RU2402782C2 - Method of manufacturing probes based on quartz resonators - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: in method of manufacturing probes based on quartz resonators, including fixation of quartz resonator, which has at least one arm, by means of first holder, application of glue on quartz resonator arm and realisation of contact between quartz resonator arm and first end of needle in zone of glue application with further orientation, before realisation of contact forced orientation of needle by three coordinates, which is specified and preserved in process of gluing, is carried out.

EFFECT: extension of functional possibilities of measuring probes and increase of their reliability.

8 cl, 2 dwg

Description

The invention relates to the field of scanning probe microscopy, and more particularly to methods for manufacturing measuring probes.

Currently, a widely used method of manufacturing probes for scanning probe microscopes (SMZ), which consists in gluing a needle to the shoulder of a quartz resonator [1-3].

The first disadvantage of this method is the lack of a fixed orientation of the needle. When the glue dries, the surface tension forces orient the needle in an uncontrolled manner, which leads to a decrease in measurement accuracy.

The second disadvantage is the insufficient strength of the needle attachment to the shoulder of the quartz resonator.

The closest in technical essence and the achieved effect is the method of forming an SPM probe described in [4]. The problem of misorientation of the needle during the hardening of the glue is solved in this case using two needles, one of which is made of soft magnetic material and glued to the first arm of the quartz resonator, and the other is made of hard magnetic material. This needle is mounted on the second arm of the quartz resonator and is used as a permanent magnet for forced mutual orientation of both needles.

This method of manufacturing an SPM probe is selected as a prototype of the proposed solution. The disadvantage of the prototype is that its scope is limited by magnetic force microscopy. For other types of force microscopy, fiber optic, tungsten, platinum-iridium and platinum-rhodium needles are used, which are not glued in this way. In addition, with a similar method for manufacturing the probe, the problem of insufficient strength of the needle fastening to the shoulder of the quartz resonator and its exact axis orientation remains unresolved.

The technical effect of the invention consists in expanding the functionality of the measuring probes and increasing their reliability.

This is achieved by the fact that in the described method of manufacturing SPM probes, the needle is forcedly oriented in three coordinates, which is refined and stored during gluing.

One of the embodiments of the invention is that after reaching contact between the shoulder of the quartz resonator and the first end of the needle, the contact area is treated with ionizing, or ultraviolet, or infrared radiation or ultrasound.

A further embodiment of the invention is that before applying the adhesive to the shoulder of the quartz resonator, the needle is immersed in hydrochloric acid and then washed with distilled water.

Another embodiment of the invention is that microdosing is used to apply glue to the shoulder of the quartz resonator.

The last embodiment of the invention is that before fixing the quartz resonator in the first holder, the quartz resonator is immersed in a liquid and its oscillations are excited at ultrasonic frequencies.

The invention is illustrated below using the drawings, which schematically depict:

figure 1 - device for the manufacture of SPM probes, top view;

figure 2 is a method of mutual orientation of the needle and the quartz resonator in the manufacturing process of the probe SPM.

A device for manufacturing SPM probes 1 comprises a first holder 2 of a quartz resonator 3, a second holder 4 of a needle 5, clamping screws 6 and 7 for attaching a quartz resonator 3 and a needle 5, and screws 8 and 9 for moving the holders 2 and 4 along the X and Y axes. The arrows show the direction of the possible movement of the holders 2 and 4. Instead of the clamping screws 6 and 7, clip clips and multi-pin connectors can also be used [5]. A clamp 10 can be mounted on the second holder 4, coupled to a screw 11 that allows the clamp 10 to move along the Z axis.

The device for the manufacture of SPM probes is not described in detail, because it is not the subject of the invention. As an embodiment of the method, holders described in [5] can also be used.

The manufacture of SPM probes is as follows. The quartz resonator 3 is fixed in the first holder 2 by means of a clamping screw 6. The surface of the quartz resonator 3 can be pre-cleaned. For this, the quartz resonator 3 is immersed in a liquid, its contacts are fixed in a multi-pin connector and alternating electric current is supplied to the contacts to excite ultrasonic vibrations. As a liquid, a surfactant or a complexing agent, for example acetonitrile, can be used [6].

