| 摘要 |
<p>1,140,874. Grinding. NORTON CO. 16 March, 1966 [19 March, 1965], No. 11596/66. Heading B3D. Apparatus for cutting thin hard material comprises multiple blades 123 separated by spacers 124 extending substantially over the whole length and width of the blades and clamped therewith in backing plates 42 carried by a blade support frame 31 which is reciprocated along slideways 23, 24 on a main support frame 14, and a workpiece feed mechanism 81 mounted on a bracket 71. The workpiece may be a thin wafer of semi-conductor material having a plurality of microminiature electronic circuits which is to be cut into a plurality of small dice of, for example, 0À030 x 0À030 inch, each bearing a complete circuit, the wafer being 0À010 inch thick. Support-structure 14 is mounted on three pads 16 on a support 12 having three feet 17. A blade-supporting frame 31 is connected by a quick-release device 61 to a plate 56 having a slot 57 engaged by an eccentrically driven pin 55 whereby the frame is reciprocated along the slideways. One end of the backing plates 42 is located by pins 131 on the frame, and the other end of the frames has means for aligning the blades with the movement of the frame. The edges of the blades may be ground so as to be in a common plane, and when worn may be adjusted by shims. The bracket 71 is secured to the support structure 14 by bolts 77 and has a nylon bearing 91 slidably supporting a cylindrical plunger 94 of the feed mechanism which is prevented from rotation by rollers 104 engaging a bar 101 fixed to an upper flange 95 supporting a workpiece supporting plate 96. The plunger is urged upwardly by weights 115 on a lever 110, which is pivotally mounted on the support 12 and is formed with a yoke having rollers 117 engaging the flange 95 and can be lowered by movement of a pivoted lever 192 engaging a roller 191 on the plunger. The plate 96 supports a series of vacuum assemblies 141 for holding the workpieces, each assembly being disposed between a pair of supports 151 having clamp member 153. To locate and orientate the workpieces, a thin transparent flat member (161, Fig. 7) is mounted on the supports and the blades are reciprocated over the member in the presence of abrasive to scribe reference lines thereon. The member is then replaced by two short blocks (162, Fig. 8) and reference lines are scribed thereon by the blades. The workpieces are then bonded to circular workpiece supports (175) and held by a light vacuum on the assemblies (141), and the thin transparent member (162), with spacing blocks (163) secured thereto, is inverted end for end and aligned, by means of a viewing device and the reference lines with the short blocks (162). The workpiece is then accurately positioned beneath the reference lines and held in position by a high vacuum. The procedure is repeated for each assembly and the transparent member removed so that the blades can be reciprocated to cut the workpiece. The procedure is then repeated with the workpiece displaced through a right-angle to produce the dice.</p> |
