JPH0223697A - Device for manufacture of printed board - Google Patents

Abstract

PURPOSE:To eliminate bubbles in a through-hole completely by providing a vibration adjuster which adjusts the number of vibration produced by a vibration generator and by making the number of vibration coincident with the number of characteristic vibration of a printed board. CONSTITUTION:When an adjusting switch 21A of a vibration regulator 21 is operated successively, frequency of alternating current output from a variable frequency power source device 20 changes accordingly. Since the number of revolution of a vibration motor 18 changes accordingly, the number of vibration of a printed board also changes. When the number of this variable vibration becomes the same as the number of characteristic vibration of the printed board and attains a resonance state, vibration of the printed board becomes maximum. The adjusting switch 21A of the vibration regulator 21 is regulated so that the number of vibration becomes the same or nearly the same as the number of characteristic vibration of the printed board. Then the regulation is finished. Vibration from the vibration motor 18 can be transmitted to the printed board effectively in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a printed circuit board manufacturing apparatus that liquid-processes printed circuit boards, and in particular to a through-hole plating pretreatment apparatus for printed circuit boards, as well as electroless plating apparatus and electroplating apparatus. It is applicable to equipment, cleaning processing equipment, etc.

(Prior Art) As already proposed by the inventors of the present invention, this type of device uses a vibration generator to vibrate a printed circuit board that is immersed in a processing liquid tank such as a plating tank and is undergoing liquid treatment. A device is known in which air bubbles in the through hole are removed by this vibration (Japanese Patent Application Laid-open No. 154797/1983).

(Problems to be Solved by the Invention) However, conventional devices have poor efficiency in removing air bubbles generated in through holes of printed circuit boards, and a solution to this problem has been desired.

In the process of investigating the cause, the inventors discovered that the natural frequency of a printed circuit board is the same as the frequency of a practical vibration generator such as a vibration motor. It was found that the vibration energy from the vibration generator is not efficiently transmitted to the printed circuit board, and the printed circuit board is not sufficiently vibrated.

Even if it is made to match the natural frequency, the printed circuit boards that are subject to vibration differ in size and weight, so the natural frequency will also vary accordingly, and there are usually several types of printed circuit boards to be processed. Therefore, it becomes increasingly difficult to match the frequency of the vibration generator to the natural frequency of the printed circuit board each time.

Therefore, based on the above findings, the present invention uses the same vibration generator to generate sufficient resonance vibration regardless of the size and weight of the printed circuit board. The purpose is to efficiently and completely remove air bubbles that occur inside the through-hole.

(Means for Solving the Problems) In order to achieve the above object, the present invention was constructed as follows.

That is, the invention of claim 1 provides a support for supporting a printed circuit board having small holes with an elastic body interposed therebetween, a processing liquid tank in which the printed circuit board supported on the support is immersed, and a processing liquid tank in which the printed circuit board is immersed. This device comprises a vibration generator that vibrates a submerged support, and a frequency adjuster that adjusts and changes the frequency of vibration generated by the vibration generator.

Further, the invention of claim 2 provides a support body that supports a printed circuit board having small holes with an elastic body interposed therebetween, a processing liquid tank in which the printed circuit board supported by the support body is immersed, and a weight of the printed circuit board. a weight sensor for detecting; a frequency calculating means for calculating the natural frequency of the printed circuit board based on the detected weight; and a vibration frequency calculating means for calculating the natural frequency of the printed circuit board based on the detected weight; and vibration generating means.

(Function) In the invention of claim 1, the operator can freely adjust the frequency of vibration generated by the vibration generator 6 by operating the frequency adjuster 21.

Therefore, by operating the frequency adjuster 21,
The frequency of vibration generated by the vibration generator 6 can be made equal to the natural frequency of the printed circuit board 3, and the vibration energy of the vibration generator 6 can be efficiently transferred to the printed circuit board 3 regardless of its size or weight. communicated.

In the invention of claim 2, the natural frequency of the printed circuit board 3 is calculated based on the weight detected by the weight sensor 17, and vibrations near this calculated value are applied to the printed circuit board 3.

