FORMATION METHOD OF SOLDER BUMP - MITSUBISHI MATERIALS CORP

Title:

FORMATION METHOD OF SOLDER BUMP

Document Type and Number:

Japanese Patent JP2016078095

Kind Code:

A

Abstract:

PROBLEM TO BE SOLVED: To provide a formation method of a solder bump which does not cause chipping in a bump precursor when separating a mask after paste printing, permits a uniform shape and size of the bump after reflow and hardly generates voids in the bump.SOLUTION: A method for forming a solder bump includes: a process of arranging a mask having an opening part onto a substrate; a process of printing a solder paste comprising flux and solder powder so as to fill the solder paste into the opening part; and a process of performing reflow processing of the bump precursor on the substrate after separating the mask to form solder bumps. The flux contains rosin, solvent and a thixotropic agent, an acid value of the flux is 100 mgKOH/g or less, a halogen content of the flux is 0.03 mass% or less and reflow processing is performed in a formic acid gas environment and/or in an environment of a gas provided by thermally decomposing formic acid.SELECTED DRAWING: None

Inventors:

YAMAMOTO YOSHIFUMI
ISHIKAWA MASAYUKI
UNO HIRONORI

Application Number:

JP2014214518A

Publication Date:

May 16, 2016

Filing Date:

October 21, 2014

Export Citation:

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