JPH04117806A - Mount structure for crystal oscillator - Google Patents

Abstract

PURPOSE:To reduce disturbance in an output waveform considerably by adhering a package of a crystal oscillator closely to a joining pattern of a printed circuit board so as to join them and connecting a power supply pattern, an output pattern, a power pin and an output pin respectively thereby strengthening the connection between a GND pattern and a crystal oscillator. CONSTITUTION:A power supply pin 11-2 and an output pin 11-3 of a crystal oscillator 11 are inserted to a throughhole of a printed, circuit board 12 to adhere a mount face of a package 11-1 and a joining pattern 12-1 provided to the surface of the printed circuit board 12 closely to connect the said joining pattern 12-1 and a cap soldered to the package 11-1 with solder 13 and the cap and a GND pattern 12-4 are made conductive by a via 12-4a. Moreover, the power supply pin 11-2, the output pin 11-3, a power supply pattern 12-2 and an output pattern 12-3 of the printed circuit board 12 are connected and the crystal oscillator 11 is mounted.

Description

[Detailed Description of the Invention] [4 Already Required] Regarding the mounting structure of a crystal oscillator on a printed board that is widely used in the configuration of various electronic devices, the ground connection of the crystal oscillator, which is being made to operate at higher frequencies, is strengthened to increase the high frequency of the printed board. In order to improve the characteristics of the crystal oscillator, the crystal oscillator circuit is installed in a package connected to the ground part of the crystal oscillator circuit, and a power supply pin and an output pin are respectively provided, and a power supply pattern and A printed board is provided with a grounding pattern and an output pattern formed on its inner layer, and a bonding pattern formed on its surface that is electrically connected to the grounding pattern and fixing the package. The packages are closely joined together, and the power supply pattern and the output pattern are connected to the power supply pin and the output pin, respectively.

[Industrial Application Field] The present invention relates to a mounting structure for a printed circuit board crystal oscillator that is widely used in the construction of various electronic devices.

BACKGROUND ART Recently, printed circuit boards for various computers and the like are required to have higher precision in the high frequency signals emitted from the crystal oscillators due to higher density packaging of electronic components and higher frequency crystal oscillators. Therefore, in the mounting of crystal oscillators, which are expected to have even higher frequencies in the future, there is a need for a new crystal oscillator mounting structure that can strengthen the ground connection as much as possible and improve the high frequency characteristics of the printed circuit board.

[Conventional technology]

The mounting structure of the conventionally widely used cap-type crystal oscillator is as shown in Figure 4, where the power supply pattern 2-2 and GND are connected.
Pattern 2-4. and output patterns 2-3 are sequentially provided on the inner layer, and a through hole of a multilayer printed board 2 has a signal transmission pattern (not shown) formed on the main surface.
Power supply pins 1-2 and output pins 13 vertically installed on the mounting surface side of the crystal oscillator 1 are electrically connected to the package Ll.
Each of ND pins 1-4 is inserted.

Then, connect the power supply pattern 2-2 of the printed board 2 and the crystal oscillator 1 to the power supply pin 1. -2, GND pattern 2-4
and GND pins 1-4. And by connecting output pattern 2-3 and output pin 1-3 with a solder dip,
Insulating protrusion 1 arranged on the mounting surface side of the crystal oscillator 1
-18, it is mounted with a minute gap provided between it and the main surface of the printed board 2.

[Problems to be Solved by the Invention] The problem with the conventional crystal oscillator mounting structure described above is that the crystal oscillator 1 mounted on the printed board 2 has a protrusion 1 disposed on the mounting side of the pan cage 1-1. A gap is formed between the main surface of the printed board 2 and the main surface of the printed board 2 due to -1a. As a result, although the pan cage 1-1 of the mounted crystal oscillator 1 is connected to the GND of the internal crystal oscillator circuit, it is in a floating state with respect to the printed board 2 and the GND is not strengthened. In high-frequency oscillation, slight waveform disturbances occur due to noise. As a result, a problem arises in that the clock precision of printed circuit boards with higher frequency and higher density packaging is reduced.

In view of the above-mentioned problems, it is an object of the present invention to provide a new crystal oscillator mounting structure that can improve the high-frequency characteristics of a printed board by strengthening the ground connection of a crystal oscillator that has a higher frequency.

[Means for Solving the Problem] As shown in FIG. 1, the present invention includes a crystal oscillation circuit installed in a package 11-1 connected to the GND of the crystal oscillation circuit, and a power pin 11-2 and a power supply pin 11-2. A crystal oscillator 11 with output pins 11-3 vertically installed, and a power supply pattern 12-
2 and GND pattern 12-4 and output pattern 12-
3 is formed on the inner layer, and a bonding pattern 12-1 is formed on the surface thereof to be electrically connected to the GND pattern 12-4 and to fix the package 11-1. The package 11-1 of the crystal oscillator 11 is brought into close contact with the package 11-1 of the crystal oscillator 11, and the package 11-1 of the crystal oscillator 11 is connected to the package 11-1 by solder 13. Connect each.

[Function] In the present invention, when the package 1 of the crystal oscillator 11 is brought into close contact with the bonding pattern 12 formed on the surface of the printed board 12 and bonded with solder 13, the crystal oscillator 11 is firmly attached to the printed board 12. Pasokashi 11-1 is fixed to
Since the GND pattern 12-4 on the inner layer is electrically conductive, the connection between the GND pattern 12-4 and the crystal oscillator 11 is strengthened, and disturbances in the output waveform are minimized, thereby improving the high frequency characteristics of the printed board 2. It becomes possible to do so.

[Example] The present invention will be described in detail below with reference to Fig. 1.77+〒3.

