EP2479767B1 - Contactor and switch - Google Patents

Description

The invention relates to a contactor actuated by a magnetic field and a switch comprising this contactor.

Contactors operable by a magnetic field are also known as "reed".

• la première lame comportant au moins un plot P_1i présentant une face de contact F_1i,
• la seconde lame comportant au moins un plot P_2i en vis-à-vis du plot P_1i et présentant une face de contact F_2i, les plots P_1i et P_2i étant en vis-à-vis lorsque l'intersection de la projection selon une direction transversale, perpendiculaire à la direction longitudinale, de la face F_1i sur la face F_2i et la face F_2i forme une zone Z_i de recouvrement dont la surface S_zi et strictement supérieure à zéro,
• au moins un plot de chaque paire de plots P_1i, P_2i en vis-à-vis étant déplaçable le long de la direction transversale, sous l'effet du champ magnétique, entre :
  • une position fermée dans laquelle les faces F_1i et F_2i sont directement en contact mécanique l'une avec l'autre pour permettre le passage d'un courant, et
  • une position ouverte dans laquelle les faces F_1i et F_2i sont séparées l'une de l'autre par un entrefer pour les isoler électriquement l'une de l'autre.

Known contactors comprise at least first and second blades of magnetic material extending along a longitudinal direction:

• the first blade comprising at least one pad P _1i having a contact face F _1i ,
• the second blade comprising at least one pad P _2i opposite the pad P _1i and having a contact face F _2i , the pads P _1i and P _2i facing each other when the intersection of the projection in a transverse direction, perpendicular to the longitudinal direction, of the face F _1i on the face F _2i and the face F _2i forms a zone Z _i of overlap whose surface S _zi and strictly greater than zero,
• at least one stud of each pair of pads P _1i , P _2i facing each other being movable along the transverse direction, under the effect of the magnetic field, between:
  • a closed position in which the faces F _1i and F _2i are in direct mechanical contact with one another to allow the passage of a current, and
  • an open position in which the faces F _1i and F _2i are separated from each other by an air gap to isolate them electrically from each other.

When at least one of the pads is in the closed position, it is said that the switch is in the closed position. The switch is in the open position when all the pins are in the open position. The document WO 02/39472 A1 describes a contactor actuable by a magnetic field according to the preamble of claim 1.

The invention aims to reduce the resistance of this contactor in the closed position. It therefore relates to a contactor according to claim 1.

The above contactor has a smaller closed position resistance than that of an identical reference contactor but provided with a single pair of pads. Indeed, since the cross section of the bridges Pt _ji is small in front of the surface S _Zi of the overlap zone (that is to say that the surface S _Ptji is less than 2/3 of the surface S _Zi ) , the majority of the magnetic flux concentrated by the pad P _1i through the overlap region instead of the Pt bridge _1i. The pads of each pair of pads P _1i , P _2i are therefore attracted to each other under the effect of the magnetic field by a force close to that observed for the reference contactor. The resistance R _i between the pads of each pair of pads P _1i , P _2i in the closed position is therefore as close to that observed for the reference contactor. However, the contactor above has n pairs of pads P _1i , P _2i and therefore n resistors R _i in parallel when the contactor is in the closed position. The resistance in the closed position of the above contactor is therefore much smaller than that of the reference contactor because of this paralleling of several resistors R _i .

In fact, the resistance in the closed position of the above contactor is close to that which would be obtained by connecting in parallel n reference contactors. However, compared to this paralleling n reference contactors, the above contactor has a much smaller footprint. Indeed, the bridges Pt _ji mechanically and electrically connect the different pads together. It is therefore not necessary to provide specific electrical tracks to connect the pairs of pads in parallel as would be the case if n reference switches were connected in parallel. In addition, the size of the contactor above is reduced. More precisely, the more the number n of pairs of studs increases, the more the first and second blades overlap. Thus, it has been estimated that the size of the contactor above is less than nS / 2, where S is the size of the reference contactor while the size of n reference contactors in parallel is substantially equal to nS. The size of the contactor is represented by the surface it occupies in a plane parallel to the longitudinal and transverse directions.

Embodiments of this contactor may include one or more of the features of the dependent claims.

• avoir une zone de recouvrement beaucoup plus petite que la surface S_1i ou S_2i du plot concentre le flux magnétique dans cette zone de recouvrement, ce qui augmente la force de contact en position fermée et diminue par conséquent la résistance du contacteur en position fermée ;
• choisir une longueur x pour la zone de recouvrement proche de la moitié de l'épaisseur e_pji permet de maximiser la force de contact tout en minimisant l'encombrement du contacteur ;
• avoir un plot P_1i en vis-à-vis du plots P_2i et du plot P_2,i+1 permet d'augmenter le nombre de contacts en position fermée et donc de diminuer encore plus la résistance du contacteur en position fermée ;
• dimensionner les différents plots et leur positionnement pour obtenir des forces de contact entre chaque paire de plots sensiblement égales permet de diminuer la résistance du contacteur en position fermée tout en limitant l'augmentation de son encombrement ;
• loger les lames entièrement à l'intérieur d'un caisson facilite la réalisation d'un capot isolant ce caisson de l'environnement extérieur.

These embodiments of the contactor further have the following advantages:

• having a recovery area much smaller than the surface S _1i or S _2i of the stud concentrates the magnetic flux in this overlap zone, which increases the contact force in the closed position and consequently reduces the resistance of the contactor in the closed position;
• choosing a length x for the overlap zone close to half the thickness e _pji makes _it possible to maximize the contact force while minimizing the size of the contactor;
• having a pad P _1i facing the pads P _2i and pad P _{2, i + 1} makes it possible to increase the number of contacts in the closed position and therefore to further reduce the resistance of the contactor in the closed position;
• sizing the different pads and their positioning to obtain contact forces between each pair of substantially equal pads reduces the resistance of the contactor in the closed position while limiting the increase in its size;
• housing the blades entirely inside a box facilitates the realization of an insulating cover this box of the external environment.

The invention also relates to a switch according to claim 8.

Size the pads P _ji whether fair saturated by the field _B0 allows to minimize congestion switch and thus the switch.

• la figure 1 est une illustration schématique d'un interrupteur équipé d'un contacteur actionnable par un champ magnétique,
• la figure 2 est une illustration schématique en coupe partielle du contacteur de la figure 1,
• la figure 3 est une illustration schématique de la conformation des extrémités de lames du contacteur de la figure 1,
• la figure 4 est un organigramme d'un procédé de dimensionnement des extrémités du contacteur de la figure 1,
• la figure 5 est un organigramme d'un procédé de fabrication du contacteur de la figure 1,
• les figures 6 à 10 sont des illustrations schématiques et en coupe verticale du contacteur de la figure 1 dans différents états de fabrication,
• les figures 11 et 12 sont des illustrations schématiques en vue de dessus de deux autres modes de réalisation possibles pour les extrémités du contacteur de la figure 1,
• la figure 13 est un organigramme d'un procédé de dimensionnement des extrémités du mode de réalisation de la figure 12, et
• la figure 14 est une illustration schématique et en vue de dessus d'un autre mode de réalisation possible des extrémités du contacteur de la figure 1.

