All Questions
Tagged with pcb-assembly pcb-design
173
questions
44
votes
5
answers
14k
views
Why did Axial Capacitors Fall Out of Use in the Industry?
When inspecting the boards from electronics made in 1980s and earlier, one distinct feature is the extensive use of axial, electrolytic capacitors as power supply filter. Axial ceramic decoupling ...
- 7,218
39
votes
5
answers
7k
views
Why does a commercial PCB need this much rework?
I found a PCB that has had some rework done. When I saw it, I thought that someone had actually repaired it after purchase:-
It's got additional wiring (white & brown) and under the hot glue are ...
- 7,567
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
21
votes
3
answers
8k
views
How to secure cables to a PCB
What is a good way to secure cables to a PCB?
There are some good advice in the following post, but the application is slightly different:
Securing electrical cables to holes in enclosures?
In this ...
- 429
20
votes
3
answers
2k
views
When and why use triangle solder joints
I found these triangular solder joints in a 24v power supply. Why are they made as triangles? This is the first time I have seen it and I was unable to google anything about it.
- 473
19
votes
1
answer
4k
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 ...
- 1,053
18
votes
4
answers
4k
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. ...
- 8,551
17
votes
5
answers
3k
views
Can extra long pads cause problems?
I am a hobbyist and I find it very difficult to solder and work with SMD components which have very small underneath pads. I can't see when the solder flows, I can't touch the pads with the multimeter,...
- 299
16
votes
6
answers
19k
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 ...
- 263
16
votes
4
answers
11k
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 ...
- 2,525
14
votes
2
answers
2k
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 ...
- 907
12
votes
3
answers
4k
views
PCB fabrication vs PCB assembly
What is the difference between PCB fabrication and assembly? Some companies like Golden Phoenix list that based on the size of PCB, it outputs a quote.
Mine was 2.1 x 1.6 inch. It outputted 29 pieces ...
- 289
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
11
votes
5
answers
3k
views
Are these tracks too close for comfort, will this distance cause any problems?
I'm doing some PCB wiring and I am connecting many buttons to an Arduino Mega's digital inputs. The idea is that the digital pins will be normally high and when I push one of the buttons, the digital ...
- 125
11
votes
2
answers
2k
views
Magnetic power connectors (ie. "dots") for slim power supply connection
This may be more of a mechanical question, but does anyone know what these magnetic power connectors are called? You see these on Fitbits and other IoT devices.
I'm building an IoT board, that has ...
- 1,907