JPH0666550B2 - Printed circuit board manufacturing equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a printed circuit board manufacturing apparatus for liquid-processing a printed circuit board, and particularly to a through hole plating pretreatment apparatus for a printed circuit board, an electroless plating apparatus, and an electroplating apparatus. It can be applied to an apparatus, a cleaning processing apparatus, and the like.

(Prior Art) As an apparatus of this type, as already proposed by the inventors of the present invention, a printed circuit board during liquid processing is vibrated by a vibration generator by immersing it in a processing liquid tank such as a plating tank. It is known that air bubbles in a through hole are removed by this vibration (Japanese Patent Laid-Open No. 62-154797).

(Problems to be Solved by the Invention) However, the conventional device is inefficient in removing bubbles generated in the through holes of the printed circuit board, and a solution to this problem has been desired.

Therefore, in the process of investigating the cause, the inventors found that the natural frequency of the printed circuit board is different from the natural frequency of a practical vibration generator, such as a vibration motor, in general. Therefore, it has been 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 matches the natural frequency, the size and weight of the printed circuit board, which is the object of vibration, are different, so the natural frequency is also different, and the number of printed circuit boards to be processed is usually different. It is increasingly difficult to match the frequency of the vibration generator with 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 sufficiently resonate regardless of the size and weight of the printed circuit board, thus reducing the size and weight of the printed circuit board. Nevertheless, the purpose is to efficiently and completely remove the bubbles generated in the through holes.

(Means for Solving Problems) In order to achieve such an object, the present invention has the following configuration.

That is, the invention of claim 1 provides a support for supporting a printed circuit board having small holes via an elastic body, a treatment liquid tank in which the printed circuit board supported by the support is immersed, and a treatment liquid tank in the treatment liquid tank. The vibration generator vibrates the immersed support, and the frequency adjuster adjusts and changes the frequency generated by the vibration generator.

The invention according to claim 2 is characterized in that a support for supporting a printed circuit board having small holes with an elastic body interposed, a treatment liquid tank for immersing the printed circuit board supported by the support, and a weight of the printed circuit board. A weight sensor for detecting, a frequency calculation means for calculating the natural frequency of the printed circuit board based on the detected weight, and a vibration of the printed circuit board so that the frequency is close to the calculated natural frequency. And a vibration generating means for generating the vibration.

[Work]

In the invention of claim 1, by operating the frequency adjuster 21,
The operator can freely adjust the number of vibrations generated by the vibration generator 6.

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

According to the second aspect of the invention, the natural frequency of the printed circuit board 3 is calculated based on the weight detected by the weight sensor 17, and the vibration in the vicinity of this calculated value is applied to the printed circuit board 3.

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

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

FIG. 1 is a schematic perspective view in which an embodiment of the present invention is applied to a printed board manufacturing process line.

In the figure, 1 and 2 are various processing liquid tanks that perform liquid processing such as plating processing and cleaning processing when the printed circuit board 3 is manufactured. The printed circuit board 3 has small holes such as the through holes 4 and is multilayered.

In the arrangement direction of the processing liquid tanks 1 and 2, a pair of carrier bar pedestals 5 and 5 are provided along the left and right of the arrangement direction. Then, on the carrier bar cradle 5, 5,
A pair of left and right vibration generators 6, 6 are arranged.

Reference numeral 7 denotes a carrier bar, to which a pair of resonance springs 8 for suspending the printed circuit board 3 are attached.
A clip 9 for connecting the printed circuit board 3 is provided at the tip of 8. Therefore, the printed circuit board 3 is supported by the carrier bar 7 via the resonance springs 8, 8.

V-shaped portions 11, 11 to be fitted with the V-shaped receivers 10, 10 provided on the vibration generator 6 are formed on both left and right ends of the carrier bar 7.
It is preferable to provide a structure utilizing electromagnetic force, air pressure, or the like at the fitting portion between the V-shaped receiver 10 and the V-shaped portion 11 in order to strengthen the coupling force at the time of fitting.

