Probe apparatus and a method for polishing a probe

A probe apparatus according to the present invention comprises a stage carrying an object of inspection thereon and rotatable and movable in the horizontal and vertical directions, a probe located over the stage and adapted to be brought into contact with the object of inspection on the stage in order to subject the object to electrical inspection, a polisher carrying section attached to the stage and capable of carrying thereon a polisher for polishing the probe, a storage mechanism for storing the polisher, and a transportation mechanism for transporting the polisher between the storage mechanism and the polisher carrying section.

BACKGROUND OF THE INVENTION 
The present invention relates to a probe apparatus and a method for 
polishing a probe. 
Conventionally, a probe apparatus 10 of the type shown in FIGS. 9 and 10 is 
used for electrical inspection of IC chips that are formed on a 
semiconductor wafer (hereinafter referred to simply as "wafer"), for 
example. As shown in these drawings, this apparatus 10 comprises a 
cassette carrying section 11 in which a cassette C stored with wafers W is 
placed, a loader section 12 including a transportation mechanism (not 
shown) for transporting each wafer W delivered from the cassette C in the 
section 11, a prober section 13 for inspecting the wafer W transported by 
means of the transportation mechanism, a controller 14 for controlling the 
prober section 13 and the loader section 12, and a display unit 15 that 
doubles as a control panel for operating the controller 14. The loader 
section 12 is provided with a sub-chuck (not shown), whereby the wafer w 
is pre-aligned on the basis of its orientation flat. The pre-aligned wafer 
W is transported to the prober section 13 by the transportation mechanism. 
The prober section 13 is provided with a main chuck 16 movable in the X-, 
Y-, and Z-directions and the .theta.-direction (direction of rotation 
around the Z-axis) and capable of carrying the wafer W thereon, an 
alignment mechanism 17 including a CCD camera, an alignment optical system 
or the like for accurately aligning the wafer W on the main chuck 16 in a 
position for inspection, and a probe card 18 having a probe 18A for 
electrically inspecting the wafer W aligned by means of the alignment 
mechanism 17. A swingable head plate 19 is mounted on the top face of the 
prober section 13. The probe card 18 is fixed to a center aperture of the 
head plate 19 by means of an insert ring 19A. A test head 20 is rotatably 
located on the prober section 13. In electrically inspecting the IC chips 
on the wafer W, the probe card 18 and a tester (not shown) are connected 
electrically to each other through the test head 20, and a given 
inspection signal from the tester is transmitted to the IC chips of the 
wafer W on the main chuck 16 via the probe card 18. 
A card transportation arm (not shown) is provided on the front side of the 
prober section 13. This transportation arm transports the probe card 18 
with a card holder to a position right under the insert ring 19A of the 
head plate 19. Normally, the card transportation arm is contained in a 
cover 21 that is attached to the front of the prober section 13. In 
changing the probe card 18, the card transportation arm is raised to a 
level position and then turned to the position right under the insert ring 
19A with the cover 21 lowered. The transportation arm, thus positioned 
right under the ring 19A, receives the probe card 18 that is automatically 
disengaged from the ring 19A, and transports it to the front of the prober 
section 13. At this time, an operator removes the card 18 on the card 
transportation arm, and places a new probe card 18 on the transportation 
arm. Thereafter, the transportation arm, carrying the new card 18 thereon, 
is turned again to the position right under the insert ring 19A. 
In the electrical inspection of the wafer W, the wafer W on the main chuck 
16 and the probe 18A are aligned with each other by means of a drive 
mechanism, such as a moving table that is movable in the X- and 
Y-directions, for example. Thereafter, the main chuck 16 is overdriven 
upward, whereupon a natural oxide film (e.g., aluminum oxide film) formed 
on the surface of an electrode pad (formed of, e.g., aluminum) of the 
wafer W is scraped off by means of the probe 18A, so that the probe 18A 
and the electrode pad can be securely brought into electrical contact with 
each other. If this inspection is repeated, however, oxide aluminum, an 
electrical insulator, may adhere to the probe 18A, or the distal end of 
the probe 18A may wear, possibly hindering the inspection thereafter. 
Conventionally, therefore, a steady inspection is secured by polishing the 
probe 18A in a manner such that a polishing plate, which is attached to a 
part of the main chuck 16, is brought into contact with the probe 18A, and 
that the chuck 16 is moved up and down. 
In general, the polishing plate is used semi-permanently without replacing. 
Accordingly, its repeated use leaves filings thereon, which float as 
particles, possibly exerting a bad influence on the inspection, as the 
main chuck 16 moves. Although the filings are removed from the polishing 
plate by suction, therefore, production of the particles cannot be fully 
prevented by that alone. The influence of the particles becomes more 
serious as the IC chips are microminiaturized, in particular. As the 
polishing plate is repeatedly used, it is gradually worn at its polishing 
surface and its polishing ability gradually decreases. Naturally, this 
problem can be solved by changing the polishing plate on each occasion. 
