JPS5831883Y2 - Electroless plating device for thin plates with through holes - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an apparatus that performs electroless plating on a thin plate-like workpiece with a through hole, such as a printed circuit board.

When manufacturing printed circuit boards, a thin (for example, 5 to 35μ) copper foil is formed on the surface of an electrically insulating thin plate and a large number of thin holes are punched in the pretreatment and binding process before circuit printing and electrolytic plating. , Clean the inside of the through hole and then apply electroless plating.

The diameter of the above-mentioned narrow through hole may be several mm, but it may also be 1 mm or less.

To perform electroless plating on the inner wall of such a narrow hole, simply immersing the workpiece in the chemical solution would cause the chemical solution to come into contact with the inner wall of the hole, and the chemical solution within the hole would not flow, so conventional methods The workpiece is placed in a cage or a net and immersed in the chemical solution, and the cage or net is shaken to shake the workpiece in the chemical solution so that the chemical solution comes into contact with the inner wall surface of the through hole and flows.

However, as described above, placing the workpiece in a cage or a net and shaking it in a chemical solution requires a great deal of labor, and furthermore, such work is not easy to automate.

The present invention was developed in view of the above-mentioned circumstances, and involves automatically and continuously passing a thin plate-shaped workpiece having through-holes through a chemical solution, and flowing the chemical solution onto the inner wall surface of the through-holes for electroless plating. The aim is to provide a device that can perform this.

``In order to achieve the above object, the present invention provides an electroless plating chemical tank having an overflow port to maintain a predetermined liquid level;
A feed roller is arranged in which thin plates are horizontally conveyed below the liquid surface of the chemical liquid tank, a chemical liquid storage tank stores the chemical liquid overflowing from the chemical liquid tank, and the chemical liquid in the chemical liquid storage tank is transferred to the chemical liquid tank. a chemical liquid pump that pumps the chemical liquid to By providing a horizontally elongated opening for feeding the thin plate and a horizontally elongated opening for feeding the thin plate at positions intersecting with the rows of the conveying rollers, the thin plate with through holes, which is the workpiece, can be moved to the liquid level of the chemical tank. It is characterized by being configured so that the chemical solution can be sprayed onto the plate surface while being conveyed horizontally below.

Next, an embodiment of the present invention will be described with reference to FIGS. 1 and 3.

FIG. 1 shows a vertical longitudinal section.

A chemical solution 2 is put into a chemical solution tank 1 for electroless plating, and overflow ports 3, 3 are bored in the side of the chemical solution tank 1 so that the level of this chemical solution does not rise above a predetermined level A. A chemical liquid storage tank 4 is provided below the chemical liquid tank to receive the chemical liquid overflowing from the flow port 3°3.

B is the liquid level of the chemical liquid in the chemical liquid storage tank 4.

A thin plate, which is a workpiece, is carried into the chemical solution 2 in the direction of arrow C by a large number of sets of feed rollers 5 a and 5 b, which will be described in detail later, and is carried out in the direction of arrow C.

An elongated horizontal opening 6 is bored at the location where the side plate of the chemical solution tank 1 intersects with the carry-in path C, and an open lower opening is similarly drilled at the location where the side plate intersects with the carry-out path.

The chemical liquid flowing out from the openings 6 and 7 is transferred to the chemical liquid storage tank 4.
The receiving plates 8, 8 are fixed between the chemical liquid tank 1 and the chemical liquid storage tank 4 so as to guide the chemical liquid.

The openings 6 and 7 are located below the predetermined liquid level A, and the chemical liquid flows out from there. Therefore, in order to maintain the liquid level in the chemical liquid tank 1 at the predetermined liquid level A, the chemical liquid pumps 9 and 9' are activated. The chemical liquid in the chemical liquid storage tank 4 is pumped up into the chemical liquid tank 1.

When the chemical liquid level in the chemical liquid tank is at the predetermined liquid level A, the openings 6 and 7
The total discharge amount of the chemical liquid pumps 9 and 9' is set to be larger than the flow rate of the chemical liquid flowing out from the openings 6 and 7 due to the hydraulic pressure corresponding to the water depth of . A predetermined liquid level A can be maintained by setting the horizontal width dimension W to be sufficiently large.

10 is a motor for driving the pump. The feed rollers 5a and 5b are arranged along the arrow C and the line connecting the same.

FIG. 2 is an explanatory diagram showing a pair of feed rollers 5 a and 5 b in a sectional view taken along line II-II of the chemical liquid tank 1 and the chemical liquid storage tank 4.

In order to guide the chemical outflow outlet E flowing out from the overflow port 3 to the chemical liquid storage tank 4 as shown by the arrow F, one side plate 4a of the chemical liquid storage tank 4 is extended upward and spaced apart from the side plate of the chemical liquid tank 1 to face the outside of the side plate. The upper end 4b is made higher than the chemical liquid level A.

A feed roller 5a is rotatably supported in the chemical liquid tank 1, and one end of the shaft 5a-1 protrudes from the side plate of the chemical liquid tank 1 and the side plate 4a of the chemical liquid storage tank 4, and a sprocket 58-2 is attached to the tip of the shaft 5a-1.
is fixed and configured to be rotationally driven by a drive chino (not shown).

Even if there is some leakage at the point where the shaft 5a1 passes through the side plate of the chemical tank 1, the leakage flow arrow G will merge with the chemical flow E and flow into the chemical storage tank 4. No problem.

In this embodiment, the feed rollers 5a and 5b are constructed by fitting tubes of flexible elastic material (for example, sponge rubber) onto roller shafts 5a+ and 5bt, respectively.

Then, the feed roller 5b is rotatably supported in parallel with the feed roller 5a with light contact therebetween.

