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Key points: 1. The reasons why the current implementation of heterojunction batteries by various manufacturers is less than expected; 1) The cost of silver paste is relatively high: the cost per watt of heterojunction battery silver paste is about 1.8-2 cents, and quotes have not yet come down.

2) Limited by production equipment, domestic manufacturers’ mass production of heterojunction cells has a thickness of 140-150 microns, but cannot reach 130 microns. Performance comparison of

2, Maiwei, Jiejia, Junshi, and Ideal heterojunction equipment: 1) Maiwei VHF+ multi-cavity: the battery conversion efficiency is higher. If the chamber is more than 2M, the uniformity will be poor, and it needs Use multiple chambers to increase throughput.

Hidden content 2) Junshi RF power supply with large cavity: the cost of amorphous battery equipment is lower, the uniformity of the cavity is better, and higher production capacity can be achieved with a smaller number of cavities, but under microcrystalline hard to use.

3) Ideal stacked type: the most perfect structural design, the highest chamber uniformity and battery conversion efficiency, but the production capacity is very small, suitable for laboratories.

4) Jiejia tube P technology: high production capacity, but poor uniformity of coating. When making HIT batteries, plating will occur.

3. The impact of copper electroplating technology on current photovoltaic cells: It is believed that copper electroplating technology is a revolutionary cost-reduction technology and the best technology to replace screen printing and silver paste. GW type copper may appear in the next two or three years. electroplating equipment .

copper plating technology will increase the conversion efficiency of the battery by 0.3% and reduce the cost per watt of the battery by 5-6 points.

4. The reasons why copper electroplating batteries cannot be mass-produced at present: 1) The cost of copper electroplating equipment is high: At present, several domestic manufacturers that apply copper electroplating technology basically use imported equipment. The equipment cost is very high, which is a key bottleneck for mass production. .

2) The production capacity of copper electroplating is low, and domestic equipment is not good enough.

3) Cost of consumables used in copper electroplating: consumables such as dry film used in copper electroplating are relatively expensive, and domestic manufacturers need to use cheaper dry films or photosensitive adhesives instead.

But materials are not the key bottleneck.

Detailed minutes: 1. What is the current development trend of heterojunction batteries?

Currently, many manufacturers including King Kong Glass , Mingyang Intelligent, and Huasheng New Energy are deploying heterojunction battery cells, but the current development situation is not as optimistic as imagined, and the actual scale of implementation is small.

had previously expected to achieve parity with PERC by the end of this year, but due to the influence of silver paste, silicon wafer thickness, target , manufacturing technology, etc., it is actually not known whether it can be achieved.

1) The cost of silver paste is higher.

Currently, heterojunction batteries consume an average of 20-22 mg of silver paste per watt, and the cost of silver paste per watt is about 1.8-2 gross, which limits the development of heterojunction batteries.

2) Limited by production equipment, the thinning effect of silicon wafers is not as good as expected.

heterojunction cells have natural thin film advantages. It was previously expected that the thickness of heterojunction cell silicon wafers will be reduced to 130 microns this year, and the cost per watt can be reduced by 6-7 cents.

The actual current thickness of heterojunction cells is still 140-150 microns.

Although there are no process problems in the production of 130-micron heterojunction battery cells, the automated picking of equipment will result in a lower yield rate for thin batteries.

3) The manufacturer's cost reduction technology is not as effective as expected.

Experts believe that the large-scale production of heterojunction batteries must further reduce costs. Currently, manufacturers use methods such as silver-coated copper and ingot single crystal to reduce the production costs of heterojunction batteries.

For example, Baofeng uses ingot single crystal technology to reduce the production cost of heterojunction cells. AVIC 600 MW heterojunction battery production line has not yet been built, but it has promoted that it will use the ingot single crystal method.

From a technical point of view, experts believe that ingot single crystal technology is not a good cost reduction solution. It is difficult to reduce the production cost of heterojunction cells using ingot single crystal technology.

