Ni-Cu-P ternary alloy coating serving as welding spot reaction barrier layer and electroplating preparation technology thereof

Abstract

The invention discloses a Ni-Cu-P ternary alloy coating serving as a welding spot reaction barrier layer and an electroplating preparation technology thereof. The Ni-Cu-P ternary alloy coating serving as the welding spot reaction barrier layer comprises the following components in percentage by weight: 70-90% of Ni, 3-10% of Cu and 7-20% of P. The thickness of the coating is 2-15mu m. The preparation method comprises the following steps of: putting an electroplated cathode piece (metallized Si chip or Cu piece) and an electroplated anode sheet (Pt piece) into electroplate liquid; introducing dipulse current for dipulse electroplating; and forming an Ni-Cu-P alloy coating on the surface of the cathode piece. The components of the Ni-Cu-P alloy coating prepared by using the electroplating preparation technology conform to the use requirement of a welding spot reaction barrier layer for electronic packaging and interconnection, the coating and the cathode piece substrate (metallized Si chip or Cu piece) are tightly combined, a plating layer is flat, and the Ni-Cu-P ternary alloy coating is fine in cellular tissue, even in thickness, and compact in structure and is basically free from holes.

Description

1. Technical field [0001] The invention relates to an alloy coating and a preparation method thereof, in particular to a Ni-Cu-P ternary alloy coating as a solder joint reaction barrier layer and its electroplating preparation process, belonging to the technical field of electronic packaging and interconnection . 2. Background technology [0002] For a long time, tin-lead (Sn-Pb) solder has been widely used in the electronic packaging industry due to its low melting point (eutectic point of 183°C), high cost performance, good electrical properties, mechanical properties and reliability. However, due to environmental protection and human health considerations, developed countries such as the European Union, the United States, and Japan have successively legislated to prohibit the production and sales of lead-containing electronic products. my country has also formulated corresponding laws and regulations, and lead-free electronic products have become the general trend . At p...

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Problems solved by technology

Here, what needs to be highlighted is: 1. The main defects of the electroless plating process are that the operating temperature is high (about 90°C), the energy consumption is high, and because of high temperature evaporation and hypophosphite ion (H 2 PO 2 - ) reacts violently at high temperature, the composition of the plating solution is difficult to maintain stability, and the service life of the plating solution is low; 2. The electroless plating of the Ni-P layer needs activation and sensitization, and expensive chemicals such as palladium chloride are required, which has high cost and complicated process

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