The invention will be better understood on reading the description which follows, given solely by way of nonlimiting example and with reference to the drawings in which:

• the figure 1 is a schematic illustration of a switch equipped with a contactor actuable by a magnetic field,
• the figure 2 is a schematic illustration in partial section of the contactor of the figure 1 ,
• the figure 3 is a schematic illustration of the conformation of the blade tips of the contactor of the figure 1 ,
• the figure 4 is a flowchart of a method of sizing the ends of the contactor of the figure 1 ,
• the figure 5 is a flowchart of a manufacturing process of the contactor of the figure 1 ,
• the Figures 6 to 10 are schematic illustrations and in vertical section of the contactor of the figure 1 in different states of manufacture,
• the Figures 11 and 12 are schematic illustrations in top view of two other possible embodiments for the ends of the contactor of the figure 1 ,
• the figure 13 is a flowchart of a method of sizing the ends of the embodiment of the figure 12 , and
• the figure 14 is a schematic illustration and in top view of another possible embodiment of the ends of the contactor of the figure 1 .

In these figures, the same references are used to designate the same elements.

In the remainder of this description, the features and functions well known to those skilled in the art are not described in detail.

• d'un micro-contacteur 2 actionnable par un champ magnétique, et
• d'une source 3 commandable de champ magnétique.

The figure 1 represents a switch 1 equipped:

• a micro-switch 2 operable by a magnetic field, and
• a controllable source 3 of magnetic field.

The source 3 generates when it is controlled a magnetic field or a magnetic induction B ₀ parallel to a longitudinal direction X. In the absence of control, the source 3 generates no magnetic field.

The micro-contactor 2 is a contactor. However, it differs from macroscopic contactors inter alia by its manufacturing process. The micro-contactors are made using the same collective manufacturing processes as those used to make the microelectronic chips. For example, the micro-contactors are made from monocrystalline silicon or machined glass chips by photolithography and etching and / or structured by epitaxial growth and deposition of metallic material.

The micro-contactor 2 is made in a plane substrate 4 which extends horizontally, that is to say here in parallel with the orthogonal directions X and Y. In the rest of this description, the vertical direction, orthogonal to the X and Y directions , is noted Z.

The substrate 4 is a rigid substrate. For example, for this purpose, its thickness, in the direction Z is greater than 200 and preferably greater than 500 microns. It is advantageously electrically insulating.

For example, here, this substrate 4 is a silicon substrate that is to say having at least 10% and typically more than 50% by weight of silicon. This substrate is inorganic and non-photosensitive. The substrate 4 has a flat horizontal top face 6.

The micro-contactor 2 comprises electrodes 8 and 10 through which circulates the current flowing through this micro-contactor. These electrodes 8 and 10 are fixed without any degree of freedom to the substrate 4. Here, these electrodes 8 and 10 are parallelepipeds whose upper faces are located in the same plane as the upper face 6. The vertical faces of these electrodes s' extend in the interior of the substrate 4. The vertical faces are connected to each other inside the substrate by a lower face, for example, parallel to the upper face.

• une position ouverte (représentée sur la figure 1) dans laquelle les lames sont isolées électriquement l'une de l'autre par un entrefer 15 rempli d'un gaz diélectrique, et
• une position fermée dans laquelle les lames sont directement mécaniquement en contact l'une avec l'autre pour permettre le passage du courant entre les électrodes 8 et 10.

Blades 12, 14 extend parallel to the direction X from the electrodes, respectively, 8 and 10. The blades 12, 14 are movable relative to each other under the effect of a parallel magnetic field. to this direction X between:

• an open position (represented on the figure 1 ) in which the blades are electrically insulated from one another by an air gap filled with a dielectric gas, and
• a closed position in which the blades are directly mechanically in contact with each other to allow the passage of current between the electrodes 8 and 10.

• une face supérieure située dans le même plan que la face supérieure 6 du substrat 4,
• des faces verticales qui s'enfoncent vers l'intérieur du substrat 4, et
• une face inférieure située en dessous de la face 6 du substrat 4 et, par exemple, parallèle à la face supérieure de cette lame.

Here, each blade has mainly the shape of a parallelepiped that extends parallel to the X direction. Thus, like the electrodes, each blade has:

• an upper face situated in the same plane as the upper face 6 of the substrate 4,
• vertical faces which sink towards the interior of the substrate 4, and
• a lower face located below the face 6 of the substrate 4 and, for example, parallel to the upper face of this blade.

Each blade 12, 14 has a proximal end, respectively 16, 18, mechanically and electrically connected, respectively, to the electrodes 8 and 10. Here, the proximal ends 16 and 18 are connected without any degree of freedom to their respective electrodes. Thus, these proximal ends 16, 18 are stationary.

In this embodiment, the blades form a single block of material with the electrode to which they are mechanically connected.

Each blade 12, 14 also has a distal end, respectively 20, 22. These distal ends 20 and 22 are vis-à-vis and separated from each other by the air gap 15 in the open position. The thickness of the gap in the Y direction is noted d. Conversely, these distal ends are directly in contact with one another in the closed position.

Here, in this embodiment, the two distal ends 20, 22 are flexible to move between the open and closed positions.

The distal ends 20, 22 move only parallel to the horizontal plane X, Y. For this purpose, they are received inside a box 24 filled with a dielectric gas such as air or other. More specifically, each distal end 20, 22 flexes to reach the closed position from the open position. The deformations experienced by each distal end 20, 22 between the closed and open positions are all elastic to allow it to automatically return to the open position in the absence of external stress.

To be flexible, each distal end 20, 22 is much longer in the X direction than thick in the Y direction. For example, each distal end 20, 22 is five, ten, or fifty times longer than it is thick. Here, the thickness of the distal end 20 is less than 100 microns and preferably less than 50 or 30 microns.

The height e _c of each distal end 20, 22 in the direction Z is typically in this example of the order of 20 to 50 microns.

Here the distal ends 20, 22 are shaped to limit the resistance of the microswitch in the closed position. An example of such a conformation is described with reference to the figure 3 .

Most of the blades 12, 14 and electrodes 8, 10 is made of soft magnetic material. A soft magnetic material is a material having a relative permeability of which the real part at low frequency is greater than or equal to 1000. Such a material typically has a coercive excitation to demagnetize less than 100 Am ^-1 . For example, the soft magnetic material used here is an alloy of iron and nickel.

