A plastic pin grid array package is detailed. Where the semiconductor device is mounted within a cavity in the printed wiring board, it is surrounded by a ring of holes that extend completely through the board. When the plastic housing is transfer molded around the face of the board, plastic will enter the holes thereby forming plastic pillars that lock the encapsulant to the board mechanically. When the package is flexed, the pillars will prevent any motion between the encapsulant and the board or the semiconductor device mounted thereupon. The invention can be applied to single or multichip packages. It can be employed in any package that is based upon a printed wiring board substrate.
A technique for providing partially and fully overmolded semiconductor packages is described which prevents delamination (detachment) of the molding compound from the substrate by allowing the molding compound to flow through holes in the substrate and forming it into rivet-like anchors on the opposite side of the substrate. Various shapes of rivet-like anchors are described. Different embodiments provide for the formation of molded standoffs and locating pins integral to the anchor structures.
A surface mount semiconductor package includes a semiconductor device, a metal pad on which the semiconductor device is mounted, and a housing formed of a flowable material which bonds to the metal pad and encapsulates the semiconductor device when cured, where the metal pad includes a waffled surface opposite the surface on which the semiconductor device is mounted for accepting solder between the metal pad and a substrate and for permitting solder wetting therebetween.
An embodiment of the present invention allows mold compound to flow underneath a substrate where the mold compound will remain in place until the process of mold formation is completed. The mold compound of the package will penetrate all available cavities where the mold compound will remain in place and harden. After hardening, the mold compound surrounding a mold anchor will support an anchored area.
A new method is provided for the creation of a mold cap. The mold cap anchoring feature of the invention is designed and incorporated from the start of the design and fabrication of the substrate. Various design options of the mold anchor of the invention can be implemented. The mold anchor of the invention allows the mold compound to flow underneath the substrate where the mold compound will remain in place until the process of mold formation is completed. The mold compound of the package will penetrate all available cavities surrounding and being accessible from the mold anchor of the invention where the mold compound will remain in place and harden. After hardening, the mold compound surrounding the mold anchor will support the anchored area.
A metallic printed board is formed by laminating an insulation layer on the surface of a metallic sheet as a base, and then electronic parts are mounted on the conductor pattern formed on the surface of the insulation layer. A double-sided printed board mounted thereon electronic parts is placed in parallel. Both the printed boards are supported and fixed monolithically by filling the space between the printed boards with an insulation resin and curing the resin. Furthermore, an insulation resin is laminated on the surface of the printed board in such a manner that the resin may cover the mounted electronic parts, and cured. The heat generated from the electronic parts can be efficiently transmitted to the insulation resins by using a resin having a high thermal conductivity for both of the insulation resins, and the heat is then emitted from the surfaces of the metallic sheet or the insulation resin.
