JP2001267487A - High frequency module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high frequency module at high performance and low cost. SOLUTION: A square hole 102 is provided at a Teflon(R) board 101, which is bonded to a glass epoxy board 106 with a bonding sheet 107. Micro strip tracks 104 and 108 as well as ground conductors 103 and 107 are provided, with a millimeter wave integrated circuit 109 in a flip-chip mounting process using a bump 110. A low frequency device 113 is mounted on a rear surface for high-density mounting. The structure is realized using a resin board for a lower cost. An MMIC 109 is flip-chip mounted using the bump 110 for less parasitic reactance component at a structure connection part, resulting in no degradation in characteristics with mounting for millimeter wave. Since a square hole is provided, no sealing resin covers the circuit surface of MMIC for least degradation in characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency module mounted with a high-frequency semiconductor integrated circuit for mounting a high-frequency semiconductor integrated circuit used for wireless communication.

[0002]

2. Description of the Related Art Hitherto, as a high-frequency module using a multilayer substrate, a module described in the 1997 IEEE MTT-S International Symposium on Microwave Digests, pages 509 to 513, is known.

FIG. 9 shows a structure of a high-frequency module using a conventional multilayer substrate. 701 polyimide multilayer substrate
It has a structure in which a rectangular hole is formed in a polyimide substrate and a high frequency integrated circuit (MMIC) 709 is embedded therein and mounted with bonding wires 710 in a polyimide substrate. 703 is a ground conductor formed on the lower surface of the polyimide substrate, and 704 is a microstrip line formed on the upper surface of the polyimide substrate. A power supply circuit and a control circuit of 712 are provided on the back surface of the alumina substrate,
The wiring between the layers is connected by 714 through holes.

[0004]

In this high-frequency module, a high-frequency circuit is formed with a multi-layered substrate and metal wiring is provided by a thin film process. However, there is a problem that the cost is very large. Further, since the power supply circuit and the control circuit are formed on the alumina substrate side, the substrate cost increases.

In addition, since the high-frequency integrated circuit is mounted face-up, it is necessary to seal it for reliability. Further, the alumina substrate has a problem that it is difficult to form a circuit having a large area due to a problem of strength. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a dielectric multilayer substrate having high performance at low cost and having sufficient mechanical strength, and a high-performance high-frequency module using this substrate. It is intended to realize inexpensively.

[0006]

According to the present invention, there is provided a high-frequency module according to the present invention, wherein the first and second dielectric substrates having conductor layers on both surfaces thereof are bonded together using an adhesive resin. The first dielectric substrate has the entire back surface of the first dielectric substrate.
Having a first transmission line on the surface and having a rectangular hole smaller than the semiconductor integrated circuit, wherein the second dielectric substrate has a second grounding conductor on the surface. , Having a second transmission line on the back surface, having a structure in which the ground conductor and the transmission line of each layer are connected by through holes,
A high-frequency circuit is formed by flip-chip mounting a semiconductor integrated circuit on the square hole, and a low-frequency circuit is formed by mounting a low-frequency device on the back surface.

According to the present invention, since the substrate material is realized by laminating a resin material, the cost can be reduced as compared with a substrate made of alumina or the like. Further, since a thin film process is not required for metal wiring, the cost is low in terms of process. In addition, since flip-chip mounting is used for mounting the semiconductor integrated circuit and sealing is performed simultaneously with mounting, there is no need to perform a new sealing step. Further, since the rectangular holes are provided in the substrate directly below the flip chip chip, the sealing resin has little influence on the semiconductor integrated circuit, and the same characteristics as in the face-up mounting state can be secured. Furthermore, it has the feature that the parasitic reactance due to the bonding wire is small, and a high-performance high-frequency module can be realized at low cost.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention according to claim 1 of the present invention is directed to a laminated dielectric substrate in which first and second dielectric substrates having conductor layers on both surfaces are bonded together using an adhesive resin. The first dielectric substrate has a first ground conductor on the entire back surface and a first transmission line on the front surface;
A structure having a square hole smaller than the semiconductor integrated circuit;
The second dielectric substrate has a structure in which a second ground conductor is provided on a front surface, a second transmission line is provided on a rear surface, and a ground conductor and a transmission line of each layer are connected to each other through holes. The semiconductor integrated circuit is flip-chip mounted on the square hole to form a high-frequency circuit, and a low-frequency device is mounted on the back surface to form a low-frequency circuit.

