Hot answers tagged

54

There is no problem routing traces through pads (like you have done). Be aware when routing power/GND of the current that will be travelling through these traces. This will dictate trace thickness. In addition, search for "power planes", "ground pours" for more information. I can see where your confusion may come from. I'm not a fan of how Eagle renders ...


14

No, it is not a problem routing through a pad. You might wish to consider adding ground and power planes to the design.


10

Probably they connect to a "bed of nails" test equipment. TP1, TP2 and two other circular pads (that appear to be referenced TP_something) are "test points" and if this circuit board is a medium to high volume then it's likely that the test points make contact with test equipment during manufacture to inject (or measure) certain voltages in order to ...


9

This is a mixed through-hole/SMT board and it was wave soldered (so all of the visible parts in your photo were literally immersed in molten solder). The only thing I see related to excess solder are the extended pads for "solder thieving" on the right-hand side of the '324 quad op-amp chip. The board was sent through the wave from left to right and the ...


9

This should not be a problem if the pad is used, i.e. soldered before use. That will increase the current carrying capacity many times. Additionally, each side of the ring looks about as thick as the trace, so even without soldering, current capacity has been doubled. But what does current carrying capacity really mean anyway? The pad is tiny, there will ...


8

These are fine. There are no acute angles in the examples you've given. In the first one, the angles are 135° and 90°. In the second one, the traces are on different layers. The reason that you are often advised not to use acute angles is that they may trap etching solution, so you may end up with over etching in the elbows. This may be a problem on very ...


7

If you increase the pad, you will probably increase the amount of paste too. Too much paste will increase the possibility of the component tombstoning as the solder melts.


6

I hope you know that a capacitor basically consists of two electrically conductive plates which are close together but do not touch. There can also be a dielectric (non conductive!) material in between. That could be FR-4 epoxy glass PCB material, like mentioned in the article. We can then use the copper on the PCB to make the conductive plates. They call ...


5

If the connections to those pins are the same VCC and same ground you will have no issues. Physically the copper track will only go as far as the pad it wont actually be left hanging over the hole upon manufacture.


5

A 'pad' on a board is simply an area of copper. In very high frequency work, it's often used for capacitors to ground, with values lower than 1pF. For any given dielectric and thickness, a certain area of pad will give you a certain capacitance. There are calculators available to estimate capacitance from geometry. The great advantage of such a capacitor ...


4

You can manually add a net using Design->Netlist->Edit nets, then select each pad and assign that net to it. But I don't see why you don't want to do this in the schematic.


4

Taking the drawings into consideration, the conclusion would be that the "Bottom" view is flipped in relation to "Recommended soldering pad" (as you imagined). Which one is correct would be hard to determine. Then, a few pages ahead: Looking by this image, which details how the LED comes in the reel, we can get further evidence that the "recommended" ...


4

Eagle will only do 4-contact thermals, and only with horizontal/vertical connections. However, you can increase the width of the connecting traces (thereby shrinking the gaps) by modifying the Width setting of the polygon you are connecting to. This doesn't require making changes to the component library. For high-current connections I generally make the ...


4

It's not directly possible to make a 1-sided pad in Eagle. There are a couple of ways, but both result in either DRC warnings or non-PTH holes (in one you basically do an SMD pad on the bottom, and put a non-PTH drill hole through it). So I won't go into these methods. There is however a workable solution that I am using in one design I have that uses a TO-...


3

2.4 GHz has a wavelength in free space of 125 mm and on a PCB it usually reduces to about 2/3 so say 83 mm. Trace lengths shorter than one tenth of a wavelength are usually regarded as not needing to be matched so if the trace length you refer to is less than about 8 mm then don't worry about it.


3

There is no direct way to center a trace between two pads other than manually specifying coordinates. That would be a bit silly. However, there are ways to address your issues. Actually, ease of solder has nothing to do with how close other copper is, as long as that other copper is covered by solder mask. Avoiding shorts due to too close traces is ...