To increase the electrical conductivity of the blades, the vertical and lower faces of these blades are covered with a conductive coating 28. It is the same for the vertical and lower faces of the electrodes 8, 10. For example, this coating is made of rhodium (Ro) or ruthenium (Ru) or platinum (Pt). The micro-contactor 2 may also comprise a cover 30 ( figure 2 ) which covers the box 24. To simplify the figure 1 , this cover has not been shown on it.

The figure 2 represents the micro-contactor 2 in vertical section along a sectional plane II shown in FIG. figure 1 . In this figure, a cover 30 which covers the housing 24 is shown. This cover 30 makes it possible to prevent impurities from penetrating inside the box 24 and impede the movement of the blades 12, 14. It also makes it possible to prevent the oxidation of the contact.

When an external magnetic field is applied parallel to the direction X, it is concentrated and guided by the blades 12 and 14. The field lines of this magnetic field are symbolized by an arrow F on the figure 1 . This creates forces in the gap 15 which tend to reduce this gap. These forces bend each distal end 20, 22 until they come into contact with each other. Thus, an external magnetic field makes it possible to move the blades 12, 14 between the open position and the closed position. When the external magnetic field disappears, the distal ends 20, 22 return to the open position in the manner of a leaf spring that is to say by elastic deformation.

The figure 3 shows in more detail the conformation of the ends 20 and 22 used to reduce the resistance of the microswitch 2 in the closed position. Here, each end 20, 22 comprises several pads P _ji arranged next to each other in the direction X, where the index j identifies the blade and the index i identifies the pad of this blade. More precisely, in the remainder of this description, the index j takes the value "1" to designate the blade 12 and the value "2" to designate the blade 14.

Two pads P _ji and P _{j, i + 1} immediately consecutive in the X direction are mechanically connected to each other via a bridge Pt _ji .

Each pad P _ji has a flat face F _ji turned towards the gap 15. Here, each pad P _1i is vis-à-vis a pad P _2i of the other blade. Two pads P _1i and P _{2i face} each other if the intersection of the face F _2i and the projection, in the direction Y, of the face F _1i on the face F _2i forms a zone Z _i of overlap whose surface S _Zi is strictly greater than zero. In the following description, two pads P _1i and P _2i vis-à-vis have the same index i.

The surface S _Ptji of the cross section of the bridge Pt _ji is strictly smaller than the surface of the cross section of the pads P _ji and P _{j, i + 1} that it connects. Here, by surface of the cross section, denotes the area of the section of the stud or of the bridge parallel to the plane defined by the directions YZ.

Here, the conformation of the ends 20 and 22 is represented in the particular case where the number n of pairs of pads P _1i , P _2i vis-à-vis is equal to two.

In addition, here, the ends 20 and 22 are identical except that they are facing each other. Indeed, the faces F _1i are turned towards the faces F _2i . Thus, subsequently, only the end 20 is described in detail.

The pad P ₁₁ is directly connected to the end 16 by a parallelepipedal arm B ₁ of length l in the direction X, of thickness e in the direction Y and of height e _c in the direction Z. The pad P ₁₁ is connected to the pad P ₁₂ by the bridge Pt ₁₁ . In this particular embodiment, the dimensions of the pads P ₁₁ and P ₁₂ are the same. Thus, only the dimensions of the pad P ₁₁ are described in more detail.

The pad P ₁₁ is a parallelepiped of length βx, thickness e _p and height e _c . The face F ₁₁ and the zone Z ₁ covering are therefore rectangles. The length of the overlap area Z ₁ in the X direction is denoted by "x". Here, the length of the pad P ₁₁ is taken proportional to the length x of the overlap zone Z ₁ . It is therefore noted in the form of a product between a constant β and the length x.

The bridge Pt ₁₁ is a parallelepiped of length e _s , thickness e _pt and height e _c . The bridge Pt ₁₁ is dimensioned so that its transverse surface S _Pt11 is at least less than two-thirds of the area S _Z1 of the recovery zone Z ₁ . When the surface S _Pt11 is less than two-thirds of the surface S _Z1 or S _Z2 , the magnetic flux concentrated by the pads P ₁₁ or P ₁₂ crosses mainly the gap 15 rather than the bridge Pt ₁₁ . This therefore makes it possible to increase the amount of magnetic flux which passes through the gap 15 via the overlapping zones. However, the contact force f _contact between the pairs of studs vis-à-vis is proportional to the magnetic flux divided by the surface through which this flow. Thus, minimizing the vertical section of the bridges Pt _1i makes _it possible to increase the contact force between the studs in the closed position and thus to reduce the resistance of the contactor in closed position.

Here, the thickness e _pt of this Pt bridge ₁₁ is at least less than one third of the thickness e _p of P ₁₁ and P ₁₂ pads. Thus, this bridge Pt ₁₁ also corresponds to the bottom of a groove of depth t _p which separates the faces F ₁₁ and F ₁₂ . The width of this groove is here equal to the length e _s of the bridge Pt ₁₁ .

It will be noted that the thickness e _p of the pad P ₁₁ is equal to the sum of the depth t _p and the thickness e _pt of the bridge Pt ₁₁ .

The total length of the end 20 is noted _p . Here, the length l _p is equal to 2βx + e _s .

$${\mathrm{S}}_{\mathrm{Zi}}\le {\mathrm{S}}_{2\mathrm{i}}/\mathrm{3},$$

où S_1i et S_2i sont les surfaces, respectivement, des faces F_1i et F_2i.The ends 20 and 22 are offset relative to each other, in the X direction, by a distance g to reduce the overlapping surfaces S _Zi . In this embodiment, the distance g is chosen so that the following two relationships are verified: $${\mathrm{S}}_{\mathrm{Zi}}\le {\mathrm{S}}_{\mathrm{1}\mathrm{i}}/\mathrm{3}$$

$${\mathrm{S}}_{\mathrm{Zi}}\le {\mathrm{S}}_{2\mathrm{i}}/\mathrm{3},$$

where S _1i and S _2i are the surfaces, respectively, of the faces F _1i and F _2i .

To simplify the figures, the representations of the ends 20, 22 are not to scale and these two relations are not represented.

Preferably, the surface S _Zi is less than one quarter to one eighth of the surfaces S _1i and S _2i .

Reduce the surface covering _Zi S makes it possible to concentrate the magnetic flux on a smaller area than the area of F _ji faces. This therefore makes it possible to increase the contact _{contact force} between these pads and thus to reduce the resistance of the contactor in the closed position.

The sizing of the ends 20 and 22 will now be described with reference to the method of the figure 4 .

