Method of loading a sputter pallet

#The present invention relates to the manufacture of magnetic and optical recording media and in particular to a method and apparatus for loading small form factor disks into sputter pallets.

#In the manufacture of magnetic and optical recording media, thin films are sputtered on rigid disk substrates. The sputter process typically takes place in high volume, multiple chamber machines that employ either static or pass-through configurations. The most common form factor for which these sputter machines are configured is 95 mm. Small form factor disks, e.g., 27.4 mm disks, however, are being increasingly used. Similar to the large form factor disks, the manufacture of small form factor disks requires that thin films are sputtered onto the small form factor disk substrates. A known method for sputtering small form factor substrates is to use a sputter pallet, commonly referred to as mini-pallets, which has a large form factor, e.g., 95 mm, and holds several of the smaller substrates. With a mini-pallet, the small form factor substrates can be sputtered without reconfiguring the sputter machine, which can be expensive and time intensive.

#A problem associated with the use of mini-pallets is that loading the small form factor disk substrates into the mini-pallet is difficult. The small form factor disks are positively held within the mini-pallet with springs. To load a disk into the mini-pallet, the spring is retracted, the disk placed into the mini-pallet, and then the spring is gently released to hold the disk in place without damaging the disk. Typically damage that occurs during loading includes chipping of the outside diameter edge of the substrate or cracking of the substrate. In addition, the placement of the substrates in the mini-pallet is critical. The disk must be aligned in the mini-pallet within approximately 0.001″. Improper loading of a disk can cause the disk to fall out during the sputter process or cause substrate damage. In addition, improper loading of the disk can lead to improper or incomplete coverage of the thin film on the surface of the disk during sputtering.

#FIG. 1 shows a perspective view of a mini-pallet loader that is used to automatically load and unload small form factor disk substrates into a sputter pallet, in accordance with an embodiment of the present invention.

#FIG. 2 shows a top view of a pallet mounted on spindle and positioned over an air track that is transporting a disk substrate.

#FIGS. 3 through 6 show side views of the pallet loader in the process of loading a disk substrate into a pallet.

#FIG. 1 shows a perspective view of loading and unloading device 100 that is used to automatically load and unload small form factor disk substrates, shown as disk 101, into a mini-pallet 102, in accordance with an embodiment of the present invention.

#As shown in FIG. 1, device 100 includes a spindle 104 upon which the mini-pallet 102 is held. An air track 106, or some similar device, positioned near the loading area of mini-pallet 102 is used to transport the disk 101 to the loading site 108 of the device 100. An actuator arm 110 is used to open and close a spring on the mini-pallet 102 during the loading process. The spindle 104 is rotated by a stepper motor 112, e.g., via a belt drive 114, and accurately positioned by a clamp actuator 116. A pallet index sensor 118 is included to ensure that the mini-pallet is positioned properly. In addition, a displacement sensor 119 is used to indicate the position of disk 101 during loading to aid in the loading process. Displacement sensor 119 is shown as located within air track 106 so that the displacement sensor 119 will be positioned under disk 101 during loading. Displacement sensor 119, however, may be located above loading site 108 so that the displacement sensor 119 is positioned over disk 101, if desired. A microprocessor 120 is coupled to and controls the actuator arm 110, stepper motor 112, clamp actuator 116, the pallet-index sensor 118, and displacement sensor. In addition, microprocessor 120 may control the means of transporting disk 101, such as the air flow within air track 106.

#FIG. 2 shows a top view of device 100 with a mini-pallet 102 mounted on spindle 104 and positioned over the air track 106, which is transporting disk 101. Mini-pallet 102 has a diameter of 3.75 inches, and a thickness of 0.05 inches and is manufactured, e.g., from stainless steel or other appropriate material. Mini-pallet 102 includes four loading areas 122 that are formed by apertures in the body of the mini-pallet, and that hold the small form factor disks when loaded. Mini-pallet 102 also includes an integral spring 124 and a plurality of contact points 126, e.g., three, that extend into the apertures. The integral spring 124 includes a gripping aperture 128, which the actuator arm 110 (shown in FIG. 1) engages to open integral spring 124. If desired an opposing gripping aperture 130 on body of mini-pallet 102 opposite gripping aperture 128 may also be engaged with actuator arm 110 to open and close spring. The mini-pallet 102 also includes a number of index marks 132, which may be, for example, apertures through mini-pallet 102 and that are used with pallet index sensor 118 to properly position each loading area 122 on mini-pallet 102 over the disk moving device for loading.