U.S. patent application number 09/931686 was filed with the patent office on 2002-03-14 for apparatus for the automated testing, calibration and characterization of test adapters.
Invention is credited to Appen, Stephan, Hubner, Michael, Kund, Michael.
Application Number | 20020030480 09/931686 |
Document ID | / |
Family ID | 7652550 |
Filed Date | 2002-03-14 |
United States Patent
Application |
20020030480 |
Kind Code |
A1 |
Appen, Stephan ; et
al. |
March 14, 2002 |
Apparatus for the automated testing, calibration and
characterization of test adapters
Abstract
The apparatus enables the automated testing, calibration and
characterization of test adapters for semiconductor devices. A
holder for the test adapter can be rotated in a defined manner. At
least one probe head is provided which can be adjusted radially
with respect to the holder. The probe head has two or more contact
pins whose spacing distance is adjustable.
Inventors: |
Appen, Stephan; (Munchen,
DE) ; Hubner, Michael; (Schonau, DE) ; Kund,
Michael; (Munchen, DE) |
Correspondence
Address: |
LERNER AND GREENBERG, P.A.
Post Office Box 2480
Hollywood
FL
33022-2480
US
|
Family ID: |
7652550 |
Appl. No.: |
09/931686 |
Filed: |
August 16, 2001 |
Current U.S.
Class: |
324/750.02 ;
324/754.03; 324/762.01 |
Current CPC
Class: |
G01R 31/2834 20130101;
G01R 31/2887 20130101 |
Class at
Publication: |
324/158.1 |
International
Class: |
G01R 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 16, 2000 |
DE |
100 39 928.2 |
Claims
We claim:
1. An apparatus for automated testing, calibration and
characterization of test adapters for semiconductor devices,
comprising: a holder for holding a test adapter; at least one probe
head adjustably disposed relative to said holder, said probe head
having at least two contact pins with an adjustable spacing
distance therebetween; and an adjustment device configured to
adjust said probe head relative to said holder.
2. The apparatus according to claim 1, wherein said at least one
probe head is one of a plurality of probe heads.
3. The apparatus according to claim 1, wherein said probe head is
movably disposed in elevation perpendicularly to a surface of said
holder.
4. The apparatus according to claim 1, wherein said adjustment
device is a robot arm and said probe head is mounted on said robot
arm.
5. The apparatus according to claim 1, which comprises a control
device connected to control a position of said probe head and a
rotation of said holder.
6. The apparatus according to claim 1, wherein said holder is
configured to hold test adapters with different diameters.
7. The apparatus according to claim 1, which comprises a stepping
motor disposed to selectively move said holder.
8. The apparatus according to claim 1, which comprises a control
device connected for controlling a distance between said contact
pins.
9. The apparatus according to claim 7, which comprises a control
device connected to said stepping motor and wherein said stepping
motor is controlled by said control device.
10. The apparatus according to claim 1, wherein the test adapter is
a test card.
11. The apparatus according to claim 1, wherein the test adapter is
formed with a number of contact surfaces one behind the other in a
radial direction of the test adapter, and said probe head has a
number of said contact pins corresponding to the number of contact
surfaces on the test adapter.
12. The apparatus according to claim 1, wherein said contact pins
are formed with pointed ends.
13. The apparatus according to claim 1, wherein said contact pins
are formed with flat ends, configured to enable contact to be made
with contact needles on the test adapter.
14. The apparatus according to claim 1, wherein said contact pins
are spring-biased contact pins.
15. The apparatus according to claim 14, wherein said contact pins
have a profile defining the spring-biased configuration
thereof.
16. The apparatus according to claim 14, wherein said contact pins
have a separate spring.
17. The apparatus according to claim 1, wherein said holder is
configured to be rotatable or movable with respect to said
adjustment device.
18. The apparatus according to claim 1, wherein said probe head is
adjustable within a coordinate system selected from the group
consisting of a polar coordinate system and a cartesian coordinate
system.
19. The apparatus according to claim 1, which comprises an
interface board and contact pins configured to contact contact
surfaces on the test adapter.
Description
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0001] The present invention relates to an apparatus for
automatically testing, calibrating and characterizing test adapters
for semiconductor devices. The semiconductor devices are preferably
integrated semiconductor circuits.
[0002] During the testing, calibration and characterization
processes, the radio-frequency characteristics of the test adapters
are investigated, in particular. However, it is also possible to
investigate direct-current characteristics.
