Prototype Assembly with Open Cavity Packages

Open Cavity Packages
Open Cavity Packages

Open cavity packages have evolved to be the preferred solution for prototype and low volume assembly of integrated circuits. For many years ceramic packages were the default option for prototype assembly of new semiconductor products. This presented a challenge for the industry because, while this type of package allowed for rapid assembly of initial samples, it rarely would represent the final product, which was typically a plastic package. This gap was noted by both the vendors of prototype assemblies and by their customers, who were looking for package solutions that could more accurately represent the production package.  This requirement gave rise to new and interesting concepts, starting with opening a plastic package using etching in order to remove the existing integrated circuit. This process was nick-named “Scoop and Goop”, referring to the removal of the old IC, “Scoop” and followed by assembly of a new IC in that package and the filling with epoxy to cover the IC, or “Goop”. This was a good first step because it had the advantage of providing a package that was the exact match to the intended production package.  However, there was a significant disadvantage when it came to the ease to wirebond, as the methods used to remove the molded plastic material were traumatic to the bond fingers.

A new approach was needed – the Open Cavity Package. Over the last decade so called pre-molded plastic packages were designed in which the plastic is molded to a copper lead frame with an open cavity (Open Cavity Package). After molding the parts are typically gold plated but in some cases the lead frame is pre plated. These pre-plated lead frames often receive palladium plating. These new packages have become the ideal method for prototype assembly and, in some cases, low volume assembly. In the industry they are referred to as open cavity plastic packages. They offer rapid prototyping combined with closely matching specifications to the actual production package, satisfying the initial obstacle faced when doing prototype or low volume assembly.

At Majelac Technologies we assemble pre molded plastic packages with formats including QFN, SOIC, and QFP. We stock pin counts ranging from 8 pins to 100 pins.  We can assembly prototypes in these packages in as little as 4 hours. For a list of available packages please check this link:

For a list of available packages please check this link

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