After the quartz resonator 3 is fixed in the first holder 2, glue is applied to the selected area 12 (FIG. 2) of the shoulder of the quartz resonator 3 using a conventional needle. There should not be too much glue, otherwise it will adversely affect the performance of the probe, namely, it will reduce its sensitivity by reducing the quality factor.

For applying glue, a microdoser can also be used, which is a wire of the same diameter as the glued needle 5. This wire is dipped into the glue by about 1-2 mm and then removed. At the same time, a drop of glue is formed at the end of the wire, sufficient for gluing the needle 5.

For gluing needles use a polymer adhesive based on epoxy resins UHU plus endfest 300 or Torr Seal (Varian). Its complete solidification occurs 24 hours after mixing the starting components.

After the adhesive has been applied to the selected region 12 of the shoulder of the quartz resonator 3, the first end of the needle 13 (FIG. 2) is cut so that the remaining length of the needle is, for example, 3 mm in length and is fixed in the second holder 4 with the clamp 10 and clamping screw 7.

In addition, you can pre-treat the needle 5. This operation may include immersion in hydrochloric acid, followed by rinsing with distilled water. For needles with a diameter of the order of 10 microns, irradiation with ultraviolet radiation can be carried out.

It should be mentioned that fiber, platinum-iridium and platinum-rhodium wire, as well as tungsten and nickel needles can be used as a needle. Fiber optic needles are widely used in near-field optical microscopy. The method of their manufacture is described, for example, in [7].

Platinum-iridium and platinum-rhodium wires have such advantages as chemical resistance, strength, elasticity. But the methods for sharpening needles made from these wires are very complicated and therefore these needles are not sharpened.

Tungsten needles also have high strength, but their surface is oxidized in air. At the same time, the oxide is easily removed, and, in addition, methods for the electrochemical sharpening of tungsten needles are well developed [5]. The use of the above needles expands the scope of SPM probes manufactured by the described method.

Nickel needles are used in magnetic force microscopy. The method of their manufacture is described in [8].

Having fixed the second end of the needle 14 (Fig. 2) in the second holder 4 by means of screws 8 and 9, coarse approach of the holders 2 and 4 is made. After making sure that the mutual orientation of the needle 5 and the shoulder of the quartz resonator 3 corresponds to the desired, continue to carefully bring the holders 2 and 4 up to achieving contact between the first end of the needle 13 and the shoulder of the quartz resonator 3 in the selected region 12. In this case, after gluing, the second end of the needle 14 will protrude about 0.5-1.5 mm above the shoulder surface of the quartz resonator 3.

At the stage of final approach of the first and second holders 2 and 4, an optical microscope can be used to facilitate visual control of the mutual orientation of the quartz resonator 3 and the needle 5.

To accelerate the curing process of the glue and improve the quality of attachment, the contact area between the needle 5 and the shoulder of the quartz resonator 3 can be treated with ionizing or infrared radiation, as well as ultrasound.

After the glue has completely hardened, the finished probe is removed from the holders 2 and 4. To do this, using the clamping screw 7, loosen the clamp 10 and carefully screw the first holder 2 back with the screw 9. Then, the clamping screw 6 of the first holder 2 is loosened and the probe is removed.

The method of forced orientation in three coordinates proposed in this invention allows us to expand the scope of SPM probes, because unlike the prototype, optical fiber, platinum-iridium and platinum-rhodium wire, as well as tungsten and nickel needles can be used here as a needle.

In addition, unlike the prototype, the proposed method makes it possible to change the amount of glue used depending on the type of needle and more accurately orient it in space. Reducing the amount of glue and the exact orientation of the needle increases the sensitivity of the manufactured probe and also expands its functionality.