① Experimental results show that using ingots to cast single crystals will lead to a 1% reduction in the conversion efficiency of heterojunction cells; under normal circumstances, the mass production efficiency of heterojunction cells is approximately 24.7%-25%. Among them, using The conversion efficiency of heterojunction cells using microcrystalline layer technology is basically 24.7%. The conversion efficiency of heterojunction cells of manufacturers with better technical level can reach 25%, while the conversion efficiency of heterojunction cells using ingot single crystal technology is difficult to reach. More than 24%.

② Even if the ingot single crystal technology reduces the single-chip production cost of heterojunction cells, due to the low conversion efficiency, the single-watt amortized cost reduction effect of silver paste, target materials, etc. is not significant. In the future, the conversion efficiency of heterojunction cells will increase. Reaching 25.5%, the cost reduction effect of ingot single crystal casting is even less significant.

4) The target cost reduction effect has not reached expectations.

5) Some manufacturers claim to have deployed several GW production lines, but they install the production lines one by one in order to seize market opportunities and will not install all the production lines at once.

6) Experts believe that as silicon wafers gradually become thinner and manufacturers gradually use cost-cutting technologies such as silver-coated copper technology, the cost per watt of heterojunction cells will not be higher than that of TOPCon, and at the end it will be equal to the cost of TOPCon.

2. When can the cost of heterojunction batteries be reduced?

Experts predict that there will be a major breakthrough in cost reduction of heterojunction batteries by the end of this year, and there will be a significant increase in the volume of heterojunction batteries next year.

With the application of silver-coated copper and the conversion efficiency of heterojunction cells reaching expectations, production capacity next year will be more than this year.

Experts believe that it will be difficult to reduce the thickness of silicon wafers to 130 mm by the end of this year, but the application of silver-coated copper is not difficult. Through the efforts of various companies, the conversion efficiency of heterojunction cells may reach 25%.

1) The application of silver-coated copper is not difficult. Manufacturers’ application of silver-coated copper will reduce the cost of heterojunction batteries by 30%. Experts predict that there will be verification results of silver-coated copper at the power station before the end of this year.

① At present, there are no big problems with the technical verification of silver-clad copper. Silver-clad copper has passed the verification on the battery side and the component side. Manufacturers can apply it on a large scale only after passing the verification on the power station side.

Because the application of silver-clad copper is a material change, not a technical change, it only needs to verify its reliability. Therefore, as long as the silver-clad copper can pass the reliability verification, manufacturers can directly use silver-clad copper, and the industrial chain will not occur. Too much change.

②Experts believe that silver-clad copper will definitely pass the verification of the power station, and it is expected that the verification results of the power station will be available before the end of the year.

Because there is currently great pressure to reduce the cost of heterojunction batteries, it will not take too long to verify whether silver-coated copper can pass the verification of the power station.

Huasheng will use silver-coated copper in 50% of its production lines by the end of this year.

③ If silver-coated copper can be applied on a large scale by the end of this year, the cost of heterojunction batteries will be reduced by 30%, which is a relatively big improvement.

2) The joint efforts of various manufacturers may improve the conversion efficiency of heterojunction cells.

① From a technical point of view, the conversion efficiency of heterojunction cells is considered good if it increases by 0.2%-0.4% per year.

Heterojunction batteries are currently at the forefront of the industry. Many forces are promoting cost reduction and efficiency improvement of heterojunction batteries. Experts believe that the conversion efficiency of heterojunction batteries will achieve a major breakthrough by the end of this year.

② The current average conversion efficiency of heterojunction cells is about 24.5%. If manufacturers can install some new production lines or transform old production lines, then the average conversion efficiency of heterojunction cells may reach 24.8%-25%. This will be by the end of this year It's possible. There are four technical paths:

3, TOPCon, heterojunction, PERC, and IBC. Which technical path is more cost-effective?