• l'intensité du champ magnétique B₀ produit par la source 3 pour déplacer le micro-contacteur 2 vers sa position fermée est de 50mT,
• la tension qui doit être commutée par le micro-contacteur 2 est au maximum de 50 volts,
• la force de contact f_contact qui s'exerce entre chaque paire de plots en position fermée est de 150µN,
• la force de rappel f_rappel qui ramène les plots vers leur position ouverte est de 20µN par contact,
• la force de rappel f_amin exercée par le pont Pt₁₁ pour ramener le plot P₁₂ vers sa position ouverte est de 20µN,
• la perméabilité relative du matériau magnétique utilisé pour réaliser les lames 20 et 22 est de 1000,
• le module de Young E du matériau magnétique est égal à 1,85.10¹¹Pa, et
• la polarisation J_s du matériau magnétique à saturation est égale à 1 T.

Here, the sizing of the ends 20 and 22 is illustrated by numerical examples given for the following situation:

• the intensity of the magnetic field B ₀ produced by the source 3 to move the microswitch 2 to its closed position is 50mT,
• the voltage to be switched by the micro-contactor 2 is at most 50 volts,
• the contact _{contact force} which is exerted between each pair of studs in the closed position is 150 μN,
• the return force f _recall that brings the pads to their open position is 20μN per contact,
• the return force f _amin exerted by the bridge Pt ₁₁ to return the pad P ₁₂ to its open position is 20μN,
• the relative permeability of the magnetic material used to make the blades 20 and 22 is 1000,
• the Young's modulus E of the magnetic material is equal to 1,85.10 ¹¹ Pa, and
• polarization J _s the saturation magnetic material is equal to 1 T.

The contact force f _contact is the force exerted by the pad P _1i on the pad P _2i in the closed position. The higher the contact force, the lower the resistance of the contact.

The restoring force f _recall is the _restoring force which is exerted on each stud and constantly urges them towards the open position.

The polarization J _s is the polarization of the magnetic material observed when it is saturated. As a first approximation, the polarization is the ratio between the intensity of the magnetic field B ₀ and the demagnetizing factor Nd.

During a step 27, the distance d of the air gap in the open position is chosen. This distance d must be large enough to electrically isolate the pads P _1i pads P _2i in the open position. It therefore depends in particular on the voltage present between the terminals 8 and 10 of the microswitch 2 in the open position. Here, this distance d is chosen to be greater than 5 μm so as to electrically isolate the pads P _1i from the pads P _2i even in the presence of a voltage of 220 volts between the terminals 8 and 10. This value of 5 μm is given in _FIG. particular case where the gap 15 is filled with air. Indeed, the disruptive field of the air is of the order of 50V / μm for dimensions as small as those of the ends 20 and 22.

Furthermore, the distance d is chosen to be small enough to remain in the zone of elastic deformation of the blades 12 and 14. The maximum limit for the distance d therefore depends on the characteristics of the magnetic material chosen, such as its Young's E modulus. remain in this zone of elastic deformation, d is chosen less than 15 .mu.m.

In this example, the distance d is set equal to 5 μm to minimize the size of the micro-contactor 2.

In a step 29, the height e _c is fixed. The higher this height e _c , the more the resistance of the micro-contactor 2 in the closed position decreases. However, manufacturing technological constraints impose an upper limit on the height e _c . Thus, here, the height e _c is chosen at most equal to 30 μm and at least greater than 10 μm. For digital applications, the height e _c is chosen to be equal to 20 μm.

During a step 31, the thickness e _p of the pads is calculated to obtain a magnetic force f _f which attracts the pad P _1i to the pad P _2i in the presence of the magnetic field B ₀ equal to 170 μN. This force f _f is opposed to the restoring force f _point and the force f _amin which are taken here equal to 20 μN. More specifically, the forces f _contact, f _f f and _return are connected to each other by the following equation: f = f _{Contact f} - f _reminder.

Thus, to obtain a contact _{contact force} of 150 μN, the force f _f is taken here equal to 170 μN.

To compute the thickness e _p , various numerical simulations using software were carried out to establish experimentally a relation connecting the force f _f to the thickness e _p . The relationship established is as follows: $$f_f=\left(3,4e_p+25\right)\frac{e_{\mathrm{vs}}}{20}$$

In this relation (1), the thickness e _p , the height e _c are expressed in μm and the force f _f is expressed in μN.

• les plots P_ji sont saturés par le champ magnétique B₀,
• la présence des ponts Pt_ij, et des bras B_j a été négligée, et
• l'épaisseur e_p est supposée comprise entre 10 et 100 µm.

This relation (1) has been established with the hypotheses:

• the pads P _ji are saturated by the magnetic field B ₀ ,
• the presence of the bridges Pt _ij , and the arms B _j has been neglected, and
• the thickness e _p is assumed to be between 10 and 100 μm.

Moreover, the relation (1) is established under the assumption that the length x of the zone Z _i of overlap is equal to half the thickness e _p . In other words, the following relation is verified: $$\boxed{\mathrm{x}={\mathrm{e}}_{\mathrm{p}}/\mathrm{2}}$$

Using this relation (1), here we obtain the value of 40 microns for the thickness e _p.

In a step 32, the length x is calculated using the relation (2). The length x is here equal to 20 microns.

During a step 33, the length βx of the pads P _ji is calculated. This length βx is determined so that each pad P _ji is completely magnetically saturated when the field B ₀ is present. Here, the length βx is calculated so that each pad P _ji is just saturated. By just saturated, denotes the fact that each pad is saturated by the field B ₀ and is not saturated by a field B ₁ identical to the field B ₀ except that intensity is equal to 80% and, preferably 90%, the intensity of the field B ₀ . For this purpose, different relations obtained by modeling the pad P _ji using the laws of electromagnetism are used.

More precisely, the following relation connecting the polarization J _s of the material to the saturation at the field B ₀ is used: $$\boxed{J_s=\frac{B_0}{\frac{1}{{\mu }_r-1}+\mathit{nd}}\approx \frac{B_0}{\mathit{nd}}}$$

In this relation (3), Nd is the demagnetizing factor of the pad P _ji . This factor Nd is based on the dimensions of the pad P _ji. The following relation which links the Nd factor to the dimensions of the stud is used: $$\boxed{\mathit{nd}=\frac{e_{\mathrm{vs}}{\mathrm{<figure-callout\; id="2"\; label="e\; p\; \beta x"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">e\; </figure-callout>}}_p}{{\left(\mathit{\beta x}\right)}^{}}\left(\mathrm{<figure-callout\; id="4"\; label="ln"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">ln</figure-callout>}\left(\frac{4\left(\mathit{\beta x}\right)}{e_{\mathrm{vs}}+e_p}\right)-1\right)}$$

This relation was obtained by considering that the relation which links the demagnetization factor Nd to the dimensions, established in the case of an ellipsoid, also applies to the case of a parallelepiped.

