U.S. patent application number 11/895469 was filed with the patent office on 2008-03-20 for probe cleaner and cleaning method.
This patent application is currently assigned to NIHON Micro Coating Co., Ltd.. Invention is credited to Kenji Kato, Jun Tamura.
Application Number | 20080070481 11/895469 |
Document ID | / |
Family ID | 39189192 |
Filed Date | 2008-03-20 |
United States Patent
Application |
20080070481 |
Kind Code |
A1 |
Tamura; Jun ; et
al. |
March 20, 2008 |
Probe cleaner and cleaning method
Abstract
A probe cleaner for removing foreign objects from the tip part
of a probe is formed with a cleaner sheet having a surface part
with microfibers and abrading particles affixed to the surface of
the microfibers at this surface part. The average fiber diameter of
the microfibers is in the range of 0.1 .mu.m or more and 20 .mu.m
or less. The average particle diameter of the abrading particles is
in the range of 0.05 .mu.m or more and 3.0 .mu.m or less. For
cleaning the tip part of a probe, the probe cleaner is set to the
surface of a table, the tip part of the probe is caused to
penetrate inside the surface part, and the probe is caused to
undergo a reciprocal motion in the direction of the thickness of
the surface part.
Inventors: |
Tamura; Jun; (Tokyo, JP)
; Kato; Kenji; (Tokyo, JP) |
Correspondence
Address: |
BEYER WEAVER LLP
P.O. BOX 70250
OAKLAND
CA
94612-0250
US
|
Assignee: |
NIHON Micro Coating Co.,
Ltd.
|
Family ID: |
39189192 |
Appl. No.: |
11/895469 |
Filed: |
August 24, 2007 |
Current U.S.
Class: |
451/28 ; 51/293;
51/307; 51/308; 51/309 |
Current CPC
Class: |
B08B 1/00 20130101; B24D
13/145 20130101; G01R 3/00 20130101 |
Class at
Publication: |
451/028 ;
051/293; 051/307; 051/308; 051/309 |
International
Class: |
B24B 1/00 20060101
B24B001/00; B24D 3/00 20060101 B24D003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 15, 2006 |
JP |
2006-250342 |
Claims
1. A probe cleaner for removing foreign objects attached to the tip
part of a probe, said probe cleaner comprising: a cleaner sheet
having a surface part with microfibers; and abrading particles
affixed to the surface of the microfibers at said surface part.
2. The probe cleaner of claim 1 wherein said microfibers have
average fiber diameter in the range of 0.1 .mu.m or more and 20
.mu.m or less.
3. The probe cleaner of claim 1 wherein said microfibers have
average fiber diameter in the range of 0.1 .mu.m or more and 10
.mu.m or less.
4. The probe cleaner of claim 1 wherein the average particle
diameter of said abrading particles is in the range of 0.05 .mu.m
or more and 3.0 .mu.m or less.
5. The probe cleaner of claim 1 wherein said abrading particles
include particles of one or more kinds selected from the group
consisting of alumina, silicon carbide, silicon oxide, zirconia,
aluminum hydroxide and diamond.
6. The probe cleaner of claim 1 wherein said cleaner sheet is a
flocked sheet having said microfibers planted on the surface of a
base sheet.
7. The probe cleaner of claim 1 wherein said cleaner sheet is a
woven or non-woven cloth sheet comprising said microfibers.
8. The probe cleaner of claim 1 wherein said probe has indentations
or protrusions at the tip.
9. A method of removing foreign objects from the tip part of a
probe, said method comprising the steps of: setting a probe cleaner
to the surface of a table, said probe cleaner comprising a cleaner
sheet having a surface part with microfibers and abrading particles
affixed to the surface of the microfibers at said surface part;
causing said tip part of said probe to penetrate inside said
surface part; and causing said probe to undergo a reciprocal motion
in the direction of the thickness of said surface part.
10. The method of claim 9 further comprising the step of pulling
out said probe from said surface part.
11. The method of claim 9 wherein said reciprocal motion is caused
while said tip part of said probe remains in the condition of
penetrating inside said surface part.
12. The method of claim 9 wherein said probe has indentation or
protrusion at said tip.
