Radio frequency module and method for manufacturing the same

• US 20030107459A1
• Filed: 10/28/2002
• Published: 06/12/2003
• Est. Priority Date: 10/30/2001
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Ogura, Hiroshi, Fujita, Suguru, Takahashi, Kazuaki
• Granted Patent: US 6,791,438 B2
• Time in Patent Office: Days
• US Class Current: 333/230
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/16153 Cap enclosing a plurality of side-by-side cavities [e.g. E-shaped cap]
• CPC Class Codes: H01P 1/2088 Integrated in a substrate
• CPC Class Codes: H01P 11/007 Manufacturing frequency-selective devices resonators H01P11/008
• CPC Class Codes: H01P 5/107 Hollow-waveguide/strip-line transitions

Abstract

A rectangular penetration hole is formed opening in the opposite two main surfaces of a first dielectric substrate. Conductors for grounding are respectively formed on the main surfaces, to cover the openings of the penetration hole. A conductor layer is formed on opposite inner walls in the penetration hole of the dielectric substrate. A waveguide is structured by a space surrounded by the conductors and the conductor layers. The waveguide is magnetically coupled with an input/output line on a second dielectric substrate through a coupling slot. Because a waveguide has walls made continuous in the dielectric substrate, a low-loss waveguide can be realized. Hence, a high-performance radio frequency module can be realized.

Claims

1. A radio frequency module comprising:

a dielectric substrate having first and second main surfaces and a rectangular penetration hole opening in the first and second main surfaces;

first and second conductors for grounding respectively provided on the first and second main surfaces to cover the openings of the penetration hole; and

a conductor layer formed on opposite wall surfaces of the penetration hole in the dielectric substrate;

wherein a waveguide structure is formed by a space surrounded by the first and second conductors and the conductor layer.

2. A radio frequency module according to claim 1, wherein air exists in the space surrounded by the first and second conductors and the conductor layer.

3. A radio frequency module according to claim 1, wherein a vacuum is given or an inert or nitrogen gas is filled in the space surrounded by the first and second conductors and the conductor layer.

4. A radio frequency module according to claim 1, wherein the dielectric substrate has a part structuring the space surrounded by the first and second conductors and the conductor layer.

5. A radio frequency module according to claim 1, further comprising a slot provided in the first conductor in a region immediately above the penetration hole provided in the dielectric substrate, another dielectric substrate superposed on the first conductor, and an input/output microstrip line provided on the other dielectric substrate in a position where an electromagnetic coupling is to be obtained with the slot.

6. A radio frequency module according to claim 1, further comprising a filter circuit, having cavity resonators coupled in plurality, formed by a waveguide structure in the dielectric substrate.

7. A radio frequency module according to claim 1, further comprising slots in both the first and second conductors, the slot provided in the first conductor being coupled with a microstrip line while the slot provided in the second conductor being coupled with a waveguide.

8. A radio frequency module comprising:

a metal plate having a penetration hole; and

first and second conductors for grounding respectively provided on first and second main surfaces of the metal plate;

wherein a waveguide structure is formed by a space surrounded by the first and second conductors for grounding and a wall surface of the penetration hole.

9. A radio frequency module according to claim 8, further comprising another dielectric substrate using a multi-layer dielectric film, a buried through-hole provided in an arbitrary position of the dielectric film, an integrated circuit mounted on the buried through-hole, an electrode, a bump and a sealing cap mounted in a peripheral region.

10. A radio frequency module according to claim 8, further comprising a slot provided in the first conductor in a region immediately above the penetration hole provided in the dielectric substrate, another dielectric substrate overlaid the first conductor, and an input/output microstrip line on the other dielectric substrate in a position where an electromagnetic coupling is obtained with the slot.

11. A radio frequency module according to claim 8, further comprising a filter circuit having cavity resonators, coupled in plurality, formed by the waveguide structure in the dielectric substrate.

12. A radio frequency module according to claim 8, further comprising slots provided in both the first and second conductors, the slot provided in the first conductor being coupled with a microstrip line while the slot provided in the second conductor being coupled with a waveguide.

13. A radio frequency module comprising:

a copper plate having a penetration hole in an arbitrary position and a multi-layer dielectric film;

a buried through-hole provided in an arbitrary position of the dielectric film;

an integrated circuit mounted on the buried through-hole;

an antenna or filter circuit formed above the penetration hole; and

a metal cap mounted over said integrated circuit and said antenna or filter circuit.

14. A method for manufacturing a radio frequency module comprising the steps of:

forming, by laser forming, a penetration hole having a plurality of rectangular portions coupled one with another in a first dielectric substrate formed, on a first main surface, with a conductor for grounding to reach the conductor;

forming a metal film on an inner wall surface of the penetration hole; and

joining a second dielectric substrate forming a conductor for grounding on one surface and an input/output line on the other surface at the surface forming the conductor onto a second main surface of the first dielectric substrate forming the metal film through a conductive double-sided adhesive sheet worked with a blank hole in a form of the penetration hole.

15. A method according to claim 14, wherein the laser working is a working using a third or fourth harmonic of an excimer laser or YAG laser.

16. A method according to claim 14, further including a process to remove a roughening from an inner wall surface of the penetration hole, the metal film being formed after the process.

17. A method for manufacturing a radio frequency module comprising the steps of:

forming, by laser working, a groove leaving a plurality of rectangular dielectric portions coupled one with another in a liquid crystal polymer substrate forming a conductor for grounding on a first main surface to reach the conductor;

forming a metal plating film on an inner wall surface of the groove;

forming, by plating, a conductor film on a second main surface of the liquid crystal polymer substrate forming the metal plating film; and

forming a slot in a position of the conductor film corresponding to an input/output line, on which a second liquid crystal polymer substrate forming the input/output line is superposed to apply heat and pressure.

18. A method according to claim 17, including a process to carry out plasma or ozone cleaning on bonding surfaces of the first and second liquid crystal polymer substrates prior to applying heat and pressure.

19. A method for manufacturing a radio frequency module comprising:

a process of forming, by laser working or blanking, a penetration hole having a plurality of rectangular portions coupled one with another in a first liquid crystal polymer substrate;

a process of forming a metal plating film on an inner wall surface of the penetration hole;

a process of forming an input/output line on one main surface of a second liquid crystal polymer substrate;

a process of forming a conductor for grounding on the other main surface of the second liquid crystal polymer substrate in a position corresponding to the input/output line; and

a process of superposing the first and second liquid crystal polymer substrates on the conductor plate to apply heat and pressure thereto.

20. A method according to claim 19, wherein, when a metal plating film is formed on the inner wall surface of the penetration hole of the first liquid crystal polymer substrate, precipitation rate of plating is controlled thereby causing precipitation of a soft plating film.

21. A method for manufacturing a radio frequency module comprising:

a process of forming, by machining or wet etching, a penetration hole leaving a plurality of rectangular portions coupled one with another in a metal plate having a conductor for grounding on a first main surface, to reach the conductor;

a process of forming an input/output line on a first main surface of a dielectric substrate;

a process of forming a conductor for grounding on a second main surface of the dielectric substrate in a position corresponding to the input/output line;

a process of placing to oppose, within a vacuum chamber, a second main surface of the metal plate and a surface forming the conductor of the dielectric substrate, and joining the metal plate and the dielectric substrate in a vacuum or inert or nitrogen gas by applying heat and pressure.

22. A method according to claim 21, including a process of any of plasma cleaning, atom beam cleaning and ion beam cleaning of joining surfaces of the metal plate and the dielectric substrate prior to applying heat and pressure.

23. A method for manufacturing a radio frequency module comprising the steps of:

cutting a dielectric substrate into a form having a plurality of rectangular portions coupled one with another;

forming a metal film on an outer peripheral wall surface of the dielectric substrate of after cutting; and

surrounding an outer periphery of the dielectric substrate formed with the metal film with synthetic resin materials.