JPH11326461A - Laser cleaning method of probe needle and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove impurities, such as aluminum or gold, adhered to the tip of a probe needle without deforming or breaking the probe needle of a probe device for inspection of the surface of a semiconductor wafer or an IC chip by contacting thereto. SOLUTION: A laser beam is applied from the front or the side of a probe needle 13 toward the tip of the probe needle 13, as much as 1 to 100 shots in a pulse state with an intensity in terms of an energy density of 100 milli- joules or more per square centimeter, and then the tip of the probe needle 13 is rapidly heated and rapidly cooled, to thereby remove impurities adhered to the tip of the probe needle 13 by abrasion. Preferably, a line beam of excimer laser is applied in the pulse state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer,
The present invention relates to a probe device for testing and inspecting electrical characteristics by contacting the surface of a C chip, an LCD (liquid crystal display device) substrate, a printed circuit board, a magnetic head, a thin film head, and the like. About.

[0002]

2. Description of the Related Art A probe device, also called a probe card or a probe board, is widely used for testing and inspecting various electric circuits. In general, as shown in FIG. 1, a probe device has a number of probe needles 13 positioned in openings 12 provided in a synthetic resin motherboard 11 and contacts various surfaces by contacting the surface of a substrate 14 such as an IC chip. Testing and inspection are performed by measuring the electrical characteristics of

The probe needle is usually made of tungsten or beryllium copper and has a thickness of about 40 to 200 μm at the root and about 20 to 40 μm at the tip. Fragments such as gold and gold come off and adhere, and the contact resistance changes, making it impossible to obtain correct measurement values. Therefore, a brush-like tool is brought into contact with the needle tip and scraped off by hand, but the number of needles can reach 500, so that it is possible to avoid the needle from being deformed or damaged. Can not. There is no device for cleaning the probe needle focusing on this point.

Japanese Patent Application Laid-Open No. 7-294555 entitled "Probe Card for High Temperature Measurement and Motherboard Used for It" describes a probe device for an IC chip. Japanese Patent Application Laid-Open No. 7-32168 “Probe card” describes a probe device for a semiconductor wafer. JP-A-7-29
No. 7240, "Positioning method and device of LCD inspection probe" describes a probe device for an LCD substrate. Japanese Patent Application Laid-Open No. Hei 8-309573 discloses an apparatus for irradiating a laser beam onto a flat plate with a linear focusing shape of a laser beam.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning method and apparatus which can remove impurities attached to the tip of a probe needle without deforming or breaking the probe needle. .

[0006]

In one aspect, the present invention provides a semiconductor wafer,
IC chips, LCD boards, printed boards, magnetic heads,
A method of cleaning a probe needle of a probe device for inspecting by contacting a surface of a thin film head or the like, wherein a laser beam is directed from the front or side of the probe needle toward the tip of the probe needle to have an energy density of 1 square cm. 100 per
Irradiate 1 to 100 shots in pulses with an intensity of millijoule or more, rapidly heat and cool the tip of the probe needle,
An object of the present invention is to provide a laser cleaning method for a probe needle, characterized by removing impurities attached to the tip of the probe needle by ablation.

The laser beam has a wavelength of 11,000.
It can be widely used from a carbon dioxide gas laser of nm to an excimer laser of wavelength 248 nm.

[0008]

According to this method, the impurities adhering to the tip of the probe needle are subjected to rapid heating / cooling by the laser beam and are removed by ablation. The portion of the probe device other than the needle and the needle itself are instantaneously cooled and return to their original state, so that they are not damaged.

In another aspect, the present invention provides a semiconductor wafer,
IC chips, LCD boards, printed boards, magnetic heads,
This is a device that cleans the probe needle of a probe device that performs inspection by contacting the surface of a thin film head or the like.A line-shaped excimer laser beam is pulsed from the front or side of the probe needle toward the tip of the probe needle. It has an irradiation mechanism and a transfer mechanism that moves the probe device holding the probe needle under a linear laser beam when performing laser irradiation, and ablates impurities adhering to the tip of the probe needle. And a laser cleaning device for a probe needle.
With this apparatus, the above-described laser cleaning method is effectively performed, and impurities at the tip of the probe needle are completely peeled and removed.

