Probe ring having electrical components affixed thereto and related apparatus and processes

An apparatus to test an integrated circuit has a plurality of contact pads electrically coupled to the integrated circuit to transfer electrical signals to and from the integrated circuit. The apparatus has a body or ring, a plurality of probes, and electrical components. The ring has a ring surface and a ring opening in the ring surface to a hollow cavity extending through the ring. The plurality of probes extend from a first location exterior of the ring to a second location over the ring opening and are affixed to the ring with an adhesive. Each probe of the plurality of probes has a contact end to electrically contact one contact pad of the plurality of contact pads. In some embodiments, at least one electrical component is secured to the ring. The at least one electrical component is electrically coupled to the plurality of contact pads. A conductive plate may also be secured to the body and be electrically coupled to at least probe of the plurality of probes and to the at least one electrical component. The ring with probes and electrical components can also be combined with a printed circuit board has

TIAL WAIVER OF COPYRIGHT PURSUANT TO 1077 O.G. 22(MAR. 20, 1987) 
.COPYRGT. Copyright. David M. Miley. 1996. All of the material in this 
patent application is subject to copyright protection under the copyright 
laws of the United States and of other countries. As of the first 
effective filing date of the present application, this material is 
protected as unpublished material. 
However, permission to copy this material is hereby granted to the extent 
that the owner of the copyright rights has no objection to the facsimile 
reproduction by anyone of the patent document or patent disclosure, as it 
appears in the United States Patent and Trademark Office patent file or 
records, but otherwise reserves all copyright rights whatsoever. 
FIELD OF INVENTION 
The present invention generally relates to the field of testing equipment 
for integrated circuits mounted on a semiconductor substrate and, 
particularly, to probe cards used by various types of testing equipment to 
test unsevered integrated circuits formed on a semiconductor substrate 
generally in wafer form and related methods to use the present invention 
and to manufacture the present invention. 
BACKGROUND 
Integrated circuits or microchips (or chips) are generally manufactured on 
a single wafer of semiconductor material (e.g., silicon). These individual 
microchips are later cut out of the wafer. Each integrated circuit on each 
microchip has contact pads that are electrically coupled to the electrical 
circuits and subcircuits embedded therein. Contact pads are exposed in 
wafer or microchip form before the microchips are packaged and are, thus, 
accessible with properly designed probes. A selected number of microchips 
are tested by automated test equipment that utilize probe rings and probe 
cards which have a number of probes that access the microchips to ensure 
they meet design specifications. 
As shown in FIGS. 1A, 1B, and 1C, a conventional probe ring assembly 50 
generally consists of conventional probe ring 11 that has central opening 
11 which provides access to microchip 20 to be tested, together with a 
series of spaced conductive individual flexible metallic needles or blades 
(probes) 12 arranged on conventional probe ring 10 around central opening 
11. Each probe 12 extends from a location away from conventional probe 
ring 10 toward the center of central opening 11, traversing both the outer 
perimeter 15 of conventional probe ring 10 and inner perimeter 16 of 
central opening 11 of conventional probe ring 10. As discussed above, 
probes 12 are adapted to electrically contact selected contact pads on 
microchip 20, which are electrically coupled to the rest of the integrated 
circuitry embedded in microchip 20, so that electrical signals may be 
transmitted to and from the integrated circuit on microchip 20. These 
signals transmit test routines that test the functionality of specific 
integrated circuits embedded in microchip 20. Epoxy layer 17 holds probes 
12 in position and, if necessary, electrically insulates probes 12 from 
each other and from conventional probe ring 10, which may consist of 
anodized Aluminum. 