Therefore, the printed circuit board 3 can automatically and efficiently vibrate regardless of its size and weight.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic perspective view of an embodiment of the present invention applied to a manufacturing process line for printed circuit boards.

In the figure, reference numerals 1 and 2 are various treatment liquid tanks that perform liquid treatments such as plating and cleaning when manufacturing the printed circuit board 3, respectively. The printed circuit board 3 has small holes such as through holes 4 and is multilayered.

In the arrangement direction of the processing liquid tanks 1 and 2, a pair of carrier bar supports 5.5 are respectively provided along the left and right sides of the arrangement direction. Then, the carrier bar holder is placed on the stand 5.5.
A pair of left and right vibration generators 6.6 are respectively arranged.

7 is a carrier bar, and a pair of resonance springs 8.8 for suspending the printed circuit board 3 are attached to each of the resonance springs 8.8.
A clip 9 for connecting the printed circuit board 3 is provided at the tip. Therefore, the printed circuit board 3 is supported by the carrier bar 7 via the resonance spring 8.8.

At both left and right ends of the carrier bar 7, there are formed figure 7 parts 11.11 which are to be fitted into figure 7 receivers 10.10 provided on the vibration generator 6. In order to strengthen the coupling force at the time of fitting, it is preferable to provide a structure that utilizes electromagnetic force, air pressure, etc. at the fitting location between the figure 7 receiver 10 and the figure 7 portion 11.

The carrier bar 7 has a pair of left and right 7-shaped portions 14.14 that fit into 7-shaped receptacles 13.13 provided on the conveying rod 12 of the conveying device.
has. The carrier bar 7 is supported by the transport rod 12 and is movable in the direction in which the processing liquid tanks 1 and 2 are arranged, and is raised and lowered at a position above the processing liquid tanks 1 and 2. When the carrier bar 7 is lowered and its 7-shaped portion 11 is fitted into the corresponding 7-shaped receiver 10.10, the carrier bar 7 is positioned and fixed at that position.

Next, the vibration generator 6 will be explained with reference to FIG. 2.

In the figure, reference numerals 15 and 15 indicate a pair of vibration isolating springs, the lower ends of which are fixed on the carrier bar holder 5, and the upper ends of which are respectively fixed to the lower surface of the diaphragm 16. The receiver is elastically supported on the stand 5. Furthermore, a seven-figure receiver 10 is fixed on the diaphragm 16.

18 is a vibration motor that vibrates the diaphragm 16, and is fixed to the lower surface of the diaphragm 16. When the vibration motor 18 rotates, the diaphragm 16 is connected to the pair of vibration isolating springs 1 by an unbalance way 18A fixed to one end of the motor shaft.
It vibrates due to the elasticity of 5.15.

As a vibration source for the diaphragm 6, a so-called electromagnetic vibrator or an air vibrator may be used instead of the vibration motor 18 described above.

Next, a block diagram of the electrical system of the embodiment configured as described above will be explained with reference to FIG. 3.

20 is a variable frequency power supply device that supplies AC power to the induction type vibration motor 18. This power supply device 20 includes, for example, a semiconductor rectifier that converts commercial power to direct current, and an inverter that converts the converted direct current to alternating current of an arbitrary frequency.

Reference numeral 21 denotes a frequency adjuster that can continuously and manually adjust the rotational speed of the vibration motor 18, in other words, the frequency of the vibration generator 6. This frequency adjuster 21 has an adjustment knob 21A.
Its frequency is adjusted by operating the .

22 is a control circuit that controls the output frequency of the variable frequency power supply device 20 in accordance with the adjustment of the frequency adjuster 21.

Next, an example of the operation of the embodiment configured as described above will be explained. Here, the processing liquid tank 1 is assumed to be a plating tank for performing electroless plating, for example.

