Questions tagged [manufacturing]

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ADC stops functioning when cold

EDIT: VERY INTERESTING TEST RESULTS I just tried inducing the thermal failure using an inverted "can of air" (likely difluoroethane). It even when its super cold, (might even be below -40C), ...
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-1 votes
0 answers
21 views

Best way to LED module depanelling & handling in LED lamp assembly?

Can someone suggest me a better way to handling & depanelling LED modules during LED lamp assembly in mass production? Current process have direct hand contact with module and have pressure on ...
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6 votes
7 answers
1k views

Component Tolerance Probability

This is more of a manufacturing question than anything else. What is the probability distribution of component tolerances? For example, let's say I ordered a 100 ohm, 5% resistor, and I order 100 ...
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8 votes
1 answer
248 views

What are the ways in which semiconductor-grade neon is critical for manufacturing?

This is a question about material use specifically in semiconductor manufacturing. CNN's Ukraine halts half of world's neon output for chips, clouding outlook begins: Ukraine's two leading suppliers ...
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  • 3,601
0 votes
0 answers
21 views

Use of memory array redundancy for performance/power

Providing redundancy in memory arrays is a common technique for increasing yield in the presence of defects and variability. Since yield in practice includes binning for performance and power ...
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1 vote
1 answer
86 views

Soldermask bridge gap too small - PCBWAY

I've got a PCB design which contains a chip that uses the QFN (7x7) package. Because of the package size the pins are very close together and the pads are 0.2mm apart, which is smaller than the ...
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  • 131
0 votes
1 answer
23 views

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.
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2 votes
2 answers
200 views

Why is that vias are generally made of tungsten while contact is made using aluminum?

From this thread: ...
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  • 137
0 votes
1 answer
44 views

IPC standards to ask manufacturer to assure a PCBA is correctly manufactured?

I'm preparing all the documentation to send to my PCBA manufacturing supplier and I wonder if there's a list of IPC standards to include in this documentation and verify they are compliant to them and ...
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0 votes
2 answers
66 views

If a PCB is inspected to an IPC-A-600 class higher than specified what are the negative impacts?

I have received several parts from a PCB manufacturer which should have been inspected to IPC-A-600 Class 2 but were instead inspected to IPC-A-600 Class 3. I believe I have received PCBs inspected to ...
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0 votes
1 answer
67 views

A possible shot in the dark - Seaward HAL-104 Tester experience?

This post might be a shot in the dark, but has anyone here had any experience with the Seaward HAL-104 tester and its remote command protocol functionality? Or perhaps know someone who has? There is ...
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  • 23
0 votes
1 answer
117 views

Blade Fuse Properties?

I am sure you have seen automotive 'Blade' fuses. They are special fuses constructed to protect equipment that is DC powered. I have asked around and determined that a 125v DC rated fuse is more than ...
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  • 836
2 votes
1 answer
320 views

What Are the Advantages and Disadvantages of "Conductive Plastic" Potentiometers

Maybe it's just the name putting me off, but I'm looking at potentiometers for a new design and I'm noticing that a lot of the cheap ones use "conductive plastic" as the resistive element. ...
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  • 4,695
0 votes
1 answer
208 views

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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  • 985
31 votes
4 answers
4k views

Why are most COB LEDs physically yellow?

Many "LEDs" found on devices nowadays appear to be yellow where the light comes from (when the device is off). Why yellow? I put LEDs in quotes because COB leds can consist of many ...
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  • 4,927
0 votes
1 answer
41 views

Node Technology in Modern Transistors

i was reading about the new 2nm chip IBM created and through some reading i learned that the "nm" part does not refer to the actual gate length like it did many years ago. Can anyone tell me ...
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  • 9
23 votes
4 answers
2k views

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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4 votes
2 answers
319 views

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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  • 539
3 votes
1 answer
146 views

What are my options for packaging a WLCSP IC as a DIP?