According to the conventional arrangement, however, the polishing plate 
can be changed only after evacuating the test head 20 from the probe 
apparatus 10 and swinging the head plate 19 open to expose the prober 
section 13. Since the polishing plate is attached to the main chuck 16 by 
means of screws or the like, moreover, its replacement is very complicated 
and takes a lot of time. 
BRIEF SUMMARY OF THE INVENTION 
A first object of the present invention is to provide a probe apparatus, 
whereby even disposable polishers can be automatically changed with high 
efficiency in a short period of time, so that high-reliability inspection 
can be effected. 
A second object of the invention is to provide a probe polishing method, 
whereby a probe of a probe apparatus can be polished with high accuracy 
depending on its type and subjected to high-accuracy inspection. 
The first object of the invention is achieved by the following probe 
apparatus. This probe apparatus comprises: a stage carrying an object of 
inspection thereon and rotatable and movable in the horizontal and 
vertical directions; a probe located over the stage and adapted to be 
brought into contact with the object of inspection on the stage in order 
to subject the object to electrical inspection; a polisher carrying 
section attached to the stage and capable of carrying thereon a polisher 
for polishing the probe; a storage mechanism for storing the polisher; and 
a transportation mechanism for transporting the polisher between the 
storage mechanism and the polisher carrying section. 
The second object of the invention is achieved by the following method for 
polishing a probe. This probe polishing method comprises the steps of: 
transporting a polisher from a polisher storage section by means of a 
transportation mechanism so that the polisher is placed on a polisher 
carrying section on a stage for carrying an object of inspection thereon; 
moving the stage, thereby bringing the polisher on the polisher carrying 
section into contact with a probe, located over the stage and adapted to 
be brought into contact with the object of inspection on the stage in 
order to subject the object to electrical inspection, and polishing the 
probe by means of the polisher; and transporting the used polisher on the 
polisher carrying section to the polisher storage section by means of the 
transportation mechanism and transporting an unused polisher from the 
polisher storage section by means of the transportation mechanism so that 
the unused polisher is placed on the polisher carrying section. 
Additional object and advantages of the invention will be set forth in the 
description which follows, and in part will be obvious from the 
description, or may be learned by practice of the invention. The object 
and advantages of the invention may be realized and obtained by means of 
the instrumentalities and combinations particularly pointed out in the 
appended claims.

DETAILED DESCRIPTION OF THE INVENTION 
An embodiment of the present invention will now be described in detail with 
reference to the accompanying drawings. 
As shown in FIG. 1, a probe apparatus 10 according to the present 
embodiment comprises a cassette carrying section 11 in which a cassette 
stored with wafers is placed, a loader section 12 including a 
transportation mechanism (not shown) for transporting each wafer delivered 
from the cassette in the section 11, a prober section 13 for inspecting 
the wafer transported by means of the transportation mechanism, a 
controller 14 for controlling the prober section 13 and the loader section 
12, and a display unit 15 that doubles as a control panel for operating 
the controller 14. The loader section 12 is provided with a sub-chuck (not 
shown), whereby the wafer is pre-aligned on the basis of its orientation 
flat or its notch. The pre-aligned wafer is transported to the prober 
section 13 by the transportation mechanism. The prober section 13 is 
provided with a main chuck 16 movable in the X-, Y-, and Z-directions and 
the .theta.-direction (direction of rotation around the Z-axis) and 
capable of carrying the wafer thereon, an alignment mechanism (not shown) 
for accurately aligning the wafer on the main chuck 16 in a position for 
inspection, and a probe card 18 (see FIG. 8B) having a probe 18A for 
electrically inspecting the wafer aligned by means of the alignment 
mechanism. A swingable head plate 19 is mounted on the top face of the 
prober section 13. The probe card 18 is fixed to a center aperture of the 
head plate 19 by means of an insert ring. A test head (not shown) is 
rotatably located on the prober section 13. In electrically inspecting the 
IC chips on the wafer, the probe card 18 and a tester (not shown) are 
connected electrically to each other through the test head, and a given 
inspection signal from the tester is transmitted to the IC chips of the 
wafer on the main chuck 16 via the probe card 18. 
A card transportation arm 9 is provided on the front side of the prober 
section 13. This transportation arm 9 transports the probe card 18 with a 
card holder to a position right under the insert ring of the head plate 
19. Normally, the arm 9 is contained in a cover 21 that is attached to the 
front of the prober section 13. In changing the probe card 18, the arm 9 
is raised to a horizontal position and then turned to the position right 
under the insert ring with the cover 21 swung open. The transportation arm 
9, thus positioned right under the insert ring, receives the probe card 18 
that is automatically disengaged from the insert ring, and transports it 
to the front of the prober section 13. At this time, an operator removes 
the card 18 on the card transportation arm 9, and places a new probe card 
18 on the arm 9. Thereafter, the arm 9, carrying the new card 18 thereon, 
is turned again to the position right under the insert ring. 
