GB1271128A - Method and apparatus for sorting semi-conductor devices - Google Patents

Abstract

1,271,128. Sorting semi-conductor dies. TELEDYNE Inc. 1 Nov., 1969, No. 53659/69. Heading B2H. [Also in Divisions B5, B8 and H1] A method of sorting semi-conductor dies from a monolithic wafer comprises scoring the surface of the wafer 10, Fig. 1, along lines 12, 14 dividing the dies 16, mounting the wafer on a flexible adhesive tape 18, Fig. 3, applying the tape and wafer to a resilient surface 22 with the wafer between the tape and surface, applying a moving line of pressure 24 against the tape parallel to the score lines to break the wafer into an array of separated dies, separating the tape with the array of dies from the surface, and removing individual dies from the tape and placing them in pre-determined groups. The wafer is initially formed with a plurality of microscopic circuits or components which may be of 5 to 10 different types and the score lines 12, 14 divide the circuits one from another. After scoring, the wafer is mounted on the adhesive tape with the score lines facing outwardly and then placed on a smooth release surface 20 covering a resilient backing member 22. A tool 24 is rubbed over the non-adhesive surface of the tape to cause the wafer to fracture along the score lines. The tape is then peeled from the surface 20 with the separated dies adhering to the tape. Before breaking, each circuit on the wafer is examined and its electrical characteristic recorded on a tape 28 which is fitted into a tape reader control 26. Sorting. The adhesive tape 18 carrying the separated dies 16 is mounted on a rest 38, Figs. 4 and 5, having a rear portion 50 of small radius and has its ends secured to clamps 52 on the front and rear surfaces of the rest, the rear clamp being carried by a slide (58, Fig. 6, not shown) acted on by a spring (60) to tension the tape, and the front clamp being connected by adjusting screws 54, 56 to a slide 58 movable by a micro-adjustment screw 44 and a Y-axis drive motor 48. The rest is adjustable in an X direction by a microadjustment screw 42 and an X-axis drive motor 46. The rest 38 is mounted on a pantograph 40 for positioning on a base 32 which has an upright 34 carrying a microscope 36 for visual inspection of the dies. Each die can be removed from the adhesive tape by an electromechanical tweezer 62 having jaws 61 on a split ring 64 actuated by a coil 66, the tweezer being actuated to embrace, grip and lift a die from the tape. The tweezer is carried by a slide 68 which is retracted under the control of the tape reader 26 to deposit the die on a selected one of a series of carrier belts 72 extending between feed spools 74 and take-up spools 76 driven by a motor 80. Packaging. Each belt 72, Fig. 7, is formed with shallow pockets 80 for receiving the dies deposited by the tweezers 62 and is indexed upon receiving a die. As the belt is indexed, an overlay of pressure sensitive adhesive tape 78 is pressed against the upper surface of the belt to seal the semi-conductor dies in the pockets.