United States Patent 3,531,856
October 6, 1970

Assembling Semiconductor Devices
Harold B Bell
George A. Doyle

Filed November 27,1964
Image of US PATENT 3,531,856

Abstract of the Disclosure

A semiconductor device is assembled and encased in plastic by a one-step transfer molding operation. In one embodiment of the process electrical leads for the device are stamped out in the form of a flat metal clip composed of a supporting frame member and a number of leads extending therefrom. The semiconductor element is mounted on one of the leads and fine wire connections are made between the semiconductor element and the remaining lead or leads. The assembled device is then placed in a transfer molt where the semiconductor element and the wire-connected lead ends are encased in plastic. Upon removal from the mold the supporting frame member is trimmed from the lead clip, thereby providing a completed unit.
Figure descriptions: cover graphic

  • Figure 1 is an enlarged view of a transistor package constructed in accordance with the concepts of the invention.
  • Figure 2 is a view similar to Figure 1, but in a transparent or shadow type of showing. The structure within the molded casing is visible and double in size relative to Figure 1.
  • Figure 2A is a single combination device lead and mounting pad for a semiconductor element corresponding to one of the three for the device of Figure 2.
  • Figures 3A-3E and a series of views illustrating the condition of the mold and semiconductor assembly during the manufacture of the transistor package of Figures 1 and 2.

 Citations [54]:
3,118,016 01/1964 Stehenson 3,298,087 01/1967 Hunt 3,171,187 03/1965 Ikeda et al 3,341,649 09/1967 James 3,262,022 07/1966 Caracciolo 3,367,025 02/1968 Doyle 3,264,712 08/1966 Hayashi et al 3,281,628 10/1966 Bauer et al
National Museum of American History
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