Copper Laminates

The bonding of metal to a plastic laminate is nowdays not an unusual application, a common example is the copper/plastic laminate used for printed circuits. No particular difficulty arises in the two stage process, a process in which the copper is bonded to the cured laminate, usually phenolic or epoxy. But problem arise in the one stage process with phenolic resin. Different phenolic resin, epoxy resins and curing agents all behave differently, as is reflected in the different blister and peel strengths obtained in bonding copper foil. Generally speaking, epoxy resins do not fulfil the combined requirement of high blister resistance and high peel strength as satisfactorily as some of the two polymer adhesive.

In a survey of adhesives for pronted circuit laminates, Rider draws attention to the corrosive effect of some hardeners used with epoxy resin having an influence on electrical properties.

Broken Bones
The mending of broken bones by adhesive bonding is a subject that has created much interest in recent years. As might be expected, a good deal of attention has been given to the use of epoxy resin. Experimental work has been done in Australia, USA. Switzerland and England, all very largely on animals. Evidence shows that the strength of the limb is regained more rapidly than by natural healing, although it does not appear that a technique has yet been developed that can be applied to human being with absolute safety.