Questions tagged [manufacturing-process]
The manufacturing-process tag has no usage guidance.
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How can a designer be sure to authorize only legit ICs? How is performed? How are cloned ICs prevented to be activated?
The above diagram is from the IC Activation (locking/unlocking) slide of Fighting against theft, cloning and counterfeiting of integrated circuits by Lilian Bossuet Associate Professor, CNRS Chaire of ...
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Populating MOLEX receptacles at industrial scale
I am a manufacturing engineer charged with implementing process improvements that reduce the total time to build an article. Our volume is such that a one minute reduction in labour results in £1K-£2K ...
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Behaviour of uninitialised RAM in an ASIC
This is a question for anyone with experience designing or with a deep knowledge of volatile memory in an ASIC. E.g. chip designers or silicon process engineers.
We are using the ET1200 EtherCAT ASIC (...
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Is BiCMOS still a popular technology?
A Google search has not yielded much fruit when it comes to this question, but I'm wondering if BiCMOS is still a reasonably popular technology (relative, of course, to any other non-CMOS technology). ...
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What shapes can IC dies be?
I know an IC die can be cut into a rectangular shape. Apparently triangles and rhombuses are also possible, but not used. What other tesselations can they be cut into?
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Unusual Transconductance Equation
I am a math-heavy electronics noob, and I was reading a paper when I came across this equation:
$$g_m=\frac{2 I_D}{\left(V_{G S}-V_{T H}\right)}\left[1-\frac{1}{2} \frac{\theta_1\left(V_{G S}-V_{T H}\...
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Lifting Pins on SMT RJ45 Connector
I'm running into an issue with a specific RJ45 SMT connector where the I'm getting at least 1 pin lifting on >50% of the boards that run through our reflow oven. The rest of the components on the ...
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Electronics Manufacturing Engineers: What needs to meet IPC-6012 the finished copper or the starting copper foil?
I have a PCB that has a finished copper thickness of 1 oz on all layers and must meet IPC-6012 requirements for Class 2.
Does this mean that the manufacturer can start with 0.5 oz copper foil then ...
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Long term availability of WS2812B or any Neo-pixel
I am considering the use of Neo-pixel or WS2812B components in a project that we are planning to run for the next ten years with mass-scale production. I am curious about the feasibility of sourcing ...
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A good method to clamp PCBs down for bed of nails fixture?
I would like to build a bed of nails fixture with pogo pins.
Is there a good method that works to hold down a PCB that is releasable and easy to pop a PCB in and out of the fixture?
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What are the primary industrial uses of gallium and germanium in electronics?
After the "neon shortage" struck I asked What are the ways in which semiconductor-grade neon is critical for manufacturing? and the answer(s) turned out to be quite informative.
Al Jazeera's ...
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Why are the challenges in using SRAM over DRAM for main memory?
Historically, when compared to DRAM (dynamic ram), SRAM (static ram) is more expensive with a lower density, but it's much faster and more efficient. As a result, SRAM is reserved for devices, such as ...
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Why does Backside Power Distribution work for high speed CPUs?
Several upcoming or future CMOS process nodes are said to offer some kind of backside power delivery for Silicon CMOS transistors, so the precious area in the lower metal layers is freed up for signal ...
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Why do JFET use buried channels?
All sketches of JFET construction that provide an actual 3D impression suggest that the channel is buried, e.g. here.
I imagine that the formation of such a channel geometry requires at least two ...
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Question on "Parts should be used within 5 days after opening." statement on component shipping package
I've been given the task of verifying a batch of ICs from a chinese broker, to see that the chips the company has bought are what the broker claims they are. The package we've received looks like this,...
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Functional discrepancy within PCBA batch
When manufacturing a small prototype batch of an embedded system at EMS I have detected different behavior between the units. All units work as expected, except that some units fail to operate same ...
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How do components not get knocked off or fall off during reflow?
I am looking at reflow ovens. A lot of them have a metal conveyor belt the boards sit on. On a double sided board, when you put the board on the metal belt, won't the metal belt knock components off ...
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Standard cell design flow in an ASIC design flow
I have a question regarding the standard cell design flow in an ASIC design flow.
That being said I understand what a gate array design flow is. It being more or less a fixed logic FPGA. Structured ...
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Can you (theoretically) reverse bias a BJT?
My understanding of how a BJT(bipolar transistor) works looks like this:
From https://www.allaboutcircuits.com/textbook/semiconductors/chpt-2/bipolar-junction-transistors/
Picture link: https://www....
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What's going wrong with my solder paste / mask?
A short question this - I've got a board with a QFN-32 0.4mm pitch footprint, I ordered this stencil, and a tube of this solder paste, and the result is in the picture below.
Now, I'm new to this, but ...
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What does it mean when it is said that an Intel CPU is assembled in Country X?
I was reading a same question posted on Quora but wanted to ask the same question here on this forum. So if the CPU states that it is assembled in some country X what does that mean exactly ? What ...
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Can through-hole leads be cut level with the PCB back while maintaining good connectivity?
If I'm using confusing terminology I apologize, this is relatively new to me and my first post on stack exchange.
My question is: Can through-hole leads be cut and filed level with the PCB back while ...
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Purpose of field implant in semiconductor manufacturing
I recently joined the semiconductor manufacturing industry.
In one of the process flows, I see a stage that has extra boron implantation step (called the field implant) in the P-WELL region.
I've ...
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Why do some exposed pads have small tabs, and does my PCB footprint need them?
I've noticed a few component packages now that have small "tabs" on the sides of their exposed pad (thermal pad). One example is the Analog Devices ADM7154 LDO:
Note the 0.356 x 0.457 mm ...
