CN110690295A - Back contact solar cell module production method and back contact solar cell module - Google Patents

Abstract

The invention provides a method for producing a back-contact solar cell assembly and a back-contact solar cell assembly, and relates to the technical field of solar photovoltaics. The method includes: printing a conductive material on a first conductive site of a first piece to form a conductive boss; the first piece is one of a metal circuit board or a back-contact solar cell; when the conductive boss is provided Insulating glue is applied on the first sheet of the second sheet; the side of the second sheet with the second conductive site is laminated with the side of the first sheet with the conductive boss, so that the conductive The boss is abutted on the second conductive site to form a combined sheet; the second sheet is: the metal circuit board and the other one of the back contact solar cell sheet; the combined sheet and the two sides of the combined sheet are encapsulated The material and the cover material are laminated, so that the insulating glue forms an adhesive film, and the adhesive film adheres the first sheet piece and the second sheet piece. The present application improves electrical connection reliability and yield.

Description

Back contact solar cell module production method and back contact solar cell module

technical field

The present invention relates to the technical field of solar photovoltaic, in particular to a method for producing a back-contact solar cell assembly and a back-contact solar cell assembly.

Background technique

The back-contact solar cell module has no busbar on the front, and the positive and negative electrodes are arranged on the back of the battery, which reduces shading, effectively increases the short-circuit circuit of the battery, improves the energy conversion efficiency of the module, and has wide application prospects.

At present, the production method of the back-contact solar cell module is mainly as follows: a conductive adhesive is arranged between the back-contact solar cell and the metal circuit board, and during the lamination process, the back-contact solar cell and the metal circuit board are electrically connected through the conductive adhesive. and bonding.

In the above-mentioned production method of the back-contact solar cell module: in the lamination process, the back-contact solar cell sheet and the metal circuit board are electrically connected and bonded by conductive adhesive, and the above-mentioned electrical connection is unreliable and the yield rate is low.

SUMMARY OF THE INVENTION

The present invention provides a back-contact solar cell assembly and a production method for the back-contact solar cell assembly, aiming at solving the problems of unreliable electrical connection and low yield of the back-contact solar cell assembly.

According to a first aspect of the present invention, a method for producing a back-contact solar cell module is provided, comprising:

Conductive bosses are formed by printing conductive materials on the first conductive sites of the first piece; the first piece is one of a metal circuit board or a back-contact solar cell;

Coating insulating glue on the first piece provided with the conductive boss;

Laminating the side of the second sheet with the second conductive site and the side of the first sheet with the conductive boss, so that the conductive boss abuts on the second conductive site , forming a combined sheet; the second sheet is: the other one of the metal circuit board and the back-contact solar cell sheet;

Laminate the combined sheet, the packaging material and the cover material on both sides of the combined sheet, so that the insulating glue forms an adhesive film, and the adhesive film adheres the first sheet and the second sheet. Two pieces.

Optionally, the insulating glue includes: a solvent, a filler, a resin, and a curing agent;

Described solvent is at least one in alcohol solvent or ester solvent;

The filler includes: silica particles;

The resin is at least one of epoxy resin, acrylic resin and silicone resin;

The curing agent is at least one of aliphatic amine curing agent, aromatic amine curing agent, acid anhydride curing agent, linear synthetic resin oligomer, phenolic resin, and imidazole curing agent.

Optionally, in the insulating glue: the mass ratio of the solvent is 5% to 20%; the mass ratio of the filler is 10% to 40%; the mass ratio of the resin is 10% to 50%; The mass proportion of the curing agent is 1% to 10%.

Optionally, the silica particles are fumed silica particles.

Optionally, the filler further includes: at least one of alumina particles, talc powder, and boron nitride particles.

Optionally, the insulating glue has a viscosity of less than or equal to 9000mPa·s at 20-25°C.

Optionally, the coating thickness of the insulating glue is: 1 to 50 microns.

Optionally, the lamination step is performed before the step of applying insulating glue;

The applying insulating glue on the first piece provided with the conductive boss includes: on the first piece provided with the conductive boss, at most along the first piece Apply insulating glue in the direction of the three sides of the piece.

Optionally, before the lamination of the combined sheet and the encapsulation material and cover material on both sides of the combined sheet, the method further includes:

The first piece is preheated.

Optionally, the temperature of the preheating is 40°C to 80°C.

Optionally, before the printing a conductive material on the first conductive site of the first piece to form the conductive boss, the method further includes: stacking the packaging material and the cover material in sequence on the first side of the first piece ; the first side is opposite to the side on which the first sheet has a first conductive site;

The step of printing a conductive material on the first conductive site of the first piece to form a conductive boss includes: using the packaging material and the cover material as a printing support substrate, and at the first conductive site of the first piece Conductive bumps are formed by printing conductive material on the dots.

According to a second aspect of the present invention, there is also provided a back-contact solar cell assembly produced by any one of the aforementioned methods.

