WO1998026894A1

WO1998026894A1 - Device for applying a liquid on an object, application to soldering a solid material in a sample-holder

Info

Publication number: WO1998026894A1
Application number: PCT/FR1997/002329
Authority: WO
Inventors: Jean-Marie Maquin
Original assignee: Commissariat A L'energie Atomique
Priority date: 1996-12-18
Filing date: 1997-12-17
Publication date: 1998-06-25
Also published as: EP0946329A1; FR2757092B1; FR2757092A1

Abstract

This device comprises means (14) for maintaining the object (4), means (16) for moving these maintaining means, a tank of liquid (18), means for applying liquid to the object which communicate with the tank and means (22) for moving the tank.

Description

DEVICE FOR APPLYING A LIQUID TO AN OBJECT, APPLICATION TO THE BRAZING OF A SOLID MATERIAL IN A

SAMPLE CARRIER.

DESCRIPTION

Technical area

The present invention relates to a device for applying a liquid to an object. It is particularly applicable to the brazing of a solid material in a sample holder.

State of the prior art

In the field of the characterization of materials for microwave components, it is necessary to precisely measure the complex dielectric permittivity and magnetic permeability of these materials over a wide range of frequencies using a network analyzer.

The materials to be measured are solid. They can be of mineral, organic, ceramic or composite type.

The instructions from the Hewlett Packard Company delivered with the HP 8510 network analyzer marketed by this Company describes how to perform this type of measurement in a coaxial line or in a rectangular guide.

A sample is measured in a sample holder whose interfaces are compatible with coaxial adapters for measurements in a coaxial line and waveguides for measurements in a rectangular guide. In all cases, the sample must be perfectly adjusted to the dimensions of the sample holder.

This operation is easier to perform in a rectangular guide than in a coaxial guide.

The presence of the eu necessary for mounting the sample inevitably induces measurement errors.

These errors have been minimized by the measurement method using soldering, which is disclosed in the following document:

(1) International application PCT / FR93 / 01104 published on May 26, 1994 under number WO 94/11746 and entitled "METHOD FOR MEASURING DIELECTRIC AND MAGNETIC PARAMETERS OF A SOLID MATERIAL, USING BRAZING OF THIS MATERIAL ON A SAMPLE HOLDER , AND DEVICES FOR IMPLEMENTING THIS PROCESS ", invention of Jacques Authesserre, René Carrera, and Jean-Marie Maquin.

This document is incorporated into the present description by reference.

This process uses a connector resulting from a modification of the coaxial connector which is marketed by the company AMPHENOL and which is discussed in document (1).

We see in Figure 1 of the accompanying drawings

(which corresponds to FIG. 1 of document (1)) a sample 2 of a material, such as barium titanate for example, for which it is desired to measure the dielectric permittivite and the magnetic permeability. The sample 2 has an annular shape and it is brazed at room temperature in a sample holder composed of a central core 4 and a ring 6. Then this sample holder provided with the sample 2 is mounted in the connector coaxial mentioned above which is an adaptation of a known coaxial connector of APC7 type (registered trademark), marketed by the company AMPHENOL and described in the following document to which reference will be made:

(2) - French patent n ° 1,535,389 applied for on September 1, 1967, issued on June 24, 1968, "Universal electrical connector" (Amphenol Corporation).

Sample 2, of annular shape, has dimensions adapted to those of the coaxial line used, namely an outer diameter between 6.99mm and 7.00mm and an inner diameter between

3.04mm and 3.05mm.

The thickness of this sample is chosen according to the estimated electromagnetic properties of the material studied. The central core 4 of the sample holder has the shape of a cylinder whose diameter is 0.1mm smaller than the inside diameter of the sample 2 (and is therefore 2.94 + 0.01mm).

The ring 6 of the sample holder has an inside diameter which is 0.1mm larger than the outside diameter of the sample and is thus worth

7.1 + 0.01mm. The clearance between the sample and the sample holder must not be too high: it must be of the order of a few hundredths of a millimeter at most. The outer diameter of the ring 6 is used for centering the assembly formed by the sample holder and the sample 2 brazed therein, relative to the axis of the coaxial line.