Processing the contact area with ionizing radiation contributes to a better mixing of the glue and a reduction in its curing time, which leads to an improvement in the quality of the attachment of the needle to the shoulder of the quartz resonator.

When using a needle with a thickness of the order of 10 μm, the surface of the needle and / or the contact area of the quartz resonator and the first end of the needle are treated with UV radiation. This contributes to the destruction of bacteria, which in size become comparable with the cross-sectional area of the needle and adversely affect the quality of adhesion. UV treatment speeds up the curing process of some types of glue and improves the bonding quality. The use of needles of such a small diameter extends the functionality of the manufactured probe.

The impact of the ultrasound on the contact area improves mixing of the components of the adhesive and leads to an increase in the reliability of fastening.

Influence of infrared radiation on the contact area accelerates the curing of the adhesive and improves the quality of adhesion.

Immersion of the needle in hydrochloric acid, followed by washing with distilled water, leads to microcavities on the surface of the needle. As a result, the contact area between the needle and the arm of the quartz resonator increases, and the bonding quality improves.

The use of microdosing for applying glue to the shoulder of a quartz resonator allows to reduce the amount of glue and thereby increase the quality factor and sensitivity of the manufactured probe and, therefore, expand its functionality.

The immersion of a quartz resonator in a liquid and the excitation of its oscillations at ultrasonic frequencies helps to clean the surface of the quartz resonator, improves the quality of gluing the needle and increases the reliability of the probe.

In conclusion, it should be noted that improving the quality of gluing the needle and, consequently, increasing the reliability of the probes leads to the expansion of their functionality, since such probes can be used in a wider range of devices. For example, in a vacuum application of scanning probe microscopy, multi-probe cartridges are used, and the reliability of a single probe plays an important role here, because replacing a failed probe is a rather time-consuming operation.

Information sources

1. US patent No. 5641896,1997.

2. British patent No. 2289759,1995.

3. W.H. J. J. Rensen, N.F. van Hulst, A.G.T.Ruiter, P.E. West, Atomic steps with tuning-fork-based noncontact atomic force microscopy, Appl. Phys. Let., V. 75, No. 11, 1999.

4. Patent of the Russian Federation No. 2208763 C 1,2001.

5. E.A. Kolenko, Technology of a laboratory experiment, S. Petersburg, 1994, p. 652-658.

6. E.Z. Mazel, F.P.Press, Planar technology of silicon devices, Moscow, 1974, p. 71.

7. Patent WO No. 03/056567 A2, 2003.

8. Japanese Patent No. 0434403, 1991.

Claims (8)

1. A method of manufacturing probes based on quartz resonators, comprising fixing a quartz resonator having at least one shoulder using a first holder, applying glue to the shoulder of the quartz resonator and making contact between the quartz resonator shoulder and the first end of the needle in the glue application zone followed by orientation, characterized in that before making contact, the needle is forcedly oriented in three coordinates, which is refined and stored during gluing. 2. The method according to claim 1, characterized in that after reaching contact between the arm of the quartz resonator and the first end of the needle, the contact area is subjected to ionizing radiation treatment. 3. The method according to claim 2, characterized in that when using a needle with a thickness of the order of 10 μm, the surface of the needle and / or the contact area of the quartz resonator and the first end of the needle are treated with UV radiation. 4. The method according to claim 1, characterized in that after reaching contact between the shoulder of the quartz resonator and the first end of the needle, the contact area is affected by ultrasound. 5. The method according to claim 1, characterized in that after reaching contact between the shoulder of the quartz resonator and the first end of the needle, the contact area is exposed to infrared radiation. 6. The method according to claim 1, characterized in that before applying glue to the shoulder of the quartz resonator, the needle is immersed in hydrochloric acid and then washed with distilled water. 7. The method according to claim 1, characterized in that microdosing is used to apply glue to the shoulder of the quartz resonator. 8. The method according to claim 1, characterized in that before fixing the quartz resonator in the first holder, the quartz resonator is immersed in a liquid and its oscillations are excited at ultrasonic frequencies.

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