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Step 1) Identify the package, note how many pins, match up the pins first. Note that sometimes the package pins are underneath the part or extended away from the part. Also get the dimensions of the part with a ruler or (preferably) calipers and match them up with a chart, write them down for a later step. Make sure that when measuring pin pitches (distance ...
49
Through-hole components are generally hand or wave soldered. These apply on local heating to the pads and not to the component itself.
SMD parts on the other hand are generally reflow soldered. This involves putting the entire part in a hot oven for an extended time. The components are generally made from porous materials which by their nature absorb ...
36
Vias in the pads are useful in high speed designs since they reduce trace length and therefore inductance (i.e. the connection goes straight from pad to plane rather than pad-trace-via-plane)
You have to check whether your PCB house can do this though, and it may cost more (via will need to be plugged and plated over to provide a smooth surface) If you can't ...
32
Larger and/or more valuable parts, such as CPUs, are typically shipped in "waffle" trays:
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Have a differently shaped solder mask on pin 1.
For surface mount processors, you could have the pin 1 pad be noticably longer than the others.
30
When soldering by hand, it is easier and faster to just ignore the bridges while you solder the part and then clean it up.
Just put some desoldering wick on the bridge, heat with your soldering iron (may need a bigger tip or more heat) and the excess solder will happily flow into the wick leaving perfect solder joints.
With practice the cleaning of even ...
29
You will likely find that 1206 are actually quite easy to hand solder. When you get used to SMD boards, you will find they are actually quite large.
With a standard iron, I find it quite simple to hand solder 0603 components, and with a small precision iron, 0402 can be done.
Your best bet and my recommendation if you haven't don't it before is to pre-...
26
You should try vacuum tweezers. They are a bit varied, there are some super cheap ones and others more sophisticated:
Cheapest option, which I dont recommend. When you press or release the vacuum pump the tweezer moves, which makes placing parts precisely a bit harder.
There are some automated versions, some come with a pedal for instance where you can ...
24
Pssshh to the guys using stencils :) Bet I can put a QFP down faster than you can paste, place, and re-flow :) Although it's nice if you want to get that center pad soldered.
Seriously though if we're talking ICs here I just flux pen a little, then put some solder on one pin in the corner. Then put the chip near it. Now just flow the solder with your ...
24
Unless you use via-in-pad, which costs more, you need room to put routing vias in between the pads, like this
24
The short answer, for your circuit, it won't matter.
When it comes to ceramics, there is a dirty little secret. When you apply a DC voltage to them, their capacitance values go down. Sometimes very significantly, like 50-60% down.
Some people have done empirical testing and found that for the same voltage and capacitance and dielectric type, then the ...
23
I just saw the SMD beak on Hack-a-day that looks like what you are looking for (I want one!)...
http://vpapanik.blogspot.de/2015/02/the-smd-beak.html
I've also had luck...
use a little piece of scotch or painter's tape on one side of a part to hold it down
tack down a couple of leads with solder
remove tape and solder down properly
For smaller parts (ie. ...
23
yes
14.6 Handling: Shipping Media
14.6.1 Mid-temperature Thin Matrix Tray The BGA packages are shipped in either a tape and reel or a mid-temperature thin matrix tray that
complies to the JEDEC standards. Typically, JEDEC trays have the same
‘x’ and ‘y’ outer dimen- sions and are easily stacked for storage and
manufacturing. For tray dimensions please refer ...
answered Nov 10 '16 at 1:36
Tony Stewart Sunnyskyguy EE75
93.6k2 gold badges34 silver badges137 bronze badges
23
My advice is to not bother doing what you're doing, and spend the $3.50US to get the part designed for the task, like https://www.digikey.com/product-detail/en/osram-opto-semiconductors-inc/SFH-7060/475-3174-2-ND/6137022
21
they suggested was that I use a stencil to apply my paste more evenly. In other words, they blew off my question.
No, they didn't. They gave you correct advice.
If you have a lot of solder on one pad and little on another, then the surface tension of the large blob can lever up the part. It is very unusual for this to happen with parts as large as 0805. ...