In the embodiment of the present invention, a conductive material is printed on the first conductive site of the first piece to form a conductive boss; the first piece is one of a metal circuit board or a back-contact solar cell; The first piece of the conductive boss is coated with insulating glue; the side of the second piece with the second conductive site is laminated with the side of the first piece with the conductive boss, so that the conductive boss abuts on the second conductive site to form a composite sheet; the second sheet is: the other one of the metal circuit board and the back-contact solar cell sheet; The combination sheet and the packaging materials and cover materials on both sides of the combination sheet are laminated, so that the insulating glue forms an adhesive film, and the adhesive film bonds the first sheet piece and the second sheet piece. pieces. Compared with the prior art, in the lamination process, the electrical connection and bonding between the metal circuit board and the back-contact solar cell are realized by the conductive adhesive. It is realized by fusion with the conductive sites on the back-contact solar cells, resulting in low electrical connection reliability and low yield. In the present application, a conductive material is printed on the first conductive site of the first piece to form a conductive boss, and insulating glue is applied on the first piece provided with the conductive boss; Cured and cross-linked into an adhesive film. On the one hand, the adhesive film has a good buffering ability to external forces, which can largely avoid the back contact of the solar cell sheet under the circumstance of external force. At the same time, the electrical connection between the metal circuit board and the back-contact solar cell is mainly through the stacking of the first piece and the second piece, and the conductive boss abuts on the first piece and the second piece. Realized on the second conductive site of the two pieces, a stable electrical connection can be realized basically without fusion, and the reliability of the electrical connection and the yield rate are improved. During the lamination process, by pressing the first piece and the second piece, the conductive boss and the second conductive site can be pressed more tightly, which further improves the electrical connection reliability and yield.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the drawings that are used in the description of the embodiments of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. , for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative labor.

FIG. 1 shows a flow chart of the steps of a production method of a back-contact solar cell assembly in an embodiment of the present invention;

FIG. 2 shows a schematic structural diagram of a back-contact solar cell in an embodiment of the present invention;

FIG. 3 shows a schematic structural diagram of an electrode in an embodiment of the present invention;

FIG. 4 shows a schematic structural diagram of a doped diffusion region in an embodiment of the present invention;

FIG. 5 shows a schematic structural diagram of a first sheet piece coated with insulating glue in an embodiment of the present invention;

FIG. 6 shows a schematic structural diagram of a back-contact solar cell assembly in an embodiment of the present invention;

FIG. 7 shows a flow chart of the steps of the production method of another back-contact solar cell module in an embodiment of the present invention;

FIG. 8 shows a schematic structural diagram of stacking packaging materials on the first side of the first sheet in an embodiment of the present invention;

FIG. 9 shows a schematic structural diagram of forming a conductive boss by printing on the first conductive site of the back-contact solar cell sheet according to an embodiment of the present invention.

Description of drawing numbers:

1- Silicon substrate, 2- Doping diffusion region, 3- Electrode, 11- Light receiving surface of silicon substrate, 5- Insulating glue, 12- Back side of silicon substrate 1, 21- P-type doping diffusion region, 22-N Type doped diffusion region, 31- negative electrode thin grid line, 32- positive electrode thin grid line, 33- negative electrode connecting electrode, 34- positive electrode connecting electrode, 10- front cover plate material, 20- front encapsulation material, 30- back contact solar energy Battery sheet, 40-adhesive film, 41-conductive boss, 50-metal circuit layer, 60-back packaging material, 70-back cover material.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Referring to FIG. 1, FIG. 1 shows a flow chart of steps of a production method of a back contact solar cell module in an embodiment of the present invention.

Step 101 , printing a conductive material on a first conductive site of a first piece to form a conductive boss; the first piece is any one of a metal circuit board or a back-contact solar cell.

In the embodiment of the present invention, the first sheet member is any one of a metal circuit board or a back-contact solar cell sheet. For example, the first piece may be a metal circuit board. Alternatively, the first sheet may be a back contact solar cell sheet. The number of back-contact solar cells is not particularly limited, and each back-contact solar cell may have approximately the same current characteristic or voltage characteristic. Specifically, it is set according to the needs of the back-contact solar cell assembly.

In the embodiment of the present invention, the back-contact solar cell is a solar cell with no busbar on the front side, and both the positive electrode and the negative electrode are arranged on the back side. In embodiments of the present invention, the back-contact solar cell sheet may be an IBC cell, a MWT cell, an EWT cell, or the like.

Referring to FIG. 2, FIG. 2 shows a schematic structural diagram of a back-contact solar cell in an embodiment of the present invention. In FIG. 2, 1 is a silicon substrate, 2 is a doped diffusion region, and 3 is an electrode. 11 is the light-receiving surface, that is, 11 is the front surface of the silicon substrate 1 . 12 is the back surface of the silicon substrate 1 . The doping diffusion region 2 and the electrode 3 are sequentially arranged on the backside of the silicon substrate 1 .