By adopting such a structure using a resin material, a low-cost laminated dielectric substrate for mounting a high-frequency integrated circuit can be realized. In addition, by providing the semiconductor integrated circuit by flip-chip mounting after providing the square holes, the sealing can be performed with almost no influence of the sealing resin.

[0010] The invention according to claims 2 to 4 of the present invention provides:
The square hole of the first dielectric substrate may be formed in a concave shape without penetrating the first dielectric substrate, or may be cut through the first dielectric substrate to an intermediate portion of the second dielectric substrate. It is characterized by having a concave shape or a shape penetrating the first and second dielectric substrates, and such a structure can be easily realized by cutting or laser processing after laminating the dielectric substrates. Therefore, it is excellent in mass productivity.

The invention according to claim 5 of the present invention is characterized in that the first dielectric substrate is a Teflon substrate and the second dielectric substrate is a glass epoxy substrate. By using a Teflon substrate having a low dielectric constant and a low dielectric loss tangent for the circuit portion, and using a glass epoxy substrate for the low-frequency circuit portion that does not require very low loss characteristics, the overall material cost can be suppressed.

The invention according to claims 6 and 7 of the present invention is characterized in that the second dielectric substrate or the first dielectric substrate is made of a glass epoxy multilayer and a Teflon multilayer, respectively. By doing so, high-density wiring becomes possible, and a compact high-frequency module can be realized.

The invention according to claims 8 and 9 of the present invention is characterized in that the ground conductor is provided on one of the back surface of the first dielectric substrate and the front surface of the second dielectric substrate.
By using only one of them as a ground conductor, a through hole for connecting the conductors becomes unnecessary.

According to a tenth aspect of the present invention, the second aspect
The second ground conductor on the surface of the dielectric substrate is selectively left in alignment with the angular hole position of the first dielectric substrate, and a third transmission line is provided in a portion where the second ground conductor is removed. This structure has a structure in which the components are provided, and by adopting such a structure, high-density wiring becomes possible and a small high-frequency module can be realized.

The eleventh aspect of the present invention provides the following.
Further, the second dielectric material is bonded by thermocompression bonding without using an adhesive resin, and a high-frequency module in which high-frequency characteristics are not deteriorated by the thermocompression resin can be realized.

According to a twelfth aspect of the present invention, the first aspect
The square hole provided in the dielectric material is formed larger than the semiconductor integrated circuit, and the semiconductor integrated circuit is embedded face-up so as to be embedded, and the first transmission line and the electrode of the semiconductor integrated circuit are connected to each other with a wire or ribbon By connecting such a structure with a plurality of resin substrates, an inexpensive high-frequency module can be realized.

According to a thirteenth aspect of the present invention, the first aspect
The feature is that the rectangular holes provided in the dielectric material are shaped larger than the semiconductor integrated circuit, and the semiconductor integrated circuit enclosed in the package is embedded and mounted, and such a structure is realized by a resin substrate. Thus, an inexpensive high-frequency module can be realized.

According to a fourteenth aspect of the present invention, the first aspect
Providing a third dielectric substrate having holes larger than the square holes provided on the first dielectric substrate, and mounting the third dielectric substrate on the first dielectric substrate using an adhesive resin. The third embodiment is characterized in that a shielding lid is bonded on the third dielectric substrate. With such a structure, a semiconductor integrated circuit can be easily sealed.

The invention according to claims 15 to 17 of the present invention is characterized in that the high-frequency module according to claims 1 to 12 is used for a radio terminal device, a radio base station device, and a radio measurement device, and is small and inexpensive. By using a high-frequency module, a small and inexpensive device can be provided.

