JP3715487B2 - Circuit board and crystal oscillator using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board for a crystal oscillator in which a plurality of circuit boards that are formed and divided from a sheet substrate are used as industrial technical fields, and in particular, a terminal electrode is prevented from being peeled when the sheet substrate is divided.
[0002]
[Prior art]
BACKGROUND OF THE INVENTION Crystal oscillators are widely used in various electronic devices including communication devices as a frequency and time reference source. In recent years, downsizing of portable devices and the like has spread, and further downsizing of crystal oscillators has been promoted. Accordingly, effective utilization of a circuit board on which a crystal resonator and other circuit elements are mounted is required.
[0003]
(Example of Prior Art) FIG. 3 is a diagram showing a crystal oscillator, particularly a circuit board, for explaining one conventional example.
The circuit board 1 is made of, for example, a glass epoxy material, and is generally divided into individual parts after forming the same electrode pattern (not shown) on the sheet substrate 2 at once. For example, an electrode pattern including the terminal electrode 3 (ab) is formed for each of a plurality of circuit board regions (a region to be the circuit substrate 1 and a substrate region) in the sheet substrate 2. The terminal electrode 3 (ab) is electrically connected to the electronic component, for example, the terminal 5 (ab) of the capacitor 4 by the solder 6.
[0004]
Then, by dividing (pressing), the dividing grooves 7 are formed on the four sides forming the outer periphery of the substrate region, and the bridging portions 8 are formed on the square portions. Furthermore, in this example, for example, a power source or a ground of each circuit board 1 is commonly connected to form an electrode line 10 connected to a measurement terminal 9 provided at one end of the sheet substrate 2. In addition, the shaded part in the figure is the real part of the sheet substrate 2, and the black dot part is the electrode.
[0005]
Next, after mounting each electronic component such as a crystal resonator constituting the oscillation circuit on the sheet substrate 2 (not shown), the oscillation frequency or the like is adjusted for each substrate region by a measuring device connected to a measurement terminal. Then, after covering with a cover (not shown), the bridge portions 8 of each substrate region (circuit substrate 1) were cut to obtain individual crystal oscillators.
[0006]
[Problems to be solved by the invention]
(Problem of the prior art) However, in the circuit board 1 having the above configuration, one of the terminal electrodes 3a is brought as close as possible to the outer periphery of the circuit board 1 because the board surface area is effectively used. For this reason, there is a problem that the outer peripheral portion of the circuit board 1 vibrates or is distorted when the dividing groove 7 is formed by punching, stress is concentrated on the junction boundary between the terminal electrode 3a and the substrate body, and the terminal electrode 3a is peeled off. It was.
[0007]
Further, in this example, since adjustment is performed collectively by the measurement terminals 9, the electrode lines 10 are formed in the bridging portions 8 of the respective circuit boards 1. And since the bridge part 8 is finally cut | disconnected, a width | variety is narrowed as much as possible. Therefore, even in this case, there is a problem of peeling off the electrode line 10 as described above.
[0008]
(Object of the invention) An object of the present invention is to provide a circuit board which prevents electrode peeling and promotes miniaturization, and a crystal oscillator using the circuit board.
[0009]
[Means for Solving the Problems]
The present invention is based on the fact that the terminal electrode protrudes from the substrate region to be the circuit board and is formed on the board body, the board body is integrally cut from the terminal electrode, and the terminal electrode is extended to the outer peripheral edge of the circuit board. Solution. An embodiment of the present invention will be described below.
[0010]
[Action]
In the present invention, since the terminal electrode protrudes from the substrate region to the substrate body and the substrate body is integrally cut from above the terminal electrode, the junction boundary portion disappears at the outer peripheral portion of the terminal electrode and the substrate body, and the same end surface Become. Therefore, the stress generated on the joint surface at the outer peripheral end is suppressed. Further, since the terminal electrode extends to the outer peripheral edge of the circuit board, the plate surface area can be effectively utilized. An embodiment of the present invention will be described below.
[0011]
【Example】
