JPH01182923A - Manufacture of magnetic disk - Google Patents

Abstract

PURPOSE:To reduced the packing material loss and to improve the productivity by applying surface defect check before a magnetic recording medium is assembled into a case such as a shell. CONSTITUTION:Before a magnetic recording medium 2 is assembled into a case, for example, a laser beam 18 scans the surface of the medium 2 to check whether or not there is any defect. That is, the surface defect check uses a surface defect means 17 comprising a projector 14 and a photodetector 16. Then only the magnetic recording medium 2 without surface defect is fed to the succeeding assembling process. Then the recording and reproduction defectives are reduced remarkably after assembling by applying assembling after the execution of the surface defect check in advance. Thus, the packing material loss is reduced and the productivity is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing a magnetic disk in which a magnetic recording medium is housed in a case such as a shell.

(Prior Art) In manufacturing magnetic disks, which consist of a disc-shaped magnetic recording medium housed in a case such as a shell, which is widely used as an external storage medium for computers and word processors, After polishing the surface of the plate-shaped magnetic recording medium, assemble the center core, A ring, center plate, shell, liner, lifter, write protector, etc., and incorporate the recording medium into the shell.
Recording and reproducing inspections are carried out one by one with this recording medium assembled into a shell as a nearly completed product, and finally a shutter spring is assembled to complete the floppy disk.

The main purpose of surface polishing of the recording medium described above is to remove defects such as protrusions on the surface, but defects that cannot be removed by this polishing alone may remain on the surface after polishing. Defects cause poor recording and reproduction.

Therefore, after polishing the surface of the recording medium, it is necessary to finally inspect whether recording and reproduction are performed correctly.
Therefore, in order to be able to be installed in a recording/playback driver, a nearly completed product with a recording medium built into the shell is installed in the driver and subjected to the above recording/playback inspection, and only non-defective products are assembled into a shutter spring to complete the product. , defective products are simply discarded.

(Problem to be Solved by the Invention) However, even in the above-described defective products, in most cases only the magnetic recording medium is defective, and the shell, liner, lifter, and other packaging materials are not defective. Therefore, as described above, it is extremely uneconomical to discard defective products after the recording/reproduction test, as this results in loss of packaging materials such as good shells and liners.

Further, as described above, discarding after assembling almost a finished product means assembling a defective product, which also reduces the productivity of the assembly line.

In view of the above circumstances, an object of the present invention is to provide a magnetic disk manufacturing method that can reduce the packaging material loss and has high productivity.

(Means for Solving the Problems) In order to achieve the above object, a magnetic disk manufacturing method according to the present invention includes the following steps: The present invention is characterized in that after the surface of the magnetic recording medium is polished, the surface defect inspection of the magnetic recording medium is performed before the magnetic recording medium is assembled into a case.

(Function) Most recording and reproducing defects are caused by surface defects in magnetic recording media. Therefore, if the surface of the magnetic recording medium is scanned with a laser beam and inspected for defects before the magnetic recording medium is assembled into the case as in the present invention, magnetic recording without surface defects can be carried out. Only the medium can be sent to the next assembly process.

Therefore, if such surface defect inspection is performed in advance before assembly, the number of recording/reproducing defective products after assembly will be significantly reduced, resulting in the reduction of packaging material loss and productivity as described above. It is possible to improve the

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

The figure is a perspective conceptual diagram showing an apparatus for carrying out a main part of an embodiment of the magnetic disk manufacturing method according to the present invention.

The illustrated device includes eight nests 4 in the circumferential direction that attract and hold a disk-shaped magnetic recording medium 2 having a hole in the center and rotate it, and first to eighth stations STI also set in the circumferential direction. ~ST8 is provided with an index table 6 which rotates intermittently in the direction of the arrow in order to sequentially position the nests 4.

The magnetic recording medium 2 is ST1 of the index table 6.
It is supplied to the nest 4 located at the host 4 and held on the host 4 by suction. Next, the magnetic recording medium 2 is sequentially sent to ST2 and ST3, and the upper surface side is surface-polished in ST2, and the lower surface side is surface-polished in ST3. These surface polishing steps are ST2,
A magnetic recording medium 2 is placed between a known polishing roll 8 constituting the polishing means 7 provided in ST3 and a backup member 10 (not shown in ST2) facing the polishing roll 8.
This is carried out by placing the recording medium 2 in contact with the polishing roll 8 which is rotating at high speed while rotating the recording medium 2.

After finishing the surface polishing, the magnetic recording medium 2 is sent to ST4,
In ST4, cleaning is performed to remove polishing debris, dust, etc. adhering to the magnetic recording medium 2. This cleaning is performed by bringing the nonwoven fabric 13 constituting the cleaning means 12 into contact with both upper and lower surfaces of the recording medium 2 while rotating the magnetic recording medium 2. In this case, the nonwoven fabric 13 is fed at a constant speed during cleaning so that a fresh surface is always cleaned.