As a transfer mechanism for performing laser irradiation using this apparatus, a transfer mechanism (such as a conveyor) for moving a probe device in a direction perpendicular to a line-shaped laser beam.
By providing a rotating mechanism (e.g., a turntable) for rotating the needle, it is possible to perform control so that the removal operation can be completed with a minimum number of shots even for rows of needles other than a rectangle.

In a preferred aspect of the present invention, the laser beam is converted into a line beam having a narrow width and a length larger than the width of the row of probe needles by an optical component such as a mirror or a slit and a homogenizer (homogenizer). It is formed.
In another preferred aspect of the present invention, the laser beam is:
The scanning mechanism scans across the width of the row of probe needles.

When performing laser irradiation, laser irradiation is performed only on the rows of probe needles on the probe device.
If a mechanism for inserting a shielding plate between the laser beam and the probe device is provided, it is possible to avoid irradiating the laser to other portions of the probe device. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

[0013]

1 and 2 are schematic views showing a principle for carrying out a laser cleaning method for a probe needle according to the present invention. A probe card 10 is made of a printed board made of epoxy resin. An opening 12 for vertically moving the probe needles is formed at the center thereof, and a number of probe needles 13 are arranged in a row in the opening. The probe needle is usually made of tungsten or beryllium copper, and has a thickness of about 40 to 200 μm at the root and about 20 to 40 μm at the tip.

In the laser cleaning method of the present invention, as an example, a laser oscillator 16 is set to a height of 10 mm and a width of 3 mm.
A beam light beam 17 of an excimer (KrF) laser having a rectangular section of 0 mm and a wavelength of 248 nm is emitted in a pulse shape. Laser intensity is about 100-600 per square cm
Millijoule, laser pulse period is about 1-100H
z, the number of shots is preferably 1 to 100 shots. As a most preferable example, when the excimer laser beam having a wavelength of 248 nm is irradiated with 10 pulses at an intensity of 200 mJ / cm 2, impurities at the tip of the probe needle can be completely removed.

The beam 17 is expanded through a cylindrical lens 18, a condenser lens 19, and a beam splitter 20 having a slit, and has a width of 0.3 mm and a length of 100 mm.
The beam is formed on the surface of the probe device 10 having a width of 100 mm or less.

The probe device 10 is mounted on a conveyor (not shown), and moves in a horizontal direction at a constant speed in accordance with the shape (rectangular / arc) and width of a row of probe needles. This moving speed is synchronized with the frequency of laser irradiation.

Thus, the impurities adhering to the probe needle on the probe device 10 are melted by the irradiation of the laser beam. It is a rapid heating of 10 to 30 nsec, and does not become magnetized due to the rapid cooling, and the surface is thinly melted and peels off.

FIG. 3 is another schematic view showing the principle of the present invention. A beam oscillating beam 34 of an excimer (KrF) laser having a wavelength of 248 nm is emitted from a laser oscillator 32 in a pulse form. The beam light beam 34 is modulated by the modulator 36 and the beam expander 3.
8. Formed into a spot beam via a cylindrical lens 40, a polygon mirror 44 rotated by a motor 42, a cylindrical lens 46, and a condensing scanning lens 48, and act as a linear beam 50 by being scanned. I do. The scanning beam 50 is applied to the surface of the probe device 10 mounted on a conveyor (not shown) and moving at a constant speed in the horizontal direction.

The scanning mechanism of the laser beam is not limited to a polygon mirror, but may be a galvanometer, an ultrasonic deflector, or other various mechanisms.

[0020]

FIG. 4 shows a preferred embodiment of the present invention. As a laser oscillator, an L4308 type manufactured by Lamta Physics Japan was used. A control device 62 for performing various controls is provided adjacent to the laser oscillator 60.

