CN210379078U - Lamination subassembly interconnect structure - Google Patents

Abstract

The utility model discloses a lamination subassembly interconnection structure, including the small piece of shingle, the small piece front printing of shingle has the front electrode, the small piece back printing of shingle has the back electrode, and the small front electrode of shingle passes through the tin cream with the small back electrode of adjacent shingle to be connected, the tin cream adopts the interval mode to scribble and establishes or print between front electrode and back electrode. The utility model discloses carry out the interconnection between the battery piece electrode under the low temperature condition, the shape of the different welding points of simultaneous design increases the pliability of battery cluster behind the lamination, reduces thermal stress, adopts high conductivity soldering tin alloy low melting point tin cream, and the mode that the interval through screen printing or quantitative coating set up realizes that tin cream subregion makes alloying interconnection between the chip, strengthens the reliability of subassembly.

Description

Lamination subassembly interconnect structure

Technical Field

The utility model relates to a solar module encapsulation manufacturing application technical field specifically is a lamination subassembly interconnection structure.

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. Considering that the stock of non-renewable energy is limited and the conventional fossil energy causes serious environmental pollution, countries in the world make respective energy development strategies to deal with the limitation of the conventional fossil energy resources and the environmental problems caused by development and utilization. Under the world trend, solar energy has become one of the most important renewable energy sources by virtue of the characteristics of reliability, safety, universality, longevity, environmental protection and resource sufficiency, and is expected to become a main pillar of global power supply in the future.

Under the background of vigorously popularizing and using the solar green energy, research and discovery of scientific researchers show that the laminated assembly technology can obviously improve the assembly power. The lamination technology cuts the whole solar cell into small patterns again through special pattern design, and then a plurality of adjacent cells or cells with better consistency of efficiency, appearance and the like are bonded together by using conductive glue or directly physically bonded by a current carrier transmission channel on the surface of the cell, thereby manufacturing the assembly. The lamination technology reduces the interconnection strips through optimizing the structure of the assembly, can reduce the loss of the assembly and improve the output power of the assembly.

The current lamination assembly mainstream process uses conductive adhesive to interconnect the cut battery pieces, and the conductive adhesive mainly comprises a conductive phase and a bonding phase and completes current transmission among the interconnected batteries. The conductive phase mainly comprises noble metals, such as pure silver particles or silver-coated copper, silver-coated nickel, silver-coated glass and other particles. The particle shape and distribution are based on satisfying the optimal electric conduction, and the more D50 < 10um flake or sphere-like combined silver powder is adopted at present. 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 common conductive adhesive manufacturer can complete the design of a conductive phase and an adhesive phase formula, so that the performance stability of the laminated assembly under an initial stage environment corrosion test and long-term outdoor practical application is ensured. Compared with the conventional alloying interconnected assembly, the laminated assembly has fewer actual large-scale application years, belongs to a brand-new assembly product at present, and the reliability of the product can be verified only after long-term outdoor comprehensive aging.

At present, the conducting material between the electrode of battery piece includes materials such as conducting resin, solder strip or tin cream among the lamination subassembly to the lamination subassembly is at the interconnection in-process, and incessant laying welding material also can cause the waste, makes the pliability of lamination subassembly relatively poor, greatly increased the cost. Moreover, the welding strip is mainly a tin-lead welding strip, the welding temperature of the welding strip is high and is harmful to the environment, and hidden cracking and fragment of the battery piece are easily caused; the conductive adhesive is mainly composed of a conductive phase and a bonding phase, wherein the bonding phase is mainly composed of a high molecular resin polymer with weather resistance, acrylic resin, organic silicon resin, epoxy resin, polyurethane and the like are usually selected according to the bonding strength and weather resistance, and the conductive phase is mainly composed of precious metals, such as pure silver particles or particles of silver-coated copper, silver-coated nickel, silver-coated glass and the like. However, silver is a noble metal, so that the cost of the conductive adhesive is very high, while the traditional solder paste needs high welding temperature, poor toughness and large thermal stress, and the reliability of the battery is reduced.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a lamination subassembly interconnect structure to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme:

an interconnection structure of a lamination assembly comprises a small laminated tile, wherein a front electrode is printed on the front surface of the small laminated tile, a back electrode is printed on the back surface of the small laminated tile, the front electrode of the small laminated tile is connected with the back electrode of the adjacent small laminated tile through tin paste, and the tin paste is coated or printed between the front electrode and the back electrode in an interval mode.

Preferably, the cross section of the solder paste is arranged to be oval, trapezoid or square.

