RU2848424C1 - Method of solar cells module manufacturing - Google Patents

Abstract

FIELD: electric elements.

SUBSTANCE: invention can be used for making three-stage solar cell modules on a germanium substrate in spacecraft solar panels. In the solar cells module manufacturing method, as the adhesion promoter, on the solar cell back side and the protective substrate inner side the first adhesive layer of epoxy adhesive “ВК-9” is applied by drop spraying, then applying a second adhesive layer of adhesion promoter “П-21”, in addition, in order to control the spreading of the silicone filler when gluing, the solar cell is turned over by fixing the support frames with guide holes on the pins of the detachable bracket, and after the silicone filler spreading, performing the solar cell and buses surface mechanical cleaning by means of two counter-rotating rollers, then performing the “СИЭЛ” silicone compound gelling with the high-viscosity consistency by the solar cell low-temperature treatment, after which performing the tires dry mechanical cleaning in the areas adjacent to the solar cell, then performing additional low-temperature treatment of solar cell to increase chemical resistance of “СИЭЛ” silicone compound, and after removing the solar cell from the support frame, performing the solar cell and tires surface finish cleaning using solvents, wherein magnetic clamp of flexible Kovar plates is applied to tires to lock the tires and prevent their deformation.

EFFECT: providing the possibility of increasing productivity by reducing the gelation time of the “СИЭЛ” compound with a highly viscous consistency, reducing the labour intensity of gluing solar cells by eliminating air cavities along the edge of the solar cell.

1 cl, 8 dwg

Description

The invention relates to electrical engineering, namely, to methods for manufacturing modules of three-cascade solar cells on a germanium substrate in solar batteries of spacecraft.

A method for manufacturing a solar cell module is known (see Russian Federation Patent No. 275820, published on October 26, 2021), adopted as an analogue, in which a layer of adhesion promoter is applied to the back side of solar cells by drop spraying, then a layer of SIEL silicone compound is applied by drop spraying to the front, back sides of the solar cell and to the surface of the protective substrate, heat treatment of the above layers of SIEL silicone compound is performed, then silicone filler is applied, a glass plate and a protective fiberglass substrate are glued to the silicone filler, while SIEL silicone compound of brand 159-322 "A" is used as a silicone filler.

The disadvantage of the analogue is the technological complexity of cleaning the solar cell from excess silicone filler SIEL brand 159-322 "A" when gluing the glass plate and protective fiberglass substrate due to the uncontrolled transition of the silicone compound SIEL from a liquid to a hardened state when heated.

The features of the analog, common with the proposed method for manufacturing a solar cell module, are as follows: a layer of adhesion promoter is applied to the back side of the solar cells, the solar cells are heat-treated, then a silicone filler is applied, and a protective glass plate and a protective fiberglass board are glued onto the silicone filler, while the SIEL silicone compound is used as the silicone filler.

A method for manufacturing a solar cell module is known (see Russian Federation Patent No. 2804057, published on September 26, 2023), adopted as a prototype, in which a glass plate, a solar cell and a protective substrate are fixed on support frames made of imidoflex film, in which guide holes are made, thereby ensuring the alignment of the glass plate, film, solar cell and protective substrate during subsequent gluing, then an adhesion promoter layer is applied to the back of the solar cells, heat treatment of the solar cells is performed, then a silicone filler is applied, gluing of the protective glass plate and the protective substrate onto the silicone filler is performed, while a mixture of components of the SIEL silicone compound brand 159-322 "A" is used as the silicone filler, taken in the ratio: paste 1 volume part, hardener 0.8 ÷ 1.2 volumetric parts, and after the gelation of the SIEL silicone compound with a highly viscous consistency, excess silicone filler is removed by mechanical cleaning, then a fixed deflection of the solar cell is created and heat treatment is performed.

A drawback of the prototype is that gelation of the highly viscous SIEL silicone compound (a state characterized by the ability to draw thin strands of SIEL compound) is achieved at room temperature after 4 to 4.5 hours, which reduces the throughput of the operation. Furthermore, during mechanical cleaning, unwanted air suction may occur along the edge of the solar cell due to localized deflection of the fiberglass board and a decrease in the adhesive strength of the silicone filler due to the passivating effect of the aminoalkyltrialkoxysilane, which is part of the Penta P-12E adhesive sublayer, on the platinum catalyst of SIEL. This necessitates additional work to fill these areas, increasing labor intensity.

