US 4,283,847 AGranted

Circuit board assembly

AssigneeLear Siegler, Inc.

InventorGordon M. May

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Abstract

An apparatus and method for assembling integrated circuits to a printed circuit board wherein integrated circuits with protective carriers are selectively dispensed from a rotary magazine, are removed from the carriers and positioned by the leads on magnetic holders on a continuous conveyor which moves the integrated circuits, thus mounted on the holders, to a lead-forming and trim assembly wherein the leads are bent downwardly and outwardly to form feet and trimmed. Thereafter the integrated circuits are moved, thus mounted on the holders, to a flux-applying assembly wherein flux is applied to the lead feet, then to a solder-applying assembly wherein solder is applied to the lead feet, and then to a program activated X-Y axis table which mounts the printed circuit board. The integrated circuits, with tinned leads, are transferred through magnetic fingers to the printed circuit board wherein electrodes solder the leads to pads on the Board. The leads are bent in a special configuration comprising four bends which assist in positioning the leads on the magnetic holder and enhances the vibrational stress resistance of the integrated circuits on the assembled printed circuit board. Special universal tooling is magnetically held on the X-Y axis table to mount the printed circuit boards in precise location on the table. The entire operation from dispensing to soldering is computer controlled.

In an apparatus for assembling integrated circuits having a body and a plurality of leads extending therefrom onto a printed circuit board comprising a plurality of solder-containing pads designed to receive the integrated circuit leads, wherein the leads of the integrated circuits are tinned and bent downwardly and laterally to form feet to contact the printed circuit pads;

a table for mounting a printed circuit board;
electrode means for soldering the integrated circuit leads to the printed circuit board at a predetermined location on the table;
means for positioning the integrated circuits on the printed circuit board at the predetermined location for soldering by the electrode means;
and
means for intermittently moving the table with respect to the electrode means to position different areas of the printed circuit board at the predetermined location beneath the electrode means;
the improvement which comprises:
a frame;
a continuous conveyor means mounted on the frame and having a plurality of spaced support means to support and retain integrated circuits by the leads thereof;
means mounted on the frame for dispensing integrated circuits seriatim onto the integrated circuit support means so that the integrated circuits are supported thereon by the leads;
means on the frame operably associated with the conveyor means for bending the leads downwardly and outwardly to form feet on the leads for contact with the printed circuit board while the leads are supported by the conveyor means integrated circuit support means;
means on the frame in proximate relationship with the conveyor means for coating the leads with solder while the integrated circuits are retained by the integrated circuit support means;
the integrated circuit positioning means comprising means for transferring the integrated circuits from the support means to the printed circuit board on the printed circuit board table into the predetermined location for soldering by the electrode means;
and
means for intermittently moving the conveyor means so that the integrated circuit support means move sequentially from the dispensing means to the lead-forming means, the solder coating means and the transferring means.

11 more elements

Abstract

Claims38