Referring to FIG. 3 , FIG. 3 shows a schematic structural diagram of an electrode in an embodiment of the present invention. The electrode 3 may include a negative electrode fine grid line 31 , a positive electrode fine grid line 32 , a negative electrode connection electrode 33 and a positive electrode connection electrode 34 . The positive electrode connection electrode 34 is electrically connected to the positive electrode fine grid line 32 , and the negative electrode connection electrode 33 is electrically connected to the negative electrode fine grid line 31 . The positive electrode thin grid lines 32 and the negative electrode thin grid lines 31 may be segmented thin grid lines or continuous thin grid lines. The positive connecting electrode 34 can be connected to all or part of the positive thin grid lines 32 in the same row or column, and the negative connecting electrode 33 can be connected to all or part of the negative thin grid lines 31 in the same row or column. The positive electrode thin grid line 32 may be in electrical contact with the P-type doping diffusion region, and the negative electrode thin grid line 31 may be in electrical contact with the N-type doping diffusion region.

Referring to FIG. 4 , FIG. 4 shows a schematic structural diagram of a doped diffusion region in an embodiment of the present invention. The doping diffusion region 2 may include a P-type doping diffusion region 21 and an N-type doping diffusion region 22 . The P-type doping diffusion regions 21 and the N-type doping diffusion regions 22 may be alternately arranged.

In the embodiment of the present invention, the function of the metal circuit board is to collect the current and the like of the back-contacted solar cells. The metal circuit board may be a metal circuit board with isolation formed by patterning. The patterning process may be to remove a part of the metal circuit board by means of laser, chemical etching or mechanical cutting to form voids, and the width of the voids may be greater than 50 microns, such as 200 microns or greater. A portion of the metal circuit board isolation is used for subsequent connection with the P-type doped diffusion region of the back-contact solar cell. The other part of the metal circuit board isolation is used for subsequent connection with the N-type doped diffusion region of the back-contact solar cell. By setting the isolation, the subsequent contact between the positive electrode and the negative electrode can be effectively avoided, and a short circuit can be effectively avoided.

In the embodiment of the present invention, the material of the metal circuit board may be at least one of copper, silver, aluminum, nickel, magnesium, iron, titanium, molybdenum, tungsten, and alloys thereof. For example, the material of the metal circuit board may be at least one element selected from copper, silver, aluminum, nickel, magnesium, iron, titanium, molybdenum, and tungsten. Alternatively, the material of the metal circuit board may be an alloy composed of at least two of copper, silver, aluminum, nickel, magnesium, iron, titanium, molybdenum, and tungsten. Alternatively, the material of the metal circuit board may be a combination of at least one element and at least one alloy.

In the embodiment of the present invention, the surface of the first sheet has several first conductive sites. The above-mentioned first conductive site is mainly used to collect or derive current. If the first piece is a back-contacting solar cell sheet, the first conductive site may be an electrode that is back-contacting the backlight surface of the solar cell sheet or a point to be connected to the electrode, and the like. For example, the first conductive site may be: a negative electrode thin grid line and a positive electrode thin grid line that are back in contact with the backlight surface of the solar cell sheet. Alternatively, the first conductive site may be: a negative electrode connection electrode, a positive electrode connection electrode, etc., which are in back contact with the backlight surface of the solar cell sheet. If the first piece is a metal circuit board, the first conductive site may be a position on the surface of the metal circuit board that is electrically connected to the electrode that contacts the solar cell on the back side. For example, the first conductive site may be a point on the surface of the metal circuit board, which is electrically connected to the negative electrode thin grid line and the positive electrode thin grid line that are in back contact with the backlight surface of the solar cell. Alternatively, the first conductive site may be a point on the surface of the metal circuit board that is electrically connected to the negative electrode connection electrode and the positive electrode connection electrode, which are in back contact with the backlight surface of the solar cell.

In the embodiment of the present invention, the conductive material may be at least one of solder paste, solder paste, isotropic conductive adhesive, anisotropic conductive adhesive, conductive ink, and conductive paste.

In the embodiments of the present invention, conductive protrusions may be formed by printing conductive materials on the first conductive sites of the first sheet by means of screen printing or inkjet printing. The above printing can be full-page printing to improve production efficiency.

For example, if the first piece is a metal circuit board, then a conductive bump is formed by printing a conductive material on the first conductive site of the metal circuit board. If the first sheet member is a back-contact solar cell sheet, then conductive protrusions are formed by printing on the first conductive sites of the back-contact solar cell sheet. For example, it is possible to print on the first conductive site of 100 back-contact solar cells at one time to form conductive bosses without printing conductive pads separately on each back-contact solar cell, so as to improve the Productivity.

The main function of the conductive boss is to electrically connect the first conductive site on the first piece with the second conductive site on the second piece, and collect or lead out current. The height of the conductive boss is set so as to be able to electrically connect the first conductive site and the second conductive site. In the embodiment of the present invention, the height of the conductive boss is not specifically limited.

