CN109417102A - For connecting the method with aluminium film as the solar battery of back contact - Google Patents
For connecting the method with aluminium film as the solar battery of back contact Download PDFInfo
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- CN109417102A CN109417102A CN201780037437.4A CN201780037437A CN109417102A CN 109417102 A CN109417102 A CN 109417102A CN 201780037437 A CN201780037437 A CN 201780037437A CN 109417102 A CN109417102 A CN 109417102A
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- aluminium
- zinc
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- solar battery
- plating
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- 238000000034 method Methods 0.000 title claims abstract description 52
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims description 64
- 229910052782 aluminium Inorganic materials 0.000 title claims description 63
- 239000004411 aluminium Substances 0.000 title claims description 61
- 239000011701 zinc Substances 0.000 claims abstract description 187
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims abstract description 95
- 229910052725 zinc Inorganic materials 0.000 claims abstract description 95
- 229910052751 metal Inorganic materials 0.000 claims abstract description 88
- 239000002184 metal Substances 0.000 claims abstract description 84
- 238000007747 plating Methods 0.000 claims abstract description 72
- 239000004065 semiconductor Substances 0.000 claims abstract description 55
- PTFCDOFLOPIGGS-UHFFFAOYSA-N Zinc dication Chemical compound [Zn+2] PTFCDOFLOPIGGS-UHFFFAOYSA-N 0.000 claims abstract description 34
- 238000005476 soldering Methods 0.000 claims abstract description 19
- 239000013078 crystal Substances 0.000 claims description 67
- 239000000758 substrate Substances 0.000 claims description 45
- 239000000463 material Substances 0.000 claims description 36
- 238000005219 brazing Methods 0.000 claims description 19
- 230000008021 deposition Effects 0.000 claims description 19
- 239000011248 coating agent Substances 0.000 claims description 18
- 238000000576 coating method Methods 0.000 claims description 18
- 238000011010 flushing procedure Methods 0.000 claims description 7
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 7
- 229910052737 gold Inorganic materials 0.000 claims description 7
- 239000010931 gold Substances 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 7
- 239000007767 bonding agent Substances 0.000 claims description 6
- VMQMZMRVKUZKQL-UHFFFAOYSA-N Cu+ Chemical compound [Cu+] VMQMZMRVKUZKQL-UHFFFAOYSA-N 0.000 claims description 5
- -1 also Substances 0.000 claims description 5
- 150000001768 cations Chemical class 0.000 claims description 5
- 238000001035 drying Methods 0.000 claims description 4
- YWMAPNNZOCSAPF-UHFFFAOYSA-N Nickel(1+) Chemical compound [Ni+] YWMAPNNZOCSAPF-UHFFFAOYSA-N 0.000 claims description 3
- 229940006444 nickel cation Drugs 0.000 claims description 3
- 238000005096 rolling process Methods 0.000 claims description 3
- 230000003746 surface roughness Effects 0.000 claims description 2
- 239000003292 glue Substances 0.000 claims 1
- 150000002500 ions Chemical class 0.000 claims 1
- 238000000151 deposition Methods 0.000 description 17
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 239000000853 adhesive Substances 0.000 description 9
- 230000001070 adhesive effect Effects 0.000 description 9
- 229910000679 solder Inorganic materials 0.000 description 9
- 229910000838 Al alloy Inorganic materials 0.000 description 7
- 241001424392 Lucia limbaria Species 0.000 description 7
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 6
- 239000010949 copper Substances 0.000 description 6
- 229910052709 silver Inorganic materials 0.000 description 6
- 239000004332 silver Substances 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 5
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 5
- 239000002245 particle Substances 0.000 description 5
- 229910052710 silicon Inorganic materials 0.000 description 5
- 239000010703 silicon Substances 0.000 description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- 229910001128 Sn alloy Inorganic materials 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 230000004907 flux Effects 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 230000003068 static effect Effects 0.000 description 4
- 239000003513 alkali Substances 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- NWONKYPBYAMBJT-UHFFFAOYSA-L zinc sulfate Chemical compound [Zn+2].[O-]S([O-])(=O)=O NWONKYPBYAMBJT-UHFFFAOYSA-L 0.000 description 3
- 230000002411 adverse Effects 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 238000005275 alloying Methods 0.000 description 2
- 229910052797 bismuth Inorganic materials 0.000 description 2
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000005115 demineralization Methods 0.000 description 2
- 230000002328 demineralizing effect Effects 0.000 description 2
- 238000000280 densification Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 238000009713 electroplating Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 238000013532 laser treatment Methods 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 230000009972 noncorrosive effect Effects 0.000 description 2
- 238000005240 physical vapour deposition Methods 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 238000007650 screen-printing Methods 0.000 description 2
- 229910052723 transition metal Inorganic materials 0.000 description 2
- 229910001316 Ag alloy Inorganic materials 0.000 description 1
- 229910000611 Zinc aluminium Inorganic materials 0.000 description 1
- HXFVOUUOTHJFPX-UHFFFAOYSA-N alumane;zinc Chemical compound [AlH3].[Zn] HXFVOUUOTHJFPX-UHFFFAOYSA-N 0.000 description 1
- 150000004645 aluminates Chemical class 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010494 dissociation reaction Methods 0.000 description 1
- 230000005593 dissociations Effects 0.000 description 1
- 238000004070 electrodeposition Methods 0.000 description 1
- HQQADJVZYDDRJT-UHFFFAOYSA-N ethene;prop-1-ene Chemical group C=C.CC=C HQQADJVZYDDRJT-UHFFFAOYSA-N 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000007888 film coating Substances 0.000 description 1
- 238000009501 film coating Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
- 229910001845 yogo sapphire Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/02—Details
- H01L31/0224—Electrodes
- H01L31/022408—Electrodes for devices characterised by at least one potential jump barrier or surface barrier
- H01L31/022425—Electrodes for devices characterised by at least one potential jump barrier or surface barrier for solar cells
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
Landscapes
- Engineering & Computer Science (AREA)
- Electromagnetism (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Photovoltaic Devices (AREA)
- Electroplating Methods And Accessories (AREA)
Abstract
The present invention relates to a kind of methods for connecting solar battery, wherein (a) is with containing Zn2+Alkaline, watery medium single side handle aluminium-film, thus the deposited metal zinc on the processed side of aluminium-film, and form aluminium-film of single side plating Zn；(b) on the back side for the semiconductor devices that aluminium-film of single side plating Zn is covered in the first solar battery by its untreated side, and locally use laser beam heats, so that the back side of aluminium-film and semiconductor devices connects, and aluminium-back contact of plating Zn is obtained；(c) by metal connector the aluminium-back contact for plating Zn is connect with the hard contact of the second solar battery, wherein the metal connector is by soldering or is adhesively fixed on aluminium-back contact of plating Zn.
Description
Solar battery generally comprises semiconductor devices, which includes the first semiconductor material, the second half leads
Body material and the transitional region (such as also referred to as pn-junction) between both semiconductor materials.It can be to these semiconductor materials
One of material is adulterated, or can also be adulterated to each in these semiconductor materials.By with the first half
First hard contact of conductor material electrical connection and the second hard contact being electrically connected with the second semiconductor material, can measure
Generated voltage in solar battery.