1) IBC: Except for , LONGi can produce HPC by transforming PERC energy, other manufacturers are currently unable to produce IBC batteries.

2) PERC: PERC technology is very mature. The cost of PERC technology batteries is about 1.07 yuan/watt. The space for cost reduction is limited. The cost of PERC batteries is slightly lower than TOPCon batteries.

3) TOPCon, heterojunction: TOPCon and heterojunction are both new technologies.

Currently, the cost of dry heterojunction cells is relatively high. Although manufacturers have relatively large plans for heterojunction cells, the implementation of heterojunction cells is not as good as that of TOPCon cells.Comparison of the performance of heterojunction equipment with different technical routes of

4, Maiwei, Jiejia, Junshi, and Ideal?

1) Maiwei VHF+ multi-chamber method: Maiwei's equipment mainly uses multi-chamber coating technology and uses the current method of VHF smooth screen to manufacture microcrystals.

Because this VHF method will produce a standing wave effect, the cavity cannot exceed two meters. If it exceeds two meters, the cavity will be uneven, so Maiwei needs to use multiple chambers or adjust the process to achieve high productivity.

2) Junshi RF method: DiaoShi RF method is different from Maiwei VHF method. DiaoShi RF method has a larger cavity than Maiwei VHF method.

Because Junshi uses RF mode and its current is 13.56 MHz, Junshi will not be affected by the standing wave effect. Its cavity can be larger and it can achieve higher production capacity with a smaller number of cavities.

3) The technical advantages and disadvantages of Maiwei VHF method and Junshi RF method: Experts believe that the performance of equipment manufactured using Maiwei VHF method and Junshi RF method is not much different at present, and the performance of equipment manufactured using Maiwei VHF method will be better in the future. excellent.

① In the amorphous era, Junshi RF technology has more advantages. In the microcrystalline era, Maiwei VRF technology has more advantages.

Because Diao Shi’s technology has higher production capacity, the equipment cost of amorphous batteries will also be lower.

As battery technology changes, manufacturers are gradually applying microcrystalline layers. From a technical point of view, because microcrystalline layers can improve the conversion efficiency of batteries, microcrystalline layer batteries using Maiwei VHF technology have more advantages.

②Mai manufactures microcrystals for VHF, and the battery conversion efficiency is higher.

uses Junshi RF method to make microcrystals. Single-sided microcrystals can increase the battery conversion efficiency by 0.3%-0.4%. Maiwei uses VHF to make microcrystals. Single-sided microcrystals can increase battery conversion efficiency by 0.5%-0.7%. The VHF method has more advantages than the Junshi RF method.

③ Because the process of P-side microcrystals is relatively difficult, using Junshi RF to manufacture P-side microcrystals may increase the battery conversion efficiency by 0.1%, or even the conversion efficiency will not increase. It is difficult to use RF to manufacture P-side microcrystals.

uses Maiwei VHF to manufacture P-surface microcrystals, and the battery conversion efficiency may increase by 0.3%.

If all manufacturers use double-sided microcrystals by the end of this year or next year, the advantages of Maiwei's VHF method will be more obvious.

4) Ideal stacking method: ∠ Advantages: The structural design is the most perfect, best meets the needs of scientific research, and its uniformity and efficiency are the highest. Hanergy and LONGi both used the stacking method to set world records.

②Disadvantages: The production capacity is extremely small, the U-shaped arrangement is difficult to manufacture, and it is difficult to mass produce, and the cost per unit production capacity is higher than that of Maiwei VHF. The

stacking method is only in the laboratory stage and cannot be applied in large-scale mass production. The mass production processes of , Tongwei, and Huasheng using the stacking method are very unsatisfactory.

5) Jiejia Tube P Technology: Jiejia has been producing plate PECVD equipment and is a leading enterprise in the equipment field.

Jiejia started late in the field of heterojunction battery manufacturing equipment. Based on its experience in hosting P-PERC, it developed tubular PECVD technology.