To set the polishing plate 31 in alignment, the main chuck 16 is moved in 
X- and Y-direction, and the corners of the plate 31 are detected by the 
alignment mechanism. The center of the polishing plate 31 and the 
inclination thereof are calculated from the corners of the plate 31 thus 
detected. 
Provided on the front side of the prober section 13, as shown in FIGS. 1 to 
3, is an automatic changing apparatus 30 for automatically changing the 
polishing plates 31 that serve to polish the tip of the probe 18A (see 
FIG. 8B). The apparatus 30 comprises a storage mechanism 32 for storing 
the polishing plates 31 and a transportation mechanism 33 for transporting 
the plates 31 between the storage mechanism 32 and the main chuck 16. As 
shown in detail in FIG. 4A, the storage mechanism 32 includes a 
rectangular first storage box 34, second storage box 35, elongate fixing 
mechanism 36 for fixing the boxes 34 and 35, and supporting mechanism 37 
for supporting the mechanism 36. The first storage box 34 stores a 
plurality of unused polishing plates 31A (e.g., 50 in number) that are 
vertically stacked in layers, while the second storage box 35 stores used 
polishing plates 31B. 
The first storage box 34 is formed of a tube having a substantially square 
cross section. A circular aperture 34A is formed in the bottom of the box 
34. The unused polishing plates 31A in the first storage box 34 are pushed 
up by a pushup member 38E of a pushup mechanism 38 (mentioned later) that 
moves up and down through the aperture 34A. A flange portion 34B is formed 
on the lower end of the box 34. Two recesses 34C are formed in each side 
face of the flange portion 34B. In this arrangement, the first storage box 
34 is fixed at a stroke to the fixing mechanism 36 with the aid of the 
flange portion 34B and the recesses 34C, as mentioned later. Notches 34D 
are formed in the upper end of the box 34. The second storage box 35 is a 
little larger than the first storage box 34, and has a tapered guide 
surface 35A on its upper end. The guide surface 35A serves to guide the 
used polishing plates 31B thereon into the second storage box 35. 
The fixing mechanism 36 fixes the first and second storage boxes 34 and 35 
in front and in rear along its longitudinal direction. More specifically, 
the mechanism 36 includes a carrying plate 36A, first, second, and third 
fixing members 36B, 36C and 36D, and operating handle 36E. The first and 
second storage boxes 34 and 35 are placed in front and in rear on the 
carrying plate 36A. The first and second fixing members 36B and 36C, which 
are located in front of the carrying plate 36A, engages the flange portion 
34B of the first storage box 34, thereby fixedly holding the box 34 on the 
plate 36A. The third fixing member 36D fixes the second storage box 35 on 
the carrying plate 36A, in a position behind the first storage box 34. The 
handle 36E is used to load into or unload the carrying plate 36A from the 
supporting mechanism 37. 
The first and second fixing members 36B and 36C have the shapes of opposite 
L's, individually, and in conjunction with the carrying plate 36A, hold 
the flange portion 34B of the first storage box 34. As shown in FIG. 4B, a 
pair of ball plungers 36F are embedded in the fixing members 36B and 36C, 
individually. The plungers 36F can engage their corresponding recesses 34C 
of the flange portion 34B. If the first storage box 34 is inserted 
sideways into the space between the fixing members 36B and 36C, therefore, 
the flange portion 34B is held between the carrying plate 36A and the 
fixing members 36B and 36C. Also, the respective distal ends of the ball 
plungers 36F are fitted into their corresponding recesses 34C, and the 
first storage box 34 is fixed on the carrying plate 36A. An aperture 7 is 
formed in that portion of the carrying plate 36A which corresponds to the 
aperture 34A of the first storage box 34. As mentioned later, moreover, 
the second fixing member 36C that adjoins the third fixing member 36D 
doubles as a fixing member for fixing the second storage box 35 in 
cooperation with the member 36D. 
The third fixing member 36D is formed of three leaf springs, and is set up 
on the carrying plate 36A so that the leaf springs can individually hold 
three side faces of the second storage box 35. The top portion of each 
leaf spring forms a guide surface that is directed so as to be exposed to 
the outside. The second fixing member 36C has surfaces that correspond to 
the respective guide surfaces of the leaf springs, and in conjunction with 
the three leaf springs, holds the remaining side face of the second 
storage box 35. When the second storage box 35 is guided along the 
respective guide surfaces of the leaf springs to be fitted into the space 
between these springs from above, therefore, it is set in the third fixing 
member 36D and fixed on the carrying plate 36A by means of the elastic 
force of the springs. 