This outside diameter is fixed at 14.85 + 0.01mm so that the ring 6 can be adjusted in the threaded sleeve of the coaxial connector used.

As the metallic material for producing the central core 4 and the ring 6, brass is preferably chosen for the reasons mentioned in document (1).

The solder 12 at room temperature, which is used, is produced using a ternary mixture of mdium, gallium and tin, the nominal composition by weight of which is as follows: Indiu: 22%, gallium: 69 ° ₀ , tin: 9%.

This ternary mixture is obtained in a crucible at about 130 °.

The mixture obtained is liquid at room temperature (about 20 ° C). It should be noted that, in the prior art described in document (1), the implementation of brazing requires a prior operation of rubbing the surfaces intended to receive the brazing with a sheet of medium. It is now indicated that this is not necessary in the present invention.

Statement of the invention The present invention relates to a device for applying the liquid solder mentioned above to the sample 2 as well as to the two elements 4 and 6 of the corresponding sample holder before the placement of the brazed sample of the holder sample in the modified connector mentioned above.

More generally, the present invention relates to a device for applying a liquid solder to at least one object.

Even more generally, the present invention relates to a device for applying a liquid to an object having at least one side wall.

Specifically, the subject of the present invention is a device for applying a liquid to at least one object having at least one side wall, this device being characterized in that it comprises: - means for maintaining the object,

means for moving these holding means along first and second directions which are coplanar and perpendicular to each other,

a liquid reservoir, means for applying the liquid to the side wall of the object, these application means being made integral with the reservoir and communicating with it, and

means of displacement of the reservoir, and therefore means of application, in a third direction which is perpendicular to the first and second directions, the side wall of the object being parallel to this third direction.

The present invention also relates to a device for applying a liquid solder to at least one object having at least one side wall, this device being characterized in that it comprises:

- means for maintaining the object,

- a solder tank,

the means for applying the solder to the side wall of the object, these application means being made integral with the tank and communicating with it, and

- Means for moving the reservoir, and therefore application means, in a third direction which is perpendicular to the first and second directions, the side wall of the object being parallel to this third direction.

According to a preferred embodiment of the device for applying a liquid solder which is the subject of the invention, the means of application comprise:

a hollow needle, the bottom of which is closed, which is parallel to the third direction and which comprises peripheral bores extending parallel to this third direction, and

means for adjusting the arrival of the solder to the needle. The adjustment means can include:

- a flexible tube which connects the reservoir to the needle, and - means for pinching this flexible tube.

The pinching means can include:

- a jack whose rod is terminated by a first stop, and

- A second stop which remains fixed relative to the jack, the flexible tube being between the first and second stops.

The device may further comprise means for rotating the reservoir and therefore means for applying the solder.

Preferably, this device further comprises means for pressurizing the reservoir with a gas which does not react with the solder. Also preferably, this device further comprises means for heating the solder tank.

According to a preferred embodiment of the invention, the means for holding the object comprise a plate comprising a housing for each object, a space being designed to allow the introduction of the means for applying the solder into this housing.

Preferably, the device also comprises means for holding each object by suction in the corresponding housing.

Brief description of the drawings

The present invention will be better understood on reading the description of exemplary embodiments given below, for information only and in no way limiting, with reference to the appended drawings in which:

FIG. 1, already described, schematically shows a sample holder usable for brazing a sample to be studied there,

FIG. 2 is a schematic view of a particular embodiment of the device which is the subject of the invention,

FIG. 3 is a schematic view of part of this device, comprising a rotating reservoir associated with a hollow needle provided with peripheral bores,

FIG. 4 is a diagrammatic section view of this needle, and FIG. 5 is a diagrammatic top view of a motorized plate forming part of the device in FIG. 2.

Detailed description of specific embodiments

The device according to the invention, which is schematically shown in Figures 2 to 5, is intended for the application of liquid solder to the two side walls of the sample 2 of Figure 1 as well as to the side wall of the core 4 of the corresponding sample holder and to the internal side wall of the ring 6 of this sample holder.

