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Fluxless Solder Applicator

IP.com Disclosure Number: IPCOM000104531D
Original Publication Date: 1993-Apr-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 1 page(s) / 31K

Publishing Venue

IBM

Related People

Coteus, PW: AUTHOR [+5]

Abstract

The application of solder to boards or substrates for semiconductor electronic circuit assembly generally requires the use of solder flux. Subsequent to the solder application, the flux must be cleaned and the cleaning solvents must be disposed of in a safe manner. All of these steps result in added costs in materials time. Solder residues not cleaned from the board may eventually result in corrosion. Environment factors are limiting the variety and quantity of flux-cleaning solvents that may be used.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Fluxless Solder Applicator

      The  application  of  solder  to  boards  or  substrates for
semiconductor electronic circuit assembly generally requires the  use
of  solder  flux.    Subsequent  to   the   solder application,  the
flux  must  be  cleaned  and the cleaning solvents must be disposed
of in a safe manner.  All of these steps result in added  costs  in
materials  time.    Solder residues not cleaned from the board may
eventually result in corrosion.  Environment factors are limiting the
variety and quantity of flux-cleaning solvents that may be used.

      It  is  possible  to  apply  solder  to a board without solder
flux if a directed gas jet is used in the  operation.  Here,  we use
a hot nitrogen, forming gas, or other suitable gas jet.  The gas jet
acts as a knife edge to  separate  the liquid  solder  into  discreet
portions  as  the applicator travels along the board or substrate.
The gas jet  or  gas knife  edge  trails  behind the applicator to
accomplish its task.  The hot gas flow must be rapid and localized.
In  an alternative  plan,  the  hot gas knife edge is followed by a
cooling gas orifice.

      The  process  may  be  enhanced   by   the   following:
Employing  a  cover  gas; Employing a large gas lens outside the area
to  be  immediately  covered  by  the  gas  knife; Oscillating or
pulsing the gas.

Disclosed Anonymously.