ITUD20090147A1 - PRINTING PROCEDURE - Google Patents

Description

Description

"PRINT PROCESS"

FIELD OF APPLICATION

The present invention relates to a printing process for depositing one or more print traces on a substrate.

Embodiments of the present invention can be used in a substrate processing line for the realization of single or multiple layer schemes.

STATE OF THE TECHNIQUE

Solar cells are photovoltaic devices that convert sunlight directly into electrical energy. Solar cells are commonly made on silicon substrates, which can be mono or multicrystalline or amorphous silicon substrates. A known type solar cell comprises a silicon substrate, or wafer, less than about 0.3 mm thick, having a thin layer of silicon on top of another zone formed on the substrate.

The printing processes, for example multilayer, for solar cells of the known art use screen printing, ink jet or other processes of a known type for the subsequent deposition, for example, of layers of the same material, or of different materials , metallic or insulating, according to a predetermined printing mask, so as to realize a desired electrical scheme, provided with thin conductive lines, with collecting and / or distribution lines and / or with insulating tracks on the substrates themselves.

The known processes, again in the case of multi-layer printing, provide for the alignment with high precision of the mask, or of the printing screen, of the printing stations or stations between one printing and the next, in such a way as to lay two on the substrate, or more, layers of the same conformation and perfectly superimposed until a predetermined height is reached.

A drawback of these known printing processes is that, to ensure, for example, a predetermined electrical conductivity of the conductive lines, it is not always possible to obtain an optimal contact surface between the electrically conductive material of each conductive line and the semiconductor material. of the substrate.

Furthermore, since each conductive line is provided with a substantially square or rectangular cross section, obtained as the sum of identical rectangular sections overlapping and relative to each layer, its overall conductivity is a function of both the height, i.e. the total number of layers, than of their width.

This entails the need to avoid the creation of conductive lines that are too narrow, but this leads to a decrease in the efficiency of the solar cells produced, substantially due to the shadow area projected by each line on the substrate.

An object of the present invention is to provide a printing process which allows to improve the printing process on the printing supports, or substrates, and to increase the efficiency and energy efficiency of the solar cells thus produced.

In order to obviate the drawbacks of the known art and to obtain these and further objects and advantages, the Applicant has studied, tested and implemented the present invention.

EXPOSURE OF THE FOUND

The present invention is expressed and characterized in the independent claims.

The related dependent claims disclose other characteristics of the present invention, or variants of the main solution idea.

In accordance with the aforementioned purpose, a printing process for printing one or more print traces on a printing support comprises two, or more, printing steps in each of which, by means of printing means, for example silk-screen printing means , laser, ink jet, or others, a layer of material is deposited on a printing substrate according to a predetermined printing profile.

According to the present invention, in each printing step, subsequent to the first, each layer of material is superimposed, at least partially, on the layer of material printed in the previous printing step. Each layer of printed material has an identical or different printing profile with respect to at least one layer of underlying material so as to achieve an equal or different contact area with respect to at least one previously printed area. In addition, the material deposited in each printing step may be the same material, or different from the material printed in a previous printing step.

Here and in the following, with print, or underlying layer, reference is made without distinction to a print, or layer, both immediately underlying and in any case previous, even if not immediately underlying.

In this way it is possible to create, for example, multilayer conductive lines in which the first layer, the one in contact with the printing support, i.e. the substrate, is made with a material comprising a glassy mixture, so as to allow, during a high temperature heat treatment, the penetration of the metal-based paste into the insulation layer and then the contact of the paste with the substrate, thus obtaining the desired contact resistance. The subsequent layers are made, for example, with purely conductive or insulating materials.

The vitreous mixture can be any of those readily available on the market.

In one embodiment, the temperature at which the heat treatment takes place is advantageously between 500 and 900 ° C, preferably about 700 ° C.

Furthermore, such successive layers being able to be printed according to different printing profiles even with respect to the first, for example with a larger transversal dimension, allow a substantial decrease in the shadow areas projected by the lines themselves on the substrate and, therefore, an increase in efficiency. conversion of solar cells made.

According to a variant of the present invention, the method provides alignment steps, each provided upstream of a corresponding printing step, in which, directly or indirectly, by means of alignment means, the printing support and the printing means are mutually aligned to print the corresponding layer in the desired position.

According to a further variant of the present invention, the method comprises detection steps, coordinated with the alignment steps in which, by means of detection means, information relating to the printing supports being processed and the related printing steps are acquired.