Optionally, the shape of the conductive boss may be circular or rectangular. This embodiment of the present invention does not specifically limit this. The conductive bosses may include: conductive bosses in contact with the positive electrodes of the back-contacting solar cells, and conductive bosses in contact with the negative electrodes of the back-contacting solar cells. Alternatively, the conductive bosses may include: conductive bosses in contact with the anode thin grid lines back-contacting the solar cell sheet, and conductive bosses in contact with the negative electrode thin grid lines back-contacting the solar cell sheet. Alternatively, the conductive pads may include conductive pads in contact with the P-type doped diffusion regions of the back-contacting solar cell, and conductive pads in contact with the N-type doped diffusion regions of the back-contacting solar cells.

Optionally, the number of the conductive protrusions may be the same as or different from the number of the first conductive sites. The number of conductive bosses corresponding to a single back-contact solar cell sheet can be 20-5000. The number of conductive bosses corresponding to the entire back-contact solar cell assembly may be 1,000-50,000. The above-mentioned number of conductive bosses facilitates the collection and conduction of current. In this embodiment of the present invention, this is not specifically limited.

For example, if the first sheet is a single back-contact solar cell sheet, then 20-5000 conductive bosses can be formed by printing conductive material on the first conductive sites of the single back-contact solar cell sheet.

Step 102 , coating insulating glue on the first piece provided with the conductive bosses.

In the embodiment of the present invention, insulating glue is coated on the first sheet member provided with the conductive bosses, and the insulating glue is used to flow and fill the surrounding area of the conductive bosses. That is, by applying insulating glue, the insulating glue flows and fills the surrounding area of the above-mentioned conductive boss on the first piece, and during the subsequent lamination process, the insulating glue is cured and cross-linked into an adhesive film. On the one hand, the adhesive film has external force The better buffering capacity can largely avoid the above-mentioned problems of cracking or fragmentation of the adhesive film when the back-contact solar cell is subjected to external force, which improves the reliability of the back-contact solar cell module; on the other hand The process of the insulating glue flowing has formed a surrounding contact with the conductive bosses, and there is no need for subsequent laser openings, no need to buckle, and high production efficiency; at the same time, there is no need to open holes to remove the insulating adhesive material, which reduces costs; Laser ablation of the opening reduces the damage to the insulating adhesive material, which is beneficial to improve the reliability of insulation and bonding.

Referring to FIG. 5 , FIG. 5 shows a schematic structural diagram of a first piece coated with insulating glue according to an embodiment of the present invention. In FIG. 5, 5 is insulating glue, and 41 is conductive boss. It can be seen that the insulating glue 5 is filled around the conductive boss 41 .

In the embodiment of the present invention, during the lamination process, the subsequent insulating glue is cured and cross-linked to form an adhesive film. The main functions of the adhesive film can be: isolating each conductive boss, avoiding short circuit of each conductive boss, and during lamination During the process, the first sheet and the second sheet are bonded to provide certain thermal conductivity, hydrophobicity, etc.; at the same time, with the help of its better buffering capacity, it can largely avoid the situation that the back-contact solar cell is subjected to external force At the same time, the above-mentioned problems of cracking or fragmentation of the adhesive film. In this embodiment of the present invention, this is not specifically limited.

In the embodiment of the present invention, the above-mentioned step 102 may be performed after the first sheet member and the second sheet member are laminated, or the above-mentioned step 102 may be performed before the first sheet member and the first sheet member are laminated. In this embodiment of the present invention, this is not specifically limited.

In the embodiment of the present invention, if the insulating glue is applied before the first sheet and the first sheet are laminated, since the second sheet is not laminated, even if the insulating glue forms bubbles, the bubbles can be easily removed. Then, the insulating glue can be applied from multiple directions. For example, if the first sheet is a back-contact solar cell, then insulating glue can be coated along each edge of the back-contact solar cell.

In the embodiment of the present invention, the viscosity of the insulating glue at room temperature may be less than or equal to a preset viscosity, which is convenient for flow. Optionally, the insulating glue has a viscosity of less than or equal to 9000mPa·s at 20-25°C.

Specifically, the viscosity of the insulating glue at 20-25° C. may be less than or equal to 9000 mPa·s (mPa·s). For example, the viscosity of the insulating glue at room temperature may be 4000-8000 mPa·s (milliPascal "seconds). In this embodiment of the present invention, this is not specifically limited.

In the embodiment of the present invention, optionally, the coating thickness of the insulating glue is: 1 to 50 microns. Furthermore, the thickness of the adhesive film formed by subsequent curing and crosslinking is also 1 to 50 microns. Compared with the prior art, the use of polyolefin, etc. to form a thickness of more than 150 microns not only reduces the thickness of the back-contact solar cell module, but at the same time, the adhesive film of this thickness has good bonding reliability in the subsequent lamination process. , and has good thermal conductivity and hydrophobic properties.