① Advantages: The production capacity of Jiejia tube P technology is higher than that of Maiwei VRF, Junshi RF and ideal stacking.

② Disadvantages: There are some defects in tube P technology that make it difficult to bring it to the market. If it can be overcome, experts believe that the advantages of tube blank technology will be great.

A. Because the tubular PECVD technology passes an electrode rod through the quartz tube , compared with Maiwei VRF, Junshi RF, and ideal stacked type, the tubular PECVD temperature uniformity is relatively poor, and the coating uniformity is poor. .

B. Tubular PECVD will produce a plating phenomenon, which is currently difficult to solve.

Although tubular PERC will also produce wrap-around plating, PERC does not have strict requirements for wrap-around plating, while heterojunction cells have stricter requirements for wrap-around plating. The wrap-around plating phenomenon will have a greater impact on the production of heterojunction cells.

③Jiejia’s tubular TOPCon will also produce wrap-around plating, but because TOPCon needs to be back-polished or back-etched, even if wrap-around plating occurs, it will be removed.

is just like the tubular PERC. Even if double-sided diffusion occurs, the back plating can be removed through the back etching process. However, heterojunction cells do not have the back processing process and cannot solve the plating phenomenon.

5. What are the characteristics of LONGi’s HPBC battery equipment?

Longi HPBC batteries may use LPCVD and laser. Laser technology is the key to its production of HPBC batteries. The specifics are not well understood.

6, what are the advantages of Maiwei’s half-chip technology?

Can other manufacturers use half-chip technology?

1) Maiwei’s half-chip technology can reduce debris and is in line with the development trend of silicon wafers.

① Half-chip technology is in line with the development trend of silicon wafers.

The size of silicon wafers is getting smaller and smaller, the thickness is getting thinner, and there will be more and more fragments. Maiwei's production of cells through half-chip technology is in line with the development trend of silicon wafers.

② half-chip technology can reduce debris, especially the debris of heterojunction cells, and solve the problem of efficiency loss of heterojunction cells at the source. The power loss caused by

half-chip components is relatively small. Manufacturers only produce half-chip components and do not produce full-chip components.

slide processing of whole components such as PERC will cause the battery conversion efficiency to decrease by 0.1%-0.15%. The heterojunction battery is a low-temperature process and uses amorphous silicon coating. If the whole piece is cut into half pieces, laser cutting The high temperature process of will destroy the passivation effect of heterojunction cells, which will reduce the efficiency conversion efficiency of heterojunction cells by 0.3%.

2) Half-slice technology is not difficult, and other manufacturers can use half-slice technology.

① Half-chip technology is the development trend of the industry. Other manufacturers can also use half-chip technology, but Maiwei was the first to use half-chip technology.

Currently, the newly installed 182mm and 210mm silicon wafer production lines use half-wafer technology.

② The technical difficulty of half-chip is not high. Manufacturers only need to adjust the automation equipment to use half-chip technology. The whole piece of

is burned on one track, and the half piece is burned on two tracks. You only need to adjust the automation equipment. What impact do

7, perovskite have on crystalline silicon cells? Will

be stacked with heterojunction or TOPCon?

Experts believe that perovskite technology will not have an impact on crystalline silicon cells at present.

Experts believe that perovskite is currently a market hype. Without 5-8 years of development time, perovskite cannot achieve mass production.

1) Although after more than ten years of development since 2010, the conversion efficiency of perovskite has increased from a few percent to very high, but perovskite cannot achieve large-scale production.

① Perovskite uses a wet coating method and cannot produce large-size perovskite cells.

② Perovskite batteries are not very stable.

At present, the problems of light decay, ultraviolet water decomposition, and photophobia of perovskite cells have not been solved. These factors will reduce the stability of perovskite cells.

2) Experts believe that perovskite may not necessarily be laminated with heterojunction and TOPCon.

