Adapting elements such as integrated circuit chips (ICs) for service is a major task in the solid state, electronics industry. Such chips may be mounted directly to a substrate and electrically connected to a circuit. More typically today, a chip is mounted in an enclosure having a system of conductors to external leads or pads for connection to sockets or circuit substrates. The enclosure may take many forms including a partial enclosure, a fully enclosed plastic or glass encapsulation or a container which may be hermetically sealed. Such enclosures protect a chip and other elements from deleterious effects of moisture, corrosion and physical abuse.
Containers which are useful for full enclosure typically include a seat to receive a component such as a lid on an accessible topside portion. The seat is made complementary with a major surface of the lid so each component is said to have a mating face. The seat may be lined with bonding material, although more often the seat is metallized and the bonding material is affixed or adhered to the lid. For precision purposes, the seat outline is generally made slightly smaller than the topside surface of an enclosure. Also, the lid is often made smaller than the seat so a fillet of bonding material may be developed about the periphery of an installed lid. Such fillet is adhered to peripheral portions of the seat to effect a good seal.
Modern electronic chips are typically tiny, and contain thousands of devices in a miniature circuit to achieve accelerated performance at low costs. The enclosures are also small to enhance performance between chips and for efficient utilization of space on service substrates. Consequently, the assembly of such enclosures is a problem because of the smallness and/or differences in size of the components. Another problem includes the sometimes tedious procedures associated with registering mating faces of components precisely with each other. It is especially a problem to assemble such enclosures when components are adapted for special bonding, for example, when hermetic sealing is to follow such assembly.
For assembling small components having mating faces on dissimilar sized surfaces, some expedients utilize frames for locating components. A first frame positions a lid with its mating face turned upward and a second, higher frame positions a larger component such as an enclosure with its mating face turned downward upon the upturned lid. Special transfer tools are utilized to handle lids by contacting only external surfaces, opposite the mating faces which often contain delicate features for bonding. Such expedients work well but contain precautionary features which are unnecessary for lids having rugged mating faces. For example, some lids have mating faces bonded with adhered glass frit or thick films of solder which are relatively resistant to abuse and may be handled by simple and economic means.
Accordingly, it is desirable to provide new and improved expedients for assembling components having mating faces, especially components which are small and dissimilar in size. Such assembly should include precise registration of mating faces, particularly when hermetic sealing is involved. Moreover, such expedients should be simple, economical and operable by unskilled personnel or by mechanization.