Hypothetically, let's say I have a chip in a super small WLCSP or BGA package that I want to have packaged as a plastic or ceramic DIP. No extra components; just the pads brought out to pins. Are ...
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10 votes
3 answers
2k views

What are some reasons for hand painted dots on chips?

I've seen lots of products with hand painted dots or markings on chips, what do they often mean? Obviously I understand everybody has their own reasons but could it be an industry common practice for ...
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  • 1,316
1 vote
6 answers
291 views

Electrically isolate bottom side of a PCB

I have a 4-layer board with no parts on the bottom side, the bottom-side solder mask fully covers all vias. I want to stick the board with a double-side adhesive foil on the metal bottom side of a ...
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0 votes
1 answer
209 views

How to read Diode Numbering System

How do I read diode numbers. I read that the numbering system for US diodes is the JEDEC system. But I don't think the JEDEC system applies to diode numbers after 1N. Everywhere I look I cant only ...
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8 votes
1 answer
162 views

How is the asymmetry of a Schottky diode obtained?

A Schottky diode is constructed with two metal conductors bonded to a doped semiconductor. One of the metal-semiconductor junctions is a Schottky contact, and the other metal-semiconductor junction is ...
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0 votes
2 answers
112 views

How would you connect a light dependent resistor / photoresistor/ CdS cell at a right angle to a surface mount board?

My project uses light dependent resistors (aka photoresistors or CdS cells). All the ones I can find for sale from the usual suppliers are through hole type. ie. they have two wire legs. The PCB I'm ...
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2 votes
4 answers
491 views

Best practice for wire harnesses in a BOM

Ive started a new job at a startup and am working on a BOM for a box build with a couple of PCBs and wire harnesses inside. Im in a bit of an impasse about how best to define wire harnesses in the BOM....
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  • 171
0 votes
1 answer
49 views

Need help understanding how motors, sensors and other components of a prototype design factor into certifications for industry sale [closed]

I have built a prototype and I now need to create a production prototype that I can use as my template for a small 10-15 product unit batch order. I am in the United States where I plan to market ...
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0 votes
1 answer
102 views

Do Professional Manufacturers Violate IPC Standards?

I lay out simple boards using BGA packages and often ignore my EDA tool's courtyards. I know these courtyards are set by IPC standards to allow for good design, but then I look at boards like the ...
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2 votes
1 answer
470 views

Accuracy of manufactured photocells (LDR) with respect to light intensity

I was looking through photocell (photoresistors) datasheets, like for instance the NORPS-12, especially the graphic on resistance value versus light intensity. In no datasheet could I find information ...
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  • 21
0 votes
2 answers
131 views

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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11 votes
3 answers
1k views

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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2 votes
2 answers
179 views

Bed-of-nails testing of ethernet signals

I'm designing a BON testing fixture for a complex board (multiple processors, fpga, memory, etc). One of the items to test is an external ethernet connection (1Gb). In the current design, the ethernet ...
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10 votes
2 answers
168 views

Why are the heatproof composites used for semiconductor packages never used for coil formers, connectors and switches?

It is very hard to destroy the material normally used for "plastic" IC and transistor packages with IR or hot air soldering tools, unless you apply a measure of heat that would reliably ...
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1 vote
0 answers
44 views

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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0 votes
0 answers
49 views

Quintic QN8007B RoHS information?

We are planning to use the Quintic QN8007B FM transmitter in our new design because it is quite cheap and has I2S interface. I believe this chip is no longer produced, but it is possible to get hold ...
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  • 115
0 votes
0 answers
44 views

Reducing Thermal Pad Size Below Official Footprint - Can It Create Manufacturability Problems?

I'm using a DP83867 Ethernet chip by Texas Instruments in an S-PQFP-G64, 10 x 10 mm package, the mechanical dimension and its recommended footprint are shown at the end of the question. As shown, the ...
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  • 3,857
4 votes
6 answers
2k views

Is it hard to do 2 sided SMD PCB in oven?