Because the conversion efficiency of perovskite cells can reach 25%, even if they are stacked with crystalline silicon, the conversion efficiency of the cells can only reach 27%-28%. The cost of stacking is high and the price/performance ratio is not high, so there is no need to stack.

If perovskites have a greater impact on crystalline silicon batteries in the future, only crystalline silicon battery manufacturers will consider stacking perovskites, and perovskite battery manufacturers will not consider stacking.

3) In terms of battery structure, the current lamination effect of perovskite and heterojunction cells is better. In the future, with the development of TOPCon batteries, the lamination effect of perovskite and TOPCon will also become better.

① Heterojunction batteries have natural composite layers, which are more suitable for stacked batteries. The

heterojunction battery only needs to stack perovskites on the composite layer, which is equivalent to being connected in series, resulting in high opening voltage and low current.

② At present, the back of TOPCon battery is PERC passivated and the front is alumina , with a conversion efficiency of 24.5%.

As TOPCon continues to compete with heterojunction cells, in the future TOPCon will also use double-sided PERC passivation to solve front-side defects and improve conversion efficiency. Then it will be better to use perovskite with TOPCon.

8 What is the impact of metallization methods such as stencil printing and laser transfer on heterojunction batteries?

Steel plate printing and laser transfer printing can reduce the production cost of batteries, but steel plate printing and laser transfer printing technology are transitional cost reduction technologies, not revolutionary technologies. Experts believe that copper electroplating is a revolutionary cost reduction technology.

1) Manufacturers use technologies such as stencil printing and laser transfer printing to reduce the production costs of electronics. In the next two years, the cost reduction effect of stencil printing, laser transfer printing and silver-coated copper will be better.

steel plate printing and laser transfer printing can make the battery grid lines narrower, which can reduce the silver consumption by ten to twenty percent and reduce the production cost of the battery.

steel plate printing can reduce the grid lines from 35 microns to 18-20 microns. Laser transfer printing can make the grid lines narrower and have better appearance, which can increase the usage rate of silver paste.

2) Copper electroplating technology is a revolutionary cost-reduction technology and the best technology to replace screen printing and silver paste.

Because pure copper paste will oxidize after curing, its resistivity will be very high, so printing technology cannot use pure copper paste, and silver-coated copper is used for transition. Copper electroplating technology can completely replace silver with copper paste, so experts believe that copper electroplating Technology is a revolutionary cost-reduction technology.

① PCB is a relatively new technology in the field of photovoltaic .

Because the photovoltaic field has high requirements for fineness, in the future the precision may be required to reach more than ten microns, and the height may be required to reach ten microns. However, the photovoltaic field in Japan requires the cost of copper plating to be lower, so even if the PCB development history is dozens of Years, or even hundreds of years, the application of PCB in the photovoltaic field is relatively new.

②The development of PCB in the photovoltaic field is relatively slow.

In addition to Cylon's development ten years ago, Junshi's entry a few years ago, and State Power Investment Corporation's development of PCB technology, domestic manufacturers rarely apply PCB technology in the photovoltaic field, and there are fewer manufacturers applying PCB technology in the photovoltaic field. PCB progress in the photovoltaic field has been very slow.

③In the past two years, as manufacturers have gradually realized that heterojunction batteries must reduce costs, and methods such as steel plate printing and laser transfer printing have limited cost reduction effects, leading manufacturers such as Longi, Tongwei, and Maiwei have gradually deployed copper electroplating technology.

experts believe that the layout of leading manufacturers such as Longi, Tongwei, and Maiwei will promote the development of copper electroplating, and GW-type PCB technology may appear in the next two to three years.

9. Currently, copper electroplating technology is used in the laboratory. How high can the battery conversion efficiency be?

What factors prevent mass production of copper electroplated batteries?

