Patent GB-1179319-A (GB)
Title: Machine for attaching a Terminal Pillar to a Transistor Chip
IPC: H01R43/02
Filed: 1967-09-01
Abstract: 1,179,319. Welding by pressure; making semi-conductors; punching. CORNING GLASS WORKS. 1 Sept., 1967 [8 Sept., 1966], No. 40070/67. Headings B3A, B3R and B3W. A machine for attaching a terminal in the form of a pillar to a metal contact plate in contact with an electrode of a transistor chip comprises a base 11, or work-table 28 mounted for movement in two directions at right angles, means for driving the work-table, numerical control means for controlling the driving means, a transistor chip support means 20a adjustably attached to the work-table 28, a holder for a thin metal sheet on the support means from which metal sheet the pillar is to be cut and simultaneously bonded to the contact plate, a vibratory bonding head 24a supported for movement into and out of contact with the metal sheet and electrical interlocking controls for controlling the movement of the bonding head, the application of energy to the head and movement of the work-table. The machine is used to form a terminal on a metal contact plate of a transistor chip by arranging a metal sheet adjacent the plate and contacting the sheet with the bonding tool which cuts a terminal pillar from the sheet and simultaneously bonds the pillar to the plate as disclosed in Specification 1,068,108. The table 28 is mounted on an upper carriage movable from left to right in Fig. 1 by screws supported on a lower carriage movable at right angles to the first movement by screws driven by a motor under the control of a programmed tape control. The table 28 carries three transistor chip supports 20a, 20b and 20c, each comprising a support block having vacuum passages for applying vacuum to a hold-down plate on the top of the block to hold the transistor chip and a foil holder in the form of a frame pivoted about one end and engageable on the other end by a solenoid armature 136, Fig. 2. This pivots the foil after bonding to break connections between the pillars and the foil sheet. The transistor supports are adjustable in two directions at right angles by micrometer screw 106, 108 and are rotatable. The bonding heads each include a bonding tip 60, Fig. 2, and a transducer 62, the assembly being pivoted at 64 for up and down movement of the tip 60. An arm 70 secured to the head carries a biasing weight 72 at one end and is engaged at the other end by a cam 80 driven from a motor 84. A station 50 at which the work is aligned relative to the worktable comprises a microscope 52 mounted above a work inspection support 56, the support being aligned under the microscope to align the table 28 and the transistor supports being movable under the microscope for inspection of the terminal pillars applied to the transistor chips. Electrical controls include a relay to apply power to the machine and a relay to control the start of welding, both relays being under the control of the programmed tape. The motor 84, Fig. 2, which positions the bonding tip 60 and which controls switches ensuring that welding cannot occur until the tip 60 is down and that the table 28 will not index until the tip 60 is up is controlled by a relay. The controls for the three bonding units are interlocked so that welding does not take place until all the tips are down. After welding and a time delay the motor 84 is driven to raise the bonding tip and the solenoids 132 are energized to smartly raise the foil holders. After a further time delay the table is caused to be indexed.