CN211428179U

CN211428179U - Laminated tile assembly and solar cell

Info

Publication number: CN211428179U
Application number: CN201921471127.6U
Authority: CN
Inventors: 孙俊; 尹丙伟; 倪孙洋; 陈登运; 李岩; 石刚; 谢毅; 刘汉元
Original assignee: Chengdu Yefan Science and Technology Co Ltd
Current assignee: Tongwei Solar Hefei Co Ltd
Priority date: 2019-09-05
Filing date: 2019-09-05
Publication date: 2020-09-04
Anticipated expiration: 2029-09-05

Abstract

The utility model relates to a fold tile subassembly, solar wafer. The laminated tile assembly comprises a plurality of solar cells, positive electrodes and back electrodes are arranged on the solar cells, the positive electrode of one of any two adjacent solar cells is in direct contact with the back electrode of the other solar cell, a connecting part is formed between the positive electrode of the other solar cell and the back electrode of the other solar cell, and accordingly conducting connection is achieved, and a containing part used for containing a bonding agent is arranged at the connecting part. According to the utility model discloses, realize electrically conductive interconnection through the direct contact of positive electrode and back electrode each other between the solar wafer, therefore can omit the conducting resin that has electric conductivity to avoid probably by the various problems that the conducting resin produced. And the solar cell is provided with a containing part for containing the adhesive, so that the adhesive can be stably positioned between two adjacent solar cells, and the firmness of the laminated assembly is improved.

Description

Laminated tile assembly and solar cell

Technical Field

The utility model relates to an energy field especially relates to a shingle assembly, solar wafer.

Background

With the increasing consumption of conventional fossil energy such as global coal, oil, natural gas and the like, the ecological environment is continuously deteriorated, and particularly, the sustainable development of the human society is seriously threatened due to the increasingly severe global climate change caused by the emission of greenhouse gases. Various countries in the world make respective energy development strategies to deal with the limitation of conventional fossil energy resources and the environmental problems caused by development and utilization. Solar energy has become one of the most important renewable energy sources by virtue of the characteristics of reliability, safety, universality, long service life, environmental protection and resource sufficiency, and is expected to become a main pillar of global power supply in the future.

In a new energy revolution process, the photovoltaic industry in China has grown into a strategic emerging industry with international competitive advantages. However, the development of the photovoltaic industry still faces many problems and challenges, and the conversion efficiency and reliability are the biggest technical obstacles restricting the development of the photovoltaic industry, while the cost control and the scale-up are economically restricted. The photovoltaic module is taken as a core component of photovoltaic power generation, and the development of high-efficiency modules by improving the conversion efficiency of the photovoltaic module is a necessary trend. Various high efficiency modules, such as shingles, half-sheets, multi-master grids, double-sided modules, etc., are currently emerging on the market. With the application places and application areas of the photovoltaic module becoming more and more extensive, the reliability requirement of the photovoltaic module becomes higher and higher, and particularly, the photovoltaic module with high efficiency and high reliability needs to be adopted in some severe or extreme weather frequent areas.

Under the background of vigorous popularization and use of green solar energy, the shingled assembly utilizes the electrical principle of low current and low loss (the power loss of the photovoltaic assembly is in direct proportion to the square of working current) so as to greatly reduce the power loss of the assembly. And secondly, the inter-cell distance region in the cell module is fully utilized to generate electricity, so that the energy density in unit area is high. In addition, the conventional photovoltaic metal welding strip for the assembly is replaced by the conductive adhesive with the elastomer characteristic at present, the photovoltaic metal welding strip shows higher series resistance in the whole battery, and the stroke of a current loop of the conductive adhesive is far smaller than that of a welding strip, so that the laminated assembly becomes a high-efficiency assembly, and meanwhile, the outdoor application reliability is more excellent than that of the conventional photovoltaic assembly, and the laminated assembly avoids stress damage of the metal welding strip to the interconnection position of the battery and other confluence areas. Especially, under the dynamic (load action of natural world such as wind, snow and the like) environment with alternating high and low temperatures, the failure probability of the conventional assembly which is interconnected and packaged by adopting the metal welding strips is far higher than that of the laminated assembly which is interconnected and cut by adopting the conductive adhesive of the elastomer and packaged by the crystalline silicon battery small pieces.

The mainstream technology of the current tile stack assembly is to use a conductive adhesive to interconnect the cut battery pieces, wherein the conductive adhesive mainly comprises a conductive phase and a bonding phase. The conductive phase mainly comprises precious metals, such as pure silver particles or particles of silver-coated copper, silver-coated nickel, silver-coated glass and the like, and is used for conducting electricity among solar cells, the particle shape and distribution of the conductive phase are based on the requirement of optimal electricity conduction, and at present, more sheet-shaped or sphere-like combined silver powder with D50 being less than 10um is adopted. The adhesive phase is mainly composed of a high molecular resin polymer having weather resistance, and acrylic resin, silicone resin, epoxy resin, polyurethane, and the like are usually selected in accordance with the adhesive strength and weather resistance. In order to enable the conductive adhesive to achieve low contact resistance, low volume resistivity and high adhesion and maintain long-term excellent weather resistance, a conductive adhesive manufacturer can generally complete the design of a conductive phase and an adhesive phase formula, so that the performance stability of the laminated tile assembly under an initial stage environment corrosion test and long-term outdoor practical application is ensured.