1) Currently, only two manufacturers, Junshi and SPIC, are developing copper electroplating technology. Under

laboratory conditions, the battery conversion efficiency of Junshi and SPIC's copper electroplating technology may exceed 24.7%-24.8%.

The battery using copper electroplating technology has a smaller shading area and lower resistivity, which results in the battery conversion efficiency being 0.3%-0.5% higher than that of screen printing.

① The light-shielding area is smaller: The grid lines of copper electroplating can be very narrow, basically reaching 25 microns, while the width of screen printing grid lines is about 80-85 microns, which is far less than that of copper electroplating.

②The resistivity is lower: Copper electroplating uses pure copper , and its resistivity is about 1.7 ohms. However, screen printing is not pure silver and will contain some organic matter or resin residues. Contact is made through granular silver powder , and its resistivity About 4.5-6 ohms, which is 3-4 times that of pure silver and much higher than copper electroplating, which results in the efficiency of screen-printed batteries being lower than that of copper electroplating batteries.

2) Although manufacturers such as Junshi have been deeply involved in the field of copper electroplating for many years and may have copper electroplating solutions, factors such as the high cost of copper electroplating equipment, low production capacity, and high cost of copper electroplating consumables prevent mass production of copper electroplated batteries.

① The equipment cost of copper electroplating is relatively high: At present, several domestic manufacturers that apply copper electroplating technology basically use imported equipment. The equipment cost is very high. Domestic manufacturers are faced with the problem of how to realize localization of equipment substitution.

Junshi may produce some of its own equipment, but most of its graphics circuits use imported equipment.

② The production capacity of copper electroplating is low: The production capacity of copper electroplating is low. How to achieve high production capacity is a problem that domestic manufacturers need to solve.

③ The cost of consumables for copper electroplating is high: Because copper electroplating includes patterning, and patterning requires the use of consumables such as dry film , the cost of applying copper electroplating is higher than applying metallic silver.

jade manufacturers need to use cheaper materials such as film or photosensitive adhesive to replace more expensive dry film materials.

10. If we can produce copper electroplated batteries, how much lower will the cost of copper electroplated batteries be than that of pure silver batteries?

Because copper electroplating technology will increase the conversion efficiency of the battery by 0.3%, and does not use metallic silver, the cost of batteries using copper electroplating technology will drop by about 5-6 cents/watt.

11. In the photovoltaic field, which domestic copper electroplating manufacturers are developing well?

Which manufacturer is most likely to mass-produce copper electroplating equipment?

1) In the photovoltaic field, the currently well-developed copper electroplating manufacturers in China mainly include Sunwell, Dongwei Technology, Gidebao, and Wuxi Kunsheng. There are also some lesser-known PCB manufacturers that are expanding into the photovoltaic field from other fields.

Sunwell and Dongwei Technology are vertical electroplating manufacturers, while Gidebao and Wuxi Kunsheng are horizontal electroplating manufacturers.

Sunwell is cooperating with Tongwei, and Gidebao is cooperating with Haiyuan on a 600-megawatt copper electroplating project.

Because Wuxi Kunsheng was previously a copper plating manufacturer in the field of television equipment, Wuxi Kunsheng also used horizontal plating technology when entering the photovoltaic field.

2) Gedeborg's equipment has technical problems that are difficult to overcome, and Dongwei's equipment has difficulty overcoming production capacity problems. Experts believe that whichever company solves its own problems first will be in a leading position.

Experts believe that Dongwei's equipment is better than Gedeborg's equipment.

① Horizontal electroplating manufacturers such as Gedeborg: Horizontal electroplating has the advantage of mass production. Adding roller countdown can expand production capacity, but horizontal electroplating also has technical flaws that are difficult to overcome.

puts 8, 10 or 16 pieces of rollers to count down. The difficulty is the same, and mass production can be achieved through horizontal drifting.