One of hard contact can be placed on the front or leading flank of solar battery (commonly referred to as front contact), and another
One hard contact is located on the back side of single battery (commonly referred to as back contact).Alternatively it is also known that following solar battery: right
In this solar battery, each hard contact is only located on rear surface of solar cell for example in the form of comb interdigital structure.
In the solar battery of this only rear-face contact, effect of obmubing can reduce.
Electric contact (back contact) on solar battery such as silicon-solar battery back side often passes through in large area
Silk-screen printing aluminium paste and cover.In order to connect (such as form to be electrically connected in series) multiple solar batteries, first overleaf
It is upper to imprint the pad that is made of silver paste, soldering connection device on these pads.The other end of the projection of connector is soldered to adjacent
Solar battery front on, to produce the series connection of each solar battery, become so-called solar battery string.
The low-cost back contact of one kind can generate as follows: arrange metal on the back side of the solar cell
Film is then locally melted by laser irradiation, wherein metal film is connect with silicon solar cell in that region.?
In design described in DE 102,012 214 253, filling is formd in adjacent area between metal film and solar battery
Have a cavity of filled media, metal film in these adjacent areas in it is non-fusible, this brings advantageous light for solar battery
Learn characteristic.Advantageously with aluminium film as metal film, because being formd in silicon local when melting the film by laser
p+It is highly doped, it is this highly doped to reduce excess carrier and recombine (so-called local back surface field) at these positions.
Solar battery and aluminium film-back contact are electrically coupled in series at solar battery string, and this series connection is such as manufacturing the sun
It can be required for battery module, however be a kind of challenge, because connector is due to the Al that is formed on aluminium quickly2O3Layer
And it cannot traditionally be soldered on aluminium.
" the Zincate processes for silicon solar cell metallization " of M.Kamp et al.
(Solar Energy Materials&Solar Cells, the 120th phase page 332,2014) describes a kind of method, at this
In method, aluminium is covered on the back side of the solar cell by physical vapour deposition (PVD) first, the subsequent aluminium-back contact uses zinc
Hydrochlorate-method metal zinc coating.The metal zinc layers are used as the substrate of the electrochemical deposition of Ni/Cu- stacks of metal layers again, in the gold
Belong to and is brazed small copper strips in layer heap.
The object of the present invention is to solar battery is connected by a kind of method, it can be as simple as possible using this method
And effectively solar battery connector is fixed on the hard contact of solar battery.Another object is to provide connection
Solar battery has big adhesive force between the hard contact and solar battery connector of solar battery.To attached
Improving for putting forth effort should not cause to bear to the efficiency of other characteristics such as solar battery as far as possible.
The purpose is achieved by a kind of method for connecting solar battery, wherein
(a) with containing Zn2+Alkaline, watery medium single side handle aluminium-film, thus in the processed side of aluminium-film
Upper deposited metal zinc, and form aluminium-film of single side plating Zn；
(b) aluminium-film of single side plating Zn is covered in by its untreated side the semiconductor device of the first solar battery
On the back side of part, and laser beam heats are locally used, so that the back side of aluminium-film and semiconductor devices connects, and obtained
Aluminium-back contact of plating Zn；
(c) by metal connector the aluminium-back contact for plating Zn is connect with the hard contact of the second solar battery,
In, the metal connector is by soldering or is adhesively fixed on aluminium-back contact of plating Zn.
Within the scope of the present invention it has been found that being that one kind is used to fix metal by the zinc-plated aluminium that wet chemical method obtains
The effectively substrate of connector (such as small copper strips).It is high on the hard contact of solar battery that connector may be implemented
Adhesive strength.It saves and other metal layers (such as passing through plating) is covered on zinc-plated aluminium before soldering connection device.Definitely
Ground says, zinc-plated aluminium has been formed for being brazed or the suitable substrate of bonding connection device.It can be very using traditional solder
It realizes well and covers metal connector, wherein obtained high adhesive force and the small electricity between connector and aluminium film
Contact transition resistance.(such as by conductive bonding agent) bonding connection device also provides high adhesive force and small electricity
Contact transition resistance.
The presence of metal zinc layers can't negatively affect the efficiency of semiconductor material and solar battery.But if using
Aluminium-back contact is generated by the aluminium film of coating with the material in addition to zinc, then shows the efficiency of solar battery compared to not plating
The aluminium film of layer decreases, and may is that because these metals have been embedded into locally highly doped region.Astoundingly
It was found that not making semiconductor material characteristic (such as characteristic of silicon) this deterioration occur using method of the invention.It may
A reason be perhaps, aluminium film heat affected zone and solar battery the back side connection before, the Zn steaming-plating of deposition is in quilt
Apply in the region of laser beam.In this way, zinc or is not only embedded into the sun with negligible small concentration
In the semiconductor devices of energy battery.
As already mentioned above, solar battery includes semiconductor devices, which includes the first semiconductor material, second
Semiconductor material and the transitional region (such as also referred to as pn-junction) between both semiconductor materials.These can partly be led
One of body material is adulterated, or can also be adulterated to each in these semiconductor materials.By with
First hard contact of semiconductor material electrical connection and the second hard contact being electrically connected with the second semiconductor material, Ke Yiliang
Take generated voltage in solar cells.Within the scope of the present invention, zinc-plated aluminium-back contact forms these hard contacts
One of.
Depending on the type of solar battery (such as monocrystalline or amorphous silicon-solar battery), art technology
Personnel substantially know must how designing semiconductor device (type, doping of the semiconductor material to be used etc.).
Solar battery is preferably silicon-solar battery, such as monocrystalline silicon-solar battery, polysilicon-solar-electricity
Pond or amorphous silicon-solar battery.But method of the invention is also suitable for connecting other solar batteries, such as III-V-half
Conductor-solar battery, II-VI-semiconductor-solar battery, I-III-VI-semiconductor-solar battery or organic solar
Battery.
If those skilled in the art are generally known, when connecting solar battery, these solar batteries pass through gold
Belong to connector to contact with each other.Metal connector is separately fixed at herein on one of hard contact of adjacent solar battery.It is described
Connection can be series connection, or be also possible to be connected in parallel.The series connection of solar battery can also be connected in parallel
It connects and combines.
As already mentioned above, the method for the invention the step of in (a), with containing Zn2+Alkaline, watery medium single side handle
Aluminium-film, thus the deposited metal zinc on the processed side of aluminium-film, and form aluminium-film of single side plating Zn.
Aluminium-film thickness is preferably in the range of 2 μm~20 μm for instance in the range of 0.5 μm~50 μm.It is this
Aluminium-film can be obtained commercially.
Aluminium-film preferably has the aluminium content of at least 80% (weight), preferably at least 90% (weight).It can be pure metal
Aluminium or aluminium alloy.The purity of metallic aluminium can along wider range, as long as can not adversely influence electric conductivity and/
Or mechanical property.For example, aluminium contains in total amount accounting less than 1% (weight), preferably smaller than 0.1% (weight) or is less than
Other metallic elements of 0.01% (weight).If aluminium-film is made of aluminium alloy, which preferably has at least 80%
The aluminium content of (weight), preferably at least 90% (weight).Those skilled in the art will know that the suitable of alloy can be melt into aluminium
Metallic element.
