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Questions tagged [materials]

The raw materials that are used to make components, devices, or products. Use this tag if a more specific tag, like 'semiconductors' or 'ceramics', is not available.

1
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3answers
93 views

Identifying FR-4 and G-10

I am evaluating a couple products -- lighting ballasts -- and noticed one of them seems to use G-10 as the PCB laminate. I assume that the beige, solder-mask-free top layer is the clue. Top: Bottom:...
5
votes
6answers
354 views

Can I use DC to drive underfloor heating wire?

I'm in the early phases of designing a new underfloor heating controller for retrofitting solar panels to locations with existing underfloor heating cables, which now take their power from the grid. ...
0
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1answer
63 views

Why carriers move when Electric field is applied on Haynes-Shockley experiment

I would like to know why excess carriers/minority move when an electric field is applied at the Haynes-Shockley expirement
1
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1answer
95 views

Is there a material that conducts heat well and has a very high melting point, but is also an insulator?

A lot of insulating materials are also non-metallic, which typically don't have a high specific heat. However, I am interested in experimenting with insulators that conduct heat as well as metal, but ...
9
votes
4answers
281 views

Contacts corroding - why?

These solder joints on the connector look strange to me (tarnished purple). In a more "advanced" state, they end up looking like this: In the last image you can see, it even "ate" the plating ...
1
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2answers
87 views

Material with fairly high resistivity, but allows flow of charge

Is there a material with fairly high resistivity (at least semi-conductor level), but also allows the flow of charge through it (and subsequently to the ground)? The flow of charge does not need to be ...
0
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0answers
36 views

Changing gate threshold voltage in IGBT

I want to divide a semiconductor chip into two sections and then build two different gate threshold voltages (Vth) for the sections. How can I do it? I think it should be done by methods (maybe by ...
0
votes
1answer
31 views

Temperature-Dependent Electrical resistance Si and SiC

In a power electronics device, it seems that silicon carbide (SiC) has a higher variation of electrical on-state resistance with temperature in comparison to silicon (Si). Does anybody know the reason?...
0
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1answer
49 views

What material to use for a capacitive sensor?

I'm doing a DIY project that I want to use a capacitive sensor for. I'm having a little plastic box and I want to send a wireless message when someone touches the top of it. I understand all the ...
1
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0answers
78 views

Aluminium foil not blocking IR signal

I am using an IR sensor (vishay tsop32 series) but I want to ensure that it only sender directly ahead so I made blinders out of pla and covered them in aluminium foil. However it seems that despite ...
1
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0answers
149 views

Can you buy Aluminum Nitride transistors?

We all know wide bandgap semiconductors, currently galium nitride and silicon carbide are the superstars becose many companies make them at relatively reasonable price. They aren't just mere lab ...
0
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1answer
66 views

Electrical Conductivity of SAC solder

Can anybody help me find the electrical conductivity of SAC 305 (96.5Sn3Ag0.5Cu) solder? It is the most common solder in semiconductor IGBT/MOSFET power switches. Many thanks and best regards,
0
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2answers
157 views

How to increase thermal shock resistance of the electronics components?

How to increase thermal shock resistance of the electronics components assembled on the PCB? Is there any material (or method) for increasing the thermal shock resistance of components? Best Regards, ...
0
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1answer
90 views

What is the advantages of InGaAs infrared image sensors? [closed]

I am currently searching the InGaAs material for infrared imaging usage. I have read some papers about it. It seems a new one. But I can not get real advantages of it, yet. What is the basic reason(...
0
votes
2answers
45 views

What is the main carrier in a semiconductor with n-type material being electrons and p-type materials being holes?

Not even gonna lie this is for a crossword. it is a 15 letter word. I have searched online, in my textbooks and I cannot figure out what it is. Closest I've found is Extrinsic Semiconductor but it's ...
0
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0answers
58 views

Material choice / optical properties for solar panel cover (glass/perspex/lexan)

First off I realise this is sort-of off-topic but this was the most relevant stack site I could think of... I have a Bosch solar panel which was damaged by couriers, the glass covering was shattered ...
4
votes
1answer
185 views

Is Beryllium Oxide still used in the industry?

