JPH06104641A - Surface mount type oscillator - Google Patents

Abstract

PURPOSE:To provide the surface mount type oscillator providing simple assembling work and with a structure facilitating a small size and a thin profile. CONSTITUTION:A chip 18 for an oscillation circuit is mounted on one side of a wiring board 16 on both sides of which wiring patterns are formed, a resonator chip 22 is mounted on the other side, and the wiring board 16 on which the oscillation circuit chip 18 and the resonator chip 22 are mounted is contained in a package 10. Terminals 14A-14D projected from a bottom face of the package 10 are connected to a wiring pattern on one side of the wiring board 16. The oscillator is mounted by directly connecting the terminals 14A-14D to the wiring pattern on the mount board.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount oscillator connected only to wiring on one surface of a mounting substrate, and more particularly to a surface mount oscillator using a resonator such as a crystal resonator or a SAW (surface acoustic wave) resonator. Regarding the oscillator.

[0002]

2. Description of the Related Art In recent years, surface mounting type oscillators, in which wiring is connected only on one surface (mounting surface) of the mounting substrate on which the oscillators are mounted, have been widely used as the mounting density has become higher. The surface mount oscillator is a bulk resonator such as a crystal or ceramic, a resonator chip such as a SAW (surface acoustic wave) resonator, a silicon transistor of an oscillation circuit, a resistor,
A hybrid IC including an oscillator circuit chip such as a capacitor is housed in a single container.

As such a surface mount type oscillator, a hermetically sealed type oscillator is becoming the mainstream because of its high reliability, in place of the resin mold type oscillator used so far. As a conventional hermetic seal type, there is one in which a hybrid IC is formed on a substrate such as alumina, a resonator chip is arranged on the hybrid IC, and the alumina substrate is housed in a metal package.

Further, wiring is performed inside the ceramic package to integrally form the package and the substrate, and silicon ICs, resistors, capacitors, etc. are arranged on the wiring inside the ceramic package, and a resonator chip is mounted thereon. There are things I try to do.

[0005]

However, in the case of using the above-mentioned metal package, the metal package itself is inexpensive in terms of material, but the lead terminals do not contact the metal package because it is a surface mount type. As described above, the insulator must be inserted into the external lead terminal to perform the lead homing, resulting in a problem that the cost becomes high.

Further, in the case of using the ceramic package, there are problems that the assembling work in the narrow package is difficult and the fixing of the resonator chip is difficult. In addition, since a metal seal frame is brazed with silver on the uppermost layer of the ceramic package for hermetic sealing, there is a problem that it is more expensive than the metal package.

Further, both in the case of using the metal package and the case of using the ceramic package, there is a problem that it is difficult to make the device compact and thin due to structural restrictions. An object of the present invention is to provide a surface-mounted oscillator having a structure that is easy to assemble and can be easily reduced in size and thickness.

[0008]

The above object is to provide a wiring board having wiring formed on both surfaces thereof, an oscillator circuit chip arranged on one surface of the wiring board, and an oscillation circuit chip arranged on the other surface of the wiring board. A resonator chip, a container for housing the wiring board, the oscillator circuit chip, and the resonator chip, and a terminal connected to a wiring on one surface of the wiring board and protruding from the bottom surface of the container. The terminal is connected only to the wiring on the mounting surface of the mounting board.

[0009]

According to the present invention, a wiring board having an oscillation circuit chip arranged on one surface and a resonator chip arranged on the other surface is housed in a container, and terminals connected to wiring on one surface of the wiring board are accommodated. Since the container is projected inward from the bottom surface of the container, it can be easily assembled and the entire structure can be easily reduced in size and thickness.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A surface mount oscillator according to an embodiment of the present invention will be described with reference to FIG. FIG. 1A is a plan view of the surface mount oscillator, and FIG. 1B is a sectional view. In this embodiment, a metal package 10 having an electromagnetic shielding property is used as a hermetically sealed container. A concave portion 10 for accommodating components is provided inside the metal package 10.
a is formed.