Description
[0001] This application claims priority on Japanese Patent
Application 2006-250342 filed Sep. 15, 2006.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a probe cleaner and a cleaning
method for cleaning the tip part of a needle-shaped object such as
a probe for the inspection of electric properties, a needle for a
clinical use and a knitting needle in the finishing step of the
production process or before and after a use. This invention
relates in particular to such a probe cleaner and cleaning method
for removing foreign objects attached to the tip part of a probe
used for the inspection of electric properties in the inspection
process of a semiconductor device.
[0003] In order to improve the production efficiency in the
production process of semiconductor devices, a probe is used to
contact electrode pads of a plurality of chips formed on a
semiconductor wafer for inspecting the electrical characteristics
of each chip by applying and detecting test signals through this
probe.
[0004] In general, such a probe is made of a hard material such as
tungsten and beryllium, while the electrode pads are made of a
relatively soft material such as aluminum. When the probe is made
to contact an electrode pad, foreign objects such as aluminum of
the electrode pad become attached to the tip part (the tip and the
side surfaces near the tip) of the probe, and this affects the
accuracy of the inspection adversely. If a large foreign object is
attached to a probe, mutually adjacent probes may become shorted,
causing chips to be destroyed. For this reason, the tip part of the
probe is cleaned for removing such foreign objects.
[0005] As disclosed in Japanese Patent Publications Tokkai 7-244074
and 2004-140013, for example, the tip part of a probe may be
cleaned by using a probe cleaner comprising a cleaner sheet made of
an elastic material such as silicon rubber and urethane rubber with
abrading particles (such as hard particles of aluminum oxide,
silicon carbide and diamond) mixed in and by causing the tip part
of the probe to penetrate into the interior of this probe cleaner
from its surface such that the abrading particles affixed to the
elastic material will work on the tip part of the probe.
[0006] As disclosed in Japanese Patent Publication Tokuhyo
2005-515645, furthermore, a probe cleaner comprising a cleaner
sheet having a sticky gel layer formed on the surface of a plate
with minute unevenness prepared thereon has also been used. After
the tip part of the probe penetrates into the interior of the gel
layer from its surface, the probe is moved while its tip remains in
contact with the unevenness of the surface of the plate such that
the tip part becomes cleaned.
[0007] As the chip size is made smaller in recent years, the
electrode pads formed on the chips are becoming smaller and the
electrode pads are coming to be formed closer to one another. For
this reason, it is becoming necessary to make the probes thin, and
relatively soft materials having improved electrical
characteristics such as beryllium-copper alloys are coming to be
used to form the probes.
[0008] If a conventional probe cleaner as described above is used
on such a probe, however, the probe is easily worn out by the
cleaning process, its useful lifetime being thus adversely
affected. The abraded condition of a probe also gives rise to the
problem of inspection errors on the electrical characteristics of
the chips.
[0009] In order to reliably contact the electrode pads on a chip,
it has also been known, as shown in FIGS. 5A and 5B, to form
indentations 32 and 35 or protrusions 31 and 34 on the tip 30 or 33
of a probe, as disclosed in Japanese Patent Publication Tokkai
8-306749.
[0010] If these conventional probe cleaners are used to clean the
tip part of such a probe, however, foreign objects attached within
the indentations in the tip part cannot be removed sufficiently and
the protrusions tend to be worn out by the cleaning process.
SUMMARY OF THE INVENTION
[0011] It is therefore an object of this invention to provide a
probe cleaner capable of cleaning the tip part of a probe without
excessively wearing out the probe by the cleaning process and in
particular cleaning the tip part of a probe having indentations or
protrusions formed on the tip part.
[0012] This invention relates to a probe cleaner and a method of
removing foreign objects attached to the tip part of a probe, and
in particular to a probe having indentations or protrusions formed
at its tip.
[0013] A probe cleaner according to this invention is characterized
as comprising a cleaner sheet having a surface part with
microfibers and abrading particles affixed to the surface of the
microfibers at this surface part. During a cleaning process, these
abrading particles affixed to the microfibers at the surface part
of the cleaner sheet work on the tip part of the probe to remove
the foreign objects attached thereto.
[0014] The average fiber diameter of the microfibers is in the
range of 0.1 .mu.m or more and 20 .mu.m or less, and preferably in
the range of 0.1 .mu.m or more and 10 .mu.m or less.