This device of FIGS. 2 to 5 comprises:

means 14 able to hold the sample 2 as well as the two elements 4 and 6 of the sample holder,

means 16 for moving the holding means 14 in two directions X and Y which are coplanar and perpendicular to each other, - a solder tank 18,

means 20 for applying the solder to the various side walls, these application means 20 being made integral with the tank and communicating with it, and

- Means 22 for moving the reservoir 18 and therefore application means 20 in a direction Z which is perpendicular to the directions X and Y.

The application means 20 comprise: a hollow needle 24 whose bottom 26 is closed and which includes peripheral bores 28 (four in the example shown) which extend over a certain length of the needle 24, and

means 30 for adjusting the arrival of the solder to the needle 24.

These adjustment means 30 include:

a flexible tube 32 which connects the reservoir 18 to the needle 24, and

means 34 for pinching this flexible tube 32. The means 34 for pinching comprise:

a jack 36 whose movable rod 38 is terminated by a first stop 40, and

a second stop 42 which remains fixed relative to the jack 36, said flexible tube 32 being between the stops 40 and 42 as seen in FIG. 3.

The device of FIGS. 2 to 5 also comprises means 44 for rotating the reservoir around an axis Ul parallel to the direction Z (the needle 24 therefore being movable in rotation around this axis Ul). The device of FIGS. 2 to 5 also comprises means 46 for pressurizing the reservoir 18 by a gas which does not react with the solder, for example argon.

Also seen in Figure 3 means 48 for heating the tank and therefore the solder that it is intended to contain.

As can be seen in FIGS. 2 and 5, the means 14 for holding the object comprise a tray 50 comprising a housing 52 intended to receive the sample 2, another housing 54 intended to receive the central core 4 and also a other housing 56 intended to receive the ring 6.

As seen in Figure 5 which is a top view of the plate 50, there is a space between the side wall of each of the housings 52 and 54 and the side wall of the component 2 or 4 corresponding to this housing for the introduction of the needle 24 in this space in order to deposit the solder on the desired side wall.

In the case of each of the components 2 and 6, it can be seen that the needle 24 can also be introduced into the corresponding housing in order to deposit the solder on the internal side wall of the component considered.

It can also be seen in FIG. 2 that means 58 are provided in the plate 50 for holding each component by suction in the corresponding housing.

We will now return in more detail to the various elements of the device in FIGS. 2 to 5 and to their relative arrangement. We see in Figure 3 the sealed reservoir 18 intended to contain the solder previously developed. This reservoir 18 is closed in leaktight manner thanks to an upper cover 59 provided with an O-ring seal 60.

This cover 59 is held against the reservoir 18 by means of an appropriate flange 62 and a nut 64 provided for tightening this flange.

The displacement means 22 in the direction Z comprise a rack 65 with a rack which is parallel to the direction Z (vertical direction in the example shown).

This bracket 65 is provided with an arm 66 parallel to the direction X (this arm being horizontal in the example shown).

A motor, not shown, allows the arm 66 to move in the direction Z.

As can be seen in FIG. 3, this arm 66 supports the reservoir 18.

This reservoir 18 is mounted rotating around the axis Ul on the arm 66 by means of a ball bearing 68.

The arm 66 also carries the means 44 for rotating the reservoir 18 around the axis Ul.

These means 44 comprise a motor 70 capable of rotating a pinion 72 around an axis U2 parallel to the direction Z.

At the base of the reservoir 18 is fixed a toothed wheel 74 whose axis is the axis Ul.

This toothed wheel is itself driven in a rotational movement around the axis Ul thanks to the pinion 72 which controls it by means of a toothed belt 76. It can be seen that the pinion 72, the toothed wheel 74 and the belt 76 are located in a housing 78 of the arm 66.

In this housing 78, below the toothed wheel 74 and therefore of the reservoir 18, are located the heating means 48 comprising a heating coil 80 in which an electric current is passed by means not shown.

The arm 66 also comprises, below the housing 78, the jack 36 whose rod 38 is perpendicular to the direction Z and therefore to the axis Ul as seen in FIG. 3.

The stop 42 is fixed to the arm 66.

