Browse Prior Art Database

Single-Component, Water-Soluble Rework Solder Flux

IP.com Disclosure Number: IPCOM000103316D
Original Publication Date: 1990-Sep-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 42K

Publishing Venue

IBM

Related People

Frazier, JD: AUTHOR [+2]

Abstract

Disclosed is a noncorrosive, single-component material useful as a rework solder flux for surface-mount circuitry which requires only water for cleanup. Rework fluxes for surface-mount technology are frequently complex mixtures. The few water-soluble rework fluxes commercially available are very corrosive and require prompt cleaning after use; the rosin-based fluxes require chlorofluorocarbon cleaning.

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Single-Component, Water-Soluble Rework Solder Flux

      Disclosed is a noncorrosive, single-component material useful
as a rework solder flux for surface-mount circuitry which requires
only water for cleanup.  Rework fluxes for surface-mount technology
are frequently complex mixtures. The few water-soluble rework fluxes
commercially available are very corrosive and require prompt cleaning
after use; the rosin-based fluxes require chlorofluorocarbon
cleaning.

      The single liquid anionic surfactant approach works well
because it possesses all the needed properties of a rework flux in
one molecule.  It (a) contains an active functionality to act as a
flux to clean the oxide layers of both the solder surface and the
copper pad, (b) has the ability to thoroughly wet the metal surfaces
due to its hydrophobic/ hydrophilic nature, (c) is a liquid for ease
of application, (d) is noncorrosive, and (e) is water cleanable.

      Those surfactants that are water soluble are the easiest to
clean after use.  The surfactants can also be diluted with a
water-soluble solvent (such as isopropyl alcohol) if a viscosity
lower than that of the neat surfactant is required.

      Such a simple system has not been disclosed in the prior art.
The prior art (referenced below) uses the surfactants combined with
other components and require chlorofluorocarbon solvents for
cleaning.

      References
(1)  Anonymous, "Fluorocarbon-soluble Strong Acid Soldering Fluxes",
Res...