An improved multi-chip module includes a main circuit board having and array of electrical interconnection pads to which are mounted a plurality of IC package units. Each IC package unit includes a pair of IC packages, both of which are mounted on opposite sides of the package carrier. The package units may be mounted on one or both sides of the main circuit board. A first primary embodiment of the invention employs a laminar package carrier having a pair of major planar surfaces. Each surface incorporates electrical contact pads. One IC package is surface mounted on each major planar surface, by interconnecting the leads of the package with the contact pads on the planar surface, to form the IC package unit. A number of other vriations exist that provide various other embodiments of the invention including one in which the carrier leads are laminated directly to the leads of an IC package.