CENTERING DEVICE

Abstract

The invention relates to a centering device (10) which comprises a first plate (17) and a second plate (19), the first plate (17) comprising a through opening delimited laterally by four side walls (16), the second plate (19) comprises a support face (20), the centering device (10) comprising a housing (13) opening out the first face (11) and delimited laterally by the four side walls (16) and by a bottom (15) carried by the support face (20), the distance between the bottom (15) and the first face (11) defining the depth of the at least one housing (13), the centering device (10) comprises elastic means interposed between the first plate (17) and the second plate (19), and configured so that, when a compressive force is exerted, the depth of the at least one housing (13) decreases with respect to a rest depth observed when no compressive force is exerted. Figure 3

Description

Title of the invention: CENTERING DEVICE FIELD OF THE INVENTION

[0001] The present invention relates to the field of microelectronics and more particularly to the shaping of image sensors. In particular, the present invention relates to a device for centering a chip on a support face of a shim. More particularly, the present invention relates to a centering device which allows better homogeneity of the deformation of the chip on the shim. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] In recent years, there has been a growing interest in the implementation of curved image sensors in mobile phones, laptops or simply in cameras. Indeed, the integration of curved sensors in optical systems requires a relatively small number of lenses, and thus makes it possible to envisage both a simple design and a more compact arrangement of optical systems.

[0003] Document [1] cited at the end of the description proposes a method for bending an image sensor. More particularly, the method described in document [1] proposes positioning a flat image sensor, by one of its faces called the contact face, on a concave face of a shim and imposing a deformation on said image sensor so that it conforms to the concave face. In particular, and as described in document [1], the deformation involves the implementation of a membrane resting on a useful face, opposite the contact face, of the image sensor and which, by a set of pressure differences, exerts a force making it possible to deform the image sensor according to a shape imposed by the concave face.

[0004] Equivalently, document [2] cited at the end of the description also discloses a method for forming curved image sensors. The method described in document [2] essentially repeats the principles given in document [1].

[0005] Furthermore, in order to ensure acceptable alignment of the image sensor on the shim, these methods may implement centering devices. More particularly, the centering device may comprise a housing opening through a front face of said centering device. The housing is in this regard configured to receive a stack formed by the shim and the sensor, and to impose centering of said sensor on the shim.

[0006] The proposed housings generally have a depth suitable for maintaining the aforementioned stack in a stable position.

[0007] This constraint therefore imposes a relatively significant depth of housing. which is not without consequences during the process of deformation of the sensor by means of the membrane.

[0008] In fact, the edge delimiting the opening of the housing forms an abrupt step that the membrane cannot conform to.

[0009] This latter aspect limits the force of the membrane on the edges of the sensor and impacts the efficiency of the sensor deformation process.

[0010] An aim of the present invention is therefore to propose a centering device which makes it possible to improve the process of deformation of a chip resting on a concave face of a shim. In particular, an aim of the present invention is to allow conformal deformation of the chip with respect to the concave surface on which it rests. More particularly, an aim of the present invention is to propose a centering device making it possible to improve the efficiency of the process of deformation of the chip at the edge of said chip. BRIEF DESCRIPTION OF THE INVENTION

[0011] The object of the invention is achieved by a centering device which comprises from a first face, flat, to a second face, flat and parallel to the first face, a first plate and a second plate, the first plate comprising at least one through opening delimited laterally by four side walls, the second plate comprises a face, called the support face opposite the second face, the centering device comprising at least one housing opening out the first face and delimited laterally by the four side walls and by a bottom carried by the support face, the distance between the bottom and the first face defining the depth of the at least one housing, the centering device further comprises elastic means interposed between the first plate and the second plate, and configured so that, when a compressive force is exerted between one and the other of the first face and the second face,the depth of the at least one housing decreases with respect to a depth called the rest depth observed when no compression force is exerted.

[0012] According to one embodiment, said centering device is configured so that the compression force leads to a deformation of the centering device, said deformation corresponding to a reduction in a thickness of said centering device, said thickness being measured between the first face and the second face.

[0013] According to one embodiment, the centering device is configured so that the deformation is an elastic deformation.

[0014] According to one embodiment, the elastic means are configured to deform preferentially with respect to the first plate and the second plate when a compressive force is exerted between one and the other of the first face and the second face.

[0015] According to one embodiment, the second plate comprises at least one pedestal, projecting relative to the support face and comprising a face, called the free face, essentially parallel to the support face, the at least one pedestal being in correspondence with the at least one opening so that the at least one pedestal forms the bottom of the at least one housing.

[0016] According to one embodiment, the pedestal has a height substantially equal to a distance separating the first plate from the second plate.

[0017] According to one embodiment, the elastic means comprise a material capable of deforming elastically under the effect of a compression force.

[0018] According to one embodiment, the material forming the elastic means is in the form of solid blocks or blocks having voids.

[0019] According to one embodiment, the elastic means comprise springs, advantageously metal springs.

[0020] According to one embodiment, the springs comprise at least one of the elements chosen from: a helical spring, a Belleville washer.

[0021] According to one embodiment, the elastic means comprise first means and second means, the first means being arranged to be the only ones to be compressed as soon as the compression force is adjusted in a first range of compressions, said first range making it possible to reduce the depth of the at least one housing from the depth H0 to the depth H1 (the depth H1 being strictly less than the depth H0), said second means being compressed, during the application of the compression force, only when the depth is less than the depth H1 and the compression force is in a second range of compression forces, said compression forces of the second range being greater than the compression forces of the first range.

[0022] According to one embodiment, the first means comprise first springs and the second means comprise second springs.

[0023] According to one embodiment, the first means comprise first elastic blocks and the second means comprise second elastic blocks.

[0024] The invention also relates to a method of deforming a chip resting on a face, called the upper face, of a shim, the upper face being concave, the method comprising:

[0025] a) providing a centering device according to one of claims 1 to 10;

[0026] b) a step of positioning at least one wedge in the at least one housing, said at least one wedge comprising two opposite faces called, respectively, rear face and upper face, said at least one wedge resting in the at least one housing by its rear face;

[0027] c) a step of positioning at least one chip, by one of its faces called the contact face, on an upper face of at least one shim;

[0028] d) a step of positioning a membrane covering, by one of its faces called the support face, the first face and a face called the useful face of the at least one chip, said useful face being opposite the contact face, the membrane hermetically separating a first space from a second space in which the main support is located housing, in the at least one centering housing, the at least one shim and the at least one chip;

[0029] e) a step of establishing a pressure difference between the first space and the second space so that the membrane applies a force, called a compression force, to the useful face of the at least one chip so that the latter adopts the shape of the support face, the compression force also being exerted between one and the other of the first face and the second face so that the depth of the at least one housing decreases with respect to a depth called the rest depth observed when no compression force is exerted.

[0030] According to one embodiment, the centering device and the pressure difference are adjusted to allow a reduction in depth of the at least one housing of between 0.5 mm and 1 mm. Brief description of the drawings

[0031] Other characteristics and advantages of the invention will emerge from the detailed description which follows with reference to the appended figures in which:

[0032] [Fig-1] [Fig.l] is a schematic representation of a centering device according to the present invention, in particular the centering device is represented by its first face, the level “AA'” is a reference of a section plane;

[0033] [Fig.2] [Fig.2] is a schematic representation of the centering device of [Fig.l] according to a section plane AA' perpendicular to the first face;

[0034] [Fig.3] [Fig.3] is a schematic representation of the centering device according to a section plane perpendicular to the first face and illustrating a housing at rest;

[0035] [Fig.4] [Fig.4] is a schematic representation of the centering device and on which a compressive force is exerted on both the first face and the second face, the compressive force leading to a reduction in the depth of the housing;

[0036] [Fig.5] [Fig.5] is a schematic representation of the centering device according to a section plane perpendicular to the first face and illustrating a housing at rest, the elastic means comprising blocks with empty sections;

[0037] [Fig.6] [Fig.6] is a schematic representation of the centering device for which the spring means comprise first blocks and second blocks, said centering device being in a so-called rest position and for which no compression force is applied, the centering device is in particular represented according to a section plane perpendicular to the first face;

[0038] [Fig.7] [Fig.7] reproduces the centering device of [Fig.6], according to a cutting plane perpendicular to the first face, and for which a compression force is exerted in the first range;

[0039] [Fig.8] [Fig.8] reproduces the centering device of [Fig.6], according to a cutting plane perpendicular to the first face, and for which a compression force is exerted in the second range;

[0040] [Fig.9] [Fig.9] is an illustration of a centering device according to the present invention and according to a section plane perpendicular to the front face, in particular, this centering device uses helical springs as elastic means;

[0041] [Fig. 10] [Fig. 10] reproduces the centering device of [Fig.9], according to a section plane perpendicular to the first face, and for which no compression force is exerted;

[0042] [Fig. 11] [Fig. 11] reproduces the centering device of [Fig.9], according to a section plane perpendicular to the first face, and for which a compression force is exerted;

[0043] [Fig. 12] [Fig. 12] is an illustration of a second plate of the centering device according to the present invention and according to a perspective view, in particular, this centering device implements as elastic means provided with a first type of springs and a second type of springs;

[0044] [Fig. 13] [Fig. 13] is a graphic illustration of the variation of the depth H (along the vertical axis) of a housing of the centering device according to the present invention as a function of the compression force (horizontal axis) applied to said device;

[0045] [Fig. 14] [Fig. 14] is a schematic representation of the sequence of steps a), b), c), and d) of the method of deforming a chip according to the present invention;

[0046] [Fig. 15] [Fig. 15] is a schematic representation of step e) of the method of deforming a chip according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0047] The present invention relates to a device for centering a chip resting, by a contact face, on a face, called the upper face and of concave shape, of a wedge.

[0048] In particular, the centering device according to the present invention is intended to improve the process of deformation of a chip resting on the upper face of the wedge.

[0049] To this end, the present invention proposes a centering device which comprises from a first face, flat, to a second face, flat and parallel to the first face, a first plate and a second plate, the first plate comprising at least one through opening delimited laterally by side walls (for example four side walls), the second plate comprises a face, called the support face opposite the second face, the centering device comprising at least one housing opening out the first face and delimited laterally by the side walls and by a bottom carried by the support face, the distance between the bottom and the first face defining the depth of the at least one housing, the centering device further comprises elastic means interposed between the first plate and the second plate, and configured so that, when a compressive force exerted between one and the other of the first face and the second face,the depth of the at least one housing decreases with respect to a depth called the rest depth observed when no compression force is exerted.

[0050] Elastic means, according to the present invention, are means capable of elastically deforming under the effect of a compressive force. It is, in this regard, understood that the elastic means are configured to return to the original firmness as soon as the compressive force is no longer applied.

[0051] Such a device can in particular be implemented using a method of deforming a chip, for example an image sensor or a display, resting on the upper face of a shim.

[0052] In particular, said method may comprise the execution of the following steps:

[0053] a) providing a centering device according to the present invention;

[0054] b) a step of positioning at least one wedge in the at least one housing, said at least one wedge comprising two opposite faces called, respectively, rear face and upper face, said at least one wedge resting in the at least one housing by its rear face;

[0055] c) a step of positioning at least one chip, by one of its faces called the contact face, on an upper face of at least one shim;

[0056] d) a step of positioning a membrane covering, by one of its faces called the support face, the first face and a face called the useful face of the at least one chip, said useful face being opposite the contact face, the membrane hermetically separating a first space from a second space in which the main support is located housing, in the at least one centering housing, the at least one shim and the at least one chip;

[0057] e) a step of establishing a pressure difference between the first space and the second space so that the membrane applies a force, called a compression force, on the useful face of the at least one chip so that the latter adopts the shape of the support face, the compression force being exerted equally between one and the other of the first face and the second face so that the depth of the at least one housing decreases with respect to a depth called the rest depth observed when no compression force is exerted.

[0058] The centering device makes it possible, when performing steps b) and c), to arrange a stack in the housing, said stack being formed of a shim and a chip resting on an upper face of said shim. The depth of the housing, measured between the bottom of the housing and the first face, is in this respect adjusted so as to limit any risk of accidental exit of the stack from the housing.

[0059] The centering device is also suitable for when a compressive force, exerted between one and the other of the first face and the second face, the depth of the at least one housing decreases with respect to a depth called the rest depth observed when no compressive force is exerted. This latter aspect is advantageously used when performing step e). Indeed, this step not only makes it possible to impose a force, via the membrane, on the useful face so as to force the chip to conform to the upper face but also to reduce the depth of the housing in which the stack formed by the shim and the chip is located. This latter effect thus allows the membrane to better fit the chip, in particular in the vicinity of its edges, and consequently to apply a force better distributed on the useful face. The conformity of the chip at the end of step e) with respect to the upper face is thus improved.

[0060] In particular, and advantageously, the stiffness of the elastic means can be adjusted to be sequential, for example to have two different levels of stiffness and depending on the compressive force exerted.

[0061] For example, the stiffness of the elastic means may have a first level of stiffness and a second level of stiffness.

[0062] The first level of stiffness allows, for a first range of compression forces, to reduce the height of the cavity while keeping the useful face at a distance from the first face.

[0063] The second level of stiffness allows, for a second range of compression forces (greater than the compression forces of the first range), to bring the useful face flush with the first face.

[0064] Thus, as soon as the compression force is in the first range (i.e. at the start of application of said force), the chip approaches the first face while remaining at a distance from the latter, so that said chip cannot “escape” from the housing. Continuing the compression force in the second range makes it possible to reduce the height of the housing a little more so that the useful face is flush with the first face. This latter aspect allows better spreading of the membrane on the useful face when said membrane applies the compression force.

[0065] This compression sequencing can also be obtained with elastic means having a constant stiffness and by adjusting only the compression force.

[0066] The remainder of the statement of the present invention refers to a housing. It is understood that this housing comprises a bottom, for example a flat bottom, surmounted by side walls, for example four side walls. More particularly, the housing, according to the principles set out below, opens through a face, called the first face, of a centering device, so that each of the side walls comprises an edge merged with the first face. The side walls, as illustrated in the figures, are moreover perpendicular to the first face. The trace of the intersection between the side walls and a plane parallel to the first face can also be a rectangle.These latter aspects are however not of a nature to limit the scope of the present invention, and the person skilled in the art will understand, simply by reading the following statement, that different forms of housing can be considered without calling into question the general principle of the present invention.

[0067] The remainder of the statement, when referring to a housing or a housing, will be limited to the description of four side walls. However, this aspect is not such as to limit the invention, and the person skilled in the art may consider a greater or lesser number of side walls.

[0068] The remainder of the statement also refers to a shim. Said shim is defined as an essentially rectangular parallelepiped block, one face of which is concave in shape. In particular, the shim according to the present invention comprises two faces, called, respectively, the upper face and the rear face, and connected by lateral faces. The lateral faces are in this respect arranged to allow the insertion, by adjustment, of the shim by its rear face into the housing. In particular, when the housing houses a shim, each lateral face is opposite and parallel to a lateral wall. Advantageously, each lateral face is against a lateral wall.

[0069] The chip intended to be curved also comprises two faces parallel to each other called, respectively, useful face and contact face, said faces being connected by a contour. Said contour defines a trace conforming to the trace of the intersection between the side walls and a plane parallel to the first face. In other words, the contour comprises as many sides as there are side walls and so that each side is arranged against a side wall when the chip is housed in the housing.

[0070] The remainder of the statement also defines a stack. This latter term refers to the stack formed by the shim and the chip resting, by its contact face, on the upper face of said shim.

[0071] [Fig.l] is a schematic representation of a centering device 10 according to the present invention. In particular, [Fig. 1] is a schematic representation of the centering device by a main face, called first face 11. It is understood that this face is essentially flat. The centering device comprises at least one housing opening out through the first face 11. In [Fig. 1], the centering device 10 comprises a plurality of housings 13, for example arranged in a matrix manner. This arrangement is not such as to limit the scope of the present invention.

[0072] By "arranged in a matrix manner" is meant a pattern formed by a set of parallel lines and a set of columns parallel to each other and perpendicular to each of the lines of the set of lines, housings 13 being arranged at the intersections of lines and columns included on the first face.

[0073] [Fig.2] also illustrates the centering device 10 according to the present invention along a section plane AA' perpendicular to the first face.

[0074] The centering device, as shown in [Fig.l] and [Fig.2], comprises two main faces, the first face 11 and a second face 12 connected by a contour surface 14. The centering device may take the form of a disc, or be rectangular in shape.

[0075] As illustrated in [Fig.3], the housing 13 comprises a bottom 15 and side walls 16 surmounting said bottom 15. This housing 13 is further characterized by its depth, called the rest depth Ho. In particular, this rest depth Ho is the distance, in a direction perpendicular to the first face, between the bottom 15 and the first face 11. Furthermore, this rest depth Ho is in particular a distance measured when no force is exerted on the centering device 10.

[0076] According to the present invention, the centering device 10 is configured so that when a compressive force F is exerted between one and the other of the first face and the second face, the depth of the at least one housing decreases with respect to the rest depth Ho. In this regard, as illustrated in [Fig. 4], under the effect of the compressive force, the depth of the housing changes from the rest depth Ho to a depth Hi less than the rest depth. For example, the difference between the rest depth Ho and the depth Hi may be between 0.5 mm and 1 mm.

[0077] According to a particularly advantageous embodiment, the centering device can be configured so that the compression force leads to a deformation of the centering device, said deformation corresponding to a reduction in a thickness of said centering device, said thickness being measured between the first face 11 and the second face 12. More particularly, the centering device 10 can be configured so that the deformation is an elastic deformation. This latter aspect is particularly advantageous insofar as it allows the device to centering to recover its initial state.

[0078] According to one embodiment, the centering device 10 comprises, stacked, from the first face 11 to the second face 12 a first plate 17, a second plate 19.

[0079] The first plate 17 comprises at least one through opening delimited laterally by four side walls, while the second plate comprises a face, called the support face 20, opposite the second face 12 (it is understood that the second face of the centering device is also a face of the second plate). It is understood, without it being necessary to specify it, that the first plate and the second plate are essentially planar.

[0080] Furthermore, it is understood, without it being necessary to specify, that the at least one housing is delimited laterally by the four side walls defining the at least one through opening, while the bottom of the at least one housing is carried by the support face 20 of the second plate 19. It is understood, without it being necessary to specify, that the support face is opposite a face of the first plate opposite the first face.

[0081] According to this arrangement, the side walls 16 of the at least one housing extend, from the first face, into the first plate 17. In other words, the at least one housing opens out through the first face 11.

[0082] The centering device 10 comprises elastic means interposed between the first plate 17 and the second plate 19. In particular, the elastic means are configured so that, when a compression force is exerted between one and the other of the first face and the second face, the depth of the at least one housing decreases with respect to a depth called the rest depth observed when no compression force is exerted.

[0083] The elastic means may also be configured to deform preferentially with respect to the first plate and the second plate when a compressive force is exerted between one and the other of the first face and the second face.

[0084] A pedestal 21 may be formed in projection relative to the support face 20. In particular, the pedestal 21 comprises a face, called the free face, essentially parallel to the support face 20, and is in correspondence with the at least one opening so that the free face of the at least one pedestal forms the bottom 15 of the at least one housing.

[0085] Advantageously, the pedestal 21 has a height at least equal to, or even greater than, the distance separating the first plate from the second plate when no compression force is exerted.

[0086] Advantageously, the elastic means may comprise a material capable of deforming elastically under the effect of a compression force.

[0087] By way of example, and as illustrated in [Fig.3], and in [Fig.5], the elastic means may be in the form of blocks 18.

[0088] More particularly, and in accordance with [Fig. 3], the blocks 18 may be solid.

[0089] According to the example presented in [Fig. 5], the blocks 18 have solid sections 18a and empty sections 18b. The distribution of the empty sections 18b and the choice of the material forming the solid sections 18a make it possible to adjust the stiffness of the elastic means.

[0090] In this regard, and in the embodiments illustrated in [Fig.3] and [Fig.5], the material forming the elastic means may comprise ethylene-propylene-diene monomer (EPDM).

[0091] Advantageously, the blocks 18 may comprise first blocks 18-1 and second blocks 18-2. In particular, the first blocks 18-1 have a first thickness E1, at rest, in a direction going from the second face 12 towards the first face 11, while the second blocks 18-2 have a second thickness E2, at rest, in a direction going from the second face 12 towards the first face 11, said second thickness being less than the first thickness E1.

[0092] By “thickness at rest” is meant a thickness of a block which is not subjected to any compressive force.

[0093] The first blocks 18-1 have a first stiffness K1, and the second blocks have a second stiffness K2 which may be greater than the first stiffness KL

[0094] In this regard, [Fig. 6] is an illustration of a centering plate 10 provided with elastic means formed by the first blocks 18-1 and the second blocks 18-2 in the absence of a compressive force. In this [Fig. 6], and in the absence of a compressive force, only the first blocks 18-1 are in contact with the first plate 17 and the second plate 19, while the second blocks rest on the support face 20 of the second plate 19 and at a distance from the first plate 17. The shim 31 also remains at a good distance from the first face 17.

