Plastic and nonmetallic article shaping or treating: processes – Direct application of fluid pressure differential to... – Producing multilayer work or article
Reexamination Certificate
2000-06-08
2002-08-20
Ortiz, Angela (Department: 1732)
Plastic and nonmetallic article shaping or treating: processes
Direct application of fluid pressure differential to...
Producing multilayer work or article
C264S102000, C264S272150, C264S272170
Reexamination Certificate
active
06436331
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a resin sealing method and apparatus of effecting resin sealing after the pad of a semiconductor chip mounted on a substrate is joined to the electrode of the substrate through a bump. Particularly, the present invention relates to a resin sealing method and apparatus filling the gap between a semiconductor chip and a substrate with resin.
2. Description of the Background Art
In a semiconductor device having the pad of the semiconductor chip and the electrode of the substrate electrically connected via a bump, resin is inserted or filled into the gap between the semiconductor chip and the substrate and is then cured. This resin sealing is carried out in order to prevent generation of cracks at the junction due to thermal stress, and intrusion of a substance that adversely affects the semiconductor chip such as intrusion of impurities and moisture.
Conventionally, the method shown in
FIGS. 5A-5D
is employed in order to insert and cure resin in the gap between a semiconductor chip and a substrate.
FIGS. 5A-5D
are plan views of a semiconductor device corresponding to respective steps of a conventional resin sealing method.
Referring to
FIG. 5A
, liquid resin
102
is applied around a semiconductor chip
101
mounted on a substrate
100
so as to substantially surround the circumference thereof. A portion of the circumference of semiconductor chip
101
that is to serve as an outlet
103
is left absent of liquid resin
102
.
Referring to
FIG. 5B
, the atmosphere around substrate
100
is reduced in pressure. Accordingly, the air present between substrate
100
and semiconductor chip
101
is output from outlet
103
as exhaust
104
.
Referring to
FIG. 5C
, the viscosity of the applied liquid resin
102
is reduced by applying heat under the state where the atmosphere around substrate
100
is reduced in pressure. As a result, liquid resin
102
reduced in viscosity flows into the gap between substrate
100
and semiconductor chip
100
by the capillary action to be connected at the portion absent of the resin to become annular. Thus, the gap between substrate
100
and semiconductor chip
101
is filled with liquid resin
102
leaving a closed cavity
105
that is reduced in pressure.
Referring to
FIG. 5D
, the atmosphere around substrate.
100
is pressurized up to the atmospheric pressure. Under atmospheric pressure, closed cavity
105
in the gap between substrate
100
and semiconductor chip
101
is compressed by the pressure difference from the surrounding space to be eliminated. In other words, the entire region of the gap between substrate
100
and semiconductor chip
100
is filled with liquid resin
102
. Then, heating is applied to cure liquid resin
102
. By the foregoing steps, cured seal resin is formed at the gap between substrate
100
and semiconductor chip
100
, and also at the circumference of semiconductor chip
101
.
The conventional resin sealing method poses the following problems shown in
FIGS. 6A-6D
.
FIGS. 6A-6D
are plan views of a semiconductor device corresponding to respective steps of a conventional resin sealing method representing the problems. Referring to
FIG. 6A
, liquid resin
102
is applied on substrate
100
, likewise FIG.
5
A. In reducing the pressure of the atmosphere around substrate
100
, there is the case where abnormal exhaust
106
penetrates through liquid resin
102
to be output from a region other than outlet
103
due to uneven application of liquid resin
102
, as shown in FIG.
6
B. Also, in pressurizing the atmosphere around substrate
100
, there is the case where liquid resin
102
compressed towards closed cavity
105
by the pressure difference from the surrounding space is partially concentrated at the corner of semiconductor chip
101
to rise over the top surface of semiconductor chip
101
. There is also the case where abnormal exhaust
106
is output from substantially the entire circumference of semiconductor chip
101
when the area of the cross section of outlet
103
is not large enough.
In the foregoing cases, a portion of liquid resin
102
will be blown off by the abnormal exhaust
106
to adhere on the top surface of semiconductor chip
101
as shown in FIG.
6
C. The adhered liquid resin
102
will remain on the top surface of semiconductor substrate
101
as resin covering
107
. This resin covering
107
is cured by the heating process as shown in
FIG. 6D
to cause appearance defect in the completed semiconductor device to degrade the yield.
SUMMARY OF THE INVENTION
In view of the foregoing, an object of the present invention is to provide a resin sealing method and apparatus to improve the yield by preventing generation of a resin covering in filling the gap between a substrate and a semiconductor chip with resin.
According to an aspect of the present invention, a resin sealing method achieving the above object has resin inserted and cured in the gap formed between a substrate and a semiconductor chip mounted on the substrate. The resin sealing method includes the steps of applying resin of a predetermined amount, which is set corresponding to the circumferential configuration of the semiconductor chip, at or along the circumference of the semiconductor chip under a state retaining a predetermined void or space between the resin and a side face of the semiconductor chip, reducing the pressure of the atmosphere around the substrate to exhaust air from the gap, reducing the viscosity of the applied resin to partially fill the gap with resin and thereby leaving a closed cavity reduced in pressure, and pressurizing the atmosphere around the substrate to compress the closed cavity from the surrounding atmosphere due to the pressure difference therebetween to entirely fill the gap with resin.
According to this resin sealing method, resin of a predetermined amount is applied at or along the circumference of the semiconductor chip in such a manner so as to retain a void or space between the resin and the side face of the semiconductor chip. Accordingly, a region absent of resin is formed surrounding the semiconductor chip at the substrate plane. By reducing the pressure of the atmosphere around the substrate, the air present between the substrate and the semiconductor chip is exhausted through the region where resin is not applied, i.e. through the gap or space formed between the resin applied at the circumferential position of the semiconductor chip and the side face of the semiconductor chip. Since this resin-free space forms a region where air can be exhausted having a large area of cross, section at the circumference of the semiconductor chip, exhaust can be effected stably.
At the corner of the semiconductor chip, the amount of resin to be applied is reduced or a region absent of applying resin is provided. As a result, exhaust can be effected in stability at the corner region where exhaust is concentrated so that the exhaust pressure is increased. Thus, there is the advantage superior in practical usage of providing a resin sealing method and apparatus that can prevent generation of a resin covering caused by abnormal exhaust and resin concentration.
In the above resin sealing method, the step of applying resin preferably has the amount of resin applied at the circumferential position of the site where the circumferential configuration of the semiconductor chip corresponds to a corner set lower than the amount of resin applied at the circumferential position of other sites of the semiconductor chip.
In a preferable embodiment of the resin sealing method of the present invention, the step of applying resin includes the step of applying resin of a predetermined amount at the circumferential position of the semiconductor chip excluding the site where the circumferential configuration of the semiconductor chip corresponds to a corner.
According to another aspect of the present invention, a resin sealing method of inserting and curing resin in a gap formed between a substrate and a semiconductor chip mounted o
Kuno Takaki
Odashima Teikou
Okamoto Hirotaka
Yamamoto Shoji
Fasse W. F.
Fasse W. G.
Ortiz Angela
Towa Corporation
LandOfFree
Method of resin sealing a gap between a semiconductor chip... 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 of resin sealing a gap between a semiconductor chip..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of resin sealing a gap between a semiconductor chip... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2973300