[0003] A test adapter may be, for example, what is referred to as a
test card, by means of which semiconductor chips are tested at
wafer level. Another example of a test adapter is a socket board,
into which individual modules are introduced for testing.
[0004] In test systems for testing, say, semiconductor chips at
wafer level, test cards are used, as is known, as test adapters.
These test cards produce the electrical connection between contact
points on the semiconductor chips in a wafer to be tested and at
least one test channel in the test system. Reference is had, in
this context, to FIG. 9 which shows a plan view of one possible
exemplary arrangement of contact surfaces 2 in an edge area 3 of a
motherboard of a test card 1. It should be understood, however,
that other configurations of a test card are also feasible as an
example of a test adapter. The contact surfaces 2 produce a contact
with the test channels in the test system, and are preferably
located on a number of circles with different radii in the edge
region 3. A large number of contact needles are provided on the
lower face of the test card 1, and are to fit such that they
reliably make contact with the contact points on the chip at wafer
level to be tested. These contact needles are preferably located in
the inner area of the test card. In this case, each contact surface
2 has at least one associated contact needle. This means that the
contact needles are electrically related with the associated
contact surfaces 2 in a precisely defined manner.
[0005] In the socket boards mentioned initially, the contact
surfaces 2 are arranged in the form of a square, rather than in the
circular configuration above.
[0006] In general, test adapters such as test cards are matched to
different semiconductor devices to be tested, that is, to their
contact points. The appropriate different test adapters are
therefore required for different types of semiconductor devices.
The test adapters therefore make it possible to use the same test
system even for different types of semiconductor devices.
[0007] We have, however, identified the fact that the electrical
characteristics of the test adapters used for testing semiconductor
devices have a considerable influence on the test results, and
hence also on the test yield. In other words, the electrical
calibration and/or characterization of test adapters is an
important element, which should not be underestimated, in the
analysis of an overall test system.
[0008] In the past, scarcely any investigations have been carried
out into the influence of test adapters on various electrical
parameters, such as line impedance, signal delay times, signal rise
times or crosstalk between their various channels in different test
systems, due to the large number of channels, which is currently
around 1600 for test cards and will amount to 3200 in the near
future. In other words, the influence of test adapters on signal
performance and signal integrity in test systems has scarcely been
considered so far.
[0009] In the current state of the art only a single appliance
exists, which has not yet been described in any great detail, on
the market, which allows semiautomatic measurement of the line
impedance and of the signal delay times in test cards. In that
case, electrical contact is made with the test card to be
investigated via an interface board, which produces the connection
between a test head of a test system and the test card even during
normal operation of the test card. That appliance can therefore be
used only with test systems provided with this interface board and
not in general form for test cards for test systems with a
different type of interface board, as well. Furthermore, only a
relatively small subset of the channels can be measured
automatically with the known appliance, as well. If it is intended
to evaluate the channels of a different subset, then a manual
change must be made to contact plugs for this subset. The
measurement of crosstalk effects between the channels of different
subsets is thus likewise impossible with the known appliance. Thus,
until now, such a measurement could be carried out only manually
and, due to the large number of channels, this was associated with
an extremely long time penalty.
SUMMARY OF THE INVENTION
[0010] It is accordingly an object of the invention to provide an
apparatus for automated testing, calibration and characterization
of different test adapters, which overcomes the above-mentioned
disadvantages of the heretofore-known devices and methods of this
general type and which allows for any desired channels of the test
adapter to be measured automatically.
[0011] With the foregoing and other objects in view there is
provided, in accordance with the invention, an apparatus for
automated testing, calibration and characterization of test
adapters for semiconductor devices. The novel apparatus
comprises:
[0012] a holder for holding a test adapter;
[0013] at least one probe head adjustably disposed relative to the
holder, the probe head having two or more contact pins whose with
an adjustable spacing distance therebetween; and
[0014] an adjustment device configured to adjust the probe head
relative to the holder.
[0015] In other words, the objects of the invention are achieved in
the context of an apparatus of the type mentioned initially, by a
holder for the test adapter and at least one probe head, which can
be adjusted with respect to the holder and has at least two contact
pins (whose spacing is adjustable).
[0016] The distance between the at least two contact pins on a
probe head can be matched to the distance, which differs with
different test adapters to be calibrated or wherein, between the
contact surfaces for signals and the associated shields.
[0017] The holder can in this case hold test adapters with
different diameters.
