probe card with the current source applying a current
directed to the P doped semiconductor material or remove heat from
the probe card with the current source applying a current directed
to the N doped semiconductor material.
Description
[0001] This application is a continuation of application Ser. No.
11/383,866 filed May 17, 2006, the contents of which are herein
incorporated by reference in its entirety.
TECHNICAL FIELD OF THE INVENTION
[0002] The invention is directed in general to a device for testing
semiconductor devices and, more specifically, to a probe card and
temperature stabilizer for testing semiconductor devices.
BACKGROUND OF THE INVENTION
[0003] The pursuit of ensuring high quality product yield within
the semiconductor manufacturing industry is an ongoing endeavor. To
that end, the industry expends significant amounts of time and
money to methodically test as many completed semiconductor devices
as possible to ensure consistent operability. One way in which they
accomplish these tests is by the use of a wafer probing apparatus.
These wafer probes typically include a prober/tester that is used
in conjunction with a separate probe card. The probe card, which is
a printed circuit board (PCB), has contact pads on a surface that
are engaged by pogo pins of the tester. The probe card includes a
ring assembly and probing needles that engage contact pads on a
semiconductor chip that is to be tested. The probing needles are
mechanically connected to the contact pads. Thus, when the pogo
pins engage the contact pads of the probe card, electrical current
can be applied to different contact pads of the semiconductor chip
to test different areas of the chip to ensure its full
operability.
[0004] Wafer probe apparatuses do have problems associated with
their use. One problematic area involves the very thin probe
needles that engage the contact pads of the semiconductor chip. Due
to the fact that they are extremely thin (about 76.2 microns or
less), they are highly susceptible to alignment issues between the
probe card and wafer probe pads associated with high temperature
wafer testing. If the needle changes too much in response to a
temperature change, it can become misaligned. This can have serious
repercussions on the accuracy of the readings, or it can cause the
needle to over scrub the semiconductor chip, which can result in
irreparable damage to the chip.
[0005] Temperature variations can also be introduced during the
testing process or when the needle is cleaned during the operation
of probing of the semiconductor chips. In such instances,
misalignment may occur. To compensate for this, additional testing
time must be taken to allow the needle to re-adjust to the
temperature change. Sometimes the needle properly re-aligns, and
sometimes it does not. This adds additional time to an already
lengthy testing process, which further decreases product output
productivity. Moreover, any chips that are damaged due to over
scrubbing by the probe needles have to be discarded, thereby
decreasing product yields as well.
[0006] Accordingly, what is needed is an apparatus and method of
testing semiconductor devices that avoids the disadvantages
associated with the above-described testing devices.
SUMMARY OF THE INVENTION
[0007] The invention, in one embodiment, provides a semiconductor
testing apparatus. In this embodiment, the apparatus comprises a
probe card having probe needles associated therewith. A temperature
stabilizer element is couplable to the probe card. The temperature
stabilizer is configured to either raise or lower a temperature of
the probe needles to reduce their movement.
[0008] In yet another embodiment, the invention provides a system
for testing a semiconductor device. In this embodiment, the system
comprises a prober configured to receive a probe card therein. The
probe card is configured to be received in the prober and includes
a plurality of contact pads located on a surface thereof. The probe
card further includes probe needles that are located under the
surface on which the contact pads are located. A temperature
stabilizer element is coupled to the probe card and is configured
to either raise or lower a temperature of the probe needles. The
system further comprises a tester comprising a testing head that
has probes located on it and each of the probes is orientable to
engage a different contact pad of the probe card and a control
module that is electrically coupled to the testing head that
controls an operation of the probes.
