Active solid-state devices (e.g. – transistors – solid-state diode – Combined with electrical contact or lead – Flip chip
Reexamination Certificate
2002-04-16
2003-12-16
Nelms, David (Department: 2818)
Active solid-state devices (e.g., transistors, solid-state diode
Combined with electrical contact or lead
Flip chip
Reexamination Certificate
active
06664645
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of mounting a semiconductor chip which is suitable for manufacturing an electromagnetic wave readable data carrier that functions as a flight tag, a label for physical distribution management, a ticket for an unmanned wicket and others, particularly relates to a method of mounting semiconductor chip in which a bare semiconductor chip can be mounted on a circuit board at a low cost by a flip-chip connecting method. The present invention also relates to a circuit board for flip-chip connection and a method of manufacturing the same. In addition, the present invention relates to an electromagnetic wave readable data carrier and a method of manufacturing the same, and an electronic component module for an electromagnetic wave readable data carrier.
2. Description of the Related Art
For this type of electromagnetic wave readable data carrier, a flight tag disclosed in Japanese Patent Unexamined Publication No. Hei. 6-243358 for example is known. It is estimated that the flight tag will be used for the management of passenger's baggage at an airport as a throwaway tag in near future. At that time, in the case of a worldwide airline company, the enormous demand such as 8.5 million pieces per month can be expected by only the company. Therefore, as to this type of flight tag, the establishment of mass production technology at an extremely low cost is desired.
The flight tag disclosed in the patent application is composed by mounting a curled conductive pattern to be an antenna coil and IC components to be a send and receive circuit, a memory and others on the single side of a rectangular substrate made of a PET film.
The body of the flight tag that holds the curled conductive pattern to be an antenna coil can be formed by selectively etching copper foil and aluminum foil respectively coated on the single side of the PET film by etching processing. Therefore, a continuous production line by roll to roll (RTR) can be readily realized by a resist formation process by well-known photolithographic technology and the succeeding wet etching process and others. In the meantime, circuit components such as a send and receive circuit and a memory to be mounted on the body of the flight tag are integrated in one chip using semiconductor integration technology.
These applicants propose that a bare semiconductor chip is first moduled by mounting the bare semiconductor chip composing the send and receive circuit, the memory respectively described above and others on a thin insulating piece (a type of circuit board) and then the productivity of a flight tag is enhanced by bonding the electronic component module on a PET film composing the body of the flight tag.
As for an electronic component mounted sheet, the advanced thinning of which is requested, such as the electronic component module bonded to the flight tag, a flip-chip connection method in which a bare semiconductor chip is directly mounted on a circuit board is often proposed.
An example of the flip-chip connection method (hereinafter called a first related art type method) is shown in FIG.
14
. In the first related art type method, a protruded terminal for connection (hereinafter called a bump) b is formed on the bottom electrode (not shown) of a semiconductor chip a and after the bump b and an electrode area d of a wiring pattern on a circuit board c are positioned, both are connected via joining material e such as solder and conductive paste.
In the first related art type method, a problem is pointed out such that the manufacturing cost is increased because (1) a process for supplying and hardening the joining material e for connecting the bump b and the electrode area d of the wiring pattern is complex, (2) an insulating resin f called underfill is filled between the chip a and the board c so as to seal a bump connection portion between the bump b and the electrode area d and thereby to acquire the reliability in the moisture-proof of the bump connected part and strength for mounting the semiconductor chip and (3) a process for filling and hardening the insulating resin f to be underfill is required.
Another example of the flip-chip connection method (a second related art type method) is shown in FIG.
15
. The second related art type method is proposed to solve the problem of the first related art type method and a bare semiconductor chip is mounted on a circuit board using an anisotropic conductive sheet proposed in Japanese Patent No. 2586154.
In the second related art type method, an anisotropic conductive sheet gin which conductive particulates are dispersed in thermoplastic or thermosetting resin is put between a bare semiconductor chip a and a circuit board c, and the resin is made to flow by thermocompression bonding, so that electric connection in the direction of the thickness is acquired by conductive particulates h put between a bump b and an electrode area d of the wiring pattern.
According to this method, there is effect that the positioning of the circuit board with the wiring pattern when the semiconductor chip is mounted on the circuit board can be relatively roughly performed. In addition, time when resin is hardened is short, for example 10 to 20 seconds, sealing material such as underfill is not required to be used, and the manufacturing cost can be reduced. To the contrary, problems are further pointed out such that (1) the anisotropic conductive sheet g is relatively high-priced, (2) the anisotropic conductive sheet cannot be used for a board without heat resistance because the high temperature of 200° C. or more is required for hardening the sheet, (3) it takes 10 to 20 seconds to harden the resin though it is a relatively short time, and it is difficult to further simplify and speed up the process and (4) the reliability of connection is low because electric connection between the bump and the wiring pattern depends upon the contact of conductive particulates dispersed in the resin.
SUMMARY OF THE INVENTION
The invention is made to solve the problems in the related art type flip-chip connection method and the object is to provide a method of mounting semiconductor chip by a flip-chip connection method in which a semiconductor chip can be mounted on a circuit board promptly, electrically and mechanically securely and further at a low cost.
Also, another object of the invention is to provide a circuit board for flip-chip connection suitable for the above-mentioned mounting method.
Also, further another object of the invention is to provide a method of manufacturing a circuit board for flip-chip connection in which the above-mentioned circuit board can be manufactured simply and at a low cost.
Further, furthermore another object of the invention is to provide an electromagnetic wave readable data carrier and a method of manufacturing the same in which an electromagnetic wave readable data carrier that functions as a flight tag, a label for physical distribution management, a ticket for an unmanned wicket and others can be produced at a low cost in a mass.
Also, further another object of the invention is to provide an electronic component module for an electromagnetic wave readable data carrier.
The person skilled in the art will easily understand further another object and the effect of the invention by referring to the description of embodiments and others.
A method of mounting a semiconductor chip according to the invention is provided with a process for pushing a melted thermoplastic resin coat aside by pressing a bump of a bare semiconductor chip on the melted thermoplastic resin coat applying an ultrasonic wave in a state in which the thermoplastic resin coat covering an electrode area on a wiring pattern is heated and melted and touching the bump and the electrode area, a process for bonding the bump and the electrode area by continuously applying an ultrasonic wave in a state in which the bump and the electrode area are touched and a process for cooling and solidifying the melted thermoplastic resin and bond
Dickstein , Shapiro, Morin & Oshinsky, LLP
Le Thao P
Nelms David
Omron Corporation
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