[0015] The average particle diameter of the abrading particles is
in the range of 0.05 .mu.m or more and 3.0 .mu.m or less. The
abrading particles of this invention include particles of one or
more kinds selected from the group consisting of alumina, silicon
carbide, silicon oxide, zirconia, aluminum hydroxide and
diamond.
[0016] The cleaner sheet of this invention is a flocked sheet
having the microfibers planted on the surface of a base sheet. The
abrading particles are affixed to the surface of the microfibers of
this flocked sheet. These microfibers with abrading particles
affixed thereto are mutually independent, not being attached to one
another. In other words, these microfibers can move individually,
independent of the other microfibers.
[0017] As a variation, the cleaner sheet of this invention may be a
woven or non-woven cloth sheet comprising microfibers having
abrading particles affixed thereto.
[0018] According to a method of this invention, foreign objects
attached to the tip part of a probe are removed by the steps of
setting a probe cleaner of this invention to the surface of a
table, causing the tip part of the probe to penetrate into the
surface part of the cleaner sheet and causing the probe to undergo
a reciprocal motion in the direction of the thickness of the
surface part. The tip part of the probe is thereafter pulled out
from the surface part. The probe may be caused to undergo a
reciprocating motion in the direction of the thickness of the
surface part while the tip part of the probe remains in the
condition of penetrating the surface part.
[0019] With the invention thus characterized, even a probe having
indentations and protrusions formed at the tip can be cleaned
easily without wearing it out excessively.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1A is a sectional view of a probe cleaner of this
invention and FIG. 1B is a partially sectional enlarged view of a
microfiber.
[0021] FIGS. 2A and 2B show a probe being cleaned according to this
invention, and FIG. 3 is a schematic drawing of a cleaning
apparatus.
[0022] FIG. 3 is a microgram of a sectional view of a probe cleaner
according to this invention.
[0023] FIG. 4 is a schematic sectional view of a probe cleaner
embodying this invention.
[0024] FIGS. 5A and 5B are each an enlarged schematic diagonal view
of the tip of a probe.
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIGS. 1A and 1B show a probe cleaner 20 embodying this
invention for removing foreign objects attached to the tip part of
a probe (shown at 12 in FIGS. 2A, 2B and 2C), comprising a cleaner
sheet 21 having a surface part 24 comprised of microfibers 25 with
abrading particles 26 attached to the surface of at least those of
the microfibers 25 on the surface part 24 of this cleaner sheet 21.
As shown in FIG. 1B, the abrading particles 26 are affixed to the
surface of the microfibers 25 by a binder 27.
[0026] In the above, the surface part 24 means a portion of the
cleaner sheet 21 that will work on the tip of the probe 12. The
thickness (or the height) of this surface part 24 is not
particularly limited by the invention and it is sufficient if it
has the length of the tip part of the probe 12 to be cleaned. It
may be in the range of 100 .mu.m or more and less than 1000 .mu.m.
As shown in FIGS. 2A and 2B, the cleaning of the tip part of the
probe 12 is carried out by sticking the tip part into the surface
part 24 of the cleaner sheet 21 by either moving the table 11 in
the direction of arrow T1 or moving the probe 12 in the direction
of arrow T2. During this cleaning operation, the abrading particles
26 affixed to the microfibers 25 at the surface part 24 of the
cleaner sheet 21 work on the tip part of the probe 12 such that
foreign objects that may be attached to the tip part of the probe
12 are removed.
[0027] The fiber diameter of the microfibers 25 is within the range
of 0.1 .mu.m or more and 20 .mu.m or less and preferably 0.1 .mu.m
or more and 10 .mu.m or less. Synthetic fibers of nylon,
polypropylene, polyethylene, polyethylene terephthalate,
polyurethane, acryl, polyvinyl chloride, vinilon or rayon may be
used as the microfibers 25.
[0028] The size of the abrading particles 26 affixed to the surface
of the microfibers 25 is less than the fiber diameter of the
microfibers 25 and preferably 1/2 or less of the fiber diameter.
This is because if the size of the abrading particles 26 is too
large, the force for stabilizing the abrading particles against the
curved surface of the fiber will become weak and the abrading
particles working on the tip part of the probe 12 may drop off and
become attached to the tip part of the probe 12 to become foreign
objects themselves. Abrading particles with average diameter in the
range of 0.05 .mu.m or more and 3.0 .mu.m or less are
preferred.
