forerunner of the integrated circuit
Today they are everywhere. Production lines controlled by computers and operated by robots. There’s no chatter of assembly workers, just the whirr and click of machines. In the mid-i940s, the workerless factory was still the stuff of science fiction. There were no computers to speak of and electronics was primitive. Yet hidden away in the English countryside was a highly automated production line called ECME, which could turn out 1500 radio receivers a day with almost no help from human hands.
John Sargrove, the visionary engineer who developed the technology, was way ahead of his
time. For more than a decade, Sargrove had been trying to figure out how to make cheaper radios. Automating the manufacturing process would help. But radios didn’t lend themselves to such methods:there were too many parts to fit together and too many wires to solder. Even a simple receiver might have 30 separate components and 80 hand-soldered connections. At every stage, things had to be tested and inspected. Making radios required highly skilled labour—and lots of it.
In 1944, Sargrove came up with the answer. His solution was to dispense with most of the fiddly bits by inventing a primitive chip—a slab of Bakelite with all the receiver’s electrical components and connections embedded in it. This was something that could be made by machines, and he designed those too. At the end of the war, Sargrove built an automatic production line, which he called ECME (electronic circuit-making equipment), in a small factory in Effingham, Surrey.
An operator sat at one end of each ECME line, feeding in the plates. She didn’t need much skill, only quick hands. From now on, everthing was controlled by electronic switches and relays ( 继电器 ) .First stop was the sandblaster (喷砂器) , which roughened the surface of the plastic so that molten metal would stick to it. The plates were then cleaned to remove any traces of grit. The machine automatically checked that the surface was roughenough before sending the plate to the spraying section.There, eight nozzles (喷嘴) rotated intoposition and sprayed molten zinc over both sides of the plate. Again, the nozzles only began to spray when a plate was in place. The plate whizzed on. The next stop was the milling machine, which ground away the surface layer of metal to leave the circuit and other components in the grooves and recesses. Now the plate was a composite of metal and plastic. It sped on to be lacquered (vt. 涂漆；使表面光泽）and have its circuits tested. By the time it emerged from the end of the line, robot hands had fitted it with sockets to attach components such as valves and loudspeakers. When ECME was working flat out, the whole process took 20 seconds.
ECME was astonishingly advanced. Electronic eyes, photocells that generated a small current when a panel arrived, triggered each step in the operation, so avoiding excessive wear and tear on the machinery. The plates were automatically tested at each stage as they moved along the conveyor. And if more than two plates in succession were duds, the machines were automatically adjusted—or if necessary halted. In a conventional factory, workers would test faulty circuits and repair them. But Sargrove’s assembly line produced circuits so cheaply they just threw away the faulty ones. Sargrove’s circuit board was even more astonishing for the time. It predated the more familiar printed circuit, with wiring printed on aboard, yet was more sophisticated. Its built-in components made it more like a modem chip.
When Sargrove unveiled his invention at a meeting of the British Institution of Radio Engineers in February 1947, the assembled engineers were impressed. So was the man from The Times. ECME, he reported the following day, “produces almost without human labour, a complete radio receiving set. This new method of production can be equally well applied to television and other forms of electronic apparatus.”
The receivers had many advantages over their predecessors. With fewer components they were more robust. Robots didn’t make the sorts of mistakes human assembly workers sometimes did. “Wiring mistakes just cannot happen,” wrote Sargrove. No wires also meant the radios were lighter