After the above-mentioned cleaning is completed, the magnetic recording medium 2 is sent to Sr1 through the idle station Sr1, and an optical surface defect inspection is performed on both the upper and lower surfaces at ST6. This surface defect inspection is performed by a surface defect inspection means 17 composed of a light projector 14 and a light receiver te. That is, the laser beam 18 that scans in the radial direction of the magnetic recording medium 2 is emitted from the projectors 14 disposed on the upper surface side and the lower surface side, and both the upper and lower surfaces of the recording medium 2 are irradiated with the laser beam 18. , the reflected light is received by the light receiver 1B, and surface defects are detected based on changes in the amount of received light. Of course, the recording medium 2 rotates once during the inspection, and the entire recording area is inspected.

When the above surface defect inspection is completed, the magnetic recording medium 2 is made of Sr.
7, the receiver is passed onto the intermediate receiver 20 of the defective product discharge station. The judgment result of the above-mentioned surface defect inspection is data shifted by the control system, and the recording medium 2 judged to be a defective product is placed on the intermediate pedestal 20 at this defective product discharge station.
As the products descend, they slide down the chute 22 and are accumulated in the defective product receiving box 24. The recording media 2 determined to be non-defective are not discharged at this defective discharge station, but are conveyed to the magazine 28 on the conveyor 2B and accumulated there.

The magnetic recording media 2 accumulated in the magazine 28 are then sent to the assembly process by the conveyor 2B, and are sent to the center core, A
Rings, center plates, shells, liners, lifters, write protectors, etc. are assembled, and in an almost complete state built into this shell, we set them one by one in a recording/reproducing drive to ensure quality and perform recording/reproducing inspections. Defective products are discarded, and a shutter spring is finally installed in only good products to complete the product.

According to the above method, a surface defect inspection is performed before the magnetic recording medium 2 is assembled into a shell, so this inspection results in records having surface defects, which account for most of the cases in which the magnetic recording medium 2 is determined to be defective in subsequent recording/reproducing inspections. The media are removed, and only those recording media, most of which are good, are sent to the next assembly process, which can significantly reduce the number of media determined to be defective in post-assembly recording/reproduction inspections. .

In addition, in the above method, a cleaning process is provided before the surface defect inspection process, and this cleaning before the surface defect inspection can cause erroneous detection in high-level surface defect inspection where the surface of the recording medium only has original defects. decreases and improves test reliability.

The present invention can be modified in various ways without departing from the spirit thereof, and is not limited to the above embodiments.

For example, surface polishing may be performed using a polishing tape, a razor, or the like instead of a polishing roll. For cleaning, other cloth or paper may be used instead of non-woven cloth, or polishing debris and dust may be blown away by blowing air. The nonwoven fabric may also be fed during cleaning by stopping the nonwoven fabric so that a certain area of the nonwoven fabric is in contact with the recording medium, and then feeding the nonwoven fabric at a certain pitch to bring out a new portion after cleaning the recording medium. Surface defect inspection is not limited to optical inspection, and in the case of optical inspection, a tungsten lamp, halogen lamp, fluorescent lamp, etc. may be used. Although the surface defect inspection is performed on the disc-shaped magnetic recording medium alone, it may also be performed on the recording medium with a center core attached. Conveyance of magnetic recording media to each station is not limited to index tables, but belt conveyors (roller conveyors, etc.) may also be used. Defective products after surface defect inspection are also collected in magazines or plastic bags. Good products after surface defect inspection may be transported one by one to the assembly process without being accumulated in a magazine.

(Effects of the Invention) As described above, in the magnetic disk manufacturing method according to the present invention, a surface defect inspection is performed before the magnetic recording medium is assembled into a case such as a shell. Most of the defective recording media are eliminated, and therefore most of the recording media sent to the assembly process are of good quality, and the number of recording media determined to be defective in post-assembly recording and reproducing inspections is significantly reduced. It is possible to reduce material loss and improve productivity.

[Brief explanation of the drawing]

The figure is a perspective view showing an apparatus for carrying out a main part of an embodiment of the magnetic disk manufacturing method according to the present invention. 2...Magnetic recording medium 7...Surface polishing means 12...Cleaning means 17...Surface defect inspection means T3

Claims (1)

[Claims] A magnetic disk manufacturing method comprising polishing the surface of a magnetic recording medium and assembling it in a case, characterized in that after polishing the surface of the magnetic recording medium, a surface defect inspection of the magnetic recording medium is performed before assembling the magnetic recording medium in the case. Production method.