The carrier bar 7 has a pair of left and right V-shaped portions 14 and 14 which are fitted with V-shaped receivers 13 and 13 provided on the transfer rod 12 of the transfer device.
The carrier bar 7 is supported by the carrier rod 12 so as to be movable in the arrangement direction of the processing liquid tanks 1 and 2, and is raised and lowered at the overhead position of the processing liquid tanks 1 and 2. When the carrier bar 7 descends and its V-shaped portion 11 fits into the corresponding V-shaped receivers 10, 10, the carrier bar 7 is positioned and fixed at that position.

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

In the figure, 15 and 15 are a pair of vibration-proof springs, the lower end of which is fixed on the carrier bar pedestal 5 and the upper end of which is fixed on the lower surface of the diaphragm 16, respectively.
Is elastically supported on the carrier bar cradle 5. Further, the V-shaped receiver 10 is fixed on the diaphragm 16.

Reference numeral 18 denotes a vibration motor that vibrates the vibration plate 16,
Fix on the bottom of 16. When the vibration motor 18 rotates, the unbalanced weight 18A fixed to one end of the motor shaft
Thus, the diaphragm 16 vibrates by receiving the elastic force of the pair of anti-vibration springs 15, 15.

As a vibration source of the vibration plate 16, 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 electric system of the embodiment configured as described above will be described with reference to FIG.

Reference numeral 20 is a variable frequency power supply device that supplies AC power to the induction type vibration motor 18. The power supply device 20 has, for example, a semiconductor rectifier that converts a commercial power supply into direct current,
It has an inverter which converts the converted direct current into alternating current of an arbitrary frequency.

Reference numeral 21 is a frequency adjuster capable of continuously and manually adjusting the rotation speed of the vibration motor 18, that is, the frequency of the vibration generator 6. The frequency adjuster 21 adjusts its frequency by operating the adjusting knob 21A.

Reference numeral 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 operation example of the embodiment thus configured will be described. Here, the treatment liquid tank 1 is a plating tank for performing electroless plating, for example.

Now, the carrier bar 7 supported by the carrier rod 12 of the carrier device
, And the V-shaped portions 11, 11 formed at the left and right ends thereof are fitted to the corresponding V-shaped receivers 10, 10 to fix the position thereof. Separates from the carrier bar 7 and returns to a predetermined position above.

When the carrier bar 7 is fixed to the V-shaped receivers 10 and 10, the printed circuit board 3 supported by the carrier bar 7 via the resonance springs 8 and 8 is completely immersed in the liquid of the processing liquid tank 1. Becomes

Next, the vibration motors 18, 18 of the vibration generators 6, 6 are respectively activated, and the vibration plates 16, 16 start vibrating. Then, the vibration of the diaphragm 16 is transmitted via the V-shaped receiver 10, the carrier bar 7, and the resonance spring 8, and the printed circuit board 3 vibrates.

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

Then, when the adjusting knob 21A of the frequency adjuster 21 is continuously operated next, the variable frequency power supply device 20 is operated according to this operation.
Since the frequency of the alternating current output from changes, and the number of rotations of the vibration motor 18 changes accordingly, the frequency of the printed circuit board 3 changes. Then, when the variable frequency becomes equal to the natural frequency of the printed circuit board 3 and becomes in a resonance state, the vibration of the printed circuit board 3 becomes maximum.

Therefore, the frequency adjuster 21 is set so as to be equal to or close to the natural frequency of the printed circuit board 3.
Adjust the adjusting knob 21A of to finish the adjustment. As a result, the vibration from the vibration motor 18 is 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 rotating the adjusting knob 21A to change the frequency of the vibration generator 6,
By stopping the adjusting knob 21 when the pointer of the accelerometer is swung to the maximum, the frequency of the vibration generator 6 can be easily adjusted to the natural frequency.

In this way, when the speed adjustment of the vibration motor 18 is completed by the operation of the frequency adjuster 21, the printed circuit boards 3 can be mass-produced under the conditions thereafter.

By doing so, the printed circuit board 3 constantly vibrates efficiently in the liquid processing liquid tank 1 in the process of forming the plated layer of the through hole 4, and this vibration causes bubbles in the through hole and the through hole 4 to enter. The generated bubbles can be completely removed. Therefore, the predetermined plating film is surely formed on the inner surfaces of all the through holes of the printed circuit board 3.

