Semiconductor device manufacturing: process – Coating with electrically or thermally conductive material – To form ohmic contact to semiconductive material
Reexamination Certificate
2000-06-29
2004-03-23
Niebling, John F. (Department: 2812)
Semiconductor device manufacturing: process
Coating with electrically or thermally conductive material
To form ohmic contact to semiconductive material
C438S616000, C438S118000, C438S119000, C438S458000, C438S464000
Reexamination Certificate
active
06709966
ABSTRACT:
BACKGROUND OF THE INVENTION
As the age of the multi-media progresses, research on the narrow-pitch multi-pin package of integrated circuits (ICs) or high-density package bare chips is becoming increasingly active. Under such circumstances, the demand for the high-density printed circuit boards with more levels, such as the high-density multi-layer printed circuit boards with line widths of 50 &mgr;m and the land diameter of (via) of 300 &mgr;m is becoming commonplace.
The fining method has been proposed in a variety of forms, but the B2 IT (Buried Bump Interconnection Technology) is known as a high-density multi-layer printed circuit board having an environment-friendly characteristic and a good cost performance.
In this method, a circuit substrate, comprising a glass-epoxy substrate and a bump provided thereon through a first circuit layer of copper foil, is provided first; then, an interlayer insulating film is laid on the first circuit layer, and a second circuit layer, including a copper foil is laid on the interlayer insulating film; then, the first circuit layer is connected to the second circuit layer by means of thermal pressure welding method. In this case, the bump protrudes through the interlayer insulating film to be connected to the second circuit layer. The bump is formed by the screen printing method.
Incidentally, the wire bonding method is one of the conventional packaging methods of semiconductors. Recently, however, the packaging method by using the bump is becoming popular because of its being suited for high-density packaging.
Similar to the above packaging method, there are the packaging methods by using TAB, flip chip, etc. As such, how to form the bump is the key technology for these methods.
As bump forming methods, the evaporation method, galvanizing method, and screen printing method have been proposed. However, these forming methods have the problems described below. That is, the forming method by using the evaporation method takes too much time to form the bump, which results in a high manufacturing cost. The forming method by using the galvanizing method has a drawback, in that it requires a complex process comprising the processes for resist application, photolithography, and etching in order to provide the openings corresponding to the size and the pitch of the electrodes and forming the bump by the galvanizing method or electroless plating method.
In contrast, the forming method by using the screen printing method is simpler and more economical in terms of the forming process, since the bump can be formed where a mask having an opening corresponding to the bump is laid on the substrate; a paste is applied on the mask; the mask is printed on the substrate by using a squeegee; then the paste is baked to remove the solvent and resin components from the paste, thereby forming the bump.
However, the forming method by using the screen printing method has a problem as described below.
The height of the bump is dependent on the film thickness. The film thickness of the mask cannot be determined freely in relation with the dimensions of the bump due to the limitation arising from the embedding ability and passability of the paste with respect to the opening of the mask. This gives rise to a problem in that the smaller the size of the bump, the lower the height of the bump. Such a problem can be overcome by repeating the screen printing process several times, but this leads to the increase in the complexity of process and forming cost.
FIG. 26
shows the conventional method of position matching between the substrate and the chip.
In this position matching method, first the position of the pad
302
of the substrate
301
relative to any given point (origin) is determined by a camera
303
. Similarly, the positions of the chip
304
the bump
305
relative to another origin are determined by a camera
306
.
Next, based on these relative positions and the above 2 origins, the substrate
301
, chip
304
or the substrate
301
and chip
304
are shifted to match the position of the pad
302
and the position of the bump
305
. Then, the chip
303
is pressed against the substrate
301
to effect the bonding between the substrate
301
and the chip
303
.
However, this conventional position matching method has a problem as described below. That is, even if the relative positions of the substrate
301
and the chip
304
are determined accurately, mismatching can occur unless the chip
304
is shifted accurately, since the substrate
301
and the chip
304
are primarily separated from each other. This will become a serious problem in the case of a highly integrated chip.
FIG. 27
shows the position matching method between another conventional substrate and a chip.
In this position matching method, first the position of the pad
302
and the substrate
301
relative to any given point (origin) that is determined by the camera
306
. Similarly, the position of the bump
305
of the chip
304
relative to the same origin is determined by the same camera
306
.
Then, based on the determined positions of the pad
302
and the bump
305
, for example, the position of the bump
305
relative to the pad
302
is determined.
Next, the position of the pad
302
is matched with the position of the bump
305
by shifting the chip
304
by the distance corresponding to the above relative positions.
Subsequently, the chip
304
is lowered and pressed against the substrate
301
, thereby effecting the bonding between the substrate
301
and the chip
304
.
However, this position matching method has a problem given below. In this position matching method, in determining the positions of the pad
302
and the bump
305
, since it is necessary to place the camera
306
between the substrate
301
and the chip
304
, the distance between the substrate
301
and the chip
304
increases. Therefore, even if the positions of the pad
302
and the bump
305
are known accurately, mismatching occurs unless the chip
304
is lowered accurately at the time of bonding.
FIG. 28
shows the conventional transfer method of the substrate or the chip.
In this transfer method, a transfer system
311
having a vacuum suction system is used. The substrate or the chip
312
is carried while being held by the transfer system
311
by means of the vacuum suction.
However, this conventional transfer method has a problem given below. That is, the large suction force acting selectively and partially acting on the substrate or the chip
312
causes the deformation or break of the substrate or the chip
312
.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a semiconductor device having a construction permitting easy formation of a necessary bump having a necessary shape, a pattern forming method permitting the formation of a pattern such as the pattern of the bump and the like and a pattern forming device.
Another object of the present invention is to provide a manufacturing method of a semiconductor device capable of preventing the positional mismatching between two members to be matched with each other at the time of the matching or the positional mismatching of the two members to be matched at the time of the connection thereof after the previous matching and a matching mark to be used therefore.
Another object of the present invention is to provide a semiconductor manufacturing method including a process for enabling a substrate or a chip to be transferred free of damage to such substrate or chip.
The semiconductor device according to the present invention is characterized by being provided with a bump including a magnetic substance. Further, in order to form the bump having such a property, the manufacturing method of the semiconductor device according to the present invention is characterized by comprising at least a process for selectively laying a conductive paste onto the substrate and a process for forming a bump including the conductive paste by letting it rise by an external field including the magnetic field of the conductive paste.
In the case of the bump
Hayasaka Nobuo
Hisatsune Yoshimi
Ikegami Hiroshi
Matsuo Mie
Okumura Katsuya
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Gurley Lynne A.
Kabushiki Kaisha Toshiba
Niebling John F.
LandOfFree
Semiconductor device, its manufacturing process, position... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Semiconductor device, its manufacturing process, position..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Semiconductor device, its manufacturing process, position... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3233809