JPH1167773A - Formation of protruding electrode onto ic pad - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protruding electrode forming method in which protruding electrodes are formed stably onto IC PADs in a single step in a short time, regardless of the number of IC PADs. SOLUTION: This forming method is provided with a process, in which a film 8 provided with a hole 8a through which an IC PAS is exposed is mounted on the surface of an IC, and a mesa part 10 of a mesa metal lead 9 is brought into contact with an IC PAD 2, to be thermal compression-bonded to the IC PAD with a thermal-compression bonding means 12, a process in which the film 8 is pulled up over the IC under a condition where the mesa part 10 is fixed onto the IC PAD by compression-bonding, and the metal lead 9 is cut at a necking part 11 formed in the metal lead, and a process in which the mesa part fixed on the PAD is pressurized from the upper part with a plate-like body 14, to form protruding electrodes 13 of a uniform height on the IC PAD.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for forming a bump electrode on an IC PAD.

[0002]

2. Description of the Related Art In recent years, methods for flip-chip mounting ICs directly on a substrate face-down have been increasing, and as the production volume increases, it is strongly desired to improve the efficiency of the process of forming protruding electrodes on IC PADs. ing. Hereinafter, a conventional method for forming a bump electrode on an IC PAD will be described with reference to the drawings.

FIG. 2 shows a conventional method of assembling a semiconductor. In FIG. 2, 1 is IC, and 2 is IC PA
D, 3 are TOOLs for forming protruding electrodes, 4 are TOs for forming protruding electrodes.
Reference numeral 5 denotes an Au ball formed at the tip of the Au wire 4, reference numeral 6 denotes a protruding electrode formed by the Au ball, 7 and a bonding stage. The operation of the method for assembling a semiconductor configured as described above will be described below.

[0004] First, the tip of the Au wire 4 is brought into contact with the IC PAD 2 of the IC 1 via the TOOL 3 for forming a protruding electrode, and the Au ball 5 formed at the tip of the Au wire 4 is subjected to heat, load and ultrasonic waves. Bonding to IC PAD2, then
IC PAD2 by pulling Au wire 4 upward
The protruding electrode 6 is formed thereon.

[0005]

However, in the above configuration, the protruding electrodes must be formed for each IC PAD, and the time required for forming the protruding electrodes increases in proportion to the increase in the number of IC PADs. There is a problem that the productivity is reduced, and that when the quality of each protruding electrode is unstable, defective protruding electrode formation frequently occurs.

The present invention has been made in view of the above problems, and has been developed in consideration of an IC PAD.
It is an object of the present invention to provide a projection electrode forming method for stably forming a projection electrode on an IC PAD in a short time at a time regardless of the number of the projection electrodes.

[0007]

In order to solve the above problems, a method of forming a projecting electrode on an IC PAD according to the present invention comprises:
It is placed on the surface, the mesa portion of the mesa-shaped metal lead is brought into contact with the ICPAD, and the mesa portion is contacted with the ICPAD by a heat-compression bonding means.
D, a step of heating and pressing the film, a step of pulling up the film to the upper part of the IC in a state where the mesa portion is fixed by pressure on the IC PAD, and cutting the lead at a constricted portion formed at the base of the mesa portion of the metal lead; A step of pressing a mesa portion fixed on the IC PAD from above with a plate-like body to form a projection electrode having a uniform height on the IC PAD.

According to the present invention, I
A hole is exposed to expose the C PAD, a mesa-shaped metal mesa portion is brought into contact with the IC PAD, and the mesa portion is exposed to heat with a tool.
The film is pulled up to the top of the IC while the mesa is fixed to the IC, and the lead is cut at the constriction of the metal lead. The height of the protruding electrode left on the IC PAD is changed to a plate shape. Since the pressure is uniformly formed by the body, the quality of the protruding electrodes is constant, and protruding electrodes free from electrode formation defects can be stably formed on the IC PAD regardless of the number of IC PADs.

[0009]

DETAILED DESCRIPTION OF THE INVENTION According to the first aspect of the present invention, a film having a hole through which an IC PAD is exposed is formed on an IC pad.
Place it on the surface and attach the mesa part of the mesa-shaped metal lead to the ICP.
AD, and the mesa part is ICP
A step of heating and pressure-bonding to the AD, a step of pulling up the film to the upper part of the IC with the mesa portion fixed by pressure to the IC PAD, and cutting the lead at a constricted portion formed at the base of the mesa part of the metal lead; A method of forming a protruding electrode on an IC PAD, comprising a step of pressing a fixed mesa portion from above with a plate-like body to form a protruding electrode having a uniform height on the IC PAD, ICPA in a stable state at once regardless of the number of PADs
It is possible to form a protruding electrode on D, and to prevent the occurrence of a defective protruding electrode formation due to uneven quality of the protruding electrode.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an example of I
FIG. 6 shows a process of a method of forming a bump electrode on a CPAD. In FIG. 1, 8 is a film tape, 9 is a metal lead, 10 is a mesa portion formed at the tip of the metal lead 9, 11 is a constricted portion formed narrower than the root of the metal lead 9, 12 is a thermocompression tool, 13
Is a protruding electrode, and 14 is a plate-like material.