One end of the flexible tube 32 is threaded over a lower part of the reservoir 18 as seen in FIG. 3.

The upper part of the needle 24 is threaded into the other end of the flexible tube 32.

Means not shown make it possible to control the movements of the rod 38 of the jack and therefore those of the movable stop 40.

We are thus able to adjust the feed rate of the needle 24.

In fact, when the rod 38 and therefore the stop 40 are in the retracted position, the flexible tube is free (not pinched) and therefore the needle has a position parallel to the axis Z, the solder being thus able to flow through the peripheral holes 28 of the needle 24. On the contrary, by advancing the rod 38 and therefore the stop 40 by a chosen distance, it is possible to compress more or less the flexible tube 32 between the stops 40 and 42 and so adjust the solder flow liquid and we are even able to pinch the flexible tube 32 enough to stop the flow of liquid solder coming from the reservoir 18.

Control means not shown allow the rotation of the motor 70 and therefore that of the reservoir 18 and the needle 24 around the axis Ul.

The means 46 for pressurizing the reservoir 18 comprise an argon inlet 82 connected to an argon reservoir, not shown.

This arrival of argon 82 allows the introduction of argon under pressure into the reservoir 18.

FIG. 3 also shows a connector 84 which communicates in leaktight manner with the interior of the reservoir 18 and which is intended to be connected to pressure control means (not shown) which make it possible to control the pressure in the reservoir 18. L argon, under slight overpressure (for example of the order of 10 Pa) in the tank 18, makes it possible to avoid the oxidation of the constituents of the liquid solder, oxidation which would risk altering the initial composition of this solder. The heating resistors 80 make it possible to maintain the reservoir and therefore the solder that it contains at a constant temperature, for example of the order of 20 ° C. to 22 ° C.

The plate 50, which is parallel to the directions X and Y (this plate being horizontal in the example shown), is mounted on conventional means 16 allowing the movement of this plate in the directions X and Y. These conventional displacement means 16 comprise a numerically controlled stepping motor (not shown), the displacements of which are carried out on ball slides by ball screws. These means 16 for moving the plate 50 are mounted on the base 86 of the bracket 65.

Control means, not shown, comprising a computer, are provided for controlling the movements of the arm 66 of the bracket in the direction Z and the movements of the plate 50 in the directions X and Y.

The displacements of the plate 50 in these directions X and Y allow the latter to describe movements adapted to the shape of the lateral surfaces to be brazed, for example circular movements for the sample 2, the core 4 and the ring 6.

It is also possible to obtain rectangular movements for samples of rectangular shape (for example samples to be measured in X-band).

The motorized stem (controlled by the computer) allows the vertical displacement of the needle 24 according to a movement adapted to the thickness of the sample 2. The side wall or walls of each of the components 2, 4 and 6 are parallel to direction Z.

The upper face of each of the components 2, 4 and 6 held in their housings is flush with the surface of the plate 50. As can be seen in FIG. 2, the bottom of the needle does not touch the bottom of the housing in which this needle is introduced to file the solder against the desired side wall of the component which is in this housing.

In addition, when the needle 24 is positioned for the application of the solder, the peripheral holes 28 of the needle hardly exceed the upper surface of the plate 50.

Since the displacements of the plate 50 in the X and Y directions and that the movements of the arm 66 of the bracket 64 in the Z direction are programmable, it is possible to position both on the plate 50, the sample 2, the core 4 and the ring 6 for successively applying the solder to them.

It is specified that the coordinates relating to the housings 52, 54 and 56 are determined with precision for the programming of the computer.

The implementation of the device in FIGS. 2 to 5 is explained below.

After cleaning the sample holder (core 4 and ring 6) and the sample 2 with ethanol, they are placed in the housings provided for this purpose in the tray 50 where they are held by suction.

After ensuring that the solder flows through the needle 24 with the desired flow rate, the reservoir 18-needle 24 assembly is rotated, and the height of the arm 66 of the stem 64 is properly adjusted so that the needle comes to bear on the side or side wall on which we want to deposit the solder.

