FR3094141A1 - method of manufacturing an optoelectronic component with optical transmission on the rear face - Google Patents

Abstract

The invention relates to a method of manufacturing an optoelectronic component with optical transmission on the rear face, formed of an optical chip 10 assembled on a control card 30, the latter comprising a transmission zone 30 allowing optical transmission of the device. 'light radiation through the control card 30, an electrical connection being made between polarization pads 31 located at an upper face 30.2 of the control board 30 and contact pads 15 located at the level of a front face 10.2 of the optical chip 10. Figure for the abstract: Figure 2G

Description

method of manufacturing an optoelectronic component with optical transmission on the rear face

The field of the invention is that of methods for manufacturing an optoelectronic component of the optical transmission type on the rear face, also called BSI (for Back Side Illumination , in English). The optoelectronic component includes at least one optical chip assembled and electrically connected to a control board. Also, the optical chip is suitable for emitting or detecting light radiation of interest through an optical face, called rear face, opposite an interconnection layer of the optical chip.

The optoelectronic components may comprise at least one optical chip assembled and electrically connected to a control card. The optical chip contains one or more diodes suitable for emitting or detecting light radiation of interest, for example one or more light-emitting diodes or photodiodes. Such an optoelectronic component can thus be a screen, a projector, an imager, among others.

In general, the optoelectronic component, and more precisely the optical chip, can be optical transmission on the front side (FSI, for Front Side Illumination , in English) or optical transmission on the back side (BSI, for Back Side Illumination ), depending on whether or not the light radiation of interest passes through a BEOL type interconnection layer (for Back End of Line ) of the optical chip. The optical chip thus has a first face, called the front face, located on the side of the interconnection layer, and a second face, called the rear face, opposite the front face, and located on the side of an active layer containing the diode or diodes. Thus, in the case of rear face optical transmission (BSI), the light radiation of interest is emitted or detected by the diodes of the active layer, and does not pass through the interconnection layer. It therefore does not undergo disturbances (absorption, diffraction, etc.) induced by the metallic interconnections present, thus significantly improving the performance of the optoelectronic component.

Figure 1 is a sectional view, schematic and partial, of such an optoelectronic component 1 according to an example of the prior art. It comprises an optical chip 10 assembled and connected to a control card 30. The optical chip 10 comprises, along the Z axis, a support 20 forming a permanent handle, an interconnection layer 13 comprising electrical interconnections 14, a layer active 12 containing one or more diodes, a substrate 11 having been previously thinned, and here at least one passive optical element 17 (filter, antireflection, lens, etc.). The optical chip 10 rests on an upper face 30.2 of the control card 30. This control card 30 makes it possible to apply a control or read signal to the diodes. For this, bias pads 31 are connected to contact pads 15 which are flush with one face of the interconnection layer 13. This face being not free, that is to say here being "buried", metallized vias 16 extend along the Z axis to connect the contact pads 15 to the rear face 10.1 of the optical chip 10. An electrical connection, here of the wire type 36, connects the metallized vias 16 to the polarization pads 31.

In this example, the method of manufacturing such an optoelectronic component 1 therefore requires a step of producing metallized vias 16, which here pass through the substrate 11, the active layer 12, and the interconnection layer 13, insofar as the contact pads 15 are not directly accessible, that is to say are not located at the level of a free face of the optical chip 10. In addition, the use of the support 20 in the form of a permanent handle results in the fact that the rear face 10.1 of the optical chip 10 is located at a significant distance vis-à-vis the upper face 30.2 of the control card 30, thus limiting the field of possible electrical connection techniques between the optical chip 10 and the control card 30. This also results in a rigidity of the optoelectronic component 1 such that it cannot be easily deformed, thus reducing the possibilities of applications of such a component.

The aim of the invention is to remedy at least in part the drawbacks of the prior art, and more particularly to propose a simplified method for manufacturing an optoelectronic component of the type with optical transmission on the rear face. The invention also aims to propose a manufacturing method making it possible to obtain an optoelectronic component of reduced thickness, possibly allowing its deformation.

For this, the object of the invention is a method of manufacturing at least one optoelectronic component formed of at least one optical chip assembled and electrically connected to a control card, the optical chip comprising at least one diode adapted to emitting or detecting light radiation through the control card.