Now, the carrier bar 7 supported by the transport rod 12 of the transport device is lowered as the transport rod 12 is lowered, and the 7-shaped portions 11.11 formed on both left and right ends of the carrier bar 7 are aligned with the corresponding 7-shaped receivers 10.
．． 10 and the position is fixed, the conveying rod 12 is detached from the carrier bar 7 and returns to a predetermined position above.

When the carrier bar 7 is fixed to the figure 7 receiver 10.10,
The printed circuit board 3 supported by the carrier bar 7 via the resonance spring 8.8 is completely immersed in the liquid in the processing liquid tank l.

Next, the vibration motors 18.18 of the vibration generators 6.6 are respectively activated, and the diaphragm 16.16 begins to vibrate. The vibration of the diaphragm 16 is transmitted via the figure-7 receiver 10, the carrier bar 7, and the resonance spring 8, causing the printed circuit board 3 to vibrate.

By the way, the printed circuit board 3 has a natural frequency determined by its own weight and the spring constant of the resonance spring 8.

Therefore, when the adjustment knob 21A of the frequency adjuster 21 is continuously operated, the frequency of the alternating current output from the variable frequency power supply device 20 changes in accordance with this operation, and the rotation of the vibration motor 18 is accordingly changed. O As the rotation number changes, the vibration frequency of the printed circuit board 3 changes. When this variable frequency becomes equal to the natural frequency of the printed circuit board 3 and a resonance state occurs, the vibration of the printed circuit board 3 becomes maximum.

Therefore, the frequency adjuster 2 is adjusted so that it is equal to the natural frequency of the printed circuit board 3 or has a value close to the natural frequency.
Adjust the adjustment knob 21A of No. 1 and complete the adjustment.

Thereby, vibrations from the vibration motor 18 are efficiently transmitted to the printed circuit board 3.

Here, an accelerometer (not shown) is attached to the printed circuit board 3 or the carrier bar 7 in advance, and while changing the frequency of the vibration generator 6 by turning the adjustment knob 21A, the pointer of the accelerometer swings to the maximum. Adjustment knob 2
1, the frequency of the vibration generator 6 can be easily matched to the natural frequency.

When the speed adjustment of the vibration motor 18 is completed by operating the frequency adjuster 21 in this way, mass production of printed circuit boards 3 becomes possible under these conditions.

In this way, during the process of forming the plating layer of the through hole 4, the printed circuit board 3 is constantly and efficiently vibrated in the liquid processing liquid tank 1, so that the vibration causes air bubbles in the through hole and the inside of the through hole 4. Generated air bubbles can be completely removed. Therefore, a predetermined plating film is reliably formed on the inner surfaces of all the through holes of the printed circuit board 3.

When the formation of the plating film on the through holes 4 is completed, the carrier bar 7 is lifted up by the transport rod 12, the printed circuit board 3 is lifted out of the processing liquid tank 1, and the printed circuit board 3 is moved to the next processing step.

Next, another embodiment of the present invention will be described with reference to FIGS. 4 and 5.

In this embodiment, in addition to the embodiments shown in FIGS. 1 and 2, a weight sensor 17 for measuring the weight of the printed circuit board 3 as shown in FIG. 4 is provided.

That is, in this embodiment, as shown in FIG.
A weight sensor 17 such as a load cell is interposed between the 6 and 7 figure receivers 10. This weight sensor 17 is provided on one or both of the vibration generators 6.

Next, the electrical system block diagram of this embodiment will be explained with reference to FIG.

In the figure, 23 is a frequency calculation circuit that calculates the rotational speed of the vibration motor 18, in other words, the frequency of vibration generated by the vibration generator 6, based on the detected weight of the printed circuit board 3 measured by the weight sensor 17. 24 is the frequency calculation circuit 23
The variable frequency power supply device 20
This is a control circuit that controls the frequency output from the

In the embodiment configured in this way, as shown in FIG.
When the figure 7 part 11 of the carrier bar 7 fits into the figure 7 receiver 10, the weight sensor 17 detects the weight of the printed circuit board 3,
The detected weight is output to the frequency setting circuit 23.

