High-frequency integrated circuit module

Details High-frequency integrated circuit module High-frequency integrated circuit module

2002-10-22

2004-10-19

Thai, Luan (Department: 2827)

Electricity: electrical systems and devices

Housing or mounting assemblies with diverse electrical...

For electronic systems and devices

C361S784000, C257S728000

Reexamination Certificate

active

06807063

ABSTRACT:

BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a high-frequency integrated circuit module for mounting an integrated circuit (IC) which operates with high-frequency waves in a high frequency band such as a microwave band and a milliwave band.
(2) Description of the Related Art
Because of the multifunction of an IC chip which operates in a microwave band or milliwave band, one IC chip requires three or more radio frequency (RF) signal terminals. Within an IC chip, the width of RF signal terminals is narrow and therefore isolation between the RF signal terminals is assured.
In general, the thickness of a circuit board is selected so that the width of lines in a package for mounting an IC chip becomes greater than that of terminals in the IC chip in consideration of signal line connections which are made for secondary mounting. At the same time, transmission and reflection characteristics are assured.
FIG. 19
shows a plan view of a prior art high-frequency IC module.
The high-frequency IC module
100
shown in
FIG. 19
includes, for example, an IC chip
100
; a metal plate (metal board)
101
; a first ceramic plate (ceramic board)
102
a
molded integrally with the metal plate
101
and constituting a feed line portion for a RF signal on one side of the metal plate
101
; and a second ceramic plate
102
b
molded integrally with the metal plate
101
and constituting a feed line portion for RF signals on the other side of the metal plate
101
.
The first ceramic plate
102
a
is provided with a microstrip transmission line
103
, which is connected with the RF signal terminal
111
of an IC chip
110
through a bonding wire. The second ceramic plate
102
b
is provided with three microstrip transmission lines
104
,
105
, and
106
, which are connected with the RF signal terminals
112
,
113
, and
114
of the IC chip
110
through bonding wires. Note in
FIG. 19
that reference numeral
107
denotes a position at which a cap for hermetically sealing the IC chip
110
is mounted.
The above-described IC chip
110
with a plurality of RF signal terminals
112
,
113
, and
114
on one side has, for example, the function of selecting one system from RF signals received from a plurality of systems. Such an IC chip can be applied to a high-frequency receiving circuit which employs an adaptive array antenna.
However, if the IC chip
110
is mounted on the above-described package having a plurality of microstrip transmission lines
104
,
105
, and
106
on one side thereof, isolation between the RF signal terminals will be degraded compared with the characteristics of the IC chip
110
, because the width of the microstrip transmission lines
104
,
105
, and
106
on the package side is greater than that of the RF signal terminals of the IC chip
110
.
That is, coupling occurs over the length of each of the microstrip transmission lines
104
,
105
, and
106
, and resonance occurs at a frequency resulting from the line length. Because of this, the transmission characteristics degrade sharply.
FIG. 20
shows a layout in the case where an electro-magnetic simulation of microstrip transmission lines close to each other is made. The transmission characteristics obtained by the simulation are shown in
FIGS. 21A and 21B
. In the simulation, a ceramic board was employed and microstrip transmission lines of 0.2 mm in thickness were assumed to be arranged at the interval of 1 mm.
FIG. 21A
shows a reflection characteristic in the case where a RF signal (for example, 30 GHz or greater) is input to an input port “1” shown in FIG.
20
.
FIG. 21B
shows a through characteristic in the case where the RF signal is input to the input port
1
.
In this case, the interval between the microstrip transmission lines is narrow and therefore coupling takes place over the length of the line. As shown at reference numerals
121
to
128
in
FIGS. 21A and 21B
, resonance takes place at specific frequencies resulting from line length and there is a sharp degradation of transmission characteristics (reflection and through characteristics) (i.e., isolation degradation).
On the other hand, if the interval between the microstrip lines is increased to 1.5 mm and 3.0 mm, as shown in
FIGS. 22A
,
22
B,
23
A, and
23
B, resonance resulting from line length is less likely to occur and that there is no isolation degradation. Note that the transmission characteristics in the case of interval=1.5 mm are shown in
FIGS. 22A and 22B
. The transmission characteristics in the case of interval=3.0 mm are shown in
FIGS. 23A and 23B
.
Thus, it is necessary that microstrip transmission lines for secondary mounting be spaced to some degree. However, since the spaces between the RF signal terminals
112
,
113
, and
114
of the IC chip
110
are narrow, the line space in a portion of the IC chip
110
becomes narrow. Because of this, the case of a RF signal of about a few GHz is considered practically negligible. However, in the case of a RF signal having an extremely high frequency of 30 GHz or greater, isolation degradation at the line-space narrowed portion is not negligible.
Particularly, in the case of a high frequency of 30 GHz or greater, the wavelength becomes about a few millimeters and performance depends on the size of a component such as an IC chip and a package. Therefore, when obtaining a high gain by a high-frequency flip-chip structure, there are cases where the operation of a circuit becomes unstable by the leakage of unnecessary high-frequency components.
SUMMARY OF THE INVENTION
The present invention has been made in view of the circumstances mentioned above. Accordingly, it is the primary object of the present invention to provide a high-frequency IC module which is capable of minimizing the leakage of unnecessary high-frequency components and assuring the required isolation between a plurality of high-frequency signal terminals disposed on one side portion of an IC chip, even when mounting an IC which processes high-frequency signals in an extremely high frequency band such as a microwave band and a milliwave band.
To achieve this end and in accordance with the present invention, there is provided a high-frequency integrated circuit (IC) module comprising:
(1) a multilayer mounting board on which an IC with a plurality of high-frequency signal terminals on one side portion thereof is mounted;
(2) a plurality of IC connecting portions disposed on one surface of the multilayer mounting board on which the IC is mounted, the IC connecting portions being respectively connected with the plurality of high-frequency signal terminals of the IC;
(3) a plurality of external connection terminal portions disposed on a side portion of the other surface of the multilayer mounting board which portion corresponds to the one side portion of the IC, at wider intervals than those between the high-frequency signal terminals of the IC;
(4) a plurality of high-frequency signal lines provided within the multilayer mounting board to transmit high-frequency signals;
(5) a plurality of first through holes for respectively connecting the inner ends of the high-frequency signal lines with the IC connecting portions;
(6) a plurality of second through holes for respectively connecting the outer ends of the high-frequency signal lines with the external connection terminal portions; and
(7) a high-frequency restricting member for ground-connecting both surfaces of the multilayer mounting board and restricting propagation of high-frequency signals, provided at least between the high-frequency signal lines and along the high-frequency signal lines.
In the high-frequency IC module of the present invention constructed as described above, between a plurality of high-frequency signal terminals provided on one surface of the multilayer mounting board and a plurality of external connection terminal portions provided on the other surface of the multilayer mounting board, high-frequency signals are transmitted within the multilayer mounting board through the above-described through hole

Affiliated with

Also associated with

Rating

High-frequency integrated circuit 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 integrated circuit module, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High-frequency integrated circuit module will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3312663