Preferably, there is quite high Zn for handling the watery medium in aluminium-back contact2+Concentration.In a kind of preferred reality
It applies in mode, the Zn in alkaline, watery medium2+Concentration be at least 1.5% (weight), preferably at least 2.0% (weight), more preferably
At least 3.0% (weight), or even at least 4.0% (weight).
Zn2+Exist in a free form, mode is, for example, so that Zn2+Compound (example under conditions of relatively alkaline
Such as relatively high pH value) dissociate in watery medium.Zn2+It can be under conditions of alkalinity for example as zincate (such as [Zn
(Ⅱ)(OH)4]2-Or similar contain Zn2+Form) be present in watery medium.This base to those skilled in the art
It is known on this.
The suitable pH value of alkaline, watery medium for example >=10, preferably >=13.
Optionally, the watery medium of alkalinity can also contain other transition-metal cations, preferably iron-cation, nickel-sun from
The combination of at least two cations in son or copper-cation or these cations.In a preferred embodiment, alkali
It is at least 0.0003% (weight), preferably at least 0.001% (weight), for example 0.0003 that property, watery medium, which also contain concentration,
Fe- cation in~30% (weight) range.If alkalinity, watery medium contain nickel-cation, these nickel-cations
Can for example exist with 0.1~5% (weight), the concentration of preferably 0.5~3% (weight).If alkalinity, watery medium contain
Copper-cation, then these copper-cations can for example with 0.01~1% (weight), preferably 0.05~0.5% (weight) it is dense
Degree exists.
From containing Zn2+Watery medium single side of the metallic zinc on aluminium-film the preferred no power of deposition carry out.No
The metal deposit of energization is a kind of method of coating implemented without using external power supply.
Those skilled in the art know oneself, use alkaline Zn2+Metallic zinc no power is deposited to aluminium-substrate by solution
On.In this process, make the Al being located on aluminium first2O3Layer dissociation.Exposed aluminium is oxidized, and is entered as aluminate
Into solution.Zn2+(such as in the form of zincate) be reduced to be deposited on there are still aluminium on metal Zn.
The adhesion that too thin zinc layers will cause soldering or bonding connector is poor.In addition, for too thin zinc layers,
There can be big contact transition resistance between connector and aluminium-back contact.On the other hand, too thick zinc layers cannot fully adhere to
On aluminium-film.Preferably, being deposited on the zinc layers on aluminium-film has in 0.1 μm~5 μ ms, preferably 0.3 μm~2.5 μm models
Enclose interior thickness.
In general, aluminium-film thickness reduces a value during Zn- deposition step (a), which is substantially equal to the Zn- of deposition
The thickness of layer.
In the middle alkalinity of step (a), watery contain Zn2+Media processes aluminium-film duration be, for example, 15s~250s.
Zinc deposition step (a) preferably carries out at a temperature in the range of 5-60 DEG C, preferably 5-45 DEG C.
In step (a), with containing Zn2+Watery medium single side handle aluminium-film.It means that aluminium-film is only
One side and contain Zn2+Media contact, and be equipped with the Zn- layer of metal, and the step on the untreated side of the film
(a) the Zn- layer of metal is not present after.If being further described further below, the film is in step (b) by described untreated
, on the back side of the semiconductor devices that i.e. no Zn- layers of side is fixed on solar battery.
Aluminium film can have coarse side and smooth side according to manufacturing condition.If the coarse side of aluminium film
With zinc coating, and smooth side leans against on the back side of semiconductor devices, then generates the improved light efficiency of solar battery.Cause
This in a preferred embodiment, Zn is contained with watery in aluminium-film side2+Medium handled, the side
Average surface roughness is larger compared to the side on opposite.
In a preferred embodiment, during zinc deposition step (a), aluminium-film is maintained at the position of basic horizontal,
Wherein, stand-by metallic zinc gives the side of coating downwardly, and with contain Zn2+Watery media contact." basic horizontal "
It means, the deviation of the film and desirable level position is up to 20%, preferably at most 10%.Here, alkaline, watery contain
Zn2+Medium be located at aluminium-film to the side of coating hereinafter, and can using usual way for example by splash or rinse with
The contact of aluminium-film side.For example, containing Zn2+Medium be located in upper opening of container, also, aluminium-film is moved to this
Above container, wherein contain Zn2+Medium only contacted from following in single side with aluminium-film.
In step (a), aluminium-film water level land arrangement, and in this case to the side of aluminium-film downwardly into
Row coating, this has positive influence to the microstructure of the metal zinc layers of deposition, and causes further to improve aluminium-back contact and fixation
The adhesive force between solar battery-connector thereon.
Alternatively also it is possible that aluminium-film is substantially perpendicularly arranged in step (a).But in principle, in step (a)
Any other arrangement (such as obliquely direction) of middle semiconductor devices is also feasible.
In a preferred embodiment, aluminium-film is during the zinc deposition step (a) relative to containing Zn2+Medium move
It is dynamic.Preferably, aluminium-film contains Zn with watery2+Medium between relative velocity be at least 0.1m/min, more preferably at least
0.2m/min.As already mentioned above, this relative movement can be realized as follows: so that aluminium-film bottom surface move through it is quiet
Only contain Zn2+Medium, alternatively, make flowing Zn2+Medium flows through the static bottom surface of aluminium-film, or both sides
Case combines.Aluminium-film contains Zn relative to watery2+The relative movement of medium can be by roll-to-roll-method come real
It is existing.Contain Zn in aluminium-film and watery during the step of Zn- is deposited (a)2+Medium between relative movement, to deposition
The microstructure of metal zinc layers has positive influence, and leads to the solar-electricity for further improving aluminium-back contact with being fixed thereon
Adhesive force between pond-connector.
If being further described further below, for passing through soldering or the gold being bonded on the aluminium-back contact for being fixed on and plating Zn
For the adhesive strength for belonging to connector, it has been suggested that particularly advantageously, the metal zinc layers deposited in step (a) are as densification
Layer exists, wherein there is also zinc-crystal grain on the surface of fine and close zinc layers, the diameter of these crystal grain is greater than 2.0 μm, and quantity is close
Degree >=5000/mm2, preferably >=10000/mm2, more preferably 5000-60000/mm2Or 10000-50000/mm2；And/or its
In, the surface of fine and close zinc layers at least 1.5%, preferably at least 3.0%, more preferable 1.5-18.0% or 3.0-15.0% it is straight
Zinc of the diameter greater than 2.0 μm-crystal grain covering.