In the embodiment of the present invention, optionally, the insulating glue includes: a solvent, a filler, a resin, and a curing agent; the solvent is at least one of an alcohol solvent or an ester solvent; the filler includes: two Silicon oxide particles; the resin is at least one of epoxy resin, acrylic resin and silicone resin; the curing agent is aliphatic amine curing agent, aromatic amine curing agent, acid anhydride curing agent, linear synthetic resin At least one of polymers, phenolic resins, and imidazole curing agents. The linear synthetic resin oligomer may contain chemical bonds such as -NH-, -CH ₂ OH-, -SH-, -COOH-, and -OH-.

Specifically, the above-mentioned insulating glue includes: a solvent, a filler, a resin, and a curing agent. The filler can have good thermal conductivity, and can subsequently absorb and disperse the heat generated by the back-contact solar cell module during use, thereby reducing the adverse impact of the hot spot effect on it and improving reliability. The filler may include submicron particles, thereby making the dispersibility of the insulating glue better. The insulating glue of this component has good flow performance, and at the same time, the adhesive film formed after cross-linking and curing has good flexibility and good bonding reliability. The filler may include silica particles. The use of silica particles is not only low in cost, but also has good adhesion performance and good thermal conductivity, etc., which in turn helps to reduce the production cost of back-contact solar cell modules, and improves adhesion reliability and thermal conductivity.

In the embodiment of the present invention, optionally, in the upper insulating glue: the mass ratio of the solvent may be 5% to 20%; the mass ratio of the filler may be 10% to 40%; the mass ratio of the resin may be 10% to 20% 50%; the mass proportion of curing agent can be 1% to 10%. The above-mentioned mass ratio distribution, the insulating glue has better flow performance, and at the same time, the adhesive film formed after cross-linking and curing has better flexibility and better bonding reliability.

For example, in the insulating glue, the mass ratio of the solvent may be 15%, the mass ratio of the filler may be 35%, the mass ratio of the resin may be 42%, and the mass ratio of the curing agent may be 8%.

For example, according to the mass ratio, the components of the insulating glue can be: 15% alcohol solvent, 35% silica particles, 42% acrylic resin, and 8% aromatic amine curing agent.

In the embodiment of the present invention, optionally, the silica particles are fumed silica particles. Specifically, fumed silica particles are smaller, have good dispersibility, are not prone to precipitation, can provide better bonding performance, have lower cost, and have better thermal conductivity. At the same time, the fumed silica particles have good hydrophobicity, which can largely reduce or prevent moisture from remaining in the manufacturing process of the back-contact solar cell module, thereby improving the reliability of the back-contact solar cell module.

In the embodiment of the present invention, optionally, the above-mentioned filler further includes: at least one of alumina particles, talc powder, and boron nitride particles. The above materials can further reduce the production cost of the back-contact solar cell module, and improve the bonding reliability and thermal conductivity.

In an embodiment of the present invention, optionally, the insulating glue further includes: at least one of a colorant, a wetting agent, and a dispersing agent. Specifically, the dispersant can be used to improve the dispersion performance of the insulating glue, make the performance uniform, improve the fluidity, and the like. The colorant can make the adhesive film formed by subsequent curing and crosslinking have a specific color, which is convenient for subsequent identification and inspection. In this embodiment of the present invention, this is not specifically limited.

Step 103: Laminate the side of the second sheet with the second conductive site and the side of the first sheet with the conductive bosses, so that the conductive bosses are in contact with the second conductive pads. On the site, a combined sheet is formed; the second sheet is: the other one of the metal circuit board and the back-contact solar cell sheet.

In the embodiment of the present invention, the second sheet member may be another one of the metal circuit board or the back-contact solar cell sheet except the first sheet member. For example, if the first piece of metal circuit board. Then, the second sheet member may be a back-contact solar cell sheet. Alternatively, if the first sheet is a back contact solar cell sheet. Then, the second piece may be a metal circuit board.

In the embodiment of the present invention, the surface of the second sheet has several second conductive sites. The above-mentioned second conductive sites are mainly used to collect or derive current. If the second piece is a back-contacting solar cell sheet, the second conductive site may be an electrode that is back-contacting the backlight surface of the solar cell sheet or a point to be connected to the electrode, and the like. For example, the second conductive site may be: a negative electrode thin grid line and a positive electrode thin grid line that are back in contact with the backlight surface of the solar cell. Alternatively, the second conductive site may be: a negative electrode connection electrode, a positive electrode connection electrode, etc., which are in back contact with the backlight surface of the solar cell sheet. If the second piece is a metal circuit board, the second conductive site may be a position on the surface of the metal circuit board, which is electrically connected to the electrode of the back contacting solar cell sheet. For example, the second conductive site may be: on the surface of the metal circuit board, a point that is electrically connected to the negative electrode thin grid lines and the positive electrode thin grid lines that are in back contact with the backlight surface of the solar cell. Alternatively, the second conductive site may be a point on the surface of the metal circuit board that is electrically connected to the negative electrode connecting electrode, the positive electrode connecting electrode, etc., which are in back contact with the backlight surface of the solar cell.