Thus, to obtain the value of the constant β, the following equation must be solved: $$\boxed{\frac{B_0}{J_s}=\frac{e_{\mathrm{vs}}{\mathrm{<figure-callout\; id="2"\; label="e\; p\; \beta x"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">e\; </figure-callout>}}_p}{{\left(\mathit{\beta x}\right)}^{}}\left(\mathrm{<figure-callout\; id="4"\; label="ln"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">ln</figure-callout>}\left(\frac{4\left(\mathit{\beta x}\right)}{e_{\mathrm{vs}}+{\mathrm{vs}}_p}\right)-1\right)}$$

The resolution of this equation gives the value "7" for the constant β. Thus the length of the pad P _ji is here 140μm.

Then, during a step 34, the length l, the thickness e, the width es and the depth t _p are determined to obtain a restoring force u _reminder equal to 20μN and a f _amin force equal to 20 μN. Here, for this, e is fixed to minimize the size of the micro-contactor 2. For example, e is chosen equal to 5 microns.

$$\boxed{{\mathrm{I}}_{\mathrm{p}}=\mathrm{2}\mathrm{\beta x}+{\mathrm{e}}_{\mathrm{s}}}$$

The distance g, in this particular case, is also fixed so that the pad P _1i is only opposite the single pad P _2i . For example, g is chosen equal to 50 microns. Once the distance g is fixed, the width e _s and the total length l _p of the end 20 are given by the following relations: $$\boxed{{\mathrm{e}}_{\mathrm{s}}=\mathrm{boy\; Wut}+\mathrm{\beta x}-\mathrm{x},}$$

$$\boxed{{\mathrm{I}}_{\mathrm{p}}=\mathrm{2}\mathrm{\beta x}+{\mathrm{e}}_{\mathrm{s}}}$$

The strength f _amin is given by the following relation: $$\boxed{f_{\mathit{amin}}=\frac{2{\mathit{\Gamma }}_{\mathit{amin}}}{e_s+\mathit{\beta x}}}$$

Γ _amin is the mechanical restoring torque exerted by the bridge Pt ₁₁ on the pad P ₁₂ .

The Γ _amin couple is given by the following relation: $$\boxed{{\mathit{\Gamma }}_{\mathit{amin}}=S_{\mathit{amin}}\frac{d}{2}\left(e_s+\mathit{\beta x}\right)}$$

The size S _amin is itself given by the following relation: $$\boxed{S_{\mathit{amin}}=\frac{E}{\frac{e_s^3}{3I_3}+\frac{{\left(\mathit{<figure-callout\; id="3"\; label="\beta x"\; filenames="imgf0001.png"\; state="\{\{state\}\}">\beta x</figure-callout>}\right)}^3}{3I_4}+\frac{1}{I_3}\left({\left(\mathit{\beta x}\right)}^2{e}_s+\left(\mathit{\beta x}\right){\left(e_s\right)}^2\right)}}$$

$$\boxed{I_4=\frac{e_c\cdot {e_p}^3}{12}}$$

The coefficients I ₃ and I ₄ are given by the following relations: $$\boxed{I_3=\frac{e_{\mathrm{vs}}\cdot {\left(e_p-{\mathrm{<figure-callout\; id="3"\; label="t\; p"\; filenames="imgf0001.png"\; state="\{\{state\}\}">t\; </figure-callout>}}_p\right)}^3}{12}}$$

$$\boxed{I_4=\frac{e_{\mathrm{vs}}<figure-callout\; id="3"\; label="\cdot \; e\; p"\; filenames="imgf0001.png"\; state="\{\{state\}\}">\cdot \; </figure-callout>{e_p}^{}{{}_{}}^3}{12}}$$

Thus, the stress fixed on the f _amin force makes it possible to calculate the depth t _p from the previous relations.

Imposing the f _amin force ≥ 20 μN makes it possible to guarantee that if the pad P ₁₁ returns to its open position under the action of the restoring _{return force} , the pad P ₁₂ will do the same, since the bridge Pt ₁₁ is sufficiently rigid for that.

Once the depth t _{p has been} calculated, the length l is calculated to verify the stress according to which the _return force f is equal to 20 μN. The _recall force is given by the following relation: $$\boxed{f_{\mathit{recall}}=\frac{{\mathrm{<figure-callout\; id="21"\; label="\Gamma \; r"\; filenames="imgf0003.png"\; state="\{\{state\}\}">\Gamma \; </figure-callout>}}_r}{21+l_p+\left(\beta -1\right)x}}$$

Γ _r is the torque of the restoring force. This torque is equal to twice the return torque Γ _meca exerted by each of the blades 12 and 14. Thus, the return torque Γ _r is defined by the following relation: $$\boxed{\mathrm{2}{\mathrm{\Gamma }}_{\mathrm{Mecca}}={\mathrm{\Gamma }}_{\mathrm{r}}}$$

où f₀ est la flèche maximale de la lame 12.The Γ _meca couple of a single blade is defined by the following relation: $$\boxed{{\mathrm{\Gamma }}_{\mathrm{Mecca}}=\mathrm{S}\mathrm{.}{\mathrm{f}}_{\mathrm{0}}\mathrm{.}\left(\mathrm{I}+{\mathrm{I}}_{\mathrm{p}}\right)}$$

where f ₀ is the maximum deflection of the blade 12.

Here, this arrow f ₀ is approximated using the following relation: $$\boxed{f_0\approx \frac{-d}{\frac{-l+\left(1-\beta \right)x}{l+l_p}-1}}$$

où les coefficients I1 et I2 sont donnés par les relations suivantes : $$\boxed{I_1=\frac{e_c\cdot e^3}{12}}$$

$$\boxed{I_2=\frac{e_c{e_p}^3}{12}}$$

The factor S of the relation (15) is given by the following relation: $$\boxed{S=\frac{\mathrm{<figure-callout\; id="3"\; label="E\; l"\; filenames="imgf0001.png"\; state="\{\{state\}\}">E\; </figure-callout>}}{\frac{l^{}}{}}}$$

where the coefficients I1 and I2 are given by the following relations: $$\boxed{I_1=\frac{e_{\mathrm{vs}}<figure-callout\; id="3"\; label="\cdot \; e"\; filenames="imgf0001.png"\; state="\{\{state\}\}">\cdot \; </figure-callout>e^{}{}^3}{12}}$$

$$\boxed{I_2=\frac{e_{\mathrm{vs}}{{\mathrm{<figure-callout\; id="3"\; label="e\; p"\; filenames="imgf0001.png"\; state="\{\{state\}\}">e\; </figure-callout>}}_p}^3}{12}}$$

The coefficients I ₃ and I ₄ have already been previously defined. From the previous relationships, the length l is calculated.

With the numerical data taken into account here, the results obtained are as follows: I = 40 μm, e = 5 μm, t _p = 30 μm and g = 50 μm.

