JPH07221495A - Automatic assembling device for crystal oscillating circuit - Google Patents

Abstract

PURPOSE:To shorten the automatic assembling process of a crystal oscillating circuit and cut down the manufacture cost by selecting an optimum crystal oscillator, which oscillates at specified oscillation frequency, from the crystal oscillator stocker, corresponding to the capacitance of the inside capacitor of an integrated circuit, and automatically mounting crystal oscillator in the specified places on a circuit board. CONSTITUTION:A measuring apparatus 8 provided with a reference crystal oscillator measures oscillation frequency by bringing its reference crystal oscillator into contact with a circuit board 3 being sent, and oscillating it. Since the oscillation frequency is in constant correlation with the capacitance of the capacitor inside an integrated circuit, the capacitance of the inside capacitor can be detected by the measurement of the oscillation frequency. Next, when it is coupled with the capacitance of the inside capacitor, a crystal oscillator, which oscillates with the specified frequency, is selected. The crystal oscillator is supplied from a crystal oscillator stocker 14 which selects and stocks crystal oscillators, according to the frequency, and an optimum crystal oscillator is mounted in the specified place of the circuit board 3, according to the results of measurement, by an automatic mounter 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic assembling apparatus for a crystal oscillator circuit. For example, in order to obtain a predetermined oscillation frequency in the crystal oscillator circuit of a quartz watch, an integrated circuit is provided on a circuit board. The present invention relates to an automatic crystal oscillator circuit assembling apparatus that selects an optimum crystal unit suitable for its own capacitance and mounts the crystal unit on a circuit board.

[0002]

2. Description of the Related Art In recent years, in assembling electronic elements on a circuit board of a quartz timepiece, automatic assembly is advancing instead of manual work, and there is an increasing demand for labor saving work.
Therefore, the present applicant has previously proposed an automatic assembling apparatus for a crystal oscillation circuit (Japanese Utility Model Publication No. Hei 3-18759) which is automatically assembled.

[0003]

However, in the above-mentioned prior art, the circuit is provided with one capacitor as a fixed load capacitance before frequency adjustment, and in order to achieve a predetermined oscillation frequency, in addition to the previous capacitor. Furthermore, a correction capacitor as a variable load capacitance is mounted. However, in this method, it is necessary to prepare a large number of small-sized capacitors for correction which have slightly different capacities, which causes a problem of high cost.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an automatic assembling apparatus for a crystal oscillation circuit which can reduce the cost for mounting a circuit board.

[0005]

An automatic assembling apparatus for a crystal oscillation circuit according to the present invention is intended to solve the above-mentioned drawbacks of the prior art. A circuit board provided with an integrated circuit for driving a crystal oscillator, A transfer device for transferring this circuit board and a reference crystal oscillator are provided, and the internal crystal capacitance of the integrated circuit is detected by contacting the circuit board on the transfer device and vibrating the reference crystal oscillator to measure the frequency. The crystal unit is a crystal unit that stores crystal units with different frequencies for each frequency, and the optimum crystal unit that can oscillate at the target oscillation frequency according to the measurement result by the crystal unit. It consists of an automatic mounting device that selects from the oscillator stock device and mounts the crystal oscillator at a predetermined location on the circuit board.The automatic mounting device is a chuck for chucking the crystal oscillator. And the head, and a movement driving means of the chuck head.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, a work transfer device 1 is composed of a belt conveyor, on which a carrier 2 is placed and sent. On the carrier, three circuit boards are shown in the illustrated example. 3 is listed. The circuit board 3 is, for example, a quartz watch circuit board as shown in FIG. 2, on which printed wiring 4 is formed, and parts such as an integrated circuit 6 for driving a quartz oscillator are attached. At this point, the crystal oscillator 5 having an optimum range of frequency such that the rate of the crystal timepiece is within a certain range is to be installed.

