JPS6237839B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cleaning device for printed circuit boards used in various electronic devices, which includes a roller conveyor for feeding the printed circuit boards and cleaning water nozzles installed opposite to the roller conveyor. In particular, a rotating cleaning water nozzle covering a running area of a roller conveyor is connected to a drive mechanism, and the roller conveyor in the cleaning area of the rotating nozzle has a back-up roller, the ring of which is in contact with a printed circuit board. This invention relates to a printed circuit board cleaning device that can completely remove burrs and smears from a large number of through holes.

In the past, as is well known, various cleaning devices have been devised and developed, and among them, cleaning devices that use jets of high-pressure water to clean the base molded products of various electromechanical parts after molding have been improved in various ways due to high needs. This has led to the adoption of superior products.

The use of such jet water cleaning is being used in a wide range of fields because of its excellent ability to reduce the amount of water used, and to peel off and remove adhered oil through the impact of the high-pressure jet.

On the other hand, the impact of jet water is certainly excellent in terms of removing facets and peeling off deposits, etc. It is effective for block-shaped molded products and molded products with deep cavities. No jet water cleaning apparatus has yet been devised or developed which has an effective function for cleaning printed circuit boards for electronic equipment, which are in high demand these days and require a high level of cleaning conditions.

That is, as shown in FIG. 2, the printed circuit board is made of a thin plate 1 made of synthetic resin of a predetermined size, and then punched and formed into through-holes 2, 2', 2'', etc. of a predetermined size and different shapes according to the design. ^2N is punched out automatically and manufactured continuously in large quantities.

By the way, in the printed circuit board 3, as a matter of course, burrs are inevitably left behind during the punching and forming process, smear is attached, and other dust is often attached, and the printed circuit board 3 is left as it is. However, when it comes to processes such as installing resistors, wiring defects, decreased accuracy, or failures can occur.

Moreover, since many of the printed circuit boards are small in size, these deposits often have a very large effect on the performance of the final product.

Up to now, cleaning has been carried out using detergents or other means to deal with this problem, but there is no mechanical advantage in removing burrs, and it is preferable to clean the surface of the substrate 1 by applying a complex frictional force. The drawback was that it caused unnecessary damage and caused errors in the electronic circuit of the final product.

Further, there was also the disadvantage that unintentional residues of chemical detergents may adhere and cause chemical changes over time to the substrate and subsequent electronic devices, resulting in changes in electronic characteristics.

In view of the problem of cleaning printed circuit boards based on the above-mentioned conventional technology, the object of the present invention is to utilize the impact cleaning function of the high-pressure cleaning water jet to apply a high-pressure jet to printed circuit boards placed and transferred on a roller conveyor. It is an object of the present invention to provide a novel printed circuit board cleaning device which jets water and allows the cleaning water jet to pass through the through holes of the printed circuit board to reliably clean the circuit board.

The structure of the present invention in accordance with the above object is that each printed circuit board loaded on a roller conveyor from the entrance side of the cleaning device is moistened with a shower to make it easier to peel off the deposits, and in the cleaning area. A high-pressure cleaning water jet is sprayed onto the front and back surfaces of the printed circuit board while rotating, without interfering with each other, to evenly wipe off the deposits on all the front and back surfaces, and also cut off and remove burrs and smears from each through hole. Therefore, in the cleaning area, the printed circuit board is in point contact with the ring of the pressure-side roller for the high-pressure cleaning water jet, and the through-hole is floated on the roller, and the high-pressure jet is discharged from the through-hole. The gist of the system is to make it easy to flow through, perform cleaning effectively, and finally transport the product out of the finishing shower.

Next, one embodiment of the present invention will be described below based on the drawings. Note that the printed circuit board 3 in FIG. 2 is a normal printed circuit board.

Reference numeral 4 denotes a cleaning device which constitutes the gist of the present invention, and in the middle upper part of the casing 5 there are a pair of left and right bearing plates 6 attached in the longitudinal direction, as shown in FIG.
6, the rollers 7, 7... arranged on the lower side are connected to the support shaft 8,
8' are pivotally supported and arranged as a roller conveyor, and the pitch is rough in FIG. The upper side of an endless chain 10 is engaged with a sprocket 9 fixed to the chain 10, and although the drive sprocket at the proximal end of the chain 10 is not shown, its shaft is engaged with a worm 11, and the worm 11 is connected to a sprocket 12, It is linked via a chain 13 to a sprocket 15 of a motor 14 attached to one side inside the casing 5.

