PLATE CLEAVAGE FOR SOLAR CELL MANUFACTURE

Abstract

Cleaving a silicon wafer for a solar cell provided with side faces (41c) following a crystalline orientation '(110)', comprising prior to a separation of the wafer into several portions, the production of at least one notch (45) parallel or substantially parallel to a given side face (41c) among said side faces. Figure for the abstract: figure 5.

Description

Title of the invention: PLATE CLEAVAGE FOR THE MANUFACTURE OF SOLAR CELLS Technical field

[0001] The present application relates to the field of solar cells also called photovoltaic cells. It applies in particular to devices with solar cell(s) resulting from the assembly of portions of silicon wafers. It relates more particularly to an improved method of dividing a silicon wafer to produce a solar cell or an assembly of solar cells. STATE OF THE PRIOR ART

[0002] A solar cell is usually formed on a plate of semiconductor material, typically silicon, commonly called a “wafer”.

[0003] For certain applications, it may be necessary to cut such a plate into several portions and produce half-cells (“half-cells” according to Anglo-Saxon terminology).

[0004] A particular application concerns the implementation of a solar module architecture of the so-called "shingle" type. Document US2017 / 0077343°Al presents, for example, such a type of solar module. The implementation of a shingle type architecture provides for the assembly of half-cells or portions of cells which are made to overlap each other.

[0005] Half-cells or portions of cells are typically obtained by cutting a plate (wafer) on which a solar cell has been at least partially produced.

[0006] When cutting the plate to obtain plate portions, an attempt is made to minimize the volume of material that is removed during the cutting process.

[0007] It is also sought not to alter the material of the plate and when this plate contains elements intended to form a solar cell, not to alter these elements.

[0008] Laser cutting involves high temperatures, typically of the order of 800°C, which can prove problematic, in particular for the production of certain types of cells such as, for example, heterojunction cells (HET) manufactured at low temperature, typically at a temperature below 250°C and preferably below 200°C.

[0009] Cutting with a blade is a technique commonly used in the field of microelectronics in order to divide a plate (wafer) into elementary portions. Such a method tends to remove a significant portion of material.

[0010] The problem arises of finding a new process for cutting plates for solar cells. Statement of the invention

[0011] An embodiment of the present invention provides a method of manufacturing a silicon support, in particular for a solar cell, comprising steps consisting of: A) Provide a silicon wafer having an upper face, a lower face opposite the upper face and side faces, the side faces following a '(110)' crystal orientation and connecting the upper face and the lower face together, B) Production of at least one notch in said plate, this notch extending parallel or substantially parallel to a given lateral face among said lateral faces of crystalline orientation '(H0)' then, C) Carry out a mechanical action on the plate so as to create a cleavage in the extension of the notch and to separate the plate into a first portion and a second portion distinct from the first portion.

[0012] In step B), the notch may be formed through another side face which is orthogonal to said given side face (41c) of the plate and / or may be formed through a given face among said upper and lower faces.

[0013] In the case where a notch is made through a given face among said upper and lower faces, one preferably remains close to said other lateral face and the notch is advantageously made so as to reach an edge between said given face and said other lateral face.

[0014] In step C), the mechanical action may consist of applying a force, in particular to said upper face or the lower face of the plate. According to a variant, the mechanical action may be a collision of a striking element with the plate or another element in contact or close to the plate. Preferably, when a percussion is carried out, this percussion is carried out close to the notch or at the level of the notch or on the notch.

[0015] Advantageously, the notch(s) is(are) formed using a laser. This makes it possible in particular to quickly make a notch and to obtain precise positioning of the notch(s).

[0016] Typically, the notch has a depth P at least equal to 1 / 3 of a thickness e of the plate, e and P being dimensions measured between said upper face and said lower face of the plate.

[0017] According to an advantageous embodiment, the notch is made through said other side face of the plate. This can make it possible, in particular, to make a notch on a plate covered, or being covered, by another plate or by another object. It can also make it possible not to alter a face on which constituent elements of a solar cell are planned or are already made.

