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
  • H01L31/04—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 adapted as photovoltaic [PV] conversion devices
• • 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
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
  • H01B1/20—Conductive material dispersed in non-conductive organic material
  • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
• • 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
• • 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
  • H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K1/00—Printed circuits
  • H05K1/02—Details
  • H05K1/09—Use of materials for the conductive, e.g. metallic pattern
  • H05K1/092—Dispersed materials, e.g. conductive pastes or inks
• • 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

Definitions

• Metal-containing composition process for the production of electrical contact structures on electronic components and electronic component
• the present invention relates to a metal-containing composition, a method for producing electrical contact structures on electronic components and an electronic component provided with such a contacting.
• Silicon solar cells usually have metallic contacts both on the front side and on the rear side. Especially the contacts on the front have to fulfill several tasks and therefore make high demands on the contacting method and also on the contact material system.
• InkJet printing aerosol printing, pad printing or fine line screen printing can be realized.
• a metal layer is applied which is optimized to have a very good electrical conductivity and, in turn, to be readily contactable.
• the glass frit melts and wets the antireflection layer
• temperatures of about 750 0 C penetrates the glass melt in which at this temperature also silver is dissolved, the anti-reflective layer and penetrates further into the silicon
• the dissolved silver is precipitated from the melt and crystallizes directly on the silicon surface in the form of small silver crystallites.
• the cooled glass forms an insulating barrier between the volume silver of the finger and the silver crystallites, which in some places is thin enough is so that a current can flow from the cell into the contacts.
• This second metal layer can be realized, for example, by galvanic reinforcement of the first layer or by printing further, particularly good conductive metal layers on the first contact layer.
• Silver about 2 to 5 wt .-% of a glass frit and from 20 to 40 wt .-% of an organic vehicle system, via which the rheology of the ink / paste is set.
• the contacts insofar as they are realized in a single printing step, e.g. Screen printing, typically have a coating height of about 15 microns and a width of 120 microns. This means that in this case a much larger contact surface is available and therefore the requirements for the contact properties of the paste can be lower. In addition, it is known that the specific contact properties deteriorate with reduced metal layer height.
• compositions for making contacts by firing are known from various references, eg US 6,036,889, US 2004/0151893, US 2006/0102228, US 4,153,907 and US 6,814,795. All known formulations have an increased contact became common when thin contact structures were used on low-doped emitters.
• compositions according to the invention contain:
• the composition according to the invention is, for example, a combination of silver and glass or low-melting oxide and a "pure" refractory oxide, thus a combination of silver and oxides, the proportion of oxide being comparatively high and the silver content being comparatively low Oxides and silver may also be known to the art MOD (organometallic decomposition materials). It is particularly advantageous in this case that a material system with a reduced proportion of silver also means a reduction in the cost of production. Moreover, it is possible for the first time with the present invention to contact solar cells with a high-impedance emitter and thus a high efficiency potential, with narrow, low-resistance contacts.
• contact widths of at least 80 microns are necessary to contact emitters with a sheet resistance> 100 ohms / square low impedance p c ⁇ 10 mOhmcm 2 .
• emitters> 100 ohms / square with contacts ⁇ 20 microns with a specific contact resistance p c ⁇ 2 mOhmcm 2 are contacted.
• a high efficiency potential eg 20.3% with a layer resistance of 110 ⁇ / square on a 2x2 cm 2 cell, to contact cost reduced.
• composition additionally at least one organic component d), selected from the group consisting of
• solvents preferably solvents having a boiling point> 100 0 C; in particular solvent selected from the group consisting of terpine oil, ethylene glycol ether, glycol ether, Diethy- lenglykolmonobutylether, N-methylpyrrolidone, ethylene glycol and / or mixtures thereof, bb) binders, in particular ethyl cellulose and / or cc) dispersants selected from the group consisting of hydroxyfunctional carboxylic acid esters having pigment affinic groups, copolymers having acidic groups, alkylolammonium salts of Block Copolytneren with acidic groups and / or mixtures or solutions thereof.
• the electrically conductive metal according to feature a) of claim 1 is selected from the group consisting of metals having an electrical conductivity of at least 40 "10 6 S / m, preferably at least 55" 10 6 S / m, in particular Is silver and / or the at least one organometallic compound of the conductive metal is selected from the group consisting of organometallic decomposition materials (MOD), preferably from metal salts of fatty acids, in particular metal resminates, more preferably from silver nitrate, silver nucleodecanoate and / or silver (hexafluoro-) acetylacetonate) (1, 5-cyclooctadiene) and mixtures thereof.
• MOD organometallic decomposition materials
• the first oxidic material b) is preferably selected from the group consisting of glass frits, preferably lead glass and / or bismuth glass frits; Lead II oxide; Bismuth trioxide and / or the organometallic compounds derived from the metals contained in the first oxidic compound are selected from the group consisting of organometallic decomposition materials (MOD), preferably from metal salts of fatty acids, in particular metal resinates, particularly preferably bismuth resinate, bismuth neodecanoate, bismuth 2-ethylhexanoate and mixtures thereof.
• MOD organometallic decomposition materials
• the second oxidic material c) is selected from the group consisting of ZnO, ZnO: Al, SnO, TiO, TiO 2 , MgO and / or those of the organometallic compounds derived from the metals contained in the second oxidic compound are selected from the group consisting of organometallic decomposition materials (MOD), preferably from metal salts of fatty acids, in particular metal resinates, more preferably zinc resinate and / or zinc neodecanoate and mixtures thereof.
• MOD organometallic decomposition materials
• the source of the abovementioned oxides or conductive metals can therefore also be organometallic compounds or metal salts, which are generally known by the term metallo organic decompositions (MOD).
• MOD metallo organic decompositions
• Metal salts of fatty acids often referred to as resinates, such as silver neodecanoate, Ag (hfa) (COD), bismuth 2-ethylhexanoate, bismuth neodecanoate, zinc neodecanoate are particularly suitable.
• Particularly advantageous in this case is the combination with a further resinate, which burns to a metal oxide, which has a melting point above 1000 0 C, such as zinc resinates, such as zinc neodecanoates.
• zinc oxide as an oxide powder or as a zinc resinate, enhances the formation of silver crystallites, which are responsible for the electrical contact during contact formation on solar cells.
• Crystal density a measure of contact quality, is significantly increased in the presence of ZnO in the contact material system.
• the low-melting or high-melting oxides a) and b) may be used as glass, i. may be present as an oxide mixture or as a respective fine oxide as coating around a silver particle.
• Blends of resinates and powders are conceivable in all combinations. Particularly promising is the combination of silver powder with resinates (bismuth resinate, zinc resinate) to produce a contact ink or paste.
• Component d) in an amount of 0 to 50% by weight, preferably between 10 and 40% by weight, more preferably between 20 and 30% by weight.
• composition according to the invention can be present in various ready-to-use formulations.
• the composition is in the form of an inkjet ink or aerosol ink, which is characterized by a viscosity ⁇ ⁇ 1000 mPas, preferably ⁇ ⁇ 100 mPas.
• the composition is in the form of a paste to be applied, for example by screen printing, wherein the paste is characterized by a viscosity 10 Pas ⁇ ⁇ 300 Pas.
• the viscosities can be varied or adjusted, for example, by adding a suitable organic substance d) according to general principles known to those skilled in the art, for example with regard to the choice of the substance or its amount or a mixture of substances and thus adapted to the particular application.
• the at least one electrically conductive metal a), the at least one oxidic material b) and / or the at least one oxidic material c) are each independently of one another as particles or powders before, wherein the average particle sizes d 50 are each independently between 1 nm and 10 microns.
• a d 50 ⁇ 200 nm is necessary for inkjet inks, preferably ⁇ 100 nm, for aerosol applications a d 50 ⁇ 1 ⁇ m and for screen printing, in particular fine line screen printing, a d 50 ⁇ 10 ⁇ m , particularly preferably d 50 ⁇ 5 microns, is particularly suitable.
• the composition according to the invention is free of particles. This is the case in particular if components a) to c) only contain the abovementioned MODs ' (organometallic decomposition materials) include. This embodiment is particularly suitable for low-viscosity compositions and offers particular advantages when structurally very fine, ie narrow, contact structures are to be produced.
• compositions according to the invention contain both particle-free and particle-containing constituents a) to c) in combination with one another.
• methods for producing an electrical contact structure on an electronic component are also specified, in which a) a composition as described above is applied to the electronic component in a mold representing the contact structure to be produced and b) the component provided with the composition is in a contact firing step a temperature between 400 and 900 0 C is heated.
• the composition is already applied to the component in a form which reflects the final contact structure, that is to say in the form of strip conductors, for example.
• the preparation is to take place in larger conductive surfaces, a corresponding surface application of the composition is possible. In doing so, the
• composition according to the invention is preferably applied by screen printing, aerosol printing, inkjet printing, pad printing, stencil printing, dispensing and / or combinations thereof.
• Advantageous temperature ranges of the heating step b) are between 700 and 850 ° C.
• the invention likewise provides an electronic component, in particular a solar cell, having an electrical contact structure, wherein the electronic component has an electrical contact structure which can be produced by the method according to the invention.
• compositions provided according to the invention are made up together
• a conductive metal especially silver
• a glass system preferably lead glass or bismuth glass, which is also covered by a well-wetted metal oxide, lead oxide (PbO) or bismuth oxide
• ZnO melting point mp 1 800 0 C.
• ZnO Al (mp 1800 0 C.)
• SnO mp 1127 0 C.
• TiO 2 m.p. 1830 0 C
• MgO mp 2800 0 C.
• ZnO melting point mp 1 800 0 C.
• ZnO Al
• SnO mp 1127 0 C.
• TiO 2 m.p. 1830 0 C
• MgO mp 2800 0 C.
• ZnO melting point mp 1 800 0 C.
• ZnO Al
• SnO mp 1127 0 C.
• TiO 2 m.p. 1830 0 C
• MgO mp 2800 0 C.
• ZnO melting point mp 1 800 0 C.
• ZnO Al
• SnO mp 1127 0 C.
• TiO 2 m.p. 1830 0 C
• MgO mp 2800 0 C.
• these oxides significantly improve both the mechanical stability and the electrical metal-semiconductor transition.
• silver such a material system is very well suited as a seed layer.
• the high melting point causes the oxides in the
• the electrical contact improves significantly, especially when using ZnO or
• ZnOrAl Both ZnO, heated above 430 ° C, and the aluminum doped zinc oxide have high electrical conductivity, which allows the current to flow better through the glass layer. Another conceivable current path leads from the silver crystallite via a conductive oxide particle to the contact silver. Owing to the property that ZnO is an n-type semiconductor, it is possible to also contact high-resistance emitters (> 70 ohms / square) with a contact compound / paste containing this oxide in a low-resistance manner. The oxides used, in particular ZnO, also promote the growth of the silver crystallites and thus their density, which are crucial for the contact formation.
• pastes or inks are produced with significantly better contact properties and tested on silicon solar cells.
• very thin contact lines (30 ⁇ m)
• very good electrical parameters could be achieved on solar cells with high-ohmic emitters (contact resistance, filling factor and efficiency of the cells).
• the newly developed printing ink can be used as a seed layer, e.g. be applied to the solar cell in an aerosol printing process, inkjet process, fine-line screen printing process or pad printing process.
• the viscosity is ⁇ > 1 Pas
• the viscosity should be ⁇ ⁇ 1 Pas and at one InkJet ink, it is necessary to reduce the viscosity to ⁇ ⁇ 100 mPas.
• the proportion of an additional metal oxide may be, for example, varies greatly ZnO and varied in a range of 3 wt .-% to 70 wt
• the proportion of the wetting glass frit, lead glass frit or bismuth frit or the wetting metal oxides, PbO, Bi 2 O 3 The proportion is preferably from 2 to 3% by weight.
• the proportion of metal oxide varies, the proportion of conductive metal (silver) is changed and moves in the range between 1% by weight and 10% by weight 30% by weight and 70% by weight.
• Seed layer ink / paste with high oxide content Seed layer ink / paste with high oxide content:
• Seed layer ink / paste in which the oxides are present as resinates and only silver in particle form is
• Zinc resinate Zinc neodecanoates
• Bismuth resinate bismuth neodecanoate
• conductive, high-melting oxides such as zinc oxide in combination with a well-wetted, low-melting oxide, such as bismuth oxide, or a well-wetting glass frit, such as lead glass frit or Bismutglasfritte
• high-emitter R sh > 70 ohms / square
• the proportion of zinc oxide can be increased up to 35 wt .-%, wherein the proportion of silver is greatly reduced.
• FIG. 1 The structure of an electronic component which can be produced by the method according to the invention using the composition according to the invention, as in the present case a coated solar cell, is shown in FIG.
• a semiconductor device e.g. out
• a conductive metal layer 7 for example made of silver or copper, is applied.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Power Engineering (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• Electromagnetism (AREA)
• General Physics & Mathematics (AREA)
• Computer Hardware Design (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Sustainable Energy (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Chemical & Material Sciences (AREA)
• Dispersion Chemistry (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Manufacturing & Machinery (AREA)
• Conductive Materials (AREA)
• Electrodes Of Semiconductors (AREA)
• Photovoltaic Devices (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2008
  • 2008-07-10 DE DE102008032554A patent/DE102008032554A1/de not_active Withdrawn
• 2009
  • 2009-07-06 JP JP2011517016A patent/JP2011527490A/ja not_active Withdrawn
  • 2009-07-06 CN CN2009801261631A patent/CN102084502A/zh active Pending
  • 2009-07-06 RU RU2010154190/28A patent/RU2010154190A/ru unknown
  • 2009-07-06 WO PCT/EP2009/004877 patent/WO2010003619A1/de active Application Filing
  • 2009-07-06 BR BRPI0915437A patent/BRPI0915437A2/pt not_active IP Right Cessation
  • 2009-07-06 CA CA2729870A patent/CA2729870A1/en not_active Abandoned
  • 2009-07-06 KR KR1020117001373A patent/KR20110026486A/ko not_active Application Discontinuation
  • 2009-07-06 EP EP09776983A patent/EP2304815A1/de not_active Withdrawn
  • 2009-07-06 US US13/003,252 patent/US20110186121A1/en not_active Abandoned
• 2010
  • 2010-12-23 IL IL210241A patent/IL210241A0/en unknown

Non-Patent Citations (1)

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