[0029] No particular limitations are imposed as to the material of
the abrading particles, and particles commonly used for polishing
may be used for the purpose of this invention. Preferable examples
include particles of alumina, silicon carbide, silicon oxide,
zirconia, aluminum hydroxide and diamond.
[0030] As shown in FIGS. 3 and 4, the cleaner sheet 21 is a flocked
sheet comprising microfibers 25 planted to a base sheet 28 such
that the aforementioned abrading particles 26 are affixed to the
surface of the microfibers 25 of this flocked sheet. These
microfibers 25 having the abrading particles 26 affixed thereonto
are in the condition of not being affixed to one another among
themselves. In other words, each of the microfibers 25 is in the
condition of being able to freely move independent of the other
microfibers 25.
[0031] The lengths of the microfibers 25 of the flocked sheet are
in the range of 100 .mu.m or more and 1000 .mu.m (1.0 mm) or less,
and preferably 400 .mu.m or more and 600 .mu.m or less. If they are
too short, this affects the fiber movements adversely. If they are
too long, they cannot easily remain independent and tend to become
tangled up such that it becomes difficult to attach the abrading
particles 26 to them individually.
[0032] As for the base sheet 28, a material with small thermal
deformations due to temperature changes is preferred. A sheet with
rate of thermal shrinkage 2% or less in the temperature range of
25.degree. C. or more and 150.degree. or less as its mechanical
characteristic is used. No particular limitations are imposed as to
the size and material of the base sheet 28. A sheet with thickness
in the range of 50 .mu.m or more and 188 .mu.m or less, made of PET
(polyethylene terephthalate), PEN (polyethylene naphthalate), PPS
(polyphenylene sulfide, PEI (polyether imide), PI (polyimide), PC
(polycarbonate), PVC (polyvinyl chloride), PP (polypropylene), PVDC
(polyvinylidene chloride), nylon, PE (polyethylene) or PES
(polyether sulfonate) may be used, but a PET sheet is
preferred.
[0033] As a practical matter, a layer of adhesive agent (referred
to as the adhesive layer, shown at 22 in FIG. 1A) is formed on the
back surface of the base sheet 28, and a peelable paper sheet
(shown at 23 in FIG. 1A) is removably pasted to the surface of this
adhesive layer 22. This peelable paper sheet 23 is peeled off from
the surface of the adhesive layer 22, and the probe cleaner 20 of
this invention is thereafter pasted on the table 11 of a probe
cleaning apparatus 10 through this adhesive layer 22, as shown in
FIG. 2C.
[0034] As a variation, a woven or non-woven cloth sheet made of
microfibers 25 described above may be used as the cleaner sheet 21
of the probe cleaner 20 of this invention. The abrading particles
26 described above are affixed at least to the surface of the
microfibers 25 at the position of the surface part 24 of this
cleaner sheet 21. This cleaner sheet 21 may also have an adhesive
layer 22 formed on its back surface so as to be pasted onto the
table 11 of the probe cleaning apparatus 10 through this adhesive
layer 22.
[0035] As an example of base sheet of this type, too, a sheet with
small thermal deformations due to temperature variations is
preferred. As explained above with reference to a flocked sheet,
there is no particular limitation as to the size or material of the
base sheet of this kind. A sheet of synthetic fibers such as
polypropylene and polyethylene with thickness in the range of 50
.mu.m or more and 188 .mu.m or less is used as the base sheet.
[0036] In this case, too, a layer of adhesive agent (referred to as
the adhesive layer, shown at 22 in FIG. 1A) is formed as a
practical matter on the back surface of the base sheet 28, and a
peelable sheet (shown at 23 in FIG. 1A) is removably pasted to the
surface of this adhesive layer 22. This peelable paper sheet 23 is
peeled off from the surface of the adhesive layer 22, and the probe
cleaner 20 of this invention is thereafter pasted on the table 11
of a probe cleaning apparatus 10 through this adhesive layer 22, as
shown in FIG. 2C.