Other than containing relatively large Zn- crystal grain (i.e. > 2.0 μm), the zinc layers of metal are preferably also containing diameter less than 1.0 μm
Significantly smaller zinc-crystal grain, wherein preferably, the relatively large part on the surface of fine and close zinc layers (such as more than 40% or
More than 50% or even more than 60%) these lesser zinc with diameter less than 1.0 μm-crystal grain covering.Preferably, diameter is big
Jointly covered in the zinc-crystal grain of 2.0 μm of zinc-crystal grain and diameter less than 1.0 μm the surface of fine and close zinc layers at least 90%,
Preferably at least 95%.Zinc-crystal grain particle size distribution on the surface of fine and close zinc layers may, for example, be double-peak type.
The metal zinc layers of this densification are shown in Fig. 1, the biggish crystal grain with relatively high number density.Zn-
The region that the region where relatively large Zn- crystal grain in layer surface is formed by significantly smaller Zn- particle respectively surrounds.It borrows
The above method parameter of walker rapid (a), can targetedly generate the zinc layers of this metal.
If fixation of the metal connector in zinc layers is carried out by soldering, the relatively big crystal grain with relative high density
This special construction is at least maintained in the region not being brazed.If the fixation is carried out by bonding, metal zinc layers
Special construction can also be maintained in the region of bonding.
In a preferred embodiment, the Zn- coating obtained in step (a) uses flushing liquor before step (b)
It rinses at least once.Aluminium-back contact first time of plating Zn is rinsed least for before step (b), and is optionally also
Subsequent rinse, preferably using the watery flushing liquor of pH > 8.5, preferred pH > 13.
Preferably, it for example to single side plates aluminium-film of Zn by being suitably heat-treated and gives drying before the step (b).
When necessary, before step (b) execution, step (a) can be repeated at least once more.But consider process efficiency, it is excellent
Step (a) is selected to be only performed once.
As already mentioned above, the method for the invention the step of in (b), aluminium-film of single side plating Zn is passed through its untreated side
Face is covered on the back side of the semiconductor devices of the first solar battery, and locally uses laser beam heats, so that aluminium-film
It is connect with the back side of semiconductor devices, and has obtained aluminium-back contact of plating Zn.
Consistent with being generally understood for those skilled in the art, the back side of semiconductor devices is the work in solar battery
In the side opposite with illuminated face (i.e. positive), the side thus form the side of backlight.Positioned at rear surface of solar cell
On hard contact also commonly referred to as carry on the back contact.
Those skilled in the art will know that aluminium film to be fixed on to the semiconductor of solar battery in the case that laser beams are used
Suitable method condition on the back side of device.It relatively may refer to the side introduced in 10 2,012 214 253 A1 of DE
Method.
The heating of part preferably carries out as follows: deposited metal zinc as much as possible, also, aluminium-film being deposited in this region
It is at least temporary melting.By fusing, in the regional area, occur between aluminium-film and the back side of semiconductor devices effectively
Connection.Due to Zn steaming-plating, in the join domain of the part, the interference of semiconductor devices is reduced or even completely avoided
Impurity.In the adjacent area that aluminium-film had not given local heating with laser beam, there are still metallic zinc-coating, and can
To be used to fix metal connector by being brazed or being bonded in step (c).
The heating of part is carried out preferably by laser beam in the case where each laser point has multiple laser pulses.This has
Conducive to the zinc layers of the evaporation metal in the region of local heating, and reduce semiconductor devices and the impurity of undesirable danger
Danger.
In a kind of advantageous design of this method, aluminium-film is in step (b) by laser beam on the side of semiconductor devices
It is locally heated around edge, so that aluminium-film is separated.Hence improve the attachment of the film on the semiconductor device.
It is also advantageous that aluminium-film adhesion is high especially in the case where covering connector.This is for example by as follows
Mode is realized: in method and step (b), aluminium-film is covered in method and step (c) with the area fraction that laser beam irradiates
It is bigger compared in aluminium-film remaining region in below connector and neighbouring region.
After on the back side that the aluminium-film for single side plating Zn is fixed on semiconductor devices, which may be used as the sun
Aluminium-back contact of the plating Zn of energy battery.
Within the scope of the present invention it is possible that solar battery is other than with aluminium-back contact, also in solar battery
Front on metal front contact.The front contact can design in a known manner.For example, front contact can have grid
Structure.Front contact can for example be made of silver or silver alloy.Front contact can be when placement aluminium-back contact in step (b) just
It has been positioned on semiconductor devices.Alternatively, front contact can be with aluminium-back contact simultaneously or or in placement aluminium-back
It is covered on semiconductor devices after contact.
In order to reduce effect of obmubing, alternatively also it is possible that only in backside contact solar battery, that is, only exist
There are the contacts of metal on the back side of semiconductor devices, to measure voltage.
If being further described further below, in step (c), metal connector is fixed on plating Zn especially by soldering
Aluminium-back contact on.Therefore, in a kind of optional embodiment, just brazing material can have been covered before step (c)
It is set on the Zn layer of aluminium-back contact metal.Preferably, material will be at least brazed in the region of metal connector to be fixed
Material covers on Zn layer.Suitable brazing material is it is known to the person skilled in the art that and will below will also be into
One step introduction.
As already mentioned above, it the method for the invention the step of in (c), plates aluminium-back contact of Zn and passes through metal connector and the
The hard contact of two solar batteries connects, wherein the metal connector is by soldering or is adhesively fixed on the first solar-electricity
On aluminium-back contact of the plating Zn in pond.
Those skilled in the art generally know the metal connector for connecting solar battery.Suitable metal connection
Device can be obtained commercially, or can be made using usual way.
Metal connector is preferably band-like or linear, but other shapes are also feasible in principle.Metal connector is excellent
It is selected as band-like.
If metal connector is fixed on aluminium-back contact of plating Zn by soldering, brazing material such as tin can be used
Or tin-alloy-on-metal connector coating.It this saves and individually supplies brazing material.It is suitable as the tin-of brazing material
Alloy is generally known.Tin-alloy for example contains lead, silver and/or bismuth as alloying element.
Brazing material preferably has the melting temperature within the scope of 180 DEG C~245 DEG C.
In a preferred embodiment, metal connector is copper strips, preferably uses tin or tin-alloy layer copper
Band.This " tin plating " copper strips can be obtained commercially.
Soldering preferably lower than 450 DEG C at a temperature of carry out.This is also commonly referred to as solder.Brazing temperature is preferably in
In the range of 175 DEG C~400 DEG C or 175 DEG C~300 DEG C.
In brazing process, using common preferably noncorrosive (" free of cleaning ") solder flux.Solder flux can cover with
On the metal connector (such as tin plating small copper strips) of brazing material coating, and/or cover in the zinc layers of deposition.
If fixation of the metal connector on the aluminium-back contact for plating Zn is carried out by bonding, preferably using conduction
Bonding agent.What this bonding agent was known to those skilled in the art, and can commercially obtain.
The second solar battery connecting with the first solar battery is preferably again following solar battery: this too
It is positive to have disposed according to the method described above the aluminium-back contact for plating Zn on battery.Hard contact about second solar battery
(such as back contact and front contact, or alternatively only carry on the back contact), thus may refer to described above.
The invention further relates to a kind of solar battery strings comprising at least two sun connected by metal connector
Energy battery, wherein at least one solar battery has aluminium-back contact using metal zinc coating, also, metal connector is straight
It connects and is soldered to or is adhered on aluminium-back contact of plating Zn.