The supporting mechanism 37 includes an L-shaped supporting base 37A 
composed of a horizontal plate portion and a vertical plate portion, a 
first supporting plate 37B projecting horizontally from the middle portion 
of the vertical plate portion of the supporting base 37A, and a first 
linear guide 37C located on the first supporting plate 37B and extending 
from the front side of the probe apparatus 10 to the rear side (along the 
direction in which the carrying plate 36A is loaded or unloaded). The 
supporting mechanism 37 further includes a second supporting plate 37D, 
which can reciprocate along the first linear guide 37C, and a second 
linear guide 37E located on the second supporting plate 37D and extending 
in the extending direction of the first linear guide 37C. An engaging 
member (not shown) on the lower surface of the carrying plate 36A engages 
the second linear guide 37E so that the carrying plate 36A can slide along 
the guide 37E. Thus, when the carrying plate 36A is pulled out with a hand 
on the operating handle 36E, the fixing mechanism 36 is drawn out from the 
first supporting plate 37B in two stages via the first and second linear 
guides 37C and 37E. 
The storage mechanism 32 is provided with the pushup mechanism 38 for 
pushing up the unused polishing plates 31A in the first storage box 34. 
The pushup mechanism 38 includes a stepping motor 38A, a gear mechanism 
38B, a rack 38C, a linear guide 38D integral with the rack 38C, and the 
pushup member 38E. The stepping motor 38A is located on the horizontal 
plate portion of the supporting base 37A, and is drivingly controlled by 
means of the controller 14. The gear mechanism 38B is rotated by means of 
the motor 38A. The rack 38C, which is in mesh with a pinion of the gear 
mechanism 38B, vertically penetrates an aperture in the horizontal plate 
portion of the supporting base 37A. The pushup member 38E is attached to 
the upper end of the rack 38C, and extends toward the aperture 34A of the 
first storage box 34 that is set in a storage position (indicated by 
two-dot chain line in FIG. 4A). When the stepping motor 38A is actuated, 
in this arrangement, the pushup member 38E moves up and down with the aid 
of the gear mechanism 38B and the rack 38C. Accordingly, the unused 
polishing plates 31A in the first storage box 34 are pushed up by the 
pushup member 38E that ascends through the aperture 34A of the box 34, and 
can come into contact with a vacuum pad 39A of the transportation 
mechanism 33, which will be mentioned later. The revolutions of the 
stepping motor 38A is detected by means of an encoder 38F (see FIG. 7), 
and a central processing unit of the controller 14 calculates the distance 
of lift of the polishing plates 31A on the basis of the resulting 
detection signal. The linear guide 38D, which is integral with the rack 
38C, moves up and down along an engaging member 38G set up on the 
horizontal plate portion of the supporting base 37A. 
As shown in detail in FIG. 5, the transportation mechanism 33 includes a 
first transportation mechanism 39 for loading, a second transportation 
mechanism 40 for unloading, a moving body 41 carrying the mechanisms 39 
and 40, and an air cylinder 43 for reciprocating the moving body 41 along 
a linear guide 42. The first transportation mechanism 39 receives the 
unused polishing plates 31A one by one from the first storage box 34 and 
moves in the Y-direction, thereby transporting them to the main chuck 16. 
The second transportation mechanism 40 receives the used polishing plates 
31B from the main chuck 16 and moves in the Y-direction, thereby 
transporting them to the second storage box 35. The first transportation 
mechanism 39 is located on the reverse side of the moving body 41, and the 
second transportation mechanism 40 on the obverse side. When the air 
cylinder 43 is actuated, in this arrangement, the moving body 41 causes 
the first and second transportation mechanisms 39 and 40 to move 
integrally for one half of the overall transportation distance, for 
example, in the Y-direction. Thereafter, the transportation mechanisms 39 
and 40 are driven individually by means of drive mechanisms (mentioned 
later), and move for the remaining half of the overall transportation 
distance. Thus, the polishing plates 31 are transported in two stages. 
This is done in consideration of the limited space. If there is sufficient 
space, therefore, the polishing plates 31 may be transported in one stage. 
As shown in FIG. 5, the transportation mechanism 33 is located on a 
supporting frame 44. In FIG. 5, numeral 45 denotes an air cylinder for 
moving the whole transportation mechanism 33 up and down. The cylinder 45 
is used to evacuate the transportation mechanism 33 to a position where it 
does not interfere with the card transportation arm 9 when the probe card 
is transported by the arm 9. 
The first and second transportation mechanisms 39 and 40 are constructed 
substantially in the same manner. The mechanisms 39 and 40 include vacuum 
pads 39A and 40A, respectively, for attracting the polishing plates 31 by 
vacuum suction. Pad portions of the vacuum pads 39A and 40A are formed of, 
for example, soft rubber such that they can softly touch the polishing 
plates 31 and undergo compressive deformation, thereby coming intimately 
into contact with the plates 31, when they attract the plates 31. 
The distal end portion of an arm 39B, which extends in the X-direction, is 
connected to the upper end portion of the vacuum pad 39A. An engaging 
member 39C is connected to the proximal end portion of the arm 39B. The 
engaging member 39C is engaged by a linear guide 39D that extends in the 
Y-direction perpendicular to the arm 39B. In FIG. 5, numeral 39E denotes 
an air cylinder for reciprocating the arm 39B (and therefore, the vacuum 
pad 39A) along the linear guide 39D. The distal end portion of an arm 40B, 
which extends in the X-direction, is connected to the upper end portion of 
the vacuum pad 40A. An engaging member 40C is connected to the proximal 
end portion of the arm 40B. The engaging member 40C is engaged by a linear 
guide 40D that extends in the Y-direction perpendicular to the arm 40B. In 
FIG. 5, numeral 40E denotes an air cylinder for reciprocating the arm 40B 
(and therefore, the vacuum pad 40A) along the linear guide 40D. 
FIG. 6 shows the first storage box 34 set in the storage position 
(indicated by two-dot chain line in FIG. 4A). As shown in FIG. 6, various 
sensors 51 to 55 are arranged in peripheral positions surrounding the 
storage position. A polishing plate presence sensor 51, a reflector-type 
sensor located under the first storage box 34, detects the presence of the 
polishing plates 31A in the box 34 through the aperture 34A thereof from 
below. In this case, the sensor 51 is situated in a position such that it 
does not interfere with the pushup member 38E getting into the first 
storage box 34 through the aperture 34A. If the polishing plates 31A are 
not detected by the sensor 51, a warning to this effect is given by means 
of a warning lamp or the like. Under the first storage box 34, a 
upper-limit sensor 52, origin sensor 53, and lower-limit sensor 54 are 
arranged vertically along the ascending/descending direction of the pushup 
member 38E. The origin sensor 53 detects a mark 38H on a rod of the pushup 
member 38E as the origin position for the member 38E. The upper- and 
lower-limit sensors 52 and 54 detect the upper- and lower-limit positions, 
respectively, for the pushup member 38E by the mark 38H. A polishing plate 
sensor 55 is located beside the notch 34D of the storage box 34. The 
sensor 55 detects the presence of the polishing plates 31A through the 
notch 34D, thereby determining whether or not the polishing plates 31A are 
raised to the level of the notch 34D of the first storage box 34 by the 
pushup member 38E. If the polishing plates 31A are detected by the sensor 
55, the pushup member 38E is raised by the motor 38A, so that the plates 
31 are pushed up for a certain distance. Thereupon, the polishing plates 
31A are set in a state such that they can be attracted to the vacuum pad 
39A. In case the pushup mechanism 38 is stopped from any cause so that the 
pushup member 38E descends while the polishing plates 31A are being pushed 
up by the member 38E, a brake 38I (see FIG. 4A) is worked to prevent the 
polishing plates 31A from falling. 
FIG. 7 schematically shows a drive circuit of the automatic changing 
apparatus 30. The air cylinders 39E, 40E, 43 and 45 in the transportation 
mechanism 33 are supplied with air from an air source 3 through an air 
channel 80. Also, the air from the cylinders 39E, 40E, 43 and 45 is 
discharged through the channel 80. Each air cylinder is provided with 
sensors 70 and 71 for detecting the extension and contraction of its 
cylinder rod. The air channel 80 is provided with solenoid valves 6 for 
controlling airflows. A sucking force from a suction device 2, such as a 
vacuum pump, acts on the vacuum pads 39A and 40A in the transportation 
mechanism 33 through suction channels 83. Each suction channel 83 is 
provided with a solenoid valve 4 for use as an on-off valve and a vacuum 
sensor 5 as a pressure sensor. The controller 14 receives detection 
signals from the sensors 5, 51 to 55, 70 and 71 and the encoder 38F 
through a detection signal line 81 as it controls the solenoid valves 4 
and 6, motor 38A, and brake 38I through a driving signal line 82 in 
accordance with given programs. 
As shown in detail in FIG. 8A, the main chuck 16 is provided with two 
polishing plate carrying regions 16A on which the polishing plates 31 are 
placed individually. As shown in FIG. 8B, a vacuum exhaust channel 16B is 
formed inside each region 16A. The channel 16B opens in a plurality of 
portions of the surface of the carrying region 16A. A vacuum exhaust tube 
16C, which is connected to the suction device 2, is connected to an 
exhaust port of the exhaust channel 16B by means of a connector. The 
exhaust tube 16C is provided with a vacuum sensor 16D for use as a 
pressure sensor and a solenoid valve 16E as an on-off valve. According to 
the present embodiment, a pressure detected by means of the vacuum sensor 
16D varies (increases) when the polishing plates 31 are transported onto 
the polishing plate carrying regions 16A. In response to a signal 
corresponding to the variation, therefore, the valve 16E is opened, 
whereupon the polishing plates 31 are attracted by vacuum suction. 