The vibration frequency setting circuit 23 calculates the rotation speed of the vibration motor 18 corresponding to the natural frequency of the printed circuit board 3 based on the detected weight. This calculated value is the same as the natural frequency of the printed circuit board 3 or a value close to the natural frequency.

As a result, the output frequency from the variable frequency power supply device 20 becomes a predetermined value, and the vibration motor 18 is controlled by the frequency setting circuit 23.
It rotates at the rotation speed calculated by .

As a result, the vibrations from the vibration motor 18 are efficiently transmitted to the printed circuit board 3, so that the inner surfaces of all the through holes of the printed circuit board 3 are A predetermined plating film is reliably formed on the surface.

In either of the two embodiments described above, the frequency of the vibration generator 6 is preferably about 10% lower than the natural frequency of the printed circuit board 3. When using an accelerometer, it is preferable that the vibration be about 2 to 4 times the force applied by the vibration generator. When it matches the natural frequency, the acceleration of the printed circuit board increases rapidly, and the force of the vibration generator increases to 10
This is because there is a risk of damaging the board.

Note that even if the frequency of the vibration generator is 10% higher than the natural frequency, the acceleration will drop by approximately 2 to 4 times, but when the vibration is stopped, it will always match the natural frequency halfway. ,
Since excessive vibration cannot be avoided, the frequency is preferably lower than the natural frequency.

(Effects of the Invention) In short, in the invention of claim 1, a frequency adjuster is provided which can freely adjust the frequency of vibration generated by the vibration generator, and the frequency of vibration can be made to match the natural frequency of the printed circuit board 3. Therefore, the vibration energy of the vibration generator is efficiently transmitted to the printed circuit board, regardless of its size or weight.

Therefore, in the invention of claim 1, the printed circuit board can be sufficiently vibrated while immersed in various treatment liquid tanks such as plating tanks and cleaning tanks, and air bubbles existing in the through holes of the printed circuit board can be completely removed. Since it can be removed, plating and cleaning processes can be performed reliably.

Further, in the invention of claim 2, a weight detection sensor is provided to detect the weight of the printed circuit board, the natural frequency of the printed circuit board is calculated based on the detected weight, and the vibration of the calculated value is imparted to the printed circuit board. As a result, vibration energy can be efficiently transmitted to the printed circuit board regardless of the size and weight of the printed circuit board. Therefore, claim 2
According to the invention of claim 1, efficient vibration of the printed circuit board can be automatically realized without any adjustment, and the printed circuit board can be processed in the same manner as the invention of claim 1.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view of an embodiment of the present invention, FIG. 2 is a diagram showing the configuration of the vibration generator, FIG. 3 is a block diagram of the electrical system of the embodiment of the present invention, and FIG. 4 is a diagram showing the other embodiment of the present invention. FIG. 5 is a block diagram of the electrical system of another embodiment. 1.2 is a processing liquid tank, 3 is a printed circuit board, 4 is a through hole, 6 is a vibration generator, 7 is a carrier bar, 8 is a resonance spring, 17 is a weight sensor, 18 is a vibration motor, 20 is a variable frequency power supply 21 is a frequency adjuster, and 23 is a frequency calculation circuit. Figure Figure Figure Figure Figure

Claims (2)

[Claims] 1. A support body that supports a printed circuit board having small holes through an elastic body, a processing liquid tank in which the printed circuit board supported on the support body is immersed, and a vibration generator that vibrates the support body immersed in the processing liquid tank. A printed circuit board manufacturing device comprising: a vibration generator; a frequency adjuster for adjusting and changing the frequency of vibration generated by the vibration generator; 2. A support body that supports a printed circuit board having small holes with an elastic body interposed therebetween; a processing liquid tank in which the printed circuit board supported by the support body is immersed; a weight sensor that detects the weight of the printed circuit board; and a weight sensor that detects the weight of the printed circuit board. a frequency calculating means for calculating the natural frequency of the printed circuit board based on the above, and a vibration generating means for vibrating the printed circuit board so as to have a frequency close to the calculated natural frequency. Printed circuit board manufacturing equipment consisting of: