Abstract In the process of soldering electrical connections in printed circuits, the printed circuit is passed through the crest of a fountain of solder which includes a water soluble hydrocarbon, polyethylene glycol, which wets the surfaces to be soldered. After soldering, a water wash is used to remove the polyethylene glycol and dross from the printed circuit work piece which may then be air dried with a dip in isopropyl alcohol if desired. The use of a water soluble additive provides the soldering advantages which are obtained with presently used non-water soluble materials, such as Shell Oil Company''s Peblum Oil (or equivalent) for example, and additionally provides the advantage of the use of an effective yet simple and inexpensive cleaning operation of the board after soldering by washing with water. This eliminates the necessity of using solvents which are relatively expensive and sometimes toxic and detrimental to the printed circuit component parts, their protective coatings, and identification markings.
The method in accordance with claim 1 wherein the step of drying the water from the washed conductor comprises the steps of: immersing the washed conductor and adhering water in an alcohol and subsequently drying the alcohol from the washed conductor.
Claim 2
Dependent Claim
52 words
The method in accordance with claim 1 further including the step of admixing a flow of soldering material and the polyethylene glycol to effect a substantially uniform dispersion of the polyethylene glycol in the soldering material, and passing the conductor through a crest of said fountain to apply the soldering material thereto.
Claim 3
Independent Claim
116 words
The method of applying solder to a conductor comprising the steps of: combining molten solder and a water-soluble polyethylene glycol hydrocarbon to improve the flow characteristics of the molten solder, said molten solder and said hydrocarbon being immiscible and said hydrocarbon removing oxides from said molten solder and acting as a wetting agent for said molten solder relative to the conductor; passing the conductor through a wave of the combined molten solder and water-soluble hydrocarbon to effect the adhesion of solder to said conductor; cooling the conductor and adhering solder to solidify said solder; washing the conductor and adhering solder with water to remove any residual water-soluble hydrocarbon; and drying the water from the washed conductor.
Claim 4
Dependent Claim
42 words
The method in accordance with claim 4 comprising the further step of adding a fluxing agent to the combined molten solder and water-soluble hydrocarbon prior to the step of passing the conductor through the combined molten solder, water-soluble hydrocarbon and fluxing material.