And after being packaged, the battery assembly connected by the conductive adhesive is subjected to environmental erosion in outdoor practical use, for example, high and low temperature alternating expansion and contraction with heat generates relative displacement between the conductive adhesives. The most serious reason is that the current is connected in a virtual way or even disconnected, and the main reason is generally that the materials are combined and then are weak in mutual connection capacity. The weak connection capability mainly shows that a process operation window is needed for the operation of the conductive adhesive in the manufacturing process, and the window is relatively narrow in the actual production process and is very easily influenced by environmental factors, such as the temperature and humidity of an operation place, the time for which the conductive adhesive stays in the air after being coated and the like, so that the conductive adhesive loses activity. Meanwhile, the phenomenon of uneven sizing and missing easily occurs under the conditions of glue dispensing, glue spraying or printing process due to the characteristic change of glue, and great hidden danger is caused to the reliability of products. And the conductive adhesive mainly comprises high polymer resin and a large amount of noble metal powder, so that the cost is high, and the ecological environment is damaged to a certain extent (the production and processing of noble metals have great pollution to the environment). Moreover, the conductive adhesive belongs to a paste, has certain fluidity in the process of gluing or laminating, and is very easy to overflow to cause short circuit of the positive electrode and the negative electrode of the laminated interconnected battery string.

That is to say, for most of the laminated assemblies made by adopting the conductive adhesive bonding mode, the characteristics of weak mutual connection strength exist, the requirement of the manufacturing process on the environment is high, the glue overflow and short circuit are easy to occur in the process, the use cost is high, the production efficiency is low, and the like.

There is therefore a need to provide a stack of tiles, a solar cell, to at least partially solve the above problems.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a stack tile subassembly, solar wafer for the positive electrode and the back electrode of two solar wafers can direct contact in order to realize electrically conductive the connection. And the solar cell is provided with a containing part for containing the adhesive, so that the adhesive can be stably positioned between two adjacent solar cells, and the firmness of the laminated assembly is improved.

According to an aspect of the present invention, a laminated assembly is provided, which includes a plurality of solar cells sequentially arranged in a laminated manner in a first direction and fixed to each other by a bonding agent, the solar cells including a substrate sheet, a positive electrode extending in a second direction being disposed on a top surface of the substrate sheet; a back electrode extending along a third direction parallel to the second direction is arranged on the bottom surface of the substrate sheet, the positive electrode of one of any two adjacent solar cell sheets is directly contacted with the back electrode of the other solar cell sheet to form a connecting part so as to realize conductive connection,

the connecting part is provided with an accommodating part for accommodating the adhesive.

In one embodiment, the receiving portion is disposed on at least one of the positive electrode and the back electrode and has an opening facing the other one of the solar cells.

In one embodiment, when the receiving portion is provided on each of the positive electrode and the back electrode, the opening of the receiving portion provided at the positive electrode is aligned with or misaligned from the opening of the receiving portion provided at the back electrode.

In one embodiment, the receiving portion includes a base portion penetrating the electrode in a fourth direction perpendicular to the solar cell sheet.

In one embodiment, the receiving part further includes a through hole part penetrating through the base sheet of the solar cell sheet in the fourth direction.

In one embodiment, a radial dimension of the base portion of the accommodating portion is greater than or equal to a radial dimension of the through-hole portion.

In one embodiment, the adhesive protrudes from the through hole portion to the solar cell sheet.

In one embodiment, the radial dimension of the portion of the adhesive protruding out of the surface of the solar cell sheet is greater than or equal to the radial dimension of the through hole portion.

In one embodiment, the adhesive extends in the through hole portion without protruding from the surface of the solar cell sheet.

In one embodiment, the accommodating portion is plural.

In one embodiment, the receiving portion further comprises a blind hole extending in the base sheet in the fourth direction.

In one embodiment, the receiving portion includes a base portion that does not penetrate through an electrode in a fourth direction perpendicular to the solar cell sheet.

In one embodiment, the adhesive is a conductive glue, or the adhesive is not conductive.

Another aspect of the present invention provides a solar cell, wherein a plurality of solar cells can be sequentially connected in a shingled manner in a first direction, the solar cell comprises a substrate, and a positive electrode extending in a second direction is disposed on a top surface of the substrate; a back electrode extending in a third direction parallel to the second direction is provided on a bottom surface of the base sheet, the solar cell sheet is configured such that a positive electrode and a back electrode of two solar cell sheets are in direct contact and form a connection portion when connected to another solar cell sheet in a shingled manner to achieve conductive connection,

the solar cell sheet is provided with an accommodating part for accommodating the adhesive at the connecting part.