As shown in FIGS. 2A, 2B, and 2C, conventional probe ring assemblies 50 are 
usually designed to fit a conventional printed circuit board opening 14 in 
a conventional printed circuit board 20 to form a conventional probe card 
30. One end of probes 12 are then soldered to selected contacts 70 on 
conventional printed circuit board 20 to selectively electrically couple 
contacts 70 to probes 12 to relay signals to and from contact pads, of 
microchip 20 to test selected integrated circuits embedded on microchip 
20. Note contacts 70 are generally oriented in a "star-burst" pattern 
around conventional printed circuit board opening 14 of conventional 
printed circuit board 20. Conventional printed circuit board 20 aligns 
with central opening 11 of conventional probe ring assembly 50 when 
conventional probe ring assembly 50 and conventional printed circuit board 
20 are fitted together. Plated-thru holes 75 are used to make electrical 
connections through conventional printed circuit board 20. First end 31 of 
conventional probe card 30 is, in turn, inserted into various types of 
testing equipment that are used to generate and transmit the test routines 
that test the functionality of the integrated circuits and subcircuits of 
microchip 20. Electrical components, such as capacitor 40, may be placed 
on conventional probe card 20 in the electrical path 33, between contacts 
70 and the contact leads 32 on first end 31 of conventional printed 
circuit board 20, such as a printed circuit trace, which generally 
consists of plated copper. In addition, electrical components may be 
placed between bands 71 and 72 that are generally used as common ground 
and/or power sources. Bands 71 and 72 are, in turn, generally connected to 
an appropriate electrical path 33 used as a ground or power source by the 
testing equipment with which conventional probe card 30 interacts. These 
electrical components adjust or modify the electrical signals transmitted 
to and from the integrated circuit via conventional probe ring assembly 50 
and conventional probe card 30 for a variety of reasons. For instance, 
capacitors 40 are generally used to increase the accuracy of the test 
results by reducing the overall distortion. 
Conventional probe ring assemblies 50 and conventional probe cards 30 have 
a number of problems. For example, the placement of electrical components, 
such as capacitor 40, on conventional printed circuit board 20 itself 
slows and interrupts the transmission and reception of electrical test 
signals to and from the selected integrated circuits being tested. The 
distance between the selected integrated circuit being tested on microchip 
20 and the capacitor 40 in conventional embodiments is, unfortunately, 
rather large in microscopic terms, which slows down the overall speed of 
the circuit and increases the distortion (e.g., due to the time delay 
associated with the capacitors and transient or ripple condition created 
by the capacitors). Most semiconductor manufacturers appreciate the 
significance of both of these factors and that conventional probe ring 
assemblies 50 and conventional probe cards 30 do not alleviate these 
concerns. 
SUMMARY 
The disclosed invention pertains to an apparatus or process that is used to 
test an integrated circuit and methods to manufacture the apparatus(es) 
used to test integrated circuits. An integrated circuit generally 
comprises a plurality of contact pads that are electrically coupled to the 
integrated circuit to transfer electrical signals to and from the 
integrated circuit. Preferred embodiments of the probe ring generally 
comprise a body (or ring), a plurality of probes, and at least one 
electrical component (e.g., capacitors, resistors, inductors, 
transformers, integrated circuits). The body or ring, which is preferably 
non-conductive and substantially circular, has a first surface and an 
opening to a hollow cavity extending therethrough. The ring comprises 
materials selected from the group consisting of ceramic, anodized 
aluminum, fiberglass, metal, and any combination thereof. The plurality of 
probes is positioned on the surface and extends from a location exterior 
to the ring to a location over the opening and is located proximate to the 
opening. The plurality of probes is attached to the ring surface. Each 
probe has a contact end to contact one contact pad of the plurality of 
contact pads. Each probe is aligned in such a way so as to orient each 
contact end of each probe of the plurality of probes over the opening to 
contact a particular contact pad. The electrical components are secured to 
the ring and selectively electrically coupled to particular probes of the 
plurality of probes. 
Some preferred embodiments place an insert in a recess created in the ring, 
so that the insert extends out into and over the opening. The insert may 
be conductive and is electrically coupled to at least one probe of the 
plurality of probes (e.g., via jumper wires) and/or to the electrical 
components. The electrical component(s) are placed on the insert and, in 
certain cases, are electrically coupled to the plurality of contact pads 
and/or the insert. In fact, the insert is preferably partitioned into a 
plurality of portions that are electrically insulated from one another, 
which enables electrical contacts (e.g., leads or pads of electrical 
components, or probes) to be electrically coupled to various portions of 
the insert. The probe ring may also have an outer perimeter and the recess 
may extend from the ring opening to the outer perimeter and the insert may 
also extend from the opening to the outer perimeter. The plurality of 
probes are affixed to said ring surface with an adhesive (e.g., epoxy), 
which electrically insulates the plurality of probes from one another and 
from the conductive insert, if used, and the epoxy also secures the 
plurality of probes and, when applicable, the insert in place. 