The movements of the plate 50 are then controlled in the X and Y directions so appropriate (programmed) as well as the opening of the flexible tube 32 for the application of the solder.

It is advisable to ensure a good regularity of the solder deposit on the lateral face considered.

At the end of the movement, when the solder has been applied, the flexible tube 32 is crushed by means of the jack 36 to stop the flow of solder. The movement of the arm 66 is controlled to raise the needle 24.

These operations are of course repeated for each side face to be brazed.

When the solder has been deposited on all the lateral faces, the sample 2 is manually assembled in its sample holder at a temperature of the order of 20 ° C. or higher than 20 ° C.

If necessary, remove the excess solder with ethanol before placing the sample and the sample holder in the connector.

The device which is the subject of the invention makes it possible to better control the brazing operation than the method disclosed in document (1) and to ensure perfect reproducibility of this brazing.

The implementation of the solder is facilitated by the present invention.

Indeed, with the invention, it is possible to eliminate the prior operation of depositing indium on the side faces to be brazed.

In addition, the conservation of the solder under an argon atmosphere makes it possible to guarantee the composition of this solder over time. The device which is the subject of the invention is adaptable to all the shapes of samples which one may need to use (for example a cylindrical shape or a rectangular shape). By way of example, the device which is the subject of the invention can be used to apply liquid solder to the sample 46 and to the corresponding sample holder 40 which are mentioned in document (1) and represented in FIGS. 3 and 4 of this document (1).

The present invention is not limited to the application of liquid solder to the lateral faces of objects such as those which are shown in FIG. 1. The invention also applies to the deposition of a liquid on one face lateral view of an object, for example to the deposit of liquids which can be used to make collages of pieces or samples.

Claims

1. Device for applying a liquid (12) to at least one object (2,4,6) having at least one side wall, this device being characterized in that it comprises:

- means (14) for holding the object,

means (16) for moving these holding means in first and second directions (X _/ Y) which are coplanar and perpendicular to each other,

- a liquid reservoir (18),

means (20) for applying the liquid to the side wall of the object, these means of application being made integral with the tank and communicating with it, and

- Means (22) for moving the reservoir, and therefore application means, in a third direction (Z) which is perpendicular to the first and second directions, the side wall of the object being parallel to this third direction.

2. Device for applying a liquid solder (12) to at least one object (2,4,6) having at least one side wall, this device being characterized in that it comprises:

- means (14) for holding the object,

- Means (16) for moving these holding means in first and second directions

(X, Y) which are coplanar and perpendicular to each other,

- a solder tank (18), - means (20) for applying the solder to the side wall of the object, these application means being made integral with the tank and communicating with it, and - means (22) for moving the tank, and therefore application means, in a third direction (Z) which is perpendicular to the first and second directions, the side wall of the object being parallel to this third direction.

3. Device according to claim 2, in which the application means (20) comprise:

a hollow needle (24), the bottom (26) of which is closed, which is parallel to the third direction and which comprises peripheral bores (28) extending parallel to this third direction, and

- Means (30) for adjusting the arrival of the solder to the needle.

4. Device according to claim 3, in which the adjustment means (30) comprise: - a flexible tube (32) which connects the reservoir to the needle, and

- Means (34) for pinching this flexible tube.

5. Device according to claim 4, in which the clamping means (34) comprise: - a jack (36) whose rod (38) is terminated by a first stop (40), and

- A second stop (42) which remains fixed relative to the jack, the flexible tube being between the first and second stops.

6. Device according to any one of claims 2 to 5, further comprising means (44) for rotating the reservoir (18) and therefore means application (20) of the solder.

7. Device according to any one of claims 2 to 6, further comprising means (46) for pressurizing the tank with a gas which does not react with the solder.

8. Device according to any one of claims 2 to 7, further comprising means (48) for heating the solder tank.

9. Device according to any one of claims 2 to 8, in which the means (14) for holding the object comprise a plate (50) comprising a housing (52,54,56) for each object, this housing being designed to allow the introduction of the means of application of the solder in this housing.

10. Device according to any one of claims 2 to 9, further comprising means (58) for holding by suction of each object in the corresponding housing.