Browse Prior Art Database

Improvement of Solderability by Laser Irradiation

IP.com Disclosure Number: IPCOM000109422D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 1 page(s) / 72K

Publishing Venue

IBM

Related People

Farrar, PA: AUTHOR [+3]

Abstract

Disclosed is a method of using laser irradiation to improve the cleanliness of the joining surfaces thereby improving the joinability of solders or components to be joined. Laser or intense photo-irradiation removes or reduces potential surface contamination or surface oxides and thus provides cleaner surfaces for joining. It is well known that the joinability or the quality of the solder joints depends on the surface cleanliness and oxide thickness of surfaces to be joined. Solder pads contaminated with organic material cannot be properly joined with chemical fluxes. Solder pads with excess oxides greatly degrade the joinability in hydrogen reduction joining processes. Components stored in ambient environment sometimes may get corroded. Poor solder joints pose the risk of reliability failure.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 64% of the total text.

Improvement of Solderability by Laser Irradiation

      Disclosed is a method of using laser irradiation to improve the
cleanliness of the joining surfaces thereby improving the joinability
of solders or components to be joined.  Laser or intense
photo-irradiation removes or reduces potential surface contamination
or surface oxides and thus provides cleaner surfaces for joining.
It is well known that the joinability or the quality of the solder
joints depends on the surface cleanliness and oxide thickness of
surfaces to be joined.  Solder pads contaminated with organic
material cannot be properly joined with chemical fluxes.  Solder pads
with excess oxides greatly degrade the joinability in hydrogen
reduction joining processes.  Components stored in ambient
environment sometimes may get corroded.  Poor solder joints pose the
risk of reliability failure.  Although the contaminants or excess
oxides sometimes can be removed in chemical etching, or by a cleaning
processes which involves wet etching, rinsing, drying, or expensive
dry plasma processes, the disclosed method is simple and can be
easily integrated into component-picking operation of the joining
process.
Laser or intense short pulse photo irradiation can remove or reduce
surface oxides and organic contamination without adversely affect the
functionality of the component.  Organic contaminants are known to
decompose or be ablated by short-pulse short-wavelength laser
irradiation pulses.  Most metal oxides ...