JPH073468A - Electroless plating cell - Google Patents

Abstract

PURPOSE:To prevent the production of fine powder and apply a high-quality plating to circular disks by injecting a treating liquid from a supply nozzle to the vanes of a water-wheel fixed to the intermediate part of a mandrel for hanging the disks and rotating the mandrel. CONSTITUTION:The mandrel 3 with many annular grooves is horizontally and freely rotatably supported by a pair of supports 11, 12 in a treating vessel 5 and the circular disks 1 having circular holes at the center are hung in these annular grooves. The water-wheel 21 having the radial vanes 20 are fixed to the longitudinal intermediate part of the mandrel 3. The water-wheel 21 having the radial vanes 20 is fixed to the longitudinal intermediate part of the mandrel 3. The plating liquid 5 fed under pressurization by a pump 28 from, a storage tank 17 is injected from the treating liquid supply nozzle 25 to these vanes 20. As a result, the mandrel 3 is rotated by means of the water-wheel 21 and further, the circular disks 1 are driven to rotate. The liquid level L of the plating liquid 5 in the treating tank 8 is maintained by a weir 13 and the plating liquid overflowing from the cell is discharged from a discharge port (not shown in Fig.). As a result, the contamination of the plating liquid 5 by the fine powder (dust) is prevented and the high-quality plating is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroless plating bath for electroless nickel plating a circular hard disk having a circular hole at the center.

[0002]

2. Description of the Related Art Conventionally, a drive motor is attached to the upper end of an elevating plate that supports one end shaft of a mandrel, and a gear fixed to the motor shaft is meshed with a gear on the mandrel via an intermediate gear. Is immersed in a plating solution and the mandrel is rotated by a drive gear to perform electroless nickel plating. However, in that case, the fine powder generated from the meshing portion of the gear enters the plating solution and adheres to the hard disk suspended on the mandrel, which significantly reduces the performance of the hard disk.

[0003]

An object of the present invention is to prevent generation of fine powder (dust) in a processing tank filled with a plating solution.

[0004]

The present invention comprises a large number of annular grooved mandrels which are rotatably supported horizontally and rotatably in a processing tank and which have a water wheel in the middle portion of their length and which hang a circular disk having circular holes, and a bottom of the processing tank. It is an electroless plating tank having a processing liquid supply nozzle for injecting the processing liquid onto the water wheel and a discharge port for the processing liquid that has passed over a weir of a predetermined level in the processing tank.

[0005]

EXAMPLE A circular hard disk 1 shown in FIG. 1 is provided with a concentric circular hole 2 and is, for example, an aluminum plate having an outer diameter of 45 mm (minimum 34 mm). The hard disk 1 is in a vertical posture, and the central hole 2 is fitted in a large number of annular grooves 4 having a semicircular cross section provided on the outer periphery of a horizontal mandrel 3 made of Teflon (trade name), and when the mandrel 3 rotates, the hard disk 1 also Followed rotation. During the electroless plating operation, the hard disk 1 is immersed in the plating solution 5 on the liquid surface L.

In FIG. 2, a plating tank and other processing tanks 8 are provided.
Upper and lower slit-shaped bearings 10 that support the left and right end portions of the mandrel 3 and the shaft portions 3a and 3b of the middle portion at the left and right end portions and the middle portion of the bottom plate 9 (for example, made of PVC or stainless steel).
A pair of supports 11 and 12 are provided for each.
The processing tank 8 in FIG. 2 has a configuration in which three mandrels 3 can be set as in FIG. 3, but it is preferable that ten or more mandrels can be set in mass production. The support 12 can be omitted. The weir 13 at the rear end of the processing tank 8 has a height that regulates the level L of the plating solution 5, and the discharge port 15 at the bottom of the liquid leakage receiving chamber 14 (FIGS. 3 and 4) behind it is a pipe 16 It communicates with the storage tank 17 via.

In FIG. 2, the radial blades 2 are provided between the adjacent shaft portions 3b, 3b of the mandrel 3 at the intermediate portion in the left-right direction.
A water wheel 21 (for example, made of PVC) having 0 is fixed, and a disc-shaped baffle plate 22 (for example, made of PVC) having a diameter larger than that of the water wheel 21 is set by a set bolt 23 near the opposite side of the shaft portion 3b from the water wheel 21. It is fixed. The baffle plate 22 prevents the disturbance of the plating solution 5 caused by the water wheel 21 from adversely affecting the hard disk 1 in the vicinity. When the water wheel 21 has baffle plates integrally on the left and right ends, the baffle plate 22 shown may be omitted.

A processing liquid (plating liquid in this case) supply nozzle 25 is fixed to the bottom plate 9 below the water turbine 21 by a set bolt 26. The nozzle 25 is connected to the discharge port of the pump 28 via the pipe 27, and once stands upright from the bottom plate 9, the nozzle 25 extends from the upper end to the tip 25a (FIG. 3).
Is projected rearward, the rear end opening surface 25b is curved in an arc shape along the tip locus of the blades 20 of the water wheel 21 when viewed from the side (FIG. 3), and the lower end portion of the rear end opening surface 25b is at the lowest end. Feather 2
It is flush with the bottom edge of 0. Reference numerals 29 at the left and right ends of the mandrel 3 are gripping parts for hanging hooks (not shown) for lifting.

The plating solution 5 in the storage tank 17 is pressurized by the pump 28, and the pressurized plating solution is vigorously ejected rearward from the nozzle 25 and collides with the blades 20, so that the water turbine 21 moves in the direction of arrow A in FIG. It is driven at a predetermined rotation speed. The mandrel 3 rotates together with the water wheel 21 at a constant speed, and the hard disk 1 suspended on the mandrel 3 also rotates, so that the hard disk 1 is electrolessly nickel plated. After a lapse of a predetermined time, the pump 28 is stopped, the mandrel 3 is pulled up, and the mandrel 3 is supplied to the treatment tank of the next step.

[0010]

According to the present invention, since the water wheel 21 is driven by the jet of the processing liquid from the nozzle 25, there is no possibility that dust due to abrasion will be mixed into the plating liquid 5, and a high quality hard disk 1 can be obtained. You can Since the structure is simple, it can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view taken along the line II of FIG.

FIG. 2 is a vertical sectional front view.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a plan view.

[Explanation of symbols]

 1 Hard Disk 2 Circular Hole 3 Mandrel 4 Annular Groove 13 Weir 15 Discharge Port 21 Hydro Turbine 25 Treatment Liquid Supply Nozzle

Claims (1)

[Claims] 1. A large number of annular grooved mandrels for suspending a circular disc having a circular hole having a water wheel at a middle portion of a length horizontally and rotatably supported in a processing tank, and treating the water wheel at the bottom of the processing tank. An electroless plating bath having a treatment liquid supply nozzle for injecting a liquid and a treatment liquid discharge port that exceeds a weir of a predetermined level in the treatment bath.