According to the present embodiment, moreover, polishing plates 31 of the 
same type or different types may be arranged individually on the two 
polishing plate carrying regions 16A. In the case where the polishing 
plates 31 of the same type are arranged individually on the two regions 
16A, different probes 18A may be polished by means of the two polishing 
plates 31, or one and the same probe 18A may be polished continuously by 
means of the two polishing plates 31. In the case where the polishing 
plates 31 of different types are arranged individually on the two regions 
16A, on the other hand, they may be ones that are different in surface 
roughness, and are used for rough polishing and finish polishing, 
individually. In this case, the rough polishing can be directly followed 
by the finish polishing. When the polishing plates 31 of two different 
types are used, they should only be alternately stacked in layers in the 
first storage box 34, for example. Alternatively, a polishing plate 31 may 
be located on one of the two polishing plate carrying regions 16A with a 
gold plate for conduction check on the other. In this case, the probe 18A 
is brought into contact with the gold plate directly after it is polished 
by means of the polishing plate 31, so that the contact resistance of the 
probe 18A can be measured by means of the gold plate. In the case where 
the gold plate is used, moreover, the timing for polishing the probe 18A 
can be settled by measuring the contact resistance with the probe 18A in 
contact with the gold plate. The "gold plate" is a gilt plate, which is 
formed by depositing gold on the surface of a silicon wafer, for example. 
The following is a description of the operation of the automatic changing 
apparatus 30 constructed in this manner and a method for polishing the 
probe. In storing the unused polishing plates 31A in the storage mechanism 
32, the fixing mechanism 36 is drawn out from the supporting mechanism 37 
with a hand on the operating handle 36E. Then, the first storage box 34, 
stored with 50 polishing plates 31A, is inserted into the space between 
the first and second fixing members 36B and 36C of the fixing mechanism 
36. At this time, the ball plungers 36F are actuated so that the first 
storage box 34 is fixed on the carrying plate 36A. Further, the second 
storage box 35 can be fixed on the plate 36A by only being fitted into the 
third fixing member 36D. After the first and second storage boxes 34 and 
35 are thus fixed on the carrying plate 36A, the fixing mechanism 36 is 
pushed and fitted into the supporting mechanism 37. In this state, the 
pushup member 38E of the pushup mechanism 38 is situated in the lowest 
position where the mark 38H is detected by the lower-limit sensor 54. When 
the inspection of a preset number of IC chips is completed, the main chuck 
16 is automatically actuated in accordance with a given program for 
polishing. More specifically, the main chuck 16 is driven according to the 
given program, whereupon the polishing plate carrying regions 16A reach 
the position under the probe card 18. When the main chuck 16 continues to 
ascend and is overdriven, thereafter, the probe 18A and one of the 
polishing plates 31 are pressed against each other. In this state, the 
main chuck 16 is moved back and forth several times in, for example, 
horizontal direction, whereby the polishing plate 31 polishes the probe 
18A. As a result, insulating material such as aluminum oxide is removed 
from the probe 18. The polishing plate 31 is displaced before every 
polishing, so that the same part will no be used repeatedly (see FIG. 8F). 
For instance, the plate 31 is moved back and forth several times in 
X-direction (each time, for 0.5 mm) in the first polishing step (see FIG. 
8C). Then, the plate 31 is moved 1 mm in both X- and Y-directions from the 
position it has assumed during the first polishing step. The plate 31 is 
moved back and forth several times in X-direction (each time, for 0.5 mm) 
in the second polishing step (see FIG. 8D). Next, the plate 31 is moved 1 
mm in both X- and Y-directions from the position it has taken during the 
second polishing step, and is moved back and forth several times in 
X-direction (each time, by 0.5 mm) in the third polishing step (see FIG. 
8E). Further, the plate 31 is moved to different positions, and moved back 
and forth repeatedly at each of these positions, performing other steps of 
polishing the probe 18A. 
The positions at which the plate 31 (or main chuck 16) is moved back and 
forth repeatedly to polish the probe 18A can be set by a computer program. 
The polishing plate 31 may be moved back and forth several times along a 
line inclined at a prescribed angle to the X-direction. Moreover, the 
polishing pattern (FIGS. 8C to 8F), polishing cycle, the number of 
polishing steps, and the like can be set by a computer program, in 
accordance with the type of the inspection which the probe 18A will 
perform. 
When the surface of the polishing plate 31B is used up, accomplishing the 
polishing described above, the plate 31B is replaced with a new one 31A, 
under the control of a prescribed program. To replace the plate 31B with a 
new one 31A, the automatic changing apparatus 30 operates as will be 
described below. 
At first, the air cylinders 40E and 43 are driven at the same time or one 
after the other with a time lag. To be more specific, the air cylinder 43 
is driven for a predetermined stroke, moving the moving body 41 toward the 
main chuck 16 along the linear guide 42. Meanwhile, the air cylinder 40E 
is driven for a predetermined stroke (e.g., the last stroke), moving the 
arm 40B toward the main chuck 16 along the linear guide 40D provided on 
the moving body 41. When the vacuum pad 40A attached to the arm 40B is 
thereby moved to a position right above the main chuck 16 already set in 
waiting state, one of the sensors 71 (70) detects the state. The main 
chuck 16 is then moved upwards to a position where the vacuum pad 40A can 
draw the polishing plate 31B. 
