Questions tagged [pcb-assembly]
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.
52
questions
30
votes
3
answers
11k
views
Should I worry about the risk of tombstoning?
A colleague has (apparently unsuccessfully :-)) tried to convince me of the risk of tombstoning
in the following situation:
He claims pad 1 for R55 and R59 will lose heat faster during ...
- 146k
75
votes
4
answers
25k
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 ...
- 1,699
40
votes
6
answers
14k
views
Why do resistors still use color coding?
I always wondered why color coding is still used on resistors in 2014.
Here is Wikipedia's word on the original reason why :
Colorbands were commonly used (especially on resistors) because they
...
- 563
21
votes
3
answers
3k
views
What are the 'knuckles' on through-hole LEDs and photodiodes for?
I am using an IR LED and a photo diode, and I have designed the PCB according to the specifications that I found on the datasheet - i.e. hole sizes for the pins being 0.6 mm. However, on these ...
- 2,188
27
votes
4
answers
22k
views
Which of these marks signifies Pin 1 on the STM32F (LQFP64)?
I'm using the STM32F105, in a LQFP64 package. It has two circular markings, on opposing corners of the IC. This picture is for a different ST ARM, but the markings and silkscreen are similar:
The ...
- 17k
21
votes
9
answers
5k
views
Sizing SMD components for Hobbyist Kits
More components are only available in SMD packages.
For hobbyist assembly the options are to buy breakout boards or
solder SMD.
Since components are usually packaged in a couple of SMD
package ...
- 11.7k
8
votes
4
answers
858
views
Is PCB testing of all nets after assembly required?
That is my first time asking an assembly house to produce 200 units of a PCB (and not the usual 3 or 5 PCBs). The assembly house came back to me saying that the testability of the board was bad and ...
- 336
17
votes
3
answers
2k
views
Replace SOT-23 (5 pin) package in production with wire
I have found a hardware bug on a board design after many PCBs have been manufactured but not populated. I can fix the problem by removing a SOT-23 component and putting a wire across two of the pads.
...
- 273
14
votes
4
answers
10k
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 quasi-...
- 5,219
12
votes
3
answers
6k
views
Soldering heatsink pad on bottom of IC
I am attempting to make a board for the tlc5951 24-channel led driver to drive an 8x8 rgb led array. I have made what I think is a good eagle library for the sop-38 package, but I am not sure what to ...
- 2,054
12
votes
1
answer
2k
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.
****...
- 3,810
10
votes
2
answers
3k
views
Double-sided Assembly
I'm going to assemble a prototype PCB which have components on both sides. I have access to a reflow oven with profiling control, solder paste and stencils (from OSH-Park)
In the reflow process for ...
- 934
10
votes
5
answers
22k
views
How to reliably secure stranded wire in terminal block?
My 18AWG stranded wire continues to come out of the terminal block it's screwed into. What are some ways that I can more reliably secure this in an industrial environment?
Strip extra wire and loop/...
- 3,162
8
votes
2
answers
5k
views
Single- vs double-sided PCB assembly costs
I'm working on a new design (still laying out the components) and I have a chance here to reduce the size of the PCB by roughly 40%-50% if I use the other side for a QFP-100 IC (so it's heavy and will ...
- 1,906
7
votes
3
answers
5k
views
Is it advisable to use lead-free PCB and solder paste on a first SMD assembly job?
I am sending my first PCB design to Sunstone for manufacture and I need to decide whether to order the board finish lead-free. All of the components are lead-free, and I have not decided on solder ...
- 385