Process for fabricating a semiconductor package and semiconductor package with leadframe
A semiconductor package includes a flat metal leadframe including spaced apart portions, at least some of which constitute electrical connection leads. A filling material fills the spaces that separate the spaced apart portions of the leadframe to form a plate before fastening an integrated circuit chip to the front of the leadframe. Electrical connections are made between the chip and the electrical connection leads. The chip is then encapsulated on the front of the leadframe using a formed or attached encapsulant.
1. A semiconductor package, comprising:
a flat metal leadframe having a plurality of spaced apart portions, at least some of which constitute electrically conductive lead portions;
a leadframe forming a plate comprising an insulating filling material that fills the spaces between each of the spaced apart electrically conductive lead portions of the leadframe in alternating fashion and which extends from one end of the leadframe to an opposite end of the leadframe, said plate having a flat front surface and a flat rear surface extending between the ends of the leadframe;
an integrated circuit chip fixed on the leadframe between the opposed ends;
electrical connectors electrically connecting the chip to the electrically conductive lead portions; and
means for encapsulating the chip, wherein the encapsulation means are attached on the front of the plate.
2. The package according to claim 1 , wherein the encapsulation means comprise an overmolded block of an encapsulating material.
3. The package according to claim 2 , wherein the chip has, on its front face, an integrated optical sensor and wherein the encapsulating material is transparent.
4. The package according to claim 1 , wherein the encapsulation means comprises an attached lid.
5. The package according to claim 4 , wherein the chip has, on its front face, an integrated optical sensor and wherein the lid carries an optical lens facing this optical sensor.
6. A leadframe, comprising:
a flat metal leadframe for an integrated circuit chip having a platform to which the integrated circuit chip can be attached and a plurality of spaced apart portions, at least some of which constitute electrically conductive lead portions to be attached to the integrated circuit chip; and
an insulating filling material that fills the spaces between each of the spaced apart electrically conductive lead portions of the flat metal leadframe in alternating fashion and which extend from one end of the flat metal leadframe to an opposite end of the flat metal leadframe so as to form a plate having a flat front surface and a flat rear surface extending between those opposed ends of the leadframe.
7. The leadframe of claim 6 wherein the flat metal leadframe further includes anchoring recesses, the filling material filling the anchoring recesses.
8. The leadframe of claim 6 wherein the filling material is a filled epoxy resin.
9. A semiconductor packaging sub-assembly, comprising:
a perforated flat metal leadframe for, an integrated circuit chip having spaced apart electrically conductive lead portions comprising a central platform and opposed electrically conductive lead portions on either side of the central platform; and
an insulating filling material that fills perforations in the flat metal leadframe between the spaced apart electrically conductive lead portions in alternating fashion to produce a plate extending from one edge of the leadframe to an opposite edge of the leadframe, the produced plate having both a front and back surface extending between the edges which is lacking any substantial frontwardly extending projections of the filling material which fills the perforations, wherein the central platform is configured to receive, subsequent to perforation filling, a semiconductor integrated circuit chip.
10. A pre-chip attachment leadframe for receiving a semiconductor integrated circuit, comprising:
a perforated flat metal leadframe having spaced apart electrically conductive lead portions comprising a central platform and opposed electrically conductive lead portions on either side of the central platform; and
an insulating filling material that fills perforations in the flat metal leadframe between the spaced apart electrically conductive lead portions in alternating fashion to produce a plate extending from a first edge of the leadframe associated with one set of electrically conductive lead portions to a second opposed edge of the leadframe associated with another set of electrically conductive lead portions, the produced plate from the first edge to the opposite second edge having both a front and back surface extending between the first and second edges that is lacking any substantial frontwardly extending projections of filling material.