Manufacturing method of single intermetallic compound micro-interconnecting structure of flip chip

Abstract

The invention discloses a manufacturing method of a single intermetallic compound micro-interconnecting structure of a flip chip, relating to the manufacturing method of an intermetallic compound micro-interconnecting structure of the flip chip and aiming at solving the problem that micro-interconnection welding spots of the flip chip fracture at connecting interfaces among brazing solder alloys, intermetallic compounds and metallic bonding pads. The technical scheme I comprises the following steps of: manufacturing a chip metallic basic layer (a chip metallic bonding pad) and a surface layer on a metallic surface of the chip, and manufacturing a substrate metallic basic layer (a substrate metallic bonding pad) and a surface layer on a metallic surface of a substrate, wherein the chip and the substrate metallic surface are made of pure Sn; coating a soldering flux on the metallic surface of the chip and the metallic surface of the substrate; and inverting the chip to ensure that the chip metallic bonding pad corresponds to the substrate metallic bonding pad, pressing, heating, cooling, and forming the intermetallic compound micro-interconnecting structure of the flip chip. The technical scheme II is different from the technical scheme I in the following steps of: coating the soldering flux on the metallic basic layer of the chip and the metallic basic layer of the substrate and inverting the chip, wherein the metallic basic layer of the chip is in contact with the metallic bonding pad of the substrate by a Sn foil. The single intermetallic compound micro-interconnecting structure is applied to an electronic packaging structure.

Description

technical field [0001] The invention relates to a method for preparing a flip-chip intermetallic compound micro-interconnection structure, which belongs to the field of electronic package structure design and manufacture. Background technique [0002] Flip-chip technology is to mount the chip directly on the surface of the substrate in an upside-down manner. This chip interconnection method can provide higher input / output connection density. The area occupied by the flip-chip is almost the same as the chip size. Small and thin encapsulation. [0003] While electronic products are developing in the direction of miniaturization and multi-function, higher requirements are also put forward for their reliability. Micro-interconnection solder joints, as a bridge between the chip and the substrate for electrical and mechanical connections, have a crucial impact on the reliability of electronic products. [0004] At present, flip-chip micro-interconnection solder joints are formed...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a method for preparing a flip-chip single intermetallic compound micro-interconnection structure, to solve the problem that the flip-chip micro-interconnection solder joint is composed of chip metal pad-intermetallic compound-brazing alloy-intermetallic compound- Substrate metal pads, due to the different materials of solder alloys, intermetallic compounds and metal pads, under the action of external force or the stress caused by the inconsistent thermal expansion and contraction of different materials, it is easy to be in the solder alloy, intermetallic compound There is a fracture at the connection interface with the metal pad, which makes the electronic product unable to work and completely fail.

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