[0037] The probe cleaner 20 of the present invention may be
produced by dispersing abrading particles in a liquid resin
solution, adding a hardening agent thereto to prepare a paint
(coating material), applying this paint on the surface of the
cleaner sheet 21 by a known coating method such as the reverse roll
coating and gravure coating, and drying it. Examples of the resin
solution to be used include one or more resin materials selected
from polyester resins, polyurethane resins, copolymerized vinyl
resins, epoxy resins and phenol resins, dissolved in a solvent.
Examples of the solvent include toluene, xylene, MEK (methylethyl
ketone), ethyl acetate, cyclohexanone, acetone and alcohols.
Examples of hardening agent include isocyanates.
[0038] The viscosity of the paint is in the range of 20 cp or more
and 300 cp or less, and preferably 50 cp or more and 150 cp or
less. If the viscosity of the paint is too low (less than 20 cp),
it tends to fall down to the lower layer of the surface part of the
cleaner sheet and a sufficient amount of the abrading particles 26
cannot be affixed to the surface of the microfibers 25 at the
surface part 24 of the cleaner sheet 21. Thus, the abrading
particles cannot work sufficiently on the tip part of the probe
during a cleaning operation. If the viscosity is too high (over 300
cp), the paint will remain at the upper layer of the surface part
24 of the cleaner sheet 21, and a layer with the abrading particles
26 fastened by the resin (binder 27) is formed such that mutually
adjacent microfibers 25 are attached together. Such a layer tends
to cause friction on the tip part of the probe 12.
[0039] The mix ratio of the abrading particles 26 in the paint is
in the range of 60 weight % or more, and preferably 80 weight % or
more and 98 weight % or less. If the ratio of the abrading
particles 26 is too low (less than 60 weight %), mutually adjacent
microfibers 25 tend to become attached to each other to form a
layer of the kind described above.
[0040] Composition of the paint is shown in Table 1 below.
TABLE-US-00001 TABLE 1 Abrading particles 60 weight %-98 weight %
Resin solution 1 weight %-35 weight % Hardening agent 1 weight %-5
weight %
[0041] As a preferred example, after abrading particles comprising
60 weight %-98 weight % of silicon carbide were heated and dried,
they were mixed with a resin solution obtained by dissolving 1
weight %-35 weight % of saturated polyester resin in a mixed
solvent of toluene, xylene, ethylene acetate and MEK to disperse
the abrading particles in the resin solution and they were
filtered. A paint was prepared immediately before it was applied to
a cleaner sheet by adding an isocyanate hardening agent by 1 weight
%-5 weight % to adjust the viscosity of the paint to 30 cp-150
cp.
[0042] As shown in FIG. 2C, the probe cleaner 20 of this invention
thus prepared is pasted on the surface of the table 11 through the
adhesive layer (shown at 22 in FIG. 1A). As shown in FIGS. 2A, 2B
and 2C, the tip part of a probe 12 is placed on the surface of this
cleaner sheet 21 and the table 11 is moved in the direction of
arrow T2 such that the tip part of the probe 12 penetrates into the
surface part 24 of the cleaner sheet 21. Next, the penetrated tip
part of the probe 12 is pulled out of the surface part 24 of the
cleaner sheet 21 by moving the table 11 in the direction of arrow
T1. By this reciprocating motion of the table 11 in the directions
of arrows T1 and T2, foreign objects attached to the tip part of
the probe 12 are removed by the surface part 24.
[0043] Cleaning tests were carried out by preparing probe cleaners
of Test and Comparison Examples and using these prepared probe
cleaners to remove foreign objects from the tip parts of probes
having indentations and protrusions at the tips. After these probes
were cleaned, they were compared regarding the removal rate from
these indentations and protrusions, and the presence or absence of
wears (abrasions) was examined by visual observation with a
microscope.
[0044] FIGS. 4A and 4B show the tips of the two kinds of probes
Test Probes A and B used for the cleaning test. The tip of Test
Probe A is shown in FIG. 5A, having an indentation and a
protrusion. The size of its bottom surface is about 90
.mu.m.times.90 .mu.m, its height is about 70 .mu.m, the diameter of
its indentation is about 50 .mu.m, and its depth is about 70 .mu.m.
With Test Probe A, the periphery of this indentation forms its
protrusion.
[0045] The tip of Test Probe B is shown in FIG. 5B, having a
plurality of indentations and protrusions. Its bottom surfaces are
about 30 .mu.m.times.30 .mu.m and its height is about 100 .mu.m.
