Cleaning and liquid contact with solids – Apparatus – Automatic controls
Reexamination Certificate
1998-09-04
2002-11-05
Stinson, Frankie L. (Department: 1746)
Cleaning and liquid contact with solids
Apparatus
Automatic controls
C134S0580DL, C134S088000, C134S155000, C134S186000, C134S184000
Reexamination Certificate
active
06474350
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cleaning device for a semiconductor inspection device and a washing liquid used therefor. More specifically, the present invention relates to a cleaning device for a probe needle of a probe card and a washing liquid used therefor.
2. Description of the Background Art
Conventionally, a device called a probe card has been used in the inspection process of semiconductor devices.
FIG. 16
is a cross sectional view of a conventional probe card. Referring to
FIG. 16
, the conventional probe card has an opening
114
formed almost at the center of a substrate
116
. In the periphery of opening
114
, a plurality of probe needles
111
are provided toward the center of opening
114
. Probe needle
111
is connected to a terminal (not shown) arranged in the periphery of substrate
116
through a wiring. In inspecting a semiconductor device, the terminal is connected to an inspection device called a prober. The probe card is arranged opposite to a surface of the semiconductor device to be inspected and is also arranged so that the tip of probe needle
111
comes in contact with an electrode formed on the surface of the semiconductor device. The electrical characteristics of the semiconductor device are thus inspected through probe needle
111
in contact with the electrode formed on the surface of the semiconductor device.
FIG. 17
is a schematic view illustrating conventional probe needle
111
shown in FIG.
16
. Referring to
FIG. 17
, the lead portion of the probe needle has a diameter D of approximately 0.25 mm, the end of the probe needle has a length L of approximately 7 mm, and the tip
112
of the probe needle that comes in contact with an electrode of a semiconductor device has a diameter d of approximately 30 &mgr;m. The materials for the probe needle include tungsten or the like.
In inspecting a semiconductor device, tip
112
of the probe needle comes in contact with an electrode
131
formed on a surface of the semiconductor device, as shown in
FIGS. 18 and 19
.
FIGS. 18 and 19
are schematic views illustrating how the tip of the probe needle comes in contact with the electrode formed on the surface of the semiconductor device. As shown in
FIG. 18
, electrode
131
formed on the surface of semiconductor device
132
is brought in contact with tip
112
of probe needle
111
by raising semiconductor device
132
toward probe needle
111
. Electrode
131
of semiconductor device
132
is formed of aluminum, and a thin aluminum oxide layer
133
is formed on a surface of electrode
131
. Since aluminum oxide layer
133
is an insulating layer, an aluminum layer
134
under aluminum oxide layer
133
cannot be brought into contact with tip
112
of probe needle
111
simply by pressing tip
112
of probe needle
111
against electrode
131
as shown in FIG.
18
. Therefore, current cannot be passed from probe needle
111
to electrode
131
.
Accordingly, semiconductor device
132
is typically further raised after tip
112
of probe needle
111
is brought into contact with electrode
131
, as shown in FIG.
19
. Probe needle
111
is thus elastically deformed and tip
112
of probe needle
111
is horizontally moved on electrode
131
. Aluminum oxide layer
133
on the surface of electrode
131
is thus partially removed from the surface of electrode
131
to allow aluminum layer
134
which is the electrode body to come into direct contact with tip
112
of probe needle
111
. The process shown in
FIG. 19
will be referred to as an overdrive process hereinafter. In this manner, tip
112
of probe needle
111
has come into contact with electrode
131
in the conventional inspection process.
However, the overdrive process as shown in
FIG. 19
causes part of aluminum oxide layer
133
removed from the surface of electrode
131
to adhere to tip
112
of probe needle
111
as shown in FIG.
20
. When a foreign matter
113
, such as aluminum oxide, which is an insulator thus adheres to tip
112
of probe needle
111
, foreign matter
113
prevents the electrical connection between tip
112
of probe needle
111
and electrode
131
(see
FIG. 19
) of the semiconductor device, making it difficult to pass a prescribed current to electrode
131
. Accordingly, repeated use of such a probe needle has disadvantageously resulted in an inaccurate inspection of semiconductor devices.
Accordingly, a probe needle cleaning operation has been performed so as to remove foreign matter
113
such as aluminum oxide from tip
112
of probe needle
111
.
FIG. 21
is a cross sectional view of an abrasive sheet for probe needles that is used in a conventional probe needle cleaning operation. Referring to
FIG. 21
, the conventional abrasive sheet
135
for probe needles employs silicon rubber
136
as a matrix, and abrasive grains
137
such as artificial powdery diamond are dispersively arranged in silicon rubber
136
. When tip
112
(see
FIG. 20
) of probe needle
111
(see
FIG. 20
) is stuck into abrasive sheet
135
prescribed times, foreign matter
113
(see
FIG. 20
) is scraped off the surface of probe needle
111
by abrasive grains
137
in abrasive sheet
135
. Foreign matter
113
has conventionally be removed from tip
112
of probe needle
111
in this manner.
FIG. 22
is a flow chart of a conventional probe needle cleaning operation. Referring to
FIG. 22
, the conventional probe needle cleaning operation consists of four steps. At step
1
, a probe card is arranged opposite to an abrasive sheet. At step
2
, the tip of a probe needle is stuck into the abrasive sheet prescribed times.
FIG. 23
is a schematic view showing the process of sticking the tip of the probe needle into the abrasive sheet prescribed times at step
2
. As shown in
FIG. 23
, tip
112
of probe needle
111
is stuck into abrasive sheet
135
to allow foreign matter
113
such as aluminum oxide adhered to tip
112
of probe needle
111
to be scraped off by abrasive grains
137
in abrasive sheet
135
.
At this stage after step
2
, however, a viscous silicon rubber film
138
which is softened silicon rubber
136
(see
FIG. 23
) as the matrix of abrasive sheet
135
adheres to tip
112
of probe needle
111
. A foreign matter
139
also adheres to silicon rubber film
138
. Foreign matter
139
includes foreign matter
113
(see
FIG. 23
) such as aluminum oxide removed from tip
112
of probe needle
111
at step
2
, abrasive grains
137
(see
FIG. 23
) removed from abrasive sheet
135
, a removed portion of silicon rubber
136
(see
FIG. 23
) which is the matrix of abrasive sheet
135
, and so on.
Accordingly, the conventional probe needle cleaning operation requires, as step
3
, the step of spraying an organic solvent on the tip of the probe needle to remove foreign matter
139
(see
FIG. 24
) adhering to tip
112
.
FIG. 25
schematically shows how step
3
is performed.
As shown in
FIG. 25
, an organic solvent
140
is sprayed on tip
112
of probe needle
111
to dissolve silicon rubber film
138
and to remove silicon rubber film
138
and foreign matter
139
from tip
112
of probe needle
111
.
When step
3
is completed, organic solvent
140
remains on probe needle
111
as shown in FIG.
26
. Accordingly, the conventional probe needle cleaning operation carries out, as step
4
, the step of blowing air to probe needle
111
(see
FIG. 26
) to dry organic solvent
140
(see
FIG. 26
) remaining on tip
112
of probe needle
111
and simultaneously blow off foreign matters and the like remaining on the surface of probe needle
111
, as shown in FIG.
22
.
The conventional probe needle cleaning operation has been performed in this manner.
Conventionally, foreign matter
113
has been removed from tip
112
of probe needle
111
by sticking tip
112
of probe needle
111
into abrasive sheet
135
as shown in FIG.
23
. However, when the step of sticking is repeated several hundred times, the side surface and the bottom surface of tip
112
of probe needle
111
have been scraped by abrasive grains
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