51
votes
Accepted
Why are the same alloys solid in solder wire and liquid in solder paste?
Solder paste is actually composed of tiny solid balls of solder suspended in flux, so it's not a liquid it just seems like it without a magnifying glass or microscope. The wiki article goes into more ...
- 676
45
votes
Accepted
Is it important to file a new soldering iron tip before tinning?
Never file a soldering tip. Filing it will remove the protective layer, allowing the metal underneath to be eaten away by solder resulting in permanent damage over time. Tin it immediately once it ...
- 48.7k
22
votes
Is it important to file a new soldering iron tip before tinning?
No.
The best way to keep a soldering iron tip in good shape is by using "tip tinner" - available at the usual places.
It is well worth the modest investment, regardless of the cost of the iron ...
- 1,760
20
votes
Using a home oven for solder paste
Lots of people use toaster ovens and electric fry pans for reflow. It can get a little touch and go with lead-free solder, and I recommend leaded solder.
Large kitchen ovens likely don't have the ...
- 30.6k
18
votes
Using a home oven for solder paste
Can you? Yes. Will it work every time... Maybe not!
There are two reasons for this.
Temperature profile and timing.
Reflow is done using two temperatures, a pre-soak temperature and a reflow ...
- 47k
18
votes
Accepted
Double-sided Assembly
You can find some good and relatively modern information in this document.
WEIGHT LIMITS FOR DOUBLE SIDED REFLOW OF QFNS
Sasha Smith, David Connell and Bev Christian
Although their tests were for ...
16
votes
Accepted
Solder paste storage
But what exactly will go wrong when it is stored at a higher
temperature or past its shelf life?
Solder paste is composed of metal microballs and flux. The metal doesn't change over time much; the ...
- 88.8k
15
votes
Is it important to file a new soldering iron tip before tinning?
As said by Ignacio ....for most modern hobby tips (certainly for PCB/electronic work) you would never file them. The surface is plated to prevent the copper heat conductor from dissolving in the ...
- 22k
15
votes
Accepted
Can aluminum solder paste be used in electronic circuits?
I would not try it.
It is made to solder to aluminum.
Aluminum has a very hard oxide coating, and the flux in the solder paste has to remove it so that the solder can stick to the metal.
That ...
- 73.6k
14
votes
Accepted
How to clean solder stencils?
I have found that the best solution (pardon the pun) is to use Isopropyl Alcohol (IPA). It removes the solder with the least amount of effort. I have had no problems when I have used Isopropyl Alcohol ...
- 691
11
votes
Accepted
using plumber's copper solder as a "solder paste" for SMD components
The "no-clean" rosin flux used in most electronics solder has two interesting properties:
The junk it leaves on the board is a pretty good insulator (not perfect, but unless you do very high ...
- 81.7k
8
votes
Accepted
Are soldering fluxes safe to touch?
There seems to be a translation issue, and it's a good job you asked the question; this is not the roisin flux commonly used in electronics, but Zinc Chloride (if my machine translation of the German ...
- 47.1k
7
votes
Is it important to file a new soldering iron tip before tinning?
Never file a soldering iron tip. I did an accidental experiment with this a while back; I'd damaged a (Antex CS) tip when it rested against some wood for a while while switched on. Since I had an "...
- 2,651
7
votes
Can aluminum solder paste be used in electronic circuits?
According to the MSDS, it's just tin with a little bit of silver (0.5%) added. That would be fine for electrical connections.
However, the flux is extremely active in order to deal with the aluminum ...
- 178k
6
votes
Solder paste storage
Thermally stable solder paste is available from a few brands. It can be stored for a year or more in room temperature. Sometimes the flux may separate a bit, but stirring with a stick will restore the ...
- 9,666
6
votes
How to solder stainless steel electrode to PCB pad?
In general, steel can be soldered fairly easily, but most if not all stainless steels cannot. Normal electronics solder flux is completely ineffective at removing the tough oxide layer of stainless.
I ...
- 16.4k
5
votes
Is it important to file a new soldering iron tip before tinning?
IF the tip of the soldering iron is either a non-longlife, non-plated type ... or no longer plated due to wear... then filing is indeed necessary. What works best is filing it when heated - this ...
- 3,135
5
votes
Is it important to file a new soldering iron tip before tinning?
Back in the Paleolithic times soldering iron tips were made of copper. You had to file the oxide and pits out of them before you could tin them. In fact, if you go back far enough, soldering irons ...
- 706
5
votes
Applying solder paste through stencil and with a machine dispenser
You will have a hard time using a needle to dispense accurately for 0.5mm pitch pads. But you might have better success with a different paste. I used to use this Kester solder paste but I found ...
- 2,177
5
votes
Using a home oven for solder paste
If you want to learn how to solder SMT components by hand in an unimpeachable fashion, I would recommend watching some of the Youtube videos by IPC (J-STD-001) certified soldering teachers. You will ...
5
votes
Why are there no nichrome resistor pastes?
Nichrome's relatively high melting point, formation of a chromium oxide passivation layer in oxygen rich environments and when made into forms with high surface areas (like powder/paste) make it ...
- 51
5
votes
Reflow Soldering at home
As others have said, don't use an oven that you put your food in!! Lead poisoning is no joke.
If you are looking for the easiest and cheapest way to do reflow soldering at home, I recommend getting ...
5
votes
Going over IC max temp in reflow oven?
The components have a temperature profile used for soldering, which is separate from the absolute max temperature during use.
For example if you open the ESP32 datasheet, there is a temperature ...
- 172k
5
votes
PCB footprint design for minimum solder use
I guess, you are looking in the wrong spot for reducing assembly cost.
Even if you manage to reduce the solder mass to an optimal minimum, your assembly house won't quote a lower price most likely. In ...
- 3,456
4
votes
Accepted
Should mounting holes have solder bumps?
Assuming that the mounting holes are plated and connected to ground, the presence of solder bumps will help in two ways -
The connection to ground can still be maintained even if the screws are not ...
- 579
4
votes
Using a home oven for solder paste
You probably wouldn't want to use a regular oven for three reasons:
Its probably not a good idea to put lead where food is.
A larger oven has more uneaven heating because there are more convection ...
- 88.8k
4
votes
using plumber's copper solder as a "solder paste" for SMD components
Zinc chloride flux is very corrosive, and can eat through the traces on a PCB if the residue is not completely removed. If this is something that needs to be working 2 months from now, don't use it.
- 4,309
4
votes
Accepted
Thermal Paste on Cold Side of Peltier Freezing and not transferring "Heat", what gives?
Yes, of course. A thermal paste intended for CPUs is rarely used below 25C. You need to read their datasheet or search for cryogenic thermal compounds.
It is probably cheaper to select some of the ...
- 689
4
votes
Accepted
Solder Pad and Stencil Mask Data Sheet - Confused
Yes they are rotated.
The "Stencil Mask" is a physical metal stencil created to be used by the assembly house to print solder paste. The grid reduces the solder coverage to the typical 70% or so for ...
4
votes
Accepted
What is the main factor silver in solder wire?
The copper keeps the silver solder from leaching copper away from the PCB foil. Sn99.3 Cu 0.7 is cheaper so it's popular for consumer products but it's not quite as good to work with as the solder ...
Only top scored, non community-wiki answers of a minimum length are eligible