3

If you know the x-y coordinates of the two pads, then just draw a trace and then edit its properties so that it is located equidistant from the two pads. Now if the pads are on grid (e.g. if you are using an 0.05" grid and 0.1" pitch ICs), then you simply draw the trace on-grid and it will automatically be in the centre. This is why trying to stick to grids ...


3

Yes, the drawings are, at best, confusing. Wesley Lee's answer has gone into that in detail. In addition to the package drawings, it does not help that the product drawing in the datasheet: differs from the image provided on the Everlight Americas website in small, but significant ways (e.g. metal areas, clarity of anode/pin 1 mark, physical shape of ...


3

I have mostly seen them being called "[solder] Thieving pad" or rarely "[solder] robber pad"


3

As well as being useful for marking particular pins, a square, octagonal or oblong pad has more copper area than a round hole of the same width. Through hole components such as connectors and large capacitors often have significant mechanical stress placed on them while the device is being operated or repaired. A larger copper area is better able to resist ...


3

Usually solder mask expansion of 2-4 mils is appropriate, but the minimum really depends on the process used. Silk screen solder mask would be the crudest. LPI is intermediate. Laser direct imaging of LPI might allow the solder mask to have zero expansion. Similarly, the minimum solder mask sliver will depend on the process and the PCB manufacturer, ...


3

I see, it's not a hole but more two pads on top of each other. Two options: Option 1: Design->Netlist->Edit Nets (add a dummy net - e.g. DUM1 and DUM2); You can then use this net in the PCB to assign it to your pads and tracks and vias. Option 2: Draw two dummy objects in the schematic, connect them and assign pads as footprints; then transfer them to the ...


3

Looks like R2 needs to be higher. The Android specs call for minimum of 1K from mic to ground. Your 1K resistor is right at the limit. An example is given for a microphone with a 5K DC resistance. So, use a larger R2, and proportionally larger R1. (R2=5K, R1=100K)


3

In relation to current, your trace is not 24mils (0.61mm) passing across the hole. This is a custom PCB, not one of those cheapo Veroboards. It's actually about 3.81mm (150mils). You need to consider that if your PCB is the standard 1.6mm thickness, and the hole is through plated, the hole has tinning on it's cylindrical perimeter. Like so:- The ...


3

It's a bit of a quirk with Eagle, but a polygon has a "width" associated with it, just like any other track. It sets the width of the aperture used to "paint" the fill inside the polygon. If this width is too large, then it can't paint the path to closely-spaced pads, as you have found. The fix is to set the polygon to use a smaller width. This allows the ...


3

Gold dissolves in tin. There is an indium solder called "TIX". It requires a strong flux, "TIX flux". You can get it on Amazon.


2

You may want to have a look at the IPC through hole standards or have a look at this page, where it is a little easier to understand. In your example: Minimum Hole Size Pad is 0.56mm x 0.52mm => sqrt(0.56^2 + 0.52^2) = 0.76mm Minimum Hole Size = Maximum Lead Diameter + 0.25mm = 0.76mm + 0.25mm If you like your components to "stick" you may want to ...


2

There are three options. Option 1 This is as suggested by @CL, and is the simplest option. Basically you route your large trace as close as you can without it sticking beyond the end of the pad, then use a narrower trace to complete the connection. This is shown in the image below. I've highlighted the narrow trace so you can see it better. Option 2 The ...


2

I'm quite sure you are looking for solder jumpers. The build-in library "jumper" has two types SJ and SJ2 with two or three terminals: And just what it looks like on the PCB, with a 1206 resistor for size comparison:


2

If you only have a few such traces, use polygons instead. It is much easier to adjust the shape according to your needs. Since PCB traces current carrying capacity is determined by heating and temperature limits, using polygon fills spreads the heat and cools the trace better if you can expand the fill into some unused space. Beware though, large copper ...


Only top voted, non community-wiki answers of a minimum length are eligible