[0018] The apparatus according to the invention thus has, in
particular, the holder which can rotate to hold test adapters with
different diameters. This holders allows the test adapter to be
rotated in a defined manner in the apparatus. A stepping motor or
the like may be used as the drive for this rotation of the
holder.
[0019] Furthermore, the apparatus according to the invention has
one or more robot arms, which can be moved in a horizontal
direction, running parallel to the plane of the test adapter, and
also in a direction at right angles to this. In this case, a probe
head is fit on each robot arm.
[0020] These robot arms and the rotation of the holder allow the
probe heads and their contact pins to be positioned on the contact
surfaces of the test adapter.
[0021] The apparatus can be matched directly to widely differing
test adapters by appropriately controlling the position of the
robot arms.
[0022] The rotation of the holder and the position of the robot
arms and probe heads can be controlled from a central computer.
This allows fully automated contact to be made with all channels,
and a corresponding fully automated investigation to be carried out
of the various electrical parameters of the test adapter.
[0023] The apparatus according to the invention can thus be matched
directly to different test adapters and measurement tasks. Since,
furthermore, it operates in a fully automated manner, it can carry
out any desired electrical calibration and characterization of test
adapters of widely differing types.
[0024] Other features which are considered as characteristic for
the invention are set forth in the appended claims.
[0025] Although the invention is illustrated and described herein
as embodied in an apparatus for automated testing, calibration and
characterization of test adapters, it is nevertheless not intended
to be limited to the details shown, since various modifications and
structural changes may be made therein without departing from the
spirit of the invention and within the scope and range of
equivalents of the claims.
[0026] The construction and method of operation of the invention,
however, together with additional objects and advantages thereof
will be best understood from the following description of specific
embodiments when read in connection with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a plan view of a first exemplary embodiment of the
apparatus according to the invention, having a robot arm with at
least one probe head;
[0028] FIG. 2 is a schematic side view of the apparatus of FIG.
1;
[0029] FIG. 3 is a plan view of a second exemplary embodiment of
the apparatus according to the invention, having two robot arms,
each having at least one probe head;
[0030] FIG. 4 is a schematic side view of the apparatus in FIG.
3;
[0031] FIG. 5 is a schematic illustration to explain the
configuration of contact pins for making contact with contact
surfaces;
[0032] FIG. 6 is a schematic illustration to explain the
configuration of contact pins for making contact with contact
needles;
[0033] FIG. 7 is a plan view of a third exemplary embodiment of the
apparatus according to the invention;
[0034] FIG. 8 is a schematic side view of the apparatus in FIG. 7;
and
[0035] FIG. 9 is a plan view of contact surfaces in the edge area
of a conventional test card.
[0036] Reference is had to the detailed description of FIG. 9
appearing in the introductory text. The same reference symbols are
used to identify the same and mutually corresponding components in
the figures.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] Referring now to the figures of the drawing in detail and
first, particularly, to FIGS. 1 and 2 thereof, there is shown a
test card 1, as an example of a test adapter with contact surfaces
2 on its upper face and contact needles 5 on its lower face. The
test card 1 is placed on a holder 4 of the apparatus, which can
rotate as shown by a double arrow 6. The apparatus also has a robot
arm 7, which can be moved as shown by a double arrow 8 in elevation
and in its distance from the test card 1. A probe head 9 on this
robot arm 7 can be moved in two directions, as shown by the double
arrow 10. This probe head 9 has two contact pins 11, which can make
contact with the contact surfaces 2 on the test card 1. The
distance between these contact pins 11 can be adjusted, so that the
apparatus can be matched to different types of test cards with
different distances between the contact surfaces 2. If required,
another probe head can also be provided on the robot arm 7.
[0038] The probe head 9 may also have more than two contact pins
10, if required. For example, it can thus be provided with four
contact pins 11. It is even possible to equip the contact head 11
with enough contact pins 11 for it to be able to simultaneously
touch all the contact surfaces 2 which are located one behind the
other in the radial direction. In the example in FIG. 1, this would
be six contact pins 11.
[0039] The holder 4 can be driven via a stepping motor 12. The
stepping motor 12 is controlled by a central control unit 13, which
also makes it possible to control and adjust the movement of the
robot arm 7 and the position of the probe head 9, as well as the
distance between the contact pins 11.
[0040] The holder 4 has an edge 14 which can be moved in the
lateral direction, so that it is suitable for holding test cards
with different diameters or else different test adapters.
