LEAD WIRE FOR SOLAR CELL, MANUFACTURING METHOD AND STORAGE METHOD THEREOF, AND SOLAR CELL

• US 20110220196A1
• Filed: 11/20/2009
• Published: 09/15/2011
• Est. Priority Date: 11/27/2008
• Status: Active Grant

• Current Assignee: Proterial Ltd.
• Original Assignee: Hitachi Metals (Thailand) Ltd.
• Inventors: Nishi, Hajime, Okikawa, Hiroshi, Sawahata, Katsunori, Akutsu, Hiroyuki, Endo, Yuju, Bando, Hiroshi, Higashidani, Iku, Takahashi, Ken, Kuroda, Hiromitsu
• Granted Patent: US 9,279,176 B2
• Time in Patent Office: Days
• US Class Current: 136/256
• CPC Class Codes: C23C 2/00344 Means for moving substrates, e.g. immersed rollers or immersed bearings
• CPC Class Codes: C23C 2/02 Pretreatment of the material to be coated, e.g. for coating on selected surface areas C23C2/30 takes precedence
• CPC Class Codes: C23C 2/022 by heating
• CPC Class Codes: C23C 2/08 Tin or alloys based thereon
• CPC Class Codes: C23C 26/02 applying molten material to the substrate
• CPC Class Codes: C23C 28/321 with at least one metal alloy layer
• CPC Class Codes: C23C 28/322 only coatings of metal elements only
• CPC Class Codes: C23C 28/345 with at least one oxide layer
• CPC Class Codes: C23C 6/00 Coating by casting molten material on the substrate
• CPC Class Codes: H01L 31/02013 comprising output lead wires elements
• CPC Class Codes: H01L 31/0508 the interconnection means having a particular shape
• CPC Class Codes: H01L 31/0512 made of a particular material or composition of materials
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

Disclosed is a lead wire for a solar cell having excellent bondability with a solar cell. The solar cell lead wire (10) has a band plate-shaped electroconductive material (12) that is formed with straight-angled cross-sectional shape and is covered by a molten solder plating layer (13), with the thickness of the oxide film on the surface of the molten solder plating layer (13) being 7 nm or less.

Claims

1. A solar cell lead wire, comprising:

a molten solder plated layer on a strip-shaped conductive material formed rectangular in a cross section thereof so as to be bonded to a solar cell,

wherein a thickness of an oxide film on a surface of the molten solder plated layer is not more than 7 nm.

2. The solar cell lead wire according to claim 1, wherein the strip-shaped conductive material comprises a flat wire having a volume resistivity of not more than 50 μ

Ω

·

mm.

3. The solar cell lead wire according to claim 1, wherein the strip-shaped conductive material comprises one of Cu, Al, Ag and Au.

4. The solar cell lead wire according to claim 1, wherein the strip-shaped conductive material comprises any one of tough pitch Cu, low-oxygen Cu, oxygen-free Cu, phosphorus deoxidized Cu and high purity Cu having a purity of not less than 99.9999%.

5. The solar cell lead wire according to claim 1, wherein the molten solder plated layer comprises a Sn-based solder, or, a Sn-based solder alloy using Sn as a first component and containing not less than 0.1 mass % of at least one element selected from the group consisting of Pb, In, Bi, Sb, Ag, Zn, Ni and Cu as a second component.

8. A storage method of a solar cell lead wire, comprising:

storing the solar cell lead wire according to claim 1 after packing with a packing material having an oxygen permeability of not more than 1 mL/m²·

day·

MPa and a water vapor permeability of not more than 0.1 g/m²·

day.

9. A storage method of a solar cell lead wire, comprising:

storing the solar cell lead wire according to claim 1 at a temperature of not more than 30°

C. and at a relative humidity of not more than 65% in an unpacked state or in a state that the packing is opened.

10. A solar cell, comprising:

the solar cell lead wire according to claim 1 that is soldered to front and back surface electrodes of a semiconductor substrate by using a solder in a molten solder plated layer.

6. A method of manufacturing a solar cell lead wire, comprising:

forming a strip-shaped conductive material by roll-processing or slit-processing a wire;

heat-treating the strip-shaped conductive material in a continuous electrical heating or continuous heating furnace or a batch heating equipment; and

when subsequently performing solder plating on the strip-shaped conductive material by supplying a molten solder, adjusting a plating temperature thereof to not more than a liquidus-line temperature of the solder plus 120°

C.

7. The method of manufacturing the solar cell lead wire according to claim 6, wherein solder plating is performed on the strip-shaped conductive material by supplying a molten solder at a plating operating atmospheric temperature of not more than 30°

C. and at a relative humidity of not more than 65% of a plating operating atmosphere.