Abstract: An improved hot air knife for use in removing excess solder from a circuit board in a mass soldering system of the type described in U.S. Pat. Nos. 4,410,126 and 4,401,253 is described. In the present invention the hot air knife comprises a commercially available square tube, one of whose edges has been cut to provide the air knife outlet. Inside this tube, there is provided a second round tube for introducing hot air into the space between the round tube and the square tube. This inner round tube has holes facing away from the outlet slit of the square tube, preferably at least 45 degrees on both sides of a plane extending from the outlet of the square tube to the opposite corner of the square tube. In a preferred embodiment of the invention there is also provided at least one baffle in the volume between the outlet holes from the inner tube and the outlet slot for the air knife.

Abstract: An improved solder reflow system for mass joining with solder electrical and electronic components affixed on a circuit board is provided. The system employs a combination of IR heating, recirculating forced hot air heating, and focused forced hot air heating to achieve solder reflow at throughput speeds and soldering quality not heretofore achievable.

Abstract: A soldering system is described in which a fluid stream is directed onto a solder board substantially immediately following the deposition of molten solder onto the boards. The apparatus includes a pair of concentric slotted tubular shells wherein one shell rapidly rotates relative to about the other to create a plurality of different angles of impingement of the air on each area of the bottom surface of the circuit board.

Abstract: A soldering system is described in which a fluid stream is directed onto a solder board substantially immediately following the deposition of molten solder onto the boards. The impinging fluid stream is rapidly oscillated to create a plurality of different angles of impingement of the air on each area of the bottom surface of the circuit board.

Abstract: An improved apparatus and method for mass soldering electrical and electronic components populating both the top and bottom surfaces of substrate circuit boards or the like in a single pass is described. The circuit boards pass through a mass soldering station first, and after a timed interval the circuit boards pass through a solder reflow station. The timed interval allows heat transfer through the circuit boards to reach its maximum.

Abstract: Contact of a soldered board by a soldering oil supplied from within a solder wave takes place immediately following deposition of molten solder onto the board. The oil causes relocation of solder on and/or removal of excess solder from the underside of the board, and any interconnections, component leads and/or component bodies carried thereon before the solder solidifies as shorts, icicles or bridges.

Abstract: A soldering system is described in which a fluid stream is directed onto a soldered board substantially immediately following deposition of molten solder onto the board. Preferably, but not necessarily, the fluid, which may comprise a gas or mixture of gases, is heated prior to contacting the board. The impinging fluid stream relocates solder on, and/or blasts excess solder from the bottom of the board, and any interconnections, component leads and/or component bodies carried thereon before the solder solidifies as shorts, icicles or bridges. If desired, liquid droplets such as soldering oil may be included in the fluid stream.