(Embodiment 1) FIG. 1 is a sectional view showing a high-frequency module according to a first embodiment of the present invention. FIG. 2 shows a three-dimensional structure of the high-frequency module according to the first embodiment of the present invention.

1 and 2, reference numeral 101 denotes a Teflon substrate used as a first dielectric substrate, 102 denotes a square hole provided in the Teflon substrate, and 103 denotes a first ground on the back surface of the first dielectric substrate. The conductor 104 is the first dielectric substrate 101
A microstrip line provided as a first transmission line provided above, a bonding sheet 105 serving as a bonding resin, a glass epoxy substrate 106 serving as a second dielectric substrate, and a surface 107 of a second dielectric substrate 107 , A second transmission line 108 on the back surface of the glass epoxy substrate, 109 a millimeter-wave integrated circuit (MMIC) as a high-frequency semiconductor integrated circuit, 110 a bump, 111 a sealing resin, and 112 a sealing resin. A low frequency device mounted on the back surface of the glass epoxy substrate, 113 is a chip component, and 114 is a through hole.

By realizing such a shape using a resin substrate, the cost can be reduced as compared with the case where a low-temperature fired ceramic substrate is integrally fired. Further, a low-loss Teflon substrate is used only for the first dielectric substrate 101 which requires high-frequency characteristics, and an inexpensive glass epoxy substrate is used as the second dielectric substrate which does not require high-frequency characteristics. A lossy and low-cost dielectric substrate can be realized.

By using flip-chip mounting with bumps 110 to mount MMIC 109, parasitic reactance components at the connection portion are smaller than in face-up mounting with bonding wires, and there is no deterioration in characteristics due to mounting even in millimeter waves. However, in normal flip-chip mounting, a sealing resin is injected between the MMIC and the mounting substrate in order to secure connection reliability, but the sealing resin, which is a dielectric material, is applied to the circuit surface of the MMIC. As a result, the characteristics deteriorate.

Therefore, the MMIC chip 1 is mounted on the Teflon substrate.
A small hole slightly smaller than 09 is formed, and MM
By mounting the IC on the bump, it is possible to prevent the sealing resin from covering the main circuit portion of the MMIC. In addition, by forming the power supply bypass capacitor of the MMIC and the intermediate frequency circuit on the glass epoxy substrate on the back surface, it is possible to realize the miniaturization of the whole module, and the millimeter wave circuit and the power supply and the intermediate frequency circuit are Since they are separated by the ground conductors 103 and 106,
Isolation between circuits can be increased.

In this embodiment, a millimeter wave circuit and
Although the power supply and the intermediate frequency circuit are formed on different surfaces, it goes without saying that a part of the power supply circuit may be formed on the millimeter wave circuit surface, for example.

Although Teflon and a glass epoxy substrate are used as substrate materials, it goes without saying that another resin material may be used.

(Embodiment 2) FIG. 3 is a sectional view showing a high-frequency module according to a second embodiment of the present invention. 3 differs from the first embodiment of FIG. 1 in that the second ground conductor 206 is selectively left instead of on the entire surface, and the third ground conductor 206 is formed on the same conductor layer as the second ground conductor.
In that the transmission line 207 is provided, the inner layer through hole 204 is used as the through hole, and the glass epoxy multilayer substrates 107a and 107b are used as the second dielectric substrate.

With such a structure, the bonding sheet 105 is made of a dielectric material, and the first ground conductor 10
A microstrip line having 3 as a ground layer can be formed. The periphery of the second ground conductor 206 is connected to the first ground conductor 103 through the inner layer through hole 214 at the peripheral portion, so that the same electrical characteristics as when the ground conductor is provided on the entire surface can be realized as the electrical characteristics. A high-density wiring can be realized by the third transmission line provided on the same plane as the second ground conductor. Further, high-density wiring can be realized by forming the glass epoxy substrate into a multilayer structure.

Although the Teflon substrate has a single layer in this embodiment, it is needless to say that a multi-layer substrate may be used.

