High-reliability copper alloy bonding wire for microelectronic packaging and manufacturing method thereof

Abstract

The invention discloses a high-reliability copper alloy bonding wire for microelectronic packaging. The high-reliability copper alloy bonding wire for microelectronic packaging is characterized in that the bonding wire comprises, by weight, 0.001%-0.005% of Ru, 0.001%-0.005% of Nb, 0.001%-0.005% of Zr, 0.001%-0.005% of Mn, 0.001%-0.005% of Mg, 0.001%-0.005% of Li, 0.001%-0.003% of Dy and the balance copper and inevitable impurities, and the content of S and O in the impurities in the whole copper alloy bonding wire is less than or equal to 0.0005%. The invention further provides a manufacturing method of the high-reliability copper alloy bonding wire for microelectronic packaging. The copper alloy bonding wire has the advantages of being high in reliability, low in hardness, good in electrical conductivity and heat conductivity and the like. The manufacturing method is easy to operate.

Description

technical field [0001] The invention relates to a bonding wire for packaging, in particular to a high-reliability copper alloy bonding wire for microelectronic packaging and a preparation method thereof. Background technique [0002] Bonding wire is used as an electrical connection wire to connect the electrodes on the semiconductor element and the external terminals, mainly 4N series (purity >99.99% (weight)) gold and other trace element alloys with a wire diameter of about 20-50 μm However, because gold is expensive and the price has continued to rise in recent years, finding materials to replace gold wires has always been a research hotspot in the field of electronic packaging. [0003] Copper is considered to be a suitable bonding wire material to replace gold due to its excellent thermal and electrical properties and lower price. However, copper wire has a series of disadvantages compared with gold wire: the surface of the wire is easily oxidized, resulting in reduce...

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Problems solved by technology

[0003] Copper is considered to be a suitable bonding wire material to replace gold due to its excellent thermal and electrical properties and lower price. However, copper wire has a series of disadvantages compared with gold wire: the surface of the wire is easily oxidized, resulting in reduced bonding strength, It is easy to cause corrosion on the surface of the wire during resin encapsulation, and the high hardness is easy to cause damage to the substrate during wiring, etc.

The copper wire with this alloy composition not only overcomes the problems of high hardness and poor welding performance of pure copper wire, but also has high conductivity and elongation, good weldability and low cost, but there are still two problems: (1) The content of O and S is not controlled. If the content of O is too high, the plasticity and toughness of the copper wire will be deteriorated, and the added elements will be oxidized so that the alloying effect is not obvious; (2) The casting process adopts the method of casting, ingot casting There is casting stress inside, and drawing is done directly without relevant heat treatment, resulting in uneven mechanical properties and component distribution of the product, which will affect the quality and life of the product

However, the bonding copper wire has the following problems: (1) the smelting process is not refined, and harmful impurities cannot be effectively removed; (2) there is no homogenization annealing process, which is prone to intragranular segregation, and cannot ensure that the added elements are in the grain The distribution is uniform, which increases the potential difference between the grain boundary and the grain, increases the tendency of the galvanic reaction, and has an adverse effect on the subsequent cold working; (3) Too many alloy elements are added, which will affect the conductivity. Second, it will lead to intermetallic compounds between elements, which weakens the effect of the elements themselves, such as the generation of brittle phases, which is more unfavorable for corrosion resistance and cold working; too many alloying elements also increase the cost

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