Long ago it was used as a heat sink compound in (among other things) power transistors. It was very good at it's job. Unfortunately, it is horribly toxic. Is it still used anywhere an EE might come ...
2
votes
1answer
151 views

Alternatives to stacked iron plates for electric motor cores?

I took apart a brushless motor to find a core made of stacked iron plates. This material is rather dense and heavy for a motor made for aviation. What lighter, less dense material can a motor core be ...
14
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4answers
6k views

Why is 5.1V the standard Zener voltage and not 5V?

Looking on Digikey there are ~1300 results for 5.1V Zener diodes compared to 6 for 5V ones. Is there any physics-related reason for this or is it something else?
7
votes
1answer
324 views

When to use which semiconductor?

So I know that silicon is the most common semiconductor out there by far. But I also know that there are countless other options; silicon carbide, germanium, SiGe alloy, gallium arsenide, aluminum ...
0
votes
0answers
62 views

Is there an electrostatic equivalent material property to magnetic retentivity?

Consider the following thought experiment: I take a chunk of some material X which contains atomic dipoles., not free charges, and subject it to an external electric field. We know that the dipoles ...
0
votes
1answer
68 views

1N5821 Schottky diode material

Is the 1N5821 Schottky diode made of silicon? Or is it composed of other materials?
0
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2answers
105 views

Can Solar Panels Be Made From Other Semiconductors?

I have heard that most solar panels use polycrystalline silicon. It seems like a very expensive material. Are there any other materials we can potentially use to capture photons in solar panels?
4
votes
2answers
817 views

Safety of Aluminium for enclosure earthing

To earth an Aluminium enclosure, is it safe to use a welded Aluminium stud and then use a nut and washer to attach a hook-ended earthing wire to the stud? Aluminium oxidises to develop a thin ...
0
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4answers
126 views

What is this amber like substance on capacitor and inductor?

What is the mysterious substance on the inductor and (failed) capacitor? What is its purpose, and how do I replace the failed capacitor with it there? The substance is hard and translucent, but I ...
0
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2answers
163 views

Flexible Potentiometer Strip

Recently I've been working on a project and have encountered a problem. The gadget I'm working on has a kind of knob that rotates and acts as a potentiometer. The problem is I can't use a normal ...
4
votes
3answers
710 views

What properties of metal makes make them suitable as EMF shielding material?

What properties of metals make them effective at shielding against EMF, and which metals are typically used? How does Aluminium, Steel, Copper and Lead compare?
0
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0answers
412 views

Maximum power and current generated from piezoelectric material

I have an application which is a steel cylinder has 20cm OD, 8cm ID and 3m length. It has an axial load of 400KN, temperature 90c and affected by about 100KN radial force. I want to redesign it with ...
1
vote
2answers
83 views

Matte Film On LCD Displays

What is the technical name of the matte material/film that is put on LCD Displays? Also what would be the method of applying such film on a blank lcd screen (if possible)? EDIT: (Not my picture, but ...
3
votes
2answers
694 views

What is this jelly like substance on electromagnetic shield of a LTE Modem?

I took apart a Huawei E3372 LTE Modem, and this is what I saw. A jelly like substance on the electromagnetic shield. It is very soft and a bit sticky. I guess it is there to dissipate the heat from ...
1
vote
1answer
434 views

What material is used in the common 5mm LED?

I am not talking about the diode part of the LED, which is different depending on the color, what I am asking, is what is the material used in the conducting pins and the insulating cover? I am ...
1
vote
2answers
353 views

Aluminum plate for EMI shielding

I'm on a job where some folks are attempting to use aluminum plates to separate weld power cables from ethernet/serial comm. To be clear, it's just wires in a cable tray separated by an aluminum plate....
2
votes
1answer
415 views

Material Suitable for Self-insulating Solders and Electrical Contacts?