Preferably at least two solar batteries, more preferably each solar battery have the aluminium-using metal zinc coating
Contact is carried on the back, also, distinguishes directly soldering or bonded metal connector on aluminium-back contact of each plating Zn.
Preferably, solar battery string can obtain according to the method described above.
Thus preferably, at least one solar battery in solar battery string in solar battery interconnected
With aluminium-back contact of plating Zn obtained according to the method described above.Preferably, the sun all connected in solar battery string
Energy battery all has aluminium-back contact of plating Zn so obtained.
Preferably, aluminium-back contact of the plating Zn of solar battery has one or more regions, exists in that region
The compacted zone being made of metallic zinc, there are also zinc-crystal grain on the surface of fine and close zinc layers, the diameter of these crystal grain is greater than 2.0 μm,
Number density >=5000/mm2, preferably >=10000/mm2, more preferably 5000-60000/mm2Or 8000-55000/mm2Or
10000-50000/mm2；And/or wherein, the surface of fine and close zinc layers at least 1.5%, preferably at least 3.0%, more preferably
Zinc-crystal grain of the 1.5-30.0% or 1.5-18.0% or 3.0-15.0% by diameter greater than 2.0 μm covers.
Other than containing relatively large Zn- crystal grain (i.e. > 2.0 μm), the zinc layers of metal are preferably also containing diameter less than 1.0 μm
Significantly smaller zinc-crystal grain, wherein preferably, the relatively large part on the surface of fine and close zinc layers (such as more than 40% or
More than 50% or even more than 60%) these lesser zinc with diameter less than 1.0 μm-crystal grain covering.Preferably, diameter is big
Jointly covered in the zinc-crystal grain of 2.0 μm of zinc-crystal grain and diameter less than 1.0 μm the surface of fine and close zinc layers at least 90%,
Preferably at least 95%.Zinc-crystal grain particle size distribution on the surface of fine and close zinc layers may, for example, be double-peak type.
Crystal grain diameter, the diameter in Zn- layer surface are greater than the number density of 2.0 μm or the Zn- crystal grain less than 1.0 μm
Corresponding apparent surface's coverage with being covered by these Zn- crystal grain, passes through Zn- layers (vertical view) scanning electron micrograph
It (REM- photo) and is determined by analyzing photo with suitable image analysis software.The diameter of crystal grain is exactly round as follows
The area of diameter, the circle is equal to projected area of the crystal grain in REM- photo.
If such as about the 5% of fine and close zinc layers surface zinc-crystal grain by diameter greater than 2.0 μm covers, this meaning
, Zn- layers of about the 5% of reflected surface in the REM- photo of vertical view is greater than 2.0 μm of this zinc-crystalline substance by diameter
Grain covering.
For example, at least 90%, preferably at least the 97% of aluminium-back contact surface of plating Zn can have this structure, i.e.,
The compacted zone being made of metallic zinc, wherein have some zinc-crystal grain on the surface of fine and close zinc layers, the diameter of these crystal grain is big
In 2.0 μm, number density >=5000/mm2, preferably >=10000/mm2, more preferably 5000-60000/mm2Or 10000-
50000/mm2；And/or wherein, the surface of fine and close zinc layers at least 1.5%, preferably at least 3.0%, more preferable 1.5-
Zinc-crystal grain of the 18.0% or 3.0-15.0% by diameter greater than 2.0 μm covers.
It is fixed on aluminium-back contact of plating Zn if metal connector has passed through soldering, in unlocked metal connector
Place, there are the regions of these larger zinc-crystal grain with comparatively high amts density.
If for example, by using Sn- alloy as solder, on aluminium-back contact that metal connector has been soldered to plating Zn
In region, there are a layer with Sn- matrix, the matrix between connector metal (such as Cu) and aluminum or aluminum alloy
With in the Zn- particle wherein spread.
It is adhesively fixed on aluminium-back contact of plating Zn if metal connector has passed through, has been fixed in metal connector
Also additionally there is the region of these larger zinc-crystal grain with comparatively high amts density in place.
It as already mentioned above, is a kind of be used to by being brazed or being adhesively fixed another by the zinc-plated aluminium that wet chemical method obtains
The effectively substrate of kind metal.In the above-described embodiment, substrate is aluminium-back contact of solar battery, with it is other too
When positive energy battery connection, metal connector is fixed on the aluminium-back contact by being brazed or being bonded.
It in principle it is known that can be using small aluminium strip as metal connector in connection.Here also have in metallic aluminium
Upper formation Al2O3Thus the problem of layer, is difficult to or even prevents that small aluminium strip is traditionally brazed to the metal in solar battery
On contact.
Therefore, the invention further relates to a kind of methods for connecting solar battery, wherein
(i) with containing Zn2+Alkaline, watery media processes are linear or band-like aluminium-substrate, to sink on aluminium-substrate
Product metallic zinc, and form aluminium-substrate of plating Zn；
(ii) make the hard contact and second of the semiconductor devices of the first solar battery by aluminium-substrate of plating Zn too
The hard contact of the semiconductor devices of positive energy battery is connected with each other, wherein the aluminium-substrate for plating Zn passes through soldering respectively or bonding is solid
It is scheduled on these hard contacts.
Linear or band-like aluminum material (such as small aluminium strip) for connecting each semiconductor devices is generally known, and can
Commercially obtain.
Aluminium-substrate can be made of metal aluminum or aluminum alloy.The spy of characteristic (especially purity) and aluminium alloy about aluminium
Property (especially aluminium content), may refer to above description.The purity of aluminium can be along wider range, as long as can not adversely
Influence electric conductivity and/or mechanical property.For example, aluminium contain in total amount accounting less than 1% (weight), preferably smaller than 0.1% (weight
Amount) or less than 0.01% (weight) other metallic elements.If aluminium-substrate is made of aluminium alloy, which preferably has
There is the aluminium content of at least 80% (weight), preferably at least 90% (weight).Those skilled in the art will know that conjunction can be melt into aluminium
The suitable metallic element of gold.
About the optimum condition of zinc deposition step (i), it may refer to above description (see zinc deposition step (a)).It is thus excellent
Choosing, for handling the watery medium of aluminium-substrate with quite high Zn2+Concentration.In a preferred embodiment, alkali
Zn in property, watery medium2+Concentration is at least 1.5% (weight), preferably at least 2.0% (weight), more preferably at least 3.0%
(weight), or even at least 4.0% (weight).In a preferred embodiment, the Zn that watery medium contains2+Concentration is
1.5% (weight)~12.0% (weight), preferably 2.0% (weight)~10.0% (weight), more preferable 3.0% (weight)~
8.0% (weight) or 4.0% (weight)~8.0% (weight).
The suitable pH value of alkaline, watery medium for example >=10, preferably >=13.