Preferred probe rings may be combined with preferred probe cards. Probe 
cards are generally comprised of a probe ring and a printed circuit board. 
The printed circuit board has a second opening therein along with a second 
opening perimeter. The printed circuit board also has a plurality of 
electrical contacts. Probes preferably have a connection end. Each 
connection end of each probe of the plurality of probes selectively 
electrically contacts one electrical contact of the plurality of 
electrical contacts. The electrical contacts may also be electrically 
coupled to the insert, when the insert is conductive. The plurality of 
electrical contacts selectively electrically couple the plurality of 
probes with testing equipment to test the integrated circuit. The 
perimeter of the ring conforms to the second opening perimeter, so that 
the ring aligns with the second opening and that the ring and the printed 
circuit board fit together. The printed circuit board may have a first end 
that is adapted to be inserted into the testing equipment. Note, however, 
printed circuit board can take any number of shapes, such as circular, 
square, rectangular, or may contact testing equipment with alternative 
techniques as well. Such as with pins, edge connectors, and elastomer. 
Preferred processes comprise the following steps (a) providing a body 
having a hole therethrough; (b) creating a recess in the body, (c) placing 
an insert in the recess so that the insert extends out over the hole; (d) 
placing a plurality of probes so each probe of the plurality of probes 
traverses the body and terminates over the hole; (e) affixing each probe 
of the plurality of probes to the body with an adhesive; and (f) placing 
electrical components on the insert and electrically coupling the 
electrical components to at least one probe of the plurality of probes. 
Additional processes comprise electrically coupling the electrical 
component to the insert and (g) creating a recess in the body that extends 
from the hole to an outer portion of the body, and (h) placing the insert 
in the recess so that the insert extends from the hole to the outer 
portion. In addition, as described above, the resulting probe ring may be 
aligned and fitted with a printed circuit board to form a probe card. 
Preferred embodiments provide a number of advantages. Preferred embodiments 
enable electrical (and electronic) components to be placed on or around 
the probe ring assembly, as opposed to on the printed circuit board of a 
probe card. This capability shortens selected conductive paths to and from 
the integrated circuit being tested. This capability enhances the overall 
speed and effectiveness of the testing procedure. For instance, the 
ability to position a capacitor in dose proximity to the tips of the 
probes dramatically shortens the distance between power and ground, which 
reduces the overall distortion of the signals transmitted to and from the 
integrated circuit and increases the bandwidth of the signals transmitted. 
Thus, preferred embodiments improve the efficiency of testing procedures 
by increasing the speed and frequency and also improve the integrity of 
the results gained by the testing operation by reducing distortion without 
necessitating substantial changes in existing testing equipment or 
procedures. Moreover, preferred embodiments can be easily retrofitted into 
existing designs utilized by existing test equipment incorporating probe 
rings and probe card, thereby making probe rings and probe cards extremely 
competitive with competing technologies, such as membrane cards and blade 
cards. 
Other advantages of the invention and/or inventions described herein will 
be explained in greater detail below.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The present inventions will be described by referring to apparatus and 
methods showing various examples of how the inventions can be made and 
used. When possible, like reference characters are used throughout the 
several views of the drawing to indicate like or corresponding parts. 
As discussed above, FIGS. 1A, 1B, and 1C respectively illustrate a top 
view, a cross-sectional view, and a bottom view of conventional probe ring 
assembly 50. Similarly, FIGS. 2A, 2B, and 2C respectively illustrate a top 
view, a side view, and a bottom view of a conventional probe card 30 
having electrical components, such as capacitor 40, affixed thereto. Once 
again, for a variety of reasons, the placement of electrical components on 
conventional printed circuit board 20 of conventional probe card 30, such 
as capacitors 40, is problematic. 
