Semiconductor apparatus and process of production thereof

Abstract

A method of producing a semiconductor apparatus, the method including forming metal ball bumps in direct contact with a circuit pattern of a semiconductor device, forming a resin film to seal spaces between the metal ball bumps, cleaning the surfaces of the metal ball bumps projecting out from the resin film using plasma cleaning by removing components inviting a rise in a connection resistance and a decline in a joint strength, forming eutectic solder layers different in composition from the metal ball bumps on the surfaces of the metal ball bumps, cutting the semiconductor substrate into unit semiconductor chips, and mounting at least one of the chips on a mounting board from a bump forming surface side of the chip so as to connect the eutectic solder layers to the mounting board with the resin film directly contacting the chip and not directly contacting the mounting board.

Description

CROSS REFERENCES TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. patent application Ser. No. 09 / 385,959 filed on Aug. 30, 1999, the entirety of which is incorporated herein by reference to the extent permitted by law. The present application claims the benefit of priority to Japanese Patent Application No. 10-247393 filed in the Japanese Patent Office on Sep. 1, 1998 and Japanese Patent Application No. 11-146942 filed in the Japanese Patent office on May 26, 1999. The entire contents both of which are incorporated herein by reference to the extent permitted by law.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a semiconductor apparatus mounted using solder or other metal bumps and a process of production of the same.[0004]2. Description of the Related Art[0005]In recent years, digital video cameras, digital cellular phones, notebook-type personal computers, and other portable electronic equipment have spread w...

AI Technical Summary

Benefits of technology

The present invention provides a semiconductor apparatus and a process of production that can reliably relieve thermal stress between a semiconductor device and mounting board without the use of a sealing resin. This is achieved by cleaning the surfaces of metal bumps and forming a resin film on the circuit pattern forming surface of the semiconductor device to seal spaces between them. The resin film is formed by plasma cleaning or laser beam irradiation and is designed to reinforce the areas around the bases of the metal bumps. The use of a high melting point solder and a eutectic solder composition in the solder bumps and solder layers, respectively, improves the reliability of the joint. The process of production involves forming metal bumps, cleaning the surfaces of the metal bumps, and mounting the semiconductor device on the mounting board.

Problems solved by technology

In this case, there is the disadvantage that the thickness of the solder bumps formed is affected by the surface conditions of the layer of material forming the underlayer of the bumps or the slight variation in the electrical resistance and that the formation of uniform solder bumps of the same height in a semiconductor chip is extremely difficult.

The thermal stress becomes a major disadvantage for the reliability of the joint by the bumps after flip-chip mounting due to the differences in the coefficients of heat expansion of the semiconductor chips and the mounting board (printed circuit board).

While the coefficient of heat expansion of silicon is 3.4 ppm / ° C., the coefficient of heat expansion of the generally widely used glass epoxy-based mounting board is a large about 15 ppm / ° C. When thermal stress is repeatedly applied to bump joints by the temperature difference caused by the on / off operation of a chip, cracks are caused in the joints and breakage or malfunctions are caused in some cases.

Here, the replacement of the entire mounting board 2 of the former case has the disadvantage of the cost ending up higher, while the forcibly tearing off of the semiconductor chip 1 of the latter case ends up damaging the mounting board 2.

Therefore, the work of replacing a defective component in the case of a defect occurring in a semiconductor chip 1, that is, the so-called rework, is difficult.

This has become one factor behind the failure of flip-chip mounting from spreading widely.

Further, along with the reduction of pitch accompanying the reduction of size of semiconductor devices, at the time of injection of the sealing resin, the circulation of the sealing resin 3 becomes poor and full injection of the sealing resin 3 can no longer be achieved, so there is also the disadvantage that the thermal stress cannot be sufficiently relieved.

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