The prototype features common with the proposed method for manufacturing a solar cell module: a glass plate, a solar cell, and a protective substrate are fixed on support frames in which guide holes are made, thereby ensuring that the glass plate, solar cell, and protective substrate are aligned with each other during subsequent gluing, then an adhesion promoter layer is applied to the back of the solar cells, the solar cells are heat treated, then a silicone filler is applied, the protective glass plate and the protective substrate are glued to the silicone filler, while a mixture of components of the SIEL silicone compound grade 159-322 "A" is used as the silicone filler, taken in the ratio: paste 1 volume part, hardener 0.8 ÷ 1.2 volume parts, after gelling of the SIEL silicone compound with a highly viscous consistency, excess silicone filler is removed by mechanical cleaning, then a fixed the solar cell is bent and heat treated.

The distinctive features that ensure that the proposed method for manufacturing a solar cell module meets the "novelty" criterion are as follows: a first adhesive layer of VK-9 epoxy glue is applied by drop spraying to the back of the solar cell and the inner side of the protective substrate as an adhesion promoter, then a second adhesive layer of P-21 adhesion promoter is applied, in addition, to control the spreading of the silicone filler during gluing, the solar cell is turned over by securing support frames with guide holes on the pins of the removable bracket, and after the silicone filler has spread, the surface of the solar cell and the tires are mechanically cleaned by means of two counter-rotating rollers, then gelation of the SIEL silicone compound with a highly viscous consistency is carried out by low-temperature treatment of the solar cell, after which dry mechanical cleaning of the tires in the areas adjacent to the solar cell is carried out, then additional low-temperature treatment of the solar cell is performed for increasing the chemical resistance of the SIEL silicone compound, and after removing the solar cell from the support frame, a final cleaning of the surface of the solar cell and the tires is carried out using solvents, while magnetic clamping of flexible kovar plates is applied to the tires to fix the position of the tires and prevent their deformation.

The technical result achieved by the proposed method for manufacturing a solar cell module consists of increasing productivity by reducing the gelation time of the SIEL compound with a highly viscous consistency, and reducing the labor intensity of gluing solar cells by eliminating air cavities along the edge of the solar cell.

The above technical result is achieved by the fact that in the proposed method for manufacturing a solar cell module, a glass plate, a solar cell and a protective substrate are fixed on support frames in which guide holes are made, thereby ensuring the alignment of the glass plate, the solar cell and the protective substrate with each other during subsequent gluing, an adhesion promoter layer is applied to the back side of the solar cells, heat treatment of the solar cells is performed, a SIEL silicone filler is applied, gluing of the protective glass plate and the protective substrate onto the silicone filler is performed, wherein a mixture of components of the SIEL silicone compound of brand 159-322 "A" is used as the silicone filler, taken in the ratio: paste 1 volume part, hardener 0.8 ÷ 1.2 volume parts, after gelation of the SIEL silicone compound with a highly viscous consistency, excess silicone filler is removed by mechanical cleaning, create a fixed deflection of the solar cell and perform heat treatment, while as an adhesion promoter, the first adhesive layer of epoxy glue VK-9 is applied by drop spraying to the back side of the solar cell and the inner side of the protective substrate, then a second adhesive layer of adhesion promoter P-21 is applied, in addition, to control the spreading of the silicone filler during gluing, turn the solar cell over by fixing the support frames with guide holes on the pins of the removable bracket, and after the silicone filler has spread, mechanical cleaning of the surface of the solar cell and tires is performed by means of two counter-rotating rollers, then gelation of the SIEL silicone compound with a highly viscous consistency is carried out by low-temperature treatment of the solar cell, after which dry mechanical cleaning of the tires in the areas adjacent to the solar cell is performed, additional low-temperature treatment of the solar cell is performed to increase the chemical resistance of the silicone SIEL compound, and after removing the solar cell from the support frame, a final cleaning of the surface of the solar cell and the busbars is carried out using solvents, while magnetic clamping of flexible kovar plates to the busbars is used to fix the position of the busbars and prevent their deformation.

To substantiate the compliance of the proposed method for manufacturing a solar cell module with the "inventive step" criterion, an analysis of known solutions was conducted using literature and the invention registry. No distinguishing features of the claimed solution that, when combined with known features, would yield the aforementioned technical result were found in the literature or the invention registry. Therefore, in the authors' opinion, the proposed method for manufacturing a solar cell module meets the "inventive step" criterion.