FIGS. 3A and 3B respectively illustrate a top view and a cross-sectional 
view of a preferred embodiment of probe ring assembly 300 having 
electrical components, such as capacitors 340, affixed to probe ring 
assembly 300. FIG. 4 illustrates a top view of an alternate preferred 
embodiment of second probe ring assembly 301 having electrical components, 
such as capacitors 340, affixed to second probe ring assembly 301. Insert 
335 is partitioned differently in probe ring assembly 300 than in second 
probe ring assembly 301. Insert 335 may be partitioned into any number of 
planes or contact areas 335A and 335B, to provide additional ground or 
power source on alternate signal paths. Note the discussion below 
pertaining to probe ring assembly 300 and second probe ring assembly 301 
as well. Both preferred embodiments shown in FIGS. 3A, 3B, and 4 shorten 
the distance between probes 312 and power and/or ground sources by placing 
capacitors 340 adjacent or adjoining probe ring assembly 300 (or second 
probe ring assembly 301), preferably on ledge 337 inside or along inner 
perimeter 316 of probe ring opening 311 of probe ring assembly 300 (or 
second probe ring assembly 301). 
More specifically, as shown in FIGS. 6A, 6B, and 6C, preferred embodiments 
have a pocket or recess 338 machined or etched into first surface 310A 
(preferably the bottom surface) of probe ring 310 that substantially 
surrounds probe ring opening 311 of probe ring 310. As shown in FIG. 6B, 
first surface 310A is typically angled at 7 degrees, but may be angled at 
any angle, including -0- degrees. Pocket or recess 338 substantially 
extends around inner perimeter 316 of probe ring opening 311 to form an 
indentation. Recess 338 holds an appropriately fashioned insert 335. 
Insert 335 conducts electrical signals from the outer perimeter 315 of 
probe ring 310 to the inner perimeter 316 of probe ring 310. Preferred 
embodiments use a double-sided copper dad printed circuit board or some 
other acceptable electrically conductive material (e.g., screen printed 
ceramic to conduct the signals). FIGS. 7A and 7B show one possible shape 
of insert 335, which conforms with the shape of recess or pocket 338 shown 
in FIGS. 6A, 6B, and 6C. 
Referring to FIGS. 6A, 6B, and 6C, note preferred embodiments have pocket 
or recess 338 divided into a plurality of areas 319A, 319B, 319C, and 
319D. Referring to FIGS. 3A, 3B, and 4, insert 335 when placed in pocket 
or recess 338 extends out past the inner perimeter 316 of probe ring 310 
(around probe ring opening 311) to form ledge 337 upon which electrical 
components 340 can be positioned or placed and/or to which attached, 
and/or electrically coupled. Insert 335 is held in place with an adhesive, 
such as Cyanoacrylate Ester (e.g., SuperGlue.TM.) or an epoxy. Preferred 
embodiments use adhesives that are by and large electrically neutral. The 
depth of pocket or recess 338 is greater than the thickness of insert 335, 
so that when probes 312 are surrounded and/or fixed in place with epoxy 
317, probes 312 are electrically isolated from one another and from insert 
335. Insert 335 may also be covered with an insulation, except when 
removed for contact purposes. Epoxy 317 in preferred embodiments 
substantially covers first surface 310A and insert 335, except for the 
portions 321A, 321B, 321C, and 321D of insert 335 that protrude beyond the 
outer perimeter 315 of probe ring 310, which are called ears, arms or 
legs. In addition, while preferred embodiments increase the overall size 
(and the perimeter) of probe ring opening 311 extending through probe ring 
310 than what would normally be the case, the use and placement of insert 
335 actually reduces the overall size (and the perimeter) of probe ring 
opening 311 to what would normally be the case, thereby creating ledge 
337. In particular, probe ring opening 311 of preferred probe rings 310 
are generally determined by a number of factors, including the customer's 
application, the overall size dimensions of the integrated circuit on 
microchip 20 under test, the gram pressures to be exerted by each probe of 
probes 312, the type of material for probes 312, and the diameter of each 
probe of probes 312. Preferred embodiments generally increase the size of 
probe ring opening 311, determined by the above considerations to be 
appropriate, by approximately 0.05' larger along both the positive and 
negative X axis, as referenced by 311A in FIG. 6C, and the positive and 
negative Y axis, as referenced by 311B in FIG. 6C, for a total of 0.1" 
along the X axis 311A and a total of 0.1" along Y axis 311B. As mentioned 
above, insert 335 preferably has an insert opening 351 that dimensionally 
matches that of what would be considered the appropriate or "normal" ring 
opening 311 for probe ring 310, but insert 335 is 0.05" smaller on all 
sides (including the corners) than that of the probe ring 310. Of course, 
the actual amounts may vary, so long as ledge 337 is created. Note probe 
ring opening 311 and insert opening 351 are aligned in FIGS. 3A, 3B, and 
4. 