Compared with the prior art, the beneficial effects of the utility model are that:

the utility model discloses a low-melting point solder paste, carry out the interconnection between the battery piece electrode under the low temperature condition, the shape of the different welding points of simultaneous design, increase the pliability of battery cluster behind the lamination, reduce thermal stress, adopt high conductivity soldering tin alloy low melting point solder paste, the mode that the interval through screen printing or quantitative coating set up, it makes alloying interconnection between the chip to realize the solder paste subregion, the reliability of reinforcing subassembly, the solder paste adopts indium tin silver, tin bismuth, one or more alloy composition in tin silver or the indium tin is made, its unique composition ratio, make solder paste cost of manufacture than the conducting resin who contains noble metal silver low, greatly reduced manufacturing cost, promote the product competitiveness of enterprise.

Drawings

Fig. 1 is a schematic view of the interconnection structure of the present invention;

fig. 2 is a schematic view of the interconnection of the shingle assembly according to the present invention;

fig. 3 is a schematic view of the back structure of the small tile-stacked piece according to the present invention.

In the figure: 1-shingled die, 2 die frontside, 3 frontside electrodes, 4 solder paste, 5 die backside, 6 backside electrodes.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1-3, the present invention provides a technical solution:

a laminated assembly interconnection structure comprises a plurality of laminated tiles 1 obtained by cutting, a front electrode 3 is printed on the front surface 2 of each laminated tile 1, front grid lines are arranged on the front surface, a back electrode 6 is printed on the back surface 5 of each laminated tile 1, as shown in the attached figure 2, the front electrode 3 of each laminated tile 1 is connected with the back electrode 6 of another adjacent laminated tile 1 through solder paste 4, the solder paste 4 is coated or printed between the front electrode 3 and the back electrode 6 in a spaced mode, the design is carried out according to discontinuous low stress, the solder paste 4 can be coated or printed on the front electrode 3 or the back electrode 6, the cross section of the solder paste 4 is set to be oval, trapezoid or square, wherein the oval arrangement is compared with the common solder paste arrangement in the contact interconnection process of the two laminated tiles 1, the oval-shaped interconnection effect of the application is better.

The melting point of the solder paste 4 is less than 160 degrees, and the low-melting-point solder paste 4 is used for interconnecting the electrodes of the battery pieces under the low-temperature condition, so that the flexibility of the battery string after lamination can be increased, and the thermal stress can be reduced.

The solder paste 4 is composed of one or more of indium tin silver, tin bismuth, tin silver or indium tin.

Example 1: the tin paste 4 is indium tin silver alloy, and the indium tin silver alloy consists of three alloy elements of indium, tin and silver, wherein the three alloy elements are indium, tin and silver; the indium content accounts for 50% of the total mass of the indium, tin and silver, the tin content accounts for 48% of the total mass of the indium, tin and silver, and the silver content accounts for 2% of the total mass of the indium, tin and silver.

Example 1-1: the tin paste 4 is indium tin silver alloy, and the indium tin silver alloy consists of three alloy elements of indium, tin and silver, wherein the three alloy elements are indium, tin and silver; the indium content accounts for 40% of the total mass of the indium, tin and silver, the tin content accounts for 59% of the total mass of the indium, tin and silver, and the silver content accounts for 1% of the total mass of the indium, tin and silver.

Examples 1 to 2: the tin paste 4 is indium tin silver alloy, and the indium tin silver alloy consists of three alloy elements of indium, tin and silver, wherein the three alloy elements are indium, tin and silver; the indium content accounts for 58 percent of the total mass of the indium, the tin and the silver, the tin content accounts for 40.5 percent of the total mass of the indium, the tin and the silver, and the silver content accounts for 1.5 percent of the total mass of the indium, the tin and the silver.

Example 2: the tin paste 4 is a tin-bismuth alloy which consists of tin and bismuth alloy elements, wherein the tin content accounts for 42% of the total mass of the tin and the bismuth, and the bismuth content accounts for 58% of the total mass of the tin and the bismuth.

Example 3: the tin paste 4 is made of tin-silver alloy, and the tin-silver alloy consists of tin and silver alloy elements, wherein the tin content accounts for 96.5% of the total mass of the tin and the silver content accounts for 3.5% of the total mass of the tin and the silver.

Example 4: the tin paste 4 replaces the indium tin silver alloy by the indium tin alloy, wherein the indium content accounts for 52% of the total mass of the indium tin, and the tin content accounts for 48% of the total mass of the indium tin.

Example 5: the solder paste 4 is a combination of an indium tin silver alloy and a tin bismuth alloy, wherein the indium tin silver alloy is an alloy with the same proportion in the first embodiment, the tin bismuth alloy is an alloy with the same proportion in the second embodiment, and the indium tin silver alloy and the tin bismuth alloy respectively account for 50% of the total mass.

