Title:
SOLDERING METHOD
Document Type and Number:
WIPO Patent Application WO/2018/096917
Kind Code:
A1
Abstract:
The purpose of the present invention is to prevent solder from scattering during a reflow process and to reliably remove oxide films formed on surfaces of the solder and an electrode. A soldering method according to the present invention has: a step for applying a solder paste to an electrode on a printed circuit board and mounting an electronic component on this solder paste; a step for volatilizing non-residue flux contained in the solder paste by heating the printed circuit board such that the interior of a chamber is in a vacuum state at about 180°C during a preheating process (section A); a step for removing an oxide film formed on the electrode etc., by heating the printed circuit board such that the interior of the chamber is in a formic acid atmosphere at about 200°C during a reduction process (section B); and a step for melting solder powder contained in the solder paste by heating the printed circuit board such that the interior of the chamber is in a vacuum state at 250°C during a main heating process (section C).
Inventors:
KAKUISHI MAMORU (JP)
UKAI RYUJI (JP)
UKAI RYUJI (JP)
Application Number:
PCT/JP2017/039984
Publication Date:
May 31, 2018
Filing Date:
November 06, 2017
Export Citation:
Assignee:
SENJU METAL INDUSTRY CO (JP)
International Classes:
H05K3/34; B23K1/00; B23K1/008; B23K3/06; B23K31/02; B23K35/26; C22C13/00
Domestic Patent References:
| WO2017057651A1 | 2017-04-06 | |||
| WO2015152387A1 | 2015-10-08 | |||
| WO2015146999A1 | 2015-10-01 |
Foreign References:
| JP2006167735A | 2006-06-29 | |||
| JP2005271059A | 2005-10-06 | |||
| JPH04220166A | 1992-08-11 | |||
| JP2004025305A | 2004-01-29 | |||
| JP2008172120A | 2008-07-24 |
Other References:
See also references of EP 3547809A4
Attorney, Agent or Firm:
YAMAGUCHI INTERNATIONAL PATENT FIRM (JP)
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