JPH0561359B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plating apparatus, and more particularly to a plating apparatus capable of obtaining a uniform distribution of plating film thickness over the entire large-sized object to be plated.

Plating technology is already widely used for forming thin films and forming minute parts by electroforming, and has become an important technology indispensable in the electronics industry and precision processing fields.

However, when attempting to form a large number of individual microcomponents on a single substrate with a high yield, a substantially uniform film thickness is required over the entire surface of the substrate, which is difficult to achieve easily.

That is, there are various conditions for obtaining a uniform plating distribution, but among them, an important condition is to keep the ion concentration supplied to the plated object constant. In principle, this ion concentration can be kept constant by constantly supplying fresh liquid to the covered surface.

FIG. 1 is a sectional view showing an example of such a conventional plating apparatus.

That is, the object 2 to be plated is inserted into a plating tank 14 filled with plating liquid f, and the process is performed by circulating the plating liquid. A metal thin film is formed on an insulator such as by a method such as vapor deposition or sputtering, and a photoresist is further formed in a predetermined pattern.

This object 2 to be plated is loaded into a substrate holder consisting of an insulator body 1 and an insulator support plate 4 immersed in a plating solution f. The support plate 4 supports the plated object 2 and at the same time blocks the plated object 2 from contact with the plating liquid at the rear. Main body 1
is a hollow insulator, and an electrode 3 is attached to one end thereof, and a part of the plated object 2 is brought into contact with this electrode 3 so that electricity can be applied to the plated object 2.

A part of the electrode 3 protrudes above the surface of the plating liquid f as a power supply connection terminal, and the part that comes into contact with the plating liquid f is shielded by an insulator 4'. The other end of the main body 1 is connected to a plating liquid inlet/outlet means to be described later.
The side wall of the main body 1 prevents the plating liquid f from flowing in from the outside and from flowing out to the outside, and the contact of the plating liquid f with the object 2 to be plated is controlled by the inflow and outflow of the plating liquid. It has come to be done only by means.

The plating liquid inflow/output means includes a plating liquid supply plate 5 made of an insulator having a plurality of plating liquid supply ports 5' scattered at a uniform density, and a plating liquid supply plate 5 made of an insulator that also has a plurality of plating liquid supply ports 5' scattered at a uniform density. A plating liquid outflow plate 6 having approximately half the number of plating liquid outflow ports 6' as the number of plating liquid outflow ports 5' provided in the plating liquid supply port 5; a hollow insulator 7 located between
and an insulating outflow pipe 8 which communicates the corresponding openings of the plating liquid supply plate 5 and the plating liquid outflow plate 6.

Piping of a circulation pump 9 for circulating plating liquid f between the plating tank 14 and the plating liquid inflow/outflow means is connected to the hollow insulator 7.

The accumulating liquid f sucked up by the circulation pump 9
is supplied to the input/output means from a main plating liquid supply port 10 provided in a part of the side wall of the hollow insulator 7.
The plating liquid f is diverted from the plating liquid supply port 5' of the plating liquid supply plate 5, and the plating liquid f is supplied almost uniformly from the front over almost the entire surface of the object 2 to be plated. ing. Further, the used plating solution is reflected from the plating surface to the front, and passes through the outflow pipe 8 from the outflow plate 6 to the anode electrode 12 in the plating tank 14.
It's leaking inside. (The arrow in the figure shows the plating liquid f.
This shows the flow of the flow. ) With the conventional plating equipment described above, when plating a large sample exceeding several centimeters in size, the effect of uneven flow of the plating liquid f due to gravity in the vertical direction appears. This had the disadvantage that the film thickness at the bottom became thicker and the uniformity deteriorated, which hindered mass production.

The purpose of the present invention is to improve the above-mentioned drawbacks, and to provide a plating device that can form a plating film with a uniform thickness over almost the entire area even when the object to be plated is large, and is suitable for mass production. It's about doing.

The plating apparatus of the present invention includes: an anode electrode disposed opposite to a surface to be plated of an object to be plated; a circulation pump for replenishing the plating solution toward the surface to be plated; a current source that supplies a predetermined current between the objects to be plated; a plating liquid supply plate made of an insulator and having a plurality of plating liquid supply ports scattered at a uniform density; a plating liquid outflow plate having approximately half the number of plating liquid outflow ports as the number of plating liquid outflow ports scattered about, and a hollow insulator positioned between the plating liquid supply plate and the plating liquid outflow plate; and a plating liquid inflow/output means comprising an insulating outflow pipe that communicates the corresponding openings of the plating liquid supply plate and the plating liquid outflow plate, wherein the plating liquid outflow port A tapered insulator is provided between the anode electrode and the anode electrode as an outflow means for collecting the plating solution into a slit-shaped outlet having a small opening size in the vertical direction and then flowing it out toward the anode electrode.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows a sectional view of an embodiment of the present invention.