Optionally, the watery medium of alkalinity can also contain other transition-metal cations, preferably iron-cation, nickel-sun from
The combination of at least two cations in son or copper-cation or these cations.In a preferred embodiment, alkali
It is at least 0.0003% (weight), preferably at least 0.001% (weight), for example 0.0003 that property, watery medium, which also contain concentration,
Fe- cation in~30% (weight) or 0.0003~0.1% (weight) range.If alkalinity, watery medium contain nickel-
Cation, then these nickel-cations can for example exist with 0.1~5% (weight), the concentration of preferably 0.5~3% (weight).
If alkalinity, watery medium contain copper-cation, these copper-cations can for example with 0.01~1% (weight), preferably
The concentration of 0.05~0.5% (weight) exists.
From containing Zn2+Watery medium deposition preferred no power of the metallic zinc on aluminium-substrate carry out.
Preferably, the Zn- layer being deposited on aluminium-substrate has in 0.1 μm~5 μ ms, preferably 0.3 μm~2.5 μm
Thickness in range.
In the middle alkalinity of step (i), watery contain Zn2+Media processes aluminium-substrate duration be, for example, 15s~
250s.Zinc deposition step (i) preferably carries out at a temperature in the range of 5-60 DEG C, preferably 5-45 DEG C.
It can be for example by being immersed in containing Zn to the processing of aluminium-substrate2+Medium in carry out, or by with containing
Zn2+Medium washes or splash carry out.
In step (i), aluminium-substrate (especially aluminium strip) for example can be arranged essentially horizontally.It is alternatively also feasible
It is that aluminium-substrate is substantially perpendicularly arranged during step (i).But in principle, in step (i) it is any other arrangement (such as
Obliquely direction) it is also feasible.
In a preferred embodiment, aluminium-substrate is during the zinc deposition step (i) relative to containing Zn2+Medium
It is mobile.Preferably, Zn is contained with watery in aluminium-back contact2+Medium between relative velocity be at least 0.1m/min, preferably extremely
It is less 0.2m/min.This relative movement can be realized for example as follows: so that aluminium-substrate moves through static contain
There is Zn2+Medium, alternatively, make flowing Zn2+Medium flows through static aluminium-substrate, or both scheme groups are closed
Come.Contain Zn2+The flow velocity (and then relative to (mobile or static) aluminium-substrate relative velocity) of medium can for example lead to
Pump power is crossed to adjust.By containing Zn in aluminium-substrate and watery during the step of Zn- is deposited (i)2+Medium between
Relative movement, it is (such as small with aluminium-substrate for being fixed thereon to may be implemented further to improve hard contact in solar battery
Aluminium strip) between adhesive force.
Preferably, the aluminium-substrate flushing liquor for plating Zn rinses at least once.About suitable flushing liquor and washing condition,
It may refer to above description.
Preferably, drying is given to aluminium-substrate of plating Zn before step (ii).
Preferably, on aluminium-substrate that brazing material is covered to plating Zn before step (ii).It is suitable to introduce again below
Brazing material.
As already mentioned above, in step (ii), the hard contact of the semiconductor devices of the first solar battery and second sun
Aluminium-substrate connection that the hard contact of the semiconductor devices of energy battery passes through plating Zn, wherein the aluminium-substrate for plating Zn passes through respectively
It is brazed or is adhesively fixed on these hard contacts.
In order to be brazed, can use those skilled in the art will know that common brazing material, such as tin-alloy.Tin-conjunction
Gold for example contains lead, silver and/or bismuth as alloying element.Brazing material preferably has the fusing point within the scope of 180 DEG C~245 DEG C
Temperature.Soldering preferably lower than 450 DEG C at a temperature of carry out.This is also commonly referred to as solder.Brazing temperature is preferably in 175 DEG C
In the range of~300 DEG C.
In brazing process, using common preferably noncorrosive (" free of cleaning ") solder flux.
If fixed carried out by bonding, preferably using conductive bonding agent.This bonding agent is for art technology
Personnel are known, and can commercially be obtained.
Metal connector is fixed on hard contact, the metal that these hard contacts can be commonly used in solar battery
Contact.For example, hard contact be silver contact (such as the silver contact generated by silk-screen printing), the contact Ni/Cu/Ag- (such as
Generated by electroplating deposition), the contact Ni/Cu- (such as being generated by electroplating deposition) or the contact Al- (for example pass through silk screen
It prints and generates).Hard contact can be back contact, or be also possible to front contact.
The invention further relates to a kind of linear or band-like aluminium-substrate for plating Zn, which preferably has one or more areas
There is the compacted zone being made of metallic zinc in domain, on the surface of fine and close zinc layers also on aluminium-substrate in that region
The diameter of zinc-crystal grain, these crystal grain is greater than 2.0 μm, number density >=5000/mm2, preferably >=10000/mm2, more preferably
5000-60000/mm2Or 8000-55000/mm2Or 10000-50000/mm2；And/or wherein, the surface of fine and close zinc layers is extremely
Few 1.5%, preferably at least 3.0%, more preferable 1.5-30.0% or 1.5-18.0% or 3.0-15.0% are greater than 2.0 μm by diameter
Zinc-crystal grain covering.
Other than containing relatively large Zn- crystal grain (i.e. > 2.0 μm), the zinc layers of metal are preferably also containing diameter less than 1.0 μm
Significantly smaller zinc-crystal grain, wherein preferably, the relatively large part on the surface of fine and close zinc layers (such as more than 40% or
More than 50% or even more than 60%) these lesser zinc with diameter less than 1.0 μm-crystal grain covering.Preferably, diameter is big
Jointly covered in the zinc-crystal grain of 2.0 μm of zinc-crystal grain and diameter less than 1.0 μm the surface of fine and close zinc layers at least 90%,
Preferably at least 95%.Zinc-crystal grain particle size distribution on the surface of fine and close zinc layers may, for example, be double-peak type.
Crystal grain diameter, the diameter in Zn- layer surface are greater than the number density of 2.0 μm or the Zn- crystal grain less than 1.0 μm
Corresponding apparent surface's coverage with being covered by these Zn- crystal grain, passes through Zn- layers (vertical view) scanning electron micrograph
It (REM- photo) and is determined by analyzing photo with suitable image analysis software.The diameter of crystal grain is exactly round as follows
The area of diameter, the circle is equal to projected area of the crystal grain in REM- photo.
If such as about the 5% of zinc layers surface zinc-crystal grain by diameter greater than 2.0 μm covers, it means that Zn-
This zinc-crystal grain of about the 5% of reflected surface in the REM- photo of vertical view of layer by diameter greater than 2.0 μm covers
Lid.
For example, aluminium-substrate surface of plating Zn at least 70%, preferably at least 90% can have this structure, i.e., by
The compacted zone that metallic zinc is constituted, in addition, having some zinc-crystal grain on the surface of fine and close zinc layers, the diameter of these crystal grain is greater than
2.0 μm, number density >=5000/mm2, preferably >=10000/mm2, more preferably 5000-60000/mm2Or 8000-55000/
mm2Or 10000-50000/mm2；And/or wherein, the surface of fine and close zinc layers at least 1.5%, preferably at least 3.0%, it is more excellent
Zinc-the crystal grain of 1.5-30.0% or 1.5-18.0% or 3.0-15.0% by diameter greater than 2.0 μm is selected to cover.
