Browse Prior Art Database

Flux Cleaning from Circuitized Boards

IP.com Disclosure Number: IPCOM000082804D
Original Publication Date: 1975-Feb-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Elmore, GV: AUTHOR

Abstract

The soldering of circuit boards can be accomplished by immersing the boards in a flux composition comprising from about 2% to 8% by weight of chelating salt or agents dissolved in a solvent, such as glycerol, and at a temperature of from 300 degrees to 350 degrees F.

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

Page 1 of 1

Flux Cleaning from Circuitized Boards

The soldering of circuit boards can be accomplished by immersing the boards in a flux composition comprising from about 2% to 8% by weight of chelating salt or agents dissolved in a solvent, such as glycerol, and at a temperature of from 300 degrees to 350 degrees F.

After the board has reached the temperature of the flux, it is passed over a fountain of molten solder. The board is removed wet from the flux. Because of the complexing ability of the flux bath for heavy metals, to rinse the board with water and dispose of the rinse water would be contrary to the environmental standards.

It has been found that organic fluids with a high-flash point, such as polyalkylene glycols, for example, UCon 50 HB - 280x (a product of the Union Carbide Corporation), and which are insoluble in the chelating salt - glycerin flux bath and which have a density less than the flux bath, will clean the residue flux from the board by displacement.

When the board is immersed in the organic fluid, preferably at a temperature of from 150 degrees F to 250 degrees F, the chelating salt glycerin flux residue is removed from the board and falls to the bottom of the immersion tank. This can be recovered and recycled. Alternatively, the board can also be sprayed with the organic fluid to provide a complete cleaning of the board.

1