Lead frame for semiconductor device and method of manufacturing of the same
View Patent ↗Provided are a semiconductor device lead frame and a method of manufacturing of the same that improve adhesive properties between plating layers when a plurality of plating layers are laminated, that control deterioration in wire bonding properties during the manufacturing process of a semiconductor device and worsening of solderability during packaging, and that effectively reduce manufacturing cost. Specifically, the lead frame ( 2 a , 2 b ) has a laminated structure that includes a lower plating layer ( 22 ) formed on a conductive base material ( 21 ) and an uppermost plating layer ( 23 ), with an organic film ( 22 ) that has metal-binding properties formed between the lower plating layer ( 21 ) and the uppermost plating layer ( 23 ). The organic film ( 22 ) is formed as a monomolecular film in which functional organic molecules ( 11 ) self assemble. Each of the organic molecules ( 11 ) has functional groups (A 1 , A 1 ) with metal-binding properties on both ends of a main chain (B 1 ).
1. A lead frame for a semiconductor device, the lead frame comprising:
an electrically conductive base;
a lower plating layer formed on the electrically conductive base;
an organic film formed on the lower plating layer; and
an uppermost plating layer formed on the organic film, wherein
the organic film has metal-binding properties with respect to the lower plating layer and the uppermost plating layer.
2. The lead frame for a semiconductor device of claim 1 , wherein
the lower plating layer is formed of a precious metal.
3. The lead frame for a semiconductor device of claim 1 , wherein
the lower plating layer and the uppermost plating layer are formed of a precious metal.
4. The lead frame for a semiconductor device of claim 1 , wherein
the organic film includes a plurality of organic molecules each having a molecular configuration with two or more polar groups, and one of the polar groups in each organic molecule is bound to metal forming the lower plating layer, so that the organic film coats the lower plating layer.
5. The lead frame for a semiconductor device of claim 1 , wherein
the organic film is formed of organic molecules that self assemble, and
the organic molecules have, at both ends, a functional group with metal-binding properties.
6. The lead frame for a semiconductor device of claim 5 , wherein
a main chain of each of the organic molecules is a compound, chemical structure, or derivative including at least one selected from the group consisting of an aryl skeleton, an acene skeleton, a pyrene skeleton, a phenanthrene skeleton, a fluorene skeleton, and a nitrogen-containing heterocycle containing at least two nitrogen atoms.
7. The lead frame for a semiconductor device of claim 6 , wherein
the nitrogen-containing heterocycle is a compound, chemical structure, or derivative including at least one selected from the group consisting of imidazole, triazole, tetrazole, oxadiazole, thiadiazole, pyrimidine, pyridazine, pyrazine, and triazine.
8. The lead frame for a semiconductor device of claim 5 , wherein
the functional group with metal-binding properties is a compound, chemical structure, or derivative including at least one selected from the group consisting of a thiol compound, a sulfide compound, and a nitrogen-containing heterocycle compound.
9. A method of manufacturing a lead frame for a semiconductor device comprising the steps of
(a) forming a lower plating layer on a conductive base;
(b) forming an organic film on a surface of the lower plating layer; and
(c) forming an uppermost plating layer on a surface of the organic film, wherein
the organic film formed in step (c) has metal-binding properties with respect to the lower plating layer and the uppermost plating layer.
10. The method of manufacturing the lead frame for a semiconductor device of claim 9 , wherein
step (b) includes creating a dispersion liquid by dispersing an organic compound in a solvent and dipping the conductive base on which the lower plating layer is formed into the dispersion liquid.