The invention further relates to aluminium-substrates of above-mentioned band-like or linear plating Zn to be used to connect when manufacturing solar battery string
The application of each solar battery.
The present invention will further be introduced by following example.
Example
The aluminium film of 99% purity of 9 μ m-thicks is directed to above 3 slots with the speed of 1m/min roll-to-rollly.First slot
Contain Zn filled with watery2+Solution, the solution contain the zinc ion of 4% (weight), 15% (weight) NaOH and
The iron ion of 0.001% (weight).Second slot contains 1% sodium hydroxide solution, and third slot contains the water of demineralization.First
A slot is used for the deposited metal zinc on one side of aluminium-film, and aluminium-film of plating Zn is rinsed with slot 2 and slot 3.All these three
Slot is all filled to the top edge of slot.Due to surface tension, aluminium film is pulled down by liquid, thus these liquid by aluminium film well
Wetting exactly only soaks to single side on downside.In this way, aluminium film only single side it is zinc-plated.Because
Aluminium film is transversely to the conveying direction than these groove widths, so each slot is completely covered by aluminium film, and based on being applied by surface tension
Power and sealed well by aluminium film, thus when aluminium film is transported to above groove edge, the solution quilt of the wet-chemical at groove edge
It strikes off, thus seldom towing.Liquid level in each slot is protected with the accuracy of 3mm or higher accuracy by automatically subsequent dispensing
It holds constant.By conveying speed and the respective width of these slots, obtain containing Zn filled with watery2+Medium slot 1 processing
Time is 90s, and the processing time of the slot 2 filled with 1% sodium hydroxide solution is 20s, the place of the slot 3 of the water filled with demineralization
The reason time is 20s.It is by infrared radiation and thermal current that aluminium film is dry after the processing of wet-chemical, finally wind.It is rolling up
Under form, aluminium-film of single side plating Zn is protected in order to avoid zinc layers aoxidize, and can save for a long time, and characteristic has no negatively
Variation.
Fig. 1 shows the REM- photo on aluminium-back contact surface of plating Zn.The photograph illustrate fine and close metallic zinc-layer,
This layer has big zinc-crystal grain of relatively high share, and the diameter of these crystal grain is at least 2 μm.Diameter is greater than 2 μm of zinc-crystal grain
With about 30000/mm2Number density exist.The 9% of metallic zinc-layer surface is covered with zinc-crystal grain that diameter is at least 2 μm
Lid.
Next, the roller with plating zinc-aluminum film is placed in the film winding device of laser system.Film is uncoiled, with ungalvanized
Side rest on the back side of semiconductor devices (silicon-substrate) of solar battery (silicon-solar battery), and use there
Negative pressure is aspirated.Zinc-plated side is locally illuminated with laser beam.Thus the aluminium film at least partially heating plating Zn, from
And of short duration fusing occurs for aluminium film in that region, wherein the connection of the back side of the aluminium film and semiconductor devices.In semiconductor device
The perimeter of part, the aluminium film for plating Zn gives laser treatment by other laser parameters, to aluminium film is separated, also, prominent
It can be removed well in the film of semiconductor device edge.
Aluminium film has coarse side and smooth side due to manufacturing condition.If the coarse side zinc of aluminium film
Coating, and smooth side leans against on the back side of semiconductor devices, then generates the improved light efficiency of solar battery.
Importantly, aluminium film is fixed on the semiconductor devices of solar battery with a side, aluminium film is on the side
Unused zinc coating, and also not no remnants of the drying of the wet chemical solution containing zinc there, because of the otherwise adhesion of aluminium film
It will deteriorate after laser treatment, the highly doped region of the part in silicon can improve the Shockley- of excess carrier
Read-Hall- is recombined.
It is used as aluminium-back contact of plating Zn by the aluminium film of the fixed plating Zn on the semiconductor device of laser.Plating Zn's
On aluminium-back contact, the small copper strips (tin plating small copper strips) for being covered with solder is brazed by 275 DEG C of infrared heating.In advance will
In solder flux (Kester company 952s) splash to brazed portions.
Fig. 2 shows the place that metal connector (small copper strips) is soldered on aluminium-back contact of plating Zn with sectional elevation
The REM- photo in region.It can be seen that there are three layers.Uppermost layer is the aluminium-layer for carrying on the back contact, and nethermost layer is metal connection
The copper of device.It is the intermediate brazing layer of attachment between them.The zinc of brazing material and zinc coating is located in the brazing layer.
Small copper strips shows the good adhesive strength on the back contact of solar battery.
The end of the projection of connector is soldered to another solar battery in known manner in subsequent soldering processes
Front on.A solar battery string is obtained, in the solar battery string, each solar battery is connected in series.Respectively
Solar battery string glass, ethylene-propylene acetate and polymer-back side film are laminated to module.
Claims (19)
1. a kind of method for connecting solar battery, wherein
(a) with containing Zn2+Alkaline, watery medium single side handle aluminium-film, thus on the processed side of aluminium-film sink
Product metallic zinc, and form aluminium-film of single side plating Zn；
(b) aluminium-film of single side plating Zn is covered in by its untreated side the semiconductor devices of the first solar battery
On the back side, and laser beam heats are locally used, so that the back side of aluminium-film and semiconductor devices connects, and is plated
The aluminium of Zn-back contact；
(c) by metal connector the aluminium-back contact for plating Zn is connect with the hard contact of the second solar battery, wherein
The metal connector is by soldering or is adhesively fixed on aluminium-back contact of plating Zn.
2. the method for claim 1, wherein the watery medium of alkalinity contains concentration and is at least 1.5% (weight)
Zn2+；And/or wherein, the watery medium of alkalinity additionally contains iron-cation, nickel-cation, copper-cation or these sun
The combination of at least two cations in ion.
3. method according to claim 1 or 2, wherein carry out to deposition no power of the metallic zinc on the aluminium-film；With/
Or in which the zinc layers on the aluminium-film are deposited on the thickness in 0.1 μm~5 μ ms.
4. method as described in any one of the preceding claims, wherein contain Zn with watery2+Media processes described in aluminium-
The average surface roughness of the side of film, the side is larger compared to the side on opposite.
5. method as described in any one of the preceding claims, wherein during step (a), the aluminium-film is maintained at base
The position of this level, also, Zn is contained with watery in the side in this case downwardly of the aluminium-film2+Medium
Contact, thus gives coating with metallic zinc.
6. method as described in any one of the preceding claims, wherein the aluminium-film contains Zn relative to watery2+Jie
Choosing of fine quality is mobile with the relative velocity of at least 0.1m/min.
7. method as described in any one of the preceding claims, wherein rinse single side with alkaline flushing liquor before step (b)
Plate the aluminium-film of Zn at least once in ground；And/or wherein, the aluminium-film that Zn to single side is plated before step (b) gives
It is dry.
8. method as described in any one of the preceding claims, wherein the method step (a) utilizes flushing liquor with optional
Flushing and/or to single side plate the drying of the aluminium-film of Zn and executed using roll-to-roll-method.