The operation of the semiconductor assembling method of the present invention will be described below with reference to FIG. FIG. 1 (a)
FIG. 4 is a perspective view showing a mesa-shaped metal lead placed on a film-shaped tape having a hole through which an IC PAD is exposed, and a mesa-shaped metal lead having a mesa portion and a constricted portion formed at the base of the mesa portion narrower than the lead; The film tape 8 has a hole 8a for exposing the IC PAD.

First, as shown in FIG. 1B, a mesa portion 10 of a mesa-shaped metal lead 9 is placed on an IC PAD 2 on an IC 1.
And heat-pressed to the IC PAD 2 by the thermo-compression tool 12. Next, the film 8 is pulled up to the upper part of the IC while the mesa portion 10 is fixed to the IC PAD 2 by pressure bonding, and as shown in FIG. The protruding electrode 13 as shown in FIG.

Next, in order to make the height of the protruding electrode 13 uniform, it is pressed from above by a plate-like body 14 having a flat surface, and an IC
A bump electrode 13 having a uniform height is formed on the pad. As described above, according to this embodiment, the film-shaped tape 8
A hole 8a for exposing the C PAD2 is opened.
The mesa portion 10 of the mesa-shaped metal lead 9 is brought into contact with the IC pad 2, and the mesa portion is heated and pressure-bonded to the IC PAD2 by the thermocompression tool TOL12. In the state where the mesa portion 10 is left, a step of cutting the metal lead 9 at the constricted portion 11 of the metal lead 9 and in order to make the height of the projecting electrode 13 formed by the mesa portion left on the IC PAD 2 uniform, By pressing the protruding electrode 13 from above with the plate-like body 14 having a flat surface, a plurality of protruding electrodes can be formed at a time on the IC PAD. Protruding electrodes can be formed on the ICPAD.

[0014]

As described above, according to the present invention, a hole for exposing an IC PAD is formed in a film-like tape, and an IC PAD is formed.
A process in which the mesa portion of the mesa-shaped metal lead is abutted against the ICPAD by hot TOOL, and the film is pulled up to the top of the IC while the IC is fixed, and the mesa-shaped portion is left in the ICPAD. A step of cutting the lead at the formed constricted portion and a step of pressing the protruding electrode from above with a plate having a flat surface to make the height of the protruding electrode remaining on the IC PAD uniform are performed on the IC PAD. Since the protruding electrodes are formed, the IC
Since multiple projecting electrodes can be formed on the PAD at one time, a uniform projecting electrode can be formed in a short time in the IC PAD.
A method for forming a bump electrode that can be formed thereon can be realized.

[Brief description of the drawings]

FIG. 1 (a) shows a mesa-shaped metal lead mounted on a film-shaped tape provided with holes and a constricted portion in which a mesa portion and a mesa-shaped root portion are formed thinner than the lead in the embodiment of the present invention. It is a perspective view which shows the mesa-shaped metal lead which has. (B) It is a side view showing the state where it heat-presses to IC PAD by thermal TOOL. (C) It is the side view which showed the state which cut | disconnects a lead in the constricted part, leaving the mesa-shaped part in IC PAD. (D) is a side view showing the protruding electrodes left on the IC PAD. (E) is a side view showing a state in which the protruding electrode is pressed from above by a plate-like body having a flat surface in order to make the height of the protruding electrode uniform.

FIG. 2 (a) is a perspective view showing a state in which an Au ball formed at the tip of an Au wire is bonded on an IC PAD on an IC via a TOOL for forming a protruding electrode by heat, load and ultrasonic waves. (B) The IC is secured by fixing the Au wire and pulling it up.
It is the side view which showed the state in which the protruding electrode was formed on PAD. FIG. 3C is a side view showing a state in which protruding electrodes are formed on the IC.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 IC 2 IC PAD 3 TOOL for forming protruding electrode 4 Au wire 5 Au ball 6 Protruding electrode 7 Bonding stage 8 Film-shaped tape 9 Mesa-shaped metal lead 10 Mesa portion 11 Narrow portion 12 Thermocompression TOOL 13 Protruding electrode 14 Plate-shaped body

Claims (1)

[Claims] 1. A step of placing a film having a hole through which an IC PAD is exposed on an IC surface, contacting a mesa portion of a mesa-shaped metal lead with the IC PAD, and thermocompression-bonding the mesa portion to the IC PAD by a thermocompression unit. And the mesa part is IC
A step of pulling up the film to the upper part of the IC in a state where the film is fixed by pressure bonding to the PAD, and cutting the metal lead at a constricted portion formed at the base of the mesa portion of the metal lead;
A method for forming a protruding electrode on an IC PAD, comprising a step of pressing a mesa portion fixed thereon from above with a plate-like body to form a protruding electrode having a uniform height on the IC PAD.