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35 votes
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Optimize heat sink design - connect cooling pad on PCB backside by vias

Ok, first I am going to try to give a nice little primer on thermal engineering, since you say you want to get a better handle on it. It sounds like you're at that point where you understand the ...
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27 votes

USB signal routing - Swap data lines using vias?

As an addition to Armandas' answer: If you want to use vias, there is a simple trick to swap the lines: Rotate the vias by 90 degrees, i.e. put them "above" each other. If you enter both vias from ...
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26 votes
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Routing traces to and from a 48 pin microcontroller becoming a mess

I have designed boards for some years and a few things do stand out. First of all please note that this is partly very subjective. For certain (mainly low speed) signals, good enough is good enough. ...
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25 votes
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How to chose via diameter and drill size based on trace width

The goal is to create a via with at least as much conductive area within the hole as the trace connecting to it (generally speaking, of course). My personal rule is to make the drill size diameter the ...
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  • 20.3k
24 votes

Via in PCB - Why not go for a solid copper filled via than a plated via?

High-current vias are relatively infrequently needed. If they are needed, and the current is higher than a regular via would handle, it is very easy to insert a through-hole pin and solder both sides....
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21 votes

Routing traces to and from a 48 pin microcontroller becoming a mess

Here are some general guidelines: Keep your ground plane intact; don't run ground through long traces. Use vias to let ground "jump" over bundles of traces and stitch the bottom/top ground ...
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  • 7,228
21 votes

Routing traces to and from a 48 pin microcontroller becoming a mess

Routing is in fact all about component placement. This is a microcontroller, so it'll have plenty of GPIO. Some of them will be swappable, some of them not. Usually all the analog inputs can be ...
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20 votes

Optimize heat sink design - connect cooling pad on PCB backside by vias

Using a linear regulator where such a lot of power is dissipated is ill-advised. Your PCB is going to be like a heater. This means that from 5.52 watts of power only 1.15 will be useful power which ...
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19 votes

Via in PCB - Why not go for a solid copper filled via than a plated via?

There is copper filled via in older technologies, I donot think you can do that now, if i remember correctly it is used for BGA . The problem is higher manufacturing cost and difficulty and the ...
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  • 566
19 votes

Why do some PCBs have these circular rings? Are they plated through hole vias?

This is a mounting hole for a screw. Smaller holes around - Vias are used to reinforce mounting point. Copper ring around the hole together with plating increases stiffness of PCB. Vias around protect ...
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  • 742
18 votes

How do you change the default via dimensions in Altium?

You can set the default via through DXP->Preferences->PCB Editor->Defaults->Via For placing vias in interactive routing, you can press 4 and cycle through sizes of via- minimum, maximum, preferred ...
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18 votes

Optimize heat sink design - connect cooling pad on PCB backside by vias

Do you see any further things I could optimize? Without giving it too much thought, about 10 11 12 13 came to mind. Thermal Pad Area Junction to Case Thermal Resistance Thin PCB Copper or Silver ...
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17 votes
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Why are vias bad?

I think the main problem is: vias could occupy significant space from other components, thus a larger board is necessary. On the first picture a TH vias allow us only four pads to be placed. But with ...
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17 votes

Why try to maximize number of grounding vias in RF PCBs?

You're actually talking about two very different things. One, via stitching, is the grid-like pattern of vias you might see connecting two ground planes. The other, via fences, are vias that ...
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14 votes

RF design stitching vias

So my question is if there is a difference on functionality between the two types of vias? No there isn't. If you would ignore all kinds of effects regarding RF, current capability and reliability. ...
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13 votes
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50MHz SPI PCB routing, use vias or resistors?

SPI bus at 50MHz can easily run a couple of inches thru a few vias without hitch. Wavelength of 50MHz is 6 metres but realistically because fast edges are used you need to think ten times faster. Even ...
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  • 385k
13 votes

Why are vias bad?

I wouldn't say that vias are bad. They are not! One useful way to use vias is to shield RF energy in a RF board, a technique called via stiching:
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13 votes
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Is it considered bad practice to put Vias on BGA pads?

Having vias placed on a pad is common practice. Nevertheless there are disadvantages which makes designers place vias next to a pad, in some cases even by removing some pads from the BGA footprint. ...
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  • 2,460
12 votes

maximum via current carrying capacity pcb

Depends on hole dia and hole's inner plating thickness. For example, a standard via with a plating thickness of 20um and with a diameter of 0.6mm allows 2.5ADC. You can calculate by yourself: http://...
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12 votes

Cost reduction by eliminating vias from PCB design

Centuries ago, when I first started designing PC boards, I believe we were charged for the number of vias/holes (or number of different hole sizes) on a board, but that charge was dropped long ago. ...
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11 votes

Vias directly on SMD pads?

I'm talking with experiences not imaginary recommandation with no actual evidence to back it up. You already asked for the smd pads not BGAs, nevertheless I saw many answers that only cover up for ...
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11 votes
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Can a via go in the middle of a trace?

VIA in trace is OK unless you are designed for high speed signals or very high current. The change in impedance and capacitance can cause signal integrity issues, reflections, for high speed signals. ...
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11 votes

Why are vias bad?

It is just one of the parameters you can use to tweak the autorouter. Via's add a little cost in drilling (even though this might not be explicitly shown on the bill), they take up space, and other ...
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10 votes
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Should you try and minimize via quantity?

For basic low frequency work vias are pretty much "meh". The only thing you need to watch for is when running larger currents - the vias tend to have a higher resistance, so dissipate more heat. ...
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10 votes
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Can Altium do via stitch patterns when interactive routing a group?

Well, I spent a solid hour or so trying to find the answer, gave up and asked here. Then a few minutes later I had the idea of seeing what shortcuts are available during routing (Ctrl-F1) and then ...
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10 votes
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Altium: Polygon Pour Direct Connect on Vias, Relief Connect on Pads

When you're setting up a new PCB rule, you can type "query text" to match objects to which the rule should apply. When I do what you're trying to do, I just use "isVia" as the query text and then set ...
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10 votes
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Cost reduction by eliminating vias from PCB design

Basically, the cost breakdown for doing the drilling of vias and other through-holes is: (1) setup time (putting the board on the machine) (2) time on the machine (3) removing the board from the ...
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10 votes

Routing traces to and from a 48 pin microcontroller becoming a mess

If you are going to stay 2-layer, then go for a structured approach, use a Manhattan layout. That means tracks only East-West on one side of the board, only North-South on the other, with a via ...
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9 votes
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Manually Drill Vias into PCB

It will be possible to drill these if you have a very rigid drill press and carbide bits. Back the PCB up with a sacrificial piece of laminate, get bright light and safety glasses and get very close ...
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9 votes
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USB signal routing - Swap data lines using vias?

Since it's hard to describe it in the comments, I'll put it as an answer. If space permits, you can route your signals like so:
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  • 7,460

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