As a result, the thin plate 11 that is the workpiece is moved between the pair of rollers 5
When inserted between a and 5b, it is conveyed in the directions of arrows C and D shown in FIG.

(See FIG. 1) The horizontal plane on which the thin plate 11 is conveyed by the feed rollers 5a, 5b, . . . in the above manner is named a conveyance surface H for convenience of explanation.

A chemical liquid injection nozzle 12°12 is placed above the above conveyance surface H.
.

Similarly, below the conveyance surface H, there are also chemical liquid injection nozzles 12',
12'... are arranged in a row and connected to the chemical pump 9',
The chemical solution is ejected toward the transport surface H.

FIG. 3 is an explanatory drawing for showing the details of the above-mentioned chemical liquid injection nozzle 12.12', and the chemical liquid injection nozzle 12.12' is drawn in the cross-sectional view taken along the plane II-II of the chemical liquid tank 1 for easy reading. Therefore, the feed rollers 5a and 5b are omitted.

11 is a thin plate being conveyed along the conveyance surface H.

The chemical liquid injection nozzle 12 is formed into a tubular shape having approximately the same length as the width of the chemical liquid tank 1, and is fixed to the inner wall surface of the chemical liquid tank 1 in parallel with the transport surface H at an appropriate distance from the transport surface H.

On the lower surface of the chemical liquid injection nozzle 12, downwardly directed injection holes 12a, 12a, . . . are arranged in a row.

Reference numeral 12b is a chemical liquid inlet port, which is connected to the chemical liquid pump 9 by piping.

The chemical liquid injection nozzle 12' is constructed in the same manner as the above-mentioned chemical liquid injection nozzle 12, and the injection holes 12a' and 12a' are connected to the conveying surface H.
It is installed horizontally below the conveyance surface H with an appropriate distance therebetween.

The device of the present invention has the above-mentioned configuration, and in order to perform electroless plating on a thin plate having through-holes, the thin plate is moved in the direction of arrow C into the chemical bath 1 while rotating the feed roller 5a in the feeding direction. At the same time, the chemical liquid pumps 9 and 9' are operated to draw up the chemical liquid from the chemical liquid storage tank 4D and jet it out from the chemical liquid injection nozzle 12, 12'.

The thin plate 11 is conveyed into the chemical bath 1 through the opening 6, passes through the electroless plating chemical 2, and is sent out from the open lower part.

While the thin plate is being fed horizontally within the chemical solution 2 along the conveyance surface H as described above, the chemical solution injection nozzle 1 is placed on both the upper and lower surfaces of the thin plate.
2. Chemical liquid is sprayed from 12'.

The injected chemical solution flows through the thin hole bored in the thin plate due to its dynamic pressure, and evenly contacts the inner wall surface of the hole.

Therefore, while the thin plate passes through the chemical bath 1, electroless plating is uniformly applied to the inner wall surface of the through hole formed in the thin plate.

As is clear from the above-mentioned operation, when electroless plating is applied to a large number of thin plates according to the apparatus of the present invention, the plating process is automatically performed when these thin plates are sequentially fed between the feed rollers 5a and 5b. Not only does this process require less labor, but it also guarantees uniformity in finished quality because each thin plate is treated uniformly.

In addition, if the workpiece is a thin plate with a through hole, electroless plating can be applied to workpieces of various shapes and sizes without the need for separate adjustment changes even if the shapes and dimensions are different. Therefore, the device of the present invention is particularly suitable for incorporating an electroless plating device into a multi-product mixed production line.

Moreover, even if the chemical solution tank 1 is covered with the lid 13, the operation is not hindered, so it is easy to prevent the vapor and droplets of the chemical solution from dispersing, and there is no risk of contaminating the working environment.

Due to the effects detailed above, when the present invention is applied, electroless plating can be applied automatically and continuously to a thin plate-shaped workpiece having a through hole, and a uniform plating layer can be applied even to the inner wall surface of a narrow through hole. It has an excellent practical effect of being able to be attached.

[Brief explanation of the drawing]

The drawings show an embodiment of the electroless plating apparatus for thin plates having through-holes according to the present invention, and FIG. 1 is a vertical cross-sectional view taken in a vertical plane;
FIG. 2 is an explanatory diagram of the feeding roller mechanism, and FIG. 3 is an explanatory diagram of the chemical liquid injection nozzle. 1... Chemical solution tank, 2... Chemical solution for electroless plating, 3... Overflow port, 4... Chemical solution storage tank, 5a, 5b... ...Feed roller, 5a-1, 5b
t...Feed roller shaft, 5a-2...Sprocket, 6, 7...Opening, 9...
Chemical pump, 11...Thin plate, 12.12'...
...Medical liquid injection nozzle, 12a, 12a'...
・Injection hole, 13... Lid.

Claims (1)

[Scope of utility model registration request] An electroless plating chemical tank provided with an overflow port to maintain a predetermined liquid level, a feed roller arranged in a row to convey the thin plate horizontally below the liquid level of the chemical tank, and the chemical liquid A chemical liquid storage tank that stores the chemical liquid overflowing from the tank, a chemical liquid pump that pumps the chemical liquid in the chemical liquid storage tank to the chemical liquid tank, and a chemical liquid pumped by the chemical liquid pump and sprays it onto the surface of the thin plate being conveyed by the roller. A horizontally elongated opening for feeding the thin plate and a horizontally elongated opening for feeding the thin plate at a position where the side surface of the chemical liquid tank intersects with the row of the conveying rollers. By providing a through-hole, the thin plate having the through-hole, which is a workpiece, can be conveyed horizontally below the liquid surface of the chemical tank and the chemical liquid can be sprayed onto the plate surface. Electroless plating equipment for thin plates.