[0095] Also, and as soon as a compressive force, in a first range of forces, is applied, only the first blocks 18-1 undergo said force. Said first blocks thus see their thickness decrease, thus leading to a reduction in the depth of the housing 13. In particular, as illustrated in [Fig.7], the depth of the housing 13 goes from a resting depth H0 to a depth H1 less than the resting depth H0, said depth H1 being a depth at which the second blocks 18-2 are in contact with the first plate and the second plate. In other words, the depth H1 is a depth for which a compressive force exerted beyond the forces included in the first range, also stresses the second blocks 18-2. Thus, for any compressive force exerted in a second range beyond the forces included in the first range, the second blocks 18-2 also undergo the compressive force, and therefore oppose the said force with the first blocks. In particular, as soon as a compressive force is exerted in the second range, the overall stiffness of the elastic means appears greater than for compressive forces included in the first range. The increase in the force in the second range makes it possible to reduce the depth of the housing a little more to a depth H2 ([Fig.8]).

[0096] Alternatively, and as illustrated in [Fig. 9], the elastic means may comprise springs 22. In particular, in [Fig. 9], the springs 22 are helical springs. However, the invention is not limited to this type of spring, and those skilled in the art may consider any other type of spring, and for example use Belleville washers. The springs 22, as illustrated in [Fig. 9], bear against one and the other of the first plate and the second plate.

[0097] [Fig. 10] shows the centering device of [Fig.9] and according to a section plane perpendicular to the first face. In this figure, no compressive force is exerted so that the wedge 31 arranged in the housing 13 remains at an appreciable distance from the first face 11. [Fig.1 1] shows the same centering device and on which a compressive force is applied. In this figure, the depth of the housings is less than the resting depth H0.

[0098] Still according to this alternative, and as illustrated in [Fig. 12], the elastic means may comprise two types of spring. In particular, the springs 22 may comprise first springs 22a and second springs 22b, the first springs having a stiffness lower than the stiffness of the second springs 22b. According to this configuration, the stiffness is modulated as a function of the compression force applied to the centering device. [Fig. 13] illustrates the effect of an increasing compression force on the depth H of a housing.

[0099] In particular, and for example, the first springs 22a and the second springs 22b may be arranged so that only the first springs are actually stressed during a first compression phase (symbolized by the pressure range “A” in [Fig. 13]). In the pressure range “A”, the height H of the housing varies according to a first slope as a function of the imposed compression force. For a pressure range “B” (associated with a second compression phase), greater than the pressures of the pressure range “A”, the second springs 22b are also stressed. In the pressure range “B”, the overall stiffness of the elastic means is greater than in the pressure range “A” so that the variation in depth H of the housing as a function of the compression force has a second slope lower in absolute value than the first slope.

[0100] Finally, in a pressure range “C”, higher than the pressures of the range of pressures “B”, the depth variation can be almost zero. It is also notable that the analysis previously given with regard to the graph in [Fig. 13] can be transposed to the embodiment for which the first blocks 18-1 and the second blocks 18-2 are considered.

[0101] This effect is advantageously used when implementing a deformation method described in the remainder of the statement.

[0102] The present invention also relates to a method of deforming a chip resting on a face, called the upper face, of a shim, the upper face being concave, the method comprising the execution of the following steps:

[0103] a) providing a centering device 10 according to the present invention;

[0104] b) a step of positioning at least one wedge 31 in the at least one housing 13, said at least one shim comprising two opposite faces called, respectively, rear face and upper face, said at least one shim resting in the at least one housing by its rear face ([Fig.5]);

[0105] c) a step of positioning at least one chip 31, by one of its faces called the contact face, on an upper face of at least one shim ([Fig.5], [Fig.14]);

[0106] d) a step of positioning a membrane 32 in covering, by one of its faces called the support face, the first face and a face called the useful face of the at least one chip, said useful face being opposite the contact face, the membrane hermetically separating a first space from a second space in which the main support is located housing, in the at least one centering housing, the at least one shim and the at least one chip ([Fig.5]);

[0107] e) a step of establishing a pressure difference between the first space and the second space so that the membrane applies a force, called a compression force, to the useful face of the at least one chip so that the latter adopts the shape of the support face, the compression force also being exerted between one and the other of the first face and the second face so that the depth of the at least one housing decreases with respect to a depth called the rest depth observed when no compression force is exerted ([Fig. 15]).

[0108] Advantageously, the centering device can be adjusted and the pressure difference adjusted to allow a reduction in depth of the at least one housing of between 0.5 mm and 1 mm.

[0109] This method can advantageously implement the centering device described in relation to [Fig. 12]. In particular, according to this configuration, step e) can comprise a gradual (or even linear) increase in the compression force.

[0110] Thus, when the applied compressive force is in the range “A”, the chip approaches the first face while remaining at a distance, so that said chip cannot “escape” from the housing. The continuation of the compressive force in the “B” range, allows the height of the housing to be reduced a little more so that the useful face is flush with the first face. This latter aspect allows for better spreading of the membrane on the useful face when said membrane applies the compressive force.

[0111] Of course, the invention is not limited to the embodiments described and variant embodiments can be made without departing from the scope of the invention as defined by the claims. References

[0112] [1] EP 3 480 850 Al;

[0113] [2] EP 3 278 363 B1.

Claims

Claims

1. Centering device (10) which comprises from a first face (11), flat, to a second face (12), flat and parallel to the first face (11), a first plate (17) and a second plate (19), the first plate (17) comprising at least one through opening delimited laterally by four side walls (16), the second plate (19) comprises a face, called the support face (20) opposite the second face (12), the centering device (10) comprising at least one housing (13) opening out the first face (11) and delimited laterally by the four side walls (16) and by a bottom (15) carried by the support face (20), the distance between the bottom (15) and the first face (11) defining the depth of the at least one housing (13), the centering device (10) further comprises elastic means interposed between the first plate (17) and the second plate (19), and configured so that,when a compressive force is exerted between one and the other of the first face (11) and the second face (12), the depth of the at least one housing (13) decreases with respect to a depth called the rest depth observed when no compressive force is exerted.

2. A centering device (10) according to claim 1, wherein said centering device (10) is configured so that the compressive force leads to a deformation of the centering device (10), said deformation corresponding to a reduction in a thickness of said centering device (10), said thickness being measured between the first face (11) and the second face (12).

3. The centering device (10) of claim 2, wherein the centering device (10) is configured such that the deformation is an elastic deformation.

4. Centering device (10) according to one of claims 1 to 3, in which the elastic means are configured to deform preferentially with respect to the first plate (17) and the second plate (19) when a compressive force is exerted between one and the other of the first face (11) and the second face (12).

5. Centering device (10) according to one of claims 1 to 4, in which the second plate (19) comprises at least one pedestal (21), projecting relative to the support face (20) and comprising a face, called the free face, essentially parallel to the support face (20), the at least one pedestal (21) being in correspondence with the at least one opening so that the at least one pedestal (21) forms the bottom (15) of the at least one housing (13).

6. A centering device (10) according to claim 5, wherein the pedestal (21) has a height substantially equal to a distance separating the first plate (17) from the second plate (19).

7. Centering device (10) according to one of claims 1 to 6, in which the elastic means comprise a material capable of deforming elastically under the effect of a compression force.

8. Centering device (10) according to claim 7, wherein the material forming the elastic means is in the form of solid blocks (18) or blocks (18) having voids.

9. Centering device (10) according to one of claims 1 to 7, in which the elastic means comprise springs (22), advantageously metal springs.

10. Centering device (10) according to claim 9, wherein the springs (22) comprise at least one of the elements chosen from: a helical spring, a belleville washer.

11. A method of deforming a chip resting on a face, called the upper face, of a shim (31), the upper face being concave, the method comprising: a) providing a centering device (10) according to one of claims 1 to 10; b) a step of positioning at least one shim (31) in the at least one housing (13), said at least one shim (31) comprising two opposite faces called, respectively, the rear face and the upper face, said at least one shim (31) resting in the at least one housing (13) by its rear face; c) a step of positioning at least one chip, by one of its faces called the contact face, on an upper face of at least one shim (31);d) a step of positioning a membrane covering, by one of its faces called the support face, the first face (11) and a face called the useful face of the at least one chip, said useful face being opposite the contact face, the membrane hermetically separating a first space from a second space in which the main support is located housing, in the at least one centering housing (13), the at least one shim (31) and the at least one chip; e) a step of establishing a pressure difference between the first space and the second space so that the membrane applies a force, called a compression force, to the useful face of the at least one chip so that the latter adopts the shape of the support face (20), the compression force also being exerted between one and the other of the first face (11) and the second face (12) so that the depth of the at least one housing (13) decreases with respect to a depth called the rest depth observed when no compression force is exerted.

12. A deformation method according to claim 11, wherein the centering device (10) and the pressure difference are adjusted to allow a reduction in depth of the at least one housing (13) of between 0.5 mm and 1 mm.

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