Example 6: the solder paste 4 comprises a combination of an indium tin silver alloy, a tin silver alloy and an indium tin alloy, wherein the indium tin silver alloy is the alloy with the same proportion in the first embodiment, the tin silver alloy is the alloy with the same proportion in the third embodiment, the indium tin alloy is the alloy with the same proportion in the fourth embodiment, the indium tin silver alloy accounts for 50% of the total mass, and the tin silver alloy and the indium tin alloy respectively account for 25% of the total mass.

The solder pastes 4 of the above-mentioned embodiments 1 to 6 can be well realized to increase the flexibility of the laminated cell string and enhance the reliability of the assembly after the fabrication.

A method for manufacturing a laminated assembly with the interconnection structure, namely a method for manufacturing the laminated assembly, needs to perform the following steps:

s1, obtaining a good suede structure by surface texturing of a monocrystalline silicon wafer, so that the specific surface area is increased, more photons can be received, and meanwhile, the reflection of incident light is reduced;

s2, cleaning residual liquid during texturing to reduce the influence of acidic and alkaline substances on battery knot making;

s3, reacting phosphorus oxychloride with the silicon wafer to obtain phosphorus atoms, wherein after a certain period of time, the 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 an N-type semiconductor and a P-type semiconductor, thereby completing the process of diffusion and junction making and realizing the conversion from light energy to electric energy;

s4, because the diffusion junction is formed 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 etched and removed through plasma etching, so that the short circuit caused by the edge is avoided, and the SE process step can be added;

s5, forming a layer of phosphorosilicate glass on the surface of the silicon wafer due to the diffusion and junction making process, and reducing the influence on the efficiency of the laminated tile battery through the phosphorosilicate glass removing process;

s6, producing a silicon dioxide layer on the front and back of the etched silicon wafer through an oxygen high-temperature furnace at a certain temperature;

s7, laminating an aluminum oxide passivation film layer in an ALD or PECVD mode;

s8, laminating a silicon nitride film layer on the aluminum oxide passivation film layer, wherein the front silicon nitride film layer is used for reducing reflection and passivation effects, and the back silicon nitride film layer is used for protecting the aluminum oxide passivation film layer;

s9, performing laser grooving on the back of the coated silicon wafer;

s10, completing back and front printing through screen printing, printing the front electrodes 3 and the back electrodes 6 of the shingle chips 1 with the cut printing patterns at the staggered positions of the front and the back, and then performing a sintering process;

s11, reducing the light attenuation of the battery through a light attenuation furnace or an electric injection furnace;

s12, finally, battery test grading is carried out;

s13, adding an online laser cutting scribing process to the whole sintered laminated cell, enabling the sintered laminated cell to enter a scribing detection position for appearance inspection and visually positioning an OK sheet, freely setting a multi-track scribing machine or presetting a cache stack area according to an online production beat so as to realize online continuous feeding operation, setting relevant parameters of a 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 and preset cutting depth, and completing splitting at the cutting position by an automatic splitting mechanism of the online laser scribing machine after completing automatic cutting so as to realize natural separation of the laminated small cell and complete cutting;

the laser cutting surface is far away from the PN junction side, leakage current caused by damage of the PN junction is avoided, the directions of the front surface and the back surface of the battery piece are confirmed before the piece is scribed and fed, and if the directions are opposite, a single 180-degree reversing device needs to be added;

s14, connecting the front electrode 3 and the back electrode 6 of the small laminated tile 1 by regions through the solder paste 4 in a mode of interval quantitative coating or screen printing;

s15, then interconnecting and stringing the laminated tile small pieces 1, and alloying by a curing furnace or a hot plate;

and S16, after the string is made, the packaging of the laminated photovoltaic module is completed through the links of automatic string typesetting and converging, glue film and backboard laying, middle inspection, laminating, trimming, framing, middle junction box curing, cleaning, testing and the like.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (2)

1. A lamination assembly interconnect structure comprising a shingled die (1), the die face (2) of the shingled die (1) being printed with a face electrode (3), the die back (5) of the shingled die (1) being printed with a back electrode (6), characterized in that: the front electrodes (3) of the small shingle pieces (1) are connected with the back electrodes (6) of the adjacent small shingle pieces (1) through solder paste (4), and the solder paste (4) is coated or printed between the front electrodes (3) and the back electrodes (6) in an interval mode.

2. A lamination assembly interconnect structure according to claim 1 wherein: the cross section of the solder paste (4) is set to be oval, trapezoid or square.

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