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Are there any resources on Column Last Attach Process? [closed]
I am trying to find resources about this process, but the only thing I have been able to find is the full form of the acronym CLAP any help is appreciated.
This process is used vehemently in the ...
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Is a cylindrical GAAfet fabricated with lithography and etching?
The GAAfet, aka the surrounding gate transistor (SGT), is basically a FinFET that surrounds the channel on all 4 sides instead of 3. However, a lot of examples show a cylinder instead of a rectangle.
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Why do old ICs especially CPUs have golden caps and bottom lids?
What was the advantage of having a golden heat spreader and bottom lid ?
Contacts make sense because of the electrical properties. This is still done today.
But what were the effects of using gold ...
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Calculations relating to carbon film resistor
Im researching on carbon film resistors and film resistors in general, hence I would like to know certain things:
Resistivity of carbon the film is made-up of? Does the resistivity depend on the type ...
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How were "old" chips manufactured, such as the 6502?
Recently, there have been several youtube vids (example) talking about how modern CPUs are manufactured. Basically, it's a complex nightmare of dropping molten tin and lighting it with light, which ...
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Environmentally sustainable electronics
I am part of my company's work to become more environmentally friendly and sustainable. On a high level for the company that means pursuing ISO certifications (such as ISO 14001) and working according ...
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Placing through hole and SMT on the same side
I have a design with huge push buttons (with 6 TH holes.)
There's a few of them so they do take up quite a bit of space mechanically from the top.
I was thinking of placing the majority of the SMT ...
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How to bond PCB and metal for high power RF boards
I want to bond a PCB (2 layer & 0.6mm thickness) to a metal (copper & 4mm thickness.) Could anyone help me with the process of bonding it? There is a power amplifier that has to be soldered ...
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What exactly makes small quantity PCB production costly compared to large quantity PCB production?
The per-PCB cost of manufacturing a small number of PCB is 10 times or more compared to the per-PCB cost of manufacturing a large number of PCBs.
So what is it exactly that adds to the cost?
People ...
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How to Design method to Program & Calibrate a Panel of PCBs
I'm designing a sensor-package PCB which needs to be programmed and calibrated while still in a panel of 10.
I'd like to avoid a large bed-of-nails type setup for this step so that the panel can ...
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starting material for silicon production
Where does silicon semiconductor manufacturing start from? I mean, what are the principal ores that may be used to start the technological process and what extraction process is used? (And what are ...
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What mechanism is responsible for the β/hFE variations in manufactured bipolar transistors?
It's common sense that the current gain β (hFE) in a bipolar junction transistor is somewhat unpredictable, and one must design a discrete transistor circuit to be insensitive to the variation of β.
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Solution to detect bad vias in production process
I face the problem of damaged (cracked) vias in a rigid/flex assembly.
It is very difficult to detect those defects before mounting the assembly. Products with cracked vias may fail during lifetime ...
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How to prevent solder getting into through hole during HASL process?
I think this is an easy enough question - I just don't know how to effectively search for the answer.
I have a PCB that came back and the programming header is plugged with solder. This most likely ...
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Circuits that take advantage of tolerances in components
Bit of a wordy question title...
I was trying to simulate an astable multivibrator the other night and the simulation refused to run. I eventually realised that because the simulation assumes perfect ...
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Failure Rate calculation based on manufacturing defects (capacitor)
Electronics failure rates typically follow the exponential distribution and models like Prism, Mil-Hdbk-217 or 217Plus (newer) are used to predict failure rates.
We are currently in the production ...
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Design for manufacturability [closed]
I am a current EEE student and was wondering how the process of design for manufacturability works?
What are the technical and safety issues that a manufacturer focuses on when designing a product to ...
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Can the TFT in LCD displays be made in the nanometer range?
Can the TFT elements and hence the pixels in an LCD display be made in the nanometer range? Say 10nm x 10nm?
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What material(s) are used in IC's as insulating layers between metal layers?
This question and the answers hits close to the topic. One picture shows it as SOD. Silicon-oxide dielectric?
I'm aware that around/within the transistor, silicon oxide is grown for insulation where ...
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How long can the leads protrude for a typical selective solder machine?
I have an LCD who's leads extend about 10mm past the board surface.
Can a typical selective solder machine fountain reach this high?
If not, any suggestions on the best way to handle long ...
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PCB design rules
To design my board, how may I ask a PCB manufacturer for the constants rules or clearance rules? What is the particular terminology that I would use at the time of asking about the design standards ...
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Why can my bare PCB be magnetized?
I am working on a magnetic sensors design and noticed that my measured magnetic field bias shifts over time. I have studied the bare PCB and measured that it can be magnetized with a strong magnet.
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What components have a MSL of 5 and 6?
Moisture Sensitivity Level (MSL) relates to the packaging and handling precautions for some semiconductors.
Components with an MSL of 1 have an unlimited floor life, whereas components with an MSL of ...
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Why are resistors tolerances relative instead of absolute?
Every resistor has a tolerance, this provides the user with an idea of the accuracy of the product. This tolerance is represented by a percentage. This means: a big value resistor will be less ...
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Process technology: LP and LPH
My question is related to the following news regarding IC process technology:
Samsung has introduced 28-nm LP HKMG and a new variant, 28-nm LPH HKMG process technology.
Following abbreviations are ...
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Component manufacturing and placement accuracy/precision
I am involved in a community project where I need to employ computer vision on common smartphone models (Samsung Galaxy S 5/6/7, iPhones etc.). Doing that involves calibrating the phone's camera for ...
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