In one embodiment, the receiving portion is provided on at least one of the positive electrode and the back electrode of the solar cell sheet, and has an opening facing the other solar cell sheet.

In one embodiment, the accommodating portion is plural.

In one embodiment, the receiving portion is a blind hole extending in the base sheet in the fourth direction.

According to the utility model discloses, when becoming the laminated tile subassembly with solar wafer interconnection, realize electrically conductive interconnection through the direct contact of positive electrode and back electrode each other between the solar wafer, therefore can omit the conducting resin that has electric conductivity. Like this, factors that easily destroy conducting resin such as environmental erosion, high low temperature alternation, expend with heat and contract with cold just can not influence the utility model discloses a shingle assembly, shingle assembly is difficult to appear the electric current virtual connection and open circuit. Moreover, as the conductive adhesive is not needed to be arranged, the problems of open circuit of the positive electrode and the negative electrode of the laminated assembly and the like caused by adhesive overflow can be avoided. In addition, because the conductivity of the adhesive is not required, the production cost of the laminated assembly is also reduced. And, be provided with the portion of accomodating that is used for holding the binder on the solar wafer, the portion of accomodating can have various structures to make the binder can be stably positioned between two adjacent solar wafer, promote the fastness of shingle assembly.

Drawings

For a better understanding of the above and other objects, features, advantages and functions of the present invention, reference should be made to the preferred embodiments illustrated in the accompanying drawings. Like reference numerals in the drawings refer to like parts. It will be appreciated by persons skilled in the art that the drawings are intended to illustrate preferred embodiments of the invention without any limiting effect on the scope of the invention, and that the various components in the drawings are not to scale.

Fig. 1 is a schematic view of a solar cell according to a preferred embodiment of the present invention, in which a first receiving portion and a second receiving portion are omitted;

fig. 2 and 3 are a top schematic view and a bottom schematic view of two solar cells interconnected in a shingled manner in the preferred embodiment;

fig. 4 is a laminated assembly in which the solar cells of the present embodiment are connected to each other in a laminated manner;

FIG. 5 is a portion of the schematic cross-sectional view taken along line B-B of FIG. 4, but showing two adjacent solar cells and the adhesive therebetween not yet contact bonded together to reveal the receptacle;

FIG. 6 is a portion of the cross-sectional schematic view taken along line A-A of FIG. 4;

fig. 7 and 8 are diagrams of two alternatives of fig. 6.

Detailed Description

Referring now to the drawings, specific embodiments of the present invention will be described in detail. What has been described herein is merely a preferred embodiment in accordance with the present invention, and those skilled in the art will appreciate that other ways of implementing the present invention on the basis of the preferred embodiment will also fall within the scope of the present invention.

The utility model provides a fold tile subassembly, solar wafer, figure 1 to figure 8 show the utility model discloses a plurality of preferred embodiments's each aspect.

Fig. 1 shows a solar cell sheet 1 according to a preferred embodiment of the present invention, and fig. 4 shows a laminated assembly 30 in which a plurality of solar cell sheets 1 in fig. 1 are arranged in a laminated manner. It should be noted that the "first direction" to be mentioned later may be understood as an arrangement direction of each solar cell sheet 1 in the shingle assembly 30, which is substantially consistent with a width direction of each substantially rectangular solar cell sheet 1, and the first direction is shown by D1 in fig. 2, 3 and 4; the "second direction" may be understood as one length direction on the top surface 25 of the substantially rectangular solar cell sheet 1, the second direction being indicated by D2 in fig. 1; the "third direction" may be understood as one length direction on the bottom surface 24 of the substantially rectangular solar cell sheet 1, the third direction being shown by D3 in fig. 1; the "fourth direction" may be understood as a thickness direction or a height direction of the solar cell sheet, and the fourth direction is illustrated by D4 in fig. 4 to 8.

Continuing with reference to fig. 1. The solar cell sheet 1 includes a base sheet, which is preferably made of silicon. The surface of the base sheet is printed with a plurality of electrodes, preferably made of silver.

Specifically, the top surface 25 of the base sheet is provided with the positive electrode 12 extending in the second direction D2; the bottom surface 24 of the base sheet is provided with a back electrode 13 extending in a third direction D3 parallel to the second direction D2. The positive electrode 12 and the back electrode 13 are spaced in the first direction D1. Preferably, when the solar cells 1 are connected in a shingled manner, the positive electrode 12 of one of any two adjacent solar cells 1 can be electrically connected in direct physical contact with the back electrode 13 of the other. Preferably, the size of the overlapping portion between two adjacent solar cell pieces in the first direction D1 is 0.05mm-5 mm.

For convenience of production and assembly, the solar cell sheet 1 may be processed such that the top surface 25 and the bottom surface 24 thereof are rectangular or substantially rectangular. The positive electrode 12 and the back electrode 13 of the same solar cell sheet 1 are disposed on diagonally opposite edges of the top surface 25 and the bottom surface 24, respectively, for example, the positive electrode 12 and the back electrode 13 may be disposed on longitudinal edges of the top surface 25 and the bottom surface 24, respectively. Thus, when two adjacent solar cells 1 are stacked, the back electrode 13 on the bottom surface 24 of the previous solar cell 1 and the positive electrode 12 on the top surface 25 of the next solar cell 1 are opposite to each other (see fig. 5), and the arrangement can avoid large-area overlapping between the solar cells 1, so that the exposed area of the stack assembly 30 is increased. Also, the first direction D1 may be a direction parallel to the lateral edges of the top and

bottom surfaces

25, 24, that is, the first direction D1 is perpendicular to the second and third directions D2, D3.

In order to save manufacturing materials of the electrodes without affecting the conductivity between the solar cells 1, the positive electrode 12 and/or the back electrode 13 may be disposed intermittently along the extending direction thereof as shown in fig. 1.

The tile stack assembly 30 of the present invention can be formed by connecting the solar cells 1 together. After the solar cells 1 are stacked and interconnected, the solar cells 1 may be fixed to each other by the adhesive 4, and the adhesive 4 may preferably have no conductivity, but the adhesive 4 may also have conductivity. For example, the adhesive 4 may be made of acrylic resin, silicone resin, epoxy resin, polyurethane, etc., and in order to form a certain thickness, some additives or substances, such as curing agent, cross-linking agent, coupling agent, rubber ball, etc., may be added to the resin.

For convenience of description, for any two solar cells interconnected in a shingled manner, one of the solar cells is referred to as a first solar cell 32, and the other solar cell is referred to as a second solar cell 31, after the first solar cell 32 and the second solar cell 31 are interconnected at the edge, the positive electrode 12 and the back electrode 13 are in direct physical contact and form a connecting part 34 (as shown in fig. 2 and 3) so as to realize conductive connection. It should be noted that the terms "first solar cell" and "second solar cell" are understood to be relative concepts rather than absolute concepts, for example, a first solar cell in one pair of adjacent solar cells may be simultaneously a second solar cell in another pair of adjacent solar cells.

In order to make the connection between the solar cells stronger, a receiving portion for receiving the adhesive 4 is provided at the connection portion 34 of the solar cells. The housing portion is provided on at least one of the positive electrode 12 and the back electrode 13 of one solar cell sheet 1, and has an opening facing the other solar cell sheet 1. For example, a first receiving part having a top opening at the top thereof may be provided at the positive electrode 12 of the first solar cell sheet 32; the back electrode 13 of the second solar cell sheet 31 may be provided with a second receiving part having a bottom opening at the bottom thereof.

In the stack tile assembly 30, only one of the first and second receiving portions may be provided, or both of the first and second receiving portions may be provided. It can be understood that when only the first accommodating portion exists, the adhesive 4 accommodated in the first accommodating portion contacts and adheres to the second solar cell sheet 31 at the top opening of the first accommodating portion; when only the second accommodating portion exists, the adhesive 4 accommodated in the second accommodating portion contacts and adheres to the first solar cell sheet 32 at the bottom opening of the second accommodating portion.

Preferably, as shown in fig. 5 to 8, a first accommodating portion and a second accommodating portion are simultaneously provided in the stack assembly 30, the top opening of the first accommodating portion and the bottom opening of the second accommodating portion can be aligned with each other so that the first accommodating portion and the second accommodating portion jointly define an accommodating cavity, and the adhesive 4 is located in the accommodating cavity so as to fix the first solar cell sheet 32 and the second solar cell sheet 31 to each other. It should be noted again that fig. 5 is a part of the schematic cross-sectional view of the laminated assembly 30 in fig. 4 taken along the line B-B, and not a complete cross-sectional view, and it is understood that there should be substantially six solar cells 1 in the complete cross-sectional view, and only two solar cells 1 adjacent to each other in the six solar cells 1 are shown in fig. 5; similarly, figure 6 is a portion, but not a complete cross-sectional view, of the stack assembly 30 of figure 4 taken along line a-a, where substantially five spaced-apart regions of conductive adhesive are included, and only three of the regions of conductive adhesive are shown in figure 6, for the same reason as figures 7 and 8.

The first receiving portion and the second receiving portion may further have a more preferable structure. For example, as shown in fig. 5 to 8, the first container part may penetrate the positive electrode 12 in the fourth direction D4, and the second container part may penetrate the back electrode 13 in the fourth direction D4, and a portion of the container part penetrating the electrodes is referred to as a base.

Preferably, as shown in fig. 6, the second receiving part does not only penetrate through the back electrode 13 of the second solar cell sheet 31, and penetrates through the entire base sheet of the second solar cell sheet 31 in the fourth direction D4, and a portion of the receiving part penetrating through the base sheet is referred to as a through-hole portion. That is to say that the position of the first electrode,

the second receiving portions have not only bottom openings but also top openings, and viewing the stack assembly 30 shown in fig. 4, the top openings 33 of the respective second receiving portions can be seen. Wherein the radial dimension of the portion of the housing that penetrates the back electrode 13 (i.e., the base portion) is greater than or equal to the radial dimension of the portion of the through-hole that penetrates the base sheet (i.e., the through-hole portion), and the adhesive 4 is poured into the through-hole and fills the through-hole. The portion of the through-hole penetrating the base sheet may be a cylindrical hole and have a diameter of 0.05 to 5mm, or may be another hole and have a maximum radial dimension of less than 10mm, and preferably, the adhesive 4 may also protrude upward from the base sheet from the top opening of the second housing part, and the radial dimension of the protruding portion protruding upward from the base sheet may be greater than or equal to the portion of the through-hole penetrating the base sheet, or the adhesive 4 may extend only in the through-hole portion without protruding from the surface of the base sheet. It should be noted that the "radial dimension" of the through hole and the adhesive 4 as referred to herein refers to a dimension in a plane parallel to the first plane, i.e., a dimension in a plane perpendicular to the fourth direction D4.

Since the adhesive 4 fills the through-hole, referring to fig. 6, the adhesive 4 can be divided into three parts: a first adhesive part 41 extending through the back electrode 13, a second adhesive part 42 extending through the base sheet and a third adhesive part 34 projecting at the top from the base sheet, the radial dimension of the first adhesive part 41 being greater than the radial dimension of the third adhesive part 43, the radial dimension of the third adhesive part 43 being greater than the radial dimension of the second adhesive part 42. This arrangement allows the portion of the adhesive 4 protruding from the base sheet and the portion penetrating through the base sheet to form a rivet-shaped structure, which ensures that the adhesive 4 is firmly contained in the base sheet and does not easily slip out or fall off from the base sheet.

Similarly, referring to fig. 7, the first receiving part may also be provided as a through hole penetrating the first solar cell sheet 32 in the fourth direction D4, the radial dimension of a portion of the through hole penetrating the positive electrode 12 being larger than the radial dimension of a portion penetrating the base sheet, when the first receiving part has not only a top opening but also a bottom opening. Preferably, the adhesive 4 contained in the first containing section has a protruding portion protruding from the bottom surface of the base sheet along the bottom opening, the protruding portion having a radial dimension larger than that of the portion of the through-hole penetrating through the base sheet.

The arrangement can directly pour the adhesive 4 into the accommodating part from the opening of the accommodating part when the adhesive 4 is applied to the solar cell, the operation is simple, and the adhesive 4 can be prevented from overflowing to other positions due to the constraint effect of the accommodating part.

Of course, it is also possible to arrange the first receiving portion without a bottom opening and the second receiving portion without a top opening, and form the first receiving portion and the second receiving portion as blind holes, and when the first receiving portion and the second receiving portion of the two solar cells 1 are aligned, the first receiving portion and the second receiving portion together define a closed receiving cavity. Fig. 8 shows such an example. In order to interconnect the solar cells 1, the first and second receiving portions are filled with adhesive, and then the positive electrodes 12 and the back electrodes 13 of the two solar cells 1 are aligned, and fig. 5 is a schematic diagram of the assembly process of the tile assembly 30. Further, the blind hole may extend in the fourth direction D4 in the electrode but not through the electrode, that is, the height of the blind hole may be smaller than the height of the electrode.

The utility model discloses still provide a manufacturing method of making above-mentioned shingle assembly 30 simultaneously, it includes following step:

manufacturing a plurality of solar cell sheets 1 as described above;

applying an adhesive 4 on each solar cell sheet 1;

the plurality of solar cells 1 are arranged in a shingled manner along the first direction D1, fixed to each other and such that the positive electrode 12 of one of any two adjacent solar cells 1 is aligned with and in direct contact with the back electrode 13 of the other.

Further, the step of manufacturing the plurality of solar cells 1 includes:

pretreating the whole solar cell;

the whole solar cell sheet after the pretreatment is cut into small pieces to form a plurality of solar cell sheets 1, and the size of the solar cell sheet in the first direction D1 may be 1/20-1/2 of the size of the whole solar cell sheet in the first direction D1.

Further, the step of pretreating the whole solar cell comprises the following steps:

printing a plurality of positive electrodes 12 and a plurality of back electrodes 13 on the whole solar cell;

the design of the positive electrode 12 and the back electrode 13 forms a housing at the gap or the clearance;

preferably, the positive electrode 12 and/or the back electrode 13 and/or the substrate sheet are processed with accommodating parts, for example, a first accommodating part is processed at the positive electrode 12, a second accommodating part is processed at the back electrode 13, if the first accommodating part and the second accommodating part are through holes penetrating through the substrate sheet, this step can be realized by laser perforation, and the top surface or the bottom surface of the whole solar cell sheet is observed, so that the plurality of accommodating parts can be seen to be arranged in an array on the whole solar cell sheet.

The step of pretreating the whole solar cell further comprises the following steps:

texturing on the surface of the total substrate sheet of the whole solar cell sheet 1;

growing and depositing an inner passivation layer on the front surface and the back surface of the total substrate sheet;

growing and depositing a middle passivation layer on the inner passivation layer;

and growing and depositing an outer passivation layer on the middle passivation layer.

More specifically, the inner passivation layer is deposited by a thermal oxidation method or a laughing gas oxidation method or an ozonization method or a nitric acid solution chemical method, and the inner passivation layer is arranged as a silicon dioxide film layer; and/or

The middle passivation layer is deposited by a PECVD or ALD layer or a PVD layer method by using a solid target material, and is set to be an aluminum oxide film layer or a film layer containing aluminum oxide; and/or

The outer passivation layer is deposited using PVD, CVD or ALD methods.

The above-described steps and other steps not mentioned can be embodied and optimized. For example, at the beginning of processing, the whole solar cell can be subjected to visual detection and relative position positioning, and the upper and lower parts of the visual detection platform are respectively provided with a high-precision CCD infrared camera for grabbing special patterns (such as mark points, primary and secondary grids and the like) and PL (photoluminescence laser detector) on the front and back surfaces of the whole solar cell so as to realize that the printing error exceeds a certain range, and the appearance defects or internal cracks are automatically identified and removed to an NG material box. The whole solar cell is subjected to accurate color, efficiency and high-low open-voltage sorting, and the whole solar cell subjected to feeding is a cell with consistent attribute (can be matched with and butted with a single solar cell sorting function). Meanwhile, the equipment feeding platform is provided with a special material box and a processing mechanism.

In the step of machining a through-hole (i.e., a preferred embodiment of the receiving portion) to the base sheet, short-circuit prevention measures for the PN junction including edge etching and the like may be provided at the perforated portion. The positive and negative electrode surfaces are subjected to texturing treatment in a direct physical bonding or non-conductive adhesive mode, and the texturing treatment can be completed through screen printing roughness design, so that the actual effective contact capacity of the positive electrode 12 and the back electrode 13 is increased.

In the texturing step, a single crystal silicon wafer is adopted to obtain a good textured structure through surface texturing, so that the specific surface area is increased, more photons (energy) can be received, meanwhile, the reflection of incident light is reduced, and the subsequent step can comprise the step of cleaning residual liquid in texturing so as to reduce the influence of acidic and alkaline substances on battery junction making. The method also comprises a step of manufacturing a PN junction after the texturing, which comprises the following steps: reacting phosphorus oxychloride with a silicon wafer to obtain phosphorus atoms; after a certain time, phosphorus atoms enter the surface layer of the silicon wafer and permeate and diffuse into the silicon wafer through gaps among the silicon atoms to form an interface of the N-type semiconductor and the P-type semiconductor. And finishing the diffusion and junction making process and realizing the conversion from light energy to electric energy. Because the diffusion junction forms a short circuit channel at the edge of the silicon wafer, photo-generated electrons collected by the front surface of the PN junction flow to the back surface of the PN junction along the region with phosphorus diffused at the edge to cause short circuit, and the PN junction at the edge is removed by etching through plasma, so that the short circuit caused by the edge can be avoided, and in addition, the SE process step can be added. Moreover, a layer of phosphorosilicate glass is formed on the surface of the silicon wafer in the diffusion junction making process, and the influence on the efficiency of the laminated cell is reduced through the phosphorosilicate glass removing process.

Further, laser grooving can be carried out on the silicon wafer after the passivation layer is formed; and sintering after printing the electrodes, reducing the light attenuation of the battery cell through a light attenuation furnace or an electric injection furnace, and finally testing and grading the battery.

The step of breaking the silicon wafer into a plurality of solar cells is preferably accomplished using a laser cutter. And adding an online laser cutting scribing process to the sintered whole silicon wafer, enabling the sintered whole silicon wafer to enter a scribing detection position for appearance inspection and visually positioning the OK wafer (poor appearance detection can be automatically shunted to the NG position), and freely setting a multi-track scribing machine or presetting a cache stack area according to the online production rhythm so as to realize online continuous feeding operation. And setting relevant parameters of the laser according to the optimal effect of cutting and scribing so as to realize higher cutting speed, narrower cutting heat affected zone and cutting line width, better uniformity, preset cutting depth and the like. And after the automatic cutting is finished, the solar cell pieces 1 are split at the cutting position by an automatic piece breaking mechanism of the online laser scribing machine, so that the solar cell pieces 1 are naturally separated. It should be noted that the laser cutting surface is far away from the side of the PN junction, so that leakage current caused by damage of the PN junction is avoided, the front and back directions of the battery piece need to be confirmed before the material is cut and fed, and if the front and back directions are opposite, a separate 180-degree reversing device needs to be added.