Circular holes are formed at four corners on the bottom surface of the metal package 10 for providing terminals, and the terminals 14A, 14B, 1 electrically insulated by the glass 12 are formed in the holes.
4C and 14D are provided. As a wiring board, a thickness of 12 on which wiring patterns connected to each other are formed.
Flexible printed circuit board 16 made of 5 μm polyimide
Is used. An IC chip 18, which is a monolithic integrated circuit forming an oscillation circuit, is mounted on the lower surface of the flexible printed board 16, and a crystal resonator chip 22 is mounted on the upper surface.

In order to connect the flexible printed board 16 and the IC chip 18, the flexible printed board 1
As shown in FIG. 1 (c), on the bottom surface of No. 6, B-TAB (Bu
mp-Tape Automated Bonding) mesa bump 16a
Are formed, and the IC chip 18 is connected through the mesa-shaped bumps 16a. In addition, as shown in FIG. 1D, transfer bumps 16b are formed on the lower surface of the flexible printed board 16, and the IC chip 18 is formed through the transfer bumps 16b.
May be connected.

On the upper surface of the flexible printed board 16, a crystal resonator chip 22 having an oscillation frequency of 16 MHz and a thickness of 0.1 mm is cantilevered by a conductive adhesive 20 on the right side. Electrode 22 on the upper surface of crystal resonator chip 22
A is electrically and mechanically connected to the wiring (not shown) of the flexible printed circuit board 16 by the conductive adhesive 20, and the electrode 22B on the lower surface of the crystal resonator chip 22 is connected by the conductive adhesive 20 to the flexible printed circuit board 16. Electrically and mechanically connected to wiring (not shown).

The flexible printed board 16 on which the IC chip 18 and the crystal resonator chip 22 are mounted is housed in the metal package 10 with the mounting surface of the IC chip 18 as the lower surface, and wiring on the lower surface of the flexible printed board 16 (not shown). ) And the terminals 14A, 14B, 14C and 14D provided on the bottom surface of the metal package 10 and protruding inward are directly electrically and mechanically connected via the conductive adhesive 24.

The upper surface of the metal package 10 has a thickness of about 0.
A 125 mm metal cap 26 is adhered to completely seal the inside of the oscillator. The surface mount oscillator of this embodiment can be formed as thin as about 1 mm in thickness. When the surface mount oscillator of this embodiment is mounted on a mounting board (not shown), the terminals 1 exposed on the bottom surface of the metal package 10 are mounted.
4A, 14B, 14C and 14D are directly connected to the wiring on the mounting surface of the mounting board through the surface.

As described above, according to this embodiment, since it is a hermetically sealed type, high reliability can be ensured, and an ultra-small and ultra-thin surface-mounted oscillator can be realized. Next, a method of manufacturing the surface mount oscillator according to this embodiment will be described with reference to FIGS.

First, bumps for connecting the IC chip 18 are formed on a flexible tape for TAB (Tape Automated Bonding) in which wiring is formed on both sides of the flexible tape (step S100). A large number of flexible printed boards 16 are formed by cutting this flexible tape. On the other hand, the wafer on which a large number of ICs to be mounted on the flexible printed board 16 are formed is diced to form the IC chip 18 (step S102).

Next, the IC formed in step S102
The chip 18 is mounted on the flexible tape formed in step S100 by the TAB (Tape Automated Bonding) technique (step S104). On the other hand, a large number of crystal resonators are formed on the wafer, and electrodes are formed on each crystal resonator (step S106). Next, the wafer on which a large number of crystal resonators are formed is diced to form the crystal resonator chip 2
2 is formed (step S108).

Next, the flexible tape is cut to cut the IC.
Flexible printed circuit board 16 on which chip 18 is mounted
To form. Next, the wirings (not shown) on the lower surface of the flexible printed board 16 are connected to the terminals 14A, 14B, 14C, 14D of the metal package 10 prepared in advance by the conductive adhesive 24, whereby the metal package 10 The flexible printed circuit board 16 having the IC chip 18 mounted therein is housed (step S110).