In the embodiment of the present invention, the side of the second sheet with the second conductive site may be stacked with the side of the first sheet with the conductive boss, so that the conductive boss abuts on the second conductive site, Form a composite sheet. In the present application, the conductive boss is mainly abutted on the second conductive site of the second piece to realize the electrical connection between the metal circuit board and the back-contacted solar cell, stable electrical connection can be achieved without fusion, and the electrical connection is improved. reliability and yield. During the lamination process, by pressing the first stacking part and the second stacking part, the conductive boss and the second conductive site can be pressed more tightly, which further improves the reliability of electrical connection and the yield.

Step 104: Laminate the composite sheet, the packaging material and the cover material on both sides of the composite sheet, so that the insulating glue forms an adhesive film, and the adhesive film adheres to the first sheet and the cover sheet. the second piece.

In the embodiment of the present invention, the packaging material and the cover plate material may be sequentially laminated on both sides of the composite sheet. The encapsulation material may include sealing materials such as EVA polyolefin, and the cover material may be a tempered glass cover or a polymer cover such as TPT, TPE, KPE, KPK, KPC or KPF. Hot pressing or bonding can be performed between the packaging material and the cover material. It should be noted that both the encapsulation material and the cover material on the light-receiving side of the composite sheet may have better light transmittance.

Laminate the combined sheet and the encapsulating material and cover material on both sides of the combined sheet to obtain a back-contact solar cell module. The above-mentioned insulating glue is used for curing and cross-linking to form an adhesive film during the lamination process, and the above-mentioned adhesive film is used for bonding the first piece and the second piece. The conductive boss is further abutted on the second conductive site of the second piece to form electrical contact, so as to enhance the current collection and conduction between the conductive boss and the second conductive site of the second piece.

The surface insulation resistance of the adhesive film can be in the range of 10 ¹² to 10 ¹⁶ Ω, so as to better avoid possible short circuits between the conductive bosses. This embodiment of the present invention does not specifically limit this.

The main functions of the adhesive film can be: isolating each conductive boss to avoid short circuit of each conductive boss; at the same time bonding the first piece and the second piece during the lamination process. In some cases, the adhesive film also provides certain thermal conductivity, hydrophobicity, etc. In this embodiment of the present invention, this is not specifically limited.

Referring to FIG. 6 , FIG. 6 shows a schematic structural diagram of a back-contact solar cell assembly in an embodiment of the present invention. In FIG. 6, 10 may be a front cover material, 20 may be a front encapsulation material, such as light-transmitting EVA or POE, 30 may be a back-contact solar cell, 40 may be an adhesive film, and 41 may be a conductive boss , 50 may be a metal circuit board, 60 may be a rear packaging material, and 70 may be a rear cover material. The front cover material 10 may be the side of the back contacting the solar cell module to receive light, and the rear cover material 70 may be the side of the back contacting the back light of the solar cell module. The front cover material 10 and the front packaging material 20 may have good light transmittance.

In the embodiment of the present invention, a conductive material is printed on the first conductive site of the first sheet to form a conductive boss, and insulating glue is applied on the first sheet provided with the conductive boss; the insulating glue is used in the lamination process. , cured and cross-linked into an adhesive film. On the one hand, the adhesive film has a good buffering ability to external force, which can largely avoid the back contact of the solar cell sheet under the condition of external force, and the above-mentioned insulating adhesive layer is cracked or fragmented At the same time, the electrical connection between the metal circuit board and the back-contact solar cell is mainly through the stacking of the first piece and the second piece, and the conductive boss abuts on the It is realized on the second conductive site of the second piece, and stable electrical connection can be realized basically without fusion, which improves the reliability of electrical connection and the yield rate. During the lamination process, by pressing the first piece and the second piece, the conductive boss and the second conductive site can be pressed more tightly, which further improves the electrical connection reliability and yield.

In the embodiment of the present invention, referring to FIG. 7 , FIG. 7 shows a flow chart of the steps of the production method of another back-contact solar cell module in the embodiment of the present invention.

Step 201, stacking packaging material and cover material in sequence on the first side of the first sheet; the first side is opposite to the side of the first sheet having the first conductive site; the first A piece is: either a metal circuit board or a back-contact solar cell.

Specifically, the first side of the first sheet member may be a side opposite to the side of the first sheet member having the first conductive site. For example, if the first piece is a back-contact solar cell, and the first conductive site is located on the side of the back-contact solar cell backlight, the first side may be the side of the first piece opposite to light-receiving. For example, if the first piece is a metal circuit board, the first conductive site is located on the side of the metal circuit board opposite to light receiving, and the first side may be the side of the metal circuit board opposite to the backlight. The encapsulation material may be stacked on the first side of the first sheet, followed by the lidding material. Referring to FIG. 8 , FIG. 8 shows a schematic structural diagram of stacking packaging materials on the first side of the first sheet according to an embodiment of the present invention. The first sheet member may be a plurality of back-contact solar cell sheets 30 . Since the encapsulation material is located on the side of the back-contact solar cell sheet opposite to receiving light, the encapsulation material may be the front encapsulation material 20 . Step 202 , using the packaging material and the cover material as a printing support substrate, printing a conductive material on the first conductive site of the first piece to form a conductive boss.