Thereafter, the solenoid valve 4 is switched on. The vacuum pad 40A is 
thereby driven, applying a suction force on the polishing plate 31B. Thus, 
the plate 31B is drawn to the vacuum pad 40A. The sensor 5 is thereby 
turned on, and the solenoid valve 16E is turned off. As a result, the 
suction force attracting the polishing plate 31B toward the polishing 
plate carrying region 16A decreases. The plate 31B is therefore 
transferred completely to the vacuum pad 40A. In this condition, the 
sensor 16D is turned off, whereby the main chuck 16 moves downwards, and 
the cylinder rods of the air cylinders 40E and 43 is driven in reverse 
direction and the vacuum pad 40A move back from the main chuck 16. 
When the cylinder rods of the air cylinders 40E and 43 return to the 
initial positions, they are detected by the sensor 70, which generates a 
detection signal. The detection signal turns off the solenoid valve 4. The 
suction force no longer acts on the vacuum pad 40A of the second 
transportation mechanism 40. The vacuum pad 40A stops holding the used 
polishing plate 31B. Released from the pad 40A, the plate 31B is discarded 
into the second storage box 35. 
Then, the polishing plate sensor 51 detects the polishing plate 31A in the 
first storage box 34 and generates a detection signal. This signal drives 
the stepping motor 38A of the pushup mechanism 38. The gear mechanism 38B 
and the lack 38C are driven, lifting the pushup member 38E. As the pushup 
member 38E moves upwards, the origin sensor 53 detects the mark 38H. At 
this time the origin position of the pushup member 38E is stored into the 
memory device incorporated in the controller 14. The pushup member 38E 
further moves upwards, passing through the opening 34A made in the bottom 
of the first storage box 34 and pushes up the polishing plate 31A. 
The polishing plate sensor 55 detects the plate 31A thus pushed up, and 
generates a detection signal. The detection signal stops the stepping 
motor 38A, whereby the pushup member 38E stops for some time. Then, the 
pushup member 38E pushes up the polishing plate 31A for the distance 
represented by the data stored in the memory device of the controller 14. 
The plate 31A is thereby set at a position where it can be attracted to 
the vacuum pad 39A. 
Thereafter, the solenoid valve 4 is driven, applying a suction force on the 
vacuum pad 39A. The polishing plate 31A is attracted to the vacuum pad 
39A. When the suction force of the pad 39A applied to the plate 31A (i.e., 
the degree of vacuum of the pad 39A) reaches a predetermined value (as is 
detected by the sensor 5), the stepping motor 38A is driven in the reverse 
direction. The pushup member 38E is thereby lowered. When the lower-limit 
sensor 54 detects that the member 38E reaches the lowest possible 
position, it generates a detection signal. This signal stops the stepping 
motor 38A, whereby the pushup mechanism 38 is stopped. At the same time, 
the air cylinders 39E and 43 are driven, either simultaneously or one 
after the other with a time lag. More specifically, the air cylinder 43 is 
driven for a predetermined stroke, moving the moving body 41 toward the 
main chuck 16 along the linear guide 42. And the air cylinder 39E is 
driven for a predetermined stroke (e.g., the last stroke), moving the arm 
39B toward the main chuck 16 along the linear guide 39D provided on the 
moving body 41. When the vacuum pad 39A attached to the arm 39B is thereby 
moved to a position right above the main chuck 16 already set in waiting 
state, one of the sensors 71 (70) detects the state. The main chuck 16 is 
then moved upwards to a position where the polishing plate carrying region 
16A can draw the polishing plate 31A. 
Then, the solenoid valve 16E operates, drawing the polishing plate 31A to 
the polishing plate carrying region 16A. At this time, the sensor 16D is 
switched on, turning the solenoid valve 4 off. Hence, the suction force of 
he vacuum pad 39A decreases. The polishing plate 31A is completely 
transferred onto the polishing plate carrying region 16A. Thereafter, the 
main chuck 16 is lowered and the air cylinders 39E and 43 are driven in 
the reverse direction, in accordance with the detection signal supplied 
from the sensor 16D. The vacuum pad 39A is thereby moved backward. 
Even in the case where the polishing plate 31 is automatically changed by 
the aforementioned operation, it is not always attracted in a 
predetermined position on the polishing plate carrying region 16A. 
Accordingly, the alignment mechanism is actuated to detect a deviation of 
the polishing plate 31 from a reference position. More specifically, the 
current position of the polishing plate 31 is accurately detected, and the 
detected position is compared with the reference position in the 
controller 14 so that the deviation can be calculated, whereupon the 
position for the plate 31 t o start polishing the probe 18A is obtained. 
Thus, in polishing the probe 18A by means of the polishing plate 31, the 
probe 18A can be brought securely into contact with the a predetermined 
position on the plate 31. 
