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Here is a picture of a certain type of chip I find a lot. The metal back seems to be brass. So whats the way to get the highest return? I'm considering putting them in a tumbler and selling them with my brass. Thanks Mike.
http://i597.photobucket.com/albums/t...s/PA210057.jpg
p.s. I love photobucket so here's how the better half at my house spends their day, Mike.
http://i597.photobucket.com/albums/t...s/PA100044.jpg
I would buy them as boards if you tossed them with motherboards... beyond that I dont know.
So they would count as additional weight to the mother boards? If so that's a lot better price than brass. Thank you, Mike.
I would take them like that yes....now if you send me a whole box of them..I wont be able to give you that price but if you have a few just toss them in..its not going to brake my back lmao
I love the bucket too :)Quote:
Originally Posted by miked
make sure you insert "IMAGE" [ img ] not "URL [ url ] that way the pic shows in the thread
:)
Miked, Those are transistors and what I do with them is I smack them with a hammer on a flat surface and that will shatter most of the black part off to leave you with a little cleaner brass part. Then I just throw them in with my misc. brass bucket, along with the prongs from the plug-ins.
I thought you where talking about the puppy's at first....I had to reread that...I think its time to put the beer down.Quote:
Originally Posted by Mechanic688
Mike I love the dogs!
Easy that is funny!
I love that, the wisdom of the elders is unrefutible. heard that many many years ago. my first wife who sadly passed last year, was Cherokee full blood. most of my relitives back in the day were cherokee, and black foot, from Oklahoma and S Dakota my first family 2 daughters both are married to Mandans, that was a simpler time and place. sry about off topic just had to say it.
They are actually copper, I snip them off and throw them in with #2 because they are coated. If you get more of them look inside the hole and you'll see the copper color. They are for taking the heat away from the aluminum plates.
That means they are worth more as copper rather than in the brass bucket. Thanks to all who added, Mike.
As ScrapperNJ26 said, these are nickel plated copper heatsink.
I would suggest to be extremly careful when breaking them apart, the semicoductor material is composed of Gallium Arsenide (GaAs), i can assure you DO NOT want to breath in that stuff. I hope you are working with a mask when you break them.
Stay Safe :)
Thank you Sam for this information.
I take it all semiconductors such as IC chips also will contain GaAs, is this pretty much correct?
Gallium arsenide (GaAs) is a compound of the elements gallium and arsenic. It is a III/V semiconductor, and is used in the manufacture of devices such as microwave frequency integrated circuits, monolithic microwave integrated circuits, infrared light-emitting diodes, laser diodes, solar cells, and optical windows.
[edit]Preparation and chemistry
In the compound, gallium has a +3 oxidation state. Gallium arsenide can be prepared by direct reaction from the elements which is used in a number of industrial processes:[3]
Crystal growth using a horizontal zone furnace in the Bridgman-Stockbarger technique, in which gallium and arsenic vapors react and free molecules deposit on a seed crystal at the cooler end of the furnace.
Liquid encapsulated Czochralski (LEC) growth is used for producing high purity single crystals that exhibit semi-insulating characteristics.
Alternative methods for producing films of GaAs include:[3][4]
VPE reaction of gaseous gallium metal and arsenic trichloride:
2 Ga + 2 AsCl3 → 2 GaAs + 3 Cl2
MOCVD reaction of trimethylgallium and arsine:
Ga(CH3)3 + AsH3 → GaAs + 3 CH4
Molecular Beam Epitaxy (MBE) of gallium and arsenic:
4Ga + As4 → 4GaAs
or
2Ga + As2 → 2GaAs
Wet etching of GaAs industrially uses an oxidizing agent, for example hydrogen peroxide or bromine water,[5] and the same strategy has been described in a patent relating to processing scrap components containing GaAs where the Ga3+ is complexed with a hydroxamic acid ("HA"), for example:[6]:
GaAs + H2O2 + "HA" → "GaA" complex + H3AsO4 + 4 H2O
Oxidation of GaAs occurs in air and degrades performance of the semiconductor. The surface can be passivated by depositing a cubic gallium(II) sulfide layer using a tert-butyl gallium sulfide compound such as (tBuGaS)7.[7]
[edit]Comparison with silicon
Gallium arsenide crystal
GaAs has some electronic properties which are superior to those of silicon. It has a higher saturated electron velocity and higher electron mobility, allowing transistors made from it to function at frequencies in excess of 250 GHz. Unlike silicon junctions, GaAs devices are relatively insensitive to heat due to their higher bandgap. Also, GaAs devices tend to have less noise than silicon devices especially at high frequencies which is a result of higher carrier mobilities and lower resistive device parasitics. These properties recommend GaAs circuitry in mobile phones, satellite communications, microwave point-to-point links, and higher frequency radar systems. It is used in the manufacture of Gunn diodes for generation of microwaves.