During a step 35, it is verified that the torque Γ ₀ exerted by the magnetic forces in the open position when the field B ₀ is present is strictly greater than the restoring torque Γ _r of the mechanical forces. If so, this ensures that the microswitch 2 moves to its closed position when the magnetic field B ₀ is present. Various numerical simulations carried out by the applicant have made it possible to establish a relationship approximating the force F ₀ exerted by the magnetic forces on the blade 12 in the open position. This relationship is as follows: $$\boxed{F_0=\left(36790+2310.e_p-\mathrm{10,465.}d+0.54d^2-\mathrm{0.116.}{e}_p\mathrm{.}d\right)\mathrm{.}\frac{e_{\mathrm{vs}}}{20}}$$

From the force F ₀ , it is also possible to deduce the torque of the magnetic forces exerted on the end 20. This pair is here given by the following relation: $$\boxed{{\mathrm{\Gamma }}_0=\left(36,790+2,310e_p-10,465d+0,54d^2-0,116e_{p}d\right)\frac{e_{\mathrm{vs}}}{20}\left(21+l_p+\left(\beta -1\right)x\right){10}^{-12}}$$

The two previous relations (20) and (21), were established using the same assumptions as for the relation (1). Moreover, in these two relations, the thickness e _p , the distance d, the height e _c are expressed in μm, the torque Γ ₀ in Nm, the force F ₀ is expressed in μN and the thickness e _p is included between 10 and 100μm.

If the torque Γ ₀ is not greater than the torque F _r , then, proceed to a step 36 in which the thickness e _{p is increased} or the thickness e is decreased. At the end of step 36, we return to step 34 to again calculate the length l and the depth t _p .

In the case where the torque Γ ₀ is greater than the torque Γ _r , then, it is verified in a step 37 if the f _amin force is much greater than or equal to 20 μN. If not, a step 38 is carried out, during which the distance g is modified. For example, the distance g is decreased. At the end of step 38, the process returns to step 34.

In the opposite case, a step 39 is performed in which the micro-contactor 2 having the determined dimensions is manufactured.

The micro-contactor having the dimensions given above occupies about a silicon surface of 650 .mu.m (= 21 + 1 _p + .beta.x-x) by 85 .mu.m (= 2e _p + d) outside the contact pad in the XY plane.

An exemplary method of manufacturing the micro-contactor 2 will now be described in more detail using the method of the invention. figure 5 .

The described manufacturing method is a collective manufacturing process using microelectronics manufacturing process technologies. It begins with the supply of a silicon wafer better known as the "Wafer" on which will be simultaneously manufactured several micro-contactors 2 using the same operations. To simplify the description which follows, the various manufacturing steps are described only in the case of a single micro-contactor. Different states of manufacture obtained during the process of the figure 3 are shown in vertical section on the Figures 6 to 10 .

In a step 40, a layer 41 ( figure 6 ) of photosensitive resin is deposited on the upper face 6 of the substrate 4. Then the areas where the cavities must be hollowed in the substrate 4 are defined by insolation of the resin. These areas correspond to the location of the electrodes and blades. This is a classic step of photolithography.

During a step 42, anisotropic etching of the zones defined for engraving cavities 44, 46 in the substrate (FIG. figure 6 ) forming a hollow pattern of the blades 12 and 14 and the electrodes 8 and 10. By anisotropic etching is meant here an etching whose burning speed in the Z direction is at least ten times and Preferably fifty or one hundred times faster than the engraving speed in the horizontal directions X and Y. In other words, the horizontal etching rate is negligible compared to the etching speed in the vertical direction. This makes it possible to obtain more vertical flanks than if the etching was carried out using other etching processes. In particular, the sides of the cavities 44, 46 thus dug are more vertical than if they had been dug in a photoresist or using another etching process. For example, plasma etching or deep silicon chemical etching is used here.

In a step 48, the photoresist layer 41 is removed and the conductive coating 28 is deposited on the whole of the upper face. Thus, this conductive coating covers not only the vertical flanks of the cavities but also the bottom of the cavities and the upper face 6 of the substrate.

In a step 50, the cavities are filled with a soft magnetic material 52 ( figure 5 ). Here, the filling is carried out by electrolytic deposition using the coating 28 as the conductive electrode. Thus, this coating 28 also fulfills the function of a seed layer. Since the coating 28 extends over the entire upper face of the substrate 4, the material 52 is also deposited on the entire upper face of the substrate 4 as well as inside the cavities 44 and 46. The state shown in FIG. on the figure 7 .

During a step 54, the chemical-mechanical planarization of the substrate 4 is carried out to restore the upper planar face 6 of the substrate 4. The chemical mechanical planarization is better known by the acronym CMP ("Chemical mechanical planarization"). This planarization step is here used to remove the material 52 and the coating 58 situated outside the cavities 44 and 46. At the end of this step, the state represented on the figure 8 .

During a step 56, the cover 30 is deposited at the location where the housing 24 is to be dug. For this, here, an excess thickness 58 is deposited ( figure 9 ) The material used to create this extra thickness 58 is capable of being etched by the same isotropic etching agent as the substrate 4. For example, here it is is silicon. This excess thickness 58 makes it possible to isolate the cap 30 from the upper face of the distal ends 20 and 22. Then, again during this step 56, a thin layer 59 is deposited on the whole of the upper face of the substrate 4. This layer thin 59 is made of a material resistant to the isotropic etching agent. Finally, in this thin layer 59 forming the cover 30, there are made inlet orifices 60 for the isotropic etching agent. To simplify the figure 9 only one of the orifices 60 has been shown. These orifices are disposed above the location where the box 24 is to be dug.

During a step 62, the substrate 4 is etched to produce the box 24. During this step, the etching is isotropic. Isotropic etching is an etching step in which the etching rates in the X, Y directions are equal to the etching rate in the Z direction to within plus or minus 50%, and preferably to plus or minus 20 or so. 10% close.

In step 62, the isotropic etching agent is contacted with the silicon to be etched via the inlet ports 60. The etching agent used is chosen not to react with the soft magnetic material. 52 and the coating 28. For example, the etching agent is an XeF ₂ gas.

Since the etching agent is an isotropic etching agent, it releases the vertical faces of the ends 20 and 22 and, at the same time, the underside, i.e., the underside, of the distal end 20 ( figure 10 ).

Thus, at the end of this isotropic etching step, the box 24 is made.

Finally, during a step 66, the inlet orifices 60 are optionally closed and the slab on which the different microswitches have been collectively made is cut out to mechanically isolate them from each other.