(Embodiment 3) FIG. 4 is a sectional structural view of a high-frequency module according to a third embodiment of the present invention. The present embodiment differs from the first embodiment in that the square holes 302 provided on the Teflon substrate 101 are formed in a concave shape without penetrating the substrate.

Such a substrate structure can be formed by laser processing, drilling, or the like after forming the substrate in the same process as that for forming a general multilayer substrate, and can be realized at low production cost.

In the present embodiment, the rectangular holes 30 are used.
Although Teflon is left in the lower part of No. 2, a hole may be drilled through Teflon by post-processing. further,
The hole may extend to a part of the glass epoxy substrate 107. Further, the glass epoxy substrate may be penetrated.

(Embodiment 4) FIG. 5 is a sectional structural view of a high-frequency module according to a fourth embodiment of the present invention. This embodiment is different from the first embodiment in that the square hole 402 provided on the Teflon substrate 101 is larger than the MMIC 409 and the MMIC 1
09 is mounted in the form of being fitted into the square hole 402 with the circuit surface facing up, and the electrodes of the MMIC 109 and the first transmission line 104 are mounted.
Are connected by a bonding wire or a ribbon.

By adopting such a shape, the parasitic reactance at the connection portion is increased as compared with flip chip mounting, but mounting is relatively easy and mounting cost can be reduced.

(Embodiment 5) FIG. 6 is a sectional structural view of a high-frequency module according to a fifth embodiment of the present invention. The present embodiment is different from the fourth embodiment in that a square hole 40 on a Teflon substrate 101 is provided.
The point is that a Teflon substrate having a square hole 502 larger than 2 is laminated, and a shielding lid 517 is further laminated thereon.

By adopting such a shape, the MMIC mounted face-up can be hermetically sealed, and the MMIC can be protected from humidity and the like.

(Embodiment 6) FIG. 7 is a sectional structural view of a high-frequency module according to a sixth embodiment of the present invention. The present embodiment differs from the fourth embodiment in that the MMIC is not a bare chip MMIC but a microstrip or coplanar line type package. The reliability can be further improved by using the MMIC enclosed in the package.

(Embodiment 7) FIG. 8 shows an example of an embodiment of a wireless terminal device using the high-frequency module of the present invention. In this embodiment, 901 is an antenna, 902 is a transmission / reception switch, 903 is a low noise amplifier, 904 is a power amplifier, 905 is a filter, 906
Is a local oscillator, 907 is a mixer, 908 is an intermediate signal processing circuit, and 909 is a baseband signal processing circuit. By using the structure of the high-frequency module of the present invention, for example, a portion 910 surrounded by a broken line can be easily integrated on one substrate, and a small-sized and low-cost wireless terminal can be realized.

In this embodiment, an example in which the present invention is applied to a wireless terminal has been described. However, similar effects can be obtained by applying the present invention to a wireless base station apparatus or a wireless measuring apparatus.

Further, in this embodiment, the broken line portion in FIG. 8 is integrated on the substrate, but the functions of the radio device other than the block diagram shown in FIG. 8 may be integrated on the same substrate. . Needless to say, the substrate may be divided into two or more substrates.

[0041]

As described above, according to the present invention, a cavity is provided in a dielectric multilayer substrate in which a dielectric material made of resin is adhered, and flip chip mounting is performed. The effect is obtained that a high-frequency module with high performance can be realized at low cost.

[Brief description of the drawings]

FIG. 1 is a structural sectional view of a high-perimeter module according to an embodiment of the present invention.

FIG. 2 is a structural diagram of a high-frequency module according to an embodiment of the present invention.

FIG. 3 is a structural diagram of a high-frequency module according to an embodiment of the present invention;

FIG. 4 is a structural diagram of a high-frequency module according to an embodiment of the present invention.

FIG. 5 is a structural diagram of a high-frequency module according to an embodiment of the present invention.

FIG. 6 is a structural diagram of a high-frequency module according to an embodiment of the present invention.

FIG. 7 is a structural diagram of a high-frequency module according to an embodiment of the present invention.

