The process of mounting electronic components onto a printed circuit board. This can be done manually with a soldering iron, or automatically using a "Pick and Place" machine.

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2answers
77 views

cylindrical pcb design and casing

I'm trying to desing a control system that measures some analog signals like differantial pressure, temperature, motor current etc... and then produces some control signals and sends information to ...
0
votes
1answer
60 views

Correcting printed PCB (add a via)

This board is a prototype for the project and is for testing. It is missing the soldermask and silkscreen layers, so correcting mistakes is very possible. The board was printed correctly, but somehow ...
0
votes
0answers
22 views

What is JTAG TCE signal designed for and what effect does it have on the boundary scannable IC?

I know for fact that some boundary scannable ICs don't have this JTAG TCE input signal but some does. Does any one know why?
3
votes
1answer
157 views

How to solder a connector when spacing of PCB pads is not equal to spacing of component pads?

After delivery of my PCB, I realized that the spacing of PCB pads is not equal to the connector pitch (the PCB footprint is bigger than the OLED connector)! (sad) Look: Any idea how to solve this ...
4
votes
5answers
278 views

Any tricks to attaching a wire or pin to a testpoint?

More and more often, I find myself needing to tear apart a device to seek out and connect to serial pads. These pads typically give me access to the underlying operating system for research or ...
3
votes
1answer
103 views

Accidentally used plumbing flux on a PCB; How do I remove it to reuse the board?

Two weeks ago, I picked the wrong tub of flux from my toolbox and used it for making a 9VAC -> 5VDC adapter. I fluxed all the components and soldered it down before realising I was using PLUMBING ...
2
votes
1answer
94 views

Moisture Senstive Devices - Shelf Life

I have a bag of DAC7512N digital to analog converter from TI. They are still sealed in the original packing, however the caution notes denote "calculated shelf life in sealed bag: 24 months" and the ...
10
votes
4answers
463 views

OK to connect boards perpendicularly like this?

Are there any disadvantages in using the following method to accomplish a perpendicular board-to-board connection? (i.e., any disadvantages in terms of board manufacturing capability/cost assembly ...
3
votes
1answer
115 views

ATmega2560 not responding on hand-assembled PCBs

I've assembled some PCBs that I had made, and I'm unable to get the ATmega2560 to respond to programming via the ICSP header. On the third board I'm trying, I have soldered on only the MCU, the ICSP ...
0
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1answer
173 views

How to hand solder pads underneath an IC? [duplicate]

I have to design a board with a package case called MSOP-16 It has a large ground pad underneath the IC. What are good methods for soldering this pad by hand with a soldering iron? Since it is a ...
2
votes
1answer
138 views

Is there a pitch limit to applying solder paste through a PCB stencil by hand?

I've ordered two stencils from two different companies, two different materials. Both times I've been completely unable to effectively apply solder paste to the pads of a QFP-64. I end up with a mess ...
2
votes
2answers
1k views

How to re-solder fine broken flex cable connection to pcb

I have a phone where the volume button button flex cable has been partially pulled away from the PCB. See this photo for what it would have looked like before being damaged: ...
0
votes
3answers
99 views

What is the optimal way of clearing solder from surface-mount PCB pads for rework?

Say I have an assembled PCB with a QFP package on it. This device gets damaged and I need to replace it. Getting the device off is straightforward, but now all the pads have solder blobs on them. Is ...
5
votes
2answers
195 views

What stages do PCB mass-assembly techniques come in?

There's a spectrum of how you get PCBs assembled. 1) Have a human pick out all the parts, solder them all on by hand, and check them all by eye. Low cost of entry. Good for low-volume high-mix work. ...
29
votes
4answers
984 views

Securing electrical cables to holes in enclosures?

Suppose I would like to insert data-cables of varying diameters -- e.g., a cable of 5 mm diameter -- into the 6 mm diameter hole of a plastic enclosure. The wires within the cable are terminated via ...
1
vote
1answer
97 views

What kind of failure would I see in moisture sensitive parts?