The adhesive can be loaded through a screen bearing or sealing cylinder, and the adhesive coating operation at a certain speed is completed in the designated area of the solar cell piece through a printing machine or high-precision adhesive dispensing/spraying equipment. The solar cell is accurately positioned through the positioning module in the printing mode, the opening of a printing pattern has an automatic position deviation rectifying function, and the center of the opening of the screen printing plate can be ensured to coincide with the center of a glue applying position (namely the position of a laser deep digging corresponding or through hole). After the glue is coated, a glue line 3D visual detection function is arranged on line, the equipment can measure volume-related parameters such as height and width of the non-conductive glue after printing on line (the glue line glue type test under the laser deep digging process needs to be detected through a software algorithm, fluctuation errors caused by structural differences to the optical test can be avoided), NG pieces with incomplete and uneven glue lines are removed, the equipment has a manual self-defining function, and different threshold values can be set for process control. Subsequently, in the interconnection process of the solar cell, the direct physical attaching device can be provided with a positioning and bonding function, for example, a positioning adhesive tape or other fixed non-conductive glue is used for bonding on the laminated assembly, so that the influence of contact displacement of the positive electrode and the negative electrode on the interconnection reliability caused by the transmission movement or the lamination process of the laminated assembly is avoided. Meanwhile, the adhesive is coated outside the connecting seam for connection and fixation after direct physical attachment, and the adhesive can be matched with a colorless transparent adhesive for use, so that the requirements of customers on appearance are met.

More specifically, the adhesive through screen opening design comprises discontinuous printing, and the cross-sectional shape of the adhesive comprises a parallelogram and a non-parallelogram (such as a circle, an ellipse and the like) and is matched with the shape of the opening of the laser deep digging process. The discontinuous size design can be matched with other design processes of the laminated assembly, and in order to ensure that the positive electrode and the back electrode of the solar cell form good contact, the binder is suitable for the buried layer structure design under the laser deep digging process (the height difference between the highest position and the electrode is less than or equal to 100um after the binder is preset in the electrode area). The buried layer structure of the battery is formed in the self-manufacturing process, and if the conventional battery structure contains an aluminum back surface field, the aluminum back surface field is not prepared in the binder area printed by the embodiment. The binder is adopted to have a thickness, and the central line of the binder is sunk through the structural design of the buried layer solar cell, so that the positive and back electrodes 13 form good contact conduction, and the binder thickness is prevented from influencing the effective contact conduction current of the positive and negative electrodes. The bonding scenario of the bonding agent is silicon nitride + bonding agent + silicon nitride, but is not limited to this scenario, including bonding of the interfaces of the various layers of the high-efficiency battery.

The solar cell laminating machine comprises a surface mount robot or a servo motion module, wherein the surface mount robot or the servo motion module can pick up solar cells and effectively laminate the solar cells according to a preset designed surface mount width, and the lamination precision comprises x and y +/-100 um; theta +/-0.03 deg., where x represents the lamination gradient, y represents the lamination overlap amount, and theta represents the lamination rotation angle; according to the precision requirement under different patch widths, the tolerance range of x \ y \ theta can be adjusted, and the requirement of the appearance and the size under a certain patch width can be ensured to be met in principle.

After lamination is completed, the complete laminated assembly is welded by automatically punching or pre-punching a wire end lead (punching a specified position is completed by end lead incoming materials) in a fixed length cutting mode, so that current is led out, and meanwhile, the positive electrode, the back electrode and the end lead are effectively connected. The end leads may include coatings of different materials (e.g., combinations of elements such as tin, lead, bismuth, silver, indium).

The prepared tile-stacked modules are arranged in series and parallel according to the typesetting requirement of the photovoltaic module, and the distance between the strings is set to a size value according to the equipotential combination appearance requirement and the gap reflection requirement, wherein the general setting comprises 0.1-100 mm. And after the tile-stacking assembly is picked up by an automatic manipulator and the string-swinging action is finished, welding the anode and the cathode of the final assembly by automatic confluence welding and outputting current and voltage, and then sequentially paving a glue film and a rear cover plate (a back plate or glass) according to the lamination to obtain a semi-finished assembly.

And (3) carrying out lamination process on the qualified semi-finished assembly after the semi-finished assembly is subjected to EL (electroluminescence) and VI (visual appearance) detection, wherein the lamination process comprises three-cavity lamination. The laminating procedure combines the new interconnection structure, and the adhesive film is thermally cured in a closed cavity by vacuumizing, heating and pressurizing so as to be tightly attached, and finally, the adhesive film is laminated into a complete structural member.

The utility model discloses a solar wafer, fold tile subassembly and manufacturing method for when the solar wafer interconnection becomes the fold tile subassembly, realize electrically conductive interconnection through the direct contact of positive electrode and back electrode each other between the solar wafer, therefore can omit the conducting resin that has electric conductivity. Like this, environmental erosion, high low temperature alternation, expend with heat and contract with cold etc. destroy the conducting resin factor just can not influence the utility model discloses a shingle assembly, therefore be difficult to appear the electric current virtual connection and open circuit. Moreover, as the conductive adhesive is not needed to be arranged, the problems of open circuit of the positive electrode and the negative electrode of the laminated assembly and the like caused by adhesive overflow can be avoided. In addition, because the conductivity of the adhesive is not required, the production cost of the laminated assembly is also reduced.

The foregoing description of various embodiments of the invention is provided to one of ordinary skill in the relevant art for the purpose of illustration. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. As noted above, various alternatives and modifications of the present invention will be apparent to those skilled in the art of the above teachings. Thus, while some alternative embodiments are specifically described, other embodiments will be apparent to, or relatively easily developed by, those of ordinary skill in the art. The present invention is intended to embrace all such alternatives, modifications and variances of the present invention described herein, as well as other embodiments that fall within the spirit and scope of the present invention as described above.

Reference numerals:

solar cell 1

Top surface 25 of solar cell sheet

Bottom surface 24 of the solar cell sheet

Positive electrode 12

Back electrode 13

Binder 4

First solar cell 32

Second solar cell 31

Connecting part 34

Top opening 33 of the second container

First adhesive part 41

Second adhesive portion 42

Third adhesive portion 43

First direction D1

Second direction D2

Third direction D3

Fourth direction D4

Claims

1. A stack of tiles assembly comprising a plurality of solar cell sheets arranged in sequence in a shingled manner in a first direction (D1) and secured to each other by an adhesive (4), the solar cell sheets comprising a substrate sheet having a top surface (25) provided with a positive electrode (12) extending in a second direction (D2); a back electrode (13) extending along a third direction (D3) parallel to the second direction is arranged on the bottom surface (24) of the substrate sheet, the positive electrode of one of any two adjacent solar cell sheets is directly contacted with the back electrode of the other solar cell sheet to form a connecting part so as to realize conductive connection,

2. The stack assembly of claim 1, wherein the receptacle is disposed on at least one of the positive electrode and the back electrode and has an opening facing the other of the solar cells.

3. The stack tile assembly of claim 2, wherein when the receiving portions are disposed on both the positive electrode and the back electrode, the opening of the receiving portion disposed at the positive electrode is aligned or misaligned with the opening of the receiving portion disposed at the back electrode.

4. The shingle assembly of claim 2, wherein the receptacle includes a base portion that extends through the electrode in a fourth direction (D4) perpendicular to the solar cell sheets.

5. The shingle assembly of claim 4, wherein the receptacle further comprises a through-hole portion that extends through the base sheet of the solar cell sheet in the fourth direction.

6. The stack assembly of claim 5, wherein a radial dimension of the base of the receptacle is greater than or equal to a radial dimension of the through-hole portion.

7. The shingle assembly of claim 5 wherein the adhesive protrudes from the through-hole portion beyond the solar cell sheet.

8. The shingle assembly of claim 7 wherein the portion of the adhesive that protrudes beyond the surface of the solar cell sheet has a radial dimension that is greater than or equal to the radial dimension of the through hole portion.

9. The shingle assembly of claim 5 wherein the adhesive extends in the through hole portion but does not protrude above the surface of the solar cell sheet.

10. The shingle assembly according to claim 1, wherein the receptacle is plural.

11. The stack assembly of claim 4, wherein the pocket further comprises a blind hole extending within the base sheet in the fourth direction.

12. The shingle assembly of claim 2, wherein the receptacle includes a base that does not extend through the electrode in a fourth direction (D4) perpendicular to the solar cell sheets.

13. The tile stack assembly of any one of claims 1-12, wherein the adhesive is a conductive glue or the adhesive is not conductive.

14. A solar cell piece, a plurality of solar cell pieces can be connected in sequence in a shingled manner in a first direction, the solar cell piece comprises a substrate piece, and a positive electrode extending along a second direction is arranged on the top surface of the substrate piece; a back electrode extending in a third direction parallel to the second direction is provided on a bottom surface of the base sheet, the solar cell sheet is configured such that a positive electrode and a back electrode of two solar cell sheets are in direct contact and form a connection portion when connected to another solar cell sheet in a shingled manner to achieve conductive connection,

the solar cell is characterized in that an accommodating part for accommodating an adhesive is arranged at the connecting part.

15. The solar cell sheet according to claim 14, wherein the receiving portion is provided on at least one of the positive electrode and the back electrode of the solar cell sheet and has an opening facing the other one of the solar cell sheets.

16. The solar cell sheet according to claim 15, wherein when the receiving portions are provided on both the positive electrode and the back electrode, the opening of the receiving portion provided at the positive electrode is aligned with or misaligned from the opening of the receiving portion provided at the back electrode.

17. The solar cell sheet according to claim 15, wherein the receiving portion comprises a base portion penetrating the electrode in a fourth direction (D4) perpendicular to the solar cell sheet.

18. The solar cell sheet according to claim 17, wherein the housing portion further comprises a through-hole portion penetrating through the base sheet of the solar cell sheet in the fourth direction.

19. The solar cell sheet according to claim 18, wherein a radial dimension of the base portion of the receiving portion is greater than or equal to a radial dimension of the through-hole portion.

20. The solar cell sheet according to claim 14, wherein the accommodating portion is plural.

21. The solar cell sheet according to claim 17, wherein the receiving portion comprises a blind hole extending in the base sheet in the fourth direction.

22. The solar cell sheet according to claim 15, wherein the receiving portion comprises a base portion that does not penetrate an electrode in a fourth direction (D4) perpendicular to the solar cell sheet.