[0009] In yet another embodiment, the invention provides a method
of fabricating a semiconductor device. The method comprises
providing an integrated circuit (IC) and testing the IC. The
testing step, in one embodiment, comprises placing the IC in a
prober, placing a probe card in the prober. The probe card has a
plurality of contact pads located on its surface that are
electrically connected to corresponding probe needles located under
the probe card. The probe needles are brought into contact with
contact pads located on the IC. A tester is positioned over the
probe card and includes a testing head having probes located
thereon. The probes are positioned onto different contact pads of
the probe card and a control module that is electrically coupled to
the testing head to test the IC is used to control the testing
process. The method of testing further includes adjusting a
temperature of the probe needles to reduce movement of the probe
needles by applying a voltage to a temperature stabilizer element
that is coupled to the probe card. The temperature stabilizer
element is configured to provide either heat or cold to the probe
card upon a change in the polarity of the applied voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a more complete understanding of the present invention,
reference is now made to the following descriptions taken in
conjunction with the accompanying drawings, in which:
[0011] FIG. 1 illustrates a semiconductor device testing apparatus
by the invention;
[0012] FIG. 2 illustrates an embodiment of a temperature
stabilizing element of the invention;
[0013] FIG. 3 illustrates an embodiment of a controller that can be
used in the invention; and
[0014] FIG. 4 illustrates a prober and tester system in which the
testing apparatus may be employed to test a semiconductor
device;
[0015] FIG. 5 illustrates the implementation of the testing
apparatus with a semiconductor device; and
[0016] FIG. 6 illustrates the implementation of the testing
apparatus with an IC.
DETAILED DESCRIPTION
[0017] FIG. 1 illustrates one embodiment of a semiconductor testing
apparatus 100 of the invention. This embodiment includes a probe
card 105. The probe card 105 may be of conventional design. In such
embodiments, the probe card 105 will include multiple levels of
circuits traces located between multiple layers of the probe card
105. It will also have a plurality of contact pads 110 located on
its surface. The probe card 105 further includes a ceramic ring
115. Probe needles 120 are located underneath the probe card 105
and are supported by the ceramic ring 115 and attached to the
ceramic ring 115 with an epoxy 122, as shown. Various probe needle
extensions 123 extend through the ceramic ring 115 and connect to
individual probe needles 120. The probe needle extensions 123 are
connected to the probe card 105 at a solder point 124. A conductive
trace, which is not shown, extends from each of the solder points
124 to the individual contact pads, thereby providing electrical
connection of the probe needles 120 to the different contact pads
110. During a testing procedure, the probe needles 120 are brought
into contact with an IC 125, which in this embodiment, does not
form a part of the semiconductor testing apparatus 100.
[0018] In one embodiment, the semiconductor testing apparatus 100
may include a stiffener 130 that is couplable to the probe card
105. When present, the stiffener 130 is used to minimize flex in
the probe card 105, and it may be of conventional design.
[0019] The apparatus 100 further includes a temperature stabilizing
element 135 that is thermally coupled to the probe needles 120. In
the illustrated embodiment, the temperature stabilizing element 135
is coupled to the stiffener 130, which in turn is thermally coupled
to the probe needles 120 by way of the ceramic ring 115. However,
in another embodiment, the temperature stabilizing element 135 may
have sufficient stiffness such that the stiffener 130 is not
needed. In such instances, the temperature stabilizing element 135
may be coupled directly to the probe card 105. Thus, the
temperature stabilizer 135 is thermally coupled to the probe
needles 120, such that a change of temperature in the temperature
stabilizer 135 is applied to and effects a temperature change of
the probe needles 120. However, in those embodiments where the
stiffener 130 is present, the temperature stabilizing element 135
is couplable to the stiffener 130. In and alternative embodiment,
the temperature stabilizing element 135 and the stiffener 130 may
form a single unit. The temperature stabilizing element 135 is
configured to either raise or lower a temperature of the probe
needles 120 to reduce their movement. These aspects of the
invention are discussed below in more detail.
[0020] In one embodiment, the apparatus 100 may also include a heat
sink 140. When present, the heat sink may be couplable to the
temperature stabilizing element 135. The heat sink 140 draws heat
from the temperature stabilizing element 135 and increases its
cooling efficiency. In other embodiments, however, the heat sink
may be integrally formed with the temperature stabilizing element
135.