I am reflowing a design using an electric skillet. When the uC and LEDs arrived they were in moisture sensitive packaging. They were in sealed bags with moisture indicator cards. After I opened them I ...
2
votes
1answer
205 views

External crystal not working

I have designed a PCB for a PIC32MX795 chip. (Datasheet) I want to use an external crystal (Link to datasheet in PDF) but when I solder the crystal to the board, I can't get my PLL to lock to 80MHz. ...
2
votes
2answers
157 views

adhesive glue before soldering

Before I solder very small electronic parts on PCB board, I want to find some needle point sized injector to inject tiny glue fix the parts, then do the soldering. Some manufacturers used that, but I ...
2
votes
4answers
2k views

How do I solder this USB Connector?

I bought this micro usb part: I need to solder it to a PCB that I designed, but I'm having a ton of trouble figuring out how to do so because the tabs are very close together and hard to reach. Is ...
3
votes
2answers
517 views

Eagle configure autorouter to solder components (except vias) only on bottom layer of double sided PCB

In double sided PCBs it is difficult to solder through hole components like IC bases, headers, etc. in the top layer. Normally the Eagle autorouter places the solder pads on both sides. That is, in a ...
8
votes
1answer
233 views

What are these spots on the PCB that are by the mounting holes?

When you look at the board, there is a weird part of the PCB right of the top left mounting hole. There is also another one above the top right mounting hole. ...
9
votes
3answers
495 views

Circuit works on breadboard but not PCB

I have a fairly simple circuit that works perfectly on the breadboard, but I am having a lot of trouble transferring it to a PCB. I am seeing very strange behavior which lies outside of my current ...
3
votes
2answers
379 views

OK to connect ring terminals directly to a PCB?

I am designing a PCB board and was wondering if there is a reason not to use ring terminals directly to a PCB. The PCB could have a pad surrounding a hole like I often see as ground connections. A ...
12
votes
2answers
286 views

Low volume PCB assembly testing

I've ordered fabrication and assembly of small PCB batches (~100) a couple of times already. Each time, the assembly factory asked me if I wanted to do testing on the boards. Since I'm not a ...
-2
votes
4answers
426 views

Software to design a 2-sided PCB with discrete components [duplicate]

I'm quite new to PCB Fabrication. I have a circuit with discrete components on a breadboard. I would like to fabricate this circuit into a 2-sided PCB containing discrete components. Something like ...
4
votes
1answer
562 views

Heat Sink for SOT223

I am designing PCB a in which I am placing a BSP296 N-channel MOSFET, for switching solenoids: MOSFET supply voltage is 24V MOSFET max power dissipation is 1.8W Max operating temperature is 150°C. ...
9
votes
4answers
926 views

Is wire wrapping still used nowadays?

I know that wire wrapping was used in critical applications where reliability was a major concern because it is more reliable than PCB based assemblies. But is it still true? The AGC (Apollo Guidance ...
11
votes
1answer
575 views

Solder Mask Color Code

Is there standard that recommend guidance of particular colors of solder mask? A while back I was told by a local assembler that BLUE typically indicates the circuit is ROHS compliant. Yet my Google ...
1
vote
6answers
311 views

PCB Prototyping and Fabrication

I have been working on a project for the past four months. Most of my development have been on breadboards and prototyping boards. I am now in the stage where I want to get a PCB printed and ...
15
votes
5answers
1k views

How do I solder headers so that they always stand straight up?

When soldering headers, usually single and double pins, I flip the board over so the pin rests on the surface and then solder them. They never come out straight. It would be great if someone has ...
1
vote
5answers
405 views

How do I dead bug solder this SOT-23 to my PCB?