Indentations are formed as valleys between the protrusions.
[0046] A cleaning apparatus as shown in FIG. 2C was used for the
cleaning test under the same conditions for both Test and
Comparison Examples. When the contact frequency of the probes to
the cleaner sheet of the probe cleaner became 1000 times, 10000
times and 100000 times, the abraded condition of the tip of the
probe was observed and the presence and absence of foreign objects
attached to the indentation-protrusion at the tip of the probe was
observed when the contact frequency reached 100000 times.
TEST EXAMPLE 1
[0047] A probe cleaner of Test Example 1 was prepared as
follows.
[0048] A paint was prepared by heating and drying 1 kg of abrading
particles of silicon carbide with average diameter of 0.05 .mu.m,
thereafter mixing them with a resin solution obtained by dissolving
310 g of saturated polyester resin in a mixed solvent of toluene,
xylene, ethyl acetate and MEK, stirring it to disperse the abrading
particles in the resin solution and thereafter filtering them, and
adding 60 g of an isocyanate hardening agent and adjusting it
immediately before it is applied onto the cleaner sheet. Its
viscosity was 50 cp.
[0049] The paint was applied to the surface of each of the
microfibers on the surface part of the flocked sheet and dried to
produce a probe cleaner.
[0050] Application of the paint was carried out by using a gravure
roller (#50 having grooves in straight lines at regular intervals
making angles of 45.degree.).
[0051] The flocked sheet was of a PET sheet of thickness 50 .mu.m
having microfibers with average fiber diameter of 10 .mu.m and
average length 500 .mu.m (500 .mu.m.+-.100 .mu.m) planted.
TEST EXAMPLE 2
[0052] The probe cleaner of Test Example 2 was prepared by using
the same material and by the same method as for Test Example 1
except that the average diameter of the abrading particles was
changed to 0.3 .mu.m.
TEST EXAMPLE 3
[0053] The probe cleaner of Test Example 3 was prepared by using
the same material and by the same method as for Test Example 1
except that the average diameter of the abrading particles was
changed to 3 .mu.m.
TEST EXAMPLE 4
[0054] The probe cleaner of Test Example 4 was prepared by using
the same material and by the same method as for Test Example 1
except that microfibers with average fiber diameter of 0.1 .mu.m
were used for the flocked sheet.
TEST EXAMPLE 5
[0055] The probe cleaner of Test Example 5 was prepared by using
the same material and by the same method as for Test Example 1
except that microfibers with average fiber diameter of 3 .mu.m were
used for the flocked sheet.
TEST EXAMPLE 6
[0056] The probe cleaner of Test Example 6 was prepared by using
the same material and by the same method as for Test Example 1
except that microfibers with average fiber diameter of 20 .mu.m
were used for the flocked sheet.
TEST EXAMPLE 7
[0057] The probe cleaner of Test Example 7 was prepared by using
the same material and by the same method as for Test Example 1
except that alumina was used as abrading particles.
TEST EXAMPLE 8
[0058] The probe cleaner of Test Example 8 was prepared by using
the same material and by the same method as for Test Example 1
except that diamond was used as abrading particles.
COMPARISON EXAMPLE 1
[0059] The probe cleaner of Comparison Example 1 was prepared by
using the same material and by the same method as for Test Example
1 except that the average diameter of the abrading particles was
changed to 5 .mu.m.
COMPARISON EXAMPLE 2
[0060] A probe cleaner of Comparison Example 2 was prepared as
follows.
[0061] A paint for aforementioned Test Example 3 (prepared by
heating and drying 1 kg of abrading particles of silicon carbide
with average diameter of 3 .mu.m, thereafter mixing them with a
resin solution obtained by dissolving 310 g of saturated polyester
resin in a mixed solvent of toluene, xylene, ethyl acetate and MEK,
stirring it to disperse the abrading particles in the resin
solution and thereafter filtering them, and adding 60 g of an
isocyanate hardening agent and adjusting it immediately before it
is applied onto the cleaner sheet, and having a viscosity of 50 cp)
was applied to the surface of a PET film by using a gravure roller
(#50 having grooves in straight lines at regular intervals making
angles of 45.degree.) and dried.