A s described above, the probe apparatus 10 according to the present 
embodiment is provided with the automatic changing apparatus 30, which 
comprises the storage mechanism 32 for storing the unused and used 
polishing plates 31 and the transportation mechanism 33. The 
transportation mechanism 33 receives the unused polishing plates 31A one 
by one from the storage mechanism 32 and transports them to the polishing 
plate carrying regions 16A of the main chuck 16. Also, the mechanism 33 
receives the used polishing plates 31B from the regions 16A and transports 
them to the storage mechanism 32. Even in the case where the polishing 
plates 31 are disposable ones, or ones of two different types depending on 
the probe 18A, therefore, the unused and used polishing plates 31 can be 
automatically changed with high efficiency in a short period of time by 
means of the transportation mechanism 33, thereby ensuring 
high-reliability inspection. Thus, the replacement operation is easy, and 
filings on the polishing plates 31 can be prevented from forming 
particles. 
The storage mechanism 32 includes the first storage box 34 storing the 
unused polishing plates 31A, second storage box 35 storing the used 
polishing plates 31B, fixing mechanism 36 for fixing the first and second 
storage boxes 34 and 35, supporting mechanism 37 for supporting the fixing 
mechanism 36, and pushup mechanism 38 for pushing up the unused polishing 
plates 31A through the aperture 34A in the bottom of the first storage box 
34. Accordingly, the unused and used polishing plates 31 can be stored in 
a regular manner, so that they can be replaced correctly with one another. 
Thus, the used polishing plates 31B can be securely discarded without the 
possibility of being reused, so that high-reliability inspection can be 
ensured. 
The transportation mechanism 33 includes the first transportation mechanism 
39 for loading, which transports the unused polishing plates 31A from the 
first storage box 34 to the polishing plate carrying regions 16A of the 
main chuck 16, and the second transportation mechanism 40 for unloading, 
which transports the used polishing plates 31B from the regions 16A to the 
second storage box 35. Further, the first and second transportation 
mechanisms 39 and 40 include the vacuum pads 39A and 40A for attracting 
the unused and used polishing plates 31, arms 39B and 40B for supporting 
the pads 39A and 40A, and air cylinders 39E and 40E for reciprocating the 
arms 39B and 40B along the linear guides 39D and 40D, respectively. 
Therefore, any used polishing plate can be reliably distinguished from any 
new polishing plate and can be replaced therewith. In the present 
embodiment, after the plate 31B which has been used is removed from the 
plate carrying region 16A by the first transportation mechanism 40, 
mechanism 40 may be located at a position where it does not interfere with 
the mechanism 39. The new polishing plate 31A may then be placed in the 
plate carrying region 16A by the mechanism 39. Finally, both 
transportation mechanisms 39 and 40 may be returned to the initial 
positions so that they may not interfere. In this case, the used polishing 
plate 31B can be replaced with the new one 31A with high efficiency, 
within a short time. 
The probe 18A may be polished by means of polishing plates 31 of two types 
that are different in surface roughness and are arranged individually on 
the two polishing plate carrying regions 16A of the main chuck 16 by means 
of the automatic changing apparatus 30. In this case, the polishing plates 
31 alternately stacked in layers in the first storage box 34 are 
successively taken out of the box 34 and transported to the two carrying 
regions 16A. Thereafter, the probe 18A is roughly polished by means of the 
rough-surface polishing plate 31, and is then finely polished by means of 
the fine-surface polishing plate 31. In changing the polishing plates 31 
used up during this series of polishing operations, the used polishing 
plates 31B are replaced individually with the unused polishing plates 31A 
through the same operations as aforesaid. According to this polishing 
method, the tip of the probe 18A can be polished so as to be smoother, so 
that the extent of contact between the probe 18A and an electrode pad can 
be improved, thus ensuring high-accuracy inspection. 
Alternatively, the probe 18A may be polished by means of the polishing 
plate 31 that is located on one of the two polishing plate carrying 
regions 16A with the gold plate (not shown) located on the other by means 
of the automatic changing apparatus 30. In this case, the probe 18A 
polished by means of the polishing plate 31 is brought into contact with 
the gold plate on the other carrying region 16A, whereupon the contact 
resistance of the polished probe 18A is measured. According to this 
method, the polished probe 18A can be checked for workmanship. 
Alternatively, the contact resistance of the polished probe 18A may be 
measured in a manner such that the probe 18A is brought into the gold 
plate before it is polished. In this case, the timing for polishing the 
probe 18A can be determined in advance by the value of the contact 
resistance, so that the inspection can be stabilized. These probe 
polishing methods may be carried out without using the automatic changing 
apparatus 30 described herein. 
Additional advantages and modifications will readily occur to those skilled 
in the art. Therefore, the invention in its broader aspects is not limited 
to the specific details and representative embodiments shown and described 
herein. Accordingly, various modifications may be made without departing 
from the spirit or scope of the general inventive concept as defined by 
the appended claims and their equivalent.