In this embodiment, a plating liquid outflow plate 6 and an anode electrode 12 are used in the conventional plating apparatus shown in FIG.
During this period, the plating solution f flowing out from the plating solution outlet 6' of the plating solution outlet plate 6 is collected in a slit-shaped outlet 13' with a small opening size in the vertical direction, and then directed toward the anode electrode 12. The plating solution is constructed by attaching a tapered insulator 13 as an outflow means to the plate 6 for outflowing the plating liquid. In this figure, reference numbers 1 to 12 are the same as in FIG. 1, and 14' is a plating tank.

Next, the operation of this embodiment will be explained. As is clear from the above, the process until the plating liquid f flows out from the plating liquid outlet 6' of the plating liquid outflow plate 6 is the same as in the case shown in FIG. 1 already described.

In this embodiment, the plating liquid f flowing out from the plating liquid outlet 6' is passed through the tapered insulator 13 having a slit-shaped outlet 13' with a small opening size in the vertical direction, as indicated by the arrow in FIG. As shown in FIG.
flows towards.

As a result, according to this embodiment, the difference in water pressure due to the effect of gravity between the upper and lower parts of the flow of the plating liquid f is eliminated, and unlike the conventional case, this difference in water pressure, which occurs noticeably when the plated object 2 is several centimeters or more, is eliminated. Since there is no difference in the flow rate of the plating liquid f, it is possible to perform plating with a uniform plating film thickness.

When performing nickel plating with a sulfamine nickel plating solution using the plating apparatus of this embodiment, for example, when the current density is 30 mA/cm ² , the liquid temperature is 50°C, the aperture density is 10 mm pitch, and the aperture is 3 mm, The growth rate is approx.
At 0.5μ/min, it is possible to suppress variations in the plating film thickness to 5% or less, even on large objects exceeding several centimeters in size. Note that if the current density is further increased, the film thickness distribution within the individual parts will deteriorate, so the above
It is preferable to perform plating at 30 mA/cm ² or less.

As explained in detail above, the plating apparatus of the present invention has an outflow means for collecting the plating liquid flowing out from the plating liquid outflow port into a slit-shaped outflow port with a small opening and then flowing out toward the anode electrode. Since it has a tapered insulator, it has the effect that even when the object to be plated is large, a uniform plating film can be formed on the surface to be plated. Therefore, according to the present invention, it is possible to obtain a tamping device which is particularly suitable for mass production of small parts at bottom view cost, and the effects thereof are great.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an example of a conventional plating apparatus, and FIG. 2 is a sectional view of an embodiment of the present invention. 1... Main body, 2... Covering object, 3... Electrode,
4...Support plate, 4'...Insulator, 5...Plating liquid supply plate, 5'...Plating liquid supply port, 6...Plating liquid outflow plate, 6'...Plating liquid Outlet, 7...
Hollow insulator, 8...Outflow pipe, 9...Circulation pump, 10...Main plating liquid supply port, 11...Current source, 12...Anode electrode, 13...Tapered insulator,
13'...Outlet, 14,14'...Plating tank, f
...Plating liquid.

Claims (1)

[Claims] 1. An anode electrode disposed opposite to the plating surface of the object to be plated, a circulation pump that replenishes the plating solution toward the surface to be plated, and a space between the anode electrode and the object to be plated. a current source that supplies a predetermined current;
A plating liquid supply plate made of an insulator and having a plurality of plating liquid supply ports scattered at a uniform density; and a plating liquid supply plate having approximately half the number of plating liquid supply ports also scattered at a uniform density. Correspondence between a plating liquid outflow plate having an outlet, a hollow insulator located between the plating liquid supply plate and the plating liquid outflow plate, and the plating liquid supply plate and the plating liquid outflow plate. In the plating device, the plating solution is supplied between the plating solution outlet and the anode electrode, and the plating solution is supplied between the plating solution outlet and the anode electrode. A plating apparatus characterized in that a tapered insulator is provided as an outflow means for collecting water in a small slit-shaped outflow port and then flowing out toward the anode electrode.