[0018] In step B) of making the notch, the plate may be arranged in a group or a stack of several plates. In this case, at least one other notch is made in step B) on at least one lateral face of at least one other plate of said group or said stack. The notches made may be aligned with each other. This saves time compared to a method in which these notches would be made on the respective upper or lower faces of a group of plates. Making several notches on a stack of plates or on a group of plates by exposing a lateral edge of the stack or group of plates to a laser is all the faster.

[0019] According to an advantageous embodiment, the mechanical action carried out in step C) may be a collision by means of a striking element and applied to said group of plates or to said stack of plates in which notches have been made or to another group of several plates or to another stack of several plates.

[0020] After manufacturing the silicon support, the first portion can be assembled with another portion of silicon or with said second portion in order to produce a solar or photovoltaic module.

[0021] The plate on which the notch is made is typically a rectangular, or pseudo-rectangular, plate, in particular square or pseudo-square.

[0022] This plate may be obtained by cutting a cylindrical ingot obtained by drawing and which includes, after drawing, marks extending over lateral zones of the ingot. The method may then further comprise steps consisting of: - identify a given plane of crystal orientation '(100)' from said marks then, - make cuts at 45° from this given plane to form a brick with lateral faces of crystalline orientation '(110)', then - cutting the brick into several plates with upper and lower faces of crystalline orientation '(100)' and side faces of crystalline orientation '(110)'.

[0023] According to one embodiment of the method, the plate may have been subjected prior to step B) to one or more steps or even to the technological steps of producing a solar cell.

[0024] The cleavage method according to the invention makes it possible to adapt to a plate which has already undergone one or more stages of solar cell manufacturing, while limiting the risks of deterioration of this cell.

[0025] Advantageously, prior to step B), a step of forming metallic elements, in particular metallic contacts, is carried out on said plate.

[0026] According to one possible implementation of the method, in particular when it aims at producing heterojunction solar cells, step B) can be carried out after the deposition of a layer, typically made of amorphous silicon, used to form this heterojunction. In this case, step B) and step C) can also be carried out on said plate before producing a passivation layer.

[0027] A method according to the invention applies particularly to the manufacture of heterojunction solar cells for which thermal budget constraints are significant. Brief description of the drawings

[0028] The present invention will be better understood on the basis of the description which follows and the appended drawings in which:

[0029] [fig. 1] serves to illustrate a formation of a silicon ingot;

[0030] [fig.2] is used to illustrate a cutting of a brick from a silicon ingot;

[0031] [fig.3] serves to illustrate a brick obtained by cutting a silicon ingot;

[0032] [fig.4] is used to illustrate a cutting of a brick into plates (wafers) for cell(s) solar cell(s) or portion(s) of solar cell(s);

[0033] [fig.5] serves to illustrate the formation of at least one starter notch on one face side of a plate (wafer) intended to accommodate at least one solar cell or at least one portion of a solar cell and provided to facilitate subsequent cutting of the plate into elementary portions;

[0034] [fig.6] serves to illustrate the formation of a starter notch on an upper or lower part of a plate;

[0035] [fig.7] serves to illustrate a first example of a method of cleaving a plate of silicon on which at least one starter notch is made, the cleavage being carried out by applying a mechanical pushing force to the plate;

[0036] [fig.8] serves to illustrate a second example of a method of cleaving a plate of silicon on which at least one primer notch has been made;

[0037] [fig.9] serves to illustrate a third example of a method of cleaving a plate of silicon on which at least one primer notch has been made, the cleavage being carried out by collision between a striker element and the plate;

[0038] [fig. 10] serves to illustrate a fourth example of a cleaving method, the cleaving being carried out by collision of a striking element which is dropped onto an edge of the plate;

[0039] [fig.l 1] serves to illustrate a fifth example of a cleavage method;

[0040] [fig. 12] serves to illustrate a division of a silicon wafer into two portions distinct;

[0041] [fig. 13] serves to illustrate an assembly of portions of silicon wafer obtained by cleavage and assembled to form an arrangement of the type commonly called “half-cell”;

[0042] [fig. 14] serves to illustrate an assembly of portions of silicon wafer obtained by cleavage and then assembled according to an arrangement of the type commonly called “shingle”;

[0043] [fig. 15] serves to illustrate another type of assembly of portions of silicon plate obtained by cleavage;