21
PCB size is not the only cost consideration and you need to consider recurring costs vs. one time (non-recurring) costs (some of the non-recurring may actually occur more than once for a 50k run).
Note that using double sided techniques rarely (if ever) yield a PCB half the size of a single sided part - in my experience you may get one that is perhaps 40% ...
20
There is no generic answer, it all depends on the components involved, let me add a few things to watch out for, and collect for the convenience a few more from the comments.
First of all, read the datasheets of all involved components, what they say about reflow in general and a second reflow possibly.
A lot of things will not be specified in the ...
20
Google translate on your phone can do this:
Parts prohibited area (部品搭軾禁止エリア)
Pattern prohibited area (パターン禁止エリア)
Soldering prohibited area (半田付け禁止エリア)
20
"F1" indicates some kind of fuse, and that "B" is the Bourns logo. Googling "Bourns A6530" leads to the TBU-CA datasheet, which says:
The TBU-CA Series of Bourns® TBU®
products are low capacitance single
bidirectional high-speed protection
components, constructed using MOSFET
semiconductor technology, and designed
to protect against faults ...
20
Those capacitors are really made similarly to the cylindrical radial lead through-hole capacitors. Two connections come out through a rubber bung (in an aluminum case that is crimped at the bottom to form a seal) and those leads are bend to form SMT leads.
From this Nichicon website (a conductive polymer type is shown, and conventional electrolytics are ...
20
This seems to be plumbing flux, which often is higher in corrosive components than electronics fluxes. Considering solder wire comes with a rosin core, you'll probably be better off without that flux, as such fluxes have the tendency to corrode electronic contacts over time.
I've never head of that happening within weeks, however.
So, my hypothesis is:
...
19
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 oomph to bring things to temp fast enough, and your IC's may not tolerate the slow temperature profile.
I think whatever appliance you use, you should dedicate ...
19
The absolute best way to do this is to preheat everything with a large high flow hot air source or oven. Apply paste first, if you have it, or a little bit of wire solder to the pad. Then pre-heat. The pre-heat temperature is around 125C or so.
Once everything is heat soaked at 125C, apply localized hot air directly to the part to be soldered and ...
19
Disclaimer: I am clueless about EE, but read Japanese well enough to look this up.
Black box: 部品搭載禁止エリア = "components/parts-loading prohibited area" (don't put stuff here, I assume).
Diagonal lines: パターン禁止エリア = "Pattern prohibited area" (I don't know what "pattern" refers to in this context, but don't do it there).
Diamond box: 半田付け禁止エリア = "solder-...
19
Do note that this IC has been discontinued and not recommended for new designs, they recommend the ACS723 instead. It also comes on a 30A version on the exact same package.
PCB trace calculators rely on basic assumptions:
Long distributed traces.
Thin conducting layers.
Acceptable application temperature rise given board geometry and trace placement
For ...
19
That looks like an LP-USML400 resettable "polyfuse" made by Way-On.
Datasheet here
19
As others have pointed out, your issue will be one of using the wrong type of flux. Plumbing flux is highly corrosive and will damage your board and components. It should not be used for soldering.
Below is an example of why you should not use plumbing flux. The board was a DIY PCB without a solder mask that was tin plated. Because of the lack of solder ...
18
In general it's bad practice: the solder paste may get sucked in the via capillarily, leaving too little to solder the part's connection. I would place the via as close as possible next to the pad, with a narrow connection which won't draw the solder paste from the pad.
There's a technique called tented via which avoids this by covering the top of the via, ...
18
My guess would be that the copper board is not being given enough time to heat up. Due to its thermal mass the copper heats up much more slowly than the solder, and the solder melts before the board reaches the correct temperature. If you choose a smaller piece of copper, or an etched PCB with less copper on it, or leave the copper board in the reflow oven ...
18
The hole for the connector would be near the center of the MCU package, away from the pins.
This is a very bad idea.
Usually the pins from through-hole parts stick through the board by at least a millimeter, more than enough to interfere with the ability to place a chip where it would cover the pin.
You could conceivably cut the pin short enough that it ...
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