• réalisation d’au moins une puce optique formée d’un substrat, d’ une couche active comportant au moins une diode, formée dans ou sur le substrat, et d’une couche d’interconnexion, recouvrant une face de la couche active, présentant une face dite avant opposée à la couche active, et comportant des plots de contact qui affleurent la face avant ainsi que des interconnexions électriques adaptées à polariser la diode à partir des plots de contact ;
• assemblage de la puce optique à un support au niveau de ladite face avant ;
• retrait au moins partiel du substrat suivant son épaisseur ;
• assemblage par report de la puce optique et du support sur la carte de commande de sorte qu’une face arrière de la puce optique, opposée à ladite face avant, soit orientée vers une face supérieure de la carte de commande sur laquelle repose la puce optique, la carte de commande comportant :
  • une zone de transmission, autorisant la transmission optique dudit rayonnement lumineux au travers de la carte de commande, la puce optique étant positionnée de sorte que la diode soit située en regard de la zone de transmission ;
  • des plots de polarisation situés au niveau de la face supérieure ;
• retrait total du support, de manière à rendre libre ladite face avant et donc accessibles les plots de contact ;
• réalisation d’une connexion électrique entre les plots de polarisation de la carte de commande et les plots de contact de la puce optique.

The process comprises the following steps:

• production of at least one optical chip formed from a substrate, an active layer comprising at least one diode, formed in or on the substrate, and an interconnection layer, covering one side of the active layer, having a so-called front face opposite the active layer, and comprising contact pads which are flush with the front face as well as electrical interconnections suitable for biasing the diode from the contact pads;
• assembly of the optical chip to a support at said front face;
• at least partial removal of the substrate along its thickness;
• assembly by transfer of the optical chip and the support on the control card so that a rear face of the optical chip, opposite to said front face, is oriented towards an upper face of the control card on which the optical chip rests , the control card comprising:
  • a transmission zone, allowing the optical transmission of said light radiation through the control card, the optical chip being positioned so that the diode is located facing the transmission zone;
  • polarization pads located at the level of the upper face;
• total removal of the support, so as to make said front face free and therefore accessible to the contact pads;
• making an electrical connection between the bias pads of the control card and the contact pads of the optical chip.

Some preferred but non-limiting aspects of this method of manufacture are as follows.

The step of making an electrical connection may include the deposition of conductive strips extending over a surface of the control card and of the optical chip, between the bias pads and the contact pads.

The step of assembling the optical chip on the control board and the step of completely removing the support can be carried out simultaneously.

The manufacturing method may also include a step of deforming the optoelectronic component with respect to a plane parallel to the upper face of the control card.

The manufacturing method may comprise, prior to the transfer step, a step of producing at least one passive optical element resting on the active layer, so that, following the transfer step, the element passive optics is located between the active layer and the control card, and located opposite the transmission zone.

The assembly of the optical chip on the upper face of the control card can be carried out by an adhesive material extending around the passive optical element.

The manufacturing method may comprise a step of producing a plurality of optical chips, these forming different parts of the same optoelectronic stack, the method comprising, after the step of assembling the support, a step of cutting the assembly formed by the optoelectronic stack assembled on the support.

• la puce optique présentant une face dite arrière et une face opposée dite face avant, et étant assemblée à la carte de commande par sa face arrière, comportant : une couche active comportant au moins une diode formée dans ou sur un substrat ; et une couche d’interconnexion, recouvrant une face de la couche active, et comportant des plots de contact qui affleurent la face avant ainsi que des interconnexions électriques adaptées à polariser la diode à partir des plots de contact ;
• la carte de commande comportant : des plots de polarisation situés au niveau d’une face supérieure sur laquelle repose la puce optique ; une zone de transmission, autorisant la transmission optique dudit rayonnement lumineux au travers de la carte de commande, la puce optique étant positionnée de sorte que la diode soit située en regard de la zone de transmission ;
• une connexion électrique entre les plots de polarisation de la carte de commande et les plots de contact de la puce optique.

The invention also relates to an optoelectronic component with optical transmission on the rear face, comprising at least one optical chip assembled and electrically connected to a control card, the optical chip comprising at least one diode suitable for emitting or detecting light radiation from interest through the order card,

• the optical chip having a so-called rear face and an opposite so-called front face, and being assembled to the control card via its rear face, comprising: an active layer comprising at least one diode formed in or on a substrate; and an interconnection layer, covering one face of the active layer, and comprising contact pads which are flush with the front face as well as electrical interconnections suitable for biasing the diode from the contact pads;
• the control card comprising: bias pads located at an upper face on which the optical chip rests; a transmission zone, allowing the optical transmission of said light radiation through the control card, the optical chip being positioned so that the diode is located facing the transmission zone;
• an electrical connection between the bias pads of the control board and the contact pads of the optical chip.

The control board may include an insulating substrate defining the top face and an electrical circuit extending over the top face.

The control card may comprise an insulating substrate made, in the transmission zone, of a material that is transparent with respect to the light radiation of interest.

The control card may comprise an insulating substrate having a through opening defining the transmission zone.

The control card can have, in the transmission zone, a homogeneous transmission coefficient with respect to the light radiation of interest.

The optoelectronic component may comprise a deformable layer, resting on the optical chip, and adapted to deform in response to the application of a control signal by the control card.

Other aspects, aims, advantages and characteristics of the invention will appear better on reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the appended drawings. on which ones :

Figure 1, already described, is a sectional view, schematic and partial, of an optoelectronic component according to an example of the prior art;

FIGS. 2A to 2G are schematic and partial cross-sectional views of an optoelectronic component for different steps of a manufacturing method according to one embodiment;

FIGS. 3A and 3B are sectional views, schematic and partial, of an optoelectronic component according to two variant embodiments.

DETAILED DISCUSSION OF PARTICULAR EMBODIMENTS

In the figures and in the remainder of the description, the same references represent identical or similar elements. In addition, the various elements are not represented to scale so as to favor the clarity of the figures. Furthermore, the different embodiments and variants are not mutually exclusive and can be combined with one another. Unless otherwise indicated, the terms “substantially”, “approximately”, “around” mean to within 10%, and preferably within 5%. Furthermore, the terms “between … and …” and equivalents mean that the terminals are included, unless otherwise stated.

The invention relates to a method for manufacturing at least one optoelectronic component with optical transmission on the rear face, in other words, an optoelectronic component of the BSI ( Back Side Illumination ) type. The term “BSI” is here to be taken in the broad sense: the optoelectronic component can thus be adapted to emit or to detect light radiation of interest. The light radiation of interest is then transmitted by a rear face of the optical chip, and not by a front face opposite the rear face and oriented on the side of an interconnection layer.

The optoelectronic component is formed of at least one optical chip assembled on a control board. The optical chip comprises at least one optically active element such as a light-emitting diode or a photodiode, and preferably, a matrix of diodes. The control card comprises an electrical circuit intended to apply to the diodes a control or reading signal (supply). It is preferably a printed circuit of the PCB type (for Printed Circuit Board , in English).

The optoelectronic compound comprises at least one optical chip whose rear face is then oriented towards the control card. Also, as described in detail later, the control card includes a transmission zone, allowing the optical transmission of the light radiation of interest from or towards the optical chip. By optical transmission of light radiation, it is meant here that the control card has, in the transmission zone, a transmission coefficient of the light radiation of interest at least equal to 50%, and preferably at least equal to 80%, or even more.

FIGS. 2A to 2G illustrate different steps of a method for manufacturing a BSI type optoelectronic component 1 according to one embodiment.

Here and for the remainder of the description, an orthogonal three-dimensional direct reference XYZ is defined, where the X and Y axes form a plane parallel to the upper face 30.2 of the control board 30, and where the Z axis is oriented from the board control 30 to the optical chip 10. In the remainder of the description, the terms “lower” and “upper” are understood as being relative to an increasing positioning in the direction +Z.

FIG. 2A illustrates a step for producing an optoelectronic stack 2. This optoelectronic stack 2 can form the same optical chip 10 or a plurality of distinct optical chips intended to be subsequently separated from each other. In this example, the optoelectronic stack 2 corresponds to a plurality of different optical chips, these possibly being identical to or different from each other in terms of optical and/or electronic properties. The optoelectronic stack 2 here comprises a substrate 11, an active layer 12 containing one or more diodes, and an interconnection layer 13.

In general, the substrate 11 is adapted to allow the formation of the active layer 12. It can be a one-piece structure, or can be formed from a stack of layers such as an SOI type substrate (for Silicon On Insulator , in English). Substrate 11 may have a thickness of the order of several tens to hundreds of microns. The active layer 12 is suitable for emitting or detecting the light radiation of interest. For this, it comprises at least one diode, and here a matrix of diodes. The diodes are made from a crystalline semiconductor material, for example a III-V semiconductor compound, that is to say comprising chemical elements from columns III and V of the periodic table, or a II-VI semiconductor compound, among others. The active layer 12 can be formed in the substrate 11 and therefore correspond to an upper zone of the substrate 11. As a variant, it can be a separate layer of the substrate 11 resting on the latter. Also, the active layer 12 is said to be formed in or on the substrate 11.

According to an embodiment in which the optical chip is a CMOS imager, the substrate 11 can be a thick substrate made for example of silicon. The active layer 12 can be, in known manner, an upper part of the thick substrate 11 in which the diodes are made, for example by ion implantation, or be a layer of silicon distinct from the thick substrate 11. Examples of such configurations are described in particular in patents EP2161751 and US7417268.

According to another embodiment, the substrate 11 is adapted to allow the formation of the active layer 12, and in particular to allow the epitaxial growth of the semiconductor compound based on which the diodes are made. It has a face which defines a nucleation surface. Thus, in the case where the active layer 12 comprises diodes made on the basis of a III-V compound, it can thus comprise a nucleation layer, for example in AlN or in a suitable material. The active layer 12 may comprise, by way of illustration, a matrix of light-emitting diodes made from GaN. The diodes may have a structure identical or similar to that described in patent application EP2960940, or to that described in the publication by Fan et al. entitled III-nitride micro-emitter arrays development and applications , J. Phys. D: Appl. Phys. 41 (2008) 094001. The diode or diodes of the active layer 12 can be produced by epitaxial growth MOCVD or equivalent.

The interconnection layer 13 comprises electrical interconnections 14 allowing the control or the reading (power supply) of the diodes of the active layer 12. It is therefore intended to electrically connect the diode or diodes of the active layer 12 to the control board 30 The electrical interconnections 14 are portions of conductive lines, for example metallic, separated from each other by a dielectric material, for example an oxide or a silicon nitride. The interconnection layer 13 therefore covers the active layer 12, and has a face opposite the active layer 12, called the front connection face 10.2, at the level of which at least two contact pads 15 are flush. Thus, by the application of an electrical bias to the contact pads 15, the diode or diodes are activated to emit or detect the light radiation of interest.

Thus, an optoelectronic stack 2 is obtained formed of the substrate 11, of the active layer 12, and of the interconnection layer 13. The optoelectronic stack 2 therefore has a front connection face 10.2 at the level of which the contact pads are flush 15. The opposite face of the optoelectronic stack 2 forms a so-called rear face 10.1. In this example, the optoelectronic stack 2 comprises several optical chips intended to be subsequently separated from each other by cutting out the optoelectronic stack 2.

FIG. 2B illustrates a step for assembling the optical chip 10, and in this example of the optoelectronic stack 2, to a support 20 here forming a temporary handle.

More precisely, the support 20 is assembled to the optoelectronic stack 2 at the level of the front face 10.2 of the latter. It is intended to allow the manipulation of the optoelectronic stack 2 during the transfer of the latter to the control card 30. It also allows, prior to the transfer step, to manipulate the optoelectronic stack 2 during a step of partial or total elimination of the substrate 11, and during a step of cutting out the optoelectronic stack 2 in order to individualize the optical chips vis-à-vis each other.

The support 20 is preferably made of a material having a coefficient of thermal expansion (CTE) close to that of the substrate 11. It can be a substrate based on silicon, sapphire or other, and its thickness can be of the order of several hundred microns.

The optoelectronic stack 2 can be assembled to the support 20 by bonding by means of an intermediate layer of glue 21 which can subsequently be removed. Thus, by way of example, it is possible to use an adhesive based on a heat-sensitive polymer, a double-sided adhesive, a material sensitive to ultraviolet rays, or any other equivalent material.

FIG. 2C illustrates a step of at least partial removal of the substrate 11 along the Z axis of its thickness. It can therefore be a thinning (partial reduction in the thickness of the substrate 11) or a total shrinkage. Preferably, the substrate 11 is thinned (partial and not total shrinkage) so as to ensure protection of the active layer 12. Moreover, in the case of a CMOS imager in which the active layer 12 is an area of the substrate 11 , this one is necessarily thinned and not completely eliminated. This step makes it possible to reduce the total thickness of the optical chip 10, thus making it possible to electrically connect the optical chip 10 to the control board 30 via conductive strips 35 deposited on the surface of the chips 10, 30, for example by screen printing. It also makes it possible to increase the optical transmission of the light radiation of interest by the substrate 11.

For this, the removal, here partial, of the substrate 11 can be carried out by a technique of the abrasion type ( grinding , in English), or by any other equivalent technique. The thinned substrate 11 can then have a final thickness of the order of a few microns to a few tens of microns, for example a thickness of approximately 10 μm. The final thickness of the thinned substrate 11 is chosen in particular according to the applications of the optoelectronic component 1, and according to the spectral range of the light radiation of interest, with the aim of limiting possible absorption of the radiation by the thinned substrate 11.

FIG. 2D illustrates a step for producing at least one passive optical element 17 on the rear face 10.1 of the optical chip 10, here on the free face of the growth substrate 11. This step is optional but advantageous. The optical element 17 can be an antireflection layer, an optical filter, a planar lens for shaping the light beam, or any other optical element. The optical element 17 here has a flat free face, so as to allow assembly to the control card 30.

Furthermore, a step of cutting out the optoelectronic stack 2 can be performed, in particular when it comprises several optical chips intended to be separated from each other. This cutting step can be performed along predefined cutting lines by known techniques, for example by mechanical and/or laser cutting, by chemical etching, by physical etching, or otherwise. This cutting step can be performed before or after the production of the optical elements. Furthermore, the support 20 is also cut, thus allowing the handling of each optical chip 10 during the next transfer step on the control board 30.

FIG. 2E illustrates a step for transferring optical chip 10 onto control card 30. More specifically, optical chip 10 is placed at its rear face 10.1 on upper face 30.2 of control card 30, and not not at its front face 10.2 as in the example of the prior art of fig.1.

The control card 30 enables the electrical biasing of the diode or diodes, so as to activate them in transmission or in detection. It thus comprises an electric circuit to be connected to the contact pads 15 of the interconnection layer 13. Thus, it comprises an electrically insulating substrate 32 and an electric circuit for controlling or reading (power supply). The upper face 30.2 therefore has an assembly surface, intended to receive the optical chip 10. At least two polarization pads 31 are located at the level of the upper face 30.2. More precisely, the polarization pads 31 can be flush with the upper face 30.2, in particular when the control card 30 is an integrated circuit, for example made of silicon (transparent to infrared), or can be placed on the upper face 30.2, in particular when the control card 30 is a printed circuit.

Preferably, the control card 30 is a PCB-type printed circuit. The substrate 32 is made of at least one electrically insulating material, for example epoxy resin or polyimide, and the electrical circuit is made in the form of metal strips defined on the upper face 30.2. The control card 30 can have a thickness and a material such that it is rigid or is flexible and deformable. It may comprise a stack of several layers of metal strips separated from each other by an insulating substrate, and interconnected by metallized holes. Substrate 32 may include one or more electrically insulating materials. Thus, it may comprise the same insulating material which extends in the transmission zone 33 as well as outside of it. As a variant, it may comprise several insulating materials, for example a first material, opaque or transparent, located outside the transmission zone 33, and a second transparent material, defining the transmission zone 33.

The control card 30 thus comprises a transmission zone 33, in other words a zone that the light radiation of interest can pass through between the lower 30.1 and upper 30.2 faces of the control card 30, without undergoing a significant absorption or a notable disturbance. . The transmission coefficient of the control card 30 is then therein at least equal to 50%, preferably at least equal to 80% or even more. In addition, the control card 30 does not include, in this transmission zone 33, metal connections likely to disturb the transmission of the light radiation of interest. This results in the fact that the transmission coefficient, in this zone, is substantially homogeneous. In this example, the transmission zone 33 of the control card 30 is formed by a transparent material. It can thus be a substrate made of glass, sapphire, transparent ceramic, among others. As a variant, as described below, the transmission zone 33 can be formed by a through opening of the control card 30. The optical chip 10 is positioned on the control card 30 so that the diode or diodes are located opposite of transmission zone 33.

Furthermore, the optical chip 10 is assembled to the control card 30, for example by gluing. In this example, an adhesive material 34 is located between the thinned substrate 11 and the upper face 30.2 of the control board 30, and preferably continuously surrounds the optical element. In this example, the adhesive material 34 is not located between the diodes and the transmission zone 33 and can therefore be substantially opaque to the light radiation of interest. As a variant, the adhesive material, then transparent, can be located opposite the transmission zone 33, at the interface between the optical element and the upper face 30.2.

FIG. 2F illustrates a step of total removal of the support 20. Thus, the front face 10.2 is made free, then allowing direct access to the contact pads 15 without having to produce metallized vias as in the example of the art front of fig.1. The temporary glue layer is also removed during this step. It should be noted that, advantageously, this step of total removal of the support 20 can be carried out simultaneously with the step of assembling the optical chip 10 on the control card 30. In this respect, a step of exposure to UV and/or or heating can make it possible to stick the optical chip 10 on the control board 30, and simultaneously, to detach the support 20 vis-à-vis the optical chip 10. Thus, the layer of glue 21 ensuring the assembly of the optical chip 10 on support 20 is adapted to be rendered non-functional or to be eliminated during exposure to predefined light radiation, for example UV, and/or annealing at a predefined temperature. In addition, the glue layer 34 ensuring the assembly of the optical chip to the control card 30 is adapted to be rendered functional during this same UV and/or thermal exposure.

Thus, an optoelectronic component 1 formed of the control card 30 and the optical chip 10 assembled together is obtained. The polarization pads 31 are accessible, as well as the contact pads 15 flush with the front connection face 10.2. Furthermore, the diodes of the optical chip 10 are located opposite the transmission zone 33 of the control card 30. In other words, the optical chip 10 is assembled, at its rear face 10.1, on the control card 30. The optoelectronic component 1 is effectively a BSI type component.

FIG. 2G illustrates an electrical connection step between the optical chip 10 and the control board 30, and more precisely between the contact pads 15 and the bias pads 31. In this example, the electrical connection is made by metal strips 35 deposited in a localized manner and extending on the upper face 30.2 of the control card 30, on the side face of the optical chip 10, and on the front face 10.2 of connection of the optical chip 10. The metal strips 35 can be produced by screen printing, inkjet printing, heliography, flexography, or others. As a variant, a wired electrical connection can be made to connect the contact pads 15 and the polarization pads 31 together. substrate 11 at least thinned, so that the thickness of the optical chip 10 between its rear face 10.1 and its front connection face 10.2 can be of the order of a few microns to a few tens of microns, for example from 5 μm to 20 μm about.

It emerges from this that the manufacturing method according to the invention is simplified compared to the method of the prior art mentioned above. Indeed, it does not include a step of assembling the optical chip 10 or the optoelectronic stack 2 on a support forming a permanent handle. On the contrary, by transferring the optical chip 10 to the control card 30 via a support 20 forming a temporary handle, the optical chip 10 is oriented so that its rear face 10.1 faces the control card 30 and no longer towards an opposite direction. This avoids having to make metallized vias for contact recovery, extending between the rear face 10.1 and the contact pads 15, as described with reference to fig.1. This is authorized by the fact that the control card 30 has a transmission zone 33 opposite which the diode(s) of the optical chip 10 are located. contact pads 15 are made free and the optical chip 10 has a particularly reduced total thickness, making it possible to make the electrical connection between the optical chip 10 and the control card 30 by metal strips 35 deposited on the surface of these elements, and not by wired connection. Moreover, in addition to the fact of obtaining a particularly compact optoelectronic component 1, the latter can also be flexible and deformable due to its low total thickness.

