What exactly does this term mean? Before semiconductors, so many TVs and radios claimed “solid-state electronics”. Aren’t electronics, electronics? Does it mean it was a step above vacuum tubes?
Also, is this a physics term? A promotional catch-phrase? Or, a trade name for certain circuitry, like “Whetstone bridge”? This has always been bugging me… - Jinx
It refers to electronic signals travelling through conductors (or semiconductors) composed of solid matter, as opposed to flowing as electron beams (or similar) in vacuum tubes and the like.
I have also heard solid-state used to refer to devices with no moving pieces, as in EEPROM vs. magnetic hard-drive. I don’t know if this usage is correct, though.
Back in the day, it was used in marketing to refer to things there were made with semiconductors. Now that tubes are gone except in microwaves, the tv screen itself, and some audi equipment (I guess), there’s not really much buzz to the term. If I see something advertised as solid-state, I’d tend to question the product for bothering to promote something so ridiculous as a feature, with an exception below. And I mean promotion. If the technical specs or a line on the box says it, oh well. But I mean, “Hundai Radio, now solid state!”
There are things, though, where it makes sense. A solid state disk drive, for example. Not a driver of disks, but you know it fills the role of a disk drive while being solid state – no platters, no moving parts (some robots use them; they’re expensive, low capacity, and slow). But it’s something truly distinguishing; not “me too.”
Note that back when, “non-solid state” included relays, not just tubes. So the continued use of “solid state” to include non-mechanical systems seems justified.
Most high-power commercial radio and TV broadcast transmitters also use tube finals. They are also found in high-power radar installations. And ham radio operators prize old tube-operated “boat anchors”.
The term ‘solid state’ typically refers to silicon, germanium, sapphire (Al[sub]2[/sub]O[sub]3[/sub]) or III-V (gallium arsenide) based monolithic circuitry. A new generation of solid states devices does indeed have moving parts. These are known as MEMS (Micro Electro Mechanical Systems), and one of the most common forms is the solid state accelerometer (scroll down for diagram). A structurally isolated mass is typically connected to strain guages that electrically respond to deflection of the body while under G-force loads.
Much more complex mechanical devices are being made. Sandia labs’ TRA (Torsional Ratcheting Actuator) is one of my favorites. You will need to pull down the menu and click on this particular item. There is an extensive photo gallery of different MEMS devices on display. One the fisr page is an excellent series of images showing a minuscule spider mite dwarfing chain gear arrays and other complex mechanical devices. Fully geared transmissions and motors about the size of a grain of sand have been fabricated in the past few years.
However, in its most common use, solid state devices are predominately electronic and typically involve etched and deposited microlayers on a single crystal (monolithic) wafer (or substrate) of some sort. There are other methods of creating mono-crystalline substrates currently being researched. Ribbon polysilicon is a continuous band of thin crystal silicon pulled off of a boule of melt. It is a favored deposition surface for high efficiency photovoltaic cells.
Solid state also refers to the band gap nature of semi-conductive materials. By nature, silicon is not conductive and must be ‘doped’ into conductivity. Its crystal lattice is forcibly injected with dopants (phosphorous, boron, antimony and arsenic) to make is electrically conductive. Solid state refers to the various conduction properties obtained through intentional introduction of these impurities.
Please refer to some of my other posts on microelectronics and integrated circuits for more insight into this fascinating science.
Incidentally, a new generation of ‘air gap’ and ‘vacuum gap’ solid state circuit structures are poised to begin the final assault on electron tube components. Although the particular application illustrated is for a microspectrometer, this link shows the basic configuration of an air gap device. (Scroll down for image.)
For a superb window on the microscopic world of materials and structures, please visit the Silicon Zoo. Whether is is beer or a butterfly’s wing, there are stunning micrographs of them and many other items. The link will take you to views of some modern integrated circuits. Be sure to back up and view the other photo galleries.
Holy Petunia, he wasn’t asking for rocket physics. Solid state means the current goes through a transistor rather than a vacuum tube. It’s a 60’s thing.
