Structure of gold fingers
View Patent ↗The present invention provides an improved structure of gold fingers, which is to redesign a conventional gold finger on a packaging substrate into a gold finger set that contains a plurality of gold finger units. Between each single gold finger unit, there exists an electrical connection. Therefore, in the structure of stacked-chip packaging, each wire that is connected through wire bonding on the same gold finger of each layer chip can separately perform wire bonding on different gold finger units of the same gold finger set. Due to the improvement on the gold finger structure, the present invention can prevent the adhesive on a chip from flowing along the wire bonding path of a layer chip and smearing the whole gold finger. Thus, other layer chips can be prevented from being unable to perform wire bonding.
1. An improved structure of gold fingers, built in a stacked-chip packaging structure, and the stacked-chip packaging structure, comprising
a packaging substrate;
a plurality of chips stacked on said packaging substrate, each said chip including at least one chip wire; and
a plurality of gold finger sets positioned on said packaging substrate, wherein each said gold finger set includes a plurality of gold finger units electrically connected to one another by a conductive material and positionally separated one from another by a solder resist structure extending above said conductive material, and wherein said at least one chip wires of said plurality of the stacked chips to be connected to one another are connected to said gold finger units of the same gold finger set, each said at least one chip wire being connected to a distinct gold finger unit.
2. The improved structure of gold fingers as claimed in claim 1 , wherein the number of said gold finger units in each said gold finger set is equal or exceeds the number of said stacked chips.
3. The improved structure of gold fingers as claimed in claim 1 , wherein said conductive material includes at least one connecting wire extending between respective gold finger units to form electrical connection therebetween.
4. The improved structure of gold fingers as claimed in claim 3 , wherein said solder resister structure covers said at least one connecting wire.
5. The improved structure of gold fingers as claimed in claim 1 , wherein said gold finger set is a complete gold finger, wherein said conductive material is a material of said complete gold finger, and wherein said solder resist structure covers a part of the surface of the complete gold finger to divide the latter into a plurality of said gold finger units.