[0021] FIG. 2 illustrates one embodiment of a temperature
stabilizing element 200 of the invention. In the illustrated
embodiment, the temperature stabilizing element 200 is comprised of
a series of P doped and N doped nodes 210. One end of the nodes 210
is electrically coupled in series by a segmented conductive layer
215, while their opposing ends are electrically coupled by an
un-segmented conductive layer 220, which is electrically connected
to the direct current source 205 by conductive wires 235. The nodes
210 may be an appropriately doped bismuth-telluride semiconductor
material. The nodes 210 are located between opposing ceramic plates
225 and 230. The ceramic plates 225 and 230 add rigidity and the
necessary electrical insulation. The temperature stabilizing
element 200 of this embodiment is based on the Peltier Effect where
DC applied across two dissimilar materials causes a temperature
differential. As the electrons move from the P type material to the
N type material through an electrical connector, the electrons jump
to a higher energy state absorbing thermal energy (cold side).
Continuing through the lattice of material, the electrons flow from
the N type material to the P type material through an electrical
connector, dropping to a lower energy state and releasing energy as
heat to the heat sink (hot side). Thermoelectric devices, such as
the one illustrated in FIG. 2 can, therefore, be used to heat and
to cool, depending on the direction of the current. The element
illustrated in FIG. 2 may be a Peltier diode, which is commercially
available.
[0022] In another embodiment, the temperature stabilizing element
200 may be a thermoelectric element. For example, the
thermoelectric element may be a heater/cooling fan combination. In
such embodiments, the heat sink may not be necessary or it may be
integrally formed with or coupled to the heater/cooling fan. In
another embodiment, however, the thermoelectric element is
configured to provide either heat or cold to a probe card,
depending on the direction (or polarity) of a current supplied by a
direct current source (DC) 205.
[0023] The ability to control the amount of heat or cold applied to
the probe needles 120 allows for better control over their
movement. A desired temperature range that reduces the movement of
the probe needles 120 can be targeted and the temperature
stabilizing element can then be used to keep the probe needles 120,
within that temperature range. This, in turn, would reduce the
amount of movement of the probe needles 120 caused by large
temperature fluctuations and reduce the amount of probe needle 120
misalignment and over-scrubbing.
[0024] The testing apparatus of the invention, in another
embodiment, may also include a controller 300, as illustrated in
FIG. 3, with continued reference to FIG. 1. The controller 300 can
be used to control the temperature stabilizer element 305 and keep
the probe needles 120 within the targeted temperature range. In one
embodiment, the controller 300 comprises a comparator/driver 310
that is connected to DC power supply Vss and Vdd, as indicated. A
temperature set element 315 is electrically coupled to the
comparator/driver 310 and to a DC source, as indicated. It is
configured to provide a desired temperature range at which the
probe needles 120 are to be maintained. In effect, it functions as
a temperature governor by providing a defined temperature range of
operation for the probe needles 120. The temperature set element
315 may be a variable resistor, a potentiometer, or similar device.
The comparator/driver 310 is also electrically coupled to a
thermocouple 320. The thermocouple 320 provides an operating
temperature of the ceramic ring 115 to the comparator/drive 310. In
one embodiment, it may be necessary to scale the voltage used to
operate the thermocouple 320 up or down. In such embodiments, the
controller 300 may also include a voltage scaling unit 325 that is
coupled to the comparator/driver 310.
[0025] In operation, a temperature of a ceramic ring 115 to which
the probe needles 120 are attached is read by the thermocouple 320.
As mentioned in certain embodiments, the thermocouple 320 may
operate on a millivolt range. In such instances, the voltage
scaling unit 325 will scale the voltage up such that the
comparator/driver 310 may be able to read the signal. The
comparator/driver 310 will compare the temperature of the ceramic
ring 115 provided by the thermocouple 320 to the set temperature
provided by the temperature set element 315. If the temperature is
outside the set temperature, the comparator/driver 310 will adjust
the voltage applied to the temperature stabilizer element 305 to
cause it to either provide heat or cold to the probe needles 120 to
bring their temperature into the set range.