According to a variant of the present invention, the method comprises at least one printing step in which an engraving material is dispensed which is capable of eroding at least part of the printing support and / or one of its coating layer and / or a layer of material already printed, so as to define a deposition seat that guarantees a better bond between a printed layer of material to the substrate.

According to a further variant of the present invention, after the step of printing the engraving material, the process provides a step of cleaning the printing support and / or the deposition seat, so as to eliminate any residual impurities before printing the next layer of material.

It also falls within the spirit of the present invention to provide that between the printing steps, or steps, or at its / their end, further processing steps of the printing supports are carried out, such as diffusion steps in a gaseous state, chemical etching steps. , control and supervision phases of processing, testing phases or others, regardless of their succession.

ILLUSTRATION OF DRAWINGS

These and other characteristics of the present invention will become clear from the following description of a preferential embodiment, given by way of non-limiting example, with reference to the attached drawings in which:

Figure 1A is an isometric schematic view of a processing system used in the present invention;

Figure 1B is a schematic plan view of the system illustrated in Figure 1;

Figure 2 is a schematic top view of two layers of material deposited during the multilayer printing process according to the present invention;

- Figure 3 is a side view of Figure 2;

Figures 4A-4D are schematic views of the processing steps of the process according to the present invention;

Figure 4E is a schematic diagram of an operating sequence according to embodiments of the present invention; Figures 5A-5D are schematic views of processing steps in a different operating sequence of the method according to the present invention;

- Figure 6 is a schematic side view of two layers of material deposited according to the multilayer printing process;

- Figure 7 is a schematic top view of Figure 6;

- Figures 8A-8D are schematic views of processing steps in an operational sequence for carrying out the printing of Figures 6 and 7.

To facilitate understanding, identical reference numbers have been used wherever possible to identify identical common elements in the figures. It should be understood that elements and features of one embodiment can be conveniently incorporated into other embodiments without further specification.

DESCRIPTION OF A PREFERENTIAL FORM OF

REALIZATION

With reference to the attached figures, a multilayer printing process can be used for printing a pattern, for example a multiple layer, on a surface of a substrate 10, or wafer, in silicon, or other semiconductor material, in a process of construction of solar cells. »In this case, reference will be made below to the construction of conductive lines 11 used to collect, in a capillary manner, the current generated by the photovoltaic effect from the solar cell over its entire surface and channel it towards conductive collection or distribution lines.

Conductive lines 11 may contain a metal, such as aluminum (Al), silver (Ag), tin (Sn), cobalt (Co), rhenium (Rh), nickel (Ni), zinc (Zn), lead (Pb), palladium (Pd), molybdenum (Mo), titanium (Ti), tantalum (Ta), vanadium (V), tungsten (W), or chromium (Cr). In one example, the conductive lines 11 are, at least partially, made with a metal paste that contains silver (Ag) or tin (Sn).

It is understood that the method according to the present invention can also be used for the production of other conductive or insulating structures.

With reference to Figures 2 and 3, in which a portion of a conductive line 11 deposited on a substrate 10 is shown, the process comprises at least two printing steps in each of which, by means of a printing station, as described below, as many layers of conductive material, or conductive lines 11, are made according to a predetermined printing profile. The printing steps may include screen printing processes, inkjet printing processes, lithographic or gummed sheet metal deposition process, or other similar metallization processes according to a pattern.

Figure 1A is an isometric schematic view and Figure 1B is a schematic top plan view illustrating an embodiment of a printing system, or system 100, which can be used in conjunction with embodiments of the present invention for printing a pattern, for example with multiple layers, on a surface of a solar cell substrate 10.

In one embodiment, the system 100 generally comprises two inlet conveyors 111, an actuator assembly 140, a plurality of processing nests 131, a plurality of processing heads 102, two output conveyors 112, and a system controller 101 . The inlet conveyors 111 are configured in a parallel processing configuration so that each can receive unprocessed substrates 10 from a feed device, such as a feed conveyor 113, and transfer each unprocessed substrate 10 to a coupled processing nest 131 to the actuator assembly 140. In addition, the outlet conveyors 112 are configured in parallel so that each can receive a processed substrate 10 from a processing nest 131 and transfer each processed substrate 10 to a substrate remover, such as a feed conveyor. evacuation 114.

In one embodiment, each evacuation conveyor 114 is adapted to transport the processed substrates 10 through an oven 199 to treat the material deposited on the substrate 10 by the processing heads 102.