The figure 11 represents a micro-contactor 80. This micro-contactor 80 is identical to the micro-contactor 2 except that the end 20 is replaced by a fixed end 82. The end 82 is here identical to the end 20 except that it is fixed without any degree of freedom to the substrate 4. The arm B ₁ is omitted.

$$\boxed{{\mathrm{\Gamma }}_{\mathrm{meca}}={\mathrm{\Gamma }}_{\mathrm{r}}}$$

$$\boxed{f_{a\min }=\frac{{\mathrm{\Gamma }}_{a\min }}{e_s+\mathit{\beta x}}}$$

$$\boxed{{\mathrm{\Gamma }}_{\mathrm{amin}}={\mathrm{S}}_{\mathrm{amin}\mathrm{.}}\mathrm{d}\mathrm{.}\left({\mathrm{e}}_{\mathrm{s}}+\mathrm{\beta x}\right)}$$

The sizing of the pads P ₂₁ and P ₂₂ is identical to that described with regard to the figure 4 except that the arrow f ₀ , the pair Γ _meca , the force F _amin and the pair Γ _amin are defined by the following relations: $$\boxed{{\mathrm{f}}_{\mathrm{0}}=\mathrm{d}}$$

$$\boxed{{\mathrm{\Gamma }}_{\mathrm{Mecca}}={\mathrm{\Gamma }}_{\mathrm{r}}}$$

$$\boxed{f_{\mathrm{at}\min }=\frac{{\mathrm{\Gamma }}_{\mathrm{at}\min }}{e_s+\mathit{\beta x}}}$$

$$\boxed{{\mathrm{\Gamma }}_{\mathrm{amin}}={\mathrm{S}}_{\mathrm{amin}\mathrm{.}}\mathrm{d}\mathrm{.}\left({\mathrm{e}}_{\mathrm{s}}+\mathrm{\beta x}\right)}$$

As in the previous embodiment, the pads P ₁₁ and P ₂₂ and the bridge Pt ₁₁ are identical, respectively, to the pads P ₂₁ and P ₂₂ and the bridge Pt ₂₁ .

The figure 12 represents a microswitch 90 identical to the microswitch 2 except that the end 20 is replaced by an end 92. To simplify this figure, only the ends 92 and 22 are shown in detail.

The end 92 is identical to the end 20 except that the distance g is chosen in this embodiment equal to -x to create a new additional zone of overlap Z ' ₁ between the pad P ₁₂ and the pad P ₂₁ . In addition, g is chosen so that the dimensions of this zone Z ' ₁ of overlap are identical to those of the zones Z ₁ and Z ₂ so as to evenly distribute the contact force between the different points of contact between the studs. Thus, in this embodiment, there are three points of contact obtained with only two pairs of pads instead of two points of contact as in the previous embodiment. The increase in the number of contact points makes it possible to reduce the resistance of the microswitch in the closed position since, as will now be described with reference to FIG. figure 13 , the ends 22 and 92 are dimensioned so that the contact forces exerted at each point of contact are identical to those that would be obtained if a single point of contact existed.

The method of sizing the micro-contactor 90 shown in FIG. figure 13 is identical to that shown on the figure 4 except that step 34 is replaced by step 100 and steps 37 and 38 are omitted.

More precisely, during step 100, the width e of the groove is fixed by the following relation: $$\boxed{{\mathrm{e}}_{\mathrm{s}}=\mathrm{\beta x}-\mathrm{2}\mathrm{x}}$$

Thus, only the length l, thickness e and the depth t _p to be determined for a _point f restoring force and a force f _amin equal to 20 μN.

As before, here, the thickness e is chosen to limit the size of the micro-contactor 90. Here, e is chosen equal to 5 microns.

The thickness t _p is determined from the stress imposed on the f _amin force using the following relationships in a manner similar to that previously described with respect to step 34.

The strength f _amin is given by the following relation: $$\boxed{f_{\mathit{amin}}=\frac{2{\mathit{\Gamma }}_{\mathit{amin}}}{2e_s+\mathit{\beta x}}}$$

Γ _amin is the mechanical return torque exerted by the Pt bridge ₁₁ of the pad P _12. It is given by the preceding relation (9). Thus, the stress fixed on the f _amin force makes it possible to calculate the depth t _p from the previous relations.

Then, the length l is determined from the stress imposed on the force _reminder . However, contrary to what was described in step 34, the restoring force is this time given by the following relation: $$\boxed{F_{\mathit{recall}}=\frac{\mathrm{}\mathit{\Gamma r}}{3l+\left(6\beta -{}^7{/}_2\right)x}}$$

As before, the restoring torque Γ _r is given by the following relation: $$\boxed{\mathrm{2}{\mathrm{\Gamma }}_{\mathrm{Mecca}}={\mathrm{\Gamma }}_{\mathrm{r}}}$$

The pair Γ _meca is given by the following relation: $$\boxed{{\mathrm{\Gamma }}_{\mathrm{Mecca}}=\mathrm{S}\mathrm{.}{\mathrm{f}}_{\mathrm{0}}\mathrm{.}\left(\mathrm{I}+{\mathrm{I}}_{\mathrm{p}}\right)}$$

In the previous relation, the length l _p of the end 92 is given by the following relation: $$\boxed{{\mathrm{I}}_{\mathrm{p}}=\mathrm{2}\mathrm{\beta x}+{\mathrm{e}}_{\mathrm{s}}}$$

The factor S of the relation (30) is determined from the same relation (17) as that given with respect to the step 34.

With the same numerical assumptions as before, the following values are obtained: the length l is equal to 35 μm, the thickness e is equal to 5 μm and the depth t _p is equal to 35 μm.

The total space excluding contact pads of the micro-contactor 90 is given by the product of the total length L _t by the total thickness and. The total length L _t is given by the following relation: $$\boxed{{\mathrm{The}}_{\mathrm{t}}=\mathrm{2}\mathrm{I}+{\mathrm{I}}_{\mathrm{p}}+\left(\mathrm{\beta }-\mathrm{1}\right)\mathrm{x}}$$

The thickness and is given by the following relation: $$\boxed{{\mathrm{E}}_{\mathrm{t}}=\mathrm{2}{\mathrm{e}}_{\mathrm{p}}+\mathrm{d}}$$

Thus, the silicon surface occupied by the blades is here 570 × 85 μm ² . The micro-contactor 90 is therefore slightly less bulky than the micro-contactor 2 and its resistance in the closed position is lower.

The figure 14 represents a micro-contactor 110 identical to the micro-contactor 90 but in which the end 92 is replaced by a fixed end 112.