As far as I am aware, and please correct me. If we have a 2-sided PCB with SMD components on the top and also bottom, first we shall put components on the top side and solder them and then on the ...
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  • 1,338
0 votes
0 answers
153 views

How does manufacturer determine initial tolerance for capacitors?

Short version: I understand resistor initial tolerance is commonly obtained through sorting process where manufacturer only picks resistor that has resistance within the advertised initial tolerance. ...
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51 votes
7 answers
16k views

Why don't we make CPUs with 1000s of layers to make use of space in the third dimension?

I am wondering why don't we make processors such as CPUs with 1000s of stacked layers to make use of space in the third dimension now that we have three-dimensional transistors. To be clear I'm ...
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  • 649
1 vote
2 answers
115 views

Finding manufacturer of product based on certifications

I really do not know where to ask this question so I am starting here. If you believe there is a better place let me know and I will gladly move post. I bought an induction cooktop from amazon and ...
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1 vote
1 answer
231 views

Why have the same chip in the same package, but with a different number of pins?

STMicroelectronics offers the following two accelerometer chips. The LIS2DW in a 14 pin LGA package The LIS2DW12 in a 12 pin LGA package These two chips are functionally equivalent and have the same ...
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  • 13
1 vote
1 answer
85 views

Do I need to Reduce the Width of a Power Trace for Thermal Relief When it's Passing Through a Pin on the Chip?

I'm routing a PCB. Currently, all power traces are 20 mils. A QFP chip on the board requires multiple voltage rails to operate, I found the easiest solution is passing a power trace through a pin on ...
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  • 3,857
1 vote
0 answers
152 views

Unknown logo on FGS25N120ANTD IGBTs. Which semiconductor manufacturer is this?

I bought 5 FGS25N120ANTD IGBTs from my local vendor a while back. I was unable to identify the manufacturer, based on the logo. Can somebody help me out?
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1 vote
0 answers
201 views

Thermal reliefs for via-in-pad under BGA?

I'm doing the layout of a high-speed (Multi gigabit) system based on an FPGA with more than a thousand BGA pads and 0.8mm pitch on a 10-layer board. I'm using via in pads that will be copper-filled ...
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  • 2,567
0 votes
2 answers
71 views

Is infrared photoemission from silicon used in IC manufacturing diagnostics?

In the video Why all solar panels are secretly LEDs (and all LEDs are secretly solar panels) a silicon photovoltaic cell from a calculator is purposefully damaged and then a 36 V bias is applied. When ...
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  • 3,601
0 votes
1 answer
55 views

How do you make custom THT (through-hole) connectors?

I have a project that requires a connector that is no longer manufactured which would interface with an old device. For prototyping, I have been salvaging this connector from old peripherals that used ...
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13 votes
4 answers
4k views

What is the minimum die area of a chip?

Silicon chips are made by slicing up wafers; in general, the fewer transistors a design needs, the smaller the area it needs, so the more chips you get out of a wafer, and the lower the cost per chip. ...
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  • 501
10 votes
1 answer
2k views

Which is better - components on both sides or components on one side of the PCB?

I am working on a PCB design. 50k PCBs will be produced. SMD components: 100 Through-hole components: 25 I need to minimize PCB size. There are no high-speed signals or sensitive signals in the ...
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  • 322
0 votes
0 answers
43 views

Creating random PCB ID via manufacturing process

I often purchase prototype PCBAs on the order of five to twenty pieces and need to uniquely identify them sans software. I usually just whip out a permanent marker and label ...
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  • 2,409
1 vote
1 answer
102 views

Hi Pot / Dielectric Pass/Fail Recording

I just graduated last year with an Electrical Engineering degree. Currently pursuing a Masters's Degree, so I am fairly new to design. We have several HiPot Testers we use on the manufacturing line. ...
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2 votes
1 answer
105 views

Providing Schematics to a Contract Manufacturer?

A contract manufacturer mentioned the types of the files that they need in order to build and assemble boards. He indicated that they need the schematics along with gerbers, drill files, bom etc.. Is ...
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