In addition, at least one channel or passageway 323A, 323B, 323C, and 323D 
(as shown in FIGS. 6A, 6B, and 6C) should be added to pocket or recess 338 
and fashioned such that the power and ground connections to microchip 20 
(the device under test) can be routed to insert 335 of probe ring assembly 
310. Preferred embodiments remove material in selected locations of an 
exterior surface of 310A of probe ring 310, so that insert 335 with 
corresponding extensions (or ears) 321A, 321B, 321C, and 321D (as shown in 
FIG. 7A), can extend from inner perimeter 316 of probe ring opening 311 of 
probe ring 310 to outer perimeter 315 of probe ring 310. Once again, the 
depth of this channel is preferably greater than the thickness of insert 
335. As shown in FIGS. 6A, 6B, and 6C, preferred embodiments have channels 
or passageways 323A, 323B, 323C, and 323D at four locations that 
effectively form the corners of a square. In addition, insert 335 
generally extends well beyond outer perimeter 315 of probe ring 310, which 
makes electrical connections to and from insert 335 easier to construct. 
For instance, referring to FIGS. 5A, 5B, and 5C, extensions or ears 321A, 
321B, 321C, and 321D are selectively electrically connected to conductive 
bands 370 and 371. Conductive band 372 is coupled to power via one hook up 
wire 374, whereas conductive band 371 is coupled to ground via another 
hookup wire 374, or vice versa. Additional hook-up wires may be used or 
the connections may be made internally, externally, directly, or 
indirectly. 
Note that insert 335 may be divided into a number of electrically isolated 
pieces (of varying shapes--as shown in FIG. 4), so that portion 335A of 
insert 335 can transmit/receive one type of signal, whereas another 
portion 335B of insert 335 can transmit/receive another signal. For 
instance, one portion may be electrically coupled to ground, whereas 
another portion can be electrically coupled to power. In this case, as 
shown in FIGS. 3A, 3B, and 4, capacitors 340, electrical components, such 
as may actually straddle two portions 335A and 335B of insert 335. 
Alternately, electrical components can merely rest on ledge 337 and be 
electrically connected to selected probes 312 via jumper wires 341. 
Appropriate portions 335A and 335B of insert 335 together form ledge 337 
to which power and ground probes of probes 312 will be terminated via 
jumper wire(s) 341. Electrical components, such as capacitor 340, will 
also be mounted to or on ledge 337. Also, once again, note the varying 
shape of portions 335A and 335B in FIG. 4 as compared to FIGS. 3A, 7A, and 
7B. 
As shown in FIGS. 5A, 5B, and 5C, probe ring 300 fits printed circuit board 
opening 314 in printed circuit board 320 to form a probe card 330. One end 
of probes 312 are then soldered to selected contacts 370 on printed 
circuit board 320 to selectively electrically couple contacts 370 to 
probes 312 to relay signals to and from contact pads of microchip 20 to 
test selected integrated circuits embedded on microchip 20. Of course, as 
shown in FIG. 5B, printed circuit board opening 314 of printed circuit 
board 320 aligns with probe ring opening 311 of probe ring 310 when probe 
ring 310 and printed circuit board 320 are fitted together. Plated-thru 
holes 375 are used to make electrical connections through printed circuit 
board 320. First end 331 of probe card 330 is, in turn, inserted into 
various types of testing equipment that are used to generate and transmit 
the test routines that test the functionality of the integrated circuits 
and subcircuits of microchip 20. Electrical components, such as capacitor 
340, may be placed on probe card 320 in the electrical path 333, between 
contacts 370 and the contact leads 332 on first end 331 of printed circuit 
board 320. In addition, electrical components may be placed between bands 
371 and 372 that are generally used as common ground and/or power sources 
and/or, as discussed above, on ledge 337. Bands 371 and 372 are, in turn, 
generally coupled to an appropriate electrical path 333 used as a ground 
or power source by the testing equipment with which probe card 330 
interacts. Note additional conductive bands may be used to provide 
additional power and ground sources or to transmit and receive test 
signals. As shown, ears 321A, 321B, 321C, and 321D, which may comprise 
copper foil/braid and have varying lengths, as selectively attached to 
bands 371 and 372. These electrical components adjust or modify the 
electrical signals transmitted to and from the integrated circuit via 
probe ring 300 and probe card 330 for a variety of reasons. As mentioned 
above, capacitors 340 are generally used to increase the accuracy of the 
test results by reducing the overall distortion as well as the speed or 
rate the integrated circuit being tested is coupled and decoupled to and 
from power and ground connections. 
