Microwave circuit package

Abstract: A microwave circuit package (10) includes a metallic base plate (3) on which are mounted a plurality of monolithic microwave integrated circuits (MMICs) (11,12,13) and a spacer (15), made of a dielectric material, separating the MMICs (11,12,13) from each other, and the MMICs (11,12,13) and spacer (15) are sealed in the package (10). The provision of the spacer (15) substantially reduces the volume of the interior space of the package (10). A dielectric substrate (14) having generally the same height as substrates of the MMICs (11,12) may also be mounted on the metallic base plate (3), and a strip conductor (14d) may be provided on the dielectric substrate (14) so as to form a microstrip line thereon.

Description: The present invention relates to an improved microwave circuit package which seals therein microwave circuitry having monolithic microwave integrated circuits (hereinafter referred to as MMICs) and which is suitable for fabrication of an integrated circuit device. Generally, in microwave circuitry using an MMIC element such as GaAs FETs (field-effect transistors), the MMIC element is connected to a driver circuit, as disclosed in JP-A-4-129402, for example. The MMIC element, in the form of a semiconductor chip, must be kept in a hermetically sealed condition and, in the known solution according to JP-A-4-129402, is connected to the driver circuit in such a manner as shown in Fig. 11. Namely, the chips of the MMIC element 51 and driver circuit 52 are formed on a ceramic circuit board 53, which is in turn mounted on a base plate 54 made of a metal material such as kovar. The driver circuit 52 is a hybrid circuit of various elements 52a such as a resistor, condenser chip and transistor chip. As shown, the driver circuit 52 has one end connected via a bonding wire 57 to a biasing direct current (DC) terminal 58 that extends through the metallic base plate 54 in an insulated condition. One end of the MMIC element 51 mounted on the metallic base plate 54 is connected via a bonding wire 59 to a high-frequency (RF) terminal 60 that extends through the metallic base plate 54 in an insulated condition. The output of the drive circuit 52 and MMIC element 51 are interconnected via a bonding wire 61, so that DC power supplied via the DC terminal 58 is transformed via the driver circuit 52 into a predetermined biasing voltage that is then applied to the MMIC element 51. High-frequency output from the MMIC element 51 is led outside by way of the bonding wire 59 and RF terminal 60. Reference numerals 58a and 60a represent insulators. An upper lid 56 is attached to the metallic base plate 54 via a ceramic package frame 55, in order to enclose a space where the above-mentioned and other components are provided. In the above-mentioned manner, a box-shaped microwave circuit package 50 is constructed. Although the MMIC element 51 and driver circuit 52 are both mounted in generally the same plane on the metallic base plate 54, it is desirable to mount a plurality of MMIC chips each having a plurality of MMIC elements integrated thereon, in order to reduce the entire package size and provide higher integration. However, if the metallic base plate 54 has a wider area, the volume of interior space of the box-shaped package tends to become greater, which would undesirably result in increased floating capacity. Thus, in the microwave band of 1GHz - 100 GHz, resonant characteristics of the package are liable to change to thereby cause unwanted abnormal resonance, with the result that electromagnetic waves of unnecessary frequencies are produced which would prevent the microwave circuit from performing its desired functions. For these reasons, it is highly desirable that the volume of the interior space of the package be optimized to permit optimal performance of the MMICs. It has already been proposed in the art to incorporate plural MMIC chips in a single microwave IC package. For shielding purposes it is known to separate adjacent IC chips from each other by means of a dielectric partition or spacer, see EP 0 486 273 A1 and US 5,113,161 A, for example. Typically, DC biasing terminals are mounted on a base plate of the package to supply DC biasing or control signals to the integrated circuits in order to control operation characteristics of the ICs. In the packages known from the above-mentioned two documents, the DC biasing terminals are formed on top of the base plate by depositing conductive material on a dielectric underlay, and they are arranged asymmetrically with respect to the spacer(s). According to the present invention there is provided a microwave circuit package according to claim 1. Preferred embodiments of the microwave circuit package are given in the dependent subclaims. In the package of the present invention, as claimed, a plurality of two or more MMICs is mounted on a single metal base plate and each pair of adjacent integrated circuits is separated by a dielectric spacer also provided on the metal base plate. The MMICs and at least one spacer are sealed in the package. Due to the spacer(s) the interior space of the package can be optimized so as to effectively prevent abnormal resonance, electromagnetic waves of undesired frequencies, etc. Particularly, by positioning the MMICs and the DC biasing terminals symmetrically about a respective spacer, all MMICs can be provided with equal resonance systems. As a result, equal operating characteristics can be achieved for all MMICs leading to an increased reliability of the microwave circuits. The microwave circuit package may further include a frame mounted on the periphery of the metallic base plate and an upper lid mounted on the top of the frame so that the MMICs are sealed in the package by the frame and upper lid. The spacer may be greater in height than the MMICs and made of the same material as the frame. Such a spacer affords the same effects as if the MMICs were separated from each other by the frame, and the MMICs can be packaged with a same resonance system. Further, the dielectric material may comprise a dielectric substrate having substantially the same height as substrates of the MMICs and mounted on the metallic base plate, the MMICs and dielectric substrate being sealed in the package. A strip conductor may be provided on the dielectric substrate so as to form a microstrip line thereon. In this case, the strip conductor and the circuit surface of the MMICs are positioned in substantially the same plane, so that abnormal resonance and electromagnetic waves of unnecessary frequencies can be more effectively prevented than in a case where the strip conductor and the circuit surface of the MMICs are not at the same height. The microstrip line may form a circuit element such as a capacitance circuit element or inductance circuit element. The strip conductor being at substantially the same height as the substrates of the MMICs, the circuit element formed by the strip conductor and the circuit surfaces of the MMICs are positioned in generally the same plane within the package. Further, the microstrip line and MMICs may be interconnected via beam leads. As a result, the microstrip line and MMICs can be interconnected with increased strength and with less inductance, which achieves enhanced operational characteristics of the microwave circuits in high-frequency ranges. For a better understanding of the present invention, various preferred embodiments will be described hereinbelow with reference to the accompanying drawings, in which: Fig. 1 is a schematic sectional view of a microwave circuit package according to a first embodiment of the present invention; Fig. 2 is a schematic plan view of the microwave circuit package of Fig. 1, with its frame and upper lid removed; Fig. 3 is a schematic sectional view of a microwave circuit package according to a second embodiment of the present invention; Fig. 4 is a schematic plan view of the microwave circuit package of Fig. 3, with its frame and upper lid removed; Fig. 5 is a schematic sectional view of a microwave circuit package according to an embodiment which is not part of the present invention; Fig. 6 is a schematic plan view of the microwave circuit package of Fig. 5, with its frame and upper lid removed; Fig. 7 is a schematic plan view of the microwave circuit package according to a third embodiment of the present invention, with its frame and upper lid removed; Fig. 8 is a schematic sectional view of a microwave circuit package according to a fourth embodiment of the present invention; Fig. 9 is a schematic plan view of the microwave circuit package of Fig. 8, with its frame and upper lid removed; Figs. 10A and 10B are diagrams illustrating examples of circuit elements formed of microstrip lines, of which Fig. 10A shows a capacitance circuit element and Fig. 10B shows an inductance circuit element; and Fig. 11 is a schematic sectional view of a conventionally-known microwave circuit package. Reference is initially taken to Figs. 1 and 2 which show a microwave circuit package 10 according to a first embodiment of the present invention. This microwave circuit package 10 includes a base plate 3 made of a metal material, such as kovar, on which are mounted two MMICs (Monolithic Microwave Integrated Circuits) 11 and 12. The package 10 also includes a ceramic package frame 5 fixedly mounted on the base plate 3 and an upper lid 6 (made of a dielectric material, for example) secured to the top surface of the frame 5, so as to seal the MMICs 11 and 12 within the package 10. A spacer 15 made of a dielectric material is also mounted on the base plate 3 to separate the MMICs 11 and 12 from each other. As seen from Figs. 1 and 2, three pairs of biasing DC terminals 34 and 35 for supplying a predetermined biasing voltage extend through the metallic base plate 3 with respective insulators 34a and 35a interposed therebetween and are connected via bonding wires 44 and 45 to a power supply terminal of the first MMIC 11. Similarly, three pairs of biasing DC terminals 36 and 37 for supplying a predetermined biasing voltage extend through the metallic base plate 3 with respective insulators 36a and 37a interposed therebetween and are connected via bonding wires 46 and 47 to a power supply terminal of the second MMIC 12. According to the first embodiment, the volume of the interior space of the microwave circuit package 10 is reduced by the provision of the spacer separating the MMICs 11 and 12 from each other. In the illustrated example, the MMICs 11 and 12 and DC terminals 34, 35 and 36, 37 are provided substantially symmetrically about the spacer 15. As shown in Fig. 2, the first MMIC 11 has a high-frequency input connected via a bonding wire to a RF terminal 11a and two high-frequency outputs connected via bonding wires to RF terminals 11b and 11c, respectively. Similarly, the second MMIC 12 has a high-frequency input connected via a bonding wire to a RF terminal 12a and two high-frequency outputs connected via bonding wires to RF terminals 12b and 12c, respectively. The DC terminals 34 to 37 each extend perpendicularly to the general plane of the metallic base plate 3 as best seen in Fig. 1, and the RF terminals 11a - 11c, 12a - 12c are provided on opposite sides (upper and lower sides in the example of Fig. 2) and extend along the surface of the metallic base plate 3. This achieves adjoining and high-density arrangement of the various components of the microwave circuit package 10. Figs. 3 and 4 show a microwave circuit package 10 according to a second embodiment the present invention, which is characterized by the provision of three MMICs. Like the above-described first embodiment, this package 10 includes a base plate 3 made of a metal material, such as kovar, on which are mounted three MMICs 11, 12 and 13. The package 10 also includes a frame 5 fixedly mounted on the base plate 3 and an upper lid 6 secured to the top surface of the frame 5, so as to seal the three MMICs 11, 12 and 13 within the package 10. A spacer 15 made of a dielectric material is mounted on the base plate 3 to separate the MMICs 11 and 12 from each other, and another spacer 16 made of a dielectric material is also mounted on the base plate 3 to separate the MMICs 12 and 13 from each other. As seen from Figs. 3 and 4, three pairs of biasing DC terminals 34 and 35 for supplying a predetermined biasing voltage extend through the metallic base plate 3 with respective insulators 34a and 35a interposed therebetween and are connected via bonding wires 44 and 45 to a power supply terminal of the first MMIC 11. Three pairs of biasing DC terminals 36 and 37 for supplying a predetermined biasing voltage extend through the metallic base plate 3 with respective insulators 36a and 37a interposed therebetween and are connected via bonding wires 46 and 47 to a power supply terminal of the second MMIC 12. Similarly, three pairs of biasing DC terminals 38 and 39 for supplying a predetermined biasing voltage extend through the metallic base plate 3 with respective insulators 38a and 39a interposed therebetween and are connected via bonding wires 48 and 49 to a power supply terminal of the third MMIC 13. According to the second embodiment, the volume of the interior space of the microwave circuit package 10 is even further reduced by the provision of the two spacers separating the MMICs 11, 12 and 13 from each other. In the illustrated example, the MMICs 11 and 12 and DC terminals 34, 35 and 36, 37 are provided substantially symmetrically about the spacer 15, and the MMICs 12 and 13 and DC terminals 36, 37 and 38, 39 are provided substantially symmetrically about the spacer 16. As shown in Fig. 4, the first MMIC 11 has a high-frequency input connected via a bonding wire to a RF terminal 11a and two high-frequency outputs connected via bonding wires to RF terminals 11b and 11c. The second MMIC 12 has a high-frequency input connected via a bonding wire to a RF terminal 12a and two high-frequency outputs connected via bonding wires to RF terminals 12b and 12c. Similarly, the third MMIC 13 has a high-frequency input connected via a bonding wire to a RF terminal 13a and two high-frequency outputs connected via bonding wires to RF terminals 13b and 13c. The DC terminals 34 to 39 each extend perpendicularly to the general plane of the metallic base plate 3 as best seen in Fig. 3, and the RF terminals 11a - 11c, 12a - 12c, 13a - 13c are provided on opposite sides (upper and lower sides in the example of Fig. 4) and extend along the surface of the metallic base plate 3. This achieves adjoining and high-density arrangement of the various components of the microwave circuit package 10. Figs. 5 and 6 show a microwave circuit package 10 according to an embodiment which is not part of the present invention. As in the first embodiment, this microwave circuit package 10 includes a base plate 3 made of a metal material, such as kovar, on which are mounted two MMICs 11 and 12. The package 10 also includes a frame 5 fixedly mounted on the base plate 3 and an upper lid 6 secured to the top surface of the frame 5, so as to seal the MMICs 11 and 12 within the package 10. As seen in Fig. 6, a dielectric substrate 14 made of a ceramic material or the like is also mounted on the metallic base plate 3 and has substantially the same height as substrates or chips of the MMICs 11 and 12. A strip conductor 14d is provided on the dielectric substrate 14, so that the strip conductor 14d, dielectric substrate 14 and metallic base plate 3 together form a microstrip line. For example, the strip conductor 14d may have a width of 0.48 mm and a height of 0.006 mm, and the dielectric substrate 14 may have a height of 0.51 mm. The dielectric substrate 14 may be made of alumina ceramic. As shown in Figs. 5 and 6, three pairs of biasing DC terminals 34 and 35 for supplying a predetermined biasing voltage extend through the metallic base plate 3 with respective insulators 34a and 35a interposed therebetween and are connected via bonding wires 44 and 45 to a power supply terminal of the first MMIC 11. Similarly, three pairs of biasing DC terminals 36 and 37 for supplying a predetermined biasing voltage extend through the metallic base plate 3 with respective insulators 36a and 37a interposed therebetween and are connected via bonding wires 46 and 47 to a power supply terminal of the second MMIC 12. According to this embodiment, the volume of the interior space of the microwave circuit package 10 is reduced by the provision of the dielectric substrate 14 having substantially the same height as the substrates of the MMICs 11 and 12. The MMICs 11 and 12 are connected with the microstrip line via beam leads 11d and 12d, respectively. More specifically, the first MMIC 11 has a high-frequency input connected via the beam lead 11d with the strip conductor 14d on the dielectric substrate 14, while the second MMIC 12a has a high-frequency input connected via the beam lead 12d with the strip conductor 14d. The first MMIC 11 also has two high-frequency outputs connected via respective bonding wires to RF terminals 11b and 11c, while the second MMIC 12 also has two high-frequency outputs connected via respective bonding wires to RF terminals 12b and 12c. The strip conductor 14d on the dielectric substrate 14 is connected via a bonding wire to a RF terminal 14a. The strip conductor 14d forms a circuit element; for example, this conductor 14d forms a distributor for distributing high-frequency signals, in order to reduce the necessary number of the RF terminals. In the embodiment of Figs. 5 and 6, the DC terminals 34 to 37 each extend perpendicularly to the general plane of the metallic base plate 3 as best seen in Fig. 5, and the RF terminals 11b, 11c, 12b, 12c and the RF terminal 14a are provided on opposite sides (upper and lower sides in the example of Fig. 6) and extend along the surface of the metallic base plate 3. This achieves adjoining and high-density arrangement of the various components of the microwave circuit package 10. Fig. 7 shows a microwave circuit package 10 according to a third embodiment of the present invention, which corresponds to a combination of the above-described first embodiment and the embodiment of Figs. 5 and 6. Namely, this microwave circuit package 10 includes two MMICs 11 and 12 mounted on a base plate 3 made of a metal material. On the metallic base plate 3, there are also mounted a spacer 15, made of a dielectric material, for separating the MMICs 11 and 12 from each other, and a dielectric substrate 14 having substantially the same height as the substrates (chips) of the MMICs 11 and 12. These components are sealed in a space defined by the metallic base plate 3, frame and upper lid (illustration of the frame and upper lid is omitted in Fig. 7). A strip conductor 14d is provided on the dielectric substrate 14, so that the strip conductor 14d, dielectric substrate 14 and metallic base plate 3 together form a microstrip line. As further shown in Fig. 7, three pairs of biasing DC terminals 34 and 35 for supplying a predetermined biasing voltage extend through the metallic base plate 3 with respective insulators interposed therebetween arid are connected via bonding wires 44 and 45 to a power supply terminal of the first MMIC 11. Similarly, three pairs of biasing DC terminals 36 and 37 for supplying a predetermined biasing voltage extend through the metallic base plate 3 with respective insulators interposed therebetween and are connected via bonding wires 46 and 47 to a power supply terminal of the second MMIC 12. According to the third embodiment, the volume of the interior space of the microwave circuit package 10 is even further reduced by the provision of the spacer 15 separating the MMICs 11 and 12 from each other and the dielectric substrate 14 having substantially the same height as the substrates of the MMICs 11 and 12. The MMICs 11 and 12 are connected with the microstrip line via beam leads 11d and 12d, respectively. More specifically, the first MMIC 11 has a high-frequency input connected via the beam lead 11d with the strip conductor 14d on the dielectric substrate 14, while the second MMIC 12a has a high-frequency input connected via the beam lead 12d with the strip conductor 14d. The first MMIC 11 also has two high-frequency outputs connected via respective bonding wires to RF terminals 11b and 11c, while the second MMIC 12 also has two high-frequency outputs connected via respective bonding wires to RF terminals 12b and 12c. The strip conductor 14d on the dielectric substrate 14 is connected via a bonding wire to a RF terminal 14a. The strip conductor 14d forms a circuit element; for example, this conductor 14d forms a distributor for distributing high-frequency signals, in order to reduce the necessary number of the RF terminals. Further, the DC terminals 34 to 37 each extend perpendicularly to the general plane of the metallic base plate 3 (see Fig. 1), and the RF terminals 11b, 11c, 12b, 12c and the RF terminal 14a are provided on opposite sides (upper and lower sides in the example of Fig. 7) and extend along the surface of the metallic base plate 3. This achieves adjoining and high-density arrangement of the various components of the microwave circuit package 10. Figs. 8 and 9 show a microwave circuit package 10 according to a fourth embodiment of the present invention, which is characterized in that a spacer and dielectric substrate are integrally formed. Namely, this microwave circuit package 10 includes substrates (chips) of two MMICs 11 and 12 mounted on a base plate 3 made of a metal material. On the metallic base plate 3, there is also mounted a T-shaped dielectric substrate 14 which includes a stem portion 14b that has generally the same height as the MMIC substrates so as to separate the MMICs 11 and 12 from each other and a flange portion 14c extending along one end of each of the MMICs 11 and 12. These components are sealed in a space defined by the metallic base plate 3, frame 5 and upper lid 6. A strip conductor 14d is provided on the dielectric substrate 14, so that the strip conductor 14d, dielectric substrate 14 and metallic base plate 3 together form a microstrip line. As further shown in Fig. 9, three pairs of biasing DC terminals 34 and 35 for supplying a predetermined biasing voltage extend through the metallic base plate 3 with respective insulators 34a and 35a interposed therebetween and are connected via bonding wires 44 and 45 to a power supply terminal of the first MMIC 11. Similarly, three pairs of biasing DC terminals 36 and 37 for supplying a predetermined biasing voltage extend through the metallic base plate 3 with respective insulators 36a and 37a interposed therebetween and are connected via bonding wires 46 and 47 to a power supply terminal of the second MMIC 12. According to the fourth embodiment, the volume of the interior space of the microwave circuit package 10 is even further reduced by the provision of the T-shaped dielectric substrate 14 having substantially the same height as the substrates of the MMICs 11 and 12. The MMICs 11 and 12 and DC terminals 34, 35 and 36, 37 are provided in substantial symmetry about the stem portion 14b of the T-shaped dielectric substrate 14. The MMICs 11 and 12 are connected with the microstrip line via beam leads 11d and 12d, respectively. More specifically, the first MMIC 11 has a high-frequency input connected via the beam lead lid with the strip conductor 14d on the dielectric substrate 14, while the second MMIC 12 has a high-frequency input connected via the beam lead 12d with the strip conductor 14d. The first MMIC 11 also has two high-frequency outputs connected via respective bonding wires to RF terminals 11b and 11c, while the second MMIC 12 also has two high-frequency outputs connected via respective bonding wires to RF terminals 12b and 12c. The strip conductor 14d on the dielectric substrate 14 is connected via a bonding wire to a RF terminal 14a. The strip conductor 14d forms a circuit element; for example, this conductor 14d forms a distributor for distributing high-frequency signals, in order to reduce the necessary number of the RF terminals. Further, the DC terminals 34 to 37 each extend perpendicularly to the general plane of the metallic base plate 3 (see Fig. 8), and the RF terminals 11b, 11c, 12b, 12c and the RF terminal 14a are provided on opposite sides (upper and lower sides in the example of Fig. 9) and extend along the surface of the metallic base plate 3. This achieves adjoining and high-density arrangement of the various components of the microwave circuit package 10. While several illustrative embodiments of the invention have been shown and described, numerous variations and alternative embodiments, such as the following, may occur to those skilled in the art. In the above-described embodiments, the strip conductor 14d on the dielectric substrate 14 (strip conductor of the microstrip line) and RF terminal 14a may be interconnected via a beam lead or ribbon made of gold or the like. Further, in the first and second embodiments shown in Figs. 1 to 4, the high-frequency inputs of the MMICs 11, 12, 13 and corresponding RF terminals 11a, 12a, 13a may be interconnected via beam leads or ribbons made of gold or the like. Similarly, the high-frequency outputs of the MMICs 11, 12, 13 and corresponding RF terminals 11b, 11c, 12b, 12c, 13b, 13c may be interconnected via beam leads or ribbons made of gold or the like. In the embodiments shown in Figs. 5 to 9, the beam leads 11d and 12d may be replaced by ribbons. Furthermore, in the above-described embodiments, a dielectric material may be interposed between each of the RF terminals and the metallic base plate 3, and each of the RF terminals and the metallic base plate 3 may be interconnected via a beam lead or ribbon made of gold or the like rather than via the bonding wire. The height of the upper lid made of a dielectric material may be reduced to downsize the microwave circuit package. Furthermore, in the above-described embodiments, the spacer 15 may be made of the same material as the package frame 5. In a case where a metallic film is formed on the inner surface of the package frame 5, a metallic film may be formed on the top or side surface of the spacer 15. The RF terminals 11a - 11c, 12a - 12c, 13a - 13c and 14a may be provided to extend perpendicularly to the general plane of the metallic base plate 3, similarly to the DC terminals 34 to 39. The bonding portions for the RF terminals may be reduced in width depending on an intended application. The above-described various embodiments of the microwave circuit package may be applied to the radar module and antenna apparatus which is proposed in Japanese Patent Application No. HEI-7-239311. In such a case, a plurality of MMICs, each including four high-frequency FETs and two mixers, are mounted within the package so as to provide multichip circuitry. In a case where the strip conductor 14d on the dielectric substrate 14 is used to form a circuit element, the width of the strip conductor 14d may be partly increased or reduced so as to provide a distributed parameter circuit element. Figs. 10A and 10B show various examples of circuit elements formed of microstrip lines (strip conductors), of which Fig. 10A shows capacitance circuit elements and Fig. 10B shows inductance circuit elements. More specifically, in Fig. 10A, (a) and (b) denote series-type circuit elements, while (c) and (d) denote parallel-type circuit elements having one or more rectangular protrusions formed by partly expanding the width of the strip conductors. In Fig. 11, (a) denotes a series-type circuit element, while (b) denotes a parallel-type circuit element formed to have a spiral shape. The above-described embodiments accomplish various benefits as set forth below. By providing a spacer separating adjacent MMICs from each other, the volume of the interior space of the package can be optimized to effectively prevent abnormal resonance, electromagnetic waves of unnecessary frequencies, etc. Particularly, by positioning the MMICs symmetrically about the spacer, the MMICs can be packaged with the same resonance system. As a result, it is possible to effectively prevent abnormal resonance, electromagnetic waves of unnecessary frequencies, etc., and the MMICs can operate with the same characteristics, which achieves increased reliability of the microwave circuits. Further, when a dielectric substrate having substantially the same height as substrates of the MMICs is mounted on the metallic base plate, and the MMICs and dielectric substrate are sealed in the package, this arrangement can also effectively reduce the volume of the interior space of the package and prevent abnormal resonance, electromagnetic waves of unnecessary frequencies, etc. Furthermore, when a strip conductor is provided on the dielectric substrate so as to form a microstrip line thereon and the strip conductor and the circuit surface of the MMICs are positioned in substantially the same plane, the wiring on the strip conductor and MMICs is positioned in substantially the same plane and hence can be made shorter. Consequently, abnormal resonance and electromagnetic waves of unnecessary frequencies can be more effectively prevented than in a case where the strip conductor and the circuit surface of the MMICs are not at the same height. This arrangement also achieves increased reliability of the microwave circuits. The microstrip line can supply high-frequency signals to the MMICs in a stable condition with less transmission loss. Further, when a circuit element such as a capacitance or inductance is formed by the microstrip line, the height and area of the circuit element can be reduced to a considerable degree. Thus, such a circuit element that was heretofore difficult to form within a MMIC in a small size can be easily packaged together with the MMICs. Furthermore, by the strip conductor forming a circuit element on the dielectric substrate at generally the same height as the substrates of the MMICs, the circuit element and the circuit surface of the MMICs can be positioned in substantially the same plane and the wiring on the circuit element and MMICs is positioned in substantially the same plane. Additionally, when the microstrip line and MMICs are interconnected via beam leads, the microstrip line and MMICs can be interconnected with increased strength and with less inductance, which achieves enhanced operational characteristics of the microwave circuit in high-frequency ranges. This arrangement also permits increased rigidity of the package against vibration, to thereby achieve increased reliability of the microwave circuits. Also, when the dielectric substrate with the strip conductor formed thereon and the substrates of the MMICs are positioned at generally the same height, the interconnection via the beam leads is greatly facilitated. Moreover, when the spacer is greater in height than the MMICs and is made of a same material as the package frame, the spacer affords the same effects as if the MMICs were separated from each other by the frame.

Claims: A microwave circuit package, comprising a metal base plate (3) having a plurality of monolithic microwave integrated circuits (11, 12, 13) mounted on a surface thereof, dielectric material (15, 16; 14) being provided on said surface of said base plate (3), pairs of adjacent integrated circuits (11, 12, 13) each being separated by a respective spacer (15, 16; 14b) formed of said dielectric material (15, 16; 14), said adjacent integrated circuits (11, 12, 13) of each said pair being arranged substantially symmetrically about said respective spacer (15, 16; 14b), said integrated circuits (11, 12, 13) and said dielectric material (15, 16; 14) being sealed in said package (10), said package further comprising a plurality of DC biasing terminals (34, 35, 36, 37, 38, 39) for supplying DC biasing signals to said integrated circuits (11, 12, 13), characterised in that said DC biasing terminals (34, 35, 36, 37, 38, 39) extend through said base plate (3) and are arranged in pairs, each said pair of DC biasing terminals (34, 35, 36, 37, 38, 39) serving for supplying a predetermined biasing voltage to an associated integrated circuit (11, 12, 13), each said pair of adjacent integrated circuits (11, 12, 13) having their associated pairs of DC biasing terminals (34, 35, 36, 37, 38, 39) arranged substantially symmetrically about said respective spacer (15, 16; 14b). The microwave circuit package of claim 1, characterised in that said DC biasing terminals (34, 35, 36, 37, 38, 39) of each said pair are arranged on sides of said associated integrated circuit (11, 12, 13) which are opposite to each other with respect to the axis of symmetry. The microwave circuit package of claim 1 or 2, characterized in that a plurality of pairs of DC biasing terminals (34, 35, 36, 37, 38, 39) are associated to each of said integrated circuits (11, 12, 13). The microwave circuit package of any one of claims 1 to 3, characterized in that said spacer (15, 16) is greater in height than said integrated circuits (11, 12, 13). The microwave circuit package of any one of claims 1 to 4, characterized in that said dielectric material (15, 16; 14) comprises a dielectric substrate (14) having substantially the same height as said integrated circuits (11, 12, 13), strip conductor means (14d) being provided on said dielectric substrate (14) so as to form a microstrip line thereon. The microwave circuit package of claim 5, characterized in that said microstrip line forms a circuit element. The microwave circuit package of claim 5 or 6, characterized in that said microstrip line is connected to a respective integrated circuit (11, 12) via a beam lead (11d, 12d). The microwave circuit package of any one of claims 5 to 7, characterized in that said dielectric substrate (14) is substantially formed into a T-shape having a stem portion (14b) and a flange portion (14c), said spacer being formed by said stem portion (14b), said flange portion (14c) being located along one end of each of said adjacent integrated circuits (11, 12) separated by said spacer, said strip conductor means (14d) being provided on said flange portion (14c). The microwave circuit package of any one of claims 1 to 8, characterized by a frame (5) mounted on a periphery of said surface of said base plate (3) and an upper lid (6) mounted on top of said frame (5) so that said integrated circuits (11, 12, 13) and said dielectric material (15, 16; 14) are sealed in said package (10) by said frame (5) and said lid (6), said frame (5) being made of the same material as said dielectric material (15, 16; 14).

Inventors: KUDOH HIROSHI, UEMATSU HIROSHI, URABE MASANOBU, KUDOH, HIROSHI, UEMATSU, HIROSHI, URABE, MASANOBU
Applicants: HONDA MOTOR CO LTD, HONDA GIKEN KOGYO KABUSHIKI KAISHA
Application year: 1997
Main classification: H01L23
IPC codes: H01L23, H01P5, H01L25, H01P3