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Browse Prior Art Database

Automatic Level Control of Liquid Flux for PIH Rework Applications

IP.com Disclosure Number: IPCOM000121154D
Original Publication Date: 1991-Jul-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 1 page(s) / 52K

Publishing Venue

IBM

Related People

Okoro, CA: AUTHOR [+2]

Abstract

Disclosed is the design of a single flux tray to optimize the pin fluxing procedure for all sizes of Pin-In-Hole (PIH) components. This device includes a calibrated liquid height adjustment, automatic fill, and constant liquid level control.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 80% of the total text.

Automatic Level Control of Liquid Flux for PIH Rework Applications

      Disclosed is the design of a single flux tray to optimize the
pin fluxing procedure for all sizes of Pin-In-Hole (PIH) components.
This device includes a calibrated liquid height adjustment, automatic
fill, and constant liquid level control.

      This design guarantees 100% control and optimization of the pin
fluxing process for all PIH components, reduces PIH solder joint
defects, and greatly enhances the reliability of the product.  The
current PIH fluxing process utilizes individual flux trays for each
different pin length.  These trays must be manually filled and the
liquid height manually maintained.  The flux height is continuously
being reduced due to the fluxing of components (also by some
operators in fluxing the card with a brush dipped in the flux), and
through evaporation.  When the flux height falls below its allowable
minimum (nominal height minus 5 mils), insufficient fluxing occurs.
Insufficient fluxing of PIH components may result in negative solder
fillet formation on the top side of the PCB, pin dewets, and/or
pin-to-solder cracks within the plated through holes (PTH's).

      This new flux tray design incorporates a one mil graduated
scale micrometer for any selected flux height to 0.500 inch.  The
liquid flux is gravity fed from an inverted flux bottle reservoir and
is controlled by an equilibrium of pressures at the liquid surface of
the flux in the tray and th...