COMPARISON EXAMPLE 3
[0062] A probe cleaner of Comparison Example 3 was prepared by
applying a paint for aforementioned Test Example 3 to the surface
of a foamed film by using a gravure roller (#50 having grooves in
straight lines at regular intervals making angles of 45.degree.)
and drying.
[0063] The compositions of the probe cleaners of Test Examples 1-8
and Comparison Examples 1-3 are summarized in Table 2 below.
Results of the test are shown in Table 3 below. TABLE-US-00002
TABLE 2 Sheet Abrading particles Fiber diameter Average diameter
Type (.mu.m) Material (.mu.m) Test Example 1 Flocked sheet 10
Silicon carbide 0.05 Test Example 2 Flocked sheet 10 Silicon
carbide 0.3 Test Example 3 Flocked sheet 10 Silicon carbide 3 Test
Example 4 Flocked sheet 0.1 Silicon carbide 0.05 Test Example 5
Flocked sheet 3 Silicon carbide 0.05 Test Example 6 Flocked sheet
20 Silicon carbide 0.05 Test Example 7 Flocked sheet 10 Alumina 0.3
Test Example 8 Flocked sheet 10 Diamond 0.3 Comparison Example 1
Flocked sheet 10 Silicon carbide 5 Comparison Example 2 PET film --
Silicon carbide 3 Comparison Example 3 Foamed film -- Silicon
carbide 3
[0064] TABLE-US-00003 TABLE 3 Test Probe A Test Probe B Removal
rate Removal rate from Wears on from Wears on indentations
indentations indentations protrusions Test Example 1 C A C A Test
Example 2 B B B B Test Example 3 A C A C Test Example 4 B A B A
Test Example 5 A A A A Test Example 6 B A B A Test Example 7 C A C
A Test Example 8 A C A C Comparison A D A D Example 1 Comparison D
A D D Example 2 Comparison D B D D Example 3
[0065] In Table 3, the symbols for the removal rate of foreign
objects from indentations are as follows:
[0066] A: 95% and over
[0067] B: 80-95%
[0068] C: 60-80%
[0069] D: Below 60%
[0070] The symbols for the wears (abrasions) are as follows:
[0071] A: No wears after 100000 contacts
[0072] B: Wears appear after 100000 contacts
[0073] C: Wears appear after 10000 contacts
[0074] D: Wears appear after 1000 contacts
[0075] It can be seen from the results of Test Examples 1-3 and
Comparison Example 1 that the removal rate from indentations drops
as the diameters of the abrading particles are made smaller,
becoming 60-80% with average particle diameter of 0.05 .mu.m (Test
Example 1). The wears become smaller as the diameters of abrading
particles are made larger, becoming not detectable after 10000
contacts with average particle diameter of 0.05 .mu.m (Test Example
3) and after 1000 contacts with average particle diameter of 5
.mu.m (Comparison Example 1).
[0076] The results of Test Examples 2, 7 and 8 show that no
significant changes appear in the removal rate of foreign objects
in indentations and the degree of wears even if the kind of
abrading particles is changed and that results better than by
Comparison Examples can be obtained.
[0077] The results of Test Examples 1 and 4-6 show that the removal
rate of foreign objects in indentations becomes lower if the fiber
diameter is reduced, becoming 80-95% if the fiber diameter is 0.1
.mu.m (Test Example 1) and that the wears begin to appear when the
contact number reaches 10000 if the fiber diameter exceeds 110
.mu.m and becomes 20 .mu.m. On the other hand, the amount of wears
does not depend very much on the fiber diameter, no wears being
detectable after 100000 contacts if the fiber diameter is in the
range of 0.1 .mu.m-20 .mu.m.
[0078] From the above, it may be concluded that it is preferable to
use microfibers with fiber diameters of 0.1 .mu.m-20 .mu.m for the
flocked sheet and abrading particles with average particle diameter
of 0.05 .mu.m-3 .mu.m to be affixed to these microfibers.
[0079] The results of Table 3 generally show that the probe
cleaners of Test Examples 1-8 have better removal rates of foreign
objects in indentations than those of Comparison Examples, causing
less wears on the indentations and protrusions on the probe.
[0080] Although probe cleaners and cleaning methods were described
above for the tip part of a probe, it goes without saying that the
present invention can be used for the removal of foreign objects
attached to the tip part of other kinds of needle such as needles
for clinical use and for sewing.
* * * * *