[0026] FIG. 4 illustrates a system for testing a semiconductor
device. In one embodiment, the system comprises a prober 405 that
includes a probe card pan 410 and which may be of conventional
design. The pan 410 is configured to receive the probe card 105 of
FIG. 1. The probe card 105 includes the plurality of contact pads
110 and the probe needles, which cannot be seen in this view. The
stiffener 130, temperature stabilizer element 135 and heat sink 140
of FIG. 1 are schematically shown as a single module 415. The
system 400 of the invention further includes a tester 420 that
comprises a testing head 425 that has probes 430 located thereon
wherein each of the probes 430 can be oriented to engage a
different contact pad 110 of the probe card 105. The testing head
425 is mechanically lowered such that each of the probes 430
contacts the correct contact pad 110.
[0027] In the illustrated embodiment, the tester 420 also comprises
a control module 435 that is electrically coupled to the testing
head 425 and controls the testing operation of the semiconductor
device. The control module 435 may be comprised of a number of IC
boards 440 and may include the controller 300 of FIG. 3. It should
be noted that both the prober 405 and tester 420 may be of
conventional design and are commercially available from a number of
suppliers.
[0028] FIG. 5 illustrates an enlarged view of a testing apparatus
500 provided by the invention. In this embodiment, the testing
apparatus 500 is engaged with a contact pad 505 of a semiconductor
device 510. In this embodiment, the test apparatus 500 includes the
probe card 105, the stiffener 130, the temperature stabilizing
element 135, and the heat sink 140 of FIG. 1. FIG. 5 further
illustrates in a general way, how the probe 430 of the tester 420
(FIG. 4) makes electrical contact with the contact pad 110. A
conductive trace 515 located within the probe card 105 provides a
conductive path from the contact pad 110 to the solder point 124.
The probe needle extension 124 extends from the solder point 124
and makes electrical connection with the probe needle 120 by way of
a conductive trace 520 that extends through the ceramic ring 115
and epoxy 122. The probe needle 120 contacts the contact pad 505,
as shown. Thus, electrical connection is made between the probe 430
and the semiconductor device 510.
[0029] During placement of the probe needle 120 on the contact pad
505, the contact pad 505 is "scrubbed" by the probe needle 120 to
remove a protective oxide coating on the contact pad 505. This is
done to insure good electrical contact between the probe needle 120
and the contact pad 505. If the temperature of probe card 105, and
thus the probe needle 120, has fluctuated enough to cause
misalignment of the probe needle 120, the probe needle 120 may over
scrub or miss the contact pad 505 altogether. In either case, the
over scrubbing can irreparably damage the semiconductor device 510.
However, with the invention the potential for any damage is reduced
because the temperature stabilizing element 135 can be used to
maintain a temperature of the probe needle 120 within a set range,
which reduces the amount of movement and misalignment of the probe
needle 120.
[0030] FIG. 6 schematically illustrates a method of testing an IC
(e.g., semiconductor device 510, FIG. 5) that is located on a
wafer. Since the components are the same as those discussed in FIG.
5, the same reference will be used. The IC 510 is provided, and it
and the probe card 105 are positioned within the prober 405 (FIG.
4), as discussed above. The probe needles 120 are brought into
contact with the pads 505 located on the IC 510 and the prober 430
is then brought into contact with contact pad 110 located on the
probe card 105. Using the prober 405 and tester 420 (FIG. 4), the
testing may then be conducted in a way known to those who are
skilled in the art. During the testing of the IC 510 or cleaning
the probe needles 120, the temperature of the probe card 105 may be
adjusted in the manner described above to reduce movement of the
probe needles 120 by applying a voltage to the temperature
stabilizer element 135 to provide either heat or cold to the probe
needles 120, depending on the direction of the current.
[0031] Those skilled in the art to which the invention relates will
appreciate that other and further additions, deletions,
substitutions and modifications may be made to the described
embodiments without departing from the scope of the invention.
* * * * *