As a two-layer adhesive coating on the back side of the solar cell and on the inner side of the protective substrate (fiberglass board), adhesive layers of VK-9 epoxy glue and P-21 adhesion promoter (TU 1-535-28-1295-2012, manufacturer National Research Center "Kurchatov Institute", Moscow) are formed. These layers have a significantly smaller deactivating effect on the platinum catalyst of the SIEL silicone filler in comparison with the Penta P-12E adhesion promoter (TU38.303-04-06-90, manufacturer Penta-91 LLC), while providing the viscosity and stickiness of the filler necessary to prevent air cavities along the edge of the solar cell. The support frames with the layers to be bonded are secured to the guide pins of a removable bracket. This allows for monitoring the silicone filler spread during bonding by inverting the solar cell without removing the support frame from the guide pins. After the silicone filler has spread, the surface can be mechanically cleaned (wiped) to remove excess uncured filler from both sides of the solar cell and busbars using counter-rotating rollers. Low-temperature treatment is used to accelerate the gelation of the silicone compound. The support frame with the solar cell is secured to a removable bracket and suspended, ensuring uniform heating of the layers to be bonded on both sides. Excess highly viscous silicone compound is removed from the busbar surface in areas adjacent to the edge of the solar cell (in an angular busbar and solar cell configuration), which are difficult to reach with the wiping roller. A thin polymer film of SIEL remains on the surface of the busbars and solar cell. Then, a low-temperature treatment is performed to increase the chemical resistance of the SIEL silicone filler to solvents and partially cure it. The surface SIEL film remains easily removable. A final cleaning of the solar cell and busbars is performed using solvents, protecting the busbars from deformation by magnetically pressing flexible Kovar plates to the busbars.

An example of a specific implementation of the proposed method for manufacturing a solar cell module is illustrated in Fig. 1÷8.

Fig. 1 shows a view of a removable bracket with guide pins. Fig. 2a, b show views of the support frame with a solar cell fixed on the guide pins of the removable bracket: a) - back side; b) - with the front side of the solar cell facing up. Fig. 3a, b, c, d show views of the front side of the solar cell and busbars: a) - before; 6, c) - during; d) - after mechanical cleaning by means of rotating rollers. Fig. 4 shows a view of solar cells during heat treatment on a suspension using a removable bracket. Fig. 5 shows a view of a solar cell during cleaning of the areas of the busbars adjacent to the edge of the solar cell. Fig. 6 shows a view of a solar cell during final cleaning using solvents. Fig. 7 shows a view of a section of the busbar adjacent to the solar cell after cleaning. Fig. 8 shows a view of a solar cell module.

A specific application example of the proposed solar module fabrication method utilizes three-stage photovoltaic converters with a GaInP/GaInAs/Ge epitaxial structure grown on a germanium substrate. The back contacts of the solar cells are made of sequentially deposited Cr/Au/Ag/Au metallization layers. The lead wires are made of silver with a thickness of ~16 µm.

The protective glass plate, solar cell, and fiberglass board are secured to support frames with guide holes. A first adhesive layer of VK-9 epoxy adhesive is applied by droplet spraying to the back of the solar cells and the inner side of the protective substrates (100-µm-thick fiberglass boards) as an adhesion promoter. After heat treatment, a second adhesive layer of P-21 adhesion promoter is applied. The solar cells are heat-treated at 100°C for approximately 30 minutes. The VK-9 epoxy adhesive coating maintains the flatness of the protective substrates during application and heat treatment of the P-21 adhesive sublayer, which is necessary to prevent deflection of the protective substrate and the formation of air pockets along the edge of the solar cell during subsequent gluing. The proposed adhesive coating P-21 based on organosilicon resins has a minimal deactivating (“poisoning”) effect on the platinum catalyst of the SIEL silicone compound and is suitable for increased thermal vacuum loads.