The above-mentioned step 202 can refer to the above-mentioned step 101. It should be noted that the laminated packaging material and the cover material can be used as the printing support substrate, and the conductive material can be printed on the first conductive site of the first piece to form the conductive boss. Furthermore, after the printing of the conductive bosses is completed, the above-mentioned laminated packaging material and cover plate material may not be removed, thereby reducing the number of steps and improving the production efficiency of the back-contact solar cell assembly.

Referring to FIG. 9 , FIG. 9 shows a schematic structural diagram of forming conductive bosses by printing on the first conductive site of the back-contact solar cell sheet according to an embodiment of the present invention. In FIG. 9 , the conductive pads 41 include conductive pads that are in electrical contact with the P-type doped diffusion regions 21 , and conductive pads that are in electrical contact with the N-type doped diffusion regions 22 .

Step 203: Laminate the side of the second sheet with the second conductive site and the side of the first sheet with the conductive boss, so that the conductive boss abuts on the second conductive On the site, a combined sheet is formed; the second sheet is: the other one of the metal circuit board and the back-contact solar cell sheet.

In this embodiment of the present invention, reference may be made to the foregoing step 103 for step 203, which is not repeated here in order to avoid repetition. Step 204: Apply insulating glue on the first sheet member provided with the conductive bosses at most along the directions of three sides of the first sheet member.

The above-mentioned step 204 can refer to the above-mentioned step 102. It should be noted that, if the second sheet is laminated on the first sheet, then, at most along the direction of the three sides of the first sheet, conductive protrusions are arranged on the first sheet. Insulating glue is coated on the first piece of the table. Further, it is avoided to apply insulating glue along the direction of the four sides of the first piece, which may easily lead to the formation of air bubbles during the flow of the insulating glue. However, since the second sheet is laminated on the first sheet first, if the insulating glue flows to form bubbles, the first sheet and the second sheet usually have low transparency, so the bubbles are not easily found. Even if bubbles are found, they are not easy to remove because they have been stacked. However, in the process of subsequent lamination and curing, the above-mentioned bubbles may expand and burst, and in severe cases, the first sheet or the second sheet is pushed away, so that the connection position of the first sheet and the second sheet is partially or completely separated, which is easy to Causes the problem of cracking or poor conduction of the back-contact solar cell module. By applying insulating glue on the first piece provided with the conductive bosses in the direction along at most three sides of the first piece, the formation of bubbles during the flow of the insulating glue can be avoided as much as possible, reducing or Avoid the problem of cracking or poor conduction of the back contact solar cell module.

Step 205, preheating the first piece.

In the embodiment of the present invention, as the temperature increases, the viscosity of the above-mentioned insulating glue decreases, and the flow performance increases. By preheating the first piece or the above-mentioned printing support substrate, etc., the insulating glue can flow quickly. Furthermore, the surrounding area of each conductive boss can be quickly filled, and the possibility of generating air bubbles during the flow of the insulating glue can be reduced.

In this embodiment of the present invention, optionally, the preheating temperature may be 40°C to 80°C. Under the above temperature range, there will be no adverse thermal influence on the first piece or the second piece, the packaging material or the cover material, etc., and the insulating glue has good flow performance and low probability of generating air bubbles. For example, the preset temperature may be 60°C.

Step 206: Laminate the composite sheet, the packaging material and the cover material on both sides of the composite sheet, so that the insulating glue forms an adhesive film, and the adhesive film adheres to the first sheet and the cover sheet. the second piece.

For the above step 206, reference may be made to the above step 104, and in order to avoid repetition, details are not repeated here.

In the embodiment of the present invention, a conductive material is printed on the first conductive site of the first sheet to form a conductive boss, and insulating glue is applied on the first sheet provided with the conductive boss; the insulating glue is used in the lamination process. , cured and cross-linked into an adhesive film. On the one hand, the adhesive film has a good buffering ability to external force, which can largely avoid the back contact of the solar cell sheet under the condition of external force, and the above-mentioned insulating adhesive layer is cracked or fragmented At the same time, the electrical connection between the metal circuit board and the back-contact solar cell is mainly through the stacking of the first piece and the second piece, and the conductive boss abuts on the It is realized on the second conductive site of the second piece, and stable electrical connection can be realized basically without fusion, which improves the reliability of electrical connection and the yield rate. During the lamination process, by pressing the first piece and the second piece, the conductive boss and the second conductive site can be pressed more tightly, which further improves the electrical connection reliability and yield.

It should be noted that, for the sake of simple description, the method embodiments are expressed as a series of action combinations, but those skilled in the art should know that the embodiments of the present application are not limited by the described action sequence, because According to the embodiments of the present application, certain steps may be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily all necessary for the embodiments of the present application.

