Metal fusion bonding – Process – Using high frequency vibratory energy
Reexamination Certificate
2001-11-19
2002-12-31
Dunn, Tom (Department: 1725)
Metal fusion bonding
Process
Using high frequency vibratory energy
C228S001100, C228S004500, C228S180500
Reexamination Certificate
active
06499648
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is related to a method and device for making a metal bump with an increased height and in particular to one which can increase the connection reliability between the metal bump and the chip and enlarging the contact area between the metal bump and the metal or solder ball.
2. Description of the Prior Art
Various kinds of methods of making metal bumps on a chip have been developed for flip chip on board (FCOB) technology with a small number of input pins or a small number of Input/Output pins or for flip chip in package (FCIP) with a large number of Input/Output pins, such as evaporation plating, splash plating, electroplating, printing, spraying, and bonding. However, the capillary tube
2
′ is still the most commonly used tool for making metal stud bumps by means of wire bonding (see FIG.
1
A). As shown, the capillary tube
2
′ has an inner diameter
21
′ with an inner wall
22
′ and has a larger diameter at the upper end than the lower end. A metal wire
3
′ is inserted into the capillary tube
2
′ and the lower end of the metal wire
3
′ is melted to form a ball shaped member
31
′ by electric spark. Then, ultrasonic vibration and pressure deformation processing are applied to the capillary tube
2
′ to join the inter-metallic compounds between wire
3
′ and the chip
1
′ (see FIG.
1
B). When the capillary tube
2
′ is removed, a metal bump
32
′ will be formed on the raised platform
11
′ of the chip
1
′ (see FIG.
1
C). Thereafter; a metal or solder ball
4
′ is soldered on the metal bump
32
′.
However, due to the limitation of the design of the capillary tube
2
′, the metal bump
32
′ will have a spherical surface which is insufficient to provide a large contact area and a reliable structure for joining other component parts. Furthermore, the bottom of the metal bump
32
′ will tend to go beyond the lower opening of the capillary tube
2
′ under pressure thereby making it difficult to control. Moreover; as the metal bump
32
′ has a spherical surface, there will not be sufficient area in contact with a metal or solder ball
4
′ (see FIG.
1
D). In addition, the metal bump
32
′ is so short that the metal or solder ball
4
′ must be soldered to the metal bump
32
′ at a very low position thereby making it difficult to make the connection between the die and the fingers of a substrate (or lead frame, chips, metal bumps or the like) and therefore influencing the qualification rate of products.
Therefore, it is an object of the present invention to provide a method and device for making a metal bump with an increased height which can obviate and mitigate the above-mentioned drawbacks.
SUMMARY OF THE INVENTION
This invention is related to a method and device for making a metal bump with an increased height.
It is the primary object of the present invention to provide a method and device for making metal bumps with an increased height which can increase the joining strength with other metal bumps or pads of a die.
It is another object of the present invention to provide a method and device for making metal bumps with an increased height which can enlarge the contact area with the metal or solder ball.
It is still another object of the present invention to provide a method and device for making metal bumps with an increased height which can increase its reliability in joining with other component parts.
It is a further object of the present invention to provide a method and device for making metal bumps which have an increased height but are small in diameter.
The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.
Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.
REFERENCES:
patent: 4415115 (1983-11-01), James
patent: 4886200 (1989-12-01), Tsumura
patent: 4974767 (1990-12-01), Alfaro et al.
patent: 5871141 (1999-02-01), Hadar et al.
patent: 5938105 (1999-08-01), Singh
patent: 6065667 (2000-05-01), Singh
patent: 6158647 (2000-12-01), Chapman et al.
patent: 6213378 (2001-04-01), Singh
patent: 6260753 (2001-07-01), Renard et al.
patent: 355088345 (1980-07-01), None
patent: 03027544 (1991-12-01), None
Chang Chung-Ming
Chang Hsuan-Jui
Chen Hui-Pin
Chiang Hua-Wen
Hu Chia-Chieh
Dunn Tom
Lei Leong C.
Orient Semiconductor Electronics Limited
Stoner Kiley
LandOfFree
Method and device for making a metal bump with an increased... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and device for making a metal bump with an increased..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and device for making a metal bump with an increased... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2980278