FIG. 3A is a schematic and partial sectional view of an optoelectronic component 1 according to a variant embodiment. In this example, the transmission zone 33 of the control card 30 is made, not of a transparent material of the insulating substrate 32 of the control card 30, but as an opening formed in the insulating substrate 32. This can then be made of a material partially or totally opaque to the light radiation of interest. Also, as illustrated in FIG. 3A, the transmission zone 33 of the control board 30 can be formed by a through opening of the insulating substrate 32. The insulating substrate 32 delimits the through opening in the XY plane, and provides laterally the mechanical support and the electrical connection of the optical chip 10. Alternatively (not shown), the opening may not be through: a thinned part remains present in the transmission zone 33. However, the thickness of the thinned part and the material of the thinned part are chosen so that the optical transmission coefficient in this zone remains at least equal to 50%, and preferably at least equal to 80% or even more. A thinned part has the particular advantage of providing protection vis-à-vis the rear face 10.1 of the optical chip 10, and here of the optical elements 17.

Furthermore, according to one embodiment, the optoelectronic component 1 may comprise an encapsulation layer 22 of the optical chip 10. As illustrated in FIG. 3A, an encapsulation material 22 covers the optical chip 10 and also rests on the upper face 30.2 of the control card 30. It can maintain the electrical connection between the chips, a mechanical protection of the front face 10.2 of the optical chip 10, an optical protection function of the optical chip 10 screws -to-vis light radiation propagating towards the front face 10.2 of the optical chip 10, etc. This encapsulation material 22 can also participate in keeping the optoelectronic component 1 deformed, that is to say in maintaining a curvature of the optoelectronic component 1 with respect to the XY plane.

According to one embodiment, the optoelectronic component 1 may comprise at least one passive optical element (optical filter, antireflection, lens, etc.) located on the lower face 30.1 of the substrate at the level of the transmission zone 33. Furthermore, the lower face 30.1 can be structured therein so as to optimize the transmission of the light radiation of interest.

According to one embodiment, the optoelectronic component 1 may have a generally curved shape with respect to the XY plane. This curved shape can be authorized by the reduced thickness of the optoelectronic component 1, for example of the order of 100 μm or even less, for example of the order of 50 μm, the optical chip 10 having a thickness for example of the order of 10 to 20µm. The curved shape of the optoelectronic component 1 makes it possible in particular to shape the light beam emitted or to be detected, thus reducing the possible need to use optical elements such as focusing or diffusing lenses.

As such, FIG. 3B is a schematic and partial sectional view of an optoelectronic component 1 according to a variant embodiment in which the optoelectronic component 1 comprises a deformable active membrane 23, for example of the piezoelectric type. The deformable membrane 23 can extend over the front face 10.2 of the optoelectronic chip, and comprise at least two contact pads 24 located on a free face of the deformable membrane 23. It is electrically insulated from the metal connection strips 35 between the contact pads 15 and bias pads 31 by an intermediate layer 25 electrically insulating. The contact pads 24 are then electrically connected to bias pads 37 arranged at the level of the upper face 30.2 of the control card 30. Thus, by applying an electric voltage to the deformable membrane 23, the latter deforms in a concave or convex manner, then inducing a deformation of the optoelectronic component 1 as a whole.

Furthermore, according to one embodiment (not shown), the optoelectronic component 1 may comprise a plurality of optical chips assembled and connected to the same control card 30. The optical chips may be identical or different from each other, in particular as regards relates to their optical and/or electronic properties, and in particular as regards the spectral range of emission or detection. Each optical chip 10 is electrically connected to bias pads 31 located at the level of the upper face 30.2 of the control card 30.

Particular embodiments have just been described. Various variations and modifications will occur to those skilled in the art.

