JP2003133353A - Device for forming metal projection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for forming a metal projection which is more firmly bonded to the leg pad of a chip than usual, capable of increasing a tin ball in contact area, when it is welded, and which is smaller in size and has a long columnar part. SOLUTION: A through-hole 21 is provided at the center of a rigid conical hard pipe 20, the lower end of an inner wall 22 of the hard pipe 20 communicates with a bell-shaped part 23. The bell-shaped part 23 has a long columnar part, and a capillary tube 2 whose bottom is annular is provided. A metal wire 3 is inserted into the through-hole 21 of the capillary tube 2, and the end of a metal wire 3 is sintered into a metal ball. When the capillary tube 2 is made to approach the leg pad 11 of a chip 1, the area of the leg pad 11 in contact with the metal ball is heated from below. The metal ball fills the bell-shaped part 23 by ultrasonic energy, so that a metal projection is formed. The capillary tube 2 is moved, the metal wire 3 is removed from the neck of the bell-shaped part 23, and a metal projection is formed into a bell shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal projection manufacturing apparatus.

[0002]

2. Description of the Related Art Flip chip bonding technology is a worldwide chip (low input leg count-low I / O count IC chip type combination (flip
chip on board (FCOB) or high I / O count IC chip flip chip in packag
e, FCIP)) mainstream packaging technology. At present, there are various techniques for producing metal protrusions on a chip, and each technique has advantages. Common techniques are steam plating, sputtering plating, electroplating, printing, jet molding and bonding molding. As shown in FIG. 1A, the metal protrusion technique of bonding molding generally uses the capillary 2 ′ of the old wire bonding technique. An inner peripheral portion 21 ′ is provided at the center of the capillary tube 2 ′, and an inner wall portion 22 ′ of the inner peripheral portion 21 ′ has a narrow lower end and a wider upper end. Figure 1B
As shown in Fig. 3, the metal wire 3'is sintered into a spherical shape 31 'at the mouth of the capillary tube 2', and the metal wire 3'is connected to the foot pad 11 'of the chip 1'by ultrasonic vibration and pressure deformation. It As shown in FIG. 1C, when the capillary tube 2'is moved, a metal projection 32 'is formed, and the tin ball 4'is welded to the metal projection 32'.

However, the above-mentioned conventional metal protrusion 3 is used.
In 2 ', when the protrusion is formed, the peripheral surface of the contact surface between the bottom surface of the protrusion and the leg pad 11' becomes a large spherical concave arc due to the limitation of the capillary tube 2 ', and the contact surface is reduced. It is stable. When the capillary tube 2 ′ is pressed downward, the metal projection 32 ′ is pushed outward, so that the area of the metal projection 32 ′ exceeds the area of the mouth portion of the capillary tube 2 ′. Therefore, it is difficult to adjust the area of the metal protrusion 32 '. Further, since the lower half of the metal protrusion 32 'has a protruding structure, the contact area is insufficient when the tin ball 4'is welded, as shown in FIG. 1D. Also, the metal protrusion 32 '
Due to the short length of the pillar, the tin ball 4'is
When welded to 2 ', the welding interval between the tip and the lead frame, tip, metal projection or welding foot laid on the substrate is insufficient,
The pass rate decreases.

[0004]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve the degree of bonding of the tip to the foot pad and to increase the contact area when the tin balls are welded, and to make the size smaller and the column longer. An object of the present invention is to provide an apparatus for manufacturing a metal protrusion.

[0005]

According to the apparatus for manufacturing a metal projection according to the present invention, an inner peripheral portion is provided at the center of a rigid conical hard tube, and the inner wall portion of the hard tube is underside. Is connected to the bell. The bell-shaped part has a high pillar shape, and a capillary tube of an inner ring is provided on the bottom surface. A metal wire is inserted inside the inner peripheral portion of the capillary tube, and the end portion of the metal wire is sintered into a spherical shape to form a metal sphere. As the capillaries approach the foot pad of the tip, the foot pad is continuously heated from below on the contact surface with the metal ball. Ultrasonic energy fills the metal spheres into the bells, forming metal protrusions. The metal projections are welded to the foot pad. The capillaries are moved, the metal wire is removed from the neck of the bell, and the metal projection is formed into a bell. The metal protrusion is formed with a convex edge bottom portion protruding by the action of the inner ring at the bottom of the bell-shaped portion.

Since the metal projection formed by the bell-shaped shape of the inner wall portion of the capillary is restricted by the bell-shaped opening, it is formed smaller. Since the convex edge is provided on the outer periphery of the bottom surface of the metal protrusion, the degree of coupling between the metal protrusion and the chip leg pad can be increased. When the metal projections formed on the foot pad of the chip are bell-shaped, the metal projection has a higher columnar shape, which improves the bondability with other substrates or chips when tin balls are welded. The metal projection has a larger contact area when it is welded to the tin ball, and is more reliably welded.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 2, according to the apparatus for manufacturing a metal protrusion according to an embodiment of the present invention, an inner peripheral portion 21 is provided at the center of a rigid conical hard tube 20, and an inner peripheral portion 21 is provided.
The lower side is connected to the inner wall portion 22 of the bell portion 23. The bell-shaped portion 23 is formed so that the pillar body 232 is formed high, and the inner ring 23 is formed on the bottom surface.
One capillary tube 2 is provided.

The metal wire 3 is inserted into the inner peripheral portion 21 of the capillary tube 2, and the end portion of the metal wire 3 arranged in the bell-shaped portion 23 of the inner wall portion 22 of the hard tube 20 is sintered into a spherical shape 31. . When the capillary tube 2 approaches the foot pad 11 of the chip 1, the foot pad 11 is continuously heated from the lower side in contact with the metal wire 3. Metal spheres are filled into the bell-shaped portion 23 by ultrasonic energy, and the metal protrusions 32 are welded to the foot pad 11. The capillary tube 2 is moved, the metal wire is removed from the neck portion of the bell-shaped portion 23, and the bell-shaped metal projection 32 is formed. The metal projection 32 is formed with a convex bottom portion 321 protruding by the action of the inner ring 231 of the bottom portion of the bell-shaped portion 23.

The area occupied by the bell-shaped metal projections 32 formed by the bell-shaped portion 23 and the inner ring 231 of the inner wall surface 22 of the capillary tube 2 is smaller than the area of the bell-shaped bottom portion of the capillary tube 2, and a metal projection having a smaller area is used. Can be formed. Since the pillar 232 of the metal protrusion 32 is high, the metal protrusion 32 and the chip 1
The welding force with the foot pad 11 is increased, and the contact area 33 between the metal protrusion 32 and the tin ball 4 is increased, resulting in a larger welding force.

[Brief description of drawings]

FIG. 1 is a schematic view showing a conventional apparatus for manufacturing metal protrusions.

FIG. 2 is a cross-sectional view showing a capillary tube of a metal projection manufacturing apparatus according to an embodiment of the present invention.

FIG. 3 is a schematic view showing a metal projection manufacturing apparatus according to an embodiment of the present invention.

[Explanation of symbols]

2 capillaries 20 hard tube 21 Inner circumference 22 Inner wall 23 Bell 32 metal protrusion 231 Inner ring 232 Pillar 321 convex edge bottom

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Chen Hui             No.58 Marine Second Road, Fengshan City, Kaohsiung, Taiwan (72) Inventor ▲ Sho ▼ Chinese literature             No. 57, 3 No. 57, Chang Fu Street, Sanmin District, Kaohsiung, Taiwan (72) Inventor Zhang             Hotei Shinryuu Nori 109, Chibu, Taiwan (72) Inventor ▲ Yu ▼ Fengchang             367-9, Zhongzheng Road, Torimatsu Township, Kaohsiung, Taiwan (72) Inventor Huang Fuyu             No.29, Bohai Street, 22, Gwangolli, Emerging District, Kaohsiung, Taiwan (72) Inventor Zhang Jiang             No.35, No.35, No. 55, Zhongshan 2nd Road, Qianzhen District, Kaohsiung City, Taiwan (72) Inventor Hu Jia Jie             546, No.11, No.12, 546, Gochang-ro, Kusunagi-ku, Kaohsiung, Taiwan             5 (72) Fumitaka Lu             No.25 Zhongxingli Guangfu Road, Magong City, Penghu County, Taiwan

Claims (2)

[Claims] 1. An inner peripheral portion is provided at a central portion of a rigid conical hard tube, and a lower side of an inner wall portion of the hard tube is connected to a bell-shaped portion.
The bell-shaped part has a high pillar shape, and a capillary tube of an inner ring is provided on the bottom surface of the bell-shaped part. 2. A metal wire is inserted into the inner peripheral portion of the capillary tube, and the end portion of the metal wire arranged in the bell-shaped portion of the hard tube is sintered into a spherical shape to form a metal ball. When the capillary approaches the foot pad of the chip, the contact surface with the metal ball is continuously heated from the lower side of the foot pad,
The metal spheres are filled into the bell-shaped portion by ultrasonic energy to form metal projections, the metal projections are welded to the foot pad, the capillaries move, and the metal wire from the neck of the bell-shaped portion is moved. An apparatus for manufacturing a metal projection, wherein the metal projection is formed into a bell shape by being cut off, and a convex edge bottom portion protruding by the action of the inner ring at the bottom of the bell shape portion is formed.