I swapped the base and emitter of my NPN transistor land pattern. If I flip over the part, the pins are in the correct orientation, although there is a 1mm between the pins and the pads. When I tried ...
6
votes
1answer
339 views

Soldering 0.5mm pitch ICs using stencil and reflow oven

I'm new to SMD soldering, and tried to assemble a couple of boards, using a reflow oven. I 'm using a stencil (Kapton - mylar) and so far it worked fine except for the LQFP48 devices (pitch 0.5mm). In ...
7
votes
1answer
504 views

Designing Pick-and-Place-friendly CAD library parts

I'm working on a PCB design with surface mount components to be manufactured by a PCB assembly shop. I'm using CADSTAR, and I had to populate the library with some components, from scratch. I'm new to ...
13
votes
5answers
605 views

Conductive object to raise 6mm height off PCB

I am designing a PCB where I expect to have a certain part assembled at the edge of each board (blue in the picture below). However, this part needs to be at connected/soldered at a height of about 6 ...
2
votes
1answer
204 views

Tips for constructing small PCBs with only one SOIC

So I'm going to repackage this breakout module for simple SPI with a bus-powered LED light strip. It seems expensive and unnecessary for advanced SMT assembly equipment and since its a small PCB with ...
1
vote
1answer
71 views

Manage Software Installs of your Semi Mass Manufactured Product

After you get an assembly house to put together your product: what are the typical approaches to install your software on every one those product? Is this something the assembly house typically do? ...
13
votes
2answers
2k views

How is this design for a basic PCB pick and place?

I have zero experience with any serious mechanical design, but out of necessity and curiosity, I'm attempting to build a pick and place machine (for my hobby projects as well as low-volume PCB ...
7
votes
3answers
353 views

Fast approaches for Soldering / PCB assembly

Our team (three hobbyists now developing our first serious device) is interested in soldering/assembling approximately 200 PCBs. We've already found a low-cost manufacturer for the raw boards, so just ...
9
votes
1answer
791 views

Is there an insulation compound for exposed leads on a PCB?

The top of the enclosure I am building is going to be the PCB. The PCB has a 7-segment LCD and the leads are somewhat exposed. Is there an insulation material I can brush on or squeeze on that will ...
9
votes
3answers
2k views

Feasibility of PCB edge plating?

How feasible is it to edge plate a PCB or at least a portion of one? I've seen it done but as I understand the outer edge is only cut after plating at most fab houses. Is this something that's ...
5
votes
3answers
1k views

Questions on mass-production soldering

Wave soldering I am trying to understand how wave soldering works. Unfortunately the Wikipedia article has has left me unsure about the process: Is the entire board with its components ...
4
votes
2answers
491 views

What equipment and tools can be used to fabricate an 8 layer PCB for a prototype that has a 584-BGA microcontroller

I am in the process of setting up a small design laboratory and one of our first projects include the use of a 584-BGA microcontroller. This means that we'd have to use an 8 layer design, something ...
4
votes
3answers
917 views

Which is easier to solder: TSSOP or QFN?

Which package easier to solder on home-brew PCBs: TSSOP QFN I generally use solder paste and hot-air / hot-plate.
4
votes
1answer
891 views

Attaching a Type K thermocouple to a breadboard / prototype board

I'm looking to prototype a low-cost thermocouple interface board. It needs to output a voltage, as opposed to using SPI like several of the ICs I have looked at, since it would be fed into a 10-bit ...
3
votes
2answers
333 views

Questions About PCBs

I understand what they are but i have a few questions... What are the multi layers on a pcb (i understand 1 and 2 is front back but what about 3, 4 ,5 etc.) In ...
6
votes
5answers
509 views

How do we test reliability and quality so as to minimize the risk of board failure in the field?

We are developing a smart cable for a customer. The market potential is hundreds of thousands of units. The vendor who designs and supplies the boards (with firmware) that will be built into the ...
7
votes
2answers
261 views

What does “run a panel” mean in the context of PCB/PCBA fabrication?

A design engineer told me our PCB prototypes would be completed soon and then he would have his assembler "run a panel". Does anyone know what that means?
7
votes
3answers
4k views

Estimating Assembly Cost

I've got a project BOM costed out and I know my PCB costs. Without sending my project out for quote I'd like to be able to estimate the assembly cost by number of SMT components placed and the number ...
-4
votes
1answer
159 views

building thin devices, how to get started? [closed]

I want to build thin devices, just as thin as those ipod touches, how do I get started? What courses, what machines, what books?
13
votes
4answers
522 views

What is the best way to short adjacent SMD pads?

Which of the three ways shown above would be the best way to short two adjacent SMD pads together, and why? These are TSSOP pads and the assembly process will be lead-free reflow, if that matters. ...