[0041] The apparatus shown in FIGS. 1 and 2 is particularly
suitable for measuring signal delay times and line impedances: this
is because only the one robot arm 7 is required in this case. The
measurement devices used for these measurements, such as network
analyzers, oscilloscopes with TDR function (TDR=Time Domain
Reflexion) and the like, generally have two channels, each with a
signal and shield. The probe head 9 together with the two contact
pins 11 which is fit on the robot arm 7 allows automatic
measurement of all the channels on the test card 1 by moving the
one contact pin 11 for a test signal into contact with a contact
surface 2, while the other contact pin 11, which is used for
grounding, is in contact, for example, with an adjacent contact
surface 11. The desired electrical parameters, such as electrical
losses, can be deduced from the delay time of the test signal
reflected at the channel end, and from the magnitude of the
reflected signal.
[0042] FIGS. 3 and 4 show a further exemplary embodiment of the
present invention, wherein a second robot arm 7' is provided with a
second probe head 9' and with two further contact pins 11'. This
second robot arm 7' can be adjusted in elevation (see the double
arrow 8') in the same way as the robot arm 7, and can likewise be
driven from the central control unit 13.
[0043] In addition, the position of the second robot arm 7' can be
rotated with respect to the holder 4, as is indicated by a double
arrow 6'.
[0044] In the exemplary embodiment shown in FIGS. 3 and 4, the
control device 13 thus controls the stepping motor 12, the upward
and downward movement of the robot arms 7 and 7' (see the double
arrows 8 and 8'), the rotational movement of the robot arm 7' (see
the double arrow 6' in FIG. 3) and the radial movement of the probe
heads 9 and 9' (see the double arrows 10 and 10').
[0045] The exemplary embodiment in FIGS. 3 and 4 is particularly
suitable for measuring crosstalk effects between different channels
on the test card 1. This is because the aim of this measurement is
to investigate the influence of the signals in two different
channels on one another, wherein case each channel is intended to
be considered together with every other channel, which leads to
well over a million measurements when there are a large number of
channels. The robot arm 7, which cannot rotate, with the probe head
9 is connected in a case such as this via the contact pins 11 to at
least one channel to be investigated. The robot arm 7', which can
rotate, with the probe head 9' is then connected via the contact
pins 11' to all the other channels, so that the influence of all
the channels on the channels mentioned above of the robot arm 7 can
be investigated in one run. The probe head 9 is then connected via
its contact pins 11 to the next channels, and the contact pins 10',
on the probe head 9' are moved into contact with all the other
channels. In this way, it is possible to measure successive
crosstalk effects between each individual channel and all the other
channels.
[0046] In the exemplary embodiment in FIGS. 3 and 4, the test card
1 can be rotated independently of the rotational movement of the
robot arm 7'. If required, it is also possible to couple the rotary
movement of the probe head 7' to the rotary movement of the holder
4.
[0047] The holder 4 is preferably designed such that it is suitable
for holding different test adapters and test cards. To this end,
the holder 4 may, for example, have adjustable outer edges 14 so
that test adapters and test cards of different diameters can be
inserted into the holder 4.
[0048] FIGS. 5 and 6 show examples of possible configurations of
the contact pins 11: as shown in FIG. 5, these may have pointed
ends and may be sprung, so that these ends rest on the contact
surfaces 2. However, it is also possible to provide contact pins
11a, 11b with flat ends (see FIG. 6), so that these flat ends can
be moved into contact with the contact needles 5 of the test card 1
which is then inserted "reversed" into the holder 4. In order to
spring out, the contact pins 11a, 11b may have a curved profile
(see reference symbols 11 and 11a in FIGS. 5 and 6), or may be
provided with a separate spring (see reference symbol 11b in FIG.
6).
[0049] FIGS. 7 and 8 show an exemplary embodiment wherein signals
are supplied from a test system with an interface board 17 via
contact pins 16 to the contact surfaces 2 of the test card 1, which
has now been inserted "reversed", and are passed to the contact
needles 5. The signals which are otherwise present on the chip are
tapped off for analysis on these contact needles 5 by means of the
springs illustrated in FIG. 6. In the present exemplary embodiment,
the radial polar-coordinate robot arms 7 are replaced by a
Cartesian (xyz) robot system which can be adjusted as shown by the
arrows 10, 15 and 18. Such a configuration provides a square
arrangement for the contact needles 5. This intrinsically allows
the entire system to be analyzed.
* * * * *