| 摘要 |
997,326. Magnetic storage apparatus. INTERNATIONAL BUSINESS MACHINES CORPORATION. June 26, 1963 [June 29, 1962], No. 25327/63. Heading H3B. [Also in Division HI] A magnetic storage array is manufactured by coating conductive wires with successive layers of wax and a ferrite resin mixture, mounting the wires in parallel alignment in two open frames, orienting the frames so that the wires are orthogonal, pressing the frames together so that the wire coatings adhere, cutting the wires away from the frames after partial curing has taken place and finally sintering the ferrite at higher temperatures. The wax and resin are burnt away during the sintering process, the wax providing a space between the wires and the surrounding ferrite which prevents fracturing of the magnetic material. The co-ordinate wires may be positioned either as shown in Fig. 1A or Fig. 2, the latter arrangement providing a web of ferrite 3 between the wires 4, 5 at each crossing point. Where more than one wire is provided in each co-ordinate at each crossing point, these wires are insulated and twisted together in Fig. 3 (not shown). Depending on the materials used, the suggested temperatures for the process are 25-150‹ C. for partial curing, increasing to 100-150‹ C. to melt the wax coating. The temperature is then raised, firstly to 600‹ C. to remove the resin and plasticizer and then to 900-1400‹ C. to sinter the ferrite. Annealed platinum, palladium, silver or copper may be used for the wires, and the wax coating may be either natural or synthetic such as beeswax, carnauba wax, polyethylene wax or paraffin wax. Other suitable wax-like substances are polyvinyl acetate, polyvinyl chloride and their copolymers. The ferrite resin comprises 40-80% by weight of calcinated ferrite powder, 5-60% of thermosetting resin plus catalyst and 0-30% of plasticizers. Suitable ferrite powders exhibiting the required rectangular hystesis loop are Fe 1 . 83 Mn 1 . 08 Cu. 09 O 4 , Fe 1 . 68 Mn 1 . 25 Cr. 06 Ni. 03 O 4 , Fe 1 . 7 Mn. 6 Mg. 7 O 4 , and Fe 1 . 65 Mn 0 . 95 Cr. 10 Zn. 25 Cu. 02 O 4 . The resins may be epoxy resins, polyester resins, melamine-formaldehyde resins or phenol aldehyde resins. Suitable catalysts for the resins are described, and examples of various viscosity control agents are given such as pine and castor oils, butyl glycidyl ether or a 1: 1 mixture of methyl ethyl ketone and amyl acetate. A modification is described in which rayon fibres are used instead of certain of the wires, the fibres being burnt out by the heat treatment to provide a hollow ferrite structure through which pluralities of metallic conductors are later threaded. |