Another advantage of GaAs is that it has a direct band gap, which means that it can be used to emit light efficiently. Silicon has an indirect bandgap and so is very poor at emitting light. Nonetheless, recent advances may make silicon LEDs and lasers possible. Due to its lower bandgap though, Si LEDs cannot emit visible light and rather work in IR range while GaAs LEDs function in visible red light.
As a wide direct band gap material and resulting resistance to radiation damage, GaAs is an excellent material for space electronics and optical windows in high power applications.
Because of its wide bandgap, pure GaAs is highly resistive. Combined with the high dielectric constant, this property makes GaAs a very good electrical substrate and unlike Si provides natural isolation between devices and circuits. This has made it an ideal material for microwave and millimeter wave integrated circuits, MMICs, where active and essential passive components can readily be produced on a single slice of GaAs.
One of the first GaAs microprocessors was developed in the early 1980s by the RCA corporation and was considered for the Star Wars program of the United States Department of Defense. Those processors were several times faster and several orders of magnitude more radiation hard than silicon counterparts, but they were rather expensive.[8] Other GaAs processors were implemented by the supercomputer vendors Cray Computer Corporation, Convex, and Alliant in an attempt to stay ahead of the ever-improving CMOS microprocessor. Cray eventually built one GaAs-based machine in the early 1990s, the Cray-3, but the effort was not adequately capitalized, and the company filed for bankruptcy in 1995.
Complex layered structures of gallium arsenide in combination with aluminium arsenide (AlAs) or the alloy AlxGa1-xAs can be grown using molecular beam epitaxy (MBE) or using metalorganic vapor phase epitaxy (MOVPE). Because GaAs and AlAs have almost the same lattice constant, the layers have very little induced strain, which allows them to be grown almost arbitrarily thick. This allows for extremely high performance high electron mobility, HEMT transistors and other quantum well devices.
[edit]Silicon advantages
Silicon has three major advantages over GaAs for integrated circuit manufacture. First, silicon is abundant and cheap to process. Si is highly abundant in the Earth's crust, in the form of silicate minerals. The economy of scale available to the silicon industry has also reduced the adoption of GaAs.
In addition, a Si crystal has an extremely stable structure mechanically and it can be grown to very large diameter boules and can be processed with very high yields. It is also a decent thermal conductor thus enable very dense packing of transistors, all very desirable for design and manufacturing of very large ICs. Such good mechanical characteristics also makes it a suitable material for the rapidly developing field of nanoelectronics.
The second major advantage of Si is the existence of silicon dioxide—one of the best insulators. Silicon dioxide can easily be incorporated onto silicon circuits, and such layers are adherent to the underlying Si. GaAs does not easily form such a stable adherent insulating layer and does not have stable oxide either.
The third, and perhaps most important, advantage of silicon is that it possesses a much higher hole mobility. This high mobility allows the fabrication of higher-speed P-channel field effect transistors, which are required for CMOS logic. Because they lack a fast CMOS structure, GaAs logic circuits have much higher power consumption, which has made them unable to compete with silicon logic circuits.
Silicon has relatively low absorptivity for the sunlight meaning about 100 micrometers of Si is needed to absorb most sunlight. Such a layer is relatively robust and easy to handle. In contrast, the absorptivity of GaAs is so high that a corresponding layer would be only a few micrometers thick and mechanically unstable.[9]
Silicon is a pure element, avoiding the problems of stoichiometric imbalance and thermal unmixing of GaAs.
Silicon has a nearly perfect lattice, impurity density is very low and allows to build very small structures (currently down to 25 nm). GaAs in contrast has a very high impurity density, which makes it difficult to build ICs with small structures, so the 500 nm process is a common process for GaAs.
[edit]Other applications
[edit]Solar cells and detectors
Another important application of GaAs is for high efficiency solar cells. Gallium arsenide (GaAs) is also known as single-crystalline thin film and are high cost high efficiency solar cells.
In 1970, the first GaAs heterostructure solar cells were created by the team led by Zhores Alferov in the USSR.[10][11][12] In the early 1980s, the efficiency of the best GaAs solar cells surpassed that of silicon solar cells, and in the 1990s GaAs solar cells took over from silicon as the cell type most commonly used for Photovoltaic arrays for satellite applications. Later, dual- and triple-junction solar cells based on GaAs with germanium and indium gallium phosphide layers were developed as the basis of a triple junction solar cell which held a record efficiency of over 32% and can operate also with light as concentrated as 2,000 suns. This kind of solar cell powers the rovers Spirit and Opportunity, which are exploring Mars' surface. Also many solar cars utilize GaAs in solar arrays.