FIG. 1 is a diagram of a crystal oscillator, particularly a circuit board, illustrating an embodiment of the present invention. In addition, the same number is attached | subjected to the part same as a prior art example figure, and the description is simplified or abbreviate | omitted. As described above, the circuit board 1 collectively forms an electrode pattern on the sheet substrate 2, forms the dividing groove 7, and is connected to the substrate body by the bridging portion 8. In this embodiment, the terminal electrode 3a is formed so as to protrude from the outer periphery of the substrate region 11 in the sheet substrate 2 (FIG. 2). Further, the electrode line 10 of the bridging portion 8 is formed on the substrate body with a width equal to or larger than the width of the bridging portion 8 after cutting (FIG. 2).
[0012]
And the outer periphery shown with the dotted-line frame of the board | substrate area | region 11 is punched, and the division | segmentation groove | channel 7 and the bridge part 8 are formed. Thereafter, circuit components constituting the oscillation circuit are mounted, adjusted and covered, and then the sheet substrate 2 is divided into individual circuit substrates 1 to obtain a plurality of crystal oscillators.
[0013]
With such a configuration, the terminal electrode 3 a is formed to protrude from the substrate region 11 of the sheet substrate 2 to the substrate body. Then, the substrate body is integrally cut from the terminal electrode 3a. Therefore, the terminal boundary 3a and the substrate body have the same end surface with the joining boundary portion disappearing at the outer peripheral portion. From this, the stress which generate | occur | produces in the joint surface of an outer peripheral end is suppressed, and electrode peeling is prevented.
[0014]
Further, since the terminal electrode 3a extends to the outer peripheral end of the circuit board 1, the plate surface area can be effectively utilized and the miniaturization is promoted. In this embodiment, since the electrode line 10 of the bridging portion 8 is cut larger than the width of the bridging portion 8, electrode peeling is prevented in this case as well.
[0015]
[Other matters]
In the above embodiment, only one of the terminal electrodes 3 (ab) 3a is extended to the outer peripheral edge of the circuit board 1. However, even when the terminal electrode 3 (ab) is formed orthogonally to the outer periphery of the circuit board, the same applies. Applicable. Moreover, although it demonstrated as a circuit board for crystal oscillators, it is applicable also to the circuit board which mounts an electronic component.
[0016]
The sheet substrate 2 is provided with a measurement terminal 9 for frequency adjustment and the like, and the electrode line 10 is formed in the bridging portion 8, but the measurement terminal 9 and the electrode line 10 are not provided, and an electrode pattern is formed on the sheet substrate 2. The present invention can be applied to the case of dividing, or the case of dividing after mounting electronic parts. In short, the present invention can be applied to the case where the dividing groove 7 is formed on the outer periphery of the substrate region in the sheet substrate 2 and then divided into individual circuit substrates 1.
[0017]
【The invention's effect】
In the present invention, the terminal electrode is formed so as to protrude from the substrate region serving as the circuit board to the board body, the board body is integrally cut from the terminal electrode, and the terminal electrode is extended to the outer peripheral end of the circuit board. A circuit board which prevents peeling and promotes miniaturization and a crystal oscillator using the circuit board can be provided.
[Brief description of the drawings]
FIG. 1 is a partially enlarged plan view of a sheet substrate after formation of dividing grooves for explaining an embodiment of the present invention.
FIG. 2 is a partially enlarged plan view of a sheet substrate before the formation of a dividing groove for explaining an embodiment of the present invention.
FIG. 3 is a partially enlarged plan view of a sheet substrate after formation of divided grooves for explaining a conventional example.
FIG. 4 is a sectional view in which an electronic component is connected to a terminal electrode for explaining a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Circuit board, 2 Sheet board | substrate, 3 Electrode terminal, 4 Capacitor, 5 terminal, 6 Solder, 7 Dividing groove, 8 Bridge part, 9 Measurement terminal, 10 Electrode line, 11 Board | substrate area | region.

Claims (2)

A terminal electrode electrically connected to the electronic component, wherein a plurality of circuit board regions are separated from the board main body by dividing grooves and connected to the board main body by a bridge part, and the bridge part is cut; In the circuit board to be divided, the terminal electrode is formed to project from the circuit board region to the board body, the board body is integrally cut from above the terminal electrode to form the dividing groove, and the terminal electrode is formed. A circuit board characterized by extending to an outer peripheral end. A crystal oscillator comprising a crystal resonator and an oscillation circuit element mounted on the circuit board according to claim 1.

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