Some of us Hams refer to tubes as “hollow state”.
No he wasn’t. He was asking for atomic physics, which is what he got.
You people seriously need to learn to speak in normal english.
Being a child of the 70’s, solid state meant not having a crystal in our radios/amplifiers/etc. It was a marketing term that meant that once the radio stopped working, either you headed down to radio shack for a new transistor and soldered it on, or you tossed the radio in the trash.
Now that I’m more “enlightened”, I realize that solid-state isn’t necessarily the best. While it’s arguable about tubes vs. transistors in musical equiptment (namely gutair amps), some tubes are genuinely useful. Better built than their predecessors, today’s tubes can control huge amounts of currents and are sometimes more survivable than transistors.
This was found out in the early 90’s when we got our hands on some of the old soviet fighters. Some MIGs still used tubes, which we laughed at, until we talked to the russian designers. Turns out, they used them because tubes suffer no effects from EMPs (Electro-Magnetic Pulses). They intentionally used tubes as backups, so if there was a nuclear detonation, their planes would still fly. This was quite a shock to most US engineers, who had focused shielding, which added considerable weight/complexity, for questionable protection.
Where in this thread was non-normal English used?
I feel sorry for their maintenance personel. Tubes simply cannot handle the stresses of military flight very well. (Neither can anything else electronic really, but solid state holds up a bit better. :p)
Back in my avionics days, the tube radios always gave us problems. And yes, the US still uses tube radios on some planes.
>I feel sorry for their maintenance personel. Tubes simply cannot handle the stresses of military flight very well. (Neither can anything else electronic really, but solid state holds up a bit better.)
The tubes I’m refering to w/the fighters aren’t exactly your run of the mill radio/amplifier vacuum tubes. They actually hold up quite well under flight stresses. Different soviet fighters had better capabibilities than most US fighters of the same era, the US just had planes with better mixes of those same capabilities. Example, some Soviet planes could turn faster, some could hit higher Mach numbers, some could carry far more weapondry. Almost none were balanced in these categories, meaning different tubes could be tailored to each plane’s role.
This isn’t an insult, they had more planes, they could “afford” the specialization, but had a conventional WW III happened back then, the US could have shuffled it’s plane’s roles a lot better, whereas if the soviets had lost a couple key bases in an initial strike, their air supremecy might have been severly hampered.
They also aren’t truly vacuum tubes, but contain various gases, depending on their placement/needs (much like modern lightbulbs), so they didn’t tend to blow themselves to peices if they were jiggled during operation, unlike some normal vactubes.
I do agree about the extra work the maintenance crews had to deal with, but it wasn’t like they had to change them that often. Besides, one could argue that the cost in spent tubes (at the time) was far less than losing all your air cover because of a single nuke.
The usage is correct but your interpretation is incorrect. The term defined what the device is, not what it is not. Whether the alternatives are mechanical, vacuum tubes or others is irrelevant. The device is or is not solid state per se and regardless of what the alternatives might be.
Solid-state electronics refers to the use of semiconductors (transistors, diodes etc). The term originated in the 60s as opposed to vacuum tubes where electrons flow and are controlled in something like a gaseous state.
It’s not that the tubes break (very rare), it’s that they are just flakey in operation. Things get jiggled out of alignment and suddenly the radio won’t pick up a certain station, but only while the plane is flying, etc. etc. And when you do have to change out a box, it’s 10 times as large and heavy as the equivalent in hardened solid state electronics, and often has arcane coupling decoupling proceedures. ( things like the main control box has to be set to a certain frequency while the receiver is removed because the channels are changed with a mechanical linkage, and even that doesn’t guarantee that you don’t have to re-calibrate the whole system over from scratch because the vacuum tube gremlins are having fun today. 
)
Mechanical systems just don’t like being heavily vibrated for long periods of time.
Strictly speaking a crystal radio is a solid-state device.
Yeah, I guess I was limiting myself to typical consumer applications – I’m an ex radar technician who decided there was more money in automotive engineering. 