The end 112 is fixed without degree of freedom to the substrate 4. The arm B ₁ is omitted.

$$\boxed{{\mathrm{\Gamma }}_{\mathrm{meca}}={\mathrm{\Gamma }}_{\mathrm{r}}}$$

$$\boxed{{\mathrm{\Gamma }}_{\mathrm{meca}}=\mathrm{S}\mathrm{.}\mathrm{d}\mathrm{.}\left(\mathrm{I}+{\mathrm{I}}_{\mathrm{p}}\right)}$$

$$\boxed{F_{\mathit{amin}}=\frac{{\mathrm{\Gamma }}_{\mathit{amin}}}{2e_s+\mathit{\beta x}}}$$

$$\boxed{{\mathrm{\Gamma }}_{\mathrm{amin}}={\mathrm{S}}_{\mathrm{amin}}\mathrm{.}\mathrm{d}\mathrm{.}\left({\mathrm{e}}_{\mathrm{s}}+\mathrm{\beta x}\right)}$$

The dimensioning of the micro-contactor 110 is deduced from what had been described with regard to the figure 13 . However, the following relationships are used instead of the corresponding relationships in the figure 13 : $$\boxed{{\mathrm{f}}_{\mathrm{0}}=\mathrm{d}}$$

$$\boxed{{\mathrm{\Gamma }}_{\mathrm{Mecca}}={\mathrm{\Gamma }}_{\mathrm{r}}}$$

$$\boxed{{\mathrm{\Gamma }}_{\mathrm{Mecca}}=\mathrm{S}\mathrm{.}\mathrm{d}\mathrm{.}\left(\mathrm{I}+{\mathrm{I}}_{\mathrm{p}}\right)}$$

$$\boxed{F_{\mathit{amin}}=\frac{{\mathrm{\Gamma }}_{\mathit{amin}}}{2e_s+\mathit{\beta x}}}$$

$$\boxed{{\mathrm{\Gamma }}_{\mathrm{amin}}={\mathrm{S}}_{\mathrm{amin}}\mathrm{.}\mathrm{d}\mathrm{.}\left({\mathrm{e}}_{\mathrm{s}}+\mathrm{\beta x}\right)}$$

Many other embodiments are possible. For example, it is not necessary to require that the length x be equal to half the thickness e _p, although this seems to make it possible to reach an optimum between the reduction of the resistance and share a limited space. For example, as a variant, x is chosen to be between e _p / 3 and e _p / 1.5. Preferably, the length x is chosen equal to e _p / 2 to plus or minus 30%.

Other methods of sizing the ends of the blades are possible. In particular, it is possible to simulate, for a set of dimensions, using a simulation software, the operation of the micro-contactor. If the constraints imposed on the operation of the simulated micro-contactor are not satisfied, the dimensions are modified and a new simulation is then carried out. Thus, by successive tests, it is possible to determine the dimensions of the ends satisfying the constraints imposed.

When dimensioning the ends of the blades, the stress force f on the _amino may be omitted.

To limit the transverse surface of the bridge P _ij , it is also possible to limit its height in the vertical direction. In a very particular case, only the height of the bridge P _ij in the vertical direction is limited to satisfy the relation S _Ptij ≤ 2 / 3S _Zi .

What has been previously described for the conformation of the ends also applies to the microswitch in which the blades move perpendicular to the plane of the substrate.

It is not necessary that the different contact forces at the different points of contact are all identical to each other. By for example, at least one of the pads can be sized to produce a contact force greater than that produced by other pads. For example, this can also be achieved by choosing different lengths for the different overlapping areas.

For the micro-switch to work properly, it is not necessary to magnetically saturate each of the pads. For example, only a few pads are sized to be saturated by the field B ₀ . As a variant, none of the pads is saturated.

What has been described here in the particular case of micro-contactors also applies to the case of contactors having macroscopic dimensions. These contactors having macroscopic dimensions are not manufactured by the same manufacturing processes as those of microelectronics. In addition, their dimensions are generally much larger. For example, the length of the blades often exceeds 1 or 3 mm.

Claims (8)

1. Contactor that can be actuated by a magnetic field, this contactor comprising at least one first and one second blades (12, 14) extending in a longitudinal direction:

   - the first blade (12) comprising at least one contact block P_1i having a contact face F_1i,

   - the second blade (14) comprising at least one contact block P_2i facing the contact block P_1i and having a contact face F_2i, the contact blocks P_1i and P_2i facing one another when the intersection of the face F_2i and of the projection in the transverse direction, at right angles to the longitudinal direction, of the face F_1i on the face F_2i forms an area of overlap whose surface S_zi is strictly greater than zero,

   - at least one contact block of each pair of contact blocks P_1i, P_2i facing one another being able to be displaced in the transverse direction, under the effect of the magnetic field, between:

   • a closed position in which the faces F_1i and F_2i are directly in mechanical contact with one another to allow the passage of a current, and

   • an open position in which the faces F_1i and F_2i are separated from one another by an air gap (15) to electrically insulate them from one another,

   - the first and second blades (12, 14) comprise contact blocks forming several pairs of contact blocks P_1i, P_2i facing one another, immediately consecutive in the longitudinal direction, and

   - each blade comprises at least one bridge Pt_ji, each bridge directly mechanically linking two immediately consecutive contact blocks P_ji, P_j,i+1 of one and the same blade, the cross section of this bridge Pt_ji being reduced relative to the cross section of the contact blocks P_ji, P_j,i+1, characterized in that said first and second blades (12,14) are made of magnetic material;

   and the surface S_Ptji of the smallest cross section of the bridge Pt_ji bearing out the following relationship: 0 < S_Ptji < 2/3S_Zi, in which j is an index identifying the blade and i is an index identifying the contact block of this blade.
2. Contactor according to Claim 1, in which the surface S_Zi of each area of overlap bears out the following two relationships: 0 < S_zi ≤ S_1i/3 and 0 < S_zi ≤ S_2i/3 in which S_ij is the surface of the contact face F_ij.
3. Contactor according to either one of the preceding claims, in which each contact block P_ji is a parallelpiped, extending parallel to the longitudinal direction, of thickness e_pji in the transverse direction and the area of overlap is a rectangle of length x in the longitudinal direction, the length x being equal to e_pji/2 to within plus or minus 30%.
4. Contactor according to any one of the preceding claims, in which at least one of the contact blocks P_ji is opposite the contact blocks P_2i and the contact block P_2,i+1.
5. Contactor according to any one of the preceding claims, in which the surfaces S_zi of the areas of overlap are all equal and the dimensions of the contact blocks P_ij are also equal to one another.
6. Contactor according to any one of the preceding claims, in which the contactor comprises a planar substrate (4) in the interior of which is hollowed out a caisson (24) and the blades (12, 14) are entirely received inside this caisson.
7. Contactor according to any one of the preceding claims, in which each bridge Pt_ji corresponds to the bottom of a groove whose opening is turned towards the air gap (15).
8. Switch comprising:

   - a contactor (2; 80; 90; 110) according to any one of the preceding claims, and

   - a source (3) of induction B₀ parallel to the longitudinal direction under the effect of which the contact blocks are displaced from their open position to their closed position,

   characterized in that the dimensions of the contact blocks are such that the intensity of the magnetic induction B₀ makes it possible to saturate these contact blocks P_1i and P_2i while a magnetic induction B₁ identical to the induction B₀ except that its intensity is equal to 80% of the intensity of the induction B₀ does not make it possible to saturate these contact blocks P_1i and P_2i.

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