Complex designs of AlxGa1-xAs-GaAs devices can be sensitive to infrared radiation (QWIP).
GaAs diodes can be used for the detection of X-rays.[13]
[edit]Light emission devices
GaAs has been used to produce (near-infrared) laser diodes since 1962.[14]
Single crystals of gallium arsenide can be manufactured by the Bridgeman technique, as the Czochralski process is difficult for this material due to its mechanical properties. However, an encapsulated Czochralski method is used to produce ultra-high purity GaAs for semi-insulators.
GaAs is often used as a substrate material for the epitaxial growth of other III-V semiconductors including: InGaAs and GaInNAs.
[edit]Safety
The toxicological properties of gallium arsenide have not been thoroughly investigated. On one hand, due to its arsenic content, it is considered highly toxic and carcinogenic. On the other hand, the crystal is stable enough that ingested pieces may be passed with negligible absorption by the body. When ground into very fine particles, such as in wafer-polishing processes, the high surface area enables more reaction with water releasing some arsine and/or dissolved arsenic. The environment, health and safety aspects of gallium arsenide sources (such as trimethylgallium and arsine) and industrial hygiene monitoring studies of metalorganic precursors have been reported.[15] California lists gallium arsenide as a carcinogen.[16]
[edit]See also
Aluminium arsenide
Aluminium gallium arsenide
Arsine
Cadmium telluride
Gallium antimonide
Gallium arsenide phosphide
Gallium manganese arsenide
Gallium phosphide
Gallium nitride
Heterostructure emitter bipolar transistor
Indium arsenide
Indium gallium arsenide
Indium phosphide
Light-emitting diode
MOVPE
Multijunction
Photomixing
Trimethylgallium
Actually, most IC's and EPROM's utilize, almost exlusivly silicon metal as semi-conductor material.Quote:
Originally Posted by injunjoe
But who know what are they NOT telling you on the 'spec sheet' and RoHS documentation... I know Silicon is doped with other elements in fraction amounts.
In any case, inhaling or ingesting represent the most danger in what we do. Try to always work with a dust mask or up wind when you disassemble or crush old electronics.
So these chips would not go good with salsa and beans?!?!
Hi, new here. Those are power transistors. Mostly found on power supply circuit boards. The backs are usually tin plated cu and used as a heat sink and ground for the chip. These are almost always screwed to a secondary heat sink. In the old days the sinks were copper but now mostly ext. al. Tore down some old servers the other day and the power supplies had cu secondary heat sinks. Gallium is in high demand in the IC industry.
They are plastic with a copper piece inside. I dont' break them up, I just toss them in my misc motor/copper bearing bucket and they get bought that way.
Newatttitude, I am restricted in what I can do physically. This has motivated me to break down everything as much as I can. So I was considering removing the cu heat sink from the rest of the transistors. This would sell at my current #2 cu price of $2.52/lb as compared to the motor price of 0.20/lb. My plan was to save them up and put them in a tumbler with some scrap steel to brake off the black part. After reading some of the entries I am reconsidering my plans.
If Gallium is indeed in hight demand perhaps there is a market for this material, Mike.
miked - just wanted to follow up on this. What did you finally decide to do with the power transistors. I get a small pile every time I clean up heat sinks and have considered setting them aside.
They are #2 copper just put them in with your copper
I want to check with my buyer to see if they can go in with the ic's that I get paid more than copper. Mike.
Currently holding some, some end up in the shred pile. Still looking for a buyer, Mike.
They are #2 copper. Why do you think you'll get a better price? You don't have to brake them apart, you'll be losing weight.
You will also find some that are gold plated, keep them seperate from the other ones.
some have good cores as well.Quote:
Originally Posted by BarrenRealms007
i would gladly buy those for copper price.
yeah dude throw it in for extra weight for motherboard that's the most you'll get there are no precious metals in transistors. only copper.
Most of the time I leave them on the boards, just unscrew them from the heat sink before I remove the heat sunk. Sometimes I can't a screwdriver in to unscrew it, those I throw in the #2 copper bucket.
Nice tip! I love PB too. Nice life for them puppies too eh. Too cute! :) lbQuote:
Originally Posted by Torker Man
So, yes then? :) lb
Is it just me or is this link fried?? Tried twice, no go. :mad: :cool: lb
What's a no-go Larry??Quote:
Originally Posted by LarryB
Hehe, means doesn't work like not doable etc. :)Quote:
Originally Posted by Mechanic688