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When he went to Western Electric to study transistors, the 35-year old Iwama was just entering his prime. But this does not entirely account for the tremendous energy with which he threw himself into his work.
Iwama's knowledge of transistors was limited to the little he had acquired on manufacturing basics from Transistor Technology. Above all, he had to take back to Japan as much information as he could. Western Electric would not provide specifications for the manufacturing equipment, but they were happy to show him around their factories. On these tours Iwama would stop in front of each item that seemed particularly interesting and ask questions in his not too perfect English. He took down the answers and included his impressions in the reports to Tokyo. Being unable to make diagrams on the spot, he would return to the hotel and test his memory for every detail of what he had seen and heard, and while his reports may not have been totally accurate, they were certainly exhaustive. The first ran to nine oversized pages, eight more on February 19, nine more on February 21, five on April 7, another five on April 9, eight on April 13, and four on April 15.
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 | | Letters sent by Kazuo Iwama from the United States in 1954. |
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Though he did not write every day, his output was prodigious.
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Based on Iwama's reports and Transistor Technology, his colleagues in Tokyo set about making a transistor of their own for Iwama to see when he returned. The first hurdle was to construct the necessary machine tools. Naturally there were none on the market for use in manufacturing semiconductors. And no matter how carefully they read Transistor Technology, the diagrams they needed could not be found there. They had no choice but to draft their own blueprints for every single piece of equipment. Akanabe started to do so, guided by suggestions from Iwata, Tsukamoto and others. But all he had to work with in the Totsuko machine shop were two small lathes, a drill press, and a milling machine -a real shoestring operation! There was no way the work could be completed on the premises, and so the machining was leased to a subcontractor. Starting from scratch, the task force devised a germanium oxide reductor using hydrogen, a zone refining slicing machine which raises the purity !!
of the product and related apparatus.
Slicing the germanium crystals called for a diamond grinder rotating on a precision high-speed shaft. No subcontractor would take on such a specialized order. But Morita had the foresight to obtain this diamond wheel in the U.S. From there on, it was up to the task force. When Akanabe was told this, he went to Furukawabashi, in those days a district of second-hand machine tool dealers, and hunted down a slicer rusting from the rain outside one of the stores. He managed to convert this slicer into the machine they needed.
Totsuko's own transistor oscillated for the first time one week before Iwama was due back from the U.S. It was of the point-contact type created by Shockley and his team at Bell Laboratories. The oscillator was hand-made by Yasuda. The first flicker of the needle was greeted with an outburst of joy. No one had expected to see a transistor finished so soon. A junction-type device followed so quickly that even Iwama, back in Japan by then, could not believe it. When shown the germanium crystals, he was not at all convinced that they were the real thing. In fact, it was not until he saw the oscillator swing its needle that he knew they had done it. It did indeed seem to be a transistor.
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