Next, the oscillator circuit in the IC chip 18 is inspected (step S112). If the inspection is passed, the process proceeds to the next step 114, but if the inspection is not passed, it is rejected as a defective product. If the inspection is passed, the crystal resonator chip 22 prepared in step S108 is cantilevered on the right side by the conductive adhesive 20 on the upper surface of the flexible printed board 16 (step S114).

Next, the crystal resonator chip 22 is finely adjusted from above the metal package 10 to adjust the oscillation frequency (step S116). As described above, according to this embodiment, there is an advantage that the oscillation frequency can be adjusted at the final stage of assembly. Next, the metal cap 26 is joined to the upper surface of the metal package 10 to completely seal the inside of the oscillator (step S118).

Next, a final inspection is performed as an oscillator (step S120). If the inspection is passed, the process proceeds to the next step S122, but if the inspection is not passed, it is rejected as a defective product. Next, the surface of the metal cap 26 is stamped (step S122), and then the metal cap 26 is packaged to complete a series of manufacturing steps (step S124).

As described above, the surface mount oscillator according to the present embodiment can be easily assembled and the frequency can be finely adjusted at the final stage. Moreover, since the TAB technology can be used, it is possible to easily mass-produce a thin surface mount oscillator having a thickness of about 1 mm. A surface mount oscillator according to another embodiment of the present invention will be described with reference to FIG. The same components as those of the surface-mounted oscillator of the embodiment shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

The surface-mounted oscillator of this embodiment uses a SAW (surface acoustic wave) resonator instead of a crystal resonator. That is, the central IDT electrode 30A is formed on the upper surface of the surface acoustic wave resonator chip 30, and the reflectors 30B and 30C are formed on both sides of the IDT electrode 30A. Both electrodes of the IDT electrode 30A are electrically and mechanically connected to the wiring (not shown) of the flexible printed board 16 by the conductive adhesive 20.

Since the surface acoustic wave resonator chip 30 has no electrodes formed on the lower surface, the flexible printed circuit board 1
It is possible to directly perform die bonding without providing a void in 6. The surface-mounted oscillator of this embodiment can be easily assembled and mass-produced in the same manner as the above-mentioned embodiments.

The present invention is not limited to the above embodiment, but various modifications can be made. For example, although a metal package is used as the container in the above embodiment, a ceramic package may be used. Further, not only the crystal resonator and the surface acoustic wave resonator but also other kinds of resonators may be used.

[0027]

As described above, according to the present invention, a wiring board having an oscillation circuit chip arranged on one surface and a resonator chip arranged on the other surface is housed in a container, and the wiring board is arranged on one surface of the wiring board. Since the terminals connected to the wiring are projected inward from the bottom surface of the container, they can be easily assembled and the entire size can be easily reduced in size and thickness.

[Brief description of drawings]

FIG. 1 is a diagram showing a surface mount oscillator according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram (Part 1) of a manufacturing process of the surface mount oscillator according to the embodiment of the present invention.

FIG. 3 is an explanatory view (No. 2) of the manufacturing process of the surface mount oscillator according to the embodiment of the present invention.

FIG. 4 is a diagram showing a surface mount oscillator according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Metal package 10a ... Recess 12 ... Glass 14A, 14B, 14C, 14D ... Terminal 16 ... Flexible printed circuit board 16a ... Mesa bump 16b ... Transfer bump 18 ... IC chip 20 ... Conductive adhesive 22 ... Crystal resonator chip 22A , 22B ... Electrode 24 ... Conductive adhesive 26 ... Metal cap 30 ... Surface acoustic wave resonator chip 30A ... IDT electrodes 30B, 30B ... Reflector

Claims (1)

[Claims] 1. A wiring board having wiring formed on both sides thereof, an oscillation circuit chip arranged on one surface of the wiring board, a resonator chip arranged on the other surface of the wiring board, and the wiring. On a mounting surface of a mounting board, a container for accommodating the substrate, the oscillation circuit chip, and the resonator chip, and a terminal connected to wiring on one surface of the wiring board and protruding from a bottom surface of the container are provided. The surface-mounted oscillator, wherein the terminal is connected only to the wiring.