Semiconductor device manufacturing: process – Semiconductor substrate dicing – With attachment to temporary support or carrier
Reexamination Certificate
2003-01-13
2004-02-10
Le, Dung A. (Department: 2818)
Semiconductor device manufacturing: process
Semiconductor substrate dicing
With attachment to temporary support or carrier
C438S460000, C257S659000, C257S660000, C331S037000, C331S067000
Reexamination Certificate
active
06689670
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a high-frequency module having a conductive cap for electromagnetically shielding a substrate and electrical components from each other, and to a manufacturing method of such a high-frequency module.
BACKGROUND OF THE INVENTION
One example of conventional high-frequency modules can be found in Japanese Unexamined Patent Publication No. 8668/1999 (Tokukaihei 11-8668) (Publication date: Jan. 12, 1999). The high-frequency module (portable phone) disclosed in this publication is manufactured by a manufacturing process as shown in FIG.
18
(
a
) through FIG.
18
(
e
), and the product module is as shown in FIG.
18
(
g
).
As shown in FIG.
18
(
a
), a series substrate
917
is divided into a plurality of substrate areas. Also, as shown in FIG.
18
(
b
), electrical components
918
make up a high-frequency circuit section. Further, a substrate
919
which is divided as shown in FIG.
18
(
d
) is electromagnetically shielded, together with the electrical components
918
, by a conductive cap
920
, as shown in FIG.
18
(
e
).
More specifically, as shown in FIG.
18
(
a
), a solder paste is applied to a predetermined position in each area of the series substrate
917
. Then, as shown in FIG.
18
(
b
), the electrical components
918
are placed on the solder paste thus applied. The solder paste is then melted in a reflow vessel. As a result, the electrical components
918
are electrically connected to one another via a pattern (not shown) which is formed in each area, thus forming the high-frequency circuit section in each area. Thereafter, as shown in FIG.
18
(
d
), the series substrate
917
is divided into individual substrates
919
by dicing. Then, as shown in FIG.
18
(
e
), a conductive cap
920
having projections
2011
which correspond to depressions
1911
is mounted on the substrate
919
. The projections
2011
are electrically connected by soldering to a metal film which is formed on the depressions
1911
and to be ground electrodes. The product as shown in FIG.
18
(
g
) is obtained after laser trimming which is performed to adjust frequency, followed by an electrical characteristics inspection.
However, the high-frequency module of the foregoing prior art had the following problems.
That is, as shown in
FIG. 19
, in steps S
11
through S
13
, the substrates
919
are provided in the form of the series substrate
917
which is yet to be divided into individual pieces, and the electrical components
918
are soldered to the substrates
919
in this state.
Meanwhile, in steps S
15
through S
18
, the substrates
919
are provided by being divided into individual pieces. That is, S
15
for mounting the cap
920
on the substrate
919
, S
16
for soldering the cap
920
to the substrate
919
, and S
17
for performing trimming are all carried out with respect to the divided individual substrate
919
.
That is, the process of mounting and soldering the cap
920
, and the process of trimming are repeated for each piece of the substrate
919
. Accordingly, the process of mounting and soldering the cap
920
, and the process of trimming need to be repeated many times. Further, automation of manufacturing steps for the divided substrates
919
requires a vast investment. It was therefore difficult to reduce the cost of the high-frequency modules.
Further, in order to meet the demand for smaller modules, the high-frequency modules are usually designed such that the electrical components
918
are provided in close proximity. Accordingly, the cap
920
and the electrical components
918
are often designed in close proximity as well.
Meanwhile, a high-temperature solder (e.g., a melting point of 220° C. or above) has been used conventionally for the soldering in the high-frequency module. The user, on the other hand, used an eutectic solder having a melting point of 183° C., should the user having purchased the high-frequency module carried out the reflow process by himself/herself. That is to say, despite the reflow process by the user, the solder in the high-frequency module did not melt again (though it becomes slightly soft). Thus, no movement of the electrical components
918
or the cap
920
was incurred in the reflow process.
However, to be more environment friendly and for other reasons, it has become common in recent years among users to use a Pb-free solder to carry out the reflow process. Pb-free solders generally have a high melting point, and when the Pb-free solder used has a melting point of, for example, 220° C., it becomes essentially the same as the melting point of the high-temperature solder used in the soldering in the high-frequency module. Thus, if the user of the high-frequency module carries out the reflow using the Pb-free solder, the solder connecting the electrical components
918
and the cap
920
melts again, and the movement of the electrical components
918
and the cap
920
is incurred. This causes “solder touch” between the electrical components
918
and/or between the electrical components
918
and the cap
920
. Therefore, there is demand in recent years for stabilizing the product quality of the high-frequency module by solving this problem.
SUMMARY OF THE INVENTION
The present invention was made in view of the foregoing problem, and it is an object of the present invention to provide high-frequency modules which can reduce the number of application points of an insulating adhesive and can suppress contact between components due to self-alignment which occurs in a reflow process, by applying the insulating adhesive between electrical components on a substrate.
In order to achieve this object, in a high-frequency module according to the present invention, a conductive cap provided for an electromagnetic shielding purpose is placed on a substrate on which a plurality of electrical components are mounted by soldering, and an insulating adhesive is applied between the plurality of electrical components.
With this arrangement, since the insulating adhesive is applied between the electrical components on the substrate, the insulating adhesive prevents such deficiencies as the “solder touch” between components due to self-alignment which is caused when the solder melts at the soldered portion in the reflow process. Thus, a highly reliable high-frequency module can be provided even when a Pb-free solder is used, and the number of application points of the insulating adhesive can be reduced.
For a fuller understanding of the nature and advantages of the invention, reference should be made to the ensuing detailed description taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 5172077 (1992-12-01), Funada
patent: 5661441 (1997-08-01), Morino et al.
patent: 5898344 (1999-04-01), Hayashi
patent: 6016090 (2000-01-01), Lio et al.
patent: 6232660 (2001-05-01), Kakimoto et al.
patent: 2616280 (1997-03-01), None
patent: 118668 (1999-01-01), None
patent: 2938820 (1999-06-01), None
Birch & Stewart Kolasch & Birch, LLP
Le Dung A.
Sharp Kabushiki Kaisha
LandOfFree
High-frequency module does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High-frequency module, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High-frequency module will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3303304