All Questions
Tagged with pcb-assembly surface-mount
57
questions
2
votes
1
answer
122
views
Unknown SMD component - PCB Designation question
I have a board we are trying to repair. We are unable to get any technical documents from the manufacturer, no schematic or BOM for the board. This has multiple switches, think metal dome you press ...
user388256
3
votes
1
answer
223
views
Identify 5 pin smd marked "KV.." from motherboard led tv Panasonic
Identify 5 pin smd from motherboard led tv Panasonic that burned.
- 31
1
vote
1
answer
103
views
Identifying an SMD component
It is related to the USB bus voltage in a Delta HMI that has been damaged. Is this a 2.4 V Zener diode? This component is marked with the letter D311 on the PCB.
0
votes
0
answers
71
views
SMD button not in jlcpcb BOM
I want to try the jlcpcb assembly service.
I created the BOM, by using the bom2grouped_csv_jlcpcb. I inspected the generated file and indeed all the SMD components ...
- 1,369
4
votes
1
answer
283
views
SMT Reflow solder quality issue with SN42/BI58 paste
I have been doing hardware design and PCBA prototyping for a while and I have issues with quality of reflow soldering. I have a small lab including a pick'n'place machine, stencil printer (eC-stencil-...
- 453
0
votes
0
answers
77
views
QFN-28 REVERSE Breakout Board
I am trying to build a PCB board that I found on GitHub. In a rash we ordered few sets of the PCBs without inquiring about the parts availability. Turns out one of the parts is not available in all ...
- 109
15
votes
3
answers
3k
views
SMD 0402 resistor flipped on its side
I received some boards back from the PCBA fab and noticed that one 0402 resistor is flipped onto its side (R25):
This site tells me this is a pick-and-place error. But the footprint happens to be one ...
0
votes
2
answers
201
views
Aligned vs not-aligned components: Which is better for PCBA process?
I am designing a Raspberry Pi hat PCB for a home automation control project.
It contains many SMD resistors and capacitors.
I was just wondering if aligned components have any benefit over not-aligned ...
- 73
6
votes
4
answers
3k
views
SMD, reflow or hot-air gun?
What are the advantages and disadvantages of using a reflow oven vs a hot air station for prototyping SMD PCB? Do you need an oven or would an air station work?
- 720
0
votes
1
answer
70
views
SMT PCBA production
I am interested in setting up an SMT factory for producing PCBA. I have researched and know the whole assembly process such as solder paste application, reflow oven, etc. Regarding the packaging of ...
- 13
2
votes
3
answers
813
views
How do I get pin headers to reflow flat to the board?
I work for a small company as an apprentice. We build mostly mass produce double sided PCBs. We are having trouble keeping the pin headers flat to the PCB through the reflow oven process.
The first ...
- 21
6
votes
1
answer
470
views
Why do I have shorts/bridges on QFN packages on PCBA during assembly? Stencil Printing problem
I am trying to do a home assembly of PCB but I have issues after reflow soldering. Especially I have bridges/shorts on the pins of QFN packages. I have assembled multiple boards other joins are okay ...
- 453
4
votes
1
answer
2k
views
Solder SMD on through hole
Can I just solder an SMD part directly on the through holes of the PCB?
The pitch of SMD matches the pitch of the through holes.
- 161
2
votes
1
answer
1k
views
What could have caused this SMD capacitor failure?
I have an 0805 capacitor that has failed short circuit on a board. The maximum voltage it would see should be 16V. It has value 4.7uF, is rated to 25V and is X7R.
I don't understand why it might have ...
1
vote
3
answers
466
views
Is there a component that will provide an elevated SMD pad?
Is there a surface-mount component I can put on a pad, that simply has another pad on top that I can solder something on to?
Here is a side view showing pins above the pads that would need bent down ...
- 355
0
votes
1
answer
325
views
Why is this resistor only connected on one side?