FIG. 1 is a schematic sectional view showing the mounting structure of a crystal oscillator according to the first embodiment of the present invention, FIG. 2 is a schematic sectional view showing the mounting structure of the second embodiment, and FIG. 3 is the third embodiment. 1 is a schematic cross-sectional view of the mounting structure of FIG. 1, in which 11 is a crystal oscillator mounted to improve high frequency characteristics, and 12 is a printed board of the first embodiment on which the crystal oscillator is mounted.

As shown in the first part, the crystal oscillator 11 has a crystal oscillation circuit disposed inside a package 11-1, a power pin 11-2 and an output pin 1-3 vertically disposed on the mounting surface side, and This is a cap-type crystal oscillator in which a cap made of metal is attached to the pan cage 11-1 and is connected to a crystal oscillator circuit (G N l).

The printed circuit board 12 has the projected dimensions of the crystal oscillator 11 to be mounted on the surface of an insulating substrate on which a power supply pattern 12-2, a GND pattern 12-4, and an output pattern 12-3 are formed on the inner layer, as shown in FIG. A bonding pattern 12-1 made of a conductor of a slightly larger size is formed, and the bonding pattern 12-1 and the GND pattern 12-4 in the inner layer are electrically connected to each other by a conductor via 12-4a.

The mounting structure of the crystal oscillator of the first embodiment using the above-mentioned members is as shown in FIG.
-2 and the output pin 11-3 into the through hole of the printed board 12, the bonding pattern 12 is formed on the mounting surface of the package 11-1 and the surface of the printed board 12.
-1 in close contact with each other, the bonding pattern 12] and the cap attached to the package 11-1 are connected by solder 13, and the cap and CHD pattern 12-4 are electrically connected through the via 12-4a, and the solder The crystal oscillator 11 is mounted by connecting the power supply pin 11-2 and output pin 1]-3 to the power supply pattern 12-2 and output pattern 12-3 of the printed circuit board 12 by dips.

In addition, as shown in the second embodiment of FIG. 2, a thick film portion is provided in the GND pattern 22-4 formed on the inner layer of the substrate, and a bond with a dimension slightly larger than the projected dimension of the package 11-1 of the crystal oscillator 11 is formed. A pattern 22-1 forms a printed board 22 exposed from one surface, and the power pin 11-2 and output pins 11-3 of the crystal oscillator 11 are connected to each other as in the first embodiment.
is inserted into the through hole to bring the mounting surface of the package 11-1 into close contact with the exposed GND pattern 22-4, and the cable 2 and the GND pattern 22-4 attached to the package 11-1 are inserted into the through hole.
It is connected to the D pattern 22-4 by solder 13, and the power supply pin 11-2 and output pin 11-3 are connected to the power supply pattern 22-2 and output pattern 22-3 inside the printed board 22.

Historically, as shown in the third embodiment of FIG. 3, a crystal oscillator 1]
The recess 32- is large enough to insert the package 11-1.
1 is provided on one surface, and a printed board 32 is formed with an inner layer GND pattern 32-4 exposed on the bottom surface thereof.

Then, the mounting surface of the package 11-1 and the exposed G
The ND pattern 32-4 is closely attached to the cap and connected by solder 13, and the power pin 11-2 is
The crystal oscillator 11 is mounted by connecting the output pin 11-3 to the power supply pattern 32-2 and output pattern 323 inside the printer I-board 32.

As a result, the connection between the ground of the crystal oscillator and the ground pattern of the printed board is strengthened, and high frequency characteristics can be improved.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the configuration is extremely simple, and even when a high-frequency crystal oscillator is mounted, the connection with ground 1- is strengthened, and the high-frequency characteristics of the printed board are improved. There are advantages such as being able to
It is possible to provide a crystal oscillator mounting structure that can be expected to have significant economic and reliability effects.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a mounting structure of a crystal oscillator according to a first embodiment of the present invention, FIG. 2 is a sectional view showing a mounting structure of a second embodiment, and FIG. 3 is a sectional view showing a mounting structure of a third embodiment. FIG. 4 is a cross-sectional view showing the mounting structure of a conventional crystal oscillator. In the figure, 11 is a crystal oscillator, 11-1 is a package, 11-2 is a power supply pin, 11-3 is an output pin, 1.2.22.32 is a printed board, 1.2-], 22-1 is a junction Pattern, 12-2
．． 22-2.32-2 is the power pattern, 12-3.22
-3.32-3 is the output pattern, 12-4.22-4.
32-4 is a GND pattern, 12-4a is a via, 13 is solder, 32-1 is a recess,

Claims (3)

[Claims] (1) Package connected to the ground part of the crystal oscillator circuit (
11-1) is equipped with the crystal oscillation circuit, and the power pin (
11-2) and an output pin (11-3), a power supply pattern (12-2) and a ground pattern (12-4).
and a printed board having an output pattern (12-3) formed on the inner layer and a bonding pattern (12-1) formed on the surface to be electrically connected to the ground pattern (12-4) and to fix the package (11-1). (12), the bonding pattern (12-1) of the printed board (12)
the package (11-1) of the crystal oscillator (11);
At the same time, the above power supply pattern (1
2-2) and a mounting structure of a crystal oscillator, characterized in that the output pattern (12-3) is connected to the power supply pin (11-2) and the output pin (11-3), respectively. (2) The printed board has a thick film part on the ground pattern (22-4) formed on the inner layer, and the crystal oscillator (1
2. The crystal oscillator mounting structure according to claim 1, wherein a bonding pattern (22-1) of a size that allows the package (11-1) of item 1) to be bonded is exposed on the surface of the substrate. (3) The printed board has a recess (32-1) large enough to insert the package (11-1) of the crystal oscillator (11) on the surface of the board, and an inner layer ground pattern ( 3. The crystal oscillator mounting structure according to claim 1, wherein 32-4) is exposed.