I have been working on this personal project of water-proofing an electronic alarm clock, when I came across the idea of making electrical contacts non-conductive when produced. Specifically I have ...
0
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2answers
63 views

Do we have a material that reshapes itself depending on applied voltage or electromagnetic field?

I am thinking to control the physical world by applying signals to a magical material. The material must have the ability to change its strength from a very solid state to a dough like state back and ...
0
votes
1answer
402 views

Soldering Nichrome wire to Stainless steel and steel to PCB

Is it possible to solder Nichrome wire (30AWG) to stainless steel and then the steel to a PCB?
1
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2answers
95 views

Help in identifing these 2 materials

i would like to know if anyone of you recognize these 2 materials and what they are used for ? A material sticky on one side normal on the other , used between capacitors and aluminum enclosure . A ...
0
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2answers
270 views

Copper brushes?

I noticed the superior choice would be a carbon based brush,however, is pure copper brush a bad choice? I'm considering copper due to the lower resistance and higher current carrying capacity. I ...
1
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1answer
81 views

Calculating resistance of an electric brush

For a certain application, I'm using carbon based brushes to transmit power from a stationary component to a moving component. I'd like to calculate the resistance of the carbon based brushes to know ...
1
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3answers
7k views

Is it possible to make a plastic touch screen as sensitive and accurate as a glass one?

I learned in this answer that touch screens with a glass front are generally more sensitive and accurate than those with plastic fronts. This corresponds with my personal experience. However, is ...
40
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6answers
18k views

Is there a technical reason why most touch screens use glass rather than plastic?

Most modern touch screens in portable devices are made of glass. This glass often breaks if accidentally dropped. Also, it is very reflective, making it difficult to use in strong light. I know that ...
1
vote
1answer
3k views

What are USB Connectors made of?

What type of metal are the tips of USB connectors/plugs typically made from? Aluminium? I've noticed they will often, quite-easily, oxidise/rust/corrode.
-8
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2answers
546 views

What alternative materials (Non-silicon) are available for semiconductors?

I'm trying to construct a simple logic gate with a transistor, but I don't want to use silicon as the semiconductor. What other materials are available to construct transistors with? Thanks for your ...
2
votes
1answer
661 views

Wireless Power Coil - Is this shielding? Field shaping?

I'm taking apart a Qi wireless power transfer receiver. The coil is etched into the pcb. The entire coil area (approximately 3.75 x 4.5 cm) is covered by a rectangular piece of hard, brittle material. ...
8
votes
2answers
777 views

What is this “paper-substrate pcb” technology called?

I took apart a broken calculator to show my daughter how it functions. It had a small "traditional" FR-4 PCB mounted underneath the LCD glass, but the pushbutton area was printed on a paper-like ...
23
votes
3answers
3k views

ICs (“chips”) are typically packaged in what material?

ICs are typically packaged (encapsulated) in a black "plastic". What is this packaging material made of? (source)
1
vote
1answer
383 views

Can Petroleum Jelly be used as a PCB resist?

I've been experimenting with various setups for PCB etching, and thought I'd share one of the more useful things I'd found, as I don't see much information about the subject anywhere else. I've been ...
4
votes
1answer
2k views

What clear plastic stripping is used to wrap a toroidal power transformer?

I'm partially rewinding a toroidal transformer just for the pure thrill of controlling the output voltage. I'm sure I'll get over it, but for the moment that prospect is pretty exciting for some ...
1
vote
4answers
175 views

Suggestions for moldable ferromagnetic material?

I'm trying to build a sort of three-axis stepper motor that consists of a sphere with a permanent bar magnet embedded in it surrounded by a cube (slightly smaller than the sphere, so that the sides of ...
3
votes
3answers
141 views

Is there an easy way to measure the thickness of the foil on FR-4

Sometimes I find myself trying to guess or recollect what foil thickness was specified for the given piece of FR-4. Shops do not always readily give it - and it appeared that what they write is not ...
2
votes
1answer
44 views

High Temperature Conductor in Air

I am trying to determine what the best material is for a high temperature conductor. It is for distributing power inside a furnace. I need to run at around 1000 celsius (the furnace is hotter but this ...