The exterior of the crystal unit 5 is composed of a cylindrical tube portion and 2
It consists of a book electrode terminal. The measuring instrument 8 is provided with a reference crystal oscillator 7, and the reference crystal oscillator 7 is brought into contact with the circuit board 3 sent by the work carrier 1 and the reference crystal oscillator is vibrated. The oscillation frequency is measured. That is, in the measuring instrument 8, as shown in FIG. 4, a measuring head 10 is supported on a support plate 9 so as to be able to move up and down, and this measuring head is provided with a necessary probe 11 and a reference crystal oscillator 7. Therefore, the probe 11 is brought into contact with a predetermined portion of the circuit board 3 to vibrate the reference crystal oscillator 7. At this time, the reference crystal resonator 7 oscillates in a state of being electrically connected to the capacitor capacity inside the integrated circuit 6,
The oscillating frequency at this time is measured by the measuring device 8. The oscillation frequency fluctuates with a certain correlation with the capacitance of the capacitor inside the integrated circuit 6.

By measuring the oscillation frequency, the integrated circuit 6
The internal capacitor capacity of is detected. That is, there is individual difference (variation) in the internal capacitor capacity of the integrated circuit 6,
Even if the reference crystal oscillator 7 is oscillated, the oscillation frequency differs from the intended oscillation frequency depending on the integrated circuit at that time. Therefore, the internal capacitance of the integrated circuit 6 can be detected based on the above-mentioned relationship between the oscillation frequency and the capacitance of the internal capacitance of the integrated circuit 6 based on this difference.

Since the internal capacitor capacitance of the integrated circuit 6 mounted on the circuit board 3 or the amount of deviation from the reference frequency is known, the desired oscillation frequency when coupled with this internal capacitor capacitance in an electric circuit. The actually used crystal unit 5 that will oscillate at is selected.
Therefore, this procedure will be described below.

Next, a solder paste is applied to the circuit board 3 by the solder printing device 12 shown in FIG. Next, the crystal unit 5 is mounted on the circuit board 3 by the automatic mounting device 13. The crystal unit 5 is composed of, for example, multiple linear vibration feeders,
In the example of FIG. 1, 16 types of crystal oscillators 5 are supplied by the crystal oscillator stock device 14 in which the crystal oscillators 5 having different frequency values are sorted and accommodated according to frequency. The automatic mounting device 13 selects the most suitable crystal oscillator 5 to obtain the target oscillation frequency from the 16 types of crystal oscillators 5 corresponding to the above measurement result, and determines the optimum crystal oscillator 5 on the circuit board 3. Put it in place.

As shown in FIGS. 1 and 5, the automatic mounting device 13 is provided with a movement driving means and a chuck head 18 which will be described later and is moved by the movement driving means. The movement drive means includes a shaft 17 rotatably supported by screws having support plates 15 and 16, a motor 19 as an example of a rotation drive means for rotationally driving the shaft 17, and the motor 19. 1
A gear 20 and a reduction gear 21 that are in mesh with each other via a shaft 9 and a shaft 9. The chuck head 18 is
An air cylinder 23, which is an example of vertical drive means, is moved by the rotation of the shaft 17, an air suction type chuck 24 that is moved up and down by the operation of the air cylinder 23, and a tip of the chuck 24 from the crystal oscillator stock device 14 is used. In order to obtain the oscillation frequency, the crystal pipe 5 is vacuum-adsorbed, and the vacuum pipe 25 is mounted and mounted on the circuit board 3 at a predetermined position.

As shown in FIGS. 2 and 3, the carrier 2 has a crystal groove 5 formed on the side of the circuit board 3 on which the crystal resonator 5 is mounted so that a cylinder portion of the crystal resonator 5 can be mounted. And a head receiving portion 2b of the crystal unit 5 for restricting movement of the crystal unit 5 in the longitudinal direction. In a state in which the crystal unit 5 is placed on the cylinder holding unit 2a, the head of the cylinder unit of the crystal unit 5 contacts the head receiving unit 2b, and the electrode terminal of the crystal unit 5 is connected to the circuit board 3 Is in contact with a predetermined position of. That is, the crystal unit 5 does not move due to rolling or the like from the position where it is placed at a predetermined position on the circuit board 3.

As shown in FIGS. 1 and 5, support plates 15 and 16 are provided.
A guide rod 22 is fixedly attached to the chuck head 18, and the guide rod 22 guides the chuck head 18. That is, the automatic mounting device 13 includes the chuck head 18, a movement driving unit that moves and drives the chuck head 18, and the support plate 1.
5, 16 and a guide rod 22.
The circuit board 3 on which the crystal unit 5 is mounted is then sent by the carrier device 1 to the heating device 26, where the solder is reflowed to fix the crystal unit 5 on the circuit board 3.