The frame 1 is installed at the inlet and outlet 17, 18 of the cleaning casing 16 in the upper part of the casing 5.
The slits 21 and 22, which are large enough to allow the printed circuit board 3 to be carried in and out, are the roller conveyors 7 and 7.
It is opened to prevent washing water from escaping and dust from entering the system.

Bulkheads 23 and 24 are vertically installed inside the frames 19 and 20 at a set interval, water showers 25 and 26 are provided on the outside facing the roller conveyors 7, and a cleaning chamber 27 is provided inside the frames 19 and 20.
It is said that

The bottom surface of the cleaning chamber 27 is formed into a chute 28, which is connected to a drainage device (not shown) within the casing 5 through a drainage pipe 29 and a filter mechanism 30 as appropriate.

31 and 31' are high-pressure jet devices, which are substantially the same; one is attached downward to the cleaning casing 16, and the rotating arm 34 is connected to the roller conveyor via a motor 32 and a gear reduction mechanism swivel mechanism 33; A pair of cleaning water nozzles 35, 35 are attached to both ends of the roller conveyor 7, and the cleaning area of the high-pressure cleaning water jet 36 is sufficiently large as shown in FIG. It is designed to cover the width of

Note that the other high pressure jet device 31' is connected to the chute 28.
The high-pressure jet device 31 is attached upward to the
is a water tank installed on the center line of the roller conveyor 7, and a water tank installed at the inner bottom of the casing 5. Both high-pressure jet devices 31 and 3 are connected to an appropriate high-pressure water source (not shown) in 37.
1' is connected.

By the way, when the conveyance printed circuit board 3 on the roller conveyor 7 receives the high-pressure cleaning water jet 36 of the high-pressure jet devices 31, 31', when it is pressed against the roller 7 by the dynamic pressure, the through-holes 2, 2', 2 ″…
When referring to the roller conveyor 7 shown in FIG. 3, the jet water 36 from the lower high-pressure jet device 31' is exposed to the bearing plates 6, 6 as shown by arrow A. The roller conveyor 7' on the pressure side of the roller conveyor 7 is supported as a back-up conveyor by support shafts 8'', 8, and the back-up roller conveyor 7' is provided with two or more rings 38, 38... are installed in a ring and are placed opposite to the roller conveyor 7 to connect the roller conveyor 7 and the ring 38,
The printed circuit board 3 is held and conveyed between the terminals 38 and 38.

A transmission gear 3 is attached to both support shafts 8' and 8.
9, 39' can be conveyed by intervening engagement, and in this case, the diameter of both is always such that the level of the printed circuit board 3 placed on the roller conveyor 7 is at the entrance 1.
If the rollers of the roller conveyor 7 and the back-up roller conveyor 7' are suitably made of elastic bodies, the printed circuit board 3 can be held and conveyed efficiently.

Further, although the embodiment in FIG. 3 is shown for the lower high-pressure jet device 31', the upper high-pressure jet device 31
For this purpose, the roller conveyor 7 and the back-up roller conveyor 7' may be appropriately designed upside down.

Note that 39 is a reflecting plate for the jet water.

In the above configuration, the motor 14 is driven, the roller conveyor 7 and the back-up roller conveyor 7' are conveyed and driven by the chain 10, and the motors 32, 32' of the high-pressure jet devices 31, 31' are driven to move the swing arm. 34, 34' are rotated to jet high-pressure cleaning water from the high-pressure water source 37 as a cleaning water jet 36 from the tip cleaning nozzles 35, 35', and the printed circuit board 3 is placed on the roller conveyor 7 from the inlet 17 side. and then feed it continuously.

After passing through the slit 21 of the frame 19, the printed circuit board 3 is washed to remove adhering dust from the shower 25, is moistened so that it can be easily peeled off, and then passes through the bulkhead 23 and enters the cleaning chamber 27.