FIG. 8 is a block diagram of a wireless device using the high-frequency module according to one embodiment of the present invention;

FIG. 9 is a diagram showing the structure of a conventional high-frequency module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Teflon board 102 Square hole 103, 106 Ground conductor 104 108 Microstrip line 105 Adhesive resin 107 Glass epoxy board 109 Millimeter-wave MMIC 110 Bump 111 Sealing resin 112 Low frequency IC 113 Chip resistance

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01P 3/08 H01L 23/14 R 5/08

Claims (17)

[Claims] 1. A laminated dielectric substrate in which first and second dielectric substrates having conductor layers on both surfaces are bonded together using an adhesive resin. , Having a first transmission line on the surface,
The second dielectric substrate has a second ground conductor on a front surface, a second transmission line on a back surface, and a first dielectric substrate. A second ground conductor and first and second transmission lines connected to each other by through holes, and the semiconductor integrated circuit is flip-chip mounted on the square holes to form a high-frequency wave circuit And a low-frequency circuit formed by mounting a low-frequency device on the back surface. 2. The method according to claim 2, wherein the first dielectric substrate has a rectangular hole formed in the first dielectric substrate.
2. The high-frequency module according to claim 1, wherein the dielectric substrate has a concave shape without penetrating the dielectric substrate. 3. The method according to claim 1, wherein the first dielectric substrate has a rectangular hole formed in the first dielectric substrate.
2. The high-frequency module according to claim 1, wherein said high-frequency module has a concave shape formed by penetrating said dielectric substrate and shaving halfway through said second dielectric substrate. 4. The method according to claim 1, wherein the first dielectric substrate has a rectangular hole formed in the first dielectric substrate.
4. The high-frequency module according to claim 1, wherein the dielectric substrate is penetrated and the second dielectric substrate is also penetrated. 5. A Teflon substrate as a first dielectric substrate and a second dielectric substrate as a second dielectric substrate.
5. The high frequency module according to claim 1, wherein said dielectric substrate is a glass epoxy substrate. 6. The high frequency module according to claim 5, wherein the second dielectric substrate is a multilayer substrate using at least two glass epoxy substrates. 7. The high-frequency module according to claim 5, wherein the first dielectric substrate is a multilayer substrate using at least two layers of a Teflon substrate. 8. The high-frequency device according to claim 1, wherein the first ground conductor on the back surface of the first dielectric substrate is eliminated and the second ground conductor on the front surface of the second dielectric substrate is left. module. 9. The high frequency device according to claim 1, wherein the second ground conductor on the front surface of the second dielectric substrate is eliminated, and the first ground conductor on the rear surface of the first dielectric substrate is left. module. 10. A second ground conductor on a surface of a second dielectric substrate is selectively left in accordance with a position of a square hole of the first dielectric substrate, and is provided at a portion where the second ground conductor is removed. , Third
9. The high-frequency module according to claim 1, further comprising: a transmission line. 11. The high-frequency module according to claim 1, wherein the first and second dielectric materials are bonded to each other by thermocompression bonding without using an adhesive resin. 12. A first transmission line and said semiconductor integrated circuit, wherein the square hole provided in the first dielectric material has a larger shape than the semiconductor integrated circuit and is mounted face-up so as to embed the semiconductor integrated circuit. 9. The high-frequency module according to claim 1, wherein said electrodes are connected by wires or ribbons. 13. The high-frequency module according to claim 8, wherein a semiconductor integrated circuit sealed in a package is used. 14. A third dielectric substrate having a hole larger than a square hole provided on the first dielectric substrate, wherein the third dielectric substrate is mounted on the first dielectric substrate. 2. The high-frequency module according to claim 1, wherein a bonding cover is attached to the third dielectric substrate, and a shielding lid is bonded on the third dielectric substrate. 15. A wireless terminal device using the dielectric laminate substrate and the high-frequency module according to claim 1. 16. A radio base station apparatus using the dielectric laminate substrate and the high-frequency module according to claim 1. 17. A wireless measuring device using the dielectric laminated substrate and the high-frequency module according to claim 1.