② Vertical electroplating manufacturers such as Dongwei: Dongwei’s copper electroplating equipment does not have many technical flaws, but its production capacity problem is difficult to solve.

vertical electroplating achieves mass production by hanging single pieces, which requires very high equipment automation. Currently, a copper electroplating production line of Dongwei can only print 3000-5000 pieces, but many manufacturers require a copper electroplating line of Dongwei The production line prints 8,000 pieces, and Dongwei's equipment cannot meet the manufacturer's requirements.

12. Are there material bottlenecks in copper electroplating?

The main bottleneck of copper electroplating mass production is equipment. Materials are the bottleneck of copper electroplating mass production, but it is not a critical bottleneck. Material problems will be solved before equipment problems.

Because the production capacity of copper electroplating involves imaging equipment, and there is a bottleneck in the equipment, some manufacturers can currently apply copper electroplating technology, but their production capacity is small and cannot be mass-produced.

13. In the field of heterojunction batteries, which domestic manufacturers are leading in low-temperature silver paste?

At present, in the field of heterojunction batteries, the main domestic manufacturers that produce low-temperature silver paste include Silver Star Technology, Suzhou Jingyin, Dike, Kuangyu Technology, and Changzhou Juhe. Experts believe that the technical levels of these manufacturers are similar, and there is no single manufacturer. The technology of this manufacturer is relatively advanced.

Because the key materials (silver powder) of these manufacturers are purchased from outside, they do not master the core technology. They only master some non-critical formula processes, and their technical levels are similar.

14. Is it necessary to use new welding ribbon equipment to produce heterojunction cells? The requirements for welding ribbons for

heterojunction batteries depend on the requirements of the welding process. At present, welding ribbons are not the main obstacle to the production of heterojunction batteries. The production of heterojunction batteries by

is a low-temperature process and requires the use of low-temperature welding processes, which may require changing the material of the welding ribbon.

At present, soldering ribbons mainly use tin-clad copper wires, and manufacturers do not have a strong willingness to replace the tin-clad copper materials. The soldering ribbon materials are not the main obstacle to the production of heterojunction batteries. How will the expiration of

15 and SmartWire patents promote the development of HJT? Is

more suitable for TOPCon or heterojunction cells?

1) The SmartWire patent is a component technology. Experts believe that the expiration of the SmartWire patent will trigger a research boom among manufacturers.

2) Both TOPCon and heterojunction cells can use SmartWire patents.

Because the SmartWire patent is a component technology, and except for a small part of the component technology differences between TOPCon and heterojunction cells, most of the component technologies are the same.

3) 3) Experts believe that the SmartWire patent will not necessarily reduce the cost of photovoltaic modules, but may reduce the cost of heterojunction cells.The

SmartWire patent can reduce the consumption of silver paste, while the low-temperature silver paste used in heterojunction batteries is more expensive. What is the layout of

16, LONGi and JA Solar in the HJT field?

1) LONGi: According to LONGi’s announcement, LONGi will install a 1.2GW HJT pilot line. Currently, a 600MW HJT pilot line has been installed.

Other manufacturers use complete line equipment, but LONGi’s 1.2GW HJT pilot line is different from other manufacturers in that LONGi uses patchwork equipment.

Because LONGi has strong R&D capabilities, it can complete the matching of equipment and lay the foundation for future equipment selection.

2) JA Solar: JA Solar has installed a Junshi production line. Currently, JA Solar has completed equipment debugging and may be undergoing process debugging.

17. How to read the data released by King Kong and Huasheng?

Will King Kong mass-produce 130 micron silicon wafers this year?

1) Two companies, King Kong and Huasheng, claim that the thickness of their silicon wafers can be reduced to 130 microns. Experts believe that this is laboratory data. If mass-produced, the thickness of their silicon wafers is unlikely to be reduced to 130 microns.

2) Currently, King Kong’s 130 micron silicon wafer production line is in the debugging stage, and the production line is not at full capacity. The specific information of King Kong’s 130 micron silicon wafer production line will be different from the released information.