Next, the glass plate, solar cell, and fiberglass board are glued onto the silicone filler, which is a mixture of components of the SIEL silicone compound brand 159-322 "A" (TU 2157-170-00209013-2016, manufactured by JSC GNIIKHTEOS), taken in the following volumetric ratio: paste - 1 part, hardener - 1 part. In this case, the layers to be glued are aligned by means of guide holes in the support frames, which are fixed on the pins of the removable bracket of the gluing device (see Figs. 1, 2). As the filler spreads, a layer of excess silicone compound is formed on the surface of the solar cells and busbars (see Fig. 3a). Excess silicone compound is removed by dry mechanical wiping using two counter-rotating (at ~240 rpm) foam rollers wrapped in lint-free TX-609 wipes (see Fig. 3b, c). The rollers provide gentle, even pressure against the surface of the solar cell and busbars, leaving a thin polymer film (see Fig. 3d) with a chemical composition altered by contact with the wiping material. This film is easily removed later with solvents. A removable clamp allows dry cleaning of solar cells from both sides without removing the support frames from the guide pins, preventing misalignment of the bonded layers with uncured silicone filler. The solar cells are then subjected to low-temperature processing at ~50°C in a heating cabinet. To ensure uniform heating from both the front and back, the solar cells are suspended on support frames secured with removable brackets (see Fig. 4). The SIEL silicone compound acquires a highly viscous consistency in approximately 30 minutes, which is more efficient than maintaining it at room temperature.

The surface of the busbars in areas directly adjacent to the solar cell is wiped clean of any remaining thickened silicone compound using a short-bristled brush (see Fig. 5). This prevents air pockets around the solar cell perimeter due to the high adhesive strength and elasticity of the SIEL compound used, as well as the minimized toxic effects of the epoxy adhesive filler and P-21 adhesion promoter on the platinum catalyst. The solar cells are then further low-temperature treated at ~50°C for 60 minutes to improve the chemical resistance of the SIEL silicone compound to solvents. This cures the SIEL silicone filler. The support frames are removed from the guide pins of the removable bracket. The solar cells are separated from the support frames and a final cleaning of the surface from the polymer film is carried out using solvents (a mixture of acetone and gasoline), while in order to prevent deformation of the tires from the impact of the cleaning material, magnetic clamping of flexible kovar plates is applied to the tires (see Fig. 6, 7).

The use of a combination of adhesive layers of VK-9 and P-21 epoxy adhesives helps maintain the flatness of the protective fiberglass substrate during gluing and minimizes the deactivating effect of catalytic "poisons" on the platinum catalyst of the SIEL silicone filler; dry mechanical cleaning with counter-rotating rollers ensures gentle removal of excess silicone filler from the surface of the solar cell and busbars; the use of a removable bracket allows mechanical wiping from both sides of the solar cell and busbars without removing the support frames from the guide pins and misaligning the layers being glued; in addition, low-temperature treatments ensure uniform heating of the solar cell, which is suspended on a removable bracket; final cleaning of the solar cell and busbars from the polymer film is carried out using solvents, while magnetic clamping with flexible kovar plates is used to fix the position of the busbars and prevent their deformation. Solar cells connected via busbars form a photovoltaic module (see Fig. 8). The SIEL compound grade 159-322A used as a filler does not require degassing and ensures a strong and flexible adhesive bond during vacuum thermal cycling.

Claims (1)

A method for manufacturing a solar cell module, including fixing a glass plate, a solar cell and a protective substrate on support frames in which guide holes are made, thereby ensuring the alignment of the glass plate, the solar cell and the protective substrate during subsequent gluing, applying an adhesion promoter layer to the back of the solar cells, performing heat treatment of the solar cells, applying SIEL silicone filler, gluing the protective glass plate and the protective substrate onto the silicone filler, wherein a mixture of components of SIEL silicone compound grade 159-322 "A" is used as the silicone filler, taken in the ratio: paste 1 volume part, hardener 0.8 ÷ 1.2 volume parts, after gelling of the SIEL silicone compound with a highly viscous consistency, removing excess silicone filler by mechanical cleaning, creating a fixed deflection of the solar cell and performing heat treatment, characterized in that a first adhesive layer of VK-9 epoxy glue is applied by drop spraying as an adhesion promoter to the back side of the solar cell and the inner side of the protective substrate, then a second adhesive layer of P-21 adhesion promoter is applied, in addition, to control the spreading of the silicone filler during gluing, the solar cell is turned over by securing the support frames with guide holes on the pins of the removable bracket, and after the silicone filler has spread, the surface of the solar cell and the tires are mechanically cleaned by means of two counter-rotating rollers, then gelation of the SIEL silicone compound with a highly viscous consistency is carried out by low-temperature treatment of the solar cell, after which dry mechanical cleaning of the tires in the areas adjacent to the solar cell is carried out, an additional low-temperature treatment of the solar cell is carried out to increase the chemical resistance of the SIEL silicone compound, and after removing After removing the solar cell from the support frame, the surface of the solar cell and the busbars is cleaned using solvents, and in order to fix the position of the busbars and prevent their deformation, magnetic pressure of flexible kovar plates is applied to the busbars.