I have taken a photo against the light so you can see through the board. It seems the circled resistor is only connected on one side. My hypothesis is that there is more than one version of this ...
1
vote
1
answer
311
views
Need help with troubleshooting PCB circuit
I recently got a freelancer to design a push-button latching circuit that powers a 12VDC motor from a 1S1P Li-po cell.
I have soldered all the components but the board does not seem to work properly; ...
- 25
0
votes
2
answers
115
views
drilling SMT footprints for fitting THT parts
I have bought by mistake some THT caps instead of SMD and would like to use them still. They were bought from a supplier who has the bad habit of not answering customer requests. These are 5000h caps, ...
- 1,061
11
votes
7
answers
5k
views
Hand soldering SMD 1206 components [closed]
Because I tried to wire-solder a protoboard which failed miserable, I'm intending to order a PCB. However, to minimize the area, I want to use some SMD1206 components. I ordered some basic ones (...
- 14k
0
votes
1
answer
787
views
Surface Mount Adapter PCB With Castellated Holes
I have some prototype boards that I would like to modify. The modification includes removing a section of circuit and replacing it with another circuit. My theory on how to do this is to make an ...
- 111
7
votes
1
answer
1k
views
How to remove kapton tape from soldered parts in bulk?
I have PCBs with SMT nuts (SMTSO2060MTJ) which has been assembled onto a PCB - the nut has kapton tape on top to allow easy pickup for assembly.
However, removing the kapton post reflow is proving ...
- 462
3
votes
4
answers
2k
views
Beyond what is recommended by fabricators, how far should traces be from SMD pads?
Having followed a fabricator's DRC (this case being OSHPark), this distance between an SMD pad and a trace is considered acceptable (see attached images).
However, I wanted to inquire about what the ...
- 33
3
votes
4
answers
2k
views
Keeping SMD parts in place while soldering with paste and heat
I was very happy to learn that I could solder SMD parts in place, by dabbing dots of solder paste on all the pads, placing my parts, and heating. I've done it using a modified toaster oven, or ...
- 3,255
1
vote
2
answers
1k
views
How to mount component perpendiculary to PCB
I'm designing small PCB(20mm*20mm) where I'm also limited by height of whole project that can't exceed 20mm. I have to place few sensors on the edge of the PCB but not facing up but facing out of the ...
- 182
6
votes
1
answer
1k
views
smd orientation for pick and place
I am trying to confirm the right orientation for all the packages I am using in Eagle before sending for pick and place assembly. After reading a bit, I understand that there is no standard from one ...
- 161
0
votes
0
answers
129
views
Assemble a 9 * 9 * 0.05 mm steel foil and castellation PCB using standard pick and place
I have a hybrid PCB where I want to assemble a very thin steel foil on a PCB using standard pick and place SMT process. the picture below describe how the foil is like:
The orange area is only hold ...
- 103
2
votes
2
answers
529
views
Damages to ICs done when cleaning boards with IPA
I have designed a PCB and soldered some SMD components on to it. When I check it, it doesn't seem to work. It was my very first SMD soldering experience and I think I used too much hot air. While ...
- 352
0
votes
2
answers
230
views
probable cause of damage to small SMD part: ESD, heat, something else?
The part in question is a 2 x 2 mm LGA accelerometer.
1. First soldering scenario, 10% non working parts after the assembly:
no ESD protection gear
hot air gun smoothly brought near / away from ...
- 1,061
0
votes
2
answers
166
views
Automatic SMT Line PCB Soldering [closed]
I am planning to create few circuit boards. I am considering getting the PCB printed from a manufacturer and do the SMT via a machine my self. Do you think it is good idea.
The reason i an planning ...
- 101
8
votes
1
answer
2k
views
Centroid of component for pick and place machine using Eagle
Just finished designing a PCB and sent the Gerbers off to my board house (Bittele) and they have requested that I also provide them with a pick and place file.
Using Eagle, I ran mountsmd.ulp and ...
- 1,420