In an embodiment of the present invention, a back-contact solar cell assembly is also provided. Referring to FIG. 6 , the back-contact solar cell assembly may include: a first sheet, a second sheet, an encapsulation material and a cover material.

The first piece is: one of the metal circuit board 50 or the back-contact solar cell sheet 30; the second piece is: the metal circuit board 50 and the back-contact solar cell sheet 30 except the first piece. One.

The surface of the first piece has a plurality of first conductive sites, and the first piece further includes: conductive bosses 41 located on the first conductive sites. The first piece further includes: an adhesive film 40 located in the area around the conductive boss 41 . The glue film 40 is formed by the insulating glue applied to the surrounding area of the conductive boss 41 , which is cured and cross-linked during the lamination process. The adhesive film 40 is used for bonding the first sheet piece and the second sheet piece.

The side of the second sheet with the second conductive site is stacked on the side of the first sheet with the conductive boss, and the conductive boss 41 is in contact with the second conductive site of the second sheet.

The combined sheet formed by the laminated first sheet and the second sheet, and the front cover material 10 on both sides of the combined sheet are the front encapsulation material 20, the rear encapsulation material 60, and the back cover material 70 laminated to obtain back contact solar cell modules. The adhesive film 40 is used to bond the first sheet and the second sheet during the lamination process.

For the back-contact solar cell assembly, reference can be made to the above-mentioned related records of the production method of the back-contact solar cell assembly, and the same technical effect can be achieved. In order to avoid repetition, details are not described here.

The embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative rather than restrictive. Under the inspiration of the present invention, without departing from the scope of protection of the present invention and the claims, many forms can be made, which all belong to the protection of the present invention.

Claims (12)

1. A method for producing a back-contact solar cell module, characterized in that, comprising: Conductive bosses are formed by printing conductive materials on the first conductive sites of the first piece; the first piece is one of a metal circuit board or a back-contact solar cell; Coating insulating glue on the first piece provided with the conductive boss; Laminating the side of the second sheet with the second conductive site and the side of the first sheet with the conductive boss, so that the conductive boss abuts on the second conductive site , forming a combined sheet; the second sheet is: the other one of the metal circuit board and the back-contact solar cell sheet; Laminate the combined sheet, the packaging material and the cover material on both sides of the combined sheet, so that the insulating glue forms an adhesive film, and the adhesive film adheres the first sheet and the second sheet. Two pieces. 2. The method according to claim 1, wherein the insulating glue comprises: a solvent, a filler, a resin, and a curing agent; Described solvent is at least one in alcohol solvent or ester solvent; The filler includes: silica particles; The resin is at least one of epoxy resin, acrylic resin and silicone resin; The curing agent is at least one of aliphatic amine curing agent, aromatic amine curing agent, acid anhydride curing agent, linear synthetic resin oligomer, phenolic resin, and imidazole curing agent. 3. The method according to claim 2, wherein, in the insulating glue: the mass ratio of the solvent is 5% to 20%; the mass ratio of the filler is 10% to 40%; the resin The mass ratio of the curing agent is 10% to 50%; the mass ratio of the curing agent is 1% to 10%. 4. The method of claim 2, wherein the silica particles are fumed silica particles. 5. The method according to any one of claims 2 to 4, wherein the filler further comprises: at least one of alumina particles, talc powder, and boron nitride particles. 6 . The method according to claim 2 , wherein the insulating glue has a viscosity of less than or equal to 9000 mPa·s at 20-25° C. 7 . 7 . The method according to claim 1 , wherein the coating thickness of the insulating glue is 1 to 50 μm. 8 . 8. The method according to any one of claims 1 to 4, wherein the laminating step is performed before the insulating glue coating step; The applying insulating glue on the first piece provided with the conductive boss includes: on the first piece provided with the conductive boss, at most along the first piece Apply insulating glue in the direction of the three sides of the piece. 9. The method according to any one of claims 1 to 4, characterized in that, before laminating the composite sheet and the encapsulation material and cover material on both sides of the composite sheet, the method further comprises: The first piece is preheated. 10 . The method according to claim 9 , wherein the temperature of the preheating is 40°C to 80°C. 11 . 11. The method according to any one of claims 1 to 4, wherein before the printing a conductive material on the first conductive site of the first sheet to form a conductive boss, the method further comprises: printing a conductive material on the first conductive site The first side of the sheet is stacked with the encapsulation material and the cover material in sequence; the first side is opposite to the side of the first sheet with the first conductive site; The step of printing a conductive material on the first conductive site of the first piece to form a conductive boss includes: using the packaging material and the cover material as a printing support substrate, on the first conductive site of the first piece Conductive bumps are formed by printing conductive material on the dots. 12 . A back-contact solar cell assembly, characterized in that, the back-contact solar cell assembly is produced by the method of any one of claims 1 to 11 .

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