When the formation of the plated film on the through holes 4 is completed, the carrier bar 7 lifts the carrier bar 7 to lift the printed circuit board 3 out of the processing liquid tank 1 and moves to the next processing step.

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

In this embodiment, in addition to the embodiment 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 V-shaped receiver 10 and the V-shaped receiver 10. This weight sensor 17 includes a vibration generator 6
Provide on one or both.

Next, a block diagram of the electric system of this embodiment will be described with reference to FIG.

In the figure, reference numeral 23 is a vibration frequency calculation circuit for calculating the rotation speed of the vibration motor 18, that is, the vibration frequency of the vibration generator 6, based on the weight detected by the weight sensor 17 of the printed circuit board 3. Reference numeral 24 is a control circuit that controls the frequency output from the variable frequency power supply device 20 in accordance with the calculated value calculated by the frequency calculation circuit 23.

In the embodiment configured as described above, as shown in FIG.
When the V-shaped portion 11 of the carrier bar 7 is fitted into the V-shaped receiver 10,
The weight sensor 17 detects the weight of the printed circuit board 3, and the detected weight is output to the frequency setting circuit 23.

The 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 near 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 rotates at the rotation speed calculated by the vibration frequency setting circuit 23.

As a result, the vibration from the vibration motor 18 is 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 similar to those described in the embodiment shown in FIGS. 1 and 2. A certain plating film is surely formed on.

In each of the two embodiments described above, the vibration frequency of the vibration generator 6 is preferably about 10% less than the natural frequency of the printed circuit board 3. In the case of using an accelerometer, it is preferable that the vibration is about 2 to 4 times the force applied by the vibration generator. This is because when the natural frequency is matched, the acceleration of the printed circuit board rapidly increases to reach several tens of times the force of the vibration generator, and there is a risk of damaging the circuit board.

Even if the vibration frequency of the vibration generator is 10% higher than the natural frequency, the acceleration will decrease by almost 2 to 4 times, but when the vibration is stopped, it will always match the natural frequency on the way. Since it is impossible to avoid excessive vibration, it is preferable that the frequency is lower than the natural frequency.

(Effect of the invention) In short, according to the invention of claim 1, a frequency adjuster capable of adjusting the generated frequency of the vibration generator is provided so that the generated frequency can be matched with 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, according to the first aspect of the invention, the printed circuit board can be sufficiently vibrated while being immersed in various processing liquid tanks such as a plating tank and a cleaning tank, and the air bubbles existing in the through holes of the printed circuit board can be completely removed. Since it can be removed, the plating process and cleaning process can be ensured.

According to the invention of claim 2, a weight detection sensor for detecting the weight of the printed circuit board is provided, the natural frequency of the printed circuit board is calculated based on the detected weight, and the calculated vibration is applied to the printed circuit board. Therefore, the 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, the 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 description of drawings]

FIG. 1 is an overall perspective view of an embodiment of the present invention, FIG. 2 is a diagram showing the configuration of its vibration generator, FIG. 3 is a block diagram of an electric system of an embodiment of the present invention, and FIG. FIG. 5 is a diagram showing a configuration of a vibration generator of the embodiment, and FIG. 5 is a block diagram of an electric 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, and 20 is a variable frequency power supply. A device, 21 is a frequency controller, and 23 is a frequency calculation circuit.

Claims (2)

[Claims] 1. A support for supporting a printed circuit board having small holes through an elastic body, a treatment liquid tank for immersing the printed circuit board supported by the support, and a support immersed in the treatment liquid tank. A printed circuit board manufacturing apparatus comprising: a vibration generator that vibrates the vibration generator; and a frequency adjuster that adjusts and changes the frequency generated by the vibration generator. 2. A support body for supporting a printed circuit board having small holes with an elastic body interposed, a treatment liquid tank for immersing the printed circuit board supported by the support body, and a weight sensor for detecting the weight of the printed circuit board. And a vibration frequency calculating means for calculating a natural frequency of the printed circuit board based on the detected weight, and a vibration generating means for vibrating the printed circuit board so as to have a frequency close to the calculated natural frequency. A printed circuit board manufacturing apparatus comprising: