Lead wire for solar cell, manufacturing method and storage method thereof, and solar cell

• US 9,279,176 B2
• Filed: 11/20/2009
• Issued: 03/08/2016
• Est. Priority Date: 11/27/2008
• Status: Active Grant

• Current Assignee: Proterial Ltd.
• Original Assignee: Hitachi Metals (Thailand) Ltd.
• Inventors: Nishi, Hajime, Endo, Yuju, Takahashi, Ken, Kuroda, Hiromitsu, Akutsu, Hiroyuki, Sawahata, Katsunori, Bando, Hiroshi, Higashidani, Iku, Okikawa, Hiroshi
• Primary Examiner(s): Semenenko, Yuriy
• Application Number:
  US12/998,727
• Publication Number:
  US 20110220196A1
• Time in Patent Office: 2,300 Days
• Field of Search: 174/126.2, 174/261, 174/260, 174/262, 174/263, 136/244, 136/256
• US Class Current: 1/1
• 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

A solar cell lead wire includes a molten solder plated layer on a strip-shaped conductive material formed rectangular in a cross section thereof so as to be bonded by soldering to an electrode of a solar cell, using a flux. A thickness of an oxide film on a surface of the molten solder plated layer, which is a sum of a thickness of an SnO layer and a thickness of an SnO₂ layer on the surface of the molten solder plated layer, is not more than 7 nm.

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 bondable to a solar cell using a flux,

wherein a thickness of an oxide film on a surface of the molten solder plated layer, which is a sum of a thickness of an SnO layer and a thickness of an SnO₂ layer, is not more than 7 nm,

said thickness predetermined as permitting an effect of breaking through the oxide film during a low temperature bonding process that is near a melting point of the molten solder plated layer and predetermined as sufficiently low in temperature to avoid a cracking of a substrate of the solar cell due to a thermal stress during said bonding process.