Metal pillar in a film-type semiconductor package
A film-type semiconductor package includes a metal lead portion arranged on a film substrate, a semiconductor chip including a pad, and a bump connecting the metal lead portion to the pad of the semiconductor chip. The bump includes a metal pillar arranged on the pad and including a first metal and a soldering portion arranged on an entire surface of the metal pillar, bonded to the metal lead portion, and including the first metal and a second metal that is different from the first metal.
1. A film-type semiconductor package comprising:
a metal lead portion on a film substrate;
a semiconductor chip including a pad; and
a bump connecting the metal lead portion to the pad of the semiconductor chip, the bump including,
a metal pillar on the pad and including a first metal; and
a soldering portion on an entire surface of the metal pillar, bonded to the metal lead portion, and including the first metal and a second metal that is different from the first metal the soldering portion having a top surface that is substantially flat; and
wherein the metal lead portion comprises a metal lead and a lead protective layer protecting a surface of the metal lead, and a lower surface of the metal lead portion is below and within the top surface of the soldering portion;
the metal lead includes a copper layer, and
the lead protective layer includes a tin layer.
2. The film-type semiconductor package of claim 1 , wherein the metal pillar comprises a gold layer or a copper layer.
3. The film-type semiconductor package of claim 1 , wherein the soldering portion comprises a gold-tin eutectic alloy layer.
4. The film-type semiconductor package of claim 3 , wherein a content of tin atoms in the gold-tin eutectic alloy layer is equal to or greater than about 25% and equal to or less than about 45%.
5. The film-type semiconductor package of claim 1 , wherein the soldering portion surrounds a bottom and opposite side surfaces of the metal lead portion.
6. The film-type semiconductor package of claim 1 , wherein a diffusion preventing layer includes a third metal that is different from the first metal and the second metal.
7. The film-type semiconductor package of claim 6 , wherein the diffusion preventing layer comprises a nickel layer.
8. A film-type semiconductor package comprising:
a metal lead portion extending from an outer lead bonding portion at one side portion of a film substrate to an inner lead bonding portion;
a semiconductor chip including a pad; and
a bump connecting the metal lead portion of the inner lead bonding portion to the pad of the semiconductor chip, the bump including,
a metal pillar on the pad and including a first metal; and
a soldering portion on an entire surface of the metal pillar, bonded to the metal lead portion, and including the first metal and a second metal that is different from the first metal the soldering portion having a top surface that is substantially flat; wherein
the metal lead portion includes a metal lead and a lead protective layer protecting a surface of the metal lead, and a lower surface of the metal lead portion is below and within the top surface of the soldering portion;
the metal lead includes a copper layer, and
the lead protective layer includes a tin layer.
9. The film-type semiconductor package of claim 8 , wherein the outer lead bonding portion comprises a connection portion bonded to an image display panel or a printed circuit board.
10. The film-type semiconductor package of claim 8 , wherein:
the metal pillar includes a gold layer or a copper layer, and
the soldering portion includes a gold-tin eutectic alloy layer.
11. The film-type semiconductor package of claim 10 , wherein a content of tin atoms in the gold-tin eutectic alloy layer is equal to or greater than about 25 at % and equal to or less than about 45 at %.
12. The film-type semiconductor package of claim 8 , further comprising:
a diffusion preventing layer on the metal pillar, the diffusion preventing layer including a nickel layer.
13. The film-type semiconductor package of claim 8 , further comprising:
a barrier layer between the pad and the metal pillar.
14. A bonding bump bonded to a lead portion in a semiconductor package, the bonding bump comprising:
a metal pillar including a first metal; and
a soldering portion including a first soldering layer on the metal pillar, the soldering portion being bonded to the lead portion and including a eutectic alloy layer of the first metal including a second metal, the soldering portion having a top surface that is substantially flat; wherein
the lead portion includes a metal lead and a lead protective layer protecting a surface of the metal lead, and a lower surface of the metal lead is below and within the top surface of the soldering portion,
the metal lead includes a copper layer, and
the lead protective layer includes a tin layer.
15. The bonding bump of claim 14 , wherein:
the soldering portion further comprises a second soldering layer; and
a melting point of the first soldering layer is lower than the melting point of the second soldering layer.
16. The bonding bump of claim 14 , wherein:
the first metal includes at least one of gold and copper; and
the second metal includes tin.
17. The semiconductor package of claim 14 , further comprising a diffusion preventing layer between the soldering portion and the pillar, the diffusion preventing layer including a third metal having a higher melting point than at least one of the first metal and the second metal.