[0044] [fig. 16] serves to illustrate an example of producing a starter notch on a solar cell plate which has already undergone technical steps in producing a solar cell and which is already provided with contacts;

[0045] [fig. 17] serves to illustrate an example of making a starter notch on a group of plates;

[0046] [fig. 18] serves to illustrate an example of cleavage carried out concomitantly on a group of plates;

[0047] [fig. 19] serves to illustrate an example of making a starter notch on a stack of plates;

[0048] [fig.20] serves to illustrate an example of making several primer notches on plates from a stack of plates;

[0049] Identical, similar or equivalent parts of the different figures bear the same numerical references so as to facilitate the transition from one figure to another.

[0050] The different parts represented in the figures are not necessarily on a uniform scale, in order to make the figures more readable.

[0051] DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

[0052] An exemplary embodiment of a method according to the invention provides for using as starting material a block of silicon also called an "ingot" 2 ([fig.l]). This ingot 2 may have a part of a generally cylindrical shape and may have been obtained by a Czochralski (Cz) type method. In this type of method, silicon charge is melted in a crucible. A single-crystal silicon seed with a precise crystallographic orientation, for example a (100) orientation, is placed in contact with the molten surface. The solidified silicon takes the crystallographic orientation of the seed which is slowly pulled until it reaches a desired diameter. Dopants, for example boron or phosphorus, may be added in order to be able to give the silicon an n-type or p-type doping.

[0053] The ingot 2 obtained is then cut, with a cut ([fig.2]) made in the direction of the height H, taken between the base 3a and the top 3b of the cylindrical part of the ingot 2, in order to form a parallelepiped block 4 also called a “brick” ([fig.3]). The cutting of the brick 4 can be carried out for example by means of a wire saw and can be carried out in the presence of a liquid containing abrasive particles in suspension.

[0054] The cutting of the brick 4 is here carried out so that it comprises lateral flanks 4c having a crystallographic orientation (110) or substantially equal to the crystallographic orientation (110). For this, a location of this orientation can be carried out from marks, for example edges present on the flank of the ingot and which provide information on the crystallographic orientation (100). We then place ourselves in a direction at 45° from this orientation (100) in order to obtain the crystallographic orientation 110. We can then check for any misorientation in a conventional manner using, for example, measuring equipment such as an X-ray goniometer.

[0055] The brick 4 is then itself cut into plates 40 ([fig.4]) commonly called “wafers” on which one or more solar cells are intended to be produced. The cutting of the brick 4 into several plates 40 is carried out this time according to a transverse cutting plane P', in other words orthogonally, or substantially orthogonally, to an axis along which the height of the brick 4 is measured or to the cutting planes used to form the brick 4 from the ingot. By “substantially orthogonally”, we typically mean a deviation of less than 0.5° and preferably less than 0.2° relative to an angle value of 90°.

[0056] Plates 40 with a thickness e of, for example, between 70 μm and 500 μm, in particular between 110 μm and 250 μm, are typically produced. Plates 40 of size, for example, commonly called M2 (dimensions in the plane of 156.75 mm * 156.75 mm) or for example, commonly called M4 (161.70 mm * 161.70 mm) or of size, for example, commonly called M6 (166 mm * 166 mm) or of size M12 (210 mm * 210 mm) may be produced.

[0057] The obtained silicon wafers 40 are provided with opposite upper 41a and lower 41b faces of rectangular or pseudo-rectangular shape and preferably square or pseudo-square, and comprise lateral faces 41c provided with a crystallographic orientation (110) and connecting the upper face and the lower face together. The upper 41a and lower 41b faces then typically have a crystallographic orientation (100). By "pseudo-rectangular", it is meant that instead of a right angle joining two orthogonal lateral faces, there may be a curved portion or a portion forming a bevel connecting these orthogonal lateral faces together.

[0058] A silicon plate 40 thus obtained can be provided to then accommodate one or more solar cells or parts of solar cells, for example of the heterojunction (HET) type.

[0059] We then seek to divide this plate 40 into several elementary portions. distinct, while limiting cutting losses and avoiding damaging this plate 40.

[0060] To do this, at least one so-called “starter” notch 45 is made, in other words a slot close to an edge of the plate 40 and which extends into the thickness e (the thickness e being a dimension measured parallel to the axis k of an orthogonal reference frame [O; i; j; k] given in [fig. 5]) of the plate 40.

[0061] The starting notch 45 is preferably made so as to extend in a plane parallel or substantially parallel to a given lateral face 41c of the plate 40 of crystallographic orientation 110. By "substantially parallel", it is meant that an angular difference between a plane containing the notch 45 and the given lateral face 41c is typically less than 0.5°, preferably less than 0.2° and advantageously less than 0.1°.

[0062] The starting notch 45 therefore has a length L (dimension measured parallel to the plane [O; i; j] and in particular to the axis i of the orthogonal reference frame [O; i; j; k] and to the given face 41c) which is less than and typically much less than the dimensions of the lateral faces 45c of the plate, and a depth P (dimension measured parallel to the plane [O; i; k], and in particular to the axis k of the orthogonal reference frame [O; i; j; k] of the orthogonal reference frame [O; i; j; k]) which may be less than the thickness e of the plate. This starting notch 45 may be provided for example with a length L of for example between 0.2 mm and 2 mm, advantageously between 0.5 mm and 1 mm. The starting notch 45 can be made with a depth P of, for example, between 30 pm and 60 pm for a plate with a total thickness e of between 130 pm and 160 pm. Preferably, the depth P of the notch made is greater than or equal to one third of the thickness e of the initial plate considered.

[0063] The notch 45 thus forms the start of a cutting or separation zone on the plate intended to be completed later.

[0064] This initiation is advantageously carried out by means of an LA laser. An LA laser with a wavelength typically located in the infrared range and for example of the order of 1024nm, with an intensity of for example between 23A and 27A and a frequency of for example between 1 kHz and 20 kHz can be used in particular.

[0065] A scanning speed of the order of, for example, 20 mm.s may typically be used.

[0066] The use of a laser to produce this primer notch 45 makes it possible in particular to obtain precise positioning and to carry out this primer quickly.

[0067] In the embodiment illustrated in [fig.5], the laser LA is directed towards a lateral face 41d of the plate 40, so as to make this notch 45 through this lateral face 41d, in other words through this lateral face 41d. The notch 45 then extends parallel to another lateral face 41c of crystallographic orientation (110). in this case, this primer is made without necessarily exposing an upper (or lower) face and therefore without risk of damaging an area dedicated to receiving a solar cell element and which is generally made on this upper face 41a (or lower 41b). A notch 45 made by aiming at a lateral face also has the advantage of being able to make this notch while the lower face 41b and / or upper face 41a is masked by, or is located on another object, in particular another plate or a support.

[0068] An alternative embodiment illustrated in [fig.6], this time provides a laser LA directed towards an upper face 41a of the plate 40, so as to make this notch 45 through the upper face 41a of the plate 40. As a variant, a notch 45 can be made through the lower face 41b of the plate 40.

[0069] It is also possible to make a notch 45 through a lateral face and then continue through the lower face 41b or upper face of the plate 40.

[0070] According to another variant, a notch 45 can be made through a lateral face and then continued on the upper face or on the lower face.

[0071] It is also possible to make this starter cut 45 using a cutting tool, in particular a tool provided with at least one point such as for example a diamond point.

[0072] The starter notch 45 can be made on a “bare” plate, obtained directly after the step described previously in connection with [fig.4] of cutting the brick 4.

[0073] Alternatively, this notch 45 can also be made while one or more technological steps for producing a solar cell or part of a solar cell have already been carried out.

[0074] Among these technological steps may be one or more or even all of the following steps: - at least one surface texturing step, - at least one doping step in particular by diffusion for example of Boron on the lower and upper faces of the plate, - at least one backside etching step, - at least one step of adding a barrier layer on the front face in order to prevent the addition of dopants during another diffusion step on the back face, - at least one doping step on the rear face, in particular by diffusion of, for example, Phosphorus, - at least one etching of diffusion barrier layer(s) as well as layers created during the diffusion of phosphorus, - at least one step of forming at least one passivation layer, - at least one step of forming one or more anti-reflective layers, - at least one step of forming metal contacts, for example by screen printing. Contacts on the front and rear faces can be made, for example, for certain types of cells. Alternatively, it is possible to form contacts on the front face and a continuous metal layer over the entire rear face.

[0075] In the case where a heterojunction cell is produced, the notch is typically produced, for example, after a step of depositing a layer such as an amorphous silicon layer used to produce the heterojunction. The notch can also be produced before passivation, in particular before formation of a passivation layer on the front face and / or the rear face or before passivation of a face revealed by this notch.

[0076] An example of carrying out a subsequent cleavage step using the primer 45 aimed at dividing the plate 40 into several distinct and separate portions is illustrated schematically in [fig.7].

[0077] In this example, the plate 40 is arranged on a cleavage support 60. A region 411 of the lower face 41b (or upper face 41a) of the plate is supported on the support 60, while another region 412 of this same face 41b (or 41a) is suspended, without being supported on this support 60 or on another support. The notch 45 is then preferably arranged so that a plane Pe orthogonal to the plate 40 and passing through this notch 45, is located near an end 61 of the support 60 and at the level of the suspended region 412. A direction force F which makes a non-zero angle with the upper face 41a or lower face 41b of the plate 40 and preferably vertical is applied to a part of the plate 40 which is suspended and which is not resting on the support 60 or on another support.From the application of the force F, the result is the propagation of a cleavage zone from the notch 45 and in a direction parallel or substantially parallel to the lateral faces 41c of crystallographic orientation 110. A separation between portions 40a and 40b of the plate 40 is thus implemented ([fig.12]). These portions 40a, 40b are typically provided to each form a half-solar cell. These portions 40a, 40b are intended to be assembled to form a photovoltaic module.

[0078] Another way of carrying out the cleavage is illustrated schematically in [fig.8]. In this example, the plate 40 this time comprises a region 411a arranged to bear on a cleavage support 60 and another region 411b which is located to bear on another support 160 or on another part 160 of a cleavage support.

[0079] The notch 45 is preferably arranged so that a plane Pe orthogonal to the plate 40 and passing through this notch 45, is located between the supports 60 160 and does not pass through any of these supports 60, 160. A suspended region 413 of the plate located between the supports 60, 160 thus comprises the cleavage notch 45. Here again, a force F is applied, this time preferably at or near the notch 45 and preferably orthogonally to the upper face 41a or lower face of the plate 40 on a part of the plate 40 which is suspended between the supports 60, 160.

[0080] Another cleavage variant is illustrated in [fig.9]. It provides for carrying out the separation this time using a striking element 170 which acts by inertia and which is made to collide with an area of ​​the plate preferably on the notch 45 or at the level of the notch 45 or close to the notch 45. Advantageously, it is provided that the striking element 170 is brought into collision with a lateral face 41d of the plate 40. Here again, this makes it possible not to come to bear on a sensitive area of ​​the plate 40 located on the upper or lower face, for example on a constituent element of a solar cell already formed on the plate.

[0081] The illustrated striker element 170 comprises a flat tip 171. Other tip shapes, in particular a rounded or angular shape, may be used.

[0082] In the embodiment illustrated in [fig.10], the striker element 170 is this time subjected to gravity and brought into collision with a lateral face 41d of the plate 40, the plate 40 being oriented vertically. The element 170 is thus made to fall so that it strikes the plate 40 at the level of the primer notch 45 and creates a shock making it possible to cause division.

[0083] An energy greater than 15 mJ can be used in order to carry out cleavage on a plate 40 with a thickness of, for example, around 180 μm.

[0084] Other cleaving methods may be provided. For example, in an exemplary embodiment illustrated in [fig. 11], the plate 40 is positioned at the edge of a support structure 160 such as a plate and has a portion facing the plate which is held fixed by a holding system such as a press 260. An edge of the plate 160 is aligned with a plane passing through the starting notch 45. A stress is then applied to a portion 40b of the plate 40 which projects from the plate and the press so as to move this portion 40b in rotation relative to an axis parallel to the plate and to the cleaving notch until a separation of the portion 40b is achieved.

[0085] Once separated, at least one of the portions 40a, 40b of the plate 40 may be subjected to one or more technological steps for producing a solar cell or even to all the technological steps for producing a solar cell, in particular as mentioned previously. These technological steps described previously may also have already been carried out when the cleavage is carried out.

[0086] In the case in particular where these technological steps described above have already been carried out when the cleavage is carried out, the portions 40a, 40b obtained at the end of the cleavage can then be passivated at the level of the face or edge exposed by the cleavage. Such passivation is typically carried out by deposition of dielectric material such as for example SiNx or A1OX deposited for example by PECVD for ("Plasma-enhanced Chemical vapor deposition", i.e. Chemical vapor deposition plasma-assisted steam).

[0087] At least one of the portions 40a, 40b of plate obtained by cleavage can be directly assembled with another portion of plate in order to constitute an assembly of half-solar cells.

[0088] In the particular embodiment of [fig. 13], the portions 40a, 40b resulting from the cleavage of the plate 40 are then assembled according to a particular arrangement where a portion 40a of plate is juxtaposed with another portion 40b, these two portions 40a, 40b then being connected to each other by means of a conductive element taking for example the form of a conductive strip 151.

[0089] In the particular embodiment of [fig. 14], the portions 40a, 40b resulting from the cleavage of the plate 40 are then assembled according to a particular arrangement of the “shingle” type, in other words where a portion 40a of the plate is in contact and overlaps another portion 40b. The other portion 40b can advantageously be connected to the portion 40a by means of a conductive adhesive 152. In the other assembly example of [fig. 15], the plate 40b also partially covers the plate 40a. The interconnection can this time be achieved using a structure of the SWCT type (“SmartWire Connection Technology” or “Smartwire” connection technology) or an element which extends over an upper face of the plate 40a as well as over a lower face of the other plate 40b which partially covers the upper face of the plate 40a.

[0090] A cleavage of the plate 40 into k (with k>2) under portions can be envisaged, in particular in the case where one wishes to produce a shingle architecture.

[0091] In the particular embodiment illustrated in [fig.16], the starter notch 45 can be made on a lateral face 41d of a cell 40' formed from a silicon plate 40 having already undergone the technological steps of solar cell manufacturing mentioned previously and which is in particular already provided with conductive contact tracks 47 on its lower face and / or on its upper face.

[0092] An advantageous embodiment provides for making a starter notch 45 on a plurality of plates and in particular on each of the plates 40 of a group of plates advantageously arranged so that their lateral faces 41d are juxtaposed or superimposed.

[0093] [fig. 17] schematically illustrates the path 700 of an element such as a laser LA for producing aligned starter notches 45 on aligned lateral faces 41d of a group 48 of plates 40. It is thus possible to quickly produce k (k> 1) starter notches 45 on k plates 40. This can make it possible to adapt such a step of producing starters to an industrial manufacturing process.

[0094] The separation or cleavage step can also be carried out by causing an element (not shown) to collide with another element brought into contact with a plate or a set of plates. In the embodiment illustrated in [fig. 18], an element is brought into collision with another element 270 arranged in contact with several plates 40 of a group 48 of plates 40. The shock thus created concomitantly on each of the respective lateral faces 41d of the plates 40 makes it possible to carry out the cleavage on a group 48 of several plates 40.

[0095] In the particular embodiment illustrated in [fig. 19], at least two plates 40 are this time stacked and subjected to treatment, in particular by laser, making it possible to produce a starting notch on each of these plates. It is thus possible to quickly produce k separations on k separate plates 40 of a stack 49. This can make it possible to adapt such a cleavage step to an industrial manufacturing process.

[0096] The cleaving method is not limited to separating a plate into two portions and making a single starter notch 45 per plate. In the embodiment example of [fig.20], where plates 40 are superimposed so as to form a stack 49, several starter notches 45 are made at the level of the same lateral face 41d, in order to divide each plate 40 into a number of portions greater than 2. The notches 45 are in this case also preferably oriented in respective directions parallel to each other and parallel to a lateral face of the plates 40 of orientation (110). The number of cleavage lines made on a lateral edge of a stack or on a lateral face of a plate depends on the number n of desired sub-cells. A cleaving method as described above can then be applied to the stack of plates.Alternatively, to carry out this cleavage, the plates can be held by a horizontal holding system of the lateral edges of the stack and rest on cleavage bars whose length corresponds to that of a plate and which are moved in translation, in particular which are raised to carry out the cleavage.

[0097] A cleaving method has been described previously using an ingot as the starting material. Alternatively, it is possible to start directly from a brick obtained after cutting the ingot, or according to another variant, to start directly from a plate obtained after cutting the brick and to which a cleaving method described previously is applied. Another variant provides for starting directly from a plate on which one or more cells or portions of solar cells have been at least partially produced. In other words, the initiation and division can be carried out on plates that have already undergone one or more or even all of the technological steps for producing a solar cell.

[0098] A cleavage method as described above is particularly applicable to solar cell technologies produced at low temperature such as heterojunction (HET) cells and for which laser cutting of the plate risks create damage.

[0099] A cleaving method as described above also applies particularly to the implementation of “half-cell” or “shingle” type assemblies in which portions of plates resulting from a cut are arranged so as to be electrically connected.

Claims

Claims

1. Method for manufacturing a silicon support, in particular for a solar cell, comprising the steps of: - cutting a cylindrical silicon ingot (2) obtained by drawing a seed (100) and which comprises, after this drawing, marks extending over lateral zones of the ingot (2), - identifying a given plane of crystalline orientation (100) from said marks then, - making cuts at 45° or substantially at 45° from this given plane to form a brick (3) provided with lateral faces of crystalline orientation '(HO)', then - cutting the brick (3) into several plates (40) provided with upper and lower faces of crystalline orientation '(100)' and lateral faces of crystalline orientation '(110)', then - A) Providing a rectangular or pseudorectangular silicon plate (40) resulting from the cutting of said brick, said plate being provided with a face (41a) superior,of a lower face (41b) opposite the upper face in a '(100)' crystal orientation and of lateral faces (41c) in a '(110)' crystal orientation which connect said upper face and said lower face together, then - B) Making at least one notch (45) in said plate (40), said notch (45) formed extending parallel or substantially parallel to a given lateral face (41c) among said lateral faces, said notch being formed through another lateral face (41d) which is orthogonal to said given lateral face (41c) of the plate and / or through a given face among said upper face and said lower face (41d), then - C) Carrying out a mechanical action on the plate (40), such as applying a force or colliding with a striking element,so as to produce a cleavage in the extension of said notch (45) and to effect a separation of the plate (40) into a first portion (40a) and at least one second portion (40b) distinct from the first portion.,

2. A method according to claim 1, wherein the notch (45) is made using a laser (L).

3. Method according to one of claims 1 or 2, in which the notch (45) has a depth P at least equal to 1 / 3 of a thickness e of the plate, e and P being dimensions measured between said upper face and said lower face.

4. Method according to one of claims 1 to 3, in which the notch (45) is made on said other lateral face (41d) of the plate (40).

5. Method according to claim 4, wherein in step B) the plate (40) is arranged in a group (48) or a stack (49) of several plates (40), at least one other notch being made on at least one lateral face of at least one other plate of said group (48) or said stack (49).

6. Method according to claim 5, wherein said mechanical action carried out in step C) is a collision by means of a striking element (170) and is applied to said group (48) or to said stack (49) or to another group of several plates or to another stack of several plates.

7. A method according to either of claims 5 or 6, wherein said notch (45) and said further notch are formed by exposing a side edge of said stack to a laser.

8. A method of manufacturing a solar module comprising manufacturing a silicon support according to one of claims 1 to 7, then assembling the first portion (40a) into a solar module with another portion of silicon or with said second portion (40b).

9. Manufacturing method according to one of claims 1 to 7, in which prior to step B), a solar cell or a portion of a solar cell is at least partially produced on said plate (40).

10. Manufacturing method according to claim 9, wherein prior to step B), a step of forming metallic elements, in particular metallic contacts, is carried out on said plate (40).

11. Manufacturing method according to claim 10, in which step step B) is carried out after a step of depositing a layer of amorphous silicon on said plate (40) and before the production of a passivation layer.

12. A method of manufacturing a heterojunction solar cell comprising implementing a method according to one of claims 1 to 7.

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