In FIG. 4, a laser beam 60 from an excimer (KrF) laser having a wavelength of 248 nm is emitted from a laser oscillator 60.
4 is emitted in a pulsed manner. The beam luminous flux 64 includes mirrors 65 and 66, a shutter 67, an attenuator 68, and a mirror 6
9, the light passes through the homogenizer 70 and the slit 71, is converted into a line beam 72, is reflected by the mirror 73, passes through the slits 74 and 75, and is irradiated onto the probe device 10.

A table 80 for supporting the probe device 10
Is fed in the front-rear direction by a table feed drive motor 82 or is rotated by a table rotation motor 84. The surface temperature of the probe device 10 is
It can be detected by a temperature sensor 86 of an infrared detection system. In order to adjust the surface temperature of the probe device 10, a fan 88 may be provided.

A cylinder mechanism 92 for inserting a shielding plate 93 between the laser beam and the probe device 10 is provided adjacent to the laser irradiation section. With this mechanism, laser irradiation can be limited only to the opening on the probe device.

The control device 62 performs the following control operation. (1) Control ON / OFF of laser beam irradiation, energy density, frequency, pulse number, etc. of the laser beam (2) Control so that the laser irradiation frequency and pulse number irradiated on the probe device are synchronized (3) ) The transfer mechanism or the rotation mechanism is controlled so that the number of laser shots per unit area becomes uniform during the movement of the probe device. (4) The laser beam is irradiated so that only a specific portion on the probe device is irradiated with the laser beam. Control the operation of the mechanism that inserts the shielding plate between the board and the substrate. (5) Control the fan speed in accordance with the signal from the temperature sensor to keep the surface temperature of the probe device constant. By the above control operation, the best laser irradiation effect can be obtained.

[0025]

As described above in detail, according to the laser cleaning method and apparatus of the probe device according to the present invention, the impurities attached to the tip of the probe needle are completely removed in a dissolved state, and the probe itself and the probe are removed. Other parts of the device are not affected. This prevents the electrical characteristics of the probe needle from changing, improves the reliability of the probe device, and further improves the quality of the semiconductor.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a structure of a probe needle and laser irradiation in a probe device.

FIG. 2 is a schematic view illustrating the principle of a probe needle laser cleaning method according to the present invention.

FIG. 3 is a schematic view illustrating the principle of a probe needle laser cleaning method according to the present invention.

FIG. 4 is a perspective view showing a preferred embodiment of the laser cleaning device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Probe apparatus 12 Aperture 13 Probe needle 14 IC chip 16, 32, 60 Laser oscillator 24, 50, 72 Line beam 82 Drive motor 84 Rotary motor 92 Shield insertion mechanism

Claims (4)

[Claims] 1. A method for cleaning a probe needle of a probe device for inspecting by contacting a surface of a semiconductor wafer, an IC chip, an LCD substrate, a printed circuit board, a magnetic head, a thin film head, or the like, comprising: The laser beam is pulsed at an energy density of at least 100 mJ / cm 2 toward the tip of the probe needle.
A laser cleaning method for a probe needle, comprising irradiating 0 shots, rapidly heating and rapidly cooling the tip of the probe needle, and removing impurities attached to the tip of the probe needle by ablation. 2. A device for cleaning a probe needle of a probe device for inspecting by contacting a surface of a semiconductor wafer, an IC chip, an LCD substrate, a printed circuit board, a magnetic head, a thin film head, etc., wherein the probe needle is in front or side of the probe needle. A mechanism that irradiates a pulse of a linear excimer laser beam from the side toward the tip of the probe needle, and a probe device that holds the probe needle when performing laser irradiation, moves the probe device below the linear laser beam. And a transfer mechanism for moving the probe needle by means of a laser beam, and removing impurities adhering to the tip of the probe needle by ablation. 3. The laser beam is formed into a line beam having a narrow width and a length greater than the width of a row of probe needles by an optical component such as a mirror or a slit and a homogenizer, and then irradiated toward the tip of the probe needle. Claim 2
A cleaning device as described. 4. The apparatus according to claim 2, further comprising a mechanism for inserting a shielding plate between the laser beam and the probe device so that, when performing the laser irradiation, only the probe needle on the probe device is irradiated with the laser. Cleaning device.