A Method for Induced Intermetallic Growth of Thin Films with Specific Grain Orientation and Quantity Using Laser Forward Transfer

Abstract

The invention discloses a method for inducing growth of an intermetallic compound with the specific grain orientation and the specific number of films through laser forward transfer printing. The method comprises the following steps that firstly, a seed layer is prepared on the surface of a substrate; secondly, a metal film is continuously prepared on the surface of the seed layer; thirdly, the Sn film is prepared on the surface of metal film; fourthly, the substrate and the two films are heated, so that the intermetallic compound film is prepared; fifthly, the intermetallic compound film is transferred to the surfaces of a chip and bonding pads of the substrate respectively; sixthly, the surface of the intermetallic compound film is plated with the Sn film; and seventhly, the bonding pads are in butt joint, pressure is applied, the bonding pads are placed in a reflow furnace, and the stages of preheating, heat preservation, reflowing and cooling are performed. By the adoption of the method, the preparation time of a welding spot of the intermetallic compound capable of being used for high-temperature packaging and interconnection is greatly shortened, the grain orientation and the number of following growing intermetallic compounds are controlled, the welding spot of the intermetallic compound is quickly prepared, and the microstructure is controllable.

Description

technical field [0001] The invention belongs to the technical field of micro-interconnection of electronic packaging, and relates to a method for rapidly preparing intermetallic compound solder joints that can be used for high-temperature packaging and interconnection, and in particular to a method of using laser forward transfer printing with specific grain orientation and quantity film induction Methods of growth of intermetallic compounds. Background technique [0002] Electronic packaging micro-interconnection technology is one of the core technologies for packaging various electronic components and components. With the development of electronic components and components in the direction of high power and high density, the service temperature and working environment of electronic components and components become more severe, which will put forward higher requirements for the bonding materials of electronic components and components, However, traditional solder alloys an...

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Problems solved by technology

According to the thermodynamic properties of nano-silver particles, the connection can be realized under the condition of less than 200 ° C, and the formation of joints can be used under the condition of more than 350 ° C, but the connection of nanoparticles takes a long time, the joint is porous structure, and the preparation cost of nano-materials is relatively high. Higher, which restricts the application of such materials; joints formed by all-intermetallic compounds can be applied under high temperature conditions, but generally the preparation time is longer, tens of minutes or even hours, and the microstructure is difficult to control, so it is difficult to realize Large-scale industrial application; the sintering of intermetallic compound nanoparticles solder paste needs to be sintered with a specification higher than or close to the melting point of intermetallic compounds, and the melting point of intermetallic compounds is generally higher (over 400 ° C), which is easy to cause damage to the device during the connection process. damage

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