Claims (13)

Method of manufacturing at least one optoelectronic component (1) formed of at least one optical chip (10) assembled and electrically connected to a control card (30), the optical chip (10) comprising at least one diode adapted to emitting or detecting light radiation through the control card (30), the method comprising the following steps:

• production of at least one optical chip (10) formed of:
  • a substrate (11),
  • an active layer (12) comprising at least one diode, formed in or on the substrate (11),
  • an interconnection layer (13), covering one face of the active layer (12), presenting a so-called front face (10.2) opposite the active layer (12), and comprising contact pads (15) which are flush with the face front (10.2) as well as electrical interconnections (14) suitable for biasing the diode from the contact pads (15);
• assembly of the optical chip (10) to a support (20) at said front face (10.2);
• at least partial removal of the substrate (11) along its thickness;
• assembly by transfer of the optical chip (10) and the support (20) on the control board (30) so that a rear face (10.1) of the optical chip (10), opposite to said front face (10.2) , or oriented towards an upper face (30.2) of the control card (30) on which the optical chip (10) rests, the control card (30) comprising:
  • a transmission zone (33), allowing the optical transmission of said light radiation through the control card (30), the optical chip (10) being positioned so that the diode is located opposite the transmission zone (33 ),
  • bias pads (31) located at the upper face (30.2);
• complete removal of the support (20), so as to make said front face (10.2) free and therefore accessible to the contact pads (15);
• making an electrical connection between the bias pads (31) of the control board (30) and the contact pads (15) of the optical chip (10).

A manufacturing method according to claim 1, wherein the step of making an electrical connection comprises depositing conductive strips (35) extending over a surface of the control board (30) and the optical chip (10 ), between the bias pads (31) and the contact pads (15). Manufacturing method according to claim 1 or 2, in which the step of assembling the optical chip (10) on the control board (30) and the step of completely removing the support (20) are carried out simultaneously . Manufacturing method according to any one of Claims 1 to 3, further comprising a step of deforming the optoelectronic component (1) with respect to a plane parallel to the upper face (30.2) of the control card ( 30). Manufacturing process according to any one of Claims 1 to 4, comprising, prior to the transfer step, a step of producing at least one passive optical element (17) resting on the active layer (12), so that, following the transfer step, the passive optical element (17) is located between the active layer (12) and the control card (30), and located opposite the transmission zone (33) . Manufacturing process according to claim 5, in which the assembly of the optical chip (10) on the upper face (30.2) of the control card (30) is carried out by an adhesive material (34) extending around the passive optical element (17). Manufacturing method according to any one of Claims 1 to 6, comprising a step of producing a plurality of optical chips, these forming different parts of a same optoelectronic stack (2), the method comprising, after step of assembling the support (20), a step of cutting out the assembly formed by the optoelectronic stack (2) assembled on the support (20). Optoelectronic component (1) with optical transmission on the rear face (10.1), comprising at least one optical chip (10) assembled and electrically connected to a control card (30), the optical chip (10) comprising at least one diode adapted to emitting or detecting light radiation of interest through the control card (30),

• the optical chip (10) having a so-called rear face (10.1) and an opposite face called the front face (10.2), and being assembled to the control card (30) by its rear face (10.1), comprising:
  • an active layer (12) comprising at least one diode formed in or on a substrate (11), and
  • an interconnection layer (13), covering one face of the active layer (12), and comprising contact pads (15) which are flush with the front face (10.2) as well as electrical interconnections (14) suitable for biasing the diode from the contact pads (15);
• the control card (30) comprising:
  • bias pads (31) located at an upper face (30.2) on which the optical chip (10) rests,
  • a transmission zone (33), allowing the optical transmission of said light radiation through the control card (30), the optical chip (10) being positioned so that the diode is located opposite the transmission zone (33 );
• an electrical connection between the bias pads (31) of the control board (30) and the contact pads (15) of the optical chip (10).

Optoelectronic component (1) according to claim 8, in which the control board (30) comprises an insulating substrate (32) defining the upper face (30.2) and an electrical circuit extending on the upper face (30.2). Optoelectronic component (1) according to Claim 8 or 9, in which the control card (30) comprises an insulating substrate (32) made, in the transmission zone (33), of a material transparent to radiation bright of interest. Optoelectronic component (1) according to any one of Claims 8 to 10, in which the control card (30) comprises an insulating substrate (32) having a through opening defining the transmission zone (33). Optoelectronic component (1) according to any one of Claims 8 to 11, in which the control card (30) has, in the transmission zone (33), a homogeneous transmission coefficient with respect to the light radiation d 'interest. Optoelectronic component (1) according to any one of Claims 8 to 12, comprising a deformable layer (23), resting on the optical chip (10), and adapted to deform in response to the application of a control signal by the control board (30).