Developing the first orbiting IC

Article By : Micah McDaniel, Texas Instruments

Bob Cook had a knack for trouble-shooting semiconductors. Jack Kilby tapped Cook as TI's lead engineer on an early NASA project.

For Charles “Bob” Cook, a project assigned by the legendary Jack Kilby led to the development of the first integrated circuits to ever orbit Earth – and a foundation for future space electronics.

Jack Kilby was a little more than two years removed from inventing the integrated circuit when he was promoted to lead Texas Instruments’ fledgling semiconductor lab. The year was 1961, and the Space Race was heating up. Kilby was working on three high-profile contracts—all were troubled.

Kilby was entrusted with making custom ICs for the Minuteman missile guidance system as well as devices for a U.S. Air Force computer system. The third project was a particularly challenging request from NASA—Kilby knew exactly who he wanted to lead the project.

Bob Cook was a young but brilliant engineer who had a knack for trouble-shooting semiconductors. Kilby hand-picked Cook as lead engineer for the NASA project. That decision would change space exploration for generations to come.

“I thought I could do it because when I looked at the challenge, it looked possible mathematically,” Cook said.

Shooting for the moon

NASA had its sights set on the moon with its future Project Apollo missions. Success required increased computing power and weight reduction via miniaturization. As a result, the space agency was already in the process of swapping circuits of discrete transistors for ICs.

Kilby had previously supplied NASA with TI’s first commercially available chip – the TI SN502 – at a cost of about $450. But NASA needed an alternative that provided more power and speed in the same amount of space.

Kilby’s challenge: design a line of digital logic ICs to replace the SN502, but with 10 times the speed and one-tenth the power consumption. to help.

And NASA wanted it in 10 months.

The IC business was still on shaky ground: early critics noted remarkably low manufacturing yields along with the business challenges posed by the transition to mass production. Nevertheless, Kilby and Patrick Haggerty, one of TI’s co-founders, believed it could be done.

They were right.

“At that time, the majority of our business was defense contracts, and they all wanted smaller and lighter devices,” said Max Post, a TI retiree who was working in the chip maker’s corporate offices at the time. “Haggerty believed very strongly in the IC, and believed it would work. It was the IC that proved to be the most important development to reduce the size and weight of those systems.”

Laying the foundation

Cook worked sunrise to sunset six days a week—plus after church on Sundays—to meet the deadline. He monitored the production line and selected each wafer carefully to get the best possible yield. About 50 percent of the chips worked, so he examined the rejects individually with tweezers to figure out what adjustments would improve the yield.

“We did two things we had never done before,” said Bob, now 88 years old and living in West Palm Beach, Fla. “We found a way to put two transistors on a chip and we put oxide on the surface of the silicon to allow us to put conductors on it to connect the transistors.”

With that, the Series 51 family of integrated circuits was born.

Series 51—featured on the November 1961 cover of Fortune magazine—was a set of six digital logic circuits based on resistor-capacitor-transistor technology with lower power and a small, flat package. TI now had its first complete, compatible logic set that served as the basis for modern computing and introduced the term “Series.” Within a span of roughly three years, the Series 51, 52, 53 and 54 brand names quickly gained recognition across the industry. The SN5400, a military-grade four-channel, two-input NAND gate used in military radios, is still available today.

“I told Jack that we can put a lot more stuff on the chip and then rig it so it will be useful for a lot of other applications,” Cook said. “The other two contracts eventually shifted to the Series 51 process and that turned their projects around. We were able to bail him out of all three of his headaches because of the device we made.”

The work done on Series 51 laid the foundation for several products that TI still sells. It ultimately served as a precursor to IC technology that enables an increasingly digital world.

“It’s safe to say that probably 99 percent of applications we interact with today—from inexpensive children’s toys to appliances to personal electronics to factory automation and control—have some sort of logic gate in them,” said Michael Shultis, a TI marketing and applications manager for logic products. “Because of what was done with the Series 51 and eventually the Series 54, today’s logic semiconductor market has exploded.”

‘Just doing my job’

Shortly after Thanksgiving 1963, and with little fanfare, NASA launched Explorer 18, the first satellite of the Interplanetary Monitoring Platform. The satellite collected data about radiation in space to support the upcoming Apollo missions.

Retired TI engineer Bob Cook holds the SN502 chip given to him by Jack Kilby as thanks for Cook’s work on Series 51.

On the surface, the launch seemed ordinary. But for the future of space electronics, it was extraordinary: At the heart of the onboard Optical Aspect Computer was a pair of Series 51 ICs designed by Cook and his team—the SN510 and the SN514. They were the first ICs to orbit the Earth.

“I didn’t know it at the time, but I thought it could happen because of who had them,” Cook said, recalling that he had no knowledge that his ICs would be the first into space. “I never knew what systems my work was going into. I was just doing my job.”

Cook left TI shortly before Explorer 18 launched. He put together a remarkable 45-year career, retiring from Siemens in 2002. He holds 22 patents, including one for airbag sensors developed before airbags became standard safety equipment in automobiles. When NASA received the Series 51, the agency sent Kilby’s original microchip—the SN502—back to TI.

Kilby gave it to Cook as a “thank you” for his work.

“I’ve had a good life and was productive in original thought all the way through my career,” Cook said. “At TI, I learned to troubleshoot semiconductors, which is at the heart of what I did the rest of my career. I was blessed with a talent, and I was given an opportunity to use it.

“Jack and I were very close and we did a lot of good things. Working with him was one of the highlights of my career,” Cook added.

This article was originally published on EE Times.

Micah McDaniel is the worldwide corporate program manager at Texas Instruments.

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