9. method as described in any one of the preceding claims, wherein in step (b), on the side of the semiconductor devices
Aluminium-the film for plating Zn around edge by laser beam local heating single side the, so that aluminium-film is separated；And/or wherein,
In step (b), being irradiated with laser beam for the aluminium-film in the region of the metal connector is covered in step (c)
Area fraction, the area fraction irradiated greater than described except metal connector aluminium-film with laser beam.
10. method as described in any one of the preceding claims, wherein with brazing material to the metal connector and/or
Plate the aluminium-back contact coating of Zn；And/or wherein, it is described soldering lower than 450 DEG C at a temperature of carry out.
11. such as method according to any one of claims 1 to 9, wherein the bonding is carried out using conductive bonding agent.
12. a kind of solar battery string comprising at least two solar batteries connected by metal connector, wherein
At least one solar battery has aluminium-back contact using metal zinc coating, also, metal connector is directly soldered to or glues
It is connected on aluminium-back contact of plating Zn.
13. solar battery string as claimed in claim 12, wherein aluminium-back contact of the plating Zn of solar battery has one
There is the compacted zone being made of metallic zinc in a or multiple regions, wherein on the surface of fine and close zinc layers also in this region
There is zinc-crystal grain, the diameter of these crystal grain is greater than 2.0 μm, number density >=5000/mm2；And/or wherein, the table of fine and close zinc layers
Zinc-crystal grain of at least the 1.5% of face by diameter greater than 2.0 μm covers.
14. solar battery string as described in claim 12 or 13, wherein there are also diameter is small on the surface of fine and close zinc layers
In 1.0 μm of zinc-crystal grain, also, zinc-crystal grain and diameter zinc-crystal grain less than 1.0 μm of the diameter greater than 2.0 μm jointly covers
Cover at least the 90% of the surface of fine and close zinc layers.
15. a kind of method for connecting solar battery, wherein
(i) with containing Zn2+Alkaline, watery media processes are linear or band-like aluminium-substrate, to deposit gold on aluminium-substrate
Belong to zinc, and forms aluminium-substrate of plating Zn；
(ii) hard contact and the second solar energy for making the semiconductor devices of the first solar battery by plating aluminium-substrate of Zn
The hard contact of the semiconductor devices of battery is connected with each other, wherein the aluminium-substrate for plating Zn passes through soldering respectively or is adhesively fixed on
On these hard contacts.
16. method as claimed in claim 15, wherein the deposition to metallic zinc in step (i) according to claim 2,3,
5, any one of 6 or 7 condition carries out；And/or wherein, fixation of the aluminium-substrate of Zn on hard contact is plated to want according to right
Any one of 10 or 11 condition is asked to carry out.
17. the application that a kind of aluminium-substrate of band-like or linear plating Zn is used to connect each solar battery.
18. application as claimed in claim 17, wherein aluminium-substrate of band-like or linear plating Zn has one or more areas
There is the compacted zone that is made of metallic zinc in this region in domain, there are also zinc-crystal grain on the surface of fine and close zinc layers, these
The diameter of crystal grain is greater than 2.0 μm, number density >=5000/mm2；And/or wherein, at least the 1.5% of the surface of fine and close zinc layers
Zinc-crystal grain covering by diameter greater than 2.0 μm.
19. a kind of aluminium-substrate of band-like or linear plating Zn, has one or more regions, exists in this region by gold
Belong to the compacted zone that zinc is constituted, there are also zinc-crystal grain on the surface of fine and close zinc layers, the diameter of these crystal grain is greater than 2.0 μm, quantity
Density >=5000/mm2；And/or wherein, at least the 1.5% of the surface of fine and close zinc layers is greater than 2.0 μm of zinc-crystal grain by diameter
Covering.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102016210910.3 | 2016-06-19 | ||
| DE102016210910.3A DE102016210910A1 (en) | 2016-06-19 | 2016-06-19 | Process for interconnecting solar cells having aluminum foil as back contact |
| PCT/EP2017/064800 WO2017220445A1 (en) | 2016-06-19 | 2017-06-16 | Method for interconnecting photovoltaic cells, which have aluminum foil as back contact |
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| Publication Number | Publication Date |
|---|---|
| CN109417102A true CN109417102A (en) | 2019-03-01 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201780037437.4A Pending CN109417102A (en) | 2016-06-19 | 2017-06-16 | For connecting the method with aluminium film as the solar battery of back contact |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP3472870A1 (en) |
| CN (1) | CN109417102A (en) |
| DE (1) | DE102016210910A1 (en) |
| WO (1) | WO2017220445A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102019120872A1 (en) | 2019-08-01 | 2021-02-04 | Infineon Technologies Ag | Soldering a conductor to an aluminum layer |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100219535A1 (en) * | 2009-02-27 | 2010-09-02 | Kutzer Martin | Method for producing a semiconductor component |
| CN102769067A (en) * | 2011-05-05 | 2012-11-07 | 太阳能界先趋有限公司 | Method for backside-contacting a silicon solar cell, and silicon solar cell with backside-contacting |
| CN104584230A (en) * | 2012-08-10 | 2015-04-29 | 弗劳恩霍弗实用研究促进协会 | Laser-based method and machining table for metallising the back of a semiconductor component |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014510408A (en) * | 2011-03-11 | 2014-04-24 | アベリー・デニソン・コーポレイション | Sheet assembly with aluminum-based electrode |
| CN103493608A (en) * | 2011-03-18 | 2014-01-01 | 应用材料公司 | Conductive foils having multiple layers and methods of forming same |
| WO2013096951A1 (en) * | 2011-12-23 | 2013-06-27 | Solexel, Inc. | High productivity spray processing for semiconductor metallization and interconnects |
| JP6141223B2 (en) * | 2013-06-14 | 2017-06-07 | 三菱電機株式会社 | Light receiving element module and manufacturing method thereof |
-
2016
- 2016-06-19 DE DE102016210910.3A patent/DE102016210910A1/en not_active Withdrawn
-
2017
- 2017-06-16 CN CN201780037437.4A patent/CN109417102A/en active Pending
- 2017-06-16 EP EP17735407.3A patent/EP3472870A1/en not_active Withdrawn
- 2017-06-16 WO PCT/EP2017/064800 patent/WO2017220445A1/en unknown
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100219535A1 (en) * | 2009-02-27 | 2010-09-02 | Kutzer Martin | Method for producing a semiconductor component |
| CN102769067A (en) * | 2011-05-05 | 2012-11-07 | 太阳能界先趋有限公司 | Method for backside-contacting a silicon solar cell, and silicon solar cell with backside-contacting |
| CN104584230A (en) * | 2012-08-10 | 2015-04-29 | 弗劳恩霍弗实用研究促进协会 | Laser-based method and machining table for metallising the back of a semiconductor component |
Non-Patent Citations (1)
| Title |
|---|
| KAMP, M等: "Zincate processes for silicon solar cell metallization", 《SOLAR ENERGY MATERIALS AND SOLAR CELLS》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| EP3472870A1 (en) | 2019-04-24 |
| WO2017220445A1 (en) | 2017-12-28 |
| DE102016210910A1 (en) | 2017-12-21 |
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