In addition, preferred process generally comprise the following steps (a) 
providing a body, such as probe ring 300 having a hole 311 therethrough; 
(b) creating a recess, such as 338, 323A, 323B, 323C or 323D in the body, 
(c) placing insert, such as insert 335 in the recess 338 so that the 
insert 335 extends out over hole 311; (d) placing a plurality of probes 
312 so each probe of the plurality of probes 312 traverses the body and 
terminates over hole 311; (e) affixing each probe of the plurality of 
probes 312 to the body with an adhesive, such as epoxy 317; and (f) 
placing electrical components 340 on the insert 335 and electrically 
coupling the electrical components 340 to at least one probe of the 
plurality of probes 312. Additional processes comprise electrically 
coupling the electrical component 340 to the insert 335 and (g) creating a 
recess 338 in the body that extends from the hole 311 to an outer portion 
of the body; and (h) placing the insert 335 in the recess 338 so that 
insert 335 extends from the hole 311 to the outer portion of the body. As 
discussed above, printed circuit board 320 and either probe ring assembly 
300 or second probe ring assembly 301 are fitted together to form probe 
card 330. 
FURTHER MODIFICATIONS AND VARIATIONS 
Although the invention has been described with reference to a specific 
embodiment, this description is not meant to be construed in a limiting 
sense. The example embodiments shown and described above are only as an 
example. Various modifications of the disclosed embodiment as well as 
alternate embodiments of the invention will become apparent to persons 
skilled in the art upon reference to the description of the invention. For 
instance, the preference of materials used for insert 335 may vary. Other 
conductive materials, besides copper, can be used to conduct signals. 
Similarly, multi-layer or buried interconnect boards may be used to 
transmit signals. Likewise, alternate materials for probe ring 310 can be 
used, such as ceramic, metal, epoxy, glass, and plastic. Probes 312 
should, of course, be conductive, but may comprise any number of 
conductive materials, such as Tungsten, Rhenium Tungsten, Beryllium 
Copper, Palladium, and Paliney-7.TM.. 
The shape of insert opening 351, probe ring opening 311, and printed 
circuit board opening 314 may vary as well. In addition, electrical 
connections can often be electrical couplings and may be made in a variety 
of ways, such as by conductive epoxy-bond, solder, wire-bond, and eutectic 
bond. Alternate connection mechanisms, such as plated-thru holes may be 
used in ears 321A, 321B, 321C, and 321D. 
Thus, even though numerous characteristics and advantages of the present 
inventions have been set forth in the foregoing description, together with 
details of the structure and function of the inventions, the disclosure is 
illustrative only, and changes may be made in the detail, especially in 
matters of shape, size and arrangement of the parts within the principles 
of the inventions to the full extent indicated by the broad general 
meaning of the terms used in the attached claims. Accordingly, it should 
be understood that the modifications and variations suggested above and 
below are not intended to be exhaustive. These examples help show the 
scope of the inventive concepts, which are covered in the appended claims. 
The appended claims are intended to cover these modifications and 
alternate embodiments. In short, the restrictive description and drawings 
of the specific examples above are not intended to point out what an 
infringement of this patent would be, but are to provide at least one 
explanation of how to make and use the inventions contained herein. The 
limits of the inventions and the bounds of the patent protection are 
measured by and defined in the following claims.