Patent GB-854714-A (GB)
Title: Improvements in magnetic core circuit packages and methods of producing such packages
IPC: G11C7/02
Filed: 1958-12-31
Abstract: 854,714. Magnetic information-storage apparatus. INTERNATIONAL BUSINESS MACHINES CORPORATION. Dec. 31, 1958 [Dec. 31, 1957], No. 42131/58. Class 40 (9). In a magnetic information-storage matrix in which the cores 10, Fig. 11, are mounted in correspondingly shaped sockets 20 formed in a moulded panel 18, the core sockets are stepped so as to provide seatings for sealing plugs 36, and the moulded panel and the plugs are apertured and grooved for the reception of matrix wiring which is formed by vacuum deposition and electroplating operations. In the arrangement shown in Fig. 11, and in Figs. 4 and 5 which respectively illustrate the front and rear of a complete panel, each core 10 is formed with three holes 12, 14, 16 for a sense conductor, the X and Y conductors and an inhibiting conductor respectively, and aligned apertures 12a, 14a, 16a, 12b, 14b, 16b are provided in the panel and plugs. Electrical interconnections between conductors which pass through the panel apertures and core holes are provided by conductors formed in grooves 22, 24, 26 and 22a, 24a, 26a on the two panel surfaces. The panel and plugs are moulded from a styrene compound and a number of plugs 36, Fig. 10, may be linked by a removable web 46 so that their insertion in alignment with the panel grooves is facilitated. After assembly, the panel is dipped into a diluted buta N thermosetting adhesive which secures the various parts together and fills the interstices between the core surfaces, the panel sockets and the plugs, thereby eliminating the possible formation of unwanted conducting paths during the conductor development operations. A suggested adhesive consists of 45% phenolic resin, 45% butadiene-acrylonitrile and 10% epoxy resin which is diluted by methyl ethyl in the proportions 1: 7 by weight. The panel is air-blasted after the dipping operation to prevent the core holes and aligned apertures from becoming blocked. After drying, the panel, core holes and apertures are formed with a continuous conductive surface by a copper vaporizing process, and this surface is subsequently built up by copper electroplating. A tin-lead coating may also be applied to inhibit oxidization and to facilitate the formation of soldered connections. The assembly is then ground by means of a surface grinder or sander so as to remove all the metal from the surface parts of the panel, separate conductors being then left in the grooves, each of which passes through a respective hole in the cores. In a modification, Fig. 12, cores 50 may be formed with five holes 52-60 and the conductors X<SP>1</SP>, Y<SP>1</SP>, S<SP>1</SP>, I<SP>1</SP> are arranged as shown. In a further modification, Fig. 13, a toroid core 60 is inserted into an annular socket 72, the central boss 70 of which is formed with apertures 74 for the matrix conductors. These apertures are aligned with and directly engage apertures 78 in a plug 68. Mention is made of the use of a single closureplate which is coextensive in outline with the matrix panel, the plate being formed with conductor grooves and apertures while the face of the panel being left smooth.