Although extremely rare, an optimum crystal that can oscillate at a desired oscillation frequency by the internal capacitor capacitance obtained by vibrating the reference crystal resonator 7 by bringing it into contact with a predetermined portion of the circuit board 3 on which the IC is mounted. The oscillator 5 may not exist. In this case, as shown in FIG. 6, the feedback signal f1 is output from the measuring device 8 to the automatic mounting device 13, and the automatic mounting device 13 is stocked in the crystal oscillator stock device 14 based on this signal. The crystal resonator 5 that can oscillate at the frequency value closest to the target frequency value is selected from the 16 kinds of crystal resonators 5 and the crystal resonator 5 is mounted on the circuit board 3. A feedback signal f2 different from the above feedback signal is output from the measuring device 8 to the out-of-frequency standard selection device 27, and after the crystal oscillator 5 is mounted on the circuit board 3, the out-of-frequency product selection device 2
By 7, the products that are out of the frequency standard are separated from the products in the frequency standard. As for the sorted out-of-specification product, the optimum chip capacitor capable of oscillating at the target oscillation frequency is selected from the chip capacitors (not shown) pre-stocked in the capacitor mounting device 28 in the next step. It is attached (externally attached) to a predetermined circuit pattern on the circuit board 3 and corrected to a product within the frequency standard.

The feature of the operation in the above embodiment is that the probe 11 of the measuring instrument 8 is first brought into contact with a predetermined portion of the circuit board 3 sent by the work transfer device 1 to vibrate the reference crystal oscillator 7 and then integrated. The internal capacitor capacity of the circuit 6 is detected, and in response to this, the optimum crystal resonator 5 that can oscillate at the target oscillation frequency for this internal capacitor capacity is selected from the crystal resonator stock device 14 and automatically selected. The crystal unit 5 is mounted on the circuit board 3 by the mounting device 13.

In the measurement by the measuring device 8, when there is no optimum one of the 16 types of crystal oscillators 5 stocked in the crystal oscillator stocking device 14 that can oscillate at the intended oscillation frequency. Selects the crystal oscillator 5 that can oscillate at the frequency closest to the target frequency value, and then mounts the optimum chip capacitor in the subsequent process to make it a product within the frequency standard. The result is stored in the crystal unit 14
If the frequency value range of the crystal oscillator 5 of the type is exceeded, it may be directly treated as a defective product without post-processing.

[0017]

According to the present invention, the optimum crystal unit that will oscillate at the target oscillation frequency is selected from the crystal unit stock device in accordance with the internal capacitor capacity of each actually used integrated circuit. Along with the selection, the crystal unit can be mounted at a predetermined location on the circuit board using the automatic mounting device, eliminating the need to prepare a large number of external load capacitors. The process can be shortened and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view of an essential part showing an embodiment of the present invention.

FIG. 2 is a plan view of a quartz watch circuit board on a carrier.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view of a measuring head.

FIG. 5 is a side view of the automatic mounting device.

FIG. 6 is a block diagram.

[Explanation of reference numerals] 1 carrier device 3 circuit board 5 crystal oscillator 6 integrated circuit 7 reference crystal oscillator 8 measuring device 13 automatic mounting device 14 crystal oscillator stock device 18 chuck head 17, 19, 20, 21 moving drive means

Claims (1)

[Claims] 1. A circuit board provided with an integrated circuit for driving a crystal unit, a transfer device for transferring the circuit board, and a reference crystal unit, which are brought into contact with the circuit board on the transfer unit. And a measuring instrument that vibrates the reference crystal oscillator to measure the frequency to detect the internal capacitance of the integrated circuit, and a crystal oscillator stock device in which crystal oscillators having different frequencies are accommodated for each frequency, Select the most suitable crystal unit that can oscillate at the target oscillation frequency from the above crystal unit, and mount the crystal unit at the specified location on the circuit board according to the measurement result by the measuring instrument. The automatic mounting device comprises a chuck head for chucking the crystal unit, and a movement driving means for the chuck head. Automated assembly apparatus of the crystal oscillator circuit according to claim Rukoto.