In the manufacture of thick film circuits, adhesives are customarily used for the attachment of discrete integrated circuit (IC) devices to conductor pads formed on the a dielectric layer of the circuit. The IC terminals formed on the exposed side of the device are then attached by wire-bonding to a number of conductor pads surrounding the IC.
A problem with circuits of the above description is that the adhesive tends to spread beyond the intended print pattern during curing, to the point of contaminating the surrounding conductor pads and interfering with subsequent wire-bonding operations. While the problem can be solved by simply increasing the distance between the IC and the surrounding conductor pads, this undesirably increases the circuit area required to mount the IC. Furthermore, the increased wire-bond connection length tends to be detrimental to circuit durability, particularly when the circuit is subjected to mechanical shock. Accordingly, what is needed is a method of manufacture that constrains the adhesive spreading so that the circuit dimensions and wire-bond lengths can be minimized.
USPTO Backgrounds
USPTO Backgrounds