From the battery side, it is difficult for automated equipment to control the fragmentation rate; from the component side, the welding process cannot guarantee the yield of 130 micron silicon wafers, so experts believe that it is difficult for King Kong to mass-produce 130 micron silicon wafers, but they do not rule out King Kong. Its relatively advanced technology enables it to produce 130 micron silicon wafers.

19. Will the thickness of TOPCon battery silicon wafers be more advantageous than the thickness of heterojunction battery silicon wafers?

1) Theoretically, the thickness of TOPCon battery silicon wafers has more advantages than the thickness of heterojunction battery silicon wafers. However, in the actual mass production process, the thickness of heterojunction battery silicon wafers has no disadvantage. Its thickness is the same as that of TOPCon battery silicon wafers. The thickness of the slices is consistent.

2)) Because heterojunction cells use low-temperature processes, produce less debris during the process, have fewer process steps, and have higher electricity-to-oil conversion efficiency, experts believe that the thickness of silicon wafers in future heterojunction cells will be thicker than that of TOPCon cells. Has advantages.

① Low-temperature process: Heterojunction batteries use low-temperature processes, while TOPCon batteries use high-temperature processes. The silicon wafers of TOPCon batteries are basically produced in a high-temperature environment of 950-1050 degrees. In the future, the silicon wafers of heterojunction batteries will be more durable than TOPCon batteries. Advantage.

The high temperature environment will change the physical properties of the silicon wafer, causing the silicon wafer to become softer. After being softened at high temperature, the silicon wafer will become more brittle. High temperatures are not suitable for thinning silicon wafers.

② Process: Heterojunction cells adopt a plate structure. Except for texturing, the entire production process is flat, producing less debris.

TOPCON batteries are either plate or vertical. The larger and thinner the silicon wafer is, the more fragments it will have.

③ Few process steps: TOPCON battery has 12-13 steps of manufacturing process, while heterojunction battery only has 4-5 steps of manufacturing process.

④Battery conversion efficiency: A. As silicon wafers gradually become thinner, the conversion efficiency of heterojunction cells may increase.

heterojunction cells use double-sided amorphous silicon passivation. The surface passivation effect is very good, which will reduce current, light absorption and resistance. As the silicon wafer gradually becomes thinner, the increase in VOC will exceed the decrease in current, and the conversion efficiency of the battery will will improve.

If other factors are not considered, if the thickness of the silicon wafer is reduced from 150 microns to 120 microns, the battery conversion efficiency will increase by 0.1%-0.15%.

B. At present, the structure of Topcon battery is not the most perfect. The back side adopts PERC structure, and the passivation effect on the back side is similar to that of heterojunction battery. Because the front side of Topcon battery adopts aluminum oxide plus silicon nitride structure, the passivation effect on the front side is similar. The effect is quite different from that of heterojunction cells. Moreover, the metallization on the front surface of Topcon battery tunnels silicon oxide and alumina, making the silver paste contact silicon. The metallization load is very large, so the load on the front surface of Topcon battery is very large. .

As the thickness of the silicon wafer gradually decreases, the current decrease of the Topcon battery is the same as that of the heterojunction. However, the opening voltage of the Topcon battery will not increase or the increase will be smaller than the current decrease. Then the conversion efficiency of the Topcon battery will decrease by 0.1%-0.2 %.

⑤Experts believe that the thickness of silicon wafers for heterojunction batteries in the future may be 10-15 microns, or even 20 microns, thinner than Topcon batteries.

Because heterojunction cells have not yet used double-sided polysilicon, the difference in the thickness of the silicon wafers of heterojunction cells and Topcon cells has not yet appeared. In the future, double-sided polysilicon will be used in heterojunction cells and automation equipment and components will adapt to the thin wafers. ation, then the difference in the thickness of the silicon wafer of the heterojunction battery and the Topcon battery will appear.

Minute source: [Wenbagu Research: wenbagu.com]