Therefore, the entire surface is cleaned by the swirling high-pressure cleaning water jet 36 of the swirling cleaning water nozzle 35 of the upper high-pressure jet device 31, and adhering dust, oil, etc. are peeled off and removed, and a large number of through holes 2, 2', 2 ″，
The jet 36 applies a strong impact action to the ring 3 to peel off the remaining burrs and smear, and the back-up roller conveyor 7' releases the ring 3 as described above.
8, 38..., so that the cleaning water jet 36 reliably passes through the through holes 2, 2', 2'', etc., and the dynamic pressure does not drop. , the cleaning is therefore complete and the surfaces and through holes 2, 2', 2''... are cleaned.

Then, when moving to the next process and reaching the upper side of the lower high-pressure jet device 31', the vertical relationship is reversed as described above, and the surface of the printed circuit board 3 is transferred to the back-up roller conveyor by the exactly same pressure applied operation. 7', all the back surface areas are cleaned by the cleaning water nozzle 35', adhering oil, fat, and dust are removed, and the water passes through the through holes 2, 2', 2''...
The upper washing water jet 36 completely removes any uncut burrs and smears, and finally the material passes through the bulk head 24 and is finished washed by the shower 26.
The completely cleaned printed circuit board 3 is carried out from the outlet 18.

During this time, the cleaning water containing dust, burrs, etc. is discharged from the tray pan of the chute 28 through the drain pipe 29 to the filter 30, solids are separated, and the water is appropriately discharged to the next stage of treatment.

In this way, each printed circuit board 3 is successively cleaned reliably, and furthermore, the through holes 2, 2', 2'', . . . are made completely through holes and then transported out.

Note that the embodiments of the present invention are not limited to the above embodiments, and various other embodiments are possible. For example, the high-pressure jet device may have not only two stages but also three or four stages, A cleaning water nozzle having an inclination angle within a design range may be provided.

As described above, in the printed circuit board cleaning apparatus according to the present invention, the cleaning water nozzle provided at the tip of the revolving arm relative to the roller conveyor is arranged so that the cleaning water jet can cover the roller conveyor. Furthermore, in the cleaning water jet area, the roller conveyor is doubled so as to follow the jet flow, and the roller conveyor on the side that holds the printed circuit board to be clamped is a pressurized back-up roller conveyor and a ring is installed around it. Unlike belt conveyors, etc., the printed circuit board is reliably exposed to multiple jets of rotating cleaning water jets, and its front and back surfaces are subjected to the impact and scratching effects of the jet, removing dust and oil, and cleaning the through holes. Residual burrs and smears can also be removed by cutting and peeling, so one pass is reliable.
It is possible to completely clean the entire surface and through-holes of a thin printed circuit board, and has the remarkable effect of giving designed characteristics to subsequent circuit printing and electronic device mounting.

In addition, since it uses a rotating high-pressure jet type cleaning water nozzle, it not only can cover a wide cleaning area, but also has high-pressure water that increases cleaning power, saves water, and also reduces power consumption. effective.

[Brief explanation of the drawing]

The drawings show one embodiment of the invention,
Fig. 1 is an overall schematic explanatory diagram, Fig. 2 is a perspective explanatory diagram of a printed circuit board, Fig. 3 is a perspective explanatory diagram of the operation of the roller conveyor and back-up roller conveyor, and Fig. 4 is a plan view of the cleaning area of the high-pressure cleaning water jet. It is a diagram. 2, 2', 2''...Through hole, 3...Printed circuit board, 7
...Roller conveyor, 35, 35'...Washing water nozzle, 4...Washing device, 32, 32'...Drive mechanism, 3
4, 34'...swivel arm, 36...jet, 7'...
Back-up roller conveyor, 38 rings.

Claims (1)

[Claims] 1. In a cleaning device having a roller conveyor arranged horizontally on a thin printed circuit board having a large number of through holes, and a cleaning water nozzle vertically arranged facing the roller conveyor, the cleaning water nozzle is is provided at the tip of the swing arm with respect to the drive mechanism, facing the roller conveyor running area,
Roller conveyors in the cleaning water jet area of the cleaning water nozzle are arranged in double pairs along the jet flow, and the back-up roller conveyor on the side opposite to the cleaning water nozzle has at least two rings that come into contact with the printed circuit board. A printed circuit board cleaning device characterized by being arranged in a circular manner.