In an embodiment of the present invention, the system 100 is a screen printing processing system and the processing heads 102 include screen printing components, which are configured to screen print a layer of material according to a pattern on a substrate 10 .

In another embodiment, the system 100 is an inkjet printing system and the processing heads 102 include inkjet printing components, which are configured to deposit a layer of material in a pattern on a substrate 10. In yet another embodiment, the system 100 is a processing system that includes components for removing material in the processing head 102, such as a laser for ablation or incision of a or more regions of a substrate 10. In other embodiments, the system 100 may comprise other substrate processing modules that require precise handling and positioning of the substrates for processing.

Figure 1A is a schematic plan view of system 100 illustrated in Figure 1. Figures 1 and 1A illustrate system 100 which has two processing nests 131 (in positions "1" and "3") each positioned both for transferring a processed substrate 10 to the outlet conveyor 112 and to receive an unworked substrate 10 from the inlet conveyor 111. Thus, in the system 100, the movement of the substrate generally follows the path "A" illustrated in Figures 1 and 1A. In this configuration, each of the other two processing nests 131 (in positions "2" and "4") is positioned under a processing head 102, so that a processing can be performed (for example silk-screen printing, jet printing of ink, removal of material) on the unprocessed substrates 10 placed on the respective processing nests 131

Such a configuration of parallel processing allows an increase in production capacity with a minimized footprint of the processing system. Although the system 100 is illustrated with two processing heads 102 and four processing nests 131, the system 100 can comprise additional processing heads 102 and / or processing nests 131 without departing from the scope of the present invention.

In one embodiment, the inlet conveyor 111 and the outlet conveyor 112 comprise at least one belt 116 for supporting and transporting the substrates 10 to a desired position in the system 100 using an actuator (not shown) that is in communication with the system controller 101. Although Figures 1 and 1A generally illustrate a substrate transfer system of the two-belt type, other types of transfer mechanisms can be used to perform the same substrate transfer and positioning functions without departing from the basic purpose of the invention. In one embodiment, the system 100 also comprises an inspection system 200, which is adapted to identify and inspect the substrates 10 before and after the processing has been carried out. The inspection system 200 may comprise one or more cameras 120 which are positioned to inspect a substrate 10 positioned in the loading / seating positions "1" and "3", as illustrated in Figures 1 and 1A. The inspection system 200 generally comprises at least one camera 120 (e.g., a CCD camera) and other electronic components which are capable of locating, inspecting, and communicating the results to the system controller 101. In one embodiment, the inspection system 200 locates the location of certain features of an input substrate 10 and communicates the inspection results to the system controller 101 for analysis of the orientation and position of the substrate 10 to assist in the precise positioning of the substrate 10 under a processing head 102 before carrying out the processing of the substrate 10.

In one embodiment, the inspection system 200 inspects the substrates 10 so that damaged or poorly processed substrates can be removed from the production line. In one embodiment, each processing nest 131 may contain a lamp, or other similar optical radiation device, to illuminate the substrate 10 positioned thereon so that it can be more easily inspected by the inspection system 200.

System controller 101 facilitates control and automation of the entire system 100 and may include a central processing unit (CPU) (not shown), memory (not shown), and auxiliary (or I / O) circuits (not shown). illustrated). The CPU can be any type of computer processor that is used in industrial settings to control different room processes and hardware devices (such as conveyors, detectors, motors, fluid dispensing devices, etc.) and monitor the system and processes of camera (such as substrate position, process times, signal detectors etc.). The memory is connected to the CPU, and may be one or more readily available, such as random access memory (RAM), read-only memory (ROM), floppy disk, hard disk, or any other form of storage. digital, local or remote. Software instructions and data can be encoded and stored in memory to drive the CPU. Auxiliary circuits are also connected to the CPU to aid the processor in a conventional manner. Auxiliary circuits may include cache circuits, power supply circuits, clock circuits, input / output circuitry, subsystems, and the like. A program (or computer instructions) readable by the system controller 101 determines which tasks can be performed on a substrate. Preferably, the program is software readable by the system controller 101, which comprises a code for generating and storing at least position information of the substrate, the movement sequence of the various controlled components, information of the substrate inspection system, and any other corresponding combination.

In one embodiment, the two processing heads 102 used in the system 100 can be conventional screen printing heads available from Applied Materials Baccini S.p.A. which are adapted to deposit the material according to a desired pattern on the surface of a substrate 10 arranged on a processing nest 131 in position â € œ2 "or" 4 "during a screen printing process. In one embodiment, the head 102 comprises a plurality of actuators, e.g., actuators 105 (e.g. stepper motors or servomotors) which are in communication with the system controller 101 and are used to adjust the position and / or angular orientation of a template of silk-screen printing (not shown) arranged in the processing head 102 with respect to the substrate 10 which is printed.

In one embodiment, the screen printing template is a leonine or metal plate with a plurality of holes, slots, or other openings made between them to define a pattern and arrangement of the screen printed material on a surface of a substrate. 10. In one embodiment, the screen printed material may comprise a conductive ink or paste, a dielectric ink or paste, a dopant gel, an etching gel, one or more masking materials, or other conductive or dielectric materials.

In general, the layers to be deposited on the surface of a substrate 10 are aligned to the substrate 10 in an automatic manner, orienting the screen printing template using the actuators 105 and the information received from the system controller 101 from the inspection system 200. In one embodiment, the processing heads 102 are adapted to deposit a metal-containing or dielectric-containing material on a solar cell substrate which has a width between about 125 mm and 156 mm and a length between about 70 mm and 156 mm.

In particular, in a first printing step, by using a first printing screen, or screen printing mask, of the screen printing station, a first layer 12 of a first metallic material is deposited in order to optimize, for example, the contact of the first layer 12 itself and, therefore, of the line 11 with the substrate 10 of semiconductor material. The first layer 12 is deposited according to a predetermined printing profile.

The first metallic material can, for example, comprise a vitrifiable mixture so as to penetrate the insulation layer and make good electrical contact with the substrate 10 itself.

The materials for the batch, as well as the materials for the insulating layer, are not limited and can be any material readily available commercially.

The first printing screen is shaped to create at least a part of the overall pattern to be printed and has a printing mask such as to define the dimensions of the portions of the pattern made with the first layer 12.

In a second printing step, by using a second printing screen of the silk-screen printing station, a second layer 14 is deposited by dispensing a second metallic material. The second layer 14 is superimposed, at least partially, on the first layer 12 as illustrated in Figures 2 and 3.

In this case, the second printing screen is designed to deposit the second layer 14 on the basis of a second printing profile, substantially similar to the first profile, but having a smaller area and corresponding to the contact surface with said layer 12.

The second printing screen, or screen printing mask, has a plurality of distinctive elements, such as holes, slots, or other openings that are narrower in width than those of the first printing screen so as to be defined, after the printing of said second layer 14, called the smallest area of the contact surface. The width values of the first print screen can be in the range from approximately 80 Î1⁄4Ï € ι to approximately 120 Î1⁄4Ï € ι, while the typical width values of the second print screen are between approximately 20 and approximately 40 Î1 ⁄4Ï € \, lower than those of the first printing screen.

The second metallic material can, for example, be devoid of the aforesaid vitrifiable mixture, being made up only of purely conductive materials, so as to optimize the electrical contact resistance between the layers 12, 14 and the conductivity of the conductive lines 11.

The printing process can also provide for further printing steps subsequent to the second for the realization, for example always by means of the second screen, of further metal layers exactly superimposed on the second layer 14, until a predetermined overall thickness is reached such as to create a line conductive 11 according to desired electrical parameters.

Alignment steps are provided upstream of a corresponding printing step, in which, by means of the actuators 105, the screen printing mask is aligned with respect to the substrate 10 so as to print the corresponding layers in the desired position.

The printing process can also foresee detection phases, coordinated with the alignment phases in which, by means of the inspection system 200, information relating to the substrates 10 being processed and the relative printing phases are acquired.

It is understood that the printing steps can be carried out in as many printing stations and that further processing steps can be provided between the printing steps, such as, for example, as many drying steps of the layers deposited in a drying oven or other suitable device.

The drying steps can be carried out in a drying oven adjacent to the processing heads 102 of the system 100, for example in position "4", or in the oven 199. An example of an oven that can be used is further described in the patent application. of the Applicant and having serial numbers 12 / 274,023, filed on October 24, 2008, which is incorporated herein by reference.

Figures 4A to 4D illustrate an operational sequence of some processing steps of the process according to the present invention.

In a first printing step (Figure 4A) on a substrate 10 of semiconductor material provided with an insulating coating or layer 16, such as an oxide layer, a layer of etching paste 18 is deposited according to a predetermined and desired profile of press.

The profile is determined in such a way as to form, for example, a selective emission structure according to a pattern in a crystalline solar cell. An example of an etching paste comprising an etching gel which can be used to form one or more layers according to a scheme is further discussed in the Applicant's US patent application and having serial numbers 12 / 274,023.

In a subsequent step (Figure 4B), the etching paste, left to act for a desired time, performs a removal / erosion action of a corresponding portion of the insulating layer 16, so as to define a printing seat 20 shaped according to the print of the etching paste 18. The material removal processing can be accomplished by using an etching paste which reacts with the insulating layer 16 to form a volatile etching product.

It is understood that after the engraving step, a cleaning step can be performed, carried out in a known way, for example through known dry or wet cleaning processes, so as to remove any impurities, or residues, of material from the printing site. 20.

In one embodiment, the cleaning process can be carried out by wetting the surfaces of the substrate 10 with a cleaning solution. In one embodiment, the cleaning process can be accomplished by wetting the substrate with a cleaning solution such as an SCI cleaning solution, an SC2 cleaning solution, an HF-last type cleaning solution, an ozonated water solution, a solution of hydrofluoric acid (HF) and hydrogen peroxide (H202), or other suitable and economical cleaning process.

In a second printing stage (Figure 4C) a first metal paste 22 is laid, according to the same printing profile of the previous printing stage, so as to lay the paste 22 in the seat 20. In this way it is possible to obtain a better biting of the first paste 22 to the substrate 10. The first metal paste 22 may, for example, comprise a vitrifiable mixture, as described above.

It is also possible, with the same height of the printing profiles, to obtain a lower height than that of the finished substrate, so as to define a protection seat for the conductive lines 11.

In a third printing step (Figure 4D) a second metal paste 26 is laid exactly above the first metal paste 22, always according to the same printing profile. Also in this case the second metallic paste 26 can be free of any vitrifiable mixtures, optimizing in this case the conductive properties of the layer thus created and of any further layers deposited above. The second metal paste 26 can only contain conductive materials, such as silver (Ag) or tin (Sn).

Figures 5A to 5D illustrate an operational sequence of some processing steps of a different embodiment of the method according to the present invention.

In a first printing step (Figure 5A) a dopant paste 28, such as a paste containing phosphorus or the like, or a doping ink, is deposited on a substrate 10 of semiconductor material, by means of a first printing screen according to a predetermined and desired profile of press.

The doping paste is chosen from among those readily available on the market, while its concentration is chosen on a case-by-case basis, this being within the normal knowledge of an expert in the sector.

In a subsequent step (Figure 5B), the dopant paste 28 diffuses inside the substrate 10 so as to define a doped portion 29, substantially according to the printing profile realized in the deposition of the dopant paste 28 and in such a way as to have a thickness desired. This diffusion step is carried out, for example, by means of a thermal annealing process or other known process of diffusion of dopant materials in substrates of semiconductor material.

The time and temperature values of the diffusion phase are coordinated with each other and are chosen from time to time on the basis of the intrinsic characteristics of the materials, this being within the reach of the knowledge of an average technician in the sector.

In a second printing phase (Figure 5C) a first metal paste 22 is laid, using a second printing screen having a narrower printing profile in width than that of the doping paste 28, so as to overlap, substantially in a central way , the first metal paste 22 on the doped region 29.

In one embodiment, the width of the printing profiles is between 50 and 110 microns.

In a third printing phase (Figure 5D) a second metal paste 26 is laid on top of the first metal paste 22, using a third printing screen having a narrower printing profile in width than that of the paste 22, so as to overlap substantially in a central way, the second dough 26 on the dough 22. Also in this case the second dough 26 is chosen in such a way as to optimize the contact with the first dough 22 below.

Figures 6 and 7 show a different embodiment of a multilayer printing for the realization of conductive lines, in which a first metal layer 12, having a width L1, is printed on a substrate 10, as previously described, having a width L1, and on which a second metal layer 26 is then deposited having a width L2 greater than the width L1. In one embodiment, the width is in the range of 30-150 microns. In this way, it is possible to define a portion of shadow 32 on the substrate 10 having inclined shading profiles and therefore narrower than that which would be obtained by printing overlapping layers having the same width. In this way it is possible to increase the effective portion of the substrate affected by the solar energy conversion, thus increasing the overall yield of the solar cell.

With reference to Figures 8A-8D, which illustrates the process for obtaining the multilayer printing of Figures 6 and 7, in a first printing step (Figure 7A) on a substrate 10 of semiconductor material provided with a coating, or layer, insulator 16, for example made by means of suitable oxides or nitrides or a sacrificial silicon layer, a layer of etching paste 18 is deposited according to a predetermined and desired printing profile such as to define the width Li of the first layer 12.

In a subsequent step (Figure 8B), the etching paste, left to act for a desired time, performs a removal / erosion action of a corresponding portion of the insulating layer 16, so as to define a printing seat 20 shaped according to the print of etching paste 18.

It is understood that, similarly to what has already been described above, one or more cleaning phases can be performed after the engraving phase, carried out in a known way, for example by known dry or wet cleaning processes, so as to remove any impurities, or residues, of material from the printing room 20.

In one embodiment, the cleaning process can be carried out by wetting the surfaces of the substrate 10 with a cleaning solution. In one embodiment, the cleaning process can be accomplished by wetting the substrate with a cleaning solution, such as SCI cleaning solution, SC2 cleaning solution, HF-last type cleaning solution, ozonated water solution , a solution of hydrofluoric acid (HF) and hydrogen peroxide (H202), or other suitable and economical cleaning process.

In a second and third printing phase, successive to each other (Figure 7C), the first metal layer 12 is deposited, according to the same printing profile of the first printing phase, so as to deposit the layer 12 in the aforementioned seat 20, according to the same printing profile has a width Lf and the second metal layer 14 partially superimposed on the first layer 12 and having a width L2.

It is understood that after each third and fourth printing step one or more heating steps can be performed, carried out per se in a known way and not described here, suitable for solidifying and / or stabilizing the layers 12, 14.

In a fourth printing step (Figure 8D) a second layer of engraving paste 18a is deposited, according to a printing profile substantially complementary to the printing profile with which the second layer of metal material 14 was made.

In a subsequent step, the etching paste 18a, as previously described, left to act for a desired time, carries out a removal / erosion action of the entire portion of the insulating layer 16, in order to achieve the final printing configuration of the Figures 5 and 6. Therefore, in addition to optimizing the conductive lines deposited through successive printing steps of layers made with different materials, each chosen according to the substrate 10 or the layer immediately below, it is also possible to create layers according to substantially different printing profiles , such as to increase the overall yield of the solar cells thus made, substantially reducing the portion of shadow 32. It is clear that modifications and / or additions of parts and / or phases can be made to the multilayer printing process described up to now, without for this reason it is beyond the scope of the present invention.

It is also clear that, although the present invention has been described with reference to some specific examples, a person skilled in the art will certainly be able to carry out many other equivalent forms of multilayer printing process, having the characteristics expressed in the claims and therefore all falling within the scope of 'scope of protection defined by them.

Claims (6)

CLAIMS 1. Printing process for printing one or more print traces on a printing support, or substrate, comprising two or more printing steps in each of which, by means of printing means, a layer of material is deposited on the support printing according to a predetermined printing profile, characterized by the fact that in each printing phase, subsequent to the first, each layer of material is superimposed, at least partially, on the layer of material printed in the previous printing phase, so that each layer of material printed has an identical or different printing profile with respect to at least one layer of underlying material so as to create an equal or different contact area with respect to at least an area previously printed, since the material deposited in each printing step is the same , or different, with respect to the material deposited in at least one of the underlying prints. 2. Process as in claim 1, characterized in that it comprises alignment steps, each provided upstream of a corresponding printing step, in which, directly or indirectly, by means of alignment means, the printing support and the printing means are mutually aligned to print a corresponding layer of material in a desired position. 3. Process as in claim 2, characterized by the fact that it comprises a plurality of detection phases, each coordinated with a corresponding alignment step in which, by means of detection means, information relating to the substrates being processed and the relative printing steps are acquired. . 4. Process as in claims 1 to 3, characterized in that it comprises at least one printing step in which an engraving material is dispensed which is capable of eroding at least part of the printing substrate and / or one of its coating and / or coating layers. a layer of material already printed, to define a place for depositing a layer of material. 5. Process as in any one of the preceding claims, characterized in that between two or more printing steps, further processing steps of the substrates are carried out, said further processing steps comprising one and / or the other of the following steps : diffusion in gaseous state of doping materials, chemical attack phases, control and supervision phases, testing phases. 6. Process as in claim 4 or 5, characterized in